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