summaryrefslogtreecommitdiffstats
path: root/drivers/rtc/rtc-ds1343.c
blob: 5208da4cf94ab2b0e69d374836acb63e83916ca6 (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
/* rtc-ds1343.c
 *
 * Driver for Dallas Semiconductor DS1343 Low Current, SPI Compatible
 * Real Time Clock
 *
 * Author : Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com>
 *	    Ankur Srivastava <sankurece@gmail.com> : DS1343 Nvram Support
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/device.h>
#include <linux/spi/spi.h>
#include <linux/regmap.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#include <linux/pm.h>
#include <linux/pm_wakeirq.h>
#include <linux/slab.h>

#define DALLAS_MAXIM_DS1343	0
#define DALLAS_MAXIM_DS1344	1

/* RTC DS1343 Registers */
#define DS1343_SECONDS_REG	0x00
#define DS1343_MINUTES_REG	0x01
#define DS1343_HOURS_REG	0x02
#define DS1343_DAY_REG		0x03
#define DS1343_DATE_REG		0x04
#define DS1343_MONTH_REG	0x05
#define DS1343_YEAR_REG		0x06
#define DS1343_ALM0_SEC_REG	0x07
#define DS1343_ALM0_MIN_REG	0x08
#define DS1343_ALM0_HOUR_REG	0x09
#define DS1343_ALM0_DAY_REG	0x0A
#define DS1343_ALM1_SEC_REG	0x0B
#define DS1343_ALM1_MIN_REG	0x0C
#define DS1343_ALM1_HOUR_REG	0x0D
#define DS1343_ALM1_DAY_REG	0x0E
#define DS1343_CONTROL_REG	0x0F
#define DS1343_STATUS_REG	0x10
#define DS1343_TRICKLE_REG	0x11
#define DS1343_NVRAM		0x20

#define DS1343_NVRAM_LEN	96

/* DS1343 Control Registers bits */
#define DS1343_EOSC		0x80
#define DS1343_DOSF		0x20
#define DS1343_EGFIL		0x10
#define DS1343_SQW		0x08
#define DS1343_INTCN		0x04
#define DS1343_A1IE		0x02
#define DS1343_A0IE		0x01

/* DS1343 Status Registers bits */
#define DS1343_OSF		0x80
#define DS1343_IRQF1		0x02
#define DS1343_IRQF0		0x01

/* DS1343 Trickle Charger Registers bits */
#define DS1343_TRICKLE_MAGIC	0xa0
#define DS1343_TRICKLE_DS1	0x08
#define DS1343_TRICKLE_1K	0x01
#define DS1343_TRICKLE_2K	0x02
#define DS1343_TRICKLE_4K	0x03

static const struct spi_device_id ds1343_id[] = {
	{ "ds1343", DALLAS_MAXIM_DS1343 },
	{ "ds1344", DALLAS_MAXIM_DS1344 },
	{ }
};
MODULE_DEVICE_TABLE(spi, ds1343_id);

struct ds1343_priv {
	struct spi_device *spi;
	struct rtc_device *rtc;
	struct regmap *map;
	struct mutex mutex;
	unsigned int irqen;
	int irq;
	int alarm_sec;
	int alarm_min;
	int alarm_hour;
	int alarm_mday;
};

static int ds1343_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
	switch (cmd) {
#ifdef RTC_SET_CHARGE
	case RTC_SET_CHARGE:
	{
		int val;

		if (copy_from_user(&val, (int __user *)arg, sizeof(int)))
			return -EFAULT;

		return regmap_write(priv->map, DS1343_TRICKLE_REG, val);
	}
	break;
#endif
	}

	return -ENOIOCTLCMD;
}

static ssize_t ds1343_show_glitchfilter(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	struct ds1343_priv *priv = dev_get_drvdata(dev);
	int glitch_filt_status, data;

	regmap_read(priv->map, DS1343_CONTROL_REG, &data);

	glitch_filt_status = !!(data & DS1343_EGFIL);

	if (glitch_filt_status)
		return sprintf(buf, "enabled\n");
	else
		return sprintf(buf, "disabled\n");
}

static ssize_t ds1343_store_glitchfilter(struct device *dev,
					struct device_attribute *attr,
					const char *buf, size_t count)
{
	struct ds1343_priv *priv = dev_get_drvdata(dev);
	int data;

	regmap_read(priv->map, DS1343_CONTROL_REG, &data);

	if (strncmp(buf, "enabled", 7) == 0)
		data |= DS1343_EGFIL;

	else if (strncmp(buf, "disabled", 8) == 0)
		data &= ~(DS1343_EGFIL);

	else
		return -EINVAL;

	regmap_write(priv->map, DS1343_CONTROL_REG, data);

	return count;
}

static DEVICE_ATTR(glitch_filter, S_IRUGO | S_IWUSR, ds1343_show_glitchfilter,
			ds1343_store_glitchfilter);

static int ds1343_nvram_write(void *priv, unsigned int off, void *val,
			      size_t bytes)
{
	struct ds1343_priv *ds1343 = priv;

	return regmap_bulk_write(ds1343->map, DS1343_NVRAM + off, val, bytes);
}

static int ds1343_nvram_read(void *priv, unsigned int off, void *val,
			     size_t bytes)
{
	struct ds1343_priv *ds1343 = priv;

	return regmap_bulk_read(ds1343->map, DS1343_NVRAM + off, val, bytes);
}

static ssize_t ds1343_show_tricklecharger(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	struct ds1343_priv *priv = dev_get_drvdata(dev);
	int data;
	char *diodes = "disabled", *resistors = " ";

	regmap_read(priv->map, DS1343_TRICKLE_REG, &data);

	if ((data & 0xf0) == DS1343_TRICKLE_MAGIC) {
		switch (data & 0x0c) {
		case DS1343_TRICKLE_DS1:
			diodes = "one diode,";
			break;

		default:
			diodes = "no diode,";
			break;
		}

		switch (data & 0x03) {
		case DS1343_TRICKLE_1K:
			resistors = "1k Ohm";
			break;

		case DS1343_TRICKLE_2K:
			resistors = "2k Ohm";
			break;

		case DS1343_TRICKLE_4K:
			resistors = "4k Ohm";
			break;

		default:
			diodes = "disabled";
			break;
		}
	}

	return sprintf(buf, "%s %s\n", diodes, resistors);
}

static DEVICE_ATTR(trickle_charger, S_IRUGO, ds1343_show_tricklecharger, NULL);

static int ds1343_sysfs_register(struct device *dev)
{
	int err;

	err = device_create_file(dev, &dev_attr_glitch_filter);
	if (err)
		return err;

	err = device_create_file(dev, &dev_attr_trickle_charger);
	if (!err)
		return 0;

	device_remove_file(dev, &dev_attr_glitch_filter);

	return err;
}

static void ds1343_sysfs_unregister(struct device *dev)
{
	device_remove_file(dev, &dev_attr_glitch_filter);
	device_remove_file(dev, &dev_attr_trickle_charger);
}

static int ds1343_read_time(struct device *dev, struct rtc_time *dt)
{
	struct ds1343_priv *priv = dev_get_drvdata(dev);
	unsigned char buf[7];
	int res;

	res = regmap_bulk_read(priv->map, DS1343_SECONDS_REG, buf, 7);
	if (res)
		return res;

	dt->tm_sec	= bcd2bin(buf[0]);
	dt->tm_min	= bcd2bin(buf[1]);
	dt->tm_hour	= bcd2bin(buf[2] & 0x3F);
	dt->tm_wday	= bcd2bin(buf[3]) - 1;
	dt->tm_mday	= bcd2bin(buf[4]);
	dt->tm_mon	= bcd2bin(buf[5] & 0x1F) - 1;
	dt->tm_year	= bcd2bin(buf[6]) + 100; /* year offset from 1900 */

	return 0;
}

static int ds1343_set_time(struct device *dev, struct rtc_time *dt)
{
	struct ds1343_priv *priv = dev_get_drvdata(dev);
	int res;

	res = regmap_write(priv->map, DS1343_SECONDS_REG,
				bin2bcd(dt->tm_sec));
	if (res)
		return res;

	res = regmap_write(priv->map, DS1343_MINUTES_REG,
				bin2bcd(dt->tm_min));
	if (res)
		return res;

	res = regmap_write(priv->map, DS1343_HOURS_REG,
				bin2bcd(dt->tm_hour) & 0x3F);
	if (res)
		return res;

	res = regmap_write(priv->map, DS1343_DAY_REG,
				bin2bcd(dt->tm_wday + 1));
	if (res)
		return res;

	res = regmap_write(priv->map, DS1343_DATE_REG,
				bin2bcd(dt->tm_mday));
	if (res)
		return res;

	res = regmap_write(priv->map, DS1343_MONTH_REG,
				bin2bcd(dt->tm_mon + 1));
	if (res)
		return res;

	dt->tm_year %= 100;

	res = regmap_write(priv->map, DS1343_YEAR_REG,
				bin2bcd(dt->tm_year));
	if (res)
		return res;

	return 0;
}

static int ds1343_update_alarm(struct device *dev)
{
	struct ds1343_priv *priv = dev_get_drvdata(dev);
	unsigned int control, stat;
	unsigned char buf[4];
	int res = 0;

	res = regmap_read(priv->map, DS1343_CONTROL_REG, &control);
	if (res)
		return res;

	res = regmap_read(priv->map, DS1343_STATUS_REG, &stat);
	if (res)
		return res;

	control &= ~(DS1343_A0IE);
	stat &= ~(DS1343_IRQF0);

	res = regmap_write(priv->map, DS1343_CONTROL_REG, control);
	if (res)
		return res;

	res = regmap_write(priv->map, DS1343_STATUS_REG, stat);
	if (res)
		return res;

	buf[0] = priv->alarm_sec < 0 || (priv->irqen & RTC_UF) ?
		0x80 : bin2bcd(priv->alarm_sec) & 0x7F;
	buf[1] = priv->alarm_min < 0 || (priv->irqen & RTC_UF) ?
		0x80 : bin2bcd(priv->alarm_min) & 0x7F;
	buf[2] = priv->alarm_hour < 0 || (priv->irqen & RTC_UF) ?
		0x80 : bin2bcd(priv->alarm_hour) & 0x3F;
	buf[3] = priv->alarm_mday < 0 || (priv->irqen & RTC_UF) ?
		0x80 : bin2bcd(priv->alarm_mday) & 0x7F;

	res = regmap_bulk_write(priv->map, DS1343_ALM0_SEC_REG, buf, 4);
	if (res)
		return res;

	if (priv->irqen) {
		control |= DS1343_A0IE;
		res = regmap_write(priv->map, DS1343_CONTROL_REG, control);
	}

	return res;
}

static int ds1343_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
	struct ds1343_priv *priv = dev_get_drvdata(dev);
	int res = 0;
	unsigned int stat;

	if (priv->irq <= 0)
		return -EINVAL;

	mutex_lock(&priv->mutex);

	res = regmap_read(priv->map, DS1343_STATUS_REG, &stat);
	if (res)
		goto out;

	alarm->enabled = !!(priv->irqen & RTC_AF);
	alarm->pending = !!(stat & DS1343_IRQF0);

	alarm->time.tm_sec = priv->alarm_sec < 0 ? 0 : priv->alarm_sec;
	alarm->time.tm_min = priv->alarm_min < 0 ? 0 : priv->alarm_min;
	alarm->time.tm_hour = priv->alarm_hour < 0 ? 0 : priv->alarm_hour;
	alarm->time.tm_mday = priv->alarm_mday < 0 ? 0 : priv->alarm_mday;

out:
	mutex_unlock(&priv->mutex);
	return res;
}

static int ds1343_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
	struct ds1343_priv *priv = dev_get_drvdata(dev);
	int res = 0;

	if (priv->irq <= 0)
		return -EINVAL;

	mutex_lock(&priv->mutex);

	priv->alarm_sec = alarm->time.tm_sec;
	priv->alarm_min = alarm->time.tm_min;
	priv->alarm_hour = alarm->time.tm_hour;
	priv->alarm_mday = alarm->time.tm_mday;

	if (alarm->enabled)
		priv->irqen |= RTC_AF;

	res = ds1343_update_alarm(dev);

	mutex_unlock(&priv->mutex);

	return res;
}

static int ds1343_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
	struct ds1343_priv *priv = dev_get_drvdata(dev);
	int res = 0;

	if (priv->irq <= 0)
		return -EINVAL;

	mutex_lock(&priv->mutex);

	if (enabled)
		priv->irqen |= RTC_AF;
	else
		priv->irqen &= ~RTC_AF;

	res = ds1343_update_alarm(dev);

	mutex_unlock(&priv->mutex);

	return res;
}

static irqreturn_t ds1343_thread(int irq, void *dev_id)
{
	struct ds1343_priv *priv = dev_id;
	unsigned int stat, control;
	int res = 0;

	mutex_lock(&priv->mutex);

	res = regmap_read(priv->map, DS1343_STATUS_REG, &stat);
	if (res)
		goto out;

	if (stat & DS1343_IRQF0) {
		stat &= ~DS1343_IRQF0;
		regmap_write(priv->map, DS1343_STATUS_REG, stat);

		res = regmap_read(priv->map, DS1343_CONTROL_REG, &control);
		if (res)
			goto out;

		control &= ~DS1343_A0IE;
		regmap_write(priv->map, DS1343_CONTROL_REG, control);

		rtc_update_irq(priv->rtc, 1, RTC_AF | RTC_IRQF);
	}

out:
	mutex_unlock(&priv->mutex);
	return IRQ_HANDLED;
}

static const struct rtc_class_ops ds1343_rtc_ops = {
	.ioctl		= ds1343_ioctl,
	.read_time	= ds1343_read_time,
	.set_time	= ds1343_set_time,
	.read_alarm	= ds1343_read_alarm,
	.set_alarm	= ds1343_set_alarm,
	.alarm_irq_enable = ds1343_alarm_irq_enable,
};

static int ds1343_probe(struct spi_device *spi)
{
	struct ds1343_priv *priv;
	struct regmap_config config = { .reg_bits = 8, .val_bits = 8,
					.write_flag_mask = 0x80, };
	unsigned int data;
	int res;
	struct nvmem_config nvmem_cfg = {
		.name = "ds1343-",
		.word_size = 1,
		.stride = 1,
		.size = DS1343_NVRAM_LEN,
		.reg_read = ds1343_nvram_read,
		.reg_write = ds1343_nvram_write,
	};

	priv = devm_kzalloc(&spi->dev, sizeof(struct ds1343_priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	priv->spi = spi;
	mutex_init(&priv->mutex);

	/* RTC DS1347 works in spi mode 3 and
	 * its chip select is active high
	 */
	spi->mode = SPI_MODE_3 | SPI_CS_HIGH;
	spi->bits_per_word = 8;
	res = spi_setup(spi);
	if (res)
		return res;

	spi_set_drvdata(spi, priv);

	priv->map = devm_regmap_init_spi(spi, &config);

	if (IS_ERR(priv->map)) {
		dev_err(&spi->dev, "spi regmap init failed for rtc ds1343\n");
		return PTR_ERR(priv->map);
	}

	res = regmap_read(priv->map, DS1343_SECONDS_REG, &data);
	if (res)
		return res;

	regmap_read(priv->map, DS1343_CONTROL_REG, &data);
	data |= DS1343_INTCN;
	data &= ~(DS1343_EOSC | DS1343_A1IE | DS1343_A0IE);
	regmap_write(priv->map, DS1343_CONTROL_REG, data);

	regmap_read(priv->map, DS1343_STATUS_REG, &data);
	data &= ~(DS1343_OSF | DS1343_IRQF1 | DS1343_IRQF0);
	regmap_write(priv->map, DS1343_STATUS_REG, data);

	priv->rtc = devm_rtc_allocate_device(&spi->dev);
	if (IS_ERR(priv->rtc))
		return PTR_ERR(priv->rtc);

	priv->rtc->nvram_old_abi = true;
	priv->rtc->ops = &ds1343_rtc_ops;

	res = rtc_register_device(priv->rtc);
	if (res)
		return res;

	nvmem_cfg.priv = priv;
	rtc_nvmem_register(priv->rtc, &nvmem_cfg);

	priv->irq = spi->irq;

	if (priv->irq >= 0) {
		res = devm_request_threaded_irq(&spi->dev, spi->irq, NULL,
						ds1343_thread, IRQF_ONESHOT,
						"ds1343", priv);
		if (res) {
			priv->irq = -1;
			dev_err(&spi->dev,
				"unable to request irq for rtc ds1343\n");
		} else {
			device_init_wakeup(&spi->dev, true);
			dev_pm_set_wake_irq(&spi->dev, spi->irq);
		}
	}

	res = ds1343_sysfs_register(&spi->dev);
	if (res)
		dev_err(&spi->dev,
			"unable to create sysfs entries for rtc ds1343\n");

	return 0;
}

static int ds1343_remove(struct spi_device *spi)
{
	struct ds1343_priv *priv = spi_get_drvdata(spi);

	if (spi->irq) {
		mutex_lock(&priv->mutex);
		priv->irqen &= ~RTC_AF;
		mutex_unlock(&priv->mutex);

		dev_pm_clear_wake_irq(&spi->dev);
		device_init_wakeup(&spi->dev, false);
		devm_free_irq(&spi->dev, spi->irq, priv);
	}

	spi_set_drvdata(spi, NULL);

	ds1343_sysfs_unregister(&spi->dev);

	return 0;
}

#ifdef CONFIG_PM_SLEEP

static int ds1343_suspend(struct device *dev)
{
	struct spi_device *spi = to_spi_device(dev);

	if (spi->irq >= 0 && device_may_wakeup(dev))
		enable_irq_wake(spi->irq);

	return 0;
}

static int ds1343_resume(struct device *dev)
{
	struct spi_device *spi = to_spi_device(dev);

	if (spi->irq >= 0 && device_may_wakeup(dev))
		disable_irq_wake(spi->irq);

	return 0;
}

#endif

static SIMPLE_DEV_PM_OPS(ds1343_pm, ds1343_suspend, ds1343_resume);

static struct spi_driver ds1343_driver = {
	.driver = {
		.name = "ds1343",
		.pm = &ds1343_pm,
	},
	.probe = ds1343_probe,
	.remove = ds1343_remove,
	.id_table = ds1343_id,
};

module_spi_driver(ds1343_driver);

MODULE_DESCRIPTION("DS1343 RTC SPI Driver");
MODULE_AUTHOR("Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com>,"
		"Ankur Srivastava <sankurece@gmail.com>");
MODULE_LICENSE("GPL v2");