diff mbox series

[03/11] gpiolib: introduce fwnode_gpiod_get_index()

Message ID 20190911075215.78047-4-dmitry.torokhov@gmail.com
State New
Headers show
Series Add support for software nodes to gpiolib | expand

Commit Message

Dmitry Torokhov Sept. 11, 2019, 7:52 a.m. UTC 
This introduces fwnode_gpiod_get_index() that iterates through common gpio
suffixes when trying to locate a GPIO within a given firmware node.

We also switch devm_fwnode_gpiod_get_index() to call
fwnode_gpiod_get_index() instead of iterating through GPIO suffixes on
its own.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---

 drivers/gpio/gpiolib-devres.c | 16 +-----------
 drivers/gpio/gpiolib.c        | 48 +++++++++++++++++++++++++++++++++++
 include/linux/gpio/consumer.h | 13 ++++++++++
 3 files changed, 62 insertions(+), 15 deletions(-)

Comments

Linus Walleij Sept. 12, 2019, 9:50 a.m. UTC | #1 
On Wed, Sep 11, 2019 at 8:52 AM Dmitry Torokhov
<dmitry.torokhov@gmail.com> wrote:

> This introduces fwnode_gpiod_get_index() that iterates through common gpio
> suffixes when trying to locate a GPIO within a given firmware node.
>
> We also switch devm_fwnode_gpiod_get_index() to call
> fwnode_gpiod_get_index() instead of iterating through GPIO suffixes on
> its own.
>
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

So I'd like to merge this as well for v5.4 because I see where
you're going with this and it's nice to have these APIs in place
for that.

Please rebase this and the other one and resend!

Yours,
Linus Walleij
diff mbox series

Patch

diff --git a/drivers/gpio/gpiolib-devres.c b/drivers/gpio/gpiolib-devres.c
index 190ce7c43b4e..693dcaf811bb 100644
--- a/drivers/gpio/gpiolib-devres.c
+++ b/drivers/gpio/gpiolib-devres.c
@@ -205,29 +205,15 @@  struct gpio_desc *devm_fwnode_gpiod_get_index(struct device *dev,
 					      enum gpiod_flags flags,
 					      const char *label)
 {
-	char prop_name[32]; /* 32 is max size of property name */
 	struct gpio_desc **dr;
 	struct gpio_desc *desc;
-	unsigned int i;
 
 	dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
 			  GFP_KERNEL);
 	if (!dr)
 		return ERR_PTR(-ENOMEM);
 
-	for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
-		if (con_id)
-			snprintf(prop_name, sizeof(prop_name), "%s-%s",
-					    con_id, gpio_suffixes[i]);
-		else
-			snprintf(prop_name, sizeof(prop_name), "%s",
-					    gpio_suffixes[i]);
-
-		desc = fwnode_get_named_gpiod(fwnode, prop_name, index, flags,
-					      label);
-		if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
-			break;
-	}
+	desc = fwnode_gpiod_get_index(fwnode, con_id, index, flags, label);
 	if (IS_ERR(desc)) {
 		devres_free(dr);
 		return desc;
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index edc1ea68db20..f15e3880aae5 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -4314,6 +4314,54 @@  static int platform_gpio_count(struct device *dev, const char *con_id)
 	return count;
 }
 
+/**
+ * fwnode_gpiod_get_index - obtain a GPIO from firmware node
+ * @fwnode:	handle of the firmware node
+ * @con_id:	function within the GPIO consumer
+ * @index:	index of the GPIO to obtain for the consumer
+ * @flags:	GPIO initialization flags
+ * @label:	label to attach to the requested GPIO
+ *
+ * This function can be used for drivers that get their configuration
+ * from opaque firmware.
+ *
+ * The function properly finds the corresponding GPIO using whatever is the
+ * underlying firmware interface and then makes sure that the GPIO
+ * descriptor is requested before it is returned to the caller.
+ *
+ * Returns:
+ * On successful request the GPIO pin is configured in accordance with
+ * provided @flags.
+ *
+ * In case of error an ERR_PTR() is returned.
+ */
+struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
+					 const char *con_id, int index,
+					 enum gpiod_flags flags,
+					 const char *label)
+{
+	struct gpio_desc *desc;
+	char prop_name[32]; /* 32 is max size of property name */
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
+		if (con_id)
+			snprintf(prop_name, sizeof(prop_name), "%s-%s",
+					    con_id, gpio_suffixes[i]);
+		else
+			snprintf(prop_name, sizeof(prop_name), "%s",
+					    gpio_suffixes[i]);
+
+		desc = fwnode_get_named_gpiod(fwnode, prop_name, index, flags,
+					      label);
+		if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
+			break;
+	}
+
+	return desc;
+}
+EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);
+
 /**
  * gpiod_count - return the number of GPIOs associated with a device / function
  *		or -ENOENT if no GPIO has been assigned to the requested function
diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h
index dc0ddcd30515..5215fdba6b9a 100644
--- a/include/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -176,6 +176,10 @@  struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
 					 const char *propname, int index,
 					 enum gpiod_flags dflags,
 					 const char *label);
+struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
+					 const char *con_id, int index,
+					 enum gpiod_flags flags,
+					 const char *label);
 struct gpio_desc *devm_fwnode_gpiod_get_index(struct device *dev,
 					      struct fwnode_handle *child,
 					      const char *con_id, int index,
@@ -531,6 +535,15 @@  struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
 	return ERR_PTR(-ENOSYS);
 }
 
+static inline
+struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
+					 const char *con_id, int index,
+					 enum gpiod_flags flags,
+					 const char *label)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
 static inline
 struct gpio_desc *devm_fwnode_gpiod_get_index(struct device *dev,
 					      struct fwnode_handle *fwnode,