xref: /linux/drivers/input/keyboard/matrix_keypad.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0) 
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/init.h>
18 #include <linux/input.h>
19 #include <linux/irq.h>
20 #include <linux/interrupt.h>
21 #include <linux/jiffies.h>
22 #include <linux/module.h>
23 #include <linux/gpio.h>
24 #include <linux/input/matrix_keypad.h>
25 #include <linux/slab.h>
26 #include <linux/of.h>
27 #include <linux/of_gpio.h>
28 #include <linux/of_platform.h>
29 
30 struct matrix_keypad {
31 	const struct matrix_keypad_platform_data *pdata;
32 	struct input_dev *input_dev;
33 	unsigned int row_shift;
34 
35 	DECLARE_BITMAP(disabled_gpios, MATRIX_MAX_ROWS);
36 
37 	uint32_t last_key_state[MATRIX_MAX_COLS];
38 	struct delayed_work work;
39 	spinlock_t lock;
40 	bool scan_pending;
41 	bool stopped;
42 	bool gpio_all_disabled;
43 };
44 
45 /*
46  * NOTE: normally the GPIO has to be put into HiZ when de-activated to cause
47  * minmal side effect when scanning other columns, here it is configured to
48  * be input, and it should work on most platforms.
49  */
50 static 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 		gpio_direction_input(pdata->col_gpios[col]);
60 	}
61 }
62 
63 static void activate_col(const struct matrix_keypad_platform_data *pdata,
64 			 int col, bool on)
65 {
66 	__activate_col(pdata, col, on);
67 
68 	if (on && pdata->col_scan_delay_us)
69 		udelay(pdata->col_scan_delay_us);
70 }
71 
72 static void activate_all_cols(const struct matrix_keypad_platform_data *pdata,
73 			      bool on)
74 {
75 	int col;
76 
77 	for (col = 0; col < pdata->num_col_gpios; col++)
78 		__activate_col(pdata, col, on);
79 }
80 
81 static bool row_asserted(const struct matrix_keypad_platform_data *pdata,
82 			 int row)
83 {
84 	return gpio_get_value_cansleep(pdata->row_gpios[row]) ?
85 			!pdata->active_low : pdata->active_low;
86 }
87 
88 static void enable_row_irqs(struct matrix_keypad *keypad)
89 {
90 	const struct matrix_keypad_platform_data *pdata = keypad->pdata;
91 	int i;
92 
93 	if (pdata->clustered_irq > 0)
94 		enable_irq(pdata->clustered_irq);
95 	else {
96 		for (i = 0; i < pdata->num_row_gpios; i++)
97 			enable_irq(gpio_to_irq(pdata->row_gpios[i]));
98 	}
99 }
100 
101 static void disable_row_irqs(struct matrix_keypad *keypad)
102 {
103 	const struct matrix_keypad_platform_data *pdata = keypad->pdata;
104 	int i;
105 
106 	if (pdata->clustered_irq > 0)
107 		disable_irq_nosync(pdata->clustered_irq);
108 	else {
109 		for (i = 0; i < pdata->num_row_gpios; i++)
110 			disable_irq_nosync(gpio_to_irq(pdata->row_gpios[i]));
111 	}
112 }
113 
114 /*
115  * This gets the keys from keyboard and reports it to input subsystem
116  */
117 static void matrix_keypad_scan(struct work_struct *work)
118 {
119 	struct matrix_keypad *keypad =
120 		container_of(work, struct matrix_keypad, work.work);
121 	struct input_dev *input_dev = keypad->input_dev;
122 	const unsigned short *keycodes = input_dev->keycode;
123 	const struct matrix_keypad_platform_data *pdata = keypad->pdata;
124 	uint32_t new_state[MATRIX_MAX_COLS];
125 	int row, col, code;
126 
127 	/* de-activate all columns for scanning */
128 	activate_all_cols(pdata, false);
129 
130 	memset(new_state, 0, sizeof(new_state));
131 
132 	/* assert each column and read the row status out */
133 	for (col = 0; col < pdata->num_col_gpios; col++) {
134 
135 		activate_col(pdata, col, true);
136 
137 		for (row = 0; row < pdata->num_row_gpios; row++)
138 			new_state[col] |=
139 				row_asserted(pdata, row) ? (1 << row) : 0;
140 
141 		activate_col(pdata, col, false);
142 	}
143 
144 	for (col = 0; col < pdata->num_col_gpios; col++) {
145 		uint32_t bits_changed;
146 
147 		bits_changed = keypad->last_key_state[col] ^ new_state[col];
148 		if (bits_changed == 0)
149 			continue;
150 
151 		for (row = 0; row < pdata->num_row_gpios; row++) {
152 			if ((bits_changed & (1 << row)) == 0)
153 				continue;
154 
155 			code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
156 			input_event(input_dev, EV_MSC, MSC_SCAN, code);
157 			input_report_key(input_dev,
158 					 keycodes[code],
159 					 new_state[col] & (1 << row));
160 		}
161 	}
162 	input_sync(input_dev);
163 
164 	memcpy(keypad->last_key_state, new_state, sizeof(new_state));
165 
166 	activate_all_cols(pdata, true);
167 
168 	/* Enable IRQs again */
169 	spin_lock_irq(&keypad->lock);
170 	keypad->scan_pending = false;
171 	enable_row_irqs(keypad);
172 	spin_unlock_irq(&keypad->lock);
173 }
174 
175 static irqreturn_t matrix_keypad_interrupt(int irq, void *id)
176 {
177 	struct matrix_keypad *keypad = id;
178 	unsigned long flags;
179 
180 	spin_lock_irqsave(&keypad->lock, flags);
181 
182 	/*
183 	 * See if another IRQ beaten us to it and scheduled the
184 	 * scan already. In that case we should not try to
185 	 * disable IRQs again.
186 	 */
187 	if (unlikely(keypad->scan_pending || keypad->stopped))
188 		goto out;
189 
190 	disable_row_irqs(keypad);
191 	keypad->scan_pending = true;
192 	schedule_delayed_work(&keypad->work,
193 		msecs_to_jiffies(keypad->pdata->debounce_ms));
194 
195 out:
196 	spin_unlock_irqrestore(&keypad->lock, flags);
197 	return IRQ_HANDLED;
198 }
199 
200 static int matrix_keypad_start(struct input_dev *dev)
201 {
202 	struct matrix_keypad *keypad = input_get_drvdata(dev);
203 
204 	keypad->stopped = false;
205 	mb();
206 
207 	/*
208 	 * Schedule an immediate key scan to capture current key state;
209 	 * columns will be activated and IRQs be enabled after the scan.
210 	 */
211 	schedule_delayed_work(&keypad->work, 0);
212 
213 	return 0;
214 }
215 
216 static void matrix_keypad_stop(struct input_dev *dev)
217 {
218 	struct matrix_keypad *keypad = input_get_drvdata(dev);
219 
220 	keypad->stopped = true;
221 	mb();
222 	flush_work(&keypad->work.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_irq(pdata->clustered_irq,
337 				matrix_keypad_interrupt,
338 				pdata->clustered_irq_flags,
339 				"matrix-keypad", keypad);
340 		if (err) {
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_irq(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) {
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 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 	if (of_get_property(np, "linux,wakeup", NULL))
429 		pdata->wakeup = true;
430 	if (of_get_property(np, "gpio-activelow", NULL))
431 		pdata->active_low = true;
432 
433 	of_property_read_u32(np, "debounce-delay-ms", &pdata->debounce_ms);
434 	of_property_read_u32(np, "col-scan-delay-us",
435 						&pdata->col_scan_delay_us);
436 
437 	gpios = devm_kzalloc(dev,
438 			     sizeof(unsigned int) *
439 				(pdata->num_row_gpios + pdata->num_col_gpios),
440 			     GFP_KERNEL);
441 	if (!gpios) {
442 		dev_err(dev, "could not allocate memory for gpios\n");
443 		return ERR_PTR(-ENOMEM);
444 	}
445 
446 	for (i = 0; i < pdata->num_row_gpios; i++)
447 		gpios[i] = of_get_named_gpio(np, "row-gpios", i);
448 
449 	for (i = 0; i < pdata->num_col_gpios; i++)
450 		gpios[pdata->num_row_gpios + i] =
451 			of_get_named_gpio(np, "col-gpios", i);
452 
453 	pdata->row_gpios = gpios;
454 	pdata->col_gpios = &gpios[pdata->num_row_gpios];
455 
456 	return pdata;
457 }
458 #else
459 static inline struct matrix_keypad_platform_data *
460 matrix_keypad_parse_dt(struct device *dev)
461 {
462 	dev_err(dev, "no platform data defined\n");
463 
464 	return ERR_PTR(-EINVAL);
465 }
466 #endif
467 
468 static int matrix_keypad_probe(struct platform_device *pdev)
469 {
470 	const struct matrix_keypad_platform_data *pdata;
471 	struct matrix_keypad *keypad;
472 	struct input_dev *input_dev;
473 	int err;
474 
475 	pdata = dev_get_platdata(&pdev->dev);
476 	if (!pdata) {
477 		pdata = matrix_keypad_parse_dt(&pdev->dev);
478 		if (IS_ERR(pdata)) {
479 			dev_err(&pdev->dev, "no platform data defined\n");
480 			return PTR_ERR(pdata);
481 		}
482 	} else if (!pdata->keymap_data) {
483 		dev_err(&pdev->dev, "no keymap data defined\n");
484 		return -EINVAL;
485 	}
486 
487 	keypad = kzalloc(sizeof(struct matrix_keypad), GFP_KERNEL);
488 	input_dev = input_allocate_device();
489 	if (!keypad || !input_dev) {
490 		err = -ENOMEM;
491 		goto err_free_mem;
492 	}
493 
494 	keypad->input_dev = input_dev;
495 	keypad->pdata = pdata;
496 	keypad->row_shift = get_count_order(pdata->num_col_gpios);
497 	keypad->stopped = true;
498 	INIT_DELAYED_WORK(&keypad->work, matrix_keypad_scan);
499 	spin_lock_init(&keypad->lock);
500 
501 	input_dev->name		= pdev->name;
502 	input_dev->id.bustype	= BUS_HOST;
503 	input_dev->dev.parent	= &pdev->dev;
504 	input_dev->open		= matrix_keypad_start;
505 	input_dev->close	= matrix_keypad_stop;
506 
507 	err = matrix_keypad_build_keymap(pdata->keymap_data, NULL,
508 					 pdata->num_row_gpios,
509 					 pdata->num_col_gpios,
510 					 NULL, input_dev);
511 	if (err) {
512 		dev_err(&pdev->dev, "failed to build keymap\n");
513 		goto err_free_mem;
514 	}
515 
516 	if (!pdata->no_autorepeat)
517 		__set_bit(EV_REP, input_dev->evbit);
518 	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
519 	input_set_drvdata(input_dev, keypad);
520 
521 	err = matrix_keypad_init_gpio(pdev, keypad);
522 	if (err)
523 		goto err_free_mem;
524 
525 	err = input_register_device(keypad->input_dev);
526 	if (err)
527 		goto err_free_gpio;
528 
529 	device_init_wakeup(&pdev->dev, pdata->wakeup);
530 	platform_set_drvdata(pdev, keypad);
531 
532 	return 0;
533 
534 err_free_gpio:
535 	matrix_keypad_free_gpio(keypad);
536 err_free_mem:
537 	input_free_device(input_dev);
538 	kfree(keypad);
539 	return err;
540 }
541 
542 static int matrix_keypad_remove(struct platform_device *pdev)
543 {
544 	struct matrix_keypad *keypad = platform_get_drvdata(pdev);
545 
546 	device_init_wakeup(&pdev->dev, 0);
547 
548 	matrix_keypad_free_gpio(keypad);
549 	input_unregister_device(keypad->input_dev);
550 	kfree(keypad);
551 
552 	return 0;
553 }
554 
555 #ifdef CONFIG_OF
556 static const struct of_device_id matrix_keypad_dt_match[] = {
557 	{ .compatible = "gpio-matrix-keypad" },
558 	{ }
559 };
560 MODULE_DEVICE_TABLE(of, matrix_keypad_dt_match);
561 #endif
562 
563 static struct platform_driver matrix_keypad_driver = {
564 	.probe		= matrix_keypad_probe,
565 	.remove		= matrix_keypad_remove,
566 	.driver		= {
567 		.name	= "matrix-keypad",
568 		.owner	= THIS_MODULE,
569 		.pm	= &matrix_keypad_pm_ops,
570 		.of_match_table = of_match_ptr(matrix_keypad_dt_match),
571 	},
572 };
573 module_platform_driver(matrix_keypad_driver);
574 
575 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
576 MODULE_DESCRIPTION("GPIO Driven Matrix Keypad Driver");
577 MODULE_LICENSE("GPL v2");
578 MODULE_ALIAS("platform:matrix-keypad");
579