xref: /openbmc/linux/drivers/rtc/rtc-rs5c372.c (revision 93dc544c)
1 /*
2  * An I2C driver for Ricoh RS5C372 and RV5C38[67] RTCs
3  *
4  * Copyright (C) 2005 Pavel Mironchik <pmironchik@optifacio.net>
5  * Copyright (C) 2006 Tower Technologies
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 
12 #include <linux/i2c.h>
13 #include <linux/rtc.h>
14 #include <linux/bcd.h>
15 
16 #define DRV_VERSION "0.5"
17 
18 
19 /*
20  * Ricoh has a family of I2C based RTCs, which differ only slightly from
21  * each other.  Differences center on pinout (e.g. how many interrupts,
22  * output clock, etc) and how the control registers are used.  The '372
23  * is significant only because that's the one this driver first supported.
24  */
25 #define RS5C372_REG_SECS	0
26 #define RS5C372_REG_MINS	1
27 #define RS5C372_REG_HOURS	2
28 #define RS5C372_REG_WDAY	3
29 #define RS5C372_REG_DAY		4
30 #define RS5C372_REG_MONTH	5
31 #define RS5C372_REG_YEAR	6
32 #define RS5C372_REG_TRIM	7
33 #	define RS5C372_TRIM_XSL		0x80
34 #	define RS5C372_TRIM_MASK	0x7F
35 
36 #define RS5C_REG_ALARM_A_MIN	8			/* or ALARM_W */
37 #define RS5C_REG_ALARM_A_HOURS	9
38 #define RS5C_REG_ALARM_A_WDAY	10
39 
40 #define RS5C_REG_ALARM_B_MIN	11			/* or ALARM_D */
41 #define RS5C_REG_ALARM_B_HOURS	12
42 #define RS5C_REG_ALARM_B_WDAY	13			/* (ALARM_B only) */
43 
44 #define RS5C_REG_CTRL1		14
45 #	define RS5C_CTRL1_AALE		(1 << 7)	/* or WALE */
46 #	define RS5C_CTRL1_BALE		(1 << 6)	/* or DALE */
47 #	define RV5C387_CTRL1_24		(1 << 5)
48 #	define RS5C372A_CTRL1_SL1	(1 << 5)
49 #	define RS5C_CTRL1_CT_MASK	(7 << 0)
50 #	define RS5C_CTRL1_CT0		(0 << 0)	/* no periodic irq */
51 #	define RS5C_CTRL1_CT4		(4 << 0)	/* 1 Hz level irq */
52 #define RS5C_REG_CTRL2		15
53 #	define RS5C372_CTRL2_24		(1 << 5)
54 #	define RS5C_CTRL2_XSTP		(1 << 4)
55 #	define RS5C_CTRL2_CTFG		(1 << 2)
56 #	define RS5C_CTRL2_AAFG		(1 << 1)	/* or WAFG */
57 #	define RS5C_CTRL2_BAFG		(1 << 0)	/* or DAFG */
58 
59 
60 /* to read (style 1) or write registers starting at R */
61 #define RS5C_ADDR(R)		(((R) << 4) | 0)
62 
63 
64 enum rtc_type {
65 	rtc_undef = 0,
66 	rtc_rs5c372a,
67 	rtc_rs5c372b,
68 	rtc_rv5c386,
69 	rtc_rv5c387a,
70 };
71 
72 static const struct i2c_device_id rs5c372_id[] = {
73 	{ "rs5c372a", rtc_rs5c372a },
74 	{ "rs5c372b", rtc_rs5c372b },
75 	{ "rv5c386", rtc_rv5c386 },
76 	{ "rv5c387a", rtc_rv5c387a },
77 	{ }
78 };
79 MODULE_DEVICE_TABLE(i2c, rs5c372_id);
80 
81 /* REVISIT:  this assumes that:
82  *  - we're in the 21st century, so it's safe to ignore the century
83  *    bit for rv5c38[67] (REG_MONTH bit 7);
84  *  - we should use ALARM_A not ALARM_B (may be wrong on some boards)
85  */
86 struct rs5c372 {
87 	struct i2c_client	*client;
88 	struct rtc_device	*rtc;
89 	enum rtc_type		type;
90 	unsigned		time24:1;
91 	unsigned		has_irq:1;
92 	char			buf[17];
93 	char			*regs;
94 };
95 
96 static int rs5c_get_regs(struct rs5c372 *rs5c)
97 {
98 	struct i2c_client	*client = rs5c->client;
99 	struct i2c_msg		msgs[] = {
100 		{ client->addr, I2C_M_RD, sizeof rs5c->buf, rs5c->buf },
101 	};
102 
103 	/* This implements the third reading method from the datasheet, using
104 	 * an internal address that's reset after each transaction (by STOP)
105 	 * to 0x0f ... so we read extra registers, and skip the first one.
106 	 *
107 	 * The first method doesn't work with the iop3xx adapter driver, on at
108 	 * least 80219 chips; this works around that bug.
109 	 */
110 	if ((i2c_transfer(client->adapter, msgs, 1)) != 1) {
111 		dev_warn(&client->dev, "can't read registers\n");
112 		return -EIO;
113 	}
114 
115 	dev_dbg(&client->dev,
116 		"%02x %02x %02x (%02x) %02x %02x %02x (%02x), "
117 		"%02x %02x %02x, %02x %02x %02x; %02x %02x\n",
118 		rs5c->regs[0],  rs5c->regs[1],  rs5c->regs[2],  rs5c->regs[3],
119 		rs5c->regs[4],  rs5c->regs[5],  rs5c->regs[6],  rs5c->regs[7],
120 		rs5c->regs[8],  rs5c->regs[9],  rs5c->regs[10], rs5c->regs[11],
121 		rs5c->regs[12], rs5c->regs[13], rs5c->regs[14], rs5c->regs[15]);
122 
123 	return 0;
124 }
125 
126 static unsigned rs5c_reg2hr(struct rs5c372 *rs5c, unsigned reg)
127 {
128 	unsigned	hour;
129 
130 	if (rs5c->time24)
131 		return BCD2BIN(reg & 0x3f);
132 
133 	hour = BCD2BIN(reg & 0x1f);
134 	if (hour == 12)
135 		hour = 0;
136 	if (reg & 0x20)
137 		hour += 12;
138 	return hour;
139 }
140 
141 static unsigned rs5c_hr2reg(struct rs5c372 *rs5c, unsigned hour)
142 {
143 	if (rs5c->time24)
144 		return BIN2BCD(hour);
145 
146 	if (hour > 12)
147 		return 0x20 | BIN2BCD(hour - 12);
148 	if (hour == 12)
149 		return 0x20 | BIN2BCD(12);
150 	if (hour == 0)
151 		return BIN2BCD(12);
152 	return BIN2BCD(hour);
153 }
154 
155 static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
156 {
157 	struct rs5c372	*rs5c = i2c_get_clientdata(client);
158 	int		status = rs5c_get_regs(rs5c);
159 
160 	if (status < 0)
161 		return status;
162 
163 	tm->tm_sec = BCD2BIN(rs5c->regs[RS5C372_REG_SECS] & 0x7f);
164 	tm->tm_min = BCD2BIN(rs5c->regs[RS5C372_REG_MINS] & 0x7f);
165 	tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]);
166 
167 	tm->tm_wday = BCD2BIN(rs5c->regs[RS5C372_REG_WDAY] & 0x07);
168 	tm->tm_mday = BCD2BIN(rs5c->regs[RS5C372_REG_DAY] & 0x3f);
169 
170 	/* tm->tm_mon is zero-based */
171 	tm->tm_mon = BCD2BIN(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1;
172 
173 	/* year is 1900 + tm->tm_year */
174 	tm->tm_year = BCD2BIN(rs5c->regs[RS5C372_REG_YEAR]) + 100;
175 
176 	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
177 		"mday=%d, mon=%d, year=%d, wday=%d\n",
178 		__func__,
179 		tm->tm_sec, tm->tm_min, tm->tm_hour,
180 		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
181 
182 	/* rtc might need initialization */
183 	return rtc_valid_tm(tm);
184 }
185 
186 static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)
187 {
188 	struct rs5c372	*rs5c = i2c_get_clientdata(client);
189 	unsigned char	buf[8];
190 
191 	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "
192 		"mday=%d, mon=%d, year=%d, wday=%d\n",
193 		__func__,
194 		tm->tm_sec, tm->tm_min, tm->tm_hour,
195 		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
196 
197 	buf[0] = RS5C_ADDR(RS5C372_REG_SECS);
198 	buf[1] = BIN2BCD(tm->tm_sec);
199 	buf[2] = BIN2BCD(tm->tm_min);
200 	buf[3] = rs5c_hr2reg(rs5c, tm->tm_hour);
201 	buf[4] = BIN2BCD(tm->tm_wday);
202 	buf[5] = BIN2BCD(tm->tm_mday);
203 	buf[6] = BIN2BCD(tm->tm_mon + 1);
204 	buf[7] = BIN2BCD(tm->tm_year - 100);
205 
206 	if ((i2c_master_send(client, buf, 8)) != 8) {
207 		dev_err(&client->dev, "%s: write error\n", __func__);
208 		return -EIO;
209 	}
210 
211 	return 0;
212 }
213 
214 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
215 #define	NEED_TRIM
216 #endif
217 
218 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
219 #define	NEED_TRIM
220 #endif
221 
222 #ifdef	NEED_TRIM
223 static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
224 {
225 	struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
226 	u8 tmp = rs5c372->regs[RS5C372_REG_TRIM];
227 
228 	if (osc)
229 		*osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;
230 
231 	if (trim) {
232 		dev_dbg(&client->dev, "%s: raw trim=%x\n", __func__, tmp);
233 		tmp &= RS5C372_TRIM_MASK;
234 		if (tmp & 0x3e) {
235 			int t = tmp & 0x3f;
236 
237 			if (tmp & 0x40)
238 				t = (~t | (s8)0xc0) + 1;
239 			else
240 				t = t - 1;
241 
242 			tmp = t * 2;
243 		} else
244 			tmp = 0;
245 		*trim = tmp;
246 	}
247 
248 	return 0;
249 }
250 #endif
251 
252 static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
253 {
254 	return rs5c372_get_datetime(to_i2c_client(dev), tm);
255 }
256 
257 static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
258 {
259 	return rs5c372_set_datetime(to_i2c_client(dev), tm);
260 }
261 
262 #if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)
263 
264 static int
265 rs5c_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
266 {
267 	struct i2c_client	*client = to_i2c_client(dev);
268 	struct rs5c372		*rs5c = i2c_get_clientdata(client);
269 	unsigned char		buf[2];
270 	int			status;
271 
272 	buf[1] = rs5c->regs[RS5C_REG_CTRL1];
273 	switch (cmd) {
274 	case RTC_UIE_OFF:
275 	case RTC_UIE_ON:
276 		/* some 327a modes use a different IRQ pin for 1Hz irqs */
277 		if (rs5c->type == rtc_rs5c372a
278 				&& (buf[1] & RS5C372A_CTRL1_SL1))
279 			return -ENOIOCTLCMD;
280 	case RTC_AIE_OFF:
281 	case RTC_AIE_ON:
282 		/* these irq management calls only make sense for chips
283 		 * which are wired up to an IRQ.
284 		 */
285 		if (!rs5c->has_irq)
286 			return -ENOIOCTLCMD;
287 		break;
288 	default:
289 		return -ENOIOCTLCMD;
290 	}
291 
292 	status = rs5c_get_regs(rs5c);
293 	if (status < 0)
294 		return status;
295 
296 	buf[0] = RS5C_ADDR(RS5C_REG_CTRL1);
297 	switch (cmd) {
298 	case RTC_AIE_OFF:	/* alarm off */
299 		buf[1] &= ~RS5C_CTRL1_AALE;
300 		break;
301 	case RTC_AIE_ON:	/* alarm on */
302 		buf[1] |= RS5C_CTRL1_AALE;
303 		break;
304 	case RTC_UIE_OFF:	/* update off */
305 		buf[1] &= ~RS5C_CTRL1_CT_MASK;
306 		break;
307 	case RTC_UIE_ON:	/* update on */
308 		buf[1] &= ~RS5C_CTRL1_CT_MASK;
309 		buf[1] |= RS5C_CTRL1_CT4;
310 		break;
311 	}
312 	if ((i2c_master_send(client, buf, 2)) != 2) {
313 		printk(KERN_WARNING "%s: can't update alarm\n",
314 			rs5c->rtc->name);
315 		status = -EIO;
316 	} else
317 		rs5c->regs[RS5C_REG_CTRL1] = buf[1];
318 	return status;
319 }
320 
321 #else
322 #define	rs5c_rtc_ioctl	NULL
323 #endif
324 
325 
326 /* NOTE:  Since RTC_WKALM_{RD,SET} were originally defined for EFI,
327  * which only exposes a polled programming interface; and since
328  * these calls map directly to those EFI requests; we don't demand
329  * we have an IRQ for this chip when we go through this API.
330  *
331  * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
332  * though, managed through RTC_AIE_{ON,OFF} requests.
333  */
334 
335 static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
336 {
337 	struct i2c_client	*client = to_i2c_client(dev);
338 	struct rs5c372		*rs5c = i2c_get_clientdata(client);
339 	int			status;
340 
341 	status = rs5c_get_regs(rs5c);
342 	if (status < 0)
343 		return status;
344 
345 	/* report alarm time */
346 	t->time.tm_sec = 0;
347 	t->time.tm_min = BCD2BIN(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
348 	t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
349 	t->time.tm_mday = -1;
350 	t->time.tm_mon = -1;
351 	t->time.tm_year = -1;
352 	t->time.tm_wday = -1;
353 	t->time.tm_yday = -1;
354 	t->time.tm_isdst = -1;
355 
356 	/* ... and status */
357 	t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);
358 	t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG);
359 
360 	return 0;
361 }
362 
363 static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t)
364 {
365 	struct i2c_client	*client = to_i2c_client(dev);
366 	struct rs5c372		*rs5c = i2c_get_clientdata(client);
367 	int			status;
368 	unsigned char		buf[4];
369 
370 	/* only handle up to 24 hours in the future, like RTC_ALM_SET */
371 	if (t->time.tm_mday != -1
372 			|| t->time.tm_mon != -1
373 			|| t->time.tm_year != -1)
374 		return -EINVAL;
375 
376 	/* REVISIT: round up tm_sec */
377 
378 	/* if needed, disable irq (clears pending status) */
379 	status = rs5c_get_regs(rs5c);
380 	if (status < 0)
381 		return status;
382 	if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) {
383 		buf[0] = RS5C_ADDR(RS5C_REG_CTRL1);
384 		buf[1] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
385 		if (i2c_master_send(client, buf, 2) != 2) {
386 			pr_debug("%s: can't disable alarm\n", rs5c->rtc->name);
387 			return -EIO;
388 		}
389 		rs5c->regs[RS5C_REG_CTRL1] = buf[1];
390 	}
391 
392 	/* set alarm */
393 	buf[0] = RS5C_ADDR(RS5C_REG_ALARM_A_MIN);
394 	buf[1] = BIN2BCD(t->time.tm_min);
395 	buf[2] = rs5c_hr2reg(rs5c, t->time.tm_hour);
396 	buf[3] = 0x7f;	/* any/all days */
397 	if ((i2c_master_send(client, buf, 4)) != 4) {
398 		pr_debug("%s: can't set alarm time\n", rs5c->rtc->name);
399 		return -EIO;
400 	}
401 
402 	/* ... and maybe enable its irq */
403 	if (t->enabled) {
404 		buf[0] = RS5C_ADDR(RS5C_REG_CTRL1);
405 		buf[1] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE;
406 		if ((i2c_master_send(client, buf, 2)) != 2)
407 			printk(KERN_WARNING "%s: can't enable alarm\n",
408 				rs5c->rtc->name);
409 		rs5c->regs[RS5C_REG_CTRL1] = buf[1];
410 	}
411 
412 	return 0;
413 }
414 
415 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
416 
417 static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
418 {
419 	int err, osc, trim;
420 
421 	err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim);
422 	if (err == 0) {
423 		seq_printf(seq, "crystal\t\t: %d.%03d KHz\n",
424 				osc / 1000, osc % 1000);
425 		seq_printf(seq, "trim\t\t: %d\n", trim);
426 	}
427 
428 	return 0;
429 }
430 
431 #else
432 #define	rs5c372_rtc_proc	NULL
433 #endif
434 
435 static const struct rtc_class_ops rs5c372_rtc_ops = {
436 	.proc		= rs5c372_rtc_proc,
437 	.ioctl		= rs5c_rtc_ioctl,
438 	.read_time	= rs5c372_rtc_read_time,
439 	.set_time	= rs5c372_rtc_set_time,
440 	.read_alarm	= rs5c_read_alarm,
441 	.set_alarm	= rs5c_set_alarm,
442 };
443 
444 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
445 
446 static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
447 				struct device_attribute *attr, char *buf)
448 {
449 	int err, trim;
450 
451 	err = rs5c372_get_trim(to_i2c_client(dev), NULL, &trim);
452 	if (err)
453 		return err;
454 
455 	return sprintf(buf, "%d\n", trim);
456 }
457 static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
458 
459 static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
460 				struct device_attribute *attr, char *buf)
461 {
462 	int err, osc;
463 
464 	err = rs5c372_get_trim(to_i2c_client(dev), &osc, NULL);
465 	if (err)
466 		return err;
467 
468 	return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);
469 }
470 static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
471 
472 static int rs5c_sysfs_register(struct device *dev)
473 {
474 	int err;
475 
476 	err = device_create_file(dev, &dev_attr_trim);
477 	if (err)
478 		return err;
479 	err = device_create_file(dev, &dev_attr_osc);
480 	if (err)
481 		device_remove_file(dev, &dev_attr_trim);
482 
483 	return err;
484 }
485 
486 static void rs5c_sysfs_unregister(struct device *dev)
487 {
488 	device_remove_file(dev, &dev_attr_trim);
489 	device_remove_file(dev, &dev_attr_osc);
490 }
491 
492 #else
493 static int rs5c_sysfs_register(struct device *dev)
494 {
495 	return 0;
496 }
497 
498 static void rs5c_sysfs_unregister(struct device *dev)
499 {
500 	/* nothing */
501 }
502 #endif	/* SYSFS */
503 
504 static struct i2c_driver rs5c372_driver;
505 
506 static int rs5c372_probe(struct i2c_client *client,
507 			 const struct i2c_device_id *id)
508 {
509 	int err = 0;
510 	struct rs5c372 *rs5c372;
511 	struct rtc_time tm;
512 
513 	dev_dbg(&client->dev, "%s\n", __func__);
514 
515 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
516 		err = -ENODEV;
517 		goto exit;
518 	}
519 
520 	if (!(rs5c372 = kzalloc(sizeof(struct rs5c372), GFP_KERNEL))) {
521 		err = -ENOMEM;
522 		goto exit;
523 	}
524 
525 	rs5c372->client = client;
526 	i2c_set_clientdata(client, rs5c372);
527 	rs5c372->type = id->driver_data;
528 
529 	/* we read registers 0x0f then 0x00-0x0f; skip the first one */
530 	rs5c372->regs = &rs5c372->buf[1];
531 
532 	err = rs5c_get_regs(rs5c372);
533 	if (err < 0)
534 		goto exit_kfree;
535 
536 	/* clock may be set for am/pm or 24 hr time */
537 	switch (rs5c372->type) {
538 	case rtc_rs5c372a:
539 	case rtc_rs5c372b:
540 		/* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
541 		 * so does periodic irq, except some 327a modes.
542 		 */
543 		if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
544 			rs5c372->time24 = 1;
545 		break;
546 	case rtc_rv5c386:
547 	case rtc_rv5c387a:
548 		if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
549 			rs5c372->time24 = 1;
550 		/* alarm uses ALARM_W; and nINTRB for alarm and periodic
551 		 * irq, on both 386 and 387
552 		 */
553 		break;
554 	default:
555 		dev_err(&client->dev, "unknown RTC type\n");
556 		goto exit_kfree;
557 	}
558 
559 	/* if the oscillator lost power and no other software (like
560 	 * the bootloader) set it up, do it here.
561 	 */
562 	if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_XSTP) {
563 		unsigned char buf[3];
564 
565 		rs5c372->regs[RS5C_REG_CTRL2] &= ~RS5C_CTRL2_XSTP;
566 
567 		buf[0] = RS5C_ADDR(RS5C_REG_CTRL1);
568 		buf[1] = rs5c372->regs[RS5C_REG_CTRL1];
569 		buf[2] = rs5c372->regs[RS5C_REG_CTRL2];
570 
571 		/* use 24hr mode */
572 		switch (rs5c372->type) {
573 		case rtc_rs5c372a:
574 		case rtc_rs5c372b:
575 			buf[2] |= RS5C372_CTRL2_24;
576 			rs5c372->time24 = 1;
577 			break;
578 		case rtc_rv5c386:
579 		case rtc_rv5c387a:
580 			buf[1] |= RV5C387_CTRL1_24;
581 			rs5c372->time24 = 1;
582 			break;
583 		default:
584 			/* impossible */
585 			break;
586 		}
587 
588 		if ((i2c_master_send(client, buf, 3)) != 3) {
589 			dev_err(&client->dev, "setup error\n");
590 			goto exit_kfree;
591 		}
592 		rs5c372->regs[RS5C_REG_CTRL1] = buf[1];
593 		rs5c372->regs[RS5C_REG_CTRL2] = buf[2];
594 	}
595 
596 	if (rs5c372_get_datetime(client, &tm) < 0)
597 		dev_warn(&client->dev, "clock needs to be set\n");
598 
599 	dev_info(&client->dev, "%s found, %s, driver version " DRV_VERSION "\n",
600 			({ char *s; switch (rs5c372->type) {
601 			case rtc_rs5c372a:	s = "rs5c372a"; break;
602 			case rtc_rs5c372b:	s = "rs5c372b"; break;
603 			case rtc_rv5c386:	s = "rv5c386"; break;
604 			case rtc_rv5c387a:	s = "rv5c387a"; break;
605 			default:		s = "chip"; break;
606 			}; s;}),
607 			rs5c372->time24 ? "24hr" : "am/pm"
608 			);
609 
610 	/* REVISIT use client->irq to register alarm irq ... */
611 
612 	rs5c372->rtc = rtc_device_register(rs5c372_driver.driver.name,
613 				&client->dev, &rs5c372_rtc_ops, THIS_MODULE);
614 
615 	if (IS_ERR(rs5c372->rtc)) {
616 		err = PTR_ERR(rs5c372->rtc);
617 		goto exit_kfree;
618 	}
619 
620 	err = rs5c_sysfs_register(&client->dev);
621 	if (err)
622 		goto exit_devreg;
623 
624 	return 0;
625 
626 exit_devreg:
627 	rtc_device_unregister(rs5c372->rtc);
628 
629 exit_kfree:
630 	kfree(rs5c372);
631 
632 exit:
633 	return err;
634 }
635 
636 static int rs5c372_remove(struct i2c_client *client)
637 {
638 	struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
639 
640 	rtc_device_unregister(rs5c372->rtc);
641 	rs5c_sysfs_unregister(&client->dev);
642 	kfree(rs5c372);
643 	return 0;
644 }
645 
646 static struct i2c_driver rs5c372_driver = {
647 	.driver		= {
648 		.name	= "rtc-rs5c372",
649 	},
650 	.probe		= rs5c372_probe,
651 	.remove		= rs5c372_remove,
652 	.id_table	= rs5c372_id,
653 };
654 
655 static __init int rs5c372_init(void)
656 {
657 	return i2c_add_driver(&rs5c372_driver);
658 }
659 
660 static __exit void rs5c372_exit(void)
661 {
662 	i2c_del_driver(&rs5c372_driver);
663 }
664 
665 module_init(rs5c372_init);
666 module_exit(rs5c372_exit);
667 
668 MODULE_AUTHOR(
669 		"Pavel Mironchik <pmironchik@optifacio.net>, "
670 		"Alessandro Zummo <a.zummo@towertech.it>");
671 MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
672 MODULE_LICENSE("GPL");
673 MODULE_VERSION(DRV_VERSION);
674