| Message ID | 1646855026-9132-2-git-send-email-stefan.wahren@i2se.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | gpiolib: of: Introduce hook for missing gpio-ranges | expand |
On Wed, Mar 9, 2022 at 8:44 PM Stefan Wahren <stefan.wahren@i2se.com> wrote: > > 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. > > Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> > --- > 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 91dcf2c..45b6edb 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 b0728c8..47a5ea0 100644 > --- a/include/linux/gpio/driver.h > +++ b/include/linux/gpio/driver.h > @@ -489,6 +489,18 @@ 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 */ > }; > > -- > 2.7.4 > Acked-by: Bartosz Golaszewski <brgl@bgdev.pl>
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index 91dcf2c..45b6edb 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 b0728c8..47a5ea0 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -489,6 +489,18 @@ 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 */ };
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. Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> --- drivers/gpio/gpiolib-of.c | 5 +++++ include/linux/gpio/driver.h | 12 ++++++++++++ 2 files changed, 17 insertions(+)