This is a note to let you know that I've just added the patch titled gpiolib: of: Introduce hook for missing gpio-ranges to the 5.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: gpiolib-of-introduce-hook-for-missing-gpio-ranges.patch and it can be found in the queue-5.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit dde603cbd86ada8c2a36ee536a133b6a317b242e Author: Stefan Wahren <stefan.wahren@xxxxxxxx> Date: Sat Apr 9 11:51:28 2022 +0200 gpiolib: of: Introduce hook for missing gpio-ranges [ Upstream commit 3550bba25d5587a701e6edf20e20984d2ee72c78 ] Since commit 2ab73c6d8323 ("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: 2ab73c6d8323 ("gpio: Support GPIO controllers without pin-ranges") Signed-off-by: Stefan Wahren <stefan.wahren@xxxxxxxx> Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx> Tested-by: Florian Fainelli <f.fainelli@xxxxxxxxx> Acked-by: Bartosz Golaszewski <brgl@xxxxxxxx> Link: https://lore.kernel.org/r/20220409095129.45786-2-stefan.wahren@xxxxxxxx Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index 7e5e51d49d09..6dec81b1f24b 100644 --- a/drivers/gpio/gpiolib-of.c +++ b/drivers/gpio/gpiolib-of.c @@ -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++) { diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index 874aabd270c9..48d03eb4e5d8 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -501,6 +501,18 @@ 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 */ };