1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * <linux/gpio.h> 4 * 5 * This is the LEGACY GPIO bulk include file, including legacy APIs. It is 6 * used for GPIO drivers still referencing the global GPIO numberspace, 7 * and should not be included in new code. 8 * 9 * If you're implementing a GPIO driver, only include <linux/gpio/driver.h> 10 * If you're implementing a GPIO consumer, only include <linux/gpio/consumer.h> 11 */ 12 #ifndef __LINUX_GPIO_H 13 #define __LINUX_GPIO_H 14 15 #include <linux/types.h> 16 17 struct device; 18 19 /* see Documentation/driver-api/gpio/legacy.rst */ 20 21 /* make these flag values available regardless of GPIO kconfig options */ 22 #define GPIOF_DIR_OUT (0 << 0) 23 #define GPIOF_DIR_IN (1 << 0) 24 25 #define GPIOF_INIT_LOW (0 << 1) 26 #define GPIOF_INIT_HIGH (1 << 1) 27 28 #define GPIOF_IN (GPIOF_DIR_IN) 29 #define GPIOF_OUT_INIT_LOW (GPIOF_DIR_OUT | GPIOF_INIT_LOW) 30 #define GPIOF_OUT_INIT_HIGH (GPIOF_DIR_OUT | GPIOF_INIT_HIGH) 31 32 /* Gpio pin is active-low */ 33 #define GPIOF_ACTIVE_LOW (1 << 2) 34 35 /** 36 * struct gpio - a structure describing a GPIO with configuration 37 * @gpio: the GPIO number 38 * @flags: GPIO configuration as specified by GPIOF_* 39 * @label: a literal description string of this GPIO 40 */ 41 struct gpio { 42 unsigned gpio; 43 unsigned long flags; 44 const char *label; 45 }; 46 47 #ifdef CONFIG_GPIOLIB 48 49 #include <linux/gpio/consumer.h> 50 51 /* 52 * "valid" GPIO numbers are nonnegative and may be passed to 53 * setup routines like gpio_request(). Only some valid numbers 54 * can successfully be requested and used. 55 * 56 * Invalid GPIO numbers are useful for indicating no-such-GPIO in 57 * platform data and other tables. 58 */ 59 static inline bool gpio_is_valid(int number) 60 { 61 /* only non-negative numbers are valid */ 62 return number >= 0; 63 } 64 65 /* 66 * Platforms may implement their GPIO interface with library code, 67 * at a small performance cost for non-inlined operations and some 68 * extra memory (for code and for per-GPIO table entries). 69 */ 70 71 /* 72 * At the end we want all GPIOs to be dynamically allocated from 0. 73 * However, some legacy drivers still perform fixed allocation. 74 * Until they are all fixed, leave 0-512 space for them. 75 */ 76 #define GPIO_DYNAMIC_BASE 512 77 /* 78 * Define the maximum of the possible GPIO in the global numberspace. 79 * While the GPIO base and numbers are positive, we limit it with signed 80 * maximum as a lot of code is using negative values for special cases. 81 */ 82 #define GPIO_DYNAMIC_MAX INT_MAX 83 84 /* Always use the library code for GPIO management calls, 85 * or when sleeping may be involved. 86 */ 87 int gpio_request(unsigned gpio, const char *label); 88 void gpio_free(unsigned gpio); 89 90 static inline int gpio_direction_input(unsigned gpio) 91 { 92 return gpiod_direction_input(gpio_to_desc(gpio)); 93 } 94 static inline int gpio_direction_output(unsigned gpio, int value) 95 { 96 return gpiod_direction_output_raw(gpio_to_desc(gpio), value); 97 } 98 99 static inline int gpio_get_value_cansleep(unsigned gpio) 100 { 101 return gpiod_get_raw_value_cansleep(gpio_to_desc(gpio)); 102 } 103 static inline void gpio_set_value_cansleep(unsigned gpio, int value) 104 { 105 return gpiod_set_raw_value_cansleep(gpio_to_desc(gpio), value); 106 } 107 108 static inline int gpio_get_value(unsigned gpio) 109 { 110 return gpiod_get_raw_value(gpio_to_desc(gpio)); 111 } 112 static inline void gpio_set_value(unsigned gpio, int value) 113 { 114 return gpiod_set_raw_value(gpio_to_desc(gpio), value); 115 } 116 117 static inline int gpio_to_irq(unsigned gpio) 118 { 119 return gpiod_to_irq(gpio_to_desc(gpio)); 120 } 121 122 int gpio_request_one(unsigned gpio, unsigned long flags, const char *label); 123 124 /* CONFIG_GPIOLIB: bindings for managed devices that want to request gpios */ 125 126 int devm_gpio_request(struct device *dev, unsigned gpio, const char *label); 127 int devm_gpio_request_one(struct device *dev, unsigned gpio, 128 unsigned long flags, const char *label); 129 130 #else /* ! CONFIG_GPIOLIB */ 131 132 #include <linux/kernel.h> 133 134 #include <asm/bug.h> 135 #include <asm/errno.h> 136 137 static inline bool gpio_is_valid(int number) 138 { 139 return false; 140 } 141 142 static inline int gpio_request(unsigned gpio, const char *label) 143 { 144 return -ENOSYS; 145 } 146 147 static inline int gpio_request_one(unsigned gpio, 148 unsigned long flags, const char *label) 149 { 150 return -ENOSYS; 151 } 152 153 static inline void gpio_free(unsigned gpio) 154 { 155 might_sleep(); 156 157 /* GPIO can never have been requested */ 158 WARN_ON(1); 159 } 160 161 static inline int gpio_direction_input(unsigned gpio) 162 { 163 return -ENOSYS; 164 } 165 166 static inline int gpio_direction_output(unsigned gpio, int value) 167 { 168 return -ENOSYS; 169 } 170 171 static inline int gpio_get_value(unsigned gpio) 172 { 173 /* GPIO can never have been requested or set as {in,out}put */ 174 WARN_ON(1); 175 return 0; 176 } 177 178 static inline void gpio_set_value(unsigned gpio, int value) 179 { 180 /* GPIO can never have been requested or set as output */ 181 WARN_ON(1); 182 } 183 184 static inline int gpio_get_value_cansleep(unsigned gpio) 185 { 186 /* GPIO can never have been requested or set as {in,out}put */ 187 WARN_ON(1); 188 return 0; 189 } 190 191 static inline void gpio_set_value_cansleep(unsigned gpio, int value) 192 { 193 /* GPIO can never have been requested or set as output */ 194 WARN_ON(1); 195 } 196 197 static inline int gpio_to_irq(unsigned gpio) 198 { 199 /* GPIO can never have been requested or set as input */ 200 WARN_ON(1); 201 return -EINVAL; 202 } 203 204 static inline int devm_gpio_request(struct device *dev, unsigned gpio, 205 const char *label) 206 { 207 WARN_ON(1); 208 return -EINVAL; 209 } 210 211 static inline int devm_gpio_request_one(struct device *dev, unsigned gpio, 212 unsigned long flags, const char *label) 213 { 214 WARN_ON(1); 215 return -EINVAL; 216 } 217 218 #endif /* ! CONFIG_GPIOLIB */ 219 220 #endif /* __LINUX_GPIO_H */ 221