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 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); 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 extern int of_gpio_simple_xlate(struct gpio_chip *gc, 65 const struct of_phandle_args *gpiospec, 66 u32 *flags); 67 68 #else /* CONFIG_OF_GPIO */ 69 70 /* Drivers may not strictly depend on the GPIO support, so let them link. */ 71 static inline int of_get_named_gpio_flags(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 static inline int of_gpio_simple_xlate(struct gpio_chip *gc, 81 const struct of_phandle_args *gpiospec, 82 u32 *flags) 83 { 84 return -ENOSYS; 85 } 86 87 #endif /* CONFIG_OF_GPIO */ 88 89 /** 90 * of_gpio_named_count() - Count GPIOs for a device 91 * @np: device node to count GPIOs for 92 * @propname: property name containing gpio specifier(s) 93 * 94 * The function returns the count of GPIOs specified for a node. 95 * Note that the empty GPIO specifiers count too. Returns either 96 * Number of gpios defined in property, 97 * -EINVAL for an incorrectly formed gpios property, or 98 * -ENOENT for a missing gpios property 99 * 100 * Example: 101 * gpios = <0 102 * &gpio1 1 2 103 * 0 104 * &gpio2 3 4>; 105 * 106 * The above example defines four GPIOs, two of which are not specified. 107 * This function will return '4' 108 */ 109 static inline int of_gpio_named_count(struct device_node *np, const char* propname) 110 { 111 return of_count_phandle_with_args(np, propname, "#gpio-cells"); 112 } 113 114 /** 115 * of_gpio_count() - Count GPIOs for a device 116 * @np: device node to count GPIOs for 117 * 118 * Same as of_gpio_named_count, but hard coded to use the 'gpios' property 119 */ 120 static inline int of_gpio_count(struct device_node *np) 121 { 122 return of_gpio_named_count(np, "gpios"); 123 } 124 125 static inline int of_get_gpio_flags(struct device_node *np, int index, 126 enum of_gpio_flags *flags) 127 { 128 return of_get_named_gpio_flags(np, "gpios", index, flags); 129 } 130 131 /** 132 * of_get_named_gpio() - Get a GPIO number to use with GPIO API 133 * @np: device node to get GPIO from 134 * @propname: Name of property containing gpio specifier(s) 135 * @index: index of the GPIO 136 * 137 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno 138 * value on the error condition. 139 */ 140 static inline int of_get_named_gpio(struct device_node *np, 141 const char *propname, int index) 142 { 143 return of_get_named_gpio_flags(np, propname, index, NULL); 144 } 145 146 /** 147 * of_get_gpio() - Get a GPIO number to use with GPIO API 148 * @np: device node to get GPIO from 149 * @index: index of the GPIO 150 * 151 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno 152 * value on the error condition. 153 */ 154 static inline int of_get_gpio(struct device_node *np, int index) 155 { 156 return of_get_gpio_flags(np, index, NULL); 157 } 158 159 #endif /* __LINUX_OF_GPIO_H */ 160