kernel-ark/include/linux/of_gpio.h
Anton Vorontsov 391c970c0d of/gpio: add default of_xlate function if device has a node pointer
Implement generic OF gpio hooks and thus make device-enabled GPIO chips
(i.e.  the ones that have gpio_chip->dev specified) automatically attach
to the OpenFirmware subsystem.  Which means that now we can handle I2C and
SPI GPIO chips almost* transparently.

* "Almost" because some chips still require platform data, and for these
  chips OF-glue is still needed, though with this change the glue will
  be much smaller.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Bill Gatliff <bgat@billgatliff.com>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
CC: linux-kernel@vger.kernel.org
CC: devicetree-discuss@lists.ozlabs.org
2010-07-05 16:14:30 -06:00

93 lines
2.4 KiB
C

/*
* OF helpers for the GPIO API
*
* Copyright (c) 2007-2008 MontaVista Software, Inc.
*
* Author: Anton Vorontsov <avorontsov@ru.mvista.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#ifndef __LINUX_OF_GPIO_H
#define __LINUX_OF_GPIO_H
#include <linux/compiler.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/gpio.h>
struct device_node;
/*
* This is Linux-specific flags. By default controllers' and Linux' mapping
* match, but GPIO controllers are free to translate their own flags to
* Linux-specific in their .xlate callback. Though, 1:1 mapping is recommended.
*/
enum of_gpio_flags {
OF_GPIO_ACTIVE_LOW = 0x1,
};
#ifdef CONFIG_OF_GPIO
/*
* OF GPIO chip for memory mapped banks
*/
struct of_mm_gpio_chip {
struct gpio_chip gc;
void (*save_regs)(struct of_mm_gpio_chip *mm_gc);
void __iomem *regs;
};
static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc)
{
return container_of(gc, struct of_mm_gpio_chip, gc);
}
extern int of_get_gpio_flags(struct device_node *np, int index,
enum of_gpio_flags *flags);
extern unsigned int of_gpio_count(struct device_node *np);
extern int of_mm_gpiochip_add(struct device_node *np,
struct of_mm_gpio_chip *mm_gc);
extern void of_gpiochip_add(struct gpio_chip *gc);
extern void of_gpiochip_remove(struct gpio_chip *gc);
extern struct gpio_chip *of_node_to_gpiochip(struct device_node *np);
#else /* CONFIG_OF_GPIO */
/* Drivers may not strictly depend on the GPIO support, so let them link. */
static inline int of_get_gpio_flags(struct device_node *np, int index,
enum of_gpio_flags *flags)
{
return -ENOSYS;
}
static inline unsigned int of_gpio_count(struct device_node *np)
{
return 0;
}
static inline void of_gpiochip_add(struct gpio_chip *gc) { }
static inline void of_gpiochip_remove(struct gpio_chip *gc) { }
#endif /* CONFIG_OF_GPIO */
/**
* of_get_gpio - Get a GPIO number to use with GPIO API
* @np: device node to get GPIO from
* @index: index of the GPIO
*
* Returns GPIO number to use with Linux generic GPIO API, or one of the errno
* value on the error condition.
*/
static inline int of_get_gpio(struct device_node *np, int index)
{
return of_get_gpio_flags(np, index, NULL);
}
#endif /* __LINUX_OF_GPIO_H */