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

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