Commit 43582f29 authored by Daniel Scally's avatar Daniel Scally Committed by Andy Shevchenko
Browse files

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: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: default avatarDaniel Scally <djrscally@gmail.com>
Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
parent 2b71b66a

drivers/gpio/gpiolib-acpi.c

+28 −0
Original line number Diff line number Diff line
@@ -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;

include/linux/gpio/consumer.h

+2 −0
Original line number Diff line number Diff line
@@ -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;