1 /*
2 * Copyright (c) 2009, 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 #include <assert.h>
33 #include <bits.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <dev/keys.h>
37 #include <dev/gpio.h>
38 #include <dev/gpio_keypad.h>
39 #include <kernel/event.h>
40 #include <kernel/timer.h>
41
42 struct gpio_kp {
43 struct gpio_keypad_info *keypad_info;
44 struct timer timer;
45 event_t full_scan;
46 int current_output;
47 unsigned int some_keys_pressed:2;
48 unsigned long keys_pressed[0];
49 };
50
51 /* TODO: Support multiple keypads? */
52 static struct gpio_kp *keypad;
53
check_output(struct gpio_kp * kp,int out,int polarity)54 static void check_output(struct gpio_kp *kp, int out, int polarity)
55 {
56 struct gpio_keypad_info *kpinfo = kp->keypad_info;
57 int key_index;
58 int in;
59 int gpio;
60 int changed = 0;
61
62 key_index = out * kpinfo->ninputs;
63 for (in = 0; in < kpinfo->ninputs; in++, key_index++) {
64 gpio = kpinfo->input_gpios[in];
65 changed = 0;
66 if (gpio_get(gpio) ^ !polarity) {
67 if (kp->some_keys_pressed < 3)
68 kp->some_keys_pressed++;
69 changed = !bitmap_set(kp->keys_pressed, key_index);
70 } else {
71 changed = bitmap_clear(kp->keys_pressed, key_index);
72 }
73 if (changed) {
74 int state = bitmap_test(kp->keys_pressed, key_index);
75 keys_post_event(kpinfo->keymap[key_index], state);
76 }
77 }
78
79 /* sets up the right state for the next poll cycle */
80 gpio = kpinfo->output_gpios[out];
81 if (kpinfo->flags & GPIOKPF_DRIVE_INACTIVE)
82 gpio_set(gpio, !polarity);
83 else
84 gpio_config(gpio, GPIO_INPUT);
85 }
86
87 static enum handler_return
gpio_keypad_timer_func(struct timer * timer,time_t now,void * arg)88 gpio_keypad_timer_func(struct timer *timer, time_t now, void *arg)
89 {
90 struct gpio_kp *kp = keypad;
91 struct gpio_keypad_info *kpinfo = kp->keypad_info;
92 int polarity = !!(kpinfo->flags & GPIOKPF_ACTIVE_HIGH);
93 int out;
94 int gpio;
95
96 out = kp->current_output;
97 if (out == kpinfo->noutputs) {
98 out = 0;
99 kp->some_keys_pressed = 0;
100 } else {
101 check_output(kp, out, polarity);
102 out++;
103 }
104
105 kp->current_output = out;
106 if (out < kpinfo->noutputs) {
107 gpio = kpinfo->output_gpios[out];
108 if (kpinfo->flags & GPIOKPF_DRIVE_INACTIVE)
109 gpio_set(gpio, polarity);
110 else
111 gpio_config(gpio, polarity ? GPIO_OUTPUT : 0);
112 timer_set_oneshot(timer, kpinfo->settle_time,
113 gpio_keypad_timer_func, NULL);
114 goto done;
115 }
116
117 if (/*!kp->use_irq*/ 1 || kp->some_keys_pressed) {
118 event_signal(&kp->full_scan, false);
119 timer_set_oneshot(timer, kpinfo->poll_time,
120 gpio_keypad_timer_func, NULL);
121 goto done;
122 }
123
124 #if 0
125 /* No keys are pressed, reenable interrupt */
126 for (out = 0; out < kpinfo->noutputs; out++) {
127 if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE)
128 gpio_set(kpinfo->output_gpios[out], polarity);
129 else
130 gpio_config(kpinfo->output_gpios[out], polarity ? GPIO_OUTPUT : 0);
131 }
132 for (in = 0; in < kpinfo->ninputs; in++)
133 enable_irq(gpio_to_irq(kpinfo->input_gpios[in]));
134 return INT_RESCHEDULE;
135 #endif
136
137 done:
138 return INT_RESCHEDULE;
139 }
140
gpio_keypad_init(struct gpio_keypad_info * kpinfo)141 void gpio_keypad_init(struct gpio_keypad_info *kpinfo)
142 {
143 int key_count;
144 int output_val;
145 int output_cfg;
146 int i;
147 int len;
148
149 ASSERT(kpinfo->keymap && kpinfo->input_gpios && kpinfo->output_gpios);
150 key_count = kpinfo->ninputs * kpinfo->noutputs;
151
152 len = sizeof(struct gpio_kp) + (sizeof(unsigned long) *
153 BITMAP_NUM_WORDS(key_count));
154 keypad = malloc(len);
155 ASSERT(keypad);
156
157 memset(keypad, 0, len);
158 keypad->keypad_info = kpinfo;
159
160 output_val = (!!(kpinfo->flags & GPIOKPF_ACTIVE_HIGH)) ^
161 (!!(kpinfo->flags & GPIOKPF_DRIVE_INACTIVE));
162 output_cfg = kpinfo->flags & GPIOKPF_DRIVE_INACTIVE ? GPIO_OUTPUT : 0;
163 for (i = 0; i < kpinfo->noutputs; i++) {
164 gpio_set(kpinfo->output_gpios[i], output_val);
165 gpio_config(kpinfo->output_gpios[i], output_cfg);
166 }
167 for (i = 0; i < kpinfo->ninputs; i++)
168 gpio_config(kpinfo->input_gpios[i], GPIO_INPUT);
169
170 keypad->current_output = kpinfo->noutputs;
171
172 event_init(&keypad->full_scan, false, EVENT_FLAG_AUTOUNSIGNAL);
173 timer_initialize(&keypad->timer);
174 timer_set_oneshot(&keypad->timer, 0, gpio_keypad_timer_func, NULL);
175
176 /* wait for the keypad to complete one full scan */
177 event_wait(&keypad->full_scan);
178 }
179