diff options
| author | Daniel Scally <djrscally@gmail.com> | 2021-06-03 23:40:04 +0100 |
|---|---|---|
| committer | Andy Shevchenko <andriy.shevchenko@linux.intel.com> | 2021-06-04 16:24:19 +0300 |
| commit | 43582f29b161d820717bc13f562bca27af12e3cf (patch) | |
| tree | 75477f0f5b79f101d2158ebd70f3d58908dc633a | |
| parent | 2b71b66ac0415db5e4b9e67b11e3af7b485bb421 (diff) | |
gpiolib: acpi: Introduce acpi_get_and_request_gpiod() helper
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.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Daniel Scally <djrscally@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
| -rw-r--r-- | drivers/gpio/gpiolib-acpi.c | 28 | ||||
| -rw-r--r-- | include/linux/gpio/consumer.h | 2 |
2 files changed, 30 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c index 3ef22a3c104d..75cd0c5a5cc4 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; |