xref: /openbmc/linux/drivers/rtc/rtc-pcf8563.c (revision b8d312aa)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * An I2C driver for the Philips PCF8563 RTC
4  * Copyright 2005-06 Tower Technologies
5  *
6  * Author: Alessandro Zummo <a.zummo@towertech.it>
7  * Maintainers: http://www.nslu2-linux.org/
8  *
9  * based on the other drivers in this same directory.
10  *
11  * http://www.semiconductors.philips.com/acrobat/datasheets/PCF8563-04.pdf
12  */
13 
14 #include <linux/clk-provider.h>
15 #include <linux/i2c.h>
16 #include <linux/bcd.h>
17 #include <linux/rtc.h>
18 #include <linux/slab.h>
19 #include <linux/module.h>
20 #include <linux/of.h>
21 #include <linux/err.h>
22 
23 #define PCF8563_REG_ST1		0x00 /* status */
24 #define PCF8563_REG_ST2		0x01
25 #define PCF8563_BIT_AIE		(1 << 1)
26 #define PCF8563_BIT_AF		(1 << 3)
27 #define PCF8563_BITS_ST2_N	(7 << 5)
28 
29 #define PCF8563_REG_SC		0x02 /* datetime */
30 #define PCF8563_REG_MN		0x03
31 #define PCF8563_REG_HR		0x04
32 #define PCF8563_REG_DM		0x05
33 #define PCF8563_REG_DW		0x06
34 #define PCF8563_REG_MO		0x07
35 #define PCF8563_REG_YR		0x08
36 
37 #define PCF8563_REG_AMN		0x09 /* alarm */
38 
39 #define PCF8563_REG_CLKO		0x0D /* clock out */
40 #define PCF8563_REG_CLKO_FE		0x80 /* clock out enabled */
41 #define PCF8563_REG_CLKO_F_MASK		0x03 /* frequenc mask */
42 #define PCF8563_REG_CLKO_F_32768HZ	0x00
43 #define PCF8563_REG_CLKO_F_1024HZ	0x01
44 #define PCF8563_REG_CLKO_F_32HZ		0x02
45 #define PCF8563_REG_CLKO_F_1HZ		0x03
46 
47 #define PCF8563_REG_TMRC	0x0E /* timer control */
48 #define PCF8563_TMRC_ENABLE	BIT(7)
49 #define PCF8563_TMRC_4096	0
50 #define PCF8563_TMRC_64		1
51 #define PCF8563_TMRC_1		2
52 #define PCF8563_TMRC_1_60	3
53 #define PCF8563_TMRC_MASK	3
54 
55 #define PCF8563_REG_TMR		0x0F /* timer */
56 
57 #define PCF8563_SC_LV		0x80 /* low voltage */
58 #define PCF8563_MO_C		0x80 /* century */
59 
60 static struct i2c_driver pcf8563_driver;
61 
62 struct pcf8563 {
63 	struct rtc_device *rtc;
64 	/*
65 	 * The meaning of MO_C bit varies by the chip type.
66 	 * From PCF8563 datasheet: this bit is toggled when the years
67 	 * register overflows from 99 to 00
68 	 *   0 indicates the century is 20xx
69 	 *   1 indicates the century is 19xx
70 	 * From RTC8564 datasheet: this bit indicates change of
71 	 * century. When the year digit data overflows from 99 to 00,
72 	 * this bit is set. By presetting it to 0 while still in the
73 	 * 20th century, it will be set in year 2000, ...
74 	 * There seems no reliable way to know how the system use this
75 	 * bit.  So let's do it heuristically, assuming we are live in
76 	 * 1970...2069.
77 	 */
78 	int c_polarity;	/* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
79 	int voltage_low; /* incicates if a low_voltage was detected */
80 
81 	struct i2c_client *client;
82 #ifdef CONFIG_COMMON_CLK
83 	struct clk_hw		clkout_hw;
84 #endif
85 };
86 
87 static int pcf8563_read_block_data(struct i2c_client *client, unsigned char reg,
88 				   unsigned char length, unsigned char *buf)
89 {
90 	struct i2c_msg msgs[] = {
91 		{/* setup read ptr */
92 			.addr = client->addr,
93 			.len = 1,
94 			.buf = &reg,
95 		},
96 		{
97 			.addr = client->addr,
98 			.flags = I2C_M_RD,
99 			.len = length,
100 			.buf = buf
101 		},
102 	};
103 
104 	if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
105 		dev_err(&client->dev, "%s: read error\n", __func__);
106 		return -EIO;
107 	}
108 
109 	return 0;
110 }
111 
112 static int pcf8563_write_block_data(struct i2c_client *client,
113 				   unsigned char reg, unsigned char length,
114 				   unsigned char *buf)
115 {
116 	int i, err;
117 
118 	for (i = 0; i < length; i++) {
119 		unsigned char data[2] = { reg + i, buf[i] };
120 
121 		err = i2c_master_send(client, data, sizeof(data));
122 		if (err != sizeof(data)) {
123 			dev_err(&client->dev,
124 				"%s: err=%d addr=%02x, data=%02x\n",
125 				__func__, err, data[0], data[1]);
126 			return -EIO;
127 		}
128 	}
129 
130 	return 0;
131 }
132 
133 static int pcf8563_set_alarm_mode(struct i2c_client *client, bool on)
134 {
135 	unsigned char buf;
136 	int err;
137 
138 	err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
139 	if (err < 0)
140 		return err;
141 
142 	if (on)
143 		buf |= PCF8563_BIT_AIE;
144 	else
145 		buf &= ~PCF8563_BIT_AIE;
146 
147 	buf &= ~(PCF8563_BIT_AF | PCF8563_BITS_ST2_N);
148 
149 	err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf);
150 	if (err < 0) {
151 		dev_err(&client->dev, "%s: write error\n", __func__);
152 		return -EIO;
153 	}
154 
155 	return 0;
156 }
157 
158 static int pcf8563_get_alarm_mode(struct i2c_client *client, unsigned char *en,
159 				  unsigned char *pen)
160 {
161 	unsigned char buf;
162 	int err;
163 
164 	err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
165 	if (err)
166 		return err;
167 
168 	if (en)
169 		*en = !!(buf & PCF8563_BIT_AIE);
170 	if (pen)
171 		*pen = !!(buf & PCF8563_BIT_AF);
172 
173 	return 0;
174 }
175 
176 static irqreturn_t pcf8563_irq(int irq, void *dev_id)
177 {
178 	struct pcf8563 *pcf8563 = i2c_get_clientdata(dev_id);
179 	int err;
180 	char pending;
181 
182 	err = pcf8563_get_alarm_mode(pcf8563->client, NULL, &pending);
183 	if (err)
184 		return IRQ_NONE;
185 
186 	if (pending) {
187 		rtc_update_irq(pcf8563->rtc, 1, RTC_IRQF | RTC_AF);
188 		pcf8563_set_alarm_mode(pcf8563->client, 1);
189 		return IRQ_HANDLED;
190 	}
191 
192 	return IRQ_NONE;
193 }
194 
195 /*
196  * In the routines that deal directly with the pcf8563 hardware, we use
197  * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
198  */
199 static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm)
200 {
201 	struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
202 	unsigned char buf[9];
203 	int err;
204 
205 	err = pcf8563_read_block_data(client, PCF8563_REG_ST1, 9, buf);
206 	if (err)
207 		return err;
208 
209 	if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {
210 		pcf8563->voltage_low = 1;
211 		dev_err(&client->dev,
212 			"low voltage detected, date/time is not reliable.\n");
213 		return -EINVAL;
214 	}
215 
216 	dev_dbg(&client->dev,
217 		"%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
218 		"mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
219 		__func__,
220 		buf[0], buf[1], buf[2], buf[3],
221 		buf[4], buf[5], buf[6], buf[7],
222 		buf[8]);
223 
224 
225 	tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
226 	tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
227 	tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
228 	tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
229 	tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
230 	tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
231 	tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]);
232 	if (tm->tm_year < 70)
233 		tm->tm_year += 100;	/* assume we are in 1970...2069 */
234 	/* detect the polarity heuristically. see note above. */
235 	pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
236 		(tm->tm_year >= 100) : (tm->tm_year < 100);
237 
238 	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
239 		"mday=%d, mon=%d, year=%d, wday=%d\n",
240 		__func__,
241 		tm->tm_sec, tm->tm_min, tm->tm_hour,
242 		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
243 
244 	return 0;
245 }
246 
247 static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm)
248 {
249 	struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
250 	unsigned char buf[9];
251 
252 	dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
253 		"mday=%d, mon=%d, year=%d, wday=%d\n",
254 		__func__,
255 		tm->tm_sec, tm->tm_min, tm->tm_hour,
256 		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
257 
258 	/* hours, minutes and seconds */
259 	buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
260 	buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
261 	buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);
262 
263 	buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);
264 
265 	/* month, 1 - 12 */
266 	buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);
267 
268 	/* year and century */
269 	buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100);
270 	if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
271 		buf[PCF8563_REG_MO] |= PCF8563_MO_C;
272 
273 	buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;
274 
275 	return pcf8563_write_block_data(client, PCF8563_REG_SC,
276 				9 - PCF8563_REG_SC, buf + PCF8563_REG_SC);
277 }
278 
279 #ifdef CONFIG_RTC_INTF_DEV
280 static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
281 {
282 	struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev));
283 	struct rtc_time tm;
284 
285 	switch (cmd) {
286 	case RTC_VL_READ:
287 		if (pcf8563->voltage_low)
288 			dev_info(dev, "low voltage detected, date/time is not reliable.\n");
289 
290 		if (copy_to_user((void __user *)arg, &pcf8563->voltage_low,
291 					sizeof(int)))
292 			return -EFAULT;
293 		return 0;
294 	case RTC_VL_CLR:
295 		/*
296 		 * Clear the VL bit in the seconds register in case
297 		 * the time has not been set already (which would
298 		 * have cleared it). This does not really matter
299 		 * because of the cached voltage_low value but do it
300 		 * anyway for consistency.
301 		 */
302 		if (pcf8563_get_datetime(to_i2c_client(dev), &tm))
303 			pcf8563_set_datetime(to_i2c_client(dev), &tm);
304 
305 		/* Clear the cached value. */
306 		pcf8563->voltage_low = 0;
307 
308 		return 0;
309 	default:
310 		return -ENOIOCTLCMD;
311 	}
312 }
313 #else
314 #define pcf8563_rtc_ioctl NULL
315 #endif
316 
317 static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
318 {
319 	return pcf8563_get_datetime(to_i2c_client(dev), tm);
320 }
321 
322 static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
323 {
324 	return pcf8563_set_datetime(to_i2c_client(dev), tm);
325 }
326 
327 static int pcf8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
328 {
329 	struct i2c_client *client = to_i2c_client(dev);
330 	unsigned char buf[4];
331 	int err;
332 
333 	err = pcf8563_read_block_data(client, PCF8563_REG_AMN, 4, buf);
334 	if (err)
335 		return err;
336 
337 	dev_dbg(&client->dev,
338 		"%s: raw data is min=%02x, hr=%02x, mday=%02x, wday=%02x\n",
339 		__func__, buf[0], buf[1], buf[2], buf[3]);
340 
341 	tm->time.tm_sec = 0;
342 	tm->time.tm_min = bcd2bin(buf[0] & 0x7F);
343 	tm->time.tm_hour = bcd2bin(buf[1] & 0x3F);
344 	tm->time.tm_mday = bcd2bin(buf[2] & 0x3F);
345 	tm->time.tm_wday = bcd2bin(buf[3] & 0x7);
346 
347 	err = pcf8563_get_alarm_mode(client, &tm->enabled, &tm->pending);
348 	if (err < 0)
349 		return err;
350 
351 	dev_dbg(&client->dev, "%s: tm is mins=%d, hours=%d, mday=%d, wday=%d,"
352 		" enabled=%d, pending=%d\n", __func__, tm->time.tm_min,
353 		tm->time.tm_hour, tm->time.tm_mday, tm->time.tm_wday,
354 		tm->enabled, tm->pending);
355 
356 	return 0;
357 }
358 
359 static int pcf8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
360 {
361 	struct i2c_client *client = to_i2c_client(dev);
362 	unsigned char buf[4];
363 	int err;
364 
365 	/* The alarm has no seconds, round up to nearest minute */
366 	if (tm->time.tm_sec) {
367 		time64_t alarm_time = rtc_tm_to_time64(&tm->time);
368 
369 		alarm_time += 60 - tm->time.tm_sec;
370 		rtc_time64_to_tm(alarm_time, &tm->time);
371 	}
372 
373 	dev_dbg(dev, "%s, min=%d hour=%d wday=%d mday=%d "
374 		"enabled=%d pending=%d\n", __func__,
375 		tm->time.tm_min, tm->time.tm_hour, tm->time.tm_wday,
376 		tm->time.tm_mday, tm->enabled, tm->pending);
377 
378 	buf[0] = bin2bcd(tm->time.tm_min);
379 	buf[1] = bin2bcd(tm->time.tm_hour);
380 	buf[2] = bin2bcd(tm->time.tm_mday);
381 	buf[3] = tm->time.tm_wday & 0x07;
382 
383 	err = pcf8563_write_block_data(client, PCF8563_REG_AMN, 4, buf);
384 	if (err)
385 		return err;
386 
387 	return pcf8563_set_alarm_mode(client, !!tm->enabled);
388 }
389 
390 static int pcf8563_irq_enable(struct device *dev, unsigned int enabled)
391 {
392 	dev_dbg(dev, "%s: en=%d\n", __func__, enabled);
393 	return pcf8563_set_alarm_mode(to_i2c_client(dev), !!enabled);
394 }
395 
396 #ifdef CONFIG_COMMON_CLK
397 /*
398  * Handling of the clkout
399  */
400 
401 #define clkout_hw_to_pcf8563(_hw) container_of(_hw, struct pcf8563, clkout_hw)
402 
403 static int clkout_rates[] = {
404 	32768,
405 	1024,
406 	32,
407 	1,
408 };
409 
410 static unsigned long pcf8563_clkout_recalc_rate(struct clk_hw *hw,
411 						unsigned long parent_rate)
412 {
413 	struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
414 	struct i2c_client *client = pcf8563->client;
415 	unsigned char buf;
416 	int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
417 
418 	if (ret < 0)
419 		return 0;
420 
421 	buf &= PCF8563_REG_CLKO_F_MASK;
422 	return clkout_rates[buf];
423 }
424 
425 static long pcf8563_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
426 				      unsigned long *prate)
427 {
428 	int i;
429 
430 	for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
431 		if (clkout_rates[i] <= rate)
432 			return clkout_rates[i];
433 
434 	return 0;
435 }
436 
437 static int pcf8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
438 				   unsigned long parent_rate)
439 {
440 	struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
441 	struct i2c_client *client = pcf8563->client;
442 	unsigned char buf;
443 	int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
444 	int i;
445 
446 	if (ret < 0)
447 		return ret;
448 
449 	for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
450 		if (clkout_rates[i] == rate) {
451 			buf &= ~PCF8563_REG_CLKO_F_MASK;
452 			buf |= i;
453 			ret = pcf8563_write_block_data(client,
454 						       PCF8563_REG_CLKO, 1,
455 						       &buf);
456 			return ret;
457 		}
458 
459 	return -EINVAL;
460 }
461 
462 static int pcf8563_clkout_control(struct clk_hw *hw, bool enable)
463 {
464 	struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
465 	struct i2c_client *client = pcf8563->client;
466 	unsigned char buf;
467 	int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
468 
469 	if (ret < 0)
470 		return ret;
471 
472 	if (enable)
473 		buf |= PCF8563_REG_CLKO_FE;
474 	else
475 		buf &= ~PCF8563_REG_CLKO_FE;
476 
477 	ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
478 	return ret;
479 }
480 
481 static int pcf8563_clkout_prepare(struct clk_hw *hw)
482 {
483 	return pcf8563_clkout_control(hw, 1);
484 }
485 
486 static void pcf8563_clkout_unprepare(struct clk_hw *hw)
487 {
488 	pcf8563_clkout_control(hw, 0);
489 }
490 
491 static int pcf8563_clkout_is_prepared(struct clk_hw *hw)
492 {
493 	struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
494 	struct i2c_client *client = pcf8563->client;
495 	unsigned char buf;
496 	int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
497 
498 	if (ret < 0)
499 		return ret;
500 
501 	return !!(buf & PCF8563_REG_CLKO_FE);
502 }
503 
504 static const struct clk_ops pcf8563_clkout_ops = {
505 	.prepare = pcf8563_clkout_prepare,
506 	.unprepare = pcf8563_clkout_unprepare,
507 	.is_prepared = pcf8563_clkout_is_prepared,
508 	.recalc_rate = pcf8563_clkout_recalc_rate,
509 	.round_rate = pcf8563_clkout_round_rate,
510 	.set_rate = pcf8563_clkout_set_rate,
511 };
512 
513 static struct clk *pcf8563_clkout_register_clk(struct pcf8563 *pcf8563)
514 {
515 	struct i2c_client *client = pcf8563->client;
516 	struct device_node *node = client->dev.of_node;
517 	struct clk *clk;
518 	struct clk_init_data init;
519 	int ret;
520 	unsigned char buf;
521 
522 	/* disable the clkout output */
523 	buf = 0;
524 	ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
525 	if (ret < 0)
526 		return ERR_PTR(ret);
527 
528 	init.name = "pcf8563-clkout";
529 	init.ops = &pcf8563_clkout_ops;
530 	init.flags = 0;
531 	init.parent_names = NULL;
532 	init.num_parents = 0;
533 	pcf8563->clkout_hw.init = &init;
534 
535 	/* optional override of the clockname */
536 	of_property_read_string(node, "clock-output-names", &init.name);
537 
538 	/* register the clock */
539 	clk = devm_clk_register(&client->dev, &pcf8563->clkout_hw);
540 
541 	if (!IS_ERR(clk))
542 		of_clk_add_provider(node, of_clk_src_simple_get, clk);
543 
544 	return clk;
545 }
546 #endif
547 
548 static const struct rtc_class_ops pcf8563_rtc_ops = {
549 	.ioctl		= pcf8563_rtc_ioctl,
550 	.read_time	= pcf8563_rtc_read_time,
551 	.set_time	= pcf8563_rtc_set_time,
552 	.read_alarm	= pcf8563_rtc_read_alarm,
553 	.set_alarm	= pcf8563_rtc_set_alarm,
554 	.alarm_irq_enable = pcf8563_irq_enable,
555 };
556 
557 static int pcf8563_probe(struct i2c_client *client,
558 				const struct i2c_device_id *id)
559 {
560 	struct pcf8563 *pcf8563;
561 	int err;
562 	unsigned char buf;
563 
564 	dev_dbg(&client->dev, "%s\n", __func__);
565 
566 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
567 		return -ENODEV;
568 
569 	pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563),
570 				GFP_KERNEL);
571 	if (!pcf8563)
572 		return -ENOMEM;
573 
574 	i2c_set_clientdata(client, pcf8563);
575 	pcf8563->client = client;
576 	device_set_wakeup_capable(&client->dev, 1);
577 
578 	/* Set timer to lowest frequency to save power (ref Haoyu datasheet) */
579 	buf = PCF8563_TMRC_1_60;
580 	err = pcf8563_write_block_data(client, PCF8563_REG_TMRC, 1, &buf);
581 	if (err < 0) {
582 		dev_err(&client->dev, "%s: write error\n", __func__);
583 		return err;
584 	}
585 
586 	/* Clear flags and disable interrupts */
587 	buf = 0;
588 	err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf);
589 	if (err < 0) {
590 		dev_err(&client->dev, "%s: write error\n", __func__);
591 		return err;
592 	}
593 
594 	pcf8563->rtc = devm_rtc_device_register(&client->dev,
595 				pcf8563_driver.driver.name,
596 				&pcf8563_rtc_ops, THIS_MODULE);
597 
598 	if (IS_ERR(pcf8563->rtc))
599 		return PTR_ERR(pcf8563->rtc);
600 
601 	if (client->irq > 0) {
602 		err = devm_request_threaded_irq(&client->dev, client->irq,
603 				NULL, pcf8563_irq,
604 				IRQF_SHARED | IRQF_ONESHOT | IRQF_TRIGGER_LOW,
605 				pcf8563_driver.driver.name, client);
606 		if (err) {
607 			dev_err(&client->dev, "unable to request IRQ %d\n",
608 								client->irq);
609 			return err;
610 		}
611 
612 	}
613 
614 #ifdef CONFIG_COMMON_CLK
615 	/* register clk in common clk framework */
616 	pcf8563_clkout_register_clk(pcf8563);
617 #endif
618 
619 	/* the pcf8563 alarm only supports a minute accuracy */
620 	pcf8563->rtc->uie_unsupported = 1;
621 
622 	return 0;
623 }
624 
625 static const struct i2c_device_id pcf8563_id[] = {
626 	{ "pcf8563", 0 },
627 	{ "rtc8564", 0 },
628 	{ }
629 };
630 MODULE_DEVICE_TABLE(i2c, pcf8563_id);
631 
632 #ifdef CONFIG_OF
633 static const struct of_device_id pcf8563_of_match[] = {
634 	{ .compatible = "nxp,pcf8563" },
635 	{}
636 };
637 MODULE_DEVICE_TABLE(of, pcf8563_of_match);
638 #endif
639 
640 static struct i2c_driver pcf8563_driver = {
641 	.driver		= {
642 		.name	= "rtc-pcf8563",
643 		.of_match_table = of_match_ptr(pcf8563_of_match),
644 	},
645 	.probe		= pcf8563_probe,
646 	.id_table	= pcf8563_id,
647 };
648 
649 module_i2c_driver(pcf8563_driver);
650 
651 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
652 MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
653 MODULE_LICENSE("GPL");
654