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 };
33
34 #ifdef CONFIG_OF_GPIO
35
36 #include <linux/kernel.h>
37
38 /*
39 * OF GPIO chip for memory mapped banks
40 */
41 struct of_mm_gpio_chip {
42 struct gpio_chip gc;
43 void (*save_regs)(struct of_mm_gpio_chip *mm_gc);
44 void __iomem *regs;
45 };
46
to_of_mm_gpio_chip(struct gpio_chip * gc)47 static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc)
48 {
49 return container_of(gc, struct of_mm_gpio_chip, gc);
50 }
51
52 extern int of_get_named_gpio_flags(struct device_node *np,
53 const char *list_name, int index, enum of_gpio_flags *flags);
54
55 extern int of_mm_gpiochip_add_data(struct device_node *np,
56 struct of_mm_gpio_chip *mm_gc,
57 void *data);
of_mm_gpiochip_add(struct device_node * np,struct of_mm_gpio_chip * mm_gc)58 static inline int of_mm_gpiochip_add(struct device_node *np,
59 struct of_mm_gpio_chip *mm_gc)
60 {
61 return of_mm_gpiochip_add_data(np, mm_gc, NULL);
62 }
63 extern void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc);
64
65 #else /* CONFIG_OF_GPIO */
66
67 #include <linux/errno.h>
68
69 /* 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)70 static inline int of_get_named_gpio_flags(struct device_node *np,
71 const char *list_name, int index, enum of_gpio_flags *flags)
72 {
73 if (flags)
74 *flags = 0;
75
76 return -ENOSYS;
77 }
78
79 #endif /* CONFIG_OF_GPIO */
80
81 /**
82 * of_gpio_named_count() - Count GPIOs for a device
83 * @np: device node to count GPIOs for
84 * @propname: property name containing gpio specifier(s)
85 *
86 * The function returns the count of GPIOs specified for a node.
87 * Note that the empty GPIO specifiers count too. Returns either
88 * Number of gpios defined in property,
89 * -EINVAL for an incorrectly formed gpios property, or
90 * -ENOENT for a missing gpios property
91 *
92 * Example:
93 * gpios = <0
94 * &gpio1 1 2
95 * 0
96 * &gpio2 3 4>;
97 *
98 * The above example defines four GPIOs, two of which are not specified.
99 * This function will return '4'
100 */
of_gpio_named_count(struct device_node * np,const char * propname)101 static inline int of_gpio_named_count(struct device_node *np, const char* propname)
102 {
103 return of_count_phandle_with_args(np, propname, "#gpio-cells");
104 }
105
106 /**
107 * of_gpio_count() - Count GPIOs for a device
108 * @np: device node to count GPIOs for
109 *
110 * Same as of_gpio_named_count, but hard coded to use the 'gpios' property
111 */
of_gpio_count(struct device_node * np)112 static inline int of_gpio_count(struct device_node *np)
113 {
114 return of_gpio_named_count(np, "gpios");
115 }
116
of_get_gpio_flags(struct device_node * np,int index,enum of_gpio_flags * flags)117 static inline int of_get_gpio_flags(struct device_node *np, int index,
118 enum of_gpio_flags *flags)
119 {
120 return of_get_named_gpio_flags(np, "gpios", index, flags);
121 }
122
123 /**
124 * of_get_named_gpio() - Get a GPIO number to use with GPIO API
125 * @np: device node to get GPIO from
126 * @propname: Name of property containing gpio specifier(s)
127 * @index: index of the GPIO
128 *
129 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
130 * value on the error condition.
131 */
of_get_named_gpio(struct device_node * np,const char * propname,int index)132 static inline int of_get_named_gpio(struct device_node *np,
133 const char *propname, int index)
134 {
135 return of_get_named_gpio_flags(np, propname, index, NULL);
136 }
137
138 /**
139 * of_get_gpio() - Get a GPIO number to use with GPIO API
140 * @np: device node to get GPIO from
141 * @index: index of the GPIO
142 *
143 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
144 * value on the error condition.
145 */
of_get_gpio(struct device_node * np,int index)146 static inline int of_get_gpio(struct device_node *np, int index)
147 {
148 return of_get_gpio_flags(np, index, NULL);
149 }
150
151 #endif /* __LINUX_OF_GPIO_H */
152
