| Message ID | 20210603224007.120560-4-djrscally@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | Introduce intel_skl_int3472 module | expand |
On Thu, Jun 03, 2021 at 11:40:04PM +0100, Daniel Scally wrote: > We need to be able to translate GPIO resources in an ACPI device's _CRS > into GPIO descriptor array. Those are represented in _CRS as a pathname > to a GPIO device plus the pin's index number: the acpi_get_gpiod() > function is perfect for that purpose. > > As it's currently only used internally within the GPIO layer, provide and > export a wrapper function that additionally holds a reference to the GPIO > device. The subject is wrong, it should be "Introduce acpi_get_and_request_gpiod() helper" or so. I can fix when applying. Btw, do I understand correctly that I may push GPIO ACPI patches independently (of the ACPI changes)? > Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> > Signed-off-by: Daniel Scally <djrscally@gmail.com> > --- > Changes since v4: > - None > > drivers/gpio/gpiolib-acpi.c | 28 ++++++++++++++++++++++++++++ > include/linux/gpio/consumer.h | 2 ++ > 2 files changed, 30 insertions(+) > > diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c > index 5b4111e4be3f..684ddb35d83b 100644 > --- a/drivers/gpio/gpiolib-acpi.c > +++ b/drivers/gpio/gpiolib-acpi.c > @@ -128,6 +128,34 @@ static struct gpio_desc *acpi_get_gpiod(char *path, int pin) > return gpiochip_get_desc(chip, pin); > } > > +/** > + * acpi_get_and_request_gpiod() - Translate ACPI GPIO pin to GPIO descriptor > + * and hold a refcount to the GPIO device. > + * @path: ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1") > + * @pin: ACPI GPIO pin number (0-based, controller-relative) > + * @label: Label to pass to gpiod_request() > + * > + * This function is a simple pass-through to acpi_get_gpiod(), except that > + * as it is intended for use outside of the GPIO layer (in a similar fashion to > + * gpiod_get_index() for example) it also holds a reference to the GPIO device. > + */ > +struct gpio_desc *acpi_get_and_request_gpiod(char *path, int pin, char *label) > +{ > + struct gpio_desc *gpio; > + int ret; > + > + gpio = acpi_get_gpiod(path, pin); > + if (IS_ERR(gpio)) > + return gpio; > + > + ret = gpiod_request(gpio, label); > + if (ret) > + return ERR_PTR(ret); > + > + return gpio; > +} > +EXPORT_SYMBOL_GPL(acpi_get_and_request_gpiod); > + > static irqreturn_t acpi_gpio_irq_handler(int irq, void *data) > { > struct acpi_gpio_event *event = data; > diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h > index c73b25bc9213..566feb56601f 100644 > --- a/include/linux/gpio/consumer.h > +++ b/include/linux/gpio/consumer.h > @@ -692,6 +692,8 @@ int devm_acpi_dev_add_driver_gpios(struct device *dev, > const struct acpi_gpio_mapping *gpios); > void devm_acpi_dev_remove_driver_gpios(struct device *dev); > > +struct gpio_desc *acpi_get_and_request_gpiod(char *path, int pin, char *label); > + > #else /* CONFIG_GPIOLIB && CONFIG_ACPI */ > > struct acpi_device; > -- > 2.25.1 >
diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c index 5b4111e4be3f..684ddb35d83b 100644 --- a/drivers/gpio/gpiolib-acpi.c +++ b/drivers/gpio/gpiolib-acpi.c @@ -128,6 +128,34 @@ static struct gpio_desc *acpi_get_gpiod(char *path, int pin) return gpiochip_get_desc(chip, pin); } +/** + * acpi_get_and_request_gpiod() - Translate ACPI GPIO pin to GPIO descriptor + * and hold a refcount to the GPIO device. + * @path: ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1") + * @pin: ACPI GPIO pin number (0-based, controller-relative) + * @label: Label to pass to gpiod_request() + * + * This function is a simple pass-through to acpi_get_gpiod(), except that + * as it is intended for use outside of the GPIO layer (in a similar fashion to + * gpiod_get_index() for example) it also holds a reference to the GPIO device. + */ +struct gpio_desc *acpi_get_and_request_gpiod(char *path, int pin, char *label) +{ + struct gpio_desc *gpio; + int ret; + + gpio = acpi_get_gpiod(path, pin); + if (IS_ERR(gpio)) + return gpio; + + ret = gpiod_request(gpio, label); + if (ret) + return ERR_PTR(ret); + + return gpio; +} +EXPORT_SYMBOL_GPL(acpi_get_and_request_gpiod); + static irqreturn_t acpi_gpio_irq_handler(int irq, void *data) { struct acpi_gpio_event *event = data; diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h index c73b25bc9213..566feb56601f 100644 --- a/include/linux/gpio/consumer.h +++ b/include/linux/gpio/consumer.h @@ -692,6 +692,8 @@ int devm_acpi_dev_add_driver_gpios(struct device *dev, const struct acpi_gpio_mapping *gpios); void devm_acpi_dev_remove_driver_gpios(struct device *dev); +struct gpio_desc *acpi_get_and_request_gpiod(char *path, int pin, char *label); + #else /* CONFIG_GPIOLIB && CONFIG_ACPI */ struct acpi_device;