xref: /openbmc/linux/drivers/rtc/rtc-abx80x.c (revision 60772e48)
1 /*
2  * A driver for the I2C members of the Abracon AB x8xx RTC family,
3  * and compatible: AB 1805 and AB 0805
4  *
5  * Copyright 2014-2015 Macq S.A.
6  *
7  * Author: Philippe De Muyter <phdm@macqel.be>
8  * Author: Alexandre Belloni <alexandre.belloni@free-electrons.com>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License version 2 as
12  * published by the Free Software Foundation.
13  *
14  */
15 
16 #include <linux/bcd.h>
17 #include <linux/i2c.h>
18 #include <linux/module.h>
19 #include <linux/rtc.h>
20 
21 #define ABX8XX_REG_HTH		0x00
22 #define ABX8XX_REG_SC		0x01
23 #define ABX8XX_REG_MN		0x02
24 #define ABX8XX_REG_HR		0x03
25 #define ABX8XX_REG_DA		0x04
26 #define ABX8XX_REG_MO		0x05
27 #define ABX8XX_REG_YR		0x06
28 #define ABX8XX_REG_WD		0x07
29 
30 #define ABX8XX_REG_AHTH		0x08
31 #define ABX8XX_REG_ASC		0x09
32 #define ABX8XX_REG_AMN		0x0a
33 #define ABX8XX_REG_AHR		0x0b
34 #define ABX8XX_REG_ADA		0x0c
35 #define ABX8XX_REG_AMO		0x0d
36 #define ABX8XX_REG_AWD		0x0e
37 
38 #define ABX8XX_REG_STATUS	0x0f
39 #define ABX8XX_STATUS_AF	BIT(2)
40 
41 #define ABX8XX_REG_CTRL1	0x10
42 #define ABX8XX_CTRL_WRITE	BIT(0)
43 #define ABX8XX_CTRL_ARST	BIT(2)
44 #define ABX8XX_CTRL_12_24	BIT(6)
45 
46 #define ABX8XX_REG_IRQ		0x12
47 #define ABX8XX_IRQ_AIE		BIT(2)
48 #define ABX8XX_IRQ_IM_1_4	(0x3 << 5)
49 
50 #define ABX8XX_REG_CD_TIMER_CTL	0x18
51 
52 #define ABX8XX_REG_OSC		0x1c
53 #define ABX8XX_OSC_FOS		BIT(3)
54 #define ABX8XX_OSC_BOS		BIT(4)
55 #define ABX8XX_OSC_ACAL_512	BIT(5)
56 #define ABX8XX_OSC_ACAL_1024	BIT(6)
57 
58 #define ABX8XX_OSC_OSEL		BIT(7)
59 
60 #define ABX8XX_REG_OSS		0x1d
61 #define ABX8XX_OSS_OF		BIT(1)
62 #define ABX8XX_OSS_OMODE	BIT(4)
63 
64 #define ABX8XX_REG_CFG_KEY	0x1f
65 #define ABX8XX_CFG_KEY_OSC	0xa1
66 #define ABX8XX_CFG_KEY_MISC	0x9d
67 
68 #define ABX8XX_REG_ID0		0x28
69 
70 #define ABX8XX_REG_TRICKLE	0x20
71 #define ABX8XX_TRICKLE_CHARGE_ENABLE	0xa0
72 #define ABX8XX_TRICKLE_STANDARD_DIODE	0x8
73 #define ABX8XX_TRICKLE_SCHOTTKY_DIODE	0x4
74 
75 static u8 trickle_resistors[] = {0, 3, 6, 11};
76 
77 enum abx80x_chip {AB0801, AB0803, AB0804, AB0805,
78 	AB1801, AB1803, AB1804, AB1805, ABX80X};
79 
80 struct abx80x_cap {
81 	u16 pn;
82 	bool has_tc;
83 };
84 
85 static struct abx80x_cap abx80x_caps[] = {
86 	[AB0801] = {.pn = 0x0801},
87 	[AB0803] = {.pn = 0x0803},
88 	[AB0804] = {.pn = 0x0804, .has_tc = true},
89 	[AB0805] = {.pn = 0x0805, .has_tc = true},
90 	[AB1801] = {.pn = 0x1801},
91 	[AB1803] = {.pn = 0x1803},
92 	[AB1804] = {.pn = 0x1804, .has_tc = true},
93 	[AB1805] = {.pn = 0x1805, .has_tc = true},
94 	[ABX80X] = {.pn = 0}
95 };
96 
97 static int abx80x_is_rc_mode(struct i2c_client *client)
98 {
99 	int flags = 0;
100 
101 	flags =  i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
102 	if (flags < 0) {
103 		dev_err(&client->dev,
104 			"Failed to read autocalibration attribute\n");
105 		return flags;
106 	}
107 
108 	return (flags & ABX8XX_OSS_OMODE) ? 1 : 0;
109 }
110 
111 static int abx80x_enable_trickle_charger(struct i2c_client *client,
112 					 u8 trickle_cfg)
113 {
114 	int err;
115 
116 	/*
117 	 * Write the configuration key register to enable access to the Trickle
118 	 * register
119 	 */
120 	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
121 					ABX8XX_CFG_KEY_MISC);
122 	if (err < 0) {
123 		dev_err(&client->dev, "Unable to write configuration key\n");
124 		return -EIO;
125 	}
126 
127 	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_TRICKLE,
128 					ABX8XX_TRICKLE_CHARGE_ENABLE |
129 					trickle_cfg);
130 	if (err < 0) {
131 		dev_err(&client->dev, "Unable to write trickle register\n");
132 		return -EIO;
133 	}
134 
135 	return 0;
136 }
137 
138 static int abx80x_rtc_read_time(struct device *dev, struct rtc_time *tm)
139 {
140 	struct i2c_client *client = to_i2c_client(dev);
141 	unsigned char buf[8];
142 	int err, flags, rc_mode = 0;
143 
144 	/* Read the Oscillator Failure only in XT mode */
145 	rc_mode = abx80x_is_rc_mode(client);
146 	if (rc_mode < 0)
147 		return rc_mode;
148 
149 	if (!rc_mode) {
150 		flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
151 		if (flags < 0)
152 			return flags;
153 
154 		if (flags & ABX8XX_OSS_OF) {
155 			dev_err(dev, "Oscillator failure, data is invalid.\n");
156 			return -EINVAL;
157 		}
158 	}
159 
160 	err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_HTH,
161 					    sizeof(buf), buf);
162 	if (err < 0) {
163 		dev_err(&client->dev, "Unable to read date\n");
164 		return -EIO;
165 	}
166 
167 	tm->tm_sec = bcd2bin(buf[ABX8XX_REG_SC] & 0x7F);
168 	tm->tm_min = bcd2bin(buf[ABX8XX_REG_MN] & 0x7F);
169 	tm->tm_hour = bcd2bin(buf[ABX8XX_REG_HR] & 0x3F);
170 	tm->tm_wday = buf[ABX8XX_REG_WD] & 0x7;
171 	tm->tm_mday = bcd2bin(buf[ABX8XX_REG_DA] & 0x3F);
172 	tm->tm_mon = bcd2bin(buf[ABX8XX_REG_MO] & 0x1F) - 1;
173 	tm->tm_year = bcd2bin(buf[ABX8XX_REG_YR]) + 100;
174 
175 	err = rtc_valid_tm(tm);
176 	if (err < 0)
177 		dev_err(&client->dev, "retrieved date/time is not valid.\n");
178 
179 	return err;
180 }
181 
182 static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm)
183 {
184 	struct i2c_client *client = to_i2c_client(dev);
185 	unsigned char buf[8];
186 	int err, flags;
187 
188 	if (tm->tm_year < 100)
189 		return -EINVAL;
190 
191 	buf[ABX8XX_REG_HTH] = 0;
192 	buf[ABX8XX_REG_SC] = bin2bcd(tm->tm_sec);
193 	buf[ABX8XX_REG_MN] = bin2bcd(tm->tm_min);
194 	buf[ABX8XX_REG_HR] = bin2bcd(tm->tm_hour);
195 	buf[ABX8XX_REG_DA] = bin2bcd(tm->tm_mday);
196 	buf[ABX8XX_REG_MO] = bin2bcd(tm->tm_mon + 1);
197 	buf[ABX8XX_REG_YR] = bin2bcd(tm->tm_year - 100);
198 	buf[ABX8XX_REG_WD] = tm->tm_wday;
199 
200 	err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_HTH,
201 					     sizeof(buf), buf);
202 	if (err < 0) {
203 		dev_err(&client->dev, "Unable to write to date registers\n");
204 		return -EIO;
205 	}
206 
207 	/* Clear the OF bit of Oscillator Status Register */
208 	flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
209 	if (flags < 0)
210 		return flags;
211 
212 	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSS,
213 					flags & ~ABX8XX_OSS_OF);
214 	if (err < 0) {
215 		dev_err(&client->dev, "Unable to write oscillator status register\n");
216 		return err;
217 	}
218 
219 	return 0;
220 }
221 
222 static irqreturn_t abx80x_handle_irq(int irq, void *dev_id)
223 {
224 	struct i2c_client *client = dev_id;
225 	struct rtc_device *rtc = i2c_get_clientdata(client);
226 	int status;
227 
228 	status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
229 	if (status < 0)
230 		return IRQ_NONE;
231 
232 	if (status & ABX8XX_STATUS_AF)
233 		rtc_update_irq(rtc, 1, RTC_AF | RTC_IRQF);
234 
235 	i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
236 
237 	return IRQ_HANDLED;
238 }
239 
240 static int abx80x_read_alarm(struct device *dev, struct rtc_wkalrm *t)
241 {
242 	struct i2c_client *client = to_i2c_client(dev);
243 	unsigned char buf[7];
244 
245 	int irq_mask, err;
246 
247 	if (client->irq <= 0)
248 		return -EINVAL;
249 
250 	err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ASC,
251 					    sizeof(buf), buf);
252 	if (err)
253 		return err;
254 
255 	irq_mask = i2c_smbus_read_byte_data(client, ABX8XX_REG_IRQ);
256 	if (irq_mask < 0)
257 		return irq_mask;
258 
259 	t->time.tm_sec = bcd2bin(buf[0] & 0x7F);
260 	t->time.tm_min = bcd2bin(buf[1] & 0x7F);
261 	t->time.tm_hour = bcd2bin(buf[2] & 0x3F);
262 	t->time.tm_mday = bcd2bin(buf[3] & 0x3F);
263 	t->time.tm_mon = bcd2bin(buf[4] & 0x1F) - 1;
264 	t->time.tm_wday = buf[5] & 0x7;
265 
266 	t->enabled = !!(irq_mask & ABX8XX_IRQ_AIE);
267 	t->pending = (buf[6] & ABX8XX_STATUS_AF) && t->enabled;
268 
269 	return err;
270 }
271 
272 static int abx80x_set_alarm(struct device *dev, struct rtc_wkalrm *t)
273 {
274 	struct i2c_client *client = to_i2c_client(dev);
275 	u8 alarm[6];
276 	int err;
277 
278 	if (client->irq <= 0)
279 		return -EINVAL;
280 
281 	alarm[0] = 0x0;
282 	alarm[1] = bin2bcd(t->time.tm_sec);
283 	alarm[2] = bin2bcd(t->time.tm_min);
284 	alarm[3] = bin2bcd(t->time.tm_hour);
285 	alarm[4] = bin2bcd(t->time.tm_mday);
286 	alarm[5] = bin2bcd(t->time.tm_mon + 1);
287 
288 	err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_AHTH,
289 					     sizeof(alarm), alarm);
290 	if (err < 0) {
291 		dev_err(&client->dev, "Unable to write alarm registers\n");
292 		return -EIO;
293 	}
294 
295 	if (t->enabled) {
296 		err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
297 						(ABX8XX_IRQ_IM_1_4 |
298 						 ABX8XX_IRQ_AIE));
299 		if (err)
300 			return err;
301 	}
302 
303 	return 0;
304 }
305 
306 static int abx80x_rtc_set_autocalibration(struct device *dev,
307 					  int autocalibration)
308 {
309 	struct i2c_client *client = to_i2c_client(dev);
310 	int retval, flags = 0;
311 
312 	if ((autocalibration != 0) && (autocalibration != 1024) &&
313 	    (autocalibration != 512)) {
314 		dev_err(dev, "autocalibration value outside permitted range\n");
315 		return -EINVAL;
316 	}
317 
318 	flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
319 	if (flags < 0)
320 		return flags;
321 
322 	if (autocalibration == 0) {
323 		flags &= ~(ABX8XX_OSC_ACAL_512 | ABX8XX_OSC_ACAL_1024);
324 	} else if (autocalibration == 1024) {
325 		/* 1024 autocalibration is 0x10 */
326 		flags |= ABX8XX_OSC_ACAL_1024;
327 		flags &= ~(ABX8XX_OSC_ACAL_512);
328 	} else {
329 		/* 512 autocalibration is 0x11 */
330 		flags |= (ABX8XX_OSC_ACAL_1024 | ABX8XX_OSC_ACAL_512);
331 	}
332 
333 	/* Unlock write access to Oscillator Control Register */
334 	retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
335 					   ABX8XX_CFG_KEY_OSC);
336 	if (retval < 0) {
337 		dev_err(dev, "Failed to write CONFIG_KEY register\n");
338 		return retval;
339 	}
340 
341 	retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);
342 
343 	return retval;
344 }
345 
346 static int abx80x_rtc_get_autocalibration(struct device *dev)
347 {
348 	struct i2c_client *client = to_i2c_client(dev);
349 	int flags = 0, autocalibration;
350 
351 	flags =  i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
352 	if (flags < 0)
353 		return flags;
354 
355 	if (flags & ABX8XX_OSC_ACAL_512)
356 		autocalibration = 512;
357 	else if (flags & ABX8XX_OSC_ACAL_1024)
358 		autocalibration = 1024;
359 	else
360 		autocalibration = 0;
361 
362 	return autocalibration;
363 }
364 
365 static ssize_t autocalibration_store(struct device *dev,
366 				     struct device_attribute *attr,
367 				     const char *buf, size_t count)
368 {
369 	int retval;
370 	unsigned long autocalibration = 0;
371 
372 	retval = kstrtoul(buf, 10, &autocalibration);
373 	if (retval < 0) {
374 		dev_err(dev, "Failed to store RTC autocalibration attribute\n");
375 		return -EINVAL;
376 	}
377 
378 	retval = abx80x_rtc_set_autocalibration(dev, autocalibration);
379 
380 	return retval ? retval : count;
381 }
382 
383 static ssize_t autocalibration_show(struct device *dev,
384 				    struct device_attribute *attr, char *buf)
385 {
386 	int autocalibration = 0;
387 
388 	autocalibration = abx80x_rtc_get_autocalibration(dev);
389 	if (autocalibration < 0) {
390 		dev_err(dev, "Failed to read RTC autocalibration\n");
391 		sprintf(buf, "0\n");
392 		return autocalibration;
393 	}
394 
395 	return sprintf(buf, "%d\n", autocalibration);
396 }
397 
398 static DEVICE_ATTR_RW(autocalibration);
399 
400 static ssize_t oscillator_store(struct device *dev,
401 				struct device_attribute *attr,
402 				const char *buf, size_t count)
403 {
404 	struct i2c_client *client = to_i2c_client(dev);
405 	int retval, flags, rc_mode = 0;
406 
407 	if (strncmp(buf, "rc", 2) == 0) {
408 		rc_mode = 1;
409 	} else if (strncmp(buf, "xtal", 4) == 0) {
410 		rc_mode = 0;
411 	} else {
412 		dev_err(dev, "Oscillator selection value outside permitted ones\n");
413 		return -EINVAL;
414 	}
415 
416 	flags =  i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
417 	if (flags < 0)
418 		return flags;
419 
420 	if (rc_mode == 0)
421 		flags &= ~(ABX8XX_OSC_OSEL);
422 	else
423 		flags |= (ABX8XX_OSC_OSEL);
424 
425 	/* Unlock write access on Oscillator Control register */
426 	retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
427 					   ABX8XX_CFG_KEY_OSC);
428 	if (retval < 0) {
429 		dev_err(dev, "Failed to write CONFIG_KEY register\n");
430 		return retval;
431 	}
432 
433 	retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);
434 	if (retval < 0) {
435 		dev_err(dev, "Failed to write Oscillator Control register\n");
436 		return retval;
437 	}
438 
439 	return retval ? retval : count;
440 }
441 
442 static ssize_t oscillator_show(struct device *dev,
443 			       struct device_attribute *attr, char *buf)
444 {
445 	int rc_mode = 0;
446 	struct i2c_client *client = to_i2c_client(dev);
447 
448 	rc_mode = abx80x_is_rc_mode(client);
449 
450 	if (rc_mode < 0) {
451 		dev_err(dev, "Failed to read RTC oscillator selection\n");
452 		sprintf(buf, "\n");
453 		return rc_mode;
454 	}
455 
456 	if (rc_mode)
457 		return sprintf(buf, "rc\n");
458 	else
459 		return sprintf(buf, "xtal\n");
460 }
461 
462 static DEVICE_ATTR_RW(oscillator);
463 
464 static struct attribute *rtc_calib_attrs[] = {
465 	&dev_attr_autocalibration.attr,
466 	&dev_attr_oscillator.attr,
467 	NULL,
468 };
469 
470 static const struct attribute_group rtc_calib_attr_group = {
471 	.attrs		= rtc_calib_attrs,
472 };
473 
474 static int abx80x_alarm_irq_enable(struct device *dev, unsigned int enabled)
475 {
476 	struct i2c_client *client = to_i2c_client(dev);
477 	int err;
478 
479 	if (enabled)
480 		err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
481 						(ABX8XX_IRQ_IM_1_4 |
482 						 ABX8XX_IRQ_AIE));
483 	else
484 		err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
485 						ABX8XX_IRQ_IM_1_4);
486 	return err;
487 }
488 
489 static const struct rtc_class_ops abx80x_rtc_ops = {
490 	.read_time	= abx80x_rtc_read_time,
491 	.set_time	= abx80x_rtc_set_time,
492 	.read_alarm	= abx80x_read_alarm,
493 	.set_alarm	= abx80x_set_alarm,
494 	.alarm_irq_enable = abx80x_alarm_irq_enable,
495 };
496 
497 static int abx80x_dt_trickle_cfg(struct device_node *np)
498 {
499 	const char *diode;
500 	int trickle_cfg = 0;
501 	int i, ret;
502 	u32 tmp;
503 
504 	ret = of_property_read_string(np, "abracon,tc-diode", &diode);
505 	if (ret)
506 		return ret;
507 
508 	if (!strcmp(diode, "standard"))
509 		trickle_cfg |= ABX8XX_TRICKLE_STANDARD_DIODE;
510 	else if (!strcmp(diode, "schottky"))
511 		trickle_cfg |= ABX8XX_TRICKLE_SCHOTTKY_DIODE;
512 	else
513 		return -EINVAL;
514 
515 	ret = of_property_read_u32(np, "abracon,tc-resistor", &tmp);
516 	if (ret)
517 		return ret;
518 
519 	for (i = 0; i < sizeof(trickle_resistors); i++)
520 		if (trickle_resistors[i] == tmp)
521 			break;
522 
523 	if (i == sizeof(trickle_resistors))
524 		return -EINVAL;
525 
526 	return (trickle_cfg | i);
527 }
528 
529 static void rtc_calib_remove_sysfs_group(void *_dev)
530 {
531 	struct device *dev = _dev;
532 
533 	sysfs_remove_group(&dev->kobj, &rtc_calib_attr_group);
534 }
535 
536 static int abx80x_probe(struct i2c_client *client,
537 			const struct i2c_device_id *id)
538 {
539 	struct device_node *np = client->dev.of_node;
540 	struct rtc_device *rtc;
541 	int i, data, err, trickle_cfg = -EINVAL;
542 	char buf[7];
543 	unsigned int part = id->driver_data;
544 	unsigned int partnumber;
545 	unsigned int majrev, minrev;
546 	unsigned int lot;
547 	unsigned int wafer;
548 	unsigned int uid;
549 
550 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
551 		return -ENODEV;
552 
553 	err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ID0,
554 					    sizeof(buf), buf);
555 	if (err < 0) {
556 		dev_err(&client->dev, "Unable to read partnumber\n");
557 		return -EIO;
558 	}
559 
560 	partnumber = (buf[0] << 8) | buf[1];
561 	majrev = buf[2] >> 3;
562 	minrev = buf[2] & 0x7;
563 	lot = ((buf[4] & 0x80) << 2) | ((buf[6] & 0x80) << 1) | buf[3];
564 	uid = ((buf[4] & 0x7f) << 8) | buf[5];
565 	wafer = (buf[6] & 0x7c) >> 2;
566 	dev_info(&client->dev, "model %04x, revision %u.%u, lot %x, wafer %x, uid %x\n",
567 		 partnumber, majrev, minrev, lot, wafer, uid);
568 
569 	data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL1);
570 	if (data < 0) {
571 		dev_err(&client->dev, "Unable to read control register\n");
572 		return -EIO;
573 	}
574 
575 	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL1,
576 					((data & ~(ABX8XX_CTRL_12_24 |
577 						   ABX8XX_CTRL_ARST)) |
578 					 ABX8XX_CTRL_WRITE));
579 	if (err < 0) {
580 		dev_err(&client->dev, "Unable to write control register\n");
581 		return -EIO;
582 	}
583 
584 	/* part autodetection */
585 	if (part == ABX80X) {
586 		for (i = 0; abx80x_caps[i].pn; i++)
587 			if (partnumber == abx80x_caps[i].pn)
588 				break;
589 		if (abx80x_caps[i].pn == 0) {
590 			dev_err(&client->dev, "Unknown part: %04x\n",
591 				partnumber);
592 			return -EINVAL;
593 		}
594 		part = i;
595 	}
596 
597 	if (partnumber != abx80x_caps[part].pn) {
598 		dev_err(&client->dev, "partnumber mismatch %04x != %04x\n",
599 			partnumber, abx80x_caps[part].pn);
600 		return -EINVAL;
601 	}
602 
603 	if (np && abx80x_caps[part].has_tc)
604 		trickle_cfg = abx80x_dt_trickle_cfg(np);
605 
606 	if (trickle_cfg > 0) {
607 		dev_info(&client->dev, "Enabling trickle charger: %02x\n",
608 			 trickle_cfg);
609 		abx80x_enable_trickle_charger(client, trickle_cfg);
610 	}
611 
612 	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CD_TIMER_CTL,
613 					BIT(2));
614 	if (err)
615 		return err;
616 
617 	rtc = devm_rtc_allocate_device(&client->dev);
618 	if (IS_ERR(rtc))
619 		return PTR_ERR(rtc);
620 
621 	rtc->ops = &abx80x_rtc_ops;
622 
623 	i2c_set_clientdata(client, rtc);
624 
625 	if (client->irq > 0) {
626 		dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
627 		err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
628 						abx80x_handle_irq,
629 						IRQF_SHARED | IRQF_ONESHOT,
630 						"abx8xx",
631 						client);
632 		if (err) {
633 			dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
634 			client->irq = 0;
635 		}
636 	}
637 
638 	/* Export sysfs entries */
639 	err = sysfs_create_group(&(&client->dev)->kobj, &rtc_calib_attr_group);
640 	if (err) {
641 		dev_err(&client->dev, "Failed to create sysfs group: %d\n",
642 			err);
643 		return err;
644 	}
645 
646 	err = devm_add_action_or_reset(&client->dev,
647 				       rtc_calib_remove_sysfs_group,
648 				       &client->dev);
649 	if (err) {
650 		dev_err(&client->dev,
651 			"Failed to add sysfs cleanup action: %d\n",
652 			err);
653 		return err;
654 	}
655 
656 	err = rtc_register_device(rtc);
657 
658 	return err;
659 }
660 
661 static int abx80x_remove(struct i2c_client *client)
662 {
663 	return 0;
664 }
665 
666 static const struct i2c_device_id abx80x_id[] = {
667 	{ "abx80x", ABX80X },
668 	{ "ab0801", AB0801 },
669 	{ "ab0803", AB0803 },
670 	{ "ab0804", AB0804 },
671 	{ "ab0805", AB0805 },
672 	{ "ab1801", AB1801 },
673 	{ "ab1803", AB1803 },
674 	{ "ab1804", AB1804 },
675 	{ "ab1805", AB1805 },
676 	{ "rv1805", AB1805 },
677 	{ }
678 };
679 MODULE_DEVICE_TABLE(i2c, abx80x_id);
680 
681 static struct i2c_driver abx80x_driver = {
682 	.driver		= {
683 		.name	= "rtc-abx80x",
684 	},
685 	.probe		= abx80x_probe,
686 	.remove		= abx80x_remove,
687 	.id_table	= abx80x_id,
688 };
689 
690 module_i2c_driver(abx80x_driver);
691 
692 MODULE_AUTHOR("Philippe De Muyter <phdm@macqel.be>");
693 MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>");
694 MODULE_DESCRIPTION("Abracon ABX80X RTC driver");
695 MODULE_LICENSE("GPL v2");
696