1 /* 2 * OF helpers for the GPIO API 3 * 4 * Copyright (c) 2007-2008 MontaVista Software, Inc. 5 * 6 * Author: Anton Vorontsov <avorontsov@ru.mvista.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 */ 13 14 #ifndef __LINUX_OF_GPIO_H 15 #define __LINUX_OF_GPIO_H 16 17 #include <linux/compiler.h> 18 #include <linux/kernel.h> 19 #include <linux/errno.h> 20 #include <linux/gpio.h> 21 #include <linux/of.h> 22 23 struct device_node; 24 25 /* 26 * This is Linux-specific flags. By default controllers' and Linux' mapping 27 * match, but GPIO controllers are free to translate their own flags to 28 * Linux-specific in their .xlate callback. Though, 1:1 mapping is recommended. 29 */ 30 enum of_gpio_flags { 31 OF_GPIO_ACTIVE_LOW = 0x1, 32 OF_GPIO_SINGLE_ENDED = 0x2, 33 OF_GPIO_OPEN_DRAIN = 0x4, 34 OF_GPIO_SLEEP_MAY_LOSE_VALUE = 0x8, 35 }; 36 37 #ifdef CONFIG_OF_GPIO 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(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 extern int of_gpio_simple_xlate(struct gpio_chip *gc, 67 const struct of_phandle_args *gpiospec, 68 u32 *flags); 69 70 #else /* CONFIG_OF_GPIO */ 71 72 /* Drivers may not strictly depend on the GPIO support, so let them link. */ 73 static inline int of_get_named_gpio_flags(struct device_node *np, 74 const char *list_name, int index, enum of_gpio_flags *flags) 75 { 76 if (flags) 77 *flags = 0; 78 79 return -ENOSYS; 80 } 81 82 static inline int of_gpio_simple_xlate(struct gpio_chip *gc, 83 const struct of_phandle_args *gpiospec, 84 u32 *flags) 85 { 86 return -ENOSYS; 87 } 88 89 #endif /* CONFIG_OF_GPIO */ 90 91 /** 92 * of_gpio_named_count() - Count GPIOs for a device 93 * @np: device node to count GPIOs for 94 * @propname: property name containing gpio specifier(s) 95 * 96 * The function returns the count of GPIOs specified for a node. 97 * Note that the empty GPIO specifiers count too. Returns either 98 * Number of gpios defined in property, 99 * -EINVAL for an incorrectly formed gpios property, or 100 * -ENOENT for a missing gpios property 101 * 102 * Example: 103 * gpios = <0 104 * &gpio1 1 2 105 * 0 106 * &gpio2 3 4>; 107 * 108 * The above example defines four GPIOs, two of which are not specified. 109 * This function will return '4' 110 */ 111 static inline int of_gpio_named_count(struct device_node *np, const char* propname) 112 { 113 return of_count_phandle_with_args(np, propname, "#gpio-cells"); 114 } 115 116 /** 117 * of_gpio_count() - Count GPIOs for a device 118 * @np: device node to count GPIOs for 119 * 120 * Same as of_gpio_named_count, but hard coded to use the 'gpios' property 121 */ 122 static inline int of_gpio_count(struct device_node *np) 123 { 124 return of_gpio_named_count(np, "gpios"); 125 } 126 127 static inline int of_get_gpio_flags(struct device_node *np, int index, 128 enum of_gpio_flags *flags) 129 { 130 return of_get_named_gpio_flags(np, "gpios", index, flags); 131 } 132 133 /** 134 * of_get_named_gpio() - Get a GPIO number to use with GPIO API 135 * @np: device node to get GPIO from 136 * @propname: Name of property containing gpio specifier(s) 137 * @index: index of the GPIO 138 * 139 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno 140 * value on the error condition. 141 */ 142 static inline int of_get_named_gpio(struct device_node *np, 143 const char *propname, int index) 144 { 145 return of_get_named_gpio_flags(np, propname, index, NULL); 146 } 147 148 /** 149 * of_get_gpio() - Get a GPIO number to use with GPIO API 150 * @np: device node to get GPIO from 151 * @index: index of the GPIO 152 * 153 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno 154 * value on the error condition. 155 */ 156 static inline int of_get_gpio(struct device_node *np, int index) 157 { 158 return of_get_gpio_flags(np, index, NULL); 159 } 160 161 #endif /* __LINUX_OF_GPIO_H */ 162