Commit e29482e8 authored by Mathias Nyman's avatar Mathias Nyman Committed by Rafael J. Wysocki
Browse files

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: default avatarMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: default avatarGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 752cad76

drivers/gpio/Kconfig

+4 −0
Original line number Diff line number Diff line
@@ -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

drivers/gpio/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -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

drivers/gpio/gpiolib-acpi.c

0 → 100644
+54 −0
Original line number Diff line number Diff line 
/*

 * 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);

include/linux/acpi_gpio.h

0 → 100644
+19 −0
Original line number Diff line number Diff line 
#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_ */

CRA Git | Maintained and supported by SUSTech CRA and CCSE