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 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); 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. */ 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 */ 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 */ 113 static inline int of_gpio_count(const struct device_node *np) 114 { 115 return of_gpio_named_count(np, "gpios"); 116 } 117 118 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 */ 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 */ 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