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 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); 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. */ 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 */ 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 */ 114 static inline int of_gpio_count(const struct device_node *np) 115 { 116 return of_gpio_named_count(np, "gpios"); 117 } 118 119 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 */ 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 */ 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