gpio: shared: ignore GPIO hogs when traversing the device tree

GPIO hogs have a "gpios" property but it's not a phandle to a remote
node - it references the parent GPIO controller. We must not try to
parse it as a phandle.

Fixes: a060b8c ("gpiolib: implement low-level, shared GPIO support")
Reported-by: Cosmin Tanislav <[email protected]>
Closes: https://lore.kernel.org/all/[email protected]/
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Bartosz Golaszewski <[email protected]>

Author: Bartosz Golaszewski

drivers/gpio/gpiolib-shared.c

@@ -83,6 +83,13 @@ static bool gpio_shared_of_node_ignore(struct device_node *node)
 	if (of_node_name_eq(node, "__symbols__"))
 		return true;
 
+	/*
+	 * GPIO hogs have a "gpios" property which is not a phandle and can't
+	 * possibly refer to a shared GPIO.
+	 */
+	if (of_property_present(node, "gpio-hog"))
+		return true;
+
 	return false;
 }