1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3 * OF helpers for the GPIO API
4 *
5 * Copyright (c) 2007-2008 MontaVista Software, Inc.
6 *
7 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
8 */
9
10 #ifndef __LINUX_OF_GPIO_H
11 #define __LINUX_OF_GPIO_H
12
13 #include <linux/compiler.h>
14 #include <linux/kernel.h>
15 #include <linux/errno.h>
16 #include <linux/gpio.h>
17 #include <linux/of.h>
18
19 struct device_node;
20
21 /*
22 * This is Linux-specific flags. By default controllers' and Linux' mapping
23 * match, but GPIO controllers are free to translate their own flags to
24 * Linux-specific in their .xlate callback. Though, 1:1 mapping is recommended.
25 */
26 enum of_gpio_flags {
27 OF_GPIO_ACTIVE_LOW = 0x1,
28 OF_GPIO_SINGLE_ENDED = 0x2,
29 OF_GPIO_OPEN_DRAIN = 0x4,
30 OF_GPIO_TRANSITORY = 0x8,
31 OF_GPIO_PULL_UP = 0x10,
32 OF_GPIO_PULL_DOWN = 0x20,
33 };
34
35 #ifdef CONFIG_OF_GPIO
36
37 /*
38 * OF GPIO chip for memory mapped banks
39 */
40 struct of_mm_gpio_chip {
41 struct gpio_chip gc;
42 void (*save_regs)(struct of_mm_gpio_chip *mm_gc);
43 void __iomem *regs;
44 };
45
to_of_mm_gpio_chip(struct gpio_chip * gc)46 static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc)
47 {
48 return container_of(gc, struct of_mm_gpio_chip, gc);
49 }
50
51 extern int of_get_named_gpio_flags(struct device_node *np,
52 const char *list_name, int index, enum of_gpio_flags *flags);
53
54 extern int of_mm_gpiochip_add_data(struct device_node *np,
55 struct of_mm_gpio_chip *mm_gc,
56 void *data);
of_mm_gpiochip_add(struct device_node * np,struct of_mm_gpio_chip * mm_gc)57 static inline int of_mm_gpiochip_add(struct device_node *np,
58 struct of_mm_gpio_chip *mm_gc)
59 {
60 return of_mm_gpiochip_add_data(np, mm_gc, NULL);
61 }
62 extern void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc);
63
64 #else /* CONFIG_OF_GPIO */
65
66 /* 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)67 static inline int of_get_named_gpio_flags(struct device_node *np,
68 const char *list_name, int index, enum of_gpio_flags *flags)
69 {
70 if (flags)
71 *flags = 0;
72
73 return -ENOSYS;
74 }
75
76 #endif /* CONFIG_OF_GPIO */
77
78 /**
79 * of_gpio_named_count() - Count GPIOs for a device
80 * @np: device node to count GPIOs for
81 * @propname: property name containing gpio specifier(s)
82 *
83 * The function returns the count of GPIOs specified for a node.
84 * Note that the empty GPIO specifiers count too. Returns either
85 * Number of gpios defined in property,
86 * -EINVAL for an incorrectly formed gpios property, or
87 * -ENOENT for a missing gpios property
88 *
89 * Example:
90 * gpios = <0
91 * &gpio1 1 2
92 * 0
93 * &gpio2 3 4>;
94 *
95 * The above example defines four GPIOs, two of which are not specified.
96 * This function will return '4'
97 */
of_gpio_named_count(struct device_node * np,const char * propname)98 static inline int of_gpio_named_count(struct device_node *np, const char* propname)
99 {
100 return of_count_phandle_with_args(np, propname, "#gpio-cells");
101 }
102
103 /**
104 * of_gpio_count() - Count GPIOs for a device
105 * @np: device node to count GPIOs for
106 *
107 * Same as of_gpio_named_count, but hard coded to use the 'gpios' property
108 */
of_gpio_count(struct device_node * np)109 static inline int of_gpio_count(struct device_node *np)
110 {
111 return of_gpio_named_count(np, "gpios");
112 }
113
of_get_gpio_flags(struct device_node * np,int index,enum of_gpio_flags * flags)114 static inline int of_get_gpio_flags(struct device_node *np, int index,
115 enum of_gpio_flags *flags)
116 {
117 return of_get_named_gpio_flags(np, "gpios", index, flags);
118 }
119
120 /**
121 * of_get_named_gpio() - Get a GPIO number to use with GPIO API
122 * @np: device node to get GPIO from
123 * @propname: Name of property containing gpio specifier(s)
124 * @index: index of the GPIO
125 *
126 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
127 * value on the error condition.
128 */
of_get_named_gpio(struct device_node * np,const char * propname,int index)129 static inline int of_get_named_gpio(struct device_node *np,
130 const char *propname, int index)
131 {
132 return of_get_named_gpio_flags(np, propname, index, NULL);
133 }
134
135 /**
136 * of_get_gpio() - Get a GPIO number to use with GPIO API
137 * @np: device node to get GPIO from
138 * @index: index of the GPIO
139 *
140 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
141 * value on the error condition.
142 */
of_get_gpio(struct device_node * np,int index)143 static inline int of_get_gpio(struct device_node *np, int index)
144 {
145 return of_get_gpio_flags(np, index, NULL);
146 }
147
148 #endif /* __LINUX_OF_GPIO_H */
149