Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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);
55
56extern void of_gpiochip_add(struct gpio_chip *gc);
57extern void of_gpiochip_remove(struct gpio_chip *gc);
58extern struct gpio_chip *of_node_to_gpiochip(struct device_node *np);
59
60#else /* CONFIG_OF_GPIO */
61
62/* Drivers may not strictly depend on the GPIO support, so let them link. */
63static inline int of_get_gpio_flags(struct device_node *np, int index,
64 enum of_gpio_flags *flags)
65{
66 return -ENOSYS;
67}
68
69static inline unsigned int of_gpio_count(struct device_node *np)
70{
71 return 0;
72}
73
74static inline void of_gpiochip_add(struct gpio_chip *gc) { }
75static inline void of_gpiochip_remove(struct gpio_chip *gc) { }
76
77#endif /* CONFIG_OF_GPIO */
78
79/**
80 * of_get_gpio - Get a GPIO number to use with GPIO API
81 * @np: device node to get GPIO from
82 * @index: index of the GPIO
83 *
84 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
85 * value on the error condition.
86 */
87static inline int of_get_gpio(struct device_node *np, int index)
88{
89 return of_get_gpio_flags(np, index, NULL);
90}
91
92#endif /* __LINUX_OF_GPIO_H */