xref: /openbmc/linux/drivers/rtc/rtc-rx8025.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
1 /*
2  * Driver for Epson's RTC module RX-8025 SA/NB
3  *
4  * Copyright (C) 2009 Wolfgang Grandegger <wg@grandegger.com>
5  *
6  * Copyright (C) 2005 by Digi International Inc.
7  * All rights reserved.
8  *
9  * Modified by fengjh at rising.com.cn
10  * <http://lists.lm-sensors.org/mailman/listinfo/lm-sensors>
11  * 2006.11
12  *
13  * Code cleanup by Sergei Poselenov, <sposelenov@emcraft.com>
14  * Converted to new style by Wolfgang Grandegger <wg@grandegger.com>
15  * Alarm and periodic interrupt added by Dmitry Rakhchev <rda@emcraft.com>
16  *
17  * This program is free software; you can redistribute it and/or
18  * modify it under the terms of the GNU General Public License
19  * version 2 as published by the Free Software Foundation.
20  */
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/slab.h>
24 #include <linux/init.h>
25 #include <linux/bcd.h>
26 #include <linux/i2c.h>
27 #include <linux/list.h>
28 #include <linux/rtc.h>
29 
30 /* Register definitions */
31 #define RX8025_REG_SEC		0x00
32 #define RX8025_REG_MIN		0x01
33 #define RX8025_REG_HOUR		0x02
34 #define RX8025_REG_WDAY		0x03
35 #define RX8025_REG_MDAY		0x04
36 #define RX8025_REG_MONTH	0x05
37 #define RX8025_REG_YEAR		0x06
38 #define RX8025_REG_DIGOFF	0x07
39 #define RX8025_REG_ALWMIN	0x08
40 #define RX8025_REG_ALWHOUR	0x09
41 #define RX8025_REG_ALWWDAY	0x0a
42 #define RX8025_REG_ALDMIN	0x0b
43 #define RX8025_REG_ALDHOUR	0x0c
44 /* 0x0d is reserved */
45 #define RX8025_REG_CTRL1	0x0e
46 #define RX8025_REG_CTRL2	0x0f
47 
48 #define RX8025_BIT_CTRL1_CT	(7 << 0)
49 /* 1 Hz periodic level irq */
50 #define RX8025_BIT_CTRL1_CT_1HZ	4
51 #define RX8025_BIT_CTRL1_TEST	(1 << 3)
52 #define RX8025_BIT_CTRL1_1224	(1 << 5)
53 #define RX8025_BIT_CTRL1_DALE	(1 << 6)
54 #define RX8025_BIT_CTRL1_WALE	(1 << 7)
55 
56 #define RX8025_BIT_CTRL2_DAFG	(1 << 0)
57 #define RX8025_BIT_CTRL2_WAFG	(1 << 1)
58 #define RX8025_BIT_CTRL2_CTFG	(1 << 2)
59 #define RX8025_BIT_CTRL2_PON	(1 << 4)
60 #define RX8025_BIT_CTRL2_XST	(1 << 5)
61 #define RX8025_BIT_CTRL2_VDET	(1 << 6)
62 
63 /* Clock precision adjustment */
64 #define RX8025_ADJ_RESOLUTION	3050 /* in ppb */
65 #define RX8025_ADJ_DATA_MAX	62
66 #define RX8025_ADJ_DATA_MIN	-62
67 
68 static const struct i2c_device_id rx8025_id[] = {
69 	{ "rx8025", 0 },
70 	{ }
71 };
72 MODULE_DEVICE_TABLE(i2c, rx8025_id);
73 
74 struct rx8025_data {
75 	struct i2c_client *client;
76 	struct rtc_device *rtc;
77 	struct work_struct work;
78 	u8 ctrl1;
79 	unsigned exiting:1;
80 };
81 
82 static int rx8025_read_reg(struct i2c_client *client, int number, u8 *value)
83 {
84 	int ret = i2c_smbus_read_byte_data(client, (number << 4) | 0x08);
85 
86 	if (ret < 0) {
87 		dev_err(&client->dev, "Unable to read register #%d\n", number);
88 		return ret;
89 	}
90 
91 	*value = ret;
92 	return 0;
93 }
94 
95 static int rx8025_read_regs(struct i2c_client *client,
96 			    int number, u8 length, u8 *values)
97 {
98 	int ret = i2c_smbus_read_i2c_block_data(client, (number << 4) | 0x08,
99 						length, values);
100 
101 	if (ret != length) {
102 		dev_err(&client->dev, "Unable to read registers #%d..#%d\n",
103 			number, number + length - 1);
104 		return ret < 0 ? ret : -EIO;
105 	}
106 
107 	return 0;
108 }
109 
110 static int rx8025_write_reg(struct i2c_client *client, int number, u8 value)
111 {
112 	int ret = i2c_smbus_write_byte_data(client, number << 4, value);
113 
114 	if (ret)
115 		dev_err(&client->dev, "Unable to write register #%d\n",
116 			number);
117 
118 	return ret;
119 }
120 
121 static int rx8025_write_regs(struct i2c_client *client,
122 			     int number, u8 length, u8 *values)
123 {
124 	int ret = i2c_smbus_write_i2c_block_data(client, (number << 4) | 0x08,
125 						 length, values);
126 
127 	if (ret)
128 		dev_err(&client->dev, "Unable to write registers #%d..#%d\n",
129 			number, number + length - 1);
130 
131 	return ret;
132 }
133 
134 static irqreturn_t rx8025_irq(int irq, void *dev_id)
135 {
136 	struct i2c_client *client = dev_id;
137 	struct rx8025_data *rx8025 = i2c_get_clientdata(client);
138 
139 	disable_irq_nosync(irq);
140 	schedule_work(&rx8025->work);
141 	return IRQ_HANDLED;
142 }
143 
144 static void rx8025_work(struct work_struct *work)
145 {
146 	struct rx8025_data *rx8025 = container_of(work, struct rx8025_data,
147 						  work);
148 	struct i2c_client *client = rx8025->client;
149 	struct mutex *lock = &rx8025->rtc->ops_lock;
150 	u8 status;
151 
152 	mutex_lock(lock);
153 
154 	if (rx8025_read_reg(client, RX8025_REG_CTRL2, &status))
155 		goto out;
156 
157 	if (!(status & RX8025_BIT_CTRL2_XST))
158 		dev_warn(&client->dev, "Oscillation stop was detected,"
159 			 "you may have to readjust the clock\n");
160 
161 	if (status & RX8025_BIT_CTRL2_CTFG) {
162 		/* periodic */
163 		status &= ~RX8025_BIT_CTRL2_CTFG;
164 		local_irq_disable();
165 		rtc_update_irq(rx8025->rtc, 1, RTC_PF | RTC_IRQF);
166 		local_irq_enable();
167 	}
168 
169 	if (status & RX8025_BIT_CTRL2_DAFG) {
170 		/* alarm */
171 		status &= RX8025_BIT_CTRL2_DAFG;
172 		if (rx8025_write_reg(client, RX8025_REG_CTRL1,
173 				     rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE))
174 			goto out;
175 		local_irq_disable();
176 		rtc_update_irq(rx8025->rtc, 1, RTC_AF | RTC_IRQF);
177 		local_irq_enable();
178 	}
179 
180 	/* acknowledge IRQ */
181 	rx8025_write_reg(client, RX8025_REG_CTRL2,
182 			 status | RX8025_BIT_CTRL2_XST);
183 
184 out:
185 	if (!rx8025->exiting)
186 		enable_irq(client->irq);
187 
188 	mutex_unlock(lock);
189 }
190 
191 static int rx8025_get_time(struct device *dev, struct rtc_time *dt)
192 {
193 	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
194 	u8 date[7];
195 	int err;
196 
197 	err = rx8025_read_regs(rx8025->client, RX8025_REG_SEC, 7, date);
198 	if (err)
199 		return err;
200 
201 	dev_dbg(dev, "%s: read 0x%02x 0x%02x "
202 		"0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n", __func__,
203 		date[0], date[1], date[2], date[3], date[4],
204 		date[5], date[6]);
205 
206 	dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
207 	dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
208 	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
209 		dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);
210 	else
211 		dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12
212 			+ (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0);
213 
214 	dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);
215 	dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
216 	dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]);
217 
218 	if (dt->tm_year < 70)
219 		dt->tm_year += 100;
220 
221 	dev_dbg(dev, "%s: date %ds %dm %dh %dmd %dm %dy\n", __func__,
222 		dt->tm_sec, dt->tm_min, dt->tm_hour,
223 		dt->tm_mday, dt->tm_mon, dt->tm_year);
224 
225 	return rtc_valid_tm(dt);
226 }
227 
228 static int rx8025_set_time(struct device *dev, struct rtc_time *dt)
229 {
230 	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
231 	u8 date[7];
232 
233 	/*
234 	 * BUG: The HW assumes every year that is a multiple of 4 to be a leap
235 	 * year.  Next time this is wrong is 2100, which will not be a leap
236 	 * year.
237 	 */
238 
239 	/*
240 	 * Here the read-only bits are written as "0".  I'm not sure if that
241 	 * is sound.
242 	 */
243 	date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
244 	date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
245 	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
246 		date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
247 	else
248 		date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
249 			| bin2bcd((dt->tm_hour + 11) % 12 + 1);
250 
251 	date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
252 	date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
253 	date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
254 	date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year % 100);
255 
256 	dev_dbg(dev,
257 		"%s: write 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n",
258 		__func__,
259 		date[0], date[1], date[2], date[3], date[4], date[5], date[6]);
260 
261 	return rx8025_write_regs(rx8025->client, RX8025_REG_SEC, 7, date);
262 }
263 
264 static int rx8025_init_client(struct i2c_client *client, int *need_reset)
265 {
266 	struct rx8025_data *rx8025 = i2c_get_clientdata(client);
267 	u8 ctrl[2], ctrl2;
268 	int need_clear = 0;
269 	int err;
270 
271 	err = rx8025_read_regs(rx8025->client, RX8025_REG_CTRL1, 2, ctrl);
272 	if (err)
273 		goto out;
274 
275 	/* Keep test bit zero ! */
276 	rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;
277 
278 	if (ctrl[1] & RX8025_BIT_CTRL2_PON) {
279 		dev_warn(&client->dev, "power-on reset was detected, "
280 			 "you may have to readjust the clock\n");
281 		*need_reset = 1;
282 	}
283 
284 	if (ctrl[1] & RX8025_BIT_CTRL2_VDET) {
285 		dev_warn(&client->dev, "a power voltage drop was detected, "
286 			 "you may have to readjust the clock\n");
287 		*need_reset = 1;
288 	}
289 
290 	if (!(ctrl[1] & RX8025_BIT_CTRL2_XST)) {
291 		dev_warn(&client->dev, "Oscillation stop was detected,"
292 			 "you may have to readjust the clock\n");
293 		*need_reset = 1;
294 	}
295 
296 	if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG | RX8025_BIT_CTRL2_WAFG)) {
297 		dev_warn(&client->dev, "Alarm was detected\n");
298 		need_clear = 1;
299 	}
300 
301 	if (!(ctrl[1] & RX8025_BIT_CTRL2_CTFG))
302 		need_clear = 1;
303 
304 	if (*need_reset || need_clear) {
305 		ctrl2 = ctrl[0];
306 		ctrl2 &= ~(RX8025_BIT_CTRL2_PON | RX8025_BIT_CTRL2_VDET |
307 			   RX8025_BIT_CTRL2_CTFG | RX8025_BIT_CTRL2_WAFG |
308 			   RX8025_BIT_CTRL2_DAFG);
309 		ctrl2 |= RX8025_BIT_CTRL2_XST;
310 
311 		err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
312 	}
313 out:
314 	return err;
315 }
316 
317 /* Alarm support */
318 static int rx8025_read_alarm(struct device *dev, struct rtc_wkalrm *t)
319 {
320 	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
321 	struct i2c_client *client = rx8025->client;
322 	u8 ctrl2, ald[2];
323 	int err;
324 
325 	if (client->irq <= 0)
326 		return -EINVAL;
327 
328 	err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);
329 	if (err)
330 		return err;
331 
332 	err = rx8025_read_reg(client, RX8025_REG_CTRL2, &ctrl2);
333 	if (err)
334 		return err;
335 
336 	dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",
337 		__func__, ald[0], ald[1], ctrl2);
338 
339 	/* Hardware alarms precision is 1 minute! */
340 	t->time.tm_sec = 0;
341 	t->time.tm_min = bcd2bin(ald[0] & 0x7f);
342 	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
343 		t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
344 	else
345 		t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
346 			+ (ald[1] & 0x20 ? 12 : 0);
347 
348 	t->time.tm_wday = -1;
349 	t->time.tm_mday = -1;
350 	t->time.tm_mon = -1;
351 	t->time.tm_year = -1;
352 
353 	dev_dbg(dev, "%s: date: %ds %dm %dh %dmd %dm %dy\n",
354 		__func__,
355 		t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
356 		t->time.tm_mday, t->time.tm_mon, t->time.tm_year);
357 	t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
358 	t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
359 
360 	return err;
361 }
362 
363 static int rx8025_set_alarm(struct device *dev, struct rtc_wkalrm *t)
364 {
365 	struct i2c_client *client = to_i2c_client(dev);
366 	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
367 	u8 ald[2];
368 	int err;
369 
370 	if (client->irq <= 0)
371 		return -EINVAL;
372 
373 	/* Hardware alarm precision is 1 minute! */
374 	ald[0] = bin2bcd(t->time.tm_min);
375 	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
376 		ald[1] = bin2bcd(t->time.tm_hour);
377 	else
378 		ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
379 			| bin2bcd((t->time.tm_hour + 11) % 12 + 1);
380 
381 	dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);
382 
383 	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
384 		rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
385 		err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
386 				       rx8025->ctrl1);
387 		if (err)
388 			return err;
389 	}
390 	err = rx8025_write_regs(rx8025->client, RX8025_REG_ALDMIN, 2, ald);
391 	if (err)
392 		return err;
393 
394 	if (t->enabled) {
395 		rx8025->ctrl1 |= RX8025_BIT_CTRL1_DALE;
396 		err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
397 				       rx8025->ctrl1);
398 		if (err)
399 			return err;
400 	}
401 
402 	return 0;
403 }
404 
405 static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
406 {
407 	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
408 	u8 ctrl1;
409 	int err;
410 
411 	ctrl1 = rx8025->ctrl1;
412 	if (enabled)
413 		ctrl1 |= RX8025_BIT_CTRL1_DALE;
414 	else
415 		ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
416 
417 	if (ctrl1 != rx8025->ctrl1) {
418 		rx8025->ctrl1 = ctrl1;
419 		err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
420 				       rx8025->ctrl1);
421 		if (err)
422 			return err;
423 	}
424 	return 0;
425 }
426 
427 static int rx8025_irq_set_state(struct device *dev, int enabled)
428 {
429 	struct i2c_client *client = to_i2c_client(dev);
430 	struct rx8025_data *rx8025 = i2c_get_clientdata(client);
431 	int ctrl1;
432 	int err;
433 
434 	if (client->irq <= 0)
435 		return -ENXIO;
436 
437 	ctrl1 = rx8025->ctrl1 & ~RX8025_BIT_CTRL1_CT;
438 	if (enabled)
439 		ctrl1 |= RX8025_BIT_CTRL1_CT_1HZ;
440 	if (ctrl1 != rx8025->ctrl1) {
441 		rx8025->ctrl1 = ctrl1;
442 		err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
443 				       rx8025->ctrl1);
444 		if (err)
445 			return err;
446 	}
447 
448 	return 0;
449 }
450 
451 static struct rtc_class_ops rx8025_rtc_ops = {
452 	.read_time = rx8025_get_time,
453 	.set_time = rx8025_set_time,
454 	.read_alarm = rx8025_read_alarm,
455 	.set_alarm = rx8025_set_alarm,
456 	.alarm_irq_enable = rx8025_alarm_irq_enable,
457 	.irq_set_state  = rx8025_irq_set_state,
458 };
459 
460 /*
461  * Clock precision adjustment support
462  *
463  * According to the RX8025 SA/NB application manual the frequency and
464  * temperature characteristics can be approximated using the following
465  * equation:
466  *
467  *   df = a * (ut - t)**2
468  *
469  *   df: Frequency deviation in any temperature
470  *   a : Coefficient = (-35 +-5) * 10**-9
471  *   ut: Ultimate temperature in degree = +25 +-5 degree
472  *   t : Any temperature in degree
473  *
474  * Note that the clock adjustment in ppb must be entered (which is
475  * the negative value of the deviation).
476  */
477 static int rx8025_get_clock_adjust(struct device *dev, int *adj)
478 {
479 	struct i2c_client *client = to_i2c_client(dev);
480 	u8 digoff;
481 	int err;
482 
483 	err = rx8025_read_reg(client, RX8025_REG_DIGOFF, &digoff);
484 	if (err)
485 		return err;
486 
487 	*adj = digoff >= 64 ? digoff - 128 : digoff;
488 	if (*adj > 0)
489 		(*adj)--;
490 	*adj *= -RX8025_ADJ_RESOLUTION;
491 
492 	return 0;
493 }
494 
495 static int rx8025_set_clock_adjust(struct device *dev, int adj)
496 {
497 	struct i2c_client *client = to_i2c_client(dev);
498 	u8 digoff;
499 	int err;
500 
501 	adj /= -RX8025_ADJ_RESOLUTION;
502 	if (adj > RX8025_ADJ_DATA_MAX)
503 		adj = RX8025_ADJ_DATA_MAX;
504 	else if (adj < RX8025_ADJ_DATA_MIN)
505 		adj = RX8025_ADJ_DATA_MIN;
506 	else if (adj > 0)
507 		adj++;
508 	else if (adj < 0)
509 		adj += 128;
510 	digoff = adj;
511 
512 	err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
513 	if (err)
514 		return err;
515 
516 	dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff);
517 
518 	return 0;
519 }
520 
521 static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
522 					      struct device_attribute *attr,
523 					      char *buf)
524 {
525 	int err, adj;
526 
527 	err = rx8025_get_clock_adjust(dev, &adj);
528 	if (err)
529 		return err;
530 
531 	return sprintf(buf, "%d\n", adj);
532 }
533 
534 static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
535 					       struct device_attribute *attr,
536 					       const char *buf, size_t count)
537 {
538 	int adj, err;
539 
540 	if (sscanf(buf, "%i", &adj) != 1)
541 		return -EINVAL;
542 
543 	err = rx8025_set_clock_adjust(dev, adj);
544 
545 	return err ? err : count;
546 }
547 
548 static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO | S_IWUSR,
549 		   rx8025_sysfs_show_clock_adjust,
550 		   rx8025_sysfs_store_clock_adjust);
551 
552 static int rx8025_sysfs_register(struct device *dev)
553 {
554 	return device_create_file(dev, &dev_attr_clock_adjust_ppb);
555 }
556 
557 static void rx8025_sysfs_unregister(struct device *dev)
558 {
559 	device_remove_file(dev, &dev_attr_clock_adjust_ppb);
560 }
561 
562 static int __devinit rx8025_probe(struct i2c_client *client,
563 				  const struct i2c_device_id *id)
564 {
565 	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
566 	struct rx8025_data *rx8025;
567 	int err, need_reset = 0;
568 
569 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
570 				     | I2C_FUNC_SMBUS_I2C_BLOCK)) {
571 		dev_err(&adapter->dev,
572 			"doesn't support required functionality\n");
573 		err = -EIO;
574 		goto errout;
575 	}
576 
577 	rx8025 = kzalloc(sizeof(*rx8025), GFP_KERNEL);
578 	if (!rx8025) {
579 		dev_err(&adapter->dev, "failed to alloc memory\n");
580 		err = -ENOMEM;
581 		goto errout;
582 	}
583 
584 	rx8025->client = client;
585 	i2c_set_clientdata(client, rx8025);
586 	INIT_WORK(&rx8025->work, rx8025_work);
587 
588 	err = rx8025_init_client(client, &need_reset);
589 	if (err)
590 		goto errout_free;
591 
592 	if (need_reset) {
593 		struct rtc_time tm;
594 		dev_info(&client->dev,
595 			 "bad conditions detected, resetting date\n");
596 		rtc_time_to_tm(0, &tm);	/* 1970/1/1 */
597 		rx8025_set_time(&client->dev, &tm);
598 	}
599 
600 	rx8025->rtc = rtc_device_register(client->name, &client->dev,
601 					  &rx8025_rtc_ops, THIS_MODULE);
602 	if (IS_ERR(rx8025->rtc)) {
603 		err = PTR_ERR(rx8025->rtc);
604 		dev_err(&client->dev, "unable to register the class device\n");
605 		goto errout_free;
606 	}
607 
608 	if (client->irq > 0) {
609 		dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
610 		err = request_irq(client->irq, rx8025_irq,
611 				  0, "rx8025", client);
612 		if (err) {
613 			dev_err(&client->dev, "unable to request IRQ\n");
614 			goto errout_reg;
615 		}
616 	}
617 
618 	rx8025->rtc->irq_freq = 1;
619 	rx8025->rtc->max_user_freq = 1;
620 
621 	err = rx8025_sysfs_register(&client->dev);
622 	if (err)
623 		goto errout_irq;
624 
625 	return 0;
626 
627 errout_irq:
628 	if (client->irq > 0)
629 		free_irq(client->irq, client);
630 
631 errout_reg:
632 	rtc_device_unregister(rx8025->rtc);
633 
634 errout_free:
635 	kfree(rx8025);
636 
637 errout:
638 	dev_err(&adapter->dev, "probing for rx8025 failed\n");
639 	return err;
640 }
641 
642 static int __devexit rx8025_remove(struct i2c_client *client)
643 {
644 	struct rx8025_data *rx8025 = i2c_get_clientdata(client);
645 	struct mutex *lock = &rx8025->rtc->ops_lock;
646 
647 	if (client->irq > 0) {
648 		mutex_lock(lock);
649 		rx8025->exiting = 1;
650 		mutex_unlock(lock);
651 
652 		free_irq(client->irq, client);
653 		cancel_work_sync(&rx8025->work);
654 	}
655 
656 	rx8025_sysfs_unregister(&client->dev);
657 	rtc_device_unregister(rx8025->rtc);
658 	kfree(rx8025);
659 	return 0;
660 }
661 
662 static struct i2c_driver rx8025_driver = {
663 	.driver = {
664 		.name = "rtc-rx8025",
665 		.owner = THIS_MODULE,
666 	},
667 	.probe		= rx8025_probe,
668 	.remove		= __devexit_p(rx8025_remove),
669 	.id_table	= rx8025_id,
670 };
671 
672 static int __init rx8025_init(void)
673 {
674 	return i2c_add_driver(&rx8025_driver);
675 }
676 
677 static void __exit rx8025_exit(void)
678 {
679 	i2c_del_driver(&rx8025_driver);
680 }
681 
682 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
683 MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
684 MODULE_LICENSE("GPL");
685 
686 module_init(rx8025_init);
687 module_exit(rx8025_exit);
688