[PATCH v2 0/8] ARM: davinci: complete the conversion to using the reset framework

[PATCH v2 0/8] ARM: davinci: complete the conversion to using the reset framework

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

This series converts the only user of the handcoded, mach-specific reset
routines in the davinci platform to using the reset framework.

Patch 1 modifies the way lookup entries are registered with the reset
framework.

Patches 2-4 add necessary lookups/DT-properties.

Patches 5-7 convert the davinci-rproc driver to the reset framework.

Patch 8 removes now dead code.

Philipp: it turned out that it's indeed better to use the reset
controller's device name for the entry lookup.

Tested both in DT and legacy modes by booting the examples from
ti-ipc-rtos recipe in meta-ti.

This series applies on top of David Lechner's common-clk-v9 branch[1]
with Philipp Zabel's reset/next branch[2] pulled in.

It can be found in my github tree as well[3].

[1] git://github.com/dlech/ev3dev-kernel.git common-clk-v9
[2] git://git.pengutronix.de/git/pza/linux reset/next
[3] git@github.com:brgl/linux.git topic/davinci-reset

v1 -> v2:
- fixed the device tree patches the descriptions of which were mixed up
- return -EPROBE_DEFER from davinci-rproc's probe() if we can't get the
  reset provider, since it's possible that the lookup table was not yet
  registered
- made the local variable naming consistent in the davinci-rproc driver
- fixed a typo in PATCH 5/8

Bartosz Golaszewski (8):
  reset: modify the way reset lookup works for board files
  ARM: davinci: dts: make psc0 a reset provider
  ARM: davinci: dts: add a reset control to the dsp node
  clk: davinci: add a reset lookup table for psc0
  remoteproc: da8xx: add the missing retval check for clk_enable()
  remoteproc: da8xx: prepare and unprepare the clock where needed
  remoteproc: da8xx: use the reset framework
  clk: davinci: kill davinci_clk_reset_assert/deassert()

 arch/arm/boot/dts/da850.dtsi               |  2 ++
 arch/arm/mach-davinci/include/mach/clock.h | 21 --------------
 drivers/clk/davinci/psc-da850.c            |  8 ++++++
 drivers/clk/davinci/psc.c                  | 19 +------------
 drivers/remoteproc/da8xx_remoteproc.c      | 44 +++++++++++++++++++++++++-----
 drivers/reset/core.c                       | 33 +++++++++++++++++++---
 include/linux/reset-controller.h           |  8 ++++--
 7 files changed, 82 insertions(+), 53 deletions(-)
 delete mode 100644 arch/arm/mach-davinci/include/mach/clock.h

-- 
2.16.1

[PATCH v2 1/8] reset: modify the way reset lookup works for board files

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Commit 7af1bb19f1d7 ("reset: add support for non-DT systems")
introduced reset control lookup mechanism for boards that still use
board files.

The routine used to register lookup entries takes the corresponding
reset_controlled_dev structure as argument.

It's been determined however that for the first user of this new
interface - davinci psc driver - it will be easier to register the
lookup entries using the reset controller device name.

This patch changes the way lookup entries are added.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/reset/core.c             | 33 +++++++++++++++++++++++++++++----
 include/linux/reset-controller.h |  8 +++++---
 2 files changed, 34 insertions(+), 7 deletions(-)

diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index 06fa4907afc4..f37048e55336 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -153,11 +153,11 @@ EXPORT_SYMBOL_GPL(devm_reset_controller_register);
 
 /**
  * reset_controller_add_lookup - register a set of lookup entries
- * @rcdev: initialized reset controller device owning the reset line
+ * @provider: name of the reset controller provider
  * @lookup: array of reset lookup entries
  * @num_entries: number of entries in the lookup array
  */
-void reset_controller_add_lookup(struct reset_controller_dev *rcdev,
+void reset_controller_add_lookup(const char *provider,
 				 struct reset_control_lookup *lookup,
 				 unsigned int num_entries)
 {
@@ -174,7 +174,7 @@ void reset_controller_add_lookup(struct reset_controller_dev *rcdev,
 			continue;
 		}
 
-		entry->rcdev = rcdev;
+		entry->provider = provider;
 		list_add_tail(&entry->list, &reset_lookup_list);
 	}
 	mutex_unlock(&reset_lookup_mutex);
@@ -526,11 +526,30 @@ struct reset_control *__of_reset_control_get(struct device_node *node,
 }
 EXPORT_SYMBOL_GPL(__of_reset_control_get);
 
+static struct reset_controller_dev *
+__reset_controller_by_name(const char *name)
+{
+	struct reset_controller_dev *rcdev;
+
+	lockdep_assert_held(&reset_list_mutex);
+
+	list_for_each_entry(rcdev, &reset_controller_list, list) {
+		if (!rcdev->dev)
+			continue;
+
+		if (!strcmp(name, dev_name(rcdev->dev)))
+			return rcdev;
+	}
+
+	return NULL;
+}
+
 static struct reset_control *
 __reset_control_get_from_lookup(struct device *dev, const char *con_id,
 				bool shared, bool optional)
 {
 	const struct reset_control_lookup *lookup;
+	struct reset_controller_dev *rcdev;
 	const char *dev_id = dev_name(dev);
 	struct reset_control *rstc = NULL;
 
@@ -547,7 +566,13 @@ __reset_control_get_from_lookup(struct device *dev, const char *con_id,
 		    ((con_id && lookup->con_id) &&
 		     !strcmp(con_id, lookup->con_id))) {
 			mutex_lock(&reset_list_mutex);
-			rstc = __reset_control_get_internal(lookup->rcdev,
+			rcdev = __reset_controller_by_name(lookup->provider);
+			if (!rcdev) {
+				mutex_unlock(&reset_list_mutex);
+				continue;
+			}
+
+			rstc = __reset_control_get_internal(rcdev,
 							    lookup->index,
 							    shared);
 			mutex_unlock(&reset_list_mutex);
diff --git a/include/linux/reset-controller.h b/include/linux/reset-controller.h
index 25698f6c1fae..1a6c25d825d3 100644
--- a/include/linux/reset-controller.h
+++ b/include/linux/reset-controller.h
@@ -30,14 +30,14 @@ struct of_phandle_args;
  * struct reset_control_lookup - represents a single lookup entry
  *
  * @list: internal list of all reset lookup entries
- * @rcdev: reset controller device controlling this reset line
+ * @provider: name of the reset controller device controlling this reset line
  * @index: ID of the reset controller in the reset controller device
  * @dev_id: name of the device associated with this reset line
  * @con_id name of the reset line (can be NULL)
  */
 struct reset_control_lookup {
 	struct list_head list;
-	struct reset_controller_dev *rcdev;
+	const char *provider;
 	unsigned int index;
 	const char *dev_id;
 	const char *con_id;
@@ -57,6 +57,7 @@ struct reset_control_lookup {
  * @owner: kernel module of the reset controller driver
  * @list: internal list of reset controller devices
  * @reset_control_head: head of internal list of requested reset controls
+ * @dev: corresponding driver model device struct
  * @of_node: corresponding device tree node as phandle target
  * @of_reset_n_cells: number of cells in reset line specifiers
  * @of_xlate: translation function to translate from specifier as found in the
@@ -68,6 +69,7 @@ struct reset_controller_dev {
 	struct module *owner;
 	struct list_head list;
 	struct list_head reset_control_head;
+	struct device *dev;
 	struct device_node *of_node;
 	int of_reset_n_cells;
 	int (*of_xlate)(struct reset_controller_dev *rcdev,
@@ -82,7 +84,7 @@ struct device;
 int devm_reset_controller_register(struct device *dev,
 				   struct reset_controller_dev *rcdev);
 
-void reset_controller_add_lookup(struct reset_controller_dev *rcdev,
+void reset_controller_add_lookup(const char *provider,
 				 struct reset_control_lookup *lookup,
 				 unsigned int num_entries);
 
-- 
2.16.1

[PATCH v2 2/8] ARM: davinci: dts: make psc0 a reset provider

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

The psc driver registers with the reset framework as a provider. Add
the #reset-cells property to the psc0 node.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 arch/arm/boot/dts/da850.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/boot/dts/da850.dtsi b/arch/arm/boot/dts/da850.dtsi
index a3b9a99b43ca..dad64dbf1f23 100644
--- a/arch/arm/boot/dts/da850.dtsi
+++ b/arch/arm/boot/dts/da850.dtsi
@@ -123,6 +123,7 @@
 			compatible = "ti,da850-psc0";
 			reg = <0x10000 0x1000>;
 			#clock-cells = <1>;
+			#reset-cells = <1>;
 			#power-domain-cells = <1>;
 			clocks = <&pll0_sysclk 1>, <&pll0_sysclk 2>,
 				 <&pll0_sysclk 4>, <&pll0_sysclk 6>,
-- 
2.16.1

[PATCH v2 3/8] ARM: davinci: dts: add a reset control to the dsp node

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

The davinci-rproc driver will soon use the reset framework. Add the
resets property to the dsp node in da850.dtsi.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 arch/arm/boot/dts/da850.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/boot/dts/da850.dtsi b/arch/arm/boot/dts/da850.dtsi
index dad64dbf1f23..5b485e44b83e 100644
--- a/arch/arm/boot/dts/da850.dtsi
+++ b/arch/arm/boot/dts/da850.dtsi
@@ -109,6 +109,7 @@
 		interrupt-parent = <&intc>;
 		interrupts = <28>;
 		clocks = <&psc0 15>;
+		resets = <&psc0 15>;
 		status = "disabled";
 	};
 	soc@1c00000 {
-- 
2.16.1

[PATCH v2 4/8] clk: davinci: add a reset lookup table for psc0

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

In order to be able to use the reset framework in legacy boot mode as
well, add the reset lookup table to the psc driver for da850 variant.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/clk/davinci/psc-da850.c | 8 ++++++++
 drivers/clk/davinci/psc.c       | 1 +
 2 files changed, 9 insertions(+)

diff --git a/drivers/clk/davinci/psc-da850.c b/drivers/clk/davinci/psc-da850.c
index ccc7eb17bf3a..395db4b2c0ee 100644
--- a/drivers/clk/davinci/psc-da850.c
+++ b/drivers/clk/davinci/psc-da850.c
@@ -6,6 +6,7 @@
  */
 
 #include <linux/clk-provider.h>
+#include <linux/reset-controller.h>
 #include <linux/clk.h>
 #include <linux/clkdev.h>
 #include <linux/init.h>
@@ -66,8 +67,15 @@ LPSC_CLKDEV3(ecap_clkdev,	"fck",	"ecap.0",
 				"fck",	"ecap.1",
 				"fck",	"ecap.2");
 
+static struct reset_control_lookup da850_psc0_reset_lookup_table[] = {
+	RESET_LOOKUP("davinci-rproc.0", NULL, 15),
+};
+
 static int da850_psc0_init(struct device *dev, void __iomem *base)
 {
+	reset_controller_add_lookup("da850-psc0",
+				    da850_psc0_reset_lookup_table,
+				    ARRAY_SIZE(da850_psc0_reset_lookup_table));
 	return davinci_psc_register_clocks(dev, da850_psc0_info, 16, base);
 }
 
diff --git a/drivers/clk/davinci/psc.c b/drivers/clk/davinci/psc.c
index 3b0e59dfbdd7..063df62381ea 100644
--- a/drivers/clk/davinci/psc.c
+++ b/drivers/clk/davinci/psc.c
@@ -425,6 +425,7 @@ __davinci_psc_register_clocks(struct device *dev,
 
 	psc->rcdev.ops = &davinci_psc_reset_ops;
 	psc->rcdev.owner = THIS_MODULE;
+	psc->rcdev.dev = dev;
 	psc->rcdev.of_node = dev->of_node;
 	psc->rcdev.of_reset_n_cells = 1;
 	psc->rcdev.of_xlate = davinci_psc_reset_of_xlate;
-- 
2.16.1

[PATCH v2 5/8] remoteproc: da8xx: add the missing retval check for clk_enable()

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

The davinci platform is being switched to using the common clock
framework, where clk_enable() can fail. Add the return value check.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/remoteproc/da8xx_remoteproc.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/remoteproc/da8xx_remoteproc.c b/drivers/remoteproc/da8xx_remoteproc.c
index bf3b9034c319..2b24291337b7 100644
--- a/drivers/remoteproc/da8xx_remoteproc.c
+++ b/drivers/remoteproc/da8xx_remoteproc.c
@@ -138,6 +138,7 @@ static int da8xx_rproc_start(struct rproc *rproc)
 	struct device *dev = rproc->dev.parent;
 	struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
 	struct clk *dsp_clk = drproc->dsp_clk;
+	int ret;
 
 	/* hw requires the start (boot) address be on 1KB boundary */
 	if (rproc->bootaddr & 0x3ff) {
@@ -148,7 +149,12 @@ static int da8xx_rproc_start(struct rproc *rproc)
 
 	writel(rproc->bootaddr, drproc->bootreg);
 
-	clk_enable(dsp_clk);
+	ret = clk_enable(dsp_clk);
+	if (ret) {
+		dev_err(dev, "clk_enable() failed: %d\n", ret);
+		return ret;
+	}
+
 	davinci_clk_reset_deassert(dsp_clk);
 
 	return 0;
-- 
2.16.1

[PATCH v2 6/8] remoteproc: da8xx: prepare and unprepare the clock where needed

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

We're currently switching the platform to using the common clock
framework. We need to explicitly prepare and unprepare the rproc
clock.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/remoteproc/da8xx_remoteproc.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/remoteproc/da8xx_remoteproc.c b/drivers/remoteproc/da8xx_remoteproc.c
index 2b24291337b7..f134192922e0 100644
--- a/drivers/remoteproc/da8xx_remoteproc.c
+++ b/drivers/remoteproc/da8xx_remoteproc.c
@@ -149,9 +149,9 @@ static int da8xx_rproc_start(struct rproc *rproc)
 
 	writel(rproc->bootaddr, drproc->bootreg);
 
-	ret = clk_enable(dsp_clk);
+	ret = clk_prepare_enable(dsp_clk);
 	if (ret) {
-		dev_err(dev, "clk_enable() failed: %d\n", ret);
+		dev_err(dev, "clk_prepare_enable() failed: %d\n", ret);
 		return ret;
 	}
 
@@ -165,7 +165,7 @@ static int da8xx_rproc_stop(struct rproc *rproc)
 	struct da8xx_rproc *drproc = rproc->priv;
 
 	davinci_clk_reset_assert(drproc->dsp_clk);
-	clk_disable(drproc->dsp_clk);
+	clk_disable_unprepare(drproc->dsp_clk);
 
 	return 0;
 }
-- 
2.16.1

[PATCH v2 7/8] remoteproc: da8xx: use the reset framework

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Switch to using the reset framework instead of handcoded reset routines
we used so far.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/remoteproc/da8xx_remoteproc.c | 34 +++++++++++++++++++++++++++++-----
 1 file changed, 29 insertions(+), 5 deletions(-)

diff --git a/drivers/remoteproc/da8xx_remoteproc.c b/drivers/remoteproc/da8xx_remoteproc.c
index f134192922e0..b99c0f0cc38e 100644
--- a/drivers/remoteproc/da8xx_remoteproc.c
+++ b/drivers/remoteproc/da8xx_remoteproc.c
@@ -10,6 +10,7 @@
 
 #include <linux/bitops.h>
 #include <linux/clk.h>
+#include <linux/reset.h>
 #include <linux/err.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
@@ -20,8 +21,6 @@
 #include <linux/platform_device.h>
 #include <linux/remoteproc.h>
 
-#include <mach/clock.h>   /* for davinci_clk_reset_assert/deassert() */
-
 #include "remoteproc_internal.h"
 
 static char *da8xx_fw_name;
@@ -72,6 +71,7 @@ struct da8xx_rproc {
 	struct da8xx_rproc_mem *mem;
 	int num_mems;
 	struct clk *dsp_clk;
+	struct reset_control *dsp_reset;
 	void (*ack_fxn)(struct irq_data *data);
 	struct irq_data *irq_data;
 	void __iomem *chipsig;
@@ -138,6 +138,7 @@ static int da8xx_rproc_start(struct rproc *rproc)
 	struct device *dev = rproc->dev.parent;
 	struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
 	struct clk *dsp_clk = drproc->dsp_clk;
+	struct reset_control *dsp_reset = drproc->dsp_reset;
 	int ret;
 
 	/* hw requires the start (boot) address be on 1KB boundary */
@@ -155,7 +156,11 @@ static int da8xx_rproc_start(struct rproc *rproc)
 		return ret;
 	}
 
-	davinci_clk_reset_deassert(dsp_clk);
+	ret = reset_control_deassert(dsp_reset);
+	if (ret) {
+		dev_err(dev, "reset_control_deassert() failed: %d\n", ret);
+		return ret;
+	}
 
 	return 0;
 }
@@ -163,8 +168,15 @@ static int da8xx_rproc_start(struct rproc *rproc)
 static int da8xx_rproc_stop(struct rproc *rproc)
 {
 	struct da8xx_rproc *drproc = rproc->priv;
+	int ret;
+
+	ret = reset_control_assert(drproc->dsp_reset);
+	if (ret) {
+		dev_err(rproc->dev.parent,
+			"reset_control_assert() failed: %d\n", ret);
+		return ret;
+	}
 
-	davinci_clk_reset_assert(drproc->dsp_clk);
 	clk_disable_unprepare(drproc->dsp_clk);
 
 	return 0;
@@ -232,6 +244,7 @@ static int da8xx_rproc_probe(struct platform_device *pdev)
 	struct resource *bootreg_res;
 	struct resource *chipsig_res;
 	struct clk *dsp_clk;
+	struct reset_control *dsp_reset;
 	void __iomem *chipsig;
 	void __iomem *bootreg;
 	int irq;
@@ -268,6 +281,17 @@ static int da8xx_rproc_probe(struct platform_device *pdev)
 		return PTR_ERR(dsp_clk);
 	}
 
+	dsp_reset = devm_reset_control_get_exclusive(dev, NULL);
+	if (IS_ERR(dsp_reset)) {
+		/* The platform lookup may not be registered yet. */
+		if (PTR_ERR(dsp_reset) == -ENOENT)
+			return -EPROBE_DEFER;
+
+		dev_err(dev, "unable to get reset control: %ld\n",
+			PTR_ERR(dsp_reset));
+		return PTR_ERR(dsp_reset);
+	}
+
 	if (dev->of_node) {
 		ret = of_reserved_mem_device_init(dev);
 		if (ret) {
@@ -309,7 +333,7 @@ static int da8xx_rproc_probe(struct platform_device *pdev)
 	 * *not* in reset, but da8xx_rproc_start() needs the DSP to be
 	 * held in reset at the time it is called.
 	 */
-	ret = davinci_clk_reset_assert(drproc->dsp_clk);
+	ret = reset_control_assert(dsp_reset);
 	if (ret)
 		goto free_rproc;
 
-- 
2.16.1

[PATCH v2 8/8] clk: davinci: kill davinci_clk_reset_assert/deassert()

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

This code is no longer used. Remove it.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: David Lechner <david@lechnology.com>
---
 arch/arm/mach-davinci/include/mach/clock.h | 21 ---------------------
 drivers/clk/davinci/psc.c                  | 18 ------------------
 2 files changed, 39 deletions(-)
 delete mode 100644 arch/arm/mach-davinci/include/mach/clock.h

diff --git a/arch/arm/mach-davinci/include/mach/clock.h b/arch/arm/mach-davinci/include/mach/clock.h
deleted file mode 100644
index 42ed4f2f5ce4..000000000000
--- a/arch/arm/mach-davinci/include/mach/clock.h
+++ /dev/null
@@ -1,21 +0,0 @@
-/*
- * arch/arm/mach-davinci/include/mach/clock.h
- *
- * Clock control driver for DaVinci - header file
- *
- * Authors: Vladimir Barinov <source@mvista.com>
- *
- * 2007 (c) MontaVista Software, Inc. This file is licensed under
- * the terms of the GNU General Public License version 2. This program
- * is licensed "as is" without any warranty of any kind, whether express
- * or implied.
- */
-#ifndef __ASM_ARCH_DAVINCI_CLOCK_H
-#define __ASM_ARCH_DAVINCI_CLOCK_H
-
-struct clk;
-
-int davinci_clk_reset_assert(struct clk *c);
-int davinci_clk_reset_deassert(struct clk *c);
-
-#endif
diff --git a/drivers/clk/davinci/psc.c b/drivers/clk/davinci/psc.c
index 063df62381ea..75c4bc6f23e3 100644
--- a/drivers/clk/davinci/psc.c
+++ b/drivers/clk/davinci/psc.c
@@ -295,24 +295,6 @@ static int davinci_lpsc_clk_reset(struct clk *clk, bool reset)
 	return 0;
 }
 
-/*
- * REVISIT: These exported functions can be removed after a non-DT lookup is
- * added to the reset controller framework and the davinci-rproc driver is
- * updated to use the generic reset controller framework.
- */
-
-int davinci_clk_reset_assert(struct clk *clk)
-{
-	return davinci_lpsc_clk_reset(clk, true);
-}
-EXPORT_SYMBOL(davinci_clk_reset_assert);
-
-int davinci_clk_reset_deassert(struct clk *clk)
-{
-	return davinci_lpsc_clk_reset(clk, false);
-}
-EXPORT_SYMBOL(davinci_clk_reset_deassert);
-
 static int davinci_psc_reset_assert(struct reset_controller_dev *rcdev,
 				    unsigned long id)
 {
-- 
2.16.1

Re: [PATCH v2 1/8] reset: modify the way reset lookup works for board files

[Philipp Zabel]

Hi Bartosz,

On Fri, 2018-03-23 at 10:36 +0100, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> 
> Commit 7af1bb19f1d7 ("reset: add support for non-DT systems")
> introduced reset control lookup mechanism for boards that still use
> board files.
> 
> The routine used to register lookup entries takes the corresponding
> reset_controlled_dev structure as argument.
> 
> It's been determined however that for the first user of this new
> interface - davinci psc driver - it will be easier to register the
> lookup entries using the reset controller device name.

Thank you, this is what I expected in the first place.

> This patch changes the way lookup entries are added.
> 
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> ---
>  drivers/reset/core.c             | 33 +++++++++++++++++++++++++++++----
>  include/linux/reset-controller.h |  8 +++++---
>  2 files changed, 34 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/reset/core.c b/drivers/reset/core.c
> index 06fa4907afc4..f37048e55336 100644
> --- a/drivers/reset/core.c
> +++ b/drivers/reset/core.c
> @@ -153,11 +153,11 @@ EXPORT_SYMBOL_GPL(devm_reset_controller_register);
>  
>  /**
>   * reset_controller_add_lookup - register a set of lookup entries
> - * @rcdev: initialized reset controller device owning the reset line
> + * @provider: name of the reset controller provider
>   * @lookup: array of reset lookup entries
>   * @num_entries: number of entries in the lookup array
>   */
> -void reset_controller_add_lookup(struct reset_controller_dev *rcdev,
> +void reset_controller_add_lookup(const char *provider,

Is there any reason not to drop the provider parameter completely?
I'd just let the user add the provider device id to the lookup, see
below.

>  				 struct reset_control_lookup *lookup,
>  				 unsigned int num_entries)
>  {
> @@ -174,7 +174,7 @@ void reset_controller_add_lookup(struct reset_controller_dev *rcdev,
>  			continue;
>  		}
>  
> -		entry->rcdev = rcdev;
> +		entry->provider = provider;
>  		list_add_tail(&entry->list, &reset_lookup_list);
>  	}
>  	mutex_unlock(&reset_lookup_mutex);
> @@ -526,11 +526,30 @@ struct reset_control *__of_reset_control_get(struct device_node *node,
>  }
>  EXPORT_SYMBOL_GPL(__of_reset_control_get);
>  
> +static struct reset_controller_dev *
> +__reset_controller_by_name(const char *name)
> +{
> +	struct reset_controller_dev *rcdev;
> +
> +	lockdep_assert_held(&reset_list_mutex);
> +
> +	list_for_each_entry(rcdev, &reset_controller_list, list) {
> +		if (!rcdev->dev)
> +			continue;
> +
> +		if (!strcmp(name, dev_name(rcdev->dev)))
> +			return rcdev;
> +	}
> +
> +	return NULL;
> +}
> +
>  static struct reset_control *
>  __reset_control_get_from_lookup(struct device *dev, const char *con_id,
>  				bool shared, bool optional)
>  {
>  	const struct reset_control_lookup *lookup;
> +	struct reset_controller_dev *rcdev;
>  	const char *dev_id = dev_name(dev);
>  	struct reset_control *rstc = NULL;
>  
> @@ -547,7 +566,13 @@ __reset_control_get_from_lookup(struct device *dev, const char *con_id,
>  		    ((con_id && lookup->con_id) &&
>  		     !strcmp(con_id, lookup->con_id))) {
>  			mutex_lock(&reset_list_mutex);
> -			rstc = __reset_control_get_internal(lookup->rcdev,
> +			rcdev = __reset_controller_by_name(lookup->provider);
> +			if (!rcdev) {
> +				mutex_unlock(&reset_list_mutex);
> +				continue;

What is the reason to continue here? If we've found a matching lookup
that contains a rcdev dev_id for which there is no reset controller,
shouldn't we just return an error?

> +			}
> +
> +			rstc = __reset_control_get_internal(rcdev,
>  							    lookup->index,
>  							    shared);
>  			mutex_unlock(&reset_list_mutex);
> diff --git a/include/linux/reset-controller.h b/include/linux/reset-controller.h
> index 25698f6c1fae..1a6c25d825d3 100644
> --- a/include/linux/reset-controller.h
> +++ b/include/linux/reset-controller.h
> @@ -30,14 +30,14 @@ struct of_phandle_args;
>   * struct reset_control_lookup - represents a single lookup entry
>   *
>   * @list: internal list of all reset lookup entries
> - * @rcdev: reset controller device controlling this reset line
> + * @provider: name of the reset controller device controlling this reset line
>   * @index: ID of the reset controller in the reset controller device
>   * @dev_id: name of the device associated with this reset line
>   * @con_id name of the reset line (can be NULL)
>   */
>  struct reset_control_lookup {
>  	struct list_head list;
> -	struct reset_controller_dev *rcdev;
> +	const char *provider;

Looks good to me, but I'd also extend RESET_LOOKUP to set the provider
instead of passing it to the reset_controller_add_lookup function,
similarly to PWM_LOOKUP:

#define RESET_LOOKUP(_provider, _index, _dev_id, _con_id)

>  	unsigned int index;
>  	const char *dev_id;
>  	const char *con_id;
> @@ -57,6 +57,7 @@ struct reset_control_lookup {
>   * @owner: kernel module of the reset controller driver
>   * @list: internal list of reset controller devices
>   * @reset_control_head: head of internal list of requested reset controls
> + * @dev: corresponding driver model device struct
>   * @of_node: corresponding device tree node as phandle target
>   * @of_reset_n_cells: number of cells in reset line specifiers
>   * @of_xlate: translation function to translate from specifier as found in the
> @@ -68,6 +69,7 @@ struct reset_controller_dev {
>  	struct module *owner;
>  	struct list_head list;
>  	struct list_head reset_control_head;
> +	struct device *dev;
>  	struct device_node *of_node;
>  	int of_reset_n_cells;
>  	int (*of_xlate)(struct reset_controller_dev *rcdev,
> @@ -82,7 +84,7 @@ struct device;
>  int devm_reset_controller_register(struct device *dev,
>  				   struct reset_controller_dev *rcdev);
>  
> -void reset_controller_add_lookup(struct reset_controller_dev *rcdev,
> +void reset_controller_add_lookup(const char *provider,
>  				 struct reset_control_lookup *lookup,
>  				 unsigned int num_entries);
>  

regards
Philipp

Re: [PATCH v2 1/8] reset: modify the way reset lookup works for board files

[Bartosz Golaszewski]

2018-03-23 11:24 GMT+01:00 Philipp Zabel <p.zabel@pengutronix.de>:
> Hi Bartosz,
>
> On Fri, 2018-03-23 at 10:36 +0100, Bartosz Golaszewski wrote:
>> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>>
>> Commit 7af1bb19f1d7 ("reset: add support for non-DT systems")
>> introduced reset control lookup mechanism for boards that still use
>> board files.
>>
>> The routine used to register lookup entries takes the corresponding
>> reset_controlled_dev structure as argument.
>>
>> It's been determined however that for the first user of this new
>> interface - davinci psc driver - it will be easier to register the
>> lookup entries using the reset controller device name.
>
> Thank you, this is what I expected in the first place.
>
>> This patch changes the way lookup entries are added.
>>
>> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>> ---
>>  drivers/reset/core.c             | 33 +++++++++++++++++++++++++++++----
>>  include/linux/reset-controller.h |  8 +++++---
>>  2 files changed, 34 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/reset/core.c b/drivers/reset/core.c
>> index 06fa4907afc4..f37048e55336 100644
>> --- a/drivers/reset/core.c
>> +++ b/drivers/reset/core.c
>> @@ -153,11 +153,11 @@ EXPORT_SYMBOL_GPL(devm_reset_controller_register);
>>
>>  /**
>>   * reset_controller_add_lookup - register a set of lookup entries
>> - * @rcdev: initialized reset controller device owning the reset line
>> + * @provider: name of the reset controller provider
>>   * @lookup: array of reset lookup entries
>>   * @num_entries: number of entries in the lookup array
>>   */
>> -void reset_controller_add_lookup(struct reset_controller_dev *rcdev,
>> +void reset_controller_add_lookup(const char *provider,
>
> Is there any reason not to drop the provider parameter completely?
> I'd just let the user add the provider device id to the lookup, see
> below.
>
>>                                struct reset_control_lookup *lookup,
>>                                unsigned int num_entries)
>>  {
>> @@ -174,7 +174,7 @@ void reset_controller_add_lookup(struct reset_controller_dev *rcdev,
>>                       continue;
>>               }
>>
>> -             entry->rcdev = rcdev;
>> +             entry->provider = provider;
>>               list_add_tail(&entry->list, &reset_lookup_list);
>>       }
>>       mutex_unlock(&reset_lookup_mutex);
>> @@ -526,11 +526,30 @@ struct reset_control *__of_reset_control_get(struct device_node *node,
>>  }
>>  EXPORT_SYMBOL_GPL(__of_reset_control_get);
>>
>> +static struct reset_controller_dev *
>> +__reset_controller_by_name(const char *name)
>> +{
>> +     struct reset_controller_dev *rcdev;
>> +
>> +     lockdep_assert_held(&reset_list_mutex);
>> +
>> +     list_for_each_entry(rcdev, &reset_controller_list, list) {
>> +             if (!rcdev->dev)
>> +                     continue;
>> +
>> +             if (!strcmp(name, dev_name(rcdev->dev)))
>> +                     return rcdev;
>> +     }
>> +
>> +     return NULL;
>> +}
>> +
>>  static struct reset_control *
>>  __reset_control_get_from_lookup(struct device *dev, const char *con_id,
>>                               bool shared, bool optional)
>>  {
>>       const struct reset_control_lookup *lookup;
>> +     struct reset_controller_dev *rcdev;
>>       const char *dev_id = dev_name(dev);
>>       struct reset_control *rstc = NULL;
>>
>> @@ -547,7 +566,13 @@ __reset_control_get_from_lookup(struct device *dev, const char *con_id,
>>                   ((con_id && lookup->con_id) &&
>>                    !strcmp(con_id, lookup->con_id))) {
>>                       mutex_lock(&reset_list_mutex);
>> -                     rstc = __reset_control_get_internal(lookup->rcdev,
>> +                     rcdev = __reset_controller_by_name(lookup->provider);
>> +                     if (!rcdev) {
>> +                             mutex_unlock(&reset_list_mutex);
>> +                             continue;
>
> What is the reason to continue here? If we've found a matching lookup
> that contains a rcdev dev_id for which there is no reset controller,
> shouldn't we just return an error?
>

Indeed. This could be used to indicate to drivers that the reset
controller may not have yet been probed() or its probe() failed. How
about returning -EPROBE_DEFER here?

Bart

>> +                     }
>> +
>> +                     rstc = __reset_control_get_internal(rcdev,
>>                                                           lookup->index,
>>                                                           shared);
>>                       mutex_unlock(&reset_list_mutex);
>> diff --git a/include/linux/reset-controller.h b/include/linux/reset-controller.h
>> index 25698f6c1fae..1a6c25d825d3 100644
>> --- a/include/linux/reset-controller.h
>> +++ b/include/linux/reset-controller.h
>> @@ -30,14 +30,14 @@ struct of_phandle_args;
>>   * struct reset_control_lookup - represents a single lookup entry
>>   *
>>   * @list: internal list of all reset lookup entries
>> - * @rcdev: reset controller device controlling this reset line
>> + * @provider: name of the reset controller device controlling this reset line
>>   * @index: ID of the reset controller in the reset controller device
>>   * @dev_id: name of the device associated with this reset line
>>   * @con_id name of the reset line (can be NULL)
>>   */
>>  struct reset_control_lookup {
>>       struct list_head list;
>> -     struct reset_controller_dev *rcdev;
>> +     const char *provider;
>
> Looks good to me, but I'd also extend RESET_LOOKUP to set the provider
> instead of passing it to the reset_controller_add_lookup function,
> similarly to PWM_LOOKUP:
>
> #define RESET_LOOKUP(_provider, _index, _dev_id, _con_id)
>

I did it mostly for brevity - I don't mind changing it if you prefer
this version.

Thanks,
Bart

Re: [PATCH v2 1/8] reset: modify the way reset lookup works for board files

[Philipp Zabel]

On Fri, 2018-03-23 at 11:46 +0100, Bartosz Golaszewski wrote:
> 2018-03-23 11:24 GMT+01:00 Philipp Zabel <p.zabel@pengutronix.de>:
> > Hi Bartosz,
> > 
> > On Fri, 2018-03-23 at 10:36 +0100, Bartosz Golaszewski wrote:
> > > From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> > > 
> > > Commit 7af1bb19f1d7 ("reset: add support for non-DT systems")
> > > introduced reset control lookup mechanism for boards that still use
> > > board files.
> > > 
> > > The routine used to register lookup entries takes the corresponding
> > > reset_controlled_dev structure as argument.
> > > 
> > > It's been determined however that for the first user of this new
> > > interface - davinci psc driver - it will be easier to register the
> > > lookup entries using the reset controller device name.
> > 
> > Thank you, this is what I expected in the first place.
> > 
> > > This patch changes the way lookup entries are added.
> > > 
> > > Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> > > ---
> > >  drivers/reset/core.c             | 33 +++++++++++++++++++++++++++++----
> > >  include/linux/reset-controller.h |  8 +++++---
> > >  2 files changed, 34 insertions(+), 7 deletions(-)
> > > 
> > > diff --git a/drivers/reset/core.c b/drivers/reset/core.c
> > > index 06fa4907afc4..f37048e55336 100644
> > > --- a/drivers/reset/core.c
> > > +++ b/drivers/reset/core.c
> > > @@ -153,11 +153,11 @@ EXPORT_SYMBOL_GPL(devm_reset_controller_register);
> > > 
> > >  /**
> > >   * reset_controller_add_lookup - register a set of lookup entries
> > > - * @rcdev: initialized reset controller device owning the reset line
> > > + * @provider: name of the reset controller provider
> > >   * @lookup: array of reset lookup entries
> > >   * @num_entries: number of entries in the lookup array
> > >   */
> > > -void reset_controller_add_lookup(struct reset_controller_dev *rcdev,
> > > +void reset_controller_add_lookup(const char *provider,
> > 
> > Is there any reason not to drop the provider parameter completely?
> > I'd just let the user add the provider device id to the lookup, see
> > below.
> > 
> > >                                struct reset_control_lookup *lookup,
> > >                                unsigned int num_entries)
> > >  {
> > > @@ -174,7 +174,7 @@ void reset_controller_add_lookup(struct reset_controller_dev *rcdev,
> > >                       continue;
> > >               }
> > > 
> > > -             entry->rcdev = rcdev;
> > > +             entry->provider = provider;
> > >               list_add_tail(&entry->list, &reset_lookup_list);
> > >       }
> > >       mutex_unlock(&reset_lookup_mutex);
> > > @@ -526,11 +526,30 @@ struct reset_control *__of_reset_control_get(struct device_node *node,
> > >  }
> > >  EXPORT_SYMBOL_GPL(__of_reset_control_get);
> > > 
> > > +static struct reset_controller_dev *
> > > +__reset_controller_by_name(const char *name)
> > > +{
> > > +     struct reset_controller_dev *rcdev;
> > > +
> > > +     lockdep_assert_held(&reset_list_mutex);
> > > +
> > > +     list_for_each_entry(rcdev, &reset_controller_list, list) {
> > > +             if (!rcdev->dev)
> > > +                     continue;
> > > +
> > > +             if (!strcmp(name, dev_name(rcdev->dev)))
> > > +                     return rcdev;
> > > +     }
> > > +
> > > +     return NULL;
> > > +}
> > > +
> > >  static struct reset_control *
> > >  __reset_control_get_from_lookup(struct device *dev, const char *con_id,
> > >                               bool shared, bool optional)
> > >  {
> > >       const struct reset_control_lookup *lookup;
> > > +     struct reset_controller_dev *rcdev;
> > >       const char *dev_id = dev_name(dev);
> > >       struct reset_control *rstc = NULL;
> > > 
> > > @@ -547,7 +566,13 @@ __reset_control_get_from_lookup(struct device *dev, const char *con_id,
> > >                   ((con_id && lookup->con_id) &&
> > >                    !strcmp(con_id, lookup->con_id))) {
> > >                       mutex_lock(&reset_list_mutex);
> > > -                     rstc = __reset_control_get_internal(lookup->rcdev,
> > > +                     rcdev = __reset_controller_by_name(lookup->provider);
> > > +                     if (!rcdev) {
> > > +                             mutex_unlock(&reset_list_mutex);
> > > +                             continue;
> > 
> > What is the reason to continue here? If we've found a matching lookup
> > that contains a rcdev dev_id for which there is no reset controller,
> > shouldn't we just return an error?
> > 
> 
> Indeed. This could be used to indicate to drivers that the reset
> controller may not have yet been probed() or its probe() failed. How
> about returning -EPROBE_DEFER here?

That is a good point. The framework doesn't know whether the
lookup->provider is bogus or whether it's correct and the corresponding
driver just hasn't registered its reset controller yet. So we have to
assume the latter and return -EPROBE_DEFER here.

> Bart
> 
> > > +                     }
> > > +
> > > +                     rstc = __reset_control_get_internal(rcdev,
> > >                                                           lookup->index,
> > >                                                           shared);
> > >                       mutex_unlock(&reset_list_mutex);
> > > diff --git a/include/linux/reset-controller.h b/include/linux/reset-controller.h
> > > index 25698f6c1fae..1a6c25d825d3 100644
> > > --- a/include/linux/reset-controller.h
> > > +++ b/include/linux/reset-controller.h
> > > @@ -30,14 +30,14 @@ struct of_phandle_args;
> > >   * struct reset_control_lookup - represents a single lookup entry
> > >   *
> > >   * @list: internal list of all reset lookup entries
> > > - * @rcdev: reset controller device controlling this reset line
> > > + * @provider: name of the reset controller device controlling this reset line
> > >   * @index: ID of the reset controller in the reset controller device
> > >   * @dev_id: name of the device associated with this reset line
> > >   * @con_id name of the reset line (can be NULL)
> > >   */
> > >  struct reset_control_lookup {
> > >       struct list_head list;
> > > -     struct reset_controller_dev *rcdev;
> > > +     const char *provider;
> > 
> > Looks good to me, but I'd also extend RESET_LOOKUP to set the provider
> > instead of passing it to the reset_controller_add_lookup function,
> > similarly to PWM_LOOKUP:
> > 
> > #define RESET_LOOKUP(_provider, _index, _dev_id, _con_id)
> > 
> 
> I did it mostly for brevity - I don't mind changing it if you prefer
> this version.

Yes, please. I like the consistency, and seeing provider and index right
next to each other will make the lookups easier to read and understand.

regards
Philipp