From 20340be21699b35591fbcded4aa09d0aa8479c83 Mon Sep 17 00:00:00 2001 From: Stefan Wahren Date: Sat, 9 Apr 2022 11:51:28 +0200 Subject: [PATCH] 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 Reviewed-by: Florian Fainelli Tested-by: Florian Fainelli Acked-by: Bartosz Golaszewski Link: https://lore.kernel.org/r/20220409095129.45786-2-stefan.wahren@i2se.com Signed-off-by: Linus Walleij Signed-off-by: Sasha Levin --- drivers/gpio/gpiolib-of.c | 5 +++++ include/linux/gpio/driver.h | 12 ++++++++++++ 2 files changed, 17 insertions(+) diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index a5b34c2487679..66e434f59f60c 100644 --- a/drivers/gpio/gpiolib-of.c +++ b/drivers/gpio/gpiolib-of.c @@ -933,6 +933,11 @@ 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 e3c29d2e68263..ad479db8f0aac 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -481,6 +481,18 @@ 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 */ };