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863fbf49 AV |
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 | ||
b908b53d AV |
17 | #include <linux/compiler.h> |
18 | #include <linux/kernel.h> | |
863fbf49 | 19 | #include <linux/errno.h> |
18ad7a61 | 20 | #include <linux/gpio.h> |
15c9a0ac | 21 | #include <linux/of.h> |
863fbf49 | 22 | |
b908b53d AV |
23 | struct device_node; |
24 | ||
25 | /* | |
26 | * This is Linux-specific flags. By default controllers' and Linux' mapping | |
27 | * match, but GPIO controllers are free to translate their own flags to | |
28 | * Linux-specific in their .xlate callback. Though, 1:1 mapping is recommended. | |
29 | */ | |
30 | enum of_gpio_flags { | |
31 | OF_GPIO_ACTIVE_LOW = 0x1, | |
32 | }; | |
33 | ||
863fbf49 AV |
34 | #ifdef CONFIG_OF_GPIO |
35 | ||
863fbf49 AV |
36 | /* |
37 | * OF GPIO chip for memory mapped banks | |
38 | */ | |
39 | struct of_mm_gpio_chip { | |
a19e3da5 | 40 | struct gpio_chip gc; |
863fbf49 AV |
41 | void (*save_regs)(struct of_mm_gpio_chip *mm_gc); |
42 | void __iomem *regs; | |
43 | }; | |
44 | ||
45 | static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc) | |
46 | { | |
a19e3da5 | 47 | return container_of(gc, struct of_mm_gpio_chip, gc); |
863fbf49 AV |
48 | } |
49 | ||
a6b09191 JB |
50 | extern int of_get_named_gpio_flags(struct device_node *np, |
51 | const char *list_name, int index, enum of_gpio_flags *flags); | |
52 | ||
863fbf49 AV |
53 | extern int of_mm_gpiochip_add(struct device_node *np, |
54 | struct of_mm_gpio_chip *mm_gc); | |
594fa265 | 55 | |
391c970c AV |
56 | extern void of_gpiochip_add(struct gpio_chip *gc); |
57 | extern void of_gpiochip_remove(struct gpio_chip *gc); | |
15c9a0ac GL |
58 | extern int of_gpio_simple_xlate(struct gpio_chip *gc, |
59 | const struct of_phandle_args *gpiospec, | |
60 | u32 *flags); | |
594fa265 | 61 | |
a19e3da5 | 62 | #else /* CONFIG_OF_GPIO */ |
863fbf49 AV |
63 | |
64 | /* Drivers may not strictly depend on the GPIO support, so let them link. */ | |
a6b09191 JB |
65 | static inline int of_get_named_gpio_flags(struct device_node *np, |
66 | const char *list_name, int index, enum of_gpio_flags *flags) | |
863fbf49 AV |
67 | { |
68 | return -ENOSYS; | |
69 | } | |
70 | ||
3038bbdf | 71 | static inline int of_gpio_simple_xlate(struct gpio_chip *gc, |
15c9a0ac GL |
72 | const struct of_phandle_args *gpiospec, |
73 | u32 *flags) | |
3038bbdf JI |
74 | { |
75 | return -ENOSYS; | |
76 | } | |
77 | ||
391c970c AV |
78 | static inline void of_gpiochip_add(struct gpio_chip *gc) { } |
79 | static inline void of_gpiochip_remove(struct gpio_chip *gc) { } | |
80 | ||
863fbf49 AV |
81 | #endif /* CONFIG_OF_GPIO */ |
82 | ||
ff64abef | 83 | /** |
e80beb27 | 84 | * of_gpio_named_count() - Count GPIOs for a device |
ff64abef | 85 | * @np: device node to count GPIOs for |
e80beb27 | 86 | * @propname: property name containing gpio specifier(s) |
ff64abef JCPV |
87 | * |
88 | * The function returns the count of GPIOs specified for a node. | |
e80beb27 GL |
89 | * Note that the empty GPIO specifiers count too. Returns either |
90 | * Number of gpios defined in property, | |
91 | * -EINVAL for an incorrectly formed gpios property, or | |
92 | * -ENOENT for a missing gpios property | |
ff64abef | 93 | * |
e80beb27 | 94 | * Example: |
ff64abef | 95 | * gpios = <0 |
e80beb27 | 96 | * &gpio1 1 2 |
ff64abef | 97 | * 0 |
e80beb27 GL |
98 | * &gpio2 3 4>; |
99 | * | |
100 | * The above example defines four GPIOs, two of which are not specified. | |
101 | * This function will return '4' | |
102 | */ | |
103 | static inline int of_gpio_named_count(struct device_node *np, const char* propname) | |
104 | { | |
105 | return of_count_phandle_with_args(np, propname, "#gpio-cells"); | |
106 | } | |
107 | ||
108 | /** | |
109 | * of_gpio_count() - Count GPIOs for a device | |
110 | * @np: device node to count GPIOs for | |
ff64abef | 111 | * |
e80beb27 | 112 | * Same as of_gpio_named_count, but hard coded to use the 'gpios' property |
ff64abef | 113 | */ |
e80beb27 | 114 | static inline int of_gpio_count(struct device_node *np) |
ff64abef JCPV |
115 | { |
116 | return of_gpio_named_count(np, "gpios"); | |
117 | } | |
118 | ||
b908b53d | 119 | /** |
a6b09191 JB |
120 | * of_get_gpio_flags() - Get a GPIO number and flags to use with GPIO API |
121 | * @np: device node to get GPIO from | |
122 | * @index: index of the GPIO | |
123 | * @flags: a flags pointer to fill in | |
124 | * | |
125 | * Returns GPIO number to use with Linux generic GPIO API, or one of the errno | |
126 | * value on the error condition. If @flags is not NULL the function also fills | |
127 | * in flags for the GPIO. | |
128 | */ | |
129 | static inline int of_get_gpio_flags(struct device_node *np, int index, | |
130 | enum of_gpio_flags *flags) | |
131 | { | |
132 | return of_get_named_gpio_flags(np, "gpios", index, flags); | |
133 | } | |
134 | ||
135 | /** | |
136 | * of_get_named_gpio() - Get a GPIO number to use with GPIO API | |
137 | * @np: device node to get GPIO from | |
138 | * @propname: Name of property containing gpio specifier(s) | |
139 | * @index: index of the GPIO | |
140 | * | |
141 | * Returns GPIO number to use with Linux generic GPIO API, or one of the errno | |
142 | * value on the error condition. | |
143 | */ | |
144 | static inline int of_get_named_gpio(struct device_node *np, | |
145 | const char *propname, int index) | |
146 | { | |
147 | return of_get_named_gpio_flags(np, propname, index, NULL); | |
148 | } | |
149 | ||
150 | /** | |
151 | * of_get_gpio() - Get a GPIO number to use with GPIO API | |
b908b53d AV |
152 | * @np: device node to get GPIO from |
153 | * @index: index of the GPIO | |
154 | * | |
155 | * Returns GPIO number to use with Linux generic GPIO API, or one of the errno | |
156 | * value on the error condition. | |
157 | */ | |
158 | static inline int of_get_gpio(struct device_node *np, int index) | |
159 | { | |
160 | return of_get_gpio_flags(np, index, NULL); | |
161 | } | |
162 | ||
863fbf49 | 163 | #endif /* __LINUX_OF_GPIO_H */ |