[PATCH v2 1/4] gpiolib: provide gpio_device_find_by_fwnode()

[Andy Shevchenko]

One of the ways of looking up GPIO devices is using their fwnode.
Provide a helper for that to avoid every user implementing their
own matching function.

Reviewed-by: Dipen Patel <dipenp@xxxxxxxxxx>
Tested-by: Dipen Patel <dipenp@xxxxxxxxxx>
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20231010151709.4104747-2-andriy.shevchenko@xxxxxxxxxxxxxxx
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
 drivers/gpio/gpiolib.c      | 20 ++++++++++++++++++++
 include/linux/gpio/driver.h |  1 +
 2 files changed, 21 insertions(+)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 7b4d12b714a3..31c06a32cb8a 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1142,6 +1142,26 @@ struct gpio_device *gpio_device_find_by_label(const char *label)
 }
 EXPORT_SYMBOL_GPL(gpio_device_find_by_label);
 
+static int gpio_chip_match_by_fwnode(struct gpio_chip *gc, void *fwnode)
+{
+	return device_match_fwnode(&gc->gpiodev->dev, fwnode);
+}
+
+/**
+ * gpio_device_find_by_fwnode() - wrapper around gpio_device_find() finding
+ *                                the GPIO device by its fwnode
+ * @fwnode: Firmware node to lookup
+ *
+ * Returns:
+ * Reference to the GPIO device or NULL. Reference must be released with
+ * gpio_device_put().
+ */
+struct gpio_device *gpio_device_find_by_fwnode(const struct fwnode_handle *fwnode)
+{
+	return gpio_device_find((void *)fwnode, gpio_chip_match_by_fwnode);
+}
+EXPORT_SYMBOL_GPL(gpio_device_find_by_fwnode);
+
 /**
  * gpio_device_get() - Increase the reference count of this GPIO device
  * @gdev: GPIO device to increase the refcount for
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index f8ad7f40100c..ae4162d3f1d3 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -611,6 +611,7 @@ struct gpio_chip *gpiochip_find(void *data,
 struct gpio_device *gpio_device_find(void *data,
 				int (*match)(struct gpio_chip *gc, void *data));
 struct gpio_device *gpio_device_find_by_label(const char *label);
+struct gpio_device *gpio_device_find_by_fwnode(const struct fwnode_handle *fwnode);
 
 struct gpio_device *gpio_device_get(struct gpio_device *gdev);
 void gpio_device_put(struct gpio_device *gdev);
-- 
2.40.0.1.gaa8946217a0b