LXR linux/include/asm-generic/gpio.h

   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 */
 173