drivers/gpio/gpio.c

/*
 * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * GPIO -- General Purpose Input/Output
 *
 * Defines a simple and generic interface to access GPIO device.
 *
 */

#include <assert.h>
#include <errno.h>
#include <gpio.h>

/*
 * The gpio implementation
 */
static const gpio_ops_t *ops;

int gpio_get_direction(int gpio)
{
	assert(ops);
	assert(ops->get_direction != 0);
	assert(gpio >= 0);

	return ops->get_direction(gpio);
}

void gpio_set_direction(int gpio, int direction)
{
	assert(ops);
	assert(ops->set_direction != 0);
	assert((direction == GPIO_DIR_OUT) || (direction == GPIO_DIR_IN));
	assert(gpio >= 0);

	ops->set_direction(gpio, direction);
}

int gpio_get_value(int gpio)
{
	assert(ops);
	assert(ops->get_value != 0);
	assert(gpio >= 0);

	return ops->get_value(gpio);
}

void gpio_set_value(int gpio, int value)
{
	assert(ops);
	assert(ops->set_value != 0);
	assert((value == GPIO_LEVEL_LOW) || (value == GPIO_LEVEL_HIGH));
	assert(gpio >= 0);

	ops->set_value(gpio, value);
}

void gpio_set_pull(int gpio, int pull)
{
	assert(ops);
	assert(ops->set_pull != 0);
	assert((pull == GPIO_PULL_NONE) || (pull == GPIO_PULL_UP) ||
	       (pull == GPIO_PULL_DOWN));
	assert(gpio >= 0);

	ops->set_pull(gpio, pull);
}

int gpio_get_pull(int gpio)
{
	assert(ops);
	assert(ops->get_pull != 0);
	assert(gpio >= 0);

	return ops->get_pull(gpio);
}

/*
 * Initialize the gpio. The fields in the provided gpio
 * ops pointer must be valid.
 */
void gpio_init(const gpio_ops_t *ops_ptr)
{
	assert(ops_ptr != 0  &&
	       (ops_ptr->get_direction != 0) &&
	       (ops_ptr->set_direction != 0) &&
	       (ops_ptr->get_value != 0) &&
	       (ops_ptr->set_value != 0));

	ops = ops_ptr;
}