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* [PATCH v9 0/3] fpga: Use standard class dev_release function
@ 2021-07-01  1:37 Russ Weight
  2021-07-01  1:37 ` [PATCH v9 1/3] fpga: mgr: Use standard dev_release for class driver Russ Weight
                   ` (2 more replies)
  0 siblings, 3 replies; 22+ messages in thread
From: Russ Weight @ 2021-07-01  1:37 UTC (permalink / raw)
  To: mdf, linux-fpga
  Cc: trix, lgoncalv, yilun.xu, hao.wu, matthew.gerlach, richard.gong,
	Russ Weight

The FPGA framework has a convention of using managed resource functions
to allow parent drivers to manage the data structures allocated by the
class drivers. They use an empty *_dev_release() function to satisfy the
class driver.

This is inconsistent with linux driver model.

These changes remove the managed resource functions and populate the class
dev_release callback functions. They also merge the create() and register()
functions into a single register() or register_full() function for each of
the fpga-mgr, fpga-region, and fpga-bridge class drivers.

The new *register_full() functions accept an info data structure to provide
flexibility in passing optional parameters. The *register() functions
support the legacy parameter list for users that don't require the use of
optional parameters.

For more context, refer to this email thread:

https://marc.info/?l=linux-fpga&m=162127412218557&w=2

I turned on the configs assocated with each of the modified files, but I
must have been missing some dependencies, because not all of them compiled.
I did a run-time test specifically with the dfl-fme infrastructure. This
would have exercised the region, bridge, and fpga-mgr frameworks.

Changelog v8 -> v9:
  - Cleaned up documentation for the FPGA Manager, Bridge, and Region
    register functions
  - Renamed fpga_*_register() to fpga_*_register_full()
  - Renamed fpga_*_register_simple() to fpga_*_register()
  - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full()
  - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register()

Changelog v7 -> v8:
  - Added reviewed-by tags.
  - Updated Documentation/driver-api/fpga/ files: fpga-mgr.rst,
    fpga-bridge.rst, and fpga-region.rst.

Changelog v6 -> v7:
  - Update the commit messages to describe the new parameters for the
    *register() functions and to mention the *register_simple() functions.
  - Fix function prototypes in header file to rename dev to parent.
  - Make use of the PTR_ERR_OR_ZERO() macro when possible.
  - Some cleanup of comments.
  - Update function definitions/prototypes to apply const to the new info
    parameter.
  - Verify that info->br_ops is non-null in the fpga_bridge_register()
    function.
  - Verify a non-null info pointer in the fpga_region_register() function.

Changelog v5 -> v6:
  - Moved FPGA manager/bridge/region optional parameters out of the ops
    structure and back into the FPGA class driver structure.
  - Changed fpga_*_register() function parameters to accept an info data
    structure to provide flexibility in passing optional parameters.
  - Added fpga_*_register_simple() functions to support current parameters
    for users that don't require use of optional parameters.

Changelog v4 -> v5:
  - Rebased on top of recently accepted patches.
  - Removed compat_id from the fpga_mgr_register() parameter list
    and added it to the fpga_manager_ops structure. This also required
    dynamically allocating the dfl-fme-ops structure in order to add
    the appropriate compat_id.
  - Created the fpga_region_ops data structure which is optionally passed
    to fpga_region_register(). compat_id, the get_bridges() pointer, and
    the priv pointer are included in the fpga_region_ops structure.

Changelog v3 -> v4:
  - Added the compat_id parameter to fpga_mgr_register() and
    devm_fpga_mgr_register() to ensure that the compat_id is set before
    the device_register() call.
  - Added the compat_id parameter to fpga_region_register() to ensure
    that the compat_id is set before the device_register() call.
  - Modified the dfl_fpga_feature_devs_enumerate() function to restore
    the fpga_region_register() call to the correct location.

Changelog v2 -> v3:
  - Cleaned up comment headers for fpga_mgr_register(), fpga_bridge_register(),
    and fpga_region_register().
  - Fixed error return on ida_simple_get() failure for fpga_mgr_register(),
    fpga_bridge_register(), and fpga_region_register().
  - Fixed error return value for fpga_bridge_register(): ERR_PTR(ret) instead
    of NULL.

Changelog v1 -> v2:
  - Restored devm_fpga_mgr_register() functionality to the fpga-mgr
    class driver, adapted for the combined create/register functionality.
  - All previous callers of devm_fpga_mgr_register() will continue to call
    devm_fpga_mgr_register().
  - replaced unnecessary ternary operators in return statements with
    standard if conditions.

Russ Weight (3):
  fpga: mgr: Use standard dev_release for class driver
  fpga: bridge: Use standard dev_release for class driver
  fpga: region: Use standard dev_release for class driver

 Documentation/driver-api/fpga/fpga-bridge.rst |   8 +-
 Documentation/driver-api/fpga/fpga-mgr.rst    |  34 ++-
 Documentation/driver-api/fpga/fpga-region.rst |   8 +-
 drivers/fpga/altera-cvp.c                     |  12 +-
 drivers/fpga/altera-fpga2sdram.c              |  12 +-
 drivers/fpga/altera-freeze-bridge.c           |  10 +-
 drivers/fpga/altera-hps2fpga.c                |  12 +-
 drivers/fpga/altera-pr-ip-core.c              |   7 +-
 drivers/fpga/altera-ps-spi.c                  |   9 +-
 drivers/fpga/dfl-fme-br.c                     |  10 +-
 drivers/fpga/dfl-fme-mgr.c                    |  22 +-
 drivers/fpga/dfl-fme-region.c                 |  17 +-
 drivers/fpga/dfl.c                            |  12 +-
 drivers/fpga/fpga-bridge.c                    | 137 ++++-------
 drivers/fpga/fpga-mgr.c                       | 215 ++++++++----------
 drivers/fpga/fpga-region.c                    | 119 ++++------
 drivers/fpga/ice40-spi.c                      |   9 +-
 drivers/fpga/machxo2-spi.c                    |   9 +-
 drivers/fpga/of-fpga-region.c                 |  10 +-
 drivers/fpga/socfpga-a10.c                    |  16 +-
 drivers/fpga/socfpga.c                        |   9 +-
 drivers/fpga/stratix10-soc.c                  |  16 +-
 drivers/fpga/ts73xx-fpga.c                    |   9 +-
 drivers/fpga/xilinx-pr-decoupler.c            |  17 +-
 drivers/fpga/xilinx-spi.c                     |  11 +-
 drivers/fpga/zynq-fpga.c                      |  16 +-
 drivers/fpga/zynqmp-fpga.c                    |   9 +-
 include/linux/fpga/fpga-bridge.h              |  33 ++-
 include/linux/fpga/fpga-mgr.h                 |  62 +++--
 include/linux/fpga/fpga-region.h              |  36 ++-
 30 files changed, 402 insertions(+), 504 deletions(-)

-- 
2.25.1


^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH v9 1/3] fpga: mgr: Use standard dev_release for class driver
  2021-07-01  1:37 [PATCH v9 0/3] fpga: Use standard class dev_release function Russ Weight
@ 2021-07-01  1:37 ` Russ Weight
  2021-07-01  5:25   ` Xu Yilun
  2021-07-06 19:04   ` Tom Rix
  2021-07-01  1:37 ` [PATCH v9 2/3] fpga: bridge: " Russ Weight
  2021-07-01  1:37 ` [PATCH v9 3/3] fpga: region: " Russ Weight
  2 siblings, 2 replies; 22+ messages in thread
From: Russ Weight @ 2021-07-01  1:37 UTC (permalink / raw)
  To: mdf, linux-fpga
  Cc: trix, lgoncalv, yilun.xu, hao.wu, matthew.gerlach, richard.gong,
	Russ Weight

The FPGA manager class driver data structure is being treated as a
managed resource instead of using the standard dev_release call-back
function to release the class data structure. This change removes
the managed resource code for the freeing of the class data structure
and combines the create() and register() functions into a single
register() or register_simple() function.

The register() function accepts an info data structure to provide
flexibility in passing optional parameters. The register_simple()
function supports the current parameter list for users that don't
require the use of optional parameters.

The devm_fpga_mgr_register() function is retained, and the
devm_fpga_mgr_register_simple() function is added.

Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Reviewed-by: Xu Yilun <yilun.xu@intel.com>
---
v9:
  - Cleaned up documentation for the FPGA Manager register functions
  - Renamed fpga_mgr_register() to fpga_mgr_register_full()
  - Renamed fpga_mgr_register_simple() to fpga_mgr_register()
  - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full()
  - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register()
v8:
  - Added reviewed-by tag.
  - Updated Documentation/driver-api/fpga/fpga-mgr.rst documentation.
v7:
  - Update the commit message to describe the new parameters for the
    *fpga_mgr_register() functions and to mention the
    *fpga_mgr_register_simple() functions.
  - Fix function prototypes in header file to rename dev to parent.
  - Make use of the PTR_ERR_OR_ZERO() macro when possible.
  - Some cleanup of comments.
  - Update function defintions/prototypes to apply const to the new info
    parameter.
v6:
  - Moved FPGA manager optional parameters out of the ops structure and
    back into the FPGA manager structure.
  - Changed fpga_mgr_register()/devm_fpga_mgr_register() parameters to
    accept an info data structure to provide flexibility in passing optional
    parameters.
  - Added fpga_mgr_register_simple()/devm_fpga_mgr_register_simple()
    functions to support current parameters for users that don't require
    the use of optional parameters.
v5:
  - Rebased on top of recently accepted patches.
  - Removed compat_id from the fpga_mgr_register() parameter list
    and added it to the fpga_manager_ops structure. This also required
    dynamically allocating the dfl-fme-ops structure in order to add
    the appropriate compat_id.
v4:
  - Added the compat_id parameter to fpga_mgr_register() and
    devm_fpga_mgr_register() to ensure that the compat_id is set before
    the device_register() call.
v3:
  - Cleaned up comment header for fpga_mgr_register()
  - Fix error return on ida_simple_get() failure
v2:
  - Restored devm_fpga_mgr_register() functionality, adapted for the combined
    create/register functionality.
  - All previous callers of devm_fpga_mgr_register() will continue to call
    devm_fpga_mgr_register().
  - replaced unnecessary ternary operators in return statements with standard
    if conditions.
---
 Documentation/driver-api/fpga/fpga-mgr.rst |  34 +++-
 drivers/fpga/altera-cvp.c                  |  12 +-
 drivers/fpga/altera-pr-ip-core.c           |   7 +-
 drivers/fpga/altera-ps-spi.c               |   9 +-
 drivers/fpga/dfl-fme-mgr.c                 |  22 +--
 drivers/fpga/fpga-mgr.c                    | 215 +++++++++------------
 drivers/fpga/ice40-spi.c                   |   9 +-
 drivers/fpga/machxo2-spi.c                 |   9 +-
 drivers/fpga/socfpga-a10.c                 |  16 +-
 drivers/fpga/socfpga.c                     |   9 +-
 drivers/fpga/stratix10-soc.c               |  16 +-
 drivers/fpga/ts73xx-fpga.c                 |   9 +-
 drivers/fpga/xilinx-spi.c                  |  11 +-
 drivers/fpga/zynq-fpga.c                   |  16 +-
 drivers/fpga/zynqmp-fpga.c                 |   9 +-
 include/linux/fpga/fpga-mgr.h              |  62 ++++--
 16 files changed, 210 insertions(+), 255 deletions(-)

diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
index 4d926b452cb3..826ed8dc9210 100644
--- a/Documentation/driver-api/fpga/fpga-mgr.rst
+++ b/Documentation/driver-api/fpga/fpga-mgr.rst
@@ -24,7 +24,7 @@ How to support a new FPGA device
 --------------------------------
 
 To add another FPGA manager, write a driver that implements a set of ops.  The
-probe function calls fpga_mgr_register(), such as::
+probe function calls fpga_mgr_register() or fpga_mgr_register_full(), such as::
 
 	static const struct fpga_manager_ops socfpga_fpga_ops = {
 		.write_init = socfpga_fpga_ops_configure_init,
@@ -49,14 +49,14 @@ probe function calls fpga_mgr_register(), such as::
 		 * them in priv
 		 */
 
-		mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
-					   &socfpga_fpga_ops, priv);
-		if (!mgr)
-			return -ENOMEM;
+		mgr = fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
+					&socfpga_fpga_ops, priv);
+		if (IS_ERR(mgr))
+			return PTR_ERR(mgr);
 
 		platform_set_drvdata(pdev, mgr);
 
-		return fpga_mgr_register(mgr);
+		return 0;
 	}
 
 	static int socfpga_fpga_remove(struct platform_device *pdev)
@@ -68,6 +68,11 @@ probe function calls fpga_mgr_register(), such as::
 		return 0;
 	}
 
+Alternatively, the probe function could call one of the resource managed
+register functions, devm_fpga_mgr_register() or devm_fpga_mgr_register_full().
+When these functions are used, the parameter syntax is the same, but the call
+to fpga_mgr_unregister() should be removed. In the above example, the
+socfpga_fpga_remove() function would not be required.
 
 The ops will implement whatever device specific register writes are needed to
 do the programming sequence for this particular FPGA.  These ops return 0 for
@@ -104,8 +109,13 @@ API for implementing a new FPGA Manager driver
 * ``fpga_mgr_states`` -  Values for :c:expr:`fpga_manager->state`.
 * struct fpga_manager -  the FPGA manager struct
 * struct fpga_manager_ops -  Low level FPGA manager driver ops
-* devm_fpga_mgr_create() -  Allocate and init a manager struct
-* fpga_mgr_register() -  Register an FPGA manager
+* fpga_mgr_register_full() -  Create and register an FPGA manager using the
+  fpga_mgr_info structure to provide the full flexibility of options
+* fpga_mgr_register() -  Create and register an FPGA manager using standard
+  arguments
+* devm_fpga_mgr_register_full() -  Resource managed version of
+  fpga_mgr_register_full()
+* devm_fpga_mgr_register() -  Resource managed version of fpga_mgr_register()
 * fpga_mgr_unregister() -  Unregister an FPGA manager
 
 .. kernel-doc:: include/linux/fpga/fpga-mgr.h
@@ -118,10 +128,16 @@ API for implementing a new FPGA Manager driver
    :functions: fpga_manager_ops
 
 .. kernel-doc:: drivers/fpga/fpga-mgr.c
-   :functions: devm_fpga_mgr_create
+   :functions: fpga_mgr_register_full
 
 .. kernel-doc:: drivers/fpga/fpga-mgr.c
    :functions: fpga_mgr_register
 
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+   :functions: devm_fpga_mgr_register_full
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+   :functions: devm_fpga_mgr_register
+
 .. kernel-doc:: drivers/fpga/fpga-mgr.c
    :functions: fpga_mgr_unregister
diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
index ccf4546eff29..4ffb9da537d8 100644
--- a/drivers/fpga/altera-cvp.c
+++ b/drivers/fpga/altera-cvp.c
@@ -652,19 +652,15 @@ static int altera_cvp_probe(struct pci_dev *pdev,
 	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
 		 ALTERA_CVP_MGR_NAME, pci_name(pdev));
 
-	mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
-				   &altera_cvp_ops, conf);
-	if (!mgr) {
-		ret = -ENOMEM;
+	mgr = fpga_mgr_register(&pdev->dev, conf->mgr_name,
+				&altera_cvp_ops, conf);
+	if (IS_ERR(mgr)) {
+		ret = PTR_ERR(mgr);
 		goto err_unmap;
 	}
 
 	pci_set_drvdata(pdev, mgr);
 
-	ret = fpga_mgr_register(mgr);
-	if (ret)
-		goto err_unmap;
-
 	return 0;
 
 err_unmap:
diff --git a/drivers/fpga/altera-pr-ip-core.c b/drivers/fpga/altera-pr-ip-core.c
index dfdf21ed34c4..be0667968d33 100644
--- a/drivers/fpga/altera-pr-ip-core.c
+++ b/drivers/fpga/altera-pr-ip-core.c
@@ -191,11 +191,8 @@ int alt_pr_register(struct device *dev, void __iomem *reg_base)
 		(val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
 		(int)(val & ALT_PR_CSR_PR_START));
 
-	mgr = devm_fpga_mgr_create(dev, dev_name(dev), &alt_pr_ops, priv);
-	if (!mgr)
-		return -ENOMEM;
-
-	return devm_fpga_mgr_register(dev, mgr);
+	mgr = devm_fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv);
+	return PTR_ERR_OR_ZERO(mgr);
 }
 EXPORT_SYMBOL_GPL(alt_pr_register);
 
diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
index 23bfd4d1ad0f..5e1e009dba89 100644
--- a/drivers/fpga/altera-ps-spi.c
+++ b/drivers/fpga/altera-ps-spi.c
@@ -302,12 +302,9 @@ static int altera_ps_probe(struct spi_device *spi)
 	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s",
 		 dev_driver_string(&spi->dev), dev_name(&spi->dev));
 
-	mgr = devm_fpga_mgr_create(&spi->dev, conf->mgr_name,
-				   &altera_ps_ops, conf);
-	if (!mgr)
-		return -ENOMEM;
-
-	return devm_fpga_mgr_register(&spi->dev, mgr);
+	mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name,
+				     &altera_ps_ops, conf);
+	return PTR_ERR_OR_ZERO(mgr);
 }
 
 static const struct spi_device_id altera_ps_spi_ids[] = {
diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
index d5861d13b306..620e7874ab53 100644
--- a/drivers/fpga/dfl-fme-mgr.c
+++ b/drivers/fpga/dfl-fme-mgr.c
@@ -282,7 +282,7 @@ static void fme_mgr_get_compat_id(void __iomem *fme_pr,
 static int fme_mgr_probe(struct platform_device *pdev)
 {
 	struct dfl_fme_mgr_pdata *pdata = dev_get_platdata(&pdev->dev);
-	struct fpga_compat_id *compat_id;
+	struct fpga_manager_info info = { 0 };
 	struct device *dev = &pdev->dev;
 	struct fme_mgr_priv *priv;
 	struct fpga_manager *mgr;
@@ -302,20 +302,16 @@ static int fme_mgr_probe(struct platform_device *pdev)
 			return PTR_ERR(priv->ioaddr);
 	}
 
-	compat_id = devm_kzalloc(dev, sizeof(*compat_id), GFP_KERNEL);
-	if (!compat_id)
+	info.name = "DFL FME FPGA Manager";
+	info.mops = &fme_mgr_ops;
+	info.priv = priv;
+	info.compat_id = devm_kzalloc(dev, sizeof(*info.compat_id), GFP_KERNEL);
+	if (!info.compat_id)
 		return -ENOMEM;
 
-	fme_mgr_get_compat_id(priv->ioaddr, compat_id);
-
-	mgr = devm_fpga_mgr_create(dev, "DFL FME FPGA Manager",
-				   &fme_mgr_ops, priv);
-	if (!mgr)
-		return -ENOMEM;
-
-	mgr->compat_id = compat_id;
-
-	return devm_fpga_mgr_register(dev, mgr);
+	fme_mgr_get_compat_id(priv->ioaddr, info.compat_id);
+	mgr = devm_fpga_mgr_register_full(dev, &info);
+	return PTR_ERR_OR_ZERO(mgr);
 }
 
 static struct platform_driver fme_mgr_driver = {
diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
index ecb4c3c795fa..5a913aa649fd 100644
--- a/drivers/fpga/fpga-mgr.c
+++ b/drivers/fpga/fpga-mgr.c
@@ -550,21 +550,19 @@ void fpga_mgr_unlock(struct fpga_manager *mgr)
 EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
 
 /**
- * fpga_mgr_create - create and initialize an FPGA manager struct
+ * fpga_mgr_register_full - create and register an FPGA Manager device
  * @parent:	fpga manager device from pdev
- * @name:	fpga manager name
- * @mops:	pointer to structure of fpga manager ops
- * @priv:	fpga manager private data
+ * @info:	parameters for fpga manager
  *
- * The caller of this function is responsible for freeing the struct with
- * fpga_mgr_free().  Using devm_fpga_mgr_create() instead is recommended.
+ * The caller of this function is responsible for calling fpga_mgr_unregister().
+ * Using devm_fpga_mgr_register_full() instead is recommended.
  *
- * Return: pointer to struct fpga_manager or NULL
+ * Return: pointer to struct fpga_manager pointer or ERR_PTR()
  */
-struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
-				     const struct fpga_manager_ops *mops,
-				     void *priv)
+struct fpga_manager *
+fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
 {
+	const struct fpga_manager_ops *mops = info->mops;
 	struct fpga_manager *mgr;
 	int id, ret;
 
@@ -572,29 +570,31 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
 	    !mops->write_init || (!mops->write && !mops->write_sg) ||
 	    (mops->write && mops->write_sg)) {
 		dev_err(parent, "Attempt to register without fpga_manager_ops\n");
-		return NULL;
+		return ERR_PTR(-EINVAL);
 	}
 
-	if (!name || !strlen(name)) {
+	if (!info->name || !strlen(info->name)) {
 		dev_err(parent, "Attempt to register with no name!\n");
-		return NULL;
+		return ERR_PTR(-EINVAL);
 	}
 
 	mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
 	if (!mgr)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
-	if (id < 0)
+	if (id < 0) {
+		ret = id;
 		goto error_kfree;
+	}
 
 	mutex_init(&mgr->ref_mutex);
 
-	mgr->name = name;
-	mgr->mops = mops;
-	mgr->priv = priv;
+	mgr->name = info->name;
+	mgr->mops = info->mops;
+	mgr->priv = info->priv;
+	mgr->compat_id = info->compat_id;
 
-	device_initialize(&mgr->dev);
 	mgr->dev.class = fpga_mgr_class;
 	mgr->dev.groups = mops->groups;
 	mgr->dev.parent = parent;
@@ -605,6 +605,19 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
 	if (ret)
 		goto error_device;
 
+	/*
+	 * Initialize framework state by requesting low level driver read state
+	 * from device.  FPGA may be in reset mode or may have been programmed
+	 * by bootloader or EEPROM.
+	 */
+	mgr->state = mgr->mops->state(mgr);
+
+	ret = device_register(&mgr->dev);
+	if (ret) {
+		put_device(&mgr->dev);
+		return ERR_PTR(ret);
+	}
+
 	return mgr;
 
 error_device:
@@ -612,96 +625,36 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
 error_kfree:
 	kfree(mgr);
 
-	return NULL;
+	return ERR_PTR(ret);
 }
-EXPORT_SYMBOL_GPL(fpga_mgr_create);
+EXPORT_SYMBOL_GPL(fpga_mgr_register_full);
 
 /**
- * fpga_mgr_free - free an FPGA manager created with fpga_mgr_create()
- * @mgr:	fpga manager struct
- */
-void fpga_mgr_free(struct fpga_manager *mgr)
-{
-	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
-	kfree(mgr);
-}
-EXPORT_SYMBOL_GPL(fpga_mgr_free);
-
-static void devm_fpga_mgr_release(struct device *dev, void *res)
-{
-	struct fpga_mgr_devres *dr = res;
-
-	fpga_mgr_free(dr->mgr);
-}
-
-/**
- * devm_fpga_mgr_create - create and initialize a managed FPGA manager struct
+ * fpga_mgr_register - create and register an FPGA Manager device
  * @parent:	fpga manager device from pdev
  * @name:	fpga manager name
  * @mops:	pointer to structure of fpga manager ops
  * @priv:	fpga manager private data
  *
- * This function is intended for use in an FPGA manager driver's probe function.
- * After the manager driver creates the manager struct with
- * devm_fpga_mgr_create(), it should register it with fpga_mgr_register().  The
- * manager driver's remove function should call fpga_mgr_unregister().  The
- * manager struct allocated with this function will be freed automatically on
- * driver detach.  This includes the case of a probe function returning error
- * before calling fpga_mgr_register(), the struct will still get cleaned up.
+ * The caller of this function is responsible for calling fpga_mgr_unregister().
+ * Using devm_fpga_mgr_register() instead is recommended. This simple
+ * version of the register function should be sufficient for most users. The
+ * fpga_mgr_register_full() function is available for users that need to pass
+ * additional, optional parameters.
  *
- * Return: pointer to struct fpga_manager or NULL
+ * Return: pointer to struct fpga_manager pointer or ERR_PTR()
  */
-struct fpga_manager *devm_fpga_mgr_create(struct device *parent, const char *name,
-					  const struct fpga_manager_ops *mops,
-					  void *priv)
+struct fpga_manager *
+fpga_mgr_register(struct device *parent, const char *name,
+		  const struct fpga_manager_ops *mops, void *priv)
 {
-	struct fpga_mgr_devres *dr;
+	struct fpga_manager_info info = { 0 };
 
-	dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL);
-	if (!dr)
-		return NULL;
+	info.name = name;
+	info.mops = mops;
+	info.priv = priv;
 
-	dr->mgr = fpga_mgr_create(parent, name, mops, priv);
-	if (!dr->mgr) {
-		devres_free(dr);
-		return NULL;
-	}
-
-	devres_add(parent, dr);
-
-	return dr->mgr;
-}
-EXPORT_SYMBOL_GPL(devm_fpga_mgr_create);
-
-/**
- * fpga_mgr_register - register an FPGA manager
- * @mgr: fpga manager struct
- *
- * Return: 0 on success, negative error code otherwise.
- */
-int fpga_mgr_register(struct fpga_manager *mgr)
-{
-	int ret;
-
-	/*
-	 * Initialize framework state by requesting low level driver read state
-	 * from device.  FPGA may be in reset mode or may have been programmed
-	 * by bootloader or EEPROM.
-	 */
-	mgr->state = mgr->mops->state(mgr);
-
-	ret = device_add(&mgr->dev);
-	if (ret)
-		goto error_device;
-
-	dev_info(&mgr->dev, "%s registered\n", mgr->name);
-
-	return 0;
-
-error_device:
-	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
-
-	return ret;
+	return fpga_mgr_register_full(parent, &info);
 }
 EXPORT_SYMBOL_GPL(fpga_mgr_register);
 
@@ -726,14 +679,6 @@ void fpga_mgr_unregister(struct fpga_manager *mgr)
 }
 EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
 
-static int fpga_mgr_devres_match(struct device *dev, void *res,
-				 void *match_data)
-{
-	struct fpga_mgr_devres *dr = res;
-
-	return match_data == dr->mgr;
-}
-
 static void devm_fpga_mgr_unregister(struct device *dev, void *res)
 {
 	struct fpga_mgr_devres *dr = res;
@@ -742,45 +687,67 @@ static void devm_fpga_mgr_unregister(struct device *dev, void *res)
 }
 
 /**
- * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
- * @dev: managing device for this FPGA manager
- * @mgr: fpga manager struct
+ * devm_fpga_mgr_register_full - resource managed variant of fpga_mgr_register()
+ * @parent:	fpga manager device from pdev
+ * @info:	parameters for fpga manager
  *
- * This is the devres variant of fpga_mgr_register() for which the unregister
+ * This is the devres variant of fpga_mgr_register_full() for which the unregister
  * function will be called automatically when the managing device is detached.
  */
-int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr)
+struct fpga_manager *
+devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
 {
 	struct fpga_mgr_devres *dr;
-	int ret;
-
-	/*
-	 * Make sure that the struct fpga_manager * that is passed in is
-	 * managed itself.
-	 */
-	if (WARN_ON(!devres_find(dev, devm_fpga_mgr_release,
-				 fpga_mgr_devres_match, mgr)))
-		return -EINVAL;
+	struct fpga_manager *mgr;
 
 	dr = devres_alloc(devm_fpga_mgr_unregister, sizeof(*dr), GFP_KERNEL);
 	if (!dr)
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 
-	ret = fpga_mgr_register(mgr);
-	if (ret) {
+	mgr = fpga_mgr_register_full(parent, info);
+	if (IS_ERR(mgr)) {
 		devres_free(dr);
-		return ret;
+		return mgr;
 	}
 
 	dr->mgr = mgr;
-	devres_add(dev, dr);
+	devres_add(parent, dr);
 
-	return 0;
+	return mgr;
+}
+EXPORT_SYMBOL_GPL(devm_fpga_mgr_register_full);
+
+/**
+ * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
+ * @parent:	fpga manager device from pdev
+ * @name:	fpga manager name
+ * @mops:	pointer to structure of fpga manager ops
+ * @priv:	fpga manager private data
+ *
+ * This is the devres variant of fpga_mgr_register() for which the
+ * unregister function will be called automatically when the managing
+ * device is detached.
+ */
+struct fpga_manager *
+devm_fpga_mgr_register(struct device *parent, const char *name,
+		       const struct fpga_manager_ops *mops, void *priv)
+{
+	struct fpga_manager_info info = { 0 };
+
+	info.name = name;
+	info.mops = mops;
+	info.priv = priv;
+
+	return devm_fpga_mgr_register_full(parent, &info);
 }
 EXPORT_SYMBOL_GPL(devm_fpga_mgr_register);
 
 static void fpga_mgr_dev_release(struct device *dev)
 {
+	struct fpga_manager *mgr = to_fpga_manager(dev);
+
+	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
+	kfree(mgr);
 }
 
 static int __init fpga_mgr_class_init(void)
diff --git a/drivers/fpga/ice40-spi.c b/drivers/fpga/ice40-spi.c
index 69dec5af23c3..b7591912248f 100644
--- a/drivers/fpga/ice40-spi.c
+++ b/drivers/fpga/ice40-spi.c
@@ -178,12 +178,9 @@ static int ice40_fpga_probe(struct spi_device *spi)
 		return ret;
 	}
 
-	mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
-				   &ice40_fpga_ops, priv);
-	if (!mgr)
-		return -ENOMEM;
-
-	return devm_fpga_mgr_register(dev, mgr);
+	mgr = devm_fpga_mgr_register(dev, "Lattice iCE40 FPGA Manager",
+				     &ice40_fpga_ops, priv);
+	return PTR_ERR_OR_ZERO(mgr);
 }
 
 static const struct of_device_id ice40_fpga_of_match[] = {
diff --git a/drivers/fpga/machxo2-spi.c b/drivers/fpga/machxo2-spi.c
index 1afb41aa20d7..8469dfb5dd21 100644
--- a/drivers/fpga/machxo2-spi.c
+++ b/drivers/fpga/machxo2-spi.c
@@ -366,12 +366,9 @@ static int machxo2_spi_probe(struct spi_device *spi)
 		return -EINVAL;
 	}
 
-	mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager",
-				   &machxo2_ops, spi);
-	if (!mgr)
-		return -ENOMEM;
-
-	return devm_fpga_mgr_register(dev, mgr);
+	mgr = devm_fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager",
+				     &machxo2_ops, spi);
+	return PTR_ERR_OR_ZERO(mgr);
 }
 
 #ifdef CONFIG_OF
diff --git a/drivers/fpga/socfpga-a10.c b/drivers/fpga/socfpga-a10.c
index 573d88bdf730..ac8e89b8a5cc 100644
--- a/drivers/fpga/socfpga-a10.c
+++ b/drivers/fpga/socfpga-a10.c
@@ -508,19 +508,15 @@ static int socfpga_a10_fpga_probe(struct platform_device *pdev)
 		return -EBUSY;
 	}
 
-	mgr = devm_fpga_mgr_create(dev, "SoCFPGA Arria10 FPGA Manager",
-				   &socfpga_a10_fpga_mgr_ops, priv);
-	if (!mgr)
-		return -ENOMEM;
-
-	platform_set_drvdata(pdev, mgr);
-
-	ret = fpga_mgr_register(mgr);
-	if (ret) {
+	mgr = fpga_mgr_register(dev, "SoCFPGA Arria10 FPGA Manager",
+				&socfpga_a10_fpga_mgr_ops, priv);
+	if (IS_ERR(mgr)) {
 		clk_disable_unprepare(priv->clk);
-		return ret;
+		return PTR_ERR(mgr);
 	}
 
+	platform_set_drvdata(pdev, mgr);
+
 	return 0;
 }
 
diff --git a/drivers/fpga/socfpga.c b/drivers/fpga/socfpga.c
index 1f467173fc1f..7e0741f99696 100644
--- a/drivers/fpga/socfpga.c
+++ b/drivers/fpga/socfpga.c
@@ -571,12 +571,9 @@ static int socfpga_fpga_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
-				   &socfpga_fpga_ops, priv);
-	if (!mgr)
-		return -ENOMEM;
-
-	return devm_fpga_mgr_register(dev, mgr);
+	mgr = devm_fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
+				     &socfpga_fpga_ops, priv);
+	return PTR_ERR_OR_ZERO(mgr);
 }
 
 #ifdef CONFIG_OF
diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
index a2cea500f7cc..9155e888a133 100644
--- a/drivers/fpga/stratix10-soc.c
+++ b/drivers/fpga/stratix10-soc.c
@@ -425,18 +425,11 @@ static int s10_probe(struct platform_device *pdev)
 
 	init_completion(&priv->status_return_completion);
 
-	mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
-			      &s10_ops, priv);
-	if (!mgr) {
-		dev_err(dev, "unable to create FPGA manager\n");
-		ret = -ENOMEM;
-		goto probe_err;
-	}
-
-	ret = fpga_mgr_register(mgr);
-	if (ret) {
+	mgr = fpga_mgr_register(dev, "Stratix10 SOC FPGA Manager",
+				&s10_ops, priv);
+	if (IS_ERR(mgr)) {
 		dev_err(dev, "unable to register FPGA manager\n");
-		fpga_mgr_free(mgr);
+		ret = PTR_ERR(mgr);
 		goto probe_err;
 	}
 
@@ -454,7 +447,6 @@ static int s10_remove(struct platform_device *pdev)
 	struct s10_priv *priv = mgr->priv;
 
 	fpga_mgr_unregister(mgr);
-	fpga_mgr_free(mgr);
 	stratix10_svc_free_channel(priv->chan);
 
 	return 0;
diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c
index 101f016c6ed8..fd52de20ddb2 100644
--- a/drivers/fpga/ts73xx-fpga.c
+++ b/drivers/fpga/ts73xx-fpga.c
@@ -122,12 +122,9 @@ static int ts73xx_fpga_probe(struct platform_device *pdev)
 	if (IS_ERR(priv->io_base))
 		return PTR_ERR(priv->io_base);
 
-	mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
-				   &ts73xx_fpga_ops, priv);
-	if (!mgr)
-		return -ENOMEM;
-
-	return devm_fpga_mgr_register(kdev, mgr);
+	mgr = devm_fpga_mgr_register(kdev, "TS-73xx FPGA Manager",
+				     &ts73xx_fpga_ops, priv);
+	return PTR_ERR_OR_ZERO(mgr);
 }
 
 static struct platform_driver ts73xx_fpga_driver = {
diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
index fee4d0abf6bf..db23626f9ab2 100644
--- a/drivers/fpga/xilinx-spi.c
+++ b/drivers/fpga/xilinx-spi.c
@@ -247,13 +247,10 @@ static int xilinx_spi_probe(struct spi_device *spi)
 		return dev_err_probe(&spi->dev, PTR_ERR(conf->done),
 				     "Failed to get DONE gpio\n");
 
-	mgr = devm_fpga_mgr_create(&spi->dev,
-				   "Xilinx Slave Serial FPGA Manager",
-				   &xilinx_spi_ops, conf);
-	if (!mgr)
-		return -ENOMEM;
-
-	return devm_fpga_mgr_register(&spi->dev, mgr);
+	mgr = devm_fpga_mgr_register(&spi->dev,
+				     "Xilinx Slave Serial FPGA Manager",
+				     &xilinx_spi_ops, conf);
+	return PTR_ERR_OR_ZERO(mgr);
 }
 
 static const struct of_device_id xlnx_spi_of_match[] = {
diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
index 9b75bd4f93d8..426aa34c6a0d 100644
--- a/drivers/fpga/zynq-fpga.c
+++ b/drivers/fpga/zynq-fpga.c
@@ -609,20 +609,16 @@ static int zynq_fpga_probe(struct platform_device *pdev)
 
 	clk_disable(priv->clk);
 
-	mgr = devm_fpga_mgr_create(dev, "Xilinx Zynq FPGA Manager",
-				   &zynq_fpga_ops, priv);
-	if (!mgr)
-		return -ENOMEM;
-
-	platform_set_drvdata(pdev, mgr);
-
-	err = fpga_mgr_register(mgr);
-	if (err) {
+	mgr = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
+				&zynq_fpga_ops, priv);
+	if (IS_ERR(mgr)) {
 		dev_err(dev, "unable to register FPGA manager\n");
 		clk_unprepare(priv->clk);
-		return err;
+		return PTR_ERR(mgr);
 	}
 
+	platform_set_drvdata(pdev, mgr);
+
 	return 0;
 }
 
diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
index 125743c9797f..975bdc4d0a65 100644
--- a/drivers/fpga/zynqmp-fpga.c
+++ b/drivers/fpga/zynqmp-fpga.c
@@ -102,12 +102,9 @@ static int zynqmp_fpga_probe(struct platform_device *pdev)
 
 	priv->dev = dev;
 
-	mgr = devm_fpga_mgr_create(dev, "Xilinx ZynqMP FPGA Manager",
-				   &zynqmp_fpga_ops, priv);
-	if (!mgr)
-		return -ENOMEM;
-
-	return devm_fpga_mgr_register(dev, mgr);
+	mgr = devm_fpga_mgr_register(dev, "Xilinx ZynqMP FPGA Manager",
+				     &zynqmp_fpga_ops, priv);
+	return PTR_ERR_OR_ZERO(mgr);
 }
 
 static const struct of_device_id zynqmp_fpga_of_match[] = {
diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
index 474c1f506307..ac3ddaf2903c 100644
--- a/include/linux/fpga/fpga-mgr.h
+++ b/include/linux/fpga/fpga-mgr.h
@@ -105,6 +105,36 @@ struct fpga_image_info {
 #endif
 };
 
+/**
+ * struct fpga_compat_id - id for compatibility check
+ *
+ * @id_h: high 64bit of the compat_id
+ * @id_l: low 64bit of the compat_id
+ */
+struct fpga_compat_id {
+	u64 id_h;
+	u64 id_l;
+};
+
+/**
+ * struct fpga_manager_info - collection of parameters for an FPGA Manager
+ * @name: fpga manager name
+ * @compat_id: FPGA manager id for compatibility check.
+ * @mops: pointer to structure of fpga manager ops
+ * @priv: fpga manager private data
+ *
+ * fpga_manager_info contains parameters for the register function. These
+ * are separated into an info structure because they some are optional
+ * others could be added to in the future. The info structure facilitates
+ * maintaining a stable API.
+ */
+struct fpga_manager_info {
+	const char *name;
+	struct fpga_compat_id *compat_id;
+	const struct fpga_manager_ops *mops;
+	void *priv;
+};
+
 /**
  * struct fpga_manager_ops - ops for low level fpga manager drivers
  * @initial_header_size: Maximum number of bytes that should be passed into write_init
@@ -143,17 +173,6 @@ struct fpga_manager_ops {
 #define FPGA_MGR_STATUS_IP_PROTOCOL_ERR		BIT(3)
 #define FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR	BIT(4)
 
-/**
- * struct fpga_compat_id - id for compatibility check
- *
- * @id_h: high 64bit of the compat_id
- * @id_l: low 64bit of the compat_id
- */
-struct fpga_compat_id {
-	u64 id_h;
-	u64 id_l;
-};
-
 /**
  * struct fpga_manager - fpga manager structure
  * @name: name of low level fpga manager
@@ -191,17 +210,18 @@ struct fpga_manager *fpga_mgr_get(struct device *dev);
 
 void fpga_mgr_put(struct fpga_manager *mgr);
 
-struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name,
-				     const struct fpga_manager_ops *mops,
-				     void *priv);
-void fpga_mgr_free(struct fpga_manager *mgr);
-int fpga_mgr_register(struct fpga_manager *mgr);
-void fpga_mgr_unregister(struct fpga_manager *mgr);
+struct fpga_manager *
+fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
 
-int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr);
+struct fpga_manager *
+fpga_mgr_register(struct device *parent, const char *name,
+		  const struct fpga_manager_ops *mops, void *priv);
+void fpga_mgr_unregister(struct fpga_manager *mgr);
 
-struct fpga_manager *devm_fpga_mgr_create(struct device *dev, const char *name,
-					  const struct fpga_manager_ops *mops,
-					  void *priv);
+struct fpga_manager *
+devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
+struct fpga_manager *
+devm_fpga_mgr_register(struct device *parent, const char *name,
+		       const struct fpga_manager_ops *mops, void *priv);
 
 #endif /*_LINUX_FPGA_MGR_H */
-- 
2.25.1


^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH v9 2/3] fpga: bridge: Use standard dev_release for class driver
  2021-07-01  1:37 [PATCH v9 0/3] fpga: Use standard class dev_release function Russ Weight
  2021-07-01  1:37 ` [PATCH v9 1/3] fpga: mgr: Use standard dev_release for class driver Russ Weight
@ 2021-07-01  1:37 ` Russ Weight
  2021-07-01  5:39   ` Xu Yilun
                     ` (2 more replies)
  2021-07-01  1:37 ` [PATCH v9 3/3] fpga: region: " Russ Weight
  2 siblings, 3 replies; 22+ messages in thread
From: Russ Weight @ 2021-07-01  1:37 UTC (permalink / raw)
  To: mdf, linux-fpga
  Cc: trix, lgoncalv, yilun.xu, hao.wu, matthew.gerlach, richard.gong,
	Russ Weight

The FPGA bridge class driver data structure is being treated as a
managed resource instead of using the standard dev_release call-back
function to release the class data structure. This change removes
the managed resource code and combines the create() and register()
functions into a single register() or register_simple() function.

The register() function accepts an info data structure to provide
flexibility in passing optional parameters. The register_simple()
function supports the current parameter list for users that don't
require the use of optional parameters.

Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Reviewed-by: Xu Yilun <yilun.xu@intel.com>
---
v9:
  - Cleaned up documentation for the FPGA Bridge register functions
  - Renamed fpga_bridge_register() to fpga_bridge_register_full()
  - Renamed fpga_bridge_register_simple() to fpga_bridge_register()
v8:
  - Added reviewed-by tag.
  - Updated Documentation/driver-api/fpga/fpga-bridge.rst documentation.
v7:
  - Update the commit message to describe the new parameters for the
    fpga_bridge_register() function and to mention the
    fpga_bridge_register_simple() function.
  - Fix function prototypes in header file to rename dev to parent.
  - Some cleanup of comments.
  - Update function defintions/prototypes to apply const to the new info
    parameter.
  - Verify that info->br_ops is non-null in register functions.
v6:
  - Changed fpga_bridge_register() parameters to accept an info data
    structure to provide flexibility in passing optional parameters.
  - Added fpga_bridge_register_simple() function to support current
    parameters for users that don't require the use of optional
    parameters.
v5:
  - Rebased on top of recently accepted patches.
v4:
  - Restore the previous format for the Return value in the comment header
    for fpga_bridge_register()
v3:
  - Cleaned up comment header for fpga_bridge_register()
  - Fix error return values for fpga_bridge_register()
v2:
  - No changes
---
 Documentation/driver-api/fpga/fpga-bridge.rst |   8 +-
 drivers/fpga/altera-fpga2sdram.c              |  12 +-
 drivers/fpga/altera-freeze-bridge.c           |  10 +-
 drivers/fpga/altera-hps2fpga.c                |  12 +-
 drivers/fpga/dfl-fme-br.c                     |  10 +-
 drivers/fpga/fpga-bridge.c                    | 137 ++++++------------
 drivers/fpga/xilinx-pr-decoupler.c            |  17 +--
 include/linux/fpga/fpga-bridge.h              |  33 +++--
 8 files changed, 101 insertions(+), 138 deletions(-)

diff --git a/Documentation/driver-api/fpga/fpga-bridge.rst b/Documentation/driver-api/fpga/fpga-bridge.rst
index 8d650b4e2ce6..38e3bac8e877 100644
--- a/Documentation/driver-api/fpga/fpga-bridge.rst
+++ b/Documentation/driver-api/fpga/fpga-bridge.rst
@@ -6,8 +6,10 @@ API to implement a new FPGA bridge
 
 * struct fpga_bridge - The FPGA Bridge structure
 * struct fpga_bridge_ops - Low level Bridge driver ops
-* devm_fpga_bridge_create() - Allocate and init a bridge struct
-* fpga_bridge_register() - Register a bridge
+* fpga_bridge_register_full() - Create and register a bridge using the
+  fpga_bridge_info structure to provide the full flexibility of options
+* fpga_bridge_register() - Create and register a bridge using standard
+  arguments
 * fpga_bridge_unregister() - Unregister a bridge
 
 .. kernel-doc:: include/linux/fpga/fpga-bridge.h
@@ -17,7 +19,7 @@ API to implement a new FPGA bridge
    :functions: fpga_bridge_ops
 
 .. kernel-doc:: drivers/fpga/fpga-bridge.c
-   :functions: devm_fpga_bridge_create
+   :functions: fpga_bridge_register_full
 
 .. kernel-doc:: drivers/fpga/fpga-bridge.c
    :functions: fpga_bridge_register
diff --git a/drivers/fpga/altera-fpga2sdram.c b/drivers/fpga/altera-fpga2sdram.c
index a78e49c63c64..66063507116b 100644
--- a/drivers/fpga/altera-fpga2sdram.c
+++ b/drivers/fpga/altera-fpga2sdram.c
@@ -121,17 +121,13 @@ static int alt_fpga_bridge_probe(struct platform_device *pdev)
 	/* Get f2s bridge configuration saved in handoff register */
 	regmap_read(sysmgr, SYSMGR_ISWGRP_HANDOFF3, &priv->mask);
 
-	br = devm_fpga_bridge_create(dev, F2S_BRIDGE_NAME,
-				     &altera_fpga2sdram_br_ops, priv);
-	if (!br)
-		return -ENOMEM;
+	br = fpga_bridge_register(dev, F2S_BRIDGE_NAME,
+				  &altera_fpga2sdram_br_ops, priv);
+	if (IS_ERR(br))
+		return PTR_ERR(mgr);
 
 	platform_set_drvdata(pdev, br);
 
-	ret = fpga_bridge_register(br);
-	if (ret)
-		return ret;
-
 	dev_info(dev, "driver initialized with handoff %08x\n", priv->mask);
 
 	if (!of_property_read_u32(dev->of_node, "bridge-enable", &enable)) {
diff --git a/drivers/fpga/altera-freeze-bridge.c b/drivers/fpga/altera-freeze-bridge.c
index dd58c4aea92e..bfbfa43cd05b 100644
--- a/drivers/fpga/altera-freeze-bridge.c
+++ b/drivers/fpga/altera-freeze-bridge.c
@@ -244,14 +244,14 @@ static int altera_freeze_br_probe(struct platform_device *pdev)
 
 	priv->base_addr = base_addr;
 
-	br = devm_fpga_bridge_create(dev, FREEZE_BRIDGE_NAME,
-				     &altera_freeze_br_br_ops, priv);
-	if (!br)
-		return -ENOMEM;
+	br = fpga_bridge_register(dev, FREEZE_BRIDGE_NAME,
+				  &altera_freeze_br_br_ops, priv);
+	if (IS_ERR(br))
+		return PTR_ERR(br);
 
 	platform_set_drvdata(pdev, br);
 
-	return fpga_bridge_register(br);
+	return 0;
 }
 
 static int altera_freeze_br_remove(struct platform_device *pdev)
diff --git a/drivers/fpga/altera-hps2fpga.c b/drivers/fpga/altera-hps2fpga.c
index 77b95f251821..aa758426c22b 100644
--- a/drivers/fpga/altera-hps2fpga.c
+++ b/drivers/fpga/altera-hps2fpga.c
@@ -180,19 +180,15 @@ static int alt_fpga_bridge_probe(struct platform_device *pdev)
 		}
 	}
 
-	br = devm_fpga_bridge_create(dev, priv->name,
-				     &altera_hps2fpga_br_ops, priv);
-	if (!br) {
-		ret = -ENOMEM;
+	br = fpga_bridge_register(dev, priv->name,
+				  &altera_hps2fpga_br_ops, priv);
+	if (IS_ERR(br)) {
+		ret = PTR_ERR(br);
 		goto err;
 	}
 
 	platform_set_drvdata(pdev, br);
 
-	ret = fpga_bridge_register(br);
-	if (ret)
-		goto err;
-
 	return 0;
 
 err:
diff --git a/drivers/fpga/dfl-fme-br.c b/drivers/fpga/dfl-fme-br.c
index 3ff9f3a687ce..808d1f4d76df 100644
--- a/drivers/fpga/dfl-fme-br.c
+++ b/drivers/fpga/dfl-fme-br.c
@@ -68,14 +68,14 @@ static int fme_br_probe(struct platform_device *pdev)
 
 	priv->pdata = dev_get_platdata(dev);
 
-	br = devm_fpga_bridge_create(dev, "DFL FPGA FME Bridge",
-				     &fme_bridge_ops, priv);
-	if (!br)
-		return -ENOMEM;
+	br = fpga_bridge_register(dev, "DFL FPGA FME Bridge",
+				  &fme_bridge_ops, priv);
+	if (IS_ERR(br))
+		return PTR_ERR(br);
 
 	platform_set_drvdata(pdev, br);
 
-	return fpga_bridge_register(br);
+	return 0;
 }
 
 static int fme_br_remove(struct platform_device *pdev)
diff --git a/drivers/fpga/fpga-bridge.c b/drivers/fpga/fpga-bridge.c
index 798f55670646..e6d98be8531b 100644
--- a/drivers/fpga/fpga-bridge.c
+++ b/drivers/fpga/fpga-bridge.c
@@ -312,55 +312,63 @@ static struct attribute *fpga_bridge_attrs[] = {
 ATTRIBUTE_GROUPS(fpga_bridge);
 
 /**
- * fpga_bridge_create - create and initialize a struct fpga_bridge
+ * fpga_bridge_register_full - create and register an FPGA Bridge device
  * @parent:	FPGA bridge device from pdev
- * @name:	FPGA bridge name
- * @br_ops:	pointer to structure of fpga bridge ops
- * @priv:	FPGA bridge private data
+ * @info:	parameters for FPGA Bridge
  *
- * The caller of this function is responsible for freeing the bridge with
- * fpga_bridge_free().  Using devm_fpga_bridge_create() instead is recommended.
- *
- * Return: struct fpga_bridge or NULL
+ * Return: struct fpga_bridge pointer or ERR_PTR()
  */
-struct fpga_bridge *fpga_bridge_create(struct device *parent, const char *name,
-				       const struct fpga_bridge_ops *br_ops,
-				       void *priv)
+struct fpga_bridge *
+fpga_bridge_register_full(struct device *parent,
+			  const struct fpga_bridge_info *info)
 {
 	struct fpga_bridge *bridge;
 	int id, ret;
 
-	if (!name || !strlen(name)) {
+	if (!info->br_ops) {
+		dev_err(parent, "Attempt to register without fpga_bridge_ops\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (!info->name || !strlen(info->name)) {
 		dev_err(parent, "Attempt to register with no name!\n");
-		return NULL;
+		return ERR_PTR(-EINVAL);
 	}
 
 	bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
 	if (!bridge)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	id = ida_simple_get(&fpga_bridge_ida, 0, 0, GFP_KERNEL);
-	if (id < 0)
+	if (id < 0) {
+		ret = id;
 		goto error_kfree;
+	}
 
 	mutex_init(&bridge->mutex);
 	INIT_LIST_HEAD(&bridge->node);
 
-	bridge->name = name;
-	bridge->br_ops = br_ops;
-	bridge->priv = priv;
+	bridge->name = info->name;
+	bridge->br_ops = info->br_ops;
+	bridge->priv = info->priv;
 
-	device_initialize(&bridge->dev);
-	bridge->dev.groups = br_ops->groups;
+	bridge->dev.groups = info->br_ops->groups;
 	bridge->dev.class = fpga_bridge_class;
 	bridge->dev.parent = parent;
 	bridge->dev.of_node = parent->of_node;
 	bridge->dev.id = id;
+	of_platform_populate(bridge->dev.of_node, NULL, NULL, &bridge->dev);
 
 	ret = dev_set_name(&bridge->dev, "br%d", id);
 	if (ret)
 		goto error_device;
 
+	ret = device_register(&bridge->dev);
+	if (ret) {
+		put_device(&bridge->dev);
+		return ERR_PTR(ret);
+	}
+
 	return bridge;
 
 error_device:
@@ -368,88 +376,35 @@ struct fpga_bridge *fpga_bridge_create(struct device *parent, const char *name,
 error_kfree:
 	kfree(bridge);
 
-	return NULL;
-}
-EXPORT_SYMBOL_GPL(fpga_bridge_create);
-
-/**
- * fpga_bridge_free - free an fpga bridge created by fpga_bridge_create()
- * @bridge:	FPGA bridge struct
- */
-void fpga_bridge_free(struct fpga_bridge *bridge)
-{
-	ida_simple_remove(&fpga_bridge_ida, bridge->dev.id);
-	kfree(bridge);
-}
-EXPORT_SYMBOL_GPL(fpga_bridge_free);
-
-static void devm_fpga_bridge_release(struct device *dev, void *res)
-{
-	struct fpga_bridge *bridge = *(struct fpga_bridge **)res;
-
-	fpga_bridge_free(bridge);
+	return ERR_PTR(ret);
 }
+EXPORT_SYMBOL_GPL(fpga_bridge_register_full);
 
 /**
- * devm_fpga_bridge_create - create and init a managed struct fpga_bridge
+ * fpga_bridge_register - create and register an FPGA Bridge device
  * @parent:	FPGA bridge device from pdev
  * @name:	FPGA bridge name
  * @br_ops:	pointer to structure of fpga bridge ops
  * @priv:	FPGA bridge private data
  *
- * This function is intended for use in an FPGA bridge driver's probe function.
- * After the bridge driver creates the struct with devm_fpga_bridge_create(), it
- * should register the bridge with fpga_bridge_register().  The bridge driver's
- * remove function should call fpga_bridge_unregister().  The bridge struct
- * allocated with this function will be freed automatically on driver detach.
- * This includes the case of a probe function returning error before calling
- * fpga_bridge_register(), the struct will still get cleaned up.
+ * This simple version of the register should be sufficient for most users.
+ * The fpga_bridge_register_full() function is available for users that need to pass
+ * additional, optional parameters.
  *
- *  Return: struct fpga_bridge or NULL
+ * Return: struct fpga_bridge pointer or ERR_PTR()
  */
-struct fpga_bridge
-*devm_fpga_bridge_create(struct device *parent, const char *name,
-			 const struct fpga_bridge_ops *br_ops, void *priv)
+struct fpga_bridge *
+fpga_bridge_register(struct device *parent, const char *name,
+		     const struct fpga_bridge_ops *br_ops,
+		     void *priv)
 {
-	struct fpga_bridge **ptr, *bridge;
-
-	ptr = devres_alloc(devm_fpga_bridge_release, sizeof(*ptr), GFP_KERNEL);
-	if (!ptr)
-		return NULL;
-
-	bridge = fpga_bridge_create(parent, name, br_ops, priv);
-	if (!bridge) {
-		devres_free(ptr);
-	} else {
-		*ptr = bridge;
-		devres_add(parent, ptr);
-	}
+	struct fpga_bridge_info info = { 0 };
 
-	return bridge;
-}
-EXPORT_SYMBOL_GPL(devm_fpga_bridge_create);
+	info.name = name;
+	info.br_ops = br_ops;
+	info.priv = priv;
 
-/**
- * fpga_bridge_register - register an FPGA bridge
- *
- * @bridge: FPGA bridge struct
- *
- * Return: 0 for success, error code otherwise.
- */
-int fpga_bridge_register(struct fpga_bridge *bridge)
-{
-	struct device *dev = &bridge->dev;
-	int ret;
-
-	ret = device_add(dev);
-	if (ret)
-		return ret;
-
-	of_platform_populate(dev->of_node, NULL, NULL, dev);
-
-	dev_info(dev->parent, "fpga bridge [%s] registered\n", bridge->name);
-
-	return 0;
+	return fpga_bridge_register_full(parent, &info);
 }
 EXPORT_SYMBOL_GPL(fpga_bridge_register);
 
@@ -475,6 +430,10 @@ EXPORT_SYMBOL_GPL(fpga_bridge_unregister);
 
 static void fpga_bridge_dev_release(struct device *dev)
 {
+	struct fpga_bridge *bridge = to_fpga_bridge(dev);
+
+	ida_simple_remove(&fpga_bridge_ida, bridge->dev.id);
+	kfree(bridge);
 }
 
 static int __init fpga_bridge_dev_init(void)
diff --git a/drivers/fpga/xilinx-pr-decoupler.c b/drivers/fpga/xilinx-pr-decoupler.c
index ea2bde6e5bc4..c004e52b9464 100644
--- a/drivers/fpga/xilinx-pr-decoupler.c
+++ b/drivers/fpga/xilinx-pr-decoupler.c
@@ -138,22 +138,17 @@ static int xlnx_pr_decoupler_probe(struct platform_device *pdev)
 
 	clk_disable(priv->clk);
 
-	br = devm_fpga_bridge_create(&pdev->dev, priv->ipconfig->name,
-				     &xlnx_pr_decoupler_br_ops, priv);
-	if (!br) {
-		err = -ENOMEM;
-		goto err_clk;
-	}
-
-	platform_set_drvdata(pdev, br);
-
-	err = fpga_bridge_register(br);
-	if (err) {
+	br = fpga_bridge_register(&pdev->dev, priv->ipconfig->name,
+				  &xlnx_pr_decoupler_br_ops, priv);
+	if (IS_ERR(br)) {
+		err = PTR_ERR(br);
 		dev_err(&pdev->dev, "unable to register %s",
 			priv->ipconfig->name);
 		goto err_clk;
 	}
 
+	platform_set_drvdata(pdev, br);
+
 	return 0;
 
 err_clk:
diff --git a/include/linux/fpga/fpga-bridge.h b/include/linux/fpga/fpga-bridge.h
index 6c3c28806ff1..f0a4d99d9c8e 100644
--- a/include/linux/fpga/fpga-bridge.h
+++ b/include/linux/fpga/fpga-bridge.h
@@ -22,6 +22,23 @@ struct fpga_bridge_ops {
 	const struct attribute_group **groups;
 };
 
+/**
+ * struct fpga_bridge_info - collection of parameters an FPGA Bridge
+ * @name: fpga bridge name
+ * @br_ops: pointer to structure of fpga bridge ops
+ * @priv: fpga bridge private data
+ *
+ * fpga_bridge_info contains parameters for the register function. These
+ * are separated into an info structure because they some are optional
+ * others could be added to in the future. The info structure facilitates
+ * maintaining a stable API.
+ */
+struct fpga_bridge_info {
+	const char *name;
+	const struct fpga_bridge_ops *br_ops;
+	void *priv;
+};
+
 /**
  * struct fpga_bridge - FPGA bridge structure
  * @name: name of low level FPGA bridge
@@ -62,15 +79,13 @@ int of_fpga_bridge_get_to_list(struct device_node *np,
 			       struct fpga_image_info *info,
 			       struct list_head *bridge_list);
 
-struct fpga_bridge *fpga_bridge_create(struct device *dev, const char *name,
-				       const struct fpga_bridge_ops *br_ops,
-				       void *priv);
-void fpga_bridge_free(struct fpga_bridge *br);
-int fpga_bridge_register(struct fpga_bridge *br);
-void fpga_bridge_unregister(struct fpga_bridge *br);
+struct fpga_bridge *
+fpga_bridge_register_full(struct device *parent, const struct fpga_bridge_info *info);
 
-struct fpga_bridge
-*devm_fpga_bridge_create(struct device *dev, const char *name,
-			 const struct fpga_bridge_ops *br_ops, void *priv);
+struct fpga_bridge *
+fpga_bridge_register(struct device *parent, const char *name,
+		     const struct fpga_bridge_ops *br_ops,
+		     void *priv);
+void fpga_bridge_unregister(struct fpga_bridge *br);
 
 #endif /* _LINUX_FPGA_BRIDGE_H */
-- 
2.25.1


^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH v9 3/3] fpga: region: Use standard dev_release for class driver
  2021-07-01  1:37 [PATCH v9 0/3] fpga: Use standard class dev_release function Russ Weight
  2021-07-01  1:37 ` [PATCH v9 1/3] fpga: mgr: Use standard dev_release for class driver Russ Weight
  2021-07-01  1:37 ` [PATCH v9 2/3] fpga: bridge: " Russ Weight
@ 2021-07-01  1:37 ` Russ Weight
  2021-07-01  5:51   ` Xu Yilun
  2 siblings, 1 reply; 22+ messages in thread
From: Russ Weight @ 2021-07-01  1:37 UTC (permalink / raw)
  To: mdf, linux-fpga
  Cc: trix, lgoncalv, yilun.xu, hao.wu, matthew.gerlach, richard.gong,
	Russ Weight

The FPGA region class driver data structure is being treated as a
managed resource instead of using the standard dev_release call-back
function to release the class data structure. This change removes the
managed resource code and combines the create() and register()
functions into a single register() or register_simple() function.

The register() function accepts an info data structure to provide
flexibility in passing optional parameters. The register_simple()
function supports the current parameter list for users that don't
require the use of optional parameters.

Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Reviewed-by: Xu Yilun <yilun.xu@intel.com>
---
v9:
  - Cleaned up documentation for the FPGA Region register functions
  - Renamed fpga_region_register() to fpga_region_register_full()
  - Renamed fpga_region_register_simple() to fpga_region_register()
v8:
  - Added reviewed-by tag.
  - Updated Documentation/driver-api/fpga/fpga-region.rst documentation.
v7:
  - Update the commit message to describe the new parameters for the
    fpga_region_register() function and to mention the
    fpga_region_register_simple() function.
  - Fix function prototypes in header file to rename dev to parent.
  - Some cleanup of comments.
  - Update function defintions/prototypes to apply const to the new info
    parameter.
  - Verify a non-null info pointer in the register() functions.
v6:
  - Moved FPGA manager optional parameters out of the ops structure and
    back into the FPGA Region structure.
  - Changed fpga_region_register() parameters to accept an info data
    structure to provide flexibility in passing optional parameters.
  - Added fpga_region_register_simple() functions to support current
    parameters for users that don't require the use of optional parameters.
v5:
  - Rebased on top of recently accepted patches.
  - Created the fpga_region_ops data structure which is optionally passed
    to fpga_region_register(). compat_id, the get_bridges() pointer, and
    the priv pointer are included in the fpga_region_ops structure.
v4:
  - Added the compat_id parameter to fpga_region_register() to ensure
    that the compat_id is set before the device_register() call.
  - Modified the dfl_fpga_feature_devs_enumerate() function to restore
    the fpga_region_register() call to the correct location.
v3:
  - Cleaned up comment header for fpga_region_register()
  - Fix fpga_region_register() error return on ida_simple_get() failure
v2:
  - No changes
---
 Documentation/driver-api/fpga/fpga-region.rst |   8 +-
 drivers/fpga/dfl-fme-region.c                 |  17 ++-
 drivers/fpga/dfl.c                            |  12 +-
 drivers/fpga/fpga-region.c                    | 119 +++++++-----------
 drivers/fpga/of-fpga-region.c                 |  10 +-
 include/linux/fpga/fpga-region.h              |  36 ++++--
 6 files changed, 91 insertions(+), 111 deletions(-)

diff --git a/Documentation/driver-api/fpga/fpga-region.rst b/Documentation/driver-api/fpga/fpga-region.rst
index 2636a27c11b2..904518190bb4 100644
--- a/Documentation/driver-api/fpga/fpga-region.rst
+++ b/Documentation/driver-api/fpga/fpga-region.rst
@@ -46,8 +46,10 @@ API to add a new FPGA region
 ----------------------------
 
 * struct fpga_region - The FPGA region struct
-* devm_fpga_region_create() - Allocate and init a region struct
-* fpga_region_register() -  Register an FPGA region
+* fpga_region_register_full() -  Create and register an FPGA region using the
+  fpga_region_info structure to provide the full flexibility of options
+* fpga_region_register() -  Create and register an FPGA region using standard
+  arguments
 * fpga_region_unregister() -  Unregister an FPGA region
 
 The FPGA region's probe function will need to get a reference to the FPGA
@@ -76,7 +78,7 @@ following APIs to handle building or tearing down that list.
    :functions: fpga_region
 
 .. kernel-doc:: drivers/fpga/fpga-region.c
-   :functions: devm_fpga_region_create
+   :functions: fpga_region_register_full
 
 .. kernel-doc:: drivers/fpga/fpga-region.c
    :functions: fpga_region_register
diff --git a/drivers/fpga/dfl-fme-region.c b/drivers/fpga/dfl-fme-region.c
index 1eeb42af1012..4aebde0a7f1c 100644
--- a/drivers/fpga/dfl-fme-region.c
+++ b/drivers/fpga/dfl-fme-region.c
@@ -30,6 +30,7 @@ static int fme_region_get_bridges(struct fpga_region *region)
 static int fme_region_probe(struct platform_device *pdev)
 {
 	struct dfl_fme_region_pdata *pdata = dev_get_platdata(&pdev->dev);
+	struct fpga_region_info info = { 0 };
 	struct device *dev = &pdev->dev;
 	struct fpga_region *region;
 	struct fpga_manager *mgr;
@@ -39,20 +40,18 @@ static int fme_region_probe(struct platform_device *pdev)
 	if (IS_ERR(mgr))
 		return -EPROBE_DEFER;
 
-	region = devm_fpga_region_create(dev, mgr, fme_region_get_bridges);
-	if (!region) {
-		ret = -ENOMEM;
+	info.mgr = mgr;
+	info.compat_id = mgr->compat_id;
+	info.get_bridges = fme_region_get_bridges;
+	info.priv = pdata;
+	region = fpga_region_register_full(dev, &info);
+	if (IS_ERR(region)) {
+		ret = PTR_ERR(region);
 		goto eprobe_mgr_put;
 	}
 
-	region->priv = pdata;
-	region->compat_id = mgr->compat_id;
 	platform_set_drvdata(pdev, region);
 
-	ret = fpga_region_register(region);
-	if (ret)
-		goto eprobe_mgr_put;
-
 	dev_dbg(dev, "DFL FME FPGA Region probed\n");
 
 	return 0;
diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
index 511b20ff35a3..3905995ef6d5 100644
--- a/drivers/fpga/dfl.c
+++ b/drivers/fpga/dfl.c
@@ -1400,19 +1400,15 @@ dfl_fpga_feature_devs_enumerate(struct dfl_fpga_enum_info *info)
 	if (!cdev)
 		return ERR_PTR(-ENOMEM);
 
-	cdev->region = devm_fpga_region_create(info->dev, NULL, NULL);
-	if (!cdev->region) {
-		ret = -ENOMEM;
-		goto free_cdev_exit;
-	}
-
 	cdev->parent = info->dev;
 	mutex_init(&cdev->lock);
 	INIT_LIST_HEAD(&cdev->port_dev_list);
 
-	ret = fpga_region_register(cdev->region);
-	if (ret)
+	cdev->region = fpga_region_register(info->dev, NULL, NULL);
+	if (IS_ERR(cdev->region)) {
+		ret = PTR_ERR(cdev->region);
 		goto free_cdev_exit;
+	}
 
 	/* create and init build info for enumeration */
 	binfo = devm_kzalloc(info->dev, sizeof(*binfo), GFP_KERNEL);
diff --git a/drivers/fpga/fpga-region.c b/drivers/fpga/fpga-region.c
index a4838715221f..8af108a383e0 100644
--- a/drivers/fpga/fpga-region.c
+++ b/drivers/fpga/fpga-region.c
@@ -180,39 +180,42 @@ static struct attribute *fpga_region_attrs[] = {
 ATTRIBUTE_GROUPS(fpga_region);
 
 /**
- * fpga_region_create - alloc and init a struct fpga_region
+ * fpga_region_register_full - create and register an FPGA Region device
  * @parent: device parent
- * @mgr: manager that programs this region
- * @get_bridges: optional function to get bridges to a list
- *
- * The caller of this function is responsible for freeing the resulting region
- * struct with fpga_region_free().  Using devm_fpga_region_create() instead is
- * recommended.
+ * @info: parameters for FPGA Region
  *
- * Return: struct fpga_region or NULL
+ * Return: struct fpga_region or ERR_PTR()
  */
-struct fpga_region
-*fpga_region_create(struct device *parent,
-		    struct fpga_manager *mgr,
-		    int (*get_bridges)(struct fpga_region *))
+struct fpga_region *
+fpga_region_register_full(struct device *parent, const struct fpga_region_info *info)
 {
 	struct fpga_region *region;
 	int id, ret = 0;
 
+	if (!info) {
+		dev_err(parent,
+			"Attempt to register without required info structure\n");
+		return ERR_PTR(-EINVAL);
+	}
+
 	region = kzalloc(sizeof(*region), GFP_KERNEL);
 	if (!region)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	id = ida_simple_get(&fpga_region_ida, 0, 0, GFP_KERNEL);
-	if (id < 0)
+	if (id < 0) {
+		ret = id;
 		goto err_free;
+	}
+
+	region->mgr = info->mgr;
+	region->compat_id = info->compat_id;
+	region->priv = info->priv;
+	region->get_bridges = info->get_bridges;
 
-	region->mgr = mgr;
-	region->get_bridges = get_bridges;
 	mutex_init(&region->mutex);
 	INIT_LIST_HEAD(&region->bridge_list);
 
-	device_initialize(&region->dev);
 	region->dev.class = fpga_region_class;
 	region->dev.parent = parent;
 	region->dev.of_node = parent->of_node;
@@ -222,6 +225,12 @@ struct fpga_region
 	if (ret)
 		goto err_remove;
 
+	ret = device_register(&region->dev);
+	if (ret) {
+		put_device(&region->dev);
+		return ERR_PTR(ret);
+	}
+
 	return region;
 
 err_remove:
@@ -229,76 +238,32 @@ struct fpga_region
 err_free:
 	kfree(region);
 
-	return NULL;
-}
-EXPORT_SYMBOL_GPL(fpga_region_create);
-
-/**
- * fpga_region_free - free an FPGA region created by fpga_region_create()
- * @region: FPGA region
- */
-void fpga_region_free(struct fpga_region *region)
-{
-	ida_simple_remove(&fpga_region_ida, region->dev.id);
-	kfree(region);
-}
-EXPORT_SYMBOL_GPL(fpga_region_free);
-
-static void devm_fpga_region_release(struct device *dev, void *res)
-{
-	struct fpga_region *region = *(struct fpga_region **)res;
-
-	fpga_region_free(region);
+	return ERR_PTR(ret);
 }
+EXPORT_SYMBOL_GPL(fpga_region_register_full);
 
 /**
- * devm_fpga_region_create - create and initialize a managed FPGA region struct
+ * fpga_region_register - create and register an FPGA Region device
  * @parent: device parent
  * @mgr: manager that programs this region
  * @get_bridges: optional function to get bridges to a list
  *
- * This function is intended for use in an FPGA region driver's probe function.
- * After the region driver creates the region struct with
- * devm_fpga_region_create(), it should register it with fpga_region_register().
- * The region driver's remove function should call fpga_region_unregister().
- * The region struct allocated with this function will be freed automatically on
- * driver detach.  This includes the case of a probe function returning error
- * before calling fpga_region_register(), the struct will still get cleaned up.
+ * This simple version of the register should be sufficient for most users.
+ * The fpga_region_register_full() function is available for users that need to
+ * pass additional, optional parameters.
  *
- * Return: struct fpga_region or NULL
+ * Return: struct fpga_region or ERR_PTR()
  */
-struct fpga_region
-*devm_fpga_region_create(struct device *parent,
-			 struct fpga_manager *mgr,
-			 int (*get_bridges)(struct fpga_region *))
+struct fpga_region *
+fpga_region_register(struct device *parent, struct fpga_manager *mgr,
+		     int (*get_bridges)(struct fpga_region *))
 {
-	struct fpga_region **ptr, *region;
-
-	ptr = devres_alloc(devm_fpga_region_release, sizeof(*ptr), GFP_KERNEL);
-	if (!ptr)
-		return NULL;
+	struct fpga_region_info info = { 0 };
 
-	region = fpga_region_create(parent, mgr, get_bridges);
-	if (!region) {
-		devres_free(ptr);
-	} else {
-		*ptr = region;
-		devres_add(parent, ptr);
-	}
+	info.mgr = mgr;
+	info.get_bridges = get_bridges;
 
-	return region;
-}
-EXPORT_SYMBOL_GPL(devm_fpga_region_create);
-
-/**
- * fpga_region_register - register an FPGA region
- * @region: FPGA region
- *
- * Return: 0 or -errno
- */
-int fpga_region_register(struct fpga_region *region)
-{
-	return device_add(&region->dev);
+	return fpga_region_register_full(parent, &info);
 }
 EXPORT_SYMBOL_GPL(fpga_region_register);
 
@@ -316,6 +281,10 @@ EXPORT_SYMBOL_GPL(fpga_region_unregister);
 
 static void fpga_region_dev_release(struct device *dev)
 {
+	struct fpga_region *region = to_fpga_region(dev);
+
+	ida_simple_remove(&fpga_region_ida, region->dev.id);
+	kfree(region);
 }
 
 /**
diff --git a/drivers/fpga/of-fpga-region.c b/drivers/fpga/of-fpga-region.c
index e3c25576b6b9..9c662db1c508 100644
--- a/drivers/fpga/of-fpga-region.c
+++ b/drivers/fpga/of-fpga-region.c
@@ -405,16 +405,12 @@ static int of_fpga_region_probe(struct platform_device *pdev)
 	if (IS_ERR(mgr))
 		return -EPROBE_DEFER;
 
-	region = devm_fpga_region_create(dev, mgr, of_fpga_region_get_bridges);
-	if (!region) {
-		ret = -ENOMEM;
+	region = fpga_region_register(dev, mgr, of_fpga_region_get_bridges);
+	if (IS_ERR(region)) {
+		ret = PTR_ERR(region);
 		goto eprobe_mgr_put;
 	}
 
-	ret = fpga_region_register(region);
-	if (ret)
-		goto eprobe_mgr_put;
-
 	of_platform_populate(np, fpga_region_of_match, NULL, &region->dev);
 	platform_set_drvdata(pdev, region);
 
diff --git a/include/linux/fpga/fpga-region.h b/include/linux/fpga/fpga-region.h
index 27cb706275db..ae111beeffba 100644
--- a/include/linux/fpga/fpga-region.h
+++ b/include/linux/fpga/fpga-region.h
@@ -7,6 +7,27 @@
 #include <linux/fpga/fpga-mgr.h>
 #include <linux/fpga/fpga-bridge.h>
 
+struct fpga_region;
+
+/**
+ * struct fpga_region_info - collection of parameters an FPGA Region
+ * @mgr: fpga region manager
+ * @compat_id: FPGA region id for compatibility check.
+ * @priv: fpga region private data
+ * @get_bridges: optional function to get bridges to a list
+ *
+ * fpga_region_info contains parameters for the register function. These
+ * are separated into an info structure because they some are optional
+ * others could be added to in the future. The info structure facilitates
+ * maintaining a stable API.
+ */
+struct fpga_region_info {
+	struct fpga_manager *mgr;
+	struct fpga_compat_id *compat_id;
+	void *priv;
+	int (*get_bridges)(struct fpga_region *region);
+};
+
 /**
  * struct fpga_region - FPGA Region structure
  * @dev: FPGA Region device
@@ -37,15 +58,12 @@ struct fpga_region *fpga_region_class_find(
 
 int fpga_region_program_fpga(struct fpga_region *region);
 
-struct fpga_region
-*fpga_region_create(struct device *dev, struct fpga_manager *mgr,
-		    int (*get_bridges)(struct fpga_region *));
-void fpga_region_free(struct fpga_region *region);
-int fpga_region_register(struct fpga_region *region);
-void fpga_region_unregister(struct fpga_region *region);
+struct fpga_region *
+fpga_region_register_full(struct device *parent, const struct fpga_region_info *info);
 
-struct fpga_region
-*devm_fpga_region_create(struct device *dev, struct fpga_manager *mgr,
-			int (*get_bridges)(struct fpga_region *));
+struct fpga_region *
+fpga_region_register(struct device *parent, struct fpga_manager *mgr,
+		     int (*get_bridges)(struct fpga_region *));
+void fpga_region_unregister(struct fpga_region *region);
 
 #endif /* _FPGA_REGION_H */
-- 
2.25.1


^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 1/3] fpga: mgr: Use standard dev_release for class driver
  2021-07-01  1:37 ` [PATCH v9 1/3] fpga: mgr: Use standard dev_release for class driver Russ Weight
@ 2021-07-01  5:25   ` Xu Yilun
  2021-07-06 23:06     ` Russ Weight
  2021-07-06 19:04   ` Tom Rix
  1 sibling, 1 reply; 22+ messages in thread
From: Xu Yilun @ 2021-07-01  5:25 UTC (permalink / raw)
  To: Russ Weight
  Cc: mdf, linux-fpga, trix, lgoncalv, hao.wu, matthew.gerlach, richard.gong

On Wed, Jun 30, 2021 at 06:37:31PM -0700, Russ Weight wrote:
> The FPGA manager class driver data structure is being treated as a
> managed resource instead of using the standard dev_release call-back
> function to release the class data structure. This change removes
> the managed resource code for the freeing of the class data structure
> and combines the create() and register() functions into a single
> register() or register_simple() function.
> 
> The register() function accepts an info data structure to provide
> flexibility in passing optional parameters. The register_simple()
> function supports the current parameter list for users that don't
> require the use of optional parameters.
> 
> The devm_fpga_mgr_register() function is retained, and the
> devm_fpga_mgr_register_simple() function is added.

The commit message is out of date.

Others are good to me. Fix the typo and you can keep my Reviewed-by.

Thanks,
Yilun

> 
> Signed-off-by: Russ Weight <russell.h.weight@intel.com>
> Reviewed-by: Xu Yilun <yilun.xu@intel.com>
> ---
> v9:
>   - Cleaned up documentation for the FPGA Manager register functions
>   - Renamed fpga_mgr_register() to fpga_mgr_register_full()
>   - Renamed fpga_mgr_register_simple() to fpga_mgr_register()
>   - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full()
>   - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register()
> v8:
>   - Added reviewed-by tag.
>   - Updated Documentation/driver-api/fpga/fpga-mgr.rst documentation.
> v7:
>   - Update the commit message to describe the new parameters for the
>     *fpga_mgr_register() functions and to mention the
>     *fpga_mgr_register_simple() functions.
>   - Fix function prototypes in header file to rename dev to parent.
>   - Make use of the PTR_ERR_OR_ZERO() macro when possible.
>   - Some cleanup of comments.
>   - Update function defintions/prototypes to apply const to the new info
>     parameter.
> v6:
>   - Moved FPGA manager optional parameters out of the ops structure and
>     back into the FPGA manager structure.
>   - Changed fpga_mgr_register()/devm_fpga_mgr_register() parameters to
>     accept an info data structure to provide flexibility in passing optional
>     parameters.
>   - Added fpga_mgr_register_simple()/devm_fpga_mgr_register_simple()
>     functions to support current parameters for users that don't require
>     the use of optional parameters.
> v5:
>   - Rebased on top of recently accepted patches.
>   - Removed compat_id from the fpga_mgr_register() parameter list
>     and added it to the fpga_manager_ops structure. This also required
>     dynamically allocating the dfl-fme-ops structure in order to add
>     the appropriate compat_id.
> v4:
>   - Added the compat_id parameter to fpga_mgr_register() and
>     devm_fpga_mgr_register() to ensure that the compat_id is set before
>     the device_register() call.
> v3:
>   - Cleaned up comment header for fpga_mgr_register()
>   - Fix error return on ida_simple_get() failure
> v2:
>   - Restored devm_fpga_mgr_register() functionality, adapted for the combined
>     create/register functionality.
>   - All previous callers of devm_fpga_mgr_register() will continue to call
>     devm_fpga_mgr_register().
>   - replaced unnecessary ternary operators in return statements with standard
>     if conditions.
> ---
>  Documentation/driver-api/fpga/fpga-mgr.rst |  34 +++-
>  drivers/fpga/altera-cvp.c                  |  12 +-
>  drivers/fpga/altera-pr-ip-core.c           |   7 +-
>  drivers/fpga/altera-ps-spi.c               |   9 +-
>  drivers/fpga/dfl-fme-mgr.c                 |  22 +--
>  drivers/fpga/fpga-mgr.c                    | 215 +++++++++------------
>  drivers/fpga/ice40-spi.c                   |   9 +-
>  drivers/fpga/machxo2-spi.c                 |   9 +-
>  drivers/fpga/socfpga-a10.c                 |  16 +-
>  drivers/fpga/socfpga.c                     |   9 +-
>  drivers/fpga/stratix10-soc.c               |  16 +-
>  drivers/fpga/ts73xx-fpga.c                 |   9 +-
>  drivers/fpga/xilinx-spi.c                  |  11 +-
>  drivers/fpga/zynq-fpga.c                   |  16 +-
>  drivers/fpga/zynqmp-fpga.c                 |   9 +-
>  include/linux/fpga/fpga-mgr.h              |  62 ++++--
>  16 files changed, 210 insertions(+), 255 deletions(-)
> 
> diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
> index 4d926b452cb3..826ed8dc9210 100644
> --- a/Documentation/driver-api/fpga/fpga-mgr.rst
> +++ b/Documentation/driver-api/fpga/fpga-mgr.rst
> @@ -24,7 +24,7 @@ How to support a new FPGA device
>  --------------------------------
>  
>  To add another FPGA manager, write a driver that implements a set of ops.  The
> -probe function calls fpga_mgr_register(), such as::
> +probe function calls fpga_mgr_register() or fpga_mgr_register_full(), such as::
>  
>  	static const struct fpga_manager_ops socfpga_fpga_ops = {
>  		.write_init = socfpga_fpga_ops_configure_init,
> @@ -49,14 +49,14 @@ probe function calls fpga_mgr_register(), such as::
>  		 * them in priv
>  		 */
>  
> -		mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
> -					   &socfpga_fpga_ops, priv);
> -		if (!mgr)
> -			return -ENOMEM;
> +		mgr = fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
> +					&socfpga_fpga_ops, priv);
> +		if (IS_ERR(mgr))
> +			return PTR_ERR(mgr);
>  
>  		platform_set_drvdata(pdev, mgr);
>  
> -		return fpga_mgr_register(mgr);
> +		return 0;
>  	}
>  
>  	static int socfpga_fpga_remove(struct platform_device *pdev)
> @@ -68,6 +68,11 @@ probe function calls fpga_mgr_register(), such as::
>  		return 0;
>  	}
>  
> +Alternatively, the probe function could call one of the resource managed
> +register functions, devm_fpga_mgr_register() or devm_fpga_mgr_register_full().
> +When these functions are used, the parameter syntax is the same, but the call
> +to fpga_mgr_unregister() should be removed. In the above example, the
> +socfpga_fpga_remove() function would not be required.
>  
>  The ops will implement whatever device specific register writes are needed to
>  do the programming sequence for this particular FPGA.  These ops return 0 for
> @@ -104,8 +109,13 @@ API for implementing a new FPGA Manager driver
>  * ``fpga_mgr_states`` -  Values for :c:expr:`fpga_manager->state`.
>  * struct fpga_manager -  the FPGA manager struct
>  * struct fpga_manager_ops -  Low level FPGA manager driver ops
> -* devm_fpga_mgr_create() -  Allocate and init a manager struct
> -* fpga_mgr_register() -  Register an FPGA manager
> +* fpga_mgr_register_full() -  Create and register an FPGA manager using the
> +  fpga_mgr_info structure to provide the full flexibility of options
> +* fpga_mgr_register() -  Create and register an FPGA manager using standard
> +  arguments
> +* devm_fpga_mgr_register_full() -  Resource managed version of
> +  fpga_mgr_register_full()
> +* devm_fpga_mgr_register() -  Resource managed version of fpga_mgr_register()
>  * fpga_mgr_unregister() -  Unregister an FPGA manager
>  
>  .. kernel-doc:: include/linux/fpga/fpga-mgr.h
> @@ -118,10 +128,16 @@ API for implementing a new FPGA Manager driver
>     :functions: fpga_manager_ops
>  
>  .. kernel-doc:: drivers/fpga/fpga-mgr.c
> -   :functions: devm_fpga_mgr_create
> +   :functions: fpga_mgr_register_full
>  
>  .. kernel-doc:: drivers/fpga/fpga-mgr.c
>     :functions: fpga_mgr_register
>  
> +.. kernel-doc:: drivers/fpga/fpga-mgr.c
> +   :functions: devm_fpga_mgr_register_full
> +
> +.. kernel-doc:: drivers/fpga/fpga-mgr.c
> +   :functions: devm_fpga_mgr_register
> +
>  .. kernel-doc:: drivers/fpga/fpga-mgr.c
>     :functions: fpga_mgr_unregister
> diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
> index ccf4546eff29..4ffb9da537d8 100644
> --- a/drivers/fpga/altera-cvp.c
> +++ b/drivers/fpga/altera-cvp.c
> @@ -652,19 +652,15 @@ static int altera_cvp_probe(struct pci_dev *pdev,
>  	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
>  		 ALTERA_CVP_MGR_NAME, pci_name(pdev));
>  
> -	mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
> -				   &altera_cvp_ops, conf);
> -	if (!mgr) {
> -		ret = -ENOMEM;
> +	mgr = fpga_mgr_register(&pdev->dev, conf->mgr_name,
> +				&altera_cvp_ops, conf);
> +	if (IS_ERR(mgr)) {
> +		ret = PTR_ERR(mgr);
>  		goto err_unmap;
>  	}
>  
>  	pci_set_drvdata(pdev, mgr);
>  
> -	ret = fpga_mgr_register(mgr);
> -	if (ret)
> -		goto err_unmap;
> -
>  	return 0;
>  
>  err_unmap:
> diff --git a/drivers/fpga/altera-pr-ip-core.c b/drivers/fpga/altera-pr-ip-core.c
> index dfdf21ed34c4..be0667968d33 100644
> --- a/drivers/fpga/altera-pr-ip-core.c
> +++ b/drivers/fpga/altera-pr-ip-core.c
> @@ -191,11 +191,8 @@ int alt_pr_register(struct device *dev, void __iomem *reg_base)
>  		(val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
>  		(int)(val & ALT_PR_CSR_PR_START));
>  
> -	mgr = devm_fpga_mgr_create(dev, dev_name(dev), &alt_pr_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(dev, mgr);
> +	mgr = devm_fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv);
> +	return PTR_ERR_OR_ZERO(mgr);
>  }
>  EXPORT_SYMBOL_GPL(alt_pr_register);
>  
> diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
> index 23bfd4d1ad0f..5e1e009dba89 100644
> --- a/drivers/fpga/altera-ps-spi.c
> +++ b/drivers/fpga/altera-ps-spi.c
> @@ -302,12 +302,9 @@ static int altera_ps_probe(struct spi_device *spi)
>  	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s",
>  		 dev_driver_string(&spi->dev), dev_name(&spi->dev));
>  
> -	mgr = devm_fpga_mgr_create(&spi->dev, conf->mgr_name,
> -				   &altera_ps_ops, conf);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(&spi->dev, mgr);
> +	mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name,
> +				     &altera_ps_ops, conf);
> +	return PTR_ERR_OR_ZERO(mgr);
>  }
>  
>  static const struct spi_device_id altera_ps_spi_ids[] = {
> diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
> index d5861d13b306..620e7874ab53 100644
> --- a/drivers/fpga/dfl-fme-mgr.c
> +++ b/drivers/fpga/dfl-fme-mgr.c
> @@ -282,7 +282,7 @@ static void fme_mgr_get_compat_id(void __iomem *fme_pr,
>  static int fme_mgr_probe(struct platform_device *pdev)
>  {
>  	struct dfl_fme_mgr_pdata *pdata = dev_get_platdata(&pdev->dev);
> -	struct fpga_compat_id *compat_id;
> +	struct fpga_manager_info info = { 0 };
>  	struct device *dev = &pdev->dev;
>  	struct fme_mgr_priv *priv;
>  	struct fpga_manager *mgr;
> @@ -302,20 +302,16 @@ static int fme_mgr_probe(struct platform_device *pdev)
>  			return PTR_ERR(priv->ioaddr);
>  	}
>  
> -	compat_id = devm_kzalloc(dev, sizeof(*compat_id), GFP_KERNEL);
> -	if (!compat_id)
> +	info.name = "DFL FME FPGA Manager";
> +	info.mops = &fme_mgr_ops;
> +	info.priv = priv;
> +	info.compat_id = devm_kzalloc(dev, sizeof(*info.compat_id), GFP_KERNEL);
> +	if (!info.compat_id)
>  		return -ENOMEM;
>  
> -	fme_mgr_get_compat_id(priv->ioaddr, compat_id);
> -
> -	mgr = devm_fpga_mgr_create(dev, "DFL FME FPGA Manager",
> -				   &fme_mgr_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	mgr->compat_id = compat_id;
> -
> -	return devm_fpga_mgr_register(dev, mgr);
> +	fme_mgr_get_compat_id(priv->ioaddr, info.compat_id);
> +	mgr = devm_fpga_mgr_register_full(dev, &info);
> +	return PTR_ERR_OR_ZERO(mgr);
>  }
>  
>  static struct platform_driver fme_mgr_driver = {
> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
> index ecb4c3c795fa..5a913aa649fd 100644
> --- a/drivers/fpga/fpga-mgr.c
> +++ b/drivers/fpga/fpga-mgr.c
> @@ -550,21 +550,19 @@ void fpga_mgr_unlock(struct fpga_manager *mgr)
>  EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
>  
>  /**
> - * fpga_mgr_create - create and initialize an FPGA manager struct
> + * fpga_mgr_register_full - create and register an FPGA Manager device
>   * @parent:	fpga manager device from pdev
> - * @name:	fpga manager name
> - * @mops:	pointer to structure of fpga manager ops
> - * @priv:	fpga manager private data
> + * @info:	parameters for fpga manager
>   *
> - * The caller of this function is responsible for freeing the struct with
> - * fpga_mgr_free().  Using devm_fpga_mgr_create() instead is recommended.
> + * The caller of this function is responsible for calling fpga_mgr_unregister().
> + * Using devm_fpga_mgr_register_full() instead is recommended.
>   *
> - * Return: pointer to struct fpga_manager or NULL
> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>   */
> -struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> -				     const struct fpga_manager_ops *mops,
> -				     void *priv)
> +struct fpga_manager *
> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>  {
> +	const struct fpga_manager_ops *mops = info->mops;
>  	struct fpga_manager *mgr;
>  	int id, ret;
>  
> @@ -572,29 +570,31 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>  	    !mops->write_init || (!mops->write && !mops->write_sg) ||
>  	    (mops->write && mops->write_sg)) {
>  		dev_err(parent, "Attempt to register without fpga_manager_ops\n");
> -		return NULL;
> +		return ERR_PTR(-EINVAL);
>  	}
>  
> -	if (!name || !strlen(name)) {
> +	if (!info->name || !strlen(info->name)) {
>  		dev_err(parent, "Attempt to register with no name!\n");
> -		return NULL;
> +		return ERR_PTR(-EINVAL);
>  	}
>  
>  	mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
>  	if (!mgr)
> -		return NULL;
> +		return ERR_PTR(-ENOMEM);
>  
>  	id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
> -	if (id < 0)
> +	if (id < 0) {
> +		ret = id;
>  		goto error_kfree;
> +	}
>  
>  	mutex_init(&mgr->ref_mutex);
>  
> -	mgr->name = name;
> -	mgr->mops = mops;
> -	mgr->priv = priv;
> +	mgr->name = info->name;
> +	mgr->mops = info->mops;
> +	mgr->priv = info->priv;
> +	mgr->compat_id = info->compat_id;
>  
> -	device_initialize(&mgr->dev);
>  	mgr->dev.class = fpga_mgr_class;
>  	mgr->dev.groups = mops->groups;
>  	mgr->dev.parent = parent;
> @@ -605,6 +605,19 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>  	if (ret)
>  		goto error_device;
>  
> +	/*
> +	 * Initialize framework state by requesting low level driver read state
> +	 * from device.  FPGA may be in reset mode or may have been programmed
> +	 * by bootloader or EEPROM.
> +	 */
> +	mgr->state = mgr->mops->state(mgr);
> +
> +	ret = device_register(&mgr->dev);
> +	if (ret) {
> +		put_device(&mgr->dev);
> +		return ERR_PTR(ret);
> +	}
> +
>  	return mgr;
>  
>  error_device:
> @@ -612,96 +625,36 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>  error_kfree:
>  	kfree(mgr);
>  
> -	return NULL;
> +	return ERR_PTR(ret);
>  }
> -EXPORT_SYMBOL_GPL(fpga_mgr_create);
> +EXPORT_SYMBOL_GPL(fpga_mgr_register_full);
>  
>  /**
> - * fpga_mgr_free - free an FPGA manager created with fpga_mgr_create()
> - * @mgr:	fpga manager struct
> - */
> -void fpga_mgr_free(struct fpga_manager *mgr)
> -{
> -	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> -	kfree(mgr);
> -}
> -EXPORT_SYMBOL_GPL(fpga_mgr_free);
> -
> -static void devm_fpga_mgr_release(struct device *dev, void *res)
> -{
> -	struct fpga_mgr_devres *dr = res;
> -
> -	fpga_mgr_free(dr->mgr);
> -}
> -
> -/**
> - * devm_fpga_mgr_create - create and initialize a managed FPGA manager struct
> + * fpga_mgr_register - create and register an FPGA Manager device
>   * @parent:	fpga manager device from pdev
>   * @name:	fpga manager name
>   * @mops:	pointer to structure of fpga manager ops
>   * @priv:	fpga manager private data
>   *
> - * This function is intended for use in an FPGA manager driver's probe function.
> - * After the manager driver creates the manager struct with
> - * devm_fpga_mgr_create(), it should register it with fpga_mgr_register().  The
> - * manager driver's remove function should call fpga_mgr_unregister().  The
> - * manager struct allocated with this function will be freed automatically on
> - * driver detach.  This includes the case of a probe function returning error
> - * before calling fpga_mgr_register(), the struct will still get cleaned up.
> + * The caller of this function is responsible for calling fpga_mgr_unregister().
> + * Using devm_fpga_mgr_register() instead is recommended. This simple
> + * version of the register function should be sufficient for most users. The
> + * fpga_mgr_register_full() function is available for users that need to pass
> + * additional, optional parameters.
>   *
> - * Return: pointer to struct fpga_manager or NULL
> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>   */
> -struct fpga_manager *devm_fpga_mgr_create(struct device *parent, const char *name,
> -					  const struct fpga_manager_ops *mops,
> -					  void *priv)
> +struct fpga_manager *
> +fpga_mgr_register(struct device *parent, const char *name,
> +		  const struct fpga_manager_ops *mops, void *priv)
>  {
> -	struct fpga_mgr_devres *dr;
> +	struct fpga_manager_info info = { 0 };
>  
> -	dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL);
> -	if (!dr)
> -		return NULL;
> +	info.name = name;
> +	info.mops = mops;
> +	info.priv = priv;
>  
> -	dr->mgr = fpga_mgr_create(parent, name, mops, priv);
> -	if (!dr->mgr) {
> -		devres_free(dr);
> -		return NULL;
> -	}
> -
> -	devres_add(parent, dr);
> -
> -	return dr->mgr;
> -}
> -EXPORT_SYMBOL_GPL(devm_fpga_mgr_create);
> -
> -/**
> - * fpga_mgr_register - register an FPGA manager
> - * @mgr: fpga manager struct
> - *
> - * Return: 0 on success, negative error code otherwise.
> - */
> -int fpga_mgr_register(struct fpga_manager *mgr)
> -{
> -	int ret;
> -
> -	/*
> -	 * Initialize framework state by requesting low level driver read state
> -	 * from device.  FPGA may be in reset mode or may have been programmed
> -	 * by bootloader or EEPROM.
> -	 */
> -	mgr->state = mgr->mops->state(mgr);
> -
> -	ret = device_add(&mgr->dev);
> -	if (ret)
> -		goto error_device;
> -
> -	dev_info(&mgr->dev, "%s registered\n", mgr->name);
> -
> -	return 0;
> -
> -error_device:
> -	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> -
> -	return ret;
> +	return fpga_mgr_register_full(parent, &info);
>  }
>  EXPORT_SYMBOL_GPL(fpga_mgr_register);
>  
> @@ -726,14 +679,6 @@ void fpga_mgr_unregister(struct fpga_manager *mgr)
>  }
>  EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
>  
> -static int fpga_mgr_devres_match(struct device *dev, void *res,
> -				 void *match_data)
> -{
> -	struct fpga_mgr_devres *dr = res;
> -
> -	return match_data == dr->mgr;
> -}
> -
>  static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>  {
>  	struct fpga_mgr_devres *dr = res;
> @@ -742,45 +687,67 @@ static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>  }
>  
>  /**
> - * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
> - * @dev: managing device for this FPGA manager
> - * @mgr: fpga manager struct
> + * devm_fpga_mgr_register_full - resource managed variant of fpga_mgr_register()
> + * @parent:	fpga manager device from pdev
> + * @info:	parameters for fpga manager
>   *
> - * This is the devres variant of fpga_mgr_register() for which the unregister
> + * This is the devres variant of fpga_mgr_register_full() for which the unregister
>   * function will be called automatically when the managing device is detached.
>   */
> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr)
> +struct fpga_manager *
> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>  {
>  	struct fpga_mgr_devres *dr;
> -	int ret;
> -
> -	/*
> -	 * Make sure that the struct fpga_manager * that is passed in is
> -	 * managed itself.
> -	 */
> -	if (WARN_ON(!devres_find(dev, devm_fpga_mgr_release,
> -				 fpga_mgr_devres_match, mgr)))
> -		return -EINVAL;
> +	struct fpga_manager *mgr;
>  
>  	dr = devres_alloc(devm_fpga_mgr_unregister, sizeof(*dr), GFP_KERNEL);
>  	if (!dr)
> -		return -ENOMEM;
> +		return ERR_PTR(-ENOMEM);
>  
> -	ret = fpga_mgr_register(mgr);
> -	if (ret) {
> +	mgr = fpga_mgr_register_full(parent, info);
> +	if (IS_ERR(mgr)) {
>  		devres_free(dr);
> -		return ret;
> +		return mgr;
>  	}
>  
>  	dr->mgr = mgr;
> -	devres_add(dev, dr);
> +	devres_add(parent, dr);
>  
> -	return 0;
> +	return mgr;
> +}
> +EXPORT_SYMBOL_GPL(devm_fpga_mgr_register_full);
> +
> +/**
> + * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
> + * @parent:	fpga manager device from pdev
> + * @name:	fpga manager name
> + * @mops:	pointer to structure of fpga manager ops
> + * @priv:	fpga manager private data
> + *
> + * This is the devres variant of fpga_mgr_register() for which the
> + * unregister function will be called automatically when the managing
> + * device is detached.
> + */
> +struct fpga_manager *
> +devm_fpga_mgr_register(struct device *parent, const char *name,
> +		       const struct fpga_manager_ops *mops, void *priv)
> +{
> +	struct fpga_manager_info info = { 0 };
> +
> +	info.name = name;
> +	info.mops = mops;
> +	info.priv = priv;
> +
> +	return devm_fpga_mgr_register_full(parent, &info);
>  }
>  EXPORT_SYMBOL_GPL(devm_fpga_mgr_register);
>  
>  static void fpga_mgr_dev_release(struct device *dev)
>  {
> +	struct fpga_manager *mgr = to_fpga_manager(dev);
> +
> +	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> +	kfree(mgr);
>  }
>  
>  static int __init fpga_mgr_class_init(void)
> diff --git a/drivers/fpga/ice40-spi.c b/drivers/fpga/ice40-spi.c
> index 69dec5af23c3..b7591912248f 100644
> --- a/drivers/fpga/ice40-spi.c
> +++ b/drivers/fpga/ice40-spi.c
> @@ -178,12 +178,9 @@ static int ice40_fpga_probe(struct spi_device *spi)
>  		return ret;
>  	}
>  
> -	mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
> -				   &ice40_fpga_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(dev, mgr);
> +	mgr = devm_fpga_mgr_register(dev, "Lattice iCE40 FPGA Manager",
> +				     &ice40_fpga_ops, priv);
> +	return PTR_ERR_OR_ZERO(mgr);
>  }
>  
>  static const struct of_device_id ice40_fpga_of_match[] = {
> diff --git a/drivers/fpga/machxo2-spi.c b/drivers/fpga/machxo2-spi.c
> index 1afb41aa20d7..8469dfb5dd21 100644
> --- a/drivers/fpga/machxo2-spi.c
> +++ b/drivers/fpga/machxo2-spi.c
> @@ -366,12 +366,9 @@ static int machxo2_spi_probe(struct spi_device *spi)
>  		return -EINVAL;
>  	}
>  
> -	mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager",
> -				   &machxo2_ops, spi);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(dev, mgr);
> +	mgr = devm_fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager",
> +				     &machxo2_ops, spi);
> +	return PTR_ERR_OR_ZERO(mgr);
>  }
>  
>  #ifdef CONFIG_OF
> diff --git a/drivers/fpga/socfpga-a10.c b/drivers/fpga/socfpga-a10.c
> index 573d88bdf730..ac8e89b8a5cc 100644
> --- a/drivers/fpga/socfpga-a10.c
> +++ b/drivers/fpga/socfpga-a10.c
> @@ -508,19 +508,15 @@ static int socfpga_a10_fpga_probe(struct platform_device *pdev)
>  		return -EBUSY;
>  	}
>  
> -	mgr = devm_fpga_mgr_create(dev, "SoCFPGA Arria10 FPGA Manager",
> -				   &socfpga_a10_fpga_mgr_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	platform_set_drvdata(pdev, mgr);
> -
> -	ret = fpga_mgr_register(mgr);
> -	if (ret) {
> +	mgr = fpga_mgr_register(dev, "SoCFPGA Arria10 FPGA Manager",
> +				&socfpga_a10_fpga_mgr_ops, priv);
> +	if (IS_ERR(mgr)) {
>  		clk_disable_unprepare(priv->clk);
> -		return ret;
> +		return PTR_ERR(mgr);
>  	}
>  
> +	platform_set_drvdata(pdev, mgr);
> +
>  	return 0;
>  }
>  
> diff --git a/drivers/fpga/socfpga.c b/drivers/fpga/socfpga.c
> index 1f467173fc1f..7e0741f99696 100644
> --- a/drivers/fpga/socfpga.c
> +++ b/drivers/fpga/socfpga.c
> @@ -571,12 +571,9 @@ static int socfpga_fpga_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
>  
> -	mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
> -				   &socfpga_fpga_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(dev, mgr);
> +	mgr = devm_fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
> +				     &socfpga_fpga_ops, priv);
> +	return PTR_ERR_OR_ZERO(mgr);
>  }
>  
>  #ifdef CONFIG_OF
> diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
> index a2cea500f7cc..9155e888a133 100644
> --- a/drivers/fpga/stratix10-soc.c
> +++ b/drivers/fpga/stratix10-soc.c
> @@ -425,18 +425,11 @@ static int s10_probe(struct platform_device *pdev)
>  
>  	init_completion(&priv->status_return_completion);
>  
> -	mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
> -			      &s10_ops, priv);
> -	if (!mgr) {
> -		dev_err(dev, "unable to create FPGA manager\n");
> -		ret = -ENOMEM;
> -		goto probe_err;
> -	}
> -
> -	ret = fpga_mgr_register(mgr);
> -	if (ret) {
> +	mgr = fpga_mgr_register(dev, "Stratix10 SOC FPGA Manager",
> +				&s10_ops, priv);
> +	if (IS_ERR(mgr)) {
>  		dev_err(dev, "unable to register FPGA manager\n");
> -		fpga_mgr_free(mgr);
> +		ret = PTR_ERR(mgr);
>  		goto probe_err;
>  	}
>  
> @@ -454,7 +447,6 @@ static int s10_remove(struct platform_device *pdev)
>  	struct s10_priv *priv = mgr->priv;
>  
>  	fpga_mgr_unregister(mgr);
> -	fpga_mgr_free(mgr);
>  	stratix10_svc_free_channel(priv->chan);
>  
>  	return 0;
> diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c
> index 101f016c6ed8..fd52de20ddb2 100644
> --- a/drivers/fpga/ts73xx-fpga.c
> +++ b/drivers/fpga/ts73xx-fpga.c
> @@ -122,12 +122,9 @@ static int ts73xx_fpga_probe(struct platform_device *pdev)
>  	if (IS_ERR(priv->io_base))
>  		return PTR_ERR(priv->io_base);
>  
> -	mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
> -				   &ts73xx_fpga_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(kdev, mgr);
> +	mgr = devm_fpga_mgr_register(kdev, "TS-73xx FPGA Manager",
> +				     &ts73xx_fpga_ops, priv);
> +	return PTR_ERR_OR_ZERO(mgr);
>  }
>  
>  static struct platform_driver ts73xx_fpga_driver = {
> diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
> index fee4d0abf6bf..db23626f9ab2 100644
> --- a/drivers/fpga/xilinx-spi.c
> +++ b/drivers/fpga/xilinx-spi.c
> @@ -247,13 +247,10 @@ static int xilinx_spi_probe(struct spi_device *spi)
>  		return dev_err_probe(&spi->dev, PTR_ERR(conf->done),
>  				     "Failed to get DONE gpio\n");
>  
> -	mgr = devm_fpga_mgr_create(&spi->dev,
> -				   "Xilinx Slave Serial FPGA Manager",
> -				   &xilinx_spi_ops, conf);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(&spi->dev, mgr);
> +	mgr = devm_fpga_mgr_register(&spi->dev,
> +				     "Xilinx Slave Serial FPGA Manager",
> +				     &xilinx_spi_ops, conf);
> +	return PTR_ERR_OR_ZERO(mgr);
>  }
>  
>  static const struct of_device_id xlnx_spi_of_match[] = {
> diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
> index 9b75bd4f93d8..426aa34c6a0d 100644
> --- a/drivers/fpga/zynq-fpga.c
> +++ b/drivers/fpga/zynq-fpga.c
> @@ -609,20 +609,16 @@ static int zynq_fpga_probe(struct platform_device *pdev)
>  
>  	clk_disable(priv->clk);
>  
> -	mgr = devm_fpga_mgr_create(dev, "Xilinx Zynq FPGA Manager",
> -				   &zynq_fpga_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	platform_set_drvdata(pdev, mgr);
> -
> -	err = fpga_mgr_register(mgr);
> -	if (err) {
> +	mgr = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
> +				&zynq_fpga_ops, priv);
> +	if (IS_ERR(mgr)) {
>  		dev_err(dev, "unable to register FPGA manager\n");
>  		clk_unprepare(priv->clk);
> -		return err;
> +		return PTR_ERR(mgr);
>  	}
>  
> +	platform_set_drvdata(pdev, mgr);
> +
>  	return 0;
>  }
>  
> diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
> index 125743c9797f..975bdc4d0a65 100644
> --- a/drivers/fpga/zynqmp-fpga.c
> +++ b/drivers/fpga/zynqmp-fpga.c
> @@ -102,12 +102,9 @@ static int zynqmp_fpga_probe(struct platform_device *pdev)
>  
>  	priv->dev = dev;
>  
> -	mgr = devm_fpga_mgr_create(dev, "Xilinx ZynqMP FPGA Manager",
> -				   &zynqmp_fpga_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(dev, mgr);
> +	mgr = devm_fpga_mgr_register(dev, "Xilinx ZynqMP FPGA Manager",
> +				     &zynqmp_fpga_ops, priv);
> +	return PTR_ERR_OR_ZERO(mgr);
>  }
>  
>  static const struct of_device_id zynqmp_fpga_of_match[] = {
> diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
> index 474c1f506307..ac3ddaf2903c 100644
> --- a/include/linux/fpga/fpga-mgr.h
> +++ b/include/linux/fpga/fpga-mgr.h
> @@ -105,6 +105,36 @@ struct fpga_image_info {
>  #endif
>  };
>  
> +/**
> + * struct fpga_compat_id - id for compatibility check
> + *
> + * @id_h: high 64bit of the compat_id
> + * @id_l: low 64bit of the compat_id
> + */
> +struct fpga_compat_id {
> +	u64 id_h;
> +	u64 id_l;
> +};
> +
> +/**
> + * struct fpga_manager_info - collection of parameters for an FPGA Manager
> + * @name: fpga manager name
> + * @compat_id: FPGA manager id for compatibility check.
> + * @mops: pointer to structure of fpga manager ops
> + * @priv: fpga manager private data
> + *
> + * fpga_manager_info contains parameters for the register function. These
> + * are separated into an info structure because they some are optional
> + * others could be added to in the future. The info structure facilitates
> + * maintaining a stable API.
> + */
> +struct fpga_manager_info {
> +	const char *name;
> +	struct fpga_compat_id *compat_id;
> +	const struct fpga_manager_ops *mops;
> +	void *priv;
> +};
> +
>  /**
>   * struct fpga_manager_ops - ops for low level fpga manager drivers
>   * @initial_header_size: Maximum number of bytes that should be passed into write_init
> @@ -143,17 +173,6 @@ struct fpga_manager_ops {
>  #define FPGA_MGR_STATUS_IP_PROTOCOL_ERR		BIT(3)
>  #define FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR	BIT(4)
>  
> -/**
> - * struct fpga_compat_id - id for compatibility check
> - *
> - * @id_h: high 64bit of the compat_id
> - * @id_l: low 64bit of the compat_id
> - */
> -struct fpga_compat_id {
> -	u64 id_h;
> -	u64 id_l;
> -};
> -
>  /**
>   * struct fpga_manager - fpga manager structure
>   * @name: name of low level fpga manager
> @@ -191,17 +210,18 @@ struct fpga_manager *fpga_mgr_get(struct device *dev);
>  
>  void fpga_mgr_put(struct fpga_manager *mgr);
>  
> -struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name,
> -				     const struct fpga_manager_ops *mops,
> -				     void *priv);
> -void fpga_mgr_free(struct fpga_manager *mgr);
> -int fpga_mgr_register(struct fpga_manager *mgr);
> -void fpga_mgr_unregister(struct fpga_manager *mgr);
> +struct fpga_manager *
> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
>  
> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr);
> +struct fpga_manager *
> +fpga_mgr_register(struct device *parent, const char *name,
> +		  const struct fpga_manager_ops *mops, void *priv);
> +void fpga_mgr_unregister(struct fpga_manager *mgr);
>  
> -struct fpga_manager *devm_fpga_mgr_create(struct device *dev, const char *name,
> -					  const struct fpga_manager_ops *mops,
> -					  void *priv);
> +struct fpga_manager *
> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
> +struct fpga_manager *
> +devm_fpga_mgr_register(struct device *parent, const char *name,
> +		       const struct fpga_manager_ops *mops, void *priv);
>  
>  #endif /*_LINUX_FPGA_MGR_H */
> -- 
> 2.25.1

^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 2/3] fpga: bridge: Use standard dev_release for class driver
  2021-07-01  1:37 ` [PATCH v9 2/3] fpga: bridge: " Russ Weight
@ 2021-07-01  5:39   ` Xu Yilun
  2021-07-06 23:06     ` Russ Weight
  2021-07-01  6:26   ` Xu Yilun
  2021-07-06 20:08   ` Tom Rix
  2 siblings, 1 reply; 22+ messages in thread
From: Xu Yilun @ 2021-07-01  5:39 UTC (permalink / raw)
  To: Russ Weight
  Cc: mdf, linux-fpga, trix, lgoncalv, hao.wu, matthew.gerlach, richard.gong

On Wed, Jun 30, 2021 at 06:37:32PM -0700, Russ Weight wrote:
> The FPGA bridge class driver data structure is being treated as a
> managed resource instead of using the standard dev_release call-back
> function to release the class data structure. This change removes
> the managed resource code and combines the create() and register()
> functions into a single register() or register_simple() function.
> 
> The register() function accepts an info data structure to provide
> flexibility in passing optional parameters. The register_simple()
> function supports the current parameter list for users that don't
> require the use of optional parameters.

Please update the commit message, others are good to me.

Thanks,
Yilun

> 
> Signed-off-by: Russ Weight <russell.h.weight@intel.com>
> Reviewed-by: Xu Yilun <yilun.xu@intel.com>
> ---
> v9:
>   - Cleaned up documentation for the FPGA Bridge register functions
>   - Renamed fpga_bridge_register() to fpga_bridge_register_full()
>   - Renamed fpga_bridge_register_simple() to fpga_bridge_register()
> v8:
>   - Added reviewed-by tag.
>   - Updated Documentation/driver-api/fpga/fpga-bridge.rst documentation.
> v7:
>   - Update the commit message to describe the new parameters for the
>     fpga_bridge_register() function and to mention the
>     fpga_bridge_register_simple() function.
>   - Fix function prototypes in header file to rename dev to parent.
>   - Some cleanup of comments.
>   - Update function defintions/prototypes to apply const to the new info
>     parameter.
>   - Verify that info->br_ops is non-null in register functions.
> v6:
>   - Changed fpga_bridge_register() parameters to accept an info data
>     structure to provide flexibility in passing optional parameters.
>   - Added fpga_bridge_register_simple() function to support current
>     parameters for users that don't require the use of optional
>     parameters.
> v5:
>   - Rebased on top of recently accepted patches.
> v4:
>   - Restore the previous format for the Return value in the comment header
>     for fpga_bridge_register()
> v3:
>   - Cleaned up comment header for fpga_bridge_register()
>   - Fix error return values for fpga_bridge_register()
> v2:
>   - No changes
> ---
>  Documentation/driver-api/fpga/fpga-bridge.rst |   8 +-
>  drivers/fpga/altera-fpga2sdram.c              |  12 +-
>  drivers/fpga/altera-freeze-bridge.c           |  10 +-
>  drivers/fpga/altera-hps2fpga.c                |  12 +-
>  drivers/fpga/dfl-fme-br.c                     |  10 +-
>  drivers/fpga/fpga-bridge.c                    | 137 ++++++------------
>  drivers/fpga/xilinx-pr-decoupler.c            |  17 +--
>  include/linux/fpga/fpga-bridge.h              |  33 +++--
>  8 files changed, 101 insertions(+), 138 deletions(-)
> 
> diff --git a/Documentation/driver-api/fpga/fpga-bridge.rst b/Documentation/driver-api/fpga/fpga-bridge.rst
> index 8d650b4e2ce6..38e3bac8e877 100644
> --- a/Documentation/driver-api/fpga/fpga-bridge.rst
> +++ b/Documentation/driver-api/fpga/fpga-bridge.rst
> @@ -6,8 +6,10 @@ API to implement a new FPGA bridge
>  
>  * struct fpga_bridge - The FPGA Bridge structure
>  * struct fpga_bridge_ops - Low level Bridge driver ops
> -* devm_fpga_bridge_create() - Allocate and init a bridge struct
> -* fpga_bridge_register() - Register a bridge
> +* fpga_bridge_register_full() - Create and register a bridge using the
> +  fpga_bridge_info structure to provide the full flexibility of options
> +* fpga_bridge_register() - Create and register a bridge using standard
> +  arguments
>  * fpga_bridge_unregister() - Unregister a bridge
>  
>  .. kernel-doc:: include/linux/fpga/fpga-bridge.h
> @@ -17,7 +19,7 @@ API to implement a new FPGA bridge
>     :functions: fpga_bridge_ops
>  
>  .. kernel-doc:: drivers/fpga/fpga-bridge.c
> -   :functions: devm_fpga_bridge_create
> +   :functions: fpga_bridge_register_full
>  
>  .. kernel-doc:: drivers/fpga/fpga-bridge.c
>     :functions: fpga_bridge_register
> diff --git a/drivers/fpga/altera-fpga2sdram.c b/drivers/fpga/altera-fpga2sdram.c
> index a78e49c63c64..66063507116b 100644
> --- a/drivers/fpga/altera-fpga2sdram.c
> +++ b/drivers/fpga/altera-fpga2sdram.c
> @@ -121,17 +121,13 @@ static int alt_fpga_bridge_probe(struct platform_device *pdev)
>  	/* Get f2s bridge configuration saved in handoff register */
>  	regmap_read(sysmgr, SYSMGR_ISWGRP_HANDOFF3, &priv->mask);
>  
> -	br = devm_fpga_bridge_create(dev, F2S_BRIDGE_NAME,
> -				     &altera_fpga2sdram_br_ops, priv);
> -	if (!br)
> -		return -ENOMEM;
> +	br = fpga_bridge_register(dev, F2S_BRIDGE_NAME,
> +				  &altera_fpga2sdram_br_ops, priv);
> +	if (IS_ERR(br))
> +		return PTR_ERR(mgr);
>  
>  	platform_set_drvdata(pdev, br);
>  
> -	ret = fpga_bridge_register(br);
> -	if (ret)
> -		return ret;
> -
>  	dev_info(dev, "driver initialized with handoff %08x\n", priv->mask);
>  
>  	if (!of_property_read_u32(dev->of_node, "bridge-enable", &enable)) {
> diff --git a/drivers/fpga/altera-freeze-bridge.c b/drivers/fpga/altera-freeze-bridge.c
> index dd58c4aea92e..bfbfa43cd05b 100644
> --- a/drivers/fpga/altera-freeze-bridge.c
> +++ b/drivers/fpga/altera-freeze-bridge.c
> @@ -244,14 +244,14 @@ static int altera_freeze_br_probe(struct platform_device *pdev)
>  
>  	priv->base_addr = base_addr;
>  
> -	br = devm_fpga_bridge_create(dev, FREEZE_BRIDGE_NAME,
> -				     &altera_freeze_br_br_ops, priv);
> -	if (!br)
> -		return -ENOMEM;
> +	br = fpga_bridge_register(dev, FREEZE_BRIDGE_NAME,
> +				  &altera_freeze_br_br_ops, priv);
> +	if (IS_ERR(br))
> +		return PTR_ERR(br);
>  
>  	platform_set_drvdata(pdev, br);
>  
> -	return fpga_bridge_register(br);
> +	return 0;
>  }
>  
>  static int altera_freeze_br_remove(struct platform_device *pdev)
> diff --git a/drivers/fpga/altera-hps2fpga.c b/drivers/fpga/altera-hps2fpga.c
> index 77b95f251821..aa758426c22b 100644
> --- a/drivers/fpga/altera-hps2fpga.c
> +++ b/drivers/fpga/altera-hps2fpga.c
> @@ -180,19 +180,15 @@ static int alt_fpga_bridge_probe(struct platform_device *pdev)
>  		}
>  	}
>  
> -	br = devm_fpga_bridge_create(dev, priv->name,
> -				     &altera_hps2fpga_br_ops, priv);
> -	if (!br) {
> -		ret = -ENOMEM;
> +	br = fpga_bridge_register(dev, priv->name,
> +				  &altera_hps2fpga_br_ops, priv);
> +	if (IS_ERR(br)) {
> +		ret = PTR_ERR(br);
>  		goto err;
>  	}
>  
>  	platform_set_drvdata(pdev, br);
>  
> -	ret = fpga_bridge_register(br);
> -	if (ret)
> -		goto err;
> -
>  	return 0;
>  
>  err:
> diff --git a/drivers/fpga/dfl-fme-br.c b/drivers/fpga/dfl-fme-br.c
> index 3ff9f3a687ce..808d1f4d76df 100644
> --- a/drivers/fpga/dfl-fme-br.c
> +++ b/drivers/fpga/dfl-fme-br.c
> @@ -68,14 +68,14 @@ static int fme_br_probe(struct platform_device *pdev)
>  
>  	priv->pdata = dev_get_platdata(dev);
>  
> -	br = devm_fpga_bridge_create(dev, "DFL FPGA FME Bridge",
> -				     &fme_bridge_ops, priv);
> -	if (!br)
> -		return -ENOMEM;
> +	br = fpga_bridge_register(dev, "DFL FPGA FME Bridge",
> +				  &fme_bridge_ops, priv);
> +	if (IS_ERR(br))
> +		return PTR_ERR(br);
>  
>  	platform_set_drvdata(pdev, br);
>  
> -	return fpga_bridge_register(br);
> +	return 0;
>  }
>  
>  static int fme_br_remove(struct platform_device *pdev)
> diff --git a/drivers/fpga/fpga-bridge.c b/drivers/fpga/fpga-bridge.c
> index 798f55670646..e6d98be8531b 100644
> --- a/drivers/fpga/fpga-bridge.c
> +++ b/drivers/fpga/fpga-bridge.c
> @@ -312,55 +312,63 @@ static struct attribute *fpga_bridge_attrs[] = {
>  ATTRIBUTE_GROUPS(fpga_bridge);
>  
>  /**
> - * fpga_bridge_create - create and initialize a struct fpga_bridge
> + * fpga_bridge_register_full - create and register an FPGA Bridge device
>   * @parent:	FPGA bridge device from pdev
> - * @name:	FPGA bridge name
> - * @br_ops:	pointer to structure of fpga bridge ops
> - * @priv:	FPGA bridge private data
> + * @info:	parameters for FPGA Bridge
>   *
> - * The caller of this function is responsible for freeing the bridge with
> - * fpga_bridge_free().  Using devm_fpga_bridge_create() instead is recommended.
> - *
> - * Return: struct fpga_bridge or NULL
> + * Return: struct fpga_bridge pointer or ERR_PTR()
>   */
> -struct fpga_bridge *fpga_bridge_create(struct device *parent, const char *name,
> -				       const struct fpga_bridge_ops *br_ops,
> -				       void *priv)
> +struct fpga_bridge *
> +fpga_bridge_register_full(struct device *parent,
> +			  const struct fpga_bridge_info *info)
>  {
>  	struct fpga_bridge *bridge;
>  	int id, ret;
>  
> -	if (!name || !strlen(name)) {
> +	if (!info->br_ops) {
> +		dev_err(parent, "Attempt to register without fpga_bridge_ops\n");
> +		return ERR_PTR(-EINVAL);
> +	}
> +
> +	if (!info->name || !strlen(info->name)) {
>  		dev_err(parent, "Attempt to register with no name!\n");
> -		return NULL;
> +		return ERR_PTR(-EINVAL);
>  	}
>  
>  	bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
>  	if (!bridge)
> -		return NULL;
> +		return ERR_PTR(-ENOMEM);
>  
>  	id = ida_simple_get(&fpga_bridge_ida, 0, 0, GFP_KERNEL);
> -	if (id < 0)
> +	if (id < 0) {
> +		ret = id;
>  		goto error_kfree;
> +	}
>  
>  	mutex_init(&bridge->mutex);
>  	INIT_LIST_HEAD(&bridge->node);
>  
> -	bridge->name = name;
> -	bridge->br_ops = br_ops;
> -	bridge->priv = priv;
> +	bridge->name = info->name;
> +	bridge->br_ops = info->br_ops;
> +	bridge->priv = info->priv;
>  
> -	device_initialize(&bridge->dev);
> -	bridge->dev.groups = br_ops->groups;
> +	bridge->dev.groups = info->br_ops->groups;
>  	bridge->dev.class = fpga_bridge_class;
>  	bridge->dev.parent = parent;
>  	bridge->dev.of_node = parent->of_node;
>  	bridge->dev.id = id;
> +	of_platform_populate(bridge->dev.of_node, NULL, NULL, &bridge->dev);
>  
>  	ret = dev_set_name(&bridge->dev, "br%d", id);
>  	if (ret)
>  		goto error_device;
>  
> +	ret = device_register(&bridge->dev);
> +	if (ret) {
> +		put_device(&bridge->dev);
> +		return ERR_PTR(ret);
> +	}
> +
>  	return bridge;
>  
>  error_device:
> @@ -368,88 +376,35 @@ struct fpga_bridge *fpga_bridge_create(struct device *parent, const char *name,
>  error_kfree:
>  	kfree(bridge);
>  
> -	return NULL;
> -}
> -EXPORT_SYMBOL_GPL(fpga_bridge_create);
> -
> -/**
> - * fpga_bridge_free - free an fpga bridge created by fpga_bridge_create()
> - * @bridge:	FPGA bridge struct
> - */
> -void fpga_bridge_free(struct fpga_bridge *bridge)
> -{
> -	ida_simple_remove(&fpga_bridge_ida, bridge->dev.id);
> -	kfree(bridge);
> -}
> -EXPORT_SYMBOL_GPL(fpga_bridge_free);
> -
> -static void devm_fpga_bridge_release(struct device *dev, void *res)
> -{
> -	struct fpga_bridge *bridge = *(struct fpga_bridge **)res;
> -
> -	fpga_bridge_free(bridge);
> +	return ERR_PTR(ret);
>  }
> +EXPORT_SYMBOL_GPL(fpga_bridge_register_full);
>  
>  /**
> - * devm_fpga_bridge_create - create and init a managed struct fpga_bridge
> + * fpga_bridge_register - create and register an FPGA Bridge device
>   * @parent:	FPGA bridge device from pdev
>   * @name:	FPGA bridge name
>   * @br_ops:	pointer to structure of fpga bridge ops
>   * @priv:	FPGA bridge private data
>   *
> - * This function is intended for use in an FPGA bridge driver's probe function.
> - * After the bridge driver creates the struct with devm_fpga_bridge_create(), it
> - * should register the bridge with fpga_bridge_register().  The bridge driver's
> - * remove function should call fpga_bridge_unregister().  The bridge struct
> - * allocated with this function will be freed automatically on driver detach.
> - * This includes the case of a probe function returning error before calling
> - * fpga_bridge_register(), the struct will still get cleaned up.
> + * This simple version of the register should be sufficient for most users.
> + * The fpga_bridge_register_full() function is available for users that need to pass
> + * additional, optional parameters.
>   *
> - *  Return: struct fpga_bridge or NULL
> + * Return: struct fpga_bridge pointer or ERR_PTR()
>   */
> -struct fpga_bridge
> -*devm_fpga_bridge_create(struct device *parent, const char *name,
> -			 const struct fpga_bridge_ops *br_ops, void *priv)
> +struct fpga_bridge *
> +fpga_bridge_register(struct device *parent, const char *name,
> +		     const struct fpga_bridge_ops *br_ops,
> +		     void *priv)
>  {
> -	struct fpga_bridge **ptr, *bridge;
> -
> -	ptr = devres_alloc(devm_fpga_bridge_release, sizeof(*ptr), GFP_KERNEL);
> -	if (!ptr)
> -		return NULL;
> -
> -	bridge = fpga_bridge_create(parent, name, br_ops, priv);
> -	if (!bridge) {
> -		devres_free(ptr);
> -	} else {
> -		*ptr = bridge;
> -		devres_add(parent, ptr);
> -	}
> +	struct fpga_bridge_info info = { 0 };
>  
> -	return bridge;
> -}
> -EXPORT_SYMBOL_GPL(devm_fpga_bridge_create);
> +	info.name = name;
> +	info.br_ops = br_ops;
> +	info.priv = priv;
>  
> -/**
> - * fpga_bridge_register - register an FPGA bridge
> - *
> - * @bridge: FPGA bridge struct
> - *
> - * Return: 0 for success, error code otherwise.
> - */
> -int fpga_bridge_register(struct fpga_bridge *bridge)
> -{
> -	struct device *dev = &bridge->dev;
> -	int ret;
> -
> -	ret = device_add(dev);
> -	if (ret)
> -		return ret;
> -
> -	of_platform_populate(dev->of_node, NULL, NULL, dev);
> -
> -	dev_info(dev->parent, "fpga bridge [%s] registered\n", bridge->name);
> -
> -	return 0;
> +	return fpga_bridge_register_full(parent, &info);
>  }
>  EXPORT_SYMBOL_GPL(fpga_bridge_register);
>  
> @@ -475,6 +430,10 @@ EXPORT_SYMBOL_GPL(fpga_bridge_unregister);
>  
>  static void fpga_bridge_dev_release(struct device *dev)
>  {
> +	struct fpga_bridge *bridge = to_fpga_bridge(dev);
> +
> +	ida_simple_remove(&fpga_bridge_ida, bridge->dev.id);
> +	kfree(bridge);
>  }
>  
>  static int __init fpga_bridge_dev_init(void)
> diff --git a/drivers/fpga/xilinx-pr-decoupler.c b/drivers/fpga/xilinx-pr-decoupler.c
> index ea2bde6e5bc4..c004e52b9464 100644
> --- a/drivers/fpga/xilinx-pr-decoupler.c
> +++ b/drivers/fpga/xilinx-pr-decoupler.c
> @@ -138,22 +138,17 @@ static int xlnx_pr_decoupler_probe(struct platform_device *pdev)
>  
>  	clk_disable(priv->clk);
>  
> -	br = devm_fpga_bridge_create(&pdev->dev, priv->ipconfig->name,
> -				     &xlnx_pr_decoupler_br_ops, priv);
> -	if (!br) {
> -		err = -ENOMEM;
> -		goto err_clk;
> -	}
> -
> -	platform_set_drvdata(pdev, br);
> -
> -	err = fpga_bridge_register(br);
> -	if (err) {
> +	br = fpga_bridge_register(&pdev->dev, priv->ipconfig->name,
> +				  &xlnx_pr_decoupler_br_ops, priv);
> +	if (IS_ERR(br)) {
> +		err = PTR_ERR(br);
>  		dev_err(&pdev->dev, "unable to register %s",
>  			priv->ipconfig->name);
>  		goto err_clk;
>  	}
>  
> +	platform_set_drvdata(pdev, br);
> +
>  	return 0;
>  
>  err_clk:
> diff --git a/include/linux/fpga/fpga-bridge.h b/include/linux/fpga/fpga-bridge.h
> index 6c3c28806ff1..f0a4d99d9c8e 100644
> --- a/include/linux/fpga/fpga-bridge.h
> +++ b/include/linux/fpga/fpga-bridge.h
> @@ -22,6 +22,23 @@ struct fpga_bridge_ops {
>  	const struct attribute_group **groups;
>  };
>  
> +/**
> + * struct fpga_bridge_info - collection of parameters an FPGA Bridge
> + * @name: fpga bridge name
> + * @br_ops: pointer to structure of fpga bridge ops
> + * @priv: fpga bridge private data
> + *
> + * fpga_bridge_info contains parameters for the register function. These
> + * are separated into an info structure because they some are optional
> + * others could be added to in the future. The info structure facilitates
> + * maintaining a stable API.
> + */
> +struct fpga_bridge_info {
> +	const char *name;
> +	const struct fpga_bridge_ops *br_ops;
> +	void *priv;
> +};
> +
>  /**
>   * struct fpga_bridge - FPGA bridge structure
>   * @name: name of low level FPGA bridge
> @@ -62,15 +79,13 @@ int of_fpga_bridge_get_to_list(struct device_node *np,
>  			       struct fpga_image_info *info,
>  			       struct list_head *bridge_list);
>  
> -struct fpga_bridge *fpga_bridge_create(struct device *dev, const char *name,
> -				       const struct fpga_bridge_ops *br_ops,
> -				       void *priv);
> -void fpga_bridge_free(struct fpga_bridge *br);
> -int fpga_bridge_register(struct fpga_bridge *br);
> -void fpga_bridge_unregister(struct fpga_bridge *br);
> +struct fpga_bridge *
> +fpga_bridge_register_full(struct device *parent, const struct fpga_bridge_info *info);
>  
> -struct fpga_bridge
> -*devm_fpga_bridge_create(struct device *dev, const char *name,
> -			 const struct fpga_bridge_ops *br_ops, void *priv);
> +struct fpga_bridge *
> +fpga_bridge_register(struct device *parent, const char *name,
> +		     const struct fpga_bridge_ops *br_ops,
> +		     void *priv);
> +void fpga_bridge_unregister(struct fpga_bridge *br);
>  
>  #endif /* _LINUX_FPGA_BRIDGE_H */
> -- 
> 2.25.1

^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 3/3] fpga: region: Use standard dev_release for class driver
  2021-07-01  1:37 ` [PATCH v9 3/3] fpga: region: " Russ Weight
@ 2021-07-01  5:51   ` Xu Yilun
  2021-07-06 23:08     ` Russ Weight
  0 siblings, 1 reply; 22+ messages in thread
From: Xu Yilun @ 2021-07-01  5:51 UTC (permalink / raw)
  To: Russ Weight
  Cc: mdf, linux-fpga, trix, lgoncalv, hao.wu, matthew.gerlach, richard.gong

On Wed, Jun 30, 2021 at 06:37:33PM -0700, Russ Weight wrote:
> The FPGA region class driver data structure is being treated as a
> managed resource instead of using the standard dev_release call-back
> function to release the class data structure. This change removes the
> managed resource code and combines the create() and register()
> functions into a single register() or register_simple() function.
> 
> The register() function accepts an info data structure to provide
> flexibility in passing optional parameters. The register_simple()
> function supports the current parameter list for users that don't
> require the use of optional parameters.

Please update the commit message, others are good to me.

Thanks,
Yilun

> 
> Signed-off-by: Russ Weight <russell.h.weight@intel.com>
> Reviewed-by: Xu Yilun <yilun.xu@intel.com>
> ---
> v9:
>   - Cleaned up documentation for the FPGA Region register functions
>   - Renamed fpga_region_register() to fpga_region_register_full()
>   - Renamed fpga_region_register_simple() to fpga_region_register()
> v8:
>   - Added reviewed-by tag.
>   - Updated Documentation/driver-api/fpga/fpga-region.rst documentation.
> v7:
>   - Update the commit message to describe the new parameters for the
>     fpga_region_register() function and to mention the
>     fpga_region_register_simple() function.
>   - Fix function prototypes in header file to rename dev to parent.
>   - Some cleanup of comments.
>   - Update function defintions/prototypes to apply const to the new info
>     parameter.
>   - Verify a non-null info pointer in the register() functions.
> v6:
>   - Moved FPGA manager optional parameters out of the ops structure and
>     back into the FPGA Region structure.
>   - Changed fpga_region_register() parameters to accept an info data
>     structure to provide flexibility in passing optional parameters.
>   - Added fpga_region_register_simple() functions to support current
>     parameters for users that don't require the use of optional parameters.
> v5:
>   - Rebased on top of recently accepted patches.
>   - Created the fpga_region_ops data structure which is optionally passed
>     to fpga_region_register(). compat_id, the get_bridges() pointer, and
>     the priv pointer are included in the fpga_region_ops structure.
> v4:
>   - Added the compat_id parameter to fpga_region_register() to ensure
>     that the compat_id is set before the device_register() call.
>   - Modified the dfl_fpga_feature_devs_enumerate() function to restore
>     the fpga_region_register() call to the correct location.
> v3:
>   - Cleaned up comment header for fpga_region_register()
>   - Fix fpga_region_register() error return on ida_simple_get() failure
> v2:
>   - No changes
> ---
>  Documentation/driver-api/fpga/fpga-region.rst |   8 +-
>  drivers/fpga/dfl-fme-region.c                 |  17 ++-
>  drivers/fpga/dfl.c                            |  12 +-
>  drivers/fpga/fpga-region.c                    | 119 +++++++-----------
>  drivers/fpga/of-fpga-region.c                 |  10 +-
>  include/linux/fpga/fpga-region.h              |  36 ++++--
>  6 files changed, 91 insertions(+), 111 deletions(-)
> 
> diff --git a/Documentation/driver-api/fpga/fpga-region.rst b/Documentation/driver-api/fpga/fpga-region.rst
> index 2636a27c11b2..904518190bb4 100644
> --- a/Documentation/driver-api/fpga/fpga-region.rst
> +++ b/Documentation/driver-api/fpga/fpga-region.rst
> @@ -46,8 +46,10 @@ API to add a new FPGA region
>  ----------------------------
>  
>  * struct fpga_region - The FPGA region struct
> -* devm_fpga_region_create() - Allocate and init a region struct
> -* fpga_region_register() -  Register an FPGA region
> +* fpga_region_register_full() -  Create and register an FPGA region using the
> +  fpga_region_info structure to provide the full flexibility of options
> +* fpga_region_register() -  Create and register an FPGA region using standard
> +  arguments
>  * fpga_region_unregister() -  Unregister an FPGA region
>  
>  The FPGA region's probe function will need to get a reference to the FPGA
> @@ -76,7 +78,7 @@ following APIs to handle building or tearing down that list.
>     :functions: fpga_region
>  
>  .. kernel-doc:: drivers/fpga/fpga-region.c
> -   :functions: devm_fpga_region_create
> +   :functions: fpga_region_register_full
>  
>  .. kernel-doc:: drivers/fpga/fpga-region.c
>     :functions: fpga_region_register
> diff --git a/drivers/fpga/dfl-fme-region.c b/drivers/fpga/dfl-fme-region.c
> index 1eeb42af1012..4aebde0a7f1c 100644
> --- a/drivers/fpga/dfl-fme-region.c
> +++ b/drivers/fpga/dfl-fme-region.c
> @@ -30,6 +30,7 @@ static int fme_region_get_bridges(struct fpga_region *region)
>  static int fme_region_probe(struct platform_device *pdev)
>  {
>  	struct dfl_fme_region_pdata *pdata = dev_get_platdata(&pdev->dev);
> +	struct fpga_region_info info = { 0 };
>  	struct device *dev = &pdev->dev;
>  	struct fpga_region *region;
>  	struct fpga_manager *mgr;
> @@ -39,20 +40,18 @@ static int fme_region_probe(struct platform_device *pdev)
>  	if (IS_ERR(mgr))
>  		return -EPROBE_DEFER;
>  
> -	region = devm_fpga_region_create(dev, mgr, fme_region_get_bridges);
> -	if (!region) {
> -		ret = -ENOMEM;
> +	info.mgr = mgr;
> +	info.compat_id = mgr->compat_id;
> +	info.get_bridges = fme_region_get_bridges;
> +	info.priv = pdata;
> +	region = fpga_region_register_full(dev, &info);
> +	if (IS_ERR(region)) {
> +		ret = PTR_ERR(region);
>  		goto eprobe_mgr_put;
>  	}
>  
> -	region->priv = pdata;
> -	region->compat_id = mgr->compat_id;
>  	platform_set_drvdata(pdev, region);
>  
> -	ret = fpga_region_register(region);
> -	if (ret)
> -		goto eprobe_mgr_put;
> -
>  	dev_dbg(dev, "DFL FME FPGA Region probed\n");
>  
>  	return 0;
> diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
> index 511b20ff35a3..3905995ef6d5 100644
> --- a/drivers/fpga/dfl.c
> +++ b/drivers/fpga/dfl.c
> @@ -1400,19 +1400,15 @@ dfl_fpga_feature_devs_enumerate(struct dfl_fpga_enum_info *info)
>  	if (!cdev)
>  		return ERR_PTR(-ENOMEM);
>  
> -	cdev->region = devm_fpga_region_create(info->dev, NULL, NULL);
> -	if (!cdev->region) {
> -		ret = -ENOMEM;
> -		goto free_cdev_exit;
> -	}
> -
>  	cdev->parent = info->dev;
>  	mutex_init(&cdev->lock);
>  	INIT_LIST_HEAD(&cdev->port_dev_list);
>  
> -	ret = fpga_region_register(cdev->region);
> -	if (ret)
> +	cdev->region = fpga_region_register(info->dev, NULL, NULL);
> +	if (IS_ERR(cdev->region)) {
> +		ret = PTR_ERR(cdev->region);
>  		goto free_cdev_exit;
> +	}
>  
>  	/* create and init build info for enumeration */
>  	binfo = devm_kzalloc(info->dev, sizeof(*binfo), GFP_KERNEL);
> diff --git a/drivers/fpga/fpga-region.c b/drivers/fpga/fpga-region.c
> index a4838715221f..8af108a383e0 100644
> --- a/drivers/fpga/fpga-region.c
> +++ b/drivers/fpga/fpga-region.c
> @@ -180,39 +180,42 @@ static struct attribute *fpga_region_attrs[] = {
>  ATTRIBUTE_GROUPS(fpga_region);
>  
>  /**
> - * fpga_region_create - alloc and init a struct fpga_region
> + * fpga_region_register_full - create and register an FPGA Region device
>   * @parent: device parent
> - * @mgr: manager that programs this region
> - * @get_bridges: optional function to get bridges to a list
> - *
> - * The caller of this function is responsible for freeing the resulting region
> - * struct with fpga_region_free().  Using devm_fpga_region_create() instead is
> - * recommended.
> + * @info: parameters for FPGA Region
>   *
> - * Return: struct fpga_region or NULL
> + * Return: struct fpga_region or ERR_PTR()
>   */
> -struct fpga_region
> -*fpga_region_create(struct device *parent,
> -		    struct fpga_manager *mgr,
> -		    int (*get_bridges)(struct fpga_region *))
> +struct fpga_region *
> +fpga_region_register_full(struct device *parent, const struct fpga_region_info *info)
>  {
>  	struct fpga_region *region;
>  	int id, ret = 0;
>  
> +	if (!info) {
> +		dev_err(parent,
> +			"Attempt to register without required info structure\n");
> +		return ERR_PTR(-EINVAL);
> +	}
> +
>  	region = kzalloc(sizeof(*region), GFP_KERNEL);
>  	if (!region)
> -		return NULL;
> +		return ERR_PTR(-ENOMEM);
>  
>  	id = ida_simple_get(&fpga_region_ida, 0, 0, GFP_KERNEL);
> -	if (id < 0)
> +	if (id < 0) {
> +		ret = id;
>  		goto err_free;
> +	}
> +
> +	region->mgr = info->mgr;
> +	region->compat_id = info->compat_id;
> +	region->priv = info->priv;
> +	region->get_bridges = info->get_bridges;
>  
> -	region->mgr = mgr;
> -	region->get_bridges = get_bridges;
>  	mutex_init(&region->mutex);
>  	INIT_LIST_HEAD(&region->bridge_list);
>  
> -	device_initialize(&region->dev);
>  	region->dev.class = fpga_region_class;
>  	region->dev.parent = parent;
>  	region->dev.of_node = parent->of_node;
> @@ -222,6 +225,12 @@ struct fpga_region
>  	if (ret)
>  		goto err_remove;
>  
> +	ret = device_register(&region->dev);
> +	if (ret) {
> +		put_device(&region->dev);
> +		return ERR_PTR(ret);
> +	}
> +
>  	return region;
>  
>  err_remove:
> @@ -229,76 +238,32 @@ struct fpga_region
>  err_free:
>  	kfree(region);
>  
> -	return NULL;
> -}
> -EXPORT_SYMBOL_GPL(fpga_region_create);
> -
> -/**
> - * fpga_region_free - free an FPGA region created by fpga_region_create()
> - * @region: FPGA region
> - */
> -void fpga_region_free(struct fpga_region *region)
> -{
> -	ida_simple_remove(&fpga_region_ida, region->dev.id);
> -	kfree(region);
> -}
> -EXPORT_SYMBOL_GPL(fpga_region_free);
> -
> -static void devm_fpga_region_release(struct device *dev, void *res)
> -{
> -	struct fpga_region *region = *(struct fpga_region **)res;
> -
> -	fpga_region_free(region);
> +	return ERR_PTR(ret);
>  }
> +EXPORT_SYMBOL_GPL(fpga_region_register_full);
>  
>  /**
> - * devm_fpga_region_create - create and initialize a managed FPGA region struct
> + * fpga_region_register - create and register an FPGA Region device
>   * @parent: device parent
>   * @mgr: manager that programs this region
>   * @get_bridges: optional function to get bridges to a list
>   *
> - * This function is intended for use in an FPGA region driver's probe function.
> - * After the region driver creates the region struct with
> - * devm_fpga_region_create(), it should register it with fpga_region_register().
> - * The region driver's remove function should call fpga_region_unregister().
> - * The region struct allocated with this function will be freed automatically on
> - * driver detach.  This includes the case of a probe function returning error
> - * before calling fpga_region_register(), the struct will still get cleaned up.
> + * This simple version of the register should be sufficient for most users.
> + * The fpga_region_register_full() function is available for users that need to
> + * pass additional, optional parameters.
>   *
> - * Return: struct fpga_region or NULL
> + * Return: struct fpga_region or ERR_PTR()
>   */
> -struct fpga_region
> -*devm_fpga_region_create(struct device *parent,
> -			 struct fpga_manager *mgr,
> -			 int (*get_bridges)(struct fpga_region *))
> +struct fpga_region *
> +fpga_region_register(struct device *parent, struct fpga_manager *mgr,
> +		     int (*get_bridges)(struct fpga_region *))
>  {
> -	struct fpga_region **ptr, *region;
> -
> -	ptr = devres_alloc(devm_fpga_region_release, sizeof(*ptr), GFP_KERNEL);
> -	if (!ptr)
> -		return NULL;
> +	struct fpga_region_info info = { 0 };
>  
> -	region = fpga_region_create(parent, mgr, get_bridges);
> -	if (!region) {
> -		devres_free(ptr);
> -	} else {
> -		*ptr = region;
> -		devres_add(parent, ptr);
> -	}
> +	info.mgr = mgr;
> +	info.get_bridges = get_bridges;
>  
> -	return region;
> -}
> -EXPORT_SYMBOL_GPL(devm_fpga_region_create);
> -
> -/**
> - * fpga_region_register - register an FPGA region
> - * @region: FPGA region
> - *
> - * Return: 0 or -errno
> - */
> -int fpga_region_register(struct fpga_region *region)
> -{
> -	return device_add(&region->dev);
> +	return fpga_region_register_full(parent, &info);
>  }
>  EXPORT_SYMBOL_GPL(fpga_region_register);
>  
> @@ -316,6 +281,10 @@ EXPORT_SYMBOL_GPL(fpga_region_unregister);
>  
>  static void fpga_region_dev_release(struct device *dev)
>  {
> +	struct fpga_region *region = to_fpga_region(dev);
> +
> +	ida_simple_remove(&fpga_region_ida, region->dev.id);
> +	kfree(region);
>  }
>  
>  /**
> diff --git a/drivers/fpga/of-fpga-region.c b/drivers/fpga/of-fpga-region.c
> index e3c25576b6b9..9c662db1c508 100644
> --- a/drivers/fpga/of-fpga-region.c
> +++ b/drivers/fpga/of-fpga-region.c
> @@ -405,16 +405,12 @@ static int of_fpga_region_probe(struct platform_device *pdev)
>  	if (IS_ERR(mgr))
>  		return -EPROBE_DEFER;
>  
> -	region = devm_fpga_region_create(dev, mgr, of_fpga_region_get_bridges);
> -	if (!region) {
> -		ret = -ENOMEM;
> +	region = fpga_region_register(dev, mgr, of_fpga_region_get_bridges);
> +	if (IS_ERR(region)) {
> +		ret = PTR_ERR(region);
>  		goto eprobe_mgr_put;
>  	}
>  
> -	ret = fpga_region_register(region);
> -	if (ret)
> -		goto eprobe_mgr_put;
> -
>  	of_platform_populate(np, fpga_region_of_match, NULL, &region->dev);
>  	platform_set_drvdata(pdev, region);
>  
> diff --git a/include/linux/fpga/fpga-region.h b/include/linux/fpga/fpga-region.h
> index 27cb706275db..ae111beeffba 100644
> --- a/include/linux/fpga/fpga-region.h
> +++ b/include/linux/fpga/fpga-region.h
> @@ -7,6 +7,27 @@
>  #include <linux/fpga/fpga-mgr.h>
>  #include <linux/fpga/fpga-bridge.h>
>  
> +struct fpga_region;
> +
> +/**
> + * struct fpga_region_info - collection of parameters an FPGA Region
> + * @mgr: fpga region manager
> + * @compat_id: FPGA region id for compatibility check.
> + * @priv: fpga region private data
> + * @get_bridges: optional function to get bridges to a list
> + *
> + * fpga_region_info contains parameters for the register function. These
> + * are separated into an info structure because they some are optional
> + * others could be added to in the future. The info structure facilitates
> + * maintaining a stable API.
> + */
> +struct fpga_region_info {
> +	struct fpga_manager *mgr;
> +	struct fpga_compat_id *compat_id;
> +	void *priv;
> +	int (*get_bridges)(struct fpga_region *region);
> +};
> +
>  /**
>   * struct fpga_region - FPGA Region structure
>   * @dev: FPGA Region device
> @@ -37,15 +58,12 @@ struct fpga_region *fpga_region_class_find(
>  
>  int fpga_region_program_fpga(struct fpga_region *region);
>  
> -struct fpga_region
> -*fpga_region_create(struct device *dev, struct fpga_manager *mgr,
> -		    int (*get_bridges)(struct fpga_region *));
> -void fpga_region_free(struct fpga_region *region);
> -int fpga_region_register(struct fpga_region *region);
> -void fpga_region_unregister(struct fpga_region *region);
> +struct fpga_region *
> +fpga_region_register_full(struct device *parent, const struct fpga_region_info *info);
>  
> -struct fpga_region
> -*devm_fpga_region_create(struct device *dev, struct fpga_manager *mgr,
> -			int (*get_bridges)(struct fpga_region *));
> +struct fpga_region *
> +fpga_region_register(struct device *parent, struct fpga_manager *mgr,
> +		     int (*get_bridges)(struct fpga_region *));
> +void fpga_region_unregister(struct fpga_region *region);
>  
>  #endif /* _FPGA_REGION_H */
> -- 
> 2.25.1

^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 2/3] fpga: bridge: Use standard dev_release for class driver
  2021-07-01  1:37 ` [PATCH v9 2/3] fpga: bridge: " Russ Weight
  2021-07-01  5:39   ` Xu Yilun
@ 2021-07-01  6:26   ` Xu Yilun
  2021-07-06 23:08     ` Russ Weight
  2021-07-06 20:08   ` Tom Rix
  2 siblings, 1 reply; 22+ messages in thread
From: Xu Yilun @ 2021-07-01  6:26 UTC (permalink / raw)
  To: Russ Weight
  Cc: mdf, linux-fpga, trix, lgoncalv, hao.wu, matthew.gerlach, richard.gong

On Wed, Jun 30, 2021 at 06:37:32PM -0700, Russ Weight wrote:
> The FPGA bridge class driver data structure is being treated as a
> managed resource instead of using the standard dev_release call-back
> function to release the class data structure. This change removes
> the managed resource code and combines the create() and register()
> functions into a single register() or register_simple() function.
> 
> The register() function accepts an info data structure to provide
> flexibility in passing optional parameters. The register_simple()
> function supports the current parameter list for users that don't
> require the use of optional parameters.
> 
> Signed-off-by: Russ Weight <russell.h.weight@intel.com>
> Reviewed-by: Xu Yilun <yilun.xu@intel.com>
> ---
> v9:
>   - Cleaned up documentation for the FPGA Bridge register functions
>   - Renamed fpga_bridge_register() to fpga_bridge_register_full()
>   - Renamed fpga_bridge_register_simple() to fpga_bridge_register()

Now we come back to the fpga_XXX_register for normal cases and
fpga_XXX_register_full for extra parameters.

But the fpga_bridge_register_full has no use case yet, should we
implement it when it is really needed?

Thanks,
Yilun

> v8:
>   - Added reviewed-by tag.
>   - Updated Documentation/driver-api/fpga/fpga-bridge.rst documentation.
> v7:
>   - Update the commit message to describe the new parameters for the
>     fpga_bridge_register() function and to mention the
>     fpga_bridge_register_simple() function.
>   - Fix function prototypes in header file to rename dev to parent.
>   - Some cleanup of comments.
>   - Update function defintions/prototypes to apply const to the new info
>     parameter.
>   - Verify that info->br_ops is non-null in register functions.
> v6:
>   - Changed fpga_bridge_register() parameters to accept an info data
>     structure to provide flexibility in passing optional parameters.
>   - Added fpga_bridge_register_simple() function to support current
>     parameters for users that don't require the use of optional
>     parameters.
> v5:
>   - Rebased on top of recently accepted patches.
> v4:
>   - Restore the previous format for the Return value in the comment header
>     for fpga_bridge_register()
> v3:
>   - Cleaned up comment header for fpga_bridge_register()
>   - Fix error return values for fpga_bridge_register()
> v2:
>   - No changes
> ---
>  Documentation/driver-api/fpga/fpga-bridge.rst |   8 +-
>  drivers/fpga/altera-fpga2sdram.c              |  12 +-
>  drivers/fpga/altera-freeze-bridge.c           |  10 +-
>  drivers/fpga/altera-hps2fpga.c                |  12 +-
>  drivers/fpga/dfl-fme-br.c                     |  10 +-
>  drivers/fpga/fpga-bridge.c                    | 137 ++++++------------
>  drivers/fpga/xilinx-pr-decoupler.c            |  17 +--
>  include/linux/fpga/fpga-bridge.h              |  33 +++--
>  8 files changed, 101 insertions(+), 138 deletions(-)
> 
> diff --git a/Documentation/driver-api/fpga/fpga-bridge.rst b/Documentation/driver-api/fpga/fpga-bridge.rst
> index 8d650b4e2ce6..38e3bac8e877 100644
> --- a/Documentation/driver-api/fpga/fpga-bridge.rst
> +++ b/Documentation/driver-api/fpga/fpga-bridge.rst
> @@ -6,8 +6,10 @@ API to implement a new FPGA bridge
>  
>  * struct fpga_bridge - The FPGA Bridge structure
>  * struct fpga_bridge_ops - Low level Bridge driver ops
> -* devm_fpga_bridge_create() - Allocate and init a bridge struct
> -* fpga_bridge_register() - Register a bridge
> +* fpga_bridge_register_full() - Create and register a bridge using the
> +  fpga_bridge_info structure to provide the full flexibility of options
> +* fpga_bridge_register() - Create and register a bridge using standard
> +  arguments
>  * fpga_bridge_unregister() - Unregister a bridge
>  
>  .. kernel-doc:: include/linux/fpga/fpga-bridge.h
> @@ -17,7 +19,7 @@ API to implement a new FPGA bridge
>     :functions: fpga_bridge_ops
>  
>  .. kernel-doc:: drivers/fpga/fpga-bridge.c
> -   :functions: devm_fpga_bridge_create
> +   :functions: fpga_bridge_register_full
>  
>  .. kernel-doc:: drivers/fpga/fpga-bridge.c
>     :functions: fpga_bridge_register
> diff --git a/drivers/fpga/altera-fpga2sdram.c b/drivers/fpga/altera-fpga2sdram.c
> index a78e49c63c64..66063507116b 100644
> --- a/drivers/fpga/altera-fpga2sdram.c
> +++ b/drivers/fpga/altera-fpga2sdram.c
> @@ -121,17 +121,13 @@ static int alt_fpga_bridge_probe(struct platform_device *pdev)
>  	/* Get f2s bridge configuration saved in handoff register */
>  	regmap_read(sysmgr, SYSMGR_ISWGRP_HANDOFF3, &priv->mask);
>  
> -	br = devm_fpga_bridge_create(dev, F2S_BRIDGE_NAME,
> -				     &altera_fpga2sdram_br_ops, priv);
> -	if (!br)
> -		return -ENOMEM;
> +	br = fpga_bridge_register(dev, F2S_BRIDGE_NAME,
> +				  &altera_fpga2sdram_br_ops, priv);
> +	if (IS_ERR(br))
> +		return PTR_ERR(mgr);
>  
>  	platform_set_drvdata(pdev, br);
>  
> -	ret = fpga_bridge_register(br);
> -	if (ret)
> -		return ret;
> -
>  	dev_info(dev, "driver initialized with handoff %08x\n", priv->mask);
>  
>  	if (!of_property_read_u32(dev->of_node, "bridge-enable", &enable)) {
> diff --git a/drivers/fpga/altera-freeze-bridge.c b/drivers/fpga/altera-freeze-bridge.c
> index dd58c4aea92e..bfbfa43cd05b 100644
> --- a/drivers/fpga/altera-freeze-bridge.c
> +++ b/drivers/fpga/altera-freeze-bridge.c
> @@ -244,14 +244,14 @@ static int altera_freeze_br_probe(struct platform_device *pdev)
>  
>  	priv->base_addr = base_addr;
>  
> -	br = devm_fpga_bridge_create(dev, FREEZE_BRIDGE_NAME,
> -				     &altera_freeze_br_br_ops, priv);
> -	if (!br)
> -		return -ENOMEM;
> +	br = fpga_bridge_register(dev, FREEZE_BRIDGE_NAME,
> +				  &altera_freeze_br_br_ops, priv);
> +	if (IS_ERR(br))
> +		return PTR_ERR(br);
>  
>  	platform_set_drvdata(pdev, br);
>  
> -	return fpga_bridge_register(br);
> +	return 0;
>  }
>  
>  static int altera_freeze_br_remove(struct platform_device *pdev)
> diff --git a/drivers/fpga/altera-hps2fpga.c b/drivers/fpga/altera-hps2fpga.c
> index 77b95f251821..aa758426c22b 100644
> --- a/drivers/fpga/altera-hps2fpga.c
> +++ b/drivers/fpga/altera-hps2fpga.c
> @@ -180,19 +180,15 @@ static int alt_fpga_bridge_probe(struct platform_device *pdev)
>  		}
>  	}
>  
> -	br = devm_fpga_bridge_create(dev, priv->name,
> -				     &altera_hps2fpga_br_ops, priv);
> -	if (!br) {
> -		ret = -ENOMEM;
> +	br = fpga_bridge_register(dev, priv->name,
> +				  &altera_hps2fpga_br_ops, priv);
> +	if (IS_ERR(br)) {
> +		ret = PTR_ERR(br);
>  		goto err;
>  	}
>  
>  	platform_set_drvdata(pdev, br);
>  
> -	ret = fpga_bridge_register(br);
> -	if (ret)
> -		goto err;
> -
>  	return 0;
>  
>  err:
> diff --git a/drivers/fpga/dfl-fme-br.c b/drivers/fpga/dfl-fme-br.c
> index 3ff9f3a687ce..808d1f4d76df 100644
> --- a/drivers/fpga/dfl-fme-br.c
> +++ b/drivers/fpga/dfl-fme-br.c
> @@ -68,14 +68,14 @@ static int fme_br_probe(struct platform_device *pdev)
>  
>  	priv->pdata = dev_get_platdata(dev);
>  
> -	br = devm_fpga_bridge_create(dev, "DFL FPGA FME Bridge",
> -				     &fme_bridge_ops, priv);
> -	if (!br)
> -		return -ENOMEM;
> +	br = fpga_bridge_register(dev, "DFL FPGA FME Bridge",
> +				  &fme_bridge_ops, priv);
> +	if (IS_ERR(br))
> +		return PTR_ERR(br);
>  
>  	platform_set_drvdata(pdev, br);
>  
> -	return fpga_bridge_register(br);
> +	return 0;
>  }
>  
>  static int fme_br_remove(struct platform_device *pdev)
> diff --git a/drivers/fpga/fpga-bridge.c b/drivers/fpga/fpga-bridge.c
> index 798f55670646..e6d98be8531b 100644
> --- a/drivers/fpga/fpga-bridge.c
> +++ b/drivers/fpga/fpga-bridge.c
> @@ -312,55 +312,63 @@ static struct attribute *fpga_bridge_attrs[] = {
>  ATTRIBUTE_GROUPS(fpga_bridge);
>  
>  /**
> - * fpga_bridge_create - create and initialize a struct fpga_bridge
> + * fpga_bridge_register_full - create and register an FPGA Bridge device
>   * @parent:	FPGA bridge device from pdev
> - * @name:	FPGA bridge name
> - * @br_ops:	pointer to structure of fpga bridge ops
> - * @priv:	FPGA bridge private data
> + * @info:	parameters for FPGA Bridge
>   *
> - * The caller of this function is responsible for freeing the bridge with
> - * fpga_bridge_free().  Using devm_fpga_bridge_create() instead is recommended.
> - *
> - * Return: struct fpga_bridge or NULL
> + * Return: struct fpga_bridge pointer or ERR_PTR()
>   */
> -struct fpga_bridge *fpga_bridge_create(struct device *parent, const char *name,
> -				       const struct fpga_bridge_ops *br_ops,
> -				       void *priv)
> +struct fpga_bridge *
> +fpga_bridge_register_full(struct device *parent,
> +			  const struct fpga_bridge_info *info)
>  {
>  	struct fpga_bridge *bridge;
>  	int id, ret;
>  
> -	if (!name || !strlen(name)) {
> +	if (!info->br_ops) {
> +		dev_err(parent, "Attempt to register without fpga_bridge_ops\n");
> +		return ERR_PTR(-EINVAL);
> +	}
> +
> +	if (!info->name || !strlen(info->name)) {
>  		dev_err(parent, "Attempt to register with no name!\n");
> -		return NULL;
> +		return ERR_PTR(-EINVAL);
>  	}
>  
>  	bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
>  	if (!bridge)
> -		return NULL;
> +		return ERR_PTR(-ENOMEM);
>  
>  	id = ida_simple_get(&fpga_bridge_ida, 0, 0, GFP_KERNEL);
> -	if (id < 0)
> +	if (id < 0) {
> +		ret = id;
>  		goto error_kfree;
> +	}
>  
>  	mutex_init(&bridge->mutex);
>  	INIT_LIST_HEAD(&bridge->node);
>  
> -	bridge->name = name;
> -	bridge->br_ops = br_ops;
> -	bridge->priv = priv;
> +	bridge->name = info->name;
> +	bridge->br_ops = info->br_ops;
> +	bridge->priv = info->priv;
>  
> -	device_initialize(&bridge->dev);
> -	bridge->dev.groups = br_ops->groups;
> +	bridge->dev.groups = info->br_ops->groups;
>  	bridge->dev.class = fpga_bridge_class;
>  	bridge->dev.parent = parent;
>  	bridge->dev.of_node = parent->of_node;
>  	bridge->dev.id = id;
> +	of_platform_populate(bridge->dev.of_node, NULL, NULL, &bridge->dev);
>  
>  	ret = dev_set_name(&bridge->dev, "br%d", id);
>  	if (ret)
>  		goto error_device;
>  
> +	ret = device_register(&bridge->dev);
> +	if (ret) {
> +		put_device(&bridge->dev);
> +		return ERR_PTR(ret);
> +	}
> +
>  	return bridge;
>  
>  error_device:
> @@ -368,88 +376,35 @@ struct fpga_bridge *fpga_bridge_create(struct device *parent, const char *name,
>  error_kfree:
>  	kfree(bridge);
>  
> -	return NULL;
> -}
> -EXPORT_SYMBOL_GPL(fpga_bridge_create);
> -
> -/**
> - * fpga_bridge_free - free an fpga bridge created by fpga_bridge_create()
> - * @bridge:	FPGA bridge struct
> - */
> -void fpga_bridge_free(struct fpga_bridge *bridge)
> -{
> -	ida_simple_remove(&fpga_bridge_ida, bridge->dev.id);
> -	kfree(bridge);
> -}
> -EXPORT_SYMBOL_GPL(fpga_bridge_free);
> -
> -static void devm_fpga_bridge_release(struct device *dev, void *res)
> -{
> -	struct fpga_bridge *bridge = *(struct fpga_bridge **)res;
> -
> -	fpga_bridge_free(bridge);
> +	return ERR_PTR(ret);
>  }
> +EXPORT_SYMBOL_GPL(fpga_bridge_register_full);
>  
>  /**
> - * devm_fpga_bridge_create - create and init a managed struct fpga_bridge
> + * fpga_bridge_register - create and register an FPGA Bridge device
>   * @parent:	FPGA bridge device from pdev
>   * @name:	FPGA bridge name
>   * @br_ops:	pointer to structure of fpga bridge ops
>   * @priv:	FPGA bridge private data
>   *
> - * This function is intended for use in an FPGA bridge driver's probe function.
> - * After the bridge driver creates the struct with devm_fpga_bridge_create(), it
> - * should register the bridge with fpga_bridge_register().  The bridge driver's
> - * remove function should call fpga_bridge_unregister().  The bridge struct
> - * allocated with this function will be freed automatically on driver detach.
> - * This includes the case of a probe function returning error before calling
> - * fpga_bridge_register(), the struct will still get cleaned up.
> + * This simple version of the register should be sufficient for most users.
> + * The fpga_bridge_register_full() function is available for users that need to pass
> + * additional, optional parameters.
>   *
> - *  Return: struct fpga_bridge or NULL
> + * Return: struct fpga_bridge pointer or ERR_PTR()
>   */
> -struct fpga_bridge
> -*devm_fpga_bridge_create(struct device *parent, const char *name,
> -			 const struct fpga_bridge_ops *br_ops, void *priv)
> +struct fpga_bridge *
> +fpga_bridge_register(struct device *parent, const char *name,
> +		     const struct fpga_bridge_ops *br_ops,
> +		     void *priv)
>  {
> -	struct fpga_bridge **ptr, *bridge;
> -
> -	ptr = devres_alloc(devm_fpga_bridge_release, sizeof(*ptr), GFP_KERNEL);
> -	if (!ptr)
> -		return NULL;
> -
> -	bridge = fpga_bridge_create(parent, name, br_ops, priv);
> -	if (!bridge) {
> -		devres_free(ptr);
> -	} else {
> -		*ptr = bridge;
> -		devres_add(parent, ptr);
> -	}
> +	struct fpga_bridge_info info = { 0 };
>  
> -	return bridge;
> -}
> -EXPORT_SYMBOL_GPL(devm_fpga_bridge_create);
> +	info.name = name;
> +	info.br_ops = br_ops;
> +	info.priv = priv;
>  
> -/**
> - * fpga_bridge_register - register an FPGA bridge
> - *
> - * @bridge: FPGA bridge struct
> - *
> - * Return: 0 for success, error code otherwise.
> - */
> -int fpga_bridge_register(struct fpga_bridge *bridge)
> -{
> -	struct device *dev = &bridge->dev;
> -	int ret;
> -
> -	ret = device_add(dev);
> -	if (ret)
> -		return ret;
> -
> -	of_platform_populate(dev->of_node, NULL, NULL, dev);
> -
> -	dev_info(dev->parent, "fpga bridge [%s] registered\n", bridge->name);
> -
> -	return 0;
> +	return fpga_bridge_register_full(parent, &info);
>  }
>  EXPORT_SYMBOL_GPL(fpga_bridge_register);
>  
> @@ -475,6 +430,10 @@ EXPORT_SYMBOL_GPL(fpga_bridge_unregister);
>  
>  static void fpga_bridge_dev_release(struct device *dev)
>  {
> +	struct fpga_bridge *bridge = to_fpga_bridge(dev);
> +
> +	ida_simple_remove(&fpga_bridge_ida, bridge->dev.id);
> +	kfree(bridge);
>  }
>  
>  static int __init fpga_bridge_dev_init(void)
> diff --git a/drivers/fpga/xilinx-pr-decoupler.c b/drivers/fpga/xilinx-pr-decoupler.c
> index ea2bde6e5bc4..c004e52b9464 100644
> --- a/drivers/fpga/xilinx-pr-decoupler.c
> +++ b/drivers/fpga/xilinx-pr-decoupler.c
> @@ -138,22 +138,17 @@ static int xlnx_pr_decoupler_probe(struct platform_device *pdev)
>  
>  	clk_disable(priv->clk);
>  
> -	br = devm_fpga_bridge_create(&pdev->dev, priv->ipconfig->name,
> -				     &xlnx_pr_decoupler_br_ops, priv);
> -	if (!br) {
> -		err = -ENOMEM;
> -		goto err_clk;
> -	}
> -
> -	platform_set_drvdata(pdev, br);
> -
> -	err = fpga_bridge_register(br);
> -	if (err) {
> +	br = fpga_bridge_register(&pdev->dev, priv->ipconfig->name,
> +				  &xlnx_pr_decoupler_br_ops, priv);
> +	if (IS_ERR(br)) {
> +		err = PTR_ERR(br);
>  		dev_err(&pdev->dev, "unable to register %s",
>  			priv->ipconfig->name);
>  		goto err_clk;
>  	}
>  
> +	platform_set_drvdata(pdev, br);
> +
>  	return 0;
>  
>  err_clk:
> diff --git a/include/linux/fpga/fpga-bridge.h b/include/linux/fpga/fpga-bridge.h
> index 6c3c28806ff1..f0a4d99d9c8e 100644
> --- a/include/linux/fpga/fpga-bridge.h
> +++ b/include/linux/fpga/fpga-bridge.h
> @@ -22,6 +22,23 @@ struct fpga_bridge_ops {
>  	const struct attribute_group **groups;
>  };
>  
> +/**
> + * struct fpga_bridge_info - collection of parameters an FPGA Bridge
> + * @name: fpga bridge name
> + * @br_ops: pointer to structure of fpga bridge ops
> + * @priv: fpga bridge private data
> + *
> + * fpga_bridge_info contains parameters for the register function. These
> + * are separated into an info structure because they some are optional
> + * others could be added to in the future. The info structure facilitates
> + * maintaining a stable API.
> + */
> +struct fpga_bridge_info {
> +	const char *name;
> +	const struct fpga_bridge_ops *br_ops;
> +	void *priv;
> +};
> +
>  /**
>   * struct fpga_bridge - FPGA bridge structure
>   * @name: name of low level FPGA bridge
> @@ -62,15 +79,13 @@ int of_fpga_bridge_get_to_list(struct device_node *np,
>  			       struct fpga_image_info *info,
>  			       struct list_head *bridge_list);
>  
> -struct fpga_bridge *fpga_bridge_create(struct device *dev, const char *name,
> -				       const struct fpga_bridge_ops *br_ops,
> -				       void *priv);
> -void fpga_bridge_free(struct fpga_bridge *br);
> -int fpga_bridge_register(struct fpga_bridge *br);
> -void fpga_bridge_unregister(struct fpga_bridge *br);
> +struct fpga_bridge *
> +fpga_bridge_register_full(struct device *parent, const struct fpga_bridge_info *info);
>  
> -struct fpga_bridge
> -*devm_fpga_bridge_create(struct device *dev, const char *name,
> -			 const struct fpga_bridge_ops *br_ops, void *priv);
> +struct fpga_bridge *
> +fpga_bridge_register(struct device *parent, const char *name,
> +		     const struct fpga_bridge_ops *br_ops,
> +		     void *priv);
> +void fpga_bridge_unregister(struct fpga_bridge *br);
>  
>  #endif /* _LINUX_FPGA_BRIDGE_H */
> -- 
> 2.25.1

^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 1/3] fpga: mgr: Use standard dev_release for class driver
  2021-07-01  1:37 ` [PATCH v9 1/3] fpga: mgr: Use standard dev_release for class driver Russ Weight
  2021-07-01  5:25   ` Xu Yilun
@ 2021-07-06 19:04   ` Tom Rix
  2021-07-06 21:02     ` Russ Weight
  2021-07-07  3:04     ` Xu Yilun
  1 sibling, 2 replies; 22+ messages in thread
From: Tom Rix @ 2021-07-06 19:04 UTC (permalink / raw)
  To: Russ Weight, mdf, linux-fpga
  Cc: lgoncalv, yilun.xu, hao.wu, matthew.gerlach, richard.gong

Russ,

My two big concerns are.

compat_id does not belong in fpga_mgr_info, it belongs in fme_mgr_priv.

there are two register functions, there should be one.


On 6/30/21 6:37 PM, Russ Weight wrote:
> The FPGA manager class driver data structure is being treated as a
> managed resource instead of using the standard dev_release call-back
> function to release the class data structure. This change removes
> the managed resource code for the freeing of the class data structure
> and combines the create() and register() functions into a single
> register() or register_simple() function.
>
> The register() function accepts an info data structure to provide
> flexibility in passing optional parameters. The register_simple()
> function supports the current parameter list for users that don't
> require the use of optional parameters.
>
> The devm_fpga_mgr_register() function is retained, and the
> devm_fpga_mgr_register_simple() function is added.
>
> Signed-off-by: Russ Weight <russell.h.weight@intel.com>
> Reviewed-by: Xu Yilun <yilun.xu@intel.com>
> ---
> v9:
>    - Cleaned up documentation for the FPGA Manager register functions
>    - Renamed fpga_mgr_register() to fpga_mgr_register_full()
>    - Renamed fpga_mgr_register_simple() to fpga_mgr_register()
>    - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full()
>    - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register()
> v8:
>    - Added reviewed-by tag.
>    - Updated Documentation/driver-api/fpga/fpga-mgr.rst documentation.
> v7:
>    - Update the commit message to describe the new parameters for the
>      *fpga_mgr_register() functions and to mention the
>      *fpga_mgr_register_simple() functions.
>    - Fix function prototypes in header file to rename dev to parent.
>    - Make use of the PTR_ERR_OR_ZERO() macro when possible.
>    - Some cleanup of comments.
>    - Update function defintions/prototypes to apply const to the new info
>      parameter.
> v6:
>    - Moved FPGA manager optional parameters out of the ops structure and
>      back into the FPGA manager structure.
>    - Changed fpga_mgr_register()/devm_fpga_mgr_register() parameters to
>      accept an info data structure to provide flexibility in passing optional
>      parameters.
>    - Added fpga_mgr_register_simple()/devm_fpga_mgr_register_simple()
>      functions to support current parameters for users that don't require
>      the use of optional parameters.
> v5:
>    - Rebased on top of recently accepted patches.
>    - Removed compat_id from the fpga_mgr_register() parameter list
>      and added it to the fpga_manager_ops structure. This also required
>      dynamically allocating the dfl-fme-ops structure in order to add
>      the appropriate compat_id.
> v4:
>    - Added the compat_id parameter to fpga_mgr_register() and
>      devm_fpga_mgr_register() to ensure that the compat_id is set before
>      the device_register() call.
> v3:
>    - Cleaned up comment header for fpga_mgr_register()
>    - Fix error return on ida_simple_get() failure
> v2:
>    - Restored devm_fpga_mgr_register() functionality, adapted for the combined
>      create/register functionality.
>    - All previous callers of devm_fpga_mgr_register() will continue to call
>      devm_fpga_mgr_register().
>    - replaced unnecessary ternary operators in return statements with standard
>      if conditions.
> ---
>   Documentation/driver-api/fpga/fpga-mgr.rst |  34 +++-
>   drivers/fpga/altera-cvp.c                  |  12 +-
>   drivers/fpga/altera-pr-ip-core.c           |   7 +-
>   drivers/fpga/altera-ps-spi.c               |   9 +-
>   drivers/fpga/dfl-fme-mgr.c                 |  22 +--
>   drivers/fpga/fpga-mgr.c                    | 215 +++++++++------------
>   drivers/fpga/ice40-spi.c                   |   9 +-
>   drivers/fpga/machxo2-spi.c                 |   9 +-
>   drivers/fpga/socfpga-a10.c                 |  16 +-
>   drivers/fpga/socfpga.c                     |   9 +-
>   drivers/fpga/stratix10-soc.c               |  16 +-
>   drivers/fpga/ts73xx-fpga.c                 |   9 +-
>   drivers/fpga/xilinx-spi.c                  |  11 +-
>   drivers/fpga/zynq-fpga.c                   |  16 +-
>   drivers/fpga/zynqmp-fpga.c                 |   9 +-
>   include/linux/fpga/fpga-mgr.h              |  62 ++++--
>   16 files changed, 210 insertions(+), 255 deletions(-)
>
> diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
> index 4d926b452cb3..826ed8dc9210 100644
> --- a/Documentation/driver-api/fpga/fpga-mgr.rst
> +++ b/Documentation/driver-api/fpga/fpga-mgr.rst
> @@ -24,7 +24,7 @@ How to support a new FPGA device
>   --------------------------------
>   
>   To add another FPGA manager, write a driver that implements a set of ops.  The
> -probe function calls fpga_mgr_register(), such as::
> +probe function calls fpga_mgr_register() or fpga_mgr_register_full(), such as::
>   
>   	static const struct fpga_manager_ops socfpga_fpga_ops = {
>   		.write_init = socfpga_fpga_ops_configure_init,
> @@ -49,14 +49,14 @@ probe function calls fpga_mgr_register(), such as::
>   		 * them in priv
>   		 */
>   
> -		mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
> -					   &socfpga_fpga_ops, priv);
> -		if (!mgr)
> -			return -ENOMEM;
> +		mgr = fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
> +					&socfpga_fpga_ops, priv);
> +		if (IS_ERR(mgr))
> +			return PTR_ERR(mgr);
>   
>   		platform_set_drvdata(pdev, mgr);
>   
> -		return fpga_mgr_register(mgr);
> +		return 0;
>   	}
>   
>   	static int socfpga_fpga_remove(struct platform_device *pdev)
> @@ -68,6 +68,11 @@ probe function calls fpga_mgr_register(), such as::
>   		return 0;
>   	}
>   
> +Alternatively, the probe function could call one of the resource managed
> +register functions, devm_fpga_mgr_register() or devm_fpga_mgr_register_full().
> +When these functions are used, the parameter syntax is the same, but the call
> +to fpga_mgr_unregister() should be removed. In the above example, the
> +socfpga_fpga_remove() function would not be required.
>   
>   The ops will implement whatever device specific register writes are needed to
>   do the programming sequence for this particular FPGA.  These ops return 0 for
> @@ -104,8 +109,13 @@ API for implementing a new FPGA Manager driver
>   * ``fpga_mgr_states`` -  Values for :c:expr:`fpga_manager->state`.
>   * struct fpga_manager -  the FPGA manager struct
>   * struct fpga_manager_ops -  Low level FPGA manager driver ops
> -* devm_fpga_mgr_create() -  Allocate and init a manager struct
> -* fpga_mgr_register() -  Register an FPGA manager
> +* fpga_mgr_register_full() -  Create and register an FPGA manager using the
> +  fpga_mgr_info structure to provide the full flexibility of options
> +* fpga_mgr_register() -  Create and register an FPGA manager using standard
> +  arguments
> +* devm_fpga_mgr_register_full() -  Resource managed version of
> +  fpga_mgr_register_full()
> +* devm_fpga_mgr_register() -  Resource managed version of fpga_mgr_register()
>   * fpga_mgr_unregister() -  Unregister an FPGA manager
>   
>   .. kernel-doc:: include/linux/fpga/fpga-mgr.h
> @@ -118,10 +128,16 @@ API for implementing a new FPGA Manager driver
>      :functions: fpga_manager_ops
>   
>   .. kernel-doc:: drivers/fpga/fpga-mgr.c
> -   :functions: devm_fpga_mgr_create
> +   :functions: fpga_mgr_register_full
>   
>   .. kernel-doc:: drivers/fpga/fpga-mgr.c
>      :functions: fpga_mgr_register
>   
> +.. kernel-doc:: drivers/fpga/fpga-mgr.c
> +   :functions: devm_fpga_mgr_register_full
> +
> +.. kernel-doc:: drivers/fpga/fpga-mgr.c
> +   :functions: devm_fpga_mgr_register
> +
>   .. kernel-doc:: drivers/fpga/fpga-mgr.c
>      :functions: fpga_mgr_unregister
> diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
> index ccf4546eff29..4ffb9da537d8 100644
> --- a/drivers/fpga/altera-cvp.c
> +++ b/drivers/fpga/altera-cvp.c
> @@ -652,19 +652,15 @@ static int altera_cvp_probe(struct pci_dev *pdev,
>   	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
>   		 ALTERA_CVP_MGR_NAME, pci_name(pdev));
>   
> -	mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
> -				   &altera_cvp_ops, conf);
> -	if (!mgr) {
> -		ret = -ENOMEM;
> +	mgr = fpga_mgr_register(&pdev->dev, conf->mgr_name,
> +				&altera_cvp_ops, conf);
> +	if (IS_ERR(mgr)) {
> +		ret = PTR_ERR(mgr);
>   		goto err_unmap;
>   	}
>   
>   	pci_set_drvdata(pdev, mgr);
>   
> -	ret = fpga_mgr_register(mgr);
> -	if (ret)
> -		goto err_unmap;
> -
>   	return 0;
>   
>   err_unmap:
> diff --git a/drivers/fpga/altera-pr-ip-core.c b/drivers/fpga/altera-pr-ip-core.c
> index dfdf21ed34c4..be0667968d33 100644
> --- a/drivers/fpga/altera-pr-ip-core.c
> +++ b/drivers/fpga/altera-pr-ip-core.c
> @@ -191,11 +191,8 @@ int alt_pr_register(struct device *dev, void __iomem *reg_base)
>   		(val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
>   		(int)(val & ALT_PR_CSR_PR_START));
>   
> -	mgr = devm_fpga_mgr_create(dev, dev_name(dev), &alt_pr_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(dev, mgr);
> +	mgr = devm_fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv);
> +	return PTR_ERR_OR_ZERO(mgr);
>   }
>   EXPORT_SYMBOL_GPL(alt_pr_register);
>   
> diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
> index 23bfd4d1ad0f..5e1e009dba89 100644
> --- a/drivers/fpga/altera-ps-spi.c
> +++ b/drivers/fpga/altera-ps-spi.c
> @@ -302,12 +302,9 @@ static int altera_ps_probe(struct spi_device *spi)
>   	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s",
>   		 dev_driver_string(&spi->dev), dev_name(&spi->dev));
>   
> -	mgr = devm_fpga_mgr_create(&spi->dev, conf->mgr_name,
> -				   &altera_ps_ops, conf);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(&spi->dev, mgr);
> +	mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name,
> +				     &altera_ps_ops, conf);
> +	return PTR_ERR_OR_ZERO(mgr);
>   }
>   
>   static const struct spi_device_id altera_ps_spi_ids[] = {
> diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
> index d5861d13b306..620e7874ab53 100644
> --- a/drivers/fpga/dfl-fme-mgr.c
> +++ b/drivers/fpga/dfl-fme-mgr.c
> @@ -282,7 +282,7 @@ static void fme_mgr_get_compat_id(void __iomem *fme_pr,
>   static int fme_mgr_probe(struct platform_device *pdev)
>   {
>   	struct dfl_fme_mgr_pdata *pdata = dev_get_platdata(&pdev->dev);
> -	struct fpga_compat_id *compat_id;
> +	struct fpga_manager_info info = { 0 };
>   	struct device *dev = &pdev->dev;
>   	struct fme_mgr_priv *priv;
>   	struct fpga_manager *mgr;
> @@ -302,20 +302,16 @@ static int fme_mgr_probe(struct platform_device *pdev)
>   			return PTR_ERR(priv->ioaddr);
>   	}
>   
> -	compat_id = devm_kzalloc(dev, sizeof(*compat_id), GFP_KERNEL);
> -	if (!compat_id)
> +	info.name = "DFL FME FPGA Manager";
> +	info.mops = &fme_mgr_ops;
> +	info.priv = priv;
> +	info.compat_id = devm_kzalloc(dev, sizeof(*info.compat_id), GFP_KERNEL);
> +	if (!info.compat_id)
>   		return -ENOMEM;
could we limp along instead of failing ?
>   
> -	fme_mgr_get_compat_id(priv->ioaddr, compat_id);
> -
> -	mgr = devm_fpga_mgr_create(dev, "DFL FME FPGA Manager",
> -				   &fme_mgr_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	mgr->compat_id = compat_id;
> -
> -	return devm_fpga_mgr_register(dev, mgr);
> +	fme_mgr_get_compat_id(priv->ioaddr, info.compat_id);
> +	mgr = devm_fpga_mgr_register_full(dev, &info);
> +	return PTR_ERR_OR_ZERO(mgr);
>   }
>   
>   static struct platform_driver fme_mgr_driver = {
> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
> index ecb4c3c795fa..5a913aa649fd 100644
> --- a/drivers/fpga/fpga-mgr.c
> +++ b/drivers/fpga/fpga-mgr.c
> @@ -550,21 +550,19 @@ void fpga_mgr_unlock(struct fpga_manager *mgr)
>   EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
>   
>   /**
> - * fpga_mgr_create - create and initialize an FPGA manager struct
> + * fpga_mgr_register_full - create and register an FPGA Manager device
>    * @parent:	fpga manager device from pdev
> - * @name:	fpga manager name
> - * @mops:	pointer to structure of fpga manager ops
> - * @priv:	fpga manager private data
> + * @info:	parameters for fpga manager
>    *
> - * The caller of this function is responsible for freeing the struct with
> - * fpga_mgr_free().  Using devm_fpga_mgr_create() instead is recommended.
> + * The caller of this function is responsible for calling fpga_mgr_unregister().
> + * Using devm_fpga_mgr_register_full() instead is recommended.
>    *
> - * Return: pointer to struct fpga_manager or NULL
> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>    */
> -struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> -				     const struct fpga_manager_ops *mops,
> -				     void *priv)
> +struct fpga_manager *
> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>   {
> +	const struct fpga_manager_ops *mops = info->mops;
>   	struct fpga_manager *mgr;
>   	int id, ret;
>   
> @@ -572,29 +570,31 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>   	    !mops->write_init || (!mops->write && !mops->write_sg) ||
>   	    (mops->write && mops->write_sg)) {
>   		dev_err(parent, "Attempt to register without fpga_manager_ops\n");
> -		return NULL;
> +		return ERR_PTR(-EINVAL);
>   	}
>   
> -	if (!name || !strlen(name)) {
> +	if (!info->name || !strlen(info->name)) {
>   		dev_err(parent, "Attempt to register with no name!\n");
> -		return NULL;
> +		return ERR_PTR(-EINVAL);
>   	}
>   
>   	mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
>   	if (!mgr)
> -		return NULL;
> +		return ERR_PTR(-ENOMEM);
>   
>   	id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
> -	if (id < 0)
> +	if (id < 0) {
> +		ret = id;
>   		goto error_kfree;
> +	}
>   
>   	mutex_init(&mgr->ref_mutex);
>   
> -	mgr->name = name;
> -	mgr->mops = mops;
> -	mgr->priv = priv;
> +	mgr->name = info->name;
> +	mgr->mops = info->mops;
> +	mgr->priv = info->priv;
> +	mgr->compat_id = info->compat_id;
>   
> -	device_initialize(&mgr->dev);
>   	mgr->dev.class = fpga_mgr_class;
>   	mgr->dev.groups = mops->groups;
>   	mgr->dev.parent = parent;
> @@ -605,6 +605,19 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>   	if (ret)
>   		goto error_device;
>   
> +	/*
> +	 * Initialize framework state by requesting low level driver read state
> +	 * from device.  FPGA may be in reset mode or may have been programmed
> +	 * by bootloader or EEPROM.
> +	 */
> +	mgr->state = mgr->mops->state(mgr);

This is existing code, but it seems wrong.

A side effect of state() should not be to initialize.

An init() should be added to mops

> +
> +	ret = device_register(&mgr->dev);
> +	if (ret) {
> +		put_device(&mgr->dev);
> +		return ERR_PTR(ret);
> +	}
> +
>   	return mgr;
>   
>   error_device:
> @@ -612,96 +625,36 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>   error_kfree:
>   	kfree(mgr);
>   
> -	return NULL;
> +	return ERR_PTR(ret);
>   }
> -EXPORT_SYMBOL_GPL(fpga_mgr_create);
> +EXPORT_SYMBOL_GPL(fpga_mgr_register_full);
>   
>   /**
> - * fpga_mgr_free - free an FPGA manager created with fpga_mgr_create()
> - * @mgr:	fpga manager struct
> - */
> -void fpga_mgr_free(struct fpga_manager *mgr)
> -{
> -	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> -	kfree(mgr);
> -}
> -EXPORT_SYMBOL_GPL(fpga_mgr_free);
> -
> -static void devm_fpga_mgr_release(struct device *dev, void *res)
> -{
> -	struct fpga_mgr_devres *dr = res;
> -
> -	fpga_mgr_free(dr->mgr);
> -}
> -
> -/**
> - * devm_fpga_mgr_create - create and initialize a managed FPGA manager struct
> + * fpga_mgr_register - create and register an FPGA Manager device
>    * @parent:	fpga manager device from pdev
>    * @name:	fpga manager name
>    * @mops:	pointer to structure of fpga manager ops
>    * @priv:	fpga manager private data
>    *
> - * This function is intended for use in an FPGA manager driver's probe function.
> - * After the manager driver creates the manager struct with
> - * devm_fpga_mgr_create(), it should register it with fpga_mgr_register().  The
> - * manager driver's remove function should call fpga_mgr_unregister().  The
> - * manager struct allocated with this function will be freed automatically on
> - * driver detach.  This includes the case of a probe function returning error
> - * before calling fpga_mgr_register(), the struct will still get cleaned up.
> + * The caller of this function is responsible for calling fpga_mgr_unregister().
> + * Using devm_fpga_mgr_register() instead is recommended. This simple
> + * version of the register function should be sufficient for most users. The
> + * fpga_mgr_register_full() function is available for users that need to pass
> + * additional, optional parameters.
>    *
> - * Return: pointer to struct fpga_manager or NULL
> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>    */
> -struct fpga_manager *devm_fpga_mgr_create(struct device *parent, const char *name,
> -					  const struct fpga_manager_ops *mops,
> -					  void *priv)
> +struct fpga_manager *
> +fpga_mgr_register(struct device *parent, const char *name,
> +		  const struct fpga_manager_ops *mops, void *priv)
>   {
> -	struct fpga_mgr_devres *dr;
> +	struct fpga_manager_info info = { 0 };
>   
> -	dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL);
> -	if (!dr)
> -		return NULL;
> +	info.name = name;
> +	info.mops = mops;
> +	info.priv = priv;
>   
> -	dr->mgr = fpga_mgr_create(parent, name, mops, priv);
> -	if (!dr->mgr) {
> -		devres_free(dr);
> -		return NULL;
> -	}
> -
> -	devres_add(parent, dr);
> -
> -	return dr->mgr;
> -}
> -EXPORT_SYMBOL_GPL(devm_fpga_mgr_create);
> -
> -/**
> - * fpga_mgr_register - register an FPGA manager
> - * @mgr: fpga manager struct
> - *
> - * Return: 0 on success, negative error code otherwise.
> - */
> -int fpga_mgr_register(struct fpga_manager *mgr)
> -{
> -	int ret;
> -
> -	/*
> -	 * Initialize framework state by requesting low level driver read state
> -	 * from device.  FPGA may be in reset mode or may have been programmed
> -	 * by bootloader or EEPROM.
> -	 */
> -	mgr->state = mgr->mops->state(mgr);
> -
> -	ret = device_add(&mgr->dev);
> -	if (ret)
> -		goto error_device;
> -
> -	dev_info(&mgr->dev, "%s registered\n", mgr->name);
> -
> -	return 0;
> -
> -error_device:
> -	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> -
> -	return ret;
> +	return fpga_mgr_register_full(parent, &info);
>   }
>   EXPORT_SYMBOL_GPL(fpga_mgr_register);
>   
> @@ -726,14 +679,6 @@ void fpga_mgr_unregister(struct fpga_manager *mgr)
>   }
>   EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
>   
> -static int fpga_mgr_devres_match(struct device *dev, void *res,
> -				 void *match_data)
> -{
> -	struct fpga_mgr_devres *dr = res;
> -
> -	return match_data == dr->mgr;
> -}
> -
>   static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>   {
>   	struct fpga_mgr_devres *dr = res;
> @@ -742,45 +687,67 @@ static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>   }
>   
>   /**
> - * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
> - * @dev: managing device for this FPGA manager
> - * @mgr: fpga manager struct
> + * devm_fpga_mgr_register_full - resource managed variant of fpga_mgr_register()
> + * @parent:	fpga manager device from pdev
> + * @info:	parameters for fpga manager
>    *
> - * This is the devres variant of fpga_mgr_register() for which the unregister
> + * This is the devres variant of fpga_mgr_register_full() for which the unregister
>    * function will be called automatically when the managing device is detached.
>    */
> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr)
> +struct fpga_manager *
> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>   {
>   	struct fpga_mgr_devres *dr;
> -	int ret;
> -
> -	/*
> -	 * Make sure that the struct fpga_manager * that is passed in is
> -	 * managed itself.
> -	 */
> -	if (WARN_ON(!devres_find(dev, devm_fpga_mgr_release,
> -				 fpga_mgr_devres_match, mgr)))
> -		return -EINVAL;
> +	struct fpga_manager *mgr;
>   
>   	dr = devres_alloc(devm_fpga_mgr_unregister, sizeof(*dr), GFP_KERNEL);
>   	if (!dr)
> -		return -ENOMEM;
> +		return ERR_PTR(-ENOMEM);
>   
> -	ret = fpga_mgr_register(mgr);
> -	if (ret) {
> +	mgr = fpga_mgr_register_full(parent, info);
> +	if (IS_ERR(mgr)) {
>   		devres_free(dr);
> -		return ret;
> +		return mgr;
>   	}
>   
>   	dr->mgr = mgr;
> -	devres_add(dev, dr);
> +	devres_add(parent, dr);
>   
> -	return 0;
> +	return mgr;
> +}
> +EXPORT_SYMBOL_GPL(devm_fpga_mgr_register_full);
> +
> +/**
> + * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
> + * @parent:	fpga manager device from pdev
> + * @name:	fpga manager name
> + * @mops:	pointer to structure of fpga manager ops
> + * @priv:	fpga manager private data
> + *
> + * This is the devres variant of fpga_mgr_register() for which the
> + * unregister function will be called automatically when the managing
> + * device is detached.
> + */
> +struct fpga_manager *
> +devm_fpga_mgr_register(struct device *parent, const char *name,
> +		       const struct fpga_manager_ops *mops, void *priv)
> +{
> +	struct fpga_manager_info info = { 0 };
> +
> +	info.name = name;
> +	info.mops = mops;
> +	info.priv = priv;
> +
> +	return devm_fpga_mgr_register_full(parent, &info);
>   }
>   EXPORT_SYMBOL_GPL(devm_fpga_mgr_register);
>   
>   static void fpga_mgr_dev_release(struct device *dev)
>   {
> +	struct fpga_manager *mgr = to_fpga_manager(dev);
> +
> +	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> +	kfree(mgr);
>   }
>   
>   static int __init fpga_mgr_class_init(void)
> diff --git a/drivers/fpga/ice40-spi.c b/drivers/fpga/ice40-spi.c
> index 69dec5af23c3..b7591912248f 100644
> --- a/drivers/fpga/ice40-spi.c
> +++ b/drivers/fpga/ice40-spi.c
> @@ -178,12 +178,9 @@ static int ice40_fpga_probe(struct spi_device *spi)
>   		return ret;
>   	}
>   
> -	mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
> -				   &ice40_fpga_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(dev, mgr);
> +	mgr = devm_fpga_mgr_register(dev, "Lattice iCE40 FPGA Manager",
> +				     &ice40_fpga_ops, priv);
> +	return PTR_ERR_OR_ZERO(mgr);
>   }
>   
>   static const struct of_device_id ice40_fpga_of_match[] = {
> diff --git a/drivers/fpga/machxo2-spi.c b/drivers/fpga/machxo2-spi.c
> index 1afb41aa20d7..8469dfb5dd21 100644
> --- a/drivers/fpga/machxo2-spi.c
> +++ b/drivers/fpga/machxo2-spi.c
> @@ -366,12 +366,9 @@ static int machxo2_spi_probe(struct spi_device *spi)
>   		return -EINVAL;
>   	}
>   
> -	mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager",
> -				   &machxo2_ops, spi);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(dev, mgr);
> +	mgr = devm_fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager",
> +				     &machxo2_ops, spi);
> +	return PTR_ERR_OR_ZERO(mgr);
>   }
>   
>   #ifdef CONFIG_OF
> diff --git a/drivers/fpga/socfpga-a10.c b/drivers/fpga/socfpga-a10.c
> index 573d88bdf730..ac8e89b8a5cc 100644
> --- a/drivers/fpga/socfpga-a10.c
> +++ b/drivers/fpga/socfpga-a10.c
> @@ -508,19 +508,15 @@ static int socfpga_a10_fpga_probe(struct platform_device *pdev)
>   		return -EBUSY;
>   	}
>   
> -	mgr = devm_fpga_mgr_create(dev, "SoCFPGA Arria10 FPGA Manager",
> -				   &socfpga_a10_fpga_mgr_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	platform_set_drvdata(pdev, mgr);
> -
> -	ret = fpga_mgr_register(mgr);
> -	if (ret) {
> +	mgr = fpga_mgr_register(dev, "SoCFPGA Arria10 FPGA Manager",
> +				&socfpga_a10_fpga_mgr_ops, priv);
> +	if (IS_ERR(mgr)) {
>   		clk_disable_unprepare(priv->clk);
> -		return ret;
> +		return PTR_ERR(mgr);
>   	}
>   
> +	platform_set_drvdata(pdev, mgr);
> +
>   	return 0;
>   }
>   
> diff --git a/drivers/fpga/socfpga.c b/drivers/fpga/socfpga.c
> index 1f467173fc1f..7e0741f99696 100644
> --- a/drivers/fpga/socfpga.c
> +++ b/drivers/fpga/socfpga.c
> @@ -571,12 +571,9 @@ static int socfpga_fpga_probe(struct platform_device *pdev)
>   	if (ret)
>   		return ret;
>   
> -	mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
> -				   &socfpga_fpga_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(dev, mgr);
> +	mgr = devm_fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
> +				     &socfpga_fpga_ops, priv);
> +	return PTR_ERR_OR_ZERO(mgr);
>   }
>   
>   #ifdef CONFIG_OF
> diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
> index a2cea500f7cc..9155e888a133 100644
> --- a/drivers/fpga/stratix10-soc.c
> +++ b/drivers/fpga/stratix10-soc.c
> @@ -425,18 +425,11 @@ static int s10_probe(struct platform_device *pdev)
>   
>   	init_completion(&priv->status_return_completion);
>   
> -	mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
> -			      &s10_ops, priv);
> -	if (!mgr) {
> -		dev_err(dev, "unable to create FPGA manager\n");
> -		ret = -ENOMEM;
> -		goto probe_err;
> -	}
> -
> -	ret = fpga_mgr_register(mgr);
> -	if (ret) {
> +	mgr = fpga_mgr_register(dev, "Stratix10 SOC FPGA Manager",
> +				&s10_ops, priv);
> +	if (IS_ERR(mgr)) {
>   		dev_err(dev, "unable to register FPGA manager\n");
> -		fpga_mgr_free(mgr);
> +		ret = PTR_ERR(mgr);
>   		goto probe_err;
>   	}
>   
> @@ -454,7 +447,6 @@ static int s10_remove(struct platform_device *pdev)
>   	struct s10_priv *priv = mgr->priv;
>   
>   	fpga_mgr_unregister(mgr);
> -	fpga_mgr_free(mgr);
>   	stratix10_svc_free_channel(priv->chan);
>   
>   	return 0;
> diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c
> index 101f016c6ed8..fd52de20ddb2 100644
> --- a/drivers/fpga/ts73xx-fpga.c
> +++ b/drivers/fpga/ts73xx-fpga.c
> @@ -122,12 +122,9 @@ static int ts73xx_fpga_probe(struct platform_device *pdev)
>   	if (IS_ERR(priv->io_base))
>   		return PTR_ERR(priv->io_base);
>   
> -	mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
> -				   &ts73xx_fpga_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(kdev, mgr);
> +	mgr = devm_fpga_mgr_register(kdev, "TS-73xx FPGA Manager",
> +				     &ts73xx_fpga_ops, priv);
> +	return PTR_ERR_OR_ZERO(mgr);
>   }
>   
>   static struct platform_driver ts73xx_fpga_driver = {
> diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
> index fee4d0abf6bf..db23626f9ab2 100644
> --- a/drivers/fpga/xilinx-spi.c
> +++ b/drivers/fpga/xilinx-spi.c
> @@ -247,13 +247,10 @@ static int xilinx_spi_probe(struct spi_device *spi)
>   		return dev_err_probe(&spi->dev, PTR_ERR(conf->done),
>   				     "Failed to get DONE gpio\n");
>   
> -	mgr = devm_fpga_mgr_create(&spi->dev,
> -				   "Xilinx Slave Serial FPGA Manager",
> -				   &xilinx_spi_ops, conf);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(&spi->dev, mgr);
> +	mgr = devm_fpga_mgr_register(&spi->dev,
> +				     "Xilinx Slave Serial FPGA Manager",
> +				     &xilinx_spi_ops, conf);
> +	return PTR_ERR_OR_ZERO(mgr);
>   }
>   
>   static const struct of_device_id xlnx_spi_of_match[] = {
> diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
> index 9b75bd4f93d8..426aa34c6a0d 100644
> --- a/drivers/fpga/zynq-fpga.c
> +++ b/drivers/fpga/zynq-fpga.c
> @@ -609,20 +609,16 @@ static int zynq_fpga_probe(struct platform_device *pdev)
>   
>   	clk_disable(priv->clk);
>   
> -	mgr = devm_fpga_mgr_create(dev, "Xilinx Zynq FPGA Manager",
> -				   &zynq_fpga_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	platform_set_drvdata(pdev, mgr);
> -
> -	err = fpga_mgr_register(mgr);
> -	if (err) {
> +	mgr = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
> +				&zynq_fpga_ops, priv);
> +	if (IS_ERR(mgr)) {
>   		dev_err(dev, "unable to register FPGA manager\n");
>   		clk_unprepare(priv->clk);
> -		return err;
> +		return PTR_ERR(mgr);
>   	}
>   
> +	platform_set_drvdata(pdev, mgr);
> +
>   	return 0;
>   }
>   
> diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
> index 125743c9797f..975bdc4d0a65 100644
> --- a/drivers/fpga/zynqmp-fpga.c
> +++ b/drivers/fpga/zynqmp-fpga.c
> @@ -102,12 +102,9 @@ static int zynqmp_fpga_probe(struct platform_device *pdev)
>   
>   	priv->dev = dev;
>   
> -	mgr = devm_fpga_mgr_create(dev, "Xilinx ZynqMP FPGA Manager",
> -				   &zynqmp_fpga_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(dev, mgr);
> +	mgr = devm_fpga_mgr_register(dev, "Xilinx ZynqMP FPGA Manager",
> +				     &zynqmp_fpga_ops, priv);
> +	return PTR_ERR_OR_ZERO(mgr);
>   }
>   
>   static const struct of_device_id zynqmp_fpga_of_match[] = {
> diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
> index 474c1f506307..ac3ddaf2903c 100644
> --- a/include/linux/fpga/fpga-mgr.h
> +++ b/include/linux/fpga/fpga-mgr.h
> @@ -105,6 +105,36 @@ struct fpga_image_info {
>   #endif
>   };
>   
> +/**
> + * struct fpga_compat_id - id for compatibility check
> + *
> + * @id_h: high 64bit of the compat_id
> + * @id_l: low 64bit of the compat_id
> + */
> +struct fpga_compat_id {
> +	u64 id_h;
> +	u64 id_l;
> +};
> +

There are two register functions are to handle this dfl only structure.

This really needs to be moved fme_mgr_priv.

> +/**
> + * struct fpga_manager_info - collection of parameters for an FPGA Manager
> + * @name: fpga manager name
> + * @compat_id: FPGA manager id for compatibility check.
> + * @mops: pointer to structure of fpga manager ops
> + * @priv: fpga manager private data
> + *
> + * fpga_manager_info contains parameters for the register function. These
> + * are separated into an info structure because they some are optional
> + * others could be added to in the future. The info structure facilitates
> + * maintaining a stable API.
> + */
> +struct fpga_manager_info {
> +	const char *name;
> +	struct fpga_compat_id *compat_id;
> +	const struct fpga_manager_ops *mops;
> +	void *priv;
> +};
> +
>   /**
>    * struct fpga_manager_ops - ops for low level fpga manager drivers
>    * @initial_header_size: Maximum number of bytes that should be passed into write_init
> @@ -143,17 +173,6 @@ struct fpga_manager_ops {
>   #define FPGA_MGR_STATUS_IP_PROTOCOL_ERR		BIT(3)
>   #define FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR	BIT(4)
>   
> -/**
> - * struct fpga_compat_id - id for compatibility check
> - *
> - * @id_h: high 64bit of the compat_id
> - * @id_l: low 64bit of the compat_id
> - */
> -struct fpga_compat_id {
> -	u64 id_h;
> -	u64 id_l;
> -};
> -
>   /**
>    * struct fpga_manager - fpga manager structure
>    * @name: name of low level fpga manager
> @@ -191,17 +210,18 @@ struct fpga_manager *fpga_mgr_get(struct device *dev);
>   
>   void fpga_mgr_put(struct fpga_manager *mgr);
>   
> -struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name,
> -				     const struct fpga_manager_ops *mops,
> -				     void *priv);
> -void fpga_mgr_free(struct fpga_manager *mgr);

removing these should cause any oot driver to fail to load.

so an oops is unlikely.

I'm ok with with api change.

> -int fpga_mgr_register(struct fpga_manager *mgr);
> -void fpga_mgr_unregister(struct fpga_manager *mgr);
> +struct fpga_manager *
> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
>   
> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr);
> +struct fpga_manager *
> +fpga_mgr_register(struct device *parent, const char *name,
> +		  const struct fpga_manager_ops *mops, void *priv);

having 2 ways to do the same thing is not great.

this should be reduced down to 1.

My preference is for the *info one as it's api will be durable.

Tom

> +void fpga_mgr_unregister(struct fpga_manager *mgr);
>   
> -struct fpga_manager *devm_fpga_mgr_create(struct device *dev, const char *name,
> -					  const struct fpga_manager_ops *mops,
> -					  void *priv);
> +struct fpga_manager *
> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
> +struct fpga_manager *
> +devm_fpga_mgr_register(struct device *parent, const char *name,
> +		       const struct fpga_manager_ops *mops, void *priv);
>   
>   #endif /*_LINUX_FPGA_MGR_H */


^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 2/3] fpga: bridge: Use standard dev_release for class driver
  2021-07-01  1:37 ` [PATCH v9 2/3] fpga: bridge: " Russ Weight
  2021-07-01  5:39   ` Xu Yilun
  2021-07-01  6:26   ` Xu Yilun
@ 2021-07-06 20:08   ` Tom Rix
  2021-07-06 22:53     ` Russ Weight
  2 siblings, 1 reply; 22+ messages in thread
From: Tom Rix @ 2021-07-06 20:08 UTC (permalink / raw)
  To: Russ Weight, mdf, linux-fpga
  Cc: lgoncalv, yilun.xu, hao.wu, matthew.gerlach, richard.gong

Russ,

Similar concern with 2 register functions as in fpga-mgr.

But here it does not seen that any instance uses 
fpga_bridge_register_full directly.

So it really isn't needed.

However if fpga-mgr changes to having a single register(... *info), 
fpga-bridge should likewise.

Peeking ahead, fpga-region looks similar.

my preference for api stability is for have mgr,bridge and region to 
have the *register_full(... *info) as the only *register()


On 6/30/21 6:37 PM, Russ Weight wrote:
> The FPGA bridge class driver data structure is being treated as a
> managed resource instead of using the standard dev_release call-back
> function to release the class data structure. This change removes
> the managed resource code and combines the create() and register()
> functions into a single register() or register_simple() function.
>
> The register() function accepts an info data structure to provide
> flexibility in passing optional parameters. The register_simple()
> function supports the current parameter list for users that don't
> require the use of optional parameters.
>
> Signed-off-by: Russ Weight <russell.h.weight@intel.com>
> Reviewed-by: Xu Yilun <yilun.xu@intel.com>
> ---
> v9:
>    - Cleaned up documentation for the FPGA Bridge register functions
>    - Renamed fpga_bridge_register() to fpga_bridge_register_full()
>    - Renamed fpga_bridge_register_simple() to fpga_bridge_register()
> v8:
>    - Added reviewed-by tag.
>    - Updated Documentation/driver-api/fpga/fpga-bridge.rst documentation.
> v7:
>    - Update the commit message to describe the new parameters for the
>      fpga_bridge_register() function and to mention the
>      fpga_bridge_register_simple() function.
>    - Fix function prototypes in header file to rename dev to parent.
>    - Some cleanup of comments.
>    - Update function defintions/prototypes to apply const to the new info
>      parameter.
>    - Verify that info->br_ops is non-null in register functions.
> v6:
>    - Changed fpga_bridge_register() parameters to accept an info data
>      structure to provide flexibility in passing optional parameters.
>    - Added fpga_bridge_register_simple() function to support current
>      parameters for users that don't require the use of optional
>      parameters.
> v5:
>    - Rebased on top of recently accepted patches.
> v4:
>    - Restore the previous format for the Return value in the comment header
>      for fpga_bridge_register()
> v3:
>    - Cleaned up comment header for fpga_bridge_register()
>    - Fix error return values for fpga_bridge_register()
> v2:
>    - No changes
> ---
>   Documentation/driver-api/fpga/fpga-bridge.rst |   8 +-
>   drivers/fpga/altera-fpga2sdram.c              |  12 +-
>   drivers/fpga/altera-freeze-bridge.c           |  10 +-
>   drivers/fpga/altera-hps2fpga.c                |  12 +-
>   drivers/fpga/dfl-fme-br.c                     |  10 +-
>   drivers/fpga/fpga-bridge.c                    | 137 ++++++------------
>   drivers/fpga/xilinx-pr-decoupler.c            |  17 +--
>   include/linux/fpga/fpga-bridge.h              |  33 +++--
>   8 files changed, 101 insertions(+), 138 deletions(-)
>
> diff --git a/Documentation/driver-api/fpga/fpga-bridge.rst b/Documentation/driver-api/fpga/fpga-bridge.rst
> index 8d650b4e2ce6..38e3bac8e877 100644
> --- a/Documentation/driver-api/fpga/fpga-bridge.rst
> +++ b/Documentation/driver-api/fpga/fpga-bridge.rst
> @@ -6,8 +6,10 @@ API to implement a new FPGA bridge
>   
>   * struct fpga_bridge - The FPGA Bridge structure
>   * struct fpga_bridge_ops - Low level Bridge driver ops
> -* devm_fpga_bridge_create() - Allocate and init a bridge struct
> -* fpga_bridge_register() - Register a bridge
> +* fpga_bridge_register_full() - Create and register a bridge using the
> +  fpga_bridge_info structure to provide the full flexibility of options
fpga_bridge_info (and fpga_mgr_info earlier) could be added to the 
kernel-doc:: list lower down
> +* fpga_bridge_register() - Create and register a bridge using standard
> +  arguments
>   * fpga_bridge_unregister() - Unregister a bridge
>   
>   .. kernel-doc:: include/linux/fpga/fpga-bridge.h
> @@ -17,7 +19,7 @@ API to implement a new FPGA bridge
>      :functions: fpga_bridge_ops
>   
>   .. kernel-doc:: drivers/fpga/fpga-bridge.c
> -   :functions: devm_fpga_bridge_create
> +   :functions: fpga_bridge_register_full
>   
>   .. kernel-doc:: drivers/fpga/fpga-bridge.c
>      :functions: fpga_bridge_register
> diff --git a/drivers/fpga/altera-fpga2sdram.c b/drivers/fpga/altera-fpga2sdram.c
> index a78e49c63c64..66063507116b 100644
> --- a/drivers/fpga/altera-fpga2sdram.c
> +++ b/drivers/fpga/altera-fpga2sdram.c
> @@ -121,17 +121,13 @@ static int alt_fpga_bridge_probe(struct platform_device *pdev)
>   	/* Get f2s bridge configuration saved in handoff register */
>   	regmap_read(sysmgr, SYSMGR_ISWGRP_HANDOFF3, &priv->mask);
>   
> -	br = devm_fpga_bridge_create(dev, F2S_BRIDGE_NAME,
> -				     &altera_fpga2sdram_br_ops, priv);
> -	if (!br)
> -		return -ENOMEM;
> +	br = fpga_bridge_register(dev, F2S_BRIDGE_NAME,
> +				  &altera_fpga2sdram_br_ops, priv);
> +	if (IS_ERR(br))
> +		return PTR_ERR(mgr);
>   
>   	platform_set_drvdata(pdev, br);
>   
> -	ret = fpga_bridge_register(br);
> -	if (ret)
> -		return ret;
> -
>   	dev_info(dev, "driver initialized with handoff %08x\n", priv->mask);
>   
>   	if (!of_property_read_u32(dev->of_node, "bridge-enable", &enable)) {
> diff --git a/drivers/fpga/altera-freeze-bridge.c b/drivers/fpga/altera-freeze-bridge.c
> index dd58c4aea92e..bfbfa43cd05b 100644
> --- a/drivers/fpga/altera-freeze-bridge.c
> +++ b/drivers/fpga/altera-freeze-bridge.c
> @@ -244,14 +244,14 @@ static int altera_freeze_br_probe(struct platform_device *pdev)
>   
>   	priv->base_addr = base_addr;
>   
> -	br = devm_fpga_bridge_create(dev, FREEZE_BRIDGE_NAME,
> -				     &altera_freeze_br_br_ops, priv);
> -	if (!br)
> -		return -ENOMEM;
> +	br = fpga_bridge_register(dev, FREEZE_BRIDGE_NAME,
> +				  &altera_freeze_br_br_ops, priv);
> +	if (IS_ERR(br))
> +		return PTR_ERR(br);
>   
>   	platform_set_drvdata(pdev, br);
>   
> -	return fpga_bridge_register(br);
> +	return 0;
>   }
>   
>   static int altera_freeze_br_remove(struct platform_device *pdev)
> diff --git a/drivers/fpga/altera-hps2fpga.c b/drivers/fpga/altera-hps2fpga.c
> index 77b95f251821..aa758426c22b 100644
> --- a/drivers/fpga/altera-hps2fpga.c
> +++ b/drivers/fpga/altera-hps2fpga.c
> @@ -180,19 +180,15 @@ static int alt_fpga_bridge_probe(struct platform_device *pdev)
>   		}
>   	}
>   
> -	br = devm_fpga_bridge_create(dev, priv->name,
> -				     &altera_hps2fpga_br_ops, priv);
> -	if (!br) {
> -		ret = -ENOMEM;
> +	br = fpga_bridge_register(dev, priv->name,
> +				  &altera_hps2fpga_br_ops, priv);
> +	if (IS_ERR(br)) {
> +		ret = PTR_ERR(br);
>   		goto err;
>   	}
>   
>   	platform_set_drvdata(pdev, br);
>   
> -	ret = fpga_bridge_register(br);
> -	if (ret)
> -		goto err;
> -
>   	return 0;
>   
>   err:
> diff --git a/drivers/fpga/dfl-fme-br.c b/drivers/fpga/dfl-fme-br.c
> index 3ff9f3a687ce..808d1f4d76df 100644
> --- a/drivers/fpga/dfl-fme-br.c
> +++ b/drivers/fpga/dfl-fme-br.c
> @@ -68,14 +68,14 @@ static int fme_br_probe(struct platform_device *pdev)
>   
>   	priv->pdata = dev_get_platdata(dev);
>   
> -	br = devm_fpga_bridge_create(dev, "DFL FPGA FME Bridge",
> -				     &fme_bridge_ops, priv);
> -	if (!br)
> -		return -ENOMEM;
> +	br = fpga_bridge_register(dev, "DFL FPGA FME Bridge",
> +				  &fme_bridge_ops, priv);
> +	if (IS_ERR(br))
> +		return PTR_ERR(br);
>   
>   	platform_set_drvdata(pdev, br);
>   
> -	return fpga_bridge_register(br);
> +	return 0;
>   }
>   
>   static int fme_br_remove(struct platform_device *pdev)
> diff --git a/drivers/fpga/fpga-bridge.c b/drivers/fpga/fpga-bridge.c
> index 798f55670646..e6d98be8531b 100644
> --- a/drivers/fpga/fpga-bridge.c
> +++ b/drivers/fpga/fpga-bridge.c
> @@ -312,55 +312,63 @@ static struct attribute *fpga_bridge_attrs[] = {
>   ATTRIBUTE_GROUPS(fpga_bridge);
>   
>   /**
> - * fpga_bridge_create - create and initialize a struct fpga_bridge
> + * fpga_bridge_register_full - create and register an FPGA Bridge device
>    * @parent:	FPGA bridge device from pdev
> - * @name:	FPGA bridge name
> - * @br_ops:	pointer to structure of fpga bridge ops
> - * @priv:	FPGA bridge private data
> + * @info:	parameters for FPGA Bridge
>    *
> - * The caller of this function is responsible for freeing the bridge with
> - * fpga_bridge_free().  Using devm_fpga_bridge_create() instead is recommended.
> - *
> - * Return: struct fpga_bridge or NULL
> + * Return: struct fpga_bridge pointer or ERR_PTR()
>    */
> -struct fpga_bridge *fpga_bridge_create(struct device *parent, const char *name,
> -				       const struct fpga_bridge_ops *br_ops,
> -				       void *priv)
> +struct fpga_bridge *
> +fpga_bridge_register_full(struct device *parent,
> +			  const struct fpga_bridge_info *info)
>   {
>   	struct fpga_bridge *bridge;
>   	int id, ret;
>   
> -	if (!name || !strlen(name)) {
> +	if (!info->br_ops) {
> +		dev_err(parent, "Attempt to register without fpga_bridge_ops\n");
> +		return ERR_PTR(-EINVAL);
> +	}
> +
> +	if (!info->name || !strlen(info->name)) {
>   		dev_err(parent, "Attempt to register with no name!\n");
> -		return NULL;
> +		return ERR_PTR(-EINVAL);
>   	}
>   
>   	bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
>   	if (!bridge)
> -		return NULL;
> +		return ERR_PTR(-ENOMEM);
>   
>   	id = ida_simple_get(&fpga_bridge_ida, 0, 0, GFP_KERNEL);
> -	if (id < 0)
> +	if (id < 0) {
> +		ret = id;
>   		goto error_kfree;
> +	}
>   
>   	mutex_init(&bridge->mutex);
>   	INIT_LIST_HEAD(&bridge->node);
>   
> -	bridge->name = name;
> -	bridge->br_ops = br_ops;
> -	bridge->priv = priv;
> +	bridge->name = info->name;
> +	bridge->br_ops = info->br_ops;
> +	bridge->priv = info->priv;
>   
> -	device_initialize(&bridge->dev);
> -	bridge->dev.groups = br_ops->groups;
> +	bridge->dev.groups = info->br_ops->groups;
>   	bridge->dev.class = fpga_bridge_class;
>   	bridge->dev.parent = parent;
>   	bridge->dev.of_node = parent->of_node;
>   	bridge->dev.id = id;
> +	of_platform_populate(bridge->dev.of_node, NULL, NULL, &bridge->dev);
>   
>   	ret = dev_set_name(&bridge->dev, "br%d", id);
>   	if (ret)
>   		goto error_device;
>   
> +	ret = device_register(&bridge->dev);
> +	if (ret) {
> +		put_device(&bridge->dev);
> +		return ERR_PTR(ret);
> +	}
> +
>   	return bridge;
>   
>   error_device:
> @@ -368,88 +376,35 @@ struct fpga_bridge *fpga_bridge_create(struct device *parent, const char *name,
>   error_kfree:
>   	kfree(bridge);
>   
> -	return NULL;
> -}
> -EXPORT_SYMBOL_GPL(fpga_bridge_create);
> -
> -/**
> - * fpga_bridge_free - free an fpga bridge created by fpga_bridge_create()
> - * @bridge:	FPGA bridge struct
> - */
> -void fpga_bridge_free(struct fpga_bridge *bridge)
> -{
> -	ida_simple_remove(&fpga_bridge_ida, bridge->dev.id);
> -	kfree(bridge);
> -}
> -EXPORT_SYMBOL_GPL(fpga_bridge_free);
> -
> -static void devm_fpga_bridge_release(struct device *dev, void *res)
> -{
> -	struct fpga_bridge *bridge = *(struct fpga_bridge **)res;
> -
> -	fpga_bridge_free(bridge);
> +	return ERR_PTR(ret);
>   }
> +EXPORT_SYMBOL_GPL(fpga_bridge_register_full);
>   
>   /**
> - * devm_fpga_bridge_create - create and init a managed struct fpga_bridge
> + * fpga_bridge_register - create and register an FPGA Bridge device
>    * @parent:	FPGA bridge device from pdev
>    * @name:	FPGA bridge name
>    * @br_ops:	pointer to structure of fpga bridge ops
>    * @priv:	FPGA bridge private data
>    *
> - * This function is intended for use in an FPGA bridge driver's probe function.
> - * After the bridge driver creates the struct with devm_fpga_bridge_create(), it
> - * should register the bridge with fpga_bridge_register().  The bridge driver's
> - * remove function should call fpga_bridge_unregister().  The bridge struct
> - * allocated with this function will be freed automatically on driver detach.
> - * This includes the case of a probe function returning error before calling
> - * fpga_bridge_register(), the struct will still get cleaned up.
> + * This simple version of the register should be sufficient for most users.
> + * The fpga_bridge_register_full() function is available for users that need to pass
> + * additional, optional parameters.
>    *
> - *  Return: struct fpga_bridge or NULL
> + * Return: struct fpga_bridge pointer or ERR_PTR()
>    */
> -struct fpga_bridge
> -*devm_fpga_bridge_create(struct device *parent, const char *name,
> -			 const struct fpga_bridge_ops *br_ops, void *priv)
> +struct fpga_bridge *
> +fpga_bridge_register(struct device *parent, const char *name,
> +		     const struct fpga_bridge_ops *br_ops,
> +		     void *priv)
>   {
> -	struct fpga_bridge **ptr, *bridge;
> -
> -	ptr = devres_alloc(devm_fpga_bridge_release, sizeof(*ptr), GFP_KERNEL);
> -	if (!ptr)
> -		return NULL;
> -
> -	bridge = fpga_bridge_create(parent, name, br_ops, priv);
> -	if (!bridge) {
> -		devres_free(ptr);
> -	} else {
> -		*ptr = bridge;
> -		devres_add(parent, ptr);
> -	}
> +	struct fpga_bridge_info info = { 0 };
>   
> -	return bridge;
> -}
> -EXPORT_SYMBOL_GPL(devm_fpga_bridge_create);
> +	info.name = name;
> +	info.br_ops = br_ops;
> +	info.priv = priv;
>   
> -/**
> - * fpga_bridge_register - register an FPGA bridge
> - *
> - * @bridge: FPGA bridge struct
> - *
> - * Return: 0 for success, error code otherwise.
> - */
> -int fpga_bridge_register(struct fpga_bridge *bridge)
> -{
> -	struct device *dev = &bridge->dev;
> -	int ret;
> -
> -	ret = device_add(dev);
> -	if (ret)
> -		return ret;
> -
> -	of_platform_populate(dev->of_node, NULL, NULL, dev);
> -
> -	dev_info(dev->parent, "fpga bridge [%s] registered\n", bridge->name);
> -
> -	return 0;
> +	return fpga_bridge_register_full(parent, &info);
>   }
>   EXPORT_SYMBOL_GPL(fpga_bridge_register);
>   
> @@ -475,6 +430,10 @@ EXPORT_SYMBOL_GPL(fpga_bridge_unregister);
>   
>   static void fpga_bridge_dev_release(struct device *dev)
>   {
> +	struct fpga_bridge *bridge = to_fpga_bridge(dev);
> +
> +	ida_simple_remove(&fpga_bridge_ida, bridge->dev.id);
> +	kfree(bridge);
>   }
>   
>   static int __init fpga_bridge_dev_init(void)
> diff --git a/drivers/fpga/xilinx-pr-decoupler.c b/drivers/fpga/xilinx-pr-decoupler.c
> index ea2bde6e5bc4..c004e52b9464 100644
> --- a/drivers/fpga/xilinx-pr-decoupler.c
> +++ b/drivers/fpga/xilinx-pr-decoupler.c
> @@ -138,22 +138,17 @@ static int xlnx_pr_decoupler_probe(struct platform_device *pdev)
>   
>   	clk_disable(priv->clk);
>   
> -	br = devm_fpga_bridge_create(&pdev->dev, priv->ipconfig->name,
> -				     &xlnx_pr_decoupler_br_ops, priv);
> -	if (!br) {
> -		err = -ENOMEM;
> -		goto err_clk;
> -	}
> -
> -	platform_set_drvdata(pdev, br);
> -
> -	err = fpga_bridge_register(br);
> -	if (err) {
> +	br = fpga_bridge_register(&pdev->dev, priv->ipconfig->name,
> +				  &xlnx_pr_decoupler_br_ops, priv);
> +	if (IS_ERR(br)) {
> +		err = PTR_ERR(br);
>   		dev_err(&pdev->dev, "unable to register %s",
>   			priv->ipconfig->name);
>   		goto err_clk;
>   	}
>   
> +	platform_set_drvdata(pdev, br);
> +
>   	return 0;
>   
>   err_clk:
> diff --git a/include/linux/fpga/fpga-bridge.h b/include/linux/fpga/fpga-bridge.h
> index 6c3c28806ff1..f0a4d99d9c8e 100644
> --- a/include/linux/fpga/fpga-bridge.h
> +++ b/include/linux/fpga/fpga-bridge.h
> @@ -22,6 +22,23 @@ struct fpga_bridge_ops {
>   	const struct attribute_group **groups;

This groups seems to be unused.

If it is, maybe it should go into info.

Tom

>   };
>   
> +/**
> + * struct fpga_bridge_info - collection of parameters an FPGA Bridge
> + * @name: fpga bridge name
> + * @br_ops: pointer to structure of fpga bridge ops
> + * @priv: fpga bridge private data
> + *
> + * fpga_bridge_info contains parameters for the register function. These
> + * are separated into an info structure because they some are optional
> + * others could be added to in the future. The info structure facilitates
> + * maintaining a stable API.
> + */
> +struct fpga_bridge_info {
> +	const char *name;
> +	const struct fpga_bridge_ops *br_ops;
> +	void *priv;
> +};
> +
>   /**
>    * struct fpga_bridge - FPGA bridge structure
>    * @name: name of low level FPGA bridge
> @@ -62,15 +79,13 @@ int of_fpga_bridge_get_to_list(struct device_node *np,
>   			       struct fpga_image_info *info,
>   			       struct list_head *bridge_list);
>   
> -struct fpga_bridge *fpga_bridge_create(struct device *dev, const char *name,
> -				       const struct fpga_bridge_ops *br_ops,
> -				       void *priv);
> -void fpga_bridge_free(struct fpga_bridge *br);
> -int fpga_bridge_register(struct fpga_bridge *br);
> -void fpga_bridge_unregister(struct fpga_bridge *br);
> +struct fpga_bridge *
> +fpga_bridge_register_full(struct device *parent, const struct fpga_bridge_info *info);
>   
> -struct fpga_bridge
> -*devm_fpga_bridge_create(struct device *dev, const char *name,
> -			 const struct fpga_bridge_ops *br_ops, void *priv);
> +struct fpga_bridge *
> +fpga_bridge_register(struct device *parent, const char *name,
> +		     const struct fpga_bridge_ops *br_ops,
> +		     void *priv);
> +void fpga_bridge_unregister(struct fpga_bridge *br);
>   
>   #endif /* _LINUX_FPGA_BRIDGE_H */


^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 1/3] fpga: mgr: Use standard dev_release for class driver
  2021-07-06 19:04   ` Tom Rix
@ 2021-07-06 21:02     ` Russ Weight
  2021-07-06 21:44       ` Tom Rix
  2021-07-07  3:01       ` Xu Yilun
  2021-07-07  3:04     ` Xu Yilun
  1 sibling, 2 replies; 22+ messages in thread
From: Russ Weight @ 2021-07-06 21:02 UTC (permalink / raw)
  To: Tom Rix, mdf, linux-fpga
  Cc: lgoncalv, yilun.xu, hao.wu, matthew.gerlach, richard.gong



On 7/6/21 12:04 PM, Tom Rix wrote:
> Russ,
>
> My two big concerns are.
>
> compat_id does not belong in fpga_mgr_info, it belongs in fme_mgr_priv.

fpga_mgr_info is a temporary structure on the stack that contains the
parameters only long enough to pass them in and have them added to the
fpga_manager structure. Do you have a concern about it being on the
fpga_manager structure.

>
> there are two register functions, there should be one.

I get what you are saying. I don't really like the idea of forcing the
complexity of the temporary structure on all callers, since only a
couple require it, but we can do that if that is the concensus.

What do others think?

>
> On 6/30/21 6:37 PM, Russ Weight wrote:
>> The FPGA manager class driver data structure is being treated as a
>> managed resource instead of using the standard dev_release call-back
>> function to release the class data structure. This change removes
>> the managed resource code for the freeing of the class data structure
>> and combines the create() and register() functions into a single
>> register() or register_simple() function.
>>
>> The register() function accepts an info data structure to provide
>> flexibility in passing optional parameters. The register_simple()
>> function supports the current parameter list for users that don't
>> require the use of optional parameters.
>>
>> The devm_fpga_mgr_register() function is retained, and the
>> devm_fpga_mgr_register_simple() function is added.
>>
>> Signed-off-by: Russ Weight <russell.h.weight@intel.com>
>> Reviewed-by: Xu Yilun <yilun.xu@intel.com>
>> ---
>> v9:
>>    - Cleaned up documentation for the FPGA Manager register functions
>>    - Renamed fpga_mgr_register() to fpga_mgr_register_full()
>>    - Renamed fpga_mgr_register_simple() to fpga_mgr_register()
>>    - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full()
>>    - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register()
>> v8:
>>    - Added reviewed-by tag.
>>    - Updated Documentation/driver-api/fpga/fpga-mgr.rst documentation.
>> v7:
>>    - Update the commit message to describe the new parameters for the
>>      *fpga_mgr_register() functions and to mention the
>>      *fpga_mgr_register_simple() functions.
>>    - Fix function prototypes in header file to rename dev to parent.
>>    - Make use of the PTR_ERR_OR_ZERO() macro when possible.
>>    - Some cleanup of comments.
>>    - Update function defintions/prototypes to apply const to the new info
>>      parameter.
>> v6:
>>    - Moved FPGA manager optional parameters out of the ops structure and
>>      back into the FPGA manager structure.
>>    - Changed fpga_mgr_register()/devm_fpga_mgr_register() parameters to
>>      accept an info data structure to provide flexibility in passing optional
>>      parameters.
>>    - Added fpga_mgr_register_simple()/devm_fpga_mgr_register_simple()
>>      functions to support current parameters for users that don't require
>>      the use of optional parameters.
>> v5:
>>    - Rebased on top of recently accepted patches.
>>    - Removed compat_id from the fpga_mgr_register() parameter list
>>      and added it to the fpga_manager_ops structure. This also required
>>      dynamically allocating the dfl-fme-ops structure in order to add
>>      the appropriate compat_id.
>> v4:
>>    - Added the compat_id parameter to fpga_mgr_register() and
>>      devm_fpga_mgr_register() to ensure that the compat_id is set before
>>      the device_register() call.
>> v3:
>>    - Cleaned up comment header for fpga_mgr_register()
>>    - Fix error return on ida_simple_get() failure
>> v2:
>>    - Restored devm_fpga_mgr_register() functionality, adapted for the combined
>>      create/register functionality.
>>    - All previous callers of devm_fpga_mgr_register() will continue to call
>>      devm_fpga_mgr_register().
>>    - replaced unnecessary ternary operators in return statements with standard
>>      if conditions.
>> ---
>>   Documentation/driver-api/fpga/fpga-mgr.rst |  34 +++-
>>   drivers/fpga/altera-cvp.c                  |  12 +-
>>   drivers/fpga/altera-pr-ip-core.c           |   7 +-
>>   drivers/fpga/altera-ps-spi.c               |   9 +-
>>   drivers/fpga/dfl-fme-mgr.c                 |  22 +--
>>   drivers/fpga/fpga-mgr.c                    | 215 +++++++++------------
>>   drivers/fpga/ice40-spi.c                   |   9 +-
>>   drivers/fpga/machxo2-spi.c                 |   9 +-
>>   drivers/fpga/socfpga-a10.c                 |  16 +-
>>   drivers/fpga/socfpga.c                     |   9 +-
>>   drivers/fpga/stratix10-soc.c               |  16 +-
>>   drivers/fpga/ts73xx-fpga.c                 |   9 +-
>>   drivers/fpga/xilinx-spi.c                  |  11 +-
>>   drivers/fpga/zynq-fpga.c                   |  16 +-
>>   drivers/fpga/zynqmp-fpga.c                 |   9 +-
>>   include/linux/fpga/fpga-mgr.h              |  62 ++++--
>>   16 files changed, 210 insertions(+), 255 deletions(-)
>>
>> diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
>> index 4d926b452cb3..826ed8dc9210 100644
>> --- a/Documentation/driver-api/fpga/fpga-mgr.rst
>> +++ b/Documentation/driver-api/fpga/fpga-mgr.rst
>> @@ -24,7 +24,7 @@ How to support a new FPGA device
>>   --------------------------------
>>     To add another FPGA manager, write a driver that implements a set of ops.  The
>> -probe function calls fpga_mgr_register(), such as::
>> +probe function calls fpga_mgr_register() or fpga_mgr_register_full(), such as::
>>         static const struct fpga_manager_ops socfpga_fpga_ops = {
>>           .write_init = socfpga_fpga_ops_configure_init,
>> @@ -49,14 +49,14 @@ probe function calls fpga_mgr_register(), such as::
>>            * them in priv
>>            */
>>   -        mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
>> -                       &socfpga_fpga_ops, priv);
>> -        if (!mgr)
>> -            return -ENOMEM;
>> +        mgr = fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
>> +                    &socfpga_fpga_ops, priv);
>> +        if (IS_ERR(mgr))
>> +            return PTR_ERR(mgr);
>>             platform_set_drvdata(pdev, mgr);
>>   -        return fpga_mgr_register(mgr);
>> +        return 0;
>>       }
>>         static int socfpga_fpga_remove(struct platform_device *pdev)
>> @@ -68,6 +68,11 @@ probe function calls fpga_mgr_register(), such as::
>>           return 0;
>>       }
>>   +Alternatively, the probe function could call one of the resource managed
>> +register functions, devm_fpga_mgr_register() or devm_fpga_mgr_register_full().
>> +When these functions are used, the parameter syntax is the same, but the call
>> +to fpga_mgr_unregister() should be removed. In the above example, the
>> +socfpga_fpga_remove() function would not be required.
>>     The ops will implement whatever device specific register writes are needed to
>>   do the programming sequence for this particular FPGA.  These ops return 0 for
>> @@ -104,8 +109,13 @@ API for implementing a new FPGA Manager driver
>>   * ``fpga_mgr_states`` -  Values for :c:expr:`fpga_manager->state`.
>>   * struct fpga_manager -  the FPGA manager struct
>>   * struct fpga_manager_ops -  Low level FPGA manager driver ops
>> -* devm_fpga_mgr_create() -  Allocate and init a manager struct
>> -* fpga_mgr_register() -  Register an FPGA manager
>> +* fpga_mgr_register_full() -  Create and register an FPGA manager using the
>> +  fpga_mgr_info structure to provide the full flexibility of options
>> +* fpga_mgr_register() -  Create and register an FPGA manager using standard
>> +  arguments
>> +* devm_fpga_mgr_register_full() -  Resource managed version of
>> +  fpga_mgr_register_full()
>> +* devm_fpga_mgr_register() -  Resource managed version of fpga_mgr_register()
>>   * fpga_mgr_unregister() -  Unregister an FPGA manager
>>     .. kernel-doc:: include/linux/fpga/fpga-mgr.h
>> @@ -118,10 +128,16 @@ API for implementing a new FPGA Manager driver
>>      :functions: fpga_manager_ops
>>     .. kernel-doc:: drivers/fpga/fpga-mgr.c
>> -   :functions: devm_fpga_mgr_create
>> +   :functions: fpga_mgr_register_full
>>     .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>      :functions: fpga_mgr_register
>>   +.. kernel-doc:: drivers/fpga/fpga-mgr.c
>> +   :functions: devm_fpga_mgr_register_full
>> +
>> +.. kernel-doc:: drivers/fpga/fpga-mgr.c
>> +   :functions: devm_fpga_mgr_register
>> +
>>   .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>      :functions: fpga_mgr_unregister
>> diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
>> index ccf4546eff29..4ffb9da537d8 100644
>> --- a/drivers/fpga/altera-cvp.c
>> +++ b/drivers/fpga/altera-cvp.c
>> @@ -652,19 +652,15 @@ static int altera_cvp_probe(struct pci_dev *pdev,
>>       snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
>>            ALTERA_CVP_MGR_NAME, pci_name(pdev));
>>   -    mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
>> -                   &altera_cvp_ops, conf);
>> -    if (!mgr) {
>> -        ret = -ENOMEM;
>> +    mgr = fpga_mgr_register(&pdev->dev, conf->mgr_name,
>> +                &altera_cvp_ops, conf);
>> +    if (IS_ERR(mgr)) {
>> +        ret = PTR_ERR(mgr);
>>           goto err_unmap;
>>       }
>>         pci_set_drvdata(pdev, mgr);
>>   -    ret = fpga_mgr_register(mgr);
>> -    if (ret)
>> -        goto err_unmap;
>> -
>>       return 0;
>>     err_unmap:
>> diff --git a/drivers/fpga/altera-pr-ip-core.c b/drivers/fpga/altera-pr-ip-core.c
>> index dfdf21ed34c4..be0667968d33 100644
>> --- a/drivers/fpga/altera-pr-ip-core.c
>> +++ b/drivers/fpga/altera-pr-ip-core.c
>> @@ -191,11 +191,8 @@ int alt_pr_register(struct device *dev, void __iomem *reg_base)
>>           (val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
>>           (int)(val & ALT_PR_CSR_PR_START));
>>   -    mgr = devm_fpga_mgr_create(dev, dev_name(dev), &alt_pr_ops, priv);
>> -    if (!mgr)
>> -        return -ENOMEM;
>> -
>> -    return devm_fpga_mgr_register(dev, mgr);
>> +    mgr = devm_fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv);
>> +    return PTR_ERR_OR_ZERO(mgr);
>>   }
>>   EXPORT_SYMBOL_GPL(alt_pr_register);
>>   diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
>> index 23bfd4d1ad0f..5e1e009dba89 100644
>> --- a/drivers/fpga/altera-ps-spi.c
>> +++ b/drivers/fpga/altera-ps-spi.c
>> @@ -302,12 +302,9 @@ static int altera_ps_probe(struct spi_device *spi)
>>       snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s",
>>            dev_driver_string(&spi->dev), dev_name(&spi->dev));
>>   -    mgr = devm_fpga_mgr_create(&spi->dev, conf->mgr_name,
>> -                   &altera_ps_ops, conf);
>> -    if (!mgr)
>> -        return -ENOMEM;
>> -
>> -    return devm_fpga_mgr_register(&spi->dev, mgr);
>> +    mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name,
>> +                     &altera_ps_ops, conf);
>> +    return PTR_ERR_OR_ZERO(mgr);
>>   }
>>     static const struct spi_device_id altera_ps_spi_ids[] = {
>> diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
>> index d5861d13b306..620e7874ab53 100644
>> --- a/drivers/fpga/dfl-fme-mgr.c
>> +++ b/drivers/fpga/dfl-fme-mgr.c
>> @@ -282,7 +282,7 @@ static void fme_mgr_get_compat_id(void __iomem *fme_pr,
>>   static int fme_mgr_probe(struct platform_device *pdev)
>>   {
>>       struct dfl_fme_mgr_pdata *pdata = dev_get_platdata(&pdev->dev);
>> -    struct fpga_compat_id *compat_id;
>> +    struct fpga_manager_info info = { 0 };
>>       struct device *dev = &pdev->dev;
>>       struct fme_mgr_priv *priv;
>>       struct fpga_manager *mgr;
>> @@ -302,20 +302,16 @@ static int fme_mgr_probe(struct platform_device *pdev)
>>               return PTR_ERR(priv->ioaddr);
>>       }
>>   -    compat_id = devm_kzalloc(dev, sizeof(*compat_id), GFP_KERNEL);
>> -    if (!compat_id)
>> +    info.name = "DFL FME FPGA Manager";
>> +    info.mops = &fme_mgr_ops;
>> +    info.priv = priv;
>> +    info.compat_id = devm_kzalloc(dev, sizeof(*info.compat_id), GFP_KERNEL);
>> +    if (!info.compat_id)
>>           return -ENOMEM;
> could we limp along instead of failing ?

The compat_id is used to verify compatibility between the static region and
the partial reconfiguration. If there is insufficient memory for the small
data structure, I think it is best to fail here. This is also consistent
current implementation.
 
>>   -    fme_mgr_get_compat_id(priv->ioaddr, compat_id);
>> -
>> -    mgr = devm_fpga_mgr_create(dev, "DFL FME FPGA Manager",
>> -                   &fme_mgr_ops, priv);
>> -    if (!mgr)
>> -        return -ENOMEM;
>> -
>> -    mgr->compat_id = compat_id;
>> -
>> -    return devm_fpga_mgr_register(dev, mgr);
>> +    fme_mgr_get_compat_id(priv->ioaddr, info.compat_id);
>> +    mgr = devm_fpga_mgr_register_full(dev, &info);
>> +    return PTR_ERR_OR_ZERO(mgr);
>>   }
>>     static struct platform_driver fme_mgr_driver = {
>> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
>> index ecb4c3c795fa..5a913aa649fd 100644
>> --- a/drivers/fpga/fpga-mgr.c
>> +++ b/drivers/fpga/fpga-mgr.c
>> @@ -550,21 +550,19 @@ void fpga_mgr_unlock(struct fpga_manager *mgr)
>>   EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
>>     /**
>> - * fpga_mgr_create - create and initialize an FPGA manager struct
>> + * fpga_mgr_register_full - create and register an FPGA Manager device
>>    * @parent:    fpga manager device from pdev
>> - * @name:    fpga manager name
>> - * @mops:    pointer to structure of fpga manager ops
>> - * @priv:    fpga manager private data
>> + * @info:    parameters for fpga manager
>>    *
>> - * The caller of this function is responsible for freeing the struct with
>> - * fpga_mgr_free().  Using devm_fpga_mgr_create() instead is recommended.
>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
>> + * Using devm_fpga_mgr_register_full() instead is recommended.
>>    *
>> - * Return: pointer to struct fpga_manager or NULL
>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>>    */
>> -struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>> -                     const struct fpga_manager_ops *mops,
>> -                     void *priv)
>> +struct fpga_manager *
>> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>>   {
>> +    const struct fpga_manager_ops *mops = info->mops;
>>       struct fpga_manager *mgr;
>>       int id, ret;
>>   @@ -572,29 +570,31 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>           !mops->write_init || (!mops->write && !mops->write_sg) ||
>>           (mops->write && mops->write_sg)) {
>>           dev_err(parent, "Attempt to register without fpga_manager_ops\n");
>> -        return NULL;
>> +        return ERR_PTR(-EINVAL);
>>       }
>>   -    if (!name || !strlen(name)) {
>> +    if (!info->name || !strlen(info->name)) {
>>           dev_err(parent, "Attempt to register with no name!\n");
>> -        return NULL;
>> +        return ERR_PTR(-EINVAL);
>>       }
>>         mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
>>       if (!mgr)
>> -        return NULL;
>> +        return ERR_PTR(-ENOMEM);
>>         id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
>> -    if (id < 0)
>> +    if (id < 0) {
>> +        ret = id;
>>           goto error_kfree;
>> +    }
>>         mutex_init(&mgr->ref_mutex);
>>   -    mgr->name = name;
>> -    mgr->mops = mops;
>> -    mgr->priv = priv;
>> +    mgr->name = info->name;
>> +    mgr->mops = info->mops;
>> +    mgr->priv = info->priv;
>> +    mgr->compat_id = info->compat_id;
>>   -    device_initialize(&mgr->dev);
>>       mgr->dev.class = fpga_mgr_class;
>>       mgr->dev.groups = mops->groups;
>>       mgr->dev.parent = parent;
>> @@ -605,6 +605,19 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>       if (ret)
>>           goto error_device;
>>   +    /*
>> +     * Initialize framework state by requesting low level driver read state
>> +     * from device.  FPGA may be in reset mode or may have been programmed
>> +     * by bootloader or EEPROM.
>> +     */
>> +    mgr->state = mgr->mops->state(mgr);
>
> This is existing code, but it seems wrong.
>
> A side effect of state() should not be to initialize.
>
> An init() should be added to mops

I think this is just capturing the state of the underlying device an
reflecting it in the fpga-manager state? Maybe someone else can comment
on this. It seems outside the scope of these patches.

>
>> +
>> +    ret = device_register(&mgr->dev);
>> +    if (ret) {
>> +        put_device(&mgr->dev);
>> +        return ERR_PTR(ret);
>> +    }
>> +
>>       return mgr;
>>     error_device:
>> @@ -612,96 +625,36 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>   error_kfree:
>>       kfree(mgr);
>>   -    return NULL;
>> +    return ERR_PTR(ret);
>>   }
>> -EXPORT_SYMBOL_GPL(fpga_mgr_create);
>> +EXPORT_SYMBOL_GPL(fpga_mgr_register_full);
>>     /**
>> - * fpga_mgr_free - free an FPGA manager created with fpga_mgr_create()
>> - * @mgr:    fpga manager struct
>> - */
>> -void fpga_mgr_free(struct fpga_manager *mgr)
>> -{
>> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>> -    kfree(mgr);
>> -}
>> -EXPORT_SYMBOL_GPL(fpga_mgr_free);
>> -
>> -static void devm_fpga_mgr_release(struct device *dev, void *res)
>> -{
>> -    struct fpga_mgr_devres *dr = res;
>> -
>> -    fpga_mgr_free(dr->mgr);
>> -}
>> -
>> -/**
>> - * devm_fpga_mgr_create - create and initialize a managed FPGA manager struct
>> + * fpga_mgr_register - create and register an FPGA Manager device
>>    * @parent:    fpga manager device from pdev
>>    * @name:    fpga manager name
>>    * @mops:    pointer to structure of fpga manager ops
>>    * @priv:    fpga manager private data
>>    *
>> - * This function is intended for use in an FPGA manager driver's probe function.
>> - * After the manager driver creates the manager struct with
>> - * devm_fpga_mgr_create(), it should register it with fpga_mgr_register().  The
>> - * manager driver's remove function should call fpga_mgr_unregister().  The
>> - * manager struct allocated with this function will be freed automatically on
>> - * driver detach.  This includes the case of a probe function returning error
>> - * before calling fpga_mgr_register(), the struct will still get cleaned up.
>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
>> + * Using devm_fpga_mgr_register() instead is recommended. This simple
>> + * version of the register function should be sufficient for most users. The
>> + * fpga_mgr_register_full() function is available for users that need to pass
>> + * additional, optional parameters.
>>    *
>> - * Return: pointer to struct fpga_manager or NULL
>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>>    */
>> -struct fpga_manager *devm_fpga_mgr_create(struct device *parent, const char *name,
>> -                      const struct fpga_manager_ops *mops,
>> -                      void *priv)
>> +struct fpga_manager *
>> +fpga_mgr_register(struct device *parent, const char *name,
>> +          const struct fpga_manager_ops *mops, void *priv)
>>   {
>> -    struct fpga_mgr_devres *dr;
>> +    struct fpga_manager_info info = { 0 };
>>   -    dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL);
>> -    if (!dr)
>> -        return NULL;
>> +    info.name = name;
>> +    info.mops = mops;
>> +    info.priv = priv;
>>   -    dr->mgr = fpga_mgr_create(parent, name, mops, priv);
>> -    if (!dr->mgr) {
>> -        devres_free(dr);
>> -        return NULL;
>> -    }
>> -
>> -    devres_add(parent, dr);
>> -
>> -    return dr->mgr;
>> -}
>> -EXPORT_SYMBOL_GPL(devm_fpga_mgr_create);
>> -
>> -/**
>> - * fpga_mgr_register - register an FPGA manager
>> - * @mgr: fpga manager struct
>> - *
>> - * Return: 0 on success, negative error code otherwise.
>> - */
>> -int fpga_mgr_register(struct fpga_manager *mgr)
>> -{
>> -    int ret;
>> -
>> -    /*
>> -     * Initialize framework state by requesting low level driver read state
>> -     * from device.  FPGA may be in reset mode or may have been programmed
>> -     * by bootloader or EEPROM.
>> -     */
>> -    mgr->state = mgr->mops->state(mgr);
>> -
>> -    ret = device_add(&mgr->dev);
>> -    if (ret)
>> -        goto error_device;
>> -
>> -    dev_info(&mgr->dev, "%s registered\n", mgr->name);
>> -
>> -    return 0;
>> -
>> -error_device:
>> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>> -
>> -    return ret;
>> +    return fpga_mgr_register_full(parent, &info);
>>   }
>>   EXPORT_SYMBOL_GPL(fpga_mgr_register);
>>   @@ -726,14 +679,6 @@ void fpga_mgr_unregister(struct fpga_manager *mgr)
>>   }
>>   EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
>>   -static int fpga_mgr_devres_match(struct device *dev, void *res,
>> -                 void *match_data)
>> -{
>> -    struct fpga_mgr_devres *dr = res;
>> -
>> -    return match_data == dr->mgr;
>> -}
>> -
>>   static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>>   {
>>       struct fpga_mgr_devres *dr = res;
>> @@ -742,45 +687,67 @@ static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>>   }
>>     /**
>> - * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
>> - * @dev: managing device for this FPGA manager
>> - * @mgr: fpga manager struct
>> + * devm_fpga_mgr_register_full - resource managed variant of fpga_mgr_register()
>> + * @parent:    fpga manager device from pdev
>> + * @info:    parameters for fpga manager
>>    *
>> - * This is the devres variant of fpga_mgr_register() for which the unregister
>> + * This is the devres variant of fpga_mgr_register_full() for which the unregister
>>    * function will be called automatically when the managing device is detached.
>>    */
>> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr)
>> +struct fpga_manager *
>> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>>   {
>>       struct fpga_mgr_devres *dr;
>> -    int ret;
>> -
>> -    /*
>> -     * Make sure that the struct fpga_manager * that is passed in is
>> -     * managed itself.
>> -     */
>> -    if (WARN_ON(!devres_find(dev, devm_fpga_mgr_release,
>> -                 fpga_mgr_devres_match, mgr)))
>> -        return -EINVAL;
>> +    struct fpga_manager *mgr;
>>         dr = devres_alloc(devm_fpga_mgr_unregister, sizeof(*dr), GFP_KERNEL);
>>       if (!dr)
>> -        return -ENOMEM;
>> +        return ERR_PTR(-ENOMEM);
>>   -    ret = fpga_mgr_register(mgr);
>> -    if (ret) {
>> +    mgr = fpga_mgr_register_full(parent, info);
>> +    if (IS_ERR(mgr)) {
>>           devres_free(dr);
>> -        return ret;
>> +        return mgr;
>>       }
>>         dr->mgr = mgr;
>> -    devres_add(dev, dr);
>> +    devres_add(parent, dr);
>>   -    return 0;
>> +    return mgr;
>> +}
>> +EXPORT_SYMBOL_GPL(devm_fpga_mgr_register_full);
>> +
>> +/**
>> + * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
>> + * @parent:    fpga manager device from pdev
>> + * @name:    fpga manager name
>> + * @mops:    pointer to structure of fpga manager ops
>> + * @priv:    fpga manager private data
>> + *
>> + * This is the devres variant of fpga_mgr_register() for which the
>> + * unregister function will be called automatically when the managing
>> + * device is detached.
>> + */
>> +struct fpga_manager *
>> +devm_fpga_mgr_register(struct device *parent, const char *name,
>> +               const struct fpga_manager_ops *mops, void *priv)
>> +{
>> +    struct fpga_manager_info info = { 0 };
>> +
>> +    info.name = name;
>> +    info.mops = mops;
>> +    info.priv = priv;
>> +
>> +    return devm_fpga_mgr_register_full(parent, &info);
>>   }
>>   EXPORT_SYMBOL_GPL(devm_fpga_mgr_register);
>>     static void fpga_mgr_dev_release(struct device *dev)
>>   {
>> +    struct fpga_manager *mgr = to_fpga_manager(dev);
>> +
>> +    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>> +    kfree(mgr);
>>   }
>>     static int __init fpga_mgr_class_init(void)
>> diff --git a/drivers/fpga/ice40-spi.c b/drivers/fpga/ice40-spi.c
>> index 69dec5af23c3..b7591912248f 100644
>> --- a/drivers/fpga/ice40-spi.c
>> +++ b/drivers/fpga/ice40-spi.c
>> @@ -178,12 +178,9 @@ static int ice40_fpga_probe(struct spi_device *spi)
>>           return ret;
>>       }
>>   -    mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
>> -                   &ice40_fpga_ops, priv);
>> -    if (!mgr)
>> -        return -ENOMEM;
>> -
>> -    return devm_fpga_mgr_register(dev, mgr);
>> +    mgr = devm_fpga_mgr_register(dev, "Lattice iCE40 FPGA Manager",
>> +                     &ice40_fpga_ops, priv);
>> +    return PTR_ERR_OR_ZERO(mgr);
>>   }
>>     static const struct of_device_id ice40_fpga_of_match[] = {
>> diff --git a/drivers/fpga/machxo2-spi.c b/drivers/fpga/machxo2-spi.c
>> index 1afb41aa20d7..8469dfb5dd21 100644
>> --- a/drivers/fpga/machxo2-spi.c
>> +++ b/drivers/fpga/machxo2-spi.c
>> @@ -366,12 +366,9 @@ static int machxo2_spi_probe(struct spi_device *spi)
>>           return -EINVAL;
>>       }
>>   -    mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager",
>> -                   &machxo2_ops, spi);
>> -    if (!mgr)
>> -        return -ENOMEM;
>> -
>> -    return devm_fpga_mgr_register(dev, mgr);
>> +    mgr = devm_fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager",
>> +                     &machxo2_ops, spi);
>> +    return PTR_ERR_OR_ZERO(mgr);
>>   }
>>     #ifdef CONFIG_OF
>> diff --git a/drivers/fpga/socfpga-a10.c b/drivers/fpga/socfpga-a10.c
>> index 573d88bdf730..ac8e89b8a5cc 100644
>> --- a/drivers/fpga/socfpga-a10.c
>> +++ b/drivers/fpga/socfpga-a10.c
>> @@ -508,19 +508,15 @@ static int socfpga_a10_fpga_probe(struct platform_device *pdev)
>>           return -EBUSY;
>>       }
>>   -    mgr = devm_fpga_mgr_create(dev, "SoCFPGA Arria10 FPGA Manager",
>> -                   &socfpga_a10_fpga_mgr_ops, priv);
>> -    if (!mgr)
>> -        return -ENOMEM;
>> -
>> -    platform_set_drvdata(pdev, mgr);
>> -
>> -    ret = fpga_mgr_register(mgr);
>> -    if (ret) {
>> +    mgr = fpga_mgr_register(dev, "SoCFPGA Arria10 FPGA Manager",
>> +                &socfpga_a10_fpga_mgr_ops, priv);
>> +    if (IS_ERR(mgr)) {
>>           clk_disable_unprepare(priv->clk);
>> -        return ret;
>> +        return PTR_ERR(mgr);
>>       }
>>   +    platform_set_drvdata(pdev, mgr);
>> +
>>       return 0;
>>   }
>>   diff --git a/drivers/fpga/socfpga.c b/drivers/fpga/socfpga.c
>> index 1f467173fc1f..7e0741f99696 100644
>> --- a/drivers/fpga/socfpga.c
>> +++ b/drivers/fpga/socfpga.c
>> @@ -571,12 +571,9 @@ static int socfpga_fpga_probe(struct platform_device *pdev)
>>       if (ret)
>>           return ret;
>>   -    mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
>> -                   &socfpga_fpga_ops, priv);
>> -    if (!mgr)
>> -        return -ENOMEM;
>> -
>> -    return devm_fpga_mgr_register(dev, mgr);
>> +    mgr = devm_fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
>> +                     &socfpga_fpga_ops, priv);
>> +    return PTR_ERR_OR_ZERO(mgr);
>>   }
>>     #ifdef CONFIG_OF
>> diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
>> index a2cea500f7cc..9155e888a133 100644
>> --- a/drivers/fpga/stratix10-soc.c
>> +++ b/drivers/fpga/stratix10-soc.c
>> @@ -425,18 +425,11 @@ static int s10_probe(struct platform_device *pdev)
>>         init_completion(&priv->status_return_completion);
>>   -    mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
>> -                  &s10_ops, priv);
>> -    if (!mgr) {
>> -        dev_err(dev, "unable to create FPGA manager\n");
>> -        ret = -ENOMEM;
>> -        goto probe_err;
>> -    }
>> -
>> -    ret = fpga_mgr_register(mgr);
>> -    if (ret) {
>> +    mgr = fpga_mgr_register(dev, "Stratix10 SOC FPGA Manager",
>> +                &s10_ops, priv);
>> +    if (IS_ERR(mgr)) {
>>           dev_err(dev, "unable to register FPGA manager\n");
>> -        fpga_mgr_free(mgr);
>> +        ret = PTR_ERR(mgr);
>>           goto probe_err;
>>       }
>>   @@ -454,7 +447,6 @@ static int s10_remove(struct platform_device *pdev)
>>       struct s10_priv *priv = mgr->priv;
>>         fpga_mgr_unregister(mgr);
>> -    fpga_mgr_free(mgr);
>>       stratix10_svc_free_channel(priv->chan);
>>         return 0;
>> diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c
>> index 101f016c6ed8..fd52de20ddb2 100644
>> --- a/drivers/fpga/ts73xx-fpga.c
>> +++ b/drivers/fpga/ts73xx-fpga.c
>> @@ -122,12 +122,9 @@ static int ts73xx_fpga_probe(struct platform_device *pdev)
>>       if (IS_ERR(priv->io_base))
>>           return PTR_ERR(priv->io_base);
>>   -    mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
>> -                   &ts73xx_fpga_ops, priv);
>> -    if (!mgr)
>> -        return -ENOMEM;
>> -
>> -    return devm_fpga_mgr_register(kdev, mgr);
>> +    mgr = devm_fpga_mgr_register(kdev, "TS-73xx FPGA Manager",
>> +                     &ts73xx_fpga_ops, priv);
>> +    return PTR_ERR_OR_ZERO(mgr);
>>   }
>>     static struct platform_driver ts73xx_fpga_driver = {
>> diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
>> index fee4d0abf6bf..db23626f9ab2 100644
>> --- a/drivers/fpga/xilinx-spi.c
>> +++ b/drivers/fpga/xilinx-spi.c
>> @@ -247,13 +247,10 @@ static int xilinx_spi_probe(struct spi_device *spi)
>>           return dev_err_probe(&spi->dev, PTR_ERR(conf->done),
>>                        "Failed to get DONE gpio\n");
>>   -    mgr = devm_fpga_mgr_create(&spi->dev,
>> -                   "Xilinx Slave Serial FPGA Manager",
>> -                   &xilinx_spi_ops, conf);
>> -    if (!mgr)
>> -        return -ENOMEM;
>> -
>> -    return devm_fpga_mgr_register(&spi->dev, mgr);
>> +    mgr = devm_fpga_mgr_register(&spi->dev,
>> +                     "Xilinx Slave Serial FPGA Manager",
>> +                     &xilinx_spi_ops, conf);
>> +    return PTR_ERR_OR_ZERO(mgr);
>>   }
>>     static const struct of_device_id xlnx_spi_of_match[] = {
>> diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
>> index 9b75bd4f93d8..426aa34c6a0d 100644
>> --- a/drivers/fpga/zynq-fpga.c
>> +++ b/drivers/fpga/zynq-fpga.c
>> @@ -609,20 +609,16 @@ static int zynq_fpga_probe(struct platform_device *pdev)
>>         clk_disable(priv->clk);
>>   -    mgr = devm_fpga_mgr_create(dev, "Xilinx Zynq FPGA Manager",
>> -                   &zynq_fpga_ops, priv);
>> -    if (!mgr)
>> -        return -ENOMEM;
>> -
>> -    platform_set_drvdata(pdev, mgr);
>> -
>> -    err = fpga_mgr_register(mgr);
>> -    if (err) {
>> +    mgr = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
>> +                &zynq_fpga_ops, priv);
>> +    if (IS_ERR(mgr)) {
>>           dev_err(dev, "unable to register FPGA manager\n");
>>           clk_unprepare(priv->clk);
>> -        return err;
>> +        return PTR_ERR(mgr);
>>       }
>>   +    platform_set_drvdata(pdev, mgr);
>> +
>>       return 0;
>>   }
>>   diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
>> index 125743c9797f..975bdc4d0a65 100644
>> --- a/drivers/fpga/zynqmp-fpga.c
>> +++ b/drivers/fpga/zynqmp-fpga.c
>> @@ -102,12 +102,9 @@ static int zynqmp_fpga_probe(struct platform_device *pdev)
>>         priv->dev = dev;
>>   -    mgr = devm_fpga_mgr_create(dev, "Xilinx ZynqMP FPGA Manager",
>> -                   &zynqmp_fpga_ops, priv);
>> -    if (!mgr)
>> -        return -ENOMEM;
>> -
>> -    return devm_fpga_mgr_register(dev, mgr);
>> +    mgr = devm_fpga_mgr_register(dev, "Xilinx ZynqMP FPGA Manager",
>> +                     &zynqmp_fpga_ops, priv);
>> +    return PTR_ERR_OR_ZERO(mgr);
>>   }
>>     static const struct of_device_id zynqmp_fpga_of_match[] = {
>> diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
>> index 474c1f506307..ac3ddaf2903c 100644
>> --- a/include/linux/fpga/fpga-mgr.h
>> +++ b/include/linux/fpga/fpga-mgr.h
>> @@ -105,6 +105,36 @@ struct fpga_image_info {
>>   #endif
>>   };
>>   +/**
>> + * struct fpga_compat_id - id for compatibility check
>> + *
>> + * @id_h: high 64bit of the compat_id
>> + * @id_l: low 64bit of the compat_id
>> + */
>> +struct fpga_compat_id {
>> +    u64 id_h;
>> +    u64 id_l;
>> +};
>> +
>
> There are two register functions are to handle this dfl only structure.
>
> This really needs to be moved fme_mgr_priv.
>
>> +/**
>> + * struct fpga_manager_info - collection of parameters for an FPGA Manager
>> + * @name: fpga manager name
>> + * @compat_id: FPGA manager id for compatibility check.
>> + * @mops: pointer to structure of fpga manager ops
>> + * @priv: fpga manager private data
>> + *
>> + * fpga_manager_info contains parameters for the register function. These
>> + * are separated into an info structure because they some are optional
>> + * others could be added to in the future. The info structure facilitates
>> + * maintaining a stable API.
>> + */
>> +struct fpga_manager_info {
>> +    const char *name;
>> +    struct fpga_compat_id *compat_id;
>> +    const struct fpga_manager_ops *mops;
>> +    void *priv;
>> +};
>> +
>>   /**
>>    * struct fpga_manager_ops - ops for low level fpga manager drivers
>>    * @initial_header_size: Maximum number of bytes that should be passed into write_init
>> @@ -143,17 +173,6 @@ struct fpga_manager_ops {
>>   #define FPGA_MGR_STATUS_IP_PROTOCOL_ERR        BIT(3)
>>   #define FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR    BIT(4)
>>   -/**
>> - * struct fpga_compat_id - id for compatibility check
>> - *
>> - * @id_h: high 64bit of the compat_id
>> - * @id_l: low 64bit of the compat_id
>> - */
>> -struct fpga_compat_id {
>> -    u64 id_h;
>> -    u64 id_l;
>> -};
>> -
>>   /**
>>    * struct fpga_manager - fpga manager structure
>>    * @name: name of low level fpga manager
>> @@ -191,17 +210,18 @@ struct fpga_manager *fpga_mgr_get(struct device *dev);
>>     void fpga_mgr_put(struct fpga_manager *mgr);
>>   -struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name,
>> -                     const struct fpga_manager_ops *mops,
>> -                     void *priv);
>> -void fpga_mgr_free(struct fpga_manager *mgr);
>
> removing these should cause any oot driver to fail to load.
>
> so an oops is unlikely.
>
> I'm ok with with api change.
>
>> -int fpga_mgr_register(struct fpga_manager *mgr);
>> -void fpga_mgr_unregister(struct fpga_manager *mgr);
>> +struct fpga_manager *
>> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
>>   -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr);
>> +struct fpga_manager *
>> +fpga_mgr_register(struct device *parent, const char *name,
>> +          const struct fpga_manager_ops *mops, void *priv);
>
> having 2 ways to do the same thing is not great.
>
> this should be reduced down to 1.
>
> My preference is for the *info one as it's api will be durable.

I would like to see if other's agree.

>
> Tom
>
>> +void fpga_mgr_unregister(struct fpga_manager *mgr);
>>   -struct fpga_manager *devm_fpga_mgr_create(struct device *dev, const char *name,
>> -                      const struct fpga_manager_ops *mops,
>> -                      void *priv);
>> +struct fpga_manager *
>> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
>> +struct fpga_manager *
>> +devm_fpga_mgr_register(struct device *parent, const char *name,
>> +               const struct fpga_manager_ops *mops, void *priv);
>>     #endif /*_LINUX_FPGA_MGR_H */
>


^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 1/3] fpga: mgr: Use standard dev_release for class driver
  2021-07-06 21:02     ` Russ Weight
@ 2021-07-06 21:44       ` Tom Rix
  2021-07-06 23:03         ` Russ Weight
  2021-07-07  3:01       ` Xu Yilun
  1 sibling, 1 reply; 22+ messages in thread
From: Tom Rix @ 2021-07-06 21:44 UTC (permalink / raw)
  To: Russ Weight, mdf, linux-fpga
  Cc: lgoncalv, yilun.xu, hao.wu, matthew.gerlach, richard.gong


On 7/6/21 2:02 PM, Russ Weight wrote:
>
> On 7/6/21 12:04 PM, Tom Rix wrote:
>> Russ,
>>
>> My two big concerns are.
>>
>> compat_id does not belong in fpga_mgr_info, it belongs in fme_mgr_priv.
> fpga_mgr_info is a temporary structure on the stack that contains the
> parameters only long enough to pass them in and have them added to the
> fpga_manager structure. Do you have a concern about it being on the
> fpga_manager structure.

My concern is compat_id should never have been part of fpga-mgr in the 
first place.

It is dfl specific, so instead of going in a common structure, it should 
go into a dfl structure

The likely place it should go is fme_mgr_priv.

The need for 2 register functions here and in fpga-region is caused by 
carrying this dfl data around in the wrong place.

Tom

>> there are two register functions, there should be one.
> I get what you are saying. I don't really like the idea of forcing the
> complexity of the temporary structure on all callers, since only a
> couple require it, but we can do that if that is the concensus.
>
> What do others think?
>
>> On 6/30/21 6:37 PM, Russ Weight wrote:
>>> The FPGA manager class driver data structure is being treated as a
>>> managed resource instead of using the standard dev_release call-back
>>> function to release the class data structure. This change removes
>>> the managed resource code for the freeing of the class data structure
>>> and combines the create() and register() functions into a single
>>> register() or register_simple() function.
>>>
>>> The register() function accepts an info data structure to provide
>>> flexibility in passing optional parameters. The register_simple()
>>> function supports the current parameter list for users that don't
>>> require the use of optional parameters.
>>>
>>> The devm_fpga_mgr_register() function is retained, and the
>>> devm_fpga_mgr_register_simple() function is added.
>>>
>>> Signed-off-by: Russ Weight <russell.h.weight@intel.com>
>>> Reviewed-by: Xu Yilun <yilun.xu@intel.com>
>>> ---
>>> v9:
>>>     - Cleaned up documentation for the FPGA Manager register functions
>>>     - Renamed fpga_mgr_register() to fpga_mgr_register_full()
>>>     - Renamed fpga_mgr_register_simple() to fpga_mgr_register()
>>>     - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full()
>>>     - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register()
>>> v8:
>>>     - Added reviewed-by tag.
>>>     - Updated Documentation/driver-api/fpga/fpga-mgr.rst documentation.
>>> v7:
>>>     - Update the commit message to describe the new parameters for the
>>>       *fpga_mgr_register() functions and to mention the
>>>       *fpga_mgr_register_simple() functions.
>>>     - Fix function prototypes in header file to rename dev to parent.
>>>     - Make use of the PTR_ERR_OR_ZERO() macro when possible.
>>>     - Some cleanup of comments.
>>>     - Update function defintions/prototypes to apply const to the new info
>>>       parameter.
>>> v6:
>>>     - Moved FPGA manager optional parameters out of the ops structure and
>>>       back into the FPGA manager structure.
>>>     - Changed fpga_mgr_register()/devm_fpga_mgr_register() parameters to
>>>       accept an info data structure to provide flexibility in passing optional
>>>       parameters.
>>>     - Added fpga_mgr_register_simple()/devm_fpga_mgr_register_simple()
>>>       functions to support current parameters for users that don't require
>>>       the use of optional parameters.
>>> v5:
>>>     - Rebased on top of recently accepted patches.
>>>     - Removed compat_id from the fpga_mgr_register() parameter list
>>>       and added it to the fpga_manager_ops structure. This also required
>>>       dynamically allocating the dfl-fme-ops structure in order to add
>>>       the appropriate compat_id.
>>> v4:
>>>     - Added the compat_id parameter to fpga_mgr_register() and
>>>       devm_fpga_mgr_register() to ensure that the compat_id is set before
>>>       the device_register() call.
>>> v3:
>>>     - Cleaned up comment header for fpga_mgr_register()
>>>     - Fix error return on ida_simple_get() failure
>>> v2:
>>>     - Restored devm_fpga_mgr_register() functionality, adapted for the combined
>>>       create/register functionality.
>>>     - All previous callers of devm_fpga_mgr_register() will continue to call
>>>       devm_fpga_mgr_register().
>>>     - replaced unnecessary ternary operators in return statements with standard
>>>       if conditions.
>>> ---
>>>    Documentation/driver-api/fpga/fpga-mgr.rst |  34 +++-
>>>    drivers/fpga/altera-cvp.c                  |  12 +-
>>>    drivers/fpga/altera-pr-ip-core.c           |   7 +-
>>>    drivers/fpga/altera-ps-spi.c               |   9 +-
>>>    drivers/fpga/dfl-fme-mgr.c                 |  22 +--
>>>    drivers/fpga/fpga-mgr.c                    | 215 +++++++++------------
>>>    drivers/fpga/ice40-spi.c                   |   9 +-
>>>    drivers/fpga/machxo2-spi.c                 |   9 +-
>>>    drivers/fpga/socfpga-a10.c                 |  16 +-
>>>    drivers/fpga/socfpga.c                     |   9 +-
>>>    drivers/fpga/stratix10-soc.c               |  16 +-
>>>    drivers/fpga/ts73xx-fpga.c                 |   9 +-
>>>    drivers/fpga/xilinx-spi.c                  |  11 +-
>>>    drivers/fpga/zynq-fpga.c                   |  16 +-
>>>    drivers/fpga/zynqmp-fpga.c                 |   9 +-
>>>    include/linux/fpga/fpga-mgr.h              |  62 ++++--
>>>    16 files changed, 210 insertions(+), 255 deletions(-)
>>>
>>> diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
>>> index 4d926b452cb3..826ed8dc9210 100644
>>> --- a/Documentation/driver-api/fpga/fpga-mgr.rst
>>> +++ b/Documentation/driver-api/fpga/fpga-mgr.rst
>>> @@ -24,7 +24,7 @@ How to support a new FPGA device
>>>    --------------------------------
>>>      To add another FPGA manager, write a driver that implements a set of ops.  The
>>> -probe function calls fpga_mgr_register(), such as::
>>> +probe function calls fpga_mgr_register() or fpga_mgr_register_full(), such as::
>>>          static const struct fpga_manager_ops socfpga_fpga_ops = {
>>>            .write_init = socfpga_fpga_ops_configure_init,
>>> @@ -49,14 +49,14 @@ probe function calls fpga_mgr_register(), such as::
>>>             * them in priv
>>>             */
>>>    -        mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
>>> -                       &socfpga_fpga_ops, priv);
>>> -        if (!mgr)
>>> -            return -ENOMEM;
>>> +        mgr = fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
>>> +                    &socfpga_fpga_ops, priv);
>>> +        if (IS_ERR(mgr))
>>> +            return PTR_ERR(mgr);
>>>              platform_set_drvdata(pdev, mgr);
>>>    -        return fpga_mgr_register(mgr);
>>> +        return 0;
>>>        }
>>>          static int socfpga_fpga_remove(struct platform_device *pdev)
>>> @@ -68,6 +68,11 @@ probe function calls fpga_mgr_register(), such as::
>>>            return 0;
>>>        }
>>>    +Alternatively, the probe function could call one of the resource managed
>>> +register functions, devm_fpga_mgr_register() or devm_fpga_mgr_register_full().
>>> +When these functions are used, the parameter syntax is the same, but the call
>>> +to fpga_mgr_unregister() should be removed. In the above example, the
>>> +socfpga_fpga_remove() function would not be required.
>>>      The ops will implement whatever device specific register writes are needed to
>>>    do the programming sequence for this particular FPGA.  These ops return 0 for
>>> @@ -104,8 +109,13 @@ API for implementing a new FPGA Manager driver
>>>    * ``fpga_mgr_states`` -  Values for :c:expr:`fpga_manager->state`.
>>>    * struct fpga_manager -  the FPGA manager struct
>>>    * struct fpga_manager_ops -  Low level FPGA manager driver ops
>>> -* devm_fpga_mgr_create() -  Allocate and init a manager struct
>>> -* fpga_mgr_register() -  Register an FPGA manager
>>> +* fpga_mgr_register_full() -  Create and register an FPGA manager using the
>>> +  fpga_mgr_info structure to provide the full flexibility of options
>>> +* fpga_mgr_register() -  Create and register an FPGA manager using standard
>>> +  arguments
>>> +* devm_fpga_mgr_register_full() -  Resource managed version of
>>> +  fpga_mgr_register_full()
>>> +* devm_fpga_mgr_register() -  Resource managed version of fpga_mgr_register()
>>>    * fpga_mgr_unregister() -  Unregister an FPGA manager
>>>      .. kernel-doc:: include/linux/fpga/fpga-mgr.h
>>> @@ -118,10 +128,16 @@ API for implementing a new FPGA Manager driver
>>>       :functions: fpga_manager_ops
>>>      .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>> -   :functions: devm_fpga_mgr_create
>>> +   :functions: fpga_mgr_register_full
>>>      .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>>       :functions: fpga_mgr_register
>>>    +.. kernel-doc:: drivers/fpga/fpga-mgr.c
>>> +   :functions: devm_fpga_mgr_register_full
>>> +
>>> +.. kernel-doc:: drivers/fpga/fpga-mgr.c
>>> +   :functions: devm_fpga_mgr_register
>>> +
>>>    .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>>       :functions: fpga_mgr_unregister
>>> diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
>>> index ccf4546eff29..4ffb9da537d8 100644
>>> --- a/drivers/fpga/altera-cvp.c
>>> +++ b/drivers/fpga/altera-cvp.c
>>> @@ -652,19 +652,15 @@ static int altera_cvp_probe(struct pci_dev *pdev,
>>>        snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
>>>             ALTERA_CVP_MGR_NAME, pci_name(pdev));
>>>    -    mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
>>> -                   &altera_cvp_ops, conf);
>>> -    if (!mgr) {
>>> -        ret = -ENOMEM;
>>> +    mgr = fpga_mgr_register(&pdev->dev, conf->mgr_name,
>>> +                &altera_cvp_ops, conf);
>>> +    if (IS_ERR(mgr)) {
>>> +        ret = PTR_ERR(mgr);
>>>            goto err_unmap;
>>>        }
>>>          pci_set_drvdata(pdev, mgr);
>>>    -    ret = fpga_mgr_register(mgr);
>>> -    if (ret)
>>> -        goto err_unmap;
>>> -
>>>        return 0;
>>>      err_unmap:
>>> diff --git a/drivers/fpga/altera-pr-ip-core.c b/drivers/fpga/altera-pr-ip-core.c
>>> index dfdf21ed34c4..be0667968d33 100644
>>> --- a/drivers/fpga/altera-pr-ip-core.c
>>> +++ b/drivers/fpga/altera-pr-ip-core.c
>>> @@ -191,11 +191,8 @@ int alt_pr_register(struct device *dev, void __iomem *reg_base)
>>>            (val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
>>>            (int)(val & ALT_PR_CSR_PR_START));
>>>    -    mgr = devm_fpga_mgr_create(dev, dev_name(dev), &alt_pr_ops, priv);
>>> -    if (!mgr)
>>> -        return -ENOMEM;
>>> -
>>> -    return devm_fpga_mgr_register(dev, mgr);
>>> +    mgr = devm_fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv);
>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>    }
>>>    EXPORT_SYMBOL_GPL(alt_pr_register);
>>>    diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
>>> index 23bfd4d1ad0f..5e1e009dba89 100644
>>> --- a/drivers/fpga/altera-ps-spi.c
>>> +++ b/drivers/fpga/altera-ps-spi.c
>>> @@ -302,12 +302,9 @@ static int altera_ps_probe(struct spi_device *spi)
>>>        snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s",
>>>             dev_driver_string(&spi->dev), dev_name(&spi->dev));
>>>    -    mgr = devm_fpga_mgr_create(&spi->dev, conf->mgr_name,
>>> -                   &altera_ps_ops, conf);
>>> -    if (!mgr)
>>> -        return -ENOMEM;
>>> -
>>> -    return devm_fpga_mgr_register(&spi->dev, mgr);
>>> +    mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name,
>>> +                     &altera_ps_ops, conf);
>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>    }
>>>      static const struct spi_device_id altera_ps_spi_ids[] = {
>>> diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
>>> index d5861d13b306..620e7874ab53 100644
>>> --- a/drivers/fpga/dfl-fme-mgr.c
>>> +++ b/drivers/fpga/dfl-fme-mgr.c
>>> @@ -282,7 +282,7 @@ static void fme_mgr_get_compat_id(void __iomem *fme_pr,
>>>    static int fme_mgr_probe(struct platform_device *pdev)
>>>    {
>>>        struct dfl_fme_mgr_pdata *pdata = dev_get_platdata(&pdev->dev);
>>> -    struct fpga_compat_id *compat_id;
>>> +    struct fpga_manager_info info = { 0 };
>>>        struct device *dev = &pdev->dev;
>>>        struct fme_mgr_priv *priv;
>>>        struct fpga_manager *mgr;
>>> @@ -302,20 +302,16 @@ static int fme_mgr_probe(struct platform_device *pdev)
>>>                return PTR_ERR(priv->ioaddr);
>>>        }
>>>    -    compat_id = devm_kzalloc(dev, sizeof(*compat_id), GFP_KERNEL);
>>> -    if (!compat_id)
>>> +    info.name = "DFL FME FPGA Manager";
>>> +    info.mops = &fme_mgr_ops;
>>> +    info.priv = priv;
>>> +    info.compat_id = devm_kzalloc(dev, sizeof(*info.compat_id), GFP_KERNEL);
>>> +    if (!info.compat_id)
>>>            return -ENOMEM;
>> could we limp along instead of failing ?
> The compat_id is used to verify compatibility between the static region and
> the partial reconfiguration. If there is insufficient memory for the small
> data structure, I think it is best to fail here. This is also consistent
> current implementation.
>   
>>>    -    fme_mgr_get_compat_id(priv->ioaddr, compat_id);
>>> -
>>> -    mgr = devm_fpga_mgr_create(dev, "DFL FME FPGA Manager",
>>> -                   &fme_mgr_ops, priv);
>>> -    if (!mgr)
>>> -        return -ENOMEM;
>>> -
>>> -    mgr->compat_id = compat_id;
>>> -
>>> -    return devm_fpga_mgr_register(dev, mgr);
>>> +    fme_mgr_get_compat_id(priv->ioaddr, info.compat_id);
>>> +    mgr = devm_fpga_mgr_register_full(dev, &info);
>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>    }
>>>      static struct platform_driver fme_mgr_driver = {
>>> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
>>> index ecb4c3c795fa..5a913aa649fd 100644
>>> --- a/drivers/fpga/fpga-mgr.c
>>> +++ b/drivers/fpga/fpga-mgr.c
>>> @@ -550,21 +550,19 @@ void fpga_mgr_unlock(struct fpga_manager *mgr)
>>>    EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
>>>      /**
>>> - * fpga_mgr_create - create and initialize an FPGA manager struct
>>> + * fpga_mgr_register_full - create and register an FPGA Manager device
>>>     * @parent:    fpga manager device from pdev
>>> - * @name:    fpga manager name
>>> - * @mops:    pointer to structure of fpga manager ops
>>> - * @priv:    fpga manager private data
>>> + * @info:    parameters for fpga manager
>>>     *
>>> - * The caller of this function is responsible for freeing the struct with
>>> - * fpga_mgr_free().  Using devm_fpga_mgr_create() instead is recommended.
>>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
>>> + * Using devm_fpga_mgr_register_full() instead is recommended.
>>>     *
>>> - * Return: pointer to struct fpga_manager or NULL
>>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>>>     */
>>> -struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>> -                     const struct fpga_manager_ops *mops,
>>> -                     void *priv)
>>> +struct fpga_manager *
>>> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>>>    {
>>> +    const struct fpga_manager_ops *mops = info->mops;
>>>        struct fpga_manager *mgr;
>>>        int id, ret;
>>>    @@ -572,29 +570,31 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>>            !mops->write_init || (!mops->write && !mops->write_sg) ||
>>>            (mops->write && mops->write_sg)) {
>>>            dev_err(parent, "Attempt to register without fpga_manager_ops\n");
>>> -        return NULL;
>>> +        return ERR_PTR(-EINVAL);
>>>        }
>>>    -    if (!name || !strlen(name)) {
>>> +    if (!info->name || !strlen(info->name)) {
>>>            dev_err(parent, "Attempt to register with no name!\n");
>>> -        return NULL;
>>> +        return ERR_PTR(-EINVAL);
>>>        }
>>>          mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
>>>        if (!mgr)
>>> -        return NULL;
>>> +        return ERR_PTR(-ENOMEM);
>>>          id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
>>> -    if (id < 0)
>>> +    if (id < 0) {
>>> +        ret = id;
>>>            goto error_kfree;
>>> +    }
>>>          mutex_init(&mgr->ref_mutex);
>>>    -    mgr->name = name;
>>> -    mgr->mops = mops;
>>> -    mgr->priv = priv;
>>> +    mgr->name = info->name;
>>> +    mgr->mops = info->mops;
>>> +    mgr->priv = info->priv;
>>> +    mgr->compat_id = info->compat_id;
>>>    -    device_initialize(&mgr->dev);
>>>        mgr->dev.class = fpga_mgr_class;
>>>        mgr->dev.groups = mops->groups;
>>>        mgr->dev.parent = parent;
>>> @@ -605,6 +605,19 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>>        if (ret)
>>>            goto error_device;
>>>    +    /*
>>> +     * Initialize framework state by requesting low level driver read state
>>> +     * from device.  FPGA may be in reset mode or may have been programmed
>>> +     * by bootloader or EEPROM.
>>> +     */
>>> +    mgr->state = mgr->mops->state(mgr);
>> This is existing code, but it seems wrong.
>>
>> A side effect of state() should not be to initialize.
>>
>> An init() should be added to mops
> I think this is just capturing the state of the underlying device an
> reflecting it in the fpga-manager state? Maybe someone else can comment
> on this. It seems outside the scope of these patches.
>
>>> +
>>> +    ret = device_register(&mgr->dev);
>>> +    if (ret) {
>>> +        put_device(&mgr->dev);
>>> +        return ERR_PTR(ret);
>>> +    }
>>> +
>>>        return mgr;
>>>      error_device:
>>> @@ -612,96 +625,36 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>>    error_kfree:
>>>        kfree(mgr);
>>>    -    return NULL;
>>> +    return ERR_PTR(ret);
>>>    }
>>> -EXPORT_SYMBOL_GPL(fpga_mgr_create);
>>> +EXPORT_SYMBOL_GPL(fpga_mgr_register_full);
>>>      /**
>>> - * fpga_mgr_free - free an FPGA manager created with fpga_mgr_create()
>>> - * @mgr:    fpga manager struct
>>> - */
>>> -void fpga_mgr_free(struct fpga_manager *mgr)
>>> -{
>>> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>>> -    kfree(mgr);
>>> -}
>>> -EXPORT_SYMBOL_GPL(fpga_mgr_free);
>>> -
>>> -static void devm_fpga_mgr_release(struct device *dev, void *res)
>>> -{
>>> -    struct fpga_mgr_devres *dr = res;
>>> -
>>> -    fpga_mgr_free(dr->mgr);
>>> -}
>>> -
>>> -/**
>>> - * devm_fpga_mgr_create - create and initialize a managed FPGA manager struct
>>> + * fpga_mgr_register - create and register an FPGA Manager device
>>>     * @parent:    fpga manager device from pdev
>>>     * @name:    fpga manager name
>>>     * @mops:    pointer to structure of fpga manager ops
>>>     * @priv:    fpga manager private data
>>>     *
>>> - * This function is intended for use in an FPGA manager driver's probe function.
>>> - * After the manager driver creates the manager struct with
>>> - * devm_fpga_mgr_create(), it should register it with fpga_mgr_register().  The
>>> - * manager driver's remove function should call fpga_mgr_unregister().  The
>>> - * manager struct allocated with this function will be freed automatically on
>>> - * driver detach.  This includes the case of a probe function returning error
>>> - * before calling fpga_mgr_register(), the struct will still get cleaned up.
>>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
>>> + * Using devm_fpga_mgr_register() instead is recommended. This simple
>>> + * version of the register function should be sufficient for most users. The
>>> + * fpga_mgr_register_full() function is available for users that need to pass
>>> + * additional, optional parameters.
>>>     *
>>> - * Return: pointer to struct fpga_manager or NULL
>>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>>>     */
>>> -struct fpga_manager *devm_fpga_mgr_create(struct device *parent, const char *name,
>>> -                      const struct fpga_manager_ops *mops,
>>> -                      void *priv)
>>> +struct fpga_manager *
>>> +fpga_mgr_register(struct device *parent, const char *name,
>>> +          const struct fpga_manager_ops *mops, void *priv)
>>>    {
>>> -    struct fpga_mgr_devres *dr;
>>> +    struct fpga_manager_info info = { 0 };
>>>    -    dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL);
>>> -    if (!dr)
>>> -        return NULL;
>>> +    info.name = name;
>>> +    info.mops = mops;
>>> +    info.priv = priv;
>>>    -    dr->mgr = fpga_mgr_create(parent, name, mops, priv);
>>> -    if (!dr->mgr) {
>>> -        devres_free(dr);
>>> -        return NULL;
>>> -    }
>>> -
>>> -    devres_add(parent, dr);
>>> -
>>> -    return dr->mgr;
>>> -}
>>> -EXPORT_SYMBOL_GPL(devm_fpga_mgr_create);
>>> -
>>> -/**
>>> - * fpga_mgr_register - register an FPGA manager
>>> - * @mgr: fpga manager struct
>>> - *
>>> - * Return: 0 on success, negative error code otherwise.
>>> - */
>>> -int fpga_mgr_register(struct fpga_manager *mgr)
>>> -{
>>> -    int ret;
>>> -
>>> -    /*
>>> -     * Initialize framework state by requesting low level driver read state
>>> -     * from device.  FPGA may be in reset mode or may have been programmed
>>> -     * by bootloader or EEPROM.
>>> -     */
>>> -    mgr->state = mgr->mops->state(mgr);
>>> -
>>> -    ret = device_add(&mgr->dev);
>>> -    if (ret)
>>> -        goto error_device;
>>> -
>>> -    dev_info(&mgr->dev, "%s registered\n", mgr->name);
>>> -
>>> -    return 0;
>>> -
>>> -error_device:
>>> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>>> -
>>> -    return ret;
>>> +    return fpga_mgr_register_full(parent, &info);
>>>    }
>>>    EXPORT_SYMBOL_GPL(fpga_mgr_register);
>>>    @@ -726,14 +679,6 @@ void fpga_mgr_unregister(struct fpga_manager *mgr)
>>>    }
>>>    EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
>>>    -static int fpga_mgr_devres_match(struct device *dev, void *res,
>>> -                 void *match_data)
>>> -{
>>> -    struct fpga_mgr_devres *dr = res;
>>> -
>>> -    return match_data == dr->mgr;
>>> -}
>>> -
>>>    static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>>>    {
>>>        struct fpga_mgr_devres *dr = res;
>>> @@ -742,45 +687,67 @@ static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>>>    }
>>>      /**
>>> - * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
>>> - * @dev: managing device for this FPGA manager
>>> - * @mgr: fpga manager struct
>>> + * devm_fpga_mgr_register_full - resource managed variant of fpga_mgr_register()
>>> + * @parent:    fpga manager device from pdev
>>> + * @info:    parameters for fpga manager
>>>     *
>>> - * This is the devres variant of fpga_mgr_register() for which the unregister
>>> + * This is the devres variant of fpga_mgr_register_full() for which the unregister
>>>     * function will be called automatically when the managing device is detached.
>>>     */
>>> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr)
>>> +struct fpga_manager *
>>> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>>>    {
>>>        struct fpga_mgr_devres *dr;
>>> -    int ret;
>>> -
>>> -    /*
>>> -     * Make sure that the struct fpga_manager * that is passed in is
>>> -     * managed itself.
>>> -     */
>>> -    if (WARN_ON(!devres_find(dev, devm_fpga_mgr_release,
>>> -                 fpga_mgr_devres_match, mgr)))
>>> -        return -EINVAL;
>>> +    struct fpga_manager *mgr;
>>>          dr = devres_alloc(devm_fpga_mgr_unregister, sizeof(*dr), GFP_KERNEL);
>>>        if (!dr)
>>> -        return -ENOMEM;
>>> +        return ERR_PTR(-ENOMEM);
>>>    -    ret = fpga_mgr_register(mgr);
>>> -    if (ret) {
>>> +    mgr = fpga_mgr_register_full(parent, info);
>>> +    if (IS_ERR(mgr)) {
>>>            devres_free(dr);
>>> -        return ret;
>>> +        return mgr;
>>>        }
>>>          dr->mgr = mgr;
>>> -    devres_add(dev, dr);
>>> +    devres_add(parent, dr);
>>>    -    return 0;
>>> +    return mgr;
>>> +}
>>> +EXPORT_SYMBOL_GPL(devm_fpga_mgr_register_full);
>>> +
>>> +/**
>>> + * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
>>> + * @parent:    fpga manager device from pdev
>>> + * @name:    fpga manager name
>>> + * @mops:    pointer to structure of fpga manager ops
>>> + * @priv:    fpga manager private data
>>> + *
>>> + * This is the devres variant of fpga_mgr_register() for which the
>>> + * unregister function will be called automatically when the managing
>>> + * device is detached.
>>> + */
>>> +struct fpga_manager *
>>> +devm_fpga_mgr_register(struct device *parent, const char *name,
>>> +               const struct fpga_manager_ops *mops, void *priv)
>>> +{
>>> +    struct fpga_manager_info info = { 0 };
>>> +
>>> +    info.name = name;
>>> +    info.mops = mops;
>>> +    info.priv = priv;
>>> +
>>> +    return devm_fpga_mgr_register_full(parent, &info);
>>>    }
>>>    EXPORT_SYMBOL_GPL(devm_fpga_mgr_register);
>>>      static void fpga_mgr_dev_release(struct device *dev)
>>>    {
>>> +    struct fpga_manager *mgr = to_fpga_manager(dev);
>>> +
>>> +    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>>> +    kfree(mgr);
>>>    }
>>>      static int __init fpga_mgr_class_init(void)
>>> diff --git a/drivers/fpga/ice40-spi.c b/drivers/fpga/ice40-spi.c
>>> index 69dec5af23c3..b7591912248f 100644
>>> --- a/drivers/fpga/ice40-spi.c
>>> +++ b/drivers/fpga/ice40-spi.c
>>> @@ -178,12 +178,9 @@ static int ice40_fpga_probe(struct spi_device *spi)
>>>            return ret;
>>>        }
>>>    -    mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
>>> -                   &ice40_fpga_ops, priv);
>>> -    if (!mgr)
>>> -        return -ENOMEM;
>>> -
>>> -    return devm_fpga_mgr_register(dev, mgr);
>>> +    mgr = devm_fpga_mgr_register(dev, "Lattice iCE40 FPGA Manager",
>>> +                     &ice40_fpga_ops, priv);
>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>    }
>>>      static const struct of_device_id ice40_fpga_of_match[] = {
>>> diff --git a/drivers/fpga/machxo2-spi.c b/drivers/fpga/machxo2-spi.c
>>> index 1afb41aa20d7..8469dfb5dd21 100644
>>> --- a/drivers/fpga/machxo2-spi.c
>>> +++ b/drivers/fpga/machxo2-spi.c
>>> @@ -366,12 +366,9 @@ static int machxo2_spi_probe(struct spi_device *spi)
>>>            return -EINVAL;
>>>        }
>>>    -    mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager",
>>> -                   &machxo2_ops, spi);
>>> -    if (!mgr)
>>> -        return -ENOMEM;
>>> -
>>> -    return devm_fpga_mgr_register(dev, mgr);
>>> +    mgr = devm_fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager",
>>> +                     &machxo2_ops, spi);
>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>    }
>>>      #ifdef CONFIG_OF
>>> diff --git a/drivers/fpga/socfpga-a10.c b/drivers/fpga/socfpga-a10.c
>>> index 573d88bdf730..ac8e89b8a5cc 100644
>>> --- a/drivers/fpga/socfpga-a10.c
>>> +++ b/drivers/fpga/socfpga-a10.c
>>> @@ -508,19 +508,15 @@ static int socfpga_a10_fpga_probe(struct platform_device *pdev)
>>>            return -EBUSY;
>>>        }
>>>    -    mgr = devm_fpga_mgr_create(dev, "SoCFPGA Arria10 FPGA Manager",
>>> -                   &socfpga_a10_fpga_mgr_ops, priv);
>>> -    if (!mgr)
>>> -        return -ENOMEM;
>>> -
>>> -    platform_set_drvdata(pdev, mgr);
>>> -
>>> -    ret = fpga_mgr_register(mgr);
>>> -    if (ret) {
>>> +    mgr = fpga_mgr_register(dev, "SoCFPGA Arria10 FPGA Manager",
>>> +                &socfpga_a10_fpga_mgr_ops, priv);
>>> +    if (IS_ERR(mgr)) {
>>>            clk_disable_unprepare(priv->clk);
>>> -        return ret;
>>> +        return PTR_ERR(mgr);
>>>        }
>>>    +    platform_set_drvdata(pdev, mgr);
>>> +
>>>        return 0;
>>>    }
>>>    diff --git a/drivers/fpga/socfpga.c b/drivers/fpga/socfpga.c
>>> index 1f467173fc1f..7e0741f99696 100644
>>> --- a/drivers/fpga/socfpga.c
>>> +++ b/drivers/fpga/socfpga.c
>>> @@ -571,12 +571,9 @@ static int socfpga_fpga_probe(struct platform_device *pdev)
>>>        if (ret)
>>>            return ret;
>>>    -    mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
>>> -                   &socfpga_fpga_ops, priv);
>>> -    if (!mgr)
>>> -        return -ENOMEM;
>>> -
>>> -    return devm_fpga_mgr_register(dev, mgr);
>>> +    mgr = devm_fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
>>> +                     &socfpga_fpga_ops, priv);
>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>    }
>>>      #ifdef CONFIG_OF
>>> diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
>>> index a2cea500f7cc..9155e888a133 100644
>>> --- a/drivers/fpga/stratix10-soc.c
>>> +++ b/drivers/fpga/stratix10-soc.c
>>> @@ -425,18 +425,11 @@ static int s10_probe(struct platform_device *pdev)
>>>          init_completion(&priv->status_return_completion);
>>>    -    mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
>>> -                  &s10_ops, priv);
>>> -    if (!mgr) {
>>> -        dev_err(dev, "unable to create FPGA manager\n");
>>> -        ret = -ENOMEM;
>>> -        goto probe_err;
>>> -    }
>>> -
>>> -    ret = fpga_mgr_register(mgr);
>>> -    if (ret) {
>>> +    mgr = fpga_mgr_register(dev, "Stratix10 SOC FPGA Manager",
>>> +                &s10_ops, priv);
>>> +    if (IS_ERR(mgr)) {
>>>            dev_err(dev, "unable to register FPGA manager\n");
>>> -        fpga_mgr_free(mgr);
>>> +        ret = PTR_ERR(mgr);
>>>            goto probe_err;
>>>        }
>>>    @@ -454,7 +447,6 @@ static int s10_remove(struct platform_device *pdev)
>>>        struct s10_priv *priv = mgr->priv;
>>>          fpga_mgr_unregister(mgr);
>>> -    fpga_mgr_free(mgr);
>>>        stratix10_svc_free_channel(priv->chan);
>>>          return 0;
>>> diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c
>>> index 101f016c6ed8..fd52de20ddb2 100644
>>> --- a/drivers/fpga/ts73xx-fpga.c
>>> +++ b/drivers/fpga/ts73xx-fpga.c
>>> @@ -122,12 +122,9 @@ static int ts73xx_fpga_probe(struct platform_device *pdev)
>>>        if (IS_ERR(priv->io_base))
>>>            return PTR_ERR(priv->io_base);
>>>    -    mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
>>> -                   &ts73xx_fpga_ops, priv);
>>> -    if (!mgr)
>>> -        return -ENOMEM;
>>> -
>>> -    return devm_fpga_mgr_register(kdev, mgr);
>>> +    mgr = devm_fpga_mgr_register(kdev, "TS-73xx FPGA Manager",
>>> +                     &ts73xx_fpga_ops, priv);
>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>    }
>>>      static struct platform_driver ts73xx_fpga_driver = {
>>> diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
>>> index fee4d0abf6bf..db23626f9ab2 100644
>>> --- a/drivers/fpga/xilinx-spi.c
>>> +++ b/drivers/fpga/xilinx-spi.c
>>> @@ -247,13 +247,10 @@ static int xilinx_spi_probe(struct spi_device *spi)
>>>            return dev_err_probe(&spi->dev, PTR_ERR(conf->done),
>>>                         "Failed to get DONE gpio\n");
>>>    -    mgr = devm_fpga_mgr_create(&spi->dev,
>>> -                   "Xilinx Slave Serial FPGA Manager",
>>> -                   &xilinx_spi_ops, conf);
>>> -    if (!mgr)
>>> -        return -ENOMEM;
>>> -
>>> -    return devm_fpga_mgr_register(&spi->dev, mgr);
>>> +    mgr = devm_fpga_mgr_register(&spi->dev,
>>> +                     "Xilinx Slave Serial FPGA Manager",
>>> +                     &xilinx_spi_ops, conf);
>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>    }
>>>      static const struct of_device_id xlnx_spi_of_match[] = {
>>> diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
>>> index 9b75bd4f93d8..426aa34c6a0d 100644
>>> --- a/drivers/fpga/zynq-fpga.c
>>> +++ b/drivers/fpga/zynq-fpga.c
>>> @@ -609,20 +609,16 @@ static int zynq_fpga_probe(struct platform_device *pdev)
>>>          clk_disable(priv->clk);
>>>    -    mgr = devm_fpga_mgr_create(dev, "Xilinx Zynq FPGA Manager",
>>> -                   &zynq_fpga_ops, priv);
>>> -    if (!mgr)
>>> -        return -ENOMEM;
>>> -
>>> -    platform_set_drvdata(pdev, mgr);
>>> -
>>> -    err = fpga_mgr_register(mgr);
>>> -    if (err) {
>>> +    mgr = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
>>> +                &zynq_fpga_ops, priv);
>>> +    if (IS_ERR(mgr)) {
>>>            dev_err(dev, "unable to register FPGA manager\n");
>>>            clk_unprepare(priv->clk);
>>> -        return err;
>>> +        return PTR_ERR(mgr);
>>>        }
>>>    +    platform_set_drvdata(pdev, mgr);
>>> +
>>>        return 0;
>>>    }
>>>    diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
>>> index 125743c9797f..975bdc4d0a65 100644
>>> --- a/drivers/fpga/zynqmp-fpga.c
>>> +++ b/drivers/fpga/zynqmp-fpga.c
>>> @@ -102,12 +102,9 @@ static int zynqmp_fpga_probe(struct platform_device *pdev)
>>>          priv->dev = dev;
>>>    -    mgr = devm_fpga_mgr_create(dev, "Xilinx ZynqMP FPGA Manager",
>>> -                   &zynqmp_fpga_ops, priv);
>>> -    if (!mgr)
>>> -        return -ENOMEM;
>>> -
>>> -    return devm_fpga_mgr_register(dev, mgr);
>>> +    mgr = devm_fpga_mgr_register(dev, "Xilinx ZynqMP FPGA Manager",
>>> +                     &zynqmp_fpga_ops, priv);
>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>    }
>>>      static const struct of_device_id zynqmp_fpga_of_match[] = {
>>> diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
>>> index 474c1f506307..ac3ddaf2903c 100644
>>> --- a/include/linux/fpga/fpga-mgr.h
>>> +++ b/include/linux/fpga/fpga-mgr.h
>>> @@ -105,6 +105,36 @@ struct fpga_image_info {
>>>    #endif
>>>    };
>>>    +/**
>>> + * struct fpga_compat_id - id for compatibility check
>>> + *
>>> + * @id_h: high 64bit of the compat_id
>>> + * @id_l: low 64bit of the compat_id
>>> + */
>>> +struct fpga_compat_id {
>>> +    u64 id_h;
>>> +    u64 id_l;
>>> +};
>>> +
>> There are two register functions are to handle this dfl only structure.
>>
>> This really needs to be moved fme_mgr_priv.
>>
>>> +/**
>>> + * struct fpga_manager_info - collection of parameters for an FPGA Manager
>>> + * @name: fpga manager name
>>> + * @compat_id: FPGA manager id for compatibility check.
>>> + * @mops: pointer to structure of fpga manager ops
>>> + * @priv: fpga manager private data
>>> + *
>>> + * fpga_manager_info contains parameters for the register function. These
>>> + * are separated into an info structure because they some are optional
>>> + * others could be added to in the future. The info structure facilitates
>>> + * maintaining a stable API.
>>> + */
>>> +struct fpga_manager_info {
>>> +    const char *name;
>>> +    struct fpga_compat_id *compat_id;
>>> +    const struct fpga_manager_ops *mops;
>>> +    void *priv;
>>> +};
>>> +
>>>    /**
>>>     * struct fpga_manager_ops - ops for low level fpga manager drivers
>>>     * @initial_header_size: Maximum number of bytes that should be passed into write_init
>>> @@ -143,17 +173,6 @@ struct fpga_manager_ops {
>>>    #define FPGA_MGR_STATUS_IP_PROTOCOL_ERR        BIT(3)
>>>    #define FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR    BIT(4)
>>>    -/**
>>> - * struct fpga_compat_id - id for compatibility check
>>> - *
>>> - * @id_h: high 64bit of the compat_id
>>> - * @id_l: low 64bit of the compat_id
>>> - */
>>> -struct fpga_compat_id {
>>> -    u64 id_h;
>>> -    u64 id_l;
>>> -};
>>> -
>>>    /**
>>>     * struct fpga_manager - fpga manager structure
>>>     * @name: name of low level fpga manager
>>> @@ -191,17 +210,18 @@ struct fpga_manager *fpga_mgr_get(struct device *dev);
>>>      void fpga_mgr_put(struct fpga_manager *mgr);
>>>    -struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name,
>>> -                     const struct fpga_manager_ops *mops,
>>> -                     void *priv);
>>> -void fpga_mgr_free(struct fpga_manager *mgr);
>> removing these should cause any oot driver to fail to load.
>>
>> so an oops is unlikely.
>>
>> I'm ok with with api change.
>>
>>> -int fpga_mgr_register(struct fpga_manager *mgr);
>>> -void fpga_mgr_unregister(struct fpga_manager *mgr);
>>> +struct fpga_manager *
>>> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
>>>    -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr);
>>> +struct fpga_manager *
>>> +fpga_mgr_register(struct device *parent, const char *name,
>>> +          const struct fpga_manager_ops *mops, void *priv);
>> having 2 ways to do the same thing is not great.
>>
>> this should be reduced down to 1.
>>
>> My preference is for the *info one as it's api will be durable.
> I would like to see if other's agree.
>
>> Tom
>>
>>> +void fpga_mgr_unregister(struct fpga_manager *mgr);
>>>    -struct fpga_manager *devm_fpga_mgr_create(struct device *dev, const char *name,
>>> -                      const struct fpga_manager_ops *mops,
>>> -                      void *priv);
>>> +struct fpga_manager *
>>> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
>>> +struct fpga_manager *
>>> +devm_fpga_mgr_register(struct device *parent, const char *name,
>>> +               const struct fpga_manager_ops *mops, void *priv);
>>>      #endif /*_LINUX_FPGA_MGR_H */


^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 2/3] fpga: bridge: Use standard dev_release for class driver
  2021-07-06 20:08   ` Tom Rix
@ 2021-07-06 22:53     ` Russ Weight
  0 siblings, 0 replies; 22+ messages in thread
From: Russ Weight @ 2021-07-06 22:53 UTC (permalink / raw)
  To: Tom Rix, mdf, linux-fpga
  Cc: lgoncalv, yilun.xu, hao.wu, matthew.gerlach, richard.gong



On 7/6/21 1:08 PM, Tom Rix wrote:
> Russ,
>
> Similar concern with 2 register functions as in fpga-mgr.
>
> But here it does not seen that any instance uses fpga_bridge_register_full directly.
>
> So it really isn't needed.

Sure - the fpga_bridge_register_full() is really not needed. I can delete that.

>
> However if fpga-mgr changes to having a single register(... *info), fpga-bridge should likewise.
>
> Peeking ahead, fpga-region looks similar.
>
> my preference for api stability is for have mgr,bridge and region to have the *register_full(... *info) as the only *register()
>
>
> On 6/30/21 6:37 PM, Russ Weight wrote:
>> The FPGA bridge class driver data structure is being treated as a
>> managed resource instead of using the standard dev_release call-back
>> function to release the class data structure. This change removes
>> the managed resource code and combines the create() and register()
>> functions into a single register() or register_simple() function.
>>
>> The register() function accepts an info data structure to provide
>> flexibility in passing optional parameters. The register_simple()
>> function supports the current parameter list for users that don't
>> require the use of optional parameters.
>>
>> Signed-off-by: Russ Weight <russell.h.weight@intel.com>
>> Reviewed-by: Xu Yilun <yilun.xu@intel.com>
>> ---
>> v9:
>>    - Cleaned up documentation for the FPGA Bridge register functions
>>    - Renamed fpga_bridge_register() to fpga_bridge_register_full()
>>    - Renamed fpga_bridge_register_simple() to fpga_bridge_register()
>> v8:
>>    - Added reviewed-by tag.
>>    - Updated Documentation/driver-api/fpga/fpga-bridge.rst documentation.
>> v7:
>>    - Update the commit message to describe the new parameters for the
>>      fpga_bridge_register() function and to mention the
>>      fpga_bridge_register_simple() function.
>>    - Fix function prototypes in header file to rename dev to parent.
>>    - Some cleanup of comments.
>>    - Update function defintions/prototypes to apply const to the new info
>>      parameter.
>>    - Verify that info->br_ops is non-null in register functions.
>> v6:
>>    - Changed fpga_bridge_register() parameters to accept an info data
>>      structure to provide flexibility in passing optional parameters.
>>    - Added fpga_bridge_register_simple() function to support current
>>      parameters for users that don't require the use of optional
>>      parameters.
>> v5:
>>    - Rebased on top of recently accepted patches.
>> v4:
>>    - Restore the previous format for the Return value in the comment header
>>      for fpga_bridge_register()
>> v3:
>>    - Cleaned up comment header for fpga_bridge_register()
>>    - Fix error return values for fpga_bridge_register()
>> v2:
>>    - No changes
>> ---
>>   Documentation/driver-api/fpga/fpga-bridge.rst |   8 +-
>>   drivers/fpga/altera-fpga2sdram.c              |  12 +-
>>   drivers/fpga/altera-freeze-bridge.c           |  10 +-
>>   drivers/fpga/altera-hps2fpga.c                |  12 +-
>>   drivers/fpga/dfl-fme-br.c                     |  10 +-
>>   drivers/fpga/fpga-bridge.c                    | 137 ++++++------------
>>   drivers/fpga/xilinx-pr-decoupler.c            |  17 +--
>>   include/linux/fpga/fpga-bridge.h              |  33 +++--
>>   8 files changed, 101 insertions(+), 138 deletions(-)
>>
>> diff --git a/Documentation/driver-api/fpga/fpga-bridge.rst b/Documentation/driver-api/fpga/fpga-bridge.rst
>> index 8d650b4e2ce6..38e3bac8e877 100644
>> --- a/Documentation/driver-api/fpga/fpga-bridge.rst
>> +++ b/Documentation/driver-api/fpga/fpga-bridge.rst
>> @@ -6,8 +6,10 @@ API to implement a new FPGA bridge
>>     * struct fpga_bridge - The FPGA Bridge structure
>>   * struct fpga_bridge_ops - Low level Bridge driver ops
>> -* devm_fpga_bridge_create() - Allocate and init a bridge struct
>> -* fpga_bridge_register() - Register a bridge
>> +* fpga_bridge_register_full() - Create and register a bridge using the
>> +  fpga_bridge_info structure to provide the full flexibility of options
> fpga_bridge_info (and fpga_mgr_info earlier) could be added to the kernel-doc:: list lower down

I wasn't sure if fpga_bridge_info needed to be document here since it is a
temporary data structure that is used only for passing argments. The data
that is passed ends up in the fpga_bridge data structure. I can add this
documentation if you think it is needed.

If we delete the fpga_bridge_register_full() function, then this temporary
structure goes away for the fpga_bridge.

>> +* fpga_bridge_register() - Create and register a bridge using standard
>> +  arguments
>>   * fpga_bridge_unregister() - Unregister a bridge
>>     .. kernel-doc:: include/linux/fpga/fpga-bridge.h
>> @@ -17,7 +19,7 @@ API to implement a new FPGA bridge
>>      :functions: fpga_bridge_ops
>>     .. kernel-doc:: drivers/fpga/fpga-bridge.c
>> -   :functions: devm_fpga_bridge_create
>> +   :functions: fpga_bridge_register_full
>>     .. kernel-doc:: drivers/fpga/fpga-bridge.c
>>      :functions: fpga_bridge_register
>> diff --git a/drivers/fpga/altera-fpga2sdram.c b/drivers/fpga/altera-fpga2sdram.c
>> index a78e49c63c64..66063507116b 100644
>> --- a/drivers/fpga/altera-fpga2sdram.c
>> +++ b/drivers/fpga/altera-fpga2sdram.c
>> @@ -121,17 +121,13 @@ static int alt_fpga_bridge_probe(struct platform_device *pdev)
>>       /* Get f2s bridge configuration saved in handoff register */
>>       regmap_read(sysmgr, SYSMGR_ISWGRP_HANDOFF3, &priv->mask);
>>   -    br = devm_fpga_bridge_create(dev, F2S_BRIDGE_NAME,
>> -                     &altera_fpga2sdram_br_ops, priv);
>> -    if (!br)
>> -        return -ENOMEM;
>> +    br = fpga_bridge_register(dev, F2S_BRIDGE_NAME,
>> +                  &altera_fpga2sdram_br_ops, priv);
>> +    if (IS_ERR(br))
>> +        return PTR_ERR(mgr);
>>         platform_set_drvdata(pdev, br);
>>   -    ret = fpga_bridge_register(br);
>> -    if (ret)
>> -        return ret;
>> -
>>       dev_info(dev, "driver initialized with handoff %08x\n", priv->mask);
>>         if (!of_property_read_u32(dev->of_node, "bridge-enable", &enable)) {
>> diff --git a/drivers/fpga/altera-freeze-bridge.c b/drivers/fpga/altera-freeze-bridge.c
>> index dd58c4aea92e..bfbfa43cd05b 100644
>> --- a/drivers/fpga/altera-freeze-bridge.c
>> +++ b/drivers/fpga/altera-freeze-bridge.c
>> @@ -244,14 +244,14 @@ static int altera_freeze_br_probe(struct platform_device *pdev)
>>         priv->base_addr = base_addr;
>>   -    br = devm_fpga_bridge_create(dev, FREEZE_BRIDGE_NAME,
>> -                     &altera_freeze_br_br_ops, priv);
>> -    if (!br)
>> -        return -ENOMEM;
>> +    br = fpga_bridge_register(dev, FREEZE_BRIDGE_NAME,
>> +                  &altera_freeze_br_br_ops, priv);
>> +    if (IS_ERR(br))
>> +        return PTR_ERR(br);
>>         platform_set_drvdata(pdev, br);
>>   -    return fpga_bridge_register(br);
>> +    return 0;
>>   }
>>     static int altera_freeze_br_remove(struct platform_device *pdev)
>> diff --git a/drivers/fpga/altera-hps2fpga.c b/drivers/fpga/altera-hps2fpga.c
>> index 77b95f251821..aa758426c22b 100644
>> --- a/drivers/fpga/altera-hps2fpga.c
>> +++ b/drivers/fpga/altera-hps2fpga.c
>> @@ -180,19 +180,15 @@ static int alt_fpga_bridge_probe(struct platform_device *pdev)
>>           }
>>       }
>>   -    br = devm_fpga_bridge_create(dev, priv->name,
>> -                     &altera_hps2fpga_br_ops, priv);
>> -    if (!br) {
>> -        ret = -ENOMEM;
>> +    br = fpga_bridge_register(dev, priv->name,
>> +                  &altera_hps2fpga_br_ops, priv);
>> +    if (IS_ERR(br)) {
>> +        ret = PTR_ERR(br);
>>           goto err;
>>       }
>>         platform_set_drvdata(pdev, br);
>>   -    ret = fpga_bridge_register(br);
>> -    if (ret)
>> -        goto err;
>> -
>>       return 0;
>>     err:
>> diff --git a/drivers/fpga/dfl-fme-br.c b/drivers/fpga/dfl-fme-br.c
>> index 3ff9f3a687ce..808d1f4d76df 100644
>> --- a/drivers/fpga/dfl-fme-br.c
>> +++ b/drivers/fpga/dfl-fme-br.c
>> @@ -68,14 +68,14 @@ static int fme_br_probe(struct platform_device *pdev)
>>         priv->pdata = dev_get_platdata(dev);
>>   -    br = devm_fpga_bridge_create(dev, "DFL FPGA FME Bridge",
>> -                     &fme_bridge_ops, priv);
>> -    if (!br)
>> -        return -ENOMEM;
>> +    br = fpga_bridge_register(dev, "DFL FPGA FME Bridge",
>> +                  &fme_bridge_ops, priv);
>> +    if (IS_ERR(br))
>> +        return PTR_ERR(br);
>>         platform_set_drvdata(pdev, br);
>>   -    return fpga_bridge_register(br);
>> +    return 0;
>>   }
>>     static int fme_br_remove(struct platform_device *pdev)
>> diff --git a/drivers/fpga/fpga-bridge.c b/drivers/fpga/fpga-bridge.c
>> index 798f55670646..e6d98be8531b 100644
>> --- a/drivers/fpga/fpga-bridge.c
>> +++ b/drivers/fpga/fpga-bridge.c
>> @@ -312,55 +312,63 @@ static struct attribute *fpga_bridge_attrs[] = {
>>   ATTRIBUTE_GROUPS(fpga_bridge);
>>     /**
>> - * fpga_bridge_create - create and initialize a struct fpga_bridge
>> + * fpga_bridge_register_full - create and register an FPGA Bridge device
>>    * @parent:    FPGA bridge device from pdev
>> - * @name:    FPGA bridge name
>> - * @br_ops:    pointer to structure of fpga bridge ops
>> - * @priv:    FPGA bridge private data
>> + * @info:    parameters for FPGA Bridge
>>    *
>> - * The caller of this function is responsible for freeing the bridge with
>> - * fpga_bridge_free().  Using devm_fpga_bridge_create() instead is recommended.
>> - *
>> - * Return: struct fpga_bridge or NULL
>> + * Return: struct fpga_bridge pointer or ERR_PTR()
>>    */
>> -struct fpga_bridge *fpga_bridge_create(struct device *parent, const char *name,
>> -                       const struct fpga_bridge_ops *br_ops,
>> -                       void *priv)
>> +struct fpga_bridge *
>> +fpga_bridge_register_full(struct device *parent,
>> +              const struct fpga_bridge_info *info)
>>   {
>>       struct fpga_bridge *bridge;
>>       int id, ret;
>>   -    if (!name || !strlen(name)) {
>> +    if (!info->br_ops) {
>> +        dev_err(parent, "Attempt to register without fpga_bridge_ops\n");
>> +        return ERR_PTR(-EINVAL);
>> +    }
>> +
>> +    if (!info->name || !strlen(info->name)) {
>>           dev_err(parent, "Attempt to register with no name!\n");
>> -        return NULL;
>> +        return ERR_PTR(-EINVAL);
>>       }
>>         bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
>>       if (!bridge)
>> -        return NULL;
>> +        return ERR_PTR(-ENOMEM);
>>         id = ida_simple_get(&fpga_bridge_ida, 0, 0, GFP_KERNEL);
>> -    if (id < 0)
>> +    if (id < 0) {
>> +        ret = id;
>>           goto error_kfree;
>> +    }
>>         mutex_init(&bridge->mutex);
>>       INIT_LIST_HEAD(&bridge->node);
>>   -    bridge->name = name;
>> -    bridge->br_ops = br_ops;
>> -    bridge->priv = priv;
>> +    bridge->name = info->name;
>> +    bridge->br_ops = info->br_ops;
>> +    bridge->priv = info->priv;
>>   -    device_initialize(&bridge->dev);
>> -    bridge->dev.groups = br_ops->groups;
>> +    bridge->dev.groups = info->br_ops->groups;
>>       bridge->dev.class = fpga_bridge_class;
>>       bridge->dev.parent = parent;
>>       bridge->dev.of_node = parent->of_node;
>>       bridge->dev.id = id;
>> +    of_platform_populate(bridge->dev.of_node, NULL, NULL, &bridge->dev);
>>         ret = dev_set_name(&bridge->dev, "br%d", id);
>>       if (ret)
>>           goto error_device;
>>   +    ret = device_register(&bridge->dev);
>> +    if (ret) {
>> +        put_device(&bridge->dev);
>> +        return ERR_PTR(ret);
>> +    }
>> +
>>       return bridge;
>>     error_device:
>> @@ -368,88 +376,35 @@ struct fpga_bridge *fpga_bridge_create(struct device *parent, const char *name,
>>   error_kfree:
>>       kfree(bridge);
>>   -    return NULL;
>> -}
>> -EXPORT_SYMBOL_GPL(fpga_bridge_create);
>> -
>> -/**
>> - * fpga_bridge_free - free an fpga bridge created by fpga_bridge_create()
>> - * @bridge:    FPGA bridge struct
>> - */
>> -void fpga_bridge_free(struct fpga_bridge *bridge)
>> -{
>> -    ida_simple_remove(&fpga_bridge_ida, bridge->dev.id);
>> -    kfree(bridge);
>> -}
>> -EXPORT_SYMBOL_GPL(fpga_bridge_free);
>> -
>> -static void devm_fpga_bridge_release(struct device *dev, void *res)
>> -{
>> -    struct fpga_bridge *bridge = *(struct fpga_bridge **)res;
>> -
>> -    fpga_bridge_free(bridge);
>> +    return ERR_PTR(ret);
>>   }
>> +EXPORT_SYMBOL_GPL(fpga_bridge_register_full);
>>     /**
>> - * devm_fpga_bridge_create - create and init a managed struct fpga_bridge
>> + * fpga_bridge_register - create and register an FPGA Bridge device
>>    * @parent:    FPGA bridge device from pdev
>>    * @name:    FPGA bridge name
>>    * @br_ops:    pointer to structure of fpga bridge ops
>>    * @priv:    FPGA bridge private data
>>    *
>> - * This function is intended for use in an FPGA bridge driver's probe function.
>> - * After the bridge driver creates the struct with devm_fpga_bridge_create(), it
>> - * should register the bridge with fpga_bridge_register().  The bridge driver's
>> - * remove function should call fpga_bridge_unregister().  The bridge struct
>> - * allocated with this function will be freed automatically on driver detach.
>> - * This includes the case of a probe function returning error before calling
>> - * fpga_bridge_register(), the struct will still get cleaned up.
>> + * This simple version of the register should be sufficient for most users.
>> + * The fpga_bridge_register_full() function is available for users that need to pass
>> + * additional, optional parameters.
>>    *
>> - *  Return: struct fpga_bridge or NULL
>> + * Return: struct fpga_bridge pointer or ERR_PTR()
>>    */
>> -struct fpga_bridge
>> -*devm_fpga_bridge_create(struct device *parent, const char *name,
>> -             const struct fpga_bridge_ops *br_ops, void *priv)
>> +struct fpga_bridge *
>> +fpga_bridge_register(struct device *parent, const char *name,
>> +             const struct fpga_bridge_ops *br_ops,
>> +             void *priv)
>>   {
>> -    struct fpga_bridge **ptr, *bridge;
>> -
>> -    ptr = devres_alloc(devm_fpga_bridge_release, sizeof(*ptr), GFP_KERNEL);
>> -    if (!ptr)
>> -        return NULL;
>> -
>> -    bridge = fpga_bridge_create(parent, name, br_ops, priv);
>> -    if (!bridge) {
>> -        devres_free(ptr);
>> -    } else {
>> -        *ptr = bridge;
>> -        devres_add(parent, ptr);
>> -    }
>> +    struct fpga_bridge_info info = { 0 };
>>   -    return bridge;
>> -}
>> -EXPORT_SYMBOL_GPL(devm_fpga_bridge_create);
>> +    info.name = name;
>> +    info.br_ops = br_ops;
>> +    info.priv = priv;
>>   -/**
>> - * fpga_bridge_register - register an FPGA bridge
>> - *
>> - * @bridge: FPGA bridge struct
>> - *
>> - * Return: 0 for success, error code otherwise.
>> - */
>> -int fpga_bridge_register(struct fpga_bridge *bridge)
>> -{
>> -    struct device *dev = &bridge->dev;
>> -    int ret;
>> -
>> -    ret = device_add(dev);
>> -    if (ret)
>> -        return ret;
>> -
>> -    of_platform_populate(dev->of_node, NULL, NULL, dev);
>> -
>> -    dev_info(dev->parent, "fpga bridge [%s] registered\n", bridge->name);
>> -
>> -    return 0;
>> +    return fpga_bridge_register_full(parent, &info);
>>   }
>>   EXPORT_SYMBOL_GPL(fpga_bridge_register);
>>   @@ -475,6 +430,10 @@ EXPORT_SYMBOL_GPL(fpga_bridge_unregister);
>>     static void fpga_bridge_dev_release(struct device *dev)
>>   {
>> +    struct fpga_bridge *bridge = to_fpga_bridge(dev);
>> +
>> +    ida_simple_remove(&fpga_bridge_ida, bridge->dev.id);
>> +    kfree(bridge);
>>   }
>>     static int __init fpga_bridge_dev_init(void)
>> diff --git a/drivers/fpga/xilinx-pr-decoupler.c b/drivers/fpga/xilinx-pr-decoupler.c
>> index ea2bde6e5bc4..c004e52b9464 100644
>> --- a/drivers/fpga/xilinx-pr-decoupler.c
>> +++ b/drivers/fpga/xilinx-pr-decoupler.c
>> @@ -138,22 +138,17 @@ static int xlnx_pr_decoupler_probe(struct platform_device *pdev)
>>         clk_disable(priv->clk);
>>   -    br = devm_fpga_bridge_create(&pdev->dev, priv->ipconfig->name,
>> -                     &xlnx_pr_decoupler_br_ops, priv);
>> -    if (!br) {
>> -        err = -ENOMEM;
>> -        goto err_clk;
>> -    }
>> -
>> -    platform_set_drvdata(pdev, br);
>> -
>> -    err = fpga_bridge_register(br);
>> -    if (err) {
>> +    br = fpga_bridge_register(&pdev->dev, priv->ipconfig->name,
>> +                  &xlnx_pr_decoupler_br_ops, priv);
>> +    if (IS_ERR(br)) {
>> +        err = PTR_ERR(br);
>>           dev_err(&pdev->dev, "unable to register %s",
>>               priv->ipconfig->name);
>>           goto err_clk;
>>       }
>>   +    platform_set_drvdata(pdev, br);
>> +
>>       return 0;
>>     err_clk:
>> diff --git a/include/linux/fpga/fpga-bridge.h b/include/linux/fpga/fpga-bridge.h
>> index 6c3c28806ff1..f0a4d99d9c8e 100644
>> --- a/include/linux/fpga/fpga-bridge.h
>> +++ b/include/linux/fpga/fpga-bridge.h
>> @@ -22,6 +22,23 @@ struct fpga_bridge_ops {
>>       const struct attribute_group **groups;
>
> This groups seems to be unused.
>
> If it is, maybe it should go into info.

Maybe - but that could be done as a separate patch, right? It is outside
the scope of what I'm trying to do.

- Russ
>
> Tom
>
>>   };
>>   +/**
>> + * struct fpga_bridge_info - collection of parameters an FPGA Bridge
>> + * @name: fpga bridge name
>> + * @br_ops: pointer to structure of fpga bridge ops
>> + * @priv: fpga bridge private data
>> + *
>> + * fpga_bridge_info contains parameters for the register function. These
>> + * are separated into an info structure because they some are optional
>> + * others could be added to in the future. The info structure facilitates
>> + * maintaining a stable API.
>> + */
>> +struct fpga_bridge_info {
>> +    const char *name;
>> +    const struct fpga_bridge_ops *br_ops;
>> +    void *priv;
>> +};
>> +
>>   /**
>>    * struct fpga_bridge - FPGA bridge structure
>>    * @name: name of low level FPGA bridge
>> @@ -62,15 +79,13 @@ int of_fpga_bridge_get_to_list(struct device_node *np,
>>                      struct fpga_image_info *info,
>>                      struct list_head *bridge_list);
>>   -struct fpga_bridge *fpga_bridge_create(struct device *dev, const char *name,
>> -                       const struct fpga_bridge_ops *br_ops,
>> -                       void *priv);
>> -void fpga_bridge_free(struct fpga_bridge *br);
>> -int fpga_bridge_register(struct fpga_bridge *br);
>> -void fpga_bridge_unregister(struct fpga_bridge *br);
>> +struct fpga_bridge *
>> +fpga_bridge_register_full(struct device *parent, const struct fpga_bridge_info *info);
>>   -struct fpga_bridge
>> -*devm_fpga_bridge_create(struct device *dev, const char *name,
>> -             const struct fpga_bridge_ops *br_ops, void *priv);
>> +struct fpga_bridge *
>> +fpga_bridge_register(struct device *parent, const char *name,
>> +             const struct fpga_bridge_ops *br_ops,
>> +             void *priv);
>> +void fpga_bridge_unregister(struct fpga_bridge *br);
>>     #endif /* _LINUX_FPGA_BRIDGE_H */
>


^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 1/3] fpga: mgr: Use standard dev_release for class driver
  2021-07-06 21:44       ` Tom Rix
@ 2021-07-06 23:03         ` Russ Weight
  2021-07-07  2:45           ` Xu Yilun
  2021-07-07 13:29           ` Tom Rix
  0 siblings, 2 replies; 22+ messages in thread
From: Russ Weight @ 2021-07-06 23:03 UTC (permalink / raw)
  To: Tom Rix, mdf, linux-fpga
  Cc: lgoncalv, yilun.xu, hao.wu, matthew.gerlach, richard.gong



On 7/6/21 2:44 PM, Tom Rix wrote:
>
> On 7/6/21 2:02 PM, Russ Weight wrote:
>>
>> On 7/6/21 12:04 PM, Tom Rix wrote:
>>> Russ,
>>>
>>> My two big concerns are.
>>>
>>> compat_id does not belong in fpga_mgr_info, it belongs in fme_mgr_priv.
>> fpga_mgr_info is a temporary structure on the stack that contains the
>> parameters only long enough to pass them in and have them added to the
>> fpga_manager structure. Do you have a concern about it being on the
>> fpga_manager structure.
>
> My concern is compat_id should never have been part of fpga-mgr in the first place.
>
> It is dfl specific, so instead of going in a common structure, it should go into a dfl structure
>
> The likely place it should go is fme_mgr_priv.
>
> The need for 2 register functions here and in fpga-region is caused by carrying this dfl data around in the wrong place.

This issue was raised for the previous patch version, and Hao pointed out that
its placement in the fpga_manager structure was a result of community discussion.

These changes aren't affecting the location of compat_id. Where it is
stored is not really within the scope of what I am trying to accomplish.
If it needs to be changed, could it be handled in a separate patch set?

- Russ

> Tom
>
>>> there are two register functions, there should be one.
>> I get what you are saying. I don't really like the idea of forcing the
>> complexity of the temporary structure on all callers, since only a
>> couple require it, but we can do that if that is the concensus.
>>
>> What do others think?
>>
>>> On 6/30/21 6:37 PM, Russ Weight wrote:
>>>> The FPGA manager class driver data structure is being treated as a
>>>> managed resource instead of using the standard dev_release call-back
>>>> function to release the class data structure. This change removes
>>>> the managed resource code for the freeing of the class data structure
>>>> and combines the create() and register() functions into a single
>>>> register() or register_simple() function.
>>>>
>>>> The register() function accepts an info data structure to provide
>>>> flexibility in passing optional parameters. The register_simple()
>>>> function supports the current parameter list for users that don't
>>>> require the use of optional parameters.
>>>>
>>>> The devm_fpga_mgr_register() function is retained, and the
>>>> devm_fpga_mgr_register_simple() function is added.
>>>>
>>>> Signed-off-by: Russ Weight <russell.h.weight@intel.com>
>>>> Reviewed-by: Xu Yilun <yilun.xu@intel.com>
>>>> ---
>>>> v9:
>>>>     - Cleaned up documentation for the FPGA Manager register functions
>>>>     - Renamed fpga_mgr_register() to fpga_mgr_register_full()
>>>>     - Renamed fpga_mgr_register_simple() to fpga_mgr_register()
>>>>     - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full()
>>>>     - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register()
>>>> v8:
>>>>     - Added reviewed-by tag.
>>>>     - Updated Documentation/driver-api/fpga/fpga-mgr.rst documentation.
>>>> v7:
>>>>     - Update the commit message to describe the new parameters for the
>>>>       *fpga_mgr_register() functions and to mention the
>>>>       *fpga_mgr_register_simple() functions.
>>>>     - Fix function prototypes in header file to rename dev to parent.
>>>>     - Make use of the PTR_ERR_OR_ZERO() macro when possible.
>>>>     - Some cleanup of comments.
>>>>     - Update function defintions/prototypes to apply const to the new info
>>>>       parameter.
>>>> v6:
>>>>     - Moved FPGA manager optional parameters out of the ops structure and
>>>>       back into the FPGA manager structure.
>>>>     - Changed fpga_mgr_register()/devm_fpga_mgr_register() parameters to
>>>>       accept an info data structure to provide flexibility in passing optional
>>>>       parameters.
>>>>     - Added fpga_mgr_register_simple()/devm_fpga_mgr_register_simple()
>>>>       functions to support current parameters for users that don't require
>>>>       the use of optional parameters.
>>>> v5:
>>>>     - Rebased on top of recently accepted patches.
>>>>     - Removed compat_id from the fpga_mgr_register() parameter list
>>>>       and added it to the fpga_manager_ops structure. This also required
>>>>       dynamically allocating the dfl-fme-ops structure in order to add
>>>>       the appropriate compat_id.
>>>> v4:
>>>>     - Added the compat_id parameter to fpga_mgr_register() and
>>>>       devm_fpga_mgr_register() to ensure that the compat_id is set before
>>>>       the device_register() call.
>>>> v3:
>>>>     - Cleaned up comment header for fpga_mgr_register()
>>>>     - Fix error return on ida_simple_get() failure
>>>> v2:
>>>>     - Restored devm_fpga_mgr_register() functionality, adapted for the combined
>>>>       create/register functionality.
>>>>     - All previous callers of devm_fpga_mgr_register() will continue to call
>>>>       devm_fpga_mgr_register().
>>>>     - replaced unnecessary ternary operators in return statements with standard
>>>>       if conditions.
>>>> ---
>>>>    Documentation/driver-api/fpga/fpga-mgr.rst |  34 +++-
>>>>    drivers/fpga/altera-cvp.c                  |  12 +-
>>>>    drivers/fpga/altera-pr-ip-core.c           |   7 +-
>>>>    drivers/fpga/altera-ps-spi.c               |   9 +-
>>>>    drivers/fpga/dfl-fme-mgr.c                 |  22 +--
>>>>    drivers/fpga/fpga-mgr.c                    | 215 +++++++++------------
>>>>    drivers/fpga/ice40-spi.c                   |   9 +-
>>>>    drivers/fpga/machxo2-spi.c                 |   9 +-
>>>>    drivers/fpga/socfpga-a10.c                 |  16 +-
>>>>    drivers/fpga/socfpga.c                     |   9 +-
>>>>    drivers/fpga/stratix10-soc.c               |  16 +-
>>>>    drivers/fpga/ts73xx-fpga.c                 |   9 +-
>>>>    drivers/fpga/xilinx-spi.c                  |  11 +-
>>>>    drivers/fpga/zynq-fpga.c                   |  16 +-
>>>>    drivers/fpga/zynqmp-fpga.c                 |   9 +-
>>>>    include/linux/fpga/fpga-mgr.h              |  62 ++++--
>>>>    16 files changed, 210 insertions(+), 255 deletions(-)
>>>>
>>>> diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
>>>> index 4d926b452cb3..826ed8dc9210 100644
>>>> --- a/Documentation/driver-api/fpga/fpga-mgr.rst
>>>> +++ b/Documentation/driver-api/fpga/fpga-mgr.rst
>>>> @@ -24,7 +24,7 @@ How to support a new FPGA device
>>>>    --------------------------------
>>>>      To add another FPGA manager, write a driver that implements a set of ops.  The
>>>> -probe function calls fpga_mgr_register(), such as::
>>>> +probe function calls fpga_mgr_register() or fpga_mgr_register_full(), such as::
>>>>          static const struct fpga_manager_ops socfpga_fpga_ops = {
>>>>            .write_init = socfpga_fpga_ops_configure_init,
>>>> @@ -49,14 +49,14 @@ probe function calls fpga_mgr_register(), such as::
>>>>             * them in priv
>>>>             */
>>>>    -        mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
>>>> -                       &socfpga_fpga_ops, priv);
>>>> -        if (!mgr)
>>>> -            return -ENOMEM;
>>>> +        mgr = fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
>>>> +                    &socfpga_fpga_ops, priv);
>>>> +        if (IS_ERR(mgr))
>>>> +            return PTR_ERR(mgr);
>>>>              platform_set_drvdata(pdev, mgr);
>>>>    -        return fpga_mgr_register(mgr);
>>>> +        return 0;
>>>>        }
>>>>          static int socfpga_fpga_remove(struct platform_device *pdev)
>>>> @@ -68,6 +68,11 @@ probe function calls fpga_mgr_register(), such as::
>>>>            return 0;
>>>>        }
>>>>    +Alternatively, the probe function could call one of the resource managed
>>>> +register functions, devm_fpga_mgr_register() or devm_fpga_mgr_register_full().
>>>> +When these functions are used, the parameter syntax is the same, but the call
>>>> +to fpga_mgr_unregister() should be removed. In the above example, the
>>>> +socfpga_fpga_remove() function would not be required.
>>>>      The ops will implement whatever device specific register writes are needed to
>>>>    do the programming sequence for this particular FPGA.  These ops return 0 for
>>>> @@ -104,8 +109,13 @@ API for implementing a new FPGA Manager driver
>>>>    * ``fpga_mgr_states`` -  Values for :c:expr:`fpga_manager->state`.
>>>>    * struct fpga_manager -  the FPGA manager struct
>>>>    * struct fpga_manager_ops -  Low level FPGA manager driver ops
>>>> -* devm_fpga_mgr_create() -  Allocate and init a manager struct
>>>> -* fpga_mgr_register() -  Register an FPGA manager
>>>> +* fpga_mgr_register_full() -  Create and register an FPGA manager using the
>>>> +  fpga_mgr_info structure to provide the full flexibility of options
>>>> +* fpga_mgr_register() -  Create and register an FPGA manager using standard
>>>> +  arguments
>>>> +* devm_fpga_mgr_register_full() -  Resource managed version of
>>>> +  fpga_mgr_register_full()
>>>> +* devm_fpga_mgr_register() -  Resource managed version of fpga_mgr_register()
>>>>    * fpga_mgr_unregister() -  Unregister an FPGA manager
>>>>      .. kernel-doc:: include/linux/fpga/fpga-mgr.h
>>>> @@ -118,10 +128,16 @@ API for implementing a new FPGA Manager driver
>>>>       :functions: fpga_manager_ops
>>>>      .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>>> -   :functions: devm_fpga_mgr_create
>>>> +   :functions: fpga_mgr_register_full
>>>>      .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>>>       :functions: fpga_mgr_register
>>>>    +.. kernel-doc:: drivers/fpga/fpga-mgr.c
>>>> +   :functions: devm_fpga_mgr_register_full
>>>> +
>>>> +.. kernel-doc:: drivers/fpga/fpga-mgr.c
>>>> +   :functions: devm_fpga_mgr_register
>>>> +
>>>>    .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>>>       :functions: fpga_mgr_unregister
>>>> diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
>>>> index ccf4546eff29..4ffb9da537d8 100644
>>>> --- a/drivers/fpga/altera-cvp.c
>>>> +++ b/drivers/fpga/altera-cvp.c
>>>> @@ -652,19 +652,15 @@ static int altera_cvp_probe(struct pci_dev *pdev,
>>>>        snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
>>>>             ALTERA_CVP_MGR_NAME, pci_name(pdev));
>>>>    -    mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
>>>> -                   &altera_cvp_ops, conf);
>>>> -    if (!mgr) {
>>>> -        ret = -ENOMEM;
>>>> +    mgr = fpga_mgr_register(&pdev->dev, conf->mgr_name,
>>>> +                &altera_cvp_ops, conf);
>>>> +    if (IS_ERR(mgr)) {
>>>> +        ret = PTR_ERR(mgr);
>>>>            goto err_unmap;
>>>>        }
>>>>          pci_set_drvdata(pdev, mgr);
>>>>    -    ret = fpga_mgr_register(mgr);
>>>> -    if (ret)
>>>> -        goto err_unmap;
>>>> -
>>>>        return 0;
>>>>      err_unmap:
>>>> diff --git a/drivers/fpga/altera-pr-ip-core.c b/drivers/fpga/altera-pr-ip-core.c
>>>> index dfdf21ed34c4..be0667968d33 100644
>>>> --- a/drivers/fpga/altera-pr-ip-core.c
>>>> +++ b/drivers/fpga/altera-pr-ip-core.c
>>>> @@ -191,11 +191,8 @@ int alt_pr_register(struct device *dev, void __iomem *reg_base)
>>>>            (val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
>>>>            (int)(val & ALT_PR_CSR_PR_START));
>>>>    -    mgr = devm_fpga_mgr_create(dev, dev_name(dev), &alt_pr_ops, priv);
>>>> -    if (!mgr)
>>>> -        return -ENOMEM;
>>>> -
>>>> -    return devm_fpga_mgr_register(dev, mgr);
>>>> +    mgr = devm_fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv);
>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>    }
>>>>    EXPORT_SYMBOL_GPL(alt_pr_register);
>>>>    diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
>>>> index 23bfd4d1ad0f..5e1e009dba89 100644
>>>> --- a/drivers/fpga/altera-ps-spi.c
>>>> +++ b/drivers/fpga/altera-ps-spi.c
>>>> @@ -302,12 +302,9 @@ static int altera_ps_probe(struct spi_device *spi)
>>>>        snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s",
>>>>             dev_driver_string(&spi->dev), dev_name(&spi->dev));
>>>>    -    mgr = devm_fpga_mgr_create(&spi->dev, conf->mgr_name,
>>>> -                   &altera_ps_ops, conf);
>>>> -    if (!mgr)
>>>> -        return -ENOMEM;
>>>> -
>>>> -    return devm_fpga_mgr_register(&spi->dev, mgr);
>>>> +    mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name,
>>>> +                     &altera_ps_ops, conf);
>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>    }
>>>>      static const struct spi_device_id altera_ps_spi_ids[] = {
>>>> diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
>>>> index d5861d13b306..620e7874ab53 100644
>>>> --- a/drivers/fpga/dfl-fme-mgr.c
>>>> +++ b/drivers/fpga/dfl-fme-mgr.c
>>>> @@ -282,7 +282,7 @@ static void fme_mgr_get_compat_id(void __iomem *fme_pr,
>>>>    static int fme_mgr_probe(struct platform_device *pdev)
>>>>    {
>>>>        struct dfl_fme_mgr_pdata *pdata = dev_get_platdata(&pdev->dev);
>>>> -    struct fpga_compat_id *compat_id;
>>>> +    struct fpga_manager_info info = { 0 };
>>>>        struct device *dev = &pdev->dev;
>>>>        struct fme_mgr_priv *priv;
>>>>        struct fpga_manager *mgr;
>>>> @@ -302,20 +302,16 @@ static int fme_mgr_probe(struct platform_device *pdev)
>>>>                return PTR_ERR(priv->ioaddr);
>>>>        }
>>>>    -    compat_id = devm_kzalloc(dev, sizeof(*compat_id), GFP_KERNEL);
>>>> -    if (!compat_id)
>>>> +    info.name = "DFL FME FPGA Manager";
>>>> +    info.mops = &fme_mgr_ops;
>>>> +    info.priv = priv;
>>>> +    info.compat_id = devm_kzalloc(dev, sizeof(*info.compat_id), GFP_KERNEL);
>>>> +    if (!info.compat_id)
>>>>            return -ENOMEM;
>>> could we limp along instead of failing ?
>> The compat_id is used to verify compatibility between the static region and
>> the partial reconfiguration. If there is insufficient memory for the small
>> data structure, I think it is best to fail here. This is also consistent
>> current implementation.
>>  
>>>>    -    fme_mgr_get_compat_id(priv->ioaddr, compat_id);
>>>> -
>>>> -    mgr = devm_fpga_mgr_create(dev, "DFL FME FPGA Manager",
>>>> -                   &fme_mgr_ops, priv);
>>>> -    if (!mgr)
>>>> -        return -ENOMEM;
>>>> -
>>>> -    mgr->compat_id = compat_id;
>>>> -
>>>> -    return devm_fpga_mgr_register(dev, mgr);
>>>> +    fme_mgr_get_compat_id(priv->ioaddr, info.compat_id);
>>>> +    mgr = devm_fpga_mgr_register_full(dev, &info);
>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>    }
>>>>      static struct platform_driver fme_mgr_driver = {
>>>> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
>>>> index ecb4c3c795fa..5a913aa649fd 100644
>>>> --- a/drivers/fpga/fpga-mgr.c
>>>> +++ b/drivers/fpga/fpga-mgr.c
>>>> @@ -550,21 +550,19 @@ void fpga_mgr_unlock(struct fpga_manager *mgr)
>>>>    EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
>>>>      /**
>>>> - * fpga_mgr_create - create and initialize an FPGA manager struct
>>>> + * fpga_mgr_register_full - create and register an FPGA Manager device
>>>>     * @parent:    fpga manager device from pdev
>>>> - * @name:    fpga manager name
>>>> - * @mops:    pointer to structure of fpga manager ops
>>>> - * @priv:    fpga manager private data
>>>> + * @info:    parameters for fpga manager
>>>>     *
>>>> - * The caller of this function is responsible for freeing the struct with
>>>> - * fpga_mgr_free().  Using devm_fpga_mgr_create() instead is recommended.
>>>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
>>>> + * Using devm_fpga_mgr_register_full() instead is recommended.
>>>>     *
>>>> - * Return: pointer to struct fpga_manager or NULL
>>>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>>>>     */
>>>> -struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>>> -                     const struct fpga_manager_ops *mops,
>>>> -                     void *priv)
>>>> +struct fpga_manager *
>>>> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>>>>    {
>>>> +    const struct fpga_manager_ops *mops = info->mops;
>>>>        struct fpga_manager *mgr;
>>>>        int id, ret;
>>>>    @@ -572,29 +570,31 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>>>            !mops->write_init || (!mops->write && !mops->write_sg) ||
>>>>            (mops->write && mops->write_sg)) {
>>>>            dev_err(parent, "Attempt to register without fpga_manager_ops\n");
>>>> -        return NULL;
>>>> +        return ERR_PTR(-EINVAL);
>>>>        }
>>>>    -    if (!name || !strlen(name)) {
>>>> +    if (!info->name || !strlen(info->name)) {
>>>>            dev_err(parent, "Attempt to register with no name!\n");
>>>> -        return NULL;
>>>> +        return ERR_PTR(-EINVAL);
>>>>        }
>>>>          mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
>>>>        if (!mgr)
>>>> -        return NULL;
>>>> +        return ERR_PTR(-ENOMEM);
>>>>          id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
>>>> -    if (id < 0)
>>>> +    if (id < 0) {
>>>> +        ret = id;
>>>>            goto error_kfree;
>>>> +    }
>>>>          mutex_init(&mgr->ref_mutex);
>>>>    -    mgr->name = name;
>>>> -    mgr->mops = mops;
>>>> -    mgr->priv = priv;
>>>> +    mgr->name = info->name;
>>>> +    mgr->mops = info->mops;
>>>> +    mgr->priv = info->priv;
>>>> +    mgr->compat_id = info->compat_id;
>>>>    -    device_initialize(&mgr->dev);
>>>>        mgr->dev.class = fpga_mgr_class;
>>>>        mgr->dev.groups = mops->groups;
>>>>        mgr->dev.parent = parent;
>>>> @@ -605,6 +605,19 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>>>        if (ret)
>>>>            goto error_device;
>>>>    +    /*
>>>> +     * Initialize framework state by requesting low level driver read state
>>>> +     * from device.  FPGA may be in reset mode or may have been programmed
>>>> +     * by bootloader or EEPROM.
>>>> +     */
>>>> +    mgr->state = mgr->mops->state(mgr);
>>> This is existing code, but it seems wrong.
>>>
>>> A side effect of state() should not be to initialize.
>>>
>>> An init() should be added to mops
>> I think this is just capturing the state of the underlying device an
>> reflecting it in the fpga-manager state? Maybe someone else can comment
>> on this. It seems outside the scope of these patches.
>>
>>>> +
>>>> +    ret = device_register(&mgr->dev);
>>>> +    if (ret) {
>>>> +        put_device(&mgr->dev);
>>>> +        return ERR_PTR(ret);
>>>> +    }
>>>> +
>>>>        return mgr;
>>>>      error_device:
>>>> @@ -612,96 +625,36 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>>>    error_kfree:
>>>>        kfree(mgr);
>>>>    -    return NULL;
>>>> +    return ERR_PTR(ret);
>>>>    }
>>>> -EXPORT_SYMBOL_GPL(fpga_mgr_create);
>>>> +EXPORT_SYMBOL_GPL(fpga_mgr_register_full);
>>>>      /**
>>>> - * fpga_mgr_free - free an FPGA manager created with fpga_mgr_create()
>>>> - * @mgr:    fpga manager struct
>>>> - */
>>>> -void fpga_mgr_free(struct fpga_manager *mgr)
>>>> -{
>>>> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>>>> -    kfree(mgr);
>>>> -}
>>>> -EXPORT_SYMBOL_GPL(fpga_mgr_free);
>>>> -
>>>> -static void devm_fpga_mgr_release(struct device *dev, void *res)
>>>> -{
>>>> -    struct fpga_mgr_devres *dr = res;
>>>> -
>>>> -    fpga_mgr_free(dr->mgr);
>>>> -}
>>>> -
>>>> -/**
>>>> - * devm_fpga_mgr_create - create and initialize a managed FPGA manager struct
>>>> + * fpga_mgr_register - create and register an FPGA Manager device
>>>>     * @parent:    fpga manager device from pdev
>>>>     * @name:    fpga manager name
>>>>     * @mops:    pointer to structure of fpga manager ops
>>>>     * @priv:    fpga manager private data
>>>>     *
>>>> - * This function is intended for use in an FPGA manager driver's probe function.
>>>> - * After the manager driver creates the manager struct with
>>>> - * devm_fpga_mgr_create(), it should register it with fpga_mgr_register().  The
>>>> - * manager driver's remove function should call fpga_mgr_unregister().  The
>>>> - * manager struct allocated with this function will be freed automatically on
>>>> - * driver detach.  This includes the case of a probe function returning error
>>>> - * before calling fpga_mgr_register(), the struct will still get cleaned up.
>>>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
>>>> + * Using devm_fpga_mgr_register() instead is recommended. This simple
>>>> + * version of the register function should be sufficient for most users. The
>>>> + * fpga_mgr_register_full() function is available for users that need to pass
>>>> + * additional, optional parameters.
>>>>     *
>>>> - * Return: pointer to struct fpga_manager or NULL
>>>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>>>>     */
>>>> -struct fpga_manager *devm_fpga_mgr_create(struct device *parent, const char *name,
>>>> -                      const struct fpga_manager_ops *mops,
>>>> -                      void *priv)
>>>> +struct fpga_manager *
>>>> +fpga_mgr_register(struct device *parent, const char *name,
>>>> +          const struct fpga_manager_ops *mops, void *priv)
>>>>    {
>>>> -    struct fpga_mgr_devres *dr;
>>>> +    struct fpga_manager_info info = { 0 };
>>>>    -    dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL);
>>>> -    if (!dr)
>>>> -        return NULL;
>>>> +    info.name = name;
>>>> +    info.mops = mops;
>>>> +    info.priv = priv;
>>>>    -    dr->mgr = fpga_mgr_create(parent, name, mops, priv);
>>>> -    if (!dr->mgr) {
>>>> -        devres_free(dr);
>>>> -        return NULL;
>>>> -    }
>>>> -
>>>> -    devres_add(parent, dr);
>>>> -
>>>> -    return dr->mgr;
>>>> -}
>>>> -EXPORT_SYMBOL_GPL(devm_fpga_mgr_create);
>>>> -
>>>> -/**
>>>> - * fpga_mgr_register - register an FPGA manager
>>>> - * @mgr: fpga manager struct
>>>> - *
>>>> - * Return: 0 on success, negative error code otherwise.
>>>> - */
>>>> -int fpga_mgr_register(struct fpga_manager *mgr)
>>>> -{
>>>> -    int ret;
>>>> -
>>>> -    /*
>>>> -     * Initialize framework state by requesting low level driver read state
>>>> -     * from device.  FPGA may be in reset mode or may have been programmed
>>>> -     * by bootloader or EEPROM.
>>>> -     */
>>>> -    mgr->state = mgr->mops->state(mgr);
>>>> -
>>>> -    ret = device_add(&mgr->dev);
>>>> -    if (ret)
>>>> -        goto error_device;
>>>> -
>>>> -    dev_info(&mgr->dev, "%s registered\n", mgr->name);
>>>> -
>>>> -    return 0;
>>>> -
>>>> -error_device:
>>>> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>>>> -
>>>> -    return ret;
>>>> +    return fpga_mgr_register_full(parent, &info);
>>>>    }
>>>>    EXPORT_SYMBOL_GPL(fpga_mgr_register);
>>>>    @@ -726,14 +679,6 @@ void fpga_mgr_unregister(struct fpga_manager *mgr)
>>>>    }
>>>>    EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
>>>>    -static int fpga_mgr_devres_match(struct device *dev, void *res,
>>>> -                 void *match_data)
>>>> -{
>>>> -    struct fpga_mgr_devres *dr = res;
>>>> -
>>>> -    return match_data == dr->mgr;
>>>> -}
>>>> -
>>>>    static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>>>>    {
>>>>        struct fpga_mgr_devres *dr = res;
>>>> @@ -742,45 +687,67 @@ static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>>>>    }
>>>>      /**
>>>> - * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
>>>> - * @dev: managing device for this FPGA manager
>>>> - * @mgr: fpga manager struct
>>>> + * devm_fpga_mgr_register_full - resource managed variant of fpga_mgr_register()
>>>> + * @parent:    fpga manager device from pdev
>>>> + * @info:    parameters for fpga manager
>>>>     *
>>>> - * This is the devres variant of fpga_mgr_register() for which the unregister
>>>> + * This is the devres variant of fpga_mgr_register_full() for which the unregister
>>>>     * function will be called automatically when the managing device is detached.
>>>>     */
>>>> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr)
>>>> +struct fpga_manager *
>>>> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>>>>    {
>>>>        struct fpga_mgr_devres *dr;
>>>> -    int ret;
>>>> -
>>>> -    /*
>>>> -     * Make sure that the struct fpga_manager * that is passed in is
>>>> -     * managed itself.
>>>> -     */
>>>> -    if (WARN_ON(!devres_find(dev, devm_fpga_mgr_release,
>>>> -                 fpga_mgr_devres_match, mgr)))
>>>> -        return -EINVAL;
>>>> +    struct fpga_manager *mgr;
>>>>          dr = devres_alloc(devm_fpga_mgr_unregister, sizeof(*dr), GFP_KERNEL);
>>>>        if (!dr)
>>>> -        return -ENOMEM;
>>>> +        return ERR_PTR(-ENOMEM);
>>>>    -    ret = fpga_mgr_register(mgr);
>>>> -    if (ret) {
>>>> +    mgr = fpga_mgr_register_full(parent, info);
>>>> +    if (IS_ERR(mgr)) {
>>>>            devres_free(dr);
>>>> -        return ret;
>>>> +        return mgr;
>>>>        }
>>>>          dr->mgr = mgr;
>>>> -    devres_add(dev, dr);
>>>> +    devres_add(parent, dr);
>>>>    -    return 0;
>>>> +    return mgr;
>>>> +}
>>>> +EXPORT_SYMBOL_GPL(devm_fpga_mgr_register_full);
>>>> +
>>>> +/**
>>>> + * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
>>>> + * @parent:    fpga manager device from pdev
>>>> + * @name:    fpga manager name
>>>> + * @mops:    pointer to structure of fpga manager ops
>>>> + * @priv:    fpga manager private data
>>>> + *
>>>> + * This is the devres variant of fpga_mgr_register() for which the
>>>> + * unregister function will be called automatically when the managing
>>>> + * device is detached.
>>>> + */
>>>> +struct fpga_manager *
>>>> +devm_fpga_mgr_register(struct device *parent, const char *name,
>>>> +               const struct fpga_manager_ops *mops, void *priv)
>>>> +{
>>>> +    struct fpga_manager_info info = { 0 };
>>>> +
>>>> +    info.name = name;
>>>> +    info.mops = mops;
>>>> +    info.priv = priv;
>>>> +
>>>> +    return devm_fpga_mgr_register_full(parent, &info);
>>>>    }
>>>>    EXPORT_SYMBOL_GPL(devm_fpga_mgr_register);
>>>>      static void fpga_mgr_dev_release(struct device *dev)
>>>>    {
>>>> +    struct fpga_manager *mgr = to_fpga_manager(dev);
>>>> +
>>>> +    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>>>> +    kfree(mgr);
>>>>    }
>>>>      static int __init fpga_mgr_class_init(void)
>>>> diff --git a/drivers/fpga/ice40-spi.c b/drivers/fpga/ice40-spi.c
>>>> index 69dec5af23c3..b7591912248f 100644
>>>> --- a/drivers/fpga/ice40-spi.c
>>>> +++ b/drivers/fpga/ice40-spi.c
>>>> @@ -178,12 +178,9 @@ static int ice40_fpga_probe(struct spi_device *spi)
>>>>            return ret;
>>>>        }
>>>>    -    mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
>>>> -                   &ice40_fpga_ops, priv);
>>>> -    if (!mgr)
>>>> -        return -ENOMEM;
>>>> -
>>>> -    return devm_fpga_mgr_register(dev, mgr);
>>>> +    mgr = devm_fpga_mgr_register(dev, "Lattice iCE40 FPGA Manager",
>>>> +                     &ice40_fpga_ops, priv);
>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>    }
>>>>      static const struct of_device_id ice40_fpga_of_match[] = {
>>>> diff --git a/drivers/fpga/machxo2-spi.c b/drivers/fpga/machxo2-spi.c
>>>> index 1afb41aa20d7..8469dfb5dd21 100644
>>>> --- a/drivers/fpga/machxo2-spi.c
>>>> +++ b/drivers/fpga/machxo2-spi.c
>>>> @@ -366,12 +366,9 @@ static int machxo2_spi_probe(struct spi_device *spi)
>>>>            return -EINVAL;
>>>>        }
>>>>    -    mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager",
>>>> -                   &machxo2_ops, spi);
>>>> -    if (!mgr)
>>>> -        return -ENOMEM;
>>>> -
>>>> -    return devm_fpga_mgr_register(dev, mgr);
>>>> +    mgr = devm_fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager",
>>>> +                     &machxo2_ops, spi);
>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>    }
>>>>      #ifdef CONFIG_OF
>>>> diff --git a/drivers/fpga/socfpga-a10.c b/drivers/fpga/socfpga-a10.c
>>>> index 573d88bdf730..ac8e89b8a5cc 100644
>>>> --- a/drivers/fpga/socfpga-a10.c
>>>> +++ b/drivers/fpga/socfpga-a10.c
>>>> @@ -508,19 +508,15 @@ static int socfpga_a10_fpga_probe(struct platform_device *pdev)
>>>>            return -EBUSY;
>>>>        }
>>>>    -    mgr = devm_fpga_mgr_create(dev, "SoCFPGA Arria10 FPGA Manager",
>>>> -                   &socfpga_a10_fpga_mgr_ops, priv);
>>>> -    if (!mgr)
>>>> -        return -ENOMEM;
>>>> -
>>>> -    platform_set_drvdata(pdev, mgr);
>>>> -
>>>> -    ret = fpga_mgr_register(mgr);
>>>> -    if (ret) {
>>>> +    mgr = fpga_mgr_register(dev, "SoCFPGA Arria10 FPGA Manager",
>>>> +                &socfpga_a10_fpga_mgr_ops, priv);
>>>> +    if (IS_ERR(mgr)) {
>>>>            clk_disable_unprepare(priv->clk);
>>>> -        return ret;
>>>> +        return PTR_ERR(mgr);
>>>>        }
>>>>    +    platform_set_drvdata(pdev, mgr);
>>>> +
>>>>        return 0;
>>>>    }
>>>>    diff --git a/drivers/fpga/socfpga.c b/drivers/fpga/socfpga.c
>>>> index 1f467173fc1f..7e0741f99696 100644
>>>> --- a/drivers/fpga/socfpga.c
>>>> +++ b/drivers/fpga/socfpga.c
>>>> @@ -571,12 +571,9 @@ static int socfpga_fpga_probe(struct platform_device *pdev)
>>>>        if (ret)
>>>>            return ret;
>>>>    -    mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
>>>> -                   &socfpga_fpga_ops, priv);
>>>> -    if (!mgr)
>>>> -        return -ENOMEM;
>>>> -
>>>> -    return devm_fpga_mgr_register(dev, mgr);
>>>> +    mgr = devm_fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
>>>> +                     &socfpga_fpga_ops, priv);
>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>    }
>>>>      #ifdef CONFIG_OF
>>>> diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
>>>> index a2cea500f7cc..9155e888a133 100644
>>>> --- a/drivers/fpga/stratix10-soc.c
>>>> +++ b/drivers/fpga/stratix10-soc.c
>>>> @@ -425,18 +425,11 @@ static int s10_probe(struct platform_device *pdev)
>>>>          init_completion(&priv->status_return_completion);
>>>>    -    mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
>>>> -                  &s10_ops, priv);
>>>> -    if (!mgr) {
>>>> -        dev_err(dev, "unable to create FPGA manager\n");
>>>> -        ret = -ENOMEM;
>>>> -        goto probe_err;
>>>> -    }
>>>> -
>>>> -    ret = fpga_mgr_register(mgr);
>>>> -    if (ret) {
>>>> +    mgr = fpga_mgr_register(dev, "Stratix10 SOC FPGA Manager",
>>>> +                &s10_ops, priv);
>>>> +    if (IS_ERR(mgr)) {
>>>>            dev_err(dev, "unable to register FPGA manager\n");
>>>> -        fpga_mgr_free(mgr);
>>>> +        ret = PTR_ERR(mgr);
>>>>            goto probe_err;
>>>>        }
>>>>    @@ -454,7 +447,6 @@ static int s10_remove(struct platform_device *pdev)
>>>>        struct s10_priv *priv = mgr->priv;
>>>>          fpga_mgr_unregister(mgr);
>>>> -    fpga_mgr_free(mgr);
>>>>        stratix10_svc_free_channel(priv->chan);
>>>>          return 0;
>>>> diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c
>>>> index 101f016c6ed8..fd52de20ddb2 100644
>>>> --- a/drivers/fpga/ts73xx-fpga.c
>>>> +++ b/drivers/fpga/ts73xx-fpga.c
>>>> @@ -122,12 +122,9 @@ static int ts73xx_fpga_probe(struct platform_device *pdev)
>>>>        if (IS_ERR(priv->io_base))
>>>>            return PTR_ERR(priv->io_base);
>>>>    -    mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
>>>> -                   &ts73xx_fpga_ops, priv);
>>>> -    if (!mgr)
>>>> -        return -ENOMEM;
>>>> -
>>>> -    return devm_fpga_mgr_register(kdev, mgr);
>>>> +    mgr = devm_fpga_mgr_register(kdev, "TS-73xx FPGA Manager",
>>>> +                     &ts73xx_fpga_ops, priv);
>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>    }
>>>>      static struct platform_driver ts73xx_fpga_driver = {
>>>> diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
>>>> index fee4d0abf6bf..db23626f9ab2 100644
>>>> --- a/drivers/fpga/xilinx-spi.c
>>>> +++ b/drivers/fpga/xilinx-spi.c
>>>> @@ -247,13 +247,10 @@ static int xilinx_spi_probe(struct spi_device *spi)
>>>>            return dev_err_probe(&spi->dev, PTR_ERR(conf->done),
>>>>                         "Failed to get DONE gpio\n");
>>>>    -    mgr = devm_fpga_mgr_create(&spi->dev,
>>>> -                   "Xilinx Slave Serial FPGA Manager",
>>>> -                   &xilinx_spi_ops, conf);
>>>> -    if (!mgr)
>>>> -        return -ENOMEM;
>>>> -
>>>> -    return devm_fpga_mgr_register(&spi->dev, mgr);
>>>> +    mgr = devm_fpga_mgr_register(&spi->dev,
>>>> +                     "Xilinx Slave Serial FPGA Manager",
>>>> +                     &xilinx_spi_ops, conf);
>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>    }
>>>>      static const struct of_device_id xlnx_spi_of_match[] = {
>>>> diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
>>>> index 9b75bd4f93d8..426aa34c6a0d 100644
>>>> --- a/drivers/fpga/zynq-fpga.c
>>>> +++ b/drivers/fpga/zynq-fpga.c
>>>> @@ -609,20 +609,16 @@ static int zynq_fpga_probe(struct platform_device *pdev)
>>>>          clk_disable(priv->clk);
>>>>    -    mgr = devm_fpga_mgr_create(dev, "Xilinx Zynq FPGA Manager",
>>>> -                   &zynq_fpga_ops, priv);
>>>> -    if (!mgr)
>>>> -        return -ENOMEM;
>>>> -
>>>> -    platform_set_drvdata(pdev, mgr);
>>>> -
>>>> -    err = fpga_mgr_register(mgr);
>>>> -    if (err) {
>>>> +    mgr = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
>>>> +                &zynq_fpga_ops, priv);
>>>> +    if (IS_ERR(mgr)) {
>>>>            dev_err(dev, "unable to register FPGA manager\n");
>>>>            clk_unprepare(priv->clk);
>>>> -        return err;
>>>> +        return PTR_ERR(mgr);
>>>>        }
>>>>    +    platform_set_drvdata(pdev, mgr);
>>>> +
>>>>        return 0;
>>>>    }
>>>>    diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
>>>> index 125743c9797f..975bdc4d0a65 100644
>>>> --- a/drivers/fpga/zynqmp-fpga.c
>>>> +++ b/drivers/fpga/zynqmp-fpga.c
>>>> @@ -102,12 +102,9 @@ static int zynqmp_fpga_probe(struct platform_device *pdev)
>>>>          priv->dev = dev;
>>>>    -    mgr = devm_fpga_mgr_create(dev, "Xilinx ZynqMP FPGA Manager",
>>>> -                   &zynqmp_fpga_ops, priv);
>>>> -    if (!mgr)
>>>> -        return -ENOMEM;
>>>> -
>>>> -    return devm_fpga_mgr_register(dev, mgr);
>>>> +    mgr = devm_fpga_mgr_register(dev, "Xilinx ZynqMP FPGA Manager",
>>>> +                     &zynqmp_fpga_ops, priv);
>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>    }
>>>>      static const struct of_device_id zynqmp_fpga_of_match[] = {
>>>> diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
>>>> index 474c1f506307..ac3ddaf2903c 100644
>>>> --- a/include/linux/fpga/fpga-mgr.h
>>>> +++ b/include/linux/fpga/fpga-mgr.h
>>>> @@ -105,6 +105,36 @@ struct fpga_image_info {
>>>>    #endif
>>>>    };
>>>>    +/**
>>>> + * struct fpga_compat_id - id for compatibility check
>>>> + *
>>>> + * @id_h: high 64bit of the compat_id
>>>> + * @id_l: low 64bit of the compat_id
>>>> + */
>>>> +struct fpga_compat_id {
>>>> +    u64 id_h;
>>>> +    u64 id_l;
>>>> +};
>>>> +
>>> There are two register functions are to handle this dfl only structure.
>>>
>>> This really needs to be moved fme_mgr_priv.
>>>
>>>> +/**
>>>> + * struct fpga_manager_info - collection of parameters for an FPGA Manager
>>>> + * @name: fpga manager name
>>>> + * @compat_id: FPGA manager id for compatibility check.
>>>> + * @mops: pointer to structure of fpga manager ops
>>>> + * @priv: fpga manager private data
>>>> + *
>>>> + * fpga_manager_info contains parameters for the register function. These
>>>> + * are separated into an info structure because they some are optional
>>>> + * others could be added to in the future. The info structure facilitates
>>>> + * maintaining a stable API.
>>>> + */
>>>> +struct fpga_manager_info {
>>>> +    const char *name;
>>>> +    struct fpga_compat_id *compat_id;
>>>> +    const struct fpga_manager_ops *mops;
>>>> +    void *priv;
>>>> +};
>>>> +
>>>>    /**
>>>>     * struct fpga_manager_ops - ops for low level fpga manager drivers
>>>>     * @initial_header_size: Maximum number of bytes that should be passed into write_init
>>>> @@ -143,17 +173,6 @@ struct fpga_manager_ops {
>>>>    #define FPGA_MGR_STATUS_IP_PROTOCOL_ERR        BIT(3)
>>>>    #define FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR    BIT(4)
>>>>    -/**
>>>> - * struct fpga_compat_id - id for compatibility check
>>>> - *
>>>> - * @id_h: high 64bit of the compat_id
>>>> - * @id_l: low 64bit of the compat_id
>>>> - */
>>>> -struct fpga_compat_id {
>>>> -    u64 id_h;
>>>> -    u64 id_l;
>>>> -};
>>>> -
>>>>    /**
>>>>     * struct fpga_manager - fpga manager structure
>>>>     * @name: name of low level fpga manager
>>>> @@ -191,17 +210,18 @@ struct fpga_manager *fpga_mgr_get(struct device *dev);
>>>>      void fpga_mgr_put(struct fpga_manager *mgr);
>>>>    -struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name,
>>>> -                     const struct fpga_manager_ops *mops,
>>>> -                     void *priv);
>>>> -void fpga_mgr_free(struct fpga_manager *mgr);
>>> removing these should cause any oot driver to fail to load.
>>>
>>> so an oops is unlikely.
>>>
>>> I'm ok with with api change.
>>>
>>>> -int fpga_mgr_register(struct fpga_manager *mgr);
>>>> -void fpga_mgr_unregister(struct fpga_manager *mgr);
>>>> +struct fpga_manager *
>>>> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
>>>>    -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr);
>>>> +struct fpga_manager *
>>>> +fpga_mgr_register(struct device *parent, const char *name,
>>>> +          const struct fpga_manager_ops *mops, void *priv);
>>> having 2 ways to do the same thing is not great.
>>>
>>> this should be reduced down to 1.
>>>
>>> My preference is for the *info one as it's api will be durable.
>> I would like to see if other's agree.
>>
>>> Tom
>>>
>>>> +void fpga_mgr_unregister(struct fpga_manager *mgr);
>>>>    -struct fpga_manager *devm_fpga_mgr_create(struct device *dev, const char *name,
>>>> -                      const struct fpga_manager_ops *mops,
>>>> -                      void *priv);
>>>> +struct fpga_manager *
>>>> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
>>>> +struct fpga_manager *
>>>> +devm_fpga_mgr_register(struct device *parent, const char *name,
>>>> +               const struct fpga_manager_ops *mops, void *priv);
>>>>      #endif /*_LINUX_FPGA_MGR_H */
>


^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 1/3] fpga: mgr: Use standard dev_release for class driver
  2021-07-01  5:25   ` Xu Yilun
@ 2021-07-06 23:06     ` Russ Weight
  0 siblings, 0 replies; 22+ messages in thread
From: Russ Weight @ 2021-07-06 23:06 UTC (permalink / raw)
  To: Xu Yilun
  Cc: mdf, linux-fpga, trix, lgoncalv, hao.wu, matthew.gerlach, richard.gong



On 6/30/21 10:25 PM, Xu Yilun wrote:
> On Wed, Jun 30, 2021 at 06:37:31PM -0700, Russ Weight wrote:
>> The FPGA manager class driver data structure is being treated as a
>> managed resource instead of using the standard dev_release call-back
>> function to release the class data structure. This change removes
>> the managed resource code for the freeing of the class data structure
>> and combines the create() and register() functions into a single
>> register() or register_simple() function.
>>
>> The register() function accepts an info data structure to provide
>> flexibility in passing optional parameters. The register_simple()
>> function supports the current parameter list for users that don't
>> require the use of optional parameters.
>>
>> The devm_fpga_mgr_register() function is retained, and the
>> devm_fpga_mgr_register_simple() function is added.
> The commit message is out of date.
>
> Others are good to me. Fix the typo and you can keep my Reviewed-by.
I thought I had fixed those... I'll take care of it.

- Russ
>
> Thanks,
> Yilun
>
>> Signed-off-by: Russ Weight <russell.h.weight@intel.com>
>> Reviewed-by: Xu Yilun <yilun.xu@intel.com>
>> ---
>> v9:
>>   - Cleaned up documentation for the FPGA Manager register functions
>>   - Renamed fpga_mgr_register() to fpga_mgr_register_full()
>>   - Renamed fpga_mgr_register_simple() to fpga_mgr_register()
>>   - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full()
>>   - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register()
>> v8:
>>   - Added reviewed-by tag.
>>   - Updated Documentation/driver-api/fpga/fpga-mgr.rst documentation.
>> v7:
>>   - Update the commit message to describe the new parameters for the
>>     *fpga_mgr_register() functions and to mention the
>>     *fpga_mgr_register_simple() functions.
>>   - Fix function prototypes in header file to rename dev to parent.
>>   - Make use of the PTR_ERR_OR_ZERO() macro when possible.
>>   - Some cleanup of comments.
>>   - Update function defintions/prototypes to apply const to the new info
>>     parameter.
>> v6:
>>   - Moved FPGA manager optional parameters out of the ops structure and
>>     back into the FPGA manager structure.
>>   - Changed fpga_mgr_register()/devm_fpga_mgr_register() parameters to
>>     accept an info data structure to provide flexibility in passing optional
>>     parameters.
>>   - Added fpga_mgr_register_simple()/devm_fpga_mgr_register_simple()
>>     functions to support current parameters for users that don't require
>>     the use of optional parameters.
>> v5:
>>   - Rebased on top of recently accepted patches.
>>   - Removed compat_id from the fpga_mgr_register() parameter list
>>     and added it to the fpga_manager_ops structure. This also required
>>     dynamically allocating the dfl-fme-ops structure in order to add
>>     the appropriate compat_id.
>> v4:
>>   - Added the compat_id parameter to fpga_mgr_register() and
>>     devm_fpga_mgr_register() to ensure that the compat_id is set before
>>     the device_register() call.
>> v3:
>>   - Cleaned up comment header for fpga_mgr_register()
>>   - Fix error return on ida_simple_get() failure
>> v2:
>>   - Restored devm_fpga_mgr_register() functionality, adapted for the combined
>>     create/register functionality.
>>   - All previous callers of devm_fpga_mgr_register() will continue to call
>>     devm_fpga_mgr_register().
>>   - replaced unnecessary ternary operators in return statements with standard
>>     if conditions.
>> ---
>>  Documentation/driver-api/fpga/fpga-mgr.rst |  34 +++-
>>  drivers/fpga/altera-cvp.c                  |  12 +-
>>  drivers/fpga/altera-pr-ip-core.c           |   7 +-
>>  drivers/fpga/altera-ps-spi.c               |   9 +-
>>  drivers/fpga/dfl-fme-mgr.c                 |  22 +--
>>  drivers/fpga/fpga-mgr.c                    | 215 +++++++++------------
>>  drivers/fpga/ice40-spi.c                   |   9 +-
>>  drivers/fpga/machxo2-spi.c                 |   9 +-
>>  drivers/fpga/socfpga-a10.c                 |  16 +-
>>  drivers/fpga/socfpga.c                     |   9 +-
>>  drivers/fpga/stratix10-soc.c               |  16 +-
>>  drivers/fpga/ts73xx-fpga.c                 |   9 +-
>>  drivers/fpga/xilinx-spi.c                  |  11 +-
>>  drivers/fpga/zynq-fpga.c                   |  16 +-
>>  drivers/fpga/zynqmp-fpga.c                 |   9 +-
>>  include/linux/fpga/fpga-mgr.h              |  62 ++++--
>>  16 files changed, 210 insertions(+), 255 deletions(-)
>>
>> diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
>> index 4d926b452cb3..826ed8dc9210 100644
>> --- a/Documentation/driver-api/fpga/fpga-mgr.rst
>> +++ b/Documentation/driver-api/fpga/fpga-mgr.rst
>> @@ -24,7 +24,7 @@ How to support a new FPGA device
>>  --------------------------------
>>  
>>  To add another FPGA manager, write a driver that implements a set of ops.  The
>> -probe function calls fpga_mgr_register(), such as::
>> +probe function calls fpga_mgr_register() or fpga_mgr_register_full(), such as::
>>  
>>  	static const struct fpga_manager_ops socfpga_fpga_ops = {
>>  		.write_init = socfpga_fpga_ops_configure_init,
>> @@ -49,14 +49,14 @@ probe function calls fpga_mgr_register(), such as::
>>  		 * them in priv
>>  		 */
>>  
>> -		mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
>> -					   &socfpga_fpga_ops, priv);
>> -		if (!mgr)
>> -			return -ENOMEM;
>> +		mgr = fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
>> +					&socfpga_fpga_ops, priv);
>> +		if (IS_ERR(mgr))
>> +			return PTR_ERR(mgr);
>>  
>>  		platform_set_drvdata(pdev, mgr);
>>  
>> -		return fpga_mgr_register(mgr);
>> +		return 0;
>>  	}
>>  
>>  	static int socfpga_fpga_remove(struct platform_device *pdev)
>> @@ -68,6 +68,11 @@ probe function calls fpga_mgr_register(), such as::
>>  		return 0;
>>  	}
>>  
>> +Alternatively, the probe function could call one of the resource managed
>> +register functions, devm_fpga_mgr_register() or devm_fpga_mgr_register_full().
>> +When these functions are used, the parameter syntax is the same, but the call
>> +to fpga_mgr_unregister() should be removed. In the above example, the
>> +socfpga_fpga_remove() function would not be required.
>>  
>>  The ops will implement whatever device specific register writes are needed to
>>  do the programming sequence for this particular FPGA.  These ops return 0 for
>> @@ -104,8 +109,13 @@ API for implementing a new FPGA Manager driver
>>  * ``fpga_mgr_states`` -  Values for :c:expr:`fpga_manager->state`.
>>  * struct fpga_manager -  the FPGA manager struct
>>  * struct fpga_manager_ops -  Low level FPGA manager driver ops
>> -* devm_fpga_mgr_create() -  Allocate and init a manager struct
>> -* fpga_mgr_register() -  Register an FPGA manager
>> +* fpga_mgr_register_full() -  Create and register an FPGA manager using the
>> +  fpga_mgr_info structure to provide the full flexibility of options
>> +* fpga_mgr_register() -  Create and register an FPGA manager using standard
>> +  arguments
>> +* devm_fpga_mgr_register_full() -  Resource managed version of
>> +  fpga_mgr_register_full()
>> +* devm_fpga_mgr_register() -  Resource managed version of fpga_mgr_register()
>>  * fpga_mgr_unregister() -  Unregister an FPGA manager
>>  
>>  .. kernel-doc:: include/linux/fpga/fpga-mgr.h
>> @@ -118,10 +128,16 @@ API for implementing a new FPGA Manager driver
>>     :functions: fpga_manager_ops
>>  
>>  .. kernel-doc:: drivers/fpga/fpga-mgr.c
>> -   :functions: devm_fpga_mgr_create
>> +   :functions: fpga_mgr_register_full
>>  
>>  .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>     :functions: fpga_mgr_register
>>  
>> +.. kernel-doc:: drivers/fpga/fpga-mgr.c
>> +   :functions: devm_fpga_mgr_register_full
>> +
>> +.. kernel-doc:: drivers/fpga/fpga-mgr.c
>> +   :functions: devm_fpga_mgr_register
>> +
>>  .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>     :functions: fpga_mgr_unregister
>> diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
>> index ccf4546eff29..4ffb9da537d8 100644
>> --- a/drivers/fpga/altera-cvp.c
>> +++ b/drivers/fpga/altera-cvp.c
>> @@ -652,19 +652,15 @@ static int altera_cvp_probe(struct pci_dev *pdev,
>>  	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
>>  		 ALTERA_CVP_MGR_NAME, pci_name(pdev));
>>  
>> -	mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
>> -				   &altera_cvp_ops, conf);
>> -	if (!mgr) {
>> -		ret = -ENOMEM;
>> +	mgr = fpga_mgr_register(&pdev->dev, conf->mgr_name,
>> +				&altera_cvp_ops, conf);
>> +	if (IS_ERR(mgr)) {
>> +		ret = PTR_ERR(mgr);
>>  		goto err_unmap;
>>  	}
>>  
>>  	pci_set_drvdata(pdev, mgr);
>>  
>> -	ret = fpga_mgr_register(mgr);
>> -	if (ret)
>> -		goto err_unmap;
>> -
>>  	return 0;
>>  
>>  err_unmap:
>> diff --git a/drivers/fpga/altera-pr-ip-core.c b/drivers/fpga/altera-pr-ip-core.c
>> index dfdf21ed34c4..be0667968d33 100644
>> --- a/drivers/fpga/altera-pr-ip-core.c
>> +++ b/drivers/fpga/altera-pr-ip-core.c
>> @@ -191,11 +191,8 @@ int alt_pr_register(struct device *dev, void __iomem *reg_base)
>>  		(val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
>>  		(int)(val & ALT_PR_CSR_PR_START));
>>  
>> -	mgr = devm_fpga_mgr_create(dev, dev_name(dev), &alt_pr_ops, priv);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> -
>> -	return devm_fpga_mgr_register(dev, mgr);
>> +	mgr = devm_fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv);
>> +	return PTR_ERR_OR_ZERO(mgr);
>>  }
>>  EXPORT_SYMBOL_GPL(alt_pr_register);
>>  
>> diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
>> index 23bfd4d1ad0f..5e1e009dba89 100644
>> --- a/drivers/fpga/altera-ps-spi.c
>> +++ b/drivers/fpga/altera-ps-spi.c
>> @@ -302,12 +302,9 @@ static int altera_ps_probe(struct spi_device *spi)
>>  	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s",
>>  		 dev_driver_string(&spi->dev), dev_name(&spi->dev));
>>  
>> -	mgr = devm_fpga_mgr_create(&spi->dev, conf->mgr_name,
>> -				   &altera_ps_ops, conf);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> -
>> -	return devm_fpga_mgr_register(&spi->dev, mgr);
>> +	mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name,
>> +				     &altera_ps_ops, conf);
>> +	return PTR_ERR_OR_ZERO(mgr);
>>  }
>>  
>>  static const struct spi_device_id altera_ps_spi_ids[] = {
>> diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
>> index d5861d13b306..620e7874ab53 100644
>> --- a/drivers/fpga/dfl-fme-mgr.c
>> +++ b/drivers/fpga/dfl-fme-mgr.c
>> @@ -282,7 +282,7 @@ static void fme_mgr_get_compat_id(void __iomem *fme_pr,
>>  static int fme_mgr_probe(struct platform_device *pdev)
>>  {
>>  	struct dfl_fme_mgr_pdata *pdata = dev_get_platdata(&pdev->dev);
>> -	struct fpga_compat_id *compat_id;
>> +	struct fpga_manager_info info = { 0 };
>>  	struct device *dev = &pdev->dev;
>>  	struct fme_mgr_priv *priv;
>>  	struct fpga_manager *mgr;
>> @@ -302,20 +302,16 @@ static int fme_mgr_probe(struct platform_device *pdev)
>>  			return PTR_ERR(priv->ioaddr);
>>  	}
>>  
>> -	compat_id = devm_kzalloc(dev, sizeof(*compat_id), GFP_KERNEL);
>> -	if (!compat_id)
>> +	info.name = "DFL FME FPGA Manager";
>> +	info.mops = &fme_mgr_ops;
>> +	info.priv = priv;
>> +	info.compat_id = devm_kzalloc(dev, sizeof(*info.compat_id), GFP_KERNEL);
>> +	if (!info.compat_id)
>>  		return -ENOMEM;
>>  
>> -	fme_mgr_get_compat_id(priv->ioaddr, compat_id);
>> -
>> -	mgr = devm_fpga_mgr_create(dev, "DFL FME FPGA Manager",
>> -				   &fme_mgr_ops, priv);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> -
>> -	mgr->compat_id = compat_id;
>> -
>> -	return devm_fpga_mgr_register(dev, mgr);
>> +	fme_mgr_get_compat_id(priv->ioaddr, info.compat_id);
>> +	mgr = devm_fpga_mgr_register_full(dev, &info);
>> +	return PTR_ERR_OR_ZERO(mgr);
>>  }
>>  
>>  static struct platform_driver fme_mgr_driver = {
>> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
>> index ecb4c3c795fa..5a913aa649fd 100644
>> --- a/drivers/fpga/fpga-mgr.c
>> +++ b/drivers/fpga/fpga-mgr.c
>> @@ -550,21 +550,19 @@ void fpga_mgr_unlock(struct fpga_manager *mgr)
>>  EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
>>  
>>  /**
>> - * fpga_mgr_create - create and initialize an FPGA manager struct
>> + * fpga_mgr_register_full - create and register an FPGA Manager device
>>   * @parent:	fpga manager device from pdev
>> - * @name:	fpga manager name
>> - * @mops:	pointer to structure of fpga manager ops
>> - * @priv:	fpga manager private data
>> + * @info:	parameters for fpga manager
>>   *
>> - * The caller of this function is responsible for freeing the struct with
>> - * fpga_mgr_free().  Using devm_fpga_mgr_create() instead is recommended.
>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
>> + * Using devm_fpga_mgr_register_full() instead is recommended.
>>   *
>> - * Return: pointer to struct fpga_manager or NULL
>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>>   */
>> -struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>> -				     const struct fpga_manager_ops *mops,
>> -				     void *priv)
>> +struct fpga_manager *
>> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>>  {
>> +	const struct fpga_manager_ops *mops = info->mops;
>>  	struct fpga_manager *mgr;
>>  	int id, ret;
>>  
>> @@ -572,29 +570,31 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>  	    !mops->write_init || (!mops->write && !mops->write_sg) ||
>>  	    (mops->write && mops->write_sg)) {
>>  		dev_err(parent, "Attempt to register without fpga_manager_ops\n");
>> -		return NULL;
>> +		return ERR_PTR(-EINVAL);
>>  	}
>>  
>> -	if (!name || !strlen(name)) {
>> +	if (!info->name || !strlen(info->name)) {
>>  		dev_err(parent, "Attempt to register with no name!\n");
>> -		return NULL;
>> +		return ERR_PTR(-EINVAL);
>>  	}
>>  
>>  	mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
>>  	if (!mgr)
>> -		return NULL;
>> +		return ERR_PTR(-ENOMEM);
>>  
>>  	id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
>> -	if (id < 0)
>> +	if (id < 0) {
>> +		ret = id;
>>  		goto error_kfree;
>> +	}
>>  
>>  	mutex_init(&mgr->ref_mutex);
>>  
>> -	mgr->name = name;
>> -	mgr->mops = mops;
>> -	mgr->priv = priv;
>> +	mgr->name = info->name;
>> +	mgr->mops = info->mops;
>> +	mgr->priv = info->priv;
>> +	mgr->compat_id = info->compat_id;
>>  
>> -	device_initialize(&mgr->dev);
>>  	mgr->dev.class = fpga_mgr_class;
>>  	mgr->dev.groups = mops->groups;
>>  	mgr->dev.parent = parent;
>> @@ -605,6 +605,19 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>  	if (ret)
>>  		goto error_device;
>>  
>> +	/*
>> +	 * Initialize framework state by requesting low level driver read state
>> +	 * from device.  FPGA may be in reset mode or may have been programmed
>> +	 * by bootloader or EEPROM.
>> +	 */
>> +	mgr->state = mgr->mops->state(mgr);
>> +
>> +	ret = device_register(&mgr->dev);
>> +	if (ret) {
>> +		put_device(&mgr->dev);
>> +		return ERR_PTR(ret);
>> +	}
>> +
>>  	return mgr;
>>  
>>  error_device:
>> @@ -612,96 +625,36 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>  error_kfree:
>>  	kfree(mgr);
>>  
>> -	return NULL;
>> +	return ERR_PTR(ret);
>>  }
>> -EXPORT_SYMBOL_GPL(fpga_mgr_create);
>> +EXPORT_SYMBOL_GPL(fpga_mgr_register_full);
>>  
>>  /**
>> - * fpga_mgr_free - free an FPGA manager created with fpga_mgr_create()
>> - * @mgr:	fpga manager struct
>> - */
>> -void fpga_mgr_free(struct fpga_manager *mgr)
>> -{
>> -	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>> -	kfree(mgr);
>> -}
>> -EXPORT_SYMBOL_GPL(fpga_mgr_free);
>> -
>> -static void devm_fpga_mgr_release(struct device *dev, void *res)
>> -{
>> -	struct fpga_mgr_devres *dr = res;
>> -
>> -	fpga_mgr_free(dr->mgr);
>> -}
>> -
>> -/**
>> - * devm_fpga_mgr_create - create and initialize a managed FPGA manager struct
>> + * fpga_mgr_register - create and register an FPGA Manager device
>>   * @parent:	fpga manager device from pdev
>>   * @name:	fpga manager name
>>   * @mops:	pointer to structure of fpga manager ops
>>   * @priv:	fpga manager private data
>>   *
>> - * This function is intended for use in an FPGA manager driver's probe function.
>> - * After the manager driver creates the manager struct with
>> - * devm_fpga_mgr_create(), it should register it with fpga_mgr_register().  The
>> - * manager driver's remove function should call fpga_mgr_unregister().  The
>> - * manager struct allocated with this function will be freed automatically on
>> - * driver detach.  This includes the case of a probe function returning error
>> - * before calling fpga_mgr_register(), the struct will still get cleaned up.
>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
>> + * Using devm_fpga_mgr_register() instead is recommended. This simple
>> + * version of the register function should be sufficient for most users. The
>> + * fpga_mgr_register_full() function is available for users that need to pass
>> + * additional, optional parameters.
>>   *
>> - * Return: pointer to struct fpga_manager or NULL
>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>>   */
>> -struct fpga_manager *devm_fpga_mgr_create(struct device *parent, const char *name,
>> -					  const struct fpga_manager_ops *mops,
>> -					  void *priv)
>> +struct fpga_manager *
>> +fpga_mgr_register(struct device *parent, const char *name,
>> +		  const struct fpga_manager_ops *mops, void *priv)
>>  {
>> -	struct fpga_mgr_devres *dr;
>> +	struct fpga_manager_info info = { 0 };
>>  
>> -	dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL);
>> -	if (!dr)
>> -		return NULL;
>> +	info.name = name;
>> +	info.mops = mops;
>> +	info.priv = priv;
>>  
>> -	dr->mgr = fpga_mgr_create(parent, name, mops, priv);
>> -	if (!dr->mgr) {
>> -		devres_free(dr);
>> -		return NULL;
>> -	}
>> -
>> -	devres_add(parent, dr);
>> -
>> -	return dr->mgr;
>> -}
>> -EXPORT_SYMBOL_GPL(devm_fpga_mgr_create);
>> -
>> -/**
>> - * fpga_mgr_register - register an FPGA manager
>> - * @mgr: fpga manager struct
>> - *
>> - * Return: 0 on success, negative error code otherwise.
>> - */
>> -int fpga_mgr_register(struct fpga_manager *mgr)
>> -{
>> -	int ret;
>> -
>> -	/*
>> -	 * Initialize framework state by requesting low level driver read state
>> -	 * from device.  FPGA may be in reset mode or may have been programmed
>> -	 * by bootloader or EEPROM.
>> -	 */
>> -	mgr->state = mgr->mops->state(mgr);
>> -
>> -	ret = device_add(&mgr->dev);
>> -	if (ret)
>> -		goto error_device;
>> -
>> -	dev_info(&mgr->dev, "%s registered\n", mgr->name);
>> -
>> -	return 0;
>> -
>> -error_device:
>> -	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>> -
>> -	return ret;
>> +	return fpga_mgr_register_full(parent, &info);
>>  }
>>  EXPORT_SYMBOL_GPL(fpga_mgr_register);
>>  
>> @@ -726,14 +679,6 @@ void fpga_mgr_unregister(struct fpga_manager *mgr)
>>  }
>>  EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
>>  
>> -static int fpga_mgr_devres_match(struct device *dev, void *res,
>> -				 void *match_data)
>> -{
>> -	struct fpga_mgr_devres *dr = res;
>> -
>> -	return match_data == dr->mgr;
>> -}
>> -
>>  static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>>  {
>>  	struct fpga_mgr_devres *dr = res;
>> @@ -742,45 +687,67 @@ static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>>  }
>>  
>>  /**
>> - * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
>> - * @dev: managing device for this FPGA manager
>> - * @mgr: fpga manager struct
>> + * devm_fpga_mgr_register_full - resource managed variant of fpga_mgr_register()
>> + * @parent:	fpga manager device from pdev
>> + * @info:	parameters for fpga manager
>>   *
>> - * This is the devres variant of fpga_mgr_register() for which the unregister
>> + * This is the devres variant of fpga_mgr_register_full() for which the unregister
>>   * function will be called automatically when the managing device is detached.
>>   */
>> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr)
>> +struct fpga_manager *
>> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>>  {
>>  	struct fpga_mgr_devres *dr;
>> -	int ret;
>> -
>> -	/*
>> -	 * Make sure that the struct fpga_manager * that is passed in is
>> -	 * managed itself.
>> -	 */
>> -	if (WARN_ON(!devres_find(dev, devm_fpga_mgr_release,
>> -				 fpga_mgr_devres_match, mgr)))
>> -		return -EINVAL;
>> +	struct fpga_manager *mgr;
>>  
>>  	dr = devres_alloc(devm_fpga_mgr_unregister, sizeof(*dr), GFP_KERNEL);
>>  	if (!dr)
>> -		return -ENOMEM;
>> +		return ERR_PTR(-ENOMEM);
>>  
>> -	ret = fpga_mgr_register(mgr);
>> -	if (ret) {
>> +	mgr = fpga_mgr_register_full(parent, info);
>> +	if (IS_ERR(mgr)) {
>>  		devres_free(dr);
>> -		return ret;
>> +		return mgr;
>>  	}
>>  
>>  	dr->mgr = mgr;
>> -	devres_add(dev, dr);
>> +	devres_add(parent, dr);
>>  
>> -	return 0;
>> +	return mgr;
>> +}
>> +EXPORT_SYMBOL_GPL(devm_fpga_mgr_register_full);
>> +
>> +/**
>> + * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
>> + * @parent:	fpga manager device from pdev
>> + * @name:	fpga manager name
>> + * @mops:	pointer to structure of fpga manager ops
>> + * @priv:	fpga manager private data
>> + *
>> + * This is the devres variant of fpga_mgr_register() for which the
>> + * unregister function will be called automatically when the managing
>> + * device is detached.
>> + */
>> +struct fpga_manager *
>> +devm_fpga_mgr_register(struct device *parent, const char *name,
>> +		       const struct fpga_manager_ops *mops, void *priv)
>> +{
>> +	struct fpga_manager_info info = { 0 };
>> +
>> +	info.name = name;
>> +	info.mops = mops;
>> +	info.priv = priv;
>> +
>> +	return devm_fpga_mgr_register_full(parent, &info);
>>  }
>>  EXPORT_SYMBOL_GPL(devm_fpga_mgr_register);
>>  
>>  static void fpga_mgr_dev_release(struct device *dev)
>>  {
>> +	struct fpga_manager *mgr = to_fpga_manager(dev);
>> +
>> +	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>> +	kfree(mgr);
>>  }
>>  
>>  static int __init fpga_mgr_class_init(void)
>> diff --git a/drivers/fpga/ice40-spi.c b/drivers/fpga/ice40-spi.c
>> index 69dec5af23c3..b7591912248f 100644
>> --- a/drivers/fpga/ice40-spi.c
>> +++ b/drivers/fpga/ice40-spi.c
>> @@ -178,12 +178,9 @@ static int ice40_fpga_probe(struct spi_device *spi)
>>  		return ret;
>>  	}
>>  
>> -	mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
>> -				   &ice40_fpga_ops, priv);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> -
>> -	return devm_fpga_mgr_register(dev, mgr);
>> +	mgr = devm_fpga_mgr_register(dev, "Lattice iCE40 FPGA Manager",
>> +				     &ice40_fpga_ops, priv);
>> +	return PTR_ERR_OR_ZERO(mgr);
>>  }
>>  
>>  static const struct of_device_id ice40_fpga_of_match[] = {
>> diff --git a/drivers/fpga/machxo2-spi.c b/drivers/fpga/machxo2-spi.c
>> index 1afb41aa20d7..8469dfb5dd21 100644
>> --- a/drivers/fpga/machxo2-spi.c
>> +++ b/drivers/fpga/machxo2-spi.c
>> @@ -366,12 +366,9 @@ static int machxo2_spi_probe(struct spi_device *spi)
>>  		return -EINVAL;
>>  	}
>>  
>> -	mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager",
>> -				   &machxo2_ops, spi);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> -
>> -	return devm_fpga_mgr_register(dev, mgr);
>> +	mgr = devm_fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager",
>> +				     &machxo2_ops, spi);
>> +	return PTR_ERR_OR_ZERO(mgr);
>>  }
>>  
>>  #ifdef CONFIG_OF
>> diff --git a/drivers/fpga/socfpga-a10.c b/drivers/fpga/socfpga-a10.c
>> index 573d88bdf730..ac8e89b8a5cc 100644
>> --- a/drivers/fpga/socfpga-a10.c
>> +++ b/drivers/fpga/socfpga-a10.c
>> @@ -508,19 +508,15 @@ static int socfpga_a10_fpga_probe(struct platform_device *pdev)
>>  		return -EBUSY;
>>  	}
>>  
>> -	mgr = devm_fpga_mgr_create(dev, "SoCFPGA Arria10 FPGA Manager",
>> -				   &socfpga_a10_fpga_mgr_ops, priv);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> -
>> -	platform_set_drvdata(pdev, mgr);
>> -
>> -	ret = fpga_mgr_register(mgr);
>> -	if (ret) {
>> +	mgr = fpga_mgr_register(dev, "SoCFPGA Arria10 FPGA Manager",
>> +				&socfpga_a10_fpga_mgr_ops, priv);
>> +	if (IS_ERR(mgr)) {
>>  		clk_disable_unprepare(priv->clk);
>> -		return ret;
>> +		return PTR_ERR(mgr);
>>  	}
>>  
>> +	platform_set_drvdata(pdev, mgr);
>> +
>>  	return 0;
>>  }
>>  
>> diff --git a/drivers/fpga/socfpga.c b/drivers/fpga/socfpga.c
>> index 1f467173fc1f..7e0741f99696 100644
>> --- a/drivers/fpga/socfpga.c
>> +++ b/drivers/fpga/socfpga.c
>> @@ -571,12 +571,9 @@ static int socfpga_fpga_probe(struct platform_device *pdev)
>>  	if (ret)
>>  		return ret;
>>  
>> -	mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
>> -				   &socfpga_fpga_ops, priv);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> -
>> -	return devm_fpga_mgr_register(dev, mgr);
>> +	mgr = devm_fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
>> +				     &socfpga_fpga_ops, priv);
>> +	return PTR_ERR_OR_ZERO(mgr);
>>  }
>>  
>>  #ifdef CONFIG_OF
>> diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
>> index a2cea500f7cc..9155e888a133 100644
>> --- a/drivers/fpga/stratix10-soc.c
>> +++ b/drivers/fpga/stratix10-soc.c
>> @@ -425,18 +425,11 @@ static int s10_probe(struct platform_device *pdev)
>>  
>>  	init_completion(&priv->status_return_completion);
>>  
>> -	mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
>> -			      &s10_ops, priv);
>> -	if (!mgr) {
>> -		dev_err(dev, "unable to create FPGA manager\n");
>> -		ret = -ENOMEM;
>> -		goto probe_err;
>> -	}
>> -
>> -	ret = fpga_mgr_register(mgr);
>> -	if (ret) {
>> +	mgr = fpga_mgr_register(dev, "Stratix10 SOC FPGA Manager",
>> +				&s10_ops, priv);
>> +	if (IS_ERR(mgr)) {
>>  		dev_err(dev, "unable to register FPGA manager\n");
>> -		fpga_mgr_free(mgr);
>> +		ret = PTR_ERR(mgr);
>>  		goto probe_err;
>>  	}
>>  
>> @@ -454,7 +447,6 @@ static int s10_remove(struct platform_device *pdev)
>>  	struct s10_priv *priv = mgr->priv;
>>  
>>  	fpga_mgr_unregister(mgr);
>> -	fpga_mgr_free(mgr);
>>  	stratix10_svc_free_channel(priv->chan);
>>  
>>  	return 0;
>> diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c
>> index 101f016c6ed8..fd52de20ddb2 100644
>> --- a/drivers/fpga/ts73xx-fpga.c
>> +++ b/drivers/fpga/ts73xx-fpga.c
>> @@ -122,12 +122,9 @@ static int ts73xx_fpga_probe(struct platform_device *pdev)
>>  	if (IS_ERR(priv->io_base))
>>  		return PTR_ERR(priv->io_base);
>>  
>> -	mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
>> -				   &ts73xx_fpga_ops, priv);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> -
>> -	return devm_fpga_mgr_register(kdev, mgr);
>> +	mgr = devm_fpga_mgr_register(kdev, "TS-73xx FPGA Manager",
>> +				     &ts73xx_fpga_ops, priv);
>> +	return PTR_ERR_OR_ZERO(mgr);
>>  }
>>  
>>  static struct platform_driver ts73xx_fpga_driver = {
>> diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
>> index fee4d0abf6bf..db23626f9ab2 100644
>> --- a/drivers/fpga/xilinx-spi.c
>> +++ b/drivers/fpga/xilinx-spi.c
>> @@ -247,13 +247,10 @@ static int xilinx_spi_probe(struct spi_device *spi)
>>  		return dev_err_probe(&spi->dev, PTR_ERR(conf->done),
>>  				     "Failed to get DONE gpio\n");
>>  
>> -	mgr = devm_fpga_mgr_create(&spi->dev,
>> -				   "Xilinx Slave Serial FPGA Manager",
>> -				   &xilinx_spi_ops, conf);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> -
>> -	return devm_fpga_mgr_register(&spi->dev, mgr);
>> +	mgr = devm_fpga_mgr_register(&spi->dev,
>> +				     "Xilinx Slave Serial FPGA Manager",
>> +				     &xilinx_spi_ops, conf);
>> +	return PTR_ERR_OR_ZERO(mgr);
>>  }
>>  
>>  static const struct of_device_id xlnx_spi_of_match[] = {
>> diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
>> index 9b75bd4f93d8..426aa34c6a0d 100644
>> --- a/drivers/fpga/zynq-fpga.c
>> +++ b/drivers/fpga/zynq-fpga.c
>> @@ -609,20 +609,16 @@ static int zynq_fpga_probe(struct platform_device *pdev)
>>  
>>  	clk_disable(priv->clk);
>>  
>> -	mgr = devm_fpga_mgr_create(dev, "Xilinx Zynq FPGA Manager",
>> -				   &zynq_fpga_ops, priv);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> -
>> -	platform_set_drvdata(pdev, mgr);
>> -
>> -	err = fpga_mgr_register(mgr);
>> -	if (err) {
>> +	mgr = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
>> +				&zynq_fpga_ops, priv);
>> +	if (IS_ERR(mgr)) {
>>  		dev_err(dev, "unable to register FPGA manager\n");
>>  		clk_unprepare(priv->clk);
>> -		return err;
>> +		return PTR_ERR(mgr);
>>  	}
>>  
>> +	platform_set_drvdata(pdev, mgr);
>> +
>>  	return 0;
>>  }
>>  
>> diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
>> index 125743c9797f..975bdc4d0a65 100644
>> --- a/drivers/fpga/zynqmp-fpga.c
>> +++ b/drivers/fpga/zynqmp-fpga.c
>> @@ -102,12 +102,9 @@ static int zynqmp_fpga_probe(struct platform_device *pdev)
>>  
>>  	priv->dev = dev;
>>  
>> -	mgr = devm_fpga_mgr_create(dev, "Xilinx ZynqMP FPGA Manager",
>> -				   &zynqmp_fpga_ops, priv);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> -
>> -	return devm_fpga_mgr_register(dev, mgr);
>> +	mgr = devm_fpga_mgr_register(dev, "Xilinx ZynqMP FPGA Manager",
>> +				     &zynqmp_fpga_ops, priv);
>> +	return PTR_ERR_OR_ZERO(mgr);
>>  }
>>  
>>  static const struct of_device_id zynqmp_fpga_of_match[] = {
>> diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
>> index 474c1f506307..ac3ddaf2903c 100644
>> --- a/include/linux/fpga/fpga-mgr.h
>> +++ b/include/linux/fpga/fpga-mgr.h
>> @@ -105,6 +105,36 @@ struct fpga_image_info {
>>  #endif
>>  };
>>  
>> +/**
>> + * struct fpga_compat_id - id for compatibility check
>> + *
>> + * @id_h: high 64bit of the compat_id
>> + * @id_l: low 64bit of the compat_id
>> + */
>> +struct fpga_compat_id {
>> +	u64 id_h;
>> +	u64 id_l;
>> +};
>> +
>> +/**
>> + * struct fpga_manager_info - collection of parameters for an FPGA Manager
>> + * @name: fpga manager name
>> + * @compat_id: FPGA manager id for compatibility check.
>> + * @mops: pointer to structure of fpga manager ops
>> + * @priv: fpga manager private data
>> + *
>> + * fpga_manager_info contains parameters for the register function. These
>> + * are separated into an info structure because they some are optional
>> + * others could be added to in the future. The info structure facilitates
>> + * maintaining a stable API.
>> + */
>> +struct fpga_manager_info {
>> +	const char *name;
>> +	struct fpga_compat_id *compat_id;
>> +	const struct fpga_manager_ops *mops;
>> +	void *priv;
>> +};
>> +
>>  /**
>>   * struct fpga_manager_ops - ops for low level fpga manager drivers
>>   * @initial_header_size: Maximum number of bytes that should be passed into write_init
>> @@ -143,17 +173,6 @@ struct fpga_manager_ops {
>>  #define FPGA_MGR_STATUS_IP_PROTOCOL_ERR		BIT(3)
>>  #define FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR	BIT(4)
>>  
>> -/**
>> - * struct fpga_compat_id - id for compatibility check
>> - *
>> - * @id_h: high 64bit of the compat_id
>> - * @id_l: low 64bit of the compat_id
>> - */
>> -struct fpga_compat_id {
>> -	u64 id_h;
>> -	u64 id_l;
>> -};
>> -
>>  /**
>>   * struct fpga_manager - fpga manager structure
>>   * @name: name of low level fpga manager
>> @@ -191,17 +210,18 @@ struct fpga_manager *fpga_mgr_get(struct device *dev);
>>  
>>  void fpga_mgr_put(struct fpga_manager *mgr);
>>  
>> -struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name,
>> -				     const struct fpga_manager_ops *mops,
>> -				     void *priv);
>> -void fpga_mgr_free(struct fpga_manager *mgr);
>> -int fpga_mgr_register(struct fpga_manager *mgr);
>> -void fpga_mgr_unregister(struct fpga_manager *mgr);
>> +struct fpga_manager *
>> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
>>  
>> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr);
>> +struct fpga_manager *
>> +fpga_mgr_register(struct device *parent, const char *name,
>> +		  const struct fpga_manager_ops *mops, void *priv);
>> +void fpga_mgr_unregister(struct fpga_manager *mgr);
>>  
>> -struct fpga_manager *devm_fpga_mgr_create(struct device *dev, const char *name,
>> -					  const struct fpga_manager_ops *mops,
>> -					  void *priv);
>> +struct fpga_manager *
>> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
>> +struct fpga_manager *
>> +devm_fpga_mgr_register(struct device *parent, const char *name,
>> +		       const struct fpga_manager_ops *mops, void *priv);
>>  
>>  #endif /*_LINUX_FPGA_MGR_H */
>> -- 
>> 2.25.1


^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 2/3] fpga: bridge: Use standard dev_release for class driver
  2021-07-01  5:39   ` Xu Yilun
@ 2021-07-06 23:06     ` Russ Weight
  0 siblings, 0 replies; 22+ messages in thread
From: Russ Weight @ 2021-07-06 23:06 UTC (permalink / raw)
  To: Xu Yilun
  Cc: mdf, linux-fpga, trix, lgoncalv, hao.wu, matthew.gerlach, richard.gong



On 6/30/21 10:39 PM, Xu Yilun wrote:
> On Wed, Jun 30, 2021 at 06:37:32PM -0700, Russ Weight wrote:
>> The FPGA bridge class driver data structure is being treated as a
>> managed resource instead of using the standard dev_release call-back
>> function to release the class data structure. This change removes
>> the managed resource code and combines the create() and register()
>> functions into a single register() or register_simple() function.
>>
>> The register() function accepts an info data structure to provide
>> flexibility in passing optional parameters. The register_simple()
>> function supports the current parameter list for users that don't
>> require the use of optional parameters.
> Please update the commit message, others are good to me.

Will do.
- Russ
>
> Thanks,
> Yilun
>
>> Signed-off-by: Russ Weight <russell.h.weight@intel.com>
>> Reviewed-by: Xu Yilun <yilun.xu@intel.com>
>> ---
>> v9:
>>   - Cleaned up documentation for the FPGA Bridge register functions
>>   - Renamed fpga_bridge_register() to fpga_bridge_register_full()
>>   - Renamed fpga_bridge_register_simple() to fpga_bridge_register()
>> v8:
>>   - Added reviewed-by tag.
>>   - Updated Documentation/driver-api/fpga/fpga-bridge.rst documentation.
>> v7:
>>   - Update the commit message to describe the new parameters for the
>>     fpga_bridge_register() function and to mention the
>>     fpga_bridge_register_simple() function.
>>   - Fix function prototypes in header file to rename dev to parent.
>>   - Some cleanup of comments.
>>   - Update function defintions/prototypes to apply const to the new info
>>     parameter.
>>   - Verify that info->br_ops is non-null in register functions.
>> v6:
>>   - Changed fpga_bridge_register() parameters to accept an info data
>>     structure to provide flexibility in passing optional parameters.
>>   - Added fpga_bridge_register_simple() function to support current
>>     parameters for users that don't require the use of optional
>>     parameters.
>> v5:
>>   - Rebased on top of recently accepted patches.
>> v4:
>>   - Restore the previous format for the Return value in the comment header
>>     for fpga_bridge_register()
>> v3:
>>   - Cleaned up comment header for fpga_bridge_register()
>>   - Fix error return values for fpga_bridge_register()
>> v2:
>>   - No changes
>> ---
>>  Documentation/driver-api/fpga/fpga-bridge.rst |   8 +-
>>  drivers/fpga/altera-fpga2sdram.c              |  12 +-
>>  drivers/fpga/altera-freeze-bridge.c           |  10 +-
>>  drivers/fpga/altera-hps2fpga.c                |  12 +-
>>  drivers/fpga/dfl-fme-br.c                     |  10 +-
>>  drivers/fpga/fpga-bridge.c                    | 137 ++++++------------
>>  drivers/fpga/xilinx-pr-decoupler.c            |  17 +--
>>  include/linux/fpga/fpga-bridge.h              |  33 +++--
>>  8 files changed, 101 insertions(+), 138 deletions(-)
>>
>> diff --git a/Documentation/driver-api/fpga/fpga-bridge.rst b/Documentation/driver-api/fpga/fpga-bridge.rst
>> index 8d650b4e2ce6..38e3bac8e877 100644
>> --- a/Documentation/driver-api/fpga/fpga-bridge.rst
>> +++ b/Documentation/driver-api/fpga/fpga-bridge.rst
>> @@ -6,8 +6,10 @@ API to implement a new FPGA bridge
>>  
>>  * struct fpga_bridge - The FPGA Bridge structure
>>  * struct fpga_bridge_ops - Low level Bridge driver ops
>> -* devm_fpga_bridge_create() - Allocate and init a bridge struct
>> -* fpga_bridge_register() - Register a bridge
>> +* fpga_bridge_register_full() - Create and register a bridge using the
>> +  fpga_bridge_info structure to provide the full flexibility of options
>> +* fpga_bridge_register() - Create and register a bridge using standard
>> +  arguments
>>  * fpga_bridge_unregister() - Unregister a bridge
>>  
>>  .. kernel-doc:: include/linux/fpga/fpga-bridge.h
>> @@ -17,7 +19,7 @@ API to implement a new FPGA bridge
>>     :functions: fpga_bridge_ops
>>  
>>  .. kernel-doc:: drivers/fpga/fpga-bridge.c
>> -   :functions: devm_fpga_bridge_create
>> +   :functions: fpga_bridge_register_full
>>  
>>  .. kernel-doc:: drivers/fpga/fpga-bridge.c
>>     :functions: fpga_bridge_register
>> diff --git a/drivers/fpga/altera-fpga2sdram.c b/drivers/fpga/altera-fpga2sdram.c
>> index a78e49c63c64..66063507116b 100644
>> --- a/drivers/fpga/altera-fpga2sdram.c
>> +++ b/drivers/fpga/altera-fpga2sdram.c
>> @@ -121,17 +121,13 @@ static int alt_fpga_bridge_probe(struct platform_device *pdev)
>>  	/* Get f2s bridge configuration saved in handoff register */
>>  	regmap_read(sysmgr, SYSMGR_ISWGRP_HANDOFF3, &priv->mask);
>>  
>> -	br = devm_fpga_bridge_create(dev, F2S_BRIDGE_NAME,
>> -				     &altera_fpga2sdram_br_ops, priv);
>> -	if (!br)
>> -		return -ENOMEM;
>> +	br = fpga_bridge_register(dev, F2S_BRIDGE_NAME,
>> +				  &altera_fpga2sdram_br_ops, priv);
>> +	if (IS_ERR(br))
>> +		return PTR_ERR(mgr);
>>  
>>  	platform_set_drvdata(pdev, br);
>>  
>> -	ret = fpga_bridge_register(br);
>> -	if (ret)
>> -		return ret;
>> -
>>  	dev_info(dev, "driver initialized with handoff %08x\n", priv->mask);
>>  
>>  	if (!of_property_read_u32(dev->of_node, "bridge-enable", &enable)) {
>> diff --git a/drivers/fpga/altera-freeze-bridge.c b/drivers/fpga/altera-freeze-bridge.c
>> index dd58c4aea92e..bfbfa43cd05b 100644
>> --- a/drivers/fpga/altera-freeze-bridge.c
>> +++ b/drivers/fpga/altera-freeze-bridge.c
>> @@ -244,14 +244,14 @@ static int altera_freeze_br_probe(struct platform_device *pdev)
>>  
>>  	priv->base_addr = base_addr;
>>  
>> -	br = devm_fpga_bridge_create(dev, FREEZE_BRIDGE_NAME,
>> -				     &altera_freeze_br_br_ops, priv);
>> -	if (!br)
>> -		return -ENOMEM;
>> +	br = fpga_bridge_register(dev, FREEZE_BRIDGE_NAME,
>> +				  &altera_freeze_br_br_ops, priv);
>> +	if (IS_ERR(br))
>> +		return PTR_ERR(br);
>>  
>>  	platform_set_drvdata(pdev, br);
>>  
>> -	return fpga_bridge_register(br);
>> +	return 0;
>>  }
>>  
>>  static int altera_freeze_br_remove(struct platform_device *pdev)
>> diff --git a/drivers/fpga/altera-hps2fpga.c b/drivers/fpga/altera-hps2fpga.c
>> index 77b95f251821..aa758426c22b 100644
>> --- a/drivers/fpga/altera-hps2fpga.c
>> +++ b/drivers/fpga/altera-hps2fpga.c
>> @@ -180,19 +180,15 @@ static int alt_fpga_bridge_probe(struct platform_device *pdev)
>>  		}
>>  	}
>>  
>> -	br = devm_fpga_bridge_create(dev, priv->name,
>> -				     &altera_hps2fpga_br_ops, priv);
>> -	if (!br) {
>> -		ret = -ENOMEM;
>> +	br = fpga_bridge_register(dev, priv->name,
>> +				  &altera_hps2fpga_br_ops, priv);
>> +	if (IS_ERR(br)) {
>> +		ret = PTR_ERR(br);
>>  		goto err;
>>  	}
>>  
>>  	platform_set_drvdata(pdev, br);
>>  
>> -	ret = fpga_bridge_register(br);
>> -	if (ret)
>> -		goto err;
>> -
>>  	return 0;
>>  
>>  err:
>> diff --git a/drivers/fpga/dfl-fme-br.c b/drivers/fpga/dfl-fme-br.c
>> index 3ff9f3a687ce..808d1f4d76df 100644
>> --- a/drivers/fpga/dfl-fme-br.c
>> +++ b/drivers/fpga/dfl-fme-br.c
>> @@ -68,14 +68,14 @@ static int fme_br_probe(struct platform_device *pdev)
>>  
>>  	priv->pdata = dev_get_platdata(dev);
>>  
>> -	br = devm_fpga_bridge_create(dev, "DFL FPGA FME Bridge",
>> -				     &fme_bridge_ops, priv);
>> -	if (!br)
>> -		return -ENOMEM;
>> +	br = fpga_bridge_register(dev, "DFL FPGA FME Bridge",
>> +				  &fme_bridge_ops, priv);
>> +	if (IS_ERR(br))
>> +		return PTR_ERR(br);
>>  
>>  	platform_set_drvdata(pdev, br);
>>  
>> -	return fpga_bridge_register(br);
>> +	return 0;
>>  }
>>  
>>  static int fme_br_remove(struct platform_device *pdev)
>> diff --git a/drivers/fpga/fpga-bridge.c b/drivers/fpga/fpga-bridge.c
>> index 798f55670646..e6d98be8531b 100644
>> --- a/drivers/fpga/fpga-bridge.c
>> +++ b/drivers/fpga/fpga-bridge.c
>> @@ -312,55 +312,63 @@ static struct attribute *fpga_bridge_attrs[] = {
>>  ATTRIBUTE_GROUPS(fpga_bridge);
>>  
>>  /**
>> - * fpga_bridge_create - create and initialize a struct fpga_bridge
>> + * fpga_bridge_register_full - create and register an FPGA Bridge device
>>   * @parent:	FPGA bridge device from pdev
>> - * @name:	FPGA bridge name
>> - * @br_ops:	pointer to structure of fpga bridge ops
>> - * @priv:	FPGA bridge private data
>> + * @info:	parameters for FPGA Bridge
>>   *
>> - * The caller of this function is responsible for freeing the bridge with
>> - * fpga_bridge_free().  Using devm_fpga_bridge_create() instead is recommended.
>> - *
>> - * Return: struct fpga_bridge or NULL
>> + * Return: struct fpga_bridge pointer or ERR_PTR()
>>   */
>> -struct fpga_bridge *fpga_bridge_create(struct device *parent, const char *name,
>> -				       const struct fpga_bridge_ops *br_ops,
>> -				       void *priv)
>> +struct fpga_bridge *
>> +fpga_bridge_register_full(struct device *parent,
>> +			  const struct fpga_bridge_info *info)
>>  {
>>  	struct fpga_bridge *bridge;
>>  	int id, ret;
>>  
>> -	if (!name || !strlen(name)) {
>> +	if (!info->br_ops) {
>> +		dev_err(parent, "Attempt to register without fpga_bridge_ops\n");
>> +		return ERR_PTR(-EINVAL);
>> +	}
>> +
>> +	if (!info->name || !strlen(info->name)) {
>>  		dev_err(parent, "Attempt to register with no name!\n");
>> -		return NULL;
>> +		return ERR_PTR(-EINVAL);
>>  	}
>>  
>>  	bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
>>  	if (!bridge)
>> -		return NULL;
>> +		return ERR_PTR(-ENOMEM);
>>  
>>  	id = ida_simple_get(&fpga_bridge_ida, 0, 0, GFP_KERNEL);
>> -	if (id < 0)
>> +	if (id < 0) {
>> +		ret = id;
>>  		goto error_kfree;
>> +	}
>>  
>>  	mutex_init(&bridge->mutex);
>>  	INIT_LIST_HEAD(&bridge->node);
>>  
>> -	bridge->name = name;
>> -	bridge->br_ops = br_ops;
>> -	bridge->priv = priv;
>> +	bridge->name = info->name;
>> +	bridge->br_ops = info->br_ops;
>> +	bridge->priv = info->priv;
>>  
>> -	device_initialize(&bridge->dev);
>> -	bridge->dev.groups = br_ops->groups;
>> +	bridge->dev.groups = info->br_ops->groups;
>>  	bridge->dev.class = fpga_bridge_class;
>>  	bridge->dev.parent = parent;
>>  	bridge->dev.of_node = parent->of_node;
>>  	bridge->dev.id = id;
>> +	of_platform_populate(bridge->dev.of_node, NULL, NULL, &bridge->dev);
>>  
>>  	ret = dev_set_name(&bridge->dev, "br%d", id);
>>  	if (ret)
>>  		goto error_device;
>>  
>> +	ret = device_register(&bridge->dev);
>> +	if (ret) {
>> +		put_device(&bridge->dev);
>> +		return ERR_PTR(ret);
>> +	}
>> +
>>  	return bridge;
>>  
>>  error_device:
>> @@ -368,88 +376,35 @@ struct fpga_bridge *fpga_bridge_create(struct device *parent, const char *name,
>>  error_kfree:
>>  	kfree(bridge);
>>  
>> -	return NULL;
>> -}
>> -EXPORT_SYMBOL_GPL(fpga_bridge_create);
>> -
>> -/**
>> - * fpga_bridge_free - free an fpga bridge created by fpga_bridge_create()
>> - * @bridge:	FPGA bridge struct
>> - */
>> -void fpga_bridge_free(struct fpga_bridge *bridge)
>> -{
>> -	ida_simple_remove(&fpga_bridge_ida, bridge->dev.id);
>> -	kfree(bridge);
>> -}
>> -EXPORT_SYMBOL_GPL(fpga_bridge_free);
>> -
>> -static void devm_fpga_bridge_release(struct device *dev, void *res)
>> -{
>> -	struct fpga_bridge *bridge = *(struct fpga_bridge **)res;
>> -
>> -	fpga_bridge_free(bridge);
>> +	return ERR_PTR(ret);
>>  }
>> +EXPORT_SYMBOL_GPL(fpga_bridge_register_full);
>>  
>>  /**
>> - * devm_fpga_bridge_create - create and init a managed struct fpga_bridge
>> + * fpga_bridge_register - create and register an FPGA Bridge device
>>   * @parent:	FPGA bridge device from pdev
>>   * @name:	FPGA bridge name
>>   * @br_ops:	pointer to structure of fpga bridge ops
>>   * @priv:	FPGA bridge private data
>>   *
>> - * This function is intended for use in an FPGA bridge driver's probe function.
>> - * After the bridge driver creates the struct with devm_fpga_bridge_create(), it
>> - * should register the bridge with fpga_bridge_register().  The bridge driver's
>> - * remove function should call fpga_bridge_unregister().  The bridge struct
>> - * allocated with this function will be freed automatically on driver detach.
>> - * This includes the case of a probe function returning error before calling
>> - * fpga_bridge_register(), the struct will still get cleaned up.
>> + * This simple version of the register should be sufficient for most users.
>> + * The fpga_bridge_register_full() function is available for users that need to pass
>> + * additional, optional parameters.
>>   *
>> - *  Return: struct fpga_bridge or NULL
>> + * Return: struct fpga_bridge pointer or ERR_PTR()
>>   */
>> -struct fpga_bridge
>> -*devm_fpga_bridge_create(struct device *parent, const char *name,
>> -			 const struct fpga_bridge_ops *br_ops, void *priv)
>> +struct fpga_bridge *
>> +fpga_bridge_register(struct device *parent, const char *name,
>> +		     const struct fpga_bridge_ops *br_ops,
>> +		     void *priv)
>>  {
>> -	struct fpga_bridge **ptr, *bridge;
>> -
>> -	ptr = devres_alloc(devm_fpga_bridge_release, sizeof(*ptr), GFP_KERNEL);
>> -	if (!ptr)
>> -		return NULL;
>> -
>> -	bridge = fpga_bridge_create(parent, name, br_ops, priv);
>> -	if (!bridge) {
>> -		devres_free(ptr);
>> -	} else {
>> -		*ptr = bridge;
>> -		devres_add(parent, ptr);
>> -	}
>> +	struct fpga_bridge_info info = { 0 };
>>  
>> -	return bridge;
>> -}
>> -EXPORT_SYMBOL_GPL(devm_fpga_bridge_create);
>> +	info.name = name;
>> +	info.br_ops = br_ops;
>> +	info.priv = priv;
>>  
>> -/**
>> - * fpga_bridge_register - register an FPGA bridge
>> - *
>> - * @bridge: FPGA bridge struct
>> - *
>> - * Return: 0 for success, error code otherwise.
>> - */
>> -int fpga_bridge_register(struct fpga_bridge *bridge)
>> -{
>> -	struct device *dev = &bridge->dev;
>> -	int ret;
>> -
>> -	ret = device_add(dev);
>> -	if (ret)
>> -		return ret;
>> -
>> -	of_platform_populate(dev->of_node, NULL, NULL, dev);
>> -
>> -	dev_info(dev->parent, "fpga bridge [%s] registered\n", bridge->name);
>> -
>> -	return 0;
>> +	return fpga_bridge_register_full(parent, &info);
>>  }
>>  EXPORT_SYMBOL_GPL(fpga_bridge_register);
>>  
>> @@ -475,6 +430,10 @@ EXPORT_SYMBOL_GPL(fpga_bridge_unregister);
>>  
>>  static void fpga_bridge_dev_release(struct device *dev)
>>  {
>> +	struct fpga_bridge *bridge = to_fpga_bridge(dev);
>> +
>> +	ida_simple_remove(&fpga_bridge_ida, bridge->dev.id);
>> +	kfree(bridge);
>>  }
>>  
>>  static int __init fpga_bridge_dev_init(void)
>> diff --git a/drivers/fpga/xilinx-pr-decoupler.c b/drivers/fpga/xilinx-pr-decoupler.c
>> index ea2bde6e5bc4..c004e52b9464 100644
>> --- a/drivers/fpga/xilinx-pr-decoupler.c
>> +++ b/drivers/fpga/xilinx-pr-decoupler.c
>> @@ -138,22 +138,17 @@ static int xlnx_pr_decoupler_probe(struct platform_device *pdev)
>>  
>>  	clk_disable(priv->clk);
>>  
>> -	br = devm_fpga_bridge_create(&pdev->dev, priv->ipconfig->name,
>> -				     &xlnx_pr_decoupler_br_ops, priv);
>> -	if (!br) {
>> -		err = -ENOMEM;
>> -		goto err_clk;
>> -	}
>> -
>> -	platform_set_drvdata(pdev, br);
>> -
>> -	err = fpga_bridge_register(br);
>> -	if (err) {
>> +	br = fpga_bridge_register(&pdev->dev, priv->ipconfig->name,
>> +				  &xlnx_pr_decoupler_br_ops, priv);
>> +	if (IS_ERR(br)) {
>> +		err = PTR_ERR(br);
>>  		dev_err(&pdev->dev, "unable to register %s",
>>  			priv->ipconfig->name);
>>  		goto err_clk;
>>  	}
>>  
>> +	platform_set_drvdata(pdev, br);
>> +
>>  	return 0;
>>  
>>  err_clk:
>> diff --git a/include/linux/fpga/fpga-bridge.h b/include/linux/fpga/fpga-bridge.h
>> index 6c3c28806ff1..f0a4d99d9c8e 100644
>> --- a/include/linux/fpga/fpga-bridge.h
>> +++ b/include/linux/fpga/fpga-bridge.h
>> @@ -22,6 +22,23 @@ struct fpga_bridge_ops {
>>  	const struct attribute_group **groups;
>>  };
>>  
>> +/**
>> + * struct fpga_bridge_info - collection of parameters an FPGA Bridge
>> + * @name: fpga bridge name
>> + * @br_ops: pointer to structure of fpga bridge ops
>> + * @priv: fpga bridge private data
>> + *
>> + * fpga_bridge_info contains parameters for the register function. These
>> + * are separated into an info structure because they some are optional
>> + * others could be added to in the future. The info structure facilitates
>> + * maintaining a stable API.
>> + */
>> +struct fpga_bridge_info {
>> +	const char *name;
>> +	const struct fpga_bridge_ops *br_ops;
>> +	void *priv;
>> +};
>> +
>>  /**
>>   * struct fpga_bridge - FPGA bridge structure
>>   * @name: name of low level FPGA bridge
>> @@ -62,15 +79,13 @@ int of_fpga_bridge_get_to_list(struct device_node *np,
>>  			       struct fpga_image_info *info,
>>  			       struct list_head *bridge_list);
>>  
>> -struct fpga_bridge *fpga_bridge_create(struct device *dev, const char *name,
>> -				       const struct fpga_bridge_ops *br_ops,
>> -				       void *priv);
>> -void fpga_bridge_free(struct fpga_bridge *br);
>> -int fpga_bridge_register(struct fpga_bridge *br);
>> -void fpga_bridge_unregister(struct fpga_bridge *br);
>> +struct fpga_bridge *
>> +fpga_bridge_register_full(struct device *parent, const struct fpga_bridge_info *info);
>>  
>> -struct fpga_bridge
>> -*devm_fpga_bridge_create(struct device *dev, const char *name,
>> -			 const struct fpga_bridge_ops *br_ops, void *priv);
>> +struct fpga_bridge *
>> +fpga_bridge_register(struct device *parent, const char *name,
>> +		     const struct fpga_bridge_ops *br_ops,
>> +		     void *priv);
>> +void fpga_bridge_unregister(struct fpga_bridge *br);
>>  
>>  #endif /* _LINUX_FPGA_BRIDGE_H */
>> -- 
>> 2.25.1


^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 2/3] fpga: bridge: Use standard dev_release for class driver
  2021-07-01  6:26   ` Xu Yilun
@ 2021-07-06 23:08     ` Russ Weight
  0 siblings, 0 replies; 22+ messages in thread
From: Russ Weight @ 2021-07-06 23:08 UTC (permalink / raw)
  To: Xu Yilun
  Cc: mdf, linux-fpga, trix, lgoncalv, hao.wu, matthew.gerlach, richard.gong



On 6/30/21 11:26 PM, Xu Yilun wrote:
> On Wed, Jun 30, 2021 at 06:37:32PM -0700, Russ Weight wrote:
>> The FPGA bridge class driver data structure is being treated as a
>> managed resource instead of using the standard dev_release call-back
>> function to release the class data structure. This change removes
>> the managed resource code and combines the create() and register()
>> functions into a single register() or register_simple() function.
>>
>> The register() function accepts an info data structure to provide
>> flexibility in passing optional parameters. The register_simple()
>> function supports the current parameter list for users that don't
>> require the use of optional parameters.
>>
>> Signed-off-by: Russ Weight <russell.h.weight@intel.com>
>> Reviewed-by: Xu Yilun <yilun.xu@intel.com>
>> ---
>> v9:
>>   - Cleaned up documentation for the FPGA Bridge register functions
>>   - Renamed fpga_bridge_register() to fpga_bridge_register_full()
>>   - Renamed fpga_bridge_register_simple() to fpga_bridge_register()
> Now we come back to the fpga_XXX_register for normal cases and
> fpga_XXX_register_full for extra parameters.
>
> But the fpga_bridge_register_full has no use case yet, should we
> implement it when it is really needed?
I was just trying to maintain consistency throughout the
framework. I can remove the unused fpga_bridge_register_full()
function.

- Russ
>
> Thanks,
> Yilun
>
>> v8:
>>   - Added reviewed-by tag.
>>   - Updated Documentation/driver-api/fpga/fpga-bridge.rst documentation.
>> v7:
>>   - Update the commit message to describe the new parameters for the
>>     fpga_bridge_register() function and to mention the
>>     fpga_bridge_register_simple() function.
>>   - Fix function prototypes in header file to rename dev to parent.
>>   - Some cleanup of comments.
>>   - Update function defintions/prototypes to apply const to the new info
>>     parameter.
>>   - Verify that info->br_ops is non-null in register functions.
>> v6:
>>   - Changed fpga_bridge_register() parameters to accept an info data
>>     structure to provide flexibility in passing optional parameters.
>>   - Added fpga_bridge_register_simple() function to support current
>>     parameters for users that don't require the use of optional
>>     parameters.
>> v5:
>>   - Rebased on top of recently accepted patches.
>> v4:
>>   - Restore the previous format for the Return value in the comment header
>>     for fpga_bridge_register()
>> v3:
>>   - Cleaned up comment header for fpga_bridge_register()
>>   - Fix error return values for fpga_bridge_register()
>> v2:
>>   - No changes
>> ---
>>  Documentation/driver-api/fpga/fpga-bridge.rst |   8 +-
>>  drivers/fpga/altera-fpga2sdram.c              |  12 +-
>>  drivers/fpga/altera-freeze-bridge.c           |  10 +-
>>  drivers/fpga/altera-hps2fpga.c                |  12 +-
>>  drivers/fpga/dfl-fme-br.c                     |  10 +-
>>  drivers/fpga/fpga-bridge.c                    | 137 ++++++------------
>>  drivers/fpga/xilinx-pr-decoupler.c            |  17 +--
>>  include/linux/fpga/fpga-bridge.h              |  33 +++--
>>  8 files changed, 101 insertions(+), 138 deletions(-)
>>
>> diff --git a/Documentation/driver-api/fpga/fpga-bridge.rst b/Documentation/driver-api/fpga/fpga-bridge.rst
>> index 8d650b4e2ce6..38e3bac8e877 100644
>> --- a/Documentation/driver-api/fpga/fpga-bridge.rst
>> +++ b/Documentation/driver-api/fpga/fpga-bridge.rst
>> @@ -6,8 +6,10 @@ API to implement a new FPGA bridge
>>  
>>  * struct fpga_bridge - The FPGA Bridge structure
>>  * struct fpga_bridge_ops - Low level Bridge driver ops
>> -* devm_fpga_bridge_create() - Allocate and init a bridge struct
>> -* fpga_bridge_register() - Register a bridge
>> +* fpga_bridge_register_full() - Create and register a bridge using the
>> +  fpga_bridge_info structure to provide the full flexibility of options
>> +* fpga_bridge_register() - Create and register a bridge using standard
>> +  arguments
>>  * fpga_bridge_unregister() - Unregister a bridge
>>  
>>  .. kernel-doc:: include/linux/fpga/fpga-bridge.h
>> @@ -17,7 +19,7 @@ API to implement a new FPGA bridge
>>     :functions: fpga_bridge_ops
>>  
>>  .. kernel-doc:: drivers/fpga/fpga-bridge.c
>> -   :functions: devm_fpga_bridge_create
>> +   :functions: fpga_bridge_register_full
>>  
>>  .. kernel-doc:: drivers/fpga/fpga-bridge.c
>>     :functions: fpga_bridge_register
>> diff --git a/drivers/fpga/altera-fpga2sdram.c b/drivers/fpga/altera-fpga2sdram.c
>> index a78e49c63c64..66063507116b 100644
>> --- a/drivers/fpga/altera-fpga2sdram.c
>> +++ b/drivers/fpga/altera-fpga2sdram.c
>> @@ -121,17 +121,13 @@ static int alt_fpga_bridge_probe(struct platform_device *pdev)
>>  	/* Get f2s bridge configuration saved in handoff register */
>>  	regmap_read(sysmgr, SYSMGR_ISWGRP_HANDOFF3, &priv->mask);
>>  
>> -	br = devm_fpga_bridge_create(dev, F2S_BRIDGE_NAME,
>> -				     &altera_fpga2sdram_br_ops, priv);
>> -	if (!br)
>> -		return -ENOMEM;
>> +	br = fpga_bridge_register(dev, F2S_BRIDGE_NAME,
>> +				  &altera_fpga2sdram_br_ops, priv);
>> +	if (IS_ERR(br))
>> +		return PTR_ERR(mgr);
>>  
>>  	platform_set_drvdata(pdev, br);
>>  
>> -	ret = fpga_bridge_register(br);
>> -	if (ret)
>> -		return ret;
>> -
>>  	dev_info(dev, "driver initialized with handoff %08x\n", priv->mask);
>>  
>>  	if (!of_property_read_u32(dev->of_node, "bridge-enable", &enable)) {
>> diff --git a/drivers/fpga/altera-freeze-bridge.c b/drivers/fpga/altera-freeze-bridge.c
>> index dd58c4aea92e..bfbfa43cd05b 100644
>> --- a/drivers/fpga/altera-freeze-bridge.c
>> +++ b/drivers/fpga/altera-freeze-bridge.c
>> @@ -244,14 +244,14 @@ static int altera_freeze_br_probe(struct platform_device *pdev)
>>  
>>  	priv->base_addr = base_addr;
>>  
>> -	br = devm_fpga_bridge_create(dev, FREEZE_BRIDGE_NAME,
>> -				     &altera_freeze_br_br_ops, priv);
>> -	if (!br)
>> -		return -ENOMEM;
>> +	br = fpga_bridge_register(dev, FREEZE_BRIDGE_NAME,
>> +				  &altera_freeze_br_br_ops, priv);
>> +	if (IS_ERR(br))
>> +		return PTR_ERR(br);
>>  
>>  	platform_set_drvdata(pdev, br);
>>  
>> -	return fpga_bridge_register(br);
>> +	return 0;
>>  }
>>  
>>  static int altera_freeze_br_remove(struct platform_device *pdev)
>> diff --git a/drivers/fpga/altera-hps2fpga.c b/drivers/fpga/altera-hps2fpga.c
>> index 77b95f251821..aa758426c22b 100644
>> --- a/drivers/fpga/altera-hps2fpga.c
>> +++ b/drivers/fpga/altera-hps2fpga.c
>> @@ -180,19 +180,15 @@ static int alt_fpga_bridge_probe(struct platform_device *pdev)
>>  		}
>>  	}
>>  
>> -	br = devm_fpga_bridge_create(dev, priv->name,
>> -				     &altera_hps2fpga_br_ops, priv);
>> -	if (!br) {
>> -		ret = -ENOMEM;
>> +	br = fpga_bridge_register(dev, priv->name,
>> +				  &altera_hps2fpga_br_ops, priv);
>> +	if (IS_ERR(br)) {
>> +		ret = PTR_ERR(br);
>>  		goto err;
>>  	}
>>  
>>  	platform_set_drvdata(pdev, br);
>>  
>> -	ret = fpga_bridge_register(br);
>> -	if (ret)
>> -		goto err;
>> -
>>  	return 0;
>>  
>>  err:
>> diff --git a/drivers/fpga/dfl-fme-br.c b/drivers/fpga/dfl-fme-br.c
>> index 3ff9f3a687ce..808d1f4d76df 100644
>> --- a/drivers/fpga/dfl-fme-br.c
>> +++ b/drivers/fpga/dfl-fme-br.c
>> @@ -68,14 +68,14 @@ static int fme_br_probe(struct platform_device *pdev)
>>  
>>  	priv->pdata = dev_get_platdata(dev);
>>  
>> -	br = devm_fpga_bridge_create(dev, "DFL FPGA FME Bridge",
>> -				     &fme_bridge_ops, priv);
>> -	if (!br)
>> -		return -ENOMEM;
>> +	br = fpga_bridge_register(dev, "DFL FPGA FME Bridge",
>> +				  &fme_bridge_ops, priv);
>> +	if (IS_ERR(br))
>> +		return PTR_ERR(br);
>>  
>>  	platform_set_drvdata(pdev, br);
>>  
>> -	return fpga_bridge_register(br);
>> +	return 0;
>>  }
>>  
>>  static int fme_br_remove(struct platform_device *pdev)
>> diff --git a/drivers/fpga/fpga-bridge.c b/drivers/fpga/fpga-bridge.c
>> index 798f55670646..e6d98be8531b 100644
>> --- a/drivers/fpga/fpga-bridge.c
>> +++ b/drivers/fpga/fpga-bridge.c
>> @@ -312,55 +312,63 @@ static struct attribute *fpga_bridge_attrs[] = {
>>  ATTRIBUTE_GROUPS(fpga_bridge);
>>  
>>  /**
>> - * fpga_bridge_create - create and initialize a struct fpga_bridge
>> + * fpga_bridge_register_full - create and register an FPGA Bridge device
>>   * @parent:	FPGA bridge device from pdev
>> - * @name:	FPGA bridge name
>> - * @br_ops:	pointer to structure of fpga bridge ops
>> - * @priv:	FPGA bridge private data
>> + * @info:	parameters for FPGA Bridge
>>   *
>> - * The caller of this function is responsible for freeing the bridge with
>> - * fpga_bridge_free().  Using devm_fpga_bridge_create() instead is recommended.
>> - *
>> - * Return: struct fpga_bridge or NULL
>> + * Return: struct fpga_bridge pointer or ERR_PTR()
>>   */
>> -struct fpga_bridge *fpga_bridge_create(struct device *parent, const char *name,
>> -				       const struct fpga_bridge_ops *br_ops,
>> -				       void *priv)
>> +struct fpga_bridge *
>> +fpga_bridge_register_full(struct device *parent,
>> +			  const struct fpga_bridge_info *info)
>>  {
>>  	struct fpga_bridge *bridge;
>>  	int id, ret;
>>  
>> -	if (!name || !strlen(name)) {
>> +	if (!info->br_ops) {
>> +		dev_err(parent, "Attempt to register without fpga_bridge_ops\n");
>> +		return ERR_PTR(-EINVAL);
>> +	}
>> +
>> +	if (!info->name || !strlen(info->name)) {
>>  		dev_err(parent, "Attempt to register with no name!\n");
>> -		return NULL;
>> +		return ERR_PTR(-EINVAL);
>>  	}
>>  
>>  	bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
>>  	if (!bridge)
>> -		return NULL;
>> +		return ERR_PTR(-ENOMEM);
>>  
>>  	id = ida_simple_get(&fpga_bridge_ida, 0, 0, GFP_KERNEL);
>> -	if (id < 0)
>> +	if (id < 0) {
>> +		ret = id;
>>  		goto error_kfree;
>> +	}
>>  
>>  	mutex_init(&bridge->mutex);
>>  	INIT_LIST_HEAD(&bridge->node);
>>  
>> -	bridge->name = name;
>> -	bridge->br_ops = br_ops;
>> -	bridge->priv = priv;
>> +	bridge->name = info->name;
>> +	bridge->br_ops = info->br_ops;
>> +	bridge->priv = info->priv;
>>  
>> -	device_initialize(&bridge->dev);
>> -	bridge->dev.groups = br_ops->groups;
>> +	bridge->dev.groups = info->br_ops->groups;
>>  	bridge->dev.class = fpga_bridge_class;
>>  	bridge->dev.parent = parent;
>>  	bridge->dev.of_node = parent->of_node;
>>  	bridge->dev.id = id;
>> +	of_platform_populate(bridge->dev.of_node, NULL, NULL, &bridge->dev);
>>  
>>  	ret = dev_set_name(&bridge->dev, "br%d", id);
>>  	if (ret)
>>  		goto error_device;
>>  
>> +	ret = device_register(&bridge->dev);
>> +	if (ret) {
>> +		put_device(&bridge->dev);
>> +		return ERR_PTR(ret);
>> +	}
>> +
>>  	return bridge;
>>  
>>  error_device:
>> @@ -368,88 +376,35 @@ struct fpga_bridge *fpga_bridge_create(struct device *parent, const char *name,
>>  error_kfree:
>>  	kfree(bridge);
>>  
>> -	return NULL;
>> -}
>> -EXPORT_SYMBOL_GPL(fpga_bridge_create);
>> -
>> -/**
>> - * fpga_bridge_free - free an fpga bridge created by fpga_bridge_create()
>> - * @bridge:	FPGA bridge struct
>> - */
>> -void fpga_bridge_free(struct fpga_bridge *bridge)
>> -{
>> -	ida_simple_remove(&fpga_bridge_ida, bridge->dev.id);
>> -	kfree(bridge);
>> -}
>> -EXPORT_SYMBOL_GPL(fpga_bridge_free);
>> -
>> -static void devm_fpga_bridge_release(struct device *dev, void *res)
>> -{
>> -	struct fpga_bridge *bridge = *(struct fpga_bridge **)res;
>> -
>> -	fpga_bridge_free(bridge);
>> +	return ERR_PTR(ret);
>>  }
>> +EXPORT_SYMBOL_GPL(fpga_bridge_register_full);
>>  
>>  /**
>> - * devm_fpga_bridge_create - create and init a managed struct fpga_bridge
>> + * fpga_bridge_register - create and register an FPGA Bridge device
>>   * @parent:	FPGA bridge device from pdev
>>   * @name:	FPGA bridge name
>>   * @br_ops:	pointer to structure of fpga bridge ops
>>   * @priv:	FPGA bridge private data
>>   *
>> - * This function is intended for use in an FPGA bridge driver's probe function.
>> - * After the bridge driver creates the struct with devm_fpga_bridge_create(), it
>> - * should register the bridge with fpga_bridge_register().  The bridge driver's
>> - * remove function should call fpga_bridge_unregister().  The bridge struct
>> - * allocated with this function will be freed automatically on driver detach.
>> - * This includes the case of a probe function returning error before calling
>> - * fpga_bridge_register(), the struct will still get cleaned up.
>> + * This simple version of the register should be sufficient for most users.
>> + * The fpga_bridge_register_full() function is available for users that need to pass
>> + * additional, optional parameters.
>>   *
>> - *  Return: struct fpga_bridge or NULL
>> + * Return: struct fpga_bridge pointer or ERR_PTR()
>>   */
>> -struct fpga_bridge
>> -*devm_fpga_bridge_create(struct device *parent, const char *name,
>> -			 const struct fpga_bridge_ops *br_ops, void *priv)
>> +struct fpga_bridge *
>> +fpga_bridge_register(struct device *parent, const char *name,
>> +		     const struct fpga_bridge_ops *br_ops,
>> +		     void *priv)
>>  {
>> -	struct fpga_bridge **ptr, *bridge;
>> -
>> -	ptr = devres_alloc(devm_fpga_bridge_release, sizeof(*ptr), GFP_KERNEL);
>> -	if (!ptr)
>> -		return NULL;
>> -
>> -	bridge = fpga_bridge_create(parent, name, br_ops, priv);
>> -	if (!bridge) {
>> -		devres_free(ptr);
>> -	} else {
>> -		*ptr = bridge;
>> -		devres_add(parent, ptr);
>> -	}
>> +	struct fpga_bridge_info info = { 0 };
>>  
>> -	return bridge;
>> -}
>> -EXPORT_SYMBOL_GPL(devm_fpga_bridge_create);
>> +	info.name = name;
>> +	info.br_ops = br_ops;
>> +	info.priv = priv;
>>  
>> -/**
>> - * fpga_bridge_register - register an FPGA bridge
>> - *
>> - * @bridge: FPGA bridge struct
>> - *
>> - * Return: 0 for success, error code otherwise.
>> - */
>> -int fpga_bridge_register(struct fpga_bridge *bridge)
>> -{
>> -	struct device *dev = &bridge->dev;
>> -	int ret;
>> -
>> -	ret = device_add(dev);
>> -	if (ret)
>> -		return ret;
>> -
>> -	of_platform_populate(dev->of_node, NULL, NULL, dev);
>> -
>> -	dev_info(dev->parent, "fpga bridge [%s] registered\n", bridge->name);
>> -
>> -	return 0;
>> +	return fpga_bridge_register_full(parent, &info);
>>  }
>>  EXPORT_SYMBOL_GPL(fpga_bridge_register);
>>  
>> @@ -475,6 +430,10 @@ EXPORT_SYMBOL_GPL(fpga_bridge_unregister);
>>  
>>  static void fpga_bridge_dev_release(struct device *dev)
>>  {
>> +	struct fpga_bridge *bridge = to_fpga_bridge(dev);
>> +
>> +	ida_simple_remove(&fpga_bridge_ida, bridge->dev.id);
>> +	kfree(bridge);
>>  }
>>  
>>  static int __init fpga_bridge_dev_init(void)
>> diff --git a/drivers/fpga/xilinx-pr-decoupler.c b/drivers/fpga/xilinx-pr-decoupler.c
>> index ea2bde6e5bc4..c004e52b9464 100644
>> --- a/drivers/fpga/xilinx-pr-decoupler.c
>> +++ b/drivers/fpga/xilinx-pr-decoupler.c
>> @@ -138,22 +138,17 @@ static int xlnx_pr_decoupler_probe(struct platform_device *pdev)
>>  
>>  	clk_disable(priv->clk);
>>  
>> -	br = devm_fpga_bridge_create(&pdev->dev, priv->ipconfig->name,
>> -				     &xlnx_pr_decoupler_br_ops, priv);
>> -	if (!br) {
>> -		err = -ENOMEM;
>> -		goto err_clk;
>> -	}
>> -
>> -	platform_set_drvdata(pdev, br);
>> -
>> -	err = fpga_bridge_register(br);
>> -	if (err) {
>> +	br = fpga_bridge_register(&pdev->dev, priv->ipconfig->name,
>> +				  &xlnx_pr_decoupler_br_ops, priv);
>> +	if (IS_ERR(br)) {
>> +		err = PTR_ERR(br);
>>  		dev_err(&pdev->dev, "unable to register %s",
>>  			priv->ipconfig->name);
>>  		goto err_clk;
>>  	}
>>  
>> +	platform_set_drvdata(pdev, br);
>> +
>>  	return 0;
>>  
>>  err_clk:
>> diff --git a/include/linux/fpga/fpga-bridge.h b/include/linux/fpga/fpga-bridge.h
>> index 6c3c28806ff1..f0a4d99d9c8e 100644
>> --- a/include/linux/fpga/fpga-bridge.h
>> +++ b/include/linux/fpga/fpga-bridge.h
>> @@ -22,6 +22,23 @@ struct fpga_bridge_ops {
>>  	const struct attribute_group **groups;
>>  };
>>  
>> +/**
>> + * struct fpga_bridge_info - collection of parameters an FPGA Bridge
>> + * @name: fpga bridge name
>> + * @br_ops: pointer to structure of fpga bridge ops
>> + * @priv: fpga bridge private data
>> + *
>> + * fpga_bridge_info contains parameters for the register function. These
>> + * are separated into an info structure because they some are optional
>> + * others could be added to in the future. The info structure facilitates
>> + * maintaining a stable API.
>> + */
>> +struct fpga_bridge_info {
>> +	const char *name;
>> +	const struct fpga_bridge_ops *br_ops;
>> +	void *priv;
>> +};
>> +
>>  /**
>>   * struct fpga_bridge - FPGA bridge structure
>>   * @name: name of low level FPGA bridge
>> @@ -62,15 +79,13 @@ int of_fpga_bridge_get_to_list(struct device_node *np,
>>  			       struct fpga_image_info *info,
>>  			       struct list_head *bridge_list);
>>  
>> -struct fpga_bridge *fpga_bridge_create(struct device *dev, const char *name,
>> -				       const struct fpga_bridge_ops *br_ops,
>> -				       void *priv);
>> -void fpga_bridge_free(struct fpga_bridge *br);
>> -int fpga_bridge_register(struct fpga_bridge *br);
>> -void fpga_bridge_unregister(struct fpga_bridge *br);
>> +struct fpga_bridge *
>> +fpga_bridge_register_full(struct device *parent, const struct fpga_bridge_info *info);
>>  
>> -struct fpga_bridge
>> -*devm_fpga_bridge_create(struct device *dev, const char *name,
>> -			 const struct fpga_bridge_ops *br_ops, void *priv);
>> +struct fpga_bridge *
>> +fpga_bridge_register(struct device *parent, const char *name,
>> +		     const struct fpga_bridge_ops *br_ops,
>> +		     void *priv);
>> +void fpga_bridge_unregister(struct fpga_bridge *br);
>>  
>>  #endif /* _LINUX_FPGA_BRIDGE_H */
>> -- 
>> 2.25.1


^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 3/3] fpga: region: Use standard dev_release for class driver
  2021-07-01  5:51   ` Xu Yilun
@ 2021-07-06 23:08     ` Russ Weight
  0 siblings, 0 replies; 22+ messages in thread
From: Russ Weight @ 2021-07-06 23:08 UTC (permalink / raw)
  To: Xu Yilun
  Cc: mdf, linux-fpga, trix, lgoncalv, hao.wu, matthew.gerlach, richard.gong



On 6/30/21 10:51 PM, Xu Yilun wrote:
> On Wed, Jun 30, 2021 at 06:37:33PM -0700, Russ Weight wrote:
>> The FPGA region class driver data structure is being treated as a
>> managed resource instead of using the standard dev_release call-back
>> function to release the class data structure. This change removes the
>> managed resource code and combines the create() and register()
>> functions into a single register() or register_simple() function.
>>
>> The register() function accepts an info data structure to provide
>> flexibility in passing optional parameters. The register_simple()
>> function supports the current parameter list for users that don't
>> require the use of optional parameters.
> Please update the commit message, others are good to me.

I'll fix it. Thanks!
- Russ
>
> Thanks,
> Yilun
>
>> Signed-off-by: Russ Weight <russell.h.weight@intel.com>
>> Reviewed-by: Xu Yilun <yilun.xu@intel.com>
>> ---
>> v9:
>>   - Cleaned up documentation for the FPGA Region register functions
>>   - Renamed fpga_region_register() to fpga_region_register_full()
>>   - Renamed fpga_region_register_simple() to fpga_region_register()
>> v8:
>>   - Added reviewed-by tag.
>>   - Updated Documentation/driver-api/fpga/fpga-region.rst documentation.
>> v7:
>>   - Update the commit message to describe the new parameters for the
>>     fpga_region_register() function and to mention the
>>     fpga_region_register_simple() function.
>>   - Fix function prototypes in header file to rename dev to parent.
>>   - Some cleanup of comments.
>>   - Update function defintions/prototypes to apply const to the new info
>>     parameter.
>>   - Verify a non-null info pointer in the register() functions.
>> v6:
>>   - Moved FPGA manager optional parameters out of the ops structure and
>>     back into the FPGA Region structure.
>>   - Changed fpga_region_register() parameters to accept an info data
>>     structure to provide flexibility in passing optional parameters.
>>   - Added fpga_region_register_simple() functions to support current
>>     parameters for users that don't require the use of optional parameters.
>> v5:
>>   - Rebased on top of recently accepted patches.
>>   - Created the fpga_region_ops data structure which is optionally passed
>>     to fpga_region_register(). compat_id, the get_bridges() pointer, and
>>     the priv pointer are included in the fpga_region_ops structure.
>> v4:
>>   - Added the compat_id parameter to fpga_region_register() to ensure
>>     that the compat_id is set before the device_register() call.
>>   - Modified the dfl_fpga_feature_devs_enumerate() function to restore
>>     the fpga_region_register() call to the correct location.
>> v3:
>>   - Cleaned up comment header for fpga_region_register()
>>   - Fix fpga_region_register() error return on ida_simple_get() failure
>> v2:
>>   - No changes
>> ---
>>  Documentation/driver-api/fpga/fpga-region.rst |   8 +-
>>  drivers/fpga/dfl-fme-region.c                 |  17 ++-
>>  drivers/fpga/dfl.c                            |  12 +-
>>  drivers/fpga/fpga-region.c                    | 119 +++++++-----------
>>  drivers/fpga/of-fpga-region.c                 |  10 +-
>>  include/linux/fpga/fpga-region.h              |  36 ++++--
>>  6 files changed, 91 insertions(+), 111 deletions(-)
>>
>> diff --git a/Documentation/driver-api/fpga/fpga-region.rst b/Documentation/driver-api/fpga/fpga-region.rst
>> index 2636a27c11b2..904518190bb4 100644
>> --- a/Documentation/driver-api/fpga/fpga-region.rst
>> +++ b/Documentation/driver-api/fpga/fpga-region.rst
>> @@ -46,8 +46,10 @@ API to add a new FPGA region
>>  ----------------------------
>>  
>>  * struct fpga_region - The FPGA region struct
>> -* devm_fpga_region_create() - Allocate and init a region struct
>> -* fpga_region_register() -  Register an FPGA region
>> +* fpga_region_register_full() -  Create and register an FPGA region using the
>> +  fpga_region_info structure to provide the full flexibility of options
>> +* fpga_region_register() -  Create and register an FPGA region using standard
>> +  arguments
>>  * fpga_region_unregister() -  Unregister an FPGA region
>>  
>>  The FPGA region's probe function will need to get a reference to the FPGA
>> @@ -76,7 +78,7 @@ following APIs to handle building or tearing down that list.
>>     :functions: fpga_region
>>  
>>  .. kernel-doc:: drivers/fpga/fpga-region.c
>> -   :functions: devm_fpga_region_create
>> +   :functions: fpga_region_register_full
>>  
>>  .. kernel-doc:: drivers/fpga/fpga-region.c
>>     :functions: fpga_region_register
>> diff --git a/drivers/fpga/dfl-fme-region.c b/drivers/fpga/dfl-fme-region.c
>> index 1eeb42af1012..4aebde0a7f1c 100644
>> --- a/drivers/fpga/dfl-fme-region.c
>> +++ b/drivers/fpga/dfl-fme-region.c
>> @@ -30,6 +30,7 @@ static int fme_region_get_bridges(struct fpga_region *region)
>>  static int fme_region_probe(struct platform_device *pdev)
>>  {
>>  	struct dfl_fme_region_pdata *pdata = dev_get_platdata(&pdev->dev);
>> +	struct fpga_region_info info = { 0 };
>>  	struct device *dev = &pdev->dev;
>>  	struct fpga_region *region;
>>  	struct fpga_manager *mgr;
>> @@ -39,20 +40,18 @@ static int fme_region_probe(struct platform_device *pdev)
>>  	if (IS_ERR(mgr))
>>  		return -EPROBE_DEFER;
>>  
>> -	region = devm_fpga_region_create(dev, mgr, fme_region_get_bridges);
>> -	if (!region) {
>> -		ret = -ENOMEM;
>> +	info.mgr = mgr;
>> +	info.compat_id = mgr->compat_id;
>> +	info.get_bridges = fme_region_get_bridges;
>> +	info.priv = pdata;
>> +	region = fpga_region_register_full(dev, &info);
>> +	if (IS_ERR(region)) {
>> +		ret = PTR_ERR(region);
>>  		goto eprobe_mgr_put;
>>  	}
>>  
>> -	region->priv = pdata;
>> -	region->compat_id = mgr->compat_id;
>>  	platform_set_drvdata(pdev, region);
>>  
>> -	ret = fpga_region_register(region);
>> -	if (ret)
>> -		goto eprobe_mgr_put;
>> -
>>  	dev_dbg(dev, "DFL FME FPGA Region probed\n");
>>  
>>  	return 0;
>> diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
>> index 511b20ff35a3..3905995ef6d5 100644
>> --- a/drivers/fpga/dfl.c
>> +++ b/drivers/fpga/dfl.c
>> @@ -1400,19 +1400,15 @@ dfl_fpga_feature_devs_enumerate(struct dfl_fpga_enum_info *info)
>>  	if (!cdev)
>>  		return ERR_PTR(-ENOMEM);
>>  
>> -	cdev->region = devm_fpga_region_create(info->dev, NULL, NULL);
>> -	if (!cdev->region) {
>> -		ret = -ENOMEM;
>> -		goto free_cdev_exit;
>> -	}
>> -
>>  	cdev->parent = info->dev;
>>  	mutex_init(&cdev->lock);
>>  	INIT_LIST_HEAD(&cdev->port_dev_list);
>>  
>> -	ret = fpga_region_register(cdev->region);
>> -	if (ret)
>> +	cdev->region = fpga_region_register(info->dev, NULL, NULL);
>> +	if (IS_ERR(cdev->region)) {
>> +		ret = PTR_ERR(cdev->region);
>>  		goto free_cdev_exit;
>> +	}
>>  
>>  	/* create and init build info for enumeration */
>>  	binfo = devm_kzalloc(info->dev, sizeof(*binfo), GFP_KERNEL);
>> diff --git a/drivers/fpga/fpga-region.c b/drivers/fpga/fpga-region.c
>> index a4838715221f..8af108a383e0 100644
>> --- a/drivers/fpga/fpga-region.c
>> +++ b/drivers/fpga/fpga-region.c
>> @@ -180,39 +180,42 @@ static struct attribute *fpga_region_attrs[] = {
>>  ATTRIBUTE_GROUPS(fpga_region);
>>  
>>  /**
>> - * fpga_region_create - alloc and init a struct fpga_region
>> + * fpga_region_register_full - create and register an FPGA Region device
>>   * @parent: device parent
>> - * @mgr: manager that programs this region
>> - * @get_bridges: optional function to get bridges to a list
>> - *
>> - * The caller of this function is responsible for freeing the resulting region
>> - * struct with fpga_region_free().  Using devm_fpga_region_create() instead is
>> - * recommended.
>> + * @info: parameters for FPGA Region
>>   *
>> - * Return: struct fpga_region or NULL
>> + * Return: struct fpga_region or ERR_PTR()
>>   */
>> -struct fpga_region
>> -*fpga_region_create(struct device *parent,
>> -		    struct fpga_manager *mgr,
>> -		    int (*get_bridges)(struct fpga_region *))
>> +struct fpga_region *
>> +fpga_region_register_full(struct device *parent, const struct fpga_region_info *info)
>>  {
>>  	struct fpga_region *region;
>>  	int id, ret = 0;
>>  
>> +	if (!info) {
>> +		dev_err(parent,
>> +			"Attempt to register without required info structure\n");
>> +		return ERR_PTR(-EINVAL);
>> +	}
>> +
>>  	region = kzalloc(sizeof(*region), GFP_KERNEL);
>>  	if (!region)
>> -		return NULL;
>> +		return ERR_PTR(-ENOMEM);
>>  
>>  	id = ida_simple_get(&fpga_region_ida, 0, 0, GFP_KERNEL);
>> -	if (id < 0)
>> +	if (id < 0) {
>> +		ret = id;
>>  		goto err_free;
>> +	}
>> +
>> +	region->mgr = info->mgr;
>> +	region->compat_id = info->compat_id;
>> +	region->priv = info->priv;
>> +	region->get_bridges = info->get_bridges;
>>  
>> -	region->mgr = mgr;
>> -	region->get_bridges = get_bridges;
>>  	mutex_init(&region->mutex);
>>  	INIT_LIST_HEAD(&region->bridge_list);
>>  
>> -	device_initialize(&region->dev);
>>  	region->dev.class = fpga_region_class;
>>  	region->dev.parent = parent;
>>  	region->dev.of_node = parent->of_node;
>> @@ -222,6 +225,12 @@ struct fpga_region
>>  	if (ret)
>>  		goto err_remove;
>>  
>> +	ret = device_register(&region->dev);
>> +	if (ret) {
>> +		put_device(&region->dev);
>> +		return ERR_PTR(ret);
>> +	}
>> +
>>  	return region;
>>  
>>  err_remove:
>> @@ -229,76 +238,32 @@ struct fpga_region
>>  err_free:
>>  	kfree(region);
>>  
>> -	return NULL;
>> -}
>> -EXPORT_SYMBOL_GPL(fpga_region_create);
>> -
>> -/**
>> - * fpga_region_free - free an FPGA region created by fpga_region_create()
>> - * @region: FPGA region
>> - */
>> -void fpga_region_free(struct fpga_region *region)
>> -{
>> -	ida_simple_remove(&fpga_region_ida, region->dev.id);
>> -	kfree(region);
>> -}
>> -EXPORT_SYMBOL_GPL(fpga_region_free);
>> -
>> -static void devm_fpga_region_release(struct device *dev, void *res)
>> -{
>> -	struct fpga_region *region = *(struct fpga_region **)res;
>> -
>> -	fpga_region_free(region);
>> +	return ERR_PTR(ret);
>>  }
>> +EXPORT_SYMBOL_GPL(fpga_region_register_full);
>>  
>>  /**
>> - * devm_fpga_region_create - create and initialize a managed FPGA region struct
>> + * fpga_region_register - create and register an FPGA Region device
>>   * @parent: device parent
>>   * @mgr: manager that programs this region
>>   * @get_bridges: optional function to get bridges to a list
>>   *
>> - * This function is intended for use in an FPGA region driver's probe function.
>> - * After the region driver creates the region struct with
>> - * devm_fpga_region_create(), it should register it with fpga_region_register().
>> - * The region driver's remove function should call fpga_region_unregister().
>> - * The region struct allocated with this function will be freed automatically on
>> - * driver detach.  This includes the case of a probe function returning error
>> - * before calling fpga_region_register(), the struct will still get cleaned up.
>> + * This simple version of the register should be sufficient for most users.
>> + * The fpga_region_register_full() function is available for users that need to
>> + * pass additional, optional parameters.
>>   *
>> - * Return: struct fpga_region or NULL
>> + * Return: struct fpga_region or ERR_PTR()
>>   */
>> -struct fpga_region
>> -*devm_fpga_region_create(struct device *parent,
>> -			 struct fpga_manager *mgr,
>> -			 int (*get_bridges)(struct fpga_region *))
>> +struct fpga_region *
>> +fpga_region_register(struct device *parent, struct fpga_manager *mgr,
>> +		     int (*get_bridges)(struct fpga_region *))
>>  {
>> -	struct fpga_region **ptr, *region;
>> -
>> -	ptr = devres_alloc(devm_fpga_region_release, sizeof(*ptr), GFP_KERNEL);
>> -	if (!ptr)
>> -		return NULL;
>> +	struct fpga_region_info info = { 0 };
>>  
>> -	region = fpga_region_create(parent, mgr, get_bridges);
>> -	if (!region) {
>> -		devres_free(ptr);
>> -	} else {
>> -		*ptr = region;
>> -		devres_add(parent, ptr);
>> -	}
>> +	info.mgr = mgr;
>> +	info.get_bridges = get_bridges;
>>  
>> -	return region;
>> -}
>> -EXPORT_SYMBOL_GPL(devm_fpga_region_create);
>> -
>> -/**
>> - * fpga_region_register - register an FPGA region
>> - * @region: FPGA region
>> - *
>> - * Return: 0 or -errno
>> - */
>> -int fpga_region_register(struct fpga_region *region)
>> -{
>> -	return device_add(&region->dev);
>> +	return fpga_region_register_full(parent, &info);
>>  }
>>  EXPORT_SYMBOL_GPL(fpga_region_register);
>>  
>> @@ -316,6 +281,10 @@ EXPORT_SYMBOL_GPL(fpga_region_unregister);
>>  
>>  static void fpga_region_dev_release(struct device *dev)
>>  {
>> +	struct fpga_region *region = to_fpga_region(dev);
>> +
>> +	ida_simple_remove(&fpga_region_ida, region->dev.id);
>> +	kfree(region);
>>  }
>>  
>>  /**
>> diff --git a/drivers/fpga/of-fpga-region.c b/drivers/fpga/of-fpga-region.c
>> index e3c25576b6b9..9c662db1c508 100644
>> --- a/drivers/fpga/of-fpga-region.c
>> +++ b/drivers/fpga/of-fpga-region.c
>> @@ -405,16 +405,12 @@ static int of_fpga_region_probe(struct platform_device *pdev)
>>  	if (IS_ERR(mgr))
>>  		return -EPROBE_DEFER;
>>  
>> -	region = devm_fpga_region_create(dev, mgr, of_fpga_region_get_bridges);
>> -	if (!region) {
>> -		ret = -ENOMEM;
>> +	region = fpga_region_register(dev, mgr, of_fpga_region_get_bridges);
>> +	if (IS_ERR(region)) {
>> +		ret = PTR_ERR(region);
>>  		goto eprobe_mgr_put;
>>  	}
>>  
>> -	ret = fpga_region_register(region);
>> -	if (ret)
>> -		goto eprobe_mgr_put;
>> -
>>  	of_platform_populate(np, fpga_region_of_match, NULL, &region->dev);
>>  	platform_set_drvdata(pdev, region);
>>  
>> diff --git a/include/linux/fpga/fpga-region.h b/include/linux/fpga/fpga-region.h
>> index 27cb706275db..ae111beeffba 100644
>> --- a/include/linux/fpga/fpga-region.h
>> +++ b/include/linux/fpga/fpga-region.h
>> @@ -7,6 +7,27 @@
>>  #include <linux/fpga/fpga-mgr.h>
>>  #include <linux/fpga/fpga-bridge.h>
>>  
>> +struct fpga_region;
>> +
>> +/**
>> + * struct fpga_region_info - collection of parameters an FPGA Region
>> + * @mgr: fpga region manager
>> + * @compat_id: FPGA region id for compatibility check.
>> + * @priv: fpga region private data
>> + * @get_bridges: optional function to get bridges to a list
>> + *
>> + * fpga_region_info contains parameters for the register function. These
>> + * are separated into an info structure because they some are optional
>> + * others could be added to in the future. The info structure facilitates
>> + * maintaining a stable API.
>> + */
>> +struct fpga_region_info {
>> +	struct fpga_manager *mgr;
>> +	struct fpga_compat_id *compat_id;
>> +	void *priv;
>> +	int (*get_bridges)(struct fpga_region *region);
>> +};
>> +
>>  /**
>>   * struct fpga_region - FPGA Region structure
>>   * @dev: FPGA Region device
>> @@ -37,15 +58,12 @@ struct fpga_region *fpga_region_class_find(
>>  
>>  int fpga_region_program_fpga(struct fpga_region *region);
>>  
>> -struct fpga_region
>> -*fpga_region_create(struct device *dev, struct fpga_manager *mgr,
>> -		    int (*get_bridges)(struct fpga_region *));
>> -void fpga_region_free(struct fpga_region *region);
>> -int fpga_region_register(struct fpga_region *region);
>> -void fpga_region_unregister(struct fpga_region *region);
>> +struct fpga_region *
>> +fpga_region_register_full(struct device *parent, const struct fpga_region_info *info);
>>  
>> -struct fpga_region
>> -*devm_fpga_region_create(struct device *dev, struct fpga_manager *mgr,
>> -			int (*get_bridges)(struct fpga_region *));
>> +struct fpga_region *
>> +fpga_region_register(struct device *parent, struct fpga_manager *mgr,
>> +		     int (*get_bridges)(struct fpga_region *));
>> +void fpga_region_unregister(struct fpga_region *region);
>>  
>>  #endif /* _FPGA_REGION_H */
>> -- 
>> 2.25.1


^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 1/3] fpga: mgr: Use standard dev_release for class driver
  2021-07-06 23:03         ` Russ Weight
@ 2021-07-07  2:45           ` Xu Yilun
  2021-07-07 13:29           ` Tom Rix
  1 sibling, 0 replies; 22+ messages in thread
From: Xu Yilun @ 2021-07-07  2:45 UTC (permalink / raw)
  To: Russ Weight
  Cc: Tom Rix, mdf, linux-fpga, lgoncalv, hao.wu, matthew.gerlach,
	richard.gong

On Tue, Jul 06, 2021 at 04:03:59PM -0700, Russ Weight wrote:
> 
> 
> On 7/6/21 2:44 PM, Tom Rix wrote:
> >
> > On 7/6/21 2:02 PM, Russ Weight wrote:
> >>
> >> On 7/6/21 12:04 PM, Tom Rix wrote:
> >>> Russ,
> >>>
> >>> My two big concerns are.
> >>>
> >>> compat_id does not belong in fpga_mgr_info, it belongs in fme_mgr_priv.
> >> fpga_mgr_info is a temporary structure on the stack that contains the
> >> parameters only long enough to pass them in and have them added to the
> >> fpga_manager structure. Do you have a concern about it being on the
> >> fpga_manager structure.
> >
> > My concern is compat_id should never have been part of fpga-mgr in the first place.
> >
> > It is dfl specific, so instead of going in a common structure, it should go into a dfl structure
> >
> > The likely place it should go is fme_mgr_priv.
> >
> > The need for 2 register functions here and in fpga-region is caused by carrying this dfl data around in the wrong place.
> 
> This issue was raised for the previous patch version, and Hao pointed out that
> its placement in the fpga_manager structure was a result of community discussion.

The previous compat_id discussion:

https://lore.kernel.org/linux-fpga/DM6PR11MB381991DCF48578CDB55FBF78850A9@DM6PR11MB3819.namprd11.prod.outlook.com/

The compatible checking for bitstreams & FPGA regions is important for
FPGA reconfiguration and could be a common need. And a uuid style
matching could be an effective way for this. Yes DFL is the only hardware
that implements the mechanism, but other driver could still benifit from
the check even if it is not done by hardware.

Thanks,
Yilun

> 
> These changes aren't affecting the location of compat_id. Where it is
> stored is not really within the scope of what I am trying to accomplish.
> If it needs to be changed, could it be handled in a separate patch set?
> 
> - Russ
> 
> > Tom
> >
> >>> there are two register functions, there should be one.
> >> I get what you are saying. I don't really like the idea of forcing the
> >> complexity of the temporary structure on all callers, since only a
> >> couple require it, but we can do that if that is the concensus.
> >>
> >> What do others think?
> >>
> >>> On 6/30/21 6:37 PM, Russ Weight wrote:
> >>>> The FPGA manager class driver data structure is being treated as a
> >>>> managed resource instead of using the standard dev_release call-back
> >>>> function to release the class data structure. This change removes
> >>>> the managed resource code for the freeing of the class data structure
> >>>> and combines the create() and register() functions into a single
> >>>> register() or register_simple() function.
> >>>>
> >>>> The register() function accepts an info data structure to provide
> >>>> flexibility in passing optional parameters. The register_simple()
> >>>> function supports the current parameter list for users that don't
> >>>> require the use of optional parameters.
> >>>>
> >>>> The devm_fpga_mgr_register() function is retained, and the
> >>>> devm_fpga_mgr_register_simple() function is added.
> >>>>
> >>>> Signed-off-by: Russ Weight <russell.h.weight@intel.com>
> >>>> Reviewed-by: Xu Yilun <yilun.xu@intel.com>
> >>>> ---
> >>>> v9:
> >>>>     - Cleaned up documentation for the FPGA Manager register functions
> >>>>     - Renamed fpga_mgr_register() to fpga_mgr_register_full()
> >>>>     - Renamed fpga_mgr_register_simple() to fpga_mgr_register()
> >>>>     - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full()
> >>>>     - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register()
> >>>> v8:
> >>>>     - Added reviewed-by tag.
> >>>>     - Updated Documentation/driver-api/fpga/fpga-mgr.rst documentation.
> >>>> v7:
> >>>>     - Update the commit message to describe the new parameters for the
> >>>>       *fpga_mgr_register() functions and to mention the
> >>>>       *fpga_mgr_register_simple() functions.
> >>>>     - Fix function prototypes in header file to rename dev to parent.
> >>>>     - Make use of the PTR_ERR_OR_ZERO() macro when possible.
> >>>>     - Some cleanup of comments.
> >>>>     - Update function defintions/prototypes to apply const to the new info
> >>>>       parameter.
> >>>> v6:
> >>>>     - Moved FPGA manager optional parameters out of the ops structure and
> >>>>       back into the FPGA manager structure.
> >>>>     - Changed fpga_mgr_register()/devm_fpga_mgr_register() parameters to
> >>>>       accept an info data structure to provide flexibility in passing optional
> >>>>       parameters.
> >>>>     - Added fpga_mgr_register_simple()/devm_fpga_mgr_register_simple()
> >>>>       functions to support current parameters for users that don't require
> >>>>       the use of optional parameters.
> >>>> v5:
> >>>>     - Rebased on top of recently accepted patches.
> >>>>     - Removed compat_id from the fpga_mgr_register() parameter list
> >>>>       and added it to the fpga_manager_ops structure. This also required
> >>>>       dynamically allocating the dfl-fme-ops structure in order to add
> >>>>       the appropriate compat_id.
> >>>> v4:
> >>>>     - Added the compat_id parameter to fpga_mgr_register() and
> >>>>       devm_fpga_mgr_register() to ensure that the compat_id is set before
> >>>>       the device_register() call.
> >>>> v3:
> >>>>     - Cleaned up comment header for fpga_mgr_register()
> >>>>     - Fix error return on ida_simple_get() failure
> >>>> v2:
> >>>>     - Restored devm_fpga_mgr_register() functionality, adapted for the combined
> >>>>       create/register functionality.
> >>>>     - All previous callers of devm_fpga_mgr_register() will continue to call
> >>>>       devm_fpga_mgr_register().
> >>>>     - replaced unnecessary ternary operators in return statements with standard
> >>>>       if conditions.
> >>>> ---
> >>>>    Documentation/driver-api/fpga/fpga-mgr.rst |  34 +++-
> >>>>    drivers/fpga/altera-cvp.c                  |  12 +-
> >>>>    drivers/fpga/altera-pr-ip-core.c           |   7 +-
> >>>>    drivers/fpga/altera-ps-spi.c               |   9 +-
> >>>>    drivers/fpga/dfl-fme-mgr.c                 |  22 +--
> >>>>    drivers/fpga/fpga-mgr.c                    | 215 +++++++++------------
> >>>>    drivers/fpga/ice40-spi.c                   |   9 +-
> >>>>    drivers/fpga/machxo2-spi.c                 |   9 +-
> >>>>    drivers/fpga/socfpga-a10.c                 |  16 +-
> >>>>    drivers/fpga/socfpga.c                     |   9 +-
> >>>>    drivers/fpga/stratix10-soc.c               |  16 +-
> >>>>    drivers/fpga/ts73xx-fpga.c                 |   9 +-
> >>>>    drivers/fpga/xilinx-spi.c                  |  11 +-
> >>>>    drivers/fpga/zynq-fpga.c                   |  16 +-
> >>>>    drivers/fpga/zynqmp-fpga.c                 |   9 +-
> >>>>    include/linux/fpga/fpga-mgr.h              |  62 ++++--
> >>>>    16 files changed, 210 insertions(+), 255 deletions(-)
> >>>>
> >>>> diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
> >>>> index 4d926b452cb3..826ed8dc9210 100644
> >>>> --- a/Documentation/driver-api/fpga/fpga-mgr.rst
> >>>> +++ b/Documentation/driver-api/fpga/fpga-mgr.rst
> >>>> @@ -24,7 +24,7 @@ How to support a new FPGA device
> >>>>    --------------------------------
> >>>>      To add another FPGA manager, write a driver that implements a set of ops.  The
> >>>> -probe function calls fpga_mgr_register(), such as::
> >>>> +probe function calls fpga_mgr_register() or fpga_mgr_register_full(), such as::
> >>>>          static const struct fpga_manager_ops socfpga_fpga_ops = {
> >>>>            .write_init = socfpga_fpga_ops_configure_init,
> >>>> @@ -49,14 +49,14 @@ probe function calls fpga_mgr_register(), such as::
> >>>>             * them in priv
> >>>>             */
> >>>>    -        mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
> >>>> -                       &socfpga_fpga_ops, priv);
> >>>> -        if (!mgr)
> >>>> -            return -ENOMEM;
> >>>> +        mgr = fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
> >>>> +                    &socfpga_fpga_ops, priv);
> >>>> +        if (IS_ERR(mgr))
> >>>> +            return PTR_ERR(mgr);
> >>>>              platform_set_drvdata(pdev, mgr);
> >>>>    -        return fpga_mgr_register(mgr);
> >>>> +        return 0;
> >>>>        }
> >>>>          static int socfpga_fpga_remove(struct platform_device *pdev)
> >>>> @@ -68,6 +68,11 @@ probe function calls fpga_mgr_register(), such as::
> >>>>            return 0;
> >>>>        }
> >>>>    +Alternatively, the probe function could call one of the resource managed
> >>>> +register functions, devm_fpga_mgr_register() or devm_fpga_mgr_register_full().
> >>>> +When these functions are used, the parameter syntax is the same, but the call
> >>>> +to fpga_mgr_unregister() should be removed. In the above example, the
> >>>> +socfpga_fpga_remove() function would not be required.
> >>>>      The ops will implement whatever device specific register writes are needed to
> >>>>    do the programming sequence for this particular FPGA.  These ops return 0 for
> >>>> @@ -104,8 +109,13 @@ API for implementing a new FPGA Manager driver
> >>>>    * ``fpga_mgr_states`` -  Values for :c:expr:`fpga_manager->state`.
> >>>>    * struct fpga_manager -  the FPGA manager struct
> >>>>    * struct fpga_manager_ops -  Low level FPGA manager driver ops
> >>>> -* devm_fpga_mgr_create() -  Allocate and init a manager struct
> >>>> -* fpga_mgr_register() -  Register an FPGA manager
> >>>> +* fpga_mgr_register_full() -  Create and register an FPGA manager using the
> >>>> +  fpga_mgr_info structure to provide the full flexibility of options
> >>>> +* fpga_mgr_register() -  Create and register an FPGA manager using standard
> >>>> +  arguments
> >>>> +* devm_fpga_mgr_register_full() -  Resource managed version of
> >>>> +  fpga_mgr_register_full()
> >>>> +* devm_fpga_mgr_register() -  Resource managed version of fpga_mgr_register()
> >>>>    * fpga_mgr_unregister() -  Unregister an FPGA manager
> >>>>      .. kernel-doc:: include/linux/fpga/fpga-mgr.h
> >>>> @@ -118,10 +128,16 @@ API for implementing a new FPGA Manager driver
> >>>>       :functions: fpga_manager_ops
> >>>>      .. kernel-doc:: drivers/fpga/fpga-mgr.c
> >>>> -   :functions: devm_fpga_mgr_create
> >>>> +   :functions: fpga_mgr_register_full
> >>>>      .. kernel-doc:: drivers/fpga/fpga-mgr.c
> >>>>       :functions: fpga_mgr_register
> >>>>    +.. kernel-doc:: drivers/fpga/fpga-mgr.c
> >>>> +   :functions: devm_fpga_mgr_register_full
> >>>> +
> >>>> +.. kernel-doc:: drivers/fpga/fpga-mgr.c
> >>>> +   :functions: devm_fpga_mgr_register
> >>>> +
> >>>>    .. kernel-doc:: drivers/fpga/fpga-mgr.c
> >>>>       :functions: fpga_mgr_unregister
> >>>> diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
> >>>> index ccf4546eff29..4ffb9da537d8 100644
> >>>> --- a/drivers/fpga/altera-cvp.c
> >>>> +++ b/drivers/fpga/altera-cvp.c
> >>>> @@ -652,19 +652,15 @@ static int altera_cvp_probe(struct pci_dev *pdev,
> >>>>        snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
> >>>>             ALTERA_CVP_MGR_NAME, pci_name(pdev));
> >>>>    -    mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
> >>>> -                   &altera_cvp_ops, conf);
> >>>> -    if (!mgr) {
> >>>> -        ret = -ENOMEM;
> >>>> +    mgr = fpga_mgr_register(&pdev->dev, conf->mgr_name,
> >>>> +                &altera_cvp_ops, conf);
> >>>> +    if (IS_ERR(mgr)) {
> >>>> +        ret = PTR_ERR(mgr);
> >>>>            goto err_unmap;
> >>>>        }
> >>>>          pci_set_drvdata(pdev, mgr);
> >>>>    -    ret = fpga_mgr_register(mgr);
> >>>> -    if (ret)
> >>>> -        goto err_unmap;
> >>>> -
> >>>>        return 0;
> >>>>      err_unmap:
> >>>> diff --git a/drivers/fpga/altera-pr-ip-core.c b/drivers/fpga/altera-pr-ip-core.c
> >>>> index dfdf21ed34c4..be0667968d33 100644
> >>>> --- a/drivers/fpga/altera-pr-ip-core.c
> >>>> +++ b/drivers/fpga/altera-pr-ip-core.c
> >>>> @@ -191,11 +191,8 @@ int alt_pr_register(struct device *dev, void __iomem *reg_base)
> >>>>            (val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
> >>>>            (int)(val & ALT_PR_CSR_PR_START));
> >>>>    -    mgr = devm_fpga_mgr_create(dev, dev_name(dev), &alt_pr_ops, priv);
> >>>> -    if (!mgr)
> >>>> -        return -ENOMEM;
> >>>> -
> >>>> -    return devm_fpga_mgr_register(dev, mgr);
> >>>> +    mgr = devm_fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv);
> >>>> +    return PTR_ERR_OR_ZERO(mgr);
> >>>>    }
> >>>>    EXPORT_SYMBOL_GPL(alt_pr_register);
> >>>>    diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
> >>>> index 23bfd4d1ad0f..5e1e009dba89 100644
> >>>> --- a/drivers/fpga/altera-ps-spi.c
> >>>> +++ b/drivers/fpga/altera-ps-spi.c
> >>>> @@ -302,12 +302,9 @@ static int altera_ps_probe(struct spi_device *spi)
> >>>>        snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s",
> >>>>             dev_driver_string(&spi->dev), dev_name(&spi->dev));
> >>>>    -    mgr = devm_fpga_mgr_create(&spi->dev, conf->mgr_name,
> >>>> -                   &altera_ps_ops, conf);
> >>>> -    if (!mgr)
> >>>> -        return -ENOMEM;
> >>>> -
> >>>> -    return devm_fpga_mgr_register(&spi->dev, mgr);
> >>>> +    mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name,
> >>>> +                     &altera_ps_ops, conf);
> >>>> +    return PTR_ERR_OR_ZERO(mgr);
> >>>>    }
> >>>>      static const struct spi_device_id altera_ps_spi_ids[] = {
> >>>> diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
> >>>> index d5861d13b306..620e7874ab53 100644
> >>>> --- a/drivers/fpga/dfl-fme-mgr.c
> >>>> +++ b/drivers/fpga/dfl-fme-mgr.c
> >>>> @@ -282,7 +282,7 @@ static void fme_mgr_get_compat_id(void __iomem *fme_pr,
> >>>>    static int fme_mgr_probe(struct platform_device *pdev)
> >>>>    {
> >>>>        struct dfl_fme_mgr_pdata *pdata = dev_get_platdata(&pdev->dev);
> >>>> -    struct fpga_compat_id *compat_id;
> >>>> +    struct fpga_manager_info info = { 0 };
> >>>>        struct device *dev = &pdev->dev;
> >>>>        struct fme_mgr_priv *priv;
> >>>>        struct fpga_manager *mgr;
> >>>> @@ -302,20 +302,16 @@ static int fme_mgr_probe(struct platform_device *pdev)
> >>>>                return PTR_ERR(priv->ioaddr);
> >>>>        }
> >>>>    -    compat_id = devm_kzalloc(dev, sizeof(*compat_id), GFP_KERNEL);
> >>>> -    if (!compat_id)
> >>>> +    info.name = "DFL FME FPGA Manager";
> >>>> +    info.mops = &fme_mgr_ops;
> >>>> +    info.priv = priv;
> >>>> +    info.compat_id = devm_kzalloc(dev, sizeof(*info.compat_id), GFP_KERNEL);
> >>>> +    if (!info.compat_id)
> >>>>            return -ENOMEM;
> >>> could we limp along instead of failing ?
> >> The compat_id is used to verify compatibility between the static region and
> >> the partial reconfiguration. If there is insufficient memory for the small
> >> data structure, I think it is best to fail here. This is also consistent
> >> current implementation.
> >>  
> >>>>    -    fme_mgr_get_compat_id(priv->ioaddr, compat_id);
> >>>> -
> >>>> -    mgr = devm_fpga_mgr_create(dev, "DFL FME FPGA Manager",
> >>>> -                   &fme_mgr_ops, priv);
> >>>> -    if (!mgr)
> >>>> -        return -ENOMEM;
> >>>> -
> >>>> -    mgr->compat_id = compat_id;
> >>>> -
> >>>> -    return devm_fpga_mgr_register(dev, mgr);
> >>>> +    fme_mgr_get_compat_id(priv->ioaddr, info.compat_id);
> >>>> +    mgr = devm_fpga_mgr_register_full(dev, &info);
> >>>> +    return PTR_ERR_OR_ZERO(mgr);
> >>>>    }
> >>>>      static struct platform_driver fme_mgr_driver = {
> >>>> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
> >>>> index ecb4c3c795fa..5a913aa649fd 100644
> >>>> --- a/drivers/fpga/fpga-mgr.c
> >>>> +++ b/drivers/fpga/fpga-mgr.c
> >>>> @@ -550,21 +550,19 @@ void fpga_mgr_unlock(struct fpga_manager *mgr)
> >>>>    EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
> >>>>      /**
> >>>> - * fpga_mgr_create - create and initialize an FPGA manager struct
> >>>> + * fpga_mgr_register_full - create and register an FPGA Manager device
> >>>>     * @parent:    fpga manager device from pdev
> >>>> - * @name:    fpga manager name
> >>>> - * @mops:    pointer to structure of fpga manager ops
> >>>> - * @priv:    fpga manager private data
> >>>> + * @info:    parameters for fpga manager
> >>>>     *
> >>>> - * The caller of this function is responsible for freeing the struct with
> >>>> - * fpga_mgr_free().  Using devm_fpga_mgr_create() instead is recommended.
> >>>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
> >>>> + * Using devm_fpga_mgr_register_full() instead is recommended.
> >>>>     *
> >>>> - * Return: pointer to struct fpga_manager or NULL
> >>>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
> >>>>     */
> >>>> -struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> >>>> -                     const struct fpga_manager_ops *mops,
> >>>> -                     void *priv)
> >>>> +struct fpga_manager *
> >>>> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
> >>>>    {
> >>>> +    const struct fpga_manager_ops *mops = info->mops;
> >>>>        struct fpga_manager *mgr;
> >>>>        int id, ret;
> >>>>    @@ -572,29 +570,31 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> >>>>            !mops->write_init || (!mops->write && !mops->write_sg) ||
> >>>>            (mops->write && mops->write_sg)) {
> >>>>            dev_err(parent, "Attempt to register without fpga_manager_ops\n");
> >>>> -        return NULL;
> >>>> +        return ERR_PTR(-EINVAL);
> >>>>        }
> >>>>    -    if (!name || !strlen(name)) {
> >>>> +    if (!info->name || !strlen(info->name)) {
> >>>>            dev_err(parent, "Attempt to register with no name!\n");
> >>>> -        return NULL;
> >>>> +        return ERR_PTR(-EINVAL);
> >>>>        }
> >>>>          mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
> >>>>        if (!mgr)
> >>>> -        return NULL;
> >>>> +        return ERR_PTR(-ENOMEM);
> >>>>          id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
> >>>> -    if (id < 0)
> >>>> +    if (id < 0) {
> >>>> +        ret = id;
> >>>>            goto error_kfree;
> >>>> +    }
> >>>>          mutex_init(&mgr->ref_mutex);
> >>>>    -    mgr->name = name;
> >>>> -    mgr->mops = mops;
> >>>> -    mgr->priv = priv;
> >>>> +    mgr->name = info->name;
> >>>> +    mgr->mops = info->mops;
> >>>> +    mgr->priv = info->priv;
> >>>> +    mgr->compat_id = info->compat_id;
> >>>>    -    device_initialize(&mgr->dev);
> >>>>        mgr->dev.class = fpga_mgr_class;
> >>>>        mgr->dev.groups = mops->groups;
> >>>>        mgr->dev.parent = parent;
> >>>> @@ -605,6 +605,19 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> >>>>        if (ret)
> >>>>            goto error_device;
> >>>>    +    /*
> >>>> +     * Initialize framework state by requesting low level driver read state
> >>>> +     * from device.  FPGA may be in reset mode or may have been programmed
> >>>> +     * by bootloader or EEPROM.
> >>>> +     */
> >>>> +    mgr->state = mgr->mops->state(mgr);
> >>> This is existing code, but it seems wrong.
> >>>
> >>> A side effect of state() should not be to initialize.
> >>>
> >>> An init() should be added to mops
> >> I think this is just capturing the state of the underlying device an
> >> reflecting it in the fpga-manager state? Maybe someone else can comment
> >> on this. It seems outside the scope of these patches.
> >>
> >>>> +
> >>>> +    ret = device_register(&mgr->dev);
> >>>> +    if (ret) {
> >>>> +        put_device(&mgr->dev);
> >>>> +        return ERR_PTR(ret);
> >>>> +    }
> >>>> +
> >>>>        return mgr;
> >>>>      error_device:
> >>>> @@ -612,96 +625,36 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> >>>>    error_kfree:
> >>>>        kfree(mgr);
> >>>>    -    return NULL;
> >>>> +    return ERR_PTR(ret);
> >>>>    }
> >>>> -EXPORT_SYMBOL_GPL(fpga_mgr_create);
> >>>> +EXPORT_SYMBOL_GPL(fpga_mgr_register_full);
> >>>>      /**
> >>>> - * fpga_mgr_free - free an FPGA manager created with fpga_mgr_create()
> >>>> - * @mgr:    fpga manager struct
> >>>> - */
> >>>> -void fpga_mgr_free(struct fpga_manager *mgr)
> >>>> -{
> >>>> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> >>>> -    kfree(mgr);
> >>>> -}
> >>>> -EXPORT_SYMBOL_GPL(fpga_mgr_free);
> >>>> -
> >>>> -static void devm_fpga_mgr_release(struct device *dev, void *res)
> >>>> -{
> >>>> -    struct fpga_mgr_devres *dr = res;
> >>>> -
> >>>> -    fpga_mgr_free(dr->mgr);
> >>>> -}
> >>>> -
> >>>> -/**
> >>>> - * devm_fpga_mgr_create - create and initialize a managed FPGA manager struct
> >>>> + * fpga_mgr_register - create and register an FPGA Manager device
> >>>>     * @parent:    fpga manager device from pdev
> >>>>     * @name:    fpga manager name
> >>>>     * @mops:    pointer to structure of fpga manager ops
> >>>>     * @priv:    fpga manager private data
> >>>>     *
> >>>> - * This function is intended for use in an FPGA manager driver's probe function.
> >>>> - * After the manager driver creates the manager struct with
> >>>> - * devm_fpga_mgr_create(), it should register it with fpga_mgr_register().  The
> >>>> - * manager driver's remove function should call fpga_mgr_unregister().  The
> >>>> - * manager struct allocated with this function will be freed automatically on
> >>>> - * driver detach.  This includes the case of a probe function returning error
> >>>> - * before calling fpga_mgr_register(), the struct will still get cleaned up.
> >>>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
> >>>> + * Using devm_fpga_mgr_register() instead is recommended. This simple
> >>>> + * version of the register function should be sufficient for most users. The
> >>>> + * fpga_mgr_register_full() function is available for users that need to pass
> >>>> + * additional, optional parameters.
> >>>>     *
> >>>> - * Return: pointer to struct fpga_manager or NULL
> >>>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
> >>>>     */
> >>>> -struct fpga_manager *devm_fpga_mgr_create(struct device *parent, const char *name,
> >>>> -                      const struct fpga_manager_ops *mops,
> >>>> -                      void *priv)
> >>>> +struct fpga_manager *
> >>>> +fpga_mgr_register(struct device *parent, const char *name,
> >>>> +          const struct fpga_manager_ops *mops, void *priv)
> >>>>    {
> >>>> -    struct fpga_mgr_devres *dr;
> >>>> +    struct fpga_manager_info info = { 0 };
> >>>>    -    dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL);
> >>>> -    if (!dr)
> >>>> -        return NULL;
> >>>> +    info.name = name;
> >>>> +    info.mops = mops;
> >>>> +    info.priv = priv;
> >>>>    -    dr->mgr = fpga_mgr_create(parent, name, mops, priv);
> >>>> -    if (!dr->mgr) {
> >>>> -        devres_free(dr);
> >>>> -        return NULL;
> >>>> -    }
> >>>> -
> >>>> -    devres_add(parent, dr);
> >>>> -
> >>>> -    return dr->mgr;
> >>>> -}
> >>>> -EXPORT_SYMBOL_GPL(devm_fpga_mgr_create);
> >>>> -
> >>>> -/**
> >>>> - * fpga_mgr_register - register an FPGA manager
> >>>> - * @mgr: fpga manager struct
> >>>> - *
> >>>> - * Return: 0 on success, negative error code otherwise.
> >>>> - */
> >>>> -int fpga_mgr_register(struct fpga_manager *mgr)
> >>>> -{
> >>>> -    int ret;
> >>>> -
> >>>> -    /*
> >>>> -     * Initialize framework state by requesting low level driver read state
> >>>> -     * from device.  FPGA may be in reset mode or may have been programmed
> >>>> -     * by bootloader or EEPROM.
> >>>> -     */
> >>>> -    mgr->state = mgr->mops->state(mgr);
> >>>> -
> >>>> -    ret = device_add(&mgr->dev);
> >>>> -    if (ret)
> >>>> -        goto error_device;
> >>>> -
> >>>> -    dev_info(&mgr->dev, "%s registered\n", mgr->name);
> >>>> -
> >>>> -    return 0;
> >>>> -
> >>>> -error_device:
> >>>> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> >>>> -
> >>>> -    return ret;
> >>>> +    return fpga_mgr_register_full(parent, &info);
> >>>>    }
> >>>>    EXPORT_SYMBOL_GPL(fpga_mgr_register);
> >>>>    @@ -726,14 +679,6 @@ void fpga_mgr_unregister(struct fpga_manager *mgr)
> >>>>    }
> >>>>    EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
> >>>>    -static int fpga_mgr_devres_match(struct device *dev, void *res,
> >>>> -                 void *match_data)
> >>>> -{
> >>>> -    struct fpga_mgr_devres *dr = res;
> >>>> -
> >>>> -    return match_data == dr->mgr;
> >>>> -}
> >>>> -
> >>>>    static void devm_fpga_mgr_unregister(struct device *dev, void *res)
> >>>>    {
> >>>>        struct fpga_mgr_devres *dr = res;
> >>>> @@ -742,45 +687,67 @@ static void devm_fpga_mgr_unregister(struct device *dev, void *res)
> >>>>    }
> >>>>      /**
> >>>> - * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
> >>>> - * @dev: managing device for this FPGA manager
> >>>> - * @mgr: fpga manager struct
> >>>> + * devm_fpga_mgr_register_full - resource managed variant of fpga_mgr_register()
> >>>> + * @parent:    fpga manager device from pdev
> >>>> + * @info:    parameters for fpga manager
> >>>>     *
> >>>> - * This is the devres variant of fpga_mgr_register() for which the unregister
> >>>> + * This is the devres variant of fpga_mgr_register_full() for which the unregister
> >>>>     * function will be called automatically when the managing device is detached.
> >>>>     */
> >>>> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr)
> >>>> +struct fpga_manager *
> >>>> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
> >>>>    {
> >>>>        struct fpga_mgr_devres *dr;
> >>>> -    int ret;
> >>>> -
> >>>> -    /*
> >>>> -     * Make sure that the struct fpga_manager * that is passed in is
> >>>> -     * managed itself.
> >>>> -     */
> >>>> -    if (WARN_ON(!devres_find(dev, devm_fpga_mgr_release,
> >>>> -                 fpga_mgr_devres_match, mgr)))
> >>>> -        return -EINVAL;
> >>>> +    struct fpga_manager *mgr;
> >>>>          dr = devres_alloc(devm_fpga_mgr_unregister, sizeof(*dr), GFP_KERNEL);
> >>>>        if (!dr)
> >>>> -        return -ENOMEM;
> >>>> +        return ERR_PTR(-ENOMEM);
> >>>>    -    ret = fpga_mgr_register(mgr);
> >>>> -    if (ret) {
> >>>> +    mgr = fpga_mgr_register_full(parent, info);
> >>>> +    if (IS_ERR(mgr)) {
> >>>>            devres_free(dr);
> >>>> -        return ret;
> >>>> +        return mgr;
> >>>>        }
> >>>>          dr->mgr = mgr;
> >>>> -    devres_add(dev, dr);
> >>>> +    devres_add(parent, dr);
> >>>>    -    return 0;
> >>>> +    return mgr;
> >>>> +}
> >>>> +EXPORT_SYMBOL_GPL(devm_fpga_mgr_register_full);
> >>>> +
> >>>> +/**
> >>>> + * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
> >>>> + * @parent:    fpga manager device from pdev
> >>>> + * @name:    fpga manager name
> >>>> + * @mops:    pointer to structure of fpga manager ops
> >>>> + * @priv:    fpga manager private data
> >>>> + *
> >>>> + * This is the devres variant of fpga_mgr_register() for which the
> >>>> + * unregister function will be called automatically when the managing
> >>>> + * device is detached.
> >>>> + */
> >>>> +struct fpga_manager *
> >>>> +devm_fpga_mgr_register(struct device *parent, const char *name,
> >>>> +               const struct fpga_manager_ops *mops, void *priv)
> >>>> +{
> >>>> +    struct fpga_manager_info info = { 0 };
> >>>> +
> >>>> +    info.name = name;
> >>>> +    info.mops = mops;
> >>>> +    info.priv = priv;
> >>>> +
> >>>> +    return devm_fpga_mgr_register_full(parent, &info);
> >>>>    }
> >>>>    EXPORT_SYMBOL_GPL(devm_fpga_mgr_register);
> >>>>      static void fpga_mgr_dev_release(struct device *dev)
> >>>>    {
> >>>> +    struct fpga_manager *mgr = to_fpga_manager(dev);
> >>>> +
> >>>> +    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> >>>> +    kfree(mgr);
> >>>>    }
> >>>>      static int __init fpga_mgr_class_init(void)
> >>>> diff --git a/drivers/fpga/ice40-spi.c b/drivers/fpga/ice40-spi.c
> >>>> index 69dec5af23c3..b7591912248f 100644
> >>>> --- a/drivers/fpga/ice40-spi.c
> >>>> +++ b/drivers/fpga/ice40-spi.c
> >>>> @@ -178,12 +178,9 @@ static int ice40_fpga_probe(struct spi_device *spi)
> >>>>            return ret;
> >>>>        }
> >>>>    -    mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
> >>>> -                   &ice40_fpga_ops, priv);
> >>>> -    if (!mgr)
> >>>> -        return -ENOMEM;
> >>>> -
> >>>> -    return devm_fpga_mgr_register(dev, mgr);
> >>>> +    mgr = devm_fpga_mgr_register(dev, "Lattice iCE40 FPGA Manager",
> >>>> +                     &ice40_fpga_ops, priv);
> >>>> +    return PTR_ERR_OR_ZERO(mgr);
> >>>>    }
> >>>>      static const struct of_device_id ice40_fpga_of_match[] = {
> >>>> diff --git a/drivers/fpga/machxo2-spi.c b/drivers/fpga/machxo2-spi.c
> >>>> index 1afb41aa20d7..8469dfb5dd21 100644
> >>>> --- a/drivers/fpga/machxo2-spi.c
> >>>> +++ b/drivers/fpga/machxo2-spi.c
> >>>> @@ -366,12 +366,9 @@ static int machxo2_spi_probe(struct spi_device *spi)
> >>>>            return -EINVAL;
> >>>>        }
> >>>>    -    mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager",
> >>>> -                   &machxo2_ops, spi);
> >>>> -    if (!mgr)
> >>>> -        return -ENOMEM;
> >>>> -
> >>>> -    return devm_fpga_mgr_register(dev, mgr);
> >>>> +    mgr = devm_fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager",
> >>>> +                     &machxo2_ops, spi);
> >>>> +    return PTR_ERR_OR_ZERO(mgr);
> >>>>    }
> >>>>      #ifdef CONFIG_OF
> >>>> diff --git a/drivers/fpga/socfpga-a10.c b/drivers/fpga/socfpga-a10.c
> >>>> index 573d88bdf730..ac8e89b8a5cc 100644
> >>>> --- a/drivers/fpga/socfpga-a10.c
> >>>> +++ b/drivers/fpga/socfpga-a10.c
> >>>> @@ -508,19 +508,15 @@ static int socfpga_a10_fpga_probe(struct platform_device *pdev)
> >>>>            return -EBUSY;
> >>>>        }
> >>>>    -    mgr = devm_fpga_mgr_create(dev, "SoCFPGA Arria10 FPGA Manager",
> >>>> -                   &socfpga_a10_fpga_mgr_ops, priv);
> >>>> -    if (!mgr)
> >>>> -        return -ENOMEM;
> >>>> -
> >>>> -    platform_set_drvdata(pdev, mgr);
> >>>> -
> >>>> -    ret = fpga_mgr_register(mgr);
> >>>> -    if (ret) {
> >>>> +    mgr = fpga_mgr_register(dev, "SoCFPGA Arria10 FPGA Manager",
> >>>> +                &socfpga_a10_fpga_mgr_ops, priv);
> >>>> +    if (IS_ERR(mgr)) {
> >>>>            clk_disable_unprepare(priv->clk);
> >>>> -        return ret;
> >>>> +        return PTR_ERR(mgr);
> >>>>        }
> >>>>    +    platform_set_drvdata(pdev, mgr);
> >>>> +
> >>>>        return 0;
> >>>>    }
> >>>>    diff --git a/drivers/fpga/socfpga.c b/drivers/fpga/socfpga.c
> >>>> index 1f467173fc1f..7e0741f99696 100644
> >>>> --- a/drivers/fpga/socfpga.c
> >>>> +++ b/drivers/fpga/socfpga.c
> >>>> @@ -571,12 +571,9 @@ static int socfpga_fpga_probe(struct platform_device *pdev)
> >>>>        if (ret)
> >>>>            return ret;
> >>>>    -    mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
> >>>> -                   &socfpga_fpga_ops, priv);
> >>>> -    if (!mgr)
> >>>> -        return -ENOMEM;
> >>>> -
> >>>> -    return devm_fpga_mgr_register(dev, mgr);
> >>>> +    mgr = devm_fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
> >>>> +                     &socfpga_fpga_ops, priv);
> >>>> +    return PTR_ERR_OR_ZERO(mgr);
> >>>>    }
> >>>>      #ifdef CONFIG_OF
> >>>> diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
> >>>> index a2cea500f7cc..9155e888a133 100644
> >>>> --- a/drivers/fpga/stratix10-soc.c
> >>>> +++ b/drivers/fpga/stratix10-soc.c
> >>>> @@ -425,18 +425,11 @@ static int s10_probe(struct platform_device *pdev)
> >>>>          init_completion(&priv->status_return_completion);
> >>>>    -    mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
> >>>> -                  &s10_ops, priv);
> >>>> -    if (!mgr) {
> >>>> -        dev_err(dev, "unable to create FPGA manager\n");
> >>>> -        ret = -ENOMEM;
> >>>> -        goto probe_err;
> >>>> -    }
> >>>> -
> >>>> -    ret = fpga_mgr_register(mgr);
> >>>> -    if (ret) {
> >>>> +    mgr = fpga_mgr_register(dev, "Stratix10 SOC FPGA Manager",
> >>>> +                &s10_ops, priv);
> >>>> +    if (IS_ERR(mgr)) {
> >>>>            dev_err(dev, "unable to register FPGA manager\n");
> >>>> -        fpga_mgr_free(mgr);
> >>>> +        ret = PTR_ERR(mgr);
> >>>>            goto probe_err;
> >>>>        }
> >>>>    @@ -454,7 +447,6 @@ static int s10_remove(struct platform_device *pdev)
> >>>>        struct s10_priv *priv = mgr->priv;
> >>>>          fpga_mgr_unregister(mgr);
> >>>> -    fpga_mgr_free(mgr);
> >>>>        stratix10_svc_free_channel(priv->chan);
> >>>>          return 0;
> >>>> diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c
> >>>> index 101f016c6ed8..fd52de20ddb2 100644
> >>>> --- a/drivers/fpga/ts73xx-fpga.c
> >>>> +++ b/drivers/fpga/ts73xx-fpga.c
> >>>> @@ -122,12 +122,9 @@ static int ts73xx_fpga_probe(struct platform_device *pdev)
> >>>>        if (IS_ERR(priv->io_base))
> >>>>            return PTR_ERR(priv->io_base);
> >>>>    -    mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
> >>>> -                   &ts73xx_fpga_ops, priv);
> >>>> -    if (!mgr)
> >>>> -        return -ENOMEM;
> >>>> -
> >>>> -    return devm_fpga_mgr_register(kdev, mgr);
> >>>> +    mgr = devm_fpga_mgr_register(kdev, "TS-73xx FPGA Manager",
> >>>> +                     &ts73xx_fpga_ops, priv);
> >>>> +    return PTR_ERR_OR_ZERO(mgr);
> >>>>    }
> >>>>      static struct platform_driver ts73xx_fpga_driver = {
> >>>> diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
> >>>> index fee4d0abf6bf..db23626f9ab2 100644
> >>>> --- a/drivers/fpga/xilinx-spi.c
> >>>> +++ b/drivers/fpga/xilinx-spi.c
> >>>> @@ -247,13 +247,10 @@ static int xilinx_spi_probe(struct spi_device *spi)
> >>>>            return dev_err_probe(&spi->dev, PTR_ERR(conf->done),
> >>>>                         "Failed to get DONE gpio\n");
> >>>>    -    mgr = devm_fpga_mgr_create(&spi->dev,
> >>>> -                   "Xilinx Slave Serial FPGA Manager",
> >>>> -                   &xilinx_spi_ops, conf);
> >>>> -    if (!mgr)
> >>>> -        return -ENOMEM;
> >>>> -
> >>>> -    return devm_fpga_mgr_register(&spi->dev, mgr);
> >>>> +    mgr = devm_fpga_mgr_register(&spi->dev,
> >>>> +                     "Xilinx Slave Serial FPGA Manager",
> >>>> +                     &xilinx_spi_ops, conf);
> >>>> +    return PTR_ERR_OR_ZERO(mgr);
> >>>>    }
> >>>>      static const struct of_device_id xlnx_spi_of_match[] = {
> >>>> diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
> >>>> index 9b75bd4f93d8..426aa34c6a0d 100644
> >>>> --- a/drivers/fpga/zynq-fpga.c
> >>>> +++ b/drivers/fpga/zynq-fpga.c
> >>>> @@ -609,20 +609,16 @@ static int zynq_fpga_probe(struct platform_device *pdev)
> >>>>          clk_disable(priv->clk);
> >>>>    -    mgr = devm_fpga_mgr_create(dev, "Xilinx Zynq FPGA Manager",
> >>>> -                   &zynq_fpga_ops, priv);
> >>>> -    if (!mgr)
> >>>> -        return -ENOMEM;
> >>>> -
> >>>> -    platform_set_drvdata(pdev, mgr);
> >>>> -
> >>>> -    err = fpga_mgr_register(mgr);
> >>>> -    if (err) {
> >>>> +    mgr = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
> >>>> +                &zynq_fpga_ops, priv);
> >>>> +    if (IS_ERR(mgr)) {
> >>>>            dev_err(dev, "unable to register FPGA manager\n");
> >>>>            clk_unprepare(priv->clk);
> >>>> -        return err;
> >>>> +        return PTR_ERR(mgr);
> >>>>        }
> >>>>    +    platform_set_drvdata(pdev, mgr);
> >>>> +
> >>>>        return 0;
> >>>>    }
> >>>>    diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
> >>>> index 125743c9797f..975bdc4d0a65 100644
> >>>> --- a/drivers/fpga/zynqmp-fpga.c
> >>>> +++ b/drivers/fpga/zynqmp-fpga.c
> >>>> @@ -102,12 +102,9 @@ static int zynqmp_fpga_probe(struct platform_device *pdev)
> >>>>          priv->dev = dev;
> >>>>    -    mgr = devm_fpga_mgr_create(dev, "Xilinx ZynqMP FPGA Manager",
> >>>> -                   &zynqmp_fpga_ops, priv);
> >>>> -    if (!mgr)
> >>>> -        return -ENOMEM;
> >>>> -
> >>>> -    return devm_fpga_mgr_register(dev, mgr);
> >>>> +    mgr = devm_fpga_mgr_register(dev, "Xilinx ZynqMP FPGA Manager",
> >>>> +                     &zynqmp_fpga_ops, priv);
> >>>> +    return PTR_ERR_OR_ZERO(mgr);
> >>>>    }
> >>>>      static const struct of_device_id zynqmp_fpga_of_match[] = {
> >>>> diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
> >>>> index 474c1f506307..ac3ddaf2903c 100644
> >>>> --- a/include/linux/fpga/fpga-mgr.h
> >>>> +++ b/include/linux/fpga/fpga-mgr.h
> >>>> @@ -105,6 +105,36 @@ struct fpga_image_info {
> >>>>    #endif
> >>>>    };
> >>>>    +/**
> >>>> + * struct fpga_compat_id - id for compatibility check
> >>>> + *
> >>>> + * @id_h: high 64bit of the compat_id
> >>>> + * @id_l: low 64bit of the compat_id
> >>>> + */
> >>>> +struct fpga_compat_id {
> >>>> +    u64 id_h;
> >>>> +    u64 id_l;
> >>>> +};
> >>>> +
> >>> There are two register functions are to handle this dfl only structure.
> >>>
> >>> This really needs to be moved fme_mgr_priv.
> >>>
> >>>> +/**
> >>>> + * struct fpga_manager_info - collection of parameters for an FPGA Manager
> >>>> + * @name: fpga manager name
> >>>> + * @compat_id: FPGA manager id for compatibility check.
> >>>> + * @mops: pointer to structure of fpga manager ops
> >>>> + * @priv: fpga manager private data
> >>>> + *
> >>>> + * fpga_manager_info contains parameters for the register function. These
> >>>> + * are separated into an info structure because they some are optional
> >>>> + * others could be added to in the future. The info structure facilitates
> >>>> + * maintaining a stable API.
> >>>> + */
> >>>> +struct fpga_manager_info {
> >>>> +    const char *name;
> >>>> +    struct fpga_compat_id *compat_id;
> >>>> +    const struct fpga_manager_ops *mops;
> >>>> +    void *priv;
> >>>> +};
> >>>> +
> >>>>    /**
> >>>>     * struct fpga_manager_ops - ops for low level fpga manager drivers
> >>>>     * @initial_header_size: Maximum number of bytes that should be passed into write_init
> >>>> @@ -143,17 +173,6 @@ struct fpga_manager_ops {
> >>>>    #define FPGA_MGR_STATUS_IP_PROTOCOL_ERR        BIT(3)
> >>>>    #define FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR    BIT(4)
> >>>>    -/**
> >>>> - * struct fpga_compat_id - id for compatibility check
> >>>> - *
> >>>> - * @id_h: high 64bit of the compat_id
> >>>> - * @id_l: low 64bit of the compat_id
> >>>> - */
> >>>> -struct fpga_compat_id {
> >>>> -    u64 id_h;
> >>>> -    u64 id_l;
> >>>> -};
> >>>> -
> >>>>    /**
> >>>>     * struct fpga_manager - fpga manager structure
> >>>>     * @name: name of low level fpga manager
> >>>> @@ -191,17 +210,18 @@ struct fpga_manager *fpga_mgr_get(struct device *dev);
> >>>>      void fpga_mgr_put(struct fpga_manager *mgr);
> >>>>    -struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name,
> >>>> -                     const struct fpga_manager_ops *mops,
> >>>> -                     void *priv);
> >>>> -void fpga_mgr_free(struct fpga_manager *mgr);
> >>> removing these should cause any oot driver to fail to load.
> >>>
> >>> so an oops is unlikely.
> >>>
> >>> I'm ok with with api change.
> >>>
> >>>> -int fpga_mgr_register(struct fpga_manager *mgr);
> >>>> -void fpga_mgr_unregister(struct fpga_manager *mgr);
> >>>> +struct fpga_manager *
> >>>> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
> >>>>    -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr);
> >>>> +struct fpga_manager *
> >>>> +fpga_mgr_register(struct device *parent, const char *name,
> >>>> +          const struct fpga_manager_ops *mops, void *priv);
> >>> having 2 ways to do the same thing is not great.
> >>>
> >>> this should be reduced down to 1.
> >>>
> >>> My preference is for the *info one as it's api will be durable.
> >> I would like to see if other's agree.
> >>
> >>> Tom
> >>>
> >>>> +void fpga_mgr_unregister(struct fpga_manager *mgr);
> >>>>    -struct fpga_manager *devm_fpga_mgr_create(struct device *dev, const char *name,
> >>>> -                      const struct fpga_manager_ops *mops,
> >>>> -                      void *priv);
> >>>> +struct fpga_manager *
> >>>> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
> >>>> +struct fpga_manager *
> >>>> +devm_fpga_mgr_register(struct device *parent, const char *name,
> >>>> +               const struct fpga_manager_ops *mops, void *priv);
> >>>>      #endif /*_LINUX_FPGA_MGR_H */
> >

^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 1/3] fpga: mgr: Use standard dev_release for class driver
  2021-07-06 21:02     ` Russ Weight
  2021-07-06 21:44       ` Tom Rix
@ 2021-07-07  3:01       ` Xu Yilun
  1 sibling, 0 replies; 22+ messages in thread
From: Xu Yilun @ 2021-07-07  3:01 UTC (permalink / raw)
  To: Russ Weight
  Cc: Tom Rix, mdf, linux-fpga, lgoncalv, hao.wu, matthew.gerlach,
	richard.gong

On Tue, Jul 06, 2021 at 02:02:20PM -0700, Russ Weight wrote:
> 
> 
> On 7/6/21 12:04 PM, Tom Rix wrote:
> > Russ,
> >
> > My two big concerns are.
> >
> > compat_id does not belong in fpga_mgr_info, it belongs in fme_mgr_priv.
> 
> fpga_mgr_info is a temporary structure on the stack that contains the
> parameters only long enough to pass them in and have them added to the
> fpga_manager structure. Do you have a concern about it being on the
> fpga_manager structure.
> 
> >
> > there are two register functions, there should be one.
> 
> I get what you are saying. I don't really like the idea of forcing the
> complexity of the temporary structure on all callers, since only a
> couple require it, but we can do that if that is the concensus.
> 
> What do others think?

The _register_full() function takes care of everything, but it do adds
the complexity for all callers. A simpler version makes their life
easier.

2 register functions is OK to me, as there are some examples in other
subsystems, some of them even have 3 or more register functions.

Thanks,
Yilun

> 
> >
> > On 6/30/21 6:37 PM, Russ Weight wrote:
> >> The FPGA manager class driver data structure is being treated as a
> >> managed resource instead of using the standard dev_release call-back
> >> function to release the class data structure. This change removes
> >> the managed resource code for the freeing of the class data structure
> >> and combines the create() and register() functions into a single
> >> register() or register_simple() function.
> >>
> >> The register() function accepts an info data structure to provide
> >> flexibility in passing optional parameters. The register_simple()
> >> function supports the current parameter list for users that don't
> >> require the use of optional parameters.
> >>
> >> The devm_fpga_mgr_register() function is retained, and the
> >> devm_fpga_mgr_register_simple() function is added.
> >>
> >> Signed-off-by: Russ Weight <russell.h.weight@intel.com>
> >> Reviewed-by: Xu Yilun <yilun.xu@intel.com>
> >> ---
> >> v9:
> >>    - Cleaned up documentation for the FPGA Manager register functions
> >>    - Renamed fpga_mgr_register() to fpga_mgr_register_full()
> >>    - Renamed fpga_mgr_register_simple() to fpga_mgr_register()
> >>    - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full()
> >>    - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register()
> >> v8:
> >>    - Added reviewed-by tag.
> >>    - Updated Documentation/driver-api/fpga/fpga-mgr.rst documentation.
> >> v7:
> >>    - Update the commit message to describe the new parameters for the
> >>      *fpga_mgr_register() functions and to mention the
> >>      *fpga_mgr_register_simple() functions.
> >>    - Fix function prototypes in header file to rename dev to parent.
> >>    - Make use of the PTR_ERR_OR_ZERO() macro when possible.
> >>    - Some cleanup of comments.
> >>    - Update function defintions/prototypes to apply const to the new info
> >>      parameter.
> >> v6:
> >>    - Moved FPGA manager optional parameters out of the ops structure and
> >>      back into the FPGA manager structure.
> >>    - Changed fpga_mgr_register()/devm_fpga_mgr_register() parameters to
> >>      accept an info data structure to provide flexibility in passing optional
> >>      parameters.
> >>    - Added fpga_mgr_register_simple()/devm_fpga_mgr_register_simple()
> >>      functions to support current parameters for users that don't require
> >>      the use of optional parameters.
> >> v5:
> >>    - Rebased on top of recently accepted patches.
> >>    - Removed compat_id from the fpga_mgr_register() parameter list
> >>      and added it to the fpga_manager_ops structure. This also required
> >>      dynamically allocating the dfl-fme-ops structure in order to add
> >>      the appropriate compat_id.
> >> v4:
> >>    - Added the compat_id parameter to fpga_mgr_register() and
> >>      devm_fpga_mgr_register() to ensure that the compat_id is set before
> >>      the device_register() call.
> >> v3:
> >>    - Cleaned up comment header for fpga_mgr_register()
> >>    - Fix error return on ida_simple_get() failure
> >> v2:
> >>    - Restored devm_fpga_mgr_register() functionality, adapted for the combined
> >>      create/register functionality.
> >>    - All previous callers of devm_fpga_mgr_register() will continue to call
> >>      devm_fpga_mgr_register().
> >>    - replaced unnecessary ternary operators in return statements with standard
> >>      if conditions.
> >> ---
> >>   Documentation/driver-api/fpga/fpga-mgr.rst |  34 +++-
> >>   drivers/fpga/altera-cvp.c                  |  12 +-
> >>   drivers/fpga/altera-pr-ip-core.c           |   7 +-
> >>   drivers/fpga/altera-ps-spi.c               |   9 +-
> >>   drivers/fpga/dfl-fme-mgr.c                 |  22 +--
> >>   drivers/fpga/fpga-mgr.c                    | 215 +++++++++------------
> >>   drivers/fpga/ice40-spi.c                   |   9 +-
> >>   drivers/fpga/machxo2-spi.c                 |   9 +-
> >>   drivers/fpga/socfpga-a10.c                 |  16 +-
> >>   drivers/fpga/socfpga.c                     |   9 +-
> >>   drivers/fpga/stratix10-soc.c               |  16 +-
> >>   drivers/fpga/ts73xx-fpga.c                 |   9 +-
> >>   drivers/fpga/xilinx-spi.c                  |  11 +-
> >>   drivers/fpga/zynq-fpga.c                   |  16 +-
> >>   drivers/fpga/zynqmp-fpga.c                 |   9 +-
> >>   include/linux/fpga/fpga-mgr.h              |  62 ++++--
> >>   16 files changed, 210 insertions(+), 255 deletions(-)
> >>
> >> diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
> >> index 4d926b452cb3..826ed8dc9210 100644
> >> --- a/Documentation/driver-api/fpga/fpga-mgr.rst
> >> +++ b/Documentation/driver-api/fpga/fpga-mgr.rst
> >> @@ -24,7 +24,7 @@ How to support a new FPGA device
> >>   --------------------------------
> >>     To add another FPGA manager, write a driver that implements a set of ops.  The
> >> -probe function calls fpga_mgr_register(), such as::
> >> +probe function calls fpga_mgr_register() or fpga_mgr_register_full(), such as::
> >>         static const struct fpga_manager_ops socfpga_fpga_ops = {
> >>           .write_init = socfpga_fpga_ops_configure_init,
> >> @@ -49,14 +49,14 @@ probe function calls fpga_mgr_register(), such as::
> >>            * them in priv
> >>            */
> >>   -        mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
> >> -                       &socfpga_fpga_ops, priv);
> >> -        if (!mgr)
> >> -            return -ENOMEM;
> >> +        mgr = fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
> >> +                    &socfpga_fpga_ops, priv);
> >> +        if (IS_ERR(mgr))
> >> +            return PTR_ERR(mgr);
> >>             platform_set_drvdata(pdev, mgr);
> >>   -        return fpga_mgr_register(mgr);
> >> +        return 0;
> >>       }
> >>         static int socfpga_fpga_remove(struct platform_device *pdev)
> >> @@ -68,6 +68,11 @@ probe function calls fpga_mgr_register(), such as::
> >>           return 0;
> >>       }
> >>   +Alternatively, the probe function could call one of the resource managed
> >> +register functions, devm_fpga_mgr_register() or devm_fpga_mgr_register_full().
> >> +When these functions are used, the parameter syntax is the same, but the call
> >> +to fpga_mgr_unregister() should be removed. In the above example, the
> >> +socfpga_fpga_remove() function would not be required.
> >>     The ops will implement whatever device specific register writes are needed to
> >>   do the programming sequence for this particular FPGA.  These ops return 0 for
> >> @@ -104,8 +109,13 @@ API for implementing a new FPGA Manager driver
> >>   * ``fpga_mgr_states`` -  Values for :c:expr:`fpga_manager->state`.
> >>   * struct fpga_manager -  the FPGA manager struct
> >>   * struct fpga_manager_ops -  Low level FPGA manager driver ops
> >> -* devm_fpga_mgr_create() -  Allocate and init a manager struct
> >> -* fpga_mgr_register() -  Register an FPGA manager
> >> +* fpga_mgr_register_full() -  Create and register an FPGA manager using the
> >> +  fpga_mgr_info structure to provide the full flexibility of options
> >> +* fpga_mgr_register() -  Create and register an FPGA manager using standard
> >> +  arguments
> >> +* devm_fpga_mgr_register_full() -  Resource managed version of
> >> +  fpga_mgr_register_full()
> >> +* devm_fpga_mgr_register() -  Resource managed version of fpga_mgr_register()
> >>   * fpga_mgr_unregister() -  Unregister an FPGA manager
> >>     .. kernel-doc:: include/linux/fpga/fpga-mgr.h
> >> @@ -118,10 +128,16 @@ API for implementing a new FPGA Manager driver
> >>      :functions: fpga_manager_ops
> >>     .. kernel-doc:: drivers/fpga/fpga-mgr.c
> >> -   :functions: devm_fpga_mgr_create
> >> +   :functions: fpga_mgr_register_full
> >>     .. kernel-doc:: drivers/fpga/fpga-mgr.c
> >>      :functions: fpga_mgr_register
> >>   +.. kernel-doc:: drivers/fpga/fpga-mgr.c
> >> +   :functions: devm_fpga_mgr_register_full
> >> +
> >> +.. kernel-doc:: drivers/fpga/fpga-mgr.c
> >> +   :functions: devm_fpga_mgr_register
> >> +
> >>   .. kernel-doc:: drivers/fpga/fpga-mgr.c
> >>      :functions: fpga_mgr_unregister
> >> diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
> >> index ccf4546eff29..4ffb9da537d8 100644
> >> --- a/drivers/fpga/altera-cvp.c
> >> +++ b/drivers/fpga/altera-cvp.c
> >> @@ -652,19 +652,15 @@ static int altera_cvp_probe(struct pci_dev *pdev,
> >>       snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
> >>            ALTERA_CVP_MGR_NAME, pci_name(pdev));
> >>   -    mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
> >> -                   &altera_cvp_ops, conf);
> >> -    if (!mgr) {
> >> -        ret = -ENOMEM;
> >> +    mgr = fpga_mgr_register(&pdev->dev, conf->mgr_name,
> >> +                &altera_cvp_ops, conf);
> >> +    if (IS_ERR(mgr)) {
> >> +        ret = PTR_ERR(mgr);
> >>           goto err_unmap;
> >>       }
> >>         pci_set_drvdata(pdev, mgr);
> >>   -    ret = fpga_mgr_register(mgr);
> >> -    if (ret)
> >> -        goto err_unmap;
> >> -
> >>       return 0;
> >>     err_unmap:
> >> diff --git a/drivers/fpga/altera-pr-ip-core.c b/drivers/fpga/altera-pr-ip-core.c
> >> index dfdf21ed34c4..be0667968d33 100644
> >> --- a/drivers/fpga/altera-pr-ip-core.c
> >> +++ b/drivers/fpga/altera-pr-ip-core.c
> >> @@ -191,11 +191,8 @@ int alt_pr_register(struct device *dev, void __iomem *reg_base)
> >>           (val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
> >>           (int)(val & ALT_PR_CSR_PR_START));
> >>   -    mgr = devm_fpga_mgr_create(dev, dev_name(dev), &alt_pr_ops, priv);
> >> -    if (!mgr)
> >> -        return -ENOMEM;
> >> -
> >> -    return devm_fpga_mgr_register(dev, mgr);
> >> +    mgr = devm_fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv);
> >> +    return PTR_ERR_OR_ZERO(mgr);
> >>   }
> >>   EXPORT_SYMBOL_GPL(alt_pr_register);
> >>   diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
> >> index 23bfd4d1ad0f..5e1e009dba89 100644
> >> --- a/drivers/fpga/altera-ps-spi.c
> >> +++ b/drivers/fpga/altera-ps-spi.c
> >> @@ -302,12 +302,9 @@ static int altera_ps_probe(struct spi_device *spi)
> >>       snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s",
> >>            dev_driver_string(&spi->dev), dev_name(&spi->dev));
> >>   -    mgr = devm_fpga_mgr_create(&spi->dev, conf->mgr_name,
> >> -                   &altera_ps_ops, conf);
> >> -    if (!mgr)
> >> -        return -ENOMEM;
> >> -
> >> -    return devm_fpga_mgr_register(&spi->dev, mgr);
> >> +    mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name,
> >> +                     &altera_ps_ops, conf);
> >> +    return PTR_ERR_OR_ZERO(mgr);
> >>   }
> >>     static const struct spi_device_id altera_ps_spi_ids[] = {
> >> diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
> >> index d5861d13b306..620e7874ab53 100644
> >> --- a/drivers/fpga/dfl-fme-mgr.c
> >> +++ b/drivers/fpga/dfl-fme-mgr.c
> >> @@ -282,7 +282,7 @@ static void fme_mgr_get_compat_id(void __iomem *fme_pr,
> >>   static int fme_mgr_probe(struct platform_device *pdev)
> >>   {
> >>       struct dfl_fme_mgr_pdata *pdata = dev_get_platdata(&pdev->dev);
> >> -    struct fpga_compat_id *compat_id;
> >> +    struct fpga_manager_info info = { 0 };
> >>       struct device *dev = &pdev->dev;
> >>       struct fme_mgr_priv *priv;
> >>       struct fpga_manager *mgr;
> >> @@ -302,20 +302,16 @@ static int fme_mgr_probe(struct platform_device *pdev)
> >>               return PTR_ERR(priv->ioaddr);
> >>       }
> >>   -    compat_id = devm_kzalloc(dev, sizeof(*compat_id), GFP_KERNEL);
> >> -    if (!compat_id)
> >> +    info.name = "DFL FME FPGA Manager";
> >> +    info.mops = &fme_mgr_ops;
> >> +    info.priv = priv;
> >> +    info.compat_id = devm_kzalloc(dev, sizeof(*info.compat_id), GFP_KERNEL);
> >> +    if (!info.compat_id)
> >>           return -ENOMEM;
> > could we limp along instead of failing ?
> 
> The compat_id is used to verify compatibility between the static region and
> the partial reconfiguration. If there is insufficient memory for the small
> data structure, I think it is best to fail here. This is also consistent
> current implementation.
>  
> >>   -    fme_mgr_get_compat_id(priv->ioaddr, compat_id);
> >> -
> >> -    mgr = devm_fpga_mgr_create(dev, "DFL FME FPGA Manager",
> >> -                   &fme_mgr_ops, priv);
> >> -    if (!mgr)
> >> -        return -ENOMEM;
> >> -
> >> -    mgr->compat_id = compat_id;
> >> -
> >> -    return devm_fpga_mgr_register(dev, mgr);
> >> +    fme_mgr_get_compat_id(priv->ioaddr, info.compat_id);
> >> +    mgr = devm_fpga_mgr_register_full(dev, &info);
> >> +    return PTR_ERR_OR_ZERO(mgr);
> >>   }
> >>     static struct platform_driver fme_mgr_driver = {
> >> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
> >> index ecb4c3c795fa..5a913aa649fd 100644
> >> --- a/drivers/fpga/fpga-mgr.c
> >> +++ b/drivers/fpga/fpga-mgr.c
> >> @@ -550,21 +550,19 @@ void fpga_mgr_unlock(struct fpga_manager *mgr)
> >>   EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
> >>     /**
> >> - * fpga_mgr_create - create and initialize an FPGA manager struct
> >> + * fpga_mgr_register_full - create and register an FPGA Manager device
> >>    * @parent:    fpga manager device from pdev
> >> - * @name:    fpga manager name
> >> - * @mops:    pointer to structure of fpga manager ops
> >> - * @priv:    fpga manager private data
> >> + * @info:    parameters for fpga manager
> >>    *
> >> - * The caller of this function is responsible for freeing the struct with
> >> - * fpga_mgr_free().  Using devm_fpga_mgr_create() instead is recommended.
> >> + * The caller of this function is responsible for calling fpga_mgr_unregister().
> >> + * Using devm_fpga_mgr_register_full() instead is recommended.
> >>    *
> >> - * Return: pointer to struct fpga_manager or NULL
> >> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
> >>    */
> >> -struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> >> -                     const struct fpga_manager_ops *mops,
> >> -                     void *priv)
> >> +struct fpga_manager *
> >> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
> >>   {
> >> +    const struct fpga_manager_ops *mops = info->mops;
> >>       struct fpga_manager *mgr;
> >>       int id, ret;
> >>   @@ -572,29 +570,31 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> >>           !mops->write_init || (!mops->write && !mops->write_sg) ||
> >>           (mops->write && mops->write_sg)) {
> >>           dev_err(parent, "Attempt to register without fpga_manager_ops\n");
> >> -        return NULL;
> >> +        return ERR_PTR(-EINVAL);
> >>       }
> >>   -    if (!name || !strlen(name)) {
> >> +    if (!info->name || !strlen(info->name)) {
> >>           dev_err(parent, "Attempt to register with no name!\n");
> >> -        return NULL;
> >> +        return ERR_PTR(-EINVAL);
> >>       }
> >>         mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
> >>       if (!mgr)
> >> -        return NULL;
> >> +        return ERR_PTR(-ENOMEM);
> >>         id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
> >> -    if (id < 0)
> >> +    if (id < 0) {
> >> +        ret = id;
> >>           goto error_kfree;
> >> +    }
> >>         mutex_init(&mgr->ref_mutex);
> >>   -    mgr->name = name;
> >> -    mgr->mops = mops;
> >> -    mgr->priv = priv;
> >> +    mgr->name = info->name;
> >> +    mgr->mops = info->mops;
> >> +    mgr->priv = info->priv;
> >> +    mgr->compat_id = info->compat_id;
> >>   -    device_initialize(&mgr->dev);
> >>       mgr->dev.class = fpga_mgr_class;
> >>       mgr->dev.groups = mops->groups;
> >>       mgr->dev.parent = parent;
> >> @@ -605,6 +605,19 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> >>       if (ret)
> >>           goto error_device;
> >>   +    /*
> >> +     * Initialize framework state by requesting low level driver read state
> >> +     * from device.  FPGA may be in reset mode or may have been programmed
> >> +     * by bootloader or EEPROM.
> >> +     */
> >> +    mgr->state = mgr->mops->state(mgr);
> >
> > This is existing code, but it seems wrong.
> >
> > A side effect of state() should not be to initialize.
> >
> > An init() should be added to mops
> 
> I think this is just capturing the state of the underlying device an
> reflecting it in the fpga-manager state? Maybe someone else can comment
> on this. It seems outside the scope of these patches.
> 
> >
> >> +
> >> +    ret = device_register(&mgr->dev);
> >> +    if (ret) {
> >> +        put_device(&mgr->dev);
> >> +        return ERR_PTR(ret);
> >> +    }
> >> +
> >>       return mgr;
> >>     error_device:
> >> @@ -612,96 +625,36 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> >>   error_kfree:
> >>       kfree(mgr);
> >>   -    return NULL;
> >> +    return ERR_PTR(ret);
> >>   }
> >> -EXPORT_SYMBOL_GPL(fpga_mgr_create);
> >> +EXPORT_SYMBOL_GPL(fpga_mgr_register_full);
> >>     /**
> >> - * fpga_mgr_free - free an FPGA manager created with fpga_mgr_create()
> >> - * @mgr:    fpga manager struct
> >> - */
> >> -void fpga_mgr_free(struct fpga_manager *mgr)
> >> -{
> >> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> >> -    kfree(mgr);
> >> -}
> >> -EXPORT_SYMBOL_GPL(fpga_mgr_free);
> >> -
> >> -static void devm_fpga_mgr_release(struct device *dev, void *res)
> >> -{
> >> -    struct fpga_mgr_devres *dr = res;
> >> -
> >> -    fpga_mgr_free(dr->mgr);
> >> -}
> >> -
> >> -/**
> >> - * devm_fpga_mgr_create - create and initialize a managed FPGA manager struct
> >> + * fpga_mgr_register - create and register an FPGA Manager device
> >>    * @parent:    fpga manager device from pdev
> >>    * @name:    fpga manager name
> >>    * @mops:    pointer to structure of fpga manager ops
> >>    * @priv:    fpga manager private data
> >>    *
> >> - * This function is intended for use in an FPGA manager driver's probe function.
> >> - * After the manager driver creates the manager struct with
> >> - * devm_fpga_mgr_create(), it should register it with fpga_mgr_register().  The
> >> - * manager driver's remove function should call fpga_mgr_unregister().  The
> >> - * manager struct allocated with this function will be freed automatically on
> >> - * driver detach.  This includes the case of a probe function returning error
> >> - * before calling fpga_mgr_register(), the struct will still get cleaned up.
> >> + * The caller of this function is responsible for calling fpga_mgr_unregister().
> >> + * Using devm_fpga_mgr_register() instead is recommended. This simple
> >> + * version of the register function should be sufficient for most users. The
> >> + * fpga_mgr_register_full() function is available for users that need to pass
> >> + * additional, optional parameters.
> >>    *
> >> - * Return: pointer to struct fpga_manager or NULL
> >> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
> >>    */
> >> -struct fpga_manager *devm_fpga_mgr_create(struct device *parent, const char *name,
> >> -                      const struct fpga_manager_ops *mops,
> >> -                      void *priv)
> >> +struct fpga_manager *
> >> +fpga_mgr_register(struct device *parent, const char *name,
> >> +          const struct fpga_manager_ops *mops, void *priv)
> >>   {
> >> -    struct fpga_mgr_devres *dr;
> >> +    struct fpga_manager_info info = { 0 };
> >>   -    dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL);
> >> -    if (!dr)
> >> -        return NULL;
> >> +    info.name = name;
> >> +    info.mops = mops;
> >> +    info.priv = priv;
> >>   -    dr->mgr = fpga_mgr_create(parent, name, mops, priv);
> >> -    if (!dr->mgr) {
> >> -        devres_free(dr);
> >> -        return NULL;
> >> -    }
> >> -
> >> -    devres_add(parent, dr);
> >> -
> >> -    return dr->mgr;
> >> -}
> >> -EXPORT_SYMBOL_GPL(devm_fpga_mgr_create);
> >> -
> >> -/**
> >> - * fpga_mgr_register - register an FPGA manager
> >> - * @mgr: fpga manager struct
> >> - *
> >> - * Return: 0 on success, negative error code otherwise.
> >> - */
> >> -int fpga_mgr_register(struct fpga_manager *mgr)
> >> -{
> >> -    int ret;
> >> -
> >> -    /*
> >> -     * Initialize framework state by requesting low level driver read state
> >> -     * from device.  FPGA may be in reset mode or may have been programmed
> >> -     * by bootloader or EEPROM.
> >> -     */
> >> -    mgr->state = mgr->mops->state(mgr);
> >> -
> >> -    ret = device_add(&mgr->dev);
> >> -    if (ret)
> >> -        goto error_device;
> >> -
> >> -    dev_info(&mgr->dev, "%s registered\n", mgr->name);
> >> -
> >> -    return 0;
> >> -
> >> -error_device:
> >> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> >> -
> >> -    return ret;
> >> +    return fpga_mgr_register_full(parent, &info);
> >>   }
> >>   EXPORT_SYMBOL_GPL(fpga_mgr_register);
> >>   @@ -726,14 +679,6 @@ void fpga_mgr_unregister(struct fpga_manager *mgr)
> >>   }
> >>   EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
> >>   -static int fpga_mgr_devres_match(struct device *dev, void *res,
> >> -                 void *match_data)
> >> -{
> >> -    struct fpga_mgr_devres *dr = res;
> >> -
> >> -    return match_data == dr->mgr;
> >> -}
> >> -
> >>   static void devm_fpga_mgr_unregister(struct device *dev, void *res)
> >>   {
> >>       struct fpga_mgr_devres *dr = res;
> >> @@ -742,45 +687,67 @@ static void devm_fpga_mgr_unregister(struct device *dev, void *res)
> >>   }
> >>     /**
> >> - * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
> >> - * @dev: managing device for this FPGA manager
> >> - * @mgr: fpga manager struct
> >> + * devm_fpga_mgr_register_full - resource managed variant of fpga_mgr_register()
> >> + * @parent:    fpga manager device from pdev
> >> + * @info:    parameters for fpga manager
> >>    *
> >> - * This is the devres variant of fpga_mgr_register() for which the unregister
> >> + * This is the devres variant of fpga_mgr_register_full() for which the unregister
> >>    * function will be called automatically when the managing device is detached.
> >>    */
> >> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr)
> >> +struct fpga_manager *
> >> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
> >>   {
> >>       struct fpga_mgr_devres *dr;
> >> -    int ret;
> >> -
> >> -    /*
> >> -     * Make sure that the struct fpga_manager * that is passed in is
> >> -     * managed itself.
> >> -     */
> >> -    if (WARN_ON(!devres_find(dev, devm_fpga_mgr_release,
> >> -                 fpga_mgr_devres_match, mgr)))
> >> -        return -EINVAL;
> >> +    struct fpga_manager *mgr;
> >>         dr = devres_alloc(devm_fpga_mgr_unregister, sizeof(*dr), GFP_KERNEL);
> >>       if (!dr)
> >> -        return -ENOMEM;
> >> +        return ERR_PTR(-ENOMEM);
> >>   -    ret = fpga_mgr_register(mgr);
> >> -    if (ret) {
> >> +    mgr = fpga_mgr_register_full(parent, info);
> >> +    if (IS_ERR(mgr)) {
> >>           devres_free(dr);
> >> -        return ret;
> >> +        return mgr;
> >>       }
> >>         dr->mgr = mgr;
> >> -    devres_add(dev, dr);
> >> +    devres_add(parent, dr);
> >>   -    return 0;
> >> +    return mgr;
> >> +}
> >> +EXPORT_SYMBOL_GPL(devm_fpga_mgr_register_full);
> >> +
> >> +/**
> >> + * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
> >> + * @parent:    fpga manager device from pdev
> >> + * @name:    fpga manager name
> >> + * @mops:    pointer to structure of fpga manager ops
> >> + * @priv:    fpga manager private data
> >> + *
> >> + * This is the devres variant of fpga_mgr_register() for which the
> >> + * unregister function will be called automatically when the managing
> >> + * device is detached.
> >> + */
> >> +struct fpga_manager *
> >> +devm_fpga_mgr_register(struct device *parent, const char *name,
> >> +               const struct fpga_manager_ops *mops, void *priv)
> >> +{
> >> +    struct fpga_manager_info info = { 0 };
> >> +
> >> +    info.name = name;
> >> +    info.mops = mops;
> >> +    info.priv = priv;
> >> +
> >> +    return devm_fpga_mgr_register_full(parent, &info);
> >>   }
> >>   EXPORT_SYMBOL_GPL(devm_fpga_mgr_register);
> >>     static void fpga_mgr_dev_release(struct device *dev)
> >>   {
> >> +    struct fpga_manager *mgr = to_fpga_manager(dev);
> >> +
> >> +    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> >> +    kfree(mgr);
> >>   }
> >>     static int __init fpga_mgr_class_init(void)
> >> diff --git a/drivers/fpga/ice40-spi.c b/drivers/fpga/ice40-spi.c
> >> index 69dec5af23c3..b7591912248f 100644
> >> --- a/drivers/fpga/ice40-spi.c
> >> +++ b/drivers/fpga/ice40-spi.c
> >> @@ -178,12 +178,9 @@ static int ice40_fpga_probe(struct spi_device *spi)
> >>           return ret;
> >>       }
> >>   -    mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
> >> -                   &ice40_fpga_ops, priv);
> >> -    if (!mgr)
> >> -        return -ENOMEM;
> >> -
> >> -    return devm_fpga_mgr_register(dev, mgr);
> >> +    mgr = devm_fpga_mgr_register(dev, "Lattice iCE40 FPGA Manager",
> >> +                     &ice40_fpga_ops, priv);
> >> +    return PTR_ERR_OR_ZERO(mgr);
> >>   }
> >>     static const struct of_device_id ice40_fpga_of_match[] = {
> >> diff --git a/drivers/fpga/machxo2-spi.c b/drivers/fpga/machxo2-spi.c
> >> index 1afb41aa20d7..8469dfb5dd21 100644
> >> --- a/drivers/fpga/machxo2-spi.c
> >> +++ b/drivers/fpga/machxo2-spi.c
> >> @@ -366,12 +366,9 @@ static int machxo2_spi_probe(struct spi_device *spi)
> >>           return -EINVAL;
> >>       }
> >>   -    mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager",
> >> -                   &machxo2_ops, spi);
> >> -    if (!mgr)
> >> -        return -ENOMEM;
> >> -
> >> -    return devm_fpga_mgr_register(dev, mgr);
> >> +    mgr = devm_fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager",
> >> +                     &machxo2_ops, spi);
> >> +    return PTR_ERR_OR_ZERO(mgr);
> >>   }
> >>     #ifdef CONFIG_OF
> >> diff --git a/drivers/fpga/socfpga-a10.c b/drivers/fpga/socfpga-a10.c
> >> index 573d88bdf730..ac8e89b8a5cc 100644
> >> --- a/drivers/fpga/socfpga-a10.c
> >> +++ b/drivers/fpga/socfpga-a10.c
> >> @@ -508,19 +508,15 @@ static int socfpga_a10_fpga_probe(struct platform_device *pdev)
> >>           return -EBUSY;
> >>       }
> >>   -    mgr = devm_fpga_mgr_create(dev, "SoCFPGA Arria10 FPGA Manager",
> >> -                   &socfpga_a10_fpga_mgr_ops, priv);
> >> -    if (!mgr)
> >> -        return -ENOMEM;
> >> -
> >> -    platform_set_drvdata(pdev, mgr);
> >> -
> >> -    ret = fpga_mgr_register(mgr);
> >> -    if (ret) {
> >> +    mgr = fpga_mgr_register(dev, "SoCFPGA Arria10 FPGA Manager",
> >> +                &socfpga_a10_fpga_mgr_ops, priv);
> >> +    if (IS_ERR(mgr)) {
> >>           clk_disable_unprepare(priv->clk);
> >> -        return ret;
> >> +        return PTR_ERR(mgr);
> >>       }
> >>   +    platform_set_drvdata(pdev, mgr);
> >> +
> >>       return 0;
> >>   }
> >>   diff --git a/drivers/fpga/socfpga.c b/drivers/fpga/socfpga.c
> >> index 1f467173fc1f..7e0741f99696 100644
> >> --- a/drivers/fpga/socfpga.c
> >> +++ b/drivers/fpga/socfpga.c
> >> @@ -571,12 +571,9 @@ static int socfpga_fpga_probe(struct platform_device *pdev)
> >>       if (ret)
> >>           return ret;
> >>   -    mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
> >> -                   &socfpga_fpga_ops, priv);
> >> -    if (!mgr)
> >> -        return -ENOMEM;
> >> -
> >> -    return devm_fpga_mgr_register(dev, mgr);
> >> +    mgr = devm_fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
> >> +                     &socfpga_fpga_ops, priv);
> >> +    return PTR_ERR_OR_ZERO(mgr);
> >>   }
> >>     #ifdef CONFIG_OF
> >> diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
> >> index a2cea500f7cc..9155e888a133 100644
> >> --- a/drivers/fpga/stratix10-soc.c
> >> +++ b/drivers/fpga/stratix10-soc.c
> >> @@ -425,18 +425,11 @@ static int s10_probe(struct platform_device *pdev)
> >>         init_completion(&priv->status_return_completion);
> >>   -    mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
> >> -                  &s10_ops, priv);
> >> -    if (!mgr) {
> >> -        dev_err(dev, "unable to create FPGA manager\n");
> >> -        ret = -ENOMEM;
> >> -        goto probe_err;
> >> -    }
> >> -
> >> -    ret = fpga_mgr_register(mgr);
> >> -    if (ret) {
> >> +    mgr = fpga_mgr_register(dev, "Stratix10 SOC FPGA Manager",
> >> +                &s10_ops, priv);
> >> +    if (IS_ERR(mgr)) {
> >>           dev_err(dev, "unable to register FPGA manager\n");
> >> -        fpga_mgr_free(mgr);
> >> +        ret = PTR_ERR(mgr);
> >>           goto probe_err;
> >>       }
> >>   @@ -454,7 +447,6 @@ static int s10_remove(struct platform_device *pdev)
> >>       struct s10_priv *priv = mgr->priv;
> >>         fpga_mgr_unregister(mgr);
> >> -    fpga_mgr_free(mgr);
> >>       stratix10_svc_free_channel(priv->chan);
> >>         return 0;
> >> diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c
> >> index 101f016c6ed8..fd52de20ddb2 100644
> >> --- a/drivers/fpga/ts73xx-fpga.c
> >> +++ b/drivers/fpga/ts73xx-fpga.c
> >> @@ -122,12 +122,9 @@ static int ts73xx_fpga_probe(struct platform_device *pdev)
> >>       if (IS_ERR(priv->io_base))
> >>           return PTR_ERR(priv->io_base);
> >>   -    mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
> >> -                   &ts73xx_fpga_ops, priv);
> >> -    if (!mgr)
> >> -        return -ENOMEM;
> >> -
> >> -    return devm_fpga_mgr_register(kdev, mgr);
> >> +    mgr = devm_fpga_mgr_register(kdev, "TS-73xx FPGA Manager",
> >> +                     &ts73xx_fpga_ops, priv);
> >> +    return PTR_ERR_OR_ZERO(mgr);
> >>   }
> >>     static struct platform_driver ts73xx_fpga_driver = {
> >> diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
> >> index fee4d0abf6bf..db23626f9ab2 100644
> >> --- a/drivers/fpga/xilinx-spi.c
> >> +++ b/drivers/fpga/xilinx-spi.c
> >> @@ -247,13 +247,10 @@ static int xilinx_spi_probe(struct spi_device *spi)
> >>           return dev_err_probe(&spi->dev, PTR_ERR(conf->done),
> >>                        "Failed to get DONE gpio\n");
> >>   -    mgr = devm_fpga_mgr_create(&spi->dev,
> >> -                   "Xilinx Slave Serial FPGA Manager",
> >> -                   &xilinx_spi_ops, conf);
> >> -    if (!mgr)
> >> -        return -ENOMEM;
> >> -
> >> -    return devm_fpga_mgr_register(&spi->dev, mgr);
> >> +    mgr = devm_fpga_mgr_register(&spi->dev,
> >> +                     "Xilinx Slave Serial FPGA Manager",
> >> +                     &xilinx_spi_ops, conf);
> >> +    return PTR_ERR_OR_ZERO(mgr);
> >>   }
> >>     static const struct of_device_id xlnx_spi_of_match[] = {
> >> diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
> >> index 9b75bd4f93d8..426aa34c6a0d 100644
> >> --- a/drivers/fpga/zynq-fpga.c
> >> +++ b/drivers/fpga/zynq-fpga.c
> >> @@ -609,20 +609,16 @@ static int zynq_fpga_probe(struct platform_device *pdev)
> >>         clk_disable(priv->clk);
> >>   -    mgr = devm_fpga_mgr_create(dev, "Xilinx Zynq FPGA Manager",
> >> -                   &zynq_fpga_ops, priv);
> >> -    if (!mgr)
> >> -        return -ENOMEM;
> >> -
> >> -    platform_set_drvdata(pdev, mgr);
> >> -
> >> -    err = fpga_mgr_register(mgr);
> >> -    if (err) {
> >> +    mgr = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
> >> +                &zynq_fpga_ops, priv);
> >> +    if (IS_ERR(mgr)) {
> >>           dev_err(dev, "unable to register FPGA manager\n");
> >>           clk_unprepare(priv->clk);
> >> -        return err;
> >> +        return PTR_ERR(mgr);
> >>       }
> >>   +    platform_set_drvdata(pdev, mgr);
> >> +
> >>       return 0;
> >>   }
> >>   diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
> >> index 125743c9797f..975bdc4d0a65 100644
> >> --- a/drivers/fpga/zynqmp-fpga.c
> >> +++ b/drivers/fpga/zynqmp-fpga.c
> >> @@ -102,12 +102,9 @@ static int zynqmp_fpga_probe(struct platform_device *pdev)
> >>         priv->dev = dev;
> >>   -    mgr = devm_fpga_mgr_create(dev, "Xilinx ZynqMP FPGA Manager",
> >> -                   &zynqmp_fpga_ops, priv);
> >> -    if (!mgr)
> >> -        return -ENOMEM;
> >> -
> >> -    return devm_fpga_mgr_register(dev, mgr);
> >> +    mgr = devm_fpga_mgr_register(dev, "Xilinx ZynqMP FPGA Manager",
> >> +                     &zynqmp_fpga_ops, priv);
> >> +    return PTR_ERR_OR_ZERO(mgr);
> >>   }
> >>     static const struct of_device_id zynqmp_fpga_of_match[] = {
> >> diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
> >> index 474c1f506307..ac3ddaf2903c 100644
> >> --- a/include/linux/fpga/fpga-mgr.h
> >> +++ b/include/linux/fpga/fpga-mgr.h
> >> @@ -105,6 +105,36 @@ struct fpga_image_info {
> >>   #endif
> >>   };
> >>   +/**
> >> + * struct fpga_compat_id - id for compatibility check
> >> + *
> >> + * @id_h: high 64bit of the compat_id
> >> + * @id_l: low 64bit of the compat_id
> >> + */
> >> +struct fpga_compat_id {
> >> +    u64 id_h;
> >> +    u64 id_l;
> >> +};
> >> +
> >
> > There are two register functions are to handle this dfl only structure.
> >
> > This really needs to be moved fme_mgr_priv.
> >
> >> +/**
> >> + * struct fpga_manager_info - collection of parameters for an FPGA Manager
> >> + * @name: fpga manager name
> >> + * @compat_id: FPGA manager id for compatibility check.
> >> + * @mops: pointer to structure of fpga manager ops
> >> + * @priv: fpga manager private data
> >> + *
> >> + * fpga_manager_info contains parameters for the register function. These
> >> + * are separated into an info structure because they some are optional
> >> + * others could be added to in the future. The info structure facilitates
> >> + * maintaining a stable API.
> >> + */
> >> +struct fpga_manager_info {
> >> +    const char *name;
> >> +    struct fpga_compat_id *compat_id;
> >> +    const struct fpga_manager_ops *mops;
> >> +    void *priv;
> >> +};
> >> +
> >>   /**
> >>    * struct fpga_manager_ops - ops for low level fpga manager drivers
> >>    * @initial_header_size: Maximum number of bytes that should be passed into write_init
> >> @@ -143,17 +173,6 @@ struct fpga_manager_ops {
> >>   #define FPGA_MGR_STATUS_IP_PROTOCOL_ERR        BIT(3)
> >>   #define FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR    BIT(4)
> >>   -/**
> >> - * struct fpga_compat_id - id for compatibility check
> >> - *
> >> - * @id_h: high 64bit of the compat_id
> >> - * @id_l: low 64bit of the compat_id
> >> - */
> >> -struct fpga_compat_id {
> >> -    u64 id_h;
> >> -    u64 id_l;
> >> -};
> >> -
> >>   /**
> >>    * struct fpga_manager - fpga manager structure
> >>    * @name: name of low level fpga manager
> >> @@ -191,17 +210,18 @@ struct fpga_manager *fpga_mgr_get(struct device *dev);
> >>     void fpga_mgr_put(struct fpga_manager *mgr);
> >>   -struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name,
> >> -                     const struct fpga_manager_ops *mops,
> >> -                     void *priv);
> >> -void fpga_mgr_free(struct fpga_manager *mgr);
> >
> > removing these should cause any oot driver to fail to load.
> >
> > so an oops is unlikely.
> >
> > I'm ok with with api change.
> >
> >> -int fpga_mgr_register(struct fpga_manager *mgr);
> >> -void fpga_mgr_unregister(struct fpga_manager *mgr);
> >> +struct fpga_manager *
> >> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
> >>   -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr);
> >> +struct fpga_manager *
> >> +fpga_mgr_register(struct device *parent, const char *name,
> >> +          const struct fpga_manager_ops *mops, void *priv);
> >
> > having 2 ways to do the same thing is not great.
> >
> > this should be reduced down to 1.
> >
> > My preference is for the *info one as it's api will be durable.
> 
> I would like to see if other's agree.
> 
> >
> > Tom
> >
> >> +void fpga_mgr_unregister(struct fpga_manager *mgr);
> >>   -struct fpga_manager *devm_fpga_mgr_create(struct device *dev, const char *name,
> >> -                      const struct fpga_manager_ops *mops,
> >> -                      void *priv);
> >> +struct fpga_manager *
> >> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
> >> +struct fpga_manager *
> >> +devm_fpga_mgr_register(struct device *parent, const char *name,
> >> +               const struct fpga_manager_ops *mops, void *priv);
> >>     #endif /*_LINUX_FPGA_MGR_H */
> >

^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 1/3] fpga: mgr: Use standard dev_release for class driver
  2021-07-06 19:04   ` Tom Rix
  2021-07-06 21:02     ` Russ Weight
@ 2021-07-07  3:04     ` Xu Yilun
  1 sibling, 0 replies; 22+ messages in thread
From: Xu Yilun @ 2021-07-07  3:04 UTC (permalink / raw)
  To: Tom Rix
  Cc: Russ Weight, mdf, linux-fpga, lgoncalv, hao.wu, matthew.gerlach,
	richard.gong

On Tue, Jul 06, 2021 at 12:04:55PM -0700, Tom Rix wrote:
> Russ,
> 
> My two big concerns are.
> 
> compat_id does not belong in fpga_mgr_info, it belongs in fme_mgr_priv.
> 
> there are two register functions, there should be one.
> 
> 
> On 6/30/21 6:37 PM, Russ Weight wrote:
> > The FPGA manager class driver data structure is being treated as a
> > managed resource instead of using the standard dev_release call-back
> > function to release the class data structure. This change removes
> > the managed resource code for the freeing of the class data structure
> > and combines the create() and register() functions into a single
> > register() or register_simple() function.
> > 
> > The register() function accepts an info data structure to provide
> > flexibility in passing optional parameters. The register_simple()
> > function supports the current parameter list for users that don't
> > require the use of optional parameters.
> > 
> > The devm_fpga_mgr_register() function is retained, and the
> > devm_fpga_mgr_register_simple() function is added.
> > 
> > Signed-off-by: Russ Weight <russell.h.weight@intel.com>
> > Reviewed-by: Xu Yilun <yilun.xu@intel.com>
> > ---
> > v9:
> >    - Cleaned up documentation for the FPGA Manager register functions
> >    - Renamed fpga_mgr_register() to fpga_mgr_register_full()
> >    - Renamed fpga_mgr_register_simple() to fpga_mgr_register()
> >    - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full()
> >    - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register()
> > v8:
> >    - Added reviewed-by tag.
> >    - Updated Documentation/driver-api/fpga/fpga-mgr.rst documentation.
> > v7:
> >    - Update the commit message to describe the new parameters for the
> >      *fpga_mgr_register() functions and to mention the
> >      *fpga_mgr_register_simple() functions.
> >    - Fix function prototypes in header file to rename dev to parent.
> >    - Make use of the PTR_ERR_OR_ZERO() macro when possible.
> >    - Some cleanup of comments.
> >    - Update function defintions/prototypes to apply const to the new info
> >      parameter.
> > v6:
> >    - Moved FPGA manager optional parameters out of the ops structure and
> >      back into the FPGA manager structure.
> >    - Changed fpga_mgr_register()/devm_fpga_mgr_register() parameters to
> >      accept an info data structure to provide flexibility in passing optional
> >      parameters.
> >    - Added fpga_mgr_register_simple()/devm_fpga_mgr_register_simple()
> >      functions to support current parameters for users that don't require
> >      the use of optional parameters.
> > v5:
> >    - Rebased on top of recently accepted patches.
> >    - Removed compat_id from the fpga_mgr_register() parameter list
> >      and added it to the fpga_manager_ops structure. This also required
> >      dynamically allocating the dfl-fme-ops structure in order to add
> >      the appropriate compat_id.
> > v4:
> >    - Added the compat_id parameter to fpga_mgr_register() and
> >      devm_fpga_mgr_register() to ensure that the compat_id is set before
> >      the device_register() call.
> > v3:
> >    - Cleaned up comment header for fpga_mgr_register()
> >    - Fix error return on ida_simple_get() failure
> > v2:
> >    - Restored devm_fpga_mgr_register() functionality, adapted for the combined
> >      create/register functionality.
> >    - All previous callers of devm_fpga_mgr_register() will continue to call
> >      devm_fpga_mgr_register().
> >    - replaced unnecessary ternary operators in return statements with standard
> >      if conditions.
> > ---
> >   Documentation/driver-api/fpga/fpga-mgr.rst |  34 +++-
> >   drivers/fpga/altera-cvp.c                  |  12 +-
> >   drivers/fpga/altera-pr-ip-core.c           |   7 +-
> >   drivers/fpga/altera-ps-spi.c               |   9 +-
> >   drivers/fpga/dfl-fme-mgr.c                 |  22 +--
> >   drivers/fpga/fpga-mgr.c                    | 215 +++++++++------------
> >   drivers/fpga/ice40-spi.c                   |   9 +-
> >   drivers/fpga/machxo2-spi.c                 |   9 +-
> >   drivers/fpga/socfpga-a10.c                 |  16 +-
> >   drivers/fpga/socfpga.c                     |   9 +-
> >   drivers/fpga/stratix10-soc.c               |  16 +-
> >   drivers/fpga/ts73xx-fpga.c                 |   9 +-
> >   drivers/fpga/xilinx-spi.c                  |  11 +-
> >   drivers/fpga/zynq-fpga.c                   |  16 +-
> >   drivers/fpga/zynqmp-fpga.c                 |   9 +-
> >   include/linux/fpga/fpga-mgr.h              |  62 ++++--
> >   16 files changed, 210 insertions(+), 255 deletions(-)
> > 
> > diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
> > index 4d926b452cb3..826ed8dc9210 100644
> > --- a/Documentation/driver-api/fpga/fpga-mgr.rst
> > +++ b/Documentation/driver-api/fpga/fpga-mgr.rst
> > @@ -24,7 +24,7 @@ How to support a new FPGA device
> >   --------------------------------
> >   To add another FPGA manager, write a driver that implements a set of ops.  The
> > -probe function calls fpga_mgr_register(), such as::
> > +probe function calls fpga_mgr_register() or fpga_mgr_register_full(), such as::
> >   	static const struct fpga_manager_ops socfpga_fpga_ops = {
> >   		.write_init = socfpga_fpga_ops_configure_init,
> > @@ -49,14 +49,14 @@ probe function calls fpga_mgr_register(), such as::
> >   		 * them in priv
> >   		 */
> > -		mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
> > -					   &socfpga_fpga_ops, priv);
> > -		if (!mgr)
> > -			return -ENOMEM;
> > +		mgr = fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
> > +					&socfpga_fpga_ops, priv);
> > +		if (IS_ERR(mgr))
> > +			return PTR_ERR(mgr);
> >   		platform_set_drvdata(pdev, mgr);
> > -		return fpga_mgr_register(mgr);
> > +		return 0;
> >   	}
> >   	static int socfpga_fpga_remove(struct platform_device *pdev)
> > @@ -68,6 +68,11 @@ probe function calls fpga_mgr_register(), such as::
> >   		return 0;
> >   	}
> > +Alternatively, the probe function could call one of the resource managed
> > +register functions, devm_fpga_mgr_register() or devm_fpga_mgr_register_full().
> > +When these functions are used, the parameter syntax is the same, but the call
> > +to fpga_mgr_unregister() should be removed. In the above example, the
> > +socfpga_fpga_remove() function would not be required.
> >   The ops will implement whatever device specific register writes are needed to
> >   do the programming sequence for this particular FPGA.  These ops return 0 for
> > @@ -104,8 +109,13 @@ API for implementing a new FPGA Manager driver
> >   * ``fpga_mgr_states`` -  Values for :c:expr:`fpga_manager->state`.
> >   * struct fpga_manager -  the FPGA manager struct
> >   * struct fpga_manager_ops -  Low level FPGA manager driver ops
> > -* devm_fpga_mgr_create() -  Allocate and init a manager struct
> > -* fpga_mgr_register() -  Register an FPGA manager
> > +* fpga_mgr_register_full() -  Create and register an FPGA manager using the
> > +  fpga_mgr_info structure to provide the full flexibility of options
> > +* fpga_mgr_register() -  Create and register an FPGA manager using standard
> > +  arguments
> > +* devm_fpga_mgr_register_full() -  Resource managed version of
> > +  fpga_mgr_register_full()
> > +* devm_fpga_mgr_register() -  Resource managed version of fpga_mgr_register()
> >   * fpga_mgr_unregister() -  Unregister an FPGA manager
> >   .. kernel-doc:: include/linux/fpga/fpga-mgr.h
> > @@ -118,10 +128,16 @@ API for implementing a new FPGA Manager driver
> >      :functions: fpga_manager_ops
> >   .. kernel-doc:: drivers/fpga/fpga-mgr.c
> > -   :functions: devm_fpga_mgr_create
> > +   :functions: fpga_mgr_register_full
> >   .. kernel-doc:: drivers/fpga/fpga-mgr.c
> >      :functions: fpga_mgr_register
> > +.. kernel-doc:: drivers/fpga/fpga-mgr.c
> > +   :functions: devm_fpga_mgr_register_full
> > +
> > +.. kernel-doc:: drivers/fpga/fpga-mgr.c
> > +   :functions: devm_fpga_mgr_register
> > +
> >   .. kernel-doc:: drivers/fpga/fpga-mgr.c
> >      :functions: fpga_mgr_unregister
> > diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
> > index ccf4546eff29..4ffb9da537d8 100644
> > --- a/drivers/fpga/altera-cvp.c
> > +++ b/drivers/fpga/altera-cvp.c
> > @@ -652,19 +652,15 @@ static int altera_cvp_probe(struct pci_dev *pdev,
> >   	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
> >   		 ALTERA_CVP_MGR_NAME, pci_name(pdev));
> > -	mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
> > -				   &altera_cvp_ops, conf);
> > -	if (!mgr) {
> > -		ret = -ENOMEM;
> > +	mgr = fpga_mgr_register(&pdev->dev, conf->mgr_name,
> > +				&altera_cvp_ops, conf);
> > +	if (IS_ERR(mgr)) {
> > +		ret = PTR_ERR(mgr);
> >   		goto err_unmap;
> >   	}
> >   	pci_set_drvdata(pdev, mgr);
> > -	ret = fpga_mgr_register(mgr);
> > -	if (ret)
> > -		goto err_unmap;
> > -
> >   	return 0;
> >   err_unmap:
> > diff --git a/drivers/fpga/altera-pr-ip-core.c b/drivers/fpga/altera-pr-ip-core.c
> > index dfdf21ed34c4..be0667968d33 100644
> > --- a/drivers/fpga/altera-pr-ip-core.c
> > +++ b/drivers/fpga/altera-pr-ip-core.c
> > @@ -191,11 +191,8 @@ int alt_pr_register(struct device *dev, void __iomem *reg_base)
> >   		(val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
> >   		(int)(val & ALT_PR_CSR_PR_START));
> > -	mgr = devm_fpga_mgr_create(dev, dev_name(dev), &alt_pr_ops, priv);
> > -	if (!mgr)
> > -		return -ENOMEM;
> > -
> > -	return devm_fpga_mgr_register(dev, mgr);
> > +	mgr = devm_fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv);
> > +	return PTR_ERR_OR_ZERO(mgr);
> >   }
> >   EXPORT_SYMBOL_GPL(alt_pr_register);
> > diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
> > index 23bfd4d1ad0f..5e1e009dba89 100644
> > --- a/drivers/fpga/altera-ps-spi.c
> > +++ b/drivers/fpga/altera-ps-spi.c
> > @@ -302,12 +302,9 @@ static int altera_ps_probe(struct spi_device *spi)
> >   	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s",
> >   		 dev_driver_string(&spi->dev), dev_name(&spi->dev));
> > -	mgr = devm_fpga_mgr_create(&spi->dev, conf->mgr_name,
> > -				   &altera_ps_ops, conf);
> > -	if (!mgr)
> > -		return -ENOMEM;
> > -
> > -	return devm_fpga_mgr_register(&spi->dev, mgr);
> > +	mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name,
> > +				     &altera_ps_ops, conf);
> > +	return PTR_ERR_OR_ZERO(mgr);
> >   }
> >   static const struct spi_device_id altera_ps_spi_ids[] = {
> > diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
> > index d5861d13b306..620e7874ab53 100644
> > --- a/drivers/fpga/dfl-fme-mgr.c
> > +++ b/drivers/fpga/dfl-fme-mgr.c
> > @@ -282,7 +282,7 @@ static void fme_mgr_get_compat_id(void __iomem *fme_pr,
> >   static int fme_mgr_probe(struct platform_device *pdev)
> >   {
> >   	struct dfl_fme_mgr_pdata *pdata = dev_get_platdata(&pdev->dev);
> > -	struct fpga_compat_id *compat_id;
> > +	struct fpga_manager_info info = { 0 };
> >   	struct device *dev = &pdev->dev;
> >   	struct fme_mgr_priv *priv;
> >   	struct fpga_manager *mgr;
> > @@ -302,20 +302,16 @@ static int fme_mgr_probe(struct platform_device *pdev)
> >   			return PTR_ERR(priv->ioaddr);
> >   	}
> > -	compat_id = devm_kzalloc(dev, sizeof(*compat_id), GFP_KERNEL);
> > -	if (!compat_id)
> > +	info.name = "DFL FME FPGA Manager";
> > +	info.mops = &fme_mgr_ops;
> > +	info.priv = priv;
> > +	info.compat_id = devm_kzalloc(dev, sizeof(*info.compat_id), GFP_KERNEL);
> > +	if (!info.compat_id)
> >   		return -ENOMEM;
> could we limp along instead of failing ?
> > -	fme_mgr_get_compat_id(priv->ioaddr, compat_id);
> > -
> > -	mgr = devm_fpga_mgr_create(dev, "DFL FME FPGA Manager",
> > -				   &fme_mgr_ops, priv);
> > -	if (!mgr)
> > -		return -ENOMEM;
> > -
> > -	mgr->compat_id = compat_id;
> > -
> > -	return devm_fpga_mgr_register(dev, mgr);
> > +	fme_mgr_get_compat_id(priv->ioaddr, info.compat_id);
> > +	mgr = devm_fpga_mgr_register_full(dev, &info);
> > +	return PTR_ERR_OR_ZERO(mgr);
> >   }
> >   static struct platform_driver fme_mgr_driver = {
> > diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
> > index ecb4c3c795fa..5a913aa649fd 100644
> > --- a/drivers/fpga/fpga-mgr.c
> > +++ b/drivers/fpga/fpga-mgr.c
> > @@ -550,21 +550,19 @@ void fpga_mgr_unlock(struct fpga_manager *mgr)
> >   EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
> >   /**
> > - * fpga_mgr_create - create and initialize an FPGA manager struct
> > + * fpga_mgr_register_full - create and register an FPGA Manager device
> >    * @parent:	fpga manager device from pdev
> > - * @name:	fpga manager name
> > - * @mops:	pointer to structure of fpga manager ops
> > - * @priv:	fpga manager private data
> > + * @info:	parameters for fpga manager
> >    *
> > - * The caller of this function is responsible for freeing the struct with
> > - * fpga_mgr_free().  Using devm_fpga_mgr_create() instead is recommended.
> > + * The caller of this function is responsible for calling fpga_mgr_unregister().
> > + * Using devm_fpga_mgr_register_full() instead is recommended.
> >    *
> > - * Return: pointer to struct fpga_manager or NULL
> > + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
> >    */
> > -struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> > -				     const struct fpga_manager_ops *mops,
> > -				     void *priv)
> > +struct fpga_manager *
> > +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
> >   {
> > +	const struct fpga_manager_ops *mops = info->mops;
> >   	struct fpga_manager *mgr;
> >   	int id, ret;
> > @@ -572,29 +570,31 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> >   	    !mops->write_init || (!mops->write && !mops->write_sg) ||
> >   	    (mops->write && mops->write_sg)) {
> >   		dev_err(parent, "Attempt to register without fpga_manager_ops\n");
> > -		return NULL;
> > +		return ERR_PTR(-EINVAL);
> >   	}
> > -	if (!name || !strlen(name)) {
> > +	if (!info->name || !strlen(info->name)) {
> >   		dev_err(parent, "Attempt to register with no name!\n");
> > -		return NULL;
> > +		return ERR_PTR(-EINVAL);
> >   	}
> >   	mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
> >   	if (!mgr)
> > -		return NULL;
> > +		return ERR_PTR(-ENOMEM);
> >   	id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
> > -	if (id < 0)
> > +	if (id < 0) {
> > +		ret = id;
> >   		goto error_kfree;
> > +	}
> >   	mutex_init(&mgr->ref_mutex);
> > -	mgr->name = name;
> > -	mgr->mops = mops;
> > -	mgr->priv = priv;
> > +	mgr->name = info->name;
> > +	mgr->mops = info->mops;
> > +	mgr->priv = info->priv;
> > +	mgr->compat_id = info->compat_id;
> > -	device_initialize(&mgr->dev);
> >   	mgr->dev.class = fpga_mgr_class;
> >   	mgr->dev.groups = mops->groups;
> >   	mgr->dev.parent = parent;
> > @@ -605,6 +605,19 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> >   	if (ret)
> >   		goto error_device;
> > +	/*
> > +	 * Initialize framework state by requesting low level driver read state
> > +	 * from device.  FPGA may be in reset mode or may have been programmed
> > +	 * by bootloader or EEPROM.
> > +	 */
> > +	mgr->state = mgr->mops->state(mgr);
> 
> This is existing code, but it seems wrong.
> 
> A side effect of state() should not be to initialize.
> 
> An init() should be added to mops

Does a check for mops->state() solves this issue? like:

	if (mgr->mops->state)
		mgr->state = mgr->mpos->state(mgr);

This could be in a separate patch.

Thanks,
Yilun

> 
> > +
> > +	ret = device_register(&mgr->dev);
> > +	if (ret) {
> > +		put_device(&mgr->dev);
> > +		return ERR_PTR(ret);
> > +	}
> > +
> >   	return mgr;
> >   error_device:
> > @@ -612,96 +625,36 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> >   error_kfree:
> >   	kfree(mgr);
> > -	return NULL;
> > +	return ERR_PTR(ret);
> >   }
> > -EXPORT_SYMBOL_GPL(fpga_mgr_create);
> > +EXPORT_SYMBOL_GPL(fpga_mgr_register_full);
> >   /**
> > - * fpga_mgr_free - free an FPGA manager created with fpga_mgr_create()
> > - * @mgr:	fpga manager struct
> > - */
> > -void fpga_mgr_free(struct fpga_manager *mgr)
> > -{
> > -	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> > -	kfree(mgr);
> > -}
> > -EXPORT_SYMBOL_GPL(fpga_mgr_free);
> > -
> > -static void devm_fpga_mgr_release(struct device *dev, void *res)
> > -{
> > -	struct fpga_mgr_devres *dr = res;
> > -
> > -	fpga_mgr_free(dr->mgr);
> > -}
> > -
> > -/**
> > - * devm_fpga_mgr_create - create and initialize a managed FPGA manager struct
> > + * fpga_mgr_register - create and register an FPGA Manager device
> >    * @parent:	fpga manager device from pdev
> >    * @name:	fpga manager name
> >    * @mops:	pointer to structure of fpga manager ops
> >    * @priv:	fpga manager private data
> >    *
> > - * This function is intended for use in an FPGA manager driver's probe function.
> > - * After the manager driver creates the manager struct with
> > - * devm_fpga_mgr_create(), it should register it with fpga_mgr_register().  The
> > - * manager driver's remove function should call fpga_mgr_unregister().  The
> > - * manager struct allocated with this function will be freed automatically on
> > - * driver detach.  This includes the case of a probe function returning error
> > - * before calling fpga_mgr_register(), the struct will still get cleaned up.
> > + * The caller of this function is responsible for calling fpga_mgr_unregister().
> > + * Using devm_fpga_mgr_register() instead is recommended. This simple
> > + * version of the register function should be sufficient for most users. The
> > + * fpga_mgr_register_full() function is available for users that need to pass
> > + * additional, optional parameters.
> >    *
> > - * Return: pointer to struct fpga_manager or NULL
> > + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
> >    */
> > -struct fpga_manager *devm_fpga_mgr_create(struct device *parent, const char *name,
> > -					  const struct fpga_manager_ops *mops,
> > -					  void *priv)
> > +struct fpga_manager *
> > +fpga_mgr_register(struct device *parent, const char *name,
> > +		  const struct fpga_manager_ops *mops, void *priv)
> >   {
> > -	struct fpga_mgr_devres *dr;
> > +	struct fpga_manager_info info = { 0 };
> > -	dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL);
> > -	if (!dr)
> > -		return NULL;
> > +	info.name = name;
> > +	info.mops = mops;
> > +	info.priv = priv;
> > -	dr->mgr = fpga_mgr_create(parent, name, mops, priv);
> > -	if (!dr->mgr) {
> > -		devres_free(dr);
> > -		return NULL;
> > -	}
> > -
> > -	devres_add(parent, dr);
> > -
> > -	return dr->mgr;
> > -}
> > -EXPORT_SYMBOL_GPL(devm_fpga_mgr_create);
> > -
> > -/**
> > - * fpga_mgr_register - register an FPGA manager
> > - * @mgr: fpga manager struct
> > - *
> > - * Return: 0 on success, negative error code otherwise.
> > - */
> > -int fpga_mgr_register(struct fpga_manager *mgr)
> > -{
> > -	int ret;
> > -
> > -	/*
> > -	 * Initialize framework state by requesting low level driver read state
> > -	 * from device.  FPGA may be in reset mode or may have been programmed
> > -	 * by bootloader or EEPROM.
> > -	 */
> > -	mgr->state = mgr->mops->state(mgr);
> > -
> > -	ret = device_add(&mgr->dev);
> > -	if (ret)
> > -		goto error_device;
> > -
> > -	dev_info(&mgr->dev, "%s registered\n", mgr->name);
> > -
> > -	return 0;
> > -
> > -error_device:
> > -	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> > -
> > -	return ret;
> > +	return fpga_mgr_register_full(parent, &info);
> >   }
> >   EXPORT_SYMBOL_GPL(fpga_mgr_register);
> > @@ -726,14 +679,6 @@ void fpga_mgr_unregister(struct fpga_manager *mgr)
> >   }
> >   EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
> > -static int fpga_mgr_devres_match(struct device *dev, void *res,
> > -				 void *match_data)
> > -{
> > -	struct fpga_mgr_devres *dr = res;
> > -
> > -	return match_data == dr->mgr;
> > -}
> > -
> >   static void devm_fpga_mgr_unregister(struct device *dev, void *res)
> >   {
> >   	struct fpga_mgr_devres *dr = res;
> > @@ -742,45 +687,67 @@ static void devm_fpga_mgr_unregister(struct device *dev, void *res)
> >   }
> >   /**
> > - * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
> > - * @dev: managing device for this FPGA manager
> > - * @mgr: fpga manager struct
> > + * devm_fpga_mgr_register_full - resource managed variant of fpga_mgr_register()
> > + * @parent:	fpga manager device from pdev
> > + * @info:	parameters for fpga manager
> >    *
> > - * This is the devres variant of fpga_mgr_register() for which the unregister
> > + * This is the devres variant of fpga_mgr_register_full() for which the unregister
> >    * function will be called automatically when the managing device is detached.
> >    */
> > -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr)
> > +struct fpga_manager *
> > +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
> >   {
> >   	struct fpga_mgr_devres *dr;
> > -	int ret;
> > -
> > -	/*
> > -	 * Make sure that the struct fpga_manager * that is passed in is
> > -	 * managed itself.
> > -	 */
> > -	if (WARN_ON(!devres_find(dev, devm_fpga_mgr_release,
> > -				 fpga_mgr_devres_match, mgr)))
> > -		return -EINVAL;
> > +	struct fpga_manager *mgr;
> >   	dr = devres_alloc(devm_fpga_mgr_unregister, sizeof(*dr), GFP_KERNEL);
> >   	if (!dr)
> > -		return -ENOMEM;
> > +		return ERR_PTR(-ENOMEM);
> > -	ret = fpga_mgr_register(mgr);
> > -	if (ret) {
> > +	mgr = fpga_mgr_register_full(parent, info);
> > +	if (IS_ERR(mgr)) {
> >   		devres_free(dr);
> > -		return ret;
> > +		return mgr;
> >   	}
> >   	dr->mgr = mgr;
> > -	devres_add(dev, dr);
> > +	devres_add(parent, dr);
> > -	return 0;
> > +	return mgr;
> > +}
> > +EXPORT_SYMBOL_GPL(devm_fpga_mgr_register_full);
> > +
> > +/**
> > + * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
> > + * @parent:	fpga manager device from pdev
> > + * @name:	fpga manager name
> > + * @mops:	pointer to structure of fpga manager ops
> > + * @priv:	fpga manager private data
> > + *
> > + * This is the devres variant of fpga_mgr_register() for which the
> > + * unregister function will be called automatically when the managing
> > + * device is detached.
> > + */
> > +struct fpga_manager *
> > +devm_fpga_mgr_register(struct device *parent, const char *name,
> > +		       const struct fpga_manager_ops *mops, void *priv)
> > +{
> > +	struct fpga_manager_info info = { 0 };
> > +
> > +	info.name = name;
> > +	info.mops = mops;
> > +	info.priv = priv;
> > +
> > +	return devm_fpga_mgr_register_full(parent, &info);
> >   }
> >   EXPORT_SYMBOL_GPL(devm_fpga_mgr_register);
> >   static void fpga_mgr_dev_release(struct device *dev)
> >   {
> > +	struct fpga_manager *mgr = to_fpga_manager(dev);
> > +
> > +	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> > +	kfree(mgr);
> >   }
> >   static int __init fpga_mgr_class_init(void)
> > diff --git a/drivers/fpga/ice40-spi.c b/drivers/fpga/ice40-spi.c
> > index 69dec5af23c3..b7591912248f 100644
> > --- a/drivers/fpga/ice40-spi.c
> > +++ b/drivers/fpga/ice40-spi.c
> > @@ -178,12 +178,9 @@ static int ice40_fpga_probe(struct spi_device *spi)
> >   		return ret;
> >   	}
> > -	mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
> > -				   &ice40_fpga_ops, priv);
> > -	if (!mgr)
> > -		return -ENOMEM;
> > -
> > -	return devm_fpga_mgr_register(dev, mgr);
> > +	mgr = devm_fpga_mgr_register(dev, "Lattice iCE40 FPGA Manager",
> > +				     &ice40_fpga_ops, priv);
> > +	return PTR_ERR_OR_ZERO(mgr);
> >   }
> >   static const struct of_device_id ice40_fpga_of_match[] = {
> > diff --git a/drivers/fpga/machxo2-spi.c b/drivers/fpga/machxo2-spi.c
> > index 1afb41aa20d7..8469dfb5dd21 100644
> > --- a/drivers/fpga/machxo2-spi.c
> > +++ b/drivers/fpga/machxo2-spi.c
> > @@ -366,12 +366,9 @@ static int machxo2_spi_probe(struct spi_device *spi)
> >   		return -EINVAL;
> >   	}
> > -	mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager",
> > -				   &machxo2_ops, spi);
> > -	if (!mgr)
> > -		return -ENOMEM;
> > -
> > -	return devm_fpga_mgr_register(dev, mgr);
> > +	mgr = devm_fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager",
> > +				     &machxo2_ops, spi);
> > +	return PTR_ERR_OR_ZERO(mgr);
> >   }
> >   #ifdef CONFIG_OF
> > diff --git a/drivers/fpga/socfpga-a10.c b/drivers/fpga/socfpga-a10.c
> > index 573d88bdf730..ac8e89b8a5cc 100644
> > --- a/drivers/fpga/socfpga-a10.c
> > +++ b/drivers/fpga/socfpga-a10.c
> > @@ -508,19 +508,15 @@ static int socfpga_a10_fpga_probe(struct platform_device *pdev)
> >   		return -EBUSY;
> >   	}
> > -	mgr = devm_fpga_mgr_create(dev, "SoCFPGA Arria10 FPGA Manager",
> > -				   &socfpga_a10_fpga_mgr_ops, priv);
> > -	if (!mgr)
> > -		return -ENOMEM;
> > -
> > -	platform_set_drvdata(pdev, mgr);
> > -
> > -	ret = fpga_mgr_register(mgr);
> > -	if (ret) {
> > +	mgr = fpga_mgr_register(dev, "SoCFPGA Arria10 FPGA Manager",
> > +				&socfpga_a10_fpga_mgr_ops, priv);
> > +	if (IS_ERR(mgr)) {
> >   		clk_disable_unprepare(priv->clk);
> > -		return ret;
> > +		return PTR_ERR(mgr);
> >   	}
> > +	platform_set_drvdata(pdev, mgr);
> > +
> >   	return 0;
> >   }
> > diff --git a/drivers/fpga/socfpga.c b/drivers/fpga/socfpga.c
> > index 1f467173fc1f..7e0741f99696 100644
> > --- a/drivers/fpga/socfpga.c
> > +++ b/drivers/fpga/socfpga.c
> > @@ -571,12 +571,9 @@ static int socfpga_fpga_probe(struct platform_device *pdev)
> >   	if (ret)
> >   		return ret;
> > -	mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
> > -				   &socfpga_fpga_ops, priv);
> > -	if (!mgr)
> > -		return -ENOMEM;
> > -
> > -	return devm_fpga_mgr_register(dev, mgr);
> > +	mgr = devm_fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
> > +				     &socfpga_fpga_ops, priv);
> > +	return PTR_ERR_OR_ZERO(mgr);
> >   }
> >   #ifdef CONFIG_OF
> > diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
> > index a2cea500f7cc..9155e888a133 100644
> > --- a/drivers/fpga/stratix10-soc.c
> > +++ b/drivers/fpga/stratix10-soc.c
> > @@ -425,18 +425,11 @@ static int s10_probe(struct platform_device *pdev)
> >   	init_completion(&priv->status_return_completion);
> > -	mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
> > -			      &s10_ops, priv);
> > -	if (!mgr) {
> > -		dev_err(dev, "unable to create FPGA manager\n");
> > -		ret = -ENOMEM;
> > -		goto probe_err;
> > -	}
> > -
> > -	ret = fpga_mgr_register(mgr);
> > -	if (ret) {
> > +	mgr = fpga_mgr_register(dev, "Stratix10 SOC FPGA Manager",
> > +				&s10_ops, priv);
> > +	if (IS_ERR(mgr)) {
> >   		dev_err(dev, "unable to register FPGA manager\n");
> > -		fpga_mgr_free(mgr);
> > +		ret = PTR_ERR(mgr);
> >   		goto probe_err;
> >   	}
> > @@ -454,7 +447,6 @@ static int s10_remove(struct platform_device *pdev)
> >   	struct s10_priv *priv = mgr->priv;
> >   	fpga_mgr_unregister(mgr);
> > -	fpga_mgr_free(mgr);
> >   	stratix10_svc_free_channel(priv->chan);
> >   	return 0;
> > diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c
> > index 101f016c6ed8..fd52de20ddb2 100644
> > --- a/drivers/fpga/ts73xx-fpga.c
> > +++ b/drivers/fpga/ts73xx-fpga.c
> > @@ -122,12 +122,9 @@ static int ts73xx_fpga_probe(struct platform_device *pdev)
> >   	if (IS_ERR(priv->io_base))
> >   		return PTR_ERR(priv->io_base);
> > -	mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
> > -				   &ts73xx_fpga_ops, priv);
> > -	if (!mgr)
> > -		return -ENOMEM;
> > -
> > -	return devm_fpga_mgr_register(kdev, mgr);
> > +	mgr = devm_fpga_mgr_register(kdev, "TS-73xx FPGA Manager",
> > +				     &ts73xx_fpga_ops, priv);
> > +	return PTR_ERR_OR_ZERO(mgr);
> >   }
> >   static struct platform_driver ts73xx_fpga_driver = {
> > diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
> > index fee4d0abf6bf..db23626f9ab2 100644
> > --- a/drivers/fpga/xilinx-spi.c
> > +++ b/drivers/fpga/xilinx-spi.c
> > @@ -247,13 +247,10 @@ static int xilinx_spi_probe(struct spi_device *spi)
> >   		return dev_err_probe(&spi->dev, PTR_ERR(conf->done),
> >   				     "Failed to get DONE gpio\n");
> > -	mgr = devm_fpga_mgr_create(&spi->dev,
> > -				   "Xilinx Slave Serial FPGA Manager",
> > -				   &xilinx_spi_ops, conf);
> > -	if (!mgr)
> > -		return -ENOMEM;
> > -
> > -	return devm_fpga_mgr_register(&spi->dev, mgr);
> > +	mgr = devm_fpga_mgr_register(&spi->dev,
> > +				     "Xilinx Slave Serial FPGA Manager",
> > +				     &xilinx_spi_ops, conf);
> > +	return PTR_ERR_OR_ZERO(mgr);
> >   }
> >   static const struct of_device_id xlnx_spi_of_match[] = {
> > diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
> > index 9b75bd4f93d8..426aa34c6a0d 100644
> > --- a/drivers/fpga/zynq-fpga.c
> > +++ b/drivers/fpga/zynq-fpga.c
> > @@ -609,20 +609,16 @@ static int zynq_fpga_probe(struct platform_device *pdev)
> >   	clk_disable(priv->clk);
> > -	mgr = devm_fpga_mgr_create(dev, "Xilinx Zynq FPGA Manager",
> > -				   &zynq_fpga_ops, priv);
> > -	if (!mgr)
> > -		return -ENOMEM;
> > -
> > -	platform_set_drvdata(pdev, mgr);
> > -
> > -	err = fpga_mgr_register(mgr);
> > -	if (err) {
> > +	mgr = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
> > +				&zynq_fpga_ops, priv);
> > +	if (IS_ERR(mgr)) {
> >   		dev_err(dev, "unable to register FPGA manager\n");
> >   		clk_unprepare(priv->clk);
> > -		return err;
> > +		return PTR_ERR(mgr);
> >   	}
> > +	platform_set_drvdata(pdev, mgr);
> > +
> >   	return 0;
> >   }
> > diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
> > index 125743c9797f..975bdc4d0a65 100644
> > --- a/drivers/fpga/zynqmp-fpga.c
> > +++ b/drivers/fpga/zynqmp-fpga.c
> > @@ -102,12 +102,9 @@ static int zynqmp_fpga_probe(struct platform_device *pdev)
> >   	priv->dev = dev;
> > -	mgr = devm_fpga_mgr_create(dev, "Xilinx ZynqMP FPGA Manager",
> > -				   &zynqmp_fpga_ops, priv);
> > -	if (!mgr)
> > -		return -ENOMEM;
> > -
> > -	return devm_fpga_mgr_register(dev, mgr);
> > +	mgr = devm_fpga_mgr_register(dev, "Xilinx ZynqMP FPGA Manager",
> > +				     &zynqmp_fpga_ops, priv);
> > +	return PTR_ERR_OR_ZERO(mgr);
> >   }
> >   static const struct of_device_id zynqmp_fpga_of_match[] = {
> > diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
> > index 474c1f506307..ac3ddaf2903c 100644
> > --- a/include/linux/fpga/fpga-mgr.h
> > +++ b/include/linux/fpga/fpga-mgr.h
> > @@ -105,6 +105,36 @@ struct fpga_image_info {
> >   #endif
> >   };
> > +/**
> > + * struct fpga_compat_id - id for compatibility check
> > + *
> > + * @id_h: high 64bit of the compat_id
> > + * @id_l: low 64bit of the compat_id
> > + */
> > +struct fpga_compat_id {
> > +	u64 id_h;
> > +	u64 id_l;
> > +};
> > +
> 
> There are two register functions are to handle this dfl only structure.
> 
> This really needs to be moved fme_mgr_priv.
> 
> > +/**
> > + * struct fpga_manager_info - collection of parameters for an FPGA Manager
> > + * @name: fpga manager name
> > + * @compat_id: FPGA manager id for compatibility check.
> > + * @mops: pointer to structure of fpga manager ops
> > + * @priv: fpga manager private data
> > + *
> > + * fpga_manager_info contains parameters for the register function. These
> > + * are separated into an info structure because they some are optional
> > + * others could be added to in the future. The info structure facilitates
> > + * maintaining a stable API.
> > + */
> > +struct fpga_manager_info {
> > +	const char *name;
> > +	struct fpga_compat_id *compat_id;
> > +	const struct fpga_manager_ops *mops;
> > +	void *priv;
> > +};
> > +
> >   /**
> >    * struct fpga_manager_ops - ops for low level fpga manager drivers
> >    * @initial_header_size: Maximum number of bytes that should be passed into write_init
> > @@ -143,17 +173,6 @@ struct fpga_manager_ops {
> >   #define FPGA_MGR_STATUS_IP_PROTOCOL_ERR		BIT(3)
> >   #define FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR	BIT(4)
> > -/**
> > - * struct fpga_compat_id - id for compatibility check
> > - *
> > - * @id_h: high 64bit of the compat_id
> > - * @id_l: low 64bit of the compat_id
> > - */
> > -struct fpga_compat_id {
> > -	u64 id_h;
> > -	u64 id_l;
> > -};
> > -
> >   /**
> >    * struct fpga_manager - fpga manager structure
> >    * @name: name of low level fpga manager
> > @@ -191,17 +210,18 @@ struct fpga_manager *fpga_mgr_get(struct device *dev);
> >   void fpga_mgr_put(struct fpga_manager *mgr);
> > -struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name,
> > -				     const struct fpga_manager_ops *mops,
> > -				     void *priv);
> > -void fpga_mgr_free(struct fpga_manager *mgr);
> 
> removing these should cause any oot driver to fail to load.
> 
> so an oops is unlikely.
> 
> I'm ok with with api change.
> 
> > -int fpga_mgr_register(struct fpga_manager *mgr);
> > -void fpga_mgr_unregister(struct fpga_manager *mgr);
> > +struct fpga_manager *
> > +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
> > -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr);
> > +struct fpga_manager *
> > +fpga_mgr_register(struct device *parent, const char *name,
> > +		  const struct fpga_manager_ops *mops, void *priv);
> 
> having 2 ways to do the same thing is not great.
> 
> this should be reduced down to 1.
> 
> My preference is for the *info one as it's api will be durable.
> 
> Tom
> 
> > +void fpga_mgr_unregister(struct fpga_manager *mgr);
> > -struct fpga_manager *devm_fpga_mgr_create(struct device *dev, const char *name,
> > -					  const struct fpga_manager_ops *mops,
> > -					  void *priv);
> > +struct fpga_manager *
> > +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
> > +struct fpga_manager *
> > +devm_fpga_mgr_register(struct device *parent, const char *name,
> > +		       const struct fpga_manager_ops *mops, void *priv);
> >   #endif /*_LINUX_FPGA_MGR_H */

^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 1/3] fpga: mgr: Use standard dev_release for class driver
  2021-07-06 23:03         ` Russ Weight
  2021-07-07  2:45           ` Xu Yilun
@ 2021-07-07 13:29           ` Tom Rix
  1 sibling, 0 replies; 22+ messages in thread
From: Tom Rix @ 2021-07-07 13:29 UTC (permalink / raw)
  To: Russ Weight, mdf, linux-fpga
  Cc: lgoncalv, yilun.xu, hao.wu, matthew.gerlach, richard.gong


On 7/6/21 4:03 PM, Russ Weight wrote:
>
> On 7/6/21 2:44 PM, Tom Rix wrote:
>> On 7/6/21 2:02 PM, Russ Weight wrote:
>>> On 7/6/21 12:04 PM, Tom Rix wrote:
>>>> Russ,
>>>>
>>>> My two big concerns are.
>>>>
>>>> compat_id does not belong in fpga_mgr_info, it belongs in fme_mgr_priv.
>>> fpga_mgr_info is a temporary structure on the stack that contains the
>>> parameters only long enough to pass them in and have them added to the
>>> fpga_manager structure. Do you have a concern about it being on the
>>> fpga_manager structure.
>> My concern is compat_id should never have been part of fpga-mgr in the first place.
>>
>> It is dfl specific, so instead of going in a common structure, it should go into a dfl structure
>>
>> The likely place it should go is fme_mgr_priv.
>>
>> The need for 2 register functions here and in fpga-region is caused by carrying this dfl data around in the wrong place.
> This issue was raised for the previous patch version, and Hao pointed out that
> its placement in the fpga_manager structure was a result of community discussion.
Everything is a community discussion, I think we got it wrong in the past.
>
> These changes aren't affecting the location of compat_id. Where it is
> stored is not really within the scope of what I am trying to accomplish.
> If it needs to be changed, could it be handled in a separate patch set?

The location is why you need the *info structs and have a 
*register_full() that dfl uses and a *register() that everyone else uses.

If you only had the *info variant of the register(), the problem would 
be abstracted somewhat away.

Since the public api is changing, I think moving the compat_id first is 
necessary.

Or once it moves the info structs will change/go away and one of the 
registers()'s will go away.

I'll have a move patchset out later today.

Tom


>
> - Russ
>
>> Tom
>>
>>>> there are two register functions, there should be one.
>>> I get what you are saying. I don't really like the idea of forcing the
>>> complexity of the temporary structure on all callers, since only a
>>> couple require it, but we can do that if that is the concensus.
>>>
>>> What do others think?
>>>
>>>> On 6/30/21 6:37 PM, Russ Weight wrote:
>>>>> The FPGA manager class driver data structure is being treated as a
>>>>> managed resource instead of using the standard dev_release call-back
>>>>> function to release the class data structure. This change removes
>>>>> the managed resource code for the freeing of the class data structure
>>>>> and combines the create() and register() functions into a single
>>>>> register() or register_simple() function.
>>>>>
>>>>> The register() function accepts an info data structure to provide
>>>>> flexibility in passing optional parameters. The register_simple()
>>>>> function supports the current parameter list for users that don't
>>>>> require the use of optional parameters.
>>>>>
>>>>> The devm_fpga_mgr_register() function is retained, and the
>>>>> devm_fpga_mgr_register_simple() function is added.
>>>>>
>>>>> Signed-off-by: Russ Weight <russell.h.weight@intel.com>
>>>>> Reviewed-by: Xu Yilun <yilun.xu@intel.com>
>>>>> ---
>>>>> v9:
>>>>>      - Cleaned up documentation for the FPGA Manager register functions
>>>>>      - Renamed fpga_mgr_register() to fpga_mgr_register_full()
>>>>>      - Renamed fpga_mgr_register_simple() to fpga_mgr_register()
>>>>>      - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full()
>>>>>      - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register()
>>>>> v8:
>>>>>      - Added reviewed-by tag.
>>>>>      - Updated Documentation/driver-api/fpga/fpga-mgr.rst documentation.
>>>>> v7:
>>>>>      - Update the commit message to describe the new parameters for the
>>>>>        *fpga_mgr_register() functions and to mention the
>>>>>        *fpga_mgr_register_simple() functions.
>>>>>      - Fix function prototypes in header file to rename dev to parent.
>>>>>      - Make use of the PTR_ERR_OR_ZERO() macro when possible.
>>>>>      - Some cleanup of comments.
>>>>>      - Update function defintions/prototypes to apply const to the new info
>>>>>        parameter.
>>>>> v6:
>>>>>      - Moved FPGA manager optional parameters out of the ops structure and
>>>>>        back into the FPGA manager structure.
>>>>>      - Changed fpga_mgr_register()/devm_fpga_mgr_register() parameters to
>>>>>        accept an info data structure to provide flexibility in passing optional
>>>>>        parameters.
>>>>>      - Added fpga_mgr_register_simple()/devm_fpga_mgr_register_simple()
>>>>>        functions to support current parameters for users that don't require
>>>>>        the use of optional parameters.
>>>>> v5:
>>>>>      - Rebased on top of recently accepted patches.
>>>>>      - Removed compat_id from the fpga_mgr_register() parameter list
>>>>>        and added it to the fpga_manager_ops structure. This also required
>>>>>        dynamically allocating the dfl-fme-ops structure in order to add
>>>>>        the appropriate compat_id.
>>>>> v4:
>>>>>      - Added the compat_id parameter to fpga_mgr_register() and
>>>>>        devm_fpga_mgr_register() to ensure that the compat_id is set before
>>>>>        the device_register() call.
>>>>> v3:
>>>>>      - Cleaned up comment header for fpga_mgr_register()
>>>>>      - Fix error return on ida_simple_get() failure
>>>>> v2:
>>>>>      - Restored devm_fpga_mgr_register() functionality, adapted for the combined
>>>>>        create/register functionality.
>>>>>      - All previous callers of devm_fpga_mgr_register() will continue to call
>>>>>        devm_fpga_mgr_register().
>>>>>      - replaced unnecessary ternary operators in return statements with standard
>>>>>        if conditions.
>>>>> ---
>>>>>     Documentation/driver-api/fpga/fpga-mgr.rst |  34 +++-
>>>>>     drivers/fpga/altera-cvp.c                  |  12 +-
>>>>>     drivers/fpga/altera-pr-ip-core.c           |   7 +-
>>>>>     drivers/fpga/altera-ps-spi.c               |   9 +-
>>>>>     drivers/fpga/dfl-fme-mgr.c                 |  22 +--
>>>>>     drivers/fpga/fpga-mgr.c                    | 215 +++++++++------------
>>>>>     drivers/fpga/ice40-spi.c                   |   9 +-
>>>>>     drivers/fpga/machxo2-spi.c                 |   9 +-
>>>>>     drivers/fpga/socfpga-a10.c                 |  16 +-
>>>>>     drivers/fpga/socfpga.c                     |   9 +-
>>>>>     drivers/fpga/stratix10-soc.c               |  16 +-
>>>>>     drivers/fpga/ts73xx-fpga.c                 |   9 +-
>>>>>     drivers/fpga/xilinx-spi.c                  |  11 +-
>>>>>     drivers/fpga/zynq-fpga.c                   |  16 +-
>>>>>     drivers/fpga/zynqmp-fpga.c                 |   9 +-
>>>>>     include/linux/fpga/fpga-mgr.h              |  62 ++++--
>>>>>     16 files changed, 210 insertions(+), 255 deletions(-)
>>>>>
>>>>> diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
>>>>> index 4d926b452cb3..826ed8dc9210 100644
>>>>> --- a/Documentation/driver-api/fpga/fpga-mgr.rst
>>>>> +++ b/Documentation/driver-api/fpga/fpga-mgr.rst
>>>>> @@ -24,7 +24,7 @@ How to support a new FPGA device
>>>>>     --------------------------------
>>>>>       To add another FPGA manager, write a driver that implements a set of ops.  The
>>>>> -probe function calls fpga_mgr_register(), such as::
>>>>> +probe function calls fpga_mgr_register() or fpga_mgr_register_full(), such as::
>>>>>           static const struct fpga_manager_ops socfpga_fpga_ops = {
>>>>>             .write_init = socfpga_fpga_ops_configure_init,
>>>>> @@ -49,14 +49,14 @@ probe function calls fpga_mgr_register(), such as::
>>>>>              * them in priv
>>>>>              */
>>>>>     -        mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
>>>>> -                       &socfpga_fpga_ops, priv);
>>>>> -        if (!mgr)
>>>>> -            return -ENOMEM;
>>>>> +        mgr = fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
>>>>> +                    &socfpga_fpga_ops, priv);
>>>>> +        if (IS_ERR(mgr))
>>>>> +            return PTR_ERR(mgr);
>>>>>               platform_set_drvdata(pdev, mgr);
>>>>>     -        return fpga_mgr_register(mgr);
>>>>> +        return 0;
>>>>>         }
>>>>>           static int socfpga_fpga_remove(struct platform_device *pdev)
>>>>> @@ -68,6 +68,11 @@ probe function calls fpga_mgr_register(), such as::
>>>>>             return 0;
>>>>>         }
>>>>>     +Alternatively, the probe function could call one of the resource managed
>>>>> +register functions, devm_fpga_mgr_register() or devm_fpga_mgr_register_full().
>>>>> +When these functions are used, the parameter syntax is the same, but the call
>>>>> +to fpga_mgr_unregister() should be removed. In the above example, the
>>>>> +socfpga_fpga_remove() function would not be required.
>>>>>       The ops will implement whatever device specific register writes are needed to
>>>>>     do the programming sequence for this particular FPGA.  These ops return 0 for
>>>>> @@ -104,8 +109,13 @@ API for implementing a new FPGA Manager driver
>>>>>     * ``fpga_mgr_states`` -  Values for :c:expr:`fpga_manager->state`.
>>>>>     * struct fpga_manager -  the FPGA manager struct
>>>>>     * struct fpga_manager_ops -  Low level FPGA manager driver ops
>>>>> -* devm_fpga_mgr_create() -  Allocate and init a manager struct
>>>>> -* fpga_mgr_register() -  Register an FPGA manager
>>>>> +* fpga_mgr_register_full() -  Create and register an FPGA manager using the
>>>>> +  fpga_mgr_info structure to provide the full flexibility of options
>>>>> +* fpga_mgr_register() -  Create and register an FPGA manager using standard
>>>>> +  arguments
>>>>> +* devm_fpga_mgr_register_full() -  Resource managed version of
>>>>> +  fpga_mgr_register_full()
>>>>> +* devm_fpga_mgr_register() -  Resource managed version of fpga_mgr_register()
>>>>>     * fpga_mgr_unregister() -  Unregister an FPGA manager
>>>>>       .. kernel-doc:: include/linux/fpga/fpga-mgr.h
>>>>> @@ -118,10 +128,16 @@ API for implementing a new FPGA Manager driver
>>>>>        :functions: fpga_manager_ops
>>>>>       .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>>>> -   :functions: devm_fpga_mgr_create
>>>>> +   :functions: fpga_mgr_register_full
>>>>>       .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>>>>        :functions: fpga_mgr_register
>>>>>     +.. kernel-doc:: drivers/fpga/fpga-mgr.c
>>>>> +   :functions: devm_fpga_mgr_register_full
>>>>> +
>>>>> +.. kernel-doc:: drivers/fpga/fpga-mgr.c
>>>>> +   :functions: devm_fpga_mgr_register
>>>>> +
>>>>>     .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>>>>        :functions: fpga_mgr_unregister
>>>>> diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
>>>>> index ccf4546eff29..4ffb9da537d8 100644
>>>>> --- a/drivers/fpga/altera-cvp.c
>>>>> +++ b/drivers/fpga/altera-cvp.c
>>>>> @@ -652,19 +652,15 @@ static int altera_cvp_probe(struct pci_dev *pdev,
>>>>>         snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
>>>>>              ALTERA_CVP_MGR_NAME, pci_name(pdev));
>>>>>     -    mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
>>>>> -                   &altera_cvp_ops, conf);
>>>>> -    if (!mgr) {
>>>>> -        ret = -ENOMEM;
>>>>> +    mgr = fpga_mgr_register(&pdev->dev, conf->mgr_name,
>>>>> +                &altera_cvp_ops, conf);
>>>>> +    if (IS_ERR(mgr)) {
>>>>> +        ret = PTR_ERR(mgr);
>>>>>             goto err_unmap;
>>>>>         }
>>>>>           pci_set_drvdata(pdev, mgr);
>>>>>     -    ret = fpga_mgr_register(mgr);
>>>>> -    if (ret)
>>>>> -        goto err_unmap;
>>>>> -
>>>>>         return 0;
>>>>>       err_unmap:
>>>>> diff --git a/drivers/fpga/altera-pr-ip-core.c b/drivers/fpga/altera-pr-ip-core.c
>>>>> index dfdf21ed34c4..be0667968d33 100644
>>>>> --- a/drivers/fpga/altera-pr-ip-core.c
>>>>> +++ b/drivers/fpga/altera-pr-ip-core.c
>>>>> @@ -191,11 +191,8 @@ int alt_pr_register(struct device *dev, void __iomem *reg_base)
>>>>>             (val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
>>>>>             (int)(val & ALT_PR_CSR_PR_START));
>>>>>     -    mgr = devm_fpga_mgr_create(dev, dev_name(dev), &alt_pr_ops, priv);
>>>>> -    if (!mgr)
>>>>> -        return -ENOMEM;
>>>>> -
>>>>> -    return devm_fpga_mgr_register(dev, mgr);
>>>>> +    mgr = devm_fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv);
>>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>>     }
>>>>>     EXPORT_SYMBOL_GPL(alt_pr_register);
>>>>>     diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
>>>>> index 23bfd4d1ad0f..5e1e009dba89 100644
>>>>> --- a/drivers/fpga/altera-ps-spi.c
>>>>> +++ b/drivers/fpga/altera-ps-spi.c
>>>>> @@ -302,12 +302,9 @@ static int altera_ps_probe(struct spi_device *spi)
>>>>>         snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s",
>>>>>              dev_driver_string(&spi->dev), dev_name(&spi->dev));
>>>>>     -    mgr = devm_fpga_mgr_create(&spi->dev, conf->mgr_name,
>>>>> -                   &altera_ps_ops, conf);
>>>>> -    if (!mgr)
>>>>> -        return -ENOMEM;
>>>>> -
>>>>> -    return devm_fpga_mgr_register(&spi->dev, mgr);
>>>>> +    mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name,
>>>>> +                     &altera_ps_ops, conf);
>>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>>     }
>>>>>       static const struct spi_device_id altera_ps_spi_ids[] = {
>>>>> diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
>>>>> index d5861d13b306..620e7874ab53 100644
>>>>> --- a/drivers/fpga/dfl-fme-mgr.c
>>>>> +++ b/drivers/fpga/dfl-fme-mgr.c
>>>>> @@ -282,7 +282,7 @@ static void fme_mgr_get_compat_id(void __iomem *fme_pr,
>>>>>     static int fme_mgr_probe(struct platform_device *pdev)
>>>>>     {
>>>>>         struct dfl_fme_mgr_pdata *pdata = dev_get_platdata(&pdev->dev);
>>>>> -    struct fpga_compat_id *compat_id;
>>>>> +    struct fpga_manager_info info = { 0 };
>>>>>         struct device *dev = &pdev->dev;
>>>>>         struct fme_mgr_priv *priv;
>>>>>         struct fpga_manager *mgr;
>>>>> @@ -302,20 +302,16 @@ static int fme_mgr_probe(struct platform_device *pdev)
>>>>>                 return PTR_ERR(priv->ioaddr);
>>>>>         }
>>>>>     -    compat_id = devm_kzalloc(dev, sizeof(*compat_id), GFP_KERNEL);
>>>>> -    if (!compat_id)
>>>>> +    info.name = "DFL FME FPGA Manager";
>>>>> +    info.mops = &fme_mgr_ops;
>>>>> +    info.priv = priv;
>>>>> +    info.compat_id = devm_kzalloc(dev, sizeof(*info.compat_id), GFP_KERNEL);
>>>>> +    if (!info.compat_id)
>>>>>             return -ENOMEM;
>>>> could we limp along instead of failing ?
>>> The compat_id is used to verify compatibility between the static region and
>>> the partial reconfiguration. If there is insufficient memory for the small
>>> data structure, I think it is best to fail here. This is also consistent
>>> current implementation.
>>>   
>>>>>     -    fme_mgr_get_compat_id(priv->ioaddr, compat_id);
>>>>> -
>>>>> -    mgr = devm_fpga_mgr_create(dev, "DFL FME FPGA Manager",
>>>>> -                   &fme_mgr_ops, priv);
>>>>> -    if (!mgr)
>>>>> -        return -ENOMEM;
>>>>> -
>>>>> -    mgr->compat_id = compat_id;
>>>>> -
>>>>> -    return devm_fpga_mgr_register(dev, mgr);
>>>>> +    fme_mgr_get_compat_id(priv->ioaddr, info.compat_id);
>>>>> +    mgr = devm_fpga_mgr_register_full(dev, &info);
>>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>>     }
>>>>>       static struct platform_driver fme_mgr_driver = {
>>>>> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
>>>>> index ecb4c3c795fa..5a913aa649fd 100644
>>>>> --- a/drivers/fpga/fpga-mgr.c
>>>>> +++ b/drivers/fpga/fpga-mgr.c
>>>>> @@ -550,21 +550,19 @@ void fpga_mgr_unlock(struct fpga_manager *mgr)
>>>>>     EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
>>>>>       /**
>>>>> - * fpga_mgr_create - create and initialize an FPGA manager struct
>>>>> + * fpga_mgr_register_full - create and register an FPGA Manager device
>>>>>      * @parent:    fpga manager device from pdev
>>>>> - * @name:    fpga manager name
>>>>> - * @mops:    pointer to structure of fpga manager ops
>>>>> - * @priv:    fpga manager private data
>>>>> + * @info:    parameters for fpga manager
>>>>>      *
>>>>> - * The caller of this function is responsible for freeing the struct with
>>>>> - * fpga_mgr_free().  Using devm_fpga_mgr_create() instead is recommended.
>>>>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
>>>>> + * Using devm_fpga_mgr_register_full() instead is recommended.
>>>>>      *
>>>>> - * Return: pointer to struct fpga_manager or NULL
>>>>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>>>>>      */
>>>>> -struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>>>> -                     const struct fpga_manager_ops *mops,
>>>>> -                     void *priv)
>>>>> +struct fpga_manager *
>>>>> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>>>>>     {
>>>>> +    const struct fpga_manager_ops *mops = info->mops;
>>>>>         struct fpga_manager *mgr;
>>>>>         int id, ret;
>>>>>     @@ -572,29 +570,31 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>>>>             !mops->write_init || (!mops->write && !mops->write_sg) ||
>>>>>             (mops->write && mops->write_sg)) {
>>>>>             dev_err(parent, "Attempt to register without fpga_manager_ops\n");
>>>>> -        return NULL;
>>>>> +        return ERR_PTR(-EINVAL);
>>>>>         }
>>>>>     -    if (!name || !strlen(name)) {
>>>>> +    if (!info->name || !strlen(info->name)) {
>>>>>             dev_err(parent, "Attempt to register with no name!\n");
>>>>> -        return NULL;
>>>>> +        return ERR_PTR(-EINVAL);
>>>>>         }
>>>>>           mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
>>>>>         if (!mgr)
>>>>> -        return NULL;
>>>>> +        return ERR_PTR(-ENOMEM);
>>>>>           id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
>>>>> -    if (id < 0)
>>>>> +    if (id < 0) {
>>>>> +        ret = id;
>>>>>             goto error_kfree;
>>>>> +    }
>>>>>           mutex_init(&mgr->ref_mutex);
>>>>>     -    mgr->name = name;
>>>>> -    mgr->mops = mops;
>>>>> -    mgr->priv = priv;
>>>>> +    mgr->name = info->name;
>>>>> +    mgr->mops = info->mops;
>>>>> +    mgr->priv = info->priv;
>>>>> +    mgr->compat_id = info->compat_id;
>>>>>     -    device_initialize(&mgr->dev);
>>>>>         mgr->dev.class = fpga_mgr_class;
>>>>>         mgr->dev.groups = mops->groups;
>>>>>         mgr->dev.parent = parent;
>>>>> @@ -605,6 +605,19 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>>>>         if (ret)
>>>>>             goto error_device;
>>>>>     +    /*
>>>>> +     * Initialize framework state by requesting low level driver read state
>>>>> +     * from device.  FPGA may be in reset mode or may have been programmed
>>>>> +     * by bootloader or EEPROM.
>>>>> +     */
>>>>> +    mgr->state = mgr->mops->state(mgr);
>>>> This is existing code, but it seems wrong.
>>>>
>>>> A side effect of state() should not be to initialize.
>>>>
>>>> An init() should be added to mops
>>> I think this is just capturing the state of the underlying device an
>>> reflecting it in the fpga-manager state? Maybe someone else can comment
>>> on this. It seems outside the scope of these patches.
>>>
>>>>> +
>>>>> +    ret = device_register(&mgr->dev);
>>>>> +    if (ret) {
>>>>> +        put_device(&mgr->dev);
>>>>> +        return ERR_PTR(ret);
>>>>> +    }
>>>>> +
>>>>>         return mgr;
>>>>>       error_device:
>>>>> @@ -612,96 +625,36 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>>>>     error_kfree:
>>>>>         kfree(mgr);
>>>>>     -    return NULL;
>>>>> +    return ERR_PTR(ret);
>>>>>     }
>>>>> -EXPORT_SYMBOL_GPL(fpga_mgr_create);
>>>>> +EXPORT_SYMBOL_GPL(fpga_mgr_register_full);
>>>>>       /**
>>>>> - * fpga_mgr_free - free an FPGA manager created with fpga_mgr_create()
>>>>> - * @mgr:    fpga manager struct
>>>>> - */
>>>>> -void fpga_mgr_free(struct fpga_manager *mgr)
>>>>> -{
>>>>> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>>>>> -    kfree(mgr);
>>>>> -}
>>>>> -EXPORT_SYMBOL_GPL(fpga_mgr_free);
>>>>> -
>>>>> -static void devm_fpga_mgr_release(struct device *dev, void *res)
>>>>> -{
>>>>> -    struct fpga_mgr_devres *dr = res;
>>>>> -
>>>>> -    fpga_mgr_free(dr->mgr);
>>>>> -}
>>>>> -
>>>>> -/**
>>>>> - * devm_fpga_mgr_create - create and initialize a managed FPGA manager struct
>>>>> + * fpga_mgr_register - create and register an FPGA Manager device
>>>>>      * @parent:    fpga manager device from pdev
>>>>>      * @name:    fpga manager name
>>>>>      * @mops:    pointer to structure of fpga manager ops
>>>>>      * @priv:    fpga manager private data
>>>>>      *
>>>>> - * This function is intended for use in an FPGA manager driver's probe function.
>>>>> - * After the manager driver creates the manager struct with
>>>>> - * devm_fpga_mgr_create(), it should register it with fpga_mgr_register().  The
>>>>> - * manager driver's remove function should call fpga_mgr_unregister().  The
>>>>> - * manager struct allocated with this function will be freed automatically on
>>>>> - * driver detach.  This includes the case of a probe function returning error
>>>>> - * before calling fpga_mgr_register(), the struct will still get cleaned up.
>>>>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
>>>>> + * Using devm_fpga_mgr_register() instead is recommended. This simple
>>>>> + * version of the register function should be sufficient for most users. The
>>>>> + * fpga_mgr_register_full() function is available for users that need to pass
>>>>> + * additional, optional parameters.
>>>>>      *
>>>>> - * Return: pointer to struct fpga_manager or NULL
>>>>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>>>>>      */
>>>>> -struct fpga_manager *devm_fpga_mgr_create(struct device *parent, const char *name,
>>>>> -                      const struct fpga_manager_ops *mops,
>>>>> -                      void *priv)
>>>>> +struct fpga_manager *
>>>>> +fpga_mgr_register(struct device *parent, const char *name,
>>>>> +          const struct fpga_manager_ops *mops, void *priv)
>>>>>     {
>>>>> -    struct fpga_mgr_devres *dr;
>>>>> +    struct fpga_manager_info info = { 0 };
>>>>>     -    dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL);
>>>>> -    if (!dr)
>>>>> -        return NULL;
>>>>> +    info.name = name;
>>>>> +    info.mops = mops;
>>>>> +    info.priv = priv;
>>>>>     -    dr->mgr = fpga_mgr_create(parent, name, mops, priv);
>>>>> -    if (!dr->mgr) {
>>>>> -        devres_free(dr);
>>>>> -        return NULL;
>>>>> -    }
>>>>> -
>>>>> -    devres_add(parent, dr);
>>>>> -
>>>>> -    return dr->mgr;
>>>>> -}
>>>>> -EXPORT_SYMBOL_GPL(devm_fpga_mgr_create);
>>>>> -
>>>>> -/**
>>>>> - * fpga_mgr_register - register an FPGA manager
>>>>> - * @mgr: fpga manager struct
>>>>> - *
>>>>> - * Return: 0 on success, negative error code otherwise.
>>>>> - */
>>>>> -int fpga_mgr_register(struct fpga_manager *mgr)
>>>>> -{
>>>>> -    int ret;
>>>>> -
>>>>> -    /*
>>>>> -     * Initialize framework state by requesting low level driver read state
>>>>> -     * from device.  FPGA may be in reset mode or may have been programmed
>>>>> -     * by bootloader or EEPROM.
>>>>> -     */
>>>>> -    mgr->state = mgr->mops->state(mgr);
>>>>> -
>>>>> -    ret = device_add(&mgr->dev);
>>>>> -    if (ret)
>>>>> -        goto error_device;
>>>>> -
>>>>> -    dev_info(&mgr->dev, "%s registered\n", mgr->name);
>>>>> -
>>>>> -    return 0;
>>>>> -
>>>>> -error_device:
>>>>> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>>>>> -
>>>>> -    return ret;
>>>>> +    return fpga_mgr_register_full(parent, &info);
>>>>>     }
>>>>>     EXPORT_SYMBOL_GPL(fpga_mgr_register);
>>>>>     @@ -726,14 +679,6 @@ void fpga_mgr_unregister(struct fpga_manager *mgr)
>>>>>     }
>>>>>     EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
>>>>>     -static int fpga_mgr_devres_match(struct device *dev, void *res,
>>>>> -                 void *match_data)
>>>>> -{
>>>>> -    struct fpga_mgr_devres *dr = res;
>>>>> -
>>>>> -    return match_data == dr->mgr;
>>>>> -}
>>>>> -
>>>>>     static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>>>>>     {
>>>>>         struct fpga_mgr_devres *dr = res;
>>>>> @@ -742,45 +687,67 @@ static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>>>>>     }
>>>>>       /**
>>>>> - * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
>>>>> - * @dev: managing device for this FPGA manager
>>>>> - * @mgr: fpga manager struct
>>>>> + * devm_fpga_mgr_register_full - resource managed variant of fpga_mgr_register()
>>>>> + * @parent:    fpga manager device from pdev
>>>>> + * @info:    parameters for fpga manager
>>>>>      *
>>>>> - * This is the devres variant of fpga_mgr_register() for which the unregister
>>>>> + * This is the devres variant of fpga_mgr_register_full() for which the unregister
>>>>>      * function will be called automatically when the managing device is detached.
>>>>>      */
>>>>> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr)
>>>>> +struct fpga_manager *
>>>>> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>>>>>     {
>>>>>         struct fpga_mgr_devres *dr;
>>>>> -    int ret;
>>>>> -
>>>>> -    /*
>>>>> -     * Make sure that the struct fpga_manager * that is passed in is
>>>>> -     * managed itself.
>>>>> -     */
>>>>> -    if (WARN_ON(!devres_find(dev, devm_fpga_mgr_release,
>>>>> -                 fpga_mgr_devres_match, mgr)))
>>>>> -        return -EINVAL;
>>>>> +    struct fpga_manager *mgr;
>>>>>           dr = devres_alloc(devm_fpga_mgr_unregister, sizeof(*dr), GFP_KERNEL);
>>>>>         if (!dr)
>>>>> -        return -ENOMEM;
>>>>> +        return ERR_PTR(-ENOMEM);
>>>>>     -    ret = fpga_mgr_register(mgr);
>>>>> -    if (ret) {
>>>>> +    mgr = fpga_mgr_register_full(parent, info);
>>>>> +    if (IS_ERR(mgr)) {
>>>>>             devres_free(dr);
>>>>> -        return ret;
>>>>> +        return mgr;
>>>>>         }
>>>>>           dr->mgr = mgr;
>>>>> -    devres_add(dev, dr);
>>>>> +    devres_add(parent, dr);
>>>>>     -    return 0;
>>>>> +    return mgr;
>>>>> +}
>>>>> +EXPORT_SYMBOL_GPL(devm_fpga_mgr_register_full);
>>>>> +
>>>>> +/**
>>>>> + * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
>>>>> + * @parent:    fpga manager device from pdev
>>>>> + * @name:    fpga manager name
>>>>> + * @mops:    pointer to structure of fpga manager ops
>>>>> + * @priv:    fpga manager private data
>>>>> + *
>>>>> + * This is the devres variant of fpga_mgr_register() for which the
>>>>> + * unregister function will be called automatically when the managing
>>>>> + * device is detached.
>>>>> + */
>>>>> +struct fpga_manager *
>>>>> +devm_fpga_mgr_register(struct device *parent, const char *name,
>>>>> +               const struct fpga_manager_ops *mops, void *priv)
>>>>> +{
>>>>> +    struct fpga_manager_info info = { 0 };
>>>>> +
>>>>> +    info.name = name;
>>>>> +    info.mops = mops;
>>>>> +    info.priv = priv;
>>>>> +
>>>>> +    return devm_fpga_mgr_register_full(parent, &info);
>>>>>     }
>>>>>     EXPORT_SYMBOL_GPL(devm_fpga_mgr_register);
>>>>>       static void fpga_mgr_dev_release(struct device *dev)
>>>>>     {
>>>>> +    struct fpga_manager *mgr = to_fpga_manager(dev);
>>>>> +
>>>>> +    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>>>>> +    kfree(mgr);
>>>>>     }
>>>>>       static int __init fpga_mgr_class_init(void)
>>>>> diff --git a/drivers/fpga/ice40-spi.c b/drivers/fpga/ice40-spi.c
>>>>> index 69dec5af23c3..b7591912248f 100644
>>>>> --- a/drivers/fpga/ice40-spi.c
>>>>> +++ b/drivers/fpga/ice40-spi.c
>>>>> @@ -178,12 +178,9 @@ static int ice40_fpga_probe(struct spi_device *spi)
>>>>>             return ret;
>>>>>         }
>>>>>     -    mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
>>>>> -                   &ice40_fpga_ops, priv);
>>>>> -    if (!mgr)
>>>>> -        return -ENOMEM;
>>>>> -
>>>>> -    return devm_fpga_mgr_register(dev, mgr);
>>>>> +    mgr = devm_fpga_mgr_register(dev, "Lattice iCE40 FPGA Manager",
>>>>> +                     &ice40_fpga_ops, priv);
>>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>>     }
>>>>>       static const struct of_device_id ice40_fpga_of_match[] = {
>>>>> diff --git a/drivers/fpga/machxo2-spi.c b/drivers/fpga/machxo2-spi.c
>>>>> index 1afb41aa20d7..8469dfb5dd21 100644
>>>>> --- a/drivers/fpga/machxo2-spi.c
>>>>> +++ b/drivers/fpga/machxo2-spi.c
>>>>> @@ -366,12 +366,9 @@ static int machxo2_spi_probe(struct spi_device *spi)
>>>>>             return -EINVAL;
>>>>>         }
>>>>>     -    mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager",
>>>>> -                   &machxo2_ops, spi);
>>>>> -    if (!mgr)
>>>>> -        return -ENOMEM;
>>>>> -
>>>>> -    return devm_fpga_mgr_register(dev, mgr);
>>>>> +    mgr = devm_fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager",
>>>>> +                     &machxo2_ops, spi);
>>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>>     }
>>>>>       #ifdef CONFIG_OF
>>>>> diff --git a/drivers/fpga/socfpga-a10.c b/drivers/fpga/socfpga-a10.c
>>>>> index 573d88bdf730..ac8e89b8a5cc 100644
>>>>> --- a/drivers/fpga/socfpga-a10.c
>>>>> +++ b/drivers/fpga/socfpga-a10.c
>>>>> @@ -508,19 +508,15 @@ static int socfpga_a10_fpga_probe(struct platform_device *pdev)
>>>>>             return -EBUSY;
>>>>>         }
>>>>>     -    mgr = devm_fpga_mgr_create(dev, "SoCFPGA Arria10 FPGA Manager",
>>>>> -                   &socfpga_a10_fpga_mgr_ops, priv);
>>>>> -    if (!mgr)
>>>>> -        return -ENOMEM;
>>>>> -
>>>>> -    platform_set_drvdata(pdev, mgr);
>>>>> -
>>>>> -    ret = fpga_mgr_register(mgr);
>>>>> -    if (ret) {
>>>>> +    mgr = fpga_mgr_register(dev, "SoCFPGA Arria10 FPGA Manager",
>>>>> +                &socfpga_a10_fpga_mgr_ops, priv);
>>>>> +    if (IS_ERR(mgr)) {
>>>>>             clk_disable_unprepare(priv->clk);
>>>>> -        return ret;
>>>>> +        return PTR_ERR(mgr);
>>>>>         }
>>>>>     +    platform_set_drvdata(pdev, mgr);
>>>>> +
>>>>>         return 0;
>>>>>     }
>>>>>     diff --git a/drivers/fpga/socfpga.c b/drivers/fpga/socfpga.c
>>>>> index 1f467173fc1f..7e0741f99696 100644
>>>>> --- a/drivers/fpga/socfpga.c
>>>>> +++ b/drivers/fpga/socfpga.c
>>>>> @@ -571,12 +571,9 @@ static int socfpga_fpga_probe(struct platform_device *pdev)
>>>>>         if (ret)
>>>>>             return ret;
>>>>>     -    mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
>>>>> -                   &socfpga_fpga_ops, priv);
>>>>> -    if (!mgr)
>>>>> -        return -ENOMEM;
>>>>> -
>>>>> -    return devm_fpga_mgr_register(dev, mgr);
>>>>> +    mgr = devm_fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
>>>>> +                     &socfpga_fpga_ops, priv);
>>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>>     }
>>>>>       #ifdef CONFIG_OF
>>>>> diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
>>>>> index a2cea500f7cc..9155e888a133 100644
>>>>> --- a/drivers/fpga/stratix10-soc.c
>>>>> +++ b/drivers/fpga/stratix10-soc.c
>>>>> @@ -425,18 +425,11 @@ static int s10_probe(struct platform_device *pdev)
>>>>>           init_completion(&priv->status_return_completion);
>>>>>     -    mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
>>>>> -                  &s10_ops, priv);
>>>>> -    if (!mgr) {
>>>>> -        dev_err(dev, "unable to create FPGA manager\n");
>>>>> -        ret = -ENOMEM;
>>>>> -        goto probe_err;
>>>>> -    }
>>>>> -
>>>>> -    ret = fpga_mgr_register(mgr);
>>>>> -    if (ret) {
>>>>> +    mgr = fpga_mgr_register(dev, "Stratix10 SOC FPGA Manager",
>>>>> +                &s10_ops, priv);
>>>>> +    if (IS_ERR(mgr)) {
>>>>>             dev_err(dev, "unable to register FPGA manager\n");
>>>>> -        fpga_mgr_free(mgr);
>>>>> +        ret = PTR_ERR(mgr);
>>>>>             goto probe_err;
>>>>>         }
>>>>>     @@ -454,7 +447,6 @@ static int s10_remove(struct platform_device *pdev)
>>>>>         struct s10_priv *priv = mgr->priv;
>>>>>           fpga_mgr_unregister(mgr);
>>>>> -    fpga_mgr_free(mgr);
>>>>>         stratix10_svc_free_channel(priv->chan);
>>>>>           return 0;
>>>>> diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c
>>>>> index 101f016c6ed8..fd52de20ddb2 100644
>>>>> --- a/drivers/fpga/ts73xx-fpga.c
>>>>> +++ b/drivers/fpga/ts73xx-fpga.c
>>>>> @@ -122,12 +122,9 @@ static int ts73xx_fpga_probe(struct platform_device *pdev)
>>>>>         if (IS_ERR(priv->io_base))
>>>>>             return PTR_ERR(priv->io_base);
>>>>>     -    mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
>>>>> -                   &ts73xx_fpga_ops, priv);
>>>>> -    if (!mgr)
>>>>> -        return -ENOMEM;
>>>>> -
>>>>> -    return devm_fpga_mgr_register(kdev, mgr);
>>>>> +    mgr = devm_fpga_mgr_register(kdev, "TS-73xx FPGA Manager",
>>>>> +                     &ts73xx_fpga_ops, priv);
>>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>>     }
>>>>>       static struct platform_driver ts73xx_fpga_driver = {
>>>>> diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
>>>>> index fee4d0abf6bf..db23626f9ab2 100644
>>>>> --- a/drivers/fpga/xilinx-spi.c
>>>>> +++ b/drivers/fpga/xilinx-spi.c
>>>>> @@ -247,13 +247,10 @@ static int xilinx_spi_probe(struct spi_device *spi)
>>>>>             return dev_err_probe(&spi->dev, PTR_ERR(conf->done),
>>>>>                          "Failed to get DONE gpio\n");
>>>>>     -    mgr = devm_fpga_mgr_create(&spi->dev,
>>>>> -                   "Xilinx Slave Serial FPGA Manager",
>>>>> -                   &xilinx_spi_ops, conf);
>>>>> -    if (!mgr)
>>>>> -        return -ENOMEM;
>>>>> -
>>>>> -    return devm_fpga_mgr_register(&spi->dev, mgr);
>>>>> +    mgr = devm_fpga_mgr_register(&spi->dev,
>>>>> +                     "Xilinx Slave Serial FPGA Manager",
>>>>> +                     &xilinx_spi_ops, conf);
>>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>>     }
>>>>>       static const struct of_device_id xlnx_spi_of_match[] = {
>>>>> diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
>>>>> index 9b75bd4f93d8..426aa34c6a0d 100644
>>>>> --- a/drivers/fpga/zynq-fpga.c
>>>>> +++ b/drivers/fpga/zynq-fpga.c
>>>>> @@ -609,20 +609,16 @@ static int zynq_fpga_probe(struct platform_device *pdev)
>>>>>           clk_disable(priv->clk);
>>>>>     -    mgr = devm_fpga_mgr_create(dev, "Xilinx Zynq FPGA Manager",
>>>>> -                   &zynq_fpga_ops, priv);
>>>>> -    if (!mgr)
>>>>> -        return -ENOMEM;
>>>>> -
>>>>> -    platform_set_drvdata(pdev, mgr);
>>>>> -
>>>>> -    err = fpga_mgr_register(mgr);
>>>>> -    if (err) {
>>>>> +    mgr = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
>>>>> +                &zynq_fpga_ops, priv);
>>>>> +    if (IS_ERR(mgr)) {
>>>>>             dev_err(dev, "unable to register FPGA manager\n");
>>>>>             clk_unprepare(priv->clk);
>>>>> -        return err;
>>>>> +        return PTR_ERR(mgr);
>>>>>         }
>>>>>     +    platform_set_drvdata(pdev, mgr);
>>>>> +
>>>>>         return 0;
>>>>>     }
>>>>>     diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
>>>>> index 125743c9797f..975bdc4d0a65 100644
>>>>> --- a/drivers/fpga/zynqmp-fpga.c
>>>>> +++ b/drivers/fpga/zynqmp-fpga.c
>>>>> @@ -102,12 +102,9 @@ static int zynqmp_fpga_probe(struct platform_device *pdev)
>>>>>           priv->dev = dev;
>>>>>     -    mgr = devm_fpga_mgr_create(dev, "Xilinx ZynqMP FPGA Manager",
>>>>> -                   &zynqmp_fpga_ops, priv);
>>>>> -    if (!mgr)
>>>>> -        return -ENOMEM;
>>>>> -
>>>>> -    return devm_fpga_mgr_register(dev, mgr);
>>>>> +    mgr = devm_fpga_mgr_register(dev, "Xilinx ZynqMP FPGA Manager",
>>>>> +                     &zynqmp_fpga_ops, priv);
>>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>>     }
>>>>>       static const struct of_device_id zynqmp_fpga_of_match[] = {
>>>>> diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
>>>>> index 474c1f506307..ac3ddaf2903c 100644
>>>>> --- a/include/linux/fpga/fpga-mgr.h
>>>>> +++ b/include/linux/fpga/fpga-mgr.h
>>>>> @@ -105,6 +105,36 @@ struct fpga_image_info {
>>>>>     #endif
>>>>>     };
>>>>>     +/**
>>>>> + * struct fpga_compat_id - id for compatibility check
>>>>> + *
>>>>> + * @id_h: high 64bit of the compat_id
>>>>> + * @id_l: low 64bit of the compat_id
>>>>> + */
>>>>> +struct fpga_compat_id {
>>>>> +    u64 id_h;
>>>>> +    u64 id_l;
>>>>> +};
>>>>> +
>>>> There are two register functions are to handle this dfl only structure.
>>>>
>>>> This really needs to be moved fme_mgr_priv.
>>>>
>>>>> +/**
>>>>> + * struct fpga_manager_info - collection of parameters for an FPGA Manager
>>>>> + * @name: fpga manager name
>>>>> + * @compat_id: FPGA manager id for compatibility check.
>>>>> + * @mops: pointer to structure of fpga manager ops
>>>>> + * @priv: fpga manager private data
>>>>> + *
>>>>> + * fpga_manager_info contains parameters for the register function. These
>>>>> + * are separated into an info structure because they some are optional
>>>>> + * others could be added to in the future. The info structure facilitates
>>>>> + * maintaining a stable API.
>>>>> + */
>>>>> +struct fpga_manager_info {
>>>>> +    const char *name;
>>>>> +    struct fpga_compat_id *compat_id;
>>>>> +    const struct fpga_manager_ops *mops;
>>>>> +    void *priv;
>>>>> +};
>>>>> +
>>>>>     /**
>>>>>      * struct fpga_manager_ops - ops for low level fpga manager drivers
>>>>>      * @initial_header_size: Maximum number of bytes that should be passed into write_init
>>>>> @@ -143,17 +173,6 @@ struct fpga_manager_ops {
>>>>>     #define FPGA_MGR_STATUS_IP_PROTOCOL_ERR        BIT(3)
>>>>>     #define FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR    BIT(4)
>>>>>     -/**
>>>>> - * struct fpga_compat_id - id for compatibility check
>>>>> - *
>>>>> - * @id_h: high 64bit of the compat_id
>>>>> - * @id_l: low 64bit of the compat_id
>>>>> - */
>>>>> -struct fpga_compat_id {
>>>>> -    u64 id_h;
>>>>> -    u64 id_l;
>>>>> -};
>>>>> -
>>>>>     /**
>>>>>      * struct fpga_manager - fpga manager structure
>>>>>      * @name: name of low level fpga manager
>>>>> @@ -191,17 +210,18 @@ struct fpga_manager *fpga_mgr_get(struct device *dev);
>>>>>       void fpga_mgr_put(struct fpga_manager *mgr);
>>>>>     -struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name,
>>>>> -                     const struct fpga_manager_ops *mops,
>>>>> -                     void *priv);
>>>>> -void fpga_mgr_free(struct fpga_manager *mgr);
>>>> removing these should cause any oot driver to fail to load.
>>>>
>>>> so an oops is unlikely.
>>>>
>>>> I'm ok with with api change.
>>>>
>>>>> -int fpga_mgr_register(struct fpga_manager *mgr);
>>>>> -void fpga_mgr_unregister(struct fpga_manager *mgr);
>>>>> +struct fpga_manager *
>>>>> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
>>>>>     -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr);
>>>>> +struct fpga_manager *
>>>>> +fpga_mgr_register(struct device *parent, const char *name,
>>>>> +          const struct fpga_manager_ops *mops, void *priv);
>>>> having 2 ways to do the same thing is not great.
>>>>
>>>> this should be reduced down to 1.
>>>>
>>>> My preference is for the *info one as it's api will be durable.
>>> I would like to see if other's agree.
>>>
>>>> Tom
>>>>
>>>>> +void fpga_mgr_unregister(struct fpga_manager *mgr);
>>>>>     -struct fpga_manager *devm_fpga_mgr_create(struct device *dev, const char *name,
>>>>> -                      const struct fpga_manager_ops *mops,
>>>>> -                      void *priv);
>>>>> +struct fpga_manager *
>>>>> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
>>>>> +struct fpga_manager *
>>>>> +devm_fpga_mgr_register(struct device *parent, const char *name,
>>>>> +               const struct fpga_manager_ops *mops, void *priv);
>>>>>       #endif /*_LINUX_FPGA_MGR_H */


^ permalink raw reply	[flat|nested] 22+ messages in thread

end of thread, other threads:[~2021-07-07 13:29 UTC | newest]

Thread overview: 22+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-07-01  1:37 [PATCH v9 0/3] fpga: Use standard class dev_release function Russ Weight
2021-07-01  1:37 ` [PATCH v9 1/3] fpga: mgr: Use standard dev_release for class driver Russ Weight
2021-07-01  5:25   ` Xu Yilun
2021-07-06 23:06     ` Russ Weight
2021-07-06 19:04   ` Tom Rix
2021-07-06 21:02     ` Russ Weight
2021-07-06 21:44       ` Tom Rix
2021-07-06 23:03         ` Russ Weight
2021-07-07  2:45           ` Xu Yilun
2021-07-07 13:29           ` Tom Rix
2021-07-07  3:01       ` Xu Yilun
2021-07-07  3:04     ` Xu Yilun
2021-07-01  1:37 ` [PATCH v9 2/3] fpga: bridge: " Russ Weight
2021-07-01  5:39   ` Xu Yilun
2021-07-06 23:06     ` Russ Weight
2021-07-01  6:26   ` Xu Yilun
2021-07-06 23:08     ` Russ Weight
2021-07-06 20:08   ` Tom Rix
2021-07-06 22:53     ` Russ Weight
2021-07-01  1:37 ` [PATCH v9 3/3] fpga: region: " Russ Weight
2021-07-01  5:51   ` Xu Yilun
2021-07-06 23:08     ` Russ Weight

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