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/drivers/input/keyboard/matrix_keypad.c

http://github.com/mirrors/linux
C | 585 lines | 448 code | 102 blank | 35 comment | 75 complexity | 25176d577c81045cce6fd2798ab9d150 MD5 | raw file
  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
 25struct 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 */
 46static 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
 60static 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
 69static 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
 78static 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
 85static 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
 98static 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 */
114static 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
172static 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
192out:
193	spin_unlock_irqrestore(&keypad->lock, flags);
194	return IRQ_HANDLED;
195}
196
197static 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
213static 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
230static 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
252static 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
273static 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
286static 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
300static SIMPLE_DEV_PM_OPS(matrix_keypad_pm_ops,
301			 matrix_keypad_suspend, matrix_keypad_resume);
302
303static 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
365err_free_irqs:
366	while (--i >= 0)
367		free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad);
368	i = pdata->num_row_gpios;
369err_free_rows:
370	while (--i >= 0)
371		gpio_free(pdata->row_gpios[i]);
372	i = pdata->num_col_gpios;
373err_free_cols:
374	while (--i >= 0)
375		gpio_free(pdata->col_gpios[i]);
376
377	return err;
378}
379
380static 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
400static struct matrix_keypad_platform_data *
401matrix_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
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(&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
544err_free_gpio:
545	matrix_keypad_free_gpio(keypad);
546err_free_mem:
547	input_free_device(input_dev);
548	kfree(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(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	= &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");