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rtc: rtc-ds1307 add ds3231
[linux-2.6/mini2440.git] / drivers / rtc / rtc-ds1307.c
blob8a6f9a9f9cb83d98c8e5b6e20a8da8c8374bb004
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 * Copyright (C) 2009 Matthias Fuchs (rx8025 support)
7 *
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.
11 */
12
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>
20
21
22
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.
27 */
28 enum ds_type {
29 ds_1307,
30 ds_1337,
31 ds_1338,
32 ds_1339,
33 ds_1340,
34 ds_1388,
35 ds_3231,
36 m41t00,
37 rx_8025,
38 // rs5c372 too? different address...
39 };
40
41
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 */
57
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.
61 */
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
90
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
97
98
99 struct ds1307 {
100 u8 offset; /* register's offset */
101 u8 regs[11];
102 enum ds_type type;
103 unsigned long flags;
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);
113 };
114
115 struct chip_desc {
116 unsigned nvram56:1;
117 unsigned alarm:1;
118 };
119
120 static const struct chip_desc chips[] = {
121 [ds_1307] = {
122 .nvram56 = 1,
123 },
124 [ds_1337] = {
125 .alarm = 1,
126 },
127 [ds_1338] = {
128 .nvram56 = 1,
129 },
130 [ds_1339] = {
131 .alarm = 1,
132 },
133 [ds_1340] = {
134 },
135 [ds_3231] = {
136 .alarm = 1,
137 },
138 [m41t00] = {
139 },
140 [rx_8025] = {
141 }, };
142
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 },
153 { }
154 };
155 MODULE_DEVICE_TABLE(i2c, ds1307_id);
156
157 /*----------------------------------------------------------------------*/
158
159 #define BLOCK_DATA_MAX_TRIES 10
160
161 static s32 ds1307_read_block_data_once(struct i2c_client *client, u8 command,
162 u8 length, u8 *values)
163 {
164 s32 i, data;
165
166 for (i = 0; i < length; i++) {
167 data = i2c_smbus_read_byte_data(client, command + i);
168 if (data < 0)
169 return data;
170 values[i] = data;
171 }
172 return i;
173 }
174
175 static s32 ds1307_read_block_data(struct i2c_client *client, u8 command,
176 u8 length, u8 *values)
177 {
178 u8 oldvalues[I2C_SMBUS_BLOCK_MAX];
179 s32 ret;
180 int tries = 0;
181
182 dev_dbg(&client->dev, "ds1307_read_block_data (length=%d)\n", length);
183 ret = ds1307_read_block_data_once(client, command, length, values);
184 if (ret < 0)
185 return ret;
186 do {
187 if (++tries > BLOCK_DATA_MAX_TRIES) {
188 dev_err(&client->dev,
189 "ds1307_read_block_data failed\n");
190 return -EIO;
191 }
192 memcpy(oldvalues, values, length);
193 ret = ds1307_read_block_data_once(client, command, length,
194 values);
195 if (ret < 0)
196 return ret;
197 } while (memcmp(oldvalues, values, length));
198 return length;
199 }
200
201 static s32 ds1307_write_block_data(struct i2c_client *client, u8 command,
202 u8 length, const u8 *values)
203 {
204 u8 currvalues[I2C_SMBUS_BLOCK_MAX];
205 int tries = 0;
206
207 dev_dbg(&client->dev, "ds1307_write_block_data (length=%d)\n", length);
208 do {
209 s32 i, ret;
210
211 if (++tries > BLOCK_DATA_MAX_TRIES) {
212 dev_err(&client->dev,
213 "ds1307_write_block_data failed\n");
214 return -EIO;
215 }
216 for (i = 0; i < length; i++) {
217 ret = i2c_smbus_write_byte_data(client, command + i,
218 values[i]);
219 if (ret < 0)
220 return ret;
221 }
222 ret = ds1307_read_block_data_once(client, command, length,
223 currvalues);
224 if (ret < 0)
225 return ret;
226 } while (memcmp(currvalues, values, length));
227 return length;
228 }
229
230 /*----------------------------------------------------------------------*/
231
232 /*
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).
238 *
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.
242 */
243 static void ds1307_work(struct work_struct *work)
244 {
245 struct ds1307 *ds1307;
246 struct i2c_client *client;
247 struct mutex *lock;
248 int stat, control;
249
250 ds1307 = container_of(work, struct ds1307, work);
251 client = ds1307->client;
252 lock = &ds1307->rtc->ops_lock;
253
254 mutex_lock(lock);
255 stat = i2c_smbus_read_byte_data(client, DS1337_REG_STATUS);
256 if (stat < 0)
257 goto out;
258
259 if (stat & DS1337_BIT_A1I) {
260 stat &= ~DS1337_BIT_A1I;
261 i2c_smbus_write_byte_data(client, DS1337_REG_STATUS, stat);
262
263 control = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
264 if (control < 0)
265 goto out;
266
267 control &= ~DS1337_BIT_A1IE;
268 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, control);
269
270 /* rtc_update_irq() assumes that it is called
271 * from IRQ-disabled context.
272 */
273 local_irq_disable();
274 rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
275 local_irq_enable();
276 }
277
278 out:
279 if (test_bit(HAS_ALARM, &ds1307->flags))
280 enable_irq(client->irq);
281 mutex_unlock(lock);
282 }
283
284 static irqreturn_t ds1307_irq(int irq, void *dev_id)
285 {
286 struct i2c_client *client = dev_id;
287 struct ds1307 *ds1307 = i2c_get_clientdata(client);
288
289 disable_irq_nosync(irq);
290 schedule_work(&ds1307->work);
291 return IRQ_HANDLED;
292 }
293
294 /*----------------------------------------------------------------------*/
295
296 static int ds1307_get_time(struct device *dev, struct rtc_time *t)
297 {
298 struct ds1307 *ds1307 = dev_get_drvdata(dev);
299 int tmp;
300
301 /* read the RTC date and time registers all at once */
302 tmp = ds1307->read_block_data(ds1307->client,
303 ds1307->offset, 7, ds1307->regs);
304 if (tmp != 7) {
305 dev_err(dev, "%s error %d\n", "read", tmp);
306 return -EIO;
307 }
308
309 dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
310 "read",
311 ds1307->regs[0], ds1307->regs[1],
312 ds1307->regs[2], ds1307->regs[3],
313 ds1307->regs[4], ds1307->regs[5],
314 ds1307->regs[6]);
315
316 t->tm_sec = bcd2bin(ds1307->regs[DS1307_REG_SECS] & 0x7f);
317 t->tm_min = bcd2bin(ds1307->regs[DS1307_REG_MIN] & 0x7f);
318 tmp = ds1307->regs[DS1307_REG_HOUR] & 0x3f;
319 t->tm_hour = bcd2bin(tmp);
320 t->tm_wday = bcd2bin(ds1307->regs[DS1307_REG_WDAY] & 0x07) - 1;
321 t->tm_mday = bcd2bin(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
322 tmp = ds1307->regs[DS1307_REG_MONTH] & 0x1f;
323 t->tm_mon = bcd2bin(tmp) - 1;
324
325 /* assume 20YY not 19YY, and ignore DS1337_BIT_CENTURY */
326 t->tm_year = bcd2bin(ds1307->regs[DS1307_REG_YEAR]) + 100;
327
328 dev_dbg(dev, "%s secs=%d, mins=%d, "
329 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
330 "read", t->tm_sec, t->tm_min,
331 t->tm_hour, t->tm_mday,
332 t->tm_mon, t->tm_year, t->tm_wday);
333
334 /* initial clock setting can be undefined */
335 return rtc_valid_tm(t);
336 }
337
338 static int ds1307_set_time(struct device *dev, struct rtc_time *t)
339 {
340 struct ds1307 *ds1307 = dev_get_drvdata(dev);
341 int result;
342 int tmp;
343 u8 *buf = ds1307->regs;
344
345 dev_dbg(dev, "%s secs=%d, mins=%d, "
346 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
347 "write", t->tm_sec, t->tm_min,
348 t->tm_hour, t->tm_mday,
349 t->tm_mon, t->tm_year, t->tm_wday);
350
351 buf[DS1307_REG_SECS] = bin2bcd(t->tm_sec);
352 buf[DS1307_REG_MIN] = bin2bcd(t->tm_min);
353 buf[DS1307_REG_HOUR] = bin2bcd(t->tm_hour);
354 buf[DS1307_REG_WDAY] = bin2bcd(t->tm_wday + 1);
355 buf[DS1307_REG_MDAY] = bin2bcd(t->tm_mday);
356 buf[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1);
357
358 /* assume 20YY not 19YY */
359 tmp = t->tm_year - 100;
360 buf[DS1307_REG_YEAR] = bin2bcd(tmp);
361
362 switch (ds1307->type) {
363 case ds_1337:
364 case ds_1339:
365 case ds_3231:
366 buf[DS1307_REG_MONTH] |= DS1337_BIT_CENTURY;
367 break;
368 case ds_1340:
369 buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN
370 | DS1340_BIT_CENTURY;
371 break;
372 default:
373 break;
374 }
375
376 dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
377 "write", buf[0], buf[1], buf[2], buf[3],
378 buf[4], buf[5], buf[6]);
379
380 result = ds1307->write_block_data(ds1307->client,
381 ds1307->offset, 7, buf);
382 if (result < 0) {
383 dev_err(dev, "%s error %d\n", "write", result);
384 return result;
385 }
386 return 0;
387 }
388
389 static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t)
390 {
391 struct i2c_client *client = to_i2c_client(dev);
392 struct ds1307 *ds1307 = i2c_get_clientdata(client);
393 int ret;
394
395 if (!test_bit(HAS_ALARM, &ds1307->flags))
396 return -EINVAL;
397
398 /* read all ALARM1, ALARM2, and status registers at once */
399 ret = ds1307->read_block_data(client,
400 DS1339_REG_ALARM1_SECS, 9, ds1307->regs);
401 if (ret != 9) {
402 dev_err(dev, "%s error %d\n", "alarm read", ret);
403 return -EIO;
404 }
405
406 dev_dbg(dev, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n",
407 "alarm read",
408 ds1307->regs[0], ds1307->regs[1],
409 ds1307->regs[2], ds1307->regs[3],
410 ds1307->regs[4], ds1307->regs[5],
411 ds1307->regs[6], ds1307->regs[7],
412 ds1307->regs[8]);
413
414 /* report alarm time (ALARM1); assume 24 hour and day-of-month modes,
415 * and that all four fields are checked matches
416 */
417 t->time.tm_sec = bcd2bin(ds1307->regs[0] & 0x7f);
418 t->time.tm_min = bcd2bin(ds1307->regs[1] & 0x7f);
419 t->time.tm_hour = bcd2bin(ds1307->regs[2] & 0x3f);
420 t->time.tm_mday = bcd2bin(ds1307->regs[3] & 0x3f);
421 t->time.tm_mon = -1;
422 t->time.tm_year = -1;
423 t->time.tm_wday = -1;
424 t->time.tm_yday = -1;
425 t->time.tm_isdst = -1;
426
427 /* ... and status */
428 t->enabled = !!(ds1307->regs[7] & DS1337_BIT_A1IE);
429 t->pending = !!(ds1307->regs[8] & DS1337_BIT_A1I);
430
431 dev_dbg(dev, "%s secs=%d, mins=%d, "
432 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
433 "alarm read", t->time.tm_sec, t->time.tm_min,
434 t->time.tm_hour, t->time.tm_mday,
435 t->enabled, t->pending);
436
437 return 0;
438 }
439
440 static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t)
441 {
442 struct i2c_client *client = to_i2c_client(dev);
443 struct ds1307 *ds1307 = i2c_get_clientdata(client);
444 unsigned char *buf = ds1307->regs;
445 u8 control, status;
446 int ret;
447
448 if (!test_bit(HAS_ALARM, &ds1307->flags))
449 return -EINVAL;
450
451 dev_dbg(dev, "%s secs=%d, mins=%d, "
452 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
453 "alarm set", t->time.tm_sec, t->time.tm_min,
454 t->time.tm_hour, t->time.tm_mday,
455 t->enabled, t->pending);
456
457 /* read current status of both alarms and the chip */
458 ret = ds1307->read_block_data(client,
459 DS1339_REG_ALARM1_SECS, 9, buf);
460 if (ret != 9) {
461 dev_err(dev, "%s error %d\n", "alarm write", ret);
462 return -EIO;
463 }
464 control = ds1307->regs[7];
465 status = ds1307->regs[8];
466
467 dev_dbg(dev, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n",
468 "alarm set (old status)",
469 ds1307->regs[0], ds1307->regs[1],
470 ds1307->regs[2], ds1307->regs[3],
471 ds1307->regs[4], ds1307->regs[5],
472 ds1307->regs[6], control, status);
473
474 /* set ALARM1, using 24 hour and day-of-month modes */
475 buf[0] = bin2bcd(t->time.tm_sec);
476 buf[1] = bin2bcd(t->time.tm_min);
477 buf[2] = bin2bcd(t->time.tm_hour);
478 buf[3] = bin2bcd(t->time.tm_mday);
479
480 /* set ALARM2 to non-garbage */
481 buf[4] = 0;
482 buf[5] = 0;
483 buf[6] = 0;
484
485 /* optionally enable ALARM1 */
486 buf[7] = control & ~(DS1337_BIT_A1IE | DS1337_BIT_A2IE);
487 if (t->enabled) {
488 dev_dbg(dev, "alarm IRQ armed\n");
489 buf[7] |= DS1337_BIT_A1IE; /* only ALARM1 is used */
490 }
491 buf[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I);
492
493 ret = ds1307->write_block_data(client,
494 DS1339_REG_ALARM1_SECS, 9, buf);
495 if (ret < 0) {
496 dev_err(dev, "can't set alarm time\n");
497 return ret;
498 }
499
500 return 0;
501 }
502
503 static int ds1307_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
504 {
505 struct i2c_client *client = to_i2c_client(dev);
506 struct ds1307 *ds1307 = i2c_get_clientdata(client);
507 int ret;
508
509 switch (cmd) {
510 case RTC_AIE_OFF:
511 if (!test_bit(HAS_ALARM, &ds1307->flags))
512 return -ENOTTY;
513
514 ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
515 if (ret < 0)
516 return ret;
517
518 ret &= ~DS1337_BIT_A1IE;
519
520 ret = i2c_smbus_write_byte_data(client,
521 DS1337_REG_CONTROL, ret);
522 if (ret < 0)
523 return ret;
524
525 break;
526
527 case RTC_AIE_ON:
528 if (!test_bit(HAS_ALARM, &ds1307->flags))
529 return -ENOTTY;
530
531 ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
532 if (ret < 0)
533 return ret;
534
535 ret |= DS1337_BIT_A1IE;
536
537 ret = i2c_smbus_write_byte_data(client,
538 DS1337_REG_CONTROL, ret);
539 if (ret < 0)
540 return ret;
541
542 break;
543
544 default:
545 return -ENOIOCTLCMD;
546 }
547
548 return 0;
549 }
550
551 static const struct rtc_class_ops ds13xx_rtc_ops = {
552 .read_time = ds1307_get_time,
553 .set_time = ds1307_set_time,
554 .read_alarm = ds1337_read_alarm,
555 .set_alarm = ds1337_set_alarm,
556 .ioctl = ds1307_ioctl,
557 };
558
559 /*----------------------------------------------------------------------*/
560
561 #define NVRAM_SIZE 56
562
563 static ssize_t
564 ds1307_nvram_read(struct kobject *kobj, struct bin_attribute *attr,
565 char *buf, loff_t off, size_t count)
566 {
567 struct i2c_client *client;
568 struct ds1307 *ds1307;
569 int result;
570
571 client = kobj_to_i2c_client(kobj);
572 ds1307 = i2c_get_clientdata(client);
573
574 if (unlikely(off >= NVRAM_SIZE))
575 return 0;
576 if ((off + count) > NVRAM_SIZE)
577 count = NVRAM_SIZE - off;
578 if (unlikely(!count))
579 return count;
580
581 result = ds1307->read_block_data(client, 8 + off, count, buf);
582 if (result < 0)
583 dev_err(&client->dev, "%s error %d\n", "nvram read", result);
584 return result;
585 }
586
587 static ssize_t
588 ds1307_nvram_write(struct kobject *kobj, struct bin_attribute *attr,
589 char *buf, loff_t off, size_t count)
590 {
591 struct i2c_client *client;
592 struct ds1307 *ds1307;
593 int result;
594
595 client = kobj_to_i2c_client(kobj);
596 ds1307 = i2c_get_clientdata(client);
597
598 if (unlikely(off >= NVRAM_SIZE))
599 return -EFBIG;
600 if ((off + count) > NVRAM_SIZE)
601 count = NVRAM_SIZE - off;
602 if (unlikely(!count))
603 return count;
604
605 result = ds1307->write_block_data(client, 8 + off, count, buf);
606 if (result < 0) {
607 dev_err(&client->dev, "%s error %d\n", "nvram write", result);
608 return result;
609 }
610 return count;
611 }
612
613 static struct bin_attribute nvram = {
614 .attr = {
615 .name = "nvram",
616 .mode = S_IRUGO | S_IWUSR,
617 },
618
619 .read = ds1307_nvram_read,
620 .write = ds1307_nvram_write,
621 .size = NVRAM_SIZE,
622 };
623
624 /*----------------------------------------------------------------------*/
625
626 static struct i2c_driver ds1307_driver;
627
628 static int __devinit ds1307_probe(struct i2c_client *client,
629 const struct i2c_device_id *id)
630 {
631 struct ds1307 *ds1307;
632 int err = -ENODEV;
633 int tmp;
634 const struct chip_desc *chip = &chips[id->driver_data];
635 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
636 int want_irq = false;
637 unsigned char *buf;
638 static const int bbsqi_bitpos[] = {
639 [ds_1337] = 0,
640 [ds_1339] = DS1339_BIT_BBSQI,
641 [ds_3231] = DS3231_BIT_BBSQW,
642 };
643
644 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)
645 && !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
646 return -EIO;
647
648 if (!(ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL)))
649 return -ENOMEM;
650
651 i2c_set_clientdata(client, ds1307);
652
653 ds1307->client = client;
654 ds1307->type = id->driver_data;
655 ds1307->offset = 0;
656
657 buf = ds1307->regs;
658 if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) {
659 ds1307->read_block_data = i2c_smbus_read_i2c_block_data;
660 ds1307->write_block_data = i2c_smbus_write_i2c_block_data;
661 } else {
662 ds1307->read_block_data = ds1307_read_block_data;
663 ds1307->write_block_data = ds1307_write_block_data;
664 }
665
666 switch (ds1307->type) {
667 case ds_1337:
668 case ds_1339:
669 case ds_3231:
670 /* has IRQ? */
671 if (ds1307->client->irq > 0 && chip->alarm) {
672 INIT_WORK(&ds1307->work, ds1307_work);
673 want_irq = true;
674 }
675 /* get registers that the "rtc" read below won't read... */
676 tmp = ds1307->read_block_data(ds1307->client,
677 DS1337_REG_CONTROL, 2, buf);
678 if (tmp != 2) {
679 pr_debug("read error %d\n", tmp);
680 err = -EIO;
681 goto exit_free;
682 }
683
684 /* oscillator off? turn it on, so clock can tick. */
685 if (ds1307->regs[0] & DS1337_BIT_nEOSC)
686 ds1307->regs[0] &= ~DS1337_BIT_nEOSC;
687
688 /* Using IRQ? Disable the square wave and both alarms.
689 * For some variants, be sure alarms can trigger when we're
690 * running on Vbackup (BBSQI/BBSQW)
691 */
692 if (want_irq) {
693 ds1307->regs[0] |= DS1337_BIT_INTCN
694 | bbsqi_bitpos[ds1307->type];
695 ds1307->regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
696 }
697
698 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL,
699 ds1307->regs[0]);
700
701 /* oscillator fault? clear flag, and warn */
702 if (ds1307->regs[1] & DS1337_BIT_OSF) {
703 i2c_smbus_write_byte_data(client, DS1337_REG_STATUS,
704 ds1307->regs[1] & ~DS1337_BIT_OSF);
705 dev_warn(&client->dev, "SET TIME!\n");
706 }
707 break;
708
709 case rx_8025:
710 tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
711 RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
712 if (tmp != 2) {
713 pr_debug("read error %d\n", tmp);
714 err = -EIO;
715 goto exit_free;
716 }
717
718 /* oscillator off? turn it on, so clock can tick. */
719 if (!(ds1307->regs[1] & RX8025_BIT_XST)) {
720 ds1307->regs[1] |= RX8025_BIT_XST;
721 i2c_smbus_write_byte_data(client,
722 RX8025_REG_CTRL2 << 4 | 0x08,
723 ds1307->regs[1]);
724 dev_warn(&client->dev,
725 "oscillator stop detected - SET TIME!\n");
726 }
727
728 if (ds1307->regs[1] & RX8025_BIT_PON) {
729 ds1307->regs[1] &= ~RX8025_BIT_PON;
730 i2c_smbus_write_byte_data(client,
731 RX8025_REG_CTRL2 << 4 | 0x08,
732 ds1307->regs[1]);
733 dev_warn(&client->dev, "power-on detected\n");
734 }
735
736 if (ds1307->regs[1] & RX8025_BIT_VDET) {
737 ds1307->regs[1] &= ~RX8025_BIT_VDET;
738 i2c_smbus_write_byte_data(client,
739 RX8025_REG_CTRL2 << 4 | 0x08,
740 ds1307->regs[1]);
741 dev_warn(&client->dev, "voltage drop detected\n");
742 }
743
744 /* make sure we are running in 24hour mode */
745 if (!(ds1307->regs[0] & RX8025_BIT_2412)) {
746 u8 hour;
747
748 /* switch to 24 hour mode */
749 i2c_smbus_write_byte_data(client,
750 RX8025_REG_CTRL1 << 4 | 0x08,
751 ds1307->regs[0] |
752 RX8025_BIT_2412);
753
754 tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
755 RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
756 if (tmp != 2) {
757 pr_debug("read error %d\n", tmp);
758 err = -EIO;
759 goto exit_free;
760 }
761
762 /* correct hour */
763 hour = bcd2bin(ds1307->regs[DS1307_REG_HOUR]);
764 if (hour == 12)
765 hour = 0;
766 if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
767 hour += 12;
768
769 i2c_smbus_write_byte_data(client,
770 DS1307_REG_HOUR << 4 | 0x08,
771 hour);
772 }
773 break;
774 case ds_1388:
775 ds1307->offset = 1; /* Seconds starts at 1 */
776 break;
777 default:
778 break;
779 }
780
781 read_rtc:
782 /* read RTC registers */
783 tmp = ds1307->read_block_data(ds1307->client, 0, 8, buf);
784 if (tmp != 8) {
785 pr_debug("read error %d\n", tmp);
786 err = -EIO;
787 goto exit_free;
788 }
789
790 /* minimal sanity checking; some chips (like DS1340) don't
791 * specify the extra bits as must-be-zero, but there are
792 * still a few values that are clearly out-of-range.
793 */
794 tmp = ds1307->regs[DS1307_REG_SECS];
795 switch (ds1307->type) {
796 case ds_1307:
797 case m41t00:
798 /* clock halted? turn it on, so clock can tick. */
799 if (tmp & DS1307_BIT_CH) {
800 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
801 dev_warn(&client->dev, "SET TIME!\n");
802 goto read_rtc;
803 }
804 break;
805 case ds_1338:
806 /* clock halted? turn it on, so clock can tick. */
807 if (tmp & DS1307_BIT_CH)
808 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
809
810 /* oscillator fault? clear flag, and warn */
811 if (ds1307->regs[DS1307_REG_CONTROL] & DS1338_BIT_OSF) {
812 i2c_smbus_write_byte_data(client, DS1307_REG_CONTROL,
813 ds1307->regs[DS1307_REG_CONTROL]
814 & ~DS1338_BIT_OSF);
815 dev_warn(&client->dev, "SET TIME!\n");
816 goto read_rtc;
817 }
818 break;
819 case ds_1340:
820 /* clock halted? turn it on, so clock can tick. */
821 if (tmp & DS1340_BIT_nEOSC)
822 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
823
824 tmp = i2c_smbus_read_byte_data(client, DS1340_REG_FLAG);
825 if (tmp < 0) {
826 pr_debug("read error %d\n", tmp);
827 err = -EIO;
828 goto exit_free;
829 }
830
831 /* oscillator fault? clear flag, and warn */
832 if (tmp & DS1340_BIT_OSF) {
833 i2c_smbus_write_byte_data(client, DS1340_REG_FLAG, 0);
834 dev_warn(&client->dev, "SET TIME!\n");
835 }
836 break;
837 case rx_8025:
838 case ds_1337:
839 case ds_1339:
840 case ds_1388:
841 case ds_3231:
842 break;
843 }
844
845 tmp = ds1307->regs[DS1307_REG_HOUR];
846 switch (ds1307->type) {
847 case ds_1340:
848 case m41t00:
849 /* NOTE: ignores century bits; fix before deploying
850 * systems that will run through year 2100.
851 */
852 break;
853 case rx_8025:
854 break;
855 default:
856 if (!(tmp & DS1307_BIT_12HR))
857 break;
858
859 /* Be sure we're in 24 hour mode. Multi-master systems
860 * take note...
861 */
862 tmp = bcd2bin(tmp & 0x1f);
863 if (tmp == 12)
864 tmp = 0;
865 if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
866 tmp += 12;
867 i2c_smbus_write_byte_data(client,
868 DS1307_REG_HOUR,
869 bin2bcd(tmp));
870 }
871
872 ds1307->rtc = rtc_device_register(client->name, &client->dev,
873 &ds13xx_rtc_ops, THIS_MODULE);
874 if (IS_ERR(ds1307->rtc)) {
875 err = PTR_ERR(ds1307->rtc);
876 dev_err(&client->dev,
877 "unable to register the class device\n");
878 goto exit_free;
879 }
880
881 if (want_irq) {
882 err = request_irq(client->irq, ds1307_irq, 0,
883 ds1307->rtc->name, client);
884 if (err) {
885 dev_err(&client->dev,
886 "unable to request IRQ!\n");
887 goto exit_irq;
888 }
889 set_bit(HAS_ALARM, &ds1307->flags);
890 dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
891 }
892
893 if (chip->nvram56) {
894 err = sysfs_create_bin_file(&client->dev.kobj, &nvram);
895 if (err == 0) {
896 set_bit(HAS_NVRAM, &ds1307->flags);
897 dev_info(&client->dev, "56 bytes nvram\n");
898 }
899 }
900
901 return 0;
902
903 exit_irq:
904 if (ds1307->rtc)
905 rtc_device_unregister(ds1307->rtc);
906 exit_free:
907 kfree(ds1307);
908 return err;
909 }
910
911 static int __devexit ds1307_remove(struct i2c_client *client)
912 {
913 struct ds1307 *ds1307 = i2c_get_clientdata(client);
914
915 if (test_and_clear_bit(HAS_ALARM, &ds1307->flags)) {
916 free_irq(client->irq, client);
917 cancel_work_sync(&ds1307->work);
918 }
919
920 if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags))
921 sysfs_remove_bin_file(&client->dev.kobj, &nvram);
922
923 rtc_device_unregister(ds1307->rtc);
924 kfree(ds1307);
925 return 0;
926 }
927
928 static struct i2c_driver ds1307_driver = {
929 .driver = {
930 .name = "rtc-ds1307",
931 .owner = THIS_MODULE,
932 },
933 .probe = ds1307_probe,
934 .remove = __devexit_p(ds1307_remove),
935 .id_table = ds1307_id,
936 };
937
938 static int __init ds1307_init(void)
939 {
940 return i2c_add_driver(&ds1307_driver);
941 }
942 module_init(ds1307_init);
943
944 static void __exit ds1307_exit(void)
945 {
946 i2c_del_driver(&ds1307_driver);
947 }
948 module_exit(ds1307_exit);
949
950 MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
951 MODULE_LICENSE("GPL");
Support for the Chinese Samsung S3C2440 based development boards