1/*
2 * GPIO driven matrix keyboard driver
3 *
4 * Copyright (c) 2008 Marek Vasut <marek.vasut@gmail.com>
5 *
6 * Based on corgikbd.c
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 */
13
14#include <linux/types.h>
15#include <linux/delay.h>
16#include <linux/platform_device.h>
17#include <linux/input.h>
18#include <linux/irq.h>
19#include <linux/interrupt.h>
20#include <linux/jiffies.h>
21#include <linux/module.h>
22#include <linux/gpio.h>
23#include <linux/input/matrix_keypad.h>
24#include <linux/slab.h>
25#include <linux/of.h>
26#include <linux/of_gpio.h>
27#include <linux/of_platform.h>
28
29struct matrix_keypad {
30 const struct matrix_keypad_platform_data *pdata;
31 struct input_dev *input_dev;
32 unsigned int row_shift;
33
34 DECLARE_BITMAP(disabled_gpios, MATRIX_MAX_ROWS);
35
36 uint32_t last_key_state[MATRIX_MAX_COLS];
37 struct delayed_work work;
38 spinlock_t lock;
39 bool scan_pending;
40 bool stopped;
41 bool gpio_all_disabled;
42};
43
44/*
45 * NOTE: If drive_inactive_cols is false, then the GPIO has to be put into
46 * HiZ when de-activated to cause minmal side effect when scanning other
47 * columns. In that case it is configured here to be input, otherwise it is
48 * driven with the inactive value.
49 */
50static void __activate_col(const struct matrix_keypad_platform_data *pdata,
51 int col, bool on)
52{
53 bool level_on = !pdata->active_low;
54
55 if (on) {
56 gpio_direction_output(pdata->col_gpios[col], level_on);
57 } else {
58 gpio_set_value_cansleep(pdata->col_gpios[col], !level_on);
59 if (!pdata->drive_inactive_cols)
60 gpio_direction_input(pdata->col_gpios[col]);
61 }
62}
63
64static void activate_col(const struct matrix_keypad_platform_data *pdata,
65 int col, bool on)
66{
67 __activate_col(pdata, col, on);
68
69 if (on && pdata->col_scan_delay_us)
70 udelay(pdata->col_scan_delay_us);
71}
72
73static void activate_all_cols(const struct matrix_keypad_platform_data *pdata,
74 bool on)
75{
76 int col;
77
78 for (col = 0; col < pdata->num_col_gpios; col++)
79 __activate_col(pdata, col, on);
80}
81
82static bool row_asserted(const struct matrix_keypad_platform_data *pdata,
83 int row)
84{
85 return gpio_get_value_cansleep(pdata->row_gpios[row]) ?
86 !pdata->active_low : pdata->active_low;
87}
88
89static void enable_row_irqs(struct matrix_keypad *keypad)
90{
91 const struct matrix_keypad_platform_data *pdata = keypad->pdata;
92 int i;
93
94 if (pdata->clustered_irq > 0)
95 enable_irq(pdata->clustered_irq);
96 else {
97 for (i = 0; i < pdata->num_row_gpios; i++)
98 enable_irq(gpio_to_irq(pdata->row_gpios[i]));
99 }
100}
101
102static void disable_row_irqs(struct matrix_keypad *keypad)
103{
104 const struct matrix_keypad_platform_data *pdata = keypad->pdata;
105 int i;
106
107 if (pdata->clustered_irq > 0)
108 disable_irq_nosync(pdata->clustered_irq);
109 else {
110 for (i = 0; i < pdata->num_row_gpios; i++)
111 disable_irq_nosync(gpio_to_irq(pdata->row_gpios[i]));
112 }
113}
114
115/*
116 * This gets the keys from keyboard and reports it to input subsystem
117 */
118static void matrix_keypad_scan(struct work_struct *work)
119{
120 struct matrix_keypad *keypad =
121 container_of(work, struct matrix_keypad, work.work);
122 struct input_dev *input_dev = keypad->input_dev;
123 const unsigned short *keycodes = input_dev->keycode;
124 const struct matrix_keypad_platform_data *pdata = keypad->pdata;
125 uint32_t new_state[MATRIX_MAX_COLS];
126 int row, col, code;
127
128 /* de-activate all columns for scanning */
129 activate_all_cols(pdata, false);
130
131 memset(new_state, 0, sizeof(new_state));
132
133 /* assert each column and read the row status out */
134 for (col = 0; col < pdata->num_col_gpios; col++) {
135
136 activate_col(pdata, col, true);
137
138 for (row = 0; row < pdata->num_row_gpios; row++)
139 new_state[col] |=
140 row_asserted(pdata, row) ? (1 << row) : 0;
141
142 activate_col(pdata, col, false);
143 }
144
145 for (col = 0; col < pdata->num_col_gpios; col++) {
146 uint32_t bits_changed;
147
148 bits_changed = keypad->last_key_state[col] ^ new_state[col];
149 if (bits_changed == 0)
150 continue;
151
152 for (row = 0; row < pdata->num_row_gpios; row++) {
153 if ((bits_changed & (1 << row)) == 0)
154 continue;
155
156 code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
157 input_event(input_dev, EV_MSC, MSC_SCAN, code);
158 input_report_key(input_dev,
159 keycodes[code],
160 new_state[col] & (1 << row));
161 }
162 }
163 input_sync(input_dev);
164
165 memcpy(keypad->last_key_state, new_state, sizeof(new_state));
166
167 activate_all_cols(pdata, true);
168
169 /* Enable IRQs again */
170 spin_lock_irq(&keypad->lock);
171 keypad->scan_pending = false;
172 enable_row_irqs(keypad);
173 spin_unlock_irq(&keypad->lock);
174}
175
176static irqreturn_t matrix_keypad_interrupt(int irq, void *id)
177{
178 struct matrix_keypad *keypad = id;
179 unsigned long flags;
180
181 spin_lock_irqsave(&keypad->lock, flags);
182
183 /*
184 * See if another IRQ beaten us to it and scheduled the
185 * scan already. In that case we should not try to
186 * disable IRQs again.
187 */
188 if (unlikely(keypad->scan_pending || keypad->stopped))
189 goto out;
190
191 disable_row_irqs(keypad);
192 keypad->scan_pending = true;
193 schedule_delayed_work(&keypad->work,
194 msecs_to_jiffies(keypad->pdata->debounce_ms));
195
196out:
197 spin_unlock_irqrestore(&keypad->lock, flags);
198 return IRQ_HANDLED;
199}
200
201static int matrix_keypad_start(struct input_dev *dev)
202{
203 struct matrix_keypad *keypad = input_get_drvdata(dev);
204
205 keypad->stopped = false;
206 mb();
207
208 /*
209 * Schedule an immediate key scan to capture current key state;
210 * columns will be activated and IRQs be enabled after the scan.
211 */
212 schedule_delayed_work(&keypad->work, 0);
213
214 return 0;
215}
216
217static void matrix_keypad_stop(struct input_dev *dev)
218{
219 struct matrix_keypad *keypad = input_get_drvdata(dev);
220
221 spin_lock_irq(&keypad->lock);
222 keypad->stopped = true;
223 spin_unlock_irq(&keypad->lock);
224
225 flush_delayed_work(&keypad->work);
226 /*
227 * matrix_keypad_scan() will leave IRQs enabled;
228 * we should disable them now.
229 */
230 disable_row_irqs(keypad);
231}
232
233#ifdef CONFIG_PM_SLEEP
234static void matrix_keypad_enable_wakeup(struct matrix_keypad *keypad)
235{
236 const struct matrix_keypad_platform_data *pdata = keypad->pdata;
237 unsigned int gpio;
238 int i;
239
240 if (pdata->clustered_irq > 0) {
241 if (enable_irq_wake(pdata->clustered_irq) == 0)
242 keypad->gpio_all_disabled = true;
243 } else {
244
245 for (i = 0; i < pdata->num_row_gpios; i++) {
246 if (!test_bit(i, keypad->disabled_gpios)) {
247 gpio = pdata->row_gpios[i];
248
249 if (enable_irq_wake(gpio_to_irq(gpio)) == 0)
250 __set_bit(i, keypad->disabled_gpios);
251 }
252 }
253 }
254}
255
256static void matrix_keypad_disable_wakeup(struct matrix_keypad *keypad)
257{
258 const struct matrix_keypad_platform_data *pdata = keypad->pdata;
259 unsigned int gpio;
260 int i;
261
262 if (pdata->clustered_irq > 0) {
263 if (keypad->gpio_all_disabled) {
264 disable_irq_wake(pdata->clustered_irq);
265 keypad->gpio_all_disabled = false;
266 }
267 } else {
268 for (i = 0; i < pdata->num_row_gpios; i++) {
269 if (test_and_clear_bit(i, keypad->disabled_gpios)) {
270 gpio = pdata->row_gpios[i];
271 disable_irq_wake(gpio_to_irq(gpio));
272 }
273 }
274 }
275}
276
277static int matrix_keypad_suspend(struct device *dev)
278{
279 struct platform_device *pdev = to_platform_device(dev);
280 struct matrix_keypad *keypad = platform_get_drvdata(pdev);
281
282 matrix_keypad_stop(keypad->input_dev);
283
284 if (device_may_wakeup(&pdev->dev))
285 matrix_keypad_enable_wakeup(keypad);
286
287 return 0;
288}
289
290static int matrix_keypad_resume(struct device *dev)
291{
292 struct platform_device *pdev = to_platform_device(dev);
293 struct matrix_keypad *keypad = platform_get_drvdata(pdev);
294
295 if (device_may_wakeup(&pdev->dev))
296 matrix_keypad_disable_wakeup(keypad);
297
298 matrix_keypad_start(keypad->input_dev);
299
300 return 0;
301}
302#endif
303
304static SIMPLE_DEV_PM_OPS(matrix_keypad_pm_ops,
305 matrix_keypad_suspend, matrix_keypad_resume);
306
307static int matrix_keypad_init_gpio(struct platform_device *pdev,
308 struct matrix_keypad *keypad)
309{
310 const struct matrix_keypad_platform_data *pdata = keypad->pdata;
311 int i, err;
312
313 /* initialized strobe lines as outputs, activated */
314 for (i = 0; i < pdata->num_col_gpios; i++) {
315 err = gpio_request(pdata->col_gpios[i], "matrix_kbd_col");
316 if (err) {
317 dev_err(&pdev->dev,
318 "failed to request GPIO%d for COL%d\n",
319 pdata->col_gpios[i], i);
320 goto err_free_cols;
321 }
322
323 gpio_direction_output(pdata->col_gpios[i], !pdata->active_low);
324 }
325
326 for (i = 0; i < pdata->num_row_gpios; i++) {
327 err = gpio_request(pdata->row_gpios[i], "matrix_kbd_row");
328 if (err) {
329 dev_err(&pdev->dev,
330 "failed to request GPIO%d for ROW%d\n",
331 pdata->row_gpios[i], i);
332 goto err_free_rows;
333 }
334
335 gpio_direction_input(pdata->row_gpios[i]);
336 }
337
338 if (pdata->clustered_irq > 0) {
339 err = request_any_context_irq(pdata->clustered_irq,
340 matrix_keypad_interrupt,
341 pdata->clustered_irq_flags,
342 "matrix-keypad", keypad);
343 if (err < 0) {
344 dev_err(&pdev->dev,
345 "Unable to acquire clustered interrupt\n");
346 goto err_free_rows;
347 }
348 } else {
349 for (i = 0; i < pdata->num_row_gpios; i++) {
350 err = request_any_context_irq(
351 gpio_to_irq(pdata->row_gpios[i]),
352 matrix_keypad_interrupt,
353 IRQF_TRIGGER_RISING |
354 IRQF_TRIGGER_FALLING,
355 "matrix-keypad", keypad);
356 if (err < 0) {
357 dev_err(&pdev->dev,
358 "Unable to acquire interrupt for GPIO line %i\n",
359 pdata->row_gpios[i]);
360 goto err_free_irqs;
361 }
362 }
363 }
364
365 /* initialized as disabled - enabled by input->open */
366 disable_row_irqs(keypad);
367 return 0;
368
369err_free_irqs:
370 while (--i >= 0)
371 free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad);
372 i = pdata->num_row_gpios;
373err_free_rows:
374 while (--i >= 0)
375 gpio_free(pdata->row_gpios[i]);
376 i = pdata->num_col_gpios;
377err_free_cols:
378 while (--i >= 0)
379 gpio_free(pdata->col_gpios[i]);
380
381 return err;
382}
383
384static void matrix_keypad_free_gpio(struct matrix_keypad *keypad)
385{
386 const struct matrix_keypad_platform_data *pdata = keypad->pdata;
387 int i;
388
389 if (pdata->clustered_irq > 0) {
390 free_irq(pdata->clustered_irq, keypad);
391 } else {
392 for (i = 0; i < pdata->num_row_gpios; i++)
393 free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad);
394 }
395
396 for (i = 0; i < pdata->num_row_gpios; i++)
397 gpio_free(pdata->row_gpios[i]);
398
399 for (i = 0; i < pdata->num_col_gpios; i++)
400 gpio_free(pdata->col_gpios[i]);
401}
402
403#ifdef CONFIG_OF
404static struct matrix_keypad_platform_data *
405matrix_keypad_parse_dt(struct device *dev)
406{
407 struct matrix_keypad_platform_data *pdata;
408 struct device_node *np = dev->of_node;
409 unsigned int *gpios;
410 int ret, i, nrow, ncol;
411
412 if (!np) {
413 dev_err(dev, "device lacks DT data\n");
414 return ERR_PTR(-ENODEV);
415 }
416
417 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
418 if (!pdata) {
419 dev_err(dev, "could not allocate memory for platform data\n");
420 return ERR_PTR(-ENOMEM);
421 }
422
423 pdata->num_row_gpios = nrow = of_gpio_named_count(np, "row-gpios");
424 pdata->num_col_gpios = ncol = of_gpio_named_count(np, "col-gpios");
425 if (nrow <= 0 || ncol <= 0) {
426 dev_err(dev, "number of keypad rows/columns not specified\n");
427 return ERR_PTR(-EINVAL);
428 }
429
430 if (of_get_property(np, "linux,no-autorepeat", NULL))
431 pdata->no_autorepeat = true;
432
433 pdata->wakeup = of_property_read_bool(np, "wakeup-source") ||
434 of_property_read_bool(np, "linux,wakeup"); /* legacy */
435
436 if (of_get_property(np, "gpio-activelow", NULL))
437 pdata->active_low = true;
438
439 pdata->drive_inactive_cols =
440 of_property_read_bool(np, "drive-inactive-cols");
441
442 of_property_read_u32(np, "debounce-delay-ms", &pdata->debounce_ms);
443 of_property_read_u32(np, "col-scan-delay-us",
444 &pdata->col_scan_delay_us);
445
446 gpios = devm_kcalloc(dev,
447 pdata->num_row_gpios + pdata->num_col_gpios,
448 sizeof(unsigned int),
449 GFP_KERNEL);
450 if (!gpios) {
451 dev_err(dev, "could not allocate memory for gpios\n");
452 return ERR_PTR(-ENOMEM);
453 }
454
455 for (i = 0; i < nrow; i++) {
456 ret = of_get_named_gpio(np, "row-gpios", i);
457 if (ret < 0)
458 return ERR_PTR(ret);
459 gpios[i] = ret;
460 }
461
462 for (i = 0; i < ncol; i++) {
463 ret = of_get_named_gpio(np, "col-gpios", i);
464 if (ret < 0)
465 return ERR_PTR(ret);
466 gpios[nrow + i] = ret;
467 }
468
469 pdata->row_gpios = gpios;
470 pdata->col_gpios = &gpios[pdata->num_row_gpios];
471
472 return pdata;
473}
474#else
475static inline struct matrix_keypad_platform_data *
476matrix_keypad_parse_dt(struct device *dev)
477{
478 dev_err(dev, "no platform data defined\n");
479
480 return ERR_PTR(-EINVAL);
481}
482#endif
483
484static int matrix_keypad_probe(struct platform_device *pdev)
485{
486 const struct matrix_keypad_platform_data *pdata;
487 struct matrix_keypad *keypad;
488 struct input_dev *input_dev;
489 int err;
490
491 pdata = dev_get_platdata(&pdev->dev);
492 if (!pdata) {
493 pdata = matrix_keypad_parse_dt(&pdev->dev);
494 if (IS_ERR(pdata))
495 return PTR_ERR(pdata);
496 } else if (!pdata->keymap_data) {
497 dev_err(&pdev->dev, "no keymap data defined\n");
498 return -EINVAL;
499 }
500
501 keypad = kzalloc(sizeof(struct matrix_keypad), GFP_KERNEL);
502 input_dev = input_allocate_device();
503 if (!keypad || !input_dev) {
504 err = -ENOMEM;
505 goto err_free_mem;
506 }
507
508 keypad->input_dev = input_dev;
509 keypad->pdata = pdata;
510 keypad->row_shift = get_count_order(pdata->num_col_gpios);
511 keypad->stopped = true;
512 INIT_DELAYED_WORK(&keypad->work, matrix_keypad_scan);
513 spin_lock_init(&keypad->lock);
514
515 input_dev->name = pdev->name;
516 input_dev->id.bustype = BUS_HOST;
517 input_dev->dev.parent = &pdev->dev;
518 input_dev->open = matrix_keypad_start;
519 input_dev->close = matrix_keypad_stop;
520
521 err = matrix_keypad_build_keymap(pdata->keymap_data, NULL,
522 pdata->num_row_gpios,
523 pdata->num_col_gpios,
524 NULL, input_dev);
525 if (err) {
526 dev_err(&pdev->dev, "failed to build keymap\n");
527 goto err_free_mem;
528 }
529
530 if (!pdata->no_autorepeat)
531 __set_bit(EV_REP, input_dev->evbit);
532 input_set_capability(input_dev, EV_MSC, MSC_SCAN);
533 input_set_drvdata(input_dev, keypad);
534
535 err = matrix_keypad_init_gpio(pdev, keypad);
536 if (err)
537 goto err_free_mem;
538
539 err = input_register_device(keypad->input_dev);
540 if (err)
541 goto err_free_gpio;
542
543 device_init_wakeup(&pdev->dev, pdata->wakeup);
544 platform_set_drvdata(pdev, keypad);
545
546 return 0;
547
548err_free_gpio:
549 matrix_keypad_free_gpio(keypad);
550err_free_mem:
551 input_free_device(input_dev);
552 kfree(keypad);
553 return err;
554}
555
556static int matrix_keypad_remove(struct platform_device *pdev)
557{
558 struct matrix_keypad *keypad = platform_get_drvdata(pdev);
559
560 matrix_keypad_free_gpio(keypad);
561 input_unregister_device(keypad->input_dev);
562 kfree(keypad);
563
564 return 0;
565}
566
567#ifdef CONFIG_OF
568static const struct of_device_id matrix_keypad_dt_match[] = {
569 { .compatible = "gpio-matrix-keypad" },
570 { }
571};
572MODULE_DEVICE_TABLE(of, matrix_keypad_dt_match);
573#endif
574
575static struct platform_driver matrix_keypad_driver = {
576 .probe = matrix_keypad_probe,
577 .remove = matrix_keypad_remove,
578 .driver = {
579 .name = "matrix-keypad",
580 .pm = &matrix_keypad_pm_ops,
581 .of_match_table = of_match_ptr(matrix_keypad_dt_match),
582 },
583};
584module_platform_driver(matrix_keypad_driver);
585
586MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
587MODULE_DESCRIPTION("GPIO Driven Matrix Keypad Driver");
588MODULE_LICENSE("GPL v2");
589MODULE_ALIAS("platform:matrix-keypad");
590