include/dev/gpio_keypad.h

/*
 * Copyright (c) 2008, Google Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *  * Neither the name of Google, Inc. nor the names of its contributors
 *    may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef __DEV_GPIO_KEYPAD_H
#define __DEV_GPIO_KEYPAD_H

#include <sys/types.h>

/* unset: drive active output low, set: drive active output high */
#define GPIOKPF_ACTIVE_HIGH		(1U << 0)
#define GPIOKPF_DRIVE_INACTIVE		(1U << 1)

struct gpio_keypad_info {
	/* size must be ninputs * noutputs */
	const uint16_t *keymap;
	unsigned *input_gpios;
	unsigned *output_gpios;
	int ninputs;
	int noutputs;
	/* time to wait before reading inputs after driving each output */
	time_t settle_time;
	time_t poll_time;
	unsigned flags;
};

void gpio_keypad_init(struct gpio_keypad_info *kpinfo);

#endif /* __DEV_GPIO_KEYPAD_H */