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/gpio/driver.h>
15 #include <linux/gpio.h> /* FIXME: Shouldn't be here */
16 #include <linux/of.h>
17
18 struct device_node;
19
20 /*
21 * This is Linux-specific flags. By default controllers' and Linux' mapping
22 * match, but GPIO controllers are free to translate their own flags to
23 * Linux-specific in their .xlate callback. Though, 1:1 mapping is recommended.
24 */
25 enum of_gpio_flags {
26 OF_GPIO_ACTIVE_LOW = 0x1,
27 OF_GPIO_SINGLE_ENDED = 0x2,
28 OF_GPIO_OPEN_DRAIN = 0x4,
29 OF_GPIO_TRANSITORY = 0x8,
30 OF_GPIO_PULL_UP = 0x10,
31 OF_GPIO_PULL_DOWN = 0x20,
32 OF_GPIO_PULL_DISABLE = 0x40,
33 };
34
35 #ifdef CONFIG_OF_GPIO
36
37 #include <linux/kernel.h>
38
39 /*
40 * OF GPIO chip for memory mapped banks
41 */
42 struct of_mm_gpio_chip {
43 struct gpio_chip gc;
44 void (*save_regs)(struct of_mm_gpio_chip *mm_gc);
45 void __iomem *regs;
46 };
47
to_of_mm_gpio_chip(struct gpio_chip * gc)48 static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc)
49 {
50 return container_of(gc, struct of_mm_gpio_chip, gc);
51 }
52
53 extern int of_get_named_gpio_flags(const struct device_node *np,
54 const char *list_name, int index, enum of_gpio_flags *flags);
55
56 extern int of_mm_gpiochip_add_data(struct device_node *np,
57 struct of_mm_gpio_chip *mm_gc,
58 void *data);
of_mm_gpiochip_add(struct device_node * np,struct of_mm_gpio_chip * mm_gc)59 static inline int of_mm_gpiochip_add(struct device_node *np,
60 struct of_mm_gpio_chip *mm_gc)
61 {
62 return of_mm_gpiochip_add_data(np, mm_gc, NULL);
63 }
64 extern void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc);
65
66 #else /* CONFIG_OF_GPIO */
67
68 #include <linux/errno.h>
69
70 /* Drivers may not strictly depend on the GPIO support, so let them link. */
of_get_named_gpio_flags(const struct device_node * np,const char * list_name,int index,enum of_gpio_flags * flags)71 static inline int of_get_named_gpio_flags(const struct device_node *np,
72 const char *list_name, int index, enum of_gpio_flags *flags)
73 {
74 if (flags)
75 *flags = 0;
76
77 return -ENOSYS;
78 }
79
80 #endif /* CONFIG_OF_GPIO */
81
82 /**
83 * of_gpio_named_count() - Count GPIOs for a device
84 * @np: device node to count GPIOs for
85 * @propname: property name containing gpio specifier(s)
86 *
87 * The function returns the count of GPIOs specified for a node.
88 * Note that the empty GPIO specifiers count too. Returns either
89 * Number of gpios defined in property,
90 * -EINVAL for an incorrectly formed gpios property, or
91 * -ENOENT for a missing gpios property
92 *
93 * Example:
94 * gpios = <0
95 * &gpio1 1 2
96 * 0
97 * &gpio2 3 4>;
98 *
99 * The above example defines four GPIOs, two of which are not specified.
100 * This function will return '4'
101 */
of_gpio_named_count(const struct device_node * np,const char * propname)102 static inline int of_gpio_named_count(const struct device_node *np,
103 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
111 *
112 * Same as of_gpio_named_count, but hard coded to use the 'gpios' property
113 */
of_gpio_count(const struct device_node * np)114 static inline int of_gpio_count(const struct device_node *np)
115 {
116 return of_gpio_named_count(np, "gpios");
117 }
118
of_get_gpio_flags(const struct device_node * np,int index,enum of_gpio_flags * flags)119 static inline int of_get_gpio_flags(const struct device_node *np, int index,
120 enum of_gpio_flags *flags)
121 {
122 return of_get_named_gpio_flags(np, "gpios", index, flags);
123 }
124
125 /**
126 * of_get_named_gpio() - Get a GPIO number to use with GPIO API
127 * @np: device node to get GPIO from
128 * @propname: Name of property containing gpio specifier(s)
129 * @index: index of the GPIO
130 *
131 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
132 * value on the error condition.
133 */
of_get_named_gpio(const struct device_node * np,const char * propname,int index)134 static inline int of_get_named_gpio(const struct device_node *np,
135 const char *propname, int index)
136 {
137 return of_get_named_gpio_flags(np, propname, index, NULL);
138 }
139
140 /**
141 * of_get_gpio() - Get a GPIO number to use with GPIO API
142 * @np: device node to get GPIO from
143 * @index: index of the GPIO
144 *
145 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
146 * value on the error condition.
147 */
of_get_gpio(const struct device_node * np,int index)148 static inline int of_get_gpio(const struct device_node *np, int index)
149 {
150 return of_get_gpio_flags(np, index, NULL);
151 }
152
153 #endif /* __LINUX_OF_GPIO_H */
154