Commit 9dbd1ab2 authored by Bartosz Golaszewski's avatar Bartosz Golaszewski
Browse files

gpiolib: check the 'ngpios' property in core gpiolib code 



Several drivers read the 'ngpios' device property on their own, but
since it's defined as a standard GPIO property in the device tree bindings
anyway, it's a good candidate for generalization. If the driver didn't
set its gc->ngpio, try to read the 'ngpios' property from the GPIO
device's firmware node before bailing out.

Signed-off-by: default avatarBartosz Golaszewski <brgl@bgdev.pl>
Suggested-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
parent e5ab49cd

drivers/gpio/gpiolib.c

+21 −0
Original line number Diff line number Diff line
@@ -599,6 +599,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, 
	int base = gc->base;

	unsigned int i;

	int ret = 0;

	u32 ngpios;



	/*

	 * First: allocate and populate the internal stat container, and
@@ -646,6 +647,26 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, 
		goto err_free_dev_name;

	}



	/*

	 * Try the device properties if the driver didn't supply the number

	 * of GPIO lines.

	 */

	if (gc->ngpio == 0) {

		ret = device_property_read_u32(&gdev->dev, "ngpios", &ngpios);

		if (ret == -ENODATA)

			/*

			 * -ENODATA means that there is no property found and

			 * we want to issue the error message to the user.

			 * Besides that, we want to return different error code

			 * to state that supplied value is not valid.

			 */

			ngpios = 0;

		else if (ret)

			goto err_free_descs;



		gc->ngpio = ngpios;

	}



	if (gc->ngpio == 0) {

		chip_err(gc, "tried to insert a GPIO chip with zero lines\n");

		ret = -EINVAL;