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 #include <linux/of.h>
22
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
34 #ifdef CONFIG_OF_GPIO
35
36 /*
37 * OF GPIO chip for memory mapped banks
38 */
39 struct of_mm_gpio_chip {
40 struct gpio_chip gc;
41 void (*save_regs)(struct of_mm_gpio_chip *mm_gc);
42 void __iomem *regs;
43 };
44
to_of_mm_gpio_chip(struct gpio_chip * gc)45 static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc)
46 {
47 return container_of(gc, struct of_mm_gpio_chip, gc);
48 }
49
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
53 extern unsigned int of_gpio_count(struct device_node *np);
54
55 extern int of_mm_gpiochip_add(struct device_node *np,
56 struct of_mm_gpio_chip *mm_gc);
57
58 extern void of_gpiochip_add(struct gpio_chip *gc);
59 extern void of_gpiochip_remove(struct gpio_chip *gc);
60 extern struct gpio_chip *of_node_to_gpiochip(struct device_node *np);
61 extern int of_gpio_simple_xlate(struct gpio_chip *gc,
62 const struct of_phandle_args *gpiospec,
63 u32 *flags);
64
65 #else /* CONFIG_OF_GPIO */
66
67 /* Drivers may not strictly depend on the GPIO support, so let them link. */
of_get_named_gpio_flags(struct device_node * np,const char * list_name,int index,enum of_gpio_flags * flags)68 static inline int of_get_named_gpio_flags(struct device_node *np,
69 const char *list_name, int index, enum of_gpio_flags *flags)
70 {
71 return -ENOSYS;
72 }
73
of_gpio_count(struct device_node * np)74 static inline unsigned int of_gpio_count(struct device_node *np)
75 {
76 return 0;
77 }
78
of_gpio_simple_xlate(struct gpio_chip * gc,const struct of_phandle_args * gpiospec,u32 * flags)79 static inline int of_gpio_simple_xlate(struct gpio_chip *gc,
80 const struct of_phandle_args *gpiospec,
81 u32 *flags)
82 {
83 return -ENOSYS;
84 }
85
of_gpiochip_add(struct gpio_chip * gc)86 static inline void of_gpiochip_add(struct gpio_chip *gc) { }
of_gpiochip_remove(struct gpio_chip * gc)87 static inline void of_gpiochip_remove(struct gpio_chip *gc) { }
88
89 #endif /* CONFIG_OF_GPIO */
90
91 /**
92 * of_get_gpio_flags() - Get a GPIO number and flags to use with GPIO API
93 * @np: device node to get GPIO from
94 * @index: index of the GPIO
95 * @flags: a flags pointer to fill in
96 *
97 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
98 * value on the error condition. If @flags is not NULL the function also fills
99 * in flags for the GPIO.
100 */
of_get_gpio_flags(struct device_node * np,int index,enum of_gpio_flags * flags)101 static inline int of_get_gpio_flags(struct device_node *np, int index,
102 enum of_gpio_flags *flags)
103 {
104 return of_get_named_gpio_flags(np, "gpios", index, flags);
105 }
106
107 /**
108 * of_get_named_gpio() - Get a GPIO number to use with GPIO API
109 * @np: device node to get GPIO from
110 * @propname: Name of property containing gpio specifier(s)
111 * @index: index of the GPIO
112 *
113 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
114 * value on the error condition.
115 */
of_get_named_gpio(struct device_node * np,const char * propname,int index)116 static inline int of_get_named_gpio(struct device_node *np,
117 const char *propname, int index)
118 {
119 return of_get_named_gpio_flags(np, propname, index, NULL);
120 }
121
122 /**
123 * of_get_gpio() - Get a GPIO number to use with GPIO API
124 * @np: device node to get GPIO from
125 * @index: index of the GPIO
126 *
127 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
128 * value on the error condition.
129 */
of_get_gpio(struct device_node * np,int index)130 static inline int of_get_gpio(struct device_node *np, int index)
131 {
132 return of_get_gpio_flags(np, index, NULL);
133 }
134
135 #endif /* __LINUX_OF_GPIO_H */
136