xref: /linux/drivers/input/keyboard/omap4-keypad.c (revision ca220141fa8ebae09765a242076b2b77338106b0)
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/clk.h>
15 #include <linux/errno.h>
16 #include <linux/io.h>
17 #include <linux/of.h>
18 #include <linux/input.h>
19 #include <linux/input/matrix_keypad.h>
20 #include <linux/slab.h>
21 #include <linux/pm_runtime.h>
22 #include <linux/pm_wakeirq.h>
23 
24 /* OMAP4 registers */
25 #define OMAP4_KBD_REVISION		0x00
26 #define OMAP4_KBD_SYSCONFIG		0x10
27 #define OMAP4_KBD_SYSSTATUS		0x14
28 #define OMAP4_KBD_IRQSTATUS		0x18
29 #define OMAP4_KBD_IRQENABLE		0x1C
30 #define OMAP4_KBD_WAKEUPENABLE		0x20
31 #define OMAP4_KBD_PENDING		0x24
32 #define OMAP4_KBD_CTRL			0x28
33 #define OMAP4_KBD_DEBOUNCINGTIME	0x2C
34 #define OMAP4_KBD_LONGKEYTIME		0x30
35 #define OMAP4_KBD_TIMEOUT		0x34
36 #define OMAP4_KBD_STATEMACHINE		0x38
37 #define OMAP4_KBD_ROWINPUTS		0x3C
38 #define OMAP4_KBD_COLUMNOUTPUTS		0x40
39 #define OMAP4_KBD_FULLCODE31_0		0x44
40 #define OMAP4_KBD_FULLCODE63_32		0x48
41 
42 /* OMAP4 bit definitions */
43 #define OMAP4_DEF_IRQENABLE_EVENTEN	BIT(0)
44 #define OMAP4_DEF_IRQENABLE_LONGKEY	BIT(1)
45 #define OMAP4_DEF_WUP_EVENT_ENA		BIT(0)
46 #define OMAP4_DEF_WUP_LONG_KEY_ENA	BIT(1)
47 #define OMAP4_DEF_CTRL_NOSOFTMODE	BIT(1)
48 #define OMAP4_DEF_CTRL_PTV_SHIFT	2
49 
50 /* OMAP4 values */
51 #define OMAP4_VAL_IRQDISABLE		0x0
52 
53 /*
54  * Errata i689: If a key is released for a time shorter than debounce time,
55  * the keyboard will idle and never detect the key release. The workaround
56  * is to use at least a 12ms debounce time. See omap5432 TRM chapter
57  * "26.4.6.2 Keyboard Controller Timer" for more information.
58  */
59 #define OMAP4_KEYPAD_PTV_DIV_128        0x6
60 #define OMAP4_KEYPAD_DEBOUNCINGTIME_MS(dbms, ptv)     \
61 	((((dbms) * 1000) / ((1 << ((ptv) + 1)) * (1000000 / 32768))) - 1)
62 #define OMAP4_VAL_DEBOUNCINGTIME_16MS					\
63 	OMAP4_KEYPAD_DEBOUNCINGTIME_MS(16, OMAP4_KEYPAD_PTV_DIV_128)
64 #define OMAP4_KEYPAD_AUTOIDLE_MS	50	/* Approximate measured time */
65 #define OMAP4_KEYPAD_IDLE_CHECK_MS	(OMAP4_KEYPAD_AUTOIDLE_MS / 2)
66 
67 enum {
68 	KBD_REVISION_OMAP4 = 0,
69 	KBD_REVISION_OMAP5,
70 };
71 
72 struct omap4_keypad {
73 	struct input_dev *input;
74 
75 	void __iomem *base;
76 	unsigned int irq;
77 	struct mutex lock;		/* for key scan */
78 
79 	unsigned int rows;
80 	unsigned int cols;
81 	u32 reg_offset;
82 	u32 irqreg_offset;
83 	unsigned int row_shift;
84 	bool no_autorepeat;
85 	u64 keys;
86 	unsigned short *keymap;
87 	struct clk *fck;
88 };
89 
90 static int kbd_readl(struct omap4_keypad *keypad_data, u32 offset)
91 {
92 	return __raw_readl(keypad_data->base +
93 				keypad_data->reg_offset + offset);
94 }
95 
96 static void kbd_writel(struct omap4_keypad *keypad_data, u32 offset, u32 value)
97 {
98 	__raw_writel(value,
99 		     keypad_data->base + keypad_data->reg_offset + offset);
100 }
101 
102 static int kbd_read_irqreg(struct omap4_keypad *keypad_data, u32 offset)
103 {
104 	return __raw_readl(keypad_data->base +
105 				keypad_data->irqreg_offset + offset);
106 }
107 
108 static void kbd_write_irqreg(struct omap4_keypad *keypad_data,
109 			     u32 offset, u32 value)
110 {
111 	__raw_writel(value,
112 		     keypad_data->base + keypad_data->irqreg_offset + offset);
113 }
114 
115 static int omap4_keypad_report_keys(struct omap4_keypad *keypad_data,
116 				    u64 keys, bool down)
117 {
118 	struct input_dev *input_dev = keypad_data->input;
119 	unsigned int col, row, code;
120 	DECLARE_BITMAP(mask, 64);
121 	unsigned long bit;
122 	int events = 0;
123 
124 	bitmap_from_u64(mask, keys);
125 
126 	for_each_set_bit(bit, mask, keypad_data->rows * BITS_PER_BYTE) {
127 		row = bit / BITS_PER_BYTE;
128 		col = bit % BITS_PER_BYTE;
129 		code = MATRIX_SCAN_CODE(row, col, keypad_data->row_shift);
130 
131 		input_event(input_dev, EV_MSC, MSC_SCAN, code);
132 		input_report_key(input_dev, keypad_data->keymap[code], down);
133 
134 		events++;
135 	}
136 
137 	if (events)
138 		input_sync(input_dev);
139 
140 	return events;
141 }
142 
143 static void omap4_keypad_scan_keys(struct omap4_keypad *keypad_data, u64 keys)
144 {
145 	u64 changed;
146 
147 	guard(mutex)(&keypad_data->lock);
148 
149 	changed = keys ^ keypad_data->keys;
150 
151 	/*
152 	 * Report key up events separately and first. This matters in case we
153 	 * lost key-up interrupt and just now catching up.
154 	 */
155 	omap4_keypad_report_keys(keypad_data, changed & ~keys, false);
156 
157 	/* Report key down events */
158 	omap4_keypad_report_keys(keypad_data, changed & keys, true);
159 
160 	keypad_data->keys = keys;
161 }
162 
163 /* Interrupt handlers */
164 static 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 
174 static 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_put_autosuspend(dev);
197 
198 	return IRQ_HANDLED;
199 }
200 
201 static int omap4_keypad_open(struct input_dev *input)
202 {
203 	struct omap4_keypad *keypad_data = input_get_drvdata(input);
204 	struct device *dev = input->dev.parent;
205 	int error;
206 
207 	error = pm_runtime_resume_and_get(dev);
208 	if (error)
209 		return error;
210 
211 	error = clk_prepare_enable(keypad_data->fck);
212 	if (error)
213 		goto out;
214 
215 	disable_irq(keypad_data->irq);
216 
217 	kbd_writel(keypad_data, OMAP4_KBD_CTRL,
218 			OMAP4_DEF_CTRL_NOSOFTMODE |
219 			(OMAP4_KEYPAD_PTV_DIV_128 << OMAP4_DEF_CTRL_PTV_SHIFT));
220 	kbd_writel(keypad_data, OMAP4_KBD_DEBOUNCINGTIME,
221 			OMAP4_VAL_DEBOUNCINGTIME_16MS);
222 	/* clear pending interrupts */
223 	kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS,
224 			 kbd_read_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS));
225 	kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQENABLE,
226 			OMAP4_DEF_IRQENABLE_EVENTEN);
227 	kbd_writel(keypad_data, OMAP4_KBD_WAKEUPENABLE,
228 			OMAP4_DEF_WUP_EVENT_ENA);
229 
230 	enable_irq(keypad_data->irq);
231 
232 out:
233 	pm_runtime_put_autosuspend(dev);
234 
235 	return error;
236 }
237 
238 static void omap4_keypad_stop(struct omap4_keypad *keypad_data)
239 {
240 	/* Disable interrupts and wake-up events */
241 	kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQENABLE,
242 			 OMAP4_VAL_IRQDISABLE);
243 	kbd_writel(keypad_data, OMAP4_KBD_WAKEUPENABLE, 0);
244 
245 	/* clear pending interrupts */
246 	kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS,
247 			 kbd_read_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS));
248 }
249 
250 static void omap4_keypad_close(struct input_dev *input)
251 {
252 	struct omap4_keypad *keypad_data = input_get_drvdata(input);
253 	struct device *dev = input->dev.parent;
254 	int error;
255 
256 	error = pm_runtime_resume_and_get(dev);
257 	if (error)
258 		dev_err(dev, "%s: pm_runtime_resume_and_get() failed: %d\n",
259 			__func__, error);
260 
261 	disable_irq(keypad_data->irq);
262 	omap4_keypad_stop(keypad_data);
263 	enable_irq(keypad_data->irq);
264 	clk_disable_unprepare(keypad_data->fck);
265 
266 	pm_runtime_put_autosuspend(dev);
267 }
268 
269 static int omap4_keypad_parse_dt(struct device *dev,
270 				 struct omap4_keypad *keypad_data)
271 {
272 	struct device_node *np = dev->of_node;
273 	int err;
274 
275 	err = matrix_keypad_parse_properties(dev, &keypad_data->rows,
276 					     &keypad_data->cols);
277 	if (err)
278 		return err;
279 
280 	keypad_data->no_autorepeat = of_property_read_bool(np, "linux,input-no-autorepeat");
281 
282 	return 0;
283 }
284 
285 static int omap4_keypad_check_revision(struct device *dev,
286 				       struct omap4_keypad *keypad_data)
287 {
288 	unsigned int rev;
289 
290 	rev = __raw_readl(keypad_data->base + OMAP4_KBD_REVISION);
291 	rev &= 0x03 << 30;
292 	rev >>= 30;
293 	switch (rev) {
294 	case KBD_REVISION_OMAP4:
295 		keypad_data->reg_offset = 0x00;
296 		keypad_data->irqreg_offset = 0x00;
297 		break;
298 	case KBD_REVISION_OMAP5:
299 		keypad_data->reg_offset = 0x10;
300 		keypad_data->irqreg_offset = 0x0c;
301 		break;
302 	default:
303 		dev_err(dev, "Keypad reports unsupported revision %d", rev);
304 		return -EINVAL;
305 	}
306 
307 	return 0;
308 }
309 
310 /*
311  * Errata ID i689 "1.32 Keyboard Key Up Event Can Be Missed".
312  * Interrupt may not happen for key-up events. We must clear stuck
313  * key-up events after the keyboard hardware has auto-idled.
314  */
315 static int omap4_keypad_runtime_suspend(struct device *dev)
316 {
317 	struct platform_device *pdev = to_platform_device(dev);
318 	struct omap4_keypad *keypad_data = platform_get_drvdata(pdev);
319 	u32 active;
320 
321 	active = kbd_readl(keypad_data, OMAP4_KBD_STATEMACHINE);
322 	if (active) {
323 		pm_runtime_mark_last_busy(dev);
324 		return -EBUSY;
325 	}
326 
327 	omap4_keypad_scan_keys(keypad_data, 0);
328 
329 	return 0;
330 }
331 
332 static const struct dev_pm_ops omap4_keypad_pm_ops = {
333 	RUNTIME_PM_OPS(omap4_keypad_runtime_suspend, NULL, NULL)
334 };
335 
336 static void omap4_disable_pm(void *d)
337 {
338 	pm_runtime_dont_use_autosuspend(d);
339 	pm_runtime_disable(d);
340 }
341 
342 static int omap4_keypad_probe(struct platform_device *pdev)
343 {
344 	struct device *dev = &pdev->dev;
345 	struct omap4_keypad *keypad_data;
346 	struct input_dev *input_dev;
347 	unsigned int max_keys;
348 	int irq;
349 	int error;
350 
351 	irq = platform_get_irq(pdev, 0);
352 	if (irq < 0)
353 		return irq;
354 
355 	keypad_data = devm_kzalloc(dev, sizeof(*keypad_data), GFP_KERNEL);
356 	if (!keypad_data) {
357 		dev_err(dev, "keypad_data memory allocation failed\n");
358 		return -ENOMEM;
359 	}
360 
361 	keypad_data->irq = irq;
362 	keypad_data->fck = devm_clk_get(&pdev->dev, "fck");
363 	if (IS_ERR(keypad_data->fck))
364 		return dev_err_probe(&pdev->dev, PTR_ERR(keypad_data->fck),
365 				     "unable to get fck");
366 
367 	mutex_init(&keypad_data->lock);
368 	platform_set_drvdata(pdev, keypad_data);
369 
370 	error = omap4_keypad_parse_dt(dev, keypad_data);
371 	if (error)
372 		return error;
373 
374 	keypad_data->base = devm_platform_ioremap_resource(pdev, 0);
375 	if (IS_ERR(keypad_data->base))
376 		return PTR_ERR(keypad_data->base);
377 
378 	pm_runtime_use_autosuspend(dev);
379 	pm_runtime_set_autosuspend_delay(dev, OMAP4_KEYPAD_IDLE_CHECK_MS);
380 	pm_runtime_enable(dev);
381 
382 	error = devm_add_action_or_reset(dev, omap4_disable_pm, dev);
383 	if (error) {
384 		dev_err(dev, "unable to register cleanup action\n");
385 		return error;
386 	}
387 
388 	/*
389 	 * Enable clocks for the keypad module so that we can read
390 	 * revision register.
391 	 */
392 	error = pm_runtime_resume_and_get(dev);
393 	if (error) {
394 		dev_err(dev, "pm_runtime_resume_and_get() failed\n");
395 		return error;
396 	}
397 
398 	error = omap4_keypad_check_revision(dev, keypad_data);
399 	if (!error) {
400 		/* Ensure device does not raise interrupts */
401 		omap4_keypad_stop(keypad_data);
402 	}
403 
404 	pm_runtime_put_autosuspend(dev);
405 	if (error)
406 		return error;
407 
408 	/* input device allocation */
409 	keypad_data->input = input_dev = devm_input_allocate_device(dev);
410 	if (!input_dev)
411 		return -ENOMEM;
412 
413 	input_dev->name = pdev->name;
414 	input_dev->id.bustype = BUS_HOST;
415 	input_dev->id.vendor = 0x0001;
416 	input_dev->id.product = 0x0001;
417 	input_dev->id.version = 0x0001;
418 
419 	input_dev->open = omap4_keypad_open;
420 	input_dev->close = omap4_keypad_close;
421 
422 	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
423 	if (!keypad_data->no_autorepeat)
424 		__set_bit(EV_REP, input_dev->evbit);
425 
426 	input_set_drvdata(input_dev, keypad_data);
427 
428 	keypad_data->row_shift = get_count_order(keypad_data->cols);
429 	max_keys = keypad_data->rows << keypad_data->row_shift;
430 	keypad_data->keymap = devm_kcalloc(dev,
431 					   max_keys,
432 					   sizeof(keypad_data->keymap[0]),
433 					   GFP_KERNEL);
434 	if (!keypad_data->keymap) {
435 		dev_err(dev, "Not enough memory for keymap\n");
436 		return -ENOMEM;
437 	}
438 
439 	error = matrix_keypad_build_keymap(NULL, NULL,
440 					   keypad_data->rows, keypad_data->cols,
441 					   keypad_data->keymap, input_dev);
442 	if (error) {
443 		dev_err(dev, "failed to build keymap\n");
444 		return error;
445 	}
446 
447 	error = devm_request_threaded_irq(dev, keypad_data->irq,
448 					  omap4_keypad_irq_handler,
449 					  omap4_keypad_irq_thread_fn,
450 					  IRQF_ONESHOT,
451 					  "omap4-keypad", keypad_data);
452 	if (error) {
453 		dev_err(dev, "failed to register interrupt\n");
454 		return error;
455 	}
456 
457 	error = input_register_device(keypad_data->input);
458 	if (error) {
459 		dev_err(dev, "failed to register input device\n");
460 		return error;
461 	}
462 
463 	device_init_wakeup(dev, true);
464 	error = dev_pm_set_wake_irq(dev, keypad_data->irq);
465 	if (error)
466 		dev_warn(dev, "failed to set up wakeup irq: %d\n", error);
467 
468 	return 0;
469 }
470 
471 static void omap4_keypad_remove(struct platform_device *pdev)
472 {
473 	dev_pm_clear_wake_irq(&pdev->dev);
474 }
475 
476 static const struct of_device_id omap_keypad_dt_match[] = {
477 	{ .compatible = "ti,omap4-keypad" },
478 	{},
479 };
480 MODULE_DEVICE_TABLE(of, omap_keypad_dt_match);
481 
482 static struct platform_driver omap4_keypad_driver = {
483 	.probe		= omap4_keypad_probe,
484 	.remove		= omap4_keypad_remove,
485 	.driver		= {
486 		.name	= "omap4-keypad",
487 		.of_match_table = omap_keypad_dt_match,
488 		.pm = pm_ptr(&omap4_keypad_pm_ops),
489 	},
490 };
491 module_platform_driver(omap4_keypad_driver);
492 
493 MODULE_AUTHOR("Texas Instruments");
494 MODULE_DESCRIPTION("OMAP4 Keypad Driver");
495 MODULE_LICENSE("GPL");
496 MODULE_ALIAS("platform:omap4-keypad");
497