[PATCH 2/2] gpio: shared: ignore GPIO hogs when traversing the device tree

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>

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: a060b8c511ab ("gpiolib: implement low-level, shared GPIO support")
Reported-by: Cosmin Tanislav <demonsingur@xxxxxxxxx>
Closes: https://lore.kernel.org/all/2d96e464-e17c-4ff5-9a08-b215b77da04f@xxxxxxxxx/
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
---
 drivers/gpio/gpiolib-shared.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/gpio/gpiolib-shared.c b/drivers/gpio/gpiolib-shared.c
index 62f32489a8a6f70c567ed93645f1e36a81612def..7e049f2153a3fcc51803dd185fe5db60daea789f 100644
--- a/drivers/gpio/gpiolib-shared.c
+++ b/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;
 }
 

-- 
2.51.0