gpio.h (4537B)
1/* SPDX-License-Identifier: GPL-2.0 */ 2#ifndef _ASM_GENERIC_GPIO_H 3#define _ASM_GENERIC_GPIO_H 4 5#include <linux/types.h> 6#include <linux/errno.h> 7 8#ifdef CONFIG_GPIOLIB 9 10#include <linux/compiler.h> 11#include <linux/gpio/driver.h> 12#include <linux/gpio/consumer.h> 13 14/* Platforms may implement their GPIO interface with library code, 15 * at a small performance cost for non-inlined operations and some 16 * extra memory (for code and for per-GPIO table entries). 17 * 18 * While the GPIO programming interface defines valid GPIO numbers 19 * to be in the range 0..MAX_INT, this library restricts them to the 20 * smaller range 0..ARCH_NR_GPIOS-1. 21 * 22 * ARCH_NR_GPIOS is somewhat arbitrary; it usually reflects the sum of 23 * builtin/SoC GPIOs plus a number of GPIOs on expanders; the latter is 24 * actually an estimate of a board-specific value. 25 */ 26 27#ifndef ARCH_NR_GPIOS 28#if defined(CONFIG_ARCH_NR_GPIO) && CONFIG_ARCH_NR_GPIO > 0 29#define ARCH_NR_GPIOS CONFIG_ARCH_NR_GPIO 30#else 31#define ARCH_NR_GPIOS 512 32#endif 33#endif 34 35/* 36 * "valid" GPIO numbers are nonnegative and may be passed to 37 * setup routines like gpio_request(). only some valid numbers 38 * can successfully be requested and used. 39 * 40 * Invalid GPIO numbers are useful for indicating no-such-GPIO in 41 * platform data and other tables. 42 */ 43 44static inline bool gpio_is_valid(int number) 45{ 46 return number >= 0 && number < ARCH_NR_GPIOS; 47} 48 49struct device; 50struct gpio; 51struct seq_file; 52struct module; 53struct device_node; 54struct gpio_desc; 55 56/* caller holds gpio_lock *OR* gpio is marked as requested */ 57static inline struct gpio_chip *gpio_to_chip(unsigned gpio) 58{ 59 return gpiod_to_chip(gpio_to_desc(gpio)); 60} 61 62/* Always use the library code for GPIO management calls, 63 * or when sleeping may be involved. 64 */ 65extern int gpio_request(unsigned gpio, const char *label); 66extern void gpio_free(unsigned gpio); 67 68static inline int gpio_direction_input(unsigned gpio) 69{ 70 return gpiod_direction_input(gpio_to_desc(gpio)); 71} 72static inline int gpio_direction_output(unsigned gpio, int value) 73{ 74 return gpiod_direction_output_raw(gpio_to_desc(gpio), value); 75} 76 77static inline int gpio_set_debounce(unsigned gpio, unsigned debounce) 78{ 79 return gpiod_set_debounce(gpio_to_desc(gpio), debounce); 80} 81 82static inline int gpio_get_value_cansleep(unsigned gpio) 83{ 84 return gpiod_get_raw_value_cansleep(gpio_to_desc(gpio)); 85} 86static inline void gpio_set_value_cansleep(unsigned gpio, int value) 87{ 88 return gpiod_set_raw_value_cansleep(gpio_to_desc(gpio), value); 89} 90 91 92/* A platform's <asm/gpio.h> code may want to inline the I/O calls when 93 * the GPIO is constant and refers to some always-present controller, 94 * giving direct access to chip registers and tight bitbanging loops. 95 */ 96static inline int __gpio_get_value(unsigned gpio) 97{ 98 return gpiod_get_raw_value(gpio_to_desc(gpio)); 99} 100static inline void __gpio_set_value(unsigned gpio, int value) 101{ 102 return gpiod_set_raw_value(gpio_to_desc(gpio), value); 103} 104 105static inline int __gpio_cansleep(unsigned gpio) 106{ 107 return gpiod_cansleep(gpio_to_desc(gpio)); 108} 109 110static inline int __gpio_to_irq(unsigned gpio) 111{ 112 return gpiod_to_irq(gpio_to_desc(gpio)); 113} 114 115extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label); 116extern int gpio_request_array(const struct gpio *array, size_t num); 117extern void gpio_free_array(const struct gpio *array, size_t num); 118 119/* 120 * A sysfs interface can be exported by individual drivers if they want, 121 * but more typically is configured entirely from userspace. 122 */ 123static inline int gpio_export(unsigned gpio, bool direction_may_change) 124{ 125 return gpiod_export(gpio_to_desc(gpio), direction_may_change); 126} 127 128static inline int gpio_export_link(struct device *dev, const char *name, 129 unsigned gpio) 130{ 131 return gpiod_export_link(dev, name, gpio_to_desc(gpio)); 132} 133 134static inline void gpio_unexport(unsigned gpio) 135{ 136 gpiod_unexport(gpio_to_desc(gpio)); 137} 138 139#else /* !CONFIG_GPIOLIB */ 140 141#include <linux/kernel.h> 142 143static inline bool gpio_is_valid(int number) 144{ 145 /* only non-negative numbers are valid */ 146 return number >= 0; 147} 148 149/* platforms that don't directly support access to GPIOs through I2C, SPI, 150 * or other blocking infrastructure can use these wrappers. 151 */ 152 153static inline int gpio_cansleep(unsigned gpio) 154{ 155 return 0; 156} 157 158static inline int gpio_get_value_cansleep(unsigned gpio) 159{ 160 might_sleep(); 161 return __gpio_get_value(gpio); 162} 163 164static inline void gpio_set_value_cansleep(unsigned gpio, int value) 165{ 166 might_sleep(); 167 __gpio_set_value(gpio, value); 168} 169 170#endif /* !CONFIG_GPIOLIB */ 171 172#endif /* _ASM_GENERIC_GPIO_H */