diff options
| author | Mathias Nyman <mathias.nyman@linux.intel.com> | 2012-11-30 12:37:36 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2012-11-30 12:37:36 +0100 |
| commit | e29482e8487954c87dc7b4fdbc53574bf1d4cce2 (patch) | |
| tree | 23b226e6ed38ad37a26a38b12662869195e0fb6a /drivers | |
| parent | 752cad760b19e85926341880dc317a99f400eacc (diff) | |
| download | linux-e29482e8487954c87dc7b4fdbc53574bf1d4cce2.tar.bz2 | |
gpio / ACPI: add ACPI support
Add support for translating ACPI GPIO pin numbers to Linux GPIO API pins.
Needs a gpio controller driver with the acpi handler hook set.
Drivers can use acpi_get_gpio() to translate ACPI5 GpioIO and GpioInt
resources to Linux GPIO's.
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpio/Kconfig | 4 | ||||
| -rw-r--r-- | drivers/gpio/Makefile | 1 | ||||
| -rw-r--r-- | drivers/gpio/gpiolib-acpi.c | 54 |
3 files changed, 59 insertions, 0 deletions
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index f11d8e3b4041..5c9b384119b8 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -49,6 +49,10 @@ config OF_GPIO def_bool y depends on OF +config GPIO_ACPI + def_bool y + depends on ACPI + config DEBUG_GPIO bool "Debug GPIO calls" depends on DEBUG_KERNEL diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 9aeed6707326..420dbaca05f1 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -4,6 +4,7 @@ ccflags-$(CONFIG_DEBUG_GPIO) += -DDEBUG obj-$(CONFIG_GPIOLIB) += gpiolib.o devres.o obj-$(CONFIG_OF_GPIO) += gpiolib-of.o +obj-$(CONFIG_GPIO_ACPI) += gpiolib-acpi.o # Device drivers. Generally keep list sorted alphabetically obj-$(CONFIG_GPIO_GENERIC) += gpio-generic.o diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c new file mode 100644 index 000000000000..cbad6e908d30 --- /dev/null +++ b/drivers/gpio/gpiolib-acpi.c @@ -0,0 +1,54 @@ +/* + * ACPI helpers for GPIO API + * + * Copyright (C) 2012, Intel Corporation + * Authors: Mathias Nyman <mathias.nyman@linux.intel.com> + * Mika Westerberg <mika.westerberg@linux.intel.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/errno.h> +#include <linux/gpio.h> +#include <linux/export.h> +#include <linux/acpi_gpio.h> +#include <linux/acpi.h> + +static int acpi_gpiochip_find(struct gpio_chip *gc, void *data) +{ + if (!gc->dev) + return false; + + return ACPI_HANDLE(gc->dev) == data; +} + +/** + * acpi_get_gpio() - Translate ACPI GPIO pin to GPIO number usable with GPIO API + * @path: ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1") + * @pin: ACPI GPIO pin number (0-based, controller-relative) + * + * Returns GPIO number to use with Linux generic GPIO API, or errno error value + */ + +int acpi_get_gpio(char *path, int pin) +{ + struct gpio_chip *chip; + acpi_handle handle; + acpi_status status; + + status = acpi_get_handle(NULL, path, &handle); + if (ACPI_FAILURE(status)) + return -ENODEV; + + chip = gpiochip_find(handle, acpi_gpiochip_find); + if (!chip) + return -ENODEV; + + if (!gpio_is_valid(chip->base + pin)) + return -EINVAL; + + return chip->base + pin; +} +EXPORT_SYMBOL_GPL(acpi_get_gpio); |