summaryrefslogtreecommitdiff
path: root/drivers/rtc/rtc-rx8010.c
blob: 772d221ec2d9f16fc879787ff2729c3c731a416b (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
/*
 * Driver for the Epson RTC module RX-8010 SJ
 *
 * Copyright(C) Timesys Corporation 2015
 * Copyright(C) General Electric Company 2015
 *
 * 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/bcd.h>
#include <linux/bitops.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/rtc.h>

#define RX8010_SEC     0x10
#define RX8010_MIN     0x11
#define RX8010_HOUR    0x12
#define RX8010_WDAY    0x13
#define RX8010_MDAY    0x14
#define RX8010_MONTH   0x15
#define RX8010_YEAR    0x16
#define RX8010_YEAR    0x16
#define RX8010_RESV17  0x17
#define RX8010_ALMIN   0x18
#define RX8010_ALHOUR  0x19
#define RX8010_ALWDAY  0x1A
#define RX8010_TCOUNT0 0x1B
#define RX8010_TCOUNT1 0x1C
#define RX8010_EXT     0x1D
#define RX8010_FLAG    0x1E
#define RX8010_CTRL    0x1F
/* 0x20 to 0x2F are user registers */
#define RX8010_RESV30  0x30
#define RX8010_RESV31  0x32
#define RX8010_IRQ     0x32

#define RX8010_EXT_WADA  BIT(3)

#define RX8010_FLAG_VLF  BIT(1)
#define RX8010_FLAG_AF   BIT(3)
#define RX8010_FLAG_TF   BIT(4)
#define RX8010_FLAG_UF   BIT(5)

#define RX8010_CTRL_AIE  BIT(3)
#define RX8010_CTRL_UIE  BIT(5)
#define RX8010_CTRL_STOP BIT(6)
#define RX8010_CTRL_TEST BIT(7)

#define RX8010_ALARM_AE  BIT(7)

static const struct i2c_device_id rx8010_id[] = {
	{ "rx8010", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, rx8010_id);

struct rx8010_data {
	struct i2c_client *client;
	struct rtc_device *rtc;
	u8 ctrlreg;
	spinlock_t flags_lock;
};

static irqreturn_t rx8010_irq_1_handler(int irq, void *dev_id)
{
	struct i2c_client *client = dev_id;
	struct rx8010_data *rx8010 = i2c_get_clientdata(client);
	int flagreg;

	spin_lock(&rx8010->flags_lock);

	flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);

	if (flagreg <= 0) {
		spin_unlock(&rx8010->flags_lock);
		return IRQ_NONE;
	}

	if (flagreg & RX8010_FLAG_VLF)
		dev_warn(&client->dev, "Frequency stop detected\n");

	if (flagreg & RX8010_FLAG_TF) {
		flagreg &= ~RX8010_FLAG_TF;
		rtc_update_irq(rx8010->rtc, 1, RTC_PF | RTC_IRQF);
	}

	if (flagreg & RX8010_FLAG_AF) {
		flagreg &= ~RX8010_FLAG_AF;
		rtc_update_irq(rx8010->rtc, 1, RTC_AF | RTC_IRQF);
	}

	if (flagreg & RX8010_FLAG_UF) {
		flagreg &= ~RX8010_FLAG_UF;
		rtc_update_irq(rx8010->rtc, 1, RTC_UF | RTC_IRQF);
	}

	i2c_smbus_write_byte_data(client, RX8010_FLAG, flagreg);

	spin_unlock(&rx8010->flags_lock);
	return IRQ_HANDLED;
}

static int rx8010_get_time(struct device *dev, struct rtc_time *dt)
{
	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
	u8 date[7];
	int flagreg;
	int err;

	flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
	if (flagreg < 0)
		return flagreg;

	if (flagreg & RX8010_FLAG_VLF) {
		dev_warn(dev, "Frequency stop detected\n");
		return -EINVAL;
	}

	err = i2c_smbus_read_i2c_block_data(rx8010->client, RX8010_SEC,
					    7, date);
	if (err != 7)
		return err < 0 ? err : -EIO;

	dt->tm_sec = bcd2bin(date[RX8010_SEC - RX8010_SEC] & 0x7f);
	dt->tm_min = bcd2bin(date[RX8010_MIN - RX8010_SEC] & 0x7f);
	dt->tm_hour = bcd2bin(date[RX8010_HOUR - RX8010_SEC] & 0x3f);
	dt->tm_mday = bcd2bin(date[RX8010_MDAY - RX8010_SEC] & 0x3f);
	dt->tm_mon = bcd2bin(date[RX8010_MONTH - RX8010_SEC] & 0x1f) - 1;
	dt->tm_year = bcd2bin(date[RX8010_YEAR - RX8010_SEC]) + 100;
	dt->tm_wday = ffs(date[RX8010_WDAY - RX8010_SEC] & 0x7f);

	return rtc_valid_tm(dt);
}

static int rx8010_set_time(struct device *dev, struct rtc_time *dt)
{
	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
	u8 date[7];
	int ctrl, flagreg;
	int ret;
	unsigned long irqflags;

	if ((dt->tm_year < 100) || (dt->tm_year > 199))
		return -EINVAL;

	/* set STOP bit before changing clock/calendar */
	ctrl = i2c_smbus_read_byte_data(rx8010->client, RX8010_CTRL);
	if (ctrl < 0)
		return ctrl;
	rx8010->ctrlreg = ctrl | RX8010_CTRL_STOP;
	ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
					rx8010->ctrlreg);
	if (ret < 0)
		return ret;

	date[RX8010_SEC - RX8010_SEC] = bin2bcd(dt->tm_sec);
	date[RX8010_MIN - RX8010_SEC] = bin2bcd(dt->tm_min);
	date[RX8010_HOUR - RX8010_SEC] = bin2bcd(dt->tm_hour);
	date[RX8010_MDAY - RX8010_SEC] = bin2bcd(dt->tm_mday);
	date[RX8010_MONTH - RX8010_SEC] = bin2bcd(dt->tm_mon + 1);
	date[RX8010_YEAR - RX8010_SEC] = bin2bcd(dt->tm_year - 100);
	date[RX8010_WDAY - RX8010_SEC] = bin2bcd(1 << dt->tm_wday);

	ret = i2c_smbus_write_i2c_block_data(rx8010->client,
					     RX8010_SEC, 7, date);
	if (ret < 0)
		return ret;

	/* clear STOP bit after changing clock/calendar */
	ctrl = i2c_smbus_read_byte_data(rx8010->client, RX8010_CTRL);
	if (ctrl < 0)
		return ctrl;
	rx8010->ctrlreg = ctrl & ~RX8010_CTRL_STOP;
	ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
					rx8010->ctrlreg);
	if (ret < 0)
		return ret;

	spin_lock_irqsave(&rx8010->flags_lock, irqflags);

	flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
	if (flagreg < 0) {
		spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
		return flagreg;
	}

	if (flagreg & RX8010_FLAG_VLF)
		ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG,
						flagreg & ~RX8010_FLAG_VLF);

	spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);

	return 0;
}

static int rx8010_init_client(struct i2c_client *client)
{
	struct rx8010_data *rx8010 = i2c_get_clientdata(client);
	u8 ctrl[2];
	int need_clear = 0, err = 0;

	/* Initialize reserved registers as specified in datasheet */
	err = i2c_smbus_write_byte_data(client, RX8010_RESV17, 0xD8);
	if (err < 0)
		return err;

	err = i2c_smbus_write_byte_data(client, RX8010_RESV30, 0x00);
	if (err < 0)
		return err;

	err = i2c_smbus_write_byte_data(client, RX8010_RESV31, 0x08);
	if (err < 0)
		return err;

	err = i2c_smbus_write_byte_data(client, RX8010_IRQ, 0x00);
	if (err < 0)
		return err;

	err = i2c_smbus_read_i2c_block_data(rx8010->client, RX8010_FLAG,
					    2, ctrl);
	if (err != 2)
		return err < 0 ? err : -EIO;

	if (ctrl[0] & RX8010_FLAG_VLF)
		dev_warn(&client->dev, "Frequency stop was detected\n");

	if (ctrl[0] & RX8010_FLAG_AF) {
		dev_warn(&client->dev, "Alarm was detected\n");
		need_clear = 1;
	}

	if (ctrl[0] & RX8010_FLAG_TF)
		need_clear = 1;

	if (ctrl[0] & RX8010_FLAG_UF)
		need_clear = 1;

	if (need_clear) {
		ctrl[0] &= ~(RX8010_FLAG_AF | RX8010_FLAG_TF | RX8010_FLAG_UF);
		err = i2c_smbus_write_byte_data(client, RX8010_FLAG, ctrl[0]);
		if (err < 0)
			return err;
	}

	rx8010->ctrlreg = (ctrl[1] & ~RX8010_CTRL_TEST);

	return err;
}

static int rx8010_read_alarm(struct device *dev, struct rtc_wkalrm *t)
{
	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
	struct i2c_client *client = rx8010->client;
	u8 alarmvals[3];
	int flagreg;
	int err;

	err = i2c_smbus_read_i2c_block_data(client, RX8010_ALMIN, 3, alarmvals);
	if (err != 3)
		return err < 0 ? err : -EIO;

	flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);
	if (flagreg < 0)
		return flagreg;

	t->time.tm_sec = 0;
	t->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);
	t->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);

	if (alarmvals[2] & RX8010_ALARM_AE)
		t->time.tm_mday = -1;
	else
		t->time.tm_mday = bcd2bin(alarmvals[2] & 0x7f);

	t->time.tm_wday = -1;
	t->time.tm_mon = -1;
	t->time.tm_year = -1;

	t->enabled = !!(rx8010->ctrlreg & RX8010_CTRL_AIE);
	t->pending = (flagreg & RX8010_FLAG_AF) && t->enabled;

	return err;
}

static int rx8010_set_alarm(struct device *dev, struct rtc_wkalrm *t)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
	u8 alarmvals[3];
	int extreg, flagreg;
	int err;
	unsigned long irqflags;

	spin_lock_irqsave(&rx8010->flags_lock, irqflags);
	flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);
	if (flagreg < 0) {
		spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
		return flagreg;
	}

	if (rx8010->ctrlreg & (RX8010_CTRL_AIE | RX8010_CTRL_UIE)) {
		rx8010->ctrlreg &= ~(RX8010_CTRL_AIE | RX8010_CTRL_UIE);
		err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
						rx8010->ctrlreg);
		if (err < 0) {
			spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
			return err;
		}
	}

	flagreg &= ~RX8010_FLAG_AF;
	err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, flagreg);
	spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
	if (err < 0)
		return err;

	alarmvals[0] = bin2bcd(t->time.tm_min);
	alarmvals[1] = bin2bcd(t->time.tm_hour);
	alarmvals[2] = bin2bcd(t->time.tm_mday);

	err = i2c_smbus_write_i2c_block_data(rx8010->client, RX8010_ALMIN,
					     2, alarmvals);
	if (err < 0)
		return err;

	extreg = i2c_smbus_read_byte_data(client, RX8010_EXT);
	if (extreg < 0)
		return extreg;

	extreg |= RX8010_EXT_WADA;
	err = i2c_smbus_write_byte_data(rx8010->client, RX8010_EXT, extreg);
	if (err < 0)
		return err;

	if (alarmvals[2] == 0)
		alarmvals[2] |= RX8010_ALARM_AE;

	err = i2c_smbus_write_byte_data(rx8010->client, RX8010_ALWDAY,
					alarmvals[2]);
	if (err < 0)
		return err;

	if (t->enabled) {
		if (rx8010->rtc->uie_rtctimer.enabled)
			rx8010->ctrlreg |= RX8010_CTRL_UIE;
		if (rx8010->rtc->aie_timer.enabled)
			rx8010->ctrlreg |=
				(RX8010_CTRL_AIE | RX8010_CTRL_UIE);

		err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
						rx8010->ctrlreg);
		if (err < 0)
			return err;
	}

	return 0;
}

static int rx8010_alarm_irq_enable(struct device *dev,
				   unsigned int enabled)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
	int flagreg;
	u8 ctrl;
	int err;

	ctrl = rx8010->ctrlreg;

	if (enabled) {
		if (rx8010->rtc->uie_rtctimer.enabled)
			ctrl |= RX8010_CTRL_UIE;
		if (rx8010->rtc->aie_timer.enabled)
			ctrl |= (RX8010_CTRL_AIE | RX8010_CTRL_UIE);
	} else {
		if (!rx8010->rtc->uie_rtctimer.enabled)
			ctrl &= ~RX8010_CTRL_UIE;
		if (!rx8010->rtc->aie_timer.enabled)
			ctrl &= ~RX8010_CTRL_AIE;
	}

	flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);
	if (flagreg < 0)
		return flagreg;

	flagreg &= ~RX8010_FLAG_AF;
	err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, flagreg);
	if (err < 0)
		return err;

	if (ctrl != rx8010->ctrlreg) {
		rx8010->ctrlreg = ctrl;
		err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
						rx8010->ctrlreg);
		if (err < 0)
			return err;
	}

	return 0;
}

static int rx8010_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
	int ret, tmp;
	int flagreg;
	unsigned long irqflags;

	switch (cmd) {
	case RTC_VL_READ:
		flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
		if (flagreg < 0)
			return flagreg;

		tmp = !!(flagreg & RX8010_FLAG_VLF);
		if (copy_to_user((void __user *)arg, &tmp, sizeof(int)))
			return -EFAULT;

		return 0;

	case RTC_VL_CLR:
		spin_lock_irqsave(&rx8010->flags_lock, irqflags);
		flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
		if (flagreg < 0) {
			spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
			return flagreg;
		}

		flagreg &= ~RX8010_FLAG_VLF;
		ret = i2c_smbus_write_byte_data(client, RX8010_FLAG, flagreg);
		spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
		if (ret < 0)
			return ret;

		return 0;

	default:
		return -ENOIOCTLCMD;
	}
}

static struct rtc_class_ops rx8010_rtc_ops = {
	.read_time = rx8010_get_time,
	.set_time = rx8010_set_time,
	.ioctl = rx8010_ioctl,
};

static int rx8010_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
	struct rx8010_data *rx8010;
	int err = 0;

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
		| I2C_FUNC_SMBUS_I2C_BLOCK)) {
		dev_err(&adapter->dev, "doesn't support required functionality\n");
		return -EIO;
	}

	rx8010 = devm_kzalloc(&client->dev, sizeof(struct rx8010_data),
			      GFP_KERNEL);
	if (!rx8010)
		return -ENOMEM;

	rx8010->client = client;
	i2c_set_clientdata(client, rx8010);

	spin_lock_init(&rx8010->flags_lock);

	err = rx8010_init_client(client);
	if (err)
		return err;

	if (client->irq > 0) {
		dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
		err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
						rx8010_irq_1_handler,
						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
						"rx8010", client);

		if (err) {
			dev_err(&client->dev, "unable to request IRQ\n");
			client->irq = 0;
		} else {
			rx8010_rtc_ops.read_alarm = rx8010_read_alarm;
			rx8010_rtc_ops.set_alarm = rx8010_set_alarm;
			rx8010_rtc_ops.alarm_irq_enable = rx8010_alarm_irq_enable;
		}
	}

	rx8010->rtc = devm_rtc_device_register(&client->dev, client->name,
		&rx8010_rtc_ops, THIS_MODULE);

	if (IS_ERR(rx8010->rtc)) {
		dev_err(&client->dev, "unable to register the class device\n");
		return PTR_ERR(rx8010->rtc);
	}

	rx8010->rtc->max_user_freq = 1;

	return err;
}

static struct i2c_driver rx8010_driver = {
	.driver = {
		.name = "rtc-rx8010",
	},
	.probe		= rx8010_probe,
	.id_table	= rx8010_id,
};

module_i2c_driver(rx8010_driver);

MODULE_AUTHOR("Akshay Bhat <akshay.bhat@timesys.com>");
MODULE_DESCRIPTION("Epson RX8010SJ RTC driver");
MODULE_LICENSE("GPL v2");