1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * OMAP4 Keypad Driver
4 *
5 * Copyright (C) 2010 Texas Instruments
6 *
7 * Author: Abraham Arce <x0066660@ti.com>
8 * Initial Code: Syed Rafiuddin <rafiuddin.syed@ti.com>
9 */
10
11#include <linux/module.h>
12#include <linux/interrupt.h>
13#include <linux/platform_device.h>
14#include <linux/errno.h>
15#include <linux/io.h>
16#include <linux/of.h>
17#include <linux/input.h>
18#include <linux/input/matrix_keypad.h>
19#include <linux/slab.h>
20#include <linux/pm_runtime.h>
21#include <linux/pm_wakeirq.h>
22
23/* OMAP4 registers */
24#define OMAP4_KBD_REVISION		0x00
25#define OMAP4_KBD_SYSCONFIG		0x10
26#define OMAP4_KBD_SYSSTATUS		0x14
27#define OMAP4_KBD_IRQSTATUS		0x18
28#define OMAP4_KBD_IRQENABLE		0x1C
29#define OMAP4_KBD_WAKEUPENABLE		0x20
30#define OMAP4_KBD_PENDING		0x24
31#define OMAP4_KBD_CTRL			0x28
32#define OMAP4_KBD_DEBOUNCINGTIME	0x2C
33#define OMAP4_KBD_LONGKEYTIME		0x30
34#define OMAP4_KBD_TIMEOUT		0x34
35#define OMAP4_KBD_STATEMACHINE		0x38
36#define OMAP4_KBD_ROWINPUTS		0x3C
37#define OMAP4_KBD_COLUMNOUTPUTS		0x40
38#define OMAP4_KBD_FULLCODE31_0		0x44
39#define OMAP4_KBD_FULLCODE63_32		0x48
40
41/* OMAP4 bit definitions */
42#define OMAP4_DEF_IRQENABLE_EVENTEN	BIT(0)
43#define OMAP4_DEF_IRQENABLE_LONGKEY	BIT(1)
44#define OMAP4_DEF_WUP_EVENT_ENA		BIT(0)
45#define OMAP4_DEF_WUP_LONG_KEY_ENA	BIT(1)
46#define OMAP4_DEF_CTRL_NOSOFTMODE	BIT(1)
47#define OMAP4_DEF_CTRL_PTV_SHIFT	2
48
49/* OMAP4 values */
50#define OMAP4_VAL_IRQDISABLE		0x0
51
52/*
53 * Errata i689: If a key is released for a time shorter than debounce time,
54 * the keyboard will idle and never detect the key release. The workaround
55 * is to use at least a 12ms debounce time. See omap5432 TRM chapter
56 * "26.4.6.2 Keyboard Controller Timer" for more information.
57 */
58#define OMAP4_KEYPAD_PTV_DIV_128        0x6
59#define OMAP4_KEYPAD_DEBOUNCINGTIME_MS(dbms, ptv)     \
60	((((dbms) * 1000) / ((1 << ((ptv) + 1)) * (1000000 / 32768))) - 1)
61#define OMAP4_VAL_DEBOUNCINGTIME_16MS					\
62	OMAP4_KEYPAD_DEBOUNCINGTIME_MS(16, OMAP4_KEYPAD_PTV_DIV_128)
63#define OMAP4_KEYPAD_AUTOIDLE_MS	50	/* Approximate measured time */
64#define OMAP4_KEYPAD_IDLE_CHECK_MS	(OMAP4_KEYPAD_AUTOIDLE_MS / 2)
65
66enum {
67	KBD_REVISION_OMAP4 = 0,
68	KBD_REVISION_OMAP5,
69};
70
71struct omap4_keypad {
72	struct input_dev *input;
73
74	void __iomem *base;
75	unsigned int irq;
76	struct mutex lock;		/* for key scan */
77
78	unsigned int rows;
79	unsigned int cols;
80	u32 reg_offset;
81	u32 irqreg_offset;
82	unsigned int row_shift;
83	bool no_autorepeat;
84	u64 keys;
85	unsigned short *keymap;
86};
87
88static int kbd_readl(struct omap4_keypad *keypad_data, u32 offset)
89{
90	return __raw_readl(keypad_data->base +
91				keypad_data->reg_offset + offset);
92}
93
94static void kbd_writel(struct omap4_keypad *keypad_data, u32 offset, u32 value)
95{
96	__raw_writel(value,
97		     keypad_data->base + keypad_data->reg_offset + offset);
98}
99
100static int kbd_read_irqreg(struct omap4_keypad *keypad_data, u32 offset)
101{
102	return __raw_readl(keypad_data->base +
103				keypad_data->irqreg_offset + offset);
104}
105
106static void kbd_write_irqreg(struct omap4_keypad *keypad_data,
107			     u32 offset, u32 value)
108{
109	__raw_writel(value,
110		     keypad_data->base + keypad_data->irqreg_offset + offset);
111}
112
113static int omap4_keypad_report_keys(struct omap4_keypad *keypad_data,
114				    u64 keys, bool down)
115{
116	struct input_dev *input_dev = keypad_data->input;
117	unsigned int col, row, code;
118	DECLARE_BITMAP(mask, 64);
119	unsigned long bit;
120	int events = 0;
121
122	bitmap_from_u64(mask, keys);
123
124	for_each_set_bit(bit, mask, keypad_data->rows * BITS_PER_BYTE) {
125		row = bit / BITS_PER_BYTE;
126		col = bit % BITS_PER_BYTE;
127		code = MATRIX_SCAN_CODE(row, col, keypad_data->row_shift);
128
129		input_event(input_dev, EV_MSC, MSC_SCAN, code);
130		input_report_key(input_dev, keypad_data->keymap[code], down);
131
132		events++;
133	}
134
135	if (events)
136		input_sync(input_dev);
137
138	return events;
139}
140
141static void omap4_keypad_scan_keys(struct omap4_keypad *keypad_data, u64 keys)
142{
143	u64 changed;
144
145	mutex_lock(&keypad_data->lock);
146
147	changed = keys ^ keypad_data->keys;
148
149	/*
150	 * Report key up events separately and first. This matters in case we
151	 * lost key-up interrupt and just now catching up.
152	 */
153	omap4_keypad_report_keys(keypad_data, changed & ~keys, false);
154
155	/* Report key down events */
156	omap4_keypad_report_keys(keypad_data, changed & keys, true);
157
158	keypad_data->keys = keys;
159
160	mutex_unlock(&keypad_data->lock);
161}
162
163/* Interrupt handlers */
164static irqreturn_t omap4_keypad_irq_handler(int irq, void *dev_id)
165{
166	struct omap4_keypad *keypad_data = dev_id;
167
168	if (kbd_read_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS))
169		return IRQ_WAKE_THREAD;
170
171	return IRQ_NONE;
172}
173
174static irqreturn_t omap4_keypad_irq_thread_fn(int irq, void *dev_id)
175{
176	struct omap4_keypad *keypad_data = dev_id;
177	struct device *dev = keypad_data->input->dev.parent;
178	u32 low, high;
179	int error;
180	u64 keys;
181
182	error = pm_runtime_resume_and_get(dev);
183	if (error)
184		return IRQ_NONE;
185
186	low = kbd_readl(keypad_data, OMAP4_KBD_FULLCODE31_0);
187	high = kbd_readl(keypad_data, OMAP4_KBD_FULLCODE63_32);
188	keys = low | (u64)high << 32;
189
190	omap4_keypad_scan_keys(keypad_data, keys);
191
192	/* clear pending interrupts */
193	kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS,
194			 kbd_read_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS));
195
196	pm_runtime_mark_last_busy(dev);
197	pm_runtime_put_autosuspend(dev);
198
199	return IRQ_HANDLED;
200}
201
202static int omap4_keypad_open(struct input_dev *input)
203{
204	struct omap4_keypad *keypad_data = input_get_drvdata(input);
205	struct device *dev = input->dev.parent;
206	int error;
207
208	error = pm_runtime_resume_and_get(dev);
209	if (error)
210		return error;
211
212	disable_irq(keypad_data->irq);
213
214	kbd_writel(keypad_data, OMAP4_KBD_CTRL,
215			OMAP4_DEF_CTRL_NOSOFTMODE |
216			(OMAP4_KEYPAD_PTV_DIV_128 << OMAP4_DEF_CTRL_PTV_SHIFT));
217	kbd_writel(keypad_data, OMAP4_KBD_DEBOUNCINGTIME,
218			OMAP4_VAL_DEBOUNCINGTIME_16MS);
219	/* clear pending interrupts */
220	kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS,
221			 kbd_read_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS));
222	kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQENABLE,
223			OMAP4_DEF_IRQENABLE_EVENTEN);
224	kbd_writel(keypad_data, OMAP4_KBD_WAKEUPENABLE,
225			OMAP4_DEF_WUP_EVENT_ENA);
226
227	enable_irq(keypad_data->irq);
228
229	pm_runtime_mark_last_busy(dev);
230	pm_runtime_put_autosuspend(dev);
231
232	return 0;
233}
234
235static void omap4_keypad_stop(struct omap4_keypad *keypad_data)
236{
237	/* Disable interrupts and wake-up events */
238	kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQENABLE,
239			 OMAP4_VAL_IRQDISABLE);
240	kbd_writel(keypad_data, OMAP4_KBD_WAKEUPENABLE, 0);
241
242	/* clear pending interrupts */
243	kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS,
244			 kbd_read_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS));
245}
246
247static void omap4_keypad_close(struct input_dev *input)
248{
249	struct omap4_keypad *keypad_data = input_get_drvdata(input);
250	struct device *dev = input->dev.parent;
251	int error;
252
253	error = pm_runtime_resume_and_get(dev);
254	if (error)
255		dev_err(dev, "%s: pm_runtime_resume_and_get() failed: %d\n",
256			__func__, error);
257
258	disable_irq(keypad_data->irq);
259	omap4_keypad_stop(keypad_data);
260	enable_irq(keypad_data->irq);
261
262	pm_runtime_mark_last_busy(dev);
263	pm_runtime_put_autosuspend(dev);
264}
265
266static int omap4_keypad_parse_dt(struct device *dev,
267				 struct omap4_keypad *keypad_data)
268{
269	struct device_node *np = dev->of_node;
270	int err;
271
272	err = matrix_keypad_parse_properties(dev, &keypad_data->rows,
273					     &keypad_data->cols);
274	if (err)
275		return err;
276
277	keypad_data->no_autorepeat = of_property_read_bool(np, "linux,input-no-autorepeat");
278
279	return 0;
280}
281
282static int omap4_keypad_check_revision(struct device *dev,
283				       struct omap4_keypad *keypad_data)
284{
285	unsigned int rev;
286
287	rev = __raw_readl(keypad_data->base + OMAP4_KBD_REVISION);
288	rev &= 0x03 << 30;
289	rev >>= 30;
290	switch (rev) {
291	case KBD_REVISION_OMAP4:
292		keypad_data->reg_offset = 0x00;
293		keypad_data->irqreg_offset = 0x00;
294		break;
295	case KBD_REVISION_OMAP5:
296		keypad_data->reg_offset = 0x10;
297		keypad_data->irqreg_offset = 0x0c;
298		break;
299	default:
300		dev_err(dev, "Keypad reports unsupported revision %d", rev);
301		return -EINVAL;
302	}
303
304	return 0;
305}
306
307/*
308 * Errata ID i689 "1.32 Keyboard Key Up Event Can Be Missed".
309 * Interrupt may not happen for key-up events. We must clear stuck
310 * key-up events after the keyboard hardware has auto-idled.
311 */
312static int omap4_keypad_runtime_suspend(struct device *dev)
313{
314	struct platform_device *pdev = to_platform_device(dev);
315	struct omap4_keypad *keypad_data = platform_get_drvdata(pdev);
316	u32 active;
317
318	active = kbd_readl(keypad_data, OMAP4_KBD_STATEMACHINE);
319	if (active) {
320		pm_runtime_mark_last_busy(dev);
321		return -EBUSY;
322	}
323
324	omap4_keypad_scan_keys(keypad_data, 0);
325
326	return 0;
327}
328
329static const struct dev_pm_ops omap4_keypad_pm_ops = {
330	RUNTIME_PM_OPS(omap4_keypad_runtime_suspend, NULL, NULL)
331};
332
333static void omap4_disable_pm(void *d)
334{
335	pm_runtime_dont_use_autosuspend(d);
336	pm_runtime_disable(d);
337}
338
339static int omap4_keypad_probe(struct platform_device *pdev)
340{
341	struct device *dev = &pdev->dev;
342	struct omap4_keypad *keypad_data;
343	struct input_dev *input_dev;
344	unsigned int max_keys;
345	int irq;
346	int error;
347
348	irq = platform_get_irq(pdev, 0);
349	if (irq < 0)
350		return irq;
351
352	keypad_data = devm_kzalloc(dev, sizeof(*keypad_data), GFP_KERNEL);
353	if (!keypad_data) {
354		dev_err(dev, "keypad_data memory allocation failed\n");
355		return -ENOMEM;
356	}
357
358	keypad_data->irq = irq;
359	mutex_init(&keypad_data->lock);
360	platform_set_drvdata(pdev, keypad_data);
361
362	error = omap4_keypad_parse_dt(dev, keypad_data);
363	if (error)
364		return error;
365
366	keypad_data->base = devm_platform_ioremap_resource(pdev, 0);
367	if (IS_ERR(keypad_data->base))
368		return PTR_ERR(keypad_data->base);
369
370	pm_runtime_use_autosuspend(dev);
371	pm_runtime_set_autosuspend_delay(dev, OMAP4_KEYPAD_IDLE_CHECK_MS);
372	pm_runtime_enable(dev);
373
374	error = devm_add_action_or_reset(dev, omap4_disable_pm, dev);
375	if (error) {
376		dev_err(dev, "unable to register cleanup action\n");
377		return error;
378	}
379
380	/*
381	 * Enable clocks for the keypad module so that we can read
382	 * revision register.
383	 */
384	error = pm_runtime_resume_and_get(dev);
385	if (error) {
386		dev_err(dev, "pm_runtime_resume_and_get() failed\n");
387		return error;
388	}
389
390	error = omap4_keypad_check_revision(dev, keypad_data);
391	if (!error) {
392		/* Ensure device does not raise interrupts */
393		omap4_keypad_stop(keypad_data);
394	}
395
396	pm_runtime_mark_last_busy(dev);
397	pm_runtime_put_autosuspend(dev);
398	if (error)
399		return error;
400
401	/* input device allocation */
402	keypad_data->input = input_dev = devm_input_allocate_device(dev);
403	if (!input_dev)
404		return -ENOMEM;
405
406	input_dev->name = pdev->name;
407	input_dev->id.bustype = BUS_HOST;
408	input_dev->id.vendor = 0x0001;
409	input_dev->id.product = 0x0001;
410	input_dev->id.version = 0x0001;
411
412	input_dev->open = omap4_keypad_open;
413	input_dev->close = omap4_keypad_close;
414
415	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
416	if (!keypad_data->no_autorepeat)
417		__set_bit(EV_REP, input_dev->evbit);
418
419	input_set_drvdata(input_dev, keypad_data);
420
421	keypad_data->row_shift = get_count_order(keypad_data->cols);
422	max_keys = keypad_data->rows << keypad_data->row_shift;
423	keypad_data->keymap = devm_kcalloc(dev,
424					   max_keys,
425					   sizeof(keypad_data->keymap[0]),
426					   GFP_KERNEL);
427	if (!keypad_data->keymap) {
428		dev_err(dev, "Not enough memory for keymap\n");
429		return -ENOMEM;
430	}
431
432	error = matrix_keypad_build_keymap(NULL, NULL,
433					   keypad_data->rows, keypad_data->cols,
434					   keypad_data->keymap, input_dev);
435	if (error) {
436		dev_err(dev, "failed to build keymap\n");
437		return error;
438	}
439
440	error = devm_request_threaded_irq(dev, keypad_data->irq,
441					  omap4_keypad_irq_handler,
442					  omap4_keypad_irq_thread_fn,
443					  IRQF_ONESHOT,
444					  "omap4-keypad", keypad_data);
445	if (error) {
446		dev_err(dev, "failed to register interrupt\n");
447		return error;
448	}
449
450	error = input_register_device(keypad_data->input);
451	if (error) {
452		dev_err(dev, "failed to register input device\n");
453		return error;
454	}
455
456	device_init_wakeup(dev, true);
457	error = dev_pm_set_wake_irq(dev, keypad_data->irq);
458	if (error)
459		dev_warn(dev, "failed to set up wakeup irq: %d\n", error);
460
461	return 0;
462}
463
464static int omap4_keypad_remove(struct platform_device *pdev)
465{
466	dev_pm_clear_wake_irq(&pdev->dev);
467
468	return 0;
469}
470
471static const struct of_device_id omap_keypad_dt_match[] = {
472	{ .compatible = "ti,omap4-keypad" },
473	{},
474};
475MODULE_DEVICE_TABLE(of, omap_keypad_dt_match);
476
477static struct platform_driver omap4_keypad_driver = {
478	.probe		= omap4_keypad_probe,
479	.remove		= omap4_keypad_remove,
480	.driver		= {
481		.name	= "omap4-keypad",
482		.of_match_table = omap_keypad_dt_match,
483		.pm = pm_ptr(&omap4_keypad_pm_ops),
484	},
485};
486module_platform_driver(omap4_keypad_driver);
487
488MODULE_AUTHOR("Texas Instruments");
489MODULE_DESCRIPTION("OMAP4 Keypad Driver");
490MODULE_LICENSE("GPL");
491MODULE_ALIAS("platform:omap4-keypad");
492