1// SPDX-License-Identifier: GPL-2.0
2/*
3 * RTC driver for the Micro Crystal RV8803
4 *
5 * Copyright (C) 2015 Micro Crystal SA
6 * Alexandre Belloni <alexandre.belloni@bootlin.com>
7 *
8 */
9
10#include <linux/bcd.h>
11#include <linux/bitops.h>
12#include <linux/bitfield.h>
13#include <linux/log2.h>
14#include <linux/i2c.h>
15#include <linux/interrupt.h>
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/of.h>
19#include <linux/rtc.h>
20
21#define RV8803_I2C_TRY_COUNT		4
22
23#define RV8803_SEC			0x00
24#define RV8803_MIN			0x01
25#define RV8803_HOUR			0x02
26#define RV8803_WEEK			0x03
27#define RV8803_DAY			0x04
28#define RV8803_MONTH			0x05
29#define RV8803_YEAR			0x06
30#define RV8803_RAM			0x07
31#define RV8803_ALARM_MIN		0x08
32#define RV8803_ALARM_HOUR		0x09
33#define RV8803_ALARM_WEEK_OR_DAY	0x0A
34#define RV8803_EXT			0x0D
35#define RV8803_FLAG			0x0E
36#define RV8803_CTRL			0x0F
37#define RV8803_OSC_OFFSET		0x2C
38
39#define RV8803_EXT_WADA			BIT(6)
40
41#define RV8803_FLAG_V1F			BIT(0)
42#define RV8803_FLAG_V2F			BIT(1)
43#define RV8803_FLAG_AF			BIT(3)
44#define RV8803_FLAG_TF			BIT(4)
45#define RV8803_FLAG_UF			BIT(5)
46
47#define RV8803_CTRL_RESET		BIT(0)
48
49#define RV8803_CTRL_EIE			BIT(2)
50#define RV8803_CTRL_AIE			BIT(3)
51#define RV8803_CTRL_TIE			BIT(4)
52#define RV8803_CTRL_UIE			BIT(5)
53
54#define RX8803_CTRL_CSEL		GENMASK(7, 6)
55
56#define RX8900_BACKUP_CTRL		0x18
57#define RX8900_FLAG_SWOFF		BIT(2)
58#define RX8900_FLAG_VDETOFF		BIT(3)
59
60enum rv8803_type {
61	rv_8803,
62	rx_8803,
63	rx_8804,
64	rx_8900
65};
66
67struct rv8803_data {
68	struct i2c_client *client;
69	struct rtc_device *rtc;
70	struct mutex flags_lock;
71	u8 ctrl;
72	u8 backup;
73	u8 alarm_invalid:1;
74	enum rv8803_type type;
75};
76
77static int rv8803_read_reg(const struct i2c_client *client, u8 reg)
78{
79	int try = RV8803_I2C_TRY_COUNT;
80	s32 ret;
81
82	/*
83	 * There is a 61µs window during which the RTC does not acknowledge I2C
84	 * transfers. In that case, ensure that there are multiple attempts.
85	 */
86	do
87		ret = i2c_smbus_read_byte_data(client, reg);
88	while ((ret == -ENXIO || ret == -EIO) && --try);
89	if (ret < 0)
90		dev_err(&client->dev, "Unable to read register 0x%02x\n", reg);
91
92	return ret;
93}
94
95static int rv8803_read_regs(const struct i2c_client *client,
96			    u8 reg, u8 count, u8 *values)
97{
98	int try = RV8803_I2C_TRY_COUNT;
99	s32 ret;
100
101	do
102		ret = i2c_smbus_read_i2c_block_data(client, reg, count, values);
103	while ((ret == -ENXIO || ret == -EIO) && --try);
104	if (ret != count) {
105		dev_err(&client->dev,
106			"Unable to read registers 0x%02x..0x%02x\n",
107			reg, reg + count - 1);
108		return ret < 0 ? ret : -EIO;
109	}
110
111	return 0;
112}
113
114static int rv8803_write_reg(const struct i2c_client *client, u8 reg, u8 value)
115{
116	int try = RV8803_I2C_TRY_COUNT;
117	s32 ret;
118
119	do
120		ret = i2c_smbus_write_byte_data(client, reg, value);
121	while ((ret == -ENXIO || ret == -EIO) && --try);
122	if (ret)
123		dev_err(&client->dev, "Unable to write register 0x%02x\n", reg);
124
125	return ret;
126}
127
128static int rv8803_write_regs(const struct i2c_client *client,
129			     u8 reg, u8 count, const u8 *values)
130{
131	int try = RV8803_I2C_TRY_COUNT;
132	s32 ret;
133
134	do
135		ret = i2c_smbus_write_i2c_block_data(client, reg, count,
136						     values);
137	while ((ret == -ENXIO || ret == -EIO) && --try);
138	if (ret)
139		dev_err(&client->dev,
140			"Unable to write registers 0x%02x..0x%02x\n",
141			reg, reg + count - 1);
142
143	return ret;
144}
145
146static int rv8803_regs_init(struct rv8803_data *rv8803)
147{
148	int ret;
149
150	ret = rv8803_write_reg(rv8803->client, RV8803_OSC_OFFSET, 0x00);
151	if (ret)
152		return ret;
153
154	ret = rv8803_write_reg(rv8803->client, RV8803_CTRL,
155			       FIELD_PREP(RX8803_CTRL_CSEL, 1)); /* 2s */
156	if (ret)
157		return ret;
158
159	ret = rv8803_write_regs(rv8803->client, RV8803_ALARM_MIN, 3,
160				(u8[]){ 0, 0, 0 });
161	if (ret)
162		return ret;
163
164	return rv8803_write_reg(rv8803->client, RV8803_RAM, 0x00);
165}
166
167static int rv8803_regs_configure(struct rv8803_data *rv8803);
168
169static int rv8803_regs_reset(struct rv8803_data *rv8803, bool full)
170{
171	/*
172	 * The RV-8803 resets all registers to POR defaults after voltage-loss,
173	 * the Epson RTCs don't, so we manually reset the remainder here.
174	 */
175	if (full || rv8803->type == rx_8803 || rv8803->type == rx_8900) {
176		int ret = rv8803_regs_init(rv8803);
177		if (ret)
178			return ret;
179	}
180
181	return rv8803_regs_configure(rv8803);
182}
183
184static irqreturn_t rv8803_handle_irq(int irq, void *dev_id)
185{
186	struct i2c_client *client = dev_id;
187	struct rv8803_data *rv8803 = i2c_get_clientdata(client);
188	unsigned long events = 0;
189	int flags;
190
191	mutex_lock(&rv8803->flags_lock);
192
193	flags = rv8803_read_reg(client, RV8803_FLAG);
194	if (flags <= 0) {
195		mutex_unlock(&rv8803->flags_lock);
196		return IRQ_NONE;
197	}
198
199	if (flags & RV8803_FLAG_V1F)
200		dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
201
202	if (flags & RV8803_FLAG_V2F)
203		dev_warn(&client->dev, "Voltage low, data loss detected.\n");
204
205	if (flags & RV8803_FLAG_TF) {
206		flags &= ~RV8803_FLAG_TF;
207		rv8803->ctrl &= ~RV8803_CTRL_TIE;
208		events |= RTC_PF;
209	}
210
211	if (flags & RV8803_FLAG_AF) {
212		flags &= ~RV8803_FLAG_AF;
213		rv8803->ctrl &= ~RV8803_CTRL_AIE;
214		events |= RTC_AF;
215	}
216
217	if (flags & RV8803_FLAG_UF) {
218		flags &= ~RV8803_FLAG_UF;
219		rv8803->ctrl &= ~RV8803_CTRL_UIE;
220		events |= RTC_UF;
221	}
222
223	if (events) {
224		rtc_update_irq(rv8803->rtc, 1, events);
225		rv8803_write_reg(client, RV8803_FLAG, flags);
226		rv8803_write_reg(rv8803->client, RV8803_CTRL, rv8803->ctrl);
227	}
228
229	mutex_unlock(&rv8803->flags_lock);
230
231	return IRQ_HANDLED;
232}
233
234static int rv8803_get_time(struct device *dev, struct rtc_time *tm)
235{
236	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
237	u8 date1[7];
238	u8 date2[7];
239	u8 *date = date1;
240	int ret, flags;
241
242	if (rv8803->alarm_invalid) {
243		dev_warn(dev, "Corruption detected, data may be invalid.\n");
244		return -EINVAL;
245	}
246
247	flags = rv8803_read_reg(rv8803->client, RV8803_FLAG);
248	if (flags < 0)
249		return flags;
250
251	if (flags & RV8803_FLAG_V2F) {
252		dev_warn(dev, "Voltage low, data is invalid.\n");
253		return -EINVAL;
254	}
255
256	ret = rv8803_read_regs(rv8803->client, RV8803_SEC, 7, date);
257	if (ret)
258		return ret;
259
260	if ((date1[RV8803_SEC] & 0x7f) == bin2bcd(59)) {
261		ret = rv8803_read_regs(rv8803->client, RV8803_SEC, 7, date2);
262		if (ret)
263			return ret;
264
265		if ((date2[RV8803_SEC] & 0x7f) != bin2bcd(59))
266			date = date2;
267	}
268
269	tm->tm_sec  = bcd2bin(date[RV8803_SEC] & 0x7f);
270	tm->tm_min  = bcd2bin(date[RV8803_MIN] & 0x7f);
271	tm->tm_hour = bcd2bin(date[RV8803_HOUR] & 0x3f);
272	tm->tm_wday = ilog2(date[RV8803_WEEK] & 0x7f);
273	tm->tm_mday = bcd2bin(date[RV8803_DAY] & 0x3f);
274	tm->tm_mon  = bcd2bin(date[RV8803_MONTH] & 0x1f) - 1;
275	tm->tm_year = bcd2bin(date[RV8803_YEAR]) + 100;
276
277	return 0;
278}
279
280static int rv8803_set_time(struct device *dev, struct rtc_time *tm)
281{
282	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
283	u8 date[7];
284	int ctrl, flags, ret;
285
286	ctrl = rv8803_read_reg(rv8803->client, RV8803_CTRL);
287	if (ctrl < 0)
288		return ctrl;
289
290	/* Stop the clock */
291	ret = rv8803_write_reg(rv8803->client, RV8803_CTRL,
292			       ctrl | RV8803_CTRL_RESET);
293	if (ret)
294		return ret;
295
296	date[RV8803_SEC]   = bin2bcd(tm->tm_sec);
297	date[RV8803_MIN]   = bin2bcd(tm->tm_min);
298	date[RV8803_HOUR]  = bin2bcd(tm->tm_hour);
299	date[RV8803_WEEK]  = 1 << (tm->tm_wday);
300	date[RV8803_DAY]   = bin2bcd(tm->tm_mday);
301	date[RV8803_MONTH] = bin2bcd(tm->tm_mon + 1);
302	date[RV8803_YEAR]  = bin2bcd(tm->tm_year - 100);
303
304	ret = rv8803_write_regs(rv8803->client, RV8803_SEC, 7, date);
305	if (ret)
306		return ret;
307
308	/* Restart the clock */
309	ret = rv8803_write_reg(rv8803->client, RV8803_CTRL,
310			       ctrl & ~RV8803_CTRL_RESET);
311	if (ret)
312		return ret;
313
314	mutex_lock(&rv8803->flags_lock);
315
316	flags = rv8803_read_reg(rv8803->client, RV8803_FLAG);
317	if (flags < 0) {
318		mutex_unlock(&rv8803->flags_lock);
319		return flags;
320	}
321
322	if ((flags & RV8803_FLAG_V2F) || rv8803->alarm_invalid) {
323		/*
324		 * If we sense corruption in the alarm registers, but see no
325		 * voltage loss flag, we can't rely on other registers having
326		 * sensible values. Reset them fully.
327		 */
328		ret = rv8803_regs_reset(rv8803, rv8803->alarm_invalid);
329		if (ret) {
330			mutex_unlock(&rv8803->flags_lock);
331			return ret;
332		}
333
334		rv8803->alarm_invalid = false;
335	}
336
337	ret = rv8803_write_reg(rv8803->client, RV8803_FLAG,
338			       flags & ~(RV8803_FLAG_V1F | RV8803_FLAG_V2F));
339
340	mutex_unlock(&rv8803->flags_lock);
341
342	return ret;
343}
344
345static int rv8803_get_alarm(struct device *dev, struct rtc_wkalrm *alrm)
346{
347	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
348	struct i2c_client *client = rv8803->client;
349	u8 alarmvals[3];
350	int flags, ret;
351
352	ret = rv8803_read_regs(client, RV8803_ALARM_MIN, 3, alarmvals);
353	if (ret)
354		return ret;
355
356	flags = rv8803_read_reg(client, RV8803_FLAG);
357	if (flags < 0)
358		return flags;
359
360	alarmvals[0] &= 0x7f;
361	alarmvals[1] &= 0x3f;
362	alarmvals[2] &= 0x3f;
363
364	if (!bcd_is_valid(alarmvals[0]) ||
365	    !bcd_is_valid(alarmvals[1]) ||
366	    !bcd_is_valid(alarmvals[2]))
367		goto err_invalid;
368
369	alrm->time.tm_sec  = 0;
370	alrm->time.tm_min  = bcd2bin(alarmvals[0]);
371	alrm->time.tm_hour = bcd2bin(alarmvals[1]);
372	alrm->time.tm_mday = bcd2bin(alarmvals[2]);
373
374	alrm->enabled = !!(rv8803->ctrl & RV8803_CTRL_AIE);
375	alrm->pending = (flags & RV8803_FLAG_AF) && alrm->enabled;
376
377	if ((unsigned int)alrm->time.tm_mday > 31 ||
378	    (unsigned int)alrm->time.tm_hour >= 24 ||
379	    (unsigned int)alrm->time.tm_min >= 60)
380		goto err_invalid;
381
382	return 0;
383
384err_invalid:
385	rv8803->alarm_invalid = true;
386	return -EINVAL;
387}
388
389static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
390{
391	struct i2c_client *client = to_i2c_client(dev);
392	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
393	u8 alarmvals[3];
394	u8 ctrl[2];
395	int ret, err;
396
397	/* The alarm has no seconds, round up to nearest minute */
398	if (alrm->time.tm_sec) {
399		time64_t alarm_time = rtc_tm_to_time64(&alrm->time);
400
401		alarm_time += 60 - alrm->time.tm_sec;
402		rtc_time64_to_tm(alarm_time, &alrm->time);
403	}
404
405	mutex_lock(&rv8803->flags_lock);
406
407	ret = rv8803_read_regs(client, RV8803_FLAG, 2, ctrl);
408	if (ret) {
409		mutex_unlock(&rv8803->flags_lock);
410		return ret;
411	}
412
413	alarmvals[0] = bin2bcd(alrm->time.tm_min);
414	alarmvals[1] = bin2bcd(alrm->time.tm_hour);
415	alarmvals[2] = bin2bcd(alrm->time.tm_mday);
416
417	if (rv8803->ctrl & (RV8803_CTRL_AIE | RV8803_CTRL_UIE)) {
418		rv8803->ctrl &= ~(RV8803_CTRL_AIE | RV8803_CTRL_UIE);
419		err = rv8803_write_reg(rv8803->client, RV8803_CTRL,
420				       rv8803->ctrl);
421		if (err) {
422			mutex_unlock(&rv8803->flags_lock);
423			return err;
424		}
425	}
426
427	ctrl[0] &= ~RV8803_FLAG_AF;
428	err = rv8803_write_reg(rv8803->client, RV8803_FLAG, ctrl[0]);
429	mutex_unlock(&rv8803->flags_lock);
430	if (err)
431		return err;
432
433	err = rv8803_write_regs(rv8803->client, RV8803_ALARM_MIN, 3, alarmvals);
434	if (err)
435		return err;
436
437	if (alrm->enabled) {
438		if (rv8803->rtc->uie_rtctimer.enabled)
439			rv8803->ctrl |= RV8803_CTRL_UIE;
440		if (rv8803->rtc->aie_timer.enabled)
441			rv8803->ctrl |= RV8803_CTRL_AIE;
442
443		err = rv8803_write_reg(rv8803->client, RV8803_CTRL,
444				       rv8803->ctrl);
445		if (err)
446			return err;
447	}
448
449	return 0;
450}
451
452static int rv8803_alarm_irq_enable(struct device *dev, unsigned int enabled)
453{
454	struct i2c_client *client = to_i2c_client(dev);
455	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
456	int ctrl, flags, err;
457
458	ctrl = rv8803->ctrl;
459
460	if (enabled) {
461		if (rv8803->rtc->uie_rtctimer.enabled)
462			ctrl |= RV8803_CTRL_UIE;
463		if (rv8803->rtc->aie_timer.enabled)
464			ctrl |= RV8803_CTRL_AIE;
465	} else {
466		if (!rv8803->rtc->uie_rtctimer.enabled)
467			ctrl &= ~RV8803_CTRL_UIE;
468		if (!rv8803->rtc->aie_timer.enabled)
469			ctrl &= ~RV8803_CTRL_AIE;
470	}
471
472	mutex_lock(&rv8803->flags_lock);
473	flags = rv8803_read_reg(client, RV8803_FLAG);
474	if (flags < 0) {
475		mutex_unlock(&rv8803->flags_lock);
476		return flags;
477	}
478	flags &= ~(RV8803_FLAG_AF | RV8803_FLAG_UF);
479	err = rv8803_write_reg(client, RV8803_FLAG, flags);
480	mutex_unlock(&rv8803->flags_lock);
481	if (err)
482		return err;
483
484	if (ctrl != rv8803->ctrl) {
485		rv8803->ctrl = ctrl;
486		err = rv8803_write_reg(client, RV8803_CTRL, rv8803->ctrl);
487		if (err)
488			return err;
489	}
490
491	return 0;
492}
493
494static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
495{
496	struct i2c_client *client = to_i2c_client(dev);
497	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
498	unsigned int vl = 0;
499	int flags, ret = 0;
500
501	switch (cmd) {
502	case RTC_VL_READ:
503		flags = rv8803_read_reg(client, RV8803_FLAG);
504		if (flags < 0)
505			return flags;
506
507		if (flags & RV8803_FLAG_V1F) {
508			dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
509			vl = RTC_VL_ACCURACY_LOW;
510		}
511
512		if (flags & RV8803_FLAG_V2F)
513			vl |= RTC_VL_DATA_INVALID;
514
515		return put_user(vl, (unsigned int __user *)arg);
516
517	case RTC_VL_CLR:
518		mutex_lock(&rv8803->flags_lock);
519		flags = rv8803_read_reg(client, RV8803_FLAG);
520		if (flags < 0) {
521			mutex_unlock(&rv8803->flags_lock);
522			return flags;
523		}
524
525		flags &= ~RV8803_FLAG_V1F;
526		ret = rv8803_write_reg(client, RV8803_FLAG, flags);
527		mutex_unlock(&rv8803->flags_lock);
528		if (ret)
529			return ret;
530
531		return 0;
532
533	default:
534		return -ENOIOCTLCMD;
535	}
536}
537
538static int rv8803_nvram_write(void *priv, unsigned int offset, void *val,
539			      size_t bytes)
540{
541	return rv8803_write_reg(priv, RV8803_RAM, *(u8 *)val);
542}
543
544static int rv8803_nvram_read(void *priv, unsigned int offset,
545			     void *val, size_t bytes)
546{
547	int ret;
548
549	ret = rv8803_read_reg(priv, RV8803_RAM);
550	if (ret < 0)
551		return ret;
552
553	*(u8 *)val = ret;
554
555	return 0;
556}
557
558static const struct rtc_class_ops rv8803_rtc_ops = {
559	.read_time = rv8803_get_time,
560	.set_time = rv8803_set_time,
561	.ioctl = rv8803_ioctl,
562	.read_alarm = rv8803_get_alarm,
563	.set_alarm = rv8803_set_alarm,
564	.alarm_irq_enable = rv8803_alarm_irq_enable,
565};
566
567static int rx8900_trickle_charger_init(struct rv8803_data *rv8803)
568{
569	struct i2c_client *client = rv8803->client;
570	struct device_node *node = client->dev.of_node;
571	int err;
572	u8 flags;
573
574	if (!node)
575		return 0;
576
577	if (rv8803->type != rx_8900)
578		return 0;
579
580	err = i2c_smbus_read_byte_data(rv8803->client, RX8900_BACKUP_CTRL);
581	if (err < 0)
582		return err;
583
584	flags = (u8)err;
585	flags &= ~(RX8900_FLAG_VDETOFF | RX8900_FLAG_SWOFF);
586	flags |= rv8803->backup;
587
588	return i2c_smbus_write_byte_data(rv8803->client, RX8900_BACKUP_CTRL,
589					 flags);
590}
591
592/* configure registers with values different than the Power-On reset defaults */
593static int rv8803_regs_configure(struct rv8803_data *rv8803)
594{
595	int err;
596
597	err = rv8803_write_reg(rv8803->client, RV8803_EXT, RV8803_EXT_WADA);
598	if (err)
599		return err;
600
601	err = rx8900_trickle_charger_init(rv8803);
602	if (err) {
603		dev_err(&rv8803->client->dev, "failed to init charger\n");
604		return err;
605	}
606
607	return 0;
608}
609
610static const struct i2c_device_id rv8803_id[] = {
611	{ "rv8803", rv_8803 },
612	{ "rv8804", rx_8804 },
613	{ "rx8803", rx_8803 },
614	{ "rx8900", rx_8900 },
615	{ }
616};
617MODULE_DEVICE_TABLE(i2c, rv8803_id);
618
619static int rv8803_probe(struct i2c_client *client)
620{
621	struct i2c_adapter *adapter = client->adapter;
622	struct rv8803_data *rv8803;
623	int err, flags;
624	struct nvmem_config nvmem_cfg = {
625		.name = "rv8803_nvram",
626		.word_size = 1,
627		.stride = 1,
628		.size = 1,
629		.reg_read = rv8803_nvram_read,
630		.reg_write = rv8803_nvram_write,
631		.priv = client,
632	};
633
634	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
635				     I2C_FUNC_SMBUS_I2C_BLOCK)) {
636		dev_err(&adapter->dev, "doesn't support I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK\n");
637		return -EIO;
638	}
639
640	rv8803 = devm_kzalloc(&client->dev, sizeof(struct rv8803_data),
641			      GFP_KERNEL);
642	if (!rv8803)
643		return -ENOMEM;
644
645	mutex_init(&rv8803->flags_lock);
646	rv8803->client = client;
647	if (client->dev.of_node) {
648		rv8803->type = (uintptr_t)of_device_get_match_data(&client->dev);
649	} else {
650		const struct i2c_device_id *id = i2c_match_id(rv8803_id, client);
651
652		rv8803->type = id->driver_data;
653	}
654	i2c_set_clientdata(client, rv8803);
655
656	flags = rv8803_read_reg(client, RV8803_FLAG);
657	if (flags < 0)
658		return flags;
659
660	if (flags & RV8803_FLAG_V1F)
661		dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
662
663	if (flags & RV8803_FLAG_V2F)
664		dev_warn(&client->dev, "Voltage low, data loss detected.\n");
665
666	if (flags & RV8803_FLAG_AF)
667		dev_warn(&client->dev, "An alarm maybe have been missed.\n");
668
669	rv8803->rtc = devm_rtc_allocate_device(&client->dev);
670	if (IS_ERR(rv8803->rtc))
671		return PTR_ERR(rv8803->rtc);
672
673	if (client->irq > 0) {
674		unsigned long irqflags = IRQF_TRIGGER_LOW;
675
676		if (dev_fwnode(&client->dev))
677			irqflags = 0;
678
679		err = devm_request_threaded_irq(&client->dev, client->irq,
680						NULL, rv8803_handle_irq,
681						irqflags | IRQF_ONESHOT,
682						"rv8803", client);
683		if (err) {
684			dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
685			client->irq = 0;
686		}
687	}
688	if (!client->irq)
689		clear_bit(RTC_FEATURE_ALARM, rv8803->rtc->features);
690
691	if (of_property_read_bool(client->dev.of_node, "epson,vdet-disable"))
692		rv8803->backup |= RX8900_FLAG_VDETOFF;
693
694	if (of_property_read_bool(client->dev.of_node, "trickle-diode-disable"))
695		rv8803->backup |= RX8900_FLAG_SWOFF;
696
697	err = rv8803_regs_configure(rv8803);
698	if (err)
699		return err;
700
701	rv8803->rtc->ops = &rv8803_rtc_ops;
702	rv8803->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
703	rv8803->rtc->range_max = RTC_TIMESTAMP_END_2099;
704	err = devm_rtc_register_device(rv8803->rtc);
705	if (err)
706		return err;
707
708	devm_rtc_nvmem_register(rv8803->rtc, &nvmem_cfg);
709
710	rv8803->rtc->max_user_freq = 1;
711
712	return 0;
713}
714
715static const __maybe_unused struct of_device_id rv8803_of_match[] = {
716	{
717		.compatible = "microcrystal,rv8803",
718		.data = (void *)rv_8803
719	},
720	{
721		.compatible = "epson,rx8803",
722		.data = (void *)rx_8803
723	},
724	{
725		.compatible = "epson,rx8804",
726		.data = (void *)rx_8804
727	},
728	{
729		.compatible = "epson,rx8900",
730		.data = (void *)rx_8900
731	},
732	{ }
733};
734MODULE_DEVICE_TABLE(of, rv8803_of_match);
735
736static struct i2c_driver rv8803_driver = {
737	.driver = {
738		.name = "rtc-rv8803",
739		.of_match_table = of_match_ptr(rv8803_of_match),
740	},
741	.probe		= rv8803_probe,
742	.id_table	= rv8803_id,
743};
744module_i2c_driver(rv8803_driver);
745
746MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
747MODULE_DESCRIPTION("Micro Crystal RV8803 RTC driver");
748MODULE_LICENSE("GPL v2");
749