xref: /linux/drivers/input/keyboard/matrix_keypad.c (revision 8795a739e5c72abeec51caf36b6df2b37e5720c5) 
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/platform_device.h>
13 #include <linux/input.h>
14 #include <linux/irq.h>
15 #include <linux/interrupt.h>
16 #include <linux/jiffies.h>
17 #include <linux/module.h>
18 #include <linux/gpio.h>
19 #include <linux/input/matrix_keypad.h>
20 #include <linux/slab.h>
21 #include <linux/of.h>
22 #include <linux/of_gpio.h>
23 #include <linux/of_platform.h>
24 
25 struct matrix_keypad {
26 	const struct matrix_keypad_platform_data *pdata;
27 	struct input_dev *input_dev;
28 	unsigned int row_shift;
29 
30 	DECLARE_BITMAP(disabled_gpios, MATRIX_MAX_ROWS);
31 
32 	uint32_t last_key_state[MATRIX_MAX_COLS];
33 	struct delayed_work work;
34 	spinlock_t lock;
35 	bool scan_pending;
36 	bool stopped;
37 	bool gpio_all_disabled;
38 };
39 
40 /*
41  * NOTE: If drive_inactive_cols is false, then the GPIO has to be put into
42  * HiZ when de-activated to cause minmal side effect when scanning other
43  * columns. In that case it is configured here to be input, otherwise it is
44  * driven with the inactive value.
45  */
46 static void __activate_col(const struct matrix_keypad_platform_data *pdata,
47 			   int col, bool on)
48 {
49 	bool level_on = !pdata->active_low;
50 
51 	if (on) {
52 		gpio_direction_output(pdata->col_gpios[col], level_on);
53 	} else {
54 		gpio_set_value_cansleep(pdata->col_gpios[col], !level_on);
55 		if (!pdata->drive_inactive_cols)
56 			gpio_direction_input(pdata->col_gpios[col]);
57 	}
58 }
59 
60 static void activate_col(const struct matrix_keypad_platform_data *pdata,
61 			 int col, bool on)
62 {
63 	__activate_col(pdata, col, on);
64 
65 	if (on && pdata->col_scan_delay_us)
66 		udelay(pdata->col_scan_delay_us);
67 }
68 
69 static void activate_all_cols(const struct matrix_keypad_platform_data *pdata,
70 			      bool on)
71 {
72 	int col;
73 
74 	for (col = 0; col < pdata->num_col_gpios; col++)
75 		__activate_col(pdata, col, on);
76 }
77 
78 static bool row_asserted(const struct matrix_keypad_platform_data *pdata,
79 			 int row)
80 {
81 	return gpio_get_value_cansleep(pdata->row_gpios[row]) ?
82 			!pdata->active_low : pdata->active_low;
83 }
84 
85 static void enable_row_irqs(struct matrix_keypad *keypad)
86 {
87 	const struct matrix_keypad_platform_data *pdata = keypad->pdata;
88 	int i;
89 
90 	if (pdata->clustered_irq > 0)
91 		enable_irq(pdata->clustered_irq);
92 	else {
93 		for (i = 0; i < pdata->num_row_gpios; i++)
94 			enable_irq(gpio_to_irq(pdata->row_gpios[i]));
95 	}
96 }
97 
98 static void disable_row_irqs(struct matrix_keypad *keypad)
99 {
100 	const struct matrix_keypad_platform_data *pdata = keypad->pdata;
101 	int i;
102 
103 	if (pdata->clustered_irq > 0)
104 		disable_irq_nosync(pdata->clustered_irq);
105 	else {
106 		for (i = 0; i < pdata->num_row_gpios; i++)
107 			disable_irq_nosync(gpio_to_irq(pdata->row_gpios[i]));
108 	}
109 }
110 
111 /*
112  * This gets the keys from keyboard and reports it to input subsystem
113  */
114 static void matrix_keypad_scan(struct work_struct *work)
115 {
116 	struct matrix_keypad *keypad =
117 		container_of(work, struct matrix_keypad, work.work);
118 	struct input_dev *input_dev = keypad->input_dev;
119 	const unsigned short *keycodes = input_dev->keycode;
120 	const struct matrix_keypad_platform_data *pdata = keypad->pdata;
121 	uint32_t new_state[MATRIX_MAX_COLS];
122 	int row, col, code;
123 
124 	/* de-activate all columns for scanning */
125 	activate_all_cols(pdata, false);
126 
127 	memset(new_state, 0, sizeof(new_state));
128 
129 	/* assert each column and read the row status out */
130 	for (col = 0; col < pdata->num_col_gpios; col++) {
131 
132 		activate_col(pdata, col, true);
133 
134 		for (row = 0; row < pdata->num_row_gpios; row++)
135 			new_state[col] |=
136 				row_asserted(pdata, row) ? (1 << row) : 0;
137 
138 		activate_col(pdata, col, false);
139 	}
140 
141 	for (col = 0; col < pdata->num_col_gpios; col++) {
142 		uint32_t bits_changed;
143 
144 		bits_changed = keypad->last_key_state[col] ^ new_state[col];
145 		if (bits_changed == 0)
146 			continue;
147 
148 		for (row = 0; row < pdata->num_row_gpios; row++) {
149 			if ((bits_changed & (1 << row)) == 0)
150 				continue;
151 
152 			code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
153 			input_event(input_dev, EV_MSC, MSC_SCAN, code);
154 			input_report_key(input_dev,
155 					 keycodes[code],
156 					 new_state[col] & (1 << row));
157 		}
158 	}
159 	input_sync(input_dev);
160 
161 	memcpy(keypad->last_key_state, new_state, sizeof(new_state));
162 
163 	activate_all_cols(pdata, true);
164 
165 	/* Enable IRQs again */
166 	spin_lock_irq(&keypad->lock);
167 	keypad->scan_pending = false;
168 	enable_row_irqs(keypad);
169 	spin_unlock_irq(&keypad->lock);
170 }
171 
172 static irqreturn_t matrix_keypad_interrupt(int irq, void *id)
173 {
174 	struct matrix_keypad *keypad = id;
175 	unsigned long flags;
176 
177 	spin_lock_irqsave(&keypad->lock, flags);
178 
179 	/*
180 	 * See if another IRQ beaten us to it and scheduled the
181 	 * scan already. In that case we should not try to
182 	 * disable IRQs again.
183 	 */
184 	if (unlikely(keypad->scan_pending || keypad->stopped))
185 		goto out;
186 
187 	disable_row_irqs(keypad);
188 	keypad->scan_pending = true;
189 	schedule_delayed_work(&keypad->work,
190 		msecs_to_jiffies(keypad->pdata->debounce_ms));
191 
192 out:
193 	spin_unlock_irqrestore(&keypad->lock, flags);
194 	return IRQ_HANDLED;
195 }
196 
197 static int matrix_keypad_start(struct input_dev *dev)
198 {
199 	struct matrix_keypad *keypad = input_get_drvdata(dev);
200 
201 	keypad->stopped = false;
202 	mb();
203 
204 	/*
205 	 * Schedule an immediate key scan to capture current key state;
206 	 * columns will be activated and IRQs be enabled after the scan.
207 	 */
208 	schedule_delayed_work(&keypad->work, 0);
209 
210 	return 0;
211 }
212 
213 static void matrix_keypad_stop(struct input_dev *dev)
214 {
215 	struct matrix_keypad *keypad = input_get_drvdata(dev);
216 
217 	spin_lock_irq(&keypad->lock);
218 	keypad->stopped = true;
219 	spin_unlock_irq(&keypad->lock);
220 
221 	flush_delayed_work(&keypad->work);
222 	/*
223 	 * matrix_keypad_scan() will leave IRQs enabled;
224 	 * we should disable them now.
225 	 */
226 	disable_row_irqs(keypad);
227 }
228 
229 #ifdef CONFIG_PM_SLEEP
230 static void matrix_keypad_enable_wakeup(struct matrix_keypad *keypad)
231 {
232 	const struct matrix_keypad_platform_data *pdata = keypad->pdata;
233 	unsigned int gpio;
234 	int i;
235 
236 	if (pdata->clustered_irq > 0) {
237 		if (enable_irq_wake(pdata->clustered_irq) == 0)
238 			keypad->gpio_all_disabled = true;
239 	} else {
240 
241 		for (i = 0; i < pdata->num_row_gpios; i++) {
242 			if (!test_bit(i, keypad->disabled_gpios)) {
243 				gpio = pdata->row_gpios[i];
244 
245 				if (enable_irq_wake(gpio_to_irq(gpio)) == 0)
246 					__set_bit(i, keypad->disabled_gpios);
247 			}
248 		}
249 	}
250 }
251 
252 static void matrix_keypad_disable_wakeup(struct matrix_keypad *keypad)
253 {
254 	const struct matrix_keypad_platform_data *pdata = keypad->pdata;
255 	unsigned int gpio;
256 	int i;
257 
258 	if (pdata->clustered_irq > 0) {
259 		if (keypad->gpio_all_disabled) {
260 			disable_irq_wake(pdata->clustered_irq);
261 			keypad->gpio_all_disabled = false;
262 		}
263 	} else {
264 		for (i = 0; i < pdata->num_row_gpios; i++) {
265 			if (test_and_clear_bit(i, keypad->disabled_gpios)) {
266 				gpio = pdata->row_gpios[i];
267 				disable_irq_wake(gpio_to_irq(gpio));
268 			}
269 		}
270 	}
271 }
272 
273 static int matrix_keypad_suspend(struct device *dev)
274 {
275 	struct platform_device *pdev = to_platform_device(dev);
276 	struct matrix_keypad *keypad = platform_get_drvdata(pdev);
277 
278 	matrix_keypad_stop(keypad->input_dev);
279 
280 	if (device_may_wakeup(&pdev->dev))
281 		matrix_keypad_enable_wakeup(keypad);
282 
283 	return 0;
284 }
285 
286 static int matrix_keypad_resume(struct device *dev)
287 {
288 	struct platform_device *pdev = to_platform_device(dev);
289 	struct matrix_keypad *keypad = platform_get_drvdata(pdev);
290 
291 	if (device_may_wakeup(&pdev->dev))
292 		matrix_keypad_disable_wakeup(keypad);
293 
294 	matrix_keypad_start(keypad->input_dev);
295 
296 	return 0;
297 }
298 #endif
299 
300 static SIMPLE_DEV_PM_OPS(matrix_keypad_pm_ops,
301 			 matrix_keypad_suspend, matrix_keypad_resume);
302 
303 static int matrix_keypad_init_gpio(struct platform_device *pdev,
304 				   struct matrix_keypad *keypad)
305 {
306 	const struct matrix_keypad_platform_data *pdata = keypad->pdata;
307 	int i, err;
308 
309 	/* initialized strobe lines as outputs, activated */
310 	for (i = 0; i < pdata->num_col_gpios; i++) {
311 		err = gpio_request(pdata->col_gpios[i], "matrix_kbd_col");
312 		if (err) {
313 			dev_err(&pdev->dev,
314 				"failed to request GPIO%d for COL%d\n",
315 				pdata->col_gpios[i], i);
316 			goto err_free_cols;
317 		}
318 
319 		gpio_direction_output(pdata->col_gpios[i], !pdata->active_low);
320 	}
321 
322 	for (i = 0; i < pdata->num_row_gpios; i++) {
323 		err = gpio_request(pdata->row_gpios[i], "matrix_kbd_row");
324 		if (err) {
325 			dev_err(&pdev->dev,
326 				"failed to request GPIO%d for ROW%d\n",
327 				pdata->row_gpios[i], i);
328 			goto err_free_rows;
329 		}
330 
331 		gpio_direction_input(pdata->row_gpios[i]);
332 	}
333 
334 	if (pdata->clustered_irq > 0) {
335 		err = request_any_context_irq(pdata->clustered_irq,
336 				matrix_keypad_interrupt,
337 				pdata->clustered_irq_flags,
338 				"matrix-keypad", keypad);
339 		if (err < 0) {
340 			dev_err(&pdev->dev,
341 				"Unable to acquire clustered interrupt\n");
342 			goto err_free_rows;
343 		}
344 	} else {
345 		for (i = 0; i < pdata->num_row_gpios; i++) {
346 			err = request_any_context_irq(
347 					gpio_to_irq(pdata->row_gpios[i]),
348 					matrix_keypad_interrupt,
349 					IRQF_TRIGGER_RISING |
350 					IRQF_TRIGGER_FALLING,
351 					"matrix-keypad", keypad);
352 			if (err < 0) {
353 				dev_err(&pdev->dev,
354 					"Unable to acquire interrupt for GPIO line %i\n",
355 					pdata->row_gpios[i]);
356 				goto err_free_irqs;
357 			}
358 		}
359 	}
360 
361 	/* initialized as disabled - enabled by input->open */
362 	disable_row_irqs(keypad);
363 	return 0;
364 
365 err_free_irqs:
366 	while (--i >= 0)
367 		free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad);
368 	i = pdata->num_row_gpios;
369 err_free_rows:
370 	while (--i >= 0)
371 		gpio_free(pdata->row_gpios[i]);
372 	i = pdata->num_col_gpios;
373 err_free_cols:
374 	while (--i >= 0)
375 		gpio_free(pdata->col_gpios[i]);
376 
377 	return err;
378 }
379 
380 static void matrix_keypad_free_gpio(struct matrix_keypad *keypad)
381 {
382 	const struct matrix_keypad_platform_data *pdata = keypad->pdata;
383 	int i;
384 
385 	if (pdata->clustered_irq > 0) {
386 		free_irq(pdata->clustered_irq, keypad);
387 	} else {
388 		for (i = 0; i < pdata->num_row_gpios; i++)
389 			free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad);
390 	}
391 
392 	for (i = 0; i < pdata->num_row_gpios; i++)
393 		gpio_free(pdata->row_gpios[i]);
394 
395 	for (i = 0; i < pdata->num_col_gpios; i++)
396 		gpio_free(pdata->col_gpios[i]);
397 }
398 
399 #ifdef CONFIG_OF
400 static struct matrix_keypad_platform_data *
401 matrix_keypad_parse_dt(struct device *dev)
402 {
403 	struct matrix_keypad_platform_data *pdata;
404 	struct device_node *np = dev->of_node;
405 	unsigned int *gpios;
406 	int ret, i, nrow, ncol;
407 
408 	if (!np) {
409 		dev_err(dev, "device lacks DT data\n");
410 		return ERR_PTR(-ENODEV);
411 	}
412 
413 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
414 	if (!pdata) {
415 		dev_err(dev, "could not allocate memory for platform data\n");
416 		return ERR_PTR(-ENOMEM);
417 	}
418 
419 	pdata->num_row_gpios = nrow = of_gpio_named_count(np, "row-gpios");
420 	pdata->num_col_gpios = ncol = of_gpio_named_count(np, "col-gpios");
421 	if (nrow <= 0 || ncol <= 0) {
422 		dev_err(dev, "number of keypad rows/columns not specified\n");
423 		return ERR_PTR(-EINVAL);
424 	}
425 
426 	if (of_get_property(np, "linux,no-autorepeat", NULL))
427 		pdata->no_autorepeat = true;
428 
429 	pdata->wakeup = of_property_read_bool(np, "wakeup-source") ||
430 			of_property_read_bool(np, "linux,wakeup"); /* legacy */
431 
432 	if (of_get_property(np, "gpio-activelow", NULL))
433 		pdata->active_low = true;
434 
435 	pdata->drive_inactive_cols =
436 		of_property_read_bool(np, "drive-inactive-cols");
437 
438 	of_property_read_u32(np, "debounce-delay-ms", &pdata->debounce_ms);
439 	of_property_read_u32(np, "col-scan-delay-us",
440 						&pdata->col_scan_delay_us);
441 
442 	gpios = devm_kcalloc(dev,
443 			     pdata->num_row_gpios + pdata->num_col_gpios,
444 			     sizeof(unsigned int),
445 			     GFP_KERNEL);
446 	if (!gpios) {
447 		dev_err(dev, "could not allocate memory for gpios\n");
448 		return ERR_PTR(-ENOMEM);
449 	}
450 
451 	for (i = 0; i < nrow; i++) {
452 		ret = of_get_named_gpio(np, "row-gpios", i);
453 		if (ret < 0)
454 			return ERR_PTR(ret);
455 		gpios[i] = ret;
456 	}
457 
458 	for (i = 0; i < ncol; i++) {
459 		ret = of_get_named_gpio(np, "col-gpios", i);
460 		if (ret < 0)
461 			return ERR_PTR(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
471 static inline struct matrix_keypad_platform_data *
472 matrix_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 
480 static 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(&pdev->dev);
488 	if (!pdata) {
489 		pdata = matrix_keypad_parse_dt(&pdev->dev);
490 		if (IS_ERR(pdata))
491 			return PTR_ERR(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(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(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(pdata->keymap_data, NULL,
518 					 pdata->num_row_gpios,
519 					 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(input_dev, EV_MSC, MSC_SCAN);
529 	input_set_drvdata(input_dev, 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(&pdev->dev, pdata->wakeup);
540 	platform_set_drvdata(pdev, keypad);
541 
542 	return 0;
543 
544 err_free_gpio:
545 	matrix_keypad_free_gpio(keypad);
546 err_free_mem:
547 	input_free_device(input_dev);
548 	kfree(keypad);
549 	return err;
550 }
551 
552 static 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(keypad);
559 
560 	return 0;
561 }
562 
563 #ifdef CONFIG_OF
564 static const struct of_device_id matrix_keypad_dt_match[] = {
565 	{ .compatible = "gpio-matrix-keypad" },
566 	{ }
567 };
568 MODULE_DEVICE_TABLE(of, matrix_keypad_dt_match);
569 #endif
570 
571 static struct platform_driver matrix_keypad_driver = {
572 	.probe		= matrix_keypad_probe,
573 	.remove		= matrix_keypad_remove,
574 	.driver		= {
575 		.name	= "matrix-keypad",
576 		.pm	= &matrix_keypad_pm_ops,
577 		.of_match_table = of_match_ptr(matrix_keypad_dt_match),
578 	},
579 };
580 module_platform_driver(matrix_keypad_driver);
581 
582 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
583 MODULE_DESCRIPTION("GPIO Driven Matrix Keypad Driver");
584 MODULE_LICENSE("GPL v2");
585 MODULE_ALIAS("platform:matrix-keypad");
586