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/kernel.h>
   6#include <linux/types.h>
   7#include <linux/errno.h>
   8#include <linux/of.h>
   9
  10#ifdef CONFIG_GPIOLIB
  11
  12#include <linux/compiler.h>
  13#include <linux/gpio/driver.h>
  14#include <linux/gpio/consumer.h>
  15
  16/* Platforms may implement their GPIO interface with library code,
  17 * at a small performance cost for non-inlined operations and some
  18 * extra memory (for code and for per-GPIO table entries).
  19 *
  20 * While the GPIO programming interface defines valid GPIO numbers
  21 * to be in the range 0..MAX_INT, this library restricts them to the
  22 * smaller range 0..ARCH_NR_GPIOS-1.
  23 *
  24 * ARCH_NR_GPIOS is somewhat arbitrary; it usually reflects the sum of
  25 * builtin/SoC GPIOs plus a number of GPIOs on expanders; the latter is
  26 * actually an estimate of a board-specific value.
  27 */
  28
  29#ifndef ARCH_NR_GPIOS
  30#if defined(CONFIG_ARCH_NR_GPIO) && CONFIG_ARCH_NR_GPIO > 0
  31#define ARCH_NR_GPIOS CONFIG_ARCH_NR_GPIO
  32#else
  33#define ARCH_NR_GPIOS           512
  34#endif
  35#endif
  36
  37/*
  38 * "valid" GPIO numbers are nonnegative and may be passed to
  39 * setup routines like gpio_request().  only some valid numbers
  40 * can successfully be requested and used.
  41 *
  42 * Invalid GPIO numbers are useful for indicating no-such-GPIO in
  43 * platform data and other tables.
  44 */
  45
  46static inline bool gpio_is_valid(int number)
  47{
  48        return number >= 0 && number < ARCH_NR_GPIOS;
  49}
  50
  51struct device;
  52struct gpio;
  53struct seq_file;
  54struct module;
  55struct device_node;
  56struct gpio_desc;
  57
  58/* caller holds gpio_lock *OR* gpio is marked as requested */
  59static inline struct gpio_chip *gpio_to_chip(unsigned gpio)
  60{
  61        return gpiod_to_chip(gpio_to_desc(gpio));
  62}
  63
  64/* Always use the library code for GPIO management calls,
  65 * or when sleeping may be involved.
  66 */
  67extern int gpio_request(unsigned gpio, const char *label);
  68extern void gpio_free(unsigned gpio);
  69
  70static inline int gpio_direction_input(unsigned gpio)
  71{
  72        return gpiod_direction_input(gpio_to_desc(gpio));
  73}
  74static inline int gpio_direction_output(unsigned gpio, int value)
  75{
  76        return gpiod_direction_output_raw(gpio_to_desc(gpio), value);
  77}
  78
  79static inline int gpio_set_debounce(unsigned gpio, unsigned debounce)
  80{
  81        return gpiod_set_debounce(gpio_to_desc(gpio), debounce);
  82}
  83
  84static inline int gpio_get_value_cansleep(unsigned gpio)
  85{
  86        return gpiod_get_raw_value_cansleep(gpio_to_desc(gpio));
  87}
  88static inline void gpio_set_value_cansleep(unsigned gpio, int value)
  89{
  90        return gpiod_set_raw_value_cansleep(gpio_to_desc(gpio), value);
  91}
  92
  93
  94/* A platform's <asm/gpio.h> code may want to inline the I/O calls when
  95 * the GPIO is constant and refers to some always-present controller,
  96 * giving direct access to chip registers and tight bitbanging loops.
  97 */
  98static inline int __gpio_get_value(unsigned gpio)
  99{
 100        return gpiod_get_raw_value(gpio_to_desc(gpio));
 101}
 102static inline void __gpio_set_value(unsigned gpio, int value)
 103{
 104        return gpiod_set_raw_value(gpio_to_desc(gpio), value);
 105}
 106
 107static inline int __gpio_cansleep(unsigned gpio)
 108{
 109        return gpiod_cansleep(gpio_to_desc(gpio));
 110}
 111
 112static inline int __gpio_to_irq(unsigned gpio)
 113{
 114        return gpiod_to_irq(gpio_to_desc(gpio));
 115}
 116
 117extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
 118extern int gpio_request_array(const struct gpio *array, size_t num);
 119extern void gpio_free_array(const struct gpio *array, size_t num);
 120
 121/*
 122 * A sysfs interface can be exported by individual drivers if they want,
 123 * but more typically is configured entirely from userspace.
 124 */
 125static inline int gpio_export(unsigned gpio, bool direction_may_change)
 126{
 127        return gpiod_export(gpio_to_desc(gpio), direction_may_change);
 128}
 129
 130static inline int gpio_export_link(struct device *dev, const char *name,
 131                                   unsigned gpio)
 132{
 133        return gpiod_export_link(dev, name, gpio_to_desc(gpio));
 134}
 135
 136static inline void gpio_unexport(unsigned gpio)
 137{
 138        gpiod_unexport(gpio_to_desc(gpio));
 139}
 140
 141#else   /* !CONFIG_GPIOLIB */
 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