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
22 struct 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 */
29 enum of_gpio_flags {
30 OF_GPIO_ACTIVE_LOW = 0x1,
31 };
32
33 #ifdef CONFIG_OF_GPIO
34
35 /*
36 * Generic OF GPIO chip
37 */
38 struct of_gpio_chip {
39 struct gpio_chip gc;
40 int gpio_cells;
41 int (*xlate)(struct of_gpio_chip *of_gc, struct device_node *np,
42 const void *gpio_spec, enum of_gpio_flags *flags);
43 };
44
to_of_gpio_chip(struct gpio_chip * gc)45 static inline struct of_gpio_chip *to_of_gpio_chip(struct gpio_chip *gc)
46 {
47 return container_of(gc, struct of_gpio_chip, gc);
48 }
49
50 /*
51 * OF GPIO chip for memory mapped banks
52 */
53 struct of_mm_gpio_chip {
54 struct of_gpio_chip of_gc;
55 void (*save_regs)(struct of_mm_gpio_chip *mm_gc);
56 void __iomem *regs;
57 };
58
to_of_mm_gpio_chip(struct gpio_chip * gc)59 static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc)
60 {
61 struct of_gpio_chip *of_gc = to_of_gpio_chip(gc);
62
63 return container_of(of_gc, struct of_mm_gpio_chip, of_gc);
64 }
65
66 extern int of_get_gpio_flags(struct device_node *np, int index,
67 enum of_gpio_flags *flags);
68 extern unsigned int of_gpio_count(struct device_node *np);
69
70 extern int of_mm_gpiochip_add(struct device_node *np,
71 struct of_mm_gpio_chip *mm_gc);
72 extern int of_gpio_simple_xlate(struct of_gpio_chip *of_gc,
73 struct device_node *np,
74 const void *gpio_spec,
75 enum of_gpio_flags *flags);
76 #else
77
78 /* Drivers may not strictly depend on the GPIO support, so let them link. */
of_get_gpio_flags(struct device_node * np,int index,enum of_gpio_flags * flags)79 static inline int of_get_gpio_flags(struct device_node *np, int index,
80 enum of_gpio_flags *flags)
81 {
82 return -ENOSYS;
83 }
84
of_gpio_count(struct device_node * np)85 static inline unsigned int of_gpio_count(struct device_node *np)
86 {
87 return 0;
88 }
89
90 #endif /* CONFIG_OF_GPIO */
91
92 /**
93 * of_get_gpio - Get a GPIO number to use with GPIO API
94 * @np: device node to get GPIO from
95 * @index: index of the GPIO
96 *
97 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
98 * value on the error condition.
99 */
of_get_gpio(struct device_node * np,int index)100 static inline int of_get_gpio(struct device_node *np, int index)
101 {
102 return of_get_gpio_flags(np, index, NULL);
103 }
104
105 #endif /* __LINUX_OF_GPIO_H */
106