xref: /linux/drivers/rtc/rtc-rs5c372.c (revision e2bfe3424b368e977002fc58f81536d5d8ea9449)
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 /* REVISIT:  this assumes that:
73  *  - we're in the 21st century, so it's safe to ignore the century
74  *    bit for rv5c38[67] (REG_MONTH bit 7);
75  *  - we should use ALARM_A not ALARM_B (may be wrong on some boards)
76  */
77 struct rs5c372 {
78 	struct i2c_client	*client;
79 	struct rtc_device	*rtc;
80 	enum rtc_type		type;
81 	unsigned		time24:1;
82 	unsigned		has_irq:1;
83 	char			buf[17];
84 	char			*regs;
85 };
86 
87 static int rs5c_get_regs(struct rs5c372 *rs5c)
88 {
89 	struct i2c_client	*client = rs5c->client;
90 	struct i2c_msg		msgs[] = {
91 		{ client->addr, I2C_M_RD, sizeof rs5c->buf, rs5c->buf },
92 	};
93 
94 	/* This implements the third reading method from the datasheet, using
95 	 * an internal address that's reset after each transaction (by STOP)
96 	 * to 0x0f ... so we read extra registers, and skip the first one.
97 	 *
98 	 * The first method doesn't work with the iop3xx adapter driver, on at
99 	 * least 80219 chips; this works around that bug.
100 	 */
101 	if ((i2c_transfer(client->adapter, msgs, 1)) != 1) {
102 		dev_warn(&client->dev, "can't read registers\n");
103 		return -EIO;
104 	}
105 
106 	dev_dbg(&client->dev,
107 		"%02x %02x %02x (%02x) %02x %02x %02x (%02x), "
108 		"%02x %02x %02x, %02x %02x %02x; %02x %02x\n",
109 		rs5c->regs[0],  rs5c->regs[1],  rs5c->regs[2],  rs5c->regs[3],
110 		rs5c->regs[4],  rs5c->regs[5],  rs5c->regs[6],  rs5c->regs[7],
111 		rs5c->regs[8],  rs5c->regs[9],  rs5c->regs[10], rs5c->regs[11],
112 		rs5c->regs[12], rs5c->regs[13], rs5c->regs[14], rs5c->regs[15]);
113 
114 	return 0;
115 }
116 
117 static unsigned rs5c_reg2hr(struct rs5c372 *rs5c, unsigned reg)
118 {
119 	unsigned	hour;
120 
121 	if (rs5c->time24)
122 		return BCD2BIN(reg & 0x3f);
123 
124 	hour = BCD2BIN(reg & 0x1f);
125 	if (hour == 12)
126 		hour = 0;
127 	if (reg & 0x20)
128 		hour += 12;
129 	return hour;
130 }
131 
132 static unsigned rs5c_hr2reg(struct rs5c372 *rs5c, unsigned hour)
133 {
134 	if (rs5c->time24)
135 		return BIN2BCD(hour);
136 
137 	if (hour > 12)
138 		return 0x20 | BIN2BCD(hour - 12);
139 	if (hour == 12)
140 		return 0x20 | BIN2BCD(12);
141 	if (hour == 0)
142 		return BIN2BCD(12);
143 	return BIN2BCD(hour);
144 }
145 
146 static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
147 {
148 	struct rs5c372	*rs5c = i2c_get_clientdata(client);
149 	int		status = rs5c_get_regs(rs5c);
150 
151 	if (status < 0)
152 		return status;
153 
154 	tm->tm_sec = BCD2BIN(rs5c->regs[RS5C372_REG_SECS] & 0x7f);
155 	tm->tm_min = BCD2BIN(rs5c->regs[RS5C372_REG_MINS] & 0x7f);
156 	tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]);
157 
158 	tm->tm_wday = BCD2BIN(rs5c->regs[RS5C372_REG_WDAY] & 0x07);
159 	tm->tm_mday = BCD2BIN(rs5c->regs[RS5C372_REG_DAY] & 0x3f);
160 
161 	/* tm->tm_mon is zero-based */
162 	tm->tm_mon = BCD2BIN(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1;
163 
164 	/* year is 1900 + tm->tm_year */
165 	tm->tm_year = BCD2BIN(rs5c->regs[RS5C372_REG_YEAR]) + 100;
166 
167 	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
168 		"mday=%d, mon=%d, year=%d, wday=%d\n",
169 		__FUNCTION__,
170 		tm->tm_sec, tm->tm_min, tm->tm_hour,
171 		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
172 
173 	/* rtc might need initialization */
174 	return rtc_valid_tm(tm);
175 }
176 
177 static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)
178 {
179 	struct rs5c372	*rs5c = i2c_get_clientdata(client);
180 	unsigned char	buf[8];
181 
182 	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "
183 		"mday=%d, mon=%d, year=%d, wday=%d\n",
184 		__FUNCTION__,
185 		tm->tm_sec, tm->tm_min, tm->tm_hour,
186 		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
187 
188 	buf[0] = RS5C_ADDR(RS5C372_REG_SECS);
189 	buf[1] = BIN2BCD(tm->tm_sec);
190 	buf[2] = BIN2BCD(tm->tm_min);
191 	buf[3] = rs5c_hr2reg(rs5c, tm->tm_hour);
192 	buf[4] = BIN2BCD(tm->tm_wday);
193 	buf[5] = BIN2BCD(tm->tm_mday);
194 	buf[6] = BIN2BCD(tm->tm_mon + 1);
195 	buf[7] = BIN2BCD(tm->tm_year - 100);
196 
197 	if ((i2c_master_send(client, buf, 8)) != 8) {
198 		dev_err(&client->dev, "%s: write error\n", __FUNCTION__);
199 		return -EIO;
200 	}
201 
202 	return 0;
203 }
204 
205 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
206 #define	NEED_TRIM
207 #endif
208 
209 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
210 #define	NEED_TRIM
211 #endif
212 
213 #ifdef	NEED_TRIM
214 static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
215 {
216 	struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
217 	u8 tmp = rs5c372->regs[RS5C372_REG_TRIM];
218 
219 	if (osc)
220 		*osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;
221 
222 	if (trim) {
223 		dev_dbg(&client->dev, "%s: raw trim=%x\n", __FUNCTION__, tmp);
224 		tmp &= RS5C372_TRIM_MASK;
225 		if (tmp & 0x3e) {
226 			int t = tmp & 0x3f;
227 
228 			if (tmp & 0x40)
229 				t = (~t | (s8)0xc0) + 1;
230 			else
231 				t = t - 1;
232 
233 			tmp = t * 2;
234 		} else
235 			tmp = 0;
236 		*trim = tmp;
237 	}
238 
239 	return 0;
240 }
241 #endif
242 
243 static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
244 {
245 	return rs5c372_get_datetime(to_i2c_client(dev), tm);
246 }
247 
248 static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
249 {
250 	return rs5c372_set_datetime(to_i2c_client(dev), tm);
251 }
252 
253 #if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)
254 
255 static int
256 rs5c_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
257 {
258 	struct i2c_client	*client = to_i2c_client(dev);
259 	struct rs5c372		*rs5c = i2c_get_clientdata(client);
260 	unsigned char		buf[2];
261 	int			status;
262 
263 	buf[1] = rs5c->regs[RS5C_REG_CTRL1];
264 	switch (cmd) {
265 	case RTC_UIE_OFF:
266 	case RTC_UIE_ON:
267 		/* some 327a modes use a different IRQ pin for 1Hz irqs */
268 		if (rs5c->type == rtc_rs5c372a
269 				&& (buf[1] & RS5C372A_CTRL1_SL1))
270 			return -ENOIOCTLCMD;
271 	case RTC_AIE_OFF:
272 	case RTC_AIE_ON:
273 		/* these irq management calls only make sense for chips
274 		 * which are wired up to an IRQ.
275 		 */
276 		if (!rs5c->has_irq)
277 			return -ENOIOCTLCMD;
278 		break;
279 	default:
280 		return -ENOIOCTLCMD;
281 	}
282 
283 	status = rs5c_get_regs(rs5c);
284 	if (status < 0)
285 		return status;
286 
287 	buf[0] = RS5C_ADDR(RS5C_REG_CTRL1);
288 	switch (cmd) {
289 	case RTC_AIE_OFF:	/* alarm off */
290 		buf[1] &= ~RS5C_CTRL1_AALE;
291 		break;
292 	case RTC_AIE_ON:	/* alarm on */
293 		buf[1] |= RS5C_CTRL1_AALE;
294 		break;
295 	case RTC_UIE_OFF:	/* update off */
296 		buf[1] &= ~RS5C_CTRL1_CT_MASK;
297 		break;
298 	case RTC_UIE_ON:	/* update on */
299 		buf[1] &= ~RS5C_CTRL1_CT_MASK;
300 		buf[1] |= RS5C_CTRL1_CT4;
301 		break;
302 	}
303 	if ((i2c_master_send(client, buf, 2)) != 2) {
304 		printk(KERN_WARNING "%s: can't update alarm\n",
305 			rs5c->rtc->name);
306 		status = -EIO;
307 	} else
308 		rs5c->regs[RS5C_REG_CTRL1] = buf[1];
309 	return status;
310 }
311 
312 #else
313 #define	rs5c_rtc_ioctl	NULL
314 #endif
315 
316 
317 /* NOTE:  Since RTC_WKALM_{RD,SET} were originally defined for EFI,
318  * which only exposes a polled programming interface; and since
319  * these calls map directly to those EFI requests; we don't demand
320  * we have an IRQ for this chip when we go through this API.
321  *
322  * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
323  * though, managed through RTC_AIE_{ON,OFF} requests.
324  */
325 
326 static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
327 {
328 	struct i2c_client	*client = to_i2c_client(dev);
329 	struct rs5c372		*rs5c = i2c_get_clientdata(client);
330 	int			status;
331 
332 	status = rs5c_get_regs(rs5c);
333 	if (status < 0)
334 		return status;
335 
336 	/* report alarm time */
337 	t->time.tm_sec = 0;
338 	t->time.tm_min = BCD2BIN(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
339 	t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
340 	t->time.tm_mday = -1;
341 	t->time.tm_mon = -1;
342 	t->time.tm_year = -1;
343 	t->time.tm_wday = -1;
344 	t->time.tm_yday = -1;
345 	t->time.tm_isdst = -1;
346 
347 	/* ... and status */
348 	t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);
349 	t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG);
350 
351 	return 0;
352 }
353 
354 static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t)
355 {
356 	struct i2c_client	*client = to_i2c_client(dev);
357 	struct rs5c372		*rs5c = i2c_get_clientdata(client);
358 	int			status;
359 	unsigned char		buf[4];
360 
361 	/* only handle up to 24 hours in the future, like RTC_ALM_SET */
362 	if (t->time.tm_mday != -1
363 			|| t->time.tm_mon != -1
364 			|| t->time.tm_year != -1)
365 		return -EINVAL;
366 
367 	/* REVISIT: round up tm_sec */
368 
369 	/* if needed, disable irq (clears pending status) */
370 	status = rs5c_get_regs(rs5c);
371 	if (status < 0)
372 		return status;
373 	if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) {
374 		buf[0] = RS5C_ADDR(RS5C_REG_CTRL1);
375 		buf[1] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
376 		if (i2c_master_send(client, buf, 2) != 2) {
377 			pr_debug("%s: can't disable alarm\n", rs5c->rtc->name);
378 			return -EIO;
379 		}
380 		rs5c->regs[RS5C_REG_CTRL1] = buf[1];
381 	}
382 
383 	/* set alarm */
384 	buf[0] = RS5C_ADDR(RS5C_REG_ALARM_A_MIN);
385 	buf[1] = BIN2BCD(t->time.tm_min);
386 	buf[2] = rs5c_hr2reg(rs5c, t->time.tm_hour);
387 	buf[3] = 0x7f;	/* any/all days */
388 	if ((i2c_master_send(client, buf, 4)) != 4) {
389 		pr_debug("%s: can't set alarm time\n", rs5c->rtc->name);
390 		return -EIO;
391 	}
392 
393 	/* ... and maybe enable its irq */
394 	if (t->enabled) {
395 		buf[0] = RS5C_ADDR(RS5C_REG_CTRL1);
396 		buf[1] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE;
397 		if ((i2c_master_send(client, buf, 2)) != 2)
398 			printk(KERN_WARNING "%s: can't enable alarm\n",
399 				rs5c->rtc->name);
400 		rs5c->regs[RS5C_REG_CTRL1] = buf[1];
401 	}
402 
403 	return 0;
404 }
405 
406 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
407 
408 static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
409 {
410 	int err, osc, trim;
411 
412 	err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim);
413 	if (err == 0) {
414 		seq_printf(seq, "crystal\t\t: %d.%03d KHz\n",
415 				osc / 1000, osc % 1000);
416 		seq_printf(seq, "trim\t\t: %d\n", trim);
417 	}
418 
419 	return 0;
420 }
421 
422 #else
423 #define	rs5c372_rtc_proc	NULL
424 #endif
425 
426 static const struct rtc_class_ops rs5c372_rtc_ops = {
427 	.proc		= rs5c372_rtc_proc,
428 	.ioctl		= rs5c_rtc_ioctl,
429 	.read_time	= rs5c372_rtc_read_time,
430 	.set_time	= rs5c372_rtc_set_time,
431 	.read_alarm	= rs5c_read_alarm,
432 	.set_alarm	= rs5c_set_alarm,
433 };
434 
435 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
436 
437 static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
438 				struct device_attribute *attr, char *buf)
439 {
440 	int err, trim;
441 
442 	err = rs5c372_get_trim(to_i2c_client(dev), NULL, &trim);
443 	if (err)
444 		return err;
445 
446 	return sprintf(buf, "%d\n", trim);
447 }
448 static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
449 
450 static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
451 				struct device_attribute *attr, char *buf)
452 {
453 	int err, osc;
454 
455 	err = rs5c372_get_trim(to_i2c_client(dev), &osc, NULL);
456 	if (err)
457 		return err;
458 
459 	return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);
460 }
461 static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
462 
463 static int rs5c_sysfs_register(struct device *dev)
464 {
465 	int err;
466 
467 	err = device_create_file(dev, &dev_attr_trim);
468 	if (err)
469 		return err;
470 	err = device_create_file(dev, &dev_attr_osc);
471 	if (err)
472 		device_remove_file(dev, &dev_attr_trim);
473 
474 	return err;
475 }
476 
477 static void rs5c_sysfs_unregister(struct device *dev)
478 {
479 	device_remove_file(dev, &dev_attr_trim);
480 	device_remove_file(dev, &dev_attr_osc);
481 }
482 
483 #else
484 static int rs5c_sysfs_register(struct device *dev)
485 {
486 	return 0;
487 }
488 
489 static void rs5c_sysfs_unregister(struct device *dev)
490 {
491 	/* nothing */
492 }
493 #endif	/* SYSFS */
494 
495 static struct i2c_driver rs5c372_driver;
496 
497 static int rs5c372_probe(struct i2c_client *client)
498 {
499 	int err = 0;
500 	struct rs5c372 *rs5c372;
501 	struct rtc_time tm;
502 
503 	dev_dbg(&client->dev, "%s\n", __FUNCTION__);
504 
505 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
506 		err = -ENODEV;
507 		goto exit;
508 	}
509 
510 	if (!(rs5c372 = kzalloc(sizeof(struct rs5c372), GFP_KERNEL))) {
511 		err = -ENOMEM;
512 		goto exit;
513 	}
514 
515 	rs5c372->client = client;
516 	i2c_set_clientdata(client, rs5c372);
517 
518 	/* we read registers 0x0f then 0x00-0x0f; skip the first one */
519 	rs5c372->regs = &rs5c372->buf[1];
520 
521 	err = rs5c_get_regs(rs5c372);
522 	if (err < 0)
523 		goto exit_kfree;
524 
525 	if (strcmp(client->name, "rs5c372a") == 0)
526 		rs5c372->type = rtc_rs5c372a;
527 	else if (strcmp(client->name, "rs5c372b") == 0)
528 		rs5c372->type = rtc_rs5c372b;
529 	else if (strcmp(client->name, "rv5c386") == 0)
530 		rs5c372->type = rtc_rv5c386;
531 	else if (strcmp(client->name, "rv5c387a") == 0)
532 		rs5c372->type = rtc_rv5c387a;
533 	else {
534 		rs5c372->type = rtc_rs5c372b;
535 		dev_warn(&client->dev, "assuming rs5c372b\n");
536 	}
537 
538 	/* clock may be set for am/pm or 24 hr time */
539 	switch (rs5c372->type) {
540 	case rtc_rs5c372a:
541 	case rtc_rs5c372b:
542 		/* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
543 		 * so does periodic irq, except some 327a modes.
544 		 */
545 		if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
546 			rs5c372->time24 = 1;
547 		break;
548 	case rtc_rv5c386:
549 	case rtc_rv5c387a:
550 		if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
551 			rs5c372->time24 = 1;
552 		/* alarm uses ALARM_W; and nINTRB for alarm and periodic
553 		 * irq, on both 386 and 387
554 		 */
555 		break;
556 	default:
557 		dev_err(&client->dev, "unknown RTC type\n");
558 		goto exit_kfree;
559 	}
560 
561 	/* if the oscillator lost power and no other software (like
562 	 * the bootloader) set it up, do it here.
563 	 */
564 	if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_XSTP) {
565 		unsigned char buf[3];
566 
567 		rs5c372->regs[RS5C_REG_CTRL2] &= ~RS5C_CTRL2_XSTP;
568 
569 		buf[0] = RS5C_ADDR(RS5C_REG_CTRL1);
570 		buf[1] = rs5c372->regs[RS5C_REG_CTRL1];
571 		buf[2] = rs5c372->regs[RS5C_REG_CTRL2];
572 
573 		/* use 24hr mode */
574 		switch (rs5c372->type) {
575 		case rtc_rs5c372a:
576 		case rtc_rs5c372b:
577 			buf[2] |= RS5C372_CTRL2_24;
578 			rs5c372->time24 = 1;
579 			break;
580 		case rtc_rv5c386:
581 		case rtc_rv5c387a:
582 			buf[1] |= RV5C387_CTRL1_24;
583 			rs5c372->time24 = 1;
584 			break;
585 		default:
586 			/* impossible */
587 			break;
588 		}
589 
590 		if ((i2c_master_send(client, buf, 3)) != 3) {
591 			dev_err(&client->dev, "setup error\n");
592 			goto exit_kfree;
593 		}
594 		rs5c372->regs[RS5C_REG_CTRL1] = buf[1];
595 		rs5c372->regs[RS5C_REG_CTRL2] = buf[2];
596 	}
597 
598 	if (rs5c372_get_datetime(client, &tm) < 0)
599 		dev_warn(&client->dev, "clock needs to be set\n");
600 
601 	dev_info(&client->dev, "%s found, %s, driver version " DRV_VERSION "\n",
602 			({ char *s; switch (rs5c372->type) {
603 			case rtc_rs5c372a:	s = "rs5c372a"; break;
604 			case rtc_rs5c372b:	s = "rs5c372b"; break;
605 			case rtc_rv5c386:	s = "rv5c386"; break;
606 			case rtc_rv5c387a:	s = "rv5c387a"; break;
607 			default:		s = "chip"; break;
608 			}; s;}),
609 			rs5c372->time24 ? "24hr" : "am/pm"
610 			);
611 
612 	/* REVISIT use client->irq to register alarm irq ... */
613 
614 	rs5c372->rtc = rtc_device_register(rs5c372_driver.driver.name,
615 				&client->dev, &rs5c372_rtc_ops, THIS_MODULE);
616 
617 	if (IS_ERR(rs5c372->rtc)) {
618 		err = PTR_ERR(rs5c372->rtc);
619 		goto exit_kfree;
620 	}
621 
622 	err = rs5c_sysfs_register(&client->dev);
623 	if (err)
624 		goto exit_devreg;
625 
626 	return 0;
627 
628 exit_devreg:
629 	rtc_device_unregister(rs5c372->rtc);
630 
631 exit_kfree:
632 	kfree(rs5c372);
633 
634 exit:
635 	return err;
636 }
637 
638 static int rs5c372_remove(struct i2c_client *client)
639 {
640 	struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
641 
642 	rtc_device_unregister(rs5c372->rtc);
643 	rs5c_sysfs_unregister(&client->dev);
644 	kfree(rs5c372);
645 	return 0;
646 }
647 
648 static struct i2c_driver rs5c372_driver = {
649 	.driver		= {
650 		.name	= "rtc-rs5c372",
651 	},
652 	.probe		= rs5c372_probe,
653 	.remove		= rs5c372_remove,
654 };
655 
656 static __init int rs5c372_init(void)
657 {
658 	return i2c_add_driver(&rs5c372_driver);
659 }
660 
661 static __exit void rs5c372_exit(void)
662 {
663 	i2c_del_driver(&rs5c372_driver);
664 }
665 
666 module_init(rs5c372_init);
667 module_exit(rs5c372_exit);
668 
669 MODULE_AUTHOR(
670 		"Pavel Mironchik <pmironchik@optifacio.net>, "
671 		"Alessandro Zummo <a.zummo@towertech.it>");
672 MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
673 MODULE_LICENSE("GPL");
674 MODULE_VERSION(DRV_VERSION);
675