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pageflag helpers for configed-out flags
[linux-2.6/linux-2.6-openrd.git] / drivers / rtc / rtc-ds1307.c
blob4fcf0734a6ef088f5bf162de0f09341bac979349
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 reg_addr;
90 u8 regs[11];
91 enum ds_type type;
92 unsigned long flags;
93 #define HAS_NVRAM 0 /* bit 0 == sysfs file active */
94 #define HAS_ALARM 1 /* bit 1 == irq claimed */
95 struct i2c_msg msg[2];
96 struct i2c_client *client;
97 struct rtc_device *rtc;
98 struct work_struct work;
99 };
100
101 struct chip_desc {
102 unsigned nvram56:1;
103 unsigned alarm:1;
104 };
105
106 static const struct chip_desc chips[] = {
107 [ds_1307] = {
108 .nvram56 = 1,
109 },
110 [ds_1337] = {
111 .alarm = 1,
112 },
113 [ds_1338] = {
114 .nvram56 = 1,
115 },
116 [ds_1339] = {
117 .alarm = 1,
118 },
119 [ds_1340] = {
120 },
121 [m41t00] = {
122 }, };
123
124 static 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 };
133 MODULE_DEVICE_TABLE(i2c, ds1307_id);
134
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 */
148 static 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
183 out:
184 if (test_bit(HAS_ALARM, &ds1307->flags))
185 enable_irq(client->irq);
186 mutex_unlock(lock);
187 }
188
189 static 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
201 static int ds1307_get_time(struct device *dev, struct rtc_time *t)
202 {
203 struct ds1307 *ds1307 = dev_get_drvdata(dev);
204 int tmp;
205
206 /* read the RTC date and time registers all at once */
207 ds1307->reg_addr = 0;
208 ds1307->msg[1].flags = I2C_M_RD;
209 ds1307->msg[1].len = 7;
210
211 tmp = i2c_transfer(to_i2c_adapter(ds1307->client->dev.parent),
212 ds1307->msg, 2);
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
243 /* initial clock setting can be undefined */
244 return rtc_valid_tm(t);
245 }
246
247 static 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",
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);
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
272 switch (ds1307->type) {
273 case ds_1337:
274 case ds_1339:
275 buf[DS1307_REG_MONTH] |= DS1337_BIT_CENTURY;
276 break;
277 case ds_1340:
278 buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN
279 | DS1340_BIT_CENTURY;
280 break;
281 default:
282 break;
283 }
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
292 result = i2c_transfer(to_i2c_adapter(ds1307->client->dev.parent),
293 &ds1307->msg[1], 1);
294 if (result != 1) {
295 dev_err(dev, "%s error %d\n", "write", tmp);
296 return -EIO;
297 }
298 return 0;
299 }
300
301 static 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
356 static 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
427 static 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
475 static const struct rtc_class_ops ds13xx_rtc_ops = {
476 .read_time = ds1307_get_time,
477 .set_time = ds1307_set_time,
478 .read_alarm = ds1307_read_alarm,
479 .set_alarm = ds1307_set_alarm,
480 .ioctl = ds1307_ioctl,
481 };
482
483 /*----------------------------------------------------------------------*/
484
485 #define NVRAM_SIZE 56
486
487 static ssize_t
488 ds1307_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
496 client = kobj_to_i2c_client(kobj);
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
526 static ssize_t
527 ds1307_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
534 client = kobj_to_i2c_client(kobj);
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
550 static 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
564 static struct i2c_driver ds1307_driver;
565
566 static int __devinit ds1307_probe(struct i2c_client *client,
567 const struct i2c_device_id *id)
568 {
569 struct ds1307 *ds1307;
570 int err = -ENODEV;
571 int tmp;
572 const struct chip_desc *chip = &chips[id->driver_data];
573 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
574 int want_irq = false;
575
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;
582
583 ds1307->client = client;
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
596 ds1307->type = id->driver_data;
597
598 switch (ds1307->type) {
599 case ds_1337:
600 case ds_1339:
601 /* has IRQ? */
602 if (ds1307->client->irq > 0 && chip->alarm) {
603 INIT_WORK(&ds1307->work, ds1307_work);
604 want_irq = true;
605 }
606
607 ds1307->reg_addr = DS1337_REG_CONTROL;
608 ds1307->msg[1].len = 2;
609
610 /* get registers that the "rtc" read below won't read... */
611 tmp = i2c_transfer(adapter, ds1307->msg, 2);
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
621 /* oscillator off? turn it on, so clock can tick. */
622 if (ds1307->regs[0] & DS1337_BIT_nEOSC)
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]);
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");
643 }
644 break;
645 default:
646 break;
647 }
648
649 read_rtc:
650 /* read RTC registers */
651
652 tmp = i2c_transfer(adapter, ds1307->msg, 2);
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];
664 switch (ds1307->type) {
665 case ds_1307:
666 case m41t00:
667 /* clock halted? turn it on, so clock can tick. */
668 if (tmp & DS1307_BIT_CH) {
669 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
670 dev_warn(&client->dev, "SET TIME!\n");
671 goto read_rtc;
672 }
673 break;
674 case ds_1338:
675 /* clock halted? turn it on, so clock can tick. */
676 if (tmp & DS1307_BIT_CH)
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,
682 ds1307->regs[DS1307_REG_CONTROL]
683 & ~DS1338_BIT_OSF);
684 dev_warn(&client->dev, "SET TIME!\n");
685 goto read_rtc;
686 }
687 break;
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;
706 case ds_1337:
707 case ds_1339:
708 break;
709 }
710
711 tmp = ds1307->regs[DS1307_REG_SECS];
712 tmp = BCD2BIN(tmp & 0x7f);
713 if (tmp > 60)
714 goto exit_bad;
715 tmp = BCD2BIN(ds1307->regs[DS1307_REG_MIN] & 0x7f);
716 if (tmp > 60)
717 goto exit_bad;
718
719 tmp = BCD2BIN(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
720 if (tmp == 0 || tmp > 31)
721 goto exit_bad;
722
723 tmp = BCD2BIN(ds1307->regs[DS1307_REG_MONTH] & 0x1f);
724 if (tmp == 0 || tmp > 12)
725 goto exit_bad;
726
727 tmp = ds1307->regs[DS1307_REG_HOUR];
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;
747 i2c_smbus_write_byte_data(client,
748 DS1307_REG_HOUR,
749 BIN2BCD(tmp));
750 }
751
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");
758 goto exit_free;
759 }
760
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
773 if (chip->nvram56) {
774 err = sysfs_create_bin_file(&client->dev.kobj, &nvram);
775 if (err == 0) {
776 set_bit(HAS_NVRAM, &ds1307->flags);
777 dev_info(&client->dev, "56 bytes nvram\n");
778 }
779 }
780
781 return 0;
782
783 exit_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]);
790 exit_irq:
791 if (ds1307->rtc)
792 rtc_device_unregister(ds1307->rtc);
793 exit_free:
794 kfree(ds1307);
795 return err;
796 }
797
798 static int __devexit ds1307_remove(struct i2c_client *client)
799 {
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 }
806
807 if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags))
808 sysfs_remove_bin_file(&client->dev.kobj, &nvram);
809
810 rtc_device_unregister(ds1307->rtc);
811 kfree(ds1307);
812 return 0;
813 }
814
815 static struct i2c_driver ds1307_driver = {
816 .driver = {
817 .name = "rtc-ds1307",
818 .owner = THIS_MODULE,
819 },
820 .probe = ds1307_probe,
821 .remove = __devexit_p(ds1307_remove),
822 .id_table = ds1307_id,
823 };
824
825 static int __init ds1307_init(void)
826 {
827 return i2c_add_driver(&ds1307_driver);
828 }
829 module_init(ds1307_init);
830
831 static void __exit ds1307_exit(void)
832 {
833 i2c_del_driver(&ds1307_driver);
834 }
835 module_exit(ds1307_exit);
836
837 MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
838 MODULE_LICENSE("GPL");
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