Commit b41ba2ec authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Bartosz Golaszewski
Browse files

gpiolib: Read "gpio-line-names" from a firmware node 



On STM32MP1, the GPIO banks are subnodes of pin-controller@50002000,
see arch/arm/boot/dts/stm32mp151.dtsi. The driver for
pin-controller@50002000 is in drivers/pinctrl/stm32/pinctrl-stm32.c
and iterates over all of its DT subnodes when registering each GPIO
bank gpiochip. Each gpiochip has:

  - gpio_chip.parent = dev,
    where dev is the device node of the pin controller
  - gpio_chip.of_node = np,
    which is the OF node of the GPIO bank

Therefore, dev_fwnode(chip->parent) != of_fwnode_handle(chip.of_node),
i.e. pin-controller@50002000 != pin-controller@50002000/gpio@5000*000.

The original code behaved correctly, as it extracted the "gpio-line-names"
from of_fwnode_handle(chip.of_node) = pin-controller@50002000/gpio@5000*000.

To achieve the same behaviour, read property from the firmware node.

Fixes: 7cba1a4d ("gpiolib: generalize devprop_gpiochip_set_names() for device properties")
Reported-by: default avatarMarek Vasut <marex@denx.de>
Reported-by: default avatarRoman Guskov <rguskov@dh-electronics.com>
Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: default avatarMarek Vasut <marex@denx.de>
Reviewed-by: default avatarMarek Vasut <marex@denx.de>
Signed-off-by: default avatarBartosz Golaszewski <bgolaszewski@baylibre.com>
parent eb441337

drivers/gpio/gpiolib.c

+4 −8
Original line number Diff line number Diff line
@@ -367,22 +367,18 @@ static int gpiochip_set_desc_names(struct gpio_chip *gc) 
 *

 * Looks for device property "gpio-line-names" and if it exists assigns

 * GPIO line names for the chip. The memory allocated for the assigned

 * names belong to the underlying software node and should not be released

 * names belong to the underlying firmware node and should not be released

 * by the caller.

 */

static int devprop_gpiochip_set_names(struct gpio_chip *chip)

{

	struct gpio_device *gdev = chip->gpiodev;

	struct device *dev = chip->parent;

	struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev);

	const char **names;

	int ret, i;

	int count;



	/* GPIO chip may not have a parent device whose properties we inspect. */

	if (!dev)

		return 0;



	count = device_property_string_array_count(dev, "gpio-line-names");

	count = fwnode_property_string_array_count(fwnode, "gpio-line-names");

	if (count < 0)

		return 0;
@@ -396,7 +392,7 @@ static int devprop_gpiochip_set_names(struct gpio_chip *chip) 
	if (!names)

		return -ENOMEM;



	ret = device_property_read_string_array(dev, "gpio-line-names",

	ret = fwnode_property_read_string_array(fwnode, "gpio-line-names",

						names, count);

	if (ret < 0) {

		dev_warn(&gdev->dev, "failed to read GPIO line names\n");