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 }; 32 33 #ifdef CONFIG_OF_GPIO 34 35 /* 36 * OF GPIO chip for memory mapped banks 37 */ 38 struct of_mm_gpio_chip { 39 struct gpio_chip gc; 40 void (*save_regs)(struct of_mm_gpio_chip *mm_gc); 41 void __iomem *regs; 42 }; 43 44 static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc) 45 { 46 return container_of(gc, struct of_mm_gpio_chip, gc); 47 } 48 49 extern int of_get_named_gpio_flags(struct device_node *np, 50 const char *list_name, int index, enum of_gpio_flags *flags); 51 52 extern int of_mm_gpiochip_add_data(struct device_node *np, 53 struct of_mm_gpio_chip *mm_gc, 54 void *data); 55 static inline int of_mm_gpiochip_add(struct device_node *np, 56 struct of_mm_gpio_chip *mm_gc) 57 { 58 return of_mm_gpiochip_add_data(np, mm_gc, NULL); 59 } 60 extern void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc); 61 62 extern int of_gpio_simple_xlate(struct gpio_chip *gc, 63 const struct of_phandle_args *gpiospec, 64 u32 *flags); 65 66 #else /* CONFIG_OF_GPIO */ 67 68 /* Drivers may not strictly depend on the GPIO support, so let them link. */ 69 static inline int of_get_named_gpio_flags(struct device_node *np, 70 const char *list_name, int index, enum of_gpio_flags *flags) 71 { 72 if (flags) 73 *flags = 0; 74 75 return -ENOSYS; 76 } 77 78 static inline int of_gpio_simple_xlate(struct gpio_chip *gc, 79 const struct of_phandle_args *gpiospec, 80 u32 *flags) 81 { 82 return -ENOSYS; 83 } 84 85 #endif /* CONFIG_OF_GPIO */ 86 87 /** 88 * of_gpio_named_count() - Count GPIOs for a device 89 * @np: device node to count GPIOs for 90 * @propname: property name containing gpio specifier(s) 91 * 92 * The function returns the count of GPIOs specified for a node. 93 * Note that the empty GPIO specifiers count too. Returns either 94 * Number of gpios defined in property, 95 * -EINVAL for an incorrectly formed gpios property, or 96 * -ENOENT for a missing gpios property 97 * 98 * Example: 99 * gpios = <0 100 * &gpio1 1 2 101 * 0 102 * &gpio2 3 4>; 103 * 104 * The above example defines four GPIOs, two of which are not specified. 105 * This function will return '4' 106 */ 107 static inline int of_gpio_named_count(struct device_node *np, const char* propname) 108 { 109 return of_count_phandle_with_args(np, propname, "#gpio-cells"); 110 } 111 112 /** 113 * of_gpio_count() - Count GPIOs for a device 114 * @np: device node to count GPIOs for 115 * 116 * Same as of_gpio_named_count, but hard coded to use the 'gpios' property 117 */ 118 static inline int of_gpio_count(struct device_node *np) 119 { 120 return of_gpio_named_count(np, "gpios"); 121 } 122 123 static inline int of_get_gpio_flags(struct device_node *np, int index, 124 enum of_gpio_flags *flags) 125 { 126 return of_get_named_gpio_flags(np, "gpios", index, flags); 127 } 128 129 /** 130 * of_get_named_gpio() - Get a GPIO number to use with GPIO API 131 * @np: device node to get GPIO from 132 * @propname: Name of property containing gpio specifier(s) 133 * @index: index of the GPIO 134 * 135 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno 136 * value on the error condition. 137 */ 138 static inline int of_get_named_gpio(struct device_node *np, 139 const char *propname, int index) 140 { 141 return of_get_named_gpio_flags(np, propname, index, NULL); 142 } 143 144 /** 145 * of_get_gpio() - Get a GPIO number to use with GPIO API 146 * @np: device node to get GPIO from 147 * @index: index of the GPIO 148 * 149 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno 150 * value on the error condition. 151 */ 152 static inline int of_get_gpio(struct device_node *np, int index) 153 { 154 return of_get_gpio_flags(np, index, NULL); 155 } 156 157 #endif /* __LINUX_OF_GPIO_H */ 158