of_gpio.h revision a19e3da5bc5fc6c10ab73f310bea80f3845b4531 
1/*
2 * OF helpers for the GPIO API
3 *
4 * Copyright (c) 2007-2008  MontaVista Software, Inc.
5 *
6 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 */
13
14#ifndef __LINUX_OF_GPIO_H
15#define __LINUX_OF_GPIO_H
16
17#include <linux/compiler.h>
18#include <linux/kernel.h>
19#include <linux/errno.h>
20#include <linux/gpio.h>
21
22struct device_node;
23
24/*
25 * This is Linux-specific flags. By default controllers' and Linux' mapping
26 * match, but GPIO controllers are free to translate their own flags to
27 * Linux-specific in their .xlate callback. Though, 1:1 mapping is recommended.
28 */
29enum of_gpio_flags {
30	OF_GPIO_ACTIVE_LOW = 0x1,
31};
32
33#ifdef CONFIG_OF_GPIO
34
35/*
36 * OF GPIO chip for memory mapped banks
37 */
38struct of_mm_gpio_chip {
39	struct gpio_chip gc;
40	void (*save_regs)(struct of_mm_gpio_chip *mm_gc);
41	void __iomem *regs;
42};
43
44static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc)
45{
46	return container_of(gc, struct of_mm_gpio_chip, gc);
47}
48
49extern int of_get_gpio_flags(struct device_node *np, int index,
50			     enum of_gpio_flags *flags);
51extern unsigned int of_gpio_count(struct device_node *np);
52
53extern int of_mm_gpiochip_add(struct device_node *np,
54			      struct of_mm_gpio_chip *mm_gc);
55extern int of_gpio_simple_xlate(struct gpio_chip *gc, struct device_node *np,
56				const void *gpio_spec, u32 *flags);
57#else /* CONFIG_OF_GPIO */
58
59/* Drivers may not strictly depend on the GPIO support, so let them link. */
60static inline int of_get_gpio_flags(struct device_node *np, int index,
61				    enum of_gpio_flags *flags)
62{
63	return -ENOSYS;
64}
65
66static inline unsigned int of_gpio_count(struct device_node *np)
67{
68	return 0;
69}
70
71#endif /* CONFIG_OF_GPIO */
72
73/**
74 * of_get_gpio - Get a GPIO number to use with GPIO API
75 * @np:		device node to get GPIO from
76 * @index:	index of the GPIO
77 *
78 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
79 * value on the error condition.
80 */
81static inline int of_get_gpio(struct device_node *np, int index)
82{
83	return of_get_gpio_flags(np, index, NULL);
84}
85
86#endif /* __LINUX_OF_GPIO_H */
87