gpio: allow passing NULL to gpio_request_by_line_name() to search all gpio controllers
The API is more convenient to use if one doesn't have to know upfront
which gpio controller has a line with the name one is searching for,
and arrange to look that device up somehow. Or implement this loop
oneself.
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index dd0bdf2..c4a7fd2 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -580,7 +580,8 @@
* This allows boards to implement common behaviours using GPIOs while not
* requiring specific GPIO offsets be used.
*
- * @dev: An instance of a GPIO controller udevice
+ * @dev: An instance of a GPIO controller udevice, or NULL to search
+ * all GPIO controller devices
* @line_name: The name of the GPIO (e.g. "bmc-secure-boot")
* @desc: A GPIO descriptor that is populated with the requested GPIO
* upon return