[linux.git] / 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_IN                ((1 << 0))
#define GPIOF_OUT_INIT_LOW      ((0 << 0) | (0 << 1))
#define GPIOF_OUT_INIT_HIGH     ((0 << 0) | (1 << 1))

/**
 * 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 {
        unsigned        gpio;
        unsigned long   flags;
        const char      *label;
};

#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)
{
        /* only non-negative numbers are valid */
        return number >= 0;
}

/*
 * 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       512
/*
 * 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        INT_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)
{
        return gpiod_direction_input(gpio_to_desc(gpio));
}
static inline int gpio_direction_output(unsigned gpio, int value)
{
        return gpiod_direction_output_raw(gpio_to_desc(gpio), value);
}

static inline int gpio_get_value_cansleep(unsigned gpio)
{
        return gpiod_get_raw_value_cansleep(gpio_to_desc(gpio));
}
static inline void gpio_set_value_cansleep(unsigned gpio, int value)
{
        return gpiod_set_raw_value_cansleep(gpio_to_desc(gpio), value);
}

static inline int gpio_get_value(unsigned gpio)
{
        return gpiod_get_raw_value(gpio_to_desc(gpio));
}
static inline void gpio_set_value(unsigned gpio, int value)
{
        return gpiod_set_raw_value(gpio_to_desc(gpio), value);
}

static inline int gpio_to_irq(unsigned gpio)
{
        return gpiod_to_irq(gpio_to_desc(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 */