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Arve Hjønnevåg72fc6242008-10-15 18:23:47 -07001/* drivers/input/misc/gpio_matrix.c
2 *
3 * Copyright (C) 2007 Google, Inc.
4 *
5 * This software is licensed under the terms of the GNU General Public
6 * License version 2, as published by the Free Software Foundation, and
7 * may be copied, distributed, and modified under those terms.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 */
15
16#include <linux/kernel.h>
17#include <linux/gpio.h>
18#include <linux/gpio_event.h>
19#include <linux/hrtimer.h>
20#include <linux/interrupt.h>
21#include <linux/slab.h>
22#include <linux/wakelock.h>
23
24struct gpio_kp {
Arve Hjønnevåg0da26bf2009-07-24 15:19:56 -070025 struct gpio_event_input_devs *input_devs;
Arve Hjønnevåg72fc6242008-10-15 18:23:47 -070026 struct gpio_event_matrix_info *keypad_info;
27 struct hrtimer timer;
28 struct wake_lock wake_lock;
29 int current_output;
30 unsigned int use_irq:1;
31 unsigned int key_state_changed:1;
32 unsigned int last_key_state_changed:1;
33 unsigned int some_keys_pressed:2;
Dima Zavin23119372010-04-09 23:26:09 -070034 unsigned int disabled_irq:1;
Arve Hjønnevåg72fc6242008-10-15 18:23:47 -070035 unsigned long keys_pressed[0];
36};
37
38static void clear_phantom_key(struct gpio_kp *kp, int out, int in)
39{
40 struct gpio_event_matrix_info *mi = kp->keypad_info;
41 int key_index = out * mi->ninputs + in;
Arve Hjønnevåg0da26bf2009-07-24 15:19:56 -070042 unsigned short keyentry = mi->keymap[key_index];
43 unsigned short keycode = keyentry & MATRIX_KEY_MASK;
44 unsigned short dev = keyentry >> MATRIX_CODE_BITS;
Arve Hjønnevåg72fc6242008-10-15 18:23:47 -070045
Arve Hjønnevåg0da26bf2009-07-24 15:19:56 -070046 if (!test_bit(keycode, kp->input_devs->dev[dev]->key)) {
Arve Hjønnevåg72fc6242008-10-15 18:23:47 -070047 if (mi->flags & GPIOKPF_PRINT_PHANTOM_KEYS)
48 pr_info("gpiomatrix: phantom key %x, %d-%d (%d-%d) "
49 "cleared\n", keycode, out, in,
50 mi->output_gpios[out], mi->input_gpios[in]);
51 __clear_bit(key_index, kp->keys_pressed);
52 } else {
53 if (mi->flags & GPIOKPF_PRINT_PHANTOM_KEYS)
54 pr_info("gpiomatrix: phantom key %x, %d-%d (%d-%d) "
55 "not cleared\n", keycode, out, in,
56 mi->output_gpios[out], mi->input_gpios[in]);
57 }
58}
59
60static int restore_keys_for_input(struct gpio_kp *kp, int out, int in)
61{
62 int rv = 0;
63 int key_index;
64
65 key_index = out * kp->keypad_info->ninputs + in;
66 while (out < kp->keypad_info->noutputs) {
67 if (test_bit(key_index, kp->keys_pressed)) {
68 rv = 1;
69 clear_phantom_key(kp, out, in);
70 }
71 key_index += kp->keypad_info->ninputs;
72 out++;
73 }
74 return rv;
75}
76
77static void remove_phantom_keys(struct gpio_kp *kp)
78{
79 int out, in, inp;
80 int key_index;
81
82 if (kp->some_keys_pressed < 3)
83 return;
84
85 for (out = 0; out < kp->keypad_info->noutputs; out++) {
86 inp = -1;
87 key_index = out * kp->keypad_info->ninputs;
88 for (in = 0; in < kp->keypad_info->ninputs; in++, key_index++) {
89 if (test_bit(key_index, kp->keys_pressed)) {
90 if (inp == -1) {
91 inp = in;
92 continue;
93 }
94 if (inp >= 0) {
95 if (!restore_keys_for_input(kp, out + 1,
96 inp))
97 break;
98 clear_phantom_key(kp, out, inp);
99 inp = -2;
100 }
101 restore_keys_for_input(kp, out, in);
102 }
103 }
104 }
105}
106
107static void report_key(struct gpio_kp *kp, int key_index, int out, int in)
108{
109 struct gpio_event_matrix_info *mi = kp->keypad_info;
110 int pressed = test_bit(key_index, kp->keys_pressed);
Arve Hjønnevåg0da26bf2009-07-24 15:19:56 -0700111 unsigned short keyentry = mi->keymap[key_index];
112 unsigned short keycode = keyentry & MATRIX_KEY_MASK;
113 unsigned short dev = keyentry >> MATRIX_CODE_BITS;
114
115 if (pressed != test_bit(keycode, kp->input_devs->dev[dev]->key)) {
Arve Hjønnevåg72fc6242008-10-15 18:23:47 -0700116 if (keycode == KEY_RESERVED) {
117 if (mi->flags & GPIOKPF_PRINT_UNMAPPED_KEYS)
118 pr_info("gpiomatrix: unmapped key, %d-%d "
119 "(%d-%d) changed to %d\n",
120 out, in, mi->output_gpios[out],
121 mi->input_gpios[in], pressed);
122 } else {
123 if (mi->flags & GPIOKPF_PRINT_MAPPED_KEYS)
124 pr_info("gpiomatrix: key %x, %d-%d (%d-%d) "
125 "changed to %d\n", keycode,
126 out, in, mi->output_gpios[out],
127 mi->input_gpios[in], pressed);
Arve Hjønnevåg0da26bf2009-07-24 15:19:56 -0700128 input_report_key(kp->input_devs->dev[dev], keycode, pressed);
Arve Hjønnevåg72fc6242008-10-15 18:23:47 -0700129 }
130 }
131}
132
133static enum hrtimer_restart gpio_keypad_timer_func(struct hrtimer *timer)
134{
135 int out, in;
136 int key_index;
137 int gpio;
138 struct gpio_kp *kp = container_of(timer, struct gpio_kp, timer);
139 struct gpio_event_matrix_info *mi = kp->keypad_info;
140 unsigned gpio_keypad_flags = mi->flags;
141 unsigned polarity = !!(gpio_keypad_flags & GPIOKPF_ACTIVE_HIGH);
142
143 out = kp->current_output;
144 if (out == mi->noutputs) {
145 out = 0;
146 kp->last_key_state_changed = kp->key_state_changed;
147 kp->key_state_changed = 0;
148 kp->some_keys_pressed = 0;
149 } else {
150 key_index = out * mi->ninputs;
151 for (in = 0; in < mi->ninputs; in++, key_index++) {
152 gpio = mi->input_gpios[in];
153 if (gpio_get_value(gpio) ^ !polarity) {
154 if (kp->some_keys_pressed < 3)
155 kp->some_keys_pressed++;
156 kp->key_state_changed |= !__test_and_set_bit(
157 key_index, kp->keys_pressed);
158 } else
159 kp->key_state_changed |= __test_and_clear_bit(
160 key_index, kp->keys_pressed);
161 }
162 gpio = mi->output_gpios[out];
163 if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE)
164 gpio_set_value(gpio, !polarity);
165 else
166 gpio_direction_input(gpio);
167 out++;
168 }
169 kp->current_output = out;
170 if (out < mi->noutputs) {
171 gpio = mi->output_gpios[out];
172 if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE)
173 gpio_set_value(gpio, polarity);
174 else
175 gpio_direction_output(gpio, polarity);
176 hrtimer_start(timer, mi->settle_time, HRTIMER_MODE_REL);
177 return HRTIMER_NORESTART;
178 }
179 if (gpio_keypad_flags & GPIOKPF_DEBOUNCE) {
180 if (kp->key_state_changed) {
181 hrtimer_start(&kp->timer, mi->debounce_delay,
182 HRTIMER_MODE_REL);
183 return HRTIMER_NORESTART;
184 }
185 kp->key_state_changed = kp->last_key_state_changed;
186 }
187 if (kp->key_state_changed) {
188 if (gpio_keypad_flags & GPIOKPF_REMOVE_SOME_PHANTOM_KEYS)
189 remove_phantom_keys(kp);
190 key_index = 0;
191 for (out = 0; out < mi->noutputs; out++)
192 for (in = 0; in < mi->ninputs; in++, key_index++)
193 report_key(kp, key_index, out, in);
194 }
195 if (!kp->use_irq || kp->some_keys_pressed) {
196 hrtimer_start(timer, mi->poll_time, HRTIMER_MODE_REL);
197 return HRTIMER_NORESTART;
198 }
199
200 /* No keys are pressed, reenable interrupt */
201 for (out = 0; out < mi->noutputs; out++) {
202 if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE)
203 gpio_set_value(mi->output_gpios[out], polarity);
204 else
205 gpio_direction_output(mi->output_gpios[out], polarity);
206 }
207 for (in = 0; in < mi->ninputs; in++)
208 enable_irq(gpio_to_irq(mi->input_gpios[in]));
209 wake_unlock(&kp->wake_lock);
210 return HRTIMER_NORESTART;
211}
212
213static irqreturn_t gpio_keypad_irq_handler(int irq_in, void *dev_id)
214{
215 int i;
216 struct gpio_kp *kp = dev_id;
217 struct gpio_event_matrix_info *mi = kp->keypad_info;
218 unsigned gpio_keypad_flags = mi->flags;
219
Dima Zavin23119372010-04-09 23:26:09 -0700220 if (!kp->use_irq) {
221 /* ignore interrupt while registering the handler */
222 kp->disabled_irq = 1;
223 disable_irq_nosync(irq_in);
Arve Hjønnevåg72fc6242008-10-15 18:23:47 -0700224 return IRQ_HANDLED;
Dima Zavin23119372010-04-09 23:26:09 -0700225 }
Arve Hjønnevåg72fc6242008-10-15 18:23:47 -0700226
227 for (i = 0; i < mi->ninputs; i++)
Arve Hjønnevåg9be7b632009-04-17 18:24:59 -0700228 disable_irq_nosync(gpio_to_irq(mi->input_gpios[i]));
Arve Hjønnevåg72fc6242008-10-15 18:23:47 -0700229 for (i = 0; i < mi->noutputs; i++) {
230 if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE)
231 gpio_set_value(mi->output_gpios[i],
232 !(gpio_keypad_flags & GPIOKPF_ACTIVE_HIGH));
233 else
234 gpio_direction_input(mi->output_gpios[i]);
235 }
236 wake_lock(&kp->wake_lock);
237 hrtimer_start(&kp->timer, ktime_set(0, 0), HRTIMER_MODE_REL);
238 return IRQ_HANDLED;
239}
240
241static int gpio_keypad_request_irqs(struct gpio_kp *kp)
242{
243 int i;
244 int err;
245 unsigned int irq;
246 unsigned long request_flags;
247 struct gpio_event_matrix_info *mi = kp->keypad_info;
248
249 switch (mi->flags & (GPIOKPF_ACTIVE_HIGH|GPIOKPF_LEVEL_TRIGGERED_IRQ)) {
250 default:
251 request_flags = IRQF_TRIGGER_FALLING;
252 break;
253 case GPIOKPF_ACTIVE_HIGH:
254 request_flags = IRQF_TRIGGER_RISING;
255 break;
256 case GPIOKPF_LEVEL_TRIGGERED_IRQ:
257 request_flags = IRQF_TRIGGER_LOW;
258 break;
259 case GPIOKPF_LEVEL_TRIGGERED_IRQ | GPIOKPF_ACTIVE_HIGH:
260 request_flags = IRQF_TRIGGER_HIGH;
261 break;
262 }
263
264 for (i = 0; i < mi->ninputs; i++) {
265 err = irq = gpio_to_irq(mi->input_gpios[i]);
266 if (err < 0)
267 goto err_gpio_get_irq_num_failed;
268 err = request_irq(irq, gpio_keypad_irq_handler, request_flags,
269 "gpio_kp", kp);
270 if (err) {
271 pr_err("gpiomatrix: request_irq failed for input %d, "
272 "irq %d\n", mi->input_gpios[i], irq);
273 goto err_request_irq_failed;
274 }
275 err = set_irq_wake(irq, 1);
276 if (err) {
277 pr_err("gpiomatrix: set_irq_wake failed for input %d, "
278 "irq %d\n", mi->input_gpios[i], irq);
279 }
280 disable_irq(irq);
Dima Zavin23119372010-04-09 23:26:09 -0700281 if (kp->disabled_irq) {
282 kp->disabled_irq = 0;
283 enable_irq(irq);
284 }
Arve Hjønnevåg72fc6242008-10-15 18:23:47 -0700285 }
286 return 0;
287
288 for (i = mi->noutputs - 1; i >= 0; i--) {
289 free_irq(gpio_to_irq(mi->input_gpios[i]), kp);
290err_request_irq_failed:
291err_gpio_get_irq_num_failed:
292 ;
293 }
294 return err;
295}
296
Arve Hjønnevåg0da26bf2009-07-24 15:19:56 -0700297int gpio_event_matrix_func(struct gpio_event_input_devs *input_devs,
Arve Hjønnevåg72fc6242008-10-15 18:23:47 -0700298 struct gpio_event_info *info, void **data, int func)
299{
300 int i;
301 int err;
302 int key_count;
303 struct gpio_kp *kp;
304 struct gpio_event_matrix_info *mi;
305
306 mi = container_of(info, struct gpio_event_matrix_info, info);
307 if (func == GPIO_EVENT_FUNC_SUSPEND || func == GPIO_EVENT_FUNC_RESUME) {
308 /* TODO: disable scanning */
309 return 0;
310 }
311
312 if (func == GPIO_EVENT_FUNC_INIT) {
313 if (mi->keymap == NULL ||
314 mi->input_gpios == NULL ||
315 mi->output_gpios == NULL) {
316 err = -ENODEV;
317 pr_err("gpiomatrix: Incomplete pdata\n");
318 goto err_invalid_platform_data;
319 }
320 key_count = mi->ninputs * mi->noutputs;
321
322 *data = kp = kzalloc(sizeof(*kp) + sizeof(kp->keys_pressed[0]) *
323 BITS_TO_LONGS(key_count), GFP_KERNEL);
324 if (kp == NULL) {
325 err = -ENOMEM;
326 pr_err("gpiomatrix: Failed to allocate private data\n");
327 goto err_kp_alloc_failed;
328 }
Arve Hjønnevåg0da26bf2009-07-24 15:19:56 -0700329 kp->input_devs = input_devs;
Arve Hjønnevåg72fc6242008-10-15 18:23:47 -0700330 kp->keypad_info = mi;
Arve Hjønnevåg72fc6242008-10-15 18:23:47 -0700331 for (i = 0; i < key_count; i++) {
Arve Hjønnevåg0da26bf2009-07-24 15:19:56 -0700332 unsigned short keyentry = mi->keymap[i];
333 unsigned short keycode = keyentry & MATRIX_KEY_MASK;
334 unsigned short dev = keyentry >> MATRIX_CODE_BITS;
335 if (dev >= input_devs->count) {
336 pr_err("gpiomatrix: bad device index %d >= "
337 "%d for key code %d\n",
338 dev, input_devs->count, keycode);
339 err = -EINVAL;
340 goto err_bad_keymap;
341 }
342 if (keycode && keycode <= KEY_MAX)
343 input_set_capability(input_devs->dev[dev],
344 EV_KEY, keycode);
Arve Hjønnevåg72fc6242008-10-15 18:23:47 -0700345 }
346
347 for (i = 0; i < mi->noutputs; i++) {
Arve Hjønnevåg72fc6242008-10-15 18:23:47 -0700348 err = gpio_request(mi->output_gpios[i], "gpio_kp_out");
349 if (err) {
350 pr_err("gpiomatrix: gpio_request failed for "
351 "output %d\n", mi->output_gpios[i]);
352 goto err_request_output_gpio_failed;
353 }
Arve Hjønnevåge7b269e2010-04-01 19:52:27 -0700354 if (gpio_cansleep(mi->output_gpios[i])) {
355 pr_err("gpiomatrix: unsupported output gpio %d,"
356 " can sleep\n", mi->output_gpios[i]);
357 err = -EINVAL;
358 goto err_output_gpio_configure_failed;
359 }
Arve Hjønnevåg72fc6242008-10-15 18:23:47 -0700360 if (mi->flags & GPIOKPF_DRIVE_INACTIVE)
361 err = gpio_direction_output(mi->output_gpios[i],
362 !(mi->flags & GPIOKPF_ACTIVE_HIGH));
363 else
364 err = gpio_direction_input(mi->output_gpios[i]);
365 if (err) {
366 pr_err("gpiomatrix: gpio_configure failed for "
367 "output %d\n", mi->output_gpios[i]);
368 goto err_output_gpio_configure_failed;
369 }
370 }
371 for (i = 0; i < mi->ninputs; i++) {
372 err = gpio_request(mi->input_gpios[i], "gpio_kp_in");
373 if (err) {
374 pr_err("gpiomatrix: gpio_request failed for "
375 "input %d\n", mi->input_gpios[i]);
376 goto err_request_input_gpio_failed;
377 }
378 err = gpio_direction_input(mi->input_gpios[i]);
379 if (err) {
380 pr_err("gpiomatrix: gpio_direction_input failed"
381 " for input %d\n", mi->input_gpios[i]);
382 goto err_gpio_direction_input_failed;
383 }
384 }
385 kp->current_output = mi->noutputs;
386 kp->key_state_changed = 1;
387
388 hrtimer_init(&kp->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
389 kp->timer.function = gpio_keypad_timer_func;
390 wake_lock_init(&kp->wake_lock, WAKE_LOCK_SUSPEND, "gpio_kp");
391 err = gpio_keypad_request_irqs(kp);
392 kp->use_irq = err == 0;
393
Arve Hjønnevåg0da26bf2009-07-24 15:19:56 -0700394 pr_info("GPIO Matrix Keypad Driver: Start keypad matrix for "
395 "%s%s in %s mode\n", input_devs->dev[0]->name,
396 (input_devs->count > 1) ? "..." : "",
Arve Hjønnevåg72fc6242008-10-15 18:23:47 -0700397 kp->use_irq ? "interrupt" : "polling");
398
399 if (kp->use_irq)
400 wake_lock(&kp->wake_lock);
401 hrtimer_start(&kp->timer, ktime_set(0, 0), HRTIMER_MODE_REL);
402
403 return 0;
404 }
405
406 err = 0;
407 kp = *data;
408
409 if (kp->use_irq)
410 for (i = mi->noutputs - 1; i >= 0; i--)
411 free_irq(gpio_to_irq(mi->input_gpios[i]), kp);
412
413 hrtimer_cancel(&kp->timer);
414 wake_lock_destroy(&kp->wake_lock);
415 for (i = mi->noutputs - 1; i >= 0; i--) {
416err_gpio_direction_input_failed:
417 gpio_free(mi->input_gpios[i]);
418err_request_input_gpio_failed:
419 ;
420 }
421 for (i = mi->noutputs - 1; i >= 0; i--) {
422err_output_gpio_configure_failed:
423 gpio_free(mi->output_gpios[i]);
424err_request_output_gpio_failed:
425 ;
426 }
Arve Hjønnevåg0da26bf2009-07-24 15:19:56 -0700427err_bad_keymap:
Arve Hjønnevåg72fc6242008-10-15 18:23:47 -0700428 kfree(kp);
429err_kp_alloc_failed:
430err_invalid_platform_data:
431 return err;
432}