From 43582f29b161d820717bc13f562bca27af12e3cf Mon Sep 17 00:00:00 2001 From: Daniel Scally Date: Thu, 3 Jun 2021 23:40:04 +0100 Subject: 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 Signed-off-by: Daniel Scally Signed-off-by: Andy Shevchenko --- drivers/gpio/gpiolib-acpi.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'drivers/gpio/gpiolib-acpi.c') 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; -- cgit