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