1 /*
2  * Copyright (c) 2008, Google Inc.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *  * Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  *  * Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in
12  *    the documentation and/or other materials provided with the
13  *    distribution.
14  *  * Neither the name of Google, Inc. nor the names of its contributors
15  *    may be used to endorse or promote products derived from this
16  *    software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
21  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
22  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
24  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
25  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
26  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
27  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
28  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef __DEV_GPIO_KEYPAD_H
33 #define __DEV_GPIO_KEYPAD_H
34 
35 #include <sys/types.h>
36 
37 /* unset: drive active output low, set: drive active output high */
38 #define GPIOKPF_ACTIVE_HIGH     (1U << 0)
39 #define GPIOKPF_DRIVE_INACTIVE      (1U << 1)
40 
41 struct gpio_keypad_info {
42     /* size must be ninputs * noutputs */
43     const uint16_t *keymap;
44     unsigned *input_gpios;
45     unsigned *output_gpios;
46     int ninputs;
47     int noutputs;
48     /* time to wait before reading inputs after driving each output */
49     time_t settle_time;
50     time_t poll_time;
51     unsigned flags;
52 };
53 
54 void gpio_keypad_init(struct gpio_keypad_info *kpinfo);
55 
56 #endif /* __DEV_GPIO_KEYPAD_H */
57