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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
33#define DS3232_REG_ALARM2 0x0B
34#define DS3232_REG_CR 0x0E
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
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
83
84
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
119
120 twelve_hr = hour & 0x40;
121 am_pm = hour & 0x20;
122 century = month & 0x80;
123
124
125
126 time->tm_sec = bcd2bin(second);
127 time->tm_min = bcd2bin(minute);
128 if (twelve_hr) {
129
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
139 time->tm_wday = bcd2bin(week) - 1;
140 time->tm_mday = bcd2bin(day);
141
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
157
158 buf[0] = bin2bcd(time->tm_sec);
159 buf[1] = bin2bcd(time->tm_min);
160 buf[2] = bin2bcd(time->tm_hour);
161
162 buf[3] = bin2bcd(time->tm_wday + 1);
163 buf[4] = bin2bcd(time->tm_mday);
164
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
178
179
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
213
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
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
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
272 control |= DS3232_REG_CR_A1IE;
273 else
274
275 control &= ~(DS3232_REG_CR_A1IE);
276 ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control);
277
278 return ret;
279}
280
281
282
283
284
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
300
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 int ret;
410 int stat, control;
411
412 rtc_lock(ds3232->rtc);
413
414 ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
415 if (ret)
416 goto unlock;
417
418 if (stat & DS3232_REG_SR_A1F) {
419 ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
420 if (ret) {
421 dev_warn(ds3232->dev,
422 "Read Control Register error %d\n", ret);
423 } else {
424
425 control &= ~(DS3232_REG_CR_A1IE);
426 ret = regmap_write(ds3232->regmap, DS3232_REG_CR,
427 control);
428 if (ret) {
429 dev_warn(ds3232->dev,
430 "Write Control Register error %d\n",
431 ret);
432 goto unlock;
433 }
434
435
436 stat &= ~DS3232_REG_SR_A1F;
437 ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat);
438 if (ret) {
439 dev_warn(ds3232->dev,
440 "Write Status Register error %d\n",
441 ret);
442 goto unlock;
443 }
444
445 rtc_update_irq(ds3232->rtc, 1, RTC_AF | RTC_IRQF);
446 }
447 }
448
449unlock:
450 rtc_unlock(ds3232->rtc);
451
452 return IRQ_HANDLED;
453}
454
455static const struct rtc_class_ops ds3232_rtc_ops = {
456 .read_time = ds3232_read_time,
457 .set_time = ds3232_set_time,
458 .read_alarm = ds3232_read_alarm,
459 .set_alarm = ds3232_set_alarm,
460 .alarm_irq_enable = ds3232_alarm_irq_enable,
461};
462
463static int ds3232_nvmem_read(void *priv, unsigned int offset, void *val,
464 size_t bytes)
465{
466 struct regmap *ds3232_regmap = (struct regmap *)priv;
467
468 return regmap_bulk_read(ds3232_regmap, DS3232_REG_SRAM_START + offset,
469 val, bytes);
470}
471
472static int ds3232_nvmem_write(void *priv, unsigned int offset, void *val,
473 size_t bytes)
474{
475 struct regmap *ds3232_regmap = (struct regmap *)priv;
476
477 return regmap_bulk_write(ds3232_regmap, DS3232_REG_SRAM_START + offset,
478 val, bytes);
479}
480
481static int ds3232_probe(struct device *dev, struct regmap *regmap, int irq,
482 const char *name)
483{
484 struct ds3232 *ds3232;
485 int ret;
486 struct nvmem_config nvmem_cfg = {
487 .name = "ds3232_sram",
488 .stride = 1,
489 .size = DS3232_REG_SRAM_SIZE,
490 .word_size = 1,
491 .reg_read = ds3232_nvmem_read,
492 .reg_write = ds3232_nvmem_write,
493 .priv = regmap,
494 .type = NVMEM_TYPE_BATTERY_BACKED
495 };
496
497 ds3232 = devm_kzalloc(dev, sizeof(*ds3232), GFP_KERNEL);
498 if (!ds3232)
499 return -ENOMEM;
500
501 ds3232->regmap = regmap;
502 ds3232->irq = irq;
503 ds3232->dev = dev;
504 dev_set_drvdata(dev, ds3232);
505
506 ret = ds3232_check_rtc_status(dev);
507 if (ret)
508 return ret;
509
510 if (ds3232->irq > 0)
511 device_init_wakeup(dev, 1);
512
513 ds3232_hwmon_register(dev, name);
514
515 ds3232->rtc = devm_rtc_device_register(dev, name, &ds3232_rtc_ops,
516 THIS_MODULE);
517 if (IS_ERR(ds3232->rtc))
518 return PTR_ERR(ds3232->rtc);
519
520 ret = devm_rtc_nvmem_register(ds3232->rtc, &nvmem_cfg);
521 if(ret)
522 return ret;
523
524 if (ds3232->irq > 0) {
525 ret = devm_request_threaded_irq(dev, ds3232->irq, NULL,
526 ds3232_irq,
527 IRQF_SHARED | IRQF_ONESHOT,
528 name, dev);
529 if (ret) {
530 device_set_wakeup_capable(dev, 0);
531 ds3232->irq = 0;
532 dev_err(dev, "unable to request IRQ\n");
533 }
534 }
535
536 return 0;
537}
538
539#ifdef CONFIG_PM_SLEEP
540static int ds3232_suspend(struct device *dev)
541{
542 struct ds3232 *ds3232 = dev_get_drvdata(dev);
543
544 if (device_may_wakeup(dev)) {
545 if (enable_irq_wake(ds3232->irq))
546 dev_warn_once(dev, "Cannot set wakeup source\n");
547 }
548
549 return 0;
550}
551
552static int ds3232_resume(struct device *dev)
553{
554 struct ds3232 *ds3232 = dev_get_drvdata(dev);
555
556 if (device_may_wakeup(dev))
557 disable_irq_wake(ds3232->irq);
558
559 return 0;
560}
561#endif
562
563static const struct dev_pm_ops ds3232_pm_ops = {
564 SET_SYSTEM_SLEEP_PM_OPS(ds3232_suspend, ds3232_resume)
565};
566
567#if IS_ENABLED(CONFIG_I2C)
568
569static int ds3232_i2c_probe(struct i2c_client *client,
570 const struct i2c_device_id *id)
571{
572 struct regmap *regmap;
573 static const struct regmap_config config = {
574 .reg_bits = 8,
575 .val_bits = 8,
576 .max_register = DS3232_REG_SRAM_END,
577 };
578
579 regmap = devm_regmap_init_i2c(client, &config);
580 if (IS_ERR(regmap)) {
581 dev_err(&client->dev, "%s: regmap allocation failed: %ld\n",
582 __func__, PTR_ERR(regmap));
583 return PTR_ERR(regmap);
584 }
585
586 return ds3232_probe(&client->dev, regmap, client->irq, client->name);
587}
588
589static const struct i2c_device_id ds3232_id[] = {
590 { "ds3232", 0 },
591 { }
592};
593MODULE_DEVICE_TABLE(i2c, ds3232_id);
594
595static const __maybe_unused struct of_device_id ds3232_of_match[] = {
596 { .compatible = "dallas,ds3232" },
597 { }
598};
599MODULE_DEVICE_TABLE(of, ds3232_of_match);
600
601static struct i2c_driver ds3232_driver = {
602 .driver = {
603 .name = "rtc-ds3232",
604 .of_match_table = of_match_ptr(ds3232_of_match),
605 .pm = &ds3232_pm_ops,
606 },
607 .probe = ds3232_i2c_probe,
608 .id_table = ds3232_id,
609};
610
611static int ds3232_register_driver(void)
612{
613 return i2c_add_driver(&ds3232_driver);
614}
615
616static void ds3232_unregister_driver(void)
617{
618 i2c_del_driver(&ds3232_driver);
619}
620
621#else
622
623static int ds3232_register_driver(void)
624{
625 return 0;
626}
627
628static void ds3232_unregister_driver(void)
629{
630}
631
632#endif
633
634#if IS_ENABLED(CONFIG_SPI_MASTER)
635
636static int ds3234_probe(struct spi_device *spi)
637{
638 int res;
639 unsigned int tmp;
640 static const struct regmap_config config = {
641 .reg_bits = 8,
642 .val_bits = 8,
643 .max_register = DS3232_REG_SRAM_END,
644 .write_flag_mask = 0x80,
645 };
646 struct regmap *regmap;
647
648 regmap = devm_regmap_init_spi(spi, &config);
649 if (IS_ERR(regmap)) {
650 dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n",
651 __func__, PTR_ERR(regmap));
652 return PTR_ERR(regmap);
653 }
654
655 spi->mode = SPI_MODE_3;
656 spi->bits_per_word = 8;
657 spi_setup(spi);
658
659 res = regmap_read(regmap, DS3232_REG_SECONDS, &tmp);
660 if (res)
661 return res;
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677 res = regmap_read(regmap, DS3232_REG_CR, &tmp);
678 if (res)
679 return res;
680 res = regmap_write(regmap, DS3232_REG_CR, tmp & 0x1c);
681 if (res)
682 return res;
683
684 res = regmap_read(regmap, DS3232_REG_SR, &tmp);
685 if (res)
686 return res;
687 res = regmap_write(regmap, DS3232_REG_SR, tmp & 0x88);
688 if (res)
689 return res;
690
691
692 res = regmap_read(regmap, DS3232_REG_CR, &tmp);
693 if (res)
694 return res;
695 dev_info(&spi->dev, "Control Reg: 0x%02x\n", tmp);
696
697 res = regmap_read(regmap, DS3232_REG_SR, &tmp);
698 if (res)
699 return res;
700 dev_info(&spi->dev, "Ctrl/Stat Reg: 0x%02x\n", tmp);
701
702 return ds3232_probe(&spi->dev, regmap, spi->irq, "ds3234");
703}
704
705static struct spi_driver ds3234_driver = {
706 .driver = {
707 .name = "ds3234",
708 },
709 .probe = ds3234_probe,
710};
711
712static int ds3234_register_driver(void)
713{
714 return spi_register_driver(&ds3234_driver);
715}
716
717static void ds3234_unregister_driver(void)
718{
719 spi_unregister_driver(&ds3234_driver);
720}
721
722#else
723
724static int ds3234_register_driver(void)
725{
726 return 0;
727}
728
729static void ds3234_unregister_driver(void)
730{
731}
732
733#endif
734
735static int __init ds323x_init(void)
736{
737 int ret;
738
739 ret = ds3232_register_driver();
740 if (ret) {
741 pr_err("Failed to register ds3232 driver: %d\n", ret);
742 return ret;
743 }
744
745 ret = ds3234_register_driver();
746 if (ret) {
747 pr_err("Failed to register ds3234 driver: %d\n", ret);
748 ds3232_unregister_driver();
749 }
750
751 return ret;
752}
753module_init(ds323x_init)
754
755static void __exit ds323x_exit(void)
756{
757 ds3234_unregister_driver();
758 ds3232_unregister_driver();
759}
760module_exit(ds323x_exit)
761
762MODULE_AUTHOR("Srikanth Srinivasan <srikanth.srinivasan@freescale.com>");
763MODULE_AUTHOR("Dennis Aberilla <denzzzhome@yahoo.com>");
764MODULE_DESCRIPTION("Maxim/Dallas DS3232/DS3234 RTC Driver");
765MODULE_LICENSE("GPL");
766MODULE_ALIAS("spi:ds3234");
767
