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.
38 // rs5c372 too? different address...
42 /* RTC registers don't differ much, except for the century flag */
43 #define DS1307_REG_SECS 0x00 /* 00-59 */
44 # define DS1307_BIT_CH 0x80
45 # define DS1340_BIT_nEOSC 0x80
46 #define DS1307_REG_MIN 0x01 /* 00-59 */
47 #define DS1307_REG_HOUR 0x02 /* 00-23, or 1-12{am,pm} */
48 # define DS1307_BIT_12HR 0x40 /* in REG_HOUR */
49 # define DS1307_BIT_PM 0x20 /* in REG_HOUR */
50 # define DS1340_BIT_CENTURY_EN 0x80 /* in REG_HOUR */
51 # define DS1340_BIT_CENTURY 0x40 /* in REG_HOUR */
52 #define DS1307_REG_WDAY 0x03 /* 01-07 */
53 #define DS1307_REG_MDAY 0x04 /* 01-31 */
54 #define DS1307_REG_MONTH 0x05 /* 01-12 */
55 # define DS1337_BIT_CENTURY 0x80 /* in REG_MONTH */
56 #define DS1307_REG_YEAR 0x06 /* 00-99 */
58 /* Other registers (control, status, alarms, trickle charge, NVRAM, etc)
59 * start at 7, and they differ a LOT. Only control and status matter for
60 * basic RTC date and time functionality; be careful using them.
62 #define DS1307_REG_CONTROL 0x07 /* or ds1338 */
63 # define DS1307_BIT_OUT 0x80
64 # define DS1338_BIT_OSF 0x20
65 # define DS1307_BIT_SQWE 0x10
66 # define DS1307_BIT_RS1 0x02
67 # define DS1307_BIT_RS0 0x01
68 #define DS1337_REG_CONTROL 0x0e
69 # define DS1337_BIT_nEOSC 0x80
70 # define DS1339_BIT_BBSQI 0x20
71 # define DS3231_BIT_BBSQW 0x40 /* same as BBSQI */
72 # define DS1337_BIT_RS2 0x10
73 # define DS1337_BIT_RS1 0x08
74 # define DS1337_BIT_INTCN 0x04
75 # define DS1337_BIT_A2IE 0x02
76 # define DS1337_BIT_A1IE 0x01
77 #define DS1340_REG_CONTROL 0x07
78 # define DS1340_BIT_OUT 0x80
79 # define DS1340_BIT_FT 0x40
80 # define DS1340_BIT_CALIB_SIGN 0x20
81 # define DS1340_M_CALIBRATION 0x1f
82 #define DS1340_REG_FLAG 0x09
83 # define DS1340_BIT_OSF 0x80
84 #define DS1337_REG_STATUS 0x0f
85 # define DS1337_BIT_OSF 0x80
86 # define DS1337_BIT_A2I 0x02
87 # define DS1337_BIT_A1I 0x01
88 #define DS1339_REG_ALARM1_SECS 0x07
89 #define DS1339_REG_TRICKLE 0x10
91 #define RX8025_REG_CTRL1 0x0e
92 # define RX8025_BIT_2412 0x20
93 #define RX8025_REG_CTRL2 0x0f
94 # define RX8025_BIT_PON 0x10
95 # define RX8025_BIT_VDET 0x40
96 # define RX8025_BIT_XST 0x20
100 u8 offset
; /* register's offset */
104 #define HAS_NVRAM 0 /* bit 0 == sysfs file active */
105 #define HAS_ALARM 1 /* bit 1 == irq claimed */
106 struct i2c_client
*client
;
107 struct rtc_device
*rtc
;
108 struct work_struct work
;
109 s32 (*read_block_data
)(struct i2c_client
*client
, u8 command
,
110 u8 length
, u8
*values
);
111 s32 (*write_block_data
)(struct i2c_client
*client
, u8 command
,
112 u8 length
, const u8
*values
);
120 static const struct chip_desc chips
[] = {
143 static const struct i2c_device_id ds1307_id
[] = {
144 { "ds1307", ds_1307
},
145 { "ds1337", ds_1337
},
146 { "ds1338", ds_1338
},
147 { "ds1339", ds_1339
},
148 { "ds1388", ds_1388
},
149 { "ds1340", ds_1340
},
150 { "ds3231", ds_3231
},
151 { "m41t00", m41t00
},
152 { "rx8025", rx_8025
},
155 MODULE_DEVICE_TABLE(i2c
, ds1307_id
);
157 /*----------------------------------------------------------------------*/
159 #define BLOCK_DATA_MAX_TRIES 10
161 static s32
ds1307_read_block_data_once(struct i2c_client
*client
, u8 command
,
162 u8 length
, u8
*values
)
166 for (i
= 0; i
< length
; i
++) {
167 data
= i2c_smbus_read_byte_data(client
, command
+ i
);
175 static s32
ds1307_read_block_data(struct i2c_client
*client
, u8 command
,
176 u8 length
, u8
*values
)
178 u8 oldvalues
[I2C_SMBUS_BLOCK_MAX
];
182 dev_dbg(&client
->dev
, "ds1307_read_block_data (length=%d)\n", length
);
183 ret
= ds1307_read_block_data_once(client
, command
, length
, values
);
187 if (++tries
> BLOCK_DATA_MAX_TRIES
) {
188 dev_err(&client
->dev
,
189 "ds1307_read_block_data failed\n");
192 memcpy(oldvalues
, values
, length
);
193 ret
= ds1307_read_block_data_once(client
, command
, length
,
197 } while (memcmp(oldvalues
, values
, length
));
201 static s32
ds1307_write_block_data(struct i2c_client
*client
, u8 command
,
202 u8 length
, const u8
*values
)
204 u8 currvalues
[I2C_SMBUS_BLOCK_MAX
];
207 dev_dbg(&client
->dev
, "ds1307_write_block_data (length=%d)\n", length
);
211 if (++tries
> BLOCK_DATA_MAX_TRIES
) {
212 dev_err(&client
->dev
,
213 "ds1307_write_block_data failed\n");
216 for (i
= 0; i
< length
; i
++) {
217 ret
= i2c_smbus_write_byte_data(client
, command
+ i
,
222 ret
= ds1307_read_block_data_once(client
, command
, length
,
226 } while (memcmp(currvalues
, values
, length
));
230 /*----------------------------------------------------------------------*/
233 * The IRQ logic includes a "real" handler running in IRQ context just
234 * long enough to schedule this workqueue entry. We need a task context
235 * to talk to the RTC, since I2C I/O calls require that; and disable the
236 * IRQ until we clear its status on the chip, so that this handler can
237 * work with any type of triggering (not just falling edge).
239 * The ds1337 and ds1339 both have two alarms, but we only use the first
240 * one (with a "seconds" field). For ds1337 we expect nINTA is our alarm
241 * signal; ds1339 chips have only one alarm signal.
243 static void ds1307_work(struct work_struct
*work
)
245 struct ds1307
*ds1307
;
246 struct i2c_client
*client
;
250 ds1307
= container_of(work
, struct ds1307
, work
);
251 client
= ds1307
->client
;
252 lock
= &ds1307
->rtc
->ops_lock
;
255 stat
= i2c_smbus_read_byte_data(client
, DS1337_REG_STATUS
);
259 if (stat
& DS1337_BIT_A1I
) {
260 stat
&= ~DS1337_BIT_A1I
;
261 i2c_smbus_write_byte_data(client
, DS1337_REG_STATUS
, stat
);
263 control
= i2c_smbus_read_byte_data(client
, DS1337_REG_CONTROL
);
267 control
&= ~DS1337_BIT_A1IE
;
268 i2c_smbus_write_byte_data(client
, DS1337_REG_CONTROL
, control
);
270 rtc_update_irq(ds1307
->rtc
, 1, RTC_AF
| RTC_IRQF
);
274 if (test_bit(HAS_ALARM
, &ds1307
->flags
))
275 enable_irq(client
->irq
);
279 static irqreturn_t
ds1307_irq(int irq
, void *dev_id
)
281 struct i2c_client
*client
= dev_id
;
282 struct ds1307
*ds1307
= i2c_get_clientdata(client
);
284 disable_irq_nosync(irq
);
285 schedule_work(&ds1307
->work
);
289 /*----------------------------------------------------------------------*/
291 static int ds1307_get_time(struct device
*dev
, struct rtc_time
*t
)
293 struct ds1307
*ds1307
= dev_get_drvdata(dev
);
296 /* read the RTC date and time registers all at once */
297 tmp
= ds1307
->read_block_data(ds1307
->client
,
298 ds1307
->offset
, 7, ds1307
->regs
);
300 dev_err(dev
, "%s error %d\n", "read", tmp
);
304 dev_dbg(dev
, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
306 ds1307
->regs
[0], ds1307
->regs
[1],
307 ds1307
->regs
[2], ds1307
->regs
[3],
308 ds1307
->regs
[4], ds1307
->regs
[5],
311 t
->tm_sec
= bcd2bin(ds1307
->regs
[DS1307_REG_SECS
] & 0x7f);
312 t
->tm_min
= bcd2bin(ds1307
->regs
[DS1307_REG_MIN
] & 0x7f);
313 tmp
= ds1307
->regs
[DS1307_REG_HOUR
] & 0x3f;
314 t
->tm_hour
= bcd2bin(tmp
);
315 t
->tm_wday
= bcd2bin(ds1307
->regs
[DS1307_REG_WDAY
] & 0x07) - 1;
316 t
->tm_mday
= bcd2bin(ds1307
->regs
[DS1307_REG_MDAY
] & 0x3f);
317 tmp
= ds1307
->regs
[DS1307_REG_MONTH
] & 0x1f;
318 t
->tm_mon
= bcd2bin(tmp
) - 1;
320 /* assume 20YY not 19YY, and ignore DS1337_BIT_CENTURY */
321 t
->tm_year
= bcd2bin(ds1307
->regs
[DS1307_REG_YEAR
]) + 100;
323 dev_dbg(dev
, "%s secs=%d, mins=%d, "
324 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
325 "read", t
->tm_sec
, t
->tm_min
,
326 t
->tm_hour
, t
->tm_mday
,
327 t
->tm_mon
, t
->tm_year
, t
->tm_wday
);
329 /* initial clock setting can be undefined */
330 return rtc_valid_tm(t
);
333 static int ds1307_set_time(struct device
*dev
, struct rtc_time
*t
)
335 struct ds1307
*ds1307
= dev_get_drvdata(dev
);
338 u8
*buf
= ds1307
->regs
;
340 dev_dbg(dev
, "%s secs=%d, mins=%d, "
341 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
342 "write", t
->tm_sec
, t
->tm_min
,
343 t
->tm_hour
, t
->tm_mday
,
344 t
->tm_mon
, t
->tm_year
, t
->tm_wday
);
346 buf
[DS1307_REG_SECS
] = bin2bcd(t
->tm_sec
);
347 buf
[DS1307_REG_MIN
] = bin2bcd(t
->tm_min
);
348 buf
[DS1307_REG_HOUR
] = bin2bcd(t
->tm_hour
);
349 buf
[DS1307_REG_WDAY
] = bin2bcd(t
->tm_wday
+ 1);
350 buf
[DS1307_REG_MDAY
] = bin2bcd(t
->tm_mday
);
351 buf
[DS1307_REG_MONTH
] = bin2bcd(t
->tm_mon
+ 1);
353 /* assume 20YY not 19YY */
354 tmp
= t
->tm_year
- 100;
355 buf
[DS1307_REG_YEAR
] = bin2bcd(tmp
);
357 switch (ds1307
->type
) {
361 buf
[DS1307_REG_MONTH
] |= DS1337_BIT_CENTURY
;
364 buf
[DS1307_REG_HOUR
] |= DS1340_BIT_CENTURY_EN
365 | DS1340_BIT_CENTURY
;
371 dev_dbg(dev
, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
372 "write", buf
[0], buf
[1], buf
[2], buf
[3],
373 buf
[4], buf
[5], buf
[6]);
375 result
= ds1307
->write_block_data(ds1307
->client
,
376 ds1307
->offset
, 7, buf
);
378 dev_err(dev
, "%s error %d\n", "write", result
);
384 static int ds1337_read_alarm(struct device
*dev
, struct rtc_wkalrm
*t
)
386 struct i2c_client
*client
= to_i2c_client(dev
);
387 struct ds1307
*ds1307
= i2c_get_clientdata(client
);
390 if (!test_bit(HAS_ALARM
, &ds1307
->flags
))
393 /* read all ALARM1, ALARM2, and status registers at once */
394 ret
= ds1307
->read_block_data(client
,
395 DS1339_REG_ALARM1_SECS
, 9, ds1307
->regs
);
397 dev_err(dev
, "%s error %d\n", "alarm read", ret
);
401 dev_dbg(dev
, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n",
403 ds1307
->regs
[0], ds1307
->regs
[1],
404 ds1307
->regs
[2], ds1307
->regs
[3],
405 ds1307
->regs
[4], ds1307
->regs
[5],
406 ds1307
->regs
[6], ds1307
->regs
[7],
409 /* report alarm time (ALARM1); assume 24 hour and day-of-month modes,
410 * and that all four fields are checked matches
412 t
->time
.tm_sec
= bcd2bin(ds1307
->regs
[0] & 0x7f);
413 t
->time
.tm_min
= bcd2bin(ds1307
->regs
[1] & 0x7f);
414 t
->time
.tm_hour
= bcd2bin(ds1307
->regs
[2] & 0x3f);
415 t
->time
.tm_mday
= bcd2bin(ds1307
->regs
[3] & 0x3f);
417 t
->time
.tm_year
= -1;
418 t
->time
.tm_wday
= -1;
419 t
->time
.tm_yday
= -1;
420 t
->time
.tm_isdst
= -1;
423 t
->enabled
= !!(ds1307
->regs
[7] & DS1337_BIT_A1IE
);
424 t
->pending
= !!(ds1307
->regs
[8] & DS1337_BIT_A1I
);
426 dev_dbg(dev
, "%s secs=%d, mins=%d, "
427 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
428 "alarm read", t
->time
.tm_sec
, t
->time
.tm_min
,
429 t
->time
.tm_hour
, t
->time
.tm_mday
,
430 t
->enabled
, t
->pending
);
435 static int ds1337_set_alarm(struct device
*dev
, struct rtc_wkalrm
*t
)
437 struct i2c_client
*client
= to_i2c_client(dev
);
438 struct ds1307
*ds1307
= i2c_get_clientdata(client
);
439 unsigned char *buf
= ds1307
->regs
;
443 if (!test_bit(HAS_ALARM
, &ds1307
->flags
))
446 dev_dbg(dev
, "%s secs=%d, mins=%d, "
447 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
448 "alarm set", t
->time
.tm_sec
, t
->time
.tm_min
,
449 t
->time
.tm_hour
, t
->time
.tm_mday
,
450 t
->enabled
, t
->pending
);
452 /* read current status of both alarms and the chip */
453 ret
= ds1307
->read_block_data(client
,
454 DS1339_REG_ALARM1_SECS
, 9, buf
);
456 dev_err(dev
, "%s error %d\n", "alarm write", ret
);
459 control
= ds1307
->regs
[7];
460 status
= ds1307
->regs
[8];
462 dev_dbg(dev
, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n",
463 "alarm set (old status)",
464 ds1307
->regs
[0], ds1307
->regs
[1],
465 ds1307
->regs
[2], ds1307
->regs
[3],
466 ds1307
->regs
[4], ds1307
->regs
[5],
467 ds1307
->regs
[6], control
, status
);
469 /* set ALARM1, using 24 hour and day-of-month modes */
470 buf
[0] = bin2bcd(t
->time
.tm_sec
);
471 buf
[1] = bin2bcd(t
->time
.tm_min
);
472 buf
[2] = bin2bcd(t
->time
.tm_hour
);
473 buf
[3] = bin2bcd(t
->time
.tm_mday
);
475 /* set ALARM2 to non-garbage */
480 /* optionally enable ALARM1 */
481 buf
[7] = control
& ~(DS1337_BIT_A1IE
| DS1337_BIT_A2IE
);
483 dev_dbg(dev
, "alarm IRQ armed\n");
484 buf
[7] |= DS1337_BIT_A1IE
; /* only ALARM1 is used */
486 buf
[8] = status
& ~(DS1337_BIT_A1I
| DS1337_BIT_A2I
);
488 ret
= ds1307
->write_block_data(client
,
489 DS1339_REG_ALARM1_SECS
, 9, buf
);
491 dev_err(dev
, "can't set alarm time\n");
498 static int ds1307_ioctl(struct device
*dev
, unsigned int cmd
, unsigned long arg
)
500 struct i2c_client
*client
= to_i2c_client(dev
);
501 struct ds1307
*ds1307
= i2c_get_clientdata(client
);
506 if (!test_bit(HAS_ALARM
, &ds1307
->flags
))
509 ret
= i2c_smbus_read_byte_data(client
, DS1337_REG_CONTROL
);
513 ret
&= ~DS1337_BIT_A1IE
;
515 ret
= i2c_smbus_write_byte_data(client
,
516 DS1337_REG_CONTROL
, ret
);
523 if (!test_bit(HAS_ALARM
, &ds1307
->flags
))
526 ret
= i2c_smbus_read_byte_data(client
, DS1337_REG_CONTROL
);
530 ret
|= DS1337_BIT_A1IE
;
532 ret
= i2c_smbus_write_byte_data(client
,
533 DS1337_REG_CONTROL
, ret
);
546 static const struct rtc_class_ops ds13xx_rtc_ops
= {
547 .read_time
= ds1307_get_time
,
548 .set_time
= ds1307_set_time
,
549 .read_alarm
= ds1337_read_alarm
,
550 .set_alarm
= ds1337_set_alarm
,
551 .ioctl
= ds1307_ioctl
,
554 /*----------------------------------------------------------------------*/
556 #define NVRAM_SIZE 56
559 ds1307_nvram_read(struct file
*filp
, struct kobject
*kobj
,
560 struct bin_attribute
*attr
,
561 char *buf
, loff_t off
, size_t count
)
563 struct i2c_client
*client
;
564 struct ds1307
*ds1307
;
567 client
= kobj_to_i2c_client(kobj
);
568 ds1307
= i2c_get_clientdata(client
);
570 if (unlikely(off
>= NVRAM_SIZE
))
572 if ((off
+ count
) > NVRAM_SIZE
)
573 count
= NVRAM_SIZE
- off
;
574 if (unlikely(!count
))
577 result
= ds1307
->read_block_data(client
, 8 + off
, count
, buf
);
579 dev_err(&client
->dev
, "%s error %d\n", "nvram read", result
);
584 ds1307_nvram_write(struct file
*filp
, struct kobject
*kobj
,
585 struct bin_attribute
*attr
,
586 char *buf
, loff_t off
, size_t count
)
588 struct i2c_client
*client
;
589 struct ds1307
*ds1307
;
592 client
= kobj_to_i2c_client(kobj
);
593 ds1307
= i2c_get_clientdata(client
);
595 if (unlikely(off
>= NVRAM_SIZE
))
597 if ((off
+ count
) > NVRAM_SIZE
)
598 count
= NVRAM_SIZE
- off
;
599 if (unlikely(!count
))
602 result
= ds1307
->write_block_data(client
, 8 + off
, count
, buf
);
604 dev_err(&client
->dev
, "%s error %d\n", "nvram write", result
);
610 static struct bin_attribute nvram
= {
613 .mode
= S_IRUGO
| S_IWUSR
,
616 .read
= ds1307_nvram_read
,
617 .write
= ds1307_nvram_write
,
621 /*----------------------------------------------------------------------*/
623 static struct i2c_driver ds1307_driver
;
625 static int __devinit
ds1307_probe(struct i2c_client
*client
,
626 const struct i2c_device_id
*id
)
628 struct ds1307
*ds1307
;
631 const struct chip_desc
*chip
= &chips
[id
->driver_data
];
632 struct i2c_adapter
*adapter
= to_i2c_adapter(client
->dev
.parent
);
633 int want_irq
= false;
635 static const int bbsqi_bitpos
[] = {
637 [ds_1339
] = DS1339_BIT_BBSQI
,
638 [ds_3231
] = DS3231_BIT_BBSQW
,
641 if (!i2c_check_functionality(adapter
, I2C_FUNC_SMBUS_BYTE_DATA
)
642 && !i2c_check_functionality(adapter
, I2C_FUNC_SMBUS_I2C_BLOCK
))
645 if (!(ds1307
= kzalloc(sizeof(struct ds1307
), GFP_KERNEL
)))
648 i2c_set_clientdata(client
, ds1307
);
650 ds1307
->client
= client
;
651 ds1307
->type
= id
->driver_data
;
655 if (i2c_check_functionality(adapter
, I2C_FUNC_SMBUS_I2C_BLOCK
)) {
656 ds1307
->read_block_data
= i2c_smbus_read_i2c_block_data
;
657 ds1307
->write_block_data
= i2c_smbus_write_i2c_block_data
;
659 ds1307
->read_block_data
= ds1307_read_block_data
;
660 ds1307
->write_block_data
= ds1307_write_block_data
;
663 switch (ds1307
->type
) {
668 if (ds1307
->client
->irq
> 0 && chip
->alarm
) {
669 INIT_WORK(&ds1307
->work
, ds1307_work
);
672 /* get registers that the "rtc" read below won't read... */
673 tmp
= ds1307
->read_block_data(ds1307
->client
,
674 DS1337_REG_CONTROL
, 2, buf
);
676 pr_debug("read error %d\n", tmp
);
681 /* oscillator off? turn it on, so clock can tick. */
682 if (ds1307
->regs
[0] & DS1337_BIT_nEOSC
)
683 ds1307
->regs
[0] &= ~DS1337_BIT_nEOSC
;
685 /* Using IRQ? Disable the square wave and both alarms.
686 * For some variants, be sure alarms can trigger when we're
687 * running on Vbackup (BBSQI/BBSQW)
690 ds1307
->regs
[0] |= DS1337_BIT_INTCN
691 | bbsqi_bitpos
[ds1307
->type
];
692 ds1307
->regs
[0] &= ~(DS1337_BIT_A2IE
| DS1337_BIT_A1IE
);
695 i2c_smbus_write_byte_data(client
, DS1337_REG_CONTROL
,
698 /* oscillator fault? clear flag, and warn */
699 if (ds1307
->regs
[1] & DS1337_BIT_OSF
) {
700 i2c_smbus_write_byte_data(client
, DS1337_REG_STATUS
,
701 ds1307
->regs
[1] & ~DS1337_BIT_OSF
);
702 dev_warn(&client
->dev
, "SET TIME!\n");
707 tmp
= i2c_smbus_read_i2c_block_data(ds1307
->client
,
708 RX8025_REG_CTRL1
<< 4 | 0x08, 2, buf
);
710 pr_debug("read error %d\n", tmp
);
715 /* oscillator off? turn it on, so clock can tick. */
716 if (!(ds1307
->regs
[1] & RX8025_BIT_XST
)) {
717 ds1307
->regs
[1] |= RX8025_BIT_XST
;
718 i2c_smbus_write_byte_data(client
,
719 RX8025_REG_CTRL2
<< 4 | 0x08,
721 dev_warn(&client
->dev
,
722 "oscillator stop detected - SET TIME!\n");
725 if (ds1307
->regs
[1] & RX8025_BIT_PON
) {
726 ds1307
->regs
[1] &= ~RX8025_BIT_PON
;
727 i2c_smbus_write_byte_data(client
,
728 RX8025_REG_CTRL2
<< 4 | 0x08,
730 dev_warn(&client
->dev
, "power-on detected\n");
733 if (ds1307
->regs
[1] & RX8025_BIT_VDET
) {
734 ds1307
->regs
[1] &= ~RX8025_BIT_VDET
;
735 i2c_smbus_write_byte_data(client
,
736 RX8025_REG_CTRL2
<< 4 | 0x08,
738 dev_warn(&client
->dev
, "voltage drop detected\n");
741 /* make sure we are running in 24hour mode */
742 if (!(ds1307
->regs
[0] & RX8025_BIT_2412
)) {
745 /* switch to 24 hour mode */
746 i2c_smbus_write_byte_data(client
,
747 RX8025_REG_CTRL1
<< 4 | 0x08,
751 tmp
= i2c_smbus_read_i2c_block_data(ds1307
->client
,
752 RX8025_REG_CTRL1
<< 4 | 0x08, 2, buf
);
754 pr_debug("read error %d\n", tmp
);
760 hour
= bcd2bin(ds1307
->regs
[DS1307_REG_HOUR
]);
763 if (ds1307
->regs
[DS1307_REG_HOUR
] & DS1307_BIT_PM
)
766 i2c_smbus_write_byte_data(client
,
767 DS1307_REG_HOUR
<< 4 | 0x08,
772 ds1307
->offset
= 1; /* Seconds starts at 1 */
779 /* read RTC registers */
780 tmp
= ds1307
->read_block_data(ds1307
->client
, 0, 8, buf
);
782 pr_debug("read error %d\n", tmp
);
787 /* minimal sanity checking; some chips (like DS1340) don't
788 * specify the extra bits as must-be-zero, but there are
789 * still a few values that are clearly out-of-range.
791 tmp
= ds1307
->regs
[DS1307_REG_SECS
];
792 switch (ds1307
->type
) {
795 /* clock halted? turn it on, so clock can tick. */
796 if (tmp
& DS1307_BIT_CH
) {
797 i2c_smbus_write_byte_data(client
, DS1307_REG_SECS
, 0);
798 dev_warn(&client
->dev
, "SET TIME!\n");
803 /* clock halted? turn it on, so clock can tick. */
804 if (tmp
& DS1307_BIT_CH
)
805 i2c_smbus_write_byte_data(client
, DS1307_REG_SECS
, 0);
807 /* oscillator fault? clear flag, and warn */
808 if (ds1307
->regs
[DS1307_REG_CONTROL
] & DS1338_BIT_OSF
) {
809 i2c_smbus_write_byte_data(client
, DS1307_REG_CONTROL
,
810 ds1307
->regs
[DS1307_REG_CONTROL
]
812 dev_warn(&client
->dev
, "SET TIME!\n");
817 /* clock halted? turn it on, so clock can tick. */
818 if (tmp
& DS1340_BIT_nEOSC
)
819 i2c_smbus_write_byte_data(client
, DS1307_REG_SECS
, 0);
821 tmp
= i2c_smbus_read_byte_data(client
, DS1340_REG_FLAG
);
823 pr_debug("read error %d\n", tmp
);
828 /* oscillator fault? clear flag, and warn */
829 if (tmp
& DS1340_BIT_OSF
) {
830 i2c_smbus_write_byte_data(client
, DS1340_REG_FLAG
, 0);
831 dev_warn(&client
->dev
, "SET TIME!\n");
842 tmp
= ds1307
->regs
[DS1307_REG_HOUR
];
843 switch (ds1307
->type
) {
846 /* NOTE: ignores century bits; fix before deploying
847 * systems that will run through year 2100.
853 if (!(tmp
& DS1307_BIT_12HR
))
856 /* Be sure we're in 24 hour mode. Multi-master systems
859 tmp
= bcd2bin(tmp
& 0x1f);
862 if (ds1307
->regs
[DS1307_REG_HOUR
] & DS1307_BIT_PM
)
864 i2c_smbus_write_byte_data(client
,
869 ds1307
->rtc
= rtc_device_register(client
->name
, &client
->dev
,
870 &ds13xx_rtc_ops
, THIS_MODULE
);
871 if (IS_ERR(ds1307
->rtc
)) {
872 err
= PTR_ERR(ds1307
->rtc
);
873 dev_err(&client
->dev
,
874 "unable to register the class device\n");
879 err
= request_irq(client
->irq
, ds1307_irq
, IRQF_SHARED
,
880 ds1307
->rtc
->name
, client
);
882 dev_err(&client
->dev
,
883 "unable to request IRQ!\n");
887 device_set_wakeup_capable(&client
->dev
, 1);
888 set_bit(HAS_ALARM
, &ds1307
->flags
);
889 dev_dbg(&client
->dev
, "got IRQ %d\n", client
->irq
);
893 err
= sysfs_create_bin_file(&client
->dev
.kobj
, &nvram
);
895 set_bit(HAS_NVRAM
, &ds1307
->flags
);
896 dev_info(&client
->dev
, "56 bytes nvram\n");
903 rtc_device_unregister(ds1307
->rtc
);
909 static int __devexit
ds1307_remove(struct i2c_client
*client
)
911 struct ds1307
*ds1307
= i2c_get_clientdata(client
);
913 if (test_and_clear_bit(HAS_ALARM
, &ds1307
->flags
)) {
914 free_irq(client
->irq
, client
);
915 cancel_work_sync(&ds1307
->work
);
918 if (test_and_clear_bit(HAS_NVRAM
, &ds1307
->flags
))
919 sysfs_remove_bin_file(&client
->dev
.kobj
, &nvram
);
921 rtc_device_unregister(ds1307
->rtc
);
926 static struct i2c_driver ds1307_driver
= {
928 .name
= "rtc-ds1307",
929 .owner
= THIS_MODULE
,
931 .probe
= ds1307_probe
,
932 .remove
= __devexit_p(ds1307_remove
),
933 .id_table
= ds1307_id
,
936 static int __init
ds1307_init(void)
938 return i2c_add_driver(&ds1307_driver
);
940 module_init(ds1307_init
);
942 static void __exit
ds1307_exit(void)
944 i2c_del_driver(&ds1307_driver
);
946 module_exit(ds1307_exit
);
948 MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
949 MODULE_LICENSE("GPL");