summaryrefslogtreecommitdiff
path: root/drivers/rtc/rtc-rx8010.c
blob: 8340ab47a05976e123f6ea643876dd7def9fc5c1 (plain) (blame)
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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Driver for the Epson RTC module RX-8010 SJ
 *
 * Copyright(C) Timesys Corporation 2015
 * Copyright(C) General Electric Company 2015
 */

#include <linux/bcd.h>
#include <linux/bitops.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/regmap.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_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		0x31
#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);

static const struct of_device_id rx8010_of_match[] = {
	{ .compatible = "epson,rx8010" },
	{ }
};
MODULE_DEVICE_TABLE(of, rx8010_of_match);

struct rx8010_data {
	struct regmap *regs;
	struct rtc_device *rtc;
	u8 ctrlreg;
};

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, err;

	mutex_lock(&rx8010->rtc->ops_lock);

	err = regmap_read(rx8010->regs, RX8010_FLAG, &flagreg);
	if (err) {
		mutex_unlock(&rx8010->rtc->ops_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);
	}

	err = regmap_write(rx8010->regs, RX8010_FLAG, flagreg);
	mutex_unlock(&rx8010->rtc->ops_lock);
	return err ? IRQ_NONE : IRQ_HANDLED;
}

static int rx8010_get_time(struct device *dev, struct rtc_time *dt)
{
	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
	u8 date[RX8010_YEAR - RX8010_SEC + 1];
	int flagreg, err;

	err = regmap_read(rx8010->regs, RX8010_FLAG, &flagreg);
	if (err)
		return err;

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

	err = regmap_bulk_read(rx8010->regs, RX8010_SEC, date, sizeof(date));
	if (err)
		return err;

	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 0;
}

static int rx8010_set_time(struct device *dev, struct rtc_time *dt)
{
	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
	u8 date[RX8010_YEAR - RX8010_SEC + 1];
	int err;

	/* set STOP bit before changing clock/calendar */
	err = regmap_set_bits(rx8010->regs, RX8010_CTRL, RX8010_CTRL_STOP);
	if (err)
		return err;

	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);

	err = regmap_bulk_write(rx8010->regs, RX8010_SEC, date, sizeof(date));
	if (err)
		return err;

	/* clear STOP bit after changing clock/calendar */
	err = regmap_clear_bits(rx8010->regs, RX8010_CTRL, RX8010_CTRL_STOP);
	if (err)
		return err;

	err = regmap_clear_bits(rx8010->regs, RX8010_FLAG, RX8010_FLAG_VLF);
	if (err)
		return err;

	return 0;
}

static int rx8010_init(struct device *dev)
{
	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
	u8 ctrl[2];
	int need_clear = 0, err;

	/* Initialize reserved registers as specified in datasheet */
	err = regmap_write(rx8010->regs, RX8010_RESV17, 0xD8);
	if (err)
		return err;

	err = regmap_write(rx8010->regs, RX8010_RESV30, 0x00);
	if (err)
		return err;

	err = regmap_write(rx8010->regs, RX8010_RESV31, 0x08);
	if (err)
		return err;

	err = regmap_write(rx8010->regs, RX8010_IRQ, 0x00);
	if (err)
		return err;

	err = regmap_bulk_read(rx8010->regs, RX8010_FLAG, ctrl, 2);
	if (err)
		return err;

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

	if (ctrl[0] & RX8010_FLAG_AF) {
		dev_warn(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 = regmap_write(rx8010->regs, RX8010_FLAG, ctrl[0]);
		if (err)
			return err;
	}

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

	return 0;
}

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

	err = regmap_bulk_read(rx8010->regs, RX8010_ALMIN, alarmvals, 3);
	if (err)
		return err;

	err = regmap_read(rx8010->regs, RX8010_FLAG, &flagreg);
	if (err)
		return err;

	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 = bcd2bin(alarmvals[2] & 0x7f);

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

	return 0;
}

static int rx8010_set_alarm(struct device *dev, struct rtc_wkalrm *t)
{
	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
	u8 alarmvals[3];
	int err;

	if (rx8010->ctrlreg & (RX8010_CTRL_AIE | RX8010_CTRL_UIE)) {
		rx8010->ctrlreg &= ~(RX8010_CTRL_AIE | RX8010_CTRL_UIE);
		err = regmap_write(rx8010->regs, RX8010_CTRL, rx8010->ctrlreg);
		if (err)
			return err;
	}

	err = regmap_clear_bits(rx8010->regs, RX8010_FLAG, RX8010_FLAG_AF);
	if (err)
		return err;

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

	err = regmap_bulk_write(rx8010->regs, RX8010_ALMIN, alarmvals, 2);
	if (err)
		return err;

	err = regmap_clear_bits(rx8010->regs, RX8010_EXT, RX8010_EXT_WADA);
	if (err)
		return err;

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

	err = regmap_write(rx8010->regs, RX8010_ALWDAY, alarmvals[2]);
	if (err)
		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 = regmap_write(rx8010->regs, RX8010_CTRL, rx8010->ctrlreg);
		if (err)
			return err;
	}

	return 0;
}

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

	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;
	}

	err = regmap_clear_bits(rx8010->regs, RX8010_FLAG, RX8010_FLAG_AF);
	if (err)
		return err;

	if (ctrl != rx8010->ctrlreg) {
		rx8010->ctrlreg = ctrl;
		err = regmap_write(rx8010->regs, RX8010_CTRL, rx8010->ctrlreg);
		if (err)
			return err;
	}

	return 0;
}

static int rx8010_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
	int tmp, flagreg, err;

	switch (cmd) {
	case RTC_VL_READ:
		err = regmap_read(rx8010->regs, RX8010_FLAG, &flagreg);
		if (err)
			return err;

		tmp = flagreg & RX8010_FLAG_VLF ? RTC_VL_DATA_INVALID : 0;
		return put_user(tmp, (unsigned int __user *)arg);

	default:
		return -ENOIOCTLCMD;
	}
}

static const struct rtc_class_ops rx8010_rtc_ops_default = {
	.read_time = rx8010_get_time,
	.set_time = rx8010_set_time,
	.ioctl = rx8010_ioctl,
};

static const struct rtc_class_ops rx8010_rtc_ops_alarm = {
	.read_time = rx8010_get_time,
	.set_time = rx8010_set_time,
	.ioctl = rx8010_ioctl,
	.read_alarm = rx8010_read_alarm,
	.set_alarm = rx8010_set_alarm,
	.alarm_irq_enable = rx8010_alarm_irq_enable,
};

static const struct regmap_config rx8010_regmap_config = {
	.name = "rx8010-rtc",
	.reg_bits = 8,
	.val_bits = 8,
};

static int rx8010_probe(struct i2c_client *client)
{
	struct device *dev = &client->dev;
	struct rx8010_data *rx8010;
	int err = 0;

	rx8010 = devm_kzalloc(dev, sizeof(*rx8010), GFP_KERNEL);
	if (!rx8010)
		return -ENOMEM;

	i2c_set_clientdata(client, rx8010);

	rx8010->regs = devm_regmap_init_i2c(client, &rx8010_regmap_config);
	if (IS_ERR(rx8010->regs))
		return PTR_ERR(rx8010->regs);

	err = rx8010_init(dev);
	if (err)
		return err;

	rx8010->rtc = devm_rtc_allocate_device(dev);
	if (IS_ERR(rx8010->rtc))
		return PTR_ERR(rx8010->rtc);

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

		rx8010->rtc->ops = &rx8010_rtc_ops_alarm;
	} else {
		rx8010->rtc->ops = &rx8010_rtc_ops_default;
	}

	rx8010->rtc->max_user_freq = 1;
	rx8010->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
	rx8010->rtc->range_max = RTC_TIMESTAMP_END_2099;

	return devm_rtc_register_device(rx8010->rtc);
}

static struct i2c_driver rx8010_driver = {
	.driver = {
		.name = "rtc-rx8010",
		.of_match_table = of_match_ptr(rx8010_of_match),
	},
	.probe_new	= 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");