2 * rtc-ds1307.c - RTC driver for some mostly-compatible I2C chips.
4 * Copyright (C) 2005 James Chapman (ds1337 core)
5 * Copyright (C) 2006 David Brownell
6 * Copyright (C) 2009 Matthias Fuchs (rx8025 support)
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/slab.h>
16 #include <linux/i2c.h>
17 #include <linux/string.h>
18 #include <linux/rtc.h>
19 #include <linux/bcd.h>
23 /* We can't determine type by probing, but if we expect pre-Linux code
24 * to have set the chip up as a clock (turning on the oscillator and
25 * setting the date and time), Linux can ignore the non-clock features.
26 * That's a natural job for a factory or repair bench.
39 // rs5c372 too? different address...
43 /* RTC registers don't differ much, except for the century flag */
44 #define DS1307_REG_SECS 0x00 /* 00-59 */
45 # define DS1307_BIT_CH 0x80
46 # define DS1340_BIT_nEOSC 0x80
47 # define MCP7941X_BIT_ST 0x80
48 #define DS1307_REG_MIN 0x01 /* 00-59 */
49 #define DS1307_REG_HOUR 0x02 /* 00-23, or 1-12{am,pm} */
50 # define DS1307_BIT_12HR 0x40 /* in REG_HOUR */
51 # define DS1307_BIT_PM 0x20 /* in REG_HOUR */
52 # define DS1340_BIT_CENTURY_EN 0x80 /* in REG_HOUR */
53 # define DS1340_BIT_CENTURY 0x40 /* in REG_HOUR */
54 #define DS1307_REG_WDAY 0x03 /* 01-07 */
55 # define MCP7941X_BIT_VBATEN 0x08
56 #define DS1307_REG_MDAY 0x04 /* 01-31 */
57 #define DS1307_REG_MONTH 0x05 /* 01-12 */
58 # define DS1337_BIT_CENTURY 0x80 /* in REG_MONTH */
59 #define DS1307_REG_YEAR 0x06 /* 00-99 */
61 /* Other registers (control, status, alarms, trickle charge, NVRAM, etc)
62 * start at 7, and they differ a LOT. Only control and status matter for
63 * basic RTC date and time functionality; be careful using them.
65 #define DS1307_REG_CONTROL 0x07 /* or ds1338 */
66 # define DS1307_BIT_OUT 0x80
67 # define DS1338_BIT_OSF 0x20
68 # define DS1307_BIT_SQWE 0x10
69 # define DS1307_BIT_RS1 0x02
70 # define DS1307_BIT_RS0 0x01
71 #define DS1337_REG_CONTROL 0x0e
72 # define DS1337_BIT_nEOSC 0x80
73 # define DS1339_BIT_BBSQI 0x20
74 # define DS3231_BIT_BBSQW 0x40 /* same as BBSQI */
75 # define DS1337_BIT_RS2 0x10
76 # define DS1337_BIT_RS1 0x08
77 # define DS1337_BIT_INTCN 0x04
78 # define DS1337_BIT_A2IE 0x02
79 # define DS1337_BIT_A1IE 0x01
80 #define DS1340_REG_CONTROL 0x07
81 # define DS1340_BIT_OUT 0x80
82 # define DS1340_BIT_FT 0x40
83 # define DS1340_BIT_CALIB_SIGN 0x20
84 # define DS1340_M_CALIBRATION 0x1f
85 #define DS1340_REG_FLAG 0x09
86 # define DS1340_BIT_OSF 0x80
87 #define DS1337_REG_STATUS 0x0f
88 # define DS1337_BIT_OSF 0x80
89 # define DS1337_BIT_A2I 0x02
90 # define DS1337_BIT_A1I 0x01
91 #define DS1339_REG_ALARM1_SECS 0x07
92 #define DS1339_REG_TRICKLE 0x10
94 #define RX8025_REG_CTRL1 0x0e
95 # define RX8025_BIT_2412 0x20
96 #define RX8025_REG_CTRL2 0x0f
97 # define RX8025_BIT_PON 0x10
98 # define RX8025_BIT_VDET 0x40
99 # define RX8025_BIT_XST 0x20
103 u8 offset; /* register's offset */
107 #define HAS_NVRAM 0 /* bit 0 == sysfs file active */
108 #define HAS_ALARM 1 /* bit 1 == irq claimed */
109 struct i2c_client *client;
110 struct rtc_device *rtc;
111 struct work_struct work;
112 s32 (*read_block_data)(const struct i2c_client *client, u8 command,
113 u8 length, u8 *values);
114 s32 (*write_block_data)(const struct i2c_client *client, u8 command,
115 u8 length, const u8 *values);
123 static const struct chip_desc chips[] = {
148 static const struct i2c_device_id ds1307_id[] = {
149 { "ds1307", ds_1307 },
150 { "ds1337", ds_1337 },
151 { "ds1338", ds_1338 },
152 { "ds1339", ds_1339 },
153 { "ds1388", ds_1388 },
154 { "ds1340", ds_1340 },
155 { "ds3231", ds_3231 },
156 { "m41t00", m41t00 },
157 { "mcp7941x", mcp7941x },
158 { "pt7c4338", ds_1307 },
159 { "rx8025", rx_8025 },
162 MODULE_DEVICE_TABLE(i2c, ds1307_id);
164 /*----------------------------------------------------------------------*/
166 #define BLOCK_DATA_MAX_TRIES 10
168 static s32 ds1307_read_block_data_once(const struct i2c_client *client,
169 u8 command, u8 length, u8 *values)
173 for (i = 0; i < length; i++) {
174 data = i2c_smbus_read_byte_data(client, command + i);
182 static s32 ds1307_read_block_data(const struct i2c_client *client, u8 command,
183 u8 length, u8 *values)
185 u8 oldvalues[I2C_SMBUS_BLOCK_MAX];
189 dev_dbg(&client->dev, "ds1307_read_block_data (length=%d)\n", length);
190 ret = ds1307_read_block_data_once(client, command, length, values);
194 if (++tries > BLOCK_DATA_MAX_TRIES) {
195 dev_err(&client->dev,
196 "ds1307_read_block_data failed\n");
199 memcpy(oldvalues, values, length);
200 ret = ds1307_read_block_data_once(client, command, length,
204 } while (memcmp(oldvalues, values, length));
208 static s32 ds1307_write_block_data(const struct i2c_client *client, u8 command,
209 u8 length, const u8 *values)
211 u8 currvalues[I2C_SMBUS_BLOCK_MAX];
214 dev_dbg(&client->dev, "ds1307_write_block_data (length=%d)\n", length);
218 if (++tries > BLOCK_DATA_MAX_TRIES) {
219 dev_err(&client->dev,
220 "ds1307_write_block_data failed\n");
223 for (i = 0; i < length; i++) {
224 ret = i2c_smbus_write_byte_data(client, command + i,
229 ret = ds1307_read_block_data_once(client, command, length,
233 } while (memcmp(currvalues, values, length));
237 /*----------------------------------------------------------------------*/
240 * The IRQ logic includes a "real" handler running in IRQ context just
241 * long enough to schedule this workqueue entry. We need a task context
242 * to talk to the RTC, since I2C I/O calls require that; and disable the
243 * IRQ until we clear its status on the chip, so that this handler can
244 * work with any type of triggering (not just falling edge).
246 * The ds1337 and ds1339 both have two alarms, but we only use the first
247 * one (with a "seconds" field). For ds1337 we expect nINTA is our alarm
248 * signal; ds1339 chips have only one alarm signal.
250 static void ds1307_work(struct work_struct *work)
252 struct ds1307 *ds1307;
253 struct i2c_client *client;
257 ds1307 = container_of(work, struct ds1307, work);
258 client = ds1307->client;
259 lock = &ds1307->rtc->ops_lock;
262 stat = i2c_smbus_read_byte_data(client, DS1337_REG_STATUS);
266 if (stat & DS1337_BIT_A1I) {
267 stat &= ~DS1337_BIT_A1I;
268 i2c_smbus_write_byte_data(client, DS1337_REG_STATUS, stat);
270 control = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
274 control &= ~DS1337_BIT_A1IE;
275 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, control);
277 rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
281 if (test_bit(HAS_ALARM, &ds1307->flags))
282 enable_irq(client->irq);
286 static irqreturn_t ds1307_irq(int irq, void *dev_id)
288 struct i2c_client *client = dev_id;
289 struct ds1307 *ds1307 = i2c_get_clientdata(client);
291 disable_irq_nosync(irq);
292 schedule_work(&ds1307->work);
296 /*----------------------------------------------------------------------*/
298 static int ds1307_get_time(struct device *dev, struct rtc_time *t)
300 struct ds1307 *ds1307 = dev_get_drvdata(dev);
303 /* read the RTC date and time registers all at once */
304 tmp = ds1307->read_block_data(ds1307->client,
305 ds1307->offset, 7, ds1307->regs);
307 dev_err(dev, "%s error %d\n", "read", tmp);
311 dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
313 ds1307->regs[0], ds1307->regs[1],
314 ds1307->regs[2], ds1307->regs[3],
315 ds1307->regs[4], ds1307->regs[5],
318 t->tm_sec = bcd2bin(ds1307->regs[DS1307_REG_SECS] & 0x7f);
319 t->tm_min = bcd2bin(ds1307->regs[DS1307_REG_MIN] & 0x7f);
320 tmp = ds1307->regs[DS1307_REG_HOUR] & 0x3f;
321 t->tm_hour = bcd2bin(tmp);
322 t->tm_wday = bcd2bin(ds1307->regs[DS1307_REG_WDAY] & 0x07) - 1;
323 t->tm_mday = bcd2bin(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
324 tmp = ds1307->regs[DS1307_REG_MONTH] & 0x1f;
325 t->tm_mon = bcd2bin(tmp) - 1;
327 /* assume 20YY not 19YY, and ignore DS1337_BIT_CENTURY */
328 t->tm_year = bcd2bin(ds1307->regs[DS1307_REG_YEAR]) + 100;
330 dev_dbg(dev, "%s secs=%d, mins=%d, "
331 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
332 "read", t->tm_sec, t->tm_min,
333 t->tm_hour, t->tm_mday,
334 t->tm_mon, t->tm_year, t->tm_wday);
336 /* initial clock setting can be undefined */
337 return rtc_valid_tm(t);
340 static int ds1307_set_time(struct device *dev, struct rtc_time *t)
342 struct ds1307 *ds1307 = dev_get_drvdata(dev);
345 u8 *buf = ds1307->regs;
347 dev_dbg(dev, "%s secs=%d, mins=%d, "
348 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
349 "write", t->tm_sec, t->tm_min,
350 t->tm_hour, t->tm_mday,
351 t->tm_mon, t->tm_year, t->tm_wday);
353 buf[DS1307_REG_SECS] = bin2bcd(t->tm_sec);
354 buf[DS1307_REG_MIN] = bin2bcd(t->tm_min);
355 buf[DS1307_REG_HOUR] = bin2bcd(t->tm_hour);
356 buf[DS1307_REG_WDAY] = bin2bcd(t->tm_wday + 1);
357 buf[DS1307_REG_MDAY] = bin2bcd(t->tm_mday);
358 buf[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1);
360 /* assume 20YY not 19YY */
361 tmp = t->tm_year - 100;
362 buf[DS1307_REG_YEAR] = bin2bcd(tmp);
364 switch (ds1307->type) {
368 buf[DS1307_REG_MONTH] |= DS1337_BIT_CENTURY;
371 buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN
372 | DS1340_BIT_CENTURY;
375 buf[DS1307_REG_SECS] |= MCP7941X_BIT_ST;
376 buf[DS1307_REG_WDAY] |= MCP7941X_BIT_VBATEN;
382 dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
383 "write", buf[0], buf[1], buf[2], buf[3],
384 buf[4], buf[5], buf[6]);
386 result = ds1307->write_block_data(ds1307->client,
387 ds1307->offset, 7, buf);
389 dev_err(dev, "%s error %d\n", "write", result);
395 static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t)
397 struct i2c_client *client = to_i2c_client(dev);
398 struct ds1307 *ds1307 = i2c_get_clientdata(client);
401 if (!test_bit(HAS_ALARM, &ds1307->flags))
404 /* read all ALARM1, ALARM2, and status registers at once */
405 ret = ds1307->read_block_data(client,
406 DS1339_REG_ALARM1_SECS, 9, ds1307->regs);
408 dev_err(dev, "%s error %d\n", "alarm read", ret);
412 dev_dbg(dev, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n",
414 ds1307->regs[0], ds1307->regs[1],
415 ds1307->regs[2], ds1307->regs[3],
416 ds1307->regs[4], ds1307->regs[5],
417 ds1307->regs[6], ds1307->regs[7],
420 /* report alarm time (ALARM1); assume 24 hour and day-of-month modes,
421 * and that all four fields are checked matches
423 t->time.tm_sec = bcd2bin(ds1307->regs[0] & 0x7f);
424 t->time.tm_min = bcd2bin(ds1307->regs[1] & 0x7f);
425 t->time.tm_hour = bcd2bin(ds1307->regs[2] & 0x3f);
426 t->time.tm_mday = bcd2bin(ds1307->regs[3] & 0x3f);
428 t->time.tm_year = -1;
429 t->time.tm_wday = -1;
430 t->time.tm_yday = -1;
431 t->time.tm_isdst = -1;
434 t->enabled = !!(ds1307->regs[7] & DS1337_BIT_A1IE);
435 t->pending = !!(ds1307->regs[8] & DS1337_BIT_A1I);
437 dev_dbg(dev, "%s secs=%d, mins=%d, "
438 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
439 "alarm read", t->time.tm_sec, t->time.tm_min,
440 t->time.tm_hour, t->time.tm_mday,
441 t->enabled, t->pending);
446 static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t)
448 struct i2c_client *client = to_i2c_client(dev);
449 struct ds1307 *ds1307 = i2c_get_clientdata(client);
450 unsigned char *buf = ds1307->regs;
454 if (!test_bit(HAS_ALARM, &ds1307->flags))
457 dev_dbg(dev, "%s secs=%d, mins=%d, "
458 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
459 "alarm set", t->time.tm_sec, t->time.tm_min,
460 t->time.tm_hour, t->time.tm_mday,
461 t->enabled, t->pending);
463 /* read current status of both alarms and the chip */
464 ret = ds1307->read_block_data(client,
465 DS1339_REG_ALARM1_SECS, 9, buf);
467 dev_err(dev, "%s error %d\n", "alarm write", ret);
470 control = ds1307->regs[7];
471 status = ds1307->regs[8];
473 dev_dbg(dev, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n",
474 "alarm set (old status)",
475 ds1307->regs[0], ds1307->regs[1],
476 ds1307->regs[2], ds1307->regs[3],
477 ds1307->regs[4], ds1307->regs[5],
478 ds1307->regs[6], control, status);
480 /* set ALARM1, using 24 hour and day-of-month modes */
481 buf[0] = bin2bcd(t->time.tm_sec);
482 buf[1] = bin2bcd(t->time.tm_min);
483 buf[2] = bin2bcd(t->time.tm_hour);
484 buf[3] = bin2bcd(t->time.tm_mday);
486 /* set ALARM2 to non-garbage */
491 /* optionally enable ALARM1 */
492 buf[7] = control & ~(DS1337_BIT_A1IE | DS1337_BIT_A2IE);
494 dev_dbg(dev, "alarm IRQ armed\n");
495 buf[7] |= DS1337_BIT_A1IE; /* only ALARM1 is used */
497 buf[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I);
499 ret = ds1307->write_block_data(client,
500 DS1339_REG_ALARM1_SECS, 9, buf);
502 dev_err(dev, "can't set alarm time\n");
509 static int ds1307_alarm_irq_enable(struct device *dev, unsigned int enabled)
511 struct i2c_client *client = to_i2c_client(dev);
512 struct ds1307 *ds1307 = i2c_get_clientdata(client);
515 if (!test_bit(HAS_ALARM, &ds1307->flags))
518 ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
523 ret |= DS1337_BIT_A1IE;
525 ret &= ~DS1337_BIT_A1IE;
527 ret = i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, ret);
534 static const struct rtc_class_ops ds13xx_rtc_ops = {
535 .read_time = ds1307_get_time,
536 .set_time = ds1307_set_time,
537 .read_alarm = ds1337_read_alarm,
538 .set_alarm = ds1337_set_alarm,
539 .alarm_irq_enable = ds1307_alarm_irq_enable,
542 /*----------------------------------------------------------------------*/
544 #define NVRAM_SIZE 56
547 ds1307_nvram_read(struct file *filp, struct kobject *kobj,
548 struct bin_attribute *attr,
549 char *buf, loff_t off, size_t count)
551 struct i2c_client *client;
552 struct ds1307 *ds1307;
555 client = kobj_to_i2c_client(kobj);
556 ds1307 = i2c_get_clientdata(client);
558 if (unlikely(off >= NVRAM_SIZE))
560 if ((off + count) > NVRAM_SIZE)
561 count = NVRAM_SIZE - off;
562 if (unlikely(!count))
565 result = ds1307->read_block_data(client, 8 + off, count, buf);
567 dev_err(&client->dev, "%s error %d\n", "nvram read", result);
572 ds1307_nvram_write(struct file *filp, struct kobject *kobj,
573 struct bin_attribute *attr,
574 char *buf, loff_t off, size_t count)
576 struct i2c_client *client;
577 struct ds1307 *ds1307;
580 client = kobj_to_i2c_client(kobj);
581 ds1307 = i2c_get_clientdata(client);
583 if (unlikely(off >= NVRAM_SIZE))
585 if ((off + count) > NVRAM_SIZE)
586 count = NVRAM_SIZE - off;
587 if (unlikely(!count))
590 result = ds1307->write_block_data(client, 8 + off, count, buf);
592 dev_err(&client->dev, "%s error %d\n", "nvram write", result);
598 static struct bin_attribute nvram = {
601 .mode = S_IRUGO | S_IWUSR,
604 .read = ds1307_nvram_read,
605 .write = ds1307_nvram_write,
609 /*----------------------------------------------------------------------*/
611 static struct i2c_driver ds1307_driver;
613 static int __devinit ds1307_probe(struct i2c_client *client,
614 const struct i2c_device_id *id)
616 struct ds1307 *ds1307;
619 const struct chip_desc *chip = &chips[id->driver_data];
620 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
621 int want_irq = false;
623 static const int bbsqi_bitpos[] = {
625 [ds_1339] = DS1339_BIT_BBSQI,
626 [ds_3231] = DS3231_BIT_BBSQW,
629 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)
630 && !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
633 if (!(ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL)))
636 i2c_set_clientdata(client, ds1307);
638 ds1307->client = client;
639 ds1307->type = id->driver_data;
643 if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) {
644 ds1307->read_block_data = i2c_smbus_read_i2c_block_data;
645 ds1307->write_block_data = i2c_smbus_write_i2c_block_data;
647 ds1307->read_block_data = ds1307_read_block_data;
648 ds1307->write_block_data = ds1307_write_block_data;
651 switch (ds1307->type) {
656 if (ds1307->client->irq > 0 && chip->alarm) {
657 INIT_WORK(&ds1307->work, ds1307_work);
660 /* get registers that the "rtc" read below won't read... */
661 tmp = ds1307->read_block_data(ds1307->client,
662 DS1337_REG_CONTROL, 2, buf);
664 pr_debug("read error %d\n", tmp);
669 /* oscillator off? turn it on, so clock can tick. */
670 if (ds1307->regs[0] & DS1337_BIT_nEOSC)
671 ds1307->regs[0] &= ~DS1337_BIT_nEOSC;
673 /* Using IRQ? Disable the square wave and both alarms.
674 * For some variants, be sure alarms can trigger when we're
675 * running on Vbackup (BBSQI/BBSQW)
678 ds1307->regs[0] |= DS1337_BIT_INTCN
679 | bbsqi_bitpos[ds1307->type];
680 ds1307->regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
683 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL,
686 /* oscillator fault? clear flag, and warn */
687 if (ds1307->regs[1] & DS1337_BIT_OSF) {
688 i2c_smbus_write_byte_data(client, DS1337_REG_STATUS,
689 ds1307->regs[1] & ~DS1337_BIT_OSF);
690 dev_warn(&client->dev, "SET TIME!\n");
695 tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
696 RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
698 pr_debug("read error %d\n", tmp);
703 /* oscillator off? turn it on, so clock can tick. */
704 if (!(ds1307->regs[1] & RX8025_BIT_XST)) {
705 ds1307->regs[1] |= RX8025_BIT_XST;
706 i2c_smbus_write_byte_data(client,
707 RX8025_REG_CTRL2 << 4 | 0x08,
709 dev_warn(&client->dev,
710 "oscillator stop detected - SET TIME!\n");
713 if (ds1307->regs[1] & RX8025_BIT_PON) {
714 ds1307->regs[1] &= ~RX8025_BIT_PON;
715 i2c_smbus_write_byte_data(client,
716 RX8025_REG_CTRL2 << 4 | 0x08,
718 dev_warn(&client->dev, "power-on detected\n");
721 if (ds1307->regs[1] & RX8025_BIT_VDET) {
722 ds1307->regs[1] &= ~RX8025_BIT_VDET;
723 i2c_smbus_write_byte_data(client,
724 RX8025_REG_CTRL2 << 4 | 0x08,
726 dev_warn(&client->dev, "voltage drop detected\n");
729 /* make sure we are running in 24hour mode */
730 if (!(ds1307->regs[0] & RX8025_BIT_2412)) {
733 /* switch to 24 hour mode */
734 i2c_smbus_write_byte_data(client,
735 RX8025_REG_CTRL1 << 4 | 0x08,
739 tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
740 RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
742 pr_debug("read error %d\n", tmp);
748 hour = bcd2bin(ds1307->regs[DS1307_REG_HOUR]);
751 if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
754 i2c_smbus_write_byte_data(client,
755 DS1307_REG_HOUR << 4 | 0x08,
760 ds1307->offset = 1; /* Seconds starts at 1 */
767 /* read RTC registers */
768 tmp = ds1307->read_block_data(ds1307->client, ds1307->offset, 8, buf);
770 pr_debug("read error %d\n", tmp);
775 /* minimal sanity checking; some chips (like DS1340) don't
776 * specify the extra bits as must-be-zero, but there are
777 * still a few values that are clearly out-of-range.
779 tmp = ds1307->regs[DS1307_REG_SECS];
780 switch (ds1307->type) {
783 /* clock halted? turn it on, so clock can tick. */
784 if (tmp & DS1307_BIT_CH) {
785 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
786 dev_warn(&client->dev, "SET TIME!\n");
791 /* clock halted? turn it on, so clock can tick. */
792 if (tmp & DS1307_BIT_CH)
793 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
795 /* oscillator fault? clear flag, and warn */
796 if (ds1307->regs[DS1307_REG_CONTROL] & DS1338_BIT_OSF) {
797 i2c_smbus_write_byte_data(client, DS1307_REG_CONTROL,
798 ds1307->regs[DS1307_REG_CONTROL]
800 dev_warn(&client->dev, "SET TIME!\n");
805 /* clock halted? turn it on, so clock can tick. */
806 if (tmp & DS1340_BIT_nEOSC)
807 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
809 tmp = i2c_smbus_read_byte_data(client, DS1340_REG_FLAG);
811 pr_debug("read error %d\n", tmp);
816 /* oscillator fault? clear flag, and warn */
817 if (tmp & DS1340_BIT_OSF) {
818 i2c_smbus_write_byte_data(client, DS1340_REG_FLAG, 0);
819 dev_warn(&client->dev, "SET TIME!\n");
823 /* make sure that the backup battery is enabled */
824 if (!(ds1307->regs[DS1307_REG_WDAY] & MCP7941X_BIT_VBATEN)) {
825 i2c_smbus_write_byte_data(client, DS1307_REG_WDAY,
826 ds1307->regs[DS1307_REG_WDAY]
827 | MCP7941X_BIT_VBATEN);
830 /* clock halted? turn it on, so clock can tick. */
831 if (!(tmp & MCP7941X_BIT_ST)) {
832 i2c_smbus_write_byte_data(client, DS1307_REG_SECS,
834 dev_warn(&client->dev, "SET TIME!\n");
847 tmp = ds1307->regs[DS1307_REG_HOUR];
848 switch (ds1307->type) {
851 /* NOTE: ignores century bits; fix before deploying
852 * systems that will run through year 2100.
858 if (!(tmp & DS1307_BIT_12HR))
861 /* Be sure we're in 24 hour mode. Multi-master systems
864 tmp = bcd2bin(tmp & 0x1f);
867 if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
869 i2c_smbus_write_byte_data(client,
870 ds1307->offset + DS1307_REG_HOUR,
874 ds1307->rtc = rtc_device_register(client->name, &client->dev,
875 &ds13xx_rtc_ops, THIS_MODULE);
876 if (IS_ERR(ds1307->rtc)) {
877 err = PTR_ERR(ds1307->rtc);
878 dev_err(&client->dev,
879 "unable to register the class device\n");
884 err = request_irq(client->irq, ds1307_irq, IRQF_SHARED,
885 ds1307->rtc->name, client);
887 dev_err(&client->dev,
888 "unable to request IRQ!\n");
892 device_set_wakeup_capable(&client->dev, 1);
893 set_bit(HAS_ALARM, &ds1307->flags);
894 dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
898 err = sysfs_create_bin_file(&client->dev.kobj, &nvram);
900 set_bit(HAS_NVRAM, &ds1307->flags);
901 dev_info(&client->dev, "56 bytes nvram\n");
908 rtc_device_unregister(ds1307->rtc);
914 static int __devexit ds1307_remove(struct i2c_client *client)
916 struct ds1307 *ds1307 = i2c_get_clientdata(client);
918 if (test_and_clear_bit(HAS_ALARM, &ds1307->flags)) {
919 free_irq(client->irq, client);
920 cancel_work_sync(&ds1307->work);
923 if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags))
924 sysfs_remove_bin_file(&client->dev.kobj, &nvram);
926 rtc_device_unregister(ds1307->rtc);
931 static struct i2c_driver ds1307_driver = {
933 .name = "rtc-ds1307",
934 .owner = THIS_MODULE,
936 .probe = ds1307_probe,
937 .remove = __devexit_p(ds1307_remove),
938 .id_table = ds1307_id,
941 static int __init ds1307_init(void)
943 return i2c_add_driver(&ds1307_driver);
945 module_init(ds1307_init);
947 static void __exit ds1307_exit(void)
949 i2c_del_driver(&ds1307_driver);
951 module_exit(ds1307_exit);
953 MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
954 MODULE_LICENSE("GPL");