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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * RTC client/driver for the Maxim/Dallas DS3232/DS3234 Real-Time Clock
4 *
5 * Copyright (C) 2009-2011 Freescale Semiconductor.
6 * Author: Jack Lan <jack.lan@freescale.com>
7 * Copyright (C) 2008 MIMOMax Wireless Ltd.
8 */
9
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/interrupt.h>
15#include <linux/i2c.h>
16#include <linux/spi/spi.h>
17#include <linux/rtc.h>
18#include <linux/bcd.h>
19#include <linux/slab.h>
20#include <linux/regmap.h>
21#include <linux/hwmon.h>
22
23#define DS3232_REG_SECONDS 0x00
24#define DS3232_REG_MINUTES 0x01
25#define DS3232_REG_HOURS 0x02
26#define DS3232_REG_AMPM 0x02
27#define DS3232_REG_DAY 0x03
28#define DS3232_REG_DATE 0x04
29#define DS3232_REG_MONTH 0x05
30#define DS3232_REG_CENTURY 0x05
31#define DS3232_REG_YEAR 0x06
32#define DS3232_REG_ALARM1 0x07 /* Alarm 1 BASE */
33#define DS3232_REG_ALARM2 0x0B /* Alarm 2 BASE */
34#define DS3232_REG_CR 0x0E /* Control register */
35# define DS3232_REG_CR_nEOSC 0x80
36# define DS3232_REG_CR_INTCN 0x04
37# define DS3232_REG_CR_A2IE 0x02
38# define DS3232_REG_CR_A1IE 0x01
39
40#define DS3232_REG_SR 0x0F /* control/status register */
41# define DS3232_REG_SR_OSF 0x80
42# define DS3232_REG_SR_BSY 0x04
43# define DS3232_REG_SR_A2F 0x02
44# define DS3232_REG_SR_A1F 0x01
45
46#define DS3232_REG_TEMPERATURE 0x11
47#define DS3232_REG_SRAM_START 0x14
48#define DS3232_REG_SRAM_END 0xFF
49
50#define DS3232_REG_SRAM_SIZE 236
51
52struct ds3232 {
53 struct device *dev;
54 struct regmap *regmap;
55 int irq;
56 struct rtc_device *rtc;
57
58 bool suspended;
59};
60
61static int ds3232_check_rtc_status(struct device *dev)
62{
63 struct ds3232 *ds3232 = dev_get_drvdata(dev);
64 int ret = 0;
65 int control, stat;
66
67 ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
68 if (ret)
69 return ret;
70
71 if (stat & DS3232_REG_SR_OSF)
72 dev_warn(dev,
73 "oscillator discontinuity flagged, "
74 "time unreliable\n");
75
76 stat &= ~(DS3232_REG_SR_OSF | DS3232_REG_SR_A1F | DS3232_REG_SR_A2F);
77
78 ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat);
79 if (ret)
80 return ret;
81
82 /* If the alarm is pending, clear it before requesting
83 * the interrupt, so an interrupt event isn't reported
84 * before everything is initialized.
85 */
86
87 ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
88 if (ret)
89 return ret;
90
91 control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE);
92 control |= DS3232_REG_CR_INTCN;
93
94 return regmap_write(ds3232->regmap, DS3232_REG_CR, control);
95}
96
97static int ds3232_read_time(struct device *dev, struct rtc_time *time)
98{
99 struct ds3232 *ds3232 = dev_get_drvdata(dev);
100 int ret;
101 u8 buf[7];
102 unsigned int year, month, day, hour, minute, second;
103 unsigned int week, twelve_hr, am_pm;
104 unsigned int century, add_century = 0;
105
106 ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_SECONDS, buf, 7);
107 if (ret)
108 return ret;
109
110 second = buf[0];
111 minute = buf[1];
112 hour = buf[2];
113 week = buf[3];
114 day = buf[4];
115 month = buf[5];
116 year = buf[6];
117
118 /* Extract additional information for AM/PM and century */
119
120 twelve_hr = hour & 0x40;
121 am_pm = hour & 0x20;
122 century = month & 0x80;
123
124 /* Write to rtc_time structure */
125
126 time->tm_sec = bcd2bin(second);
127 time->tm_min = bcd2bin(minute);
128 if (twelve_hr) {
129 /* Convert to 24 hr */
130 if (am_pm)
131 time->tm_hour = bcd2bin(hour & 0x1F) + 12;
132 else
133 time->tm_hour = bcd2bin(hour & 0x1F);
134 } else {
135 time->tm_hour = bcd2bin(hour);
136 }
137
138 /* Day of the week in linux range is 0~6 while 1~7 in RTC chip */
139 time->tm_wday = bcd2bin(week) - 1;
140 time->tm_mday = bcd2bin(day);
141 /* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */
142 time->tm_mon = bcd2bin(month & 0x7F) - 1;
143 if (century)
144 add_century = 100;
145
146 time->tm_year = bcd2bin(year) + add_century;
147
148 return 0;
149}
150
151static int ds3232_set_time(struct device *dev, struct rtc_time *time)
152{
153 struct ds3232 *ds3232 = dev_get_drvdata(dev);
154 u8 buf[7];
155
156 /* Extract time from rtc_time and load into ds3232*/
157
158 buf[0] = bin2bcd(time->tm_sec);
159 buf[1] = bin2bcd(time->tm_min);
160 buf[2] = bin2bcd(time->tm_hour);
161 /* Day of the week in linux range is 0~6 while 1~7 in RTC chip */
162 buf[3] = bin2bcd(time->tm_wday + 1);
163 buf[4] = bin2bcd(time->tm_mday); /* Date */
164 /* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */
165 buf[5] = bin2bcd(time->tm_mon + 1);
166 if (time->tm_year >= 100) {
167 buf[5] |= 0x80;
168 buf[6] = bin2bcd(time->tm_year - 100);
169 } else {
170 buf[6] = bin2bcd(time->tm_year);
171 }
172
173 return regmap_bulk_write(ds3232->regmap, DS3232_REG_SECONDS, buf, 7);
174}
175
176/*
177 * DS3232 has two alarm, we only use alarm1
178 * According to linux specification, only support one-shot alarm
179 * no periodic alarm mode
180 */
181static int ds3232_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
182{
183 struct ds3232 *ds3232 = dev_get_drvdata(dev);
184 int control, stat;
185 int ret;
186 u8 buf[4];
187
188 ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
189 if (ret)
190 goto out;
191 ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
192 if (ret)
193 goto out;
194 ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_ALARM1, buf, 4);
195 if (ret)
196 goto out;
197
198 alarm->time.tm_sec = bcd2bin(buf[0] & 0x7F);
199 alarm->time.tm_min = bcd2bin(buf[1] & 0x7F);
200 alarm->time.tm_hour = bcd2bin(buf[2] & 0x7F);
201 alarm->time.tm_mday = bcd2bin(buf[3] & 0x7F);
202
203 alarm->enabled = !!(control & DS3232_REG_CR_A1IE);
204 alarm->pending = !!(stat & DS3232_REG_SR_A1F);
205
206 ret = 0;
207out:
208 return ret;
209}
210
211/*
212 * linux rtc-module does not support wday alarm
213 * and only 24h time mode supported indeed
214 */
215static int ds3232_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
216{
217 struct ds3232 *ds3232 = dev_get_drvdata(dev);
218 int control, stat;
219 int ret;
220 u8 buf[4];
221
222 if (ds3232->irq <= 0)
223 return -EINVAL;
224
225 buf[0] = bin2bcd(alarm->time.tm_sec);
226 buf[1] = bin2bcd(alarm->time.tm_min);
227 buf[2] = bin2bcd(alarm->time.tm_hour);
228 buf[3] = bin2bcd(alarm->time.tm_mday);
229
230 /* clear alarm interrupt enable bit */
231 ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
232 if (ret)
233 goto out;
234 control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE);
235 ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control);
236 if (ret)
237 goto out;
238
239 /* clear any pending alarm flag */
240 ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
241 if (ret)
242 goto out;
243 stat &= ~(DS3232_REG_SR_A1F | DS3232_REG_SR_A2F);
244 ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat);
245 if (ret)
246 goto out;
247
248 ret = regmap_bulk_write(ds3232->regmap, DS3232_REG_ALARM1, buf, 4);
249 if (ret)
250 goto out;
251
252 if (alarm->enabled) {
253 control |= DS3232_REG_CR_A1IE;
254 ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control);
255 }
256out:
257 return ret;
258}
259
260static int ds3232_update_alarm(struct device *dev, unsigned int enabled)
261{
262 struct ds3232 *ds3232 = dev_get_drvdata(dev);
263 int control;
264 int ret;
265
266 ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
267 if (ret)
268 return ret;
269
270 if (enabled)
271 /* enable alarm1 interrupt */
272 control |= DS3232_REG_CR_A1IE;
273 else
274 /* disable alarm1 interrupt */
275 control &= ~(DS3232_REG_CR_A1IE);
276 ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control);
277
278 return ret;
279}
280
281/*
282 * Temperature sensor support for ds3232/ds3234 devices.
283 * A user-initiated temperature conversion is not started by this function,
284 * so the temperature is updated once every 64 seconds.
285 */
286static int ds3232_hwmon_read_temp(struct device *dev, long int *mC)
287{
288 struct ds3232 *ds3232 = dev_get_drvdata(dev);
289 u8 temp_buf[2];
290 s16 temp;
291 int ret;
292
293 ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_TEMPERATURE, temp_buf,
294 sizeof(temp_buf));
295 if (ret < 0)
296 return ret;
297
298 /*
299 * Temperature is represented as a 10-bit code with a resolution of
300 * 0.25 degree celsius and encoded in two's complement format.
301 */
302 temp = (temp_buf[0] << 8) | temp_buf[1];
303 temp >>= 6;
304 *mC = temp * 250;
305
306 return 0;
307}
308
309static umode_t ds3232_hwmon_is_visible(const void *data,
310 enum hwmon_sensor_types type,
311 u32 attr, int channel)
312{
313 if (type != hwmon_temp)
314 return 0;
315
316 switch (attr) {
317 case hwmon_temp_input:
318 return 0444;
319 default:
320 return 0;
321 }
322}
323
324static int ds3232_hwmon_read(struct device *dev,
325 enum hwmon_sensor_types type,
326 u32 attr, int channel, long *temp)
327{
328 int err;
329
330 switch (attr) {
331 case hwmon_temp_input:
332 err = ds3232_hwmon_read_temp(dev, temp);
333 break;
334 default:
335 err = -EOPNOTSUPP;
336 break;
337 }
338
339 return err;
340}
341
342static u32 ds3232_hwmon_chip_config[] = {
343 HWMON_C_REGISTER_TZ,
344 0
345};
346
347static const struct hwmon_channel_info ds3232_hwmon_chip = {
348 .type = hwmon_chip,
349 .config = ds3232_hwmon_chip_config,
350};
351
352static u32 ds3232_hwmon_temp_config[] = {
353 HWMON_T_INPUT,
354 0
355};
356
357static const struct hwmon_channel_info ds3232_hwmon_temp = {
358 .type = hwmon_temp,
359 .config = ds3232_hwmon_temp_config,
360};
361
362static const struct hwmon_channel_info *ds3232_hwmon_info[] = {
363 &ds3232_hwmon_chip,
364 &ds3232_hwmon_temp,
365 NULL
366};
367
368static const struct hwmon_ops ds3232_hwmon_hwmon_ops = {
369 .is_visible = ds3232_hwmon_is_visible,
370 .read = ds3232_hwmon_read,
371};
372
373static const struct hwmon_chip_info ds3232_hwmon_chip_info = {
374 .ops = &ds3232_hwmon_hwmon_ops,
375 .info = ds3232_hwmon_info,
376};
377
378static void ds3232_hwmon_register(struct device *dev, const char *name)
379{
380 struct ds3232 *ds3232 = dev_get_drvdata(dev);
381 struct device *hwmon_dev;
382
383 if (!IS_ENABLED(CONFIG_RTC_DRV_DS3232_HWMON))
384 return;
385
386 hwmon_dev = devm_hwmon_device_register_with_info(dev, name, ds3232,
387 &ds3232_hwmon_chip_info,
388 NULL);
389 if (IS_ERR(hwmon_dev)) {
390 dev_err(dev, "unable to register hwmon device %ld\n",
391 PTR_ERR(hwmon_dev));
392 }
393}
394
395static int ds3232_alarm_irq_enable(struct device *dev, unsigned int enabled)
396{
397 struct ds3232 *ds3232 = dev_get_drvdata(dev);
398
399 if (ds3232->irq <= 0)
400 return -EINVAL;
401
402 return ds3232_update_alarm(dev, enabled);
403}
404
405static irqreturn_t ds3232_irq(int irq, void *dev_id)
406{
407 struct device *dev = dev_id;
408 struct ds3232 *ds3232 = dev_get_drvdata(dev);
409 struct mutex *lock = &ds3232->rtc->ops_lock;
410 int ret;
411 int stat, control;
412
413 mutex_lock(lock);
414
415 ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
416 if (ret)
417 goto unlock;
418
419 if (stat & DS3232_REG_SR_A1F) {
420 ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
421 if (ret) {
422 dev_warn(ds3232->dev,
423 "Read Control Register error %d\n", ret);
424 } else {
425 /* disable alarm1 interrupt */
426 control &= ~(DS3232_REG_CR_A1IE);
427 ret = regmap_write(ds3232->regmap, DS3232_REG_CR,
428 control);
429 if (ret) {
430 dev_warn(ds3232->dev,
431 "Write Control Register error %d\n",
432 ret);
433 goto unlock;
434 }
435
436 /* clear the alarm pend flag */
437 stat &= ~DS3232_REG_SR_A1F;
438 ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat);
439 if (ret) {
440 dev_warn(ds3232->dev,
441 "Write Status Register error %d\n",
442 ret);
443 goto unlock;
444 }
445
446 rtc_update_irq(ds3232->rtc, 1, RTC_AF | RTC_IRQF);
447 }
448 }
449
450unlock:
451 mutex_unlock(lock);
452
453 return IRQ_HANDLED;
454}
455
456static const struct rtc_class_ops ds3232_rtc_ops = {
457 .read_time = ds3232_read_time,
458 .set_time = ds3232_set_time,
459 .read_alarm = ds3232_read_alarm,
460 .set_alarm = ds3232_set_alarm,
461 .alarm_irq_enable = ds3232_alarm_irq_enable,
462};
463
464static int ds3232_nvmem_read(void *priv, unsigned int offset, void *val,
465 size_t bytes)
466{
467 struct regmap *ds3232_regmap = (struct regmap *)priv;
468
469 return regmap_bulk_read(ds3232_regmap, DS3232_REG_SRAM_START + offset,
470 val, bytes);
471}
472
473static int ds3232_nvmem_write(void *priv, unsigned int offset, void *val,
474 size_t bytes)
475{
476 struct regmap *ds3232_regmap = (struct regmap *)priv;
477
478 return regmap_bulk_write(ds3232_regmap, DS3232_REG_SRAM_START + offset,
479 val, bytes);
480}
481
482static int ds3232_probe(struct device *dev, struct regmap *regmap, int irq,
483 const char *name)
484{
485 struct ds3232 *ds3232;
486 int ret;
487 struct nvmem_config nvmem_cfg = {
488 .name = "ds3232_sram",
489 .stride = 1,
490 .size = DS3232_REG_SRAM_SIZE,
491 .word_size = 1,
492 .reg_read = ds3232_nvmem_read,
493 .reg_write = ds3232_nvmem_write,
494 .priv = regmap,
495 .type = NVMEM_TYPE_BATTERY_BACKED
496 };
497
498 ds3232 = devm_kzalloc(dev, sizeof(*ds3232), GFP_KERNEL);
499 if (!ds3232)
500 return -ENOMEM;
501
502 ds3232->regmap = regmap;
503 ds3232->irq = irq;
504 ds3232->dev = dev;
505 dev_set_drvdata(dev, ds3232);
506
507 ret = ds3232_check_rtc_status(dev);
508 if (ret)
509 return ret;
510
511 if (ds3232->irq > 0)
512 device_init_wakeup(dev, 1);
513
514 ds3232_hwmon_register(dev, name);
515
516 ds3232->rtc = devm_rtc_device_register(dev, name, &ds3232_rtc_ops,
517 THIS_MODULE);
518 if (IS_ERR(ds3232->rtc))
519 return PTR_ERR(ds3232->rtc);
520
521 ret = rtc_nvmem_register(ds3232->rtc, &nvmem_cfg);
522 if(ret)
523 return ret;
524
525 if (ds3232->irq > 0) {
526 ret = devm_request_threaded_irq(dev, ds3232->irq, NULL,
527 ds3232_irq,
528 IRQF_SHARED | IRQF_ONESHOT,
529 name, dev);
530 if (ret) {
531 device_set_wakeup_capable(dev, 0);
532 ds3232->irq = 0;
533 dev_err(dev, "unable to request IRQ\n");
534 }
535 }
536
537 return 0;
538}
539
540#ifdef CONFIG_PM_SLEEP
541static int ds3232_suspend(struct device *dev)
542{
543 struct ds3232 *ds3232 = dev_get_drvdata(dev);
544
545 if (device_may_wakeup(dev)) {
546 if (enable_irq_wake(ds3232->irq))
547 dev_warn_once(dev, "Cannot set wakeup source\n");
548 }
549
550 return 0;
551}
552
553static int ds3232_resume(struct device *dev)
554{
555 struct ds3232 *ds3232 = dev_get_drvdata(dev);
556
557 if (device_may_wakeup(dev))
558 disable_irq_wake(ds3232->irq);
559
560 return 0;
561}
562#endif
563
564static const struct dev_pm_ops ds3232_pm_ops = {
565 SET_SYSTEM_SLEEP_PM_OPS(ds3232_suspend, ds3232_resume)
566};
567
568#if IS_ENABLED(CONFIG_I2C)
569
570static int ds3232_i2c_probe(struct i2c_client *client,
571 const struct i2c_device_id *id)
572{
573 struct regmap *regmap;
574 static const struct regmap_config config = {
575 .reg_bits = 8,
576 .val_bits = 8,
577 .max_register = DS3232_REG_SRAM_END,
578 };
579
580 regmap = devm_regmap_init_i2c(client, &config);
581 if (IS_ERR(regmap)) {
582 dev_err(&client->dev, "%s: regmap allocation failed: %ld\n",
583 __func__, PTR_ERR(regmap));
584 return PTR_ERR(regmap);
585 }
586
587 return ds3232_probe(&client->dev, regmap, client->irq, client->name);
588}
589
590static const struct i2c_device_id ds3232_id[] = {
591 { "ds3232", 0 },
592 { }
593};
594MODULE_DEVICE_TABLE(i2c, ds3232_id);
595
596static const struct of_device_id ds3232_of_match[] = {
597 { .compatible = "dallas,ds3232" },
598 { }
599};
600MODULE_DEVICE_TABLE(of, ds3232_of_match);
601
602static struct i2c_driver ds3232_driver = {
603 .driver = {
604 .name = "rtc-ds3232",
605 .of_match_table = of_match_ptr(ds3232_of_match),
606 .pm = &ds3232_pm_ops,
607 },
608 .probe = ds3232_i2c_probe,
609 .id_table = ds3232_id,
610};
611
612static int ds3232_register_driver(void)
613{
614 return i2c_add_driver(&ds3232_driver);
615}
616
617static void ds3232_unregister_driver(void)
618{
619 i2c_del_driver(&ds3232_driver);
620}
621
622#else
623
624static int ds3232_register_driver(void)
625{
626 return 0;
627}
628
629static void ds3232_unregister_driver(void)
630{
631}
632
633#endif
634
635#if IS_ENABLED(CONFIG_SPI_MASTER)
636
637static int ds3234_probe(struct spi_device *spi)
638{
639 int res;
640 unsigned int tmp;
641 static const struct regmap_config config = {
642 .reg_bits = 8,
643 .val_bits = 8,
644 .max_register = DS3232_REG_SRAM_END,
645 .write_flag_mask = 0x80,
646 };
647 struct regmap *regmap;
648
649 regmap = devm_regmap_init_spi(spi, &config);
650 if (IS_ERR(regmap)) {
651 dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n",
652 __func__, PTR_ERR(regmap));
653 return PTR_ERR(regmap);
654 }
655
656 spi->mode = SPI_MODE_3;
657 spi->bits_per_word = 8;
658 spi_setup(spi);
659
660 res = regmap_read(regmap, DS3232_REG_SECONDS, &tmp);
661 if (res)
662 return res;
663
664 /* Control settings
665 *
666 * CONTROL_REG
667 * BIT 7 6 5 4 3 2 1 0
668 * EOSC BBSQW CONV RS2 RS1 INTCN A2IE A1IE
669 *
670 * 0 0 0 1 1 1 0 0
671 *
672 * CONTROL_STAT_REG
673 * BIT 7 6 5 4 3 2 1 0
674 * OSF BB32kHz CRATE1 CRATE0 EN32kHz BSY A2F A1F
675 *
676 * 1 0 0 0 1 0 0 0
677 */
678 res = regmap_read(regmap, DS3232_REG_CR, &tmp);
679 if (res)
680 return res;
681 res = regmap_write(regmap, DS3232_REG_CR, tmp & 0x1c);
682 if (res)
683 return res;
684
685 res = regmap_read(regmap, DS3232_REG_SR, &tmp);
686 if (res)
687 return res;
688 res = regmap_write(regmap, DS3232_REG_SR, tmp & 0x88);
689 if (res)
690 return res;
691
692 /* Print our settings */
693 res = regmap_read(regmap, DS3232_REG_CR, &tmp);
694 if (res)
695 return res;
696 dev_info(&spi->dev, "Control Reg: 0x%02x\n", tmp);
697
698 res = regmap_read(regmap, DS3232_REG_SR, &tmp);
699 if (res)
700 return res;
701 dev_info(&spi->dev, "Ctrl/Stat Reg: 0x%02x\n", tmp);
702
703 return ds3232_probe(&spi->dev, regmap, spi->irq, "ds3234");
704}
705
706static struct spi_driver ds3234_driver = {
707 .driver = {
708 .name = "ds3234",
709 },
710 .probe = ds3234_probe,
711};
712
713static int ds3234_register_driver(void)
714{
715 return spi_register_driver(&ds3234_driver);
716}
717
718static void ds3234_unregister_driver(void)
719{
720 spi_unregister_driver(&ds3234_driver);
721}
722
723#else
724
725static int ds3234_register_driver(void)
726{
727 return 0;
728}
729
730static void ds3234_unregister_driver(void)
731{
732}
733
734#endif
735
736static int __init ds323x_init(void)
737{
738 int ret;
739
740 ret = ds3232_register_driver();
741 if (ret) {
742 pr_err("Failed to register ds3232 driver: %d\n", ret);
743 return ret;
744 }
745
746 ret = ds3234_register_driver();
747 if (ret) {
748 pr_err("Failed to register ds3234 driver: %d\n", ret);
749 ds3232_unregister_driver();
750 }
751
752 return ret;
753}
754module_init(ds323x_init)
755
756static void __exit ds323x_exit(void)
757{
758 ds3234_unregister_driver();
759 ds3232_unregister_driver();
760}
761module_exit(ds323x_exit)
762
763MODULE_AUTHOR("Srikanth Srinivasan <srikanth.srinivasan@freescale.com>");
764MODULE_AUTHOR("Dennis Aberilla <denzzzhome@yahoo.com>");
765MODULE_DESCRIPTION("Maxim/Dallas DS3232/DS3234 RTC Driver");
766MODULE_LICENSE("GPL");
767MODULE_ALIAS("spi:ds3234");
1/*
2 * RTC client/driver for the Maxim/Dallas DS3232 Real-Time Clock over I2C
3 *
4 * Copyright (C) 2009-2011 Freescale Semiconductor.
5 * Author: Jack Lan <jack.lan@freescale.com>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2 of the License, or (at your
10 * option) any later version.
11 */
12/*
13 * It would be more efficient to use i2c msgs/i2c_transfer directly but, as
14 * recommened in .../Documentation/i2c/writing-clients section
15 * "Sending and receiving", using SMBus level communication is preferred.
16 */
17
18#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/interrupt.h>
21#include <linux/i2c.h>
22#include <linux/rtc.h>
23#include <linux/bcd.h>
24#include <linux/workqueue.h>
25#include <linux/slab.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
50struct ds3232 {
51 struct i2c_client *client;
52 struct rtc_device *rtc;
53 struct work_struct work;
54
55 /* The mutex protects alarm operations, and prevents a race
56 * between the enable_irq() in the workqueue and the free_irq()
57 * in the remove function.
58 */
59 struct mutex mutex;
60 bool suspended;
61 int exiting;
62};
63
64static struct i2c_driver ds3232_driver;
65
66static int ds3232_check_rtc_status(struct i2c_client *client)
67{
68 int ret = 0;
69 int control, stat;
70
71 stat = i2c_smbus_read_byte_data(client, DS3232_REG_SR);
72 if (stat < 0)
73 return stat;
74
75 if (stat & DS3232_REG_SR_OSF)
76 dev_warn(&client->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 = i2c_smbus_write_byte_data(client, DS3232_REG_SR, stat);
83 if (ret < 0)
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 control = i2c_smbus_read_byte_data(client, DS3232_REG_CR);
92 if (control < 0)
93 return control;
94
95 control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE);
96 control |= DS3232_REG_CR_INTCN;
97
98 return i2c_smbus_write_byte_data(client, DS3232_REG_CR, control);
99}
100
101static int ds3232_read_time(struct device *dev, struct rtc_time *time)
102{
103 struct i2c_client *client = to_i2c_client(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 = i2c_smbus_read_i2c_block_data(client, DS3232_REG_SECONDS, 7, buf);
111
112 if (ret < 0)
113 return ret;
114 if (ret < 7)
115 return -EIO;
116
117 second = buf[0];
118 minute = buf[1];
119 hour = buf[2];
120 week = buf[3];
121 day = buf[4];
122 month = buf[5];
123 year = buf[6];
124
125 /* Extract additional information for AM/PM and century */
126
127 twelve_hr = hour & 0x40;
128 am_pm = hour & 0x20;
129 century = month & 0x80;
130
131 /* Write to rtc_time structure */
132
133 time->tm_sec = bcd2bin(second);
134 time->tm_min = bcd2bin(minute);
135 if (twelve_hr) {
136 /* Convert to 24 hr */
137 if (am_pm)
138 time->tm_hour = bcd2bin(hour & 0x1F) + 12;
139 else
140 time->tm_hour = bcd2bin(hour & 0x1F);
141 } else {
142 time->tm_hour = bcd2bin(hour);
143 }
144
145 /* Day of the week in linux range is 0~6 while 1~7 in RTC chip */
146 time->tm_wday = bcd2bin(week) - 1;
147 time->tm_mday = bcd2bin(day);
148 /* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */
149 time->tm_mon = bcd2bin(month & 0x7F) - 1;
150 if (century)
151 add_century = 100;
152
153 time->tm_year = bcd2bin(year) + add_century;
154
155 return rtc_valid_tm(time);
156}
157
158static int ds3232_set_time(struct device *dev, struct rtc_time *time)
159{
160 struct i2c_client *client = to_i2c_client(dev);
161 u8 buf[7];
162
163 /* Extract time from rtc_time and load into ds3232*/
164
165 buf[0] = bin2bcd(time->tm_sec);
166 buf[1] = bin2bcd(time->tm_min);
167 buf[2] = bin2bcd(time->tm_hour);
168 /* Day of the week in linux range is 0~6 while 1~7 in RTC chip */
169 buf[3] = bin2bcd(time->tm_wday + 1);
170 buf[4] = bin2bcd(time->tm_mday); /* Date */
171 /* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */
172 buf[5] = bin2bcd(time->tm_mon + 1);
173 if (time->tm_year >= 100) {
174 buf[5] |= 0x80;
175 buf[6] = bin2bcd(time->tm_year - 100);
176 } else {
177 buf[6] = bin2bcd(time->tm_year);
178 }
179
180 return i2c_smbus_write_i2c_block_data(client,
181 DS3232_REG_SECONDS, 7, buf);
182}
183
184/*
185 * DS3232 has two alarm, we only use alarm1
186 * According to linux specification, only support one-shot alarm
187 * no periodic alarm mode
188 */
189static int ds3232_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
190{
191 struct i2c_client *client = to_i2c_client(dev);
192 struct ds3232 *ds3232 = i2c_get_clientdata(client);
193 int control, stat;
194 int ret;
195 u8 buf[4];
196
197 mutex_lock(&ds3232->mutex);
198
199 ret = i2c_smbus_read_byte_data(client, DS3232_REG_SR);
200 if (ret < 0)
201 goto out;
202 stat = ret;
203 ret = i2c_smbus_read_byte_data(client, DS3232_REG_CR);
204 if (ret < 0)
205 goto out;
206 control = ret;
207 ret = i2c_smbus_read_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf);
208 if (ret < 0)
209 goto out;
210
211 alarm->time.tm_sec = bcd2bin(buf[0] & 0x7F);
212 alarm->time.tm_min = bcd2bin(buf[1] & 0x7F);
213 alarm->time.tm_hour = bcd2bin(buf[2] & 0x7F);
214 alarm->time.tm_mday = bcd2bin(buf[3] & 0x7F);
215
216 alarm->time.tm_mon = -1;
217 alarm->time.tm_year = -1;
218 alarm->time.tm_wday = -1;
219 alarm->time.tm_yday = -1;
220 alarm->time.tm_isdst = -1;
221
222 alarm->enabled = !!(control & DS3232_REG_CR_A1IE);
223 alarm->pending = !!(stat & DS3232_REG_SR_A1F);
224
225 ret = 0;
226out:
227 mutex_unlock(&ds3232->mutex);
228 return ret;
229}
230
231/*
232 * linux rtc-module does not support wday alarm
233 * and only 24h time mode supported indeed
234 */
235static int ds3232_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
236{
237 struct i2c_client *client = to_i2c_client(dev);
238 struct ds3232 *ds3232 = i2c_get_clientdata(client);
239 int control, stat;
240 int ret;
241 u8 buf[4];
242
243 if (client->irq <= 0)
244 return -EINVAL;
245
246 mutex_lock(&ds3232->mutex);
247
248 buf[0] = bin2bcd(alarm->time.tm_sec);
249 buf[1] = bin2bcd(alarm->time.tm_min);
250 buf[2] = bin2bcd(alarm->time.tm_hour);
251 buf[3] = bin2bcd(alarm->time.tm_mday);
252
253 /* clear alarm interrupt enable bit */
254 ret = i2c_smbus_read_byte_data(client, DS3232_REG_CR);
255 if (ret < 0)
256 goto out;
257 control = ret;
258 control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE);
259 ret = i2c_smbus_write_byte_data(client, DS3232_REG_CR, control);
260 if (ret < 0)
261 goto out;
262
263 /* clear any pending alarm flag */
264 ret = i2c_smbus_read_byte_data(client, DS3232_REG_SR);
265 if (ret < 0)
266 goto out;
267 stat = ret;
268 stat &= ~(DS3232_REG_SR_A1F | DS3232_REG_SR_A2F);
269 ret = i2c_smbus_write_byte_data(client, DS3232_REG_SR, stat);
270 if (ret < 0)
271 goto out;
272
273 ret = i2c_smbus_write_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf);
274
275 if (alarm->enabled) {
276 control |= DS3232_REG_CR_A1IE;
277 ret = i2c_smbus_write_byte_data(client, DS3232_REG_CR, control);
278 }
279out:
280 mutex_unlock(&ds3232->mutex);
281 return ret;
282}
283
284static void ds3232_update_alarm(struct i2c_client *client)
285{
286 struct ds3232 *ds3232 = i2c_get_clientdata(client);
287 int control;
288 int ret;
289 u8 buf[4];
290
291 mutex_lock(&ds3232->mutex);
292
293 ret = i2c_smbus_read_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf);
294 if (ret < 0)
295 goto unlock;
296
297 buf[0] = bcd2bin(buf[0]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ?
298 0x80 : buf[0];
299 buf[1] = bcd2bin(buf[1]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ?
300 0x80 : buf[1];
301 buf[2] = bcd2bin(buf[2]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ?
302 0x80 : buf[2];
303 buf[3] = bcd2bin(buf[3]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ?
304 0x80 : buf[3];
305
306 ret = i2c_smbus_write_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf);
307 if (ret < 0)
308 goto unlock;
309
310 control = i2c_smbus_read_byte_data(client, DS3232_REG_CR);
311 if (control < 0)
312 goto unlock;
313
314 if (ds3232->rtc->irq_data & (RTC_AF | RTC_UF))
315 /* enable alarm1 interrupt */
316 control |= DS3232_REG_CR_A1IE;
317 else
318 /* disable alarm1 interrupt */
319 control &= ~(DS3232_REG_CR_A1IE);
320 i2c_smbus_write_byte_data(client, DS3232_REG_CR, control);
321
322unlock:
323 mutex_unlock(&ds3232->mutex);
324}
325
326static int ds3232_alarm_irq_enable(struct device *dev, unsigned int enabled)
327{
328 struct i2c_client *client = to_i2c_client(dev);
329 struct ds3232 *ds3232 = i2c_get_clientdata(client);
330
331 if (client->irq <= 0)
332 return -EINVAL;
333
334 if (enabled)
335 ds3232->rtc->irq_data |= RTC_AF;
336 else
337 ds3232->rtc->irq_data &= ~RTC_AF;
338
339 ds3232_update_alarm(client);
340 return 0;
341}
342
343static irqreturn_t ds3232_irq(int irq, void *dev_id)
344{
345 struct i2c_client *client = dev_id;
346 struct ds3232 *ds3232 = i2c_get_clientdata(client);
347
348 disable_irq_nosync(irq);
349
350 /*
351 * If rtc as a wakeup source, can't schedule the work
352 * at system resume flow, because at this time the i2c bus
353 * has not been resumed.
354 */
355 if (!ds3232->suspended)
356 schedule_work(&ds3232->work);
357
358 return IRQ_HANDLED;
359}
360
361static void ds3232_work(struct work_struct *work)
362{
363 struct ds3232 *ds3232 = container_of(work, struct ds3232, work);
364 struct i2c_client *client = ds3232->client;
365 int stat, control;
366
367 mutex_lock(&ds3232->mutex);
368
369 stat = i2c_smbus_read_byte_data(client, DS3232_REG_SR);
370 if (stat < 0)
371 goto unlock;
372
373 if (stat & DS3232_REG_SR_A1F) {
374 control = i2c_smbus_read_byte_data(client, DS3232_REG_CR);
375 if (control < 0) {
376 pr_warn("Read DS3232 Control Register error."
377 "Disable IRQ%d.\n", client->irq);
378 } else {
379 /* disable alarm1 interrupt */
380 control &= ~(DS3232_REG_CR_A1IE);
381 i2c_smbus_write_byte_data(client, DS3232_REG_CR,
382 control);
383
384 /* clear the alarm pend flag */
385 stat &= ~DS3232_REG_SR_A1F;
386 i2c_smbus_write_byte_data(client, DS3232_REG_SR, stat);
387
388 rtc_update_irq(ds3232->rtc, 1, RTC_AF | RTC_IRQF);
389
390 if (!ds3232->exiting)
391 enable_irq(client->irq);
392 }
393 }
394
395unlock:
396 mutex_unlock(&ds3232->mutex);
397}
398
399static const struct rtc_class_ops ds3232_rtc_ops = {
400 .read_time = ds3232_read_time,
401 .set_time = ds3232_set_time,
402 .read_alarm = ds3232_read_alarm,
403 .set_alarm = ds3232_set_alarm,
404 .alarm_irq_enable = ds3232_alarm_irq_enable,
405};
406
407static int ds3232_probe(struct i2c_client *client,
408 const struct i2c_device_id *id)
409{
410 struct ds3232 *ds3232;
411 int ret;
412
413 ds3232 = devm_kzalloc(&client->dev, sizeof(struct ds3232), GFP_KERNEL);
414 if (!ds3232)
415 return -ENOMEM;
416
417 ds3232->client = client;
418 i2c_set_clientdata(client, ds3232);
419
420 INIT_WORK(&ds3232->work, ds3232_work);
421 mutex_init(&ds3232->mutex);
422
423 ret = ds3232_check_rtc_status(client);
424 if (ret)
425 return ret;
426
427 if (client->irq > 0) {
428 ret = devm_request_irq(&client->dev, client->irq, ds3232_irq,
429 IRQF_SHARED, "ds3232", client);
430 if (ret) {
431 dev_err(&client->dev, "unable to request IRQ\n");
432 }
433 device_init_wakeup(&client->dev, 1);
434 }
435 ds3232->rtc = devm_rtc_device_register(&client->dev, client->name,
436 &ds3232_rtc_ops, THIS_MODULE);
437 return PTR_ERR_OR_ZERO(ds3232->rtc);
438}
439
440static int ds3232_remove(struct i2c_client *client)
441{
442 struct ds3232 *ds3232 = i2c_get_clientdata(client);
443
444 if (client->irq >= 0) {
445 mutex_lock(&ds3232->mutex);
446 ds3232->exiting = 1;
447 mutex_unlock(&ds3232->mutex);
448
449 devm_free_irq(&client->dev, client->irq, client);
450 cancel_work_sync(&ds3232->work);
451 }
452
453 return 0;
454}
455
456#ifdef CONFIG_PM_SLEEP
457static int ds3232_suspend(struct device *dev)
458{
459 struct ds3232 *ds3232 = dev_get_drvdata(dev);
460 struct i2c_client *client = to_i2c_client(dev);
461
462 if (device_can_wakeup(dev)) {
463 ds3232->suspended = true;
464 irq_set_irq_wake(client->irq, 1);
465 }
466
467 return 0;
468}
469
470static int ds3232_resume(struct device *dev)
471{
472 struct ds3232 *ds3232 = dev_get_drvdata(dev);
473 struct i2c_client *client = to_i2c_client(dev);
474
475 if (ds3232->suspended) {
476 ds3232->suspended = false;
477
478 /* Clear the hardware alarm pend flag */
479 schedule_work(&ds3232->work);
480
481 irq_set_irq_wake(client->irq, 0);
482 }
483
484 return 0;
485}
486#endif
487
488static const struct dev_pm_ops ds3232_pm_ops = {
489 SET_SYSTEM_SLEEP_PM_OPS(ds3232_suspend, ds3232_resume)
490};
491
492static const struct i2c_device_id ds3232_id[] = {
493 { "ds3232", 0 },
494 { }
495};
496MODULE_DEVICE_TABLE(i2c, ds3232_id);
497
498static struct i2c_driver ds3232_driver = {
499 .driver = {
500 .name = "rtc-ds3232",
501 .owner = THIS_MODULE,
502 .pm = &ds3232_pm_ops,
503 },
504 .probe = ds3232_probe,
505 .remove = ds3232_remove,
506 .id_table = ds3232_id,
507};
508
509module_i2c_driver(ds3232_driver);
510
511MODULE_AUTHOR("Srikanth Srinivasan <srikanth.srinivasan@freescale.com>");
512MODULE_DESCRIPTION("Maxim/Dallas DS3232 RTC Driver");
513MODULE_LICENSE("GPL");