1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * GPIO driven matrix keyboard driver
4 *
5 * Copyright (c) 2008 Marek Vasut <marek.vasut@gmail.com>
6 *
7 * Based on corgikbd.c
8 */
9
10#include <linux/types.h>
11#include <linux/delay.h>
12#include <linux/gpio/consumer.h>
13#include <linux/platform_device.h>
14#include <linux/input.h>
15#include <linux/irq.h>
16#include <linux/interrupt.h>
17#include <linux/jiffies.h>
18#include <linux/module.h>
19#include <linux/gpio.h>
20#include <linux/input/matrix_keypad.h>
21#include <linux/slab.h>
22#include <linux/of.h>
23#include <linux/of_gpio.h>
24#include <linux/of_platform.h>
25
26struct matrix_keypad {
27 const struct matrix_keypad_platform_data *pdata;
28 struct input_dev *input_dev;
29 unsigned int row_shift;
30
31 DECLARE_BITMAP(disabled_gpios, MATRIX_MAX_ROWS);
32
33 uint32_t last_key_state[MATRIX_MAX_COLS];
34 struct delayed_work work;
35 spinlock_t lock;
36 bool scan_pending;
37 bool stopped;
38 bool gpio_all_disabled;
39};
40
41/*
42 * NOTE: If drive_inactive_cols is false, then the GPIO has to be put into
43 * HiZ when de-activated to cause minmal side effect when scanning other
44 * columns. In that case it is configured here to be input, otherwise it is
45 * driven with the inactive value.
46 */
47static void __activate_col(const struct matrix_keypad_platform_data *pdata,
48 int col, bool on)
49{
50 bool level_on = !pdata->active_low;
51
52 if (on) {
53 gpio_direction_output(gpio: pdata->col_gpios[col], value: level_on);
54 } else {
55 gpio_set_value_cansleep(gpio: pdata->col_gpios[col], value: !level_on);
56 if (!pdata->drive_inactive_cols)
57 gpio_direction_input(gpio: pdata->col_gpios[col]);
58 }
59}
60
61static void activate_col(const struct matrix_keypad_platform_data *pdata,
62 int col, bool on)
63{
64 __activate_col(pdata, col, on);
65
66 if (on && pdata->col_scan_delay_us)
67 udelay(pdata->col_scan_delay_us);
68}
69
70static void activate_all_cols(const struct matrix_keypad_platform_data *pdata,
71 bool on)
72{
73 int col;
74
75 for (col = 0; col < pdata->num_col_gpios; col++)
76 __activate_col(pdata, col, on);
77}
78
79static bool row_asserted(const struct matrix_keypad_platform_data *pdata,
80 int row)
81{
82 return gpio_get_value_cansleep(gpio: pdata->row_gpios[row]) ?
83 !pdata->active_low : pdata->active_low;
84}
85
86static void enable_row_irqs(struct matrix_keypad *keypad)
87{
88 const struct matrix_keypad_platform_data *pdata = keypad->pdata;
89 int i;
90
91 if (pdata->clustered_irq > 0)
92 enable_irq(irq: pdata->clustered_irq);
93 else {
94 for (i = 0; i < pdata->num_row_gpios; i++)
95 enable_irq(irq: gpio_to_irq(gpio: pdata->row_gpios[i]));
96 }
97}
98
99static void disable_row_irqs(struct matrix_keypad *keypad)
100{
101 const struct matrix_keypad_platform_data *pdata = keypad->pdata;
102 int i;
103
104 if (pdata->clustered_irq > 0)
105 disable_irq_nosync(irq: pdata->clustered_irq);
106 else {
107 for (i = 0; i < pdata->num_row_gpios; i++)
108 disable_irq_nosync(irq: gpio_to_irq(gpio: pdata->row_gpios[i]));
109 }
110}
111
112/*
113 * This gets the keys from keyboard and reports it to input subsystem
114 */
115static void matrix_keypad_scan(struct work_struct *work)
116{
117 struct matrix_keypad *keypad =
118 container_of(work, struct matrix_keypad, work.work);
119 struct input_dev *input_dev = keypad->input_dev;
120 const unsigned short *keycodes = input_dev->keycode;
121 const struct matrix_keypad_platform_data *pdata = keypad->pdata;
122 uint32_t new_state[MATRIX_MAX_COLS];
123 int row, col, code;
124
125 /* de-activate all columns for scanning */
126 activate_all_cols(pdata, on: false);
127
128 memset(new_state, 0, sizeof(new_state));
129
130 for (row = 0; row < pdata->num_row_gpios; row++)
131 gpio_direction_input(gpio: pdata->row_gpios[row]);
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, on: 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, on: 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(dev: input_dev, EV_MSC, MSC_SCAN, value: code);
158 input_report_key(dev: input_dev,
159 code: keycodes[code],
160 value: new_state[col] & (1 << row));
161 }
162 }
163 input_sync(dev: input_dev);
164
165 memcpy(keypad->last_key_state, new_state, sizeof(new_state));
166
167 activate_all_cols(pdata, on: true);
168
169 /* Enable IRQs again */
170 spin_lock_irq(lock: &keypad->lock);
171 keypad->scan_pending = false;
172 enable_row_irqs(keypad);
173 spin_unlock_irq(lock: &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(dwork: &keypad->work,
194 delay: msecs_to_jiffies(m: keypad->pdata->debounce_ms));
195
196out:
197 spin_unlock_irqrestore(lock: &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(dwork: &keypad->work, delay: 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(lock: &keypad->lock);
222 keypad->stopped = true;
223 spin_unlock_irq(lock: &keypad->lock);
224
225 flush_delayed_work(dwork: &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
233static void matrix_keypad_enable_wakeup(struct matrix_keypad *keypad)
234{
235 const struct matrix_keypad_platform_data *pdata = keypad->pdata;
236 unsigned int gpio;
237 int i;
238
239 if (pdata->clustered_irq > 0) {
240 if (enable_irq_wake(irq: pdata->clustered_irq) == 0)
241 keypad->gpio_all_disabled = true;
242 } else {
243
244 for (i = 0; i < pdata->num_row_gpios; i++) {
245 if (!test_bit(i, keypad->disabled_gpios)) {
246 gpio = pdata->row_gpios[i];
247
248 if (enable_irq_wake(irq: gpio_to_irq(gpio)) == 0)
249 __set_bit(i, keypad->disabled_gpios);
250 }
251 }
252 }
253}
254
255static void matrix_keypad_disable_wakeup(struct matrix_keypad *keypad)
256{
257 const struct matrix_keypad_platform_data *pdata = keypad->pdata;
258 unsigned int gpio;
259 int i;
260
261 if (pdata->clustered_irq > 0) {
262 if (keypad->gpio_all_disabled) {
263 disable_irq_wake(irq: pdata->clustered_irq);
264 keypad->gpio_all_disabled = false;
265 }
266 } else {
267 for (i = 0; i < pdata->num_row_gpios; i++) {
268 if (test_and_clear_bit(nr: i, addr: keypad->disabled_gpios)) {
269 gpio = pdata->row_gpios[i];
270 disable_irq_wake(irq: gpio_to_irq(gpio));
271 }
272 }
273 }
274}
275
276static int matrix_keypad_suspend(struct device *dev)
277{
278 struct platform_device *pdev = to_platform_device(dev);
279 struct matrix_keypad *keypad = platform_get_drvdata(pdev);
280
281 matrix_keypad_stop(dev: keypad->input_dev);
282
283 if (device_may_wakeup(dev: &pdev->dev))
284 matrix_keypad_enable_wakeup(keypad);
285
286 return 0;
287}
288
289static int matrix_keypad_resume(struct device *dev)
290{
291 struct platform_device *pdev = to_platform_device(dev);
292 struct matrix_keypad *keypad = platform_get_drvdata(pdev);
293
294 if (device_may_wakeup(dev: &pdev->dev))
295 matrix_keypad_disable_wakeup(keypad);
296
297 matrix_keypad_start(dev: keypad->input_dev);
298
299 return 0;
300}
301
302static DEFINE_SIMPLE_DEV_PM_OPS(matrix_keypad_pm_ops,
303 matrix_keypad_suspend, matrix_keypad_resume);
304
305static int matrix_keypad_init_gpio(struct platform_device *pdev,
306 struct matrix_keypad *keypad)
307{
308 const struct matrix_keypad_platform_data *pdata = keypad->pdata;
309 int i, err;
310
311 /* initialized strobe lines as outputs, activated */
312 for (i = 0; i < pdata->num_col_gpios; i++) {
313 err = gpio_request(gpio: pdata->col_gpios[i], label: "matrix_kbd_col");
314 if (err) {
315 dev_err(&pdev->dev,
316 "failed to request GPIO%d for COL%d\n",
317 pdata->col_gpios[i], i);
318 goto err_free_cols;
319 }
320
321 gpio_direction_output(gpio: pdata->col_gpios[i], value: !pdata->active_low);
322 }
323
324 for (i = 0; i < pdata->num_row_gpios; i++) {
325 err = gpio_request(gpio: pdata->row_gpios[i], label: "matrix_kbd_row");
326 if (err) {
327 dev_err(&pdev->dev,
328 "failed to request GPIO%d for ROW%d\n",
329 pdata->row_gpios[i], i);
330 goto err_free_rows;
331 }
332
333 gpio_direction_input(gpio: pdata->row_gpios[i]);
334 }
335
336 if (pdata->clustered_irq > 0) {
337 err = request_any_context_irq(irq: pdata->clustered_irq,
338 handler: matrix_keypad_interrupt,
339 flags: pdata->clustered_irq_flags,
340 name: "matrix-keypad", dev_id: keypad);
341 if (err < 0) {
342 dev_err(&pdev->dev,
343 "Unable to acquire clustered interrupt\n");
344 goto err_free_rows;
345 }
346 } else {
347 for (i = 0; i < pdata->num_row_gpios; i++) {
348 err = request_any_context_irq(
349 irq: gpio_to_irq(gpio: pdata->row_gpios[i]),
350 handler: matrix_keypad_interrupt,
351 IRQF_TRIGGER_RISING |
352 IRQF_TRIGGER_FALLING,
353 name: "matrix-keypad", dev_id: keypad);
354 if (err < 0) {
355 dev_err(&pdev->dev,
356 "Unable to acquire interrupt for GPIO line %i\n",
357 pdata->row_gpios[i]);
358 goto err_free_irqs;
359 }
360 }
361 }
362
363 /* initialized as disabled - enabled by input->open */
364 disable_row_irqs(keypad);
365 return 0;
366
367err_free_irqs:
368 while (--i >= 0)
369 free_irq(gpio_to_irq(gpio: pdata->row_gpios[i]), keypad);
370 i = pdata->num_row_gpios;
371err_free_rows:
372 while (--i >= 0)
373 gpio_free(gpio: pdata->row_gpios[i]);
374 i = pdata->num_col_gpios;
375err_free_cols:
376 while (--i >= 0)
377 gpio_free(gpio: pdata->col_gpios[i]);
378
379 return err;
380}
381
382static void matrix_keypad_free_gpio(struct matrix_keypad *keypad)
383{
384 const struct matrix_keypad_platform_data *pdata = keypad->pdata;
385 int i;
386
387 if (pdata->clustered_irq > 0) {
388 free_irq(pdata->clustered_irq, keypad);
389 } else {
390 for (i = 0; i < pdata->num_row_gpios; i++)
391 free_irq(gpio_to_irq(gpio: pdata->row_gpios[i]), keypad);
392 }
393
394 for (i = 0; i < pdata->num_row_gpios; i++)
395 gpio_free(gpio: pdata->row_gpios[i]);
396
397 for (i = 0; i < pdata->num_col_gpios; i++)
398 gpio_free(gpio: pdata->col_gpios[i]);
399}
400
401#ifdef CONFIG_OF
402static struct matrix_keypad_platform_data *
403matrix_keypad_parse_dt(struct device *dev)
404{
405 struct matrix_keypad_platform_data *pdata;
406 struct device_node *np = dev->of_node;
407 unsigned int *gpios;
408 int ret, i, nrow, ncol;
409
410 if (!np) {
411 dev_err(dev, "device lacks DT data\n");
412 return ERR_PTR(error: -ENODEV);
413 }
414
415 pdata = devm_kzalloc(dev, size: sizeof(*pdata), GFP_KERNEL);
416 if (!pdata) {
417 dev_err(dev, "could not allocate memory for platform data\n");
418 return ERR_PTR(error: -ENOMEM);
419 }
420
421 pdata->num_row_gpios = nrow = gpiod_count(dev, con_id: "row");
422 pdata->num_col_gpios = ncol = gpiod_count(dev, con_id: "col");
423 if (nrow < 0 || ncol < 0) {
424 dev_err(dev, "number of keypad rows/columns not specified\n");
425 return ERR_PTR(error: -EINVAL);
426 }
427
428 pdata->no_autorepeat = of_property_read_bool(np, propname: "linux,no-autorepeat");
429
430 pdata->wakeup = of_property_read_bool(np, propname: "wakeup-source") ||
431 of_property_read_bool(np, propname: "linux,wakeup"); /* legacy */
432
433 pdata->active_low = of_property_read_bool(np, propname: "gpio-activelow");
434
435 pdata->drive_inactive_cols =
436 of_property_read_bool(np, propname: "drive-inactive-cols");
437
438 of_property_read_u32(np, propname: "debounce-delay-ms", out_value: &pdata->debounce_ms);
439 of_property_read_u32(np, propname: "col-scan-delay-us",
440 out_value: &pdata->col_scan_delay_us);
441
442 gpios = devm_kcalloc(dev,
443 n: pdata->num_row_gpios + pdata->num_col_gpios,
444 size: sizeof(unsigned int),
445 GFP_KERNEL);
446 if (!gpios) {
447 dev_err(dev, "could not allocate memory for gpios\n");
448 return ERR_PTR(error: -ENOMEM);
449 }
450
451 for (i = 0; i < nrow; i++) {
452 ret = of_get_named_gpio(np, list_name: "row-gpios", index: i);
453 if (ret < 0)
454 return ERR_PTR(error: ret);
455 gpios[i] = ret;
456 }
457
458 for (i = 0; i < ncol; i++) {
459 ret = of_get_named_gpio(np, list_name: "col-gpios", index: i);
460 if (ret < 0)
461 return ERR_PTR(error: ret);
462 gpios[nrow + i] = ret;
463 }
464
465 pdata->row_gpios = gpios;
466 pdata->col_gpios = &gpios[pdata->num_row_gpios];
467
468 return pdata;
469}
470#else
471static inline struct matrix_keypad_platform_data *
472matrix_keypad_parse_dt(struct device *dev)
473{
474 dev_err(dev, "no platform data defined\n");
475
476 return ERR_PTR(-EINVAL);
477}
478#endif
479
480static int matrix_keypad_probe(struct platform_device *pdev)
481{
482 const struct matrix_keypad_platform_data *pdata;
483 struct matrix_keypad *keypad;
484 struct input_dev *input_dev;
485 int err;
486
487 pdata = dev_get_platdata(dev: &pdev->dev);
488 if (!pdata) {
489 pdata = matrix_keypad_parse_dt(dev: &pdev->dev);
490 if (IS_ERR(ptr: pdata))
491 return PTR_ERR(ptr: pdata);
492 } else if (!pdata->keymap_data) {
493 dev_err(&pdev->dev, "no keymap data defined\n");
494 return -EINVAL;
495 }
496
497 keypad = kzalloc(size: sizeof(struct matrix_keypad), GFP_KERNEL);
498 input_dev = input_allocate_device();
499 if (!keypad || !input_dev) {
500 err = -ENOMEM;
501 goto err_free_mem;
502 }
503
504 keypad->input_dev = input_dev;
505 keypad->pdata = pdata;
506 keypad->row_shift = get_count_order(count: pdata->num_col_gpios);
507 keypad->stopped = true;
508 INIT_DELAYED_WORK(&keypad->work, matrix_keypad_scan);
509 spin_lock_init(&keypad->lock);
510
511 input_dev->name = pdev->name;
512 input_dev->id.bustype = BUS_HOST;
513 input_dev->dev.parent = &pdev->dev;
514 input_dev->open = matrix_keypad_start;
515 input_dev->close = matrix_keypad_stop;
516
517 err = matrix_keypad_build_keymap(keymap_data: pdata->keymap_data, NULL,
518 rows: pdata->num_row_gpios,
519 cols: pdata->num_col_gpios,
520 NULL, input_dev);
521 if (err) {
522 dev_err(&pdev->dev, "failed to build keymap\n");
523 goto err_free_mem;
524 }
525
526 if (!pdata->no_autorepeat)
527 __set_bit(EV_REP, input_dev->evbit);
528 input_set_capability(dev: input_dev, EV_MSC, MSC_SCAN);
529 input_set_drvdata(dev: input_dev, data: keypad);
530
531 err = matrix_keypad_init_gpio(pdev, keypad);
532 if (err)
533 goto err_free_mem;
534
535 err = input_register_device(keypad->input_dev);
536 if (err)
537 goto err_free_gpio;
538
539 device_init_wakeup(dev: &pdev->dev, enable: pdata->wakeup);
540 platform_set_drvdata(pdev, data: keypad);
541
542 return 0;
543
544err_free_gpio:
545 matrix_keypad_free_gpio(keypad);
546err_free_mem:
547 input_free_device(dev: input_dev);
548 kfree(objp: keypad);
549 return err;
550}
551
552static int matrix_keypad_remove(struct platform_device *pdev)
553{
554 struct matrix_keypad *keypad = platform_get_drvdata(pdev);
555
556 matrix_keypad_free_gpio(keypad);
557 input_unregister_device(keypad->input_dev);
558 kfree(objp: keypad);
559
560 return 0;
561}
562
563#ifdef CONFIG_OF
564static const struct of_device_id matrix_keypad_dt_match[] = {
565 { .compatible = "gpio-matrix-keypad" },
566 { }
567};
568MODULE_DEVICE_TABLE(of, matrix_keypad_dt_match);
569#endif
570
571static struct platform_driver matrix_keypad_driver = {
572 .probe = matrix_keypad_probe,
573 .remove = matrix_keypad_remove,
574 .driver = {
575 .name = "matrix-keypad",
576 .pm = pm_sleep_ptr(&matrix_keypad_pm_ops),
577 .of_match_table = of_match_ptr(matrix_keypad_dt_match),
578 },
579};
580module_platform_driver(matrix_keypad_driver);
581
582MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
583MODULE_DESCRIPTION("GPIO Driven Matrix Keypad Driver");
584MODULE_LICENSE("GPL v2");
585MODULE_ALIAS("platform:matrix-keypad");
586

source code of linux/drivers/input/keyboard/matrix_keypad.c