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/input.h>
18#include <linux/irq.h>
19#include <linux/interrupt.h>
20#include <linux/jiffies.h>
21#include <linux/module.h>
22#include <linux/gpio.h>
23#include <linux/input/matrix_keypad.h>
24#include <linux/slab.h>
25#include <linux/of.h>
26#include <linux/of_gpio.h>
27#include <linux/of_platform.h>
28
29struct matrix_keypad {
30	const struct matrix_keypad_platform_data *pdata;
31	struct input_dev *input_dev;
32	unsigned int row_shift;
33
34	DECLARE_BITMAP(disabled_gpios, MATRIX_MAX_ROWS);
35
36	uint32_t last_key_state[MATRIX_MAX_COLS];
37	struct delayed_work work;
38	spinlock_t lock;
39	bool scan_pending;
40	bool stopped;
41	bool gpio_all_disabled;
42};
43
44/*
45 * NOTE: normally the GPIO has to be put into HiZ when de-activated to cause
46 * minmal side effect when scanning other columns, here it is configured to
47 * be input, and it should work on most platforms.
48 */
49static void __activate_col(const struct matrix_keypad_platform_data *pdata,
50			   int col, bool on)
51{
52	bool level_on = !pdata->active_low;
53
54	if (on) {
55		gpio_direction_output(pdata->col_gpios[col], level_on);
56	} else {
57		gpio_set_value_cansleep(pdata->col_gpios[col], !level_on);
58		gpio_direction_input(pdata->col_gpios[col]);
59	}
60}
61
62static void activate_col(const struct matrix_keypad_platform_data *pdata,
63			 int col, bool on)
64{
65	__activate_col(pdata, col, on);
66
67	if (on && pdata->col_scan_delay_us)
68		udelay(pdata->col_scan_delay_us);
69}
70
71static void activate_all_cols(const struct matrix_keypad_platform_data *pdata,
72			      bool on)
73{
74	int col;
75
76	for (col = 0; col < pdata->num_col_gpios; col++)
77		__activate_col(pdata, col, on);
78}
79
80static bool row_asserted(const struct matrix_keypad_platform_data *pdata,
81			 int row)
82{
83	return gpio_get_value_cansleep(pdata->row_gpios[row]) ?
84			!pdata->active_low : pdata->active_low;
85}
86
87static void enable_row_irqs(struct matrix_keypad *keypad)
88{
89	const struct matrix_keypad_platform_data *pdata = keypad->pdata;
90	int i;
91
92	if (pdata->clustered_irq > 0)
93		enable_irq(pdata->clustered_irq);
94	else {
95		for (i = 0; i < pdata->num_row_gpios; i++)
96			enable_irq(gpio_to_irq(pdata->row_gpios[i]));
97	}
98}
99
100static void disable_row_irqs(struct matrix_keypad *keypad)
101{
102	const struct matrix_keypad_platform_data *pdata = keypad->pdata;
103	int i;
104
105	if (pdata->clustered_irq > 0)
106		disable_irq_nosync(pdata->clustered_irq);
107	else {
108		for (i = 0; i < pdata->num_row_gpios; i++)
109			disable_irq_nosync(gpio_to_irq(pdata->row_gpios[i]));
110	}
111}
112
113/*
114 * This gets the keys from keyboard and reports it to input subsystem
115 */
116static void matrix_keypad_scan(struct work_struct *work)
117{
118	struct matrix_keypad *keypad =
119		container_of(work, struct matrix_keypad, work.work);
120	struct input_dev *input_dev = keypad->input_dev;
121	const unsigned short *keycodes = input_dev->keycode;
122	const struct matrix_keypad_platform_data *pdata = keypad->pdata;
123	uint32_t new_state[MATRIX_MAX_COLS];
124	int row, col, code;
125
126	/* de-activate all columns for scanning */
127	activate_all_cols(pdata, false);
128
129	memset(new_state, 0, sizeof(new_state));
130
131	/* assert each column and read the row status out */
132	for (col = 0; col < pdata->num_col_gpios; col++) {
133
134		activate_col(pdata, col, true);
135
136		for (row = 0; row < pdata->num_row_gpios; row++)
137			new_state[col] |=
138				row_asserted(pdata, row) ? (1 << row) : 0;
139
140		activate_col(pdata, col, false);
141	}
142
143	for (col = 0; col < pdata->num_col_gpios; col++) {
144		uint32_t bits_changed;
145
146		bits_changed = keypad->last_key_state[col] ^ new_state[col];
147		if (bits_changed == 0)
148			continue;
149
150		for (row = 0; row < pdata->num_row_gpios; row++) {
151			if ((bits_changed & (1 << row)) == 0)
152				continue;
153
154			code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
155			input_event(input_dev, EV_MSC, MSC_SCAN, code);
156			input_report_key(input_dev,
157					 keycodes[code],
158					 new_state[col] & (1 << row));
159		}
160	}
161	input_sync(input_dev);
162
163	memcpy(keypad->last_key_state, new_state, sizeof(new_state));
164
165	activate_all_cols(pdata, true);
166
167	/* Enable IRQs again */
168	spin_lock_irq(&keypad->lock);
169	keypad->scan_pending = false;
170	enable_row_irqs(keypad);
171	spin_unlock_irq(&keypad->lock);
172}
173
174static irqreturn_t matrix_keypad_interrupt(int irq, void *id)
175{
176	struct matrix_keypad *keypad = id;
177	unsigned long flags;
178
179	spin_lock_irqsave(&keypad->lock, flags);
180
181	/*
182	 * See if another IRQ beaten us to it and scheduled the
183	 * scan already. In that case we should not try to
184	 * disable IRQs again.
185	 */
186	if (unlikely(keypad->scan_pending || keypad->stopped))
187		goto out;
188
189	disable_row_irqs(keypad);
190	keypad->scan_pending = true;
191	schedule_delayed_work(&keypad->work,
192		msecs_to_jiffies(keypad->pdata->debounce_ms));
193
194out:
195	spin_unlock_irqrestore(&keypad->lock, flags);
196	return IRQ_HANDLED;
197}
198
199static int matrix_keypad_start(struct input_dev *dev)
200{
201	struct matrix_keypad *keypad = input_get_drvdata(dev);
202
203	keypad->stopped = false;
204	mb();
205
206	/*
207	 * Schedule an immediate key scan to capture current key state;
208	 * columns will be activated and IRQs be enabled after the scan.
209	 */
210	schedule_delayed_work(&keypad->work, 0);
211
212	return 0;
213}
214
215static void matrix_keypad_stop(struct input_dev *dev)
216{
217	struct matrix_keypad *keypad = input_get_drvdata(dev);
218
219	keypad->stopped = true;
220	mb();
221	flush_work(&keypad->work.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 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
459static inline struct matrix_keypad_platform_data *
460matrix_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
468static 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
534err_free_gpio:
535	matrix_keypad_free_gpio(keypad);
536err_free_mem:
537	input_free_device(input_dev);
538	kfree(keypad);
539	return err;
540}
541
542static 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
556static const struct of_device_id matrix_keypad_dt_match[] = {
557	{ .compatible = "gpio-matrix-keypad" },
558	{ }
559};
560MODULE_DEVICE_TABLE(of, matrix_keypad_dt_match);
561#endif
562
563static struct platform_driver matrix_keypad_driver = {
564	.probe		= matrix_keypad_probe,
565	.remove		= matrix_keypad_remove,
566	.driver		= {
567		.name	= "matrix-keypad",
568		.pm	= &matrix_keypad_pm_ops,
569		.of_match_table = of_match_ptr(matrix_keypad_dt_match),
570	},
571};
572module_platform_driver(matrix_keypad_driver);
573
574MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
575MODULE_DESCRIPTION("GPIO Driven Matrix Keypad Driver");
576MODULE_LICENSE("GPL v2");
577MODULE_ALIAS("platform:matrix-keypad");
578