Merge branch 'r6040-next'
[linux/fpc-iii.git] / drivers / rtc / rtc-ds3232.c
blob04fbd7fffd0d8f2af296b35ac3dcb049c5cd8002
1 /*
2 * RTC client/driver for the Maxim/Dallas DS3232/DS3234 Real-Time Clock
4 * Copyright (C) 2009-2011 Freescale Semiconductor.
5 * Author: Jack Lan <jack.lan@freescale.com>
6 * Copyright (C) 2008 MIMOMax Wireless Ltd.
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.
14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>
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
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
49 struct ds3232 {
50 struct device *dev;
51 struct regmap *regmap;
52 int irq;
53 struct rtc_device *rtc;
55 bool suspended;
58 static int ds3232_check_rtc_status(struct device *dev)
60 struct ds3232 *ds3232 = dev_get_drvdata(dev);
61 int ret = 0;
62 int control, stat;
64 ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
65 if (ret)
66 return ret;
68 if (stat & DS3232_REG_SR_OSF)
69 dev_warn(dev,
70 "oscillator discontinuity flagged, "
71 "time unreliable\n");
73 stat &= ~(DS3232_REG_SR_OSF | DS3232_REG_SR_A1F | DS3232_REG_SR_A2F);
75 ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat);
76 if (ret)
77 return ret;
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.
84 ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
85 if (ret)
86 return ret;
88 control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE);
89 control |= DS3232_REG_CR_INTCN;
91 return regmap_write(ds3232->regmap, DS3232_REG_CR, control);
94 static int ds3232_read_time(struct device *dev, struct rtc_time *time)
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;
103 ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_SECONDS, buf, 7);
104 if (ret)
105 return ret;
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];
115 /* Extract additional information for AM/PM and century */
117 twelve_hr = hour & 0x40;
118 am_pm = hour & 0x20;
119 century = month & 0x80;
121 /* Write to rtc_time structure */
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);
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;
143 time->tm_year = bcd2bin(year) + add_century;
145 return rtc_valid_tm(time);
148 static int ds3232_set_time(struct device *dev, struct rtc_time *time)
150 struct ds3232 *ds3232 = dev_get_drvdata(dev);
151 u8 buf[7];
153 /* Extract time from rtc_time and load into ds3232*/
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);
170 return regmap_bulk_write(ds3232->regmap, DS3232_REG_SECONDS, buf, 7);
174 * DS3232 has two alarm, we only use alarm1
175 * According to linux specification, only support one-shot alarm
176 * no periodic alarm mode
178 static int ds3232_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
180 struct ds3232 *ds3232 = dev_get_drvdata(dev);
181 int control, stat;
182 int ret;
183 u8 buf[4];
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;
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);
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;
206 alarm->enabled = !!(control & DS3232_REG_CR_A1IE);
207 alarm->pending = !!(stat & DS3232_REG_SR_A1F);
209 ret = 0;
210 out:
211 return ret;
215 * linux rtc-module does not support wday alarm
216 * and only 24h time mode supported indeed
218 static int ds3232_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
220 struct ds3232 *ds3232 = dev_get_drvdata(dev);
221 int control, stat;
222 int ret;
223 u8 buf[4];
225 if (ds3232->irq <= 0)
226 return -EINVAL;
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);
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;
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;
251 ret = regmap_bulk_write(ds3232->regmap, DS3232_REG_ALARM1, buf, 4);
252 if (ret)
253 goto out;
255 if (alarm->enabled) {
256 control |= DS3232_REG_CR_A1IE;
257 ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control);
259 out:
260 return ret;
263 static int ds3232_update_alarm(struct device *dev, unsigned int enabled)
265 struct ds3232 *ds3232 = dev_get_drvdata(dev);
266 int control;
267 int ret;
269 ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
270 if (ret)
271 return ret;
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);
281 return ret;
284 static int ds3232_alarm_irq_enable(struct device *dev, unsigned int enabled)
286 struct ds3232 *ds3232 = dev_get_drvdata(dev);
288 if (ds3232->irq <= 0)
289 return -EINVAL;
291 return ds3232_update_alarm(dev, enabled);
294 static irqreturn_t ds3232_irq(int irq, void *dev_id)
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;
302 mutex_lock(lock);
304 ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
305 if (ret)
306 goto unlock;
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;
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;
335 rtc_update_irq(ds3232->rtc, 1, RTC_AF | RTC_IRQF);
339 unlock:
340 mutex_unlock(lock);
342 return IRQ_HANDLED;
345 static 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,
353 static int ds3232_probe(struct device *dev, struct regmap *regmap, int irq,
354 const char *name)
356 struct ds3232 *ds3232;
357 int ret;
359 ds3232 = devm_kzalloc(dev, sizeof(*ds3232), GFP_KERNEL);
360 if (!ds3232)
361 return -ENOMEM;
363 ds3232->regmap = regmap;
364 ds3232->irq = irq;
365 ds3232->dev = dev;
366 dev_set_drvdata(dev, ds3232);
368 ret = ds3232_check_rtc_status(dev);
369 if (ret)
370 return ret;
372 ds3232->rtc = devm_rtc_device_register(dev, name, &ds3232_rtc_ops,
373 THIS_MODULE);
374 if (IS_ERR(ds3232->rtc))
375 return PTR_ERR(ds3232->rtc);
377 if (ds3232->irq > 0) {
378 ret = devm_request_threaded_irq(dev, ds3232->irq, NULL,
379 ds3232_irq,
380 IRQF_SHARED | IRQF_ONESHOT,
381 name, dev);
382 if (ret) {
383 ds3232->irq = 0;
384 dev_err(dev, "unable to request IRQ\n");
385 } else
386 device_init_wakeup(dev, 1);
389 return 0;
392 #ifdef CONFIG_PM_SLEEP
393 static int ds3232_suspend(struct device *dev)
395 struct ds3232 *ds3232 = dev_get_drvdata(dev);
397 if (device_may_wakeup(dev)) {
398 if (enable_irq_wake(ds3232->irq))
399 dev_warn_once(dev, "Cannot set wakeup source\n");
402 return 0;
405 static int ds3232_resume(struct device *dev)
407 struct ds3232 *ds3232 = dev_get_drvdata(dev);
409 if (device_may_wakeup(dev))
410 disable_irq_wake(ds3232->irq);
412 return 0;
414 #endif
416 static const struct dev_pm_ops ds3232_pm_ops = {
417 SET_SYSTEM_SLEEP_PM_OPS(ds3232_suspend, ds3232_resume)
420 #if IS_ENABLED(CONFIG_I2C)
422 static int ds3232_i2c_probe(struct i2c_client *client,
423 const struct i2c_device_id *id)
425 struct regmap *regmap;
426 static const struct regmap_config config = {
427 .reg_bits = 8,
428 .val_bits = 8,
431 regmap = devm_regmap_init_i2c(client, &config);
432 if (IS_ERR(regmap)) {
433 dev_err(&client->dev, "%s: regmap allocation failed: %ld\n",
434 __func__, PTR_ERR(regmap));
435 return PTR_ERR(regmap);
438 return ds3232_probe(&client->dev, regmap, client->irq, client->name);
441 static const struct i2c_device_id ds3232_id[] = {
442 { "ds3232", 0 },
445 MODULE_DEVICE_TABLE(i2c, ds3232_id);
447 static struct i2c_driver ds3232_driver = {
448 .driver = {
449 .name = "rtc-ds3232",
450 .pm = &ds3232_pm_ops,
452 .probe = ds3232_i2c_probe,
453 .id_table = ds3232_id,
456 static int ds3232_register_driver(void)
458 return i2c_add_driver(&ds3232_driver);
461 static void ds3232_unregister_driver(void)
463 i2c_del_driver(&ds3232_driver);
466 #else
468 static int ds3232_register_driver(void)
470 return 0;
473 static void ds3232_unregister_driver(void)
477 #endif
479 #if IS_ENABLED(CONFIG_SPI_MASTER)
481 static int ds3234_probe(struct spi_device *spi)
483 int res;
484 unsigned int tmp;
485 static const struct regmap_config config = {
486 .reg_bits = 8,
487 .val_bits = 8,
488 .write_flag_mask = 0x80,
490 struct regmap *regmap;
492 regmap = devm_regmap_init_spi(spi, &config);
493 if (IS_ERR(regmap)) {
494 dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n",
495 __func__, PTR_ERR(regmap));
496 return PTR_ERR(regmap);
499 spi->mode = SPI_MODE_3;
500 spi->bits_per_word = 8;
501 spi_setup(spi);
503 res = regmap_read(regmap, DS3232_REG_SECONDS, &tmp);
504 if (res)
505 return res;
507 /* Control settings
509 * CONTROL_REG
510 * BIT 7 6 5 4 3 2 1 0
511 * EOSC BBSQW CONV RS2 RS1 INTCN A2IE A1IE
513 * 0 0 0 1 1 1 0 0
515 * CONTROL_STAT_REG
516 * BIT 7 6 5 4 3 2 1 0
517 * OSF BB32kHz CRATE1 CRATE0 EN32kHz BSY A2F A1F
519 * 1 0 0 0 1 0 0 0
521 res = regmap_read(regmap, DS3232_REG_CR, &tmp);
522 if (res)
523 return res;
524 res = regmap_write(regmap, DS3232_REG_CR, tmp & 0x1c);
525 if (res)
526 return res;
528 res = regmap_read(regmap, DS3232_REG_SR, &tmp);
529 if (res)
530 return res;
531 res = regmap_write(regmap, DS3232_REG_SR, tmp & 0x88);
532 if (res)
533 return res;
535 /* Print our settings */
536 res = regmap_read(regmap, DS3232_REG_CR, &tmp);
537 if (res)
538 return res;
539 dev_info(&spi->dev, "Control Reg: 0x%02x\n", tmp);
541 res = regmap_read(regmap, DS3232_REG_SR, &tmp);
542 if (res)
543 return res;
544 dev_info(&spi->dev, "Ctrl/Stat Reg: 0x%02x\n", tmp);
546 return ds3232_probe(&spi->dev, regmap, spi->irq, "ds3234");
549 static struct spi_driver ds3234_driver = {
550 .driver = {
551 .name = "ds3234",
553 .probe = ds3234_probe,
556 static int ds3234_register_driver(void)
558 return spi_register_driver(&ds3234_driver);
561 static void ds3234_unregister_driver(void)
563 spi_unregister_driver(&ds3234_driver);
566 #else
568 static int ds3234_register_driver(void)
570 return 0;
573 static void ds3234_unregister_driver(void)
577 #endif
579 static int __init ds323x_init(void)
581 int ret;
583 ret = ds3232_register_driver();
584 if (ret) {
585 pr_err("Failed to register ds3232 driver: %d\n", ret);
586 return ret;
589 ret = ds3234_register_driver();
590 if (ret) {
591 pr_err("Failed to register ds3234 driver: %d\n", ret);
592 ds3232_unregister_driver();
595 return ret;
597 module_init(ds323x_init)
599 static void __exit ds323x_exit(void)
601 ds3234_unregister_driver();
602 ds3232_unregister_driver();
604 module_exit(ds323x_exit)
606 MODULE_AUTHOR("Srikanth Srinivasan <srikanth.srinivasan@freescale.com>");
607 MODULE_AUTHOR("Dennis Aberilla <denzzzhome@yahoo.com>");
608 MODULE_DESCRIPTION("Maxim/Dallas DS3232/DS3234 RTC Driver");
609 MODULE_LICENSE("GPL");
610 MODULE_ALIAS("spi:ds3234");