linux/include/asm-generic/gpio.h
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   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#include <linux/pinctrl/pinctrl.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#define ARCH_NR_GPIOS           256
  31#endif
  32
  33/*
  34 * "valid" GPIO numbers are nonnegative and may be passed to
  35 * setup routines like gpio_request().  only some valid numbers
  36 * can successfully be requested and used.
  37 *
  38 * Invalid GPIO numbers are useful for indicating no-such-GPIO in
  39 * platform data and other tables.
  40 */
  41
  42static inline bool gpio_is_valid(int number)
  43{
  44        return number >= 0 && number < ARCH_NR_GPIOS;
  45}
  46
  47struct device;
  48struct gpio;
  49struct seq_file;
  50struct module;
  51struct device_node;
  52struct gpio_desc;
  53
  54/* caller holds gpio_lock *OR* gpio is marked as requested */
  55static inline struct gpio_chip *gpio_to_chip(unsigned gpio)
  56{
  57        return gpiod_to_chip(gpio_to_desc(gpio));
  58}
  59
  60/* Always use the library code for GPIO management calls,
  61 * or when sleeping may be involved.
  62 */
  63extern int gpio_request(unsigned gpio, const char *label);
  64extern void gpio_free(unsigned gpio);
  65
  66static inline int gpio_direction_input(unsigned gpio)
  67{
  68        return gpiod_direction_input(gpio_to_desc(gpio));
  69}
  70static inline int gpio_direction_output(unsigned gpio, int value)
  71{
  72        return gpiod_direction_output_raw(gpio_to_desc(gpio), value);
  73}
  74
  75static inline int gpio_set_debounce(unsigned gpio, unsigned debounce)
  76{
  77        return gpiod_set_debounce(gpio_to_desc(gpio), debounce);
  78}
  79
  80static inline int gpio_get_value_cansleep(unsigned gpio)
  81{
  82        return gpiod_get_raw_value_cansleep(gpio_to_desc(gpio));
  83}
  84static inline void gpio_set_value_cansleep(unsigned gpio, int value)
  85{
  86        return gpiod_set_raw_value_cansleep(gpio_to_desc(gpio), value);
  87}
  88
  89
  90/* A platform's <asm/gpio.h> code may want to inline the I/O calls when
  91 * the GPIO is constant and refers to some always-present controller,
  92 * giving direct access to chip registers and tight bitbanging loops.
  93 */
  94static inline int __gpio_get_value(unsigned gpio)
  95{
  96        return gpiod_get_raw_value(gpio_to_desc(gpio));
  97}
  98static inline void __gpio_set_value(unsigned gpio, int value)
  99{
 100        return gpiod_set_raw_value(gpio_to_desc(gpio), value);
 101}
 102
 103static inline int __gpio_cansleep(unsigned gpio)
 104{
 105        return gpiod_cansleep(gpio_to_desc(gpio));
 106}
 107
 108static inline int __gpio_to_irq(unsigned gpio)
 109{
 110        return gpiod_to_irq(gpio_to_desc(gpio));
 111}
 112
 113extern int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset);
 114extern void gpio_unlock_as_irq(struct gpio_chip *chip, unsigned int offset);
 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 int gpio_sysfs_set_active_low(unsigned gpio, int value)
 136{
 137        return gpiod_sysfs_set_active_low(gpio_to_desc(gpio), value);
 138}
 139
 140static inline void gpio_unexport(unsigned gpio)
 141{
 142        gpiod_unexport(gpio_to_desc(gpio));
 143}
 144
 145#ifdef CONFIG_PINCTRL
 146
 147/**
 148 * struct gpio_pin_range - pin range controlled by a gpio chip
 149 * @head: list for maintaining set of pin ranges, used internally
 150 * @pctldev: pinctrl device which handles corresponding pins
 151 * @range: actual range of pins controlled by a gpio controller
 152 */
 153
 154struct gpio_pin_range {
 155        struct list_head node;
 156        struct pinctrl_dev *pctldev;
 157        struct pinctrl_gpio_range range;
 158};
 159
 160int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
 161                           unsigned int gpio_offset, unsigned int pin_offset,
 162                           unsigned int npins);
 163int gpiochip_add_pingroup_range(struct gpio_chip *chip,
 164                        struct pinctrl_dev *pctldev,
 165                        unsigned int gpio_offset, const char *pin_group);
 166void gpiochip_remove_pin_ranges(struct gpio_chip *chip);
 167
 168#else
 169
 170static inline int
 171gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
 172                       unsigned int gpio_offset, unsigned int pin_offset,
 173                       unsigned int npins)
 174{
 175        return 0;
 176}
 177static inline int
 178gpiochip_add_pingroup_range(struct gpio_chip *chip,
 179                        struct pinctrl_dev *pctldev,
 180                        unsigned int gpio_offset, const char *pin_group)
 181{
 182        return 0;
 183}
 184
 185static inline void
 186gpiochip_remove_pin_ranges(struct gpio_chip *chip)
 187{
 188}
 189
 190#endif /* CONFIG_PINCTRL */
 191
 192#else   /* !CONFIG_GPIOLIB */
 193
 194static inline bool gpio_is_valid(int number)
 195{
 196        /* only non-negative numbers are valid */
 197        return number >= 0;
 198}
 199
 200/* platforms that don't directly support access to GPIOs through I2C, SPI,
 201 * or other blocking infrastructure can use these wrappers.
 202 */
 203
 204static inline int gpio_cansleep(unsigned gpio)
 205{
 206        return 0;
 207}
 208
 209static inline int gpio_get_value_cansleep(unsigned gpio)
 210{
 211        might_sleep();
 212        return __gpio_get_value(gpio);
 213}
 214
 215static inline void gpio_set_value_cansleep(unsigned gpio, int value)
 216{
 217        might_sleep();
 218        __gpio_set_value(gpio, value);
 219}
 220
 221#endif /* !CONFIG_GPIOLIB */
 222
 223#endif /* _ASM_GENERIC_GPIO_H */
 224