[PATCH v10 0/6] Introduce PRU remoteproc consumer API

[PATCH v10 0/6] Introduce PRU remoteproc consumer API

[MD Danish Anwar]

The Programmable Real-Time Unit and Industrial Communication Subsystem
(PRU-ICSS or simply PRUSS) on various TI SoCs consists of dual 32-bit
RISC cores (Programmable Real-Time Units, or PRUs) for program execution.

There are 3 foundation components for PRUSS subsystem: the PRUSS platform
driver, the PRUSS INTC driver and the PRUSS remoteproc driver. All were
already merged and can be found under:

1) drivers/soc/ti/pruss.c
   Documentation/devicetree/bindings/soc/ti/ti,pruss.yaml
2) drivers/irqchip/irq-pruss-intc.c
   Documentation/devicetree/bindings/interrupt-controller/ti,pruss-intc.yaml
3) drivers/remoteproc/pru_rproc.c
   Documentation/devicetree/bindings/remoteproc/ti,pru-rproc.yaml

The programmable nature of the PRUs provide flexibility to implement custom
peripheral interfaces, fast real-time responses, or specialized data handling.
Example of a PRU consumer drivers will be:
  - Software UART over PRUSS
  - PRU-ICSS Ethernet EMAC

In order to make usage of common PRU resources and allow the consumer drivers to
configure the PRU hardware for specific usage the PRU API is introduced.

This is the v10 of the patch series [1]. This version of the patchset 
addresses the comments made on v9 [9] of the series. 

Two more patch series have been posted ([2] and [3]) that depends on this
series, one has been posted to the soc/ti/ tree and another  
to the networking tree. All the 3 series including this one, has been 
sent as RFC [4] to get comments and to explain the dependencies.

Changes from v9 to v10 :

*) There was compilation issue in v9 of the series because of dependencies 
between 2nd and 3rd patch of the series. Fixed the dependencies in this series.
*) Added enum documentation following the kernel-doc style [11] as asked by 
Roger for 3/6 patch of the series.

Changes from v8 [8] to v9 :

*) Fixed the warnings generated by running checkpatch.pl script.
*) Added Review/Ack tags.
*) Listed just the SoBs tags for all the patches as suggested by Mathieu.
*) Removed a comment for an already documented field in patch 5/6 of this series.

Changes from v7 [7] to v8 :

*) Removed get_device(&rproc->dev) from API __pru_rproc_get() in patch 2/5 of 
this series as asked by Roger. 
*) Replaced all the SoBs (other than mine) to Co-developed-by tags for all 
the patches in this series as asked by Mathieu.
*) Added a new patch (3/6) in this series for Introduction of pruss_pru_id enum.
Previously this enum was part of patch 2/6. As asked by Roger removed this enum 
(and the APIs that are using the enum) from patch 2/6 and added it in new patch.
*) Removed a comment for an already documented field in patch 2/6 of this series.
*) Changed 'pru' to 'PRU' in comment of API pru_rproc_set_firmware() as asked by 
Roger.

Changes from v6 [6] to v7 :

*) Removed example section from ti,pru-consumer.yaml as the full example 
included compatible property as well which is not introduced in this series 
thus creating dt check binding error. Removing the example section fixes the
dt binding check error. The example section will be included in 
"ti,icssg-prueth.yaml" in the next version of series [3]
*) Updated the commit message for patch 1/5 of this series to address Krzysztof's 
comment.

Changes from v5 [5] to v6  :

*) Added rproc_get_by_phandle() in pru_rproc_get() 
*) Provided background of Ctable in the commit messege.
*) Removed patch "" [10] (6th Patch of the v5 of this series)
   as it has dependency on series [2], thus creating a cyclic dependency.

The patch [10] will be sent along with the next version of series [2].

[1] https://patchwork.kernel.org/project/linux-remoteproc/cover/20220603121520.13730-1-p-mohan@ti.com/
[2] https://lore.kernel.org/all/20220418123004.9332-1-p-mohan@ti.com/
[3] https://lore.kernel.org/all/20220531095108.21757-1-p-mohan@ti.com/
[4] https://patchwork.kernel.org/project/linux-remoteproc/cover/20220406094358.7895-1-p-mohan@ti.com/
[5] https://lore.kernel.org/all/20220607045650.4999-1-p-mohan@ti.com/
[6] https://lore.kernel.org/all/20221012114429.2341215-1-danishanwar@ti.com/
[7] https://lore.kernel.org/all/20221031073801.130541-1-danishanwar@ti.com/
[8] https://lore.kernel.org/all/20221116121634.2901265-1-danishanwar@ti.com/
[9] https://lore.kernel.org/all/20221118111924.3277838-1-danishanwar@ti.com/
[10] https://lore.kernel.org/all/20220607045650.4999-7-p-mohan@ti.com/
[11] https://www.kernel.org/doc/html/v6.0/doc-guide/kernel-doc.html#structure-union-and-enumeration-documentation

Thanks and Regards,
Md Danish Anwar

MD Danish Anwar (1):
  remoteproc: pru: Add enum for PRU Core Indentifiers.

Roger Quadros (1):
  remoteproc: pru: Add pru_rproc_set_ctable() function

Suman Anna (2):
  dt-bindings: remoteproc: Add PRU consumer bindings
  remoteproc: pru: Make sysfs entries read-only for PRU client driven
    boots

Tero Kristo (2):
  remoteproc: pru: Add APIs to get and put the PRU cores
  remoteproc: pru: Configure firmware based on client setup

 .../bindings/remoteproc/ti,pru-consumer.yaml  |  60 +++++
 drivers/remoteproc/pru_rproc.c                | 235 +++++++++++++++++-
 include/linux/pruss.h                         |  83 +++++++
 3 files changed, 373 insertions(+), 5 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/remoteproc/ti,pru-consumer.yaml
 create mode 100644 include/linux/pruss.h

-- 
2.25.1

[PATCH v10 1/6] dt-bindings: remoteproc: Add PRU consumer bindings

[MD Danish Anwar]

From: Suman Anna <s-anna@ti.com>

Add DT schema binding for PRU consumers. The binding includes
all the common properties that can be used by different PRU consumer
or application nodes and supported by the PRU remoteproc driver.
These are used to configure the PRU hardware for specific user
applications.

The application nodes themselves should define their own bindings.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../bindings/remoteproc/ti,pru-consumer.yaml  | 60 +++++++++++++++++++
 1 file changed, 60 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/remoteproc/ti,pru-consumer.yaml

diff --git a/Documentation/devicetree/bindings/remoteproc/ti,pru-consumer.yaml b/Documentation/devicetree/bindings/remoteproc/ti,pru-consumer.yaml
new file mode 100644
index 000000000000..c6d86964b72a
--- /dev/null
+++ b/Documentation/devicetree/bindings/remoteproc/ti,pru-consumer.yaml
@@ -0,0 +1,60 @@
+# SPDX-License-Identifier: (GPL-2.0-only or BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/remoteproc/ti,pru-consumer.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Common TI PRU Consumer Binding
+
+maintainers:
+  - Suman Anna <s-anna@ti.com>
+
+description: |
+  A PRU application/consumer/user node typically uses one or more PRU device
+  nodes to implement a PRU application/functionality. Each application/client
+  node would need a reference to at least a PRU node, and optionally define
+  some properties needed for hardware/firmware configuration. The below
+  properties are a list of common properties supported by the PRU remoteproc
+  infrastructure.
+
+  The application nodes shall define their own bindings like regular platform
+  devices, so below are in addition to each node's bindings.
+
+properties:
+  ti,prus:
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    description: phandles to the PRU, RTU or Tx_PRU nodes used
+    minItems: 1
+    maxItems: 6
+    items:
+      maxItems: 1
+
+  firmware-name:
+    $ref: /schemas/types.yaml#/definitions/string-array
+    minItems: 1
+    maxItems: 6
+    description: |
+      firmwares for the PRU cores, the default firmware for the core from
+      the PRU node will be used if not provided. The firmware names should
+      correspond to the PRU cores listed in the 'ti,prus' property
+
+  ti,pruss-gp-mux-sel:
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    minItems: 1
+    maxItems: 6
+    items:
+      enum: [0, 1, 2, 3, 4]
+    description: |
+      array of values for the GP_MUX_SEL under PRUSS_GPCFG register for a PRU.
+      This selects the internal muxing scheme for the PRU instance. Values
+      should correspond to the PRU cores listed in the 'ti,prus' property. The
+      GP_MUX_SEL setting is a per-slice setting (one setting for PRU0, RTU0,
+      and Tx_PRU0 on K3 SoCs). Use the same value for all cores within the
+      same slice in the associative array. If the array size is smaller than
+      the size of 'ti,prus' property, the default out-of-reset value (0) for the
+      PRU core is used.
+
+required:
+  - ti,prus
+
+additionalProperties: true
-- 
2.25.1

[PATCH v10 2/6] remoteproc: pru: Add APIs to get and put the PRU cores

[MD Danish Anwar]

From: Tero Kristo <t-kristo@ti.com>

Add two new APIs, pru_rproc_get() and pru_rproc_put(), to the PRU
driver to allow client drivers to acquire and release the remoteproc
device associated with a PRU core. The PRU cores are treated as
resources with only one client owning it at a time.

The pru_rproc_get() function returns the rproc handle corresponding
to a PRU core identified by the device tree "ti,prus" property under
the client node. The pru_rproc_put() is the complementary function
to pru_rproc_get().

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
---
 drivers/remoteproc/pru_rproc.c | 126 ++++++++++++++++++++++++++++++++-
 include/linux/pruss.h          |  46 ++++++++++++
 2 files changed, 170 insertions(+), 2 deletions(-)
 create mode 100644 include/linux/pruss.h

diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
index 128bf9912f2c..b4498a505108 100644
--- a/drivers/remoteproc/pru_rproc.c
+++ b/drivers/remoteproc/pru_rproc.c
@@ -2,12 +2,14 @@
 /*
  * PRU-ICSS remoteproc driver for various TI SoCs
  *
- * Copyright (C) 2014-2020 Texas Instruments Incorporated - https://www.ti.com/
+ * Copyright (C) 2014-2022 Texas Instruments Incorporated - https://www.ti.com/
  *
  * Author(s):
  *	Suman Anna <s-anna@ti.com>
  *	Andrew F. Davis <afd@ti.com>
  *	Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org> for Texas Instruments
+ *	Puranjay Mohan <p-mohan@ti.com>
+ *	Md Danish Anwar <danishanwar@ti.com>
  */
 
 #include <linux/bitops.h>
@@ -16,6 +18,7 @@
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/of_irq.h>
+#include <linux/pruss.h>
 #include <linux/pruss_driver.h>
 #include <linux/remoteproc.h>
 
@@ -111,6 +114,8 @@ struct pru_private_data {
  * @rproc: remoteproc pointer for this PRU core
  * @data: PRU core specific data
  * @mem_regions: data for each of the PRU memory regions
+ * @client_np: client device node
+ * @lock: mutex to protect client usage
  * @fw_name: name of firmware image used during loading
  * @mapped_irq: virtual interrupt numbers of created fw specific mapping
  * @pru_interrupt_map: pointer to interrupt mapping description (firmware)
@@ -126,6 +131,8 @@ struct pru_rproc {
 	struct rproc *rproc;
 	const struct pru_private_data *data;
 	struct pruss_mem_region mem_regions[PRU_IOMEM_MAX];
+	struct device_node *client_np;
+	struct mutex lock;
 	const char *fw_name;
 	unsigned int *mapped_irq;
 	struct pru_irq_rsc *pru_interrupt_map;
@@ -146,6 +153,117 @@ void pru_control_write_reg(struct pru_rproc *pru, unsigned int reg, u32 val)
 	writel_relaxed(val, pru->mem_regions[PRU_IOMEM_CTRL].va + reg);
 }
 
+static struct rproc *__pru_rproc_get(struct device_node *np, int index)
+{
+	struct rproc *rproc;
+	phandle rproc_phandle;
+	int ret;
+
+	ret = of_property_read_u32_index(np, "ti,prus", index, &rproc_phandle);
+	if (ret)
+		return ERR_PTR(ret);
+
+	rproc = rproc_get_by_phandle(rproc_phandle);
+	if (!rproc) {
+		ret = -EPROBE_DEFER;
+		goto err_no_rproc_handle;
+	}
+
+	/* make sure it is PRU rproc */
+	if (!is_pru_rproc(rproc->dev.parent)) {
+		rproc_put(rproc);
+		return ERR_PTR(-ENODEV);
+	}
+
+	return rproc;
+
+err_no_rproc_handle:
+	rproc_put(rproc);
+	return ERR_PTR(ret);
+}
+
+/**
+ * pru_rproc_get() - get the PRU rproc instance from a device node
+ * @np: the user/client device node
+ * @index: index to use for the ti,prus property
+ *
+ * This function looks through a client device node's "ti,prus" property at
+ * index @index and returns the rproc handle for a valid PRU remote processor if
+ * found. The function allows only one user to own the PRU rproc resource at a
+ * time. Caller must call pru_rproc_put() when done with using the rproc, not
+ * required if the function returns a failure.
+ *
+ * Return: rproc handle on success, and an ERR_PTR on failure using one
+ * of the following error values
+ *    -ENODEV if device is not found
+ *    -EBUSY if PRU is already acquired by anyone
+ *    -EPROBE_DEFER is PRU device is not probed yet
+ */
+struct rproc *pru_rproc_get(struct device_node *np, int index)
+{
+	struct rproc *rproc;
+	struct pru_rproc *pru;
+	struct device *dev;
+	int ret;
+
+	rproc = __pru_rproc_get(np, index);
+	if (IS_ERR(rproc))
+		return rproc;
+
+	pru = rproc->priv;
+	dev = &rproc->dev;
+
+	mutex_lock(&pru->lock);
+
+	if (pru->client_np) {
+		mutex_unlock(&pru->lock);
+		put_device(dev);
+		ret = -EBUSY;
+		goto err_no_rproc_handle;
+	}
+
+	pru->client_np = np;
+
+	mutex_unlock(&pru->lock);
+
+	return rproc;
+
+err_no_rproc_handle:
+	rproc_put(rproc);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(pru_rproc_get);
+
+/**
+ * pru_rproc_put() - release the PRU rproc resource
+ * @rproc: the rproc resource to release
+ *
+ * Releases the PRU rproc resource and makes it available to other
+ * users.
+ */
+void pru_rproc_put(struct rproc *rproc)
+{
+	struct pru_rproc *pru;
+
+	if (IS_ERR_OR_NULL(rproc) || !is_pru_rproc(rproc->dev.parent))
+		return;
+
+	pru = rproc->priv;
+
+	mutex_lock(&pru->lock);
+
+	if (!pru->client_np) {
+		mutex_unlock(&pru->lock);
+		return;
+	}
+
+	pru->client_np = NULL;
+	mutex_unlock(&pru->lock);
+
+	rproc_put(rproc);
+}
+EXPORT_SYMBOL_GPL(pru_rproc_put);
+
 static inline u32 pru_debug_read_reg(struct pru_rproc *pru, unsigned int reg)
 {
 	return readl_relaxed(pru->mem_regions[PRU_IOMEM_DEBUG].va + reg);
@@ -816,6 +934,8 @@ static int pru_rproc_probe(struct platform_device *pdev)
 	pru->pruss = platform_get_drvdata(ppdev);
 	pru->rproc = rproc;
 	pru->fw_name = fw_name;
+	pru->client_np = NULL;
+	mutex_init(&pru->lock);
 
 	for (i = 0; i < ARRAY_SIZE(mem_names); i++) {
 		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
@@ -904,7 +1024,7 @@ MODULE_DEVICE_TABLE(of, pru_rproc_match);
 
 static struct platform_driver pru_rproc_driver = {
 	.driver = {
-		.name   = "pru-rproc",
+		.name   = PRU_RPROC_DRVNAME,
 		.of_match_table = pru_rproc_match,
 		.suppress_bind_attrs = true,
 	},
@@ -916,5 +1036,7 @@ module_platform_driver(pru_rproc_driver);
 MODULE_AUTHOR("Suman Anna <s-anna@ti.com>");
 MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
 MODULE_AUTHOR("Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>");
+MODULE_AUTHOR("Puranjay Mohan <p-mohan@ti.com>");
+MODULE_AUTHOR("Md Danish Anwar <danishanwar@ti.com>");
 MODULE_DESCRIPTION("PRU-ICSS Remote Processor Driver");
 MODULE_LICENSE("GPL v2");
diff --git a/include/linux/pruss.h b/include/linux/pruss.h
new file mode 100644
index 000000000000..5c5d14b1249d
--- /dev/null
+++ b/include/linux/pruss.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/**
+ * PRU-ICSS Subsystem user interfaces
+ *
+ * Copyright (C) 2015-2022 Texas Instruments Incorporated - http://www.ti.com
+ *	Suman Anna <s-anna@ti.com>
+ */
+
+#ifndef __LINUX_PRUSS_H
+#define __LINUX_PRUSS_H
+
+#include <linux/device.h>
+#include <linux/types.h>
+
+#define PRU_RPROC_DRVNAME "pru-rproc"
+
+struct device_node;
+
+#if IS_ENABLED(CONFIG_PRU_REMOTEPROC)
+
+struct rproc *pru_rproc_get(struct device_node *np, int index);
+void pru_rproc_put(struct rproc *rproc);
+
+#else
+
+static inline struct rproc *
+pru_rproc_get(struct device_node *np, int index)
+{
+	return ERR_PTR(-EOPNOTSUPP);
+}
+
+static inline void pru_rproc_put(struct rproc *rproc) { }
+
+#endif /* CONFIG_PRU_REMOTEPROC */
+
+static inline bool is_pru_rproc(struct device *dev)
+{
+	const char *drv_name = dev_driver_string(dev);
+
+	if (strncmp(drv_name, PRU_RPROC_DRVNAME, sizeof(PRU_RPROC_DRVNAME)))
+		return false;
+
+	return true;
+}
+
+#endif /* __LINUX_PRUSS_H */
-- 
2.25.1

[PATCH v10 3/6] remoteproc: pru: Add enum for PRU Core Indentifiers.

[MD Danish Anwar]

Introducing enum pruss_pru_id for PRU Core Identifiers.
PRUSS_PRU0 indicates PRU Core 0.
PRUSS_PRU1 indicates PRU Core 1.
PRUSS_NUM_PRUS indicates the total number of PRU Cores.

Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
---
 drivers/remoteproc/pru_rproc.c | 16 ++++++++++++----
 include/linux/pruss.h          | 19 +++++++++++++++++--
 2 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
index b4498a505108..7d4ed39b3772 100644
--- a/drivers/remoteproc/pru_rproc.c
+++ b/drivers/remoteproc/pru_rproc.c
@@ -186,6 +186,7 @@ static struct rproc *__pru_rproc_get(struct device_node *np, int index)
  * pru_rproc_get() - get the PRU rproc instance from a device node
  * @np: the user/client device node
  * @index: index to use for the ti,prus property
+ * @pru_id: optional pointer to return the PRU remoteproc processor id
  *
  * This function looks through a client device node's "ti,prus" property at
  * index @index and returns the rproc handle for a valid PRU remote processor if
@@ -193,13 +194,17 @@ static struct rproc *__pru_rproc_get(struct device_node *np, int index)
  * time. Caller must call pru_rproc_put() when done with using the rproc, not
  * required if the function returns a failure.
  *
+ * When optional @pru_id pointer is passed the PRU remoteproc processor id is
+ * returned.
+ *
  * Return: rproc handle on success, and an ERR_PTR on failure using one
  * of the following error values
  *    -ENODEV if device is not found
  *    -EBUSY if PRU is already acquired by anyone
  *    -EPROBE_DEFER is PRU device is not probed yet
  */
-struct rproc *pru_rproc_get(struct device_node *np, int index)
+struct rproc *pru_rproc_get(struct device_node *np, int index,
+			    enum pruss_pru_id *pru_id)
 {
 	struct rproc *rproc;
 	struct pru_rproc *pru;
@@ -226,6 +231,9 @@ struct rproc *pru_rproc_get(struct device_node *np, int index)
 
 	mutex_unlock(&pru->lock);
 
+	if (pru_id)
+		*pru_id = pru->id;
+
 	return rproc;
 
 err_no_rproc_handle:
@@ -556,7 +564,7 @@ static void *pru_d_da_to_va(struct pru_rproc *pru, u32 da, size_t len)
 	dram0 = pruss->mem_regions[PRUSS_MEM_DRAM0];
 	dram1 = pruss->mem_regions[PRUSS_MEM_DRAM1];
 	/* PRU1 has its local RAM addresses reversed */
-	if (pru->id == 1)
+	if (pru->id == PRUSS_PRU1)
 		swap(dram0, dram1);
 	shrd_ram = pruss->mem_regions[PRUSS_MEM_SHRD_RAM2];
 
@@ -865,14 +873,14 @@ static int pru_rproc_set_id(struct pru_rproc *pru)
 	case RTU0_IRAM_ADDR_MASK:
 		fallthrough;
 	case PRU0_IRAM_ADDR_MASK:
-		pru->id = 0;
+		pru->id = PRUSS_PRU0;
 		break;
 	case TX_PRU1_IRAM_ADDR_MASK:
 		fallthrough;
 	case RTU1_IRAM_ADDR_MASK:
 		fallthrough;
 	case PRU1_IRAM_ADDR_MASK:
-		pru->id = 1;
+		pru->id = PRUSS_PRU1;
 		break;
 	default:
 		ret = -EINVAL;
diff --git a/include/linux/pruss.h b/include/linux/pruss.h
index 5c5d14b1249d..efe89c586b4b 100644
--- a/include/linux/pruss.h
+++ b/include/linux/pruss.h
@@ -14,17 +14,32 @@
 
 #define PRU_RPROC_DRVNAME "pru-rproc"
 
+/**
+ * enum pruss_pru_id - PRU core identifiers
+ * @PRUSS_PRU0: PRU Core 0.
+ * @PRUSS_PRU1: PRU Core 1.
+ * @PRUSS_NUM_PRUS: Total number of PRU Cores available.
+ *
+ */
+
+enum pruss_pru_id {
+	PRUSS_PRU0 = 0,
+	PRUSS_PRU1,
+	PRUSS_NUM_PRUS,
+};
+
 struct device_node;
 
 #if IS_ENABLED(CONFIG_PRU_REMOTEPROC)
 
-struct rproc *pru_rproc_get(struct device_node *np, int index);
+struct rproc *pru_rproc_get(struct device_node *np, int index,
+			    enum pruss_pru_id *pru_id);
 void pru_rproc_put(struct rproc *rproc);
 
 #else
 
 static inline struct rproc *
-pru_rproc_get(struct device_node *np, int index)
+pru_rproc_get(struct device_node *np, int index, enum pruss_pru_id *pru_id)
 {
 	return ERR_PTR(-EOPNOTSUPP);
 }
-- 
2.25.1

[PATCH v10 4/6] remoteproc: pru: Make sysfs entries read-only for PRU client driven boots

[MD Danish Anwar]

From: Suman Anna <s-anna@ti.com>

The PRU remoteproc driver is not configured for 'auto-boot' by default,
and allows to be booted either by in-kernel PRU client drivers or by
userspace using the generic remoteproc sysfs interfaces. The sysfs
interfaces should not be permitted to change the remoteproc firmwares
or states when a PRU is being managed by an in-kernel client driver.
Use the newly introduced remoteproc generic 'sysfs_read_only' flag to
provide these restrictions by setting and clearing it appropriately
during the PRU acquire and release steps.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
Reviewed-by: Roger Quadros <rogerq@kernel.org>
---
 drivers/remoteproc/pru_rproc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
index 7d4ed39b3772..bca7550d79d2 100644
--- a/drivers/remoteproc/pru_rproc.c
+++ b/drivers/remoteproc/pru_rproc.c
@@ -228,6 +228,7 @@ struct rproc *pru_rproc_get(struct device_node *np, int index,
 	}
 
 	pru->client_np = np;
+	rproc->sysfs_read_only = true;
 
 	mutex_unlock(&pru->lock);
 
@@ -266,6 +267,7 @@ void pru_rproc_put(struct rproc *rproc)
 	}
 
 	pru->client_np = NULL;
+	rproc->sysfs_read_only = false;
 	mutex_unlock(&pru->lock);
 
 	rproc_put(rproc);
-- 
2.25.1

[PATCH v10 5/6] remoteproc: pru: Add pru_rproc_set_ctable() function

[MD Danish Anwar]

From: Roger Quadros <rogerq@ti.com>

Some firmwares expect the OS drivers to configure the CTABLE
entries publishing dynamically allocated memory regions. For
example, the PRU Ethernet firmwares use the C28 and C30 entries
for retrieving the Shared RAM and System SRAM (OCMC) areas
allocated by the PRU Ethernet client driver.

Provide a way for users to do that through a new API,
pru_rproc_set_ctable(). The API returns 0 on success and
a negative value on error.

NOTE:
The programmable CTABLE entries are typically re-programmed by
the PRU firmwares when dealing with a certain block of memory
during block processing. This API provides an interface to the
PRU client drivers to publish a dynamically allocated memory
block with the PRU firmware using a CTABLE entry instead of a
negotiated address in shared memory. Additional synchronization
may be needed between the PRU client drivers and firmwares if
different addresses needs to be published at run-time reusing
the same CTABLE entry.

CTABLE for stands for "constant table".
Each CTable entry just holds the upper address bits so PRU can
reference to external memory with larger address bits.

For use case please see
prueth_sw_emac_config() in "drivers/net/ethernet/ti/prueth_switch.c"

            /* Set in constant table C28 of PRUn to ICSS Shared memory */
             pru_rproc_set_ctable(prueth->pru0, PRU_C28, sharedramaddr);
             pru_rproc_set_ctable(prueth->pru1, PRU_C28, sharedramaddr);

            /* Set in constant table C30 of PRUn to OCMC memory */
             pru_rproc_set_ctable(prueth->pru0, PRU_C30, ocmcaddr);
             pru_rproc_set_ctable(prueth->pru1, PRU_C30, ocmcaddr);

Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
---
 drivers/remoteproc/pru_rproc.c | 59 ++++++++++++++++++++++++++++++++++
 include/linux/pruss.h          | 22 +++++++++++++
 2 files changed, 81 insertions(+)

diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
index bca7550d79d2..f4a34cc6bcc6 100644
--- a/drivers/remoteproc/pru_rproc.c
+++ b/drivers/remoteproc/pru_rproc.c
@@ -120,6 +120,7 @@ struct pru_private_data {
  * @mapped_irq: virtual interrupt numbers of created fw specific mapping
  * @pru_interrupt_map: pointer to interrupt mapping description (firmware)
  * @pru_interrupt_map_sz: pru_interrupt_map size
+ * @rmw_lock: lock for read, modify, write operations on registers
  * @dbg_single_step: debug state variable to set PRU into single step mode
  * @dbg_continuous: debug state variable to restore PRU execution mode
  * @evt_count: number of mapped events
@@ -137,6 +138,7 @@ struct pru_rproc {
 	unsigned int *mapped_irq;
 	struct pru_irq_rsc *pru_interrupt_map;
 	size_t pru_interrupt_map_sz;
+	spinlock_t rmw_lock;
 	u32 dbg_single_step;
 	u32 dbg_continuous;
 	u8 evt_count;
@@ -153,6 +155,23 @@ void pru_control_write_reg(struct pru_rproc *pru, unsigned int reg, u32 val)
 	writel_relaxed(val, pru->mem_regions[PRU_IOMEM_CTRL].va + reg);
 }
 
+static inline
+void pru_control_set_reg(struct pru_rproc *pru, unsigned int reg,
+			 u32 mask, u32 set)
+{
+	u32 val;
+	unsigned long flags;
+
+	spin_lock_irqsave(&pru->rmw_lock, flags);
+
+	val = pru_control_read_reg(pru, reg);
+	val &= ~mask;
+	val |= (set & mask);
+	pru_control_write_reg(pru, reg, val);
+
+	spin_unlock_irqrestore(&pru->rmw_lock, flags);
+}
+
 static struct rproc *__pru_rproc_get(struct device_node *np, int index)
 {
 	struct rproc *rproc;
@@ -274,6 +293,45 @@ void pru_rproc_put(struct rproc *rproc)
 }
 EXPORT_SYMBOL_GPL(pru_rproc_put);
 
+/**
+ * pru_rproc_set_ctable() - set the constant table index for the PRU
+ * @rproc: the rproc instance of the PRU
+ * @c: constant table index to set
+ * @addr: physical address to set it to
+ *
+ * Return: 0 on success, or errno in error case.
+ */
+int pru_rproc_set_ctable(struct rproc *rproc, enum pru_ctable_idx c, u32 addr)
+{
+	struct pru_rproc *pru = rproc->priv;
+	unsigned int reg;
+	u32 mask, set;
+	u16 idx;
+	u16 idx_mask;
+
+	if (IS_ERR_OR_NULL(rproc))
+		return -EINVAL;
+
+	if (!rproc->dev.parent || !is_pru_rproc(rproc->dev.parent))
+		return -ENODEV;
+
+	/* pointer is 16 bit and index is 8-bit so mask out the rest */
+	idx_mask = (c >= PRU_C28) ? 0xFFFF : 0xFF;
+
+	/* ctable uses bit 8 and upwards only */
+	idx = (addr >> 8) & idx_mask;
+
+	/* configurable ctable (i.e. C24) starts at PRU_CTRL_CTBIR0 */
+	reg = PRU_CTRL_CTBIR0 + 4 * (c >> 1);
+	mask = idx_mask << (16 * (c & 1));
+	set = idx << (16 * (c & 1));
+
+	pru_control_set_reg(pru, reg, mask, set);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pru_rproc_set_ctable);
+
 static inline u32 pru_debug_read_reg(struct pru_rproc *pru, unsigned int reg)
 {
 	return readl_relaxed(pru->mem_regions[PRU_IOMEM_DEBUG].va + reg);
@@ -945,6 +1003,7 @@ static int pru_rproc_probe(struct platform_device *pdev)
 	pru->rproc = rproc;
 	pru->fw_name = fw_name;
 	pru->client_np = NULL;
+	spin_lock_init(&pru->rmw_lock);
 	mutex_init(&pru->lock);
 
 	for (i = 0; i < ARRAY_SIZE(mem_names); i++) {
diff --git a/include/linux/pruss.h b/include/linux/pruss.h
index efe89c586b4b..5c20da98a4b8 100644
--- a/include/linux/pruss.h
+++ b/include/linux/pruss.h
@@ -28,13 +28,29 @@ enum pruss_pru_id {
 	PRUSS_NUM_PRUS,
 };
 
+/*
+ * enum pru_ctable_idx - Configurable Constant table index identifiers
+ */
+enum pru_ctable_idx {
+	PRU_C24 = 0,
+	PRU_C25,
+	PRU_C26,
+	PRU_C27,
+	PRU_C28,
+	PRU_C29,
+	PRU_C30,
+	PRU_C31,
+};
+
 struct device_node;
+struct rproc;
 
 #if IS_ENABLED(CONFIG_PRU_REMOTEPROC)
 
 struct rproc *pru_rproc_get(struct device_node *np, int index,
 			    enum pruss_pru_id *pru_id);
 void pru_rproc_put(struct rproc *rproc);
+int pru_rproc_set_ctable(struct rproc *rproc, enum pru_ctable_idx c, u32 addr);
 
 #else
 
@@ -46,6 +62,12 @@ pru_rproc_get(struct device_node *np, int index, enum pruss_pru_id *pru_id)
 
 static inline void pru_rproc_put(struct rproc *rproc) { }
 
+static inline int pru_rproc_set_ctable(struct rproc *rproc,
+				       enum pru_ctable_idx c, u32 addr)
+{
+	return -EOPNOTSUPP;
+}
+
 #endif /* CONFIG_PRU_REMOTEPROC */
 
 static inline bool is_pru_rproc(struct device *dev)
-- 
2.25.1

[PATCH v10 6/6] remoteproc: pru: Configure firmware based on client setup

[MD Danish Anwar]

From: Tero Kristo <t-kristo@ti.com>

Client device node property firmware-name is now used to configure
firmware for the PRU instances. The default firmware is also
restored once releasing the PRU resource.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
Reviewed-by: Roger Quadros <rogerq@kernel.org>
---
 drivers/remoteproc/pru_rproc.c | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
index f4a34cc6bcc6..39e05623a84e 100644
--- a/drivers/remoteproc/pru_rproc.c
+++ b/drivers/remoteproc/pru_rproc.c
@@ -172,6 +172,23 @@ void pru_control_set_reg(struct pru_rproc *pru, unsigned int reg,
 	spin_unlock_irqrestore(&pru->rmw_lock, flags);
 }
 
+/**
+ * pru_rproc_set_firmware() - set firmware for a PRU core
+ * @rproc: the rproc instance of the PRU
+ * @fw_name: the new firmware name, or NULL if default is desired
+ *
+ * Return: 0 on success, or errno in error case.
+ */
+static int pru_rproc_set_firmware(struct rproc *rproc, const char *fw_name)
+{
+	struct pru_rproc *pru = rproc->priv;
+
+	if (!fw_name)
+		fw_name = pru->fw_name;
+
+	return rproc_set_firmware(rproc, fw_name);
+}
+
 static struct rproc *__pru_rproc_get(struct device_node *np, int index)
 {
 	struct rproc *rproc;
@@ -228,6 +245,7 @@ struct rproc *pru_rproc_get(struct device_node *np, int index,
 	struct rproc *rproc;
 	struct pru_rproc *pru;
 	struct device *dev;
+	const char *fw_name;
 	int ret;
 
 	rproc = __pru_rproc_get(np, index);
@@ -254,11 +272,25 @@ struct rproc *pru_rproc_get(struct device_node *np, int index,
 	if (pru_id)
 		*pru_id = pru->id;
 
+	ret = of_property_read_string_index(np, "firmware-name", index,
+					    &fw_name);
+	if (!ret) {
+		ret = pru_rproc_set_firmware(rproc, fw_name);
+		if (ret) {
+			dev_err(dev, "failed to set firmware: %d\n", ret);
+			goto err;
+		}
+	}
+
 	return rproc;
 
 err_no_rproc_handle:
 	rproc_put(rproc);
 	return ERR_PTR(ret);
+
+err:
+	pru_rproc_put(rproc);
+	return ERR_PTR(ret);
 }
 EXPORT_SYMBOL_GPL(pru_rproc_get);
 
@@ -278,6 +310,8 @@ void pru_rproc_put(struct rproc *rproc)
 
 	pru = rproc->priv;
 
+	pru_rproc_set_firmware(rproc, NULL);
+
 	mutex_lock(&pru->lock);
 
 	if (!pru->client_np) {
-- 
2.25.1

Re: [PATCH v10 3/6] remoteproc: pru: Add enum for PRU Core Indentifiers.

[Roger Quadros]

Danish,

On 01/12/2022 13:04, MD Danish Anwar wrote:
> Introducing enum pruss_pru_id for PRU Core Identifiers.
> PRUSS_PRU0 indicates PRU Core 0.
> PRUSS_PRU1 indicates PRU Core 1.
> PRUSS_NUM_PRUS indicates the total number of PRU Cores.
> 
> Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
> ---
>  drivers/remoteproc/pru_rproc.c | 16 ++++++++++++----
>  include/linux/pruss.h          | 19 +++++++++++++++++--
>  2 files changed, 29 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
> index b4498a505108..7d4ed39b3772 100644
> --- a/drivers/remoteproc/pru_rproc.c
> +++ b/drivers/remoteproc/pru_rproc.c
> @@ -186,6 +186,7 @@ static struct rproc *__pru_rproc_get(struct device_node *np, int index)
>   * pru_rproc_get() - get the PRU rproc instance from a device node
>   * @np: the user/client device node
>   * @index: index to use for the ti,prus property
> + * @pru_id: optional pointer to return the PRU remoteproc processor id
>   *
>   * This function looks through a client device node's "ti,prus" property at
>   * index @index and returns the rproc handle for a valid PRU remote processor if
> @@ -193,13 +194,17 @@ static struct rproc *__pru_rproc_get(struct device_node *np, int index)
>   * time. Caller must call pru_rproc_put() when done with using the rproc, not
>   * required if the function returns a failure.
>   *
> + * When optional @pru_id pointer is passed the PRU remoteproc processor id is
> + * returned.
> + *
>   * Return: rproc handle on success, and an ERR_PTR on failure using one
>   * of the following error values
>   *    -ENODEV if device is not found
>   *    -EBUSY if PRU is already acquired by anyone
>   *    -EPROBE_DEFER is PRU device is not probed yet
>   */
> -struct rproc *pru_rproc_get(struct device_node *np, int index)
> +struct rproc *pru_rproc_get(struct device_node *np, int index,
> +			    enum pruss_pru_id *pru_id)

You just introduced pru_rproc_get() in the previous patch and are
now updating it here.

Instead, what you need to do is, first introduce enum pruss_pru_id
and make any changes to code using hardcoded values for PRU ID.
This patch will have to introduce <linux/pruss.h> as it doesn't exist yet.
Hopefully this clears the chicken/egg situation.

Then introduce pru_rproc_get() patch with the final desired arguments.

>  {
>  	struct rproc *rproc;
>  	struct pru_rproc *pru;
> @@ -226,6 +231,9 @@ struct rproc *pru_rproc_get(struct device_node *np, int index)
>  
>  	mutex_unlock(&pru->lock);
>  
> +	if (pru_id)
> +		*pru_id = pru->id;
> +
>  	return rproc;
>  
>  err_no_rproc_handle:
> @@ -556,7 +564,7 @@ static void *pru_d_da_to_va(struct pru_rproc *pru, u32 da, size_t len)
>  	dram0 = pruss->mem_regions[PRUSS_MEM_DRAM0];
>  	dram1 = pruss->mem_regions[PRUSS_MEM_DRAM1];
>  	/* PRU1 has its local RAM addresses reversed */
> -	if (pru->id == 1)
> +	if (pru->id == PRUSS_PRU1)
>  		swap(dram0, dram1);
>  	shrd_ram = pruss->mem_regions[PRUSS_MEM_SHRD_RAM2];
>  
> @@ -865,14 +873,14 @@ static int pru_rproc_set_id(struct pru_rproc *pru)
>  	case RTU0_IRAM_ADDR_MASK:
>  		fallthrough;
>  	case PRU0_IRAM_ADDR_MASK:
> -		pru->id = 0;
> +		pru->id = PRUSS_PRU0;
>  		break;
>  	case TX_PRU1_IRAM_ADDR_MASK:
>  		fallthrough;
>  	case RTU1_IRAM_ADDR_MASK:
>  		fallthrough;
>  	case PRU1_IRAM_ADDR_MASK:
> -		pru->id = 1;
> +		pru->id = PRUSS_PRU1;
>  		break;
>  	default:
>  		ret = -EINVAL;
> diff --git a/include/linux/pruss.h b/include/linux/pruss.h
> index 5c5d14b1249d..efe89c586b4b 100644
> --- a/include/linux/pruss.h
> +++ b/include/linux/pruss.h
> @@ -14,17 +14,32 @@
>  
>  #define PRU_RPROC_DRVNAME "pru-rproc"
>  
> +/**
> + * enum pruss_pru_id - PRU core identifiers
> + * @PRUSS_PRU0: PRU Core 0.
> + * @PRUSS_PRU1: PRU Core 1.
> + * @PRUSS_NUM_PRUS: Total number of PRU Cores available.
> + *
> + */
> +
> +enum pruss_pru_id {
> +	PRUSS_PRU0 = 0,
> +	PRUSS_PRU1,
> +	PRUSS_NUM_PRUS,
> +};
> +
>  struct device_node;
>  
>  #if IS_ENABLED(CONFIG_PRU_REMOTEPROC)
>  
> -struct rproc *pru_rproc_get(struct device_node *np, int index);
> +struct rproc *pru_rproc_get(struct device_node *np, int index,
> +			    enum pruss_pru_id *pru_id);
>  void pru_rproc_put(struct rproc *rproc);
>  
>  #else
>  
>  static inline struct rproc *
> -pru_rproc_get(struct device_node *np, int index)
> +pru_rproc_get(struct device_node *np, int index, enum pruss_pru_id *pru_id)
>  {
>  	return ERR_PTR(-EOPNOTSUPP);
>  }

--
cheers,
-roger

Re: [EXTERNAL] Re: [PATCH v10 3/6] remoteproc: pru: Add enum for PRU Core Indentifiers.

[Md Danish Anwar]

Hi Roger,

On 01/12/22 5:28 pm, Roger Quadros wrote:
> Danish,
> 
> On 01/12/2022 13:04, MD Danish Anwar wrote:
>> Introducing enum pruss_pru_id for PRU Core Identifiers.
>> PRUSS_PRU0 indicates PRU Core 0.
>> PRUSS_PRU1 indicates PRU Core 1.
>> PRUSS_NUM_PRUS indicates the total number of PRU Cores.
>>
>> Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
>> ---
>>   drivers/remoteproc/pru_rproc.c | 16 ++++++++++++----
>>   include/linux/pruss.h          | 19 +++++++++++++++++--
>>   2 files changed, 29 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
>> index b4498a505108..7d4ed39b3772 100644
>> --- a/drivers/remoteproc/pru_rproc.c
>> +++ b/drivers/remoteproc/pru_rproc.c
>> @@ -186,6 +186,7 @@ static struct rproc *__pru_rproc_get(struct device_node *np, int index)
>>    * pru_rproc_get() - get the PRU rproc instance from a device node
>>    * @np: the user/client device node
>>    * @index: index to use for the ti,prus property
>> + * @pru_id: optional pointer to return the PRU remoteproc processor id
>>    *
>>    * This function looks through a client device node's "ti,prus" property at
>>    * index @index and returns the rproc handle for a valid PRU remote processor if
>> @@ -193,13 +194,17 @@ static struct rproc *__pru_rproc_get(struct device_node *np, int index)
>>    * time. Caller must call pru_rproc_put() when done with using the rproc, not
>>    * required if the function returns a failure.
>>    *
>> + * When optional @pru_id pointer is passed the PRU remoteproc processor id is
>> + * returned.
>> + *
>>    * Return: rproc handle on success, and an ERR_PTR on failure using one
>>    * of the following error values
>>    *    -ENODEV if device is not found
>>    *    -EBUSY if PRU is already acquired by anyone
>>    *    -EPROBE_DEFER is PRU device is not probed yet
>>    */
>> -struct rproc *pru_rproc_get(struct device_node *np, int index)
>> +struct rproc *pru_rproc_get(struct device_node *np, int index,
>> +			    enum pruss_pru_id *pru_id)
> 
> You just introduced pru_rproc_get() in the previous patch and are
> now updating it here.
> 

That's because there is dependency between these two patches. The enum 
pruss_pru_id is declared inside linux/pruss.h file which is introduced 
in pru_rproc_get() patch. But pru_rproc_get() and pru_rproc_put() APIs 
use the enum as function argument. So I decided to keep pru_rproc_get() 
patch as second patch of this series(as it introduces <linux/pruss.h> 
where eventually the enum will be introduced).

Then I kept the enum introduction patch as third patch of the series and 
with this patch I modified pru_rproc_get() API by adding pru_id field in 
the function argument.

> Instead, what you need to do is, first introduce enum pruss_pru_id
> and make any changes to code using hardcoded values for PRU ID.
> This patch will have to introduce <linux/pruss.h> as it doesn't exist yet.

This also came to my mind. But I thought introduction of enum 
pruss_pru_id patch should just introduce the enum and modify APIs which 
uses the enum accordingly. I wanted to keep the introduction of 
<linux/pruss.h> file with the pru_rproc_get() patch as it was. That's 
why I kept pru_rproc_get() patch ahead of enum patch.

> Hopefully this clears the chicken/egg situation.
> 
> Then introduce pru_rproc_get() patch with the final desired arguments.
> 
>>   {
>>   	struct rproc *rproc;
>>   	struct pru_rproc *pru;
>> @@ -226,6 +231,9 @@ struct rproc *pru_rproc_get(struct device_node *np, int index)
>>   
>>   	mutex_unlock(&pru->lock);
>>   
>> +	if (pru_id)
>> +		*pru_id = pru->id;
>> +
>>   	return rproc;
>>   
>>   err_no_rproc_handle:
>> @@ -556,7 +564,7 @@ static void *pru_d_da_to_va(struct pru_rproc *pru, u32 da, size_t len)
>>   	dram0 = pruss->mem_regions[PRUSS_MEM_DRAM0];
>>   	dram1 = pruss->mem_regions[PRUSS_MEM_DRAM1];
>>   	/* PRU1 has its local RAM addresses reversed */
>> -	if (pru->id == 1)
>> +	if (pru->id == PRUSS_PRU1)
>>   		swap(dram0, dram1);
>>   	shrd_ram = pruss->mem_regions[PRUSS_MEM_SHRD_RAM2];
>>   
>> @@ -865,14 +873,14 @@ static int pru_rproc_set_id(struct pru_rproc *pru)
>>   	case RTU0_IRAM_ADDR_MASK:
>>   		fallthrough;
>>   	case PRU0_IRAM_ADDR_MASK:
>> -		pru->id = 0;
>> +		pru->id = PRUSS_PRU0;
>>   		break;
>>   	case TX_PRU1_IRAM_ADDR_MASK:
>>   		fallthrough;
>>   	case RTU1_IRAM_ADDR_MASK:
>>   		fallthrough;
>>   	case PRU1_IRAM_ADDR_MASK:
>> -		pru->id = 1;
>> +		pru->id = PRUSS_PRU1;
>>   		break;
>>   	default:
>>   		ret = -EINVAL;
>> diff --git a/include/linux/pruss.h b/include/linux/pruss.h
>> index 5c5d14b1249d..efe89c586b4b 100644
>> --- a/include/linux/pruss.h
>> +++ b/include/linux/pruss.h
>> @@ -14,17 +14,32 @@
>>   
>>   #define PRU_RPROC_DRVNAME "pru-rproc"
>>   
>> +/**
>> + * enum pruss_pru_id - PRU core identifiers
>> + * @PRUSS_PRU0: PRU Core 0.
>> + * @PRUSS_PRU1: PRU Core 1.
>> + * @PRUSS_NUM_PRUS: Total number of PRU Cores available.
>> + *
>> + */
>> +
>> +enum pruss_pru_id {
>> +	PRUSS_PRU0 = 0,
>> +	PRUSS_PRU1,
>> +	PRUSS_NUM_PRUS,
>> +};
>> +
>>   struct device_node;
>>   
>>   #if IS_ENABLED(CONFIG_PRU_REMOTEPROC)
>>   
>> -struct rproc *pru_rproc_get(struct device_node *np, int index);
>> +struct rproc *pru_rproc_get(struct device_node *np, int index,
>> +			    enum pruss_pru_id *pru_id);
>>   void pru_rproc_put(struct rproc *rproc);
>>   
>>   #else
>>   
>>   static inline struct rproc *
>> -pru_rproc_get(struct device_node *np, int index)
>> +pru_rproc_get(struct device_node *np, int index, enum pruss_pru_id *pru_id)
>>   {
>>   	return ERR_PTR(-EOPNOTSUPP);
>>   }
> 
> --
> cheers,
> -roger

Thanks,
Danish.

Re: [EXTERNAL] Re: [PATCH v10 3/6] remoteproc: pru: Add enum for PRU Core Indentifiers.

[Md Danish Anwar]

Hi Roger,

On 01/12/22 19:13, Md Danish Anwar wrote:
> Hi Roger,
> 
> On 01/12/22 5:28 pm, Roger Quadros wrote:
>> Danish,
>>
>> On 01/12/2022 13:04, MD Danish Anwar wrote:
>>> Introducing enum pruss_pru_id for PRU Core Identifiers.
>>> PRUSS_PRU0 indicates PRU Core 0.
>>> PRUSS_PRU1 indicates PRU Core 1.
>>> PRUSS_NUM_PRUS indicates the total number of PRU Cores.
>>>
>>> Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
>>> ---
>>>   drivers/remoteproc/pru_rproc.c | 16 ++++++++++++----
>>>   include/linux/pruss.h          | 19 +++++++++++++++++--
>>>   2 files changed, 29 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
>>> index b4498a505108..7d4ed39b3772 100644
>>> --- a/drivers/remoteproc/pru_rproc.c
>>> +++ b/drivers/remoteproc/pru_rproc.c
>>> @@ -186,6 +186,7 @@ static struct rproc *__pru_rproc_get(struct device_node
>>> *np, int index)
>>>    * pru_rproc_get() - get the PRU rproc instance from a device node
>>>    * @np: the user/client device node
>>>    * @index: index to use for the ti,prus property
>>> + * @pru_id: optional pointer to return the PRU remoteproc processor id
>>>    *
>>>    * This function looks through a client device node's "ti,prus" property at
>>>    * index @index and returns the rproc handle for a valid PRU remote
>>> processor if
>>> @@ -193,13 +194,17 @@ static struct rproc *__pru_rproc_get(struct
>>> device_node *np, int index)
>>>    * time. Caller must call pru_rproc_put() when done with using the rproc, not
>>>    * required if the function returns a failure.
>>>    *
>>> + * When optional @pru_id pointer is passed the PRU remoteproc processor id is
>>> + * returned.
>>> + *
>>>    * Return: rproc handle on success, and an ERR_PTR on failure using one
>>>    * of the following error values
>>>    *    -ENODEV if device is not found
>>>    *    -EBUSY if PRU is already acquired by anyone
>>>    *    -EPROBE_DEFER is PRU device is not probed yet
>>>    */
>>> -struct rproc *pru_rproc_get(struct device_node *np, int index)
>>> +struct rproc *pru_rproc_get(struct device_node *np, int index,
>>> +                enum pruss_pru_id *pru_id)
>>
>> You just introduced pru_rproc_get() in the previous patch and are
>> now updating it here.
>>
> 
> That's because there is dependency between these two patches. The enum
> pruss_pru_id is declared inside linux/pruss.h file which is introduced in
> pru_rproc_get() patch. But pru_rproc_get() and pru_rproc_put() APIs use the
> enum as function argument. So I decided to keep pru_rproc_get() patch as second
> patch of this series(as it introduces <linux/pruss.h> where eventually the enum
> will be introduced).
> 
> Then I kept the enum introduction patch as third patch of the series and with
> this patch I modified pru_rproc_get() API by adding pru_id field in the
> function argument.
> 
>> Instead, what you need to do is, first introduce enum pruss_pru_id
>> and make any changes to code using hardcoded values for PRU ID.
>> This patch will have to introduce <linux/pruss.h> as it doesn't exist yet.
> 

I will be posting this series again with your suggestion by keeping enum patch
first and then the pru_rproc_get() patch.

> This also came to my mind. But I thought introduction of enum pruss_pru_id
> patch should just introduce the enum and modify APIs which uses the enum
> accordingly. I wanted to keep the introduction of <linux/pruss.h> file with the
> pru_rproc_get() patch as it was. That's why I kept pru_rproc_get() patch ahead
> of enum patch.
> 
>> Hopefully this clears the chicken/egg situation.
>>
>> Then introduce pru_rproc_get() patch with the final desired arguments.
>>
>>>   {
>>>       struct rproc *rproc;
>>>       struct pru_rproc *pru;
>>> @@ -226,6 +231,9 @@ struct rproc *pru_rproc_get(struct device_node *np, int
>>> index)
>>>         mutex_unlock(&pru->lock);
>>>   +    if (pru_id)
>>> +        *pru_id = pru->id;
>>> +
>>>       return rproc;
>>>     err_no_rproc_handle:
>>> @@ -556,7 +564,7 @@ static void *pru_d_da_to_va(struct pru_rproc *pru, u32
>>> da, size_t len)
>>>       dram0 = pruss->mem_regions[PRUSS_MEM_DRAM0];
>>>       dram1 = pruss->mem_regions[PRUSS_MEM_DRAM1];
>>>       /* PRU1 has its local RAM addresses reversed */
>>> -    if (pru->id == 1)
>>> +    if (pru->id == PRUSS_PRU1)
>>>           swap(dram0, dram1);
>>>       shrd_ram = pruss->mem_regions[PRUSS_MEM_SHRD_RAM2];
>>>   @@ -865,14 +873,14 @@ static int pru_rproc_set_id(struct pru_rproc *pru)
>>>       case RTU0_IRAM_ADDR_MASK:
>>>           fallthrough;
>>>       case PRU0_IRAM_ADDR_MASK:
>>> -        pru->id = 0;
>>> +        pru->id = PRUSS_PRU0;
>>>           break;
>>>       case TX_PRU1_IRAM_ADDR_MASK:
>>>           fallthrough;
>>>       case RTU1_IRAM_ADDR_MASK:
>>>           fallthrough;
>>>       case PRU1_IRAM_ADDR_MASK:
>>> -        pru->id = 1;
>>> +        pru->id = PRUSS_PRU1;
>>>           break;
>>>       default:
>>>           ret = -EINVAL;
>>> diff --git a/include/linux/pruss.h b/include/linux/pruss.h
>>> index 5c5d14b1249d..efe89c586b4b 100644
>>> --- a/include/linux/pruss.h
>>> +++ b/include/linux/pruss.h
>>> @@ -14,17 +14,32 @@
>>>     #define PRU_RPROC_DRVNAME "pru-rproc"
>>>   +/**
>>> + * enum pruss_pru_id - PRU core identifiers
>>> + * @PRUSS_PRU0: PRU Core 0.
>>> + * @PRUSS_PRU1: PRU Core 1.
>>> + * @PRUSS_NUM_PRUS: Total number of PRU Cores available.
>>> + *
>>> + */
>>> +
>>> +enum pruss_pru_id {
>>> +    PRUSS_PRU0 = 0,
>>> +    PRUSS_PRU1,
>>> +    PRUSS_NUM_PRUS,
>>> +};
>>> +
>>>   struct device_node;
>>>     #if IS_ENABLED(CONFIG_PRU_REMOTEPROC)
>>>   -struct rproc *pru_rproc_get(struct device_node *np, int index);
>>> +struct rproc *pru_rproc_get(struct device_node *np, int index,
>>> +                enum pruss_pru_id *pru_id);
>>>   void pru_rproc_put(struct rproc *rproc);
>>>     #else
>>>     static inline struct rproc *
>>> -pru_rproc_get(struct device_node *np, int index)
>>> +pru_rproc_get(struct device_node *np, int index, enum pruss_pru_id *pru_id)
>>>   {
>>>       return ERR_PTR(-EOPNOTSUPP);
>>>   }
>>
>> -- 
>> cheers,
>> -roger
> 
> Thanks,
> Danish.

Thanks,
Danish.