From: Stefan Wahren stefan.wahren@i2se.com
[ 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@i2se.com Reviewed-by: Florian Fainelli f.fainelli@gmail.com Tested-by: Florian Fainelli f.fainelli@gmail.com Acked-by: Bartosz Golaszewski brgl@bgdev.pl Link: https://lore.kernel.org/r/20220409095129.45786-2-stefan.wahren@i2se.com Signed-off-by: Linus Walleij linus.walleij@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 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 */ };