[PATCH V2 0/3] Change gpio_regulator_probe() to use managed resources.

[PATCH V2 0/3] Change gpio_regulator_probe() to use managed resources.

[Rob Jones]

Extend the use of managed resource functions in regulator by replacing
all calls to unmanaged resource allocation functions in
gpio_regulator_probe() with their managed equivalent.

Add a new function, devm_kmemdup(), to drivers/base/devres.c to support this.

Rob Jones (3):
  base: Add block copy func. for managed devices
  gpio: allow gpio array requests for managed devices
  regulator: use managed resources for gpio_regulator_probe().

 drivers/base/devres.c              |   25 +++++++++++++
 drivers/gpio/devres.c              |   63 ++++++++++++++++++++++++++++++++
 drivers/regulator/gpio-regulator.c |   70 ++++++++++++------------------------
 include/linux/device.h             |    2 ++
 include/linux/gpio.h               |    4 +++
 5 files changed, 117 insertions(+), 47 deletions(-)

-- 
1.7.10.4

Incorporates requested changes.

Note that this patch series no longer includes a change to devm_kstrdup()
as this was not essential to the primary aim of the series. This will be
submitted later once devm_kmemdup() has been accepted.

[PATCH V2 1/3] base: Add block copy func. for managed devices

[Rob Jones]

Add function devm_kmemdup() which is exactly analogous to the
non-managed device function kmemdup().

Reviewed-by: Ian Molton <ian.molton@codethink.co.uk>
Signed-off-by: Rob Jones <rob.jones@codethink.co.uk>
---
 drivers/base/devres.c  |   25 +++++++++++++++++++++++++
 include/linux/device.h |    2 ++
 2 files changed, 27 insertions(+)

diff --git a/drivers/base/devres.c b/drivers/base/devres.c
index db4e264..77a6ce7 100644
--- a/drivers/base/devres.c
+++ b/drivers/base/devres.c
@@ -817,6 +817,31 @@ char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp)
 EXPORT_SYMBOL_GPL(devm_kstrdup);
 
 /**
+ * devm_kmemdup - Allocate resource managed space and
+ *                copy existing data into that.
+ * @dev:	Device to allocate memory for
+ * @s:		The memory block to duplicate
+ * @gfp:	The GFP mask used in the devm_kmalloc() call when
+ *		allocating memory
+ * RETURNS:
+ * Pointer to allocated string on success, NULL on failure.
+ */
+void *devm_kmemdup(struct device *dev, const void *s, size_t size, gfp_t gfp)
+{
+	void *buf;
+
+	if (!s || (size == 0))
+		return NULL;
+
+	buf = devm_kmalloc(dev, size, gfp);
+	if (buf)
+		memcpy(buf, s, size);
+
+	return buf;
+}
+EXPORT_SYMBOL_GPL(devm_kmemdup);
+
+/**
  * devm_kfree - Resource-managed kfree
  * @dev: Device this memory belongs to
  * @p: Memory to free
diff --git a/include/linux/device.h b/include/linux/device.h
index d1d1c05..7ace116 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -623,6 +623,8 @@ static inline void *devm_kcalloc(struct device *dev,
 }
 extern void devm_kfree(struct device *dev, void *p);
 extern char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp);
+extern void *devm_kmemdup(struct device *dev,
+			  const void *s, size_t size, gfp_t gfp);
 
 void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res);
 void __iomem *devm_request_and_ioremap(struct device *dev,
-- 
1.7.10.4

[PATCH V2 2/3] gpio: allow gpio array requests for managed devices

[Rob Jones]

Add functions devm_gpio_request_array() and devm_gpio_free_array()
which are exactly analogous to the equivalent non-managed device
functions gpio_request_array() and gpio_free_array(), which can be
found in the module gpiolib.c.

Reviewed-by: Ian Molton <ian.molton@codethink.co.uk>
Signed-off-by: Rob Jones <rob.jones@codethink.co.uk>
---
 drivers/gpio/devres.c |   63 +++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/gpio.h  |    4 ++++
 2 files changed, 67 insertions(+)

diff --git a/drivers/gpio/devres.c b/drivers/gpio/devres.c
index 307464f..b97c34b 100644
--- a/drivers/gpio/devres.c
+++ b/drivers/gpio/devres.c
@@ -186,6 +186,69 @@ int devm_gpio_request_one(struct device *dev, unsigned gpio,
 EXPORT_SYMBOL(devm_gpio_request_one);
 
 /**
+ * devm_gpio_request_array - request multiple GPIOs in a single call
+ *			     for a managed device
+ * @dev:	device requesting the gpio
+ * @array:	array of the 'struct gpio'
+ * @num:	how many GPIOs in the array
+ *
+ * Except for the extra @dev argument, this function takes the
+ * same arguments and performs the same function as
+ * gpio_request().  GPIOs requested with this function will be
+ * automatically freed on driver detach.
+ *
+ * Note that if any gpio request returns an error, any gpios previously
+ * obtained are immediately freed and the error code is returned,
+ * meaning that the whole call failed and no gpios are obtained, no
+ * indication is provided as to which particular request failed.
+ *
+ * If GPIOs allocated with this function need to be freed separately,
+ * devm_gpio_free_array() or devm_gpio_free() must be used.
+ */
+int devm_gpio_request_array(struct device *dev,
+			    const struct gpio *array,
+			    size_t num)
+{
+	int i, err = 0;
+
+	for (i = 0; i < num; i++, array++) {
+		err = devm_gpio_request_one(dev,
+					    array->gpio,
+					    array->flags,
+					    array->label);
+		if (err) {
+			while (i--)
+				devm_gpio_free(dev, (--array)->gpio);
+			break;
+		}
+	}
+
+	return err;
+}
+EXPORT_SYMBOL(devm_gpio_request_array);
+
+/**
+ * devm_gpio_free_array - release multiple GPIOs in a single call
+ *			  for a managed device
+ * @dev:	device requesting the gpio
+ * @array:	array of the 'struct gpio'
+ * @num:	how many GPIOs in the array
+ *
+ * Except for the extra @dev argument, this function takes the
+ * same arguments and performs the same function as gpio_free_array().
+ * This function instead of gpio_free_array() should be used to
+ * manually free GPIOs allocated with devm_gpio_request().
+ */
+void devm_gpio_free_array(struct device *dev,
+			  const struct gpio *array,
+			  size_t num)
+{
+	while (num--)
+		devm_gpio_free(dev, (array++)->gpio);
+}
+EXPORT_SYMBOL(devm_gpio_free_array);
+
+/**
  *      devm_gpio_free - free a GPIO
  *      @dev: device to free GPIO for
  *      @gpio: GPIO to free
diff --git a/include/linux/gpio.h b/include/linux/gpio.h
index 85aa5d0..12d5648 100644
--- a/include/linux/gpio.h
+++ b/include/linux/gpio.h
@@ -84,6 +84,10 @@ struct device;
 int devm_gpio_request(struct device *dev, unsigned gpio, const char *label);
 int devm_gpio_request_one(struct device *dev, unsigned gpio,
 			  unsigned long flags, const char *label);
+int devm_gpio_request_array(struct device *dev, const struct gpio *array,
+			    size_t num);
+void devm_gpio_free_array(struct device *dev, const struct gpio *array,
+			 size_t num);
 void devm_gpio_free(struct device *dev, unsigned int gpio);
 
 #else /* ! CONFIG_GPIOLIB */
-- 
1.7.10.4

Re: [PATCH V2 2/3] gpio: allow gpio array requests for managed devices

[Linus Walleij]

On Wed, Jul 2, 2014 at 12:05 PM, Rob Jones <rob.jones@codethink.co.uk> wrote:

> Add functions devm_gpio_request_array() and devm_gpio_free_array()
> which are exactly analogous to the equivalent non-managed device
> functions gpio_request_array() and gpio_free_array(), which can be
> found in the module gpiolib.c.
>
> Reviewed-by: Ian Molton <ian.molton@codethink.co.uk>
> Signed-off-by: Rob Jones <rob.jones@codethink.co.uk>

OK I guess this needs to be merged through the regulator tree
so here is:
Acked-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij

[PATCH V2 3/3] regulator: use managed resources for gpio_regulator_probe().

[Rob Jones]

Use managed resource functions for all resource allocations in
gpio_regulator_probe().

Remove gpio_regulator_remove() as it is now redundant.

Reviewed-by: Ian Molton <ian.molton@codethink.co.uk>
Signed-off-by: Rob Jones <rob.jones@codethink.co.uk>
---
 drivers/regulator/gpio-regulator.c |   70 ++++++++++++------------------------
 1 file changed, 23 insertions(+), 47 deletions(-)

diff --git a/drivers/regulator/gpio-regulator.c b/drivers/regulator/gpio-regulator.c
index 989b23b..6edde12 100644
--- a/drivers/regulator/gpio-regulator.c
+++ b/drivers/regulator/gpio-regulator.c
@@ -254,30 +254,31 @@ static int gpio_regulator_probe(struct platform_device *pdev)
 	if (drvdata == NULL)
 		return -ENOMEM;
 
-	drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
+	drvdata->desc.name = devm_kstrdup(&pdev->dev,
+					  config->supply_name,
+					  GFP_KERNEL);
 	if (drvdata->desc.name == NULL) {
 		dev_err(&pdev->dev, "Failed to allocate supply name\n");
-		ret = -ENOMEM;
-		goto err;
+		return -ENOMEM;
 	}
 
-	drvdata->gpios = kmemdup(config->gpios,
-				 config->nr_gpios * sizeof(struct gpio),
-				 GFP_KERNEL);
+	drvdata->gpios = devm_kmemdup(&pdev->dev,
+				      config->gpios,
+				      config->nr_gpios * sizeof(struct gpio),
+				      GFP_KERNEL);
 	if (drvdata->gpios == NULL) {
 		dev_err(&pdev->dev, "Failed to allocate gpio data\n");
-		ret = -ENOMEM;
-		goto err_name;
+		return -ENOMEM;
 	}
 
-	drvdata->states = kmemdup(config->states,
-				  config->nr_states *
+	drvdata->states = devm_kmemdup(&pdev->dev,
+				       config->states,
+				       config->nr_states *
 					 sizeof(struct gpio_regulator_state),
-				  GFP_KERNEL);
+				       GFP_KERNEL);
 	if (drvdata->states == NULL) {
 		dev_err(&pdev->dev, "Failed to allocate state data\n");
-		ret = -ENOMEM;
-		goto err_memgpio;
+		return -ENOMEM;
 	}
 	drvdata->nr_states = config->nr_states;
 
@@ -297,16 +298,17 @@ static int gpio_regulator_probe(struct platform_device *pdev)
 		break;
 	default:
 		dev_err(&pdev->dev, "No regulator type set\n");
-		ret = -EINVAL;
-		goto err_memgpio;
+		return -EINVAL;
 	}
 
 	drvdata->nr_gpios = config->nr_gpios;
-	ret = gpio_request_array(drvdata->gpios, drvdata->nr_gpios);
+	ret = devm_gpio_request_array(&pdev->dev,
+				      drvdata->gpios,
+				      drvdata->nr_gpios);
 	if (ret) {
 		dev_err(&pdev->dev,
 		   "Could not obtain regulator setting GPIOs: %d\n", ret);
-		goto err_memstate;
+		return ret;
 	}
 
 	/* build initial state from gpio init data. */
@@ -337,43 +339,18 @@ static int gpio_regulator_probe(struct platform_device *pdev)
 			cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
 	}
 
-	drvdata->dev = regulator_register(&drvdata->desc, &cfg);
+	drvdata->dev = devm_regulator_register(&pdev->dev,
+					       &drvdata->desc,
+					       &cfg);
 	if (IS_ERR(drvdata->dev)) {
 		ret = PTR_ERR(drvdata->dev);
 		dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
-		goto err_stategpio;
+		return ret;
 	}
 
 	platform_set_drvdata(pdev, drvdata);
 
 	return 0;
-
-err_stategpio:
-	gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
-err_memstate:
-	kfree(drvdata->states);
-err_memgpio:
-	kfree(drvdata->gpios);
-err_name:
-	kfree(drvdata->desc.name);
-err:
-	return ret;
-}
-
-static int gpio_regulator_remove(struct platform_device *pdev)
-{
-	struct gpio_regulator_data *drvdata = platform_get_drvdata(pdev);
-
-	regulator_unregister(drvdata->dev);
-
-	gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
-
-	kfree(drvdata->states);
-	kfree(drvdata->gpios);
-
-	kfree(drvdata->desc.name);
-
-	return 0;
 }
 
 #if defined(CONFIG_OF)
@@ -385,7 +362,6 @@ static const struct of_device_id regulator_gpio_of_match[] = {
 
 static struct platform_driver gpio_regulator_driver = {
 	.probe		= gpio_regulator_probe,
-	.remove		= gpio_regulator_remove,
 	.driver		= {
 		.name		= "gpio-regulator",
 		.owner		= THIS_MODULE,
-- 
1.7.10.4