xref: /openbmc/linux/drivers/rtc/rtc-rs5c372.c (revision 9cfc5c90)
1 /*
2  * An I2C driver for Ricoh RS5C372, R2025S/D and RV5C38[67] RTCs
3  *
4  * Copyright (C) 2005 Pavel Mironchik <pmironchik@optifacio.net>
5  * Copyright (C) 2006 Tower Technologies
6  * Copyright (C) 2008 Paul Mundt
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12 
13 #include <linux/i2c.h>
14 #include <linux/rtc.h>
15 #include <linux/bcd.h>
16 #include <linux/slab.h>
17 #include <linux/module.h>
18 
19 #define DRV_VERSION "0.6"
20 
21 
22 /*
23  * Ricoh has a family of I2C based RTCs, which differ only slightly from
24  * each other.  Differences center on pinout (e.g. how many interrupts,
25  * output clock, etc) and how the control registers are used.  The '372
26  * is significant only because that's the one this driver first supported.
27  */
28 #define RS5C372_REG_SECS	0
29 #define RS5C372_REG_MINS	1
30 #define RS5C372_REG_HOURS	2
31 #define RS5C372_REG_WDAY	3
32 #define RS5C372_REG_DAY		4
33 #define RS5C372_REG_MONTH	5
34 #define RS5C372_REG_YEAR	6
35 #define RS5C372_REG_TRIM	7
36 #	define RS5C372_TRIM_XSL		0x80
37 #	define RS5C372_TRIM_MASK	0x7F
38 
39 #define RS5C_REG_ALARM_A_MIN	8			/* or ALARM_W */
40 #define RS5C_REG_ALARM_A_HOURS	9
41 #define RS5C_REG_ALARM_A_WDAY	10
42 
43 #define RS5C_REG_ALARM_B_MIN	11			/* or ALARM_D */
44 #define RS5C_REG_ALARM_B_HOURS	12
45 #define RS5C_REG_ALARM_B_WDAY	13			/* (ALARM_B only) */
46 
47 #define RS5C_REG_CTRL1		14
48 #	define RS5C_CTRL1_AALE		(1 << 7)	/* or WALE */
49 #	define RS5C_CTRL1_BALE		(1 << 6)	/* or DALE */
50 #	define RV5C387_CTRL1_24		(1 << 5)
51 #	define RS5C372A_CTRL1_SL1	(1 << 5)
52 #	define RS5C_CTRL1_CT_MASK	(7 << 0)
53 #	define RS5C_CTRL1_CT0		(0 << 0)	/* no periodic irq */
54 #	define RS5C_CTRL1_CT4		(4 << 0)	/* 1 Hz level irq */
55 #define RS5C_REG_CTRL2		15
56 #	define RS5C372_CTRL2_24		(1 << 5)
57 #	define R2025_CTRL2_XST		(1 << 5)
58 #	define RS5C_CTRL2_XSTP		(1 << 4)	/* only if !R2025S/D */
59 #	define RS5C_CTRL2_CTFG		(1 << 2)
60 #	define RS5C_CTRL2_AAFG		(1 << 1)	/* or WAFG */
61 #	define RS5C_CTRL2_BAFG		(1 << 0)	/* or DAFG */
62 
63 
64 /* to read (style 1) or write registers starting at R */
65 #define RS5C_ADDR(R)		(((R) << 4) | 0)
66 
67 
68 enum rtc_type {
69 	rtc_undef = 0,
70 	rtc_r2025sd,
71 	rtc_r2221tl,
72 	rtc_rs5c372a,
73 	rtc_rs5c372b,
74 	rtc_rv5c386,
75 	rtc_rv5c387a,
76 };
77 
78 static const struct i2c_device_id rs5c372_id[] = {
79 	{ "r2025sd", rtc_r2025sd },
80 	{ "r2221tl", rtc_r2221tl },
81 	{ "rs5c372a", rtc_rs5c372a },
82 	{ "rs5c372b", rtc_rs5c372b },
83 	{ "rv5c386", rtc_rv5c386 },
84 	{ "rv5c387a", rtc_rv5c387a },
85 	{ }
86 };
87 MODULE_DEVICE_TABLE(i2c, rs5c372_id);
88 
89 /* REVISIT:  this assumes that:
90  *  - we're in the 21st century, so it's safe to ignore the century
91  *    bit for rv5c38[67] (REG_MONTH bit 7);
92  *  - we should use ALARM_A not ALARM_B (may be wrong on some boards)
93  */
94 struct rs5c372 {
95 	struct i2c_client	*client;
96 	struct rtc_device	*rtc;
97 	enum rtc_type		type;
98 	unsigned		time24:1;
99 	unsigned		has_irq:1;
100 	unsigned		smbus:1;
101 	char			buf[17];
102 	char			*regs;
103 };
104 
105 static int rs5c_get_regs(struct rs5c372 *rs5c)
106 {
107 	struct i2c_client	*client = rs5c->client;
108 	struct i2c_msg		msgs[] = {
109 		{
110 			.addr = client->addr,
111 			.flags = I2C_M_RD,
112 			.len = sizeof(rs5c->buf),
113 			.buf = rs5c->buf
114 		},
115 	};
116 
117 	/* This implements the third reading method from the datasheet, using
118 	 * an internal address that's reset after each transaction (by STOP)
119 	 * to 0x0f ... so we read extra registers, and skip the first one.
120 	 *
121 	 * The first method doesn't work with the iop3xx adapter driver, on at
122 	 * least 80219 chips; this works around that bug.
123 	 *
124 	 * The third method on the other hand doesn't work for the SMBus-only
125 	 * configurations, so we use the the first method there, stripping off
126 	 * the extra register in the process.
127 	 */
128 	if (rs5c->smbus) {
129 		int addr = RS5C_ADDR(RS5C372_REG_SECS);
130 		int size = sizeof(rs5c->buf) - 1;
131 
132 		if (i2c_smbus_read_i2c_block_data(client, addr, size,
133 						  rs5c->buf + 1) != size) {
134 			dev_warn(&client->dev, "can't read registers\n");
135 			return -EIO;
136 		}
137 	} else {
138 		if ((i2c_transfer(client->adapter, msgs, 1)) != 1) {
139 			dev_warn(&client->dev, "can't read registers\n");
140 			return -EIO;
141 		}
142 	}
143 
144 	dev_dbg(&client->dev,
145 		"%3ph (%02x) %3ph (%02x), %3ph, %3ph; %02x %02x\n",
146 		rs5c->regs + 0, rs5c->regs[3],
147 		rs5c->regs + 4, rs5c->regs[7],
148 		rs5c->regs + 8, rs5c->regs + 11,
149 		rs5c->regs[14], rs5c->regs[15]);
150 
151 	return 0;
152 }
153 
154 static unsigned rs5c_reg2hr(struct rs5c372 *rs5c, unsigned reg)
155 {
156 	unsigned	hour;
157 
158 	if (rs5c->time24)
159 		return bcd2bin(reg & 0x3f);
160 
161 	hour = bcd2bin(reg & 0x1f);
162 	if (hour == 12)
163 		hour = 0;
164 	if (reg & 0x20)
165 		hour += 12;
166 	return hour;
167 }
168 
169 static unsigned rs5c_hr2reg(struct rs5c372 *rs5c, unsigned hour)
170 {
171 	if (rs5c->time24)
172 		return bin2bcd(hour);
173 
174 	if (hour > 12)
175 		return 0x20 | bin2bcd(hour - 12);
176 	if (hour == 12)
177 		return 0x20 | bin2bcd(12);
178 	if (hour == 0)
179 		return bin2bcd(12);
180 	return bin2bcd(hour);
181 }
182 
183 static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
184 {
185 	struct rs5c372	*rs5c = i2c_get_clientdata(client);
186 	int		status = rs5c_get_regs(rs5c);
187 
188 	if (status < 0)
189 		return status;
190 
191 	tm->tm_sec = bcd2bin(rs5c->regs[RS5C372_REG_SECS] & 0x7f);
192 	tm->tm_min = bcd2bin(rs5c->regs[RS5C372_REG_MINS] & 0x7f);
193 	tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]);
194 
195 	tm->tm_wday = bcd2bin(rs5c->regs[RS5C372_REG_WDAY] & 0x07);
196 	tm->tm_mday = bcd2bin(rs5c->regs[RS5C372_REG_DAY] & 0x3f);
197 
198 	/* tm->tm_mon is zero-based */
199 	tm->tm_mon = bcd2bin(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1;
200 
201 	/* year is 1900 + tm->tm_year */
202 	tm->tm_year = bcd2bin(rs5c->regs[RS5C372_REG_YEAR]) + 100;
203 
204 	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
205 		"mday=%d, mon=%d, year=%d, wday=%d\n",
206 		__func__,
207 		tm->tm_sec, tm->tm_min, tm->tm_hour,
208 		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
209 
210 	/* rtc might need initialization */
211 	return rtc_valid_tm(tm);
212 }
213 
214 static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)
215 {
216 	struct rs5c372	*rs5c = i2c_get_clientdata(client);
217 	unsigned char	buf[7];
218 	int		addr;
219 
220 	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "
221 		"mday=%d, mon=%d, year=%d, wday=%d\n",
222 		__func__,
223 		tm->tm_sec, tm->tm_min, tm->tm_hour,
224 		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
225 
226 	addr   = RS5C_ADDR(RS5C372_REG_SECS);
227 	buf[0] = bin2bcd(tm->tm_sec);
228 	buf[1] = bin2bcd(tm->tm_min);
229 	buf[2] = rs5c_hr2reg(rs5c, tm->tm_hour);
230 	buf[3] = bin2bcd(tm->tm_wday);
231 	buf[4] = bin2bcd(tm->tm_mday);
232 	buf[5] = bin2bcd(tm->tm_mon + 1);
233 	buf[6] = bin2bcd(tm->tm_year - 100);
234 
235 	if (i2c_smbus_write_i2c_block_data(client, addr, sizeof(buf), buf) < 0) {
236 		dev_err(&client->dev, "%s: write error\n", __func__);
237 		return -EIO;
238 	}
239 
240 	return 0;
241 }
242 
243 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
244 #define	NEED_TRIM
245 #endif
246 
247 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
248 #define	NEED_TRIM
249 #endif
250 
251 #ifdef	NEED_TRIM
252 static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
253 {
254 	struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
255 	u8 tmp = rs5c372->regs[RS5C372_REG_TRIM];
256 
257 	if (osc)
258 		*osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;
259 
260 	if (trim) {
261 		dev_dbg(&client->dev, "%s: raw trim=%x\n", __func__, tmp);
262 		tmp &= RS5C372_TRIM_MASK;
263 		if (tmp & 0x3e) {
264 			int t = tmp & 0x3f;
265 
266 			if (tmp & 0x40)
267 				t = (~t | (s8)0xc0) + 1;
268 			else
269 				t = t - 1;
270 
271 			tmp = t * 2;
272 		} else
273 			tmp = 0;
274 		*trim = tmp;
275 	}
276 
277 	return 0;
278 }
279 #endif
280 
281 static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
282 {
283 	return rs5c372_get_datetime(to_i2c_client(dev), tm);
284 }
285 
286 static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
287 {
288 	return rs5c372_set_datetime(to_i2c_client(dev), tm);
289 }
290 
291 
292 static int rs5c_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
293 {
294 	struct i2c_client	*client = to_i2c_client(dev);
295 	struct rs5c372		*rs5c = i2c_get_clientdata(client);
296 	unsigned char		buf;
297 	int			status, addr;
298 
299 	buf = rs5c->regs[RS5C_REG_CTRL1];
300 
301 	if (!rs5c->has_irq)
302 		return -EINVAL;
303 
304 	status = rs5c_get_regs(rs5c);
305 	if (status < 0)
306 		return status;
307 
308 	addr = RS5C_ADDR(RS5C_REG_CTRL1);
309 	if (enabled)
310 		buf |= RS5C_CTRL1_AALE;
311 	else
312 		buf &= ~RS5C_CTRL1_AALE;
313 
314 	if (i2c_smbus_write_byte_data(client, addr, buf) < 0) {
315 		dev_warn(dev, "can't update alarm\n");
316 		status = -EIO;
317 	} else
318 		rs5c->regs[RS5C_REG_CTRL1] = buf;
319 
320 	return status;
321 }
322 
323 
324 /* NOTE:  Since RTC_WKALM_{RD,SET} were originally defined for EFI,
325  * which only exposes a polled programming interface; and since
326  * these calls map directly to those EFI requests; we don't demand
327  * we have an IRQ for this chip when we go through this API.
328  *
329  * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
330  * though, managed through RTC_AIE_{ON,OFF} requests.
331  */
332 
333 static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
334 {
335 	struct i2c_client	*client = to_i2c_client(dev);
336 	struct rs5c372		*rs5c = i2c_get_clientdata(client);
337 	int			status;
338 
339 	status = rs5c_get_regs(rs5c);
340 	if (status < 0)
341 		return status;
342 
343 	/* report alarm time */
344 	t->time.tm_sec = 0;
345 	t->time.tm_min = bcd2bin(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
346 	t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
347 	t->time.tm_mday = -1;
348 	t->time.tm_mon = -1;
349 	t->time.tm_year = -1;
350 	t->time.tm_wday = -1;
351 	t->time.tm_yday = -1;
352 	t->time.tm_isdst = -1;
353 
354 	/* ... and status */
355 	t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);
356 	t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG);
357 
358 	return 0;
359 }
360 
361 static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t)
362 {
363 	struct i2c_client	*client = to_i2c_client(dev);
364 	struct rs5c372		*rs5c = i2c_get_clientdata(client);
365 	int			status, addr, i;
366 	unsigned char		buf[3];
367 
368 	/* only handle up to 24 hours in the future, like RTC_ALM_SET */
369 	if (t->time.tm_mday != -1
370 			|| t->time.tm_mon != -1
371 			|| t->time.tm_year != -1)
372 		return -EINVAL;
373 
374 	/* REVISIT: round up tm_sec */
375 
376 	/* if needed, disable irq (clears pending status) */
377 	status = rs5c_get_regs(rs5c);
378 	if (status < 0)
379 		return status;
380 	if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) {
381 		addr = RS5C_ADDR(RS5C_REG_CTRL1);
382 		buf[0] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
383 		if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0) {
384 			dev_dbg(dev, "can't disable alarm\n");
385 			return -EIO;
386 		}
387 		rs5c->regs[RS5C_REG_CTRL1] = buf[0];
388 	}
389 
390 	/* set alarm */
391 	buf[0] = bin2bcd(t->time.tm_min);
392 	buf[1] = rs5c_hr2reg(rs5c, t->time.tm_hour);
393 	buf[2] = 0x7f;	/* any/all days */
394 
395 	for (i = 0; i < sizeof(buf); i++) {
396 		addr = RS5C_ADDR(RS5C_REG_ALARM_A_MIN + i);
397 		if (i2c_smbus_write_byte_data(client, addr, buf[i]) < 0) {
398 			dev_dbg(dev, "can't set alarm time\n");
399 			return -EIO;
400 		}
401 	}
402 
403 	/* ... and maybe enable its irq */
404 	if (t->enabled) {
405 		addr = RS5C_ADDR(RS5C_REG_CTRL1);
406 		buf[0] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE;
407 		if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0)
408 			dev_warn(dev, "can't enable alarm\n");
409 		rs5c->regs[RS5C_REG_CTRL1] = buf[0];
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 	.read_time	= rs5c372_rtc_read_time,
438 	.set_time	= rs5c372_rtc_set_time,
439 	.read_alarm	= rs5c_read_alarm,
440 	.set_alarm	= rs5c_set_alarm,
441 	.alarm_irq_enable = rs5c_rtc_alarm_irq_enable,
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 rs5c_oscillator_setup(struct rs5c372 *rs5c372)
507 {
508 	unsigned char buf[2];
509 	int addr, i, ret = 0;
510 
511 	if (rs5c372->type == rtc_r2025sd) {
512 		if (!(rs5c372->regs[RS5C_REG_CTRL2] & R2025_CTRL2_XST))
513 			return ret;
514 		rs5c372->regs[RS5C_REG_CTRL2] &= ~R2025_CTRL2_XST;
515 	} else {
516 		if (!(rs5c372->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_XSTP))
517 			return ret;
518 		rs5c372->regs[RS5C_REG_CTRL2] &= ~RS5C_CTRL2_XSTP;
519 	}
520 
521 	addr   = RS5C_ADDR(RS5C_REG_CTRL1);
522 	buf[0] = rs5c372->regs[RS5C_REG_CTRL1];
523 	buf[1] = rs5c372->regs[RS5C_REG_CTRL2];
524 
525 	/* use 24hr mode */
526 	switch (rs5c372->type) {
527 	case rtc_rs5c372a:
528 	case rtc_rs5c372b:
529 		buf[1] |= RS5C372_CTRL2_24;
530 		rs5c372->time24 = 1;
531 		break;
532 	case rtc_r2025sd:
533 	case rtc_r2221tl:
534 	case rtc_rv5c386:
535 	case rtc_rv5c387a:
536 		buf[0] |= RV5C387_CTRL1_24;
537 		rs5c372->time24 = 1;
538 		break;
539 	default:
540 		/* impossible */
541 		break;
542 	}
543 
544 	for (i = 0; i < sizeof(buf); i++) {
545 		addr = RS5C_ADDR(RS5C_REG_CTRL1 + i);
546 		ret = i2c_smbus_write_byte_data(rs5c372->client, addr, buf[i]);
547 		if (unlikely(ret < 0))
548 			return ret;
549 	}
550 
551 	rs5c372->regs[RS5C_REG_CTRL1] = buf[0];
552 	rs5c372->regs[RS5C_REG_CTRL2] = buf[1];
553 
554 	return 0;
555 }
556 
557 static int rs5c372_probe(struct i2c_client *client,
558 			 const struct i2c_device_id *id)
559 {
560 	int err = 0;
561 	int smbus_mode = 0;
562 	struct rs5c372 *rs5c372;
563 	struct rtc_time tm;
564 
565 	dev_dbg(&client->dev, "%s\n", __func__);
566 
567 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
568 			I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) {
569 		/*
570 		 * If we don't have any master mode adapter, try breaking
571 		 * it down in to the barest of capabilities.
572 		 */
573 		if (i2c_check_functionality(client->adapter,
574 				I2C_FUNC_SMBUS_BYTE_DATA |
575 				I2C_FUNC_SMBUS_I2C_BLOCK))
576 			smbus_mode = 1;
577 		else {
578 			/* Still no good, give up */
579 			err = -ENODEV;
580 			goto exit;
581 		}
582 	}
583 
584 	rs5c372 = devm_kzalloc(&client->dev, sizeof(struct rs5c372),
585 				GFP_KERNEL);
586 	if (!rs5c372) {
587 		err = -ENOMEM;
588 		goto exit;
589 	}
590 
591 	rs5c372->client = client;
592 	i2c_set_clientdata(client, rs5c372);
593 	rs5c372->type = id->driver_data;
594 
595 	/* we read registers 0x0f then 0x00-0x0f; skip the first one */
596 	rs5c372->regs = &rs5c372->buf[1];
597 	rs5c372->smbus = smbus_mode;
598 
599 	err = rs5c_get_regs(rs5c372);
600 	if (err < 0)
601 		goto exit;
602 
603 	/* clock may be set for am/pm or 24 hr time */
604 	switch (rs5c372->type) {
605 	case rtc_rs5c372a:
606 	case rtc_rs5c372b:
607 		/* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
608 		 * so does periodic irq, except some 327a modes.
609 		 */
610 		if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
611 			rs5c372->time24 = 1;
612 		break;
613 	case rtc_r2025sd:
614 	case rtc_r2221tl:
615 	case rtc_rv5c386:
616 	case rtc_rv5c387a:
617 		if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
618 			rs5c372->time24 = 1;
619 		/* alarm uses ALARM_W; and nINTRB for alarm and periodic
620 		 * irq, on both 386 and 387
621 		 */
622 		break;
623 	default:
624 		dev_err(&client->dev, "unknown RTC type\n");
625 		goto exit;
626 	}
627 
628 	/* if the oscillator lost power and no other software (like
629 	 * the bootloader) set it up, do it here.
630 	 *
631 	 * The R2025S/D does this a little differently than the other
632 	 * parts, so we special case that..
633 	 */
634 	err = rs5c_oscillator_setup(rs5c372);
635 	if (unlikely(err < 0)) {
636 		dev_err(&client->dev, "setup error\n");
637 		goto exit;
638 	}
639 
640 	if (rs5c372_get_datetime(client, &tm) < 0)
641 		dev_warn(&client->dev, "clock needs to be set\n");
642 
643 	dev_info(&client->dev, "%s found, %s, driver version " DRV_VERSION "\n",
644 			({ char *s; switch (rs5c372->type) {
645 			case rtc_r2025sd:	s = "r2025sd"; break;
646 			case rtc_r2221tl:	s = "r2221tl"; break;
647 			case rtc_rs5c372a:	s = "rs5c372a"; break;
648 			case rtc_rs5c372b:	s = "rs5c372b"; break;
649 			case rtc_rv5c386:	s = "rv5c386"; break;
650 			case rtc_rv5c387a:	s = "rv5c387a"; break;
651 			default:		s = "chip"; break;
652 			}; s;}),
653 			rs5c372->time24 ? "24hr" : "am/pm"
654 			);
655 
656 	/* REVISIT use client->irq to register alarm irq ... */
657 	rs5c372->rtc = devm_rtc_device_register(&client->dev,
658 					rs5c372_driver.driver.name,
659 					&rs5c372_rtc_ops, THIS_MODULE);
660 
661 	if (IS_ERR(rs5c372->rtc)) {
662 		err = PTR_ERR(rs5c372->rtc);
663 		goto exit;
664 	}
665 
666 	err = rs5c_sysfs_register(&client->dev);
667 	if (err)
668 		goto exit;
669 
670 	return 0;
671 
672 exit:
673 	return err;
674 }
675 
676 static int rs5c372_remove(struct i2c_client *client)
677 {
678 	rs5c_sysfs_unregister(&client->dev);
679 	return 0;
680 }
681 
682 static struct i2c_driver rs5c372_driver = {
683 	.driver		= {
684 		.name	= "rtc-rs5c372",
685 	},
686 	.probe		= rs5c372_probe,
687 	.remove		= rs5c372_remove,
688 	.id_table	= rs5c372_id,
689 };
690 
691 module_i2c_driver(rs5c372_driver);
692 
693 MODULE_AUTHOR(
694 		"Pavel Mironchik <pmironchik@optifacio.net>, "
695 		"Alessandro Zummo <a.zummo@towertech.it>, "
696 		"Paul Mundt <lethal@linux-sh.org>");
697 MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
698 MODULE_LICENSE("GPL");
699 MODULE_VERSION(DRV_VERSION);
700