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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
26#define DS3232_REG_SECONDS 0x00
27#define DS3232_REG_MINUTES 0x01
28#define DS3232_REG_HOURS 0x02
29#define DS3232_REG_AMPM 0x02
30#define DS3232_REG_DAY 0x03
31#define DS3232_REG_DATE 0x04
32#define DS3232_REG_MONTH 0x05
33#define DS3232_REG_CENTURY 0x05
34#define DS3232_REG_YEAR 0x06
35#define DS3232_REG_ALARM1 0x07 /* Alarm 1 BASE */
36#define DS3232_REG_ALARM2 0x0B /* Alarm 2 BASE */
37#define DS3232_REG_CR 0x0E /* Control register */
38# define DS3232_REG_CR_nEOSC 0x80
39# define DS3232_REG_CR_INTCN 0x04
40# define DS3232_REG_CR_A2IE 0x02
41# define DS3232_REG_CR_A1IE 0x01
42
43#define DS3232_REG_SR 0x0F /* control/status register */
44# define DS3232_REG_SR_OSF 0x80
45# define DS3232_REG_SR_BSY 0x04
46# define DS3232_REG_SR_A2F 0x02
47# define DS3232_REG_SR_A1F 0x01
48
49struct ds3232 {
50 struct device *dev;
51 struct regmap *regmap;
52 int irq;
53 struct rtc_device *rtc;
54
55 bool suspended;
56};
57
58static int ds3232_check_rtc_status(struct device *dev)
59{
60 struct ds3232 *ds3232 = dev_get_drvdata(dev);
61 int ret = 0;
62 int control, stat;
63
64 ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
65 if (ret)
66 return ret;
67
68 if (stat & DS3232_REG_SR_OSF)
69 dev_warn(dev,
70 "oscillator discontinuity flagged, "
71 "time unreliable\n");
72
73 stat &= ~(DS3232_REG_SR_OSF | DS3232_REG_SR_A1F | DS3232_REG_SR_A2F);
74
75 ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat);
76 if (ret)
77 return ret;
78
79 /* If the alarm is pending, clear it before requesting
80 * the interrupt, so an interrupt event isn't reported
81 * before everything is initialized.
82 */
83
84 ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
85 if (ret)
86 return ret;
87
88 control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE);
89 control |= DS3232_REG_CR_INTCN;
90
91 return regmap_write(ds3232->regmap, DS3232_REG_CR, control);
92}
93
94static int ds3232_read_time(struct device *dev, struct rtc_time *time)
95{
96 struct ds3232 *ds3232 = dev_get_drvdata(dev);
97 int ret;
98 u8 buf[7];
99 unsigned int year, month, day, hour, minute, second;
100 unsigned int week, twelve_hr, am_pm;
101 unsigned int century, add_century = 0;
102
103 ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_SECONDS, buf, 7);
104 if (ret)
105 return ret;
106
107 second = buf[0];
108 minute = buf[1];
109 hour = buf[2];
110 week = buf[3];
111 day = buf[4];
112 month = buf[5];
113 year = buf[6];
114
115 /* Extract additional information for AM/PM and century */
116
117 twelve_hr = hour & 0x40;
118 am_pm = hour & 0x20;
119 century = month & 0x80;
120
121 /* Write to rtc_time structure */
122
123 time->tm_sec = bcd2bin(second);
124 time->tm_min = bcd2bin(minute);
125 if (twelve_hr) {
126 /* Convert to 24 hr */
127 if (am_pm)
128 time->tm_hour = bcd2bin(hour & 0x1F) + 12;
129 else
130 time->tm_hour = bcd2bin(hour & 0x1F);
131 } else {
132 time->tm_hour = bcd2bin(hour);
133 }
134
135 /* Day of the week in linux range is 0~6 while 1~7 in RTC chip */
136 time->tm_wday = bcd2bin(week) - 1;
137 time->tm_mday = bcd2bin(day);
138 /* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */
139 time->tm_mon = bcd2bin(month & 0x7F) - 1;
140 if (century)
141 add_century = 100;
142
143 time->tm_year = bcd2bin(year) + add_century;
144
145 return rtc_valid_tm(time);
146}
147
148static int ds3232_set_time(struct device *dev, struct rtc_time *time)
149{
150 struct ds3232 *ds3232 = dev_get_drvdata(dev);
151 u8 buf[7];
152
153 /* Extract time from rtc_time and load into ds3232*/
154
155 buf[0] = bin2bcd(time->tm_sec);
156 buf[1] = bin2bcd(time->tm_min);
157 buf[2] = bin2bcd(time->tm_hour);
158 /* Day of the week in linux range is 0~6 while 1~7 in RTC chip */
159 buf[3] = bin2bcd(time->tm_wday + 1);
160 buf[4] = bin2bcd(time->tm_mday); /* Date */
161 /* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */
162 buf[5] = bin2bcd(time->tm_mon + 1);
163 if (time->tm_year >= 100) {
164 buf[5] |= 0x80;
165 buf[6] = bin2bcd(time->tm_year - 100);
166 } else {
167 buf[6] = bin2bcd(time->tm_year);
168 }
169
170 return regmap_bulk_write(ds3232->regmap, DS3232_REG_SECONDS, buf, 7);
171}
172
173/*
174 * DS3232 has two alarm, we only use alarm1
175 * According to linux specification, only support one-shot alarm
176 * no periodic alarm mode
177 */
178static int ds3232_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
179{
180 struct ds3232 *ds3232 = dev_get_drvdata(dev);
181 int control, stat;
182 int ret;
183 u8 buf[4];
184
185 ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
186 if (ret)
187 goto out;
188 ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
189 if (ret)
190 goto out;
191 ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_ALARM1, buf, 4);
192 if (ret)
193 goto out;
194
195 alarm->time.tm_sec = bcd2bin(buf[0] & 0x7F);
196 alarm->time.tm_min = bcd2bin(buf[1] & 0x7F);
197 alarm->time.tm_hour = bcd2bin(buf[2] & 0x7F);
198 alarm->time.tm_mday = bcd2bin(buf[3] & 0x7F);
199
200 alarm->time.tm_mon = -1;
201 alarm->time.tm_year = -1;
202 alarm->time.tm_wday = -1;
203 alarm->time.tm_yday = -1;
204 alarm->time.tm_isdst = -1;
205
206 alarm->enabled = !!(control & DS3232_REG_CR_A1IE);
207 alarm->pending = !!(stat & DS3232_REG_SR_A1F);
208
209 ret = 0;
210out:
211 return ret;
212}
213
214/*
215 * linux rtc-module does not support wday alarm
216 * and only 24h time mode supported indeed
217 */
218static int ds3232_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
219{
220 struct ds3232 *ds3232 = dev_get_drvdata(dev);
221 int control, stat;
222 int ret;
223 u8 buf[4];
224
225 if (ds3232->irq <= 0)
226 return -EINVAL;
227
228 buf[0] = bin2bcd(alarm->time.tm_sec);
229 buf[1] = bin2bcd(alarm->time.tm_min);
230 buf[2] = bin2bcd(alarm->time.tm_hour);
231 buf[3] = bin2bcd(alarm->time.tm_mday);
232
233 /* clear alarm interrupt enable bit */
234 ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
235 if (ret)
236 goto out;
237 control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE);
238 ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control);
239 if (ret)
240 goto out;
241
242 /* clear any pending alarm flag */
243 ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
244 if (ret)
245 goto out;
246 stat &= ~(DS3232_REG_SR_A1F | DS3232_REG_SR_A2F);
247 ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat);
248 if (ret)
249 goto out;
250
251 ret = regmap_bulk_write(ds3232->regmap, DS3232_REG_ALARM1, buf, 4);
252 if (ret)
253 goto out;
254
255 if (alarm->enabled) {
256 control |= DS3232_REG_CR_A1IE;
257 ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control);
258 }
259out:
260 return ret;
261}
262
263static int ds3232_update_alarm(struct device *dev, unsigned int enabled)
264{
265 struct ds3232 *ds3232 = dev_get_drvdata(dev);
266 int control;
267 int ret;
268
269 ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
270 if (ret)
271 return ret;
272
273 if (enabled)
274 /* enable alarm1 interrupt */
275 control |= DS3232_REG_CR_A1IE;
276 else
277 /* disable alarm1 interrupt */
278 control &= ~(DS3232_REG_CR_A1IE);
279 ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control);
280
281 return ret;
282}
283
284static int ds3232_alarm_irq_enable(struct device *dev, unsigned int enabled)
285{
286 struct ds3232 *ds3232 = dev_get_drvdata(dev);
287
288 if (ds3232->irq <= 0)
289 return -EINVAL;
290
291 return ds3232_update_alarm(dev, enabled);
292}
293
294static irqreturn_t ds3232_irq(int irq, void *dev_id)
295{
296 struct device *dev = dev_id;
297 struct ds3232 *ds3232 = dev_get_drvdata(dev);
298 struct mutex *lock = &ds3232->rtc->ops_lock;
299 int ret;
300 int stat, control;
301
302 mutex_lock(lock);
303
304 ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
305 if (ret)
306 goto unlock;
307
308 if (stat & DS3232_REG_SR_A1F) {
309 ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
310 if (ret) {
311 dev_warn(ds3232->dev,
312 "Read Control Register error %d\n", ret);
313 } else {
314 /* disable alarm1 interrupt */
315 control &= ~(DS3232_REG_CR_A1IE);
316 ret = regmap_write(ds3232->regmap, DS3232_REG_CR,
317 control);
318 if (ret) {
319 dev_warn(ds3232->dev,
320 "Write Control Register error %d\n",
321 ret);
322 goto unlock;
323 }
324
325 /* clear the alarm pend flag */
326 stat &= ~DS3232_REG_SR_A1F;
327 ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat);
328 if (ret) {
329 dev_warn(ds3232->dev,
330 "Write Status Register error %d\n",
331 ret);
332 goto unlock;
333 }
334
335 rtc_update_irq(ds3232->rtc, 1, RTC_AF | RTC_IRQF);
336 }
337 }
338
339unlock:
340 mutex_unlock(lock);
341
342 return IRQ_HANDLED;
343}
344
345static const struct rtc_class_ops ds3232_rtc_ops = {
346 .read_time = ds3232_read_time,
347 .set_time = ds3232_set_time,
348 .read_alarm = ds3232_read_alarm,
349 .set_alarm = ds3232_set_alarm,
350 .alarm_irq_enable = ds3232_alarm_irq_enable,
351};
352
353static int ds3232_probe(struct device *dev, struct regmap *regmap, int irq,
354 const char *name)
355{
356 struct ds3232 *ds3232;
357 int ret;
358
359 ds3232 = devm_kzalloc(dev, sizeof(*ds3232), GFP_KERNEL);
360 if (!ds3232)
361 return -ENOMEM;
362
363 ds3232->regmap = regmap;
364 ds3232->irq = irq;
365 ds3232->dev = dev;
366 dev_set_drvdata(dev, ds3232);
367
368 ret = ds3232_check_rtc_status(dev);
369 if (ret)
370 return ret;
371
372 if (ds3232->irq > 0) {
373 ret = devm_request_threaded_irq(dev, ds3232->irq, NULL,
374 ds3232_irq,
375 IRQF_SHARED | IRQF_ONESHOT,
376 name, dev);
377 if (ret) {
378 ds3232->irq = 0;
379 dev_err(dev, "unable to request IRQ\n");
380 } else
381 device_init_wakeup(dev, 1);
382 }
383 ds3232->rtc = devm_rtc_device_register(dev, name, &ds3232_rtc_ops,
384 THIS_MODULE);
385
386 return PTR_ERR_OR_ZERO(ds3232->rtc);
387}
388
389#ifdef CONFIG_PM_SLEEP
390static int ds3232_suspend(struct device *dev)
391{
392 struct ds3232 *ds3232 = dev_get_drvdata(dev);
393
394 if (device_may_wakeup(dev)) {
395 if (enable_irq_wake(ds3232->irq))
396 dev_warn_once(dev, "Cannot set wakeup source\n");
397 }
398
399 return 0;
400}
401
402static int ds3232_resume(struct device *dev)
403{
404 struct ds3232 *ds3232 = dev_get_drvdata(dev);
405
406 if (device_may_wakeup(dev))
407 disable_irq_wake(ds3232->irq);
408
409 return 0;
410}
411#endif
412
413static const struct dev_pm_ops ds3232_pm_ops = {
414 SET_SYSTEM_SLEEP_PM_OPS(ds3232_suspend, ds3232_resume)
415};
416
417#if IS_ENABLED(CONFIG_I2C)
418
419static int ds3232_i2c_probe(struct i2c_client *client,
420 const struct i2c_device_id *id)
421{
422 struct regmap *regmap;
423 static const struct regmap_config config = {
424 .reg_bits = 8,
425 .val_bits = 8,
426 };
427
428 regmap = devm_regmap_init_i2c(client, &config);
429 if (IS_ERR(regmap)) {
430 dev_err(&client->dev, "%s: regmap allocation failed: %ld\n",
431 __func__, PTR_ERR(regmap));
432 return PTR_ERR(regmap);
433 }
434
435 return ds3232_probe(&client->dev, regmap, client->irq, client->name);
436}
437
438static const struct i2c_device_id ds3232_id[] = {
439 { "ds3232", 0 },
440 { }
441};
442MODULE_DEVICE_TABLE(i2c, ds3232_id);
443
444static struct i2c_driver ds3232_driver = {
445 .driver = {
446 .name = "rtc-ds3232",
447 .pm = &ds3232_pm_ops,
448 },
449 .probe = ds3232_i2c_probe,
450 .id_table = ds3232_id,
451};
452
453static int ds3232_register_driver(void)
454{
455 return i2c_add_driver(&ds3232_driver);
456}
457
458static void ds3232_unregister_driver(void)
459{
460 i2c_del_driver(&ds3232_driver);
461}
462
463#else
464
465static int ds3232_register_driver(void)
466{
467 return 0;
468}
469
470static void ds3232_unregister_driver(void)
471{
472}
473
474#endif
475
476#if IS_ENABLED(CONFIG_SPI_MASTER)
477
478static int ds3234_probe(struct spi_device *spi)
479{
480 int res;
481 unsigned int tmp;
482 static const struct regmap_config config = {
483 .reg_bits = 8,
484 .val_bits = 8,
485 .write_flag_mask = 0x80,
486 };
487 struct regmap *regmap;
488
489 regmap = devm_regmap_init_spi(spi, &config);
490 if (IS_ERR(regmap)) {
491 dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n",
492 __func__, PTR_ERR(regmap));
493 return PTR_ERR(regmap);
494 }
495
496 spi->mode = SPI_MODE_3;
497 spi->bits_per_word = 8;
498 spi_setup(spi);
499
500 res = regmap_read(regmap, DS3232_REG_SECONDS, &tmp);
501 if (res)
502 return res;
503
504 /* Control settings
505 *
506 * CONTROL_REG
507 * BIT 7 6 5 4 3 2 1 0
508 * EOSC BBSQW CONV RS2 RS1 INTCN A2IE A1IE
509 *
510 * 0 0 0 1 1 1 0 0
511 *
512 * CONTROL_STAT_REG
513 * BIT 7 6 5 4 3 2 1 0
514 * OSF BB32kHz CRATE1 CRATE0 EN32kHz BSY A2F A1F
515 *
516 * 1 0 0 0 1 0 0 0
517 */
518 res = regmap_read(regmap, DS3232_REG_CR, &tmp);
519 if (res)
520 return res;
521 res = regmap_write(regmap, DS3232_REG_CR, tmp & 0x1c);
522 if (res)
523 return res;
524
525 res = regmap_read(regmap, DS3232_REG_SR, &tmp);
526 if (res)
527 return res;
528 res = regmap_write(regmap, DS3232_REG_SR, tmp & 0x88);
529 if (res)
530 return res;
531
532 /* Print our settings */
533 res = regmap_read(regmap, DS3232_REG_CR, &tmp);
534 if (res)
535 return res;
536 dev_info(&spi->dev, "Control Reg: 0x%02x\n", tmp);
537
538 res = regmap_read(regmap, DS3232_REG_SR, &tmp);
539 if (res)
540 return res;
541 dev_info(&spi->dev, "Ctrl/Stat Reg: 0x%02x\n", tmp);
542
543 return ds3232_probe(&spi->dev, regmap, spi->irq, "ds3234");
544}
545
546static struct spi_driver ds3234_driver = {
547 .driver = {
548 .name = "ds3234",
549 },
550 .probe = ds3234_probe,
551};
552
553static int ds3234_register_driver(void)
554{
555 return spi_register_driver(&ds3234_driver);
556}
557
558static void ds3234_unregister_driver(void)
559{
560 spi_unregister_driver(&ds3234_driver);
561}
562
563#else
564
565static int ds3234_register_driver(void)
566{
567 return 0;
568}
569
570static void ds3234_unregister_driver(void)
571{
572}
573
574#endif
575
576static int __init ds323x_init(void)
577{
578 int ret;
579
580 ret = ds3232_register_driver();
581 if (ret) {
582 pr_err("Failed to register ds3232 driver: %d\n", ret);
583 return ret;
584 }
585
586 ret = ds3234_register_driver();
587 if (ret) {
588 pr_err("Failed to register ds3234 driver: %d\n", ret);
589 ds3232_unregister_driver();
590 }
591
592 return ret;
593}
594module_init(ds323x_init)
595
596static void __exit ds323x_exit(void)
597{
598 ds3234_unregister_driver();
599 ds3232_unregister_driver();
600}
601module_exit(ds323x_exit)
602
603MODULE_AUTHOR("Srikanth Srinivasan <srikanth.srinivasan@freescale.com>");
604MODULE_AUTHOR("Dennis Aberilla <denzzzhome@yahoo.com>");
605MODULE_DESCRIPTION("Maxim/Dallas DS3232/DS3234 RTC Driver");
606MODULE_LICENSE("GPL");
607MODULE_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 int exiting;
61};
62
63static struct i2c_driver ds3232_driver;
64
65static int ds3232_check_rtc_status(struct i2c_client *client)
66{
67 int ret = 0;
68 int control, stat;
69
70 stat = i2c_smbus_read_byte_data(client, DS3232_REG_SR);
71 if (stat < 0)
72 return stat;
73
74 if (stat & DS3232_REG_SR_OSF)
75 dev_warn(&client->dev,
76 "oscillator discontinuity flagged, "
77 "time unreliable\n");
78
79 stat &= ~(DS3232_REG_SR_OSF | DS3232_REG_SR_A1F | DS3232_REG_SR_A2F);
80
81 ret = i2c_smbus_write_byte_data(client, DS3232_REG_SR, stat);
82 if (ret < 0)
83 return ret;
84
85 /* If the alarm is pending, clear it before requesting
86 * the interrupt, so an interrupt event isn't reported
87 * before everything is initialized.
88 */
89
90 control = i2c_smbus_read_byte_data(client, DS3232_REG_CR);
91 if (control < 0)
92 return control;
93
94 control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE);
95 control |= DS3232_REG_CR_INTCN;
96
97 return i2c_smbus_write_byte_data(client, DS3232_REG_CR, control);
98}
99
100static int ds3232_read_time(struct device *dev, struct rtc_time *time)
101{
102 struct i2c_client *client = to_i2c_client(dev);
103 int ret;
104 u8 buf[7];
105 unsigned int year, month, day, hour, minute, second;
106 unsigned int week, twelve_hr, am_pm;
107 unsigned int century, add_century = 0;
108
109 ret = i2c_smbus_read_i2c_block_data(client, DS3232_REG_SECONDS, 7, buf);
110
111 if (ret < 0)
112 return ret;
113 if (ret < 7)
114 return -EIO;
115
116 second = buf[0];
117 minute = buf[1];
118 hour = buf[2];
119 week = buf[3];
120 day = buf[4];
121 month = buf[5];
122 year = buf[6];
123
124 /* Extract additional information for AM/PM and century */
125
126 twelve_hr = hour & 0x40;
127 am_pm = hour & 0x20;
128 century = month & 0x80;
129
130 /* Write to rtc_time structure */
131
132 time->tm_sec = bcd2bin(second);
133 time->tm_min = bcd2bin(minute);
134 if (twelve_hr) {
135 /* Convert to 24 hr */
136 if (am_pm)
137 time->tm_hour = bcd2bin(hour & 0x1F) + 12;
138 else
139 time->tm_hour = bcd2bin(hour & 0x1F);
140 } else {
141 time->tm_hour = bcd2bin(hour);
142 }
143
144 /* Day of the week in linux range is 0~6 while 1~7 in RTC chip */
145 time->tm_wday = bcd2bin(week) - 1;
146 time->tm_mday = bcd2bin(day);
147 /* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */
148 time->tm_mon = bcd2bin(month & 0x7F) - 1;
149 if (century)
150 add_century = 100;
151
152 time->tm_year = bcd2bin(year) + add_century;
153
154 return rtc_valid_tm(time);
155}
156
157static int ds3232_set_time(struct device *dev, struct rtc_time *time)
158{
159 struct i2c_client *client = to_i2c_client(dev);
160 u8 buf[7];
161
162 /* Extract time from rtc_time and load into ds3232*/
163
164 buf[0] = bin2bcd(time->tm_sec);
165 buf[1] = bin2bcd(time->tm_min);
166 buf[2] = bin2bcd(time->tm_hour);
167 /* Day of the week in linux range is 0~6 while 1~7 in RTC chip */
168 buf[3] = bin2bcd(time->tm_wday + 1);
169 buf[4] = bin2bcd(time->tm_mday); /* Date */
170 /* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */
171 buf[5] = bin2bcd(time->tm_mon + 1);
172 if (time->tm_year >= 100) {
173 buf[5] |= 0x80;
174 buf[6] = bin2bcd(time->tm_year - 100);
175 } else {
176 buf[6] = bin2bcd(time->tm_year);
177 }
178
179 return i2c_smbus_write_i2c_block_data(client,
180 DS3232_REG_SECONDS, 7, buf);
181}
182
183/*
184 * DS3232 has two alarm, we only use alarm1
185 * According to linux specification, only support one-shot alarm
186 * no periodic alarm mode
187 */
188static int ds3232_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
189{
190 struct i2c_client *client = to_i2c_client(dev);
191 struct ds3232 *ds3232 = i2c_get_clientdata(client);
192 int control, stat;
193 int ret;
194 u8 buf[4];
195
196 mutex_lock(&ds3232->mutex);
197
198 ret = i2c_smbus_read_byte_data(client, DS3232_REG_SR);
199 if (ret < 0)
200 goto out;
201 stat = ret;
202 ret = i2c_smbus_read_byte_data(client, DS3232_REG_CR);
203 if (ret < 0)
204 goto out;
205 control = ret;
206 ret = i2c_smbus_read_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf);
207 if (ret < 0)
208 goto out;
209
210 alarm->time.tm_sec = bcd2bin(buf[0] & 0x7F);
211 alarm->time.tm_min = bcd2bin(buf[1] & 0x7F);
212 alarm->time.tm_hour = bcd2bin(buf[2] & 0x7F);
213 alarm->time.tm_mday = bcd2bin(buf[3] & 0x7F);
214
215 alarm->time.tm_mon = -1;
216 alarm->time.tm_year = -1;
217 alarm->time.tm_wday = -1;
218 alarm->time.tm_yday = -1;
219 alarm->time.tm_isdst = -1;
220
221 alarm->enabled = !!(control & DS3232_REG_CR_A1IE);
222 alarm->pending = !!(stat & DS3232_REG_SR_A1F);
223
224 ret = 0;
225out:
226 mutex_unlock(&ds3232->mutex);
227 return ret;
228}
229
230/*
231 * linux rtc-module does not support wday alarm
232 * and only 24h time mode supported indeed
233 */
234static int ds3232_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
235{
236 struct i2c_client *client = to_i2c_client(dev);
237 struct ds3232 *ds3232 = i2c_get_clientdata(client);
238 int control, stat;
239 int ret;
240 u8 buf[4];
241
242 if (client->irq <= 0)
243 return -EINVAL;
244
245 mutex_lock(&ds3232->mutex);
246
247 buf[0] = bin2bcd(alarm->time.tm_sec);
248 buf[1] = bin2bcd(alarm->time.tm_min);
249 buf[2] = bin2bcd(alarm->time.tm_hour);
250 buf[3] = bin2bcd(alarm->time.tm_mday);
251
252 /* clear alarm interrupt enable bit */
253 ret = i2c_smbus_read_byte_data(client, DS3232_REG_CR);
254 if (ret < 0)
255 goto out;
256 control = ret;
257 control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE);
258 ret = i2c_smbus_write_byte_data(client, DS3232_REG_CR, control);
259 if (ret < 0)
260 goto out;
261
262 /* clear any pending alarm flag */
263 ret = i2c_smbus_read_byte_data(client, DS3232_REG_SR);
264 if (ret < 0)
265 goto out;
266 stat = ret;
267 stat &= ~(DS3232_REG_SR_A1F | DS3232_REG_SR_A2F);
268 ret = i2c_smbus_write_byte_data(client, DS3232_REG_SR, stat);
269 if (ret < 0)
270 goto out;
271
272 ret = i2c_smbus_write_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf);
273
274 if (alarm->enabled) {
275 control |= DS3232_REG_CR_A1IE;
276 ret = i2c_smbus_write_byte_data(client, DS3232_REG_CR, control);
277 }
278out:
279 mutex_unlock(&ds3232->mutex);
280 return ret;
281}
282
283static void ds3232_update_alarm(struct i2c_client *client)
284{
285 struct ds3232 *ds3232 = i2c_get_clientdata(client);
286 int control;
287 int ret;
288 u8 buf[4];
289
290 mutex_lock(&ds3232->mutex);
291
292 ret = i2c_smbus_read_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf);
293 if (ret < 0)
294 goto unlock;
295
296 buf[0] = bcd2bin(buf[0]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ?
297 0x80 : buf[0];
298 buf[1] = bcd2bin(buf[1]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ?
299 0x80 : buf[1];
300 buf[2] = bcd2bin(buf[2]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ?
301 0x80 : buf[2];
302 buf[3] = bcd2bin(buf[3]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ?
303 0x80 : buf[3];
304
305 ret = i2c_smbus_write_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf);
306 if (ret < 0)
307 goto unlock;
308
309 control = i2c_smbus_read_byte_data(client, DS3232_REG_CR);
310 if (control < 0)
311 goto unlock;
312
313 if (ds3232->rtc->irq_data & (RTC_AF | RTC_UF))
314 /* enable alarm1 interrupt */
315 control |= DS3232_REG_CR_A1IE;
316 else
317 /* disable alarm1 interrupt */
318 control &= ~(DS3232_REG_CR_A1IE);
319 i2c_smbus_write_byte_data(client, DS3232_REG_CR, control);
320
321unlock:
322 mutex_unlock(&ds3232->mutex);
323}
324
325static int ds3232_alarm_irq_enable(struct device *dev, unsigned int enabled)
326{
327 struct i2c_client *client = to_i2c_client(dev);
328 struct ds3232 *ds3232 = i2c_get_clientdata(client);
329
330 if (client->irq <= 0)
331 return -EINVAL;
332
333 if (enabled)
334 ds3232->rtc->irq_data |= RTC_AF;
335 else
336 ds3232->rtc->irq_data &= ~RTC_AF;
337
338 ds3232_update_alarm(client);
339 return 0;
340}
341
342static irqreturn_t ds3232_irq(int irq, void *dev_id)
343{
344 struct i2c_client *client = dev_id;
345 struct ds3232 *ds3232 = i2c_get_clientdata(client);
346
347 disable_irq_nosync(irq);
348 schedule_work(&ds3232->work);
349 return IRQ_HANDLED;
350}
351
352static void ds3232_work(struct work_struct *work)
353{
354 struct ds3232 *ds3232 = container_of(work, struct ds3232, work);
355 struct i2c_client *client = ds3232->client;
356 int stat, control;
357
358 mutex_lock(&ds3232->mutex);
359
360 stat = i2c_smbus_read_byte_data(client, DS3232_REG_SR);
361 if (stat < 0)
362 goto unlock;
363
364 if (stat & DS3232_REG_SR_A1F) {
365 control = i2c_smbus_read_byte_data(client, DS3232_REG_CR);
366 if (control < 0)
367 goto out;
368 /* disable alarm1 interrupt */
369 control &= ~(DS3232_REG_CR_A1IE);
370 i2c_smbus_write_byte_data(client, DS3232_REG_CR, control);
371
372 /* clear the alarm pend flag */
373 stat &= ~DS3232_REG_SR_A1F;
374 i2c_smbus_write_byte_data(client, DS3232_REG_SR, stat);
375
376 rtc_update_irq(ds3232->rtc, 1, RTC_AF | RTC_IRQF);
377 }
378
379out:
380 if (!ds3232->exiting)
381 enable_irq(client->irq);
382unlock:
383 mutex_unlock(&ds3232->mutex);
384}
385
386static const struct rtc_class_ops ds3232_rtc_ops = {
387 .read_time = ds3232_read_time,
388 .set_time = ds3232_set_time,
389 .read_alarm = ds3232_read_alarm,
390 .set_alarm = ds3232_set_alarm,
391 .alarm_irq_enable = ds3232_alarm_irq_enable,
392};
393
394static int __devinit ds3232_probe(struct i2c_client *client,
395 const struct i2c_device_id *id)
396{
397 struct ds3232 *ds3232;
398 int ret;
399
400 ds3232 = kzalloc(sizeof(struct ds3232), GFP_KERNEL);
401 if (!ds3232)
402 return -ENOMEM;
403
404 ds3232->client = client;
405 i2c_set_clientdata(client, ds3232);
406
407 INIT_WORK(&ds3232->work, ds3232_work);
408 mutex_init(&ds3232->mutex);
409
410 ret = ds3232_check_rtc_status(client);
411 if (ret)
412 goto out_free;
413
414 ds3232->rtc = rtc_device_register(client->name, &client->dev,
415 &ds3232_rtc_ops, THIS_MODULE);
416 if (IS_ERR(ds3232->rtc)) {
417 ret = PTR_ERR(ds3232->rtc);
418 dev_err(&client->dev, "unable to register the class device\n");
419 goto out_irq;
420 }
421
422 if (client->irq >= 0) {
423 ret = request_irq(client->irq, ds3232_irq, 0,
424 "ds3232", client);
425 if (ret) {
426 dev_err(&client->dev, "unable to request IRQ\n");
427 goto out_free;
428 }
429 }
430
431 return 0;
432
433out_irq:
434 if (client->irq >= 0)
435 free_irq(client->irq, client);
436
437out_free:
438 kfree(ds3232);
439 return ret;
440}
441
442static int __devexit ds3232_remove(struct i2c_client *client)
443{
444 struct ds3232 *ds3232 = i2c_get_clientdata(client);
445
446 if (client->irq >= 0) {
447 mutex_lock(&ds3232->mutex);
448 ds3232->exiting = 1;
449 mutex_unlock(&ds3232->mutex);
450
451 free_irq(client->irq, client);
452 cancel_work_sync(&ds3232->work);
453 }
454
455 rtc_device_unregister(ds3232->rtc);
456 kfree(ds3232);
457 return 0;
458}
459
460static const struct i2c_device_id ds3232_id[] = {
461 { "ds3232", 0 },
462 { }
463};
464MODULE_DEVICE_TABLE(i2c, ds3232_id);
465
466static struct i2c_driver ds3232_driver = {
467 .driver = {
468 .name = "rtc-ds3232",
469 .owner = THIS_MODULE,
470 },
471 .probe = ds3232_probe,
472 .remove = __devexit_p(ds3232_remove),
473 .id_table = ds3232_id,
474};
475
476static int __init ds3232_init(void)
477{
478 return i2c_add_driver(&ds3232_driver);
479}
480
481static void __exit ds3232_exit(void)
482{
483 i2c_del_driver(&ds3232_driver);
484}
485
486module_init(ds3232_init);
487module_exit(ds3232_exit);
488
489MODULE_AUTHOR("Srikanth Srinivasan <srikanth.srinivasan@freescale.com>");
490MODULE_DESCRIPTION("Maxim/Dallas DS3232 RTC Driver");
491MODULE_LICENSE("GPL");