diff options
| -rw-r--r-- | drivers/gpio/Kconfig | 4 | ||||
| -rw-r--r-- | drivers/gpio/Makefile | 1 | ||||
| -rw-r--r-- | drivers/gpio/gpiolib-acpi.c | 54 | ||||
| -rw-r--r-- | include/linux/acpi_gpio.h | 19 |
4 files changed, 78 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); diff --git a/include/linux/acpi_gpio.h b/include/linux/acpi_gpio.h new file mode 100644 index 000000000000..91615a389b65 --- /dev/null +++ b/include/linux/acpi_gpio.h @@ -0,0 +1,19 @@ +#ifndef _LINUX_ACPI_GPIO_H_ +#define _LINUX_ACPI_GPIO_H_ + +#include <linux/errno.h> + +#ifdef CONFIG_GPIO_ACPI + +int acpi_get_gpio(char *path, int pin); + +#else /* CONFIG_GPIO_ACPI */ + +static inline int acpi_get_gpio(char *path, int pin) +{ + return -ENODEV; +} + +#endif /* CONFIG_GPIO_ACPI */ + +#endif /* _LINUX_ACPI_GPIO_H_ */ |