Commit 3550bba2 authored by Stefan Wahren's avatar Stefan Wahren Committed by Linus Walleij
Browse files

gpiolib: of: Introduce hook for missing gpio-ranges 



Since commit 2ab73c6d ("gpio: Support GPIO controllers without pin-ranges")
the device tree nodes of GPIO controller need the gpio-ranges property to
handle gpio-hogs. Unfortunately it's impossible to guarantee that every new
kernel is shipped with an updated device tree binary.

In order to provide backward compatibility with those older DTB, we need a
callback within of_gpiochip_add_pin_range() so the relevant platform driver
can handle this case.

Fixes: 2ab73c6d ("gpio: Support GPIO controllers without pin-ranges")
Signed-off-by: default avatarStefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Tested-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Acked-by: default avatarBartosz Golaszewski <brgl@bgdev.pl>
Link: https://lore.kernel.org/r/20220409095129.45786-2-stefan.wahren@i2se.com


Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 1a08cb73

drivers/gpio/gpiolib-of.c

+5 −0
Original line number Diff line number Diff line
@@ -931,6 +931,11 @@ static int of_gpiochip_add_pin_range(struct gpio_chip *chip) 
	if (!np)

		return 0;



	if (!of_property_read_bool(np, "gpio-ranges") &&

	    chip->of_gpio_ranges_fallback) {

		return chip->of_gpio_ranges_fallback(chip, np);

	}



	group_names = of_find_property(np, group_names_propname, NULL);



	for (;; index++) {

include/linux/gpio/driver.h

+12 −0
Original line number Diff line number Diff line
@@ -492,6 +492,18 @@ struct gpio_chip { 
	 */

	int (*of_xlate)(struct gpio_chip *gc,

			const struct of_phandle_args *gpiospec, u32 *flags);



	/**

	 * @of_gpio_ranges_fallback:

	 *

	 * Optional hook for the case that no gpio-ranges property is defined

	 * within the device tree node "np" (usually DT before introduction

	 * of gpio-ranges). So this callback is helpful to provide the

	 * necessary backward compatibility for the pin ranges.

	 */

	int (*of_gpio_ranges_fallback)(struct gpio_chip *gc,

				       struct device_node *np);



#endif /* CONFIG_OF_GPIO */

};