xref: /openbmc/linux/drivers/rtc/rtc-ds3232.c (revision cb1aaebe)
1 /*
2  * RTC client/driver for the Maxim/Dallas DS3232/DS3234 Real-Time Clock
3  *
4  * Copyright (C) 2009-2011 Freescale Semiconductor.
5  * Author: Jack Lan <jack.lan@freescale.com>
6  * Copyright (C) 2008 MIMOMax Wireless Ltd.
7  *
8  * This program is free software; you can redistribute  it and/or modify it
9  * under  the terms of  the GNU General  Public License as published by the
10  * Free Software Foundation;  either version 2 of the  License, or (at your
11  * option) any later version.
12  */
13 
14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15 
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/interrupt.h>
19 #include <linux/i2c.h>
20 #include <linux/spi/spi.h>
21 #include <linux/rtc.h>
22 #include <linux/bcd.h>
23 #include <linux/slab.h>
24 #include <linux/regmap.h>
25 #include <linux/hwmon.h>
26 
27 #define DS3232_REG_SECONDS      0x00
28 #define DS3232_REG_MINUTES      0x01
29 #define DS3232_REG_HOURS        0x02
30 #define DS3232_REG_AMPM         0x02
31 #define DS3232_REG_DAY          0x03
32 #define DS3232_REG_DATE         0x04
33 #define DS3232_REG_MONTH        0x05
34 #define DS3232_REG_CENTURY      0x05
35 #define DS3232_REG_YEAR         0x06
36 #define DS3232_REG_ALARM1       0x07       /* Alarm 1 BASE */
37 #define DS3232_REG_ALARM2       0x0B       /* Alarm 2 BASE */
38 #define DS3232_REG_CR           0x0E       /* Control register */
39 #       define DS3232_REG_CR_nEOSC   0x80
40 #       define DS3232_REG_CR_INTCN   0x04
41 #       define DS3232_REG_CR_A2IE    0x02
42 #       define DS3232_REG_CR_A1IE    0x01
43 
44 #define DS3232_REG_SR           0x0F       /* control/status register */
45 #       define DS3232_REG_SR_OSF     0x80
46 #       define DS3232_REG_SR_BSY     0x04
47 #       define DS3232_REG_SR_A2F     0x02
48 #       define DS3232_REG_SR_A1F     0x01
49 
50 #define DS3232_REG_TEMPERATURE	0x11
51 #define DS3232_REG_SRAM_START   0x14
52 #define DS3232_REG_SRAM_END     0xFF
53 
54 #define DS3232_REG_SRAM_SIZE    236
55 
56 struct ds3232 {
57 	struct device *dev;
58 	struct regmap *regmap;
59 	int irq;
60 	struct rtc_device *rtc;
61 
62 	bool suspended;
63 };
64 
65 static int ds3232_check_rtc_status(struct device *dev)
66 {
67 	struct ds3232 *ds3232 = dev_get_drvdata(dev);
68 	int ret = 0;
69 	int control, stat;
70 
71 	ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
72 	if (ret)
73 		return ret;
74 
75 	if (stat & DS3232_REG_SR_OSF)
76 		dev_warn(dev,
77 				"oscillator discontinuity flagged, "
78 				"time unreliable\n");
79 
80 	stat &= ~(DS3232_REG_SR_OSF | DS3232_REG_SR_A1F | DS3232_REG_SR_A2F);
81 
82 	ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat);
83 	if (ret)
84 		return ret;
85 
86 	/* If the alarm is pending, clear it before requesting
87 	 * the interrupt, so an interrupt event isn't reported
88 	 * before everything is initialized.
89 	 */
90 
91 	ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
92 	if (ret)
93 		return ret;
94 
95 	control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE);
96 	control |= DS3232_REG_CR_INTCN;
97 
98 	return regmap_write(ds3232->regmap, DS3232_REG_CR, control);
99 }
100 
101 static int ds3232_read_time(struct device *dev, struct rtc_time *time)
102 {
103 	struct ds3232 *ds3232 = dev_get_drvdata(dev);
104 	int ret;
105 	u8 buf[7];
106 	unsigned int year, month, day, hour, minute, second;
107 	unsigned int week, twelve_hr, am_pm;
108 	unsigned int century, add_century = 0;
109 
110 	ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_SECONDS, buf, 7);
111 	if (ret)
112 		return ret;
113 
114 	second = buf[0];
115 	minute = buf[1];
116 	hour = buf[2];
117 	week = buf[3];
118 	day = buf[4];
119 	month = buf[5];
120 	year = buf[6];
121 
122 	/* Extract additional information for AM/PM and century */
123 
124 	twelve_hr = hour & 0x40;
125 	am_pm = hour & 0x20;
126 	century = month & 0x80;
127 
128 	/* Write to rtc_time structure */
129 
130 	time->tm_sec = bcd2bin(second);
131 	time->tm_min = bcd2bin(minute);
132 	if (twelve_hr) {
133 		/* Convert to 24 hr */
134 		if (am_pm)
135 			time->tm_hour = bcd2bin(hour & 0x1F) + 12;
136 		else
137 			time->tm_hour = bcd2bin(hour & 0x1F);
138 	} else {
139 		time->tm_hour = bcd2bin(hour);
140 	}
141 
142 	/* Day of the week in linux range is 0~6 while 1~7 in RTC chip */
143 	time->tm_wday = bcd2bin(week) - 1;
144 	time->tm_mday = bcd2bin(day);
145 	/* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */
146 	time->tm_mon = bcd2bin(month & 0x7F) - 1;
147 	if (century)
148 		add_century = 100;
149 
150 	time->tm_year = bcd2bin(year) + add_century;
151 
152 	return 0;
153 }
154 
155 static int ds3232_set_time(struct device *dev, struct rtc_time *time)
156 {
157 	struct ds3232 *ds3232 = dev_get_drvdata(dev);
158 	u8 buf[7];
159 
160 	/* Extract time from rtc_time and load into ds3232*/
161 
162 	buf[0] = bin2bcd(time->tm_sec);
163 	buf[1] = bin2bcd(time->tm_min);
164 	buf[2] = bin2bcd(time->tm_hour);
165 	/* Day of the week in linux range is 0~6 while 1~7 in RTC chip */
166 	buf[3] = bin2bcd(time->tm_wday + 1);
167 	buf[4] = bin2bcd(time->tm_mday); /* Date */
168 	/* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */
169 	buf[5] = bin2bcd(time->tm_mon + 1);
170 	if (time->tm_year >= 100) {
171 		buf[5] |= 0x80;
172 		buf[6] = bin2bcd(time->tm_year - 100);
173 	} else {
174 		buf[6] = bin2bcd(time->tm_year);
175 	}
176 
177 	return regmap_bulk_write(ds3232->regmap, DS3232_REG_SECONDS, buf, 7);
178 }
179 
180 /*
181  * DS3232 has two alarm, we only use alarm1
182  * According to linux specification, only support one-shot alarm
183  * no periodic alarm mode
184  */
185 static int ds3232_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
186 {
187 	struct ds3232 *ds3232 = dev_get_drvdata(dev);
188 	int control, stat;
189 	int ret;
190 	u8 buf[4];
191 
192 	ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
193 	if (ret)
194 		goto out;
195 	ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
196 	if (ret)
197 		goto out;
198 	ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_ALARM1, buf, 4);
199 	if (ret)
200 		goto out;
201 
202 	alarm->time.tm_sec = bcd2bin(buf[0] & 0x7F);
203 	alarm->time.tm_min = bcd2bin(buf[1] & 0x7F);
204 	alarm->time.tm_hour = bcd2bin(buf[2] & 0x7F);
205 	alarm->time.tm_mday = bcd2bin(buf[3] & 0x7F);
206 
207 	alarm->enabled = !!(control & DS3232_REG_CR_A1IE);
208 	alarm->pending = !!(stat & DS3232_REG_SR_A1F);
209 
210 	ret = 0;
211 out:
212 	return ret;
213 }
214 
215 /*
216  * linux rtc-module does not support wday alarm
217  * and only 24h time mode supported indeed
218  */
219 static int ds3232_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
220 {
221 	struct ds3232 *ds3232 = dev_get_drvdata(dev);
222 	int control, stat;
223 	int ret;
224 	u8 buf[4];
225 
226 	if (ds3232->irq <= 0)
227 		return -EINVAL;
228 
229 	buf[0] = bin2bcd(alarm->time.tm_sec);
230 	buf[1] = bin2bcd(alarm->time.tm_min);
231 	buf[2] = bin2bcd(alarm->time.tm_hour);
232 	buf[3] = bin2bcd(alarm->time.tm_mday);
233 
234 	/* clear alarm interrupt enable bit */
235 	ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
236 	if (ret)
237 		goto out;
238 	control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE);
239 	ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control);
240 	if (ret)
241 		goto out;
242 
243 	/* clear any pending alarm flag */
244 	ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
245 	if (ret)
246 		goto out;
247 	stat &= ~(DS3232_REG_SR_A1F | DS3232_REG_SR_A2F);
248 	ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat);
249 	if (ret)
250 		goto out;
251 
252 	ret = regmap_bulk_write(ds3232->regmap, DS3232_REG_ALARM1, buf, 4);
253 	if (ret)
254 		goto out;
255 
256 	if (alarm->enabled) {
257 		control |= DS3232_REG_CR_A1IE;
258 		ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control);
259 	}
260 out:
261 	return ret;
262 }
263 
264 static int ds3232_update_alarm(struct device *dev, unsigned int enabled)
265 {
266 	struct ds3232 *ds3232 = dev_get_drvdata(dev);
267 	int control;
268 	int ret;
269 
270 	ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
271 	if (ret)
272 		return ret;
273 
274 	if (enabled)
275 		/* enable alarm1 interrupt */
276 		control |= DS3232_REG_CR_A1IE;
277 	else
278 		/* disable alarm1 interrupt */
279 		control &= ~(DS3232_REG_CR_A1IE);
280 	ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control);
281 
282 	return ret;
283 }
284 
285 /*
286  * Temperature sensor support for ds3232/ds3234 devices.
287  * A user-initiated temperature conversion is not started by this function,
288  * so the temperature is updated once every 64 seconds.
289  */
290 static int ds3232_hwmon_read_temp(struct device *dev, long int *mC)
291 {
292 	struct ds3232 *ds3232 = dev_get_drvdata(dev);
293 	u8 temp_buf[2];
294 	s16 temp;
295 	int ret;
296 
297 	ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_TEMPERATURE, temp_buf,
298 			       sizeof(temp_buf));
299 	if (ret < 0)
300 		return ret;
301 
302 	/*
303 	 * Temperature is represented as a 10-bit code with a resolution of
304 	 * 0.25 degree celsius and encoded in two's complement format.
305 	 */
306 	temp = (temp_buf[0] << 8) | temp_buf[1];
307 	temp >>= 6;
308 	*mC = temp * 250;
309 
310 	return 0;
311 }
312 
313 static umode_t ds3232_hwmon_is_visible(const void *data,
314 				       enum hwmon_sensor_types type,
315 				       u32 attr, int channel)
316 {
317 	if (type != hwmon_temp)
318 		return 0;
319 
320 	switch (attr) {
321 	case hwmon_temp_input:
322 		return 0444;
323 	default:
324 		return 0;
325 	}
326 }
327 
328 static int ds3232_hwmon_read(struct device *dev,
329 			     enum hwmon_sensor_types type,
330 			     u32 attr, int channel, long *temp)
331 {
332 	int err;
333 
334 	switch (attr) {
335 	case hwmon_temp_input:
336 		err = ds3232_hwmon_read_temp(dev, temp);
337 		break;
338 	default:
339 		err = -EOPNOTSUPP;
340 		break;
341 	}
342 
343 	return err;
344 }
345 
346 static u32 ds3232_hwmon_chip_config[] = {
347 	HWMON_C_REGISTER_TZ,
348 	0
349 };
350 
351 static const struct hwmon_channel_info ds3232_hwmon_chip = {
352 	.type = hwmon_chip,
353 	.config = ds3232_hwmon_chip_config,
354 };
355 
356 static u32 ds3232_hwmon_temp_config[] = {
357 	HWMON_T_INPUT,
358 	0
359 };
360 
361 static const struct hwmon_channel_info ds3232_hwmon_temp = {
362 	.type = hwmon_temp,
363 	.config = ds3232_hwmon_temp_config,
364 };
365 
366 static const struct hwmon_channel_info *ds3232_hwmon_info[] = {
367 	&ds3232_hwmon_chip,
368 	&ds3232_hwmon_temp,
369 	NULL
370 };
371 
372 static const struct hwmon_ops ds3232_hwmon_hwmon_ops = {
373 	.is_visible = ds3232_hwmon_is_visible,
374 	.read = ds3232_hwmon_read,
375 };
376 
377 static const struct hwmon_chip_info ds3232_hwmon_chip_info = {
378 	.ops = &ds3232_hwmon_hwmon_ops,
379 	.info = ds3232_hwmon_info,
380 };
381 
382 static void ds3232_hwmon_register(struct device *dev, const char *name)
383 {
384 	struct ds3232 *ds3232 = dev_get_drvdata(dev);
385 	struct device *hwmon_dev;
386 
387 	if (!IS_ENABLED(CONFIG_RTC_DRV_DS3232_HWMON))
388 		return;
389 
390 	hwmon_dev = devm_hwmon_device_register_with_info(dev, name, ds3232,
391 							&ds3232_hwmon_chip_info,
392 							NULL);
393 	if (IS_ERR(hwmon_dev)) {
394 		dev_err(dev, "unable to register hwmon device %ld\n",
395 			PTR_ERR(hwmon_dev));
396 	}
397 }
398 
399 static int ds3232_alarm_irq_enable(struct device *dev, unsigned int enabled)
400 {
401 	struct ds3232 *ds3232 = dev_get_drvdata(dev);
402 
403 	if (ds3232->irq <= 0)
404 		return -EINVAL;
405 
406 	return ds3232_update_alarm(dev, enabled);
407 }
408 
409 static irqreturn_t ds3232_irq(int irq, void *dev_id)
410 {
411 	struct device *dev = dev_id;
412 	struct ds3232 *ds3232 = dev_get_drvdata(dev);
413 	struct mutex *lock = &ds3232->rtc->ops_lock;
414 	int ret;
415 	int stat, control;
416 
417 	mutex_lock(lock);
418 
419 	ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
420 	if (ret)
421 		goto unlock;
422 
423 	if (stat & DS3232_REG_SR_A1F) {
424 		ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
425 		if (ret) {
426 			dev_warn(ds3232->dev,
427 				 "Read Control Register error %d\n", ret);
428 		} else {
429 			/* disable alarm1 interrupt */
430 			control &= ~(DS3232_REG_CR_A1IE);
431 			ret = regmap_write(ds3232->regmap, DS3232_REG_CR,
432 					   control);
433 			if (ret) {
434 				dev_warn(ds3232->dev,
435 					 "Write Control Register error %d\n",
436 					 ret);
437 				goto unlock;
438 			}
439 
440 			/* clear the alarm pend flag */
441 			stat &= ~DS3232_REG_SR_A1F;
442 			ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat);
443 			if (ret) {
444 				dev_warn(ds3232->dev,
445 					 "Write Status Register error %d\n",
446 					 ret);
447 				goto unlock;
448 			}
449 
450 			rtc_update_irq(ds3232->rtc, 1, RTC_AF | RTC_IRQF);
451 		}
452 	}
453 
454 unlock:
455 	mutex_unlock(lock);
456 
457 	return IRQ_HANDLED;
458 }
459 
460 static const struct rtc_class_ops ds3232_rtc_ops = {
461 	.read_time = ds3232_read_time,
462 	.set_time = ds3232_set_time,
463 	.read_alarm = ds3232_read_alarm,
464 	.set_alarm = ds3232_set_alarm,
465 	.alarm_irq_enable = ds3232_alarm_irq_enable,
466 };
467 
468 static int ds3232_nvmem_read(void *priv, unsigned int offset, void *val,
469 			     size_t bytes)
470 {
471 	struct regmap *ds3232_regmap = (struct regmap *)priv;
472 
473 	return regmap_bulk_read(ds3232_regmap, DS3232_REG_SRAM_START + offset,
474 				val, bytes);
475 }
476 
477 static int ds3232_nvmem_write(void *priv, unsigned int offset, void *val,
478 			      size_t bytes)
479 {
480 	struct regmap *ds3232_regmap = (struct regmap *)priv;
481 
482 	return regmap_bulk_write(ds3232_regmap, DS3232_REG_SRAM_START + offset,
483 				 val, bytes);
484 }
485 
486 static int ds3232_probe(struct device *dev, struct regmap *regmap, int irq,
487 			const char *name)
488 {
489 	struct ds3232 *ds3232;
490 	int ret;
491 	struct nvmem_config nvmem_cfg = {
492 		.name = "ds3232_sram",
493 		.stride = 1,
494 		.size = DS3232_REG_SRAM_SIZE,
495 		.word_size = 1,
496 		.reg_read = ds3232_nvmem_read,
497 		.reg_write = ds3232_nvmem_write,
498 		.priv = regmap,
499 		.type = NVMEM_TYPE_BATTERY_BACKED
500 	};
501 
502 	ds3232 = devm_kzalloc(dev, sizeof(*ds3232), GFP_KERNEL);
503 	if (!ds3232)
504 		return -ENOMEM;
505 
506 	ds3232->regmap = regmap;
507 	ds3232->irq = irq;
508 	ds3232->dev = dev;
509 	dev_set_drvdata(dev, ds3232);
510 
511 	ret = ds3232_check_rtc_status(dev);
512 	if (ret)
513 		return ret;
514 
515 	if (ds3232->irq > 0)
516 		device_init_wakeup(dev, 1);
517 
518 	ds3232_hwmon_register(dev, name);
519 
520 	ds3232->rtc = devm_rtc_device_register(dev, name, &ds3232_rtc_ops,
521 						THIS_MODULE);
522 	if (IS_ERR(ds3232->rtc))
523 		return PTR_ERR(ds3232->rtc);
524 
525 	ret = rtc_nvmem_register(ds3232->rtc, &nvmem_cfg);
526 	if(ret)
527 		return ret;
528 
529 	if (ds3232->irq > 0) {
530 		ret = devm_request_threaded_irq(dev, ds3232->irq, NULL,
531 						ds3232_irq,
532 						IRQF_SHARED | IRQF_ONESHOT,
533 						name, dev);
534 		if (ret) {
535 			device_set_wakeup_capable(dev, 0);
536 			ds3232->irq = 0;
537 			dev_err(dev, "unable to request IRQ\n");
538 		}
539 	}
540 
541 	return 0;
542 }
543 
544 #ifdef CONFIG_PM_SLEEP
545 static int ds3232_suspend(struct device *dev)
546 {
547 	struct ds3232 *ds3232 = dev_get_drvdata(dev);
548 
549 	if (device_may_wakeup(dev)) {
550 		if (enable_irq_wake(ds3232->irq))
551 			dev_warn_once(dev, "Cannot set wakeup source\n");
552 	}
553 
554 	return 0;
555 }
556 
557 static int ds3232_resume(struct device *dev)
558 {
559 	struct ds3232 *ds3232 = dev_get_drvdata(dev);
560 
561 	if (device_may_wakeup(dev))
562 		disable_irq_wake(ds3232->irq);
563 
564 	return 0;
565 }
566 #endif
567 
568 static const struct dev_pm_ops ds3232_pm_ops = {
569 	SET_SYSTEM_SLEEP_PM_OPS(ds3232_suspend, ds3232_resume)
570 };
571 
572 #if IS_ENABLED(CONFIG_I2C)
573 
574 static int ds3232_i2c_probe(struct i2c_client *client,
575 			    const struct i2c_device_id *id)
576 {
577 	struct regmap *regmap;
578 	static const struct regmap_config config = {
579 		.reg_bits = 8,
580 		.val_bits = 8,
581 		.max_register = DS3232_REG_SRAM_END,
582 	};
583 
584 	regmap = devm_regmap_init_i2c(client, &config);
585 	if (IS_ERR(regmap)) {
586 		dev_err(&client->dev, "%s: regmap allocation failed: %ld\n",
587 			__func__, PTR_ERR(regmap));
588 		return PTR_ERR(regmap);
589 	}
590 
591 	return ds3232_probe(&client->dev, regmap, client->irq, client->name);
592 }
593 
594 static const struct i2c_device_id ds3232_id[] = {
595 	{ "ds3232", 0 },
596 	{ }
597 };
598 MODULE_DEVICE_TABLE(i2c, ds3232_id);
599 
600 static const struct of_device_id ds3232_of_match[] = {
601 	{ .compatible = "dallas,ds3232" },
602 	{ }
603 };
604 MODULE_DEVICE_TABLE(of, ds3232_of_match);
605 
606 static struct i2c_driver ds3232_driver = {
607 	.driver = {
608 		.name = "rtc-ds3232",
609 		.of_match_table = of_match_ptr(ds3232_of_match),
610 		.pm	= &ds3232_pm_ops,
611 	},
612 	.probe = ds3232_i2c_probe,
613 	.id_table = ds3232_id,
614 };
615 
616 static int ds3232_register_driver(void)
617 {
618 	return i2c_add_driver(&ds3232_driver);
619 }
620 
621 static void ds3232_unregister_driver(void)
622 {
623 	i2c_del_driver(&ds3232_driver);
624 }
625 
626 #else
627 
628 static int ds3232_register_driver(void)
629 {
630 	return 0;
631 }
632 
633 static void ds3232_unregister_driver(void)
634 {
635 }
636 
637 #endif
638 
639 #if IS_ENABLED(CONFIG_SPI_MASTER)
640 
641 static int ds3234_probe(struct spi_device *spi)
642 {
643 	int res;
644 	unsigned int tmp;
645 	static const struct regmap_config config = {
646 		.reg_bits = 8,
647 		.val_bits = 8,
648 		.max_register = DS3232_REG_SRAM_END,
649 		.write_flag_mask = 0x80,
650 	};
651 	struct regmap *regmap;
652 
653 	regmap = devm_regmap_init_spi(spi, &config);
654 	if (IS_ERR(regmap)) {
655 		dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n",
656 			__func__, PTR_ERR(regmap));
657 		return PTR_ERR(regmap);
658 	}
659 
660 	spi->mode = SPI_MODE_3;
661 	spi->bits_per_word = 8;
662 	spi_setup(spi);
663 
664 	res = regmap_read(regmap, DS3232_REG_SECONDS, &tmp);
665 	if (res)
666 		return res;
667 
668 	/* Control settings
669 	 *
670 	 * CONTROL_REG
671 	 * BIT 7	6	5	4	3	2	1	0
672 	 *     EOSC	BBSQW	CONV	RS2	RS1	INTCN	A2IE	A1IE
673 	 *
674 	 *     0	0	0	1	1	1	0	0
675 	 *
676 	 * CONTROL_STAT_REG
677 	 * BIT 7	6	5	4	3	2	1	0
678 	 *     OSF	BB32kHz	CRATE1	CRATE0	EN32kHz	BSY	A2F	A1F
679 	 *
680 	 *     1	0	0	0	1	0	0	0
681 	 */
682 	res = regmap_read(regmap, DS3232_REG_CR, &tmp);
683 	if (res)
684 		return res;
685 	res = regmap_write(regmap, DS3232_REG_CR, tmp & 0x1c);
686 	if (res)
687 		return res;
688 
689 	res = regmap_read(regmap, DS3232_REG_SR, &tmp);
690 	if (res)
691 		return res;
692 	res = regmap_write(regmap, DS3232_REG_SR, tmp & 0x88);
693 	if (res)
694 		return res;
695 
696 	/* Print our settings */
697 	res = regmap_read(regmap, DS3232_REG_CR, &tmp);
698 	if (res)
699 		return res;
700 	dev_info(&spi->dev, "Control Reg: 0x%02x\n", tmp);
701 
702 	res = regmap_read(regmap, DS3232_REG_SR, &tmp);
703 	if (res)
704 		return res;
705 	dev_info(&spi->dev, "Ctrl/Stat Reg: 0x%02x\n", tmp);
706 
707 	return ds3232_probe(&spi->dev, regmap, spi->irq, "ds3234");
708 }
709 
710 static struct spi_driver ds3234_driver = {
711 	.driver = {
712 		.name	 = "ds3234",
713 	},
714 	.probe	 = ds3234_probe,
715 };
716 
717 static int ds3234_register_driver(void)
718 {
719 	return spi_register_driver(&ds3234_driver);
720 }
721 
722 static void ds3234_unregister_driver(void)
723 {
724 	spi_unregister_driver(&ds3234_driver);
725 }
726 
727 #else
728 
729 static int ds3234_register_driver(void)
730 {
731 	return 0;
732 }
733 
734 static void ds3234_unregister_driver(void)
735 {
736 }
737 
738 #endif
739 
740 static int __init ds323x_init(void)
741 {
742 	int ret;
743 
744 	ret = ds3232_register_driver();
745 	if (ret) {
746 		pr_err("Failed to register ds3232 driver: %d\n", ret);
747 		return ret;
748 	}
749 
750 	ret = ds3234_register_driver();
751 	if (ret) {
752 		pr_err("Failed to register ds3234 driver: %d\n", ret);
753 		ds3232_unregister_driver();
754 	}
755 
756 	return ret;
757 }
758 module_init(ds323x_init)
759 
760 static void __exit ds323x_exit(void)
761 {
762 	ds3234_unregister_driver();
763 	ds3232_unregister_driver();
764 }
765 module_exit(ds323x_exit)
766 
767 MODULE_AUTHOR("Srikanth Srinivasan <srikanth.srinivasan@freescale.com>");
768 MODULE_AUTHOR("Dennis Aberilla <denzzzhome@yahoo.com>");
769 MODULE_DESCRIPTION("Maxim/Dallas DS3232/DS3234 RTC Driver");
770 MODULE_LICENSE("GPL");
771 MODULE_ALIAS("spi:ds3234");
772