gpio: add parameter to allow the use named gpios

The gpio binding document says that new code should always use named
gpios. Patch 40b73183 added support to parse a list of gpios from child
nodes, but does not make it possible to use named gpios. This patch adds
the con_id property and implements it is done in gpiolib.c, where the
old-style of using unnamed gpios still works.

Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>
Acked-by: Bryan Wu <cooloney@gmail.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

4 files changed, 20 insertions, 3 deletions

diff --git a/drivers/gpio/devres.c b/drivers/gpio/devres.c
index 13dbd3dfc33a..12c2082f968e 100644
--- a/drivers/gpio/devres.c
+++ b/drivers/gpio/devres.c
@@ -111,23 +111,39 @@ EXPORT_SYMBOL(__devm_gpiod_get_index);
 /**
  * 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)
 {
+        static const char const *suffixes[] = { "gpios", "gpio" };
+        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);
 
-        desc = fwnode_get_named_gpiod(child, "gpios");
+        for (i = 0; i < ARRAY_SIZE(suffixes); i++) {
+                if (con_id)
+                        snprintf(prop_name, sizeof(prop_name), "%s-%s",
+                                            con_id, suffixes[i]);
+                else
+                        snprintf(prop_name, sizeof(prop_name), "%s",
+                                                               suffixes[i]);
+
+                desc = fwnode_get_named_gpiod(child, prop_name);
+                if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
+                        break;
+        }
         if (IS_ERR(desc)) {
                 devres_free(dr);
                 return desc;
diff --git a/drivers/input/keyboard/gpio_keys_polled.c b/drivers/input/keyboard/gpio_keys_polled.c
index 90df4df58b07..097d7216d98e 100644
--- a/drivers/input/keyboard/gpio_keys_polled.c
+++ b/drivers/input/keyboard/gpio_keys_polled.c
@@ -125,7 +125,7 @@ static struct gpio_keys_platform_data *gpio_keys_polled_get_devtree_pdata(struct
         device_for_each_child_node(dev, child) {
                 struct gpio_desc *desc;
 
-                desc = devm_get_gpiod_from_child(dev, child);
+                desc = devm_get_gpiod_from_child(dev, NULL, child);
                 if (IS_ERR(desc)) {
                         error = PTR_ERR(desc);
                         if (error != -EPROBE_DEFER)
diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c
index d26af0a79a90..15eb3f86f670 100644
--- a/drivers/leds/leds-gpio.c
+++ b/drivers/leds/leds-gpio.c
@@ -184,7 +184,7 @@ static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)
                 struct gpio_led led = {};
                 const char *state = NULL;
 
-                led.gpiod = devm_get_gpiod_from_child(dev, child);
+                led.gpiod = devm_get_gpiod_from_child(dev, NULL, child);
                 if (IS_ERR(led.gpiod)) {
                         fwnode_handle_put(child);
                         ret = PTR_ERR(led.gpiod);
diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h
index 45afc2dee560..ed20759229eb 100644
--- a/include/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -110,6 +110,7 @@ struct fwnode_handle;
 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
                                          const char *propname);
 struct gpio_desc *devm_get_gpiod_from_child(struct device *dev,
+                                            const char *con_id,
                                             struct fwnode_handle *child);
 #else /* CONFIG_GPIOLIB */