diff mbox

[1/5] gpio: Add the devm_get_index_gpiod_from_child() helper

Message ID 1485534846-28111-2-git-send-email-boris.brezillon@free-electrons.com (mailing list archive)
State Not Applicable
Headers show

Commit Message

Boris BREZILLON Jan. 27, 2017, 4:34 p.m. UTC
devm_get_gpiod_from_child() currently allows GPIO users to request a GPIO
that is defined in a child fwnode instead of directly in the device
fwnode. Extend this API by adding the devm_get_index_gpiod_from_child()
helpers which does the same except you can also specify an index in case
the 'xx-gpios' property describe several GPIOs.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
I've added a new function instead of modifying the existing
devm_get_gpiod_from_child() helper to avoid patching all users of this
function.
Note that fwnode_get_named_gpiod() has been modified because there's no
external users.
---
 drivers/gpio/devres.c         | 30 +++++++++++++++++++++++++-----
 drivers/gpio/gpiolib.c        |  9 +++++----
 include/linux/gpio/consumer.h | 15 +++++++++++++--
 3 files changed, 43 insertions(+), 11 deletions(-)

Comments

Linus Walleij Jan. 30, 2017, 9:49 a.m. UTC | #1
On Fri, Jan 27, 2017 at 5:34 PM, Boris Brezillon
<boris.brezillon@free-electrons.com> wrote:

> devm_get_gpiod_from_child() currently allows GPIO users to request a GPIO
> that is defined in a child fwnode instead of directly in the device
> fwnode. Extend this API by adding the devm_get_index_gpiod_from_child()
> helpers which does the same except you can also specify an index in case
> the 'xx-gpios' property describe several GPIOs.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

Cc Russell who faced this problem in the mvebu PCI driver (IIRC).

(...)

> +struct gpio_desc *devm_get_index_gpiod_from_child(struct device *dev,
> +                                                 const char *con_id,
> +                                                 int index,
> +                                                 struct fwnode_handle *child)
>  {
>         static const char * const suffixes[] = { "gpios", "gpio" };
>         char prop_name[32]; /* 32 is max size of property name */
> @@ -154,7 +157,7 @@ struct gpio_desc *devm_get_gpiod_from_child(struct device *dev,
>                         snprintf(prop_name, sizeof(prop_name), "%s",
>                                                                suffixes[i]);
>
> -               desc = fwnode_get_named_gpiod(child, prop_name);
> +               desc = fwnode_get_named_gpiod(child, prop_name, index);
>                 if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
>                         break;
>         }
> @@ -168,6 +171,23 @@ struct gpio_desc *devm_get_gpiod_from_child(struct device *dev,
>
>         return desc;
>  }
> +EXPORT_SYMBOL(devm_get_index_gpiod_from_child);

Rename this devm_fwnode_get_index_gpiod_from_child()
so that it fits the namespace of the other fwnode functions.

> + * devm_get_gpiod_from_child - get a GPIO descriptor from a device's child node
> + * @dev:       GPIO consumer
> + * @con_id:    function within the GPIO consumer
> + * @child:     firmware node (child of @dev)
> + *
> + * GPIO descriptors returned from this function are automatically disposed on
> + * driver detach.
> + */
> +struct gpio_desc *devm_get_gpiod_from_child(struct device *dev,
> +                                           const char *con_id,
> +                                           struct fwnode_handle *child)
> +{
> +       return devm_get_index_gpiod_from_child(dev, con_id, 0, child);
> +}

Take the opportunity to rename this devm_fwnode_get_gpiod_from_child()
as well.

I don't remember exactly why this wasn't added earlier, there was some
problem with referencing nodes that do not have devices.

Yours,
Linus Walleij
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Boris BREZILLON Jan. 30, 2017, 10:19 a.m. UTC | #2
Hi Linus,

On Mon, 30 Jan 2017 10:49:23 +0100
Linus Walleij <linus.walleij@linaro.org> wrote:

> On Fri, Jan 27, 2017 at 5:34 PM, Boris Brezillon
> <boris.brezillon@free-electrons.com> wrote:
> 
> > devm_get_gpiod_from_child() currently allows GPIO users to request a GPIO
> > that is defined in a child fwnode instead of directly in the device
> > fwnode. Extend this API by adding the devm_get_index_gpiod_from_child()
> > helpers which does the same except you can also specify an index in case
> > the 'xx-gpios' property describe several GPIOs.
> >
> > Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>  
> 
> Cc Russell who faced this problem in the mvebu PCI driver (IIRC).
> 
> (...)
> 
> > +struct gpio_desc *devm_get_index_gpiod_from_child(struct device *dev,
> > +                                                 const char *con_id,
> > +                                                 int index,
> > +                                                 struct fwnode_handle *child)
> >  {
> >         static const char * const suffixes[] = { "gpios", "gpio" };
> >         char prop_name[32]; /* 32 is max size of property name */
> > @@ -154,7 +157,7 @@ struct gpio_desc *devm_get_gpiod_from_child(struct device *dev,
> >                         snprintf(prop_name, sizeof(prop_name), "%s",
> >                                                                suffixes[i]);
> >
> > -               desc = fwnode_get_named_gpiod(child, prop_name);
> > +               desc = fwnode_get_named_gpiod(child, prop_name, index);
> >                 if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
> >                         break;
> >         }
> > @@ -168,6 +171,23 @@ struct gpio_desc *devm_get_gpiod_from_child(struct device *dev,
> >
> >         return desc;
> >  }
> > +EXPORT_SYMBOL(devm_get_index_gpiod_from_child);  
> 
> Rename this devm_fwnode_get_index_gpiod_from_child()
> so that it fits the namespace of the other fwnode functions.

Okay.

> 
> > + * devm_get_gpiod_from_child - get a GPIO descriptor from a device's child node
> > + * @dev:       GPIO consumer
> > + * @con_id:    function within the GPIO consumer
> > + * @child:     firmware node (child of @dev)
> > + *
> > + * GPIO descriptors returned from this function are automatically disposed on
> > + * driver detach.
> > + */
> > +struct gpio_desc *devm_get_gpiod_from_child(struct device *dev,
> > +                                           const char *con_id,
> > +                                           struct fwnode_handle *child)
> > +{
> > +       return devm_get_index_gpiod_from_child(dev, con_id, 0, child);
> > +}  
> 
> Take the opportunity to rename this devm_fwnode_get_gpiod_from_child()
> as well.

Sure, I'll provide a separate patch renaming this function.

Thanks,

Boris
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diff mbox

Patch

diff --git a/drivers/gpio/devres.c b/drivers/gpio/devres.c
index b760cbbb41d8..4dbab629a05e 100644
--- a/drivers/gpio/devres.c
+++ b/drivers/gpio/devres.c
@@ -123,17 +123,20 @@  struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev,
 EXPORT_SYMBOL(devm_gpiod_get_index);
 
 /**
- * devm_get_gpiod_from_child - get a GPIO descriptor from a device's child node
+ * devm_get_index_gpiod_from_child - get a GPIO descriptor from a device's
+ *				     child node
  * @dev:	GPIO consumer
  * @con_id:	function within the GPIO consumer
+ * @index:	index of the GPIO to obtain in the consumer
  * @child:	firmware node (child of @dev)
  *
  * GPIO descriptors returned from this function are automatically disposed on
  * driver detach.
  */
-struct gpio_desc *devm_get_gpiod_from_child(struct device *dev,
-					    const char *con_id,
-					    struct fwnode_handle *child)
+struct gpio_desc *devm_get_index_gpiod_from_child(struct device *dev,
+						  const char *con_id,
+						  int index,
+						  struct fwnode_handle *child)
 {
 	static const char * const suffixes[] = { "gpios", "gpio" };
 	char prop_name[32]; /* 32 is max size of property name */
@@ -154,7 +157,7 @@  struct gpio_desc *devm_get_gpiod_from_child(struct device *dev,
 			snprintf(prop_name, sizeof(prop_name), "%s",
 							       suffixes[i]);
 
-		desc = fwnode_get_named_gpiod(child, prop_name);
+		desc = fwnode_get_named_gpiod(child, prop_name, index);
 		if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
 			break;
 	}
@@ -168,6 +171,23 @@  struct gpio_desc *devm_get_gpiod_from_child(struct device *dev,
 
 	return desc;
 }
+EXPORT_SYMBOL(devm_get_index_gpiod_from_child);
+
+/**
+ * devm_get_gpiod_from_child - get a GPIO descriptor from a device's child node
+ * @dev:	GPIO consumer
+ * @con_id:	function within the GPIO consumer
+ * @child:	firmware node (child of @dev)
+ *
+ * GPIO descriptors returned from this function are automatically disposed on
+ * driver detach.
+ */
+struct gpio_desc *devm_get_gpiod_from_child(struct device *dev,
+					    const char *con_id,
+					    struct fwnode_handle *child)
+{
+	return devm_get_index_gpiod_from_child(dev, con_id, 0, child);
+}
 EXPORT_SYMBOL(devm_get_gpiod_from_child);
 
 /**
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 86bf3b84ada5..9b7a7734e742 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -3309,6 +3309,7 @@  EXPORT_SYMBOL_GPL(gpiod_get_index);
  * fwnode_get_named_gpiod - obtain a GPIO from firmware node
  * @fwnode:	handle of the firmware node
  * @propname:	name of the firmware property representing the GPIO
+ * @index:	index of the GPIO to obtain in the consumer
  *
  * This function can be used for drivers that get their configuration
  * from firmware.
@@ -3320,7 +3321,7 @@  EXPORT_SYMBOL_GPL(gpiod_get_index);
  * In case of error an ERR_PTR() is returned.
  */
 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
-					 const char *propname)
+					 const char *propname, int index)
 {
 	struct gpio_desc *desc = ERR_PTR(-ENODEV);
 	bool active_low = false;
@@ -3333,8 +3334,8 @@  struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
 	if (is_of_node(fwnode)) {
 		enum of_gpio_flags flags;
 
-		desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname, 0,
-						&flags);
+		desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname,
+						index, &flags);
 		if (!IS_ERR(desc)) {
 			active_low = flags & OF_GPIO_ACTIVE_LOW;
 			single_ended = flags & OF_GPIO_SINGLE_ENDED;
@@ -3342,7 +3343,7 @@  struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
 	} else if (is_acpi_node(fwnode)) {
 		struct acpi_gpio_info info;
 
-		desc = acpi_node_get_gpiod(fwnode, propname, 0, &info);
+		desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
 		if (!IS_ERR(desc))
 			active_low = info.polarity == GPIO_ACTIVE_LOW;
 	}
diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h
index fb0fde686cb1..5b3c025333a6 100644
--- a/include/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -135,7 +135,11 @@  int desc_to_gpio(const struct gpio_desc *desc);
 struct fwnode_handle;
 
 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
-					 const char *propname);
+					 const char *propname, int index);
+struct gpio_desc *devm_get_index_gpiod_from_child(struct device *dev,
+						  const char *con_id,
+						  int index,
+						  struct fwnode_handle *child);
 struct gpio_desc *devm_get_gpiod_from_child(struct device *dev,
 					    const char *con_id,
 					    struct fwnode_handle *child);
@@ -412,7 +416,14 @@  static inline int desc_to_gpio(const struct gpio_desc *desc)
 struct fwnode_handle;
 
 static inline struct gpio_desc *fwnode_get_named_gpiod(
-	struct fwnode_handle *fwnode, const char *propname)
+	struct fwnode_handle *fwnode, const char *propname, int index)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
+static inline struct gpio_desc *devm_get_index_gpiod_from_child(
+	struct device *dev, const char *con_id, int index,
+	struct fwnode_handle *child)
 {
 	return ERR_PTR(-ENOSYS);
 }