summaryrefslogtreecommitdiffstats
path: root/drivers/rtc/rtc-bd70528.c
blob: bbbb1f07c91ffe5029d5320c98c7d7f8f0b4b817 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
// SPDX-License-Identifier: GPL-2.0-or-later
//
// Copyright (C) 2018 ROHM Semiconductors
//
// RTC driver for ROHM BD70528 PMIC

#include <linux/bcd.h>
#include <linux/mfd/rohm-bd70528.h>
#include <linux/mfd/rohm-bd71828.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/rtc.h>

/*
 * We read regs RTC_SEC => RTC_YEAR
 * this struct is ordered according to chip registers.
 * Keep it u8 only (or packed) to avoid padding issues.
 */
struct bd70528_rtc_day {
	u8 sec;
	u8 min;
	u8 hour;
} __packed;

struct bd70528_rtc_data {
	struct bd70528_rtc_day time;
	u8 week;
	u8 day;
	u8 month;
	u8 year;
} __packed;

struct bd70528_rtc_wake {
	struct bd70528_rtc_day time;
	u8 ctrl;
} __packed;

struct bd71828_rtc_alm {
	struct bd70528_rtc_data alm0;
	struct bd70528_rtc_data alm1;
	u8 alm_mask;
	u8 alm1_mask;
} __packed;

struct bd70528_rtc_alm {
	struct bd70528_rtc_data data;
	u8 alm_mask;
	u8 alm_repeat;
} __packed;

struct bd70528_rtc {
	struct rohm_regmap_dev *parent;
	struct device *dev;
	u8 reg_time_start;
	bool has_rtc_timers;
};

static int bd70528_set_wake(struct rohm_regmap_dev *bd70528,
			    int enable, int *old_state)
{
	int ret;
	unsigned int ctrl_reg;

	ret = regmap_read(bd70528->regmap, BD70528_REG_WAKE_EN, &ctrl_reg);
	if (ret)
		return ret;

	if (old_state) {
		if (ctrl_reg & BD70528_MASK_WAKE_EN)
			*old_state |= BD70528_WAKE_STATE_BIT;
		else
			*old_state &= ~BD70528_WAKE_STATE_BIT;

		if (!enable == !(*old_state & BD70528_WAKE_STATE_BIT))
			return 0;
	}

	if (enable)
		ctrl_reg |= BD70528_MASK_WAKE_EN;
	else
		ctrl_reg &= ~BD70528_MASK_WAKE_EN;

	return regmap_write(bd70528->regmap, BD70528_REG_WAKE_EN,
			    ctrl_reg);
}

static int bd70528_set_elapsed_tmr(struct rohm_regmap_dev *bd70528,
				   int enable, int *old_state)
{
	int ret;
	unsigned int ctrl_reg;

	/*
	 * TBD
	 * What is the purpose of elapsed timer ?
	 * Is the timeout registers counting down, or is the disable - re-enable
	 * going to restart the elapsed-time counting? If counting is restarted
	 * the timeout should be decreased by the amount of time that has
	 * elapsed since starting the timer. Maybe we should store the monotonic
	 * clock value when timer is started so that if RTC is set while timer
	 * is armed we could do the compensation. This is a hack if RTC/system
	 * clk are drifting. OTOH, RTC controlled via I2C is in any case
	 * inaccurate...
	 */
	ret = regmap_read(bd70528->regmap, BD70528_REG_ELAPSED_TIMER_EN,
			  &ctrl_reg);
	if (ret)
		return ret;

	if (old_state) {
		if (ctrl_reg & BD70528_MASK_ELAPSED_TIMER_EN)
			*old_state |= BD70528_ELAPSED_STATE_BIT;
		else
			*old_state &= ~BD70528_ELAPSED_STATE_BIT;

		if ((!enable) == (!(*old_state & BD70528_ELAPSED_STATE_BIT)))
			return 0;
	}

	if (enable)
		ctrl_reg |= BD70528_MASK_ELAPSED_TIMER_EN;
	else
		ctrl_reg &= ~BD70528_MASK_ELAPSED_TIMER_EN;

	return regmap_write(bd70528->regmap, BD70528_REG_ELAPSED_TIMER_EN,
			    ctrl_reg);
}

static int bd70528_set_rtc_based_timers(struct bd70528_rtc *r, int new_state,
					int *old_state)
{
	int ret;

	ret = bd70528_wdt_set(r->parent, new_state & BD70528_WDT_STATE_BIT,
			      old_state);
	if (ret) {
		dev_err(r->dev,
			"Failed to disable WDG for RTC setting (%d)\n", ret);
		return ret;
	}
	ret = bd70528_set_elapsed_tmr(r->parent,
				      new_state & BD70528_ELAPSED_STATE_BIT,
				      old_state);
	if (ret) {
		dev_err(r->dev,
			"Failed to disable 'elapsed timer' for RTC setting\n");
		return ret;
	}
	ret = bd70528_set_wake(r->parent, new_state & BD70528_WAKE_STATE_BIT,
			       old_state);
	if (ret) {
		dev_err(r->dev,
			"Failed to disable 'wake timer' for RTC setting\n");
		return ret;
	}

	return ret;
}

static int bd70528_re_enable_rtc_based_timers(struct bd70528_rtc *r,
					      int old_state)
{
	if (!r->has_rtc_timers)
		return 0;

	return bd70528_set_rtc_based_timers(r, old_state, NULL);
}

static int bd70528_disable_rtc_based_timers(struct bd70528_rtc *r,
					    int *old_state)
{
	if (!r->has_rtc_timers)
		return 0;

	return bd70528_set_rtc_based_timers(r, 0, old_state);
}

static inline void tmday2rtc(struct rtc_time *t, struct bd70528_rtc_day *d)
{
	d->sec &= ~BD70528_MASK_RTC_SEC;
	d->min &= ~BD70528_MASK_RTC_MINUTE;
	d->hour &= ~BD70528_MASK_RTC_HOUR;
	d->sec |= bin2bcd(t->tm_sec);
	d->min |= bin2bcd(t->tm_min);
	d->hour |= bin2bcd(t->tm_hour);
}

static inline void tm2rtc(struct rtc_time *t, struct bd70528_rtc_data *r)
{
	r->day &= ~BD70528_MASK_RTC_DAY;
	r->week &= ~BD70528_MASK_RTC_WEEK;
	r->month &= ~BD70528_MASK_RTC_MONTH;
	/*
	 * PM and 24H bits are not used by Wake - thus we clear them
	 * here and not in tmday2rtc() which is also used by wake.
	 */
	r->time.hour &= ~(BD70528_MASK_RTC_HOUR_PM | BD70528_MASK_RTC_HOUR_24H);

	tmday2rtc(t, &r->time);
	/*
	 * We do always set time in 24H mode.
	 */
	r->time.hour |= BD70528_MASK_RTC_HOUR_24H;
	r->day |= bin2bcd(t->tm_mday);
	r->week |= bin2bcd(t->tm_wday);
	r->month |= bin2bcd(t->tm_mon + 1);
	r->year = bin2bcd(t->tm_year - 100);
}

static inline void rtc2tm(struct bd70528_rtc_data *r, struct rtc_time *t)
{
	t->tm_sec = bcd2bin(r->time.sec & BD70528_MASK_RTC_SEC);
	t->tm_min = bcd2bin(r->time.min & BD70528_MASK_RTC_MINUTE);
	t->tm_hour = bcd2bin(r->time.hour & BD70528_MASK_RTC_HOUR);
	/*
	 * If RTC is in 12H mode, then bit BD70528_MASK_RTC_HOUR_PM
	 * is not BCD value but tells whether it is AM or PM
	 */
	if (!(r->time.hour & BD70528_MASK_RTC_HOUR_24H)) {
		t->tm_hour %= 12;
		if (r->time.hour & BD70528_MASK_RTC_HOUR_PM)
			t->tm_hour += 12;
	}
	t->tm_mday = bcd2bin(r->day & BD70528_MASK_RTC_DAY);
	t->tm_mon = bcd2bin(r->month & BD70528_MASK_RTC_MONTH) - 1;
	t->tm_year = 100 + bcd2bin(r->year & BD70528_MASK_RTC_YEAR);
	t->tm_wday = bcd2bin(r->week & BD70528_MASK_RTC_WEEK);
}

static int bd71828_set_alarm(struct device *dev, struct rtc_wkalrm *a)
{
	int ret;
	struct bd71828_rtc_alm alm;
	struct bd70528_rtc *r = dev_get_drvdata(dev);
	struct rohm_regmap_dev *parent = r->parent;

	ret = regmap_bulk_read(parent->regmap, BD71828_REG_RTC_ALM_START,
			       &alm, sizeof(alm));
	if (ret) {
		dev_err(dev, "Failed to read alarm regs\n");
		return ret;
	}

	tm2rtc(&a->time, &alm.alm0);

	if (!a->enabled)
		alm.alm_mask &= ~BD70528_MASK_ALM_EN;
	else
		alm.alm_mask |= BD70528_MASK_ALM_EN;

	ret = regmap_bulk_write(parent->regmap, BD71828_REG_RTC_ALM_START,
				&alm, sizeof(alm));
	if (ret)
		dev_err(dev, "Failed to set alarm time\n");

	return ret;

}

static int bd70528_set_alarm(struct device *dev, struct rtc_wkalrm *a)
{
	struct bd70528_rtc_wake wake;
	struct bd70528_rtc_alm alm;
	int ret;
	struct bd70528_rtc *r = dev_get_drvdata(dev);
	struct rohm_regmap_dev *parent = r->parent;

	ret = regmap_bulk_read(parent->regmap, BD70528_REG_RTC_WAKE_START,
			       &wake, sizeof(wake));
	if (ret) {
		dev_err(dev, "Failed to read wake regs\n");
		return ret;
	}

	ret = regmap_bulk_read(parent->regmap, BD70528_REG_RTC_ALM_START,
			       &alm, sizeof(alm));
	if (ret) {
		dev_err(dev, "Failed to read alarm regs\n");
		return ret;
	}

	tm2rtc(&a->time, &alm.data);
	tmday2rtc(&a->time, &wake.time);

	if (a->enabled) {
		alm.alm_mask &= ~BD70528_MASK_ALM_EN;
		wake.ctrl |= BD70528_MASK_WAKE_EN;
	} else {
		alm.alm_mask |= BD70528_MASK_ALM_EN;
		wake.ctrl &= ~BD70528_MASK_WAKE_EN;
	}

	ret = regmap_bulk_write(parent->regmap,
				BD70528_REG_RTC_WAKE_START, &wake,
				sizeof(wake));
	if (ret) {
		dev_err(dev, "Failed to set wake time\n");
		return ret;
	}
	ret = regmap_bulk_write(parent->regmap, BD70528_REG_RTC_ALM_START,
				&alm, sizeof(alm));
	if (ret)
		dev_err(dev, "Failed to set alarm time\n");

	return ret;
}

static int bd71828_read_alarm(struct device *dev, struct rtc_wkalrm *a)
{
	int ret;
	struct bd71828_rtc_alm alm;
	struct bd70528_rtc *r = dev_get_drvdata(dev);
	struct rohm_regmap_dev *parent = r->parent;

	ret = regmap_bulk_read(parent->regmap, BD71828_REG_RTC_ALM_START,
			       &alm, sizeof(alm));
	if (ret) {
		dev_err(dev, "Failed to read alarm regs\n");
		return ret;
	}

	rtc2tm(&alm.alm0, &a->time);
	a->time.tm_mday = -1;
	a->time.tm_mon = -1;
	a->time.tm_year = -1;
	a->enabled = !!(alm.alm_mask & BD70528_MASK_ALM_EN);
	a->pending = 0;

	return 0;
}

static int bd70528_read_alarm(struct device *dev, struct rtc_wkalrm *a)
{
	struct bd70528_rtc_alm alm;
	int ret;
	struct bd70528_rtc *r = dev_get_drvdata(dev);
	struct rohm_regmap_dev *parent = r->parent;

	ret = regmap_bulk_read(parent->regmap, BD70528_REG_RTC_ALM_START,
			       &alm, sizeof(alm));
	if (ret) {
		dev_err(dev, "Failed to read alarm regs\n");
		return ret;
	}

	rtc2tm(&alm.data, &a->time);
	a->time.tm_mday = -1;
	a->time.tm_mon = -1;
	a->time.tm_year = -1;
	a->enabled = !(alm.alm_mask & BD70528_MASK_ALM_EN);
	a->pending = 0;

	return 0;
}

static int bd70528_set_time_locked(struct device *dev, struct rtc_time *t)
{
	int ret, tmpret, old_states;
	struct bd70528_rtc_data rtc_data;
	struct bd70528_rtc *r = dev_get_drvdata(dev);
	struct rohm_regmap_dev *parent = r->parent;

	ret = bd70528_disable_rtc_based_timers(r, &old_states);
	if (ret)
		return ret;

	tmpret = regmap_bulk_read(parent->regmap,
				  r->reg_time_start, &rtc_data,
				  sizeof(rtc_data));
	if (tmpret) {
		dev_err(dev, "Failed to read RTC time registers\n");
		goto renable_out;
	}
	tm2rtc(t, &rtc_data);

	tmpret = regmap_bulk_write(parent->regmap,
				   r->reg_time_start, &rtc_data,
				   sizeof(rtc_data));
	if (tmpret) {
		dev_err(dev, "Failed to set RTC time\n");
		goto renable_out;
	}

renable_out:
	ret = bd70528_re_enable_rtc_based_timers(r, old_states);
	if (tmpret)
		ret = tmpret;

	return ret;
}

static int bd71828_set_time(struct device *dev, struct rtc_time *t)
{
	return bd70528_set_time_locked(dev, t);
}

static int bd70528_set_time(struct device *dev, struct rtc_time *t)
{
	int ret;
	struct bd70528_rtc *r = dev_get_drvdata(dev);

	bd70528_wdt_lock(r->parent);
	ret = bd70528_set_time_locked(dev, t);
	bd70528_wdt_unlock(r->parent);
	return ret;
}

static int bd70528_get_time(struct device *dev, struct rtc_time *t)
{
	struct bd70528_rtc *r = dev_get_drvdata(dev);
	struct rohm_regmap_dev *parent = r->parent;
	struct bd70528_rtc_data rtc_data;
	int ret;

	/* read the RTC date and time registers all at once */
	ret = regmap_bulk_read(parent->regmap,
			       r->reg_time_start, &rtc_data,
			       sizeof(rtc_data));
	if (ret) {
		dev_err(dev, "Failed to read RTC time (err %d)\n", ret);
		return ret;
	}

	rtc2tm(&rtc_data, t);

	return 0;
}

static int bd70528_alm_enable(struct device *dev, unsigned int enabled)
{
	int ret;
	unsigned int enableval = BD70528_MASK_ALM_EN;
	struct bd70528_rtc *r = dev_get_drvdata(dev);

	if (enabled)
		enableval = 0;

	bd70528_wdt_lock(r->parent);
	ret = bd70528_set_wake(r->parent, enabled, NULL);
	if (ret) {
		dev_err(dev, "Failed to change wake state\n");
		goto out_unlock;
	}
	ret = regmap_update_bits(r->parent->regmap, BD70528_REG_RTC_ALM_MASK,
				 BD70528_MASK_ALM_EN, enableval);
	if (ret)
		dev_err(dev, "Failed to change alarm state\n");

out_unlock:
	bd70528_wdt_unlock(r->parent);
	return ret;
}

static int bd71828_alm_enable(struct device *dev, unsigned int enabled)
{
	int ret;
	struct bd70528_rtc *r = dev_get_drvdata(dev);
	unsigned int enableval = BD70528_MASK_ALM_EN;

	if (!enabled)
		enableval = 0;

	ret = regmap_update_bits(r->parent->regmap, BD71828_REG_RTC_ALM0_MASK,
				 BD70528_MASK_ALM_EN, enableval);
	if (ret)
		dev_err(dev, "Failed to change alarm state\n");

	return ret;
}

static const struct rtc_class_ops bd70528_rtc_ops = {
	.read_time		= bd70528_get_time,
	.set_time		= bd70528_set_time,
	.read_alarm		= bd70528_read_alarm,
	.set_alarm		= bd70528_set_alarm,
	.alarm_irq_enable	= bd70528_alm_enable,
};

static const struct rtc_class_ops bd71828_rtc_ops = {
	.read_time		= bd70528_get_time,
	.set_time		= bd71828_set_time,
	.read_alarm		= bd71828_read_alarm,
	.set_alarm		= bd71828_set_alarm,
	.alarm_irq_enable	= bd71828_alm_enable,
};

static irqreturn_t alm_hndlr(int irq, void *data)
{
	struct rtc_device *rtc = data;

	rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF | RTC_PF);
	return IRQ_HANDLED;
}

static int bd70528_probe(struct platform_device *pdev)
{
	struct bd70528_rtc *bd_rtc;
	const struct rtc_class_ops *rtc_ops;
	struct rohm_regmap_dev *parent;
	const char *irq_name;
	int ret;
	struct rtc_device *rtc;
	int irq;
	unsigned int hr;
	bool enable_main_irq = false;
	u8 hour_reg;
	enum rohm_chip_type chip = platform_get_device_id(pdev)->driver_data;

	parent = dev_get_drvdata(pdev->dev.parent);
	if (!parent) {
		dev_err(&pdev->dev, "No MFD driver data\n");
		return -EINVAL;
	}
	bd_rtc = devm_kzalloc(&pdev->dev, sizeof(*bd_rtc), GFP_KERNEL);
	if (!bd_rtc)
		return -ENOMEM;

	bd_rtc->parent = parent;
	bd_rtc->dev = &pdev->dev;

	switch (chip) {
	case ROHM_CHIP_TYPE_BD70528:
		irq_name = "bd70528-rtc-alm";
		bd_rtc->has_rtc_timers = true;
		bd_rtc->reg_time_start = BD70528_REG_RTC_START;
		hour_reg = BD70528_REG_RTC_HOUR;
		enable_main_irq = true;
		rtc_ops = &bd70528_rtc_ops;
		break;
	case ROHM_CHIP_TYPE_BD71828:
		irq_name = "bd71828-rtc-alm-0";
		bd_rtc->reg_time_start = BD71828_REG_RTC_START;
		hour_reg = BD71828_REG_RTC_HOUR;
		rtc_ops = &bd71828_rtc_ops;
		break;
	default:
		dev_err(&pdev->dev, "Unknown chip\n");
		return -ENOENT;
	}

	irq = platform_get_irq_byname(pdev, irq_name);

	if (irq < 0) {
		dev_err(&pdev->dev, "Failed to get irq\n");
		return irq;
	}

	platform_set_drvdata(pdev, bd_rtc);

	ret = regmap_read(parent->regmap, hour_reg, &hr);

	if (ret) {
		dev_err(&pdev->dev, "Failed to reag RTC clock\n");
		return ret;
	}

	if (!(hr & BD70528_MASK_RTC_HOUR_24H)) {
		struct rtc_time t;

		ret = rtc_ops->read_time(&pdev->dev, &t);

		if (!ret)
			ret = rtc_ops->set_time(&pdev->dev, &t);

		if (ret) {
			dev_err(&pdev->dev,
				"Setting 24H clock for RTC failed\n");
			return ret;
		}
	}

	device_set_wakeup_capable(&pdev->dev, true);
	device_wakeup_enable(&pdev->dev);

	rtc = devm_rtc_allocate_device(&pdev->dev);
	if (IS_ERR(rtc)) {
		dev_err(&pdev->dev, "RTC device creation failed\n");
		return PTR_ERR(rtc);
	}

	rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
	rtc->range_max = RTC_TIMESTAMP_END_2099;
	rtc->ops = rtc_ops;

	/* Request alarm IRQ prior to registerig the RTC */
	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, &alm_hndlr,
					IRQF_ONESHOT, "bd70528-rtc", rtc);
	if (ret)
		return ret;

	/*
	 *  BD70528 irq controller is not touching the main mask register.
	 *  So enable the RTC block interrupts at main level. We can just
	 *  leave them enabled as irq-controller should disable irqs
	 *  from sub-registers when IRQ is disabled or freed.
	 */
	if (enable_main_irq) {
		ret = regmap_update_bits(parent->regmap,
				 BD70528_REG_INT_MAIN_MASK,
				 BD70528_INT_RTC_MASK, 0);
		if (ret) {
			dev_err(&pdev->dev, "Failed to enable RTC interrupts\n");
			return ret;
		}
	}

	return rtc_register_device(rtc);
}

static const struct platform_device_id bd718x7_rtc_id[] = {
	{ "bd70528-rtc", ROHM_CHIP_TYPE_BD70528 },
	{ "bd71828-rtc", ROHM_CHIP_TYPE_BD71828 },
	{ },
};
MODULE_DEVICE_TABLE(platform, bd718x7_rtc_id);

static struct platform_driver bd70528_rtc = {
	.driver = {
		.name = "bd70528-rtc"
	},
	.probe = bd70528_probe,
	.id_table = bd718x7_rtc_id,
};

module_platform_driver(bd70528_rtc);

MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
MODULE_DESCRIPTION("ROHM BD70528 and BD71828 PMIC RTC driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:bd70528-rtc");