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[deliverable/linux.git] / drivers / rtc / rtc-ds1307.c
CommitLineData
1abb0dc9
DB		 1/*
2 * rtc-ds1307.c - RTC driver for some mostly-compatible I2C chips.
3 *
4 * Copyright (C) 2005 James Chapman (ds1337 core)
5 * Copyright (C) 2006 David Brownell
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/slab.h>
15#include <linux/i2c.h>
16#include <linux/string.h>
17#include <linux/rtc.h>
18#include <linux/bcd.h>
19
20
21
22/* We can't determine type by probing, but if we expect pre-Linux code
23 * to have set the chip up as a clock (turning on the oscillator and
24 * setting the date and time), Linux can ignore the non-clock features.
25 * That's a natural job for a factory or repair bench.
1abb0dc9
DB		 26 */
27enum ds_type {
045e0e85
DB		 28 ds_1307,
29 ds_1337,
30 ds_1338,
31 ds_1339,
32 ds_1340,
33 m41t00,
1abb0dc9
DB		 34 // rs5c372 too? different address...
35};
36
1abb0dc9
DB		 37
38/* RTC registers don't differ much, except for the century flag */
39#define DS1307_REG_SECS 0x00 /* 00-59 */
40# define DS1307_BIT_CH 0x80
be5f59f4 41# define DS1340_BIT_nEOSC 0x80
1abb0dc9
DB		 42#define DS1307_REG_MIN 0x01 /* 00-59 */
43#define DS1307_REG_HOUR 0x02 /* 00-23, or 1-12{am,pm} */
c065f35c
DB		 44# define DS1307_BIT_12HR 0x40 /* in REG_HOUR */
45# define DS1307_BIT_PM 0x20 /* in REG_HOUR */
1abb0dc9
DB		 46# define DS1340_BIT_CENTURY_EN 0x80 /* in REG_HOUR */
47# define DS1340_BIT_CENTURY 0x40 /* in REG_HOUR */
48#define DS1307_REG_WDAY 0x03 /* 01-07 */
49#define DS1307_REG_MDAY 0x04 /* 01-31 */
50#define DS1307_REG_MONTH 0x05 /* 01-12 */
51# define DS1337_BIT_CENTURY 0x80 /* in REG_MONTH */
52#define DS1307_REG_YEAR 0x06 /* 00-99 */
53
54/* Other registers (control, status, alarms, trickle charge, NVRAM, etc)
045e0e85
DB		 55 * start at 7, and they differ a LOT. Only control and status matter for
56 * basic RTC date and time functionality; be careful using them.
1abb0dc9 57 */
045e0e85 58#define DS1307_REG_CONTROL 0x07 /* or ds1338 */
1abb0dc9 59# define DS1307_BIT_OUT 0x80
be5f59f4 60# define DS1338_BIT_OSF 0x20
1abb0dc9
DB		 61# define DS1307_BIT_SQWE 0x10
62# define DS1307_BIT_RS1 0x02
63# define DS1307_BIT_RS0 0x01
64#define DS1337_REG_CONTROL 0x0e
65# define DS1337_BIT_nEOSC 0x80
cb49a5e9 66# define DS1339_BIT_BBSQI 0x20
1abb0dc9
DB		 67# define DS1337_BIT_RS2 0x10
68# define DS1337_BIT_RS1 0x08
69# define DS1337_BIT_INTCN 0x04
70# define DS1337_BIT_A2IE 0x02
71# define DS1337_BIT_A1IE 0x01
045e0e85
DB		 72#define DS1340_REG_CONTROL 0x07
73# define DS1340_BIT_OUT 0x80
74# define DS1340_BIT_FT 0x40
75# define DS1340_BIT_CALIB_SIGN 0x20
76# define DS1340_M_CALIBRATION 0x1f
be5f59f4
RG		 77#define DS1340_REG_FLAG 0x09
78# define DS1340_BIT_OSF 0x80
1abb0dc9
DB		 79#define DS1337_REG_STATUS 0x0f
80# define DS1337_BIT_OSF 0x80
81# define DS1337_BIT_A2I 0x02
82# define DS1337_BIT_A1I 0x01
cb49a5e9 83#define DS1339_REG_ALARM1_SECS 0x07
1abb0dc9
DB		 84#define DS1339_REG_TRICKLE 0x10
85
86
87
88struct ds1307 {
89 u8 reg_addr;
cb49a5e9 90 u8 regs[11];
1abb0dc9 91 enum ds_type type;
cb49a5e9
RG		 92 unsigned long flags;
93#define HAS_NVRAM 0 /* bit 0 == sysfs file active */
94#define HAS_ALARM 1 /* bit 1 == irq claimed */
1abb0dc9 95 struct i2c_msg msg[2];
045e0e85 96 struct i2c_client *client;
1abb0dc9 97 struct rtc_device *rtc;
cb49a5e9 98 struct work_struct work;
1abb0dc9
DB		 99};
100
045e0e85 101struct chip_desc {
045e0e85
DB		 102 unsigned nvram56:1;
103 unsigned alarm:1;
045e0e85
DB		 104};
105
3760f736
JD		 106static const struct chip_desc chips[] = {
107[ds_1307] = {
045e0e85 108 .nvram56 = 1,
3760f736
JD		 109},
110[ds_1337] = {
045e0e85 111 .alarm = 1,
3760f736
JD		 112},
113[ds_1338] = {
045e0e85 114 .nvram56 = 1,
3760f736
JD		 115},
116[ds_1339] = {
045e0e85 117 .alarm = 1,
3760f736
JD		 118},
119[ds_1340] = {
120},
121[m41t00] = {
045e0e85
DB		 122}, };
123
3760f736
JD		 124static const struct i2c_device_id ds1307_id[] = {
125 { "ds1307", ds_1307 },
126 { "ds1337", ds_1337 },
127 { "ds1338", ds_1338 },
128 { "ds1339", ds_1339 },
129 { "ds1340", ds_1340 },
130 { "m41t00", m41t00 },
131 { }
132};
133MODULE_DEVICE_TABLE(i2c, ds1307_id);
1abb0dc9 134
cb49a5e9
RG		 135/*----------------------------------------------------------------------*/
136
137/*
138 * The IRQ logic includes a "real" handler running in IRQ context just
139 * long enough to schedule this workqueue entry. We need a task context
140 * to talk to the RTC, since I2C I/O calls require that; and disable the
141 * IRQ until we clear its status on the chip, so that this handler can
142 * work with any type of triggering (not just falling edge).
143 *
144 * The ds1337 and ds1339 both have two alarms, but we only use the first
145 * one (with a "seconds" field). For ds1337 we expect nINTA is our alarm
146 * signal; ds1339 chips have only one alarm signal.
147 */
148static void ds1307_work(struct work_struct *work)
149{
150 struct ds1307 *ds1307;
151 struct i2c_client *client;
152 struct mutex *lock;
153 int stat, control;
154
155 ds1307 = container_of(work, struct ds1307, work);
156 client = ds1307->client;
157 lock = &ds1307->rtc->ops_lock;
158
159 mutex_lock(lock);
160 stat = i2c_smbus_read_byte_data(client, DS1337_REG_STATUS);
161 if (stat < 0)
162 goto out;
163
164 if (stat & DS1337_BIT_A1I) {
165 stat &= ~DS1337_BIT_A1I;
166 i2c_smbus_write_byte_data(client, DS1337_REG_STATUS, stat);
167
168 control = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
169 if (control < 0)
170 goto out;
171
172 control &= ~DS1337_BIT_A1IE;
173 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, control);
174
175 /* rtc_update_irq() assumes that it is called
176 * from IRQ-disabled context.
177 */
178 local_irq_disable();
179 rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
180 local_irq_enable();
181 }
182
183out:
184 if (test_bit(HAS_ALARM, &ds1307->flags))
185 enable_irq(client->irq);
186 mutex_unlock(lock);
187}
188
189static irqreturn_t ds1307_irq(int irq, void *dev_id)
190{
191 struct i2c_client *client = dev_id;
192 struct ds1307 *ds1307 = i2c_get_clientdata(client);
193
194 disable_irq_nosync(irq);
195 schedule_work(&ds1307->work);
196 return IRQ_HANDLED;
197}
198
199/*----------------------------------------------------------------------*/
200
1abb0dc9
DB		 201static int ds1307_get_time(struct device *dev, struct rtc_time *t)
202{
203 struct ds1307 *ds1307 = dev_get_drvdata(dev);
204 int tmp;
205
045e0e85 206 /* read the RTC date and time registers all at once */
cb49a5e9 207 ds1307->reg_addr = 0;
1abb0dc9
DB		 208 ds1307->msg[1].flags = I2C_M_RD;
209 ds1307->msg[1].len = 7;
210
045e0e85
DB		 211 tmp = i2c_transfer(to_i2c_adapter(ds1307->client->dev.parent),
212 ds1307->msg, 2);
1abb0dc9
DB		 213 if (tmp != 2) {
214 dev_err(dev, "%s error %d\n", "read", tmp);
215 return -EIO;
216 }
217
218 dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
219 "read",
220 ds1307->regs[0], ds1307->regs[1],
221 ds1307->regs[2], ds1307->regs[3],
222 ds1307->regs[4], ds1307->regs[5],
223 ds1307->regs[6]);
224
225 t->tm_sec = BCD2BIN(ds1307->regs[DS1307_REG_SECS] & 0x7f);
226 t->tm_min = BCD2BIN(ds1307->regs[DS1307_REG_MIN] & 0x7f);
227 tmp = ds1307->regs[DS1307_REG_HOUR] & 0x3f;
228 t->tm_hour = BCD2BIN(tmp);
229 t->tm_wday = BCD2BIN(ds1307->regs[DS1307_REG_WDAY] & 0x07) - 1;
230 t->tm_mday = BCD2BIN(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
231 tmp = ds1307->regs[DS1307_REG_MONTH] & 0x1f;
232 t->tm_mon = BCD2BIN(tmp) - 1;
233
234 /* assume 20YY not 19YY, and ignore DS1337_BIT_CENTURY */
235 t->tm_year = BCD2BIN(ds1307->regs[DS1307_REG_YEAR]) + 100;
236
237 dev_dbg(dev, "%s secs=%d, mins=%d, "
238 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
239 "read", t->tm_sec, t->tm_min,
240 t->tm_hour, t->tm_mday,
241 t->tm_mon, t->tm_year, t->tm_wday);
242
045e0e85
DB		 243 /* initial clock setting can be undefined */
244 return rtc_valid_tm(t);
1abb0dc9
DB		 245}
246
247static int ds1307_set_time(struct device *dev, struct rtc_time *t)
248{
249 struct ds1307 *ds1307 = dev_get_drvdata(dev);
250 int result;
251 int tmp;
252 u8 *buf = ds1307->regs;
253
254 dev_dbg(dev, "%s secs=%d, mins=%d, "
255 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
11966adc
JG		 256 "write", t->tm_sec, t->tm_min,
257 t->tm_hour, t->tm_mday,
258 t->tm_mon, t->tm_year, t->tm_wday);
1abb0dc9
DB		 259
260 *buf++ = 0; /* first register addr */
261 buf[DS1307_REG_SECS] = BIN2BCD(t->tm_sec);
262 buf[DS1307_REG_MIN] = BIN2BCD(t->tm_min);
263 buf[DS1307_REG_HOUR] = BIN2BCD(t->tm_hour);
264 buf[DS1307_REG_WDAY] = BIN2BCD(t->tm_wday + 1);
265 buf[DS1307_REG_MDAY] = BIN2BCD(t->tm_mday);
266 buf[DS1307_REG_MONTH] = BIN2BCD(t->tm_mon + 1);
267
268 /* assume 20YY not 19YY */
269 tmp = t->tm_year - 100;
270 buf[DS1307_REG_YEAR] = BIN2BCD(tmp);
271
be5f59f4
RG		 272 switch (ds1307->type) {
273 case ds_1337:
274 case ds_1339:
1abb0dc9 275 buf[DS1307_REG_MONTH] |= DS1337_BIT_CENTURY;
be5f59f4
RG		 276 break;
277 case ds_1340:
1abb0dc9
DB		 278 buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN
279 | DS1340_BIT_CENTURY;
be5f59f4
RG		 280 break;
281 default:
282 break;
283 }
1abb0dc9
DB		 284
285 ds1307->msg[1].flags = 0;
286 ds1307->msg[1].len = 8;
287
288 dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
289 "write", buf[0], buf[1], buf[2], buf[3],
290 buf[4], buf[5], buf[6]);
291
045e0e85
DB		 292 result = i2c_transfer(to_i2c_adapter(ds1307->client->dev.parent),
293 &ds1307->msg[1], 1);
1abb0dc9
DB		 294 if (result != 1) {
295 dev_err(dev, "%s error %d\n", "write", tmp);
296 return -EIO;
297 }
298 return 0;
299}
300
cb49a5e9
RG		 301static int ds1307_read_alarm(struct device *dev, struct rtc_wkalrm *t)
302{
303 struct i2c_client *client = to_i2c_client(dev);
304 struct ds1307 *ds1307 = i2c_get_clientdata(client);
305 int ret;
306
307 if (!test_bit(HAS_ALARM, &ds1307->flags))
308 return -EINVAL;
309
310 /* read all ALARM1, ALARM2, and status registers at once */
311 ds1307->reg_addr = DS1339_REG_ALARM1_SECS;
312 ds1307->msg[1].flags = I2C_M_RD;
313 ds1307->msg[1].len = 9;
314
315 ret = i2c_transfer(to_i2c_adapter(client->dev.parent),
316 ds1307->msg, 2);
317 if (ret != 2) {
318 dev_err(dev, "%s error %d\n", "alarm read", ret);
319 return -EIO;
320 }
321
322 dev_dbg(dev, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n",
323 "alarm read",
324 ds1307->regs[0], ds1307->regs[1],
325 ds1307->regs[2], ds1307->regs[3],
326 ds1307->regs[4], ds1307->regs[5],
327 ds1307->regs[6], ds1307->regs[7],
328 ds1307->regs[8]);
329
330 /* report alarm time (ALARM1); assume 24 hour and day-of-month modes,
331 * and that all four fields are checked matches
332 */
333 t->time.tm_sec = bcd2bin(ds1307->regs[0] & 0x7f);
334 t->time.tm_min = bcd2bin(ds1307->regs[1] & 0x7f);
335 t->time.tm_hour = bcd2bin(ds1307->regs[2] & 0x3f);
336 t->time.tm_mday = bcd2bin(ds1307->regs[3] & 0x3f);
337 t->time.tm_mon = -1;
338 t->time.tm_year = -1;
339 t->time.tm_wday = -1;
340 t->time.tm_yday = -1;
341 t->time.tm_isdst = -1;
342
343 /* ... and status */
344 t->enabled = !!(ds1307->regs[7] & DS1337_BIT_A1IE);
345 t->pending = !!(ds1307->regs[8] & DS1337_BIT_A1I);
346
347 dev_dbg(dev, "%s secs=%d, mins=%d, "
348 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
349 "alarm read", t->time.tm_sec, t->time.tm_min,
350 t->time.tm_hour, t->time.tm_mday,
351 t->enabled, t->pending);
352
353 return 0;
354}
355
356static int ds1307_set_alarm(struct device *dev, struct rtc_wkalrm *t)
357{
358 struct i2c_client *client = to_i2c_client(dev);
359 struct ds1307 *ds1307 = i2c_get_clientdata(client);
360 unsigned char *buf = ds1307->regs;
361 u8 control, status;
362 int ret;
363
364 if (!test_bit(HAS_ALARM, &ds1307->flags))
365 return -EINVAL;
366
367 dev_dbg(dev, "%s secs=%d, mins=%d, "
368 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
369 "alarm set", t->time.tm_sec, t->time.tm_min,
370 t->time.tm_hour, t->time.tm_mday,
371 t->enabled, t->pending);
372
373 /* read current status of both alarms and the chip */
374 ds1307->reg_addr = DS1339_REG_ALARM1_SECS;
375 ds1307->msg[1].flags = I2C_M_RD;
376 ds1307->msg[1].len = 9;
377
378 ret = i2c_transfer(to_i2c_adapter(client->dev.parent),
379 ds1307->msg, 2);
380 if (ret != 2) {
381 dev_err(dev, "%s error %d\n", "alarm write", ret);
382 return -EIO;
383 }
384 control = ds1307->regs[7];
385 status = ds1307->regs[8];
386
387 dev_dbg(dev, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n",
388 "alarm set (old status)",
389 ds1307->regs[0], ds1307->regs[1],
390 ds1307->regs[2], ds1307->regs[3],
391 ds1307->regs[4], ds1307->regs[5],
392 ds1307->regs[6], control, status);
393
394 /* set ALARM1, using 24 hour and day-of-month modes */
395 *buf++ = DS1339_REG_ALARM1_SECS; /* first register addr */
396 buf[0] = bin2bcd(t->time.tm_sec);
397 buf[1] = bin2bcd(t->time.tm_min);
398 buf[2] = bin2bcd(t->time.tm_hour);
399 buf[3] = bin2bcd(t->time.tm_mday);
400
401 /* set ALARM2 to non-garbage */
402 buf[4] = 0;
403 buf[5] = 0;
404 buf[6] = 0;
405
406 /* optionally enable ALARM1 */
407 buf[7] = control & ~(DS1337_BIT_A1IE | DS1337_BIT_A2IE);
408 if (t->enabled) {
409 dev_dbg(dev, "alarm IRQ armed\n");
410 buf[7] |= DS1337_BIT_A1IE; /* only ALARM1 is used */
411 }
412 buf[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I);
413
414 ds1307->msg[1].flags = 0;
415 ds1307->msg[1].len = 10;
416
417 ret = i2c_transfer(to_i2c_adapter(client->dev.parent),
418 &ds1307->msg[1], 1);
419 if (ret != 1) {
420 dev_err(dev, "can't set alarm time\n");
421 return -EIO;
422 }
423
424 return 0;
425}
426
427static int ds1307_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
428{
429 struct i2c_client *client = to_i2c_client(dev);
430 struct ds1307 *ds1307 = i2c_get_clientdata(client);
431 int ret;
432
433 switch (cmd) {
434 case RTC_AIE_OFF:
435 if (!test_bit(HAS_ALARM, &ds1307->flags))
436 return -ENOTTY;
437
438 ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
439 if (ret < 0)
440 return ret;
441
442 ret &= ~DS1337_BIT_A1IE;
443
444 ret = i2c_smbus_write_byte_data(client,
445 DS1337_REG_CONTROL, ret);
446 if (ret < 0)
447 return ret;
448
449 break;
450
451 case RTC_AIE_ON:
452 if (!test_bit(HAS_ALARM, &ds1307->flags))
453 return -ENOTTY;
454
455 ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
456 if (ret < 0)
457 return ret;
458
459 ret |= DS1337_BIT_A1IE;
460
461 ret = i2c_smbus_write_byte_data(client,
462 DS1337_REG_CONTROL, ret);
463 if (ret < 0)
464 return ret;
465
466 break;
467
468 default:
469 return -ENOIOCTLCMD;
470 }
471
472 return 0;
473}
474
ff8371ac 475static const struct rtc_class_ops ds13xx_rtc_ops = {
1abb0dc9
DB		 476 .read_time = ds1307_get_time,
477 .set_time = ds1307_set_time,
cb49a5e9
RG		 478 .read_alarm = ds1307_read_alarm,
479 .set_alarm = ds1307_set_alarm,
480 .ioctl = ds1307_ioctl,
1abb0dc9
DB		 481};
482
682d73f6
DB		 483/*----------------------------------------------------------------------*/
484
485#define NVRAM_SIZE 56
486
487static ssize_t
488ds1307_nvram_read(struct kobject *kobj, struct bin_attribute *attr,
489 char *buf, loff_t off, size_t count)
490{
491 struct i2c_client *client;
492 struct ds1307 *ds1307;
493 struct i2c_msg msg[2];
494 int result;
495
fcd8db00 496 client = kobj_to_i2c_client(kobj);
682d73f6
DB		 497 ds1307 = i2c_get_clientdata(client);
498
499 if (unlikely(off >= NVRAM_SIZE))
500 return 0;
501 if ((off + count) > NVRAM_SIZE)
502 count = NVRAM_SIZE - off;
503 if (unlikely(!count))
504 return count;
505
506 msg[0].addr = client->addr;
507 msg[0].flags = 0;
508 msg[0].len = 1;
509 msg[0].buf = buf;
510
511 buf[0] = 8 + off;
512
513 msg[1].addr = client->addr;
514 msg[1].flags = I2C_M_RD;
515 msg[1].len = count;
516 msg[1].buf = buf;
517
518 result = i2c_transfer(to_i2c_adapter(client->dev.parent), msg, 2);
519 if (result != 2) {
520 dev_err(&client->dev, "%s error %d\n", "nvram read", result);
521 return -EIO;
522 }
523 return count;
524}
525
526static ssize_t
527ds1307_nvram_write(struct kobject *kobj, struct bin_attribute *attr,
528 char *buf, loff_t off, size_t count)
529{
530 struct i2c_client *client;
531 u8 buffer[NVRAM_SIZE + 1];
532 int ret;
533
fcd8db00 534 client = kobj_to_i2c_client(kobj);
682d73f6
DB		 535
536 if (unlikely(off >= NVRAM_SIZE))
537 return -EFBIG;
538 if ((off + count) > NVRAM_SIZE)
539 count = NVRAM_SIZE - off;
540 if (unlikely(!count))
541 return count;
542
543 buffer[0] = 8 + off;
544 memcpy(buffer + 1, buf, count);
545
546 ret = i2c_master_send(client, buffer, count + 1);
547 return (ret < 0) ? ret : (ret - 1);
548}
549
550static struct bin_attribute nvram = {
551 .attr = {
552 .name = "nvram",
553 .mode = S_IRUGO | S_IWUSR,
554 .owner = THIS_MODULE,
555 },
556
557 .read = ds1307_nvram_read,
558 .write = ds1307_nvram_write,
559 .size = NVRAM_SIZE,
560};
561
562/*----------------------------------------------------------------------*/
563
1abb0dc9
DB		 564static struct i2c_driver ds1307_driver;
565
d2653e92
JD		 566static int __devinit ds1307_probe(struct i2c_client *client,
567 const struct i2c_device_id *id)
1abb0dc9
DB		 568{
569 struct ds1307 *ds1307;
570 int err = -ENODEV;
1abb0dc9 571 int tmp;
3760f736 572 const struct chip_desc *chip = &chips[id->driver_data];
c065f35c 573 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
cb49a5e9 574 int want_irq = false;
1abb0dc9 575
c065f35c
DB		 576 if (!i2c_check_functionality(adapter,
577 I2C_FUNC_I2C | I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
578 return -EIO;
579
580 if (!(ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL)))
581 return -ENOMEM;
045e0e85
DB		 582
583 ds1307->client = client;
1abb0dc9
DB		 584 i2c_set_clientdata(client, ds1307);
585
586 ds1307->msg[0].addr = client->addr;
587 ds1307->msg[0].flags = 0;
588 ds1307->msg[0].len = 1;
589 ds1307->msg[0].buf = &ds1307->reg_addr;
590
591 ds1307->msg[1].addr = client->addr;
592 ds1307->msg[1].flags = I2C_M_RD;
593 ds1307->msg[1].len = sizeof(ds1307->regs);
594 ds1307->msg[1].buf = ds1307->regs;
595
3760f736 596 ds1307->type = id->driver_data;
045e0e85
DB		 597
598 switch (ds1307->type) {
599 case ds_1337:
600 case ds_1339:
cb49a5e9
RG		 601 /* has IRQ? */
602 if (ds1307->client->irq > 0 && chip->alarm) {
603 INIT_WORK(&ds1307->work, ds1307_work);
604 want_irq = true;
605 }
606
1abb0dc9
DB		 607 ds1307->reg_addr = DS1337_REG_CONTROL;
608 ds1307->msg[1].len = 2;
609
be5f59f4 610 /* get registers that the "rtc" read below won't read... */
045e0e85 611 tmp = i2c_transfer(adapter, ds1307->msg, 2);
1abb0dc9
DB		 612 if (tmp != 2) {
613 pr_debug("read error %d\n", tmp);
614 err = -EIO;
615 goto exit_free;
616 }
617
618 ds1307->reg_addr = 0;
619 ds1307->msg[1].len = sizeof(ds1307->regs);
620
be5f59f4
RG		 621 /* oscillator off? turn it on, so clock can tick. */
622 if (ds1307->regs[0] & DS1337_BIT_nEOSC)
cb49a5e9
RG		 623 ds1307->regs[0] &= ~DS1337_BIT_nEOSC;
624
625 /* Using IRQ? Disable the square wave and both alarms.
626 * For ds1339, be sure alarms can trigger when we're
627 * running on Vbackup (BBSQI); we assume ds1337 will
628 * ignore that bit
629 */
630 if (want_irq) {
631 ds1307->regs[0] |= DS1337_BIT_INTCN | DS1339_BIT_BBSQI;
632 ds1307->regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
633 }
634
635 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL,
636 ds1307->regs[0]);
be5f59f4
RG		 637
638 /* oscillator fault? clear flag, and warn */
639 if (ds1307->regs[1] & DS1337_BIT_OSF) {
640 i2c_smbus_write_byte_data(client, DS1337_REG_STATUS,
641 ds1307->regs[1] & ~DS1337_BIT_OSF);
642 dev_warn(&client->dev, "SET TIME!\n");
1abb0dc9 643 }
045e0e85
DB		 644 break;
645 default:
646 break;
647 }
1abb0dc9
DB		 648
649read_rtc:
650 /* read RTC registers */
651
045e0e85 652 tmp = i2c_transfer(adapter, ds1307->msg, 2);
1abb0dc9
DB		 653 if (tmp != 2) {
654 pr_debug("read error %d\n", tmp);
655 err = -EIO;
656 goto exit_free;
657 }
658
659 /* minimal sanity checking; some chips (like DS1340) don't
660 * specify the extra bits as must-be-zero, but there are
661 * still a few values that are clearly out-of-range.
662 */
663 tmp = ds1307->regs[DS1307_REG_SECS];
045e0e85
DB		 664 switch (ds1307->type) {
665 case ds_1307:
045e0e85 666 case m41t00:
be5f59f4 667 /* clock halted? turn it on, so clock can tick. */
045e0e85 668 if (tmp & DS1307_BIT_CH) {
be5f59f4
RG		 669 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
670 dev_warn(&client->dev, "SET TIME!\n");
045e0e85 671 goto read_rtc;
1abb0dc9 672 }
045e0e85 673 break;
be5f59f4
RG		 674 case ds_1338:
675 /* clock halted? turn it on, so clock can tick. */
045e0e85 676 if (tmp & DS1307_BIT_CH)
be5f59f4
RG		 677 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
678
679 /* oscillator fault? clear flag, and warn */
680 if (ds1307->regs[DS1307_REG_CONTROL] & DS1338_BIT_OSF) {
681 i2c_smbus_write_byte_data(client, DS1307_REG_CONTROL,
bd16f9eb 682 ds1307->regs[DS1307_REG_CONTROL]
be5f59f4
RG		 683 & ~DS1338_BIT_OSF);
684 dev_warn(&client->dev, "SET TIME!\n");
685 goto read_rtc;
686 }
045e0e85 687 break;
fcd8db00
R		 688 case ds_1340:
689 /* clock halted? turn it on, so clock can tick. */
690 if (tmp & DS1340_BIT_nEOSC)
691 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
692
693 tmp = i2c_smbus_read_byte_data(client, DS1340_REG_FLAG);
694 if (tmp < 0) {
695 pr_debug("read error %d\n", tmp);
696 err = -EIO;
697 goto exit_free;
698 }
699
700 /* oscillator fault? clear flag, and warn */
701 if (tmp & DS1340_BIT_OSF) {
702 i2c_smbus_write_byte_data(client, DS1340_REG_FLAG, 0);
703 dev_warn(&client->dev, "SET TIME!\n");
704 }
705 break;
c065f35c
DB		 706 case ds_1337:
707 case ds_1339:
045e0e85 708 break;
1abb0dc9 709 }
045e0e85
DB		 710
711 tmp = ds1307->regs[DS1307_REG_SECS];
1abb0dc9
DB		 712 tmp = BCD2BIN(tmp & 0x7f);
713 if (tmp > 60)
c065f35c 714 goto exit_bad;
1abb0dc9
DB		 715 tmp = BCD2BIN(ds1307->regs[DS1307_REG_MIN] & 0x7f);
716 if (tmp > 60)
c065f35c 717 goto exit_bad;
1abb0dc9
DB		 718
719 tmp = BCD2BIN(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
720 if (tmp == 0 || tmp > 31)
c065f35c 721 goto exit_bad;
1abb0dc9
DB		 722
723 tmp = BCD2BIN(ds1307->regs[DS1307_REG_MONTH] & 0x1f);
724 if (tmp == 0 || tmp > 12)
c065f35c 725 goto exit_bad;
1abb0dc9 726
1abb0dc9 727 tmp = ds1307->regs[DS1307_REG_HOUR];
c065f35c
DB		 728 switch (ds1307->type) {
729 case ds_1340:
730 case m41t00:
731 /* NOTE: ignores century bits; fix before deploying
732 * systems that will run through year 2100.
733 */
734 break;
735 default:
736 if (!(tmp & DS1307_BIT_12HR))
737 break;
738
739 /* Be sure we're in 24 hour mode. Multi-master systems
740 * take note...
741 */
742 tmp = BCD2BIN(tmp & 0x1f);
743 if (tmp == 12)
744 tmp = 0;
745 if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
746 tmp += 12;
1abb0dc9
DB		 747 i2c_smbus_write_byte_data(client,
748 DS1307_REG_HOUR,
749 BIN2BCD(tmp));
750 }
751
1abb0dc9
DB		 752 ds1307->rtc = rtc_device_register(client->name, &client->dev,
753 &ds13xx_rtc_ops, THIS_MODULE);
754 if (IS_ERR(ds1307->rtc)) {
755 err = PTR_ERR(ds1307->rtc);
756 dev_err(&client->dev,
757 "unable to register the class device\n");
c065f35c 758 goto exit_free;
1abb0dc9
DB		 759 }
760
cb49a5e9
RG		 761 if (want_irq) {
762 err = request_irq(client->irq, ds1307_irq, 0,
763 ds1307->rtc->name, client);
764 if (err) {
765 dev_err(&client->dev,
766 "unable to request IRQ!\n");
767 goto exit_irq;
768 }
769 set_bit(HAS_ALARM, &ds1307->flags);
770 dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
771 }
772
682d73f6
DB		 773 if (chip->nvram56) {
774 err = sysfs_create_bin_file(&client->dev.kobj, &nvram);
775 if (err == 0) {
cb49a5e9 776 set_bit(HAS_NVRAM, &ds1307->flags);
682d73f6
DB		 777 dev_info(&client->dev, "56 bytes nvram\n");
778 }
779 }
780
1abb0dc9
DB		 781 return 0;
782
c065f35c
DB		 783exit_bad:
784 dev_dbg(&client->dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
785 "bogus register",
786 ds1307->regs[0], ds1307->regs[1],
787 ds1307->regs[2], ds1307->regs[3],
788 ds1307->regs[4], ds1307->regs[5],
789 ds1307->regs[6]);
cb49a5e9
RG		 790exit_irq:
791 if (ds1307->rtc)
792 rtc_device_unregister(ds1307->rtc);
1abb0dc9
DB		 793exit_free:
794 kfree(ds1307);
1abb0dc9
DB		 795 return err;
796}
797
c065f35c 798static int __devexit ds1307_remove(struct i2c_client *client)
1abb0dc9 799{
cb49a5e9
RG		 800 struct ds1307 *ds1307 = i2c_get_clientdata(client);
801
802 if (test_and_clear_bit(HAS_ALARM, &ds1307->flags)) {
803 free_irq(client->irq, client);
804 cancel_work_sync(&ds1307->work);
805 }
1abb0dc9 806
cb49a5e9 807 if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags))
682d73f6
DB		 808 sysfs_remove_bin_file(&client->dev.kobj, &nvram);
809
1abb0dc9 810 rtc_device_unregister(ds1307->rtc);
1abb0dc9
DB		 811 kfree(ds1307);
812 return 0;
813}
814
815static struct i2c_driver ds1307_driver = {
816 .driver = {
c065f35c 817 .name = "rtc-ds1307",
1abb0dc9
DB		 818 .owner = THIS_MODULE,
819 },
c065f35c
DB		 820 .probe = ds1307_probe,
821 .remove = __devexit_p(ds1307_remove),
3760f736 822 .id_table = ds1307_id,
1abb0dc9
DB		 823};
824
825static int __init ds1307_init(void)
826{
827 return i2c_add_driver(&ds1307_driver);
828}
829module_init(ds1307_init);
830
831static void __exit ds1307_exit(void)
832{
833 i2c_del_driver(&ds1307_driver);
834}
835module_exit(ds1307_exit);
836
837MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
838MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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