| Message ID | 20210222130735.1313443-5-djrscally@gmail.com (mailing list archive) |
|---|---|
| State | Deferred, archived |
| Headers | show |
| Series | Introduce intel_skl_int3472 module | expand |
On Mon, Feb 22, 2021 at 3:13 PM Daniel Scally <djrscally@gmail.com> wrote: > > I need to be able to translate GPIO resources in an ACPI device's _CRS I -> we > into GPIO descriptor array. Those are represented in _CRS as a pathname > to a GPIO device plus the pin's index number: this function is perfect Which one? "the acpi_...() function" > 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. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> after addressing above and beyond :-) > > Signed-off-by: Daniel Scally <djrscally@gmail.com> > --- > Changes in v3: > > - Having realised that it wasn't taking a reference to the GPIO device, > I decided the best thing to do was leave the existing function as-is > (apart from renaming) and provide a wrapper that simply passes > through to the original and takes a reference before returning the > struct gpio_desc > > Because of the change to that functionality, I dropped the R-b's from > the last version. > > drivers/gpio/gpiolib-acpi.c | 36 +++++++++++++++++++++++++++++++---- > include/linux/gpio/consumer.h | 7 +++++++ > 2 files changed, 39 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c > index e4d728fda982..0cc7cc327757 100644 > --- a/drivers/gpio/gpiolib-acpi.c > +++ b/drivers/gpio/gpiolib-acpi.c > @@ -102,7 +102,8 @@ static int acpi_gpiochip_find(struct gpio_chip *gc, void *data) > } > > /** > - * acpi_get_gpiod() - Translate ACPI GPIO pin to GPIO descriptor usable with GPIO API > + * __acpi_get_gpiod() - Translate ACPI GPIO pin to GPIO descriptor usable with Can we rename it better, i.e. w/o __, like "acpi_gpio_pin_to_gpiod()" or so? > + * GPIO API > * @path: ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1") > * @pin: ACPI GPIO pin number (0-based, controller-relative) > * > @@ -111,7 +112,7 @@ static int acpi_gpiochip_find(struct gpio_chip *gc, void *data) > * controller does not have GPIO chip registered at the moment. This is to > * support probe deferral. > */ > -static struct gpio_desc *acpi_get_gpiod(char *path, int pin) > +static struct gpio_desc *__acpi_get_gpiod(char *path, int pin) > { > struct gpio_chip *chip; > acpi_handle handle; > @@ -128,6 +129,33 @@ static struct gpio_desc *acpi_get_gpiod(char *path, int pin) > return gpiochip_get_desc(chip, pin); > } > > +/** > + * acpi_get_gpiod() - Translate ACPI GPIO pin to GPIO descriptor usable with > + * GPIO API, 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_gpiod(char *path, int pin, char *label) Name better to reflect the action, perhaps "acpi_gpio_get_and_request_desc()" or so. > +{ > + struct gpio_desc *gpio = __acpi_get_gpiod(path, pin); Please, split it, so the assignment goes... > + int ret; ...here. > + if (IS_ERR(gpio)) > + return gpio; > + > + ret = gpiod_request(gpio, label); > + if (ret) > + return ERR_PTR(ret); > + > + return gpio; > +} > +EXPORT_SYMBOL_GPL(acpi_get_gpiod); > + > static irqreturn_t acpi_gpio_irq_handler(int irq, void *data) > { > struct acpi_gpio_event *event = data; > @@ -689,8 +717,8 @@ static int acpi_populate_gpio_lookup(struct acpi_resource *ares, void *data) > if (pin_index >= agpio->pin_table_length) > return 1; > > - lookup->desc = acpi_get_gpiod(agpio->resource_source.string_ptr, > - agpio->pin_table[pin_index]); > + lookup->desc = __acpi_get_gpiod(agpio->resource_source.string_ptr, > + agpio->pin_table[pin_index]); > lookup->info.pin_config = agpio->pin_config; > lookup->info.debounce = agpio->debounce_timeout; > lookup->info.gpioint = gpioint; > diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h > index ef49307611d2..6eee751f44dd 100644 > --- a/include/linux/gpio/consumer.h > +++ b/include/linux/gpio/consumer.h > @@ -690,6 +690,8 @@ 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_gpiod(char *path, int pin, char *label); > + > #else /* CONFIG_GPIOLIB && CONFIG_ACPI */ > > struct acpi_device; > @@ -708,6 +710,11 @@ static inline int devm_acpi_dev_add_driver_gpios(struct device *dev, > } > static inline void devm_acpi_dev_remove_driver_gpios(struct device *dev) {} > > +struct gpio_desc *acpi_get_gpiod(char *path, int pin, char *label) > +{ > + return NULL; > +} > + > #endif /* CONFIG_GPIOLIB && CONFIG_ACPI */ > > > -- > 2.25.1 >
diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c index e4d728fda982..0cc7cc327757 100644 --- a/drivers/gpio/gpiolib-acpi.c +++ b/drivers/gpio/gpiolib-acpi.c @@ -102,7 +102,8 @@ static int acpi_gpiochip_find(struct gpio_chip *gc, void *data) } /** - * acpi_get_gpiod() - Translate ACPI GPIO pin to GPIO descriptor usable with GPIO API + * __acpi_get_gpiod() - Translate ACPI GPIO pin to GPIO descriptor usable with + * GPIO API * @path: ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1") * @pin: ACPI GPIO pin number (0-based, controller-relative) * @@ -111,7 +112,7 @@ static int acpi_gpiochip_find(struct gpio_chip *gc, void *data) * controller does not have GPIO chip registered at the moment. This is to * support probe deferral. */ -static struct gpio_desc *acpi_get_gpiod(char *path, int pin) +static struct gpio_desc *__acpi_get_gpiod(char *path, int pin) { struct gpio_chip *chip; acpi_handle handle; @@ -128,6 +129,33 @@ static struct gpio_desc *acpi_get_gpiod(char *path, int pin) return gpiochip_get_desc(chip, pin); } +/** + * acpi_get_gpiod() - Translate ACPI GPIO pin to GPIO descriptor usable with + * GPIO API, 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_gpiod(char *path, int pin, char *label) +{ + struct gpio_desc *gpio = __acpi_get_gpiod(path, pin); + int ret; + + if (IS_ERR(gpio)) + return gpio; + + ret = gpiod_request(gpio, label); + if (ret) + return ERR_PTR(ret); + + return gpio; +} +EXPORT_SYMBOL_GPL(acpi_get_gpiod); + static irqreturn_t acpi_gpio_irq_handler(int irq, void *data) { struct acpi_gpio_event *event = data; @@ -689,8 +717,8 @@ static int acpi_populate_gpio_lookup(struct acpi_resource *ares, void *data) if (pin_index >= agpio->pin_table_length) return 1; - lookup->desc = acpi_get_gpiod(agpio->resource_source.string_ptr, - agpio->pin_table[pin_index]); + lookup->desc = __acpi_get_gpiod(agpio->resource_source.string_ptr, + agpio->pin_table[pin_index]); lookup->info.pin_config = agpio->pin_config; lookup->info.debounce = agpio->debounce_timeout; lookup->info.gpioint = gpioint; diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h index ef49307611d2..6eee751f44dd 100644 --- a/include/linux/gpio/consumer.h +++ b/include/linux/gpio/consumer.h @@ -690,6 +690,8 @@ 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_gpiod(char *path, int pin, char *label); + #else /* CONFIG_GPIOLIB && CONFIG_ACPI */ struct acpi_device; @@ -708,6 +710,11 @@ static inline int devm_acpi_dev_add_driver_gpios(struct device *dev, } static inline void devm_acpi_dev_remove_driver_gpios(struct device *dev) {} +struct gpio_desc *acpi_get_gpiod(char *path, int pin, char *label) +{ + return NULL; +} + #endif /* CONFIG_GPIOLIB && CONFIG_ACPI */
I 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: this 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. Signed-off-by: Daniel Scally <djrscally@gmail.com> --- Changes in v3: - Having realised that it wasn't taking a reference to the GPIO device, I decided the best thing to do was leave the existing function as-is (apart from renaming) and provide a wrapper that simply passes through to the original and takes a reference before returning the struct gpio_desc Because of the change to that functionality, I dropped the R-b's from the last version. drivers/gpio/gpiolib-acpi.c | 36 +++++++++++++++++++++++++++++++---- include/linux/gpio/consumer.h | 7 +++++++ 2 files changed, 39 insertions(+), 4 deletions(-)