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(const 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(const struct device_node * np,const char * list_name,int index,enum of_gpio_flags * flags)70 static inline int of_get_named_gpio_flags(const 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(const struct device_node * np,const char * propname)101 static inline int of_gpio_named_count(const struct device_node *np,
102 				      const char *propname)
103 {
104 	return of_count_phandle_with_args(np, propname, "#gpio-cells");
105 }
106 
107 /**
108  * of_gpio_count() - Count GPIOs for a device
109  * @np:		device node to count GPIOs for
110  *
111  * Same as of_gpio_named_count, but hard coded to use the 'gpios' property
112  */
of_gpio_count(const struct device_node * np)113 static inline int of_gpio_count(const struct device_node *np)
114 {
115 	return of_gpio_named_count(np, "gpios");
116 }
117 
of_get_gpio_flags(const struct device_node * np,int index,enum of_gpio_flags * flags)118 static inline int of_get_gpio_flags(const struct device_node *np, int index,
119 		      enum of_gpio_flags *flags)
120 {
121 	return of_get_named_gpio_flags(np, "gpios", index, flags);
122 }
123 
124 /**
125  * of_get_named_gpio() - Get a GPIO number to use with GPIO API
126  * @np:		device node to get GPIO from
127  * @propname:	Name of property containing gpio specifier(s)
128  * @index:	index of the GPIO
129  *
130  * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
131  * value on the error condition.
132  */
of_get_named_gpio(const struct device_node * np,const char * propname,int index)133 static inline int of_get_named_gpio(const struct device_node *np,
134                                    const char *propname, int index)
135 {
136 	return of_get_named_gpio_flags(np, propname, index, NULL);
137 }
138 
139 /**
140  * of_get_gpio() - Get a GPIO number to use with GPIO API
141  * @np:		device node to get GPIO from
142  * @index:	index of the GPIO
143  *
144  * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
145  * value on the error condition.
146  */
of_get_gpio(const struct device_node * np,int index)147 static inline int of_get_gpio(const struct device_node *np, int index)
148 {
149 	return of_get_gpio_flags(np, index, NULL);
150 }
151 
152 #endif /* __LINUX_OF_GPIO_H */
153