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added 2.6.29.6 aldebaran kernel
[nao-ulib.git] / kernel / 2.6.29.6-aldebaran-rt / drivers / rtc / rtc-ds1307.c
blob7e5155e88ac75a19c9a4f6809298da344f020516
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.
26 */
27 enum ds_type {
28 ds_1307,
29 ds_1337,
30 ds_1338,
31 ds_1339,
32 ds_1340,
33 m41t00,
34 // rs5c372 too? different address...
35 };
36
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
41 # define DS1340_BIT_nEOSC 0x80
42 #define DS1307_REG_MIN 0x01 /* 00-59 */
43 #define DS1307_REG_HOUR 0x02 /* 00-23, or 1-12{am,pm} */
44 # define DS1307_BIT_12HR 0x40 /* in REG_HOUR */
45 # define DS1307_BIT_PM 0x20 /* in REG_HOUR */
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)
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.
57 */
58 #define DS1307_REG_CONTROL 0x07 /* or ds1338 */
59 # define DS1307_BIT_OUT 0x80
60 # define DS1338_BIT_OSF 0x20
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
66 # define DS1339_BIT_BBSQI 0x20
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
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
77 #define DS1340_REG_FLAG 0x09
78 # define DS1340_BIT_OSF 0x80
79 #define DS1337_REG_STATUS 0x0f
80 # define DS1337_BIT_OSF 0x80
81 # define DS1337_BIT_A2I 0x02
82 # define DS1337_BIT_A1I 0x01
83 #define DS1339_REG_ALARM1_SECS 0x07
84 #define DS1339_REG_TRICKLE 0x10
85
86
87
88 struct ds1307 {
89 u8 regs[11];
90 enum ds_type type;
91 unsigned long flags;
92 #define HAS_NVRAM 0 /* bit 0 == sysfs file active */
93 #define HAS_ALARM 1 /* bit 1 == irq claimed */
94 struct i2c_client *client;
95 struct rtc_device *rtc;
96 struct work_struct work;
97 };
98
99 struct chip_desc {
100 unsigned nvram56:1;
101 unsigned alarm:1;
102 };
103
104 static const struct chip_desc chips[] = {
105 [ds_1307] = {
106 .nvram56 = 1,
107 },
108 [ds_1337] = {
109 .alarm = 1,
110 },
111 [ds_1338] = {
112 .nvram56 = 1,
113 },
114 [ds_1339] = {
115 .alarm = 1,
116 },
117 [ds_1340] = {
118 },
119 [m41t00] = {
120 }, };
121
122 static const struct i2c_device_id ds1307_id[] = {
123 { "ds1307", ds_1307 },
124 { "ds1337", ds_1337 },
125 { "ds1338", ds_1338 },
126 { "ds1339", ds_1339 },
127 { "ds1340", ds_1340 },
128 { "m41t00", m41t00 },
129 { }
130 };
131 MODULE_DEVICE_TABLE(i2c, ds1307_id);
132
133 /*----------------------------------------------------------------------*/
134
135 /*
136 * The IRQ logic includes a "real" handler running in IRQ context just
137 * long enough to schedule this workqueue entry. We need a task context
138 * to talk to the RTC, since I2C I/O calls require that; and disable the
139 * IRQ until we clear its status on the chip, so that this handler can
140 * work with any type of triggering (not just falling edge).
141 *
142 * The ds1337 and ds1339 both have two alarms, but we only use the first
143 * one (with a "seconds" field). For ds1337 we expect nINTA is our alarm
144 * signal; ds1339 chips have only one alarm signal.
145 */
146 static void ds1307_work(struct work_struct *work)
147 {
148 struct ds1307 *ds1307;
149 struct i2c_client *client;
150 struct mutex *lock;
151 int stat, control;
152
153 ds1307 = container_of(work, struct ds1307, work);
154 client = ds1307->client;
155 lock = &ds1307->rtc->ops_lock;
156
157 mutex_lock(lock);
158 stat = i2c_smbus_read_byte_data(client, DS1337_REG_STATUS);
159 if (stat < 0)
160 goto out;
161
162 if (stat & DS1337_BIT_A1I) {
163 stat &= ~DS1337_BIT_A1I;
164 i2c_smbus_write_byte_data(client, DS1337_REG_STATUS, stat);
165
166 control = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
167 if (control < 0)
168 goto out;
169
170 control &= ~DS1337_BIT_A1IE;
171 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, control);
172
173 /* rtc_update_irq() assumes that it is called
174 * from IRQ-disabled context.
175 */
176 local_irq_disable();
177 rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
178 local_irq_enable();
179 }
180
181 out:
182 if (test_bit(HAS_ALARM, &ds1307->flags))
183 enable_irq(client->irq);
184 mutex_unlock(lock);
185 }
186
187 static irqreturn_t ds1307_irq(int irq, void *dev_id)
188 {
189 struct i2c_client *client = dev_id;
190 struct ds1307 *ds1307 = i2c_get_clientdata(client);
191
192 disable_irq_nosync(irq);
193 schedule_work(&ds1307->work);
194 return IRQ_HANDLED;
195 }
196
197 /*----------------------------------------------------------------------*/
198
199 static int ds1307_get_time(struct device *dev, struct rtc_time *t)
200 {
201 struct ds1307 *ds1307 = dev_get_drvdata(dev);
202 int tmp;
203
204 /* read the RTC date and time registers all at once */
205 tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
206 DS1307_REG_SECS, 7, ds1307->regs);
207 if (tmp != 7) {
208 dev_err(dev, "%s error %d\n", "read", tmp);
209 return -EIO;
210 }
211
212 dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
213 "read",
214 ds1307->regs[0], ds1307->regs[1],
215 ds1307->regs[2], ds1307->regs[3],
216 ds1307->regs[4], ds1307->regs[5],
217 ds1307->regs[6]);
218
219 t->tm_sec = bcd2bin(ds1307->regs[DS1307_REG_SECS] & 0x7f);
220 t->tm_min = bcd2bin(ds1307->regs[DS1307_REG_MIN] & 0x7f);
221 tmp = ds1307->regs[DS1307_REG_HOUR] & 0x3f;
222 t->tm_hour = bcd2bin(tmp);
223 t->tm_wday = bcd2bin(ds1307->regs[DS1307_REG_WDAY] & 0x07) - 1;
224 t->tm_mday = bcd2bin(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
225 tmp = ds1307->regs[DS1307_REG_MONTH] & 0x1f;
226 t->tm_mon = bcd2bin(tmp) - 1;
227
228 /* assume 20YY not 19YY, and ignore DS1337_BIT_CENTURY */
229 t->tm_year = bcd2bin(ds1307->regs[DS1307_REG_YEAR]) + 100;
230
231 dev_dbg(dev, "%s secs=%d, mins=%d, "
232 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
233 "read", t->tm_sec, t->tm_min,
234 t->tm_hour, t->tm_mday,
235 t->tm_mon, t->tm_year, t->tm_wday);
236
237 /* initial clock setting can be undefined */
238 return rtc_valid_tm(t);
239 }
240
241 static int ds1307_set_time(struct device *dev, struct rtc_time *t)
242 {
243 struct ds1307 *ds1307 = dev_get_drvdata(dev);
244 int result;
245 int tmp;
246 u8 *buf = ds1307->regs;
247
248 dev_dbg(dev, "%s secs=%d, mins=%d, "
249 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
250 "write", t->tm_sec, t->tm_min,
251 t->tm_hour, t->tm_mday,
252 t->tm_mon, t->tm_year, t->tm_wday);
253
254 buf[DS1307_REG_SECS] = bin2bcd(t->tm_sec);
255 buf[DS1307_REG_MIN] = bin2bcd(t->tm_min);
256 buf[DS1307_REG_HOUR] = bin2bcd(t->tm_hour);
257 buf[DS1307_REG_WDAY] = bin2bcd(t->tm_wday + 1);
258 buf[DS1307_REG_MDAY] = bin2bcd(t->tm_mday);
259 buf[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1);
260
261 /* assume 20YY not 19YY */
262 tmp = t->tm_year - 100;
263 buf[DS1307_REG_YEAR] = bin2bcd(tmp);
264
265 switch (ds1307->type) {
266 case ds_1337:
267 case ds_1339:
268 buf[DS1307_REG_MONTH] |= DS1337_BIT_CENTURY;
269 break;
270 case ds_1340:
271 buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN
272 | DS1340_BIT_CENTURY;
273 break;
274 default:
275 break;
276 }
277
278 dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
279 "write", buf[0], buf[1], buf[2], buf[3],
280 buf[4], buf[5], buf[6]);
281
282 result = i2c_smbus_write_i2c_block_data(ds1307->client, 0, 7, buf);
283 if (result < 0) {
284 dev_err(dev, "%s error %d\n", "write", result);
285 return result;
286 }
287 return 0;
288 }
289
290 static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t)
291 {
292 struct i2c_client *client = to_i2c_client(dev);
293 struct ds1307 *ds1307 = i2c_get_clientdata(client);
294 int ret;
295
296 if (!test_bit(HAS_ALARM, &ds1307->flags))
297 return -EINVAL;
298
299 /* read all ALARM1, ALARM2, and status registers at once */
300 ret = i2c_smbus_read_i2c_block_data(client,
301 DS1339_REG_ALARM1_SECS, 9, ds1307->regs);
302 if (ret != 9) {
303 dev_err(dev, "%s error %d\n", "alarm read", ret);
304 return -EIO;
305 }
306
307 dev_dbg(dev, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n",
308 "alarm read",
309 ds1307->regs[0], ds1307->regs[1],
310 ds1307->regs[2], ds1307->regs[3],
311 ds1307->regs[4], ds1307->regs[5],
312 ds1307->regs[6], ds1307->regs[7],
313 ds1307->regs[8]);
314
315 /* report alarm time (ALARM1); assume 24 hour and day-of-month modes,
316 * and that all four fields are checked matches
317 */
318 t->time.tm_sec = bcd2bin(ds1307->regs[0] & 0x7f);
319 t->time.tm_min = bcd2bin(ds1307->regs[1] & 0x7f);
320 t->time.tm_hour = bcd2bin(ds1307->regs[2] & 0x3f);
321 t->time.tm_mday = bcd2bin(ds1307->regs[3] & 0x3f);
322 t->time.tm_mon = -1;
323 t->time.tm_year = -1;
324 t->time.tm_wday = -1;
325 t->time.tm_yday = -1;
326 t->time.tm_isdst = -1;
327
328 /* ... and status */
329 t->enabled = !!(ds1307->regs[7] & DS1337_BIT_A1IE);
330 t->pending = !!(ds1307->regs[8] & DS1337_BIT_A1I);
331
332 dev_dbg(dev, "%s secs=%d, mins=%d, "
333 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
334 "alarm read", t->time.tm_sec, t->time.tm_min,
335 t->time.tm_hour, t->time.tm_mday,
336 t->enabled, t->pending);
337
338 return 0;
339 }
340
341 static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t)
342 {
343 struct i2c_client *client = to_i2c_client(dev);
344 struct ds1307 *ds1307 = i2c_get_clientdata(client);
345 unsigned char *buf = ds1307->regs;
346 u8 control, status;
347 int ret;
348
349 if (!test_bit(HAS_ALARM, &ds1307->flags))
350 return -EINVAL;
351
352 dev_dbg(dev, "%s secs=%d, mins=%d, "
353 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
354 "alarm set", t->time.tm_sec, t->time.tm_min,
355 t->time.tm_hour, t->time.tm_mday,
356 t->enabled, t->pending);
357
358 /* read current status of both alarms and the chip */
359 ret = i2c_smbus_read_i2c_block_data(client,
360 DS1339_REG_ALARM1_SECS, 9, buf);
361 if (ret != 9) {
362 dev_err(dev, "%s error %d\n", "alarm write", ret);
363 return -EIO;
364 }
365 control = ds1307->regs[7];
366 status = ds1307->regs[8];
367
368 dev_dbg(dev, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n",
369 "alarm set (old status)",
370 ds1307->regs[0], ds1307->regs[1],
371 ds1307->regs[2], ds1307->regs[3],
372 ds1307->regs[4], ds1307->regs[5],
373 ds1307->regs[6], control, status);
374
375 /* set ALARM1, using 24 hour and day-of-month modes */
376 buf[0] = bin2bcd(t->time.tm_sec);
377 buf[1] = bin2bcd(t->time.tm_min);
378 buf[2] = bin2bcd(t->time.tm_hour);
379 buf[3] = bin2bcd(t->time.tm_mday);
380
381 /* set ALARM2 to non-garbage */
382 buf[4] = 0;
383 buf[5] = 0;
384 buf[6] = 0;
385
386 /* optionally enable ALARM1 */
387 buf[7] = control & ~(DS1337_BIT_A1IE | DS1337_BIT_A2IE);
388 if (t->enabled) {
389 dev_dbg(dev, "alarm IRQ armed\n");
390 buf[7] |= DS1337_BIT_A1IE; /* only ALARM1 is used */
391 }
392 buf[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I);
393
394 ret = i2c_smbus_write_i2c_block_data(client,
395 DS1339_REG_ALARM1_SECS, 9, buf);
396 if (ret < 0) {
397 dev_err(dev, "can't set alarm time\n");
398 return ret;
399 }
400
401 return 0;
402 }
403
404 static int ds1307_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
405 {
406 struct i2c_client *client = to_i2c_client(dev);
407 struct ds1307 *ds1307 = i2c_get_clientdata(client);
408 int ret;
409
410 switch (cmd) {
411 case RTC_AIE_OFF:
412 if (!test_bit(HAS_ALARM, &ds1307->flags))
413 return -ENOTTY;
414
415 ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
416 if (ret < 0)
417 return ret;
418
419 ret &= ~DS1337_BIT_A1IE;
420
421 ret = i2c_smbus_write_byte_data(client,
422 DS1337_REG_CONTROL, ret);
423 if (ret < 0)
424 return ret;
425
426 break;
427
428 case RTC_AIE_ON:
429 if (!test_bit(HAS_ALARM, &ds1307->flags))
430 return -ENOTTY;
431
432 ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
433 if (ret < 0)
434 return ret;
435
436 ret |= DS1337_BIT_A1IE;
437
438 ret = i2c_smbus_write_byte_data(client,
439 DS1337_REG_CONTROL, ret);
440 if (ret < 0)
441 return ret;
442
443 break;
444
445 default:
446 return -ENOIOCTLCMD;
447 }
448
449 return 0;
450 }
451
452 static const struct rtc_class_ops ds13xx_rtc_ops = {
453 .read_time = ds1307_get_time,
454 .set_time = ds1307_set_time,
455 .read_alarm = ds1337_read_alarm,
456 .set_alarm = ds1337_set_alarm,
457 .ioctl = ds1307_ioctl,
458 };
459
460 /*----------------------------------------------------------------------*/
461
462 #define NVRAM_SIZE 56
463
464 static ssize_t
465 ds1307_nvram_read(struct kobject *kobj, struct bin_attribute *attr,
466 char *buf, loff_t off, size_t count)
467 {
468 struct i2c_client *client;
469 struct ds1307 *ds1307;
470 int result;
471
472 client = kobj_to_i2c_client(kobj);
473 ds1307 = i2c_get_clientdata(client);
474
475 if (unlikely(off >= NVRAM_SIZE))
476 return 0;
477 if ((off + count) > NVRAM_SIZE)
478 count = NVRAM_SIZE - off;
479 if (unlikely(!count))
480 return count;
481
482 result = i2c_smbus_read_i2c_block_data(client, 8 + off, count, buf);
483 if (result < 0)
484 dev_err(&client->dev, "%s error %d\n", "nvram read", result);
485 return result;
486 }
487
488 static ssize_t
489 ds1307_nvram_write(struct kobject *kobj, struct bin_attribute *attr,
490 char *buf, loff_t off, size_t count)
491 {
492 struct i2c_client *client;
493 int result;
494
495 client = kobj_to_i2c_client(kobj);
496
497 if (unlikely(off >= NVRAM_SIZE))
498 return -EFBIG;
499 if ((off + count) > NVRAM_SIZE)
500 count = NVRAM_SIZE - off;
501 if (unlikely(!count))
502 return count;
503
504 result = i2c_smbus_write_i2c_block_data(client, 8 + off, count, buf);
505 if (result < 0) {
506 dev_err(&client->dev, "%s error %d\n", "nvram write", result);
507 return result;
508 }
509 return count;
510 }
511
512 static struct bin_attribute nvram = {
513 .attr = {
514 .name = "nvram",
515 .mode = S_IRUGO | S_IWUSR,
516 },
517
518 .read = ds1307_nvram_read,
519 .write = ds1307_nvram_write,
520 .size = NVRAM_SIZE,
521 };
522
523 /*----------------------------------------------------------------------*/
524
525 static struct i2c_driver ds1307_driver;
526
527 static int __devinit ds1307_probe(struct i2c_client *client,
528 const struct i2c_device_id *id)
529 {
530 struct ds1307 *ds1307;
531 int err = -ENODEV;
532 int tmp;
533 const struct chip_desc *chip = &chips[id->driver_data];
534 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
535 int want_irq = false;
536 unsigned char *buf;
537
538 if (!i2c_check_functionality(adapter,
539 I2C_FUNC_SMBUS_WRITE_BYTE_DATA |
540 I2C_FUNC_SMBUS_I2C_BLOCK))
541 return -EIO;
542
543 if (!(ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL)))
544 return -ENOMEM;
545
546 ds1307->client = client;
547 i2c_set_clientdata(client, ds1307);
548 ds1307->type = id->driver_data;
549 buf = ds1307->regs;
550
551 switch (ds1307->type) {
552 case ds_1337:
553 case ds_1339:
554 /* has IRQ? */
555 if (ds1307->client->irq > 0 && chip->alarm) {
556 INIT_WORK(&ds1307->work, ds1307_work);
557 want_irq = true;
558 }
559 /* get registers that the "rtc" read below won't read... */
560 tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
561 DS1337_REG_CONTROL, 2, buf);
562 if (tmp != 2) {
563 pr_debug("read error %d\n", tmp);
564 err = -EIO;
565 goto exit_free;
566 }
567
568 /* oscillator off? turn it on, so clock can tick. */
569 if (ds1307->regs[0] & DS1337_BIT_nEOSC)
570 ds1307->regs[0] &= ~DS1337_BIT_nEOSC;
571
572 /* Using IRQ? Disable the square wave and both alarms.
573 * For ds1339, be sure alarms can trigger when we're
574 * running on Vbackup (BBSQI); we assume ds1337 will
575 * ignore that bit
576 */
577 if (want_irq) {
578 ds1307->regs[0] |= DS1337_BIT_INTCN | DS1339_BIT_BBSQI;
579 ds1307->regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
580 }
581
582 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL,
583 ds1307->regs[0]);
584
585 /* oscillator fault? clear flag, and warn */
586 if (ds1307->regs[1] & DS1337_BIT_OSF) {
587 i2c_smbus_write_byte_data(client, DS1337_REG_STATUS,
588 ds1307->regs[1] & ~DS1337_BIT_OSF);
589 dev_warn(&client->dev, "SET TIME!\n");
590 }
591 break;
592 default:
593 break;
594 }
595
596 read_rtc:
597 /* read RTC registers */
598 tmp = i2c_smbus_read_i2c_block_data(ds1307->client, 0, 8, buf);
599 if (tmp != 8) {
600 pr_debug("read error %d\n", tmp);
601 err = -EIO;
602 goto exit_free;
603 }
604
605 /* minimal sanity checking; some chips (like DS1340) don't
606 * specify the extra bits as must-be-zero, but there are
607 * still a few values that are clearly out-of-range.
608 */
609 tmp = ds1307->regs[DS1307_REG_SECS];
610 switch (ds1307->type) {
611 case ds_1307:
612 case m41t00:
613 /* clock halted? turn it on, so clock can tick. */
614 if (tmp & DS1307_BIT_CH) {
615 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
616 dev_warn(&client->dev, "SET TIME!\n");
617 goto read_rtc;
618 }
619 break;
620 case ds_1338:
621 /* clock halted? turn it on, so clock can tick. */
622 if (tmp & DS1307_BIT_CH)
623 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
624
625 /* oscillator fault? clear flag, and warn */
626 if (ds1307->regs[DS1307_REG_CONTROL] & DS1338_BIT_OSF) {
627 i2c_smbus_write_byte_data(client, DS1307_REG_CONTROL,
628 ds1307->regs[DS1307_REG_CONTROL]
629 & ~DS1338_BIT_OSF);
630 dev_warn(&client->dev, "SET TIME!\n");
631 goto read_rtc;
632 }
633 break;
634 case ds_1340:
635 /* clock halted? turn it on, so clock can tick. */
636 if (tmp & DS1340_BIT_nEOSC)
637 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
638
639 tmp = i2c_smbus_read_byte_data(client, DS1340_REG_FLAG);
640 if (tmp < 0) {
641 pr_debug("read error %d\n", tmp);
642 err = -EIO;
643 goto exit_free;
644 }
645
646 /* oscillator fault? clear flag, and warn */
647 if (tmp & DS1340_BIT_OSF) {
648 i2c_smbus_write_byte_data(client, DS1340_REG_FLAG, 0);
649 dev_warn(&client->dev, "SET TIME!\n");
650 }
651 break;
652 case ds_1337:
653 case ds_1339:
654 break;
655 }
656
657 tmp = ds1307->regs[DS1307_REG_HOUR];
658 switch (ds1307->type) {
659 case ds_1340:
660 case m41t00:
661 /* NOTE: ignores century bits; fix before deploying
662 * systems that will run through year 2100.
663 */
664 break;
665 default:
666 if (!(tmp & DS1307_BIT_12HR))
667 break;
668
669 /* Be sure we're in 24 hour mode. Multi-master systems
670 * take note...
671 */
672 tmp = bcd2bin(tmp & 0x1f);
673 if (tmp == 12)
674 tmp = 0;
675 if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
676 tmp += 12;
677 i2c_smbus_write_byte_data(client,
678 DS1307_REG_HOUR,
679 bin2bcd(tmp));
680 }
681
682 ds1307->rtc = rtc_device_register(client->name, &client->dev,
683 &ds13xx_rtc_ops, THIS_MODULE);
684 if (IS_ERR(ds1307->rtc)) {
685 err = PTR_ERR(ds1307->rtc);
686 dev_err(&client->dev,
687 "unable to register the class device\n");
688 goto exit_free;
689 }
690
691 if (want_irq) {
692 err = request_irq(client->irq, ds1307_irq, 0,
693 ds1307->rtc->name, client);
694 if (err) {
695 dev_err(&client->dev,
696 "unable to request IRQ!\n");
697 goto exit_irq;
698 }
699 set_bit(HAS_ALARM, &ds1307->flags);
700 dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
701 }
702
703 if (chip->nvram56) {
704 err = sysfs_create_bin_file(&client->dev.kobj, &nvram);
705 if (err == 0) {
706 set_bit(HAS_NVRAM, &ds1307->flags);
707 dev_info(&client->dev, "56 bytes nvram\n");
708 }
709 }
710
711 return 0;
712
713 exit_irq:
714 if (ds1307->rtc)
715 rtc_device_unregister(ds1307->rtc);
716 exit_free:
717 kfree(ds1307);
718 return err;
719 }
720
721 static int __devexit ds1307_remove(struct i2c_client *client)
722 {
723 struct ds1307 *ds1307 = i2c_get_clientdata(client);
724
725 if (test_and_clear_bit(HAS_ALARM, &ds1307->flags)) {
726 free_irq(client->irq, client);
727 cancel_work_sync(&ds1307->work);
728 }
729
730 if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags))
731 sysfs_remove_bin_file(&client->dev.kobj, &nvram);
732
733 rtc_device_unregister(ds1307->rtc);
734 kfree(ds1307);
735 return 0;
736 }
737
738 static struct i2c_driver ds1307_driver = {
739 .driver = {
740 .name = "rtc-ds1307",
741 .owner = THIS_MODULE,
742 },
743 .probe = ds1307_probe,
744 .remove = __devexit_p(ds1307_remove),
745 .id_table = ds1307_id,
746 };
747
748 static int __init ds1307_init(void)
749 {
750 return i2c_add_driver(&ds1307_driver);
751 }
752 module_init(ds1307_init);
753
754 static void __exit ds1307_exit(void)
755 {
756 i2c_del_driver(&ds1307_driver);
757 }
758 module_exit(ds1307_exit);
759
760 MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
761 MODULE_LICENSE("GPL");
Nao low-level kernelspace/userspace library that runs on our robots, Nao-Team HTWK