linux/include/linux/gpio.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * NOTE: This header *must not* be included.
 *
 * This is the LEGACY GPIO bulk include file, including legacy APIs. It is
 * used for GPIO drivers still referencing the global GPIO numberspace,
 * and should not be included in new code.
 *
 * If you're implementing a GPIO driver, only include <linux/gpio/driver.h>
 * If you're implementing a GPIO consumer, only include <linux/gpio/consumer.h>
 */
#ifndef __LINUX_GPIO_H
#define __LINUX_GPIO_H

#include <linux/types.h>

struct device;

/* make these flag values available regardless of GPIO kconfig options */
#define GPIOF_DIR_OUT …
#define GPIOF_DIR_IN …

#define GPIOF_INIT_LOW …
#define GPIOF_INIT_HIGH …

#define GPIOF_IN …
#define GPIOF_OUT_INIT_LOW …
#define GPIOF_OUT_INIT_HIGH …

/* Gpio pin is active-low */
#define GPIOF_ACTIVE_LOW …

/**
 * struct gpio - a structure describing a GPIO with configuration
 * @gpio:	the GPIO number
 * @flags:	GPIO configuration as specified by GPIOF_*
 * @label:	a literal description string of this GPIO
 */
struct gpio { … };

#ifdef CONFIG_GPIOLIB

#include <linux/gpio/consumer.h>

/*
 * "valid" GPIO numbers are nonnegative and may be passed to
 * setup routines like gpio_request().  Only some valid numbers
 * can successfully be requested and used.
 *
 * Invalid GPIO numbers are useful for indicating no-such-GPIO in
 * platform data and other tables.
 */
static inline bool gpio_is_valid(int number)
{ … }

/*
 * Platforms may implement their GPIO interface with library code,
 * at a small performance cost for non-inlined operations and some
 * extra memory (for code and for per-GPIO table entries).
 */

/*
 * At the end we want all GPIOs to be dynamically allocated from 0.
 * However, some legacy drivers still perform fixed allocation.
 * Until they are all fixed, leave 0-512 space for them.
 */
#define GPIO_DYNAMIC_BASE …
/*
 * Define the maximum of the possible GPIO in the global numberspace.
 * While the GPIO base and numbers are positive, we limit it with signed
 * maximum as a lot of code is using negative values for special cases.
 */
#define GPIO_DYNAMIC_MAX …

/* Always use the library code for GPIO management calls,
 * or when sleeping may be involved.
 */
int gpio_request(unsigned gpio, const char *label);
void gpio_free(unsigned gpio);

static inline int gpio_direction_input(unsigned gpio)
{ … }
static inline int gpio_direction_output(unsigned gpio, int value)
{ … }

static inline int gpio_get_value_cansleep(unsigned gpio)
{ … }
static inline void gpio_set_value_cansleep(unsigned gpio, int value)
{ … }

static inline int gpio_get_value(unsigned gpio)
{ … }
static inline void gpio_set_value(unsigned gpio, int value)
{ … }

static inline int gpio_to_irq(unsigned gpio)
{ … }

int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);

int devm_gpio_request(struct device *dev, unsigned gpio, const char *label);
int devm_gpio_request_one(struct device *dev, unsigned gpio,
			  unsigned long flags, const char *label);

#else /* ! CONFIG_GPIOLIB */

#include <linux/kernel.h>

#include <asm/bug.h>
#include <asm/errno.h>

static inline bool gpio_is_valid(int number)
{
	return false;
}

static inline int gpio_request(unsigned gpio, const char *label)
{
	return -ENOSYS;
}

static inline int gpio_request_one(unsigned gpio,
					unsigned long flags, const char *label)
{
	return -ENOSYS;
}

static inline void gpio_free(unsigned gpio)
{
	might_sleep();

	/* GPIO can never have been requested */
	WARN_ON(1);
}

static inline int gpio_direction_input(unsigned gpio)
{
	return -ENOSYS;
}

static inline int gpio_direction_output(unsigned gpio, int value)
{
	return -ENOSYS;
}

static inline int gpio_get_value(unsigned gpio)
{
	/* GPIO can never have been requested or set as {in,out}put */
	WARN_ON(1);
	return 0;
}

static inline void gpio_set_value(unsigned gpio, int value)
{
	/* GPIO can never have been requested or set as output */
	WARN_ON(1);
}

static inline int gpio_get_value_cansleep(unsigned gpio)
{
	/* GPIO can never have been requested or set as {in,out}put */
	WARN_ON(1);
	return 0;
}

static inline void gpio_set_value_cansleep(unsigned gpio, int value)
{
	/* GPIO can never have been requested or set as output */
	WARN_ON(1);
}

static inline int gpio_to_irq(unsigned gpio)
{
	/* GPIO can never have been requested or set as input */
	WARN_ON(1);
	return -EINVAL;
}

static inline int devm_gpio_request(struct device *dev, unsigned gpio,
				    const char *label)
{
	WARN_ON(1);
	return -EINVAL;
}

static inline int devm_gpio_request_one(struct device *dev, unsigned gpio,
					unsigned long flags, const char *label)
{
	WARN_ON(1);
	return -EINVAL;
}

#endif /* ! CONFIG_GPIOLIB */

#endif /* __LINUX_GPIO_H */