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#define ARCH_NR_GPIOS           512
  30#endif
  31
  32/*
  33 * "valid" GPIO numbers are nonnegative and may be passed to
  34 * setup routines like gpio_request().  only some valid numbers
  35 * can successfully be requested and used.
  36 *
  37 * Invalid GPIO numbers are useful for indicating no-such-GPIO in
  38 * platform data and other tables.
  39 */
  40
  41static inline bool gpio_is_valid(int number)
  42{
  43        return number >= 0 && number < ARCH_NR_GPIOS;
  44}
  45
  46struct device;
  47struct gpio;
  48struct seq_file;
  49struct module;
  50struct device_node;
  51struct gpio_desc;
  52
  53/* caller holds gpio_lock *OR* gpio is marked as requested */
  54static inline struct gpio_chip *gpio_to_chip(unsigned gpio)
  55{
  56        return gpiod_to_chip(gpio_to_desc(gpio));
  57}
  58
  59/* Always use the library code for GPIO management calls,
  60 * or when sleeping may be involved.
  61 */
  62extern int gpio_request(unsigned gpio, const char *label);
  63extern void gpio_free(unsigned gpio);
  64
  65static inline int gpio_direction_input(unsigned gpio)
  66{
  67        return gpiod_direction_input(gpio_to_desc(gpio));
  68}
  69static inline int gpio_direction_output(unsigned gpio, int value)
  70{
  71        return gpiod_direction_output_raw(gpio_to_desc(gpio), value);
  72}
  73
  74static inline int gpio_set_debounce(unsigned gpio, unsigned debounce)
  75{
  76        return gpiod_set_debounce(gpio_to_desc(gpio), debounce);
  77}
  78
  79static inline int gpio_get_value_cansleep(unsigned gpio)
  80{
  81        return gpiod_get_raw_value_cansleep(gpio_to_desc(gpio));
  82}
  83static inline void gpio_set_value_cansleep(unsigned gpio, int value)
  84{
  85        return gpiod_set_raw_value_cansleep(gpio_to_desc(gpio), value);
  86}
  87
  88
  89/* A platform's <asm/gpio.h> code may want to inline the I/O calls when
  90 * the GPIO is constant and refers to some always-present controller,
  91 * giving direct access to chip registers and tight bitbanging loops.
  92 */
  93static inline int __gpio_get_value(unsigned gpio)
  94{
  95        return gpiod_get_raw_value(gpio_to_desc(gpio));
  96}
  97static inline void __gpio_set_value(unsigned gpio, int value)
  98{
  99        return gpiod_set_raw_value(gpio_to_desc(gpio), value);
 100}
 101
 102static inline int __gpio_cansleep(unsigned gpio)
 103{
 104        return gpiod_cansleep(gpio_to_desc(gpio));
 105}
 106
 107static inline int __gpio_to_irq(unsigned gpio)
 108{
 109        return gpiod_to_irq(gpio_to_desc(gpio));
 110}
 111
 112extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
 113extern int gpio_request_array(const struct gpio *array, size_t num);
 114extern void gpio_free_array(const struct gpio *array, size_t num);
 115
 116/*
 117 * A sysfs interface can be exported by individual drivers if they want,
 118 * but more typically is configured entirely from userspace.
 119 */
 120static inline int gpio_export(unsigned gpio, bool direction_may_change)
 121{
 122        return gpiod_export(gpio_to_desc(gpio), direction_may_change);
 123}
 124
 125static inline int gpio_export_link(struct device *dev, const char *name,
 126                                   unsigned gpio)
 127{
 128        return gpiod_export_link(dev, name, gpio_to_desc(gpio));
 129}
 130
 131static inline void gpio_unexport(unsigned gpio)
 132{
 133        gpiod_unexport(gpio_to_desc(gpio));
 134}
 135
 136#else   /* !CONFIG_GPIOLIB */
 137
 138static inline bool gpio_is_valid(int number)
 139{
 140        /* only non-negative numbers are valid */
 141        return number >= 0;
 142}
 143
 144/* platforms that don't directly support access to GPIOs through I2C, SPI,
 145 * or other blocking infrastructure can use these wrappers.
 146 */
 147
 148static inline int gpio_cansleep(unsigned gpio)
 149{
 150        return 0;
 151}
 152
 153static inline int gpio_get_value_cansleep(unsigned gpio)
 154{
 155        might_sleep();
 156        return __gpio_get_value(gpio);
 157}
 158
 159static inline void gpio_set_value_cansleep(unsigned gpio, int value)
 160{
 161        might_sleep();
 162        __gpio_set_value(gpio, value);
 163}
 164
 165#endif /* !CONFIG_GPIOLIB */
 166
 167#endif /* _ASM_GENERIC_GPIO_H */
 168