1 /* 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
24 struct gpio_kp {
25 struct gpio_event_input_devs *input_devs;
26 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;
34 unsigned int disabled_irq:1;
35 unsigned long keys_pressed[0];
36 };
37
clear_phantom_key(struct gpio_kp * kp,int out,int in)38 static 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;
42 unsigned short keyentry = mi->keymap[key_index];
43 unsigned short keycode = keyentry & MATRIX_KEY_MASK;
44 unsigned short dev = keyentry >> MATRIX_CODE_BITS;
45
46 if (!test_bit(keycode, kp->input_devs->dev[dev]->key)) {
47 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
restore_keys_for_input(struct gpio_kp * kp,int out,int in)60 static 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
remove_phantom_keys(struct gpio_kp * kp)77 static 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
report_key(struct gpio_kp * kp,int key_index,int out,int in)107 static 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);
111 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)) {
116 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);
128 input_report_key(kp->input_devs->dev[dev], keycode, pressed);
129 }
130 }
131 }
132
report_sync(struct gpio_kp * kp)133 static void report_sync(struct gpio_kp *kp)
134 {
135 int i;
136
137 for (i = 0; i < kp->input_devs->count; i++)
138 input_sync(kp->input_devs->dev[i]);
139 }
140
gpio_keypad_timer_func(struct hrtimer * timer)141 static enum hrtimer_restart gpio_keypad_timer_func(struct hrtimer *timer)
142 {
143 int out, in;
144 int key_index;
145 int gpio;
146 struct gpio_kp *kp = container_of(timer, struct gpio_kp, timer);
147 struct gpio_event_matrix_info *mi = kp->keypad_info;
148 unsigned gpio_keypad_flags = mi->flags;
149 unsigned polarity = !!(gpio_keypad_flags & GPIOKPF_ACTIVE_HIGH);
150
151 out = kp->current_output;
152 if (out == mi->noutputs) {
153 out = 0;
154 kp->last_key_state_changed = kp->key_state_changed;
155 kp->key_state_changed = 0;
156 kp->some_keys_pressed = 0;
157 } else {
158 key_index = out * mi->ninputs;
159 for (in = 0; in < mi->ninputs; in++, key_index++) {
160 gpio = mi->input_gpios[in];
161 if (gpio_get_value(gpio) ^ !polarity) {
162 if (kp->some_keys_pressed < 3)
163 kp->some_keys_pressed++;
164 kp->key_state_changed |= !__test_and_set_bit(
165 key_index, kp->keys_pressed);
166 } else
167 kp->key_state_changed |= __test_and_clear_bit(
168 key_index, kp->keys_pressed);
169 }
170 gpio = mi->output_gpios[out];
171 if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE)
172 gpio_set_value(gpio, !polarity);
173 else
174 gpio_direction_input(gpio);
175 out++;
176 }
177 kp->current_output = out;
178 if (out < mi->noutputs) {
179 gpio = mi->output_gpios[out];
180 if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE)
181 gpio_set_value(gpio, polarity);
182 else
183 gpio_direction_output(gpio, polarity);
184 hrtimer_start(timer, mi->settle_time, HRTIMER_MODE_REL);
185 return HRTIMER_NORESTART;
186 }
187 if (gpio_keypad_flags & GPIOKPF_DEBOUNCE) {
188 if (kp->key_state_changed) {
189 hrtimer_start(&kp->timer, mi->debounce_delay,
190 HRTIMER_MODE_REL);
191 return HRTIMER_NORESTART;
192 }
193 kp->key_state_changed = kp->last_key_state_changed;
194 }
195 if (kp->key_state_changed) {
196 if (gpio_keypad_flags & GPIOKPF_REMOVE_SOME_PHANTOM_KEYS)
197 remove_phantom_keys(kp);
198 key_index = 0;
199 for (out = 0; out < mi->noutputs; out++)
200 for (in = 0; in < mi->ninputs; in++, key_index++)
201 report_key(kp, key_index, out, in);
202 report_sync(kp);
203 }
204 if (!kp->use_irq || kp->some_keys_pressed) {
205 hrtimer_start(timer, mi->poll_time, HRTIMER_MODE_REL);
206 return HRTIMER_NORESTART;
207 }
208
209 /* No keys are pressed, reenable interrupt */
210 for (out = 0; out < mi->noutputs; out++) {
211 if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE)
212 gpio_set_value(mi->output_gpios[out], polarity);
213 else
214 gpio_direction_output(mi->output_gpios[out], polarity);
215 }
216 for (in = 0; in < mi->ninputs; in++)
217 enable_irq(gpio_to_irq(mi->input_gpios[in]));
218 wake_unlock(&kp->wake_lock);
219 return HRTIMER_NORESTART;
220 }
221
gpio_keypad_irq_handler(int irq_in,void * dev_id)222 static irqreturn_t gpio_keypad_irq_handler(int irq_in, void *dev_id)
223 {
224 int i;
225 struct gpio_kp *kp = dev_id;
226 struct gpio_event_matrix_info *mi = kp->keypad_info;
227 unsigned gpio_keypad_flags = mi->flags;
228
229 if (!kp->use_irq) {
230 /* ignore interrupt while registering the handler */
231 kp->disabled_irq = 1;
232 disable_irq_nosync(irq_in);
233 return IRQ_HANDLED;
234 }
235
236 for (i = 0; i < mi->ninputs; i++)
237 disable_irq_nosync(gpio_to_irq(mi->input_gpios[i]));
238 for (i = 0; i < mi->noutputs; i++) {
239 if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE)
240 gpio_set_value(mi->output_gpios[i],
241 !(gpio_keypad_flags & GPIOKPF_ACTIVE_HIGH));
242 else
243 gpio_direction_input(mi->output_gpios[i]);
244 }
245 wake_lock(&kp->wake_lock);
246 hrtimer_start(&kp->timer, ktime_set(0, 0), HRTIMER_MODE_REL);
247 return IRQ_HANDLED;
248 }
249
gpio_keypad_request_irqs(struct gpio_kp * kp)250 static int gpio_keypad_request_irqs(struct gpio_kp *kp)
251 {
252 int i;
253 int err;
254 unsigned int irq;
255 unsigned long request_flags;
256 struct gpio_event_matrix_info *mi = kp->keypad_info;
257
258 switch (mi->flags & (GPIOKPF_ACTIVE_HIGH|GPIOKPF_LEVEL_TRIGGERED_IRQ)) {
259 default:
260 request_flags = IRQF_TRIGGER_FALLING;
261 break;
262 case GPIOKPF_ACTIVE_HIGH:
263 request_flags = IRQF_TRIGGER_RISING;
264 break;
265 case GPIOKPF_LEVEL_TRIGGERED_IRQ:
266 request_flags = IRQF_TRIGGER_LOW;
267 break;
268 case GPIOKPF_LEVEL_TRIGGERED_IRQ | GPIOKPF_ACTIVE_HIGH:
269 request_flags = IRQF_TRIGGER_HIGH;
270 break;
271 }
272
273 for (i = 0; i < mi->ninputs; i++) {
274 err = irq = gpio_to_irq(mi->input_gpios[i]);
275 if (err < 0)
276 goto err_gpio_get_irq_num_failed;
277 err = request_irq(irq, gpio_keypad_irq_handler, request_flags,
278 "gpio_kp", kp);
279 if (err) {
280 pr_err("gpiomatrix: request_irq failed for input %d, "
281 "irq %d\n", mi->input_gpios[i], irq);
282 goto err_request_irq_failed;
283 }
284 err = enable_irq_wake(irq);
285 if (err) {
286 pr_err("gpiomatrix: set_irq_wake failed for input %d, "
287 "irq %d\n", mi->input_gpios[i], irq);
288 }
289 disable_irq(irq);
290 if (kp->disabled_irq) {
291 kp->disabled_irq = 0;
292 enable_irq(irq);
293 }
294 }
295 return 0;
296
297 for (i = mi->noutputs - 1; i >= 0; i--) {
298 free_irq(gpio_to_irq(mi->input_gpios[i]), kp);
299 err_request_irq_failed:
300 err_gpio_get_irq_num_failed:
301 ;
302 }
303 return err;
304 }
305
gpio_event_matrix_func(struct gpio_event_input_devs * input_devs,struct gpio_event_info * info,void ** data,int func)306 int gpio_event_matrix_func(struct gpio_event_input_devs *input_devs,
307 struct gpio_event_info *info, void **data, int func)
308 {
309 int i;
310 int err;
311 int key_count;
312 struct gpio_kp *kp;
313 struct gpio_event_matrix_info *mi;
314
315 mi = container_of(info, struct gpio_event_matrix_info, info);
316 if (func == GPIO_EVENT_FUNC_SUSPEND || func == GPIO_EVENT_FUNC_RESUME) {
317 /* TODO: disable scanning */
318 return 0;
319 }
320
321 if (func == GPIO_EVENT_FUNC_INIT) {
322 if (mi->keymap == NULL ||
323 mi->input_gpios == NULL ||
324 mi->output_gpios == NULL) {
325 err = -ENODEV;
326 pr_err("gpiomatrix: Incomplete pdata\n");
327 goto err_invalid_platform_data;
328 }
329 key_count = mi->ninputs * mi->noutputs;
330
331 *data = kp = kzalloc(sizeof(*kp) + sizeof(kp->keys_pressed[0]) *
332 BITS_TO_LONGS(key_count), GFP_KERNEL);
333 if (kp == NULL) {
334 err = -ENOMEM;
335 pr_err("gpiomatrix: Failed to allocate private data\n");
336 goto err_kp_alloc_failed;
337 }
338 kp->input_devs = input_devs;
339 kp->keypad_info = mi;
340 for (i = 0; i < key_count; i++) {
341 unsigned short keyentry = mi->keymap[i];
342 unsigned short keycode = keyentry & MATRIX_KEY_MASK;
343 unsigned short dev = keyentry >> MATRIX_CODE_BITS;
344 if (dev >= input_devs->count) {
345 pr_err("gpiomatrix: bad device index %d >= "
346 "%d for key code %d\n",
347 dev, input_devs->count, keycode);
348 err = -EINVAL;
349 goto err_bad_keymap;
350 }
351 if (keycode && keycode <= KEY_MAX)
352 input_set_capability(input_devs->dev[dev],
353 EV_KEY, keycode);
354 }
355
356 for (i = 0; i < mi->noutputs; i++) {
357 err = gpio_request(mi->output_gpios[i], "gpio_kp_out");
358 if (err) {
359 pr_err("gpiomatrix: gpio_request failed for "
360 "output %d\n", mi->output_gpios[i]);
361 goto err_request_output_gpio_failed;
362 }
363 if (gpio_cansleep(mi->output_gpios[i])) {
364 pr_err("gpiomatrix: unsupported output gpio %d,"
365 " can sleep\n", mi->output_gpios[i]);
366 err = -EINVAL;
367 goto err_output_gpio_configure_failed;
368 }
369 if (mi->flags & GPIOKPF_DRIVE_INACTIVE)
370 err = gpio_direction_output(mi->output_gpios[i],
371 !(mi->flags & GPIOKPF_ACTIVE_HIGH));
372 else
373 err = gpio_direction_input(mi->output_gpios[i]);
374 if (err) {
375 pr_err("gpiomatrix: gpio_configure failed for "
376 "output %d\n", mi->output_gpios[i]);
377 goto err_output_gpio_configure_failed;
378 }
379 }
380 for (i = 0; i < mi->ninputs; i++) {
381 err = gpio_request(mi->input_gpios[i], "gpio_kp_in");
382 if (err) {
383 pr_err("gpiomatrix: gpio_request failed for "
384 "input %d\n", mi->input_gpios[i]);
385 goto err_request_input_gpio_failed;
386 }
387 err = gpio_direction_input(mi->input_gpios[i]);
388 if (err) {
389 pr_err("gpiomatrix: gpio_direction_input failed"
390 " for input %d\n", mi->input_gpios[i]);
391 goto err_gpio_direction_input_failed;
392 }
393 }
394 kp->current_output = mi->noutputs;
395 kp->key_state_changed = 1;
396
397 hrtimer_init(&kp->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
398 kp->timer.function = gpio_keypad_timer_func;
399 wake_lock_init(&kp->wake_lock, WAKE_LOCK_SUSPEND, "gpio_kp");
400 err = gpio_keypad_request_irqs(kp);
401 kp->use_irq = err == 0;
402
403 pr_info("GPIO Matrix Keypad Driver: Start keypad matrix for "
404 "%s%s in %s mode\n", input_devs->dev[0]->name,
405 (input_devs->count > 1) ? "..." : "",
406 kp->use_irq ? "interrupt" : "polling");
407
408 if (kp->use_irq)
409 wake_lock(&kp->wake_lock);
410 hrtimer_start(&kp->timer, ktime_set(0, 0), HRTIMER_MODE_REL);
411
412 return 0;
413 }
414
415 err = 0;
416 kp = *data;
417
418 if (kp->use_irq)
419 for (i = mi->noutputs - 1; i >= 0; i--)
420 free_irq(gpio_to_irq(mi->input_gpios[i]), kp);
421
422 hrtimer_cancel(&kp->timer);
423 wake_lock_destroy(&kp->wake_lock);
424 for (i = mi->noutputs - 1; i >= 0; i--) {
425 err_gpio_direction_input_failed:
426 gpio_free(mi->input_gpios[i]);
427 err_request_input_gpio_failed:
428 ;
429 }
430 for (i = mi->noutputs - 1; i >= 0; i--) {
431 err_output_gpio_configure_failed:
432 gpio_free(mi->output_gpios[i]);
433 err_request_output_gpio_failed:
434 ;
435 }
436 err_bad_keymap:
437 kfree(kp);
438 err_kp_alloc_failed:
439 err_invalid_platform_data:
440 return err;
441 }
442