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mm: vmscan: fix force-scanning small targets without swap
[linux-2.6.git] / drivers / rtc / rtc-ds1307.c
blobb2005b44e4f7cc0ee053ab9ee37896e7bce66a2f
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)(const struct i2c_client *client, u8 command,
110 u8 length, u8 *values);
111 s32 (*write_block_data)(const 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 { "pt7c4338", ds_1307 },
153 { "rx8025", rx_8025 },
154 { }
155 };
156 MODULE_DEVICE_TABLE(i2c, ds1307_id);
157
158 /*----------------------------------------------------------------------*/
159
160 #define BLOCK_DATA_MAX_TRIES 10
161
162 static s32 ds1307_read_block_data_once(const struct i2c_client *client,
163 u8 command, u8 length, u8 *values)
164 {
165 s32 i, data;
166
167 for (i = 0; i < length; i++) {
168 data = i2c_smbus_read_byte_data(client, command + i);
169 if (data < 0)
170 return data;
171 values[i] = data;
172 }
173 return i;
174 }
175
176 static s32 ds1307_read_block_data(const struct i2c_client *client, u8 command,
177 u8 length, u8 *values)
178 {
179 u8 oldvalues[I2C_SMBUS_BLOCK_MAX];
180 s32 ret;
181 int tries = 0;
182
183 dev_dbg(&client->dev, "ds1307_read_block_data (length=%d)\n", length);
184 ret = ds1307_read_block_data_once(client, command, length, values);
185 if (ret < 0)
186 return ret;
187 do {
188 if (++tries > BLOCK_DATA_MAX_TRIES) {
189 dev_err(&client->dev,
190 "ds1307_read_block_data failed\n");
191 return -EIO;
192 }
193 memcpy(oldvalues, values, length);
194 ret = ds1307_read_block_data_once(client, command, length,
195 values);
196 if (ret < 0)
197 return ret;
198 } while (memcmp(oldvalues, values, length));
199 return length;
200 }
201
202 static s32 ds1307_write_block_data(const struct i2c_client *client, u8 command,
203 u8 length, const u8 *values)
204 {
205 u8 currvalues[I2C_SMBUS_BLOCK_MAX];
206 int tries = 0;
207
208 dev_dbg(&client->dev, "ds1307_write_block_data (length=%d)\n", length);
209 do {
210 s32 i, ret;
211
212 if (++tries > BLOCK_DATA_MAX_TRIES) {
213 dev_err(&client->dev,
214 "ds1307_write_block_data failed\n");
215 return -EIO;
216 }
217 for (i = 0; i < length; i++) {
218 ret = i2c_smbus_write_byte_data(client, command + i,
219 values[i]);
220 if (ret < 0)
221 return ret;
222 }
223 ret = ds1307_read_block_data_once(client, command, length,
224 currvalues);
225 if (ret < 0)
226 return ret;
227 } while (memcmp(currvalues, values, length));
228 return length;
229 }
230
231 /*----------------------------------------------------------------------*/
232
233 /*
234 * The IRQ logic includes a "real" handler running in IRQ context just
235 * long enough to schedule this workqueue entry. We need a task context
236 * to talk to the RTC, since I2C I/O calls require that; and disable the
237 * IRQ until we clear its status on the chip, so that this handler can
238 * work with any type of triggering (not just falling edge).
239 *
240 * The ds1337 and ds1339 both have two alarms, but we only use the first
241 * one (with a "seconds" field). For ds1337 we expect nINTA is our alarm
242 * signal; ds1339 chips have only one alarm signal.
243 */
244 static void ds1307_work(struct work_struct *work)
245 {
246 struct ds1307 *ds1307;
247 struct i2c_client *client;
248 struct mutex *lock;
249 int stat, control;
250
251 ds1307 = container_of(work, struct ds1307, work);
252 client = ds1307->client;
253 lock = &ds1307->rtc->ops_lock;
254
255 mutex_lock(lock);
256 stat = i2c_smbus_read_byte_data(client, DS1337_REG_STATUS);
257 if (stat < 0)
258 goto out;
259
260 if (stat & DS1337_BIT_A1I) {
261 stat &= ~DS1337_BIT_A1I;
262 i2c_smbus_write_byte_data(client, DS1337_REG_STATUS, stat);
263
264 control = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
265 if (control < 0)
266 goto out;
267
268 control &= ~DS1337_BIT_A1IE;
269 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, control);
270
271 rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
272 }
273
274 out:
275 if (test_bit(HAS_ALARM, &ds1307->flags))
276 enable_irq(client->irq);
277 mutex_unlock(lock);
278 }
279
280 static irqreturn_t ds1307_irq(int irq, void *dev_id)
281 {
282 struct i2c_client *client = dev_id;
283 struct ds1307 *ds1307 = i2c_get_clientdata(client);
284
285 disable_irq_nosync(irq);
286 schedule_work(&ds1307->work);
287 return IRQ_HANDLED;
288 }
289
290 /*----------------------------------------------------------------------*/
291
292 static int ds1307_get_time(struct device *dev, struct rtc_time *t)
293 {
294 struct ds1307 *ds1307 = dev_get_drvdata(dev);
295 int tmp;
296
297 /* read the RTC date and time registers all at once */
298 tmp = ds1307->read_block_data(ds1307->client,
299 ds1307->offset, 7, ds1307->regs);
300 if (tmp != 7) {
301 dev_err(dev, "%s error %d\n", "read", tmp);
302 return -EIO;
303 }
304
305 dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
306 "read",
307 ds1307->regs[0], ds1307->regs[1],
308 ds1307->regs[2], ds1307->regs[3],
309 ds1307->regs[4], ds1307->regs[5],
310 ds1307->regs[6]);
311
312 t->tm_sec = bcd2bin(ds1307->regs[DS1307_REG_SECS] & 0x7f);
313 t->tm_min = bcd2bin(ds1307->regs[DS1307_REG_MIN] & 0x7f);
314 tmp = ds1307->regs[DS1307_REG_HOUR] & 0x3f;
315 t->tm_hour = bcd2bin(tmp);
316 t->tm_wday = bcd2bin(ds1307->regs[DS1307_REG_WDAY] & 0x07) - 1;
317 t->tm_mday = bcd2bin(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
318 tmp = ds1307->regs[DS1307_REG_MONTH] & 0x1f;
319 t->tm_mon = bcd2bin(tmp) - 1;
320
321 /* assume 20YY not 19YY, and ignore DS1337_BIT_CENTURY */
322 t->tm_year = bcd2bin(ds1307->regs[DS1307_REG_YEAR]) + 100;
323
324 dev_dbg(dev, "%s secs=%d, mins=%d, "
325 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
326 "read", t->tm_sec, t->tm_min,
327 t->tm_hour, t->tm_mday,
328 t->tm_mon, t->tm_year, t->tm_wday);
329
330 /* initial clock setting can be undefined */
331 return rtc_valid_tm(t);
332 }
333
334 static int ds1307_set_time(struct device *dev, struct rtc_time *t)
335 {
336 struct ds1307 *ds1307 = dev_get_drvdata(dev);
337 int result;
338 int tmp;
339 u8 *buf = ds1307->regs;
340
341 dev_dbg(dev, "%s secs=%d, mins=%d, "
342 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
343 "write", t->tm_sec, t->tm_min,
344 t->tm_hour, t->tm_mday,
345 t->tm_mon, t->tm_year, t->tm_wday);
346
347 buf[DS1307_REG_SECS] = bin2bcd(t->tm_sec);
348 buf[DS1307_REG_MIN] = bin2bcd(t->tm_min);
349 buf[DS1307_REG_HOUR] = bin2bcd(t->tm_hour);
350 buf[DS1307_REG_WDAY] = bin2bcd(t->tm_wday + 1);
351 buf[DS1307_REG_MDAY] = bin2bcd(t->tm_mday);
352 buf[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1);
353
354 /* assume 20YY not 19YY */
355 tmp = t->tm_year - 100;
356 buf[DS1307_REG_YEAR] = bin2bcd(tmp);
357
358 switch (ds1307->type) {
359 case ds_1337:
360 case ds_1339:
361 case ds_3231:
362 buf[DS1307_REG_MONTH] |= DS1337_BIT_CENTURY;
363 break;
364 case ds_1340:
365 buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN
366 | DS1340_BIT_CENTURY;
367 break;
368 default:
369 break;
370 }
371
372 dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
373 "write", buf[0], buf[1], buf[2], buf[3],
374 buf[4], buf[5], buf[6]);
375
376 result = ds1307->write_block_data(ds1307->client,
377 ds1307->offset, 7, buf);
378 if (result < 0) {
379 dev_err(dev, "%s error %d\n", "write", result);
380 return result;
381 }
382 return 0;
383 }
384
385 static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t)
386 {
387 struct i2c_client *client = to_i2c_client(dev);
388 struct ds1307 *ds1307 = i2c_get_clientdata(client);
389 int ret;
390
391 if (!test_bit(HAS_ALARM, &ds1307->flags))
392 return -EINVAL;
393
394 /* read all ALARM1, ALARM2, and status registers at once */
395 ret = ds1307->read_block_data(client,
396 DS1339_REG_ALARM1_SECS, 9, ds1307->regs);
397 if (ret != 9) {
398 dev_err(dev, "%s error %d\n", "alarm read", ret);
399 return -EIO;
400 }
401
402 dev_dbg(dev, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n",
403 "alarm read",
404 ds1307->regs[0], ds1307->regs[1],
405 ds1307->regs[2], ds1307->regs[3],
406 ds1307->regs[4], ds1307->regs[5],
407 ds1307->regs[6], ds1307->regs[7],
408 ds1307->regs[8]);
409
410 /* report alarm time (ALARM1); assume 24 hour and day-of-month modes,
411 * and that all four fields are checked matches
412 */
413 t->time.tm_sec = bcd2bin(ds1307->regs[0] & 0x7f);
414 t->time.tm_min = bcd2bin(ds1307->regs[1] & 0x7f);
415 t->time.tm_hour = bcd2bin(ds1307->regs[2] & 0x3f);
416 t->time.tm_mday = bcd2bin(ds1307->regs[3] & 0x3f);
417 t->time.tm_mon = -1;
418 t->time.tm_year = -1;
419 t->time.tm_wday = -1;
420 t->time.tm_yday = -1;
421 t->time.tm_isdst = -1;
422
423 /* ... and status */
424 t->enabled = !!(ds1307->regs[7] & DS1337_BIT_A1IE);
425 t->pending = !!(ds1307->regs[8] & DS1337_BIT_A1I);
426
427 dev_dbg(dev, "%s secs=%d, mins=%d, "
428 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
429 "alarm read", t->time.tm_sec, t->time.tm_min,
430 t->time.tm_hour, t->time.tm_mday,
431 t->enabled, t->pending);
432
433 return 0;
434 }
435
436 static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t)
437 {
438 struct i2c_client *client = to_i2c_client(dev);
439 struct ds1307 *ds1307 = i2c_get_clientdata(client);
440 unsigned char *buf = ds1307->regs;
441 u8 control, status;
442 int ret;
443
444 if (!test_bit(HAS_ALARM, &ds1307->flags))
445 return -EINVAL;
446
447 dev_dbg(dev, "%s secs=%d, mins=%d, "
448 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
449 "alarm set", t->time.tm_sec, t->time.tm_min,
450 t->time.tm_hour, t->time.tm_mday,
451 t->enabled, t->pending);
452
453 /* read current status of both alarms and the chip */
454 ret = ds1307->read_block_data(client,
455 DS1339_REG_ALARM1_SECS, 9, buf);
456 if (ret != 9) {
457 dev_err(dev, "%s error %d\n", "alarm write", ret);
458 return -EIO;
459 }
460 control = ds1307->regs[7];
461 status = ds1307->regs[8];
462
463 dev_dbg(dev, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n",
464 "alarm set (old status)",
465 ds1307->regs[0], ds1307->regs[1],
466 ds1307->regs[2], ds1307->regs[3],
467 ds1307->regs[4], ds1307->regs[5],
468 ds1307->regs[6], control, status);
469
470 /* set ALARM1, using 24 hour and day-of-month modes */
471 buf[0] = bin2bcd(t->time.tm_sec);
472 buf[1] = bin2bcd(t->time.tm_min);
473 buf[2] = bin2bcd(t->time.tm_hour);
474 buf[3] = bin2bcd(t->time.tm_mday);
475
476 /* set ALARM2 to non-garbage */
477 buf[4] = 0;
478 buf[5] = 0;
479 buf[6] = 0;
480
481 /* optionally enable ALARM1 */
482 buf[7] = control & ~(DS1337_BIT_A1IE | DS1337_BIT_A2IE);
483 if (t->enabled) {
484 dev_dbg(dev, "alarm IRQ armed\n");
485 buf[7] |= DS1337_BIT_A1IE; /* only ALARM1 is used */
486 }
487 buf[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I);
488
489 ret = ds1307->write_block_data(client,
490 DS1339_REG_ALARM1_SECS, 9, buf);
491 if (ret < 0) {
492 dev_err(dev, "can't set alarm time\n");
493 return ret;
494 }
495
496 return 0;
497 }
498
499 static int ds1307_alarm_irq_enable(struct device *dev, unsigned int enabled)
500 {
501 struct i2c_client *client = to_i2c_client(dev);
502 struct ds1307 *ds1307 = i2c_get_clientdata(client);
503 int ret;
504
505 if (!test_bit(HAS_ALARM, &ds1307->flags))
506 return -ENOTTY;
507
508 ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
509 if (ret < 0)
510 return ret;
511
512 if (enabled)
513 ret |= DS1337_BIT_A1IE;
514 else
515 ret &= ~DS1337_BIT_A1IE;
516
517 ret = i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, ret);
518 if (ret < 0)
519 return ret;
520
521 return 0;
522 }
523
524 static const struct rtc_class_ops ds13xx_rtc_ops = {
525 .read_time = ds1307_get_time,
526 .set_time = ds1307_set_time,
527 .read_alarm = ds1337_read_alarm,
528 .set_alarm = ds1337_set_alarm,
529 .alarm_irq_enable = ds1307_alarm_irq_enable,
530 };
531
532 /*----------------------------------------------------------------------*/
533
534 #define NVRAM_SIZE 56
535
536 static ssize_t
537 ds1307_nvram_read(struct file *filp, struct kobject *kobj,
538 struct bin_attribute *attr,
539 char *buf, loff_t off, size_t count)
540 {
541 struct i2c_client *client;
542 struct ds1307 *ds1307;
543 int result;
544
545 client = kobj_to_i2c_client(kobj);
546 ds1307 = i2c_get_clientdata(client);
547
548 if (unlikely(off >= NVRAM_SIZE))
549 return 0;
550 if ((off + count) > NVRAM_SIZE)
551 count = NVRAM_SIZE - off;
552 if (unlikely(!count))
553 return count;
554
555 result = ds1307->read_block_data(client, 8 + off, count, buf);
556 if (result < 0)
557 dev_err(&client->dev, "%s error %d\n", "nvram read", result);
558 return result;
559 }
560
561 static ssize_t
562 ds1307_nvram_write(struct file *filp, struct kobject *kobj,
563 struct bin_attribute *attr,
564 char *buf, loff_t off, size_t count)
565 {
566 struct i2c_client *client;
567 struct ds1307 *ds1307;
568 int result;
569
570 client = kobj_to_i2c_client(kobj);
571 ds1307 = i2c_get_clientdata(client);
572
573 if (unlikely(off >= NVRAM_SIZE))
574 return -EFBIG;
575 if ((off + count) > NVRAM_SIZE)
576 count = NVRAM_SIZE - off;
577 if (unlikely(!count))
578 return count;
579
580 result = ds1307->write_block_data(client, 8 + off, count, buf);
581 if (result < 0) {
582 dev_err(&client->dev, "%s error %d\n", "nvram write", result);
583 return result;
584 }
585 return count;
586 }
587
588 static struct bin_attribute nvram = {
589 .attr = {
590 .name = "nvram",
591 .mode = S_IRUGO | S_IWUSR,
592 },
593
594 .read = ds1307_nvram_read,
595 .write = ds1307_nvram_write,
596 .size = NVRAM_SIZE,
597 };
598
599 /*----------------------------------------------------------------------*/
600
601 static struct i2c_driver ds1307_driver;
602
603 static int __devinit ds1307_probe(struct i2c_client *client,
604 const struct i2c_device_id *id)
605 {
606 struct ds1307 *ds1307;
607 int err = -ENODEV;
608 int tmp;
609 const struct chip_desc *chip = &chips[id->driver_data];
610 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
611 int want_irq = false;
612 unsigned char *buf;
613 static const int bbsqi_bitpos[] = {
614 [ds_1337] = 0,
615 [ds_1339] = DS1339_BIT_BBSQI,
616 [ds_3231] = DS3231_BIT_BBSQW,
617 };
618
619 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)
620 && !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
621 return -EIO;
622
623 if (!(ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL)))
624 return -ENOMEM;
625
626 i2c_set_clientdata(client, ds1307);
627
628 ds1307->client = client;
629 ds1307->type = id->driver_data;
630 ds1307->offset = 0;
631
632 buf = ds1307->regs;
633 if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) {
634 ds1307->read_block_data = i2c_smbus_read_i2c_block_data;
635 ds1307->write_block_data = i2c_smbus_write_i2c_block_data;
636 } else {
637 ds1307->read_block_data = ds1307_read_block_data;
638 ds1307->write_block_data = ds1307_write_block_data;
639 }
640
641 switch (ds1307->type) {
642 case ds_1337:
643 case ds_1339:
644 case ds_3231:
645 /* has IRQ? */
646 if (ds1307->client->irq > 0 && chip->alarm) {
647 INIT_WORK(&ds1307->work, ds1307_work);
648 want_irq = true;
649 }
650 /* get registers that the "rtc" read below won't read... */
651 tmp = ds1307->read_block_data(ds1307->client,
652 DS1337_REG_CONTROL, 2, buf);
653 if (tmp != 2) {
654 pr_debug("read error %d\n", tmp);
655 err = -EIO;
656 goto exit_free;
657 }
658
659 /* oscillator off? turn it on, so clock can tick. */
660 if (ds1307->regs[0] & DS1337_BIT_nEOSC)
661 ds1307->regs[0] &= ~DS1337_BIT_nEOSC;
662
663 /* Using IRQ? Disable the square wave and both alarms.
664 * For some variants, be sure alarms can trigger when we're
665 * running on Vbackup (BBSQI/BBSQW)
666 */
667 if (want_irq) {
668 ds1307->regs[0] |= DS1337_BIT_INTCN
669 | bbsqi_bitpos[ds1307->type];
670 ds1307->regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
671 }
672
673 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL,
674 ds1307->regs[0]);
675
676 /* oscillator fault? clear flag, and warn */
677 if (ds1307->regs[1] & DS1337_BIT_OSF) {
678 i2c_smbus_write_byte_data(client, DS1337_REG_STATUS,
679 ds1307->regs[1] & ~DS1337_BIT_OSF);
680 dev_warn(&client->dev, "SET TIME!\n");
681 }
682 break;
683
684 case rx_8025:
685 tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
686 RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
687 if (tmp != 2) {
688 pr_debug("read error %d\n", tmp);
689 err = -EIO;
690 goto exit_free;
691 }
692
693 /* oscillator off? turn it on, so clock can tick. */
694 if (!(ds1307->regs[1] & RX8025_BIT_XST)) {
695 ds1307->regs[1] |= RX8025_BIT_XST;
696 i2c_smbus_write_byte_data(client,
697 RX8025_REG_CTRL2 << 4 | 0x08,
698 ds1307->regs[1]);
699 dev_warn(&client->dev,
700 "oscillator stop detected - SET TIME!\n");
701 }
702
703 if (ds1307->regs[1] & RX8025_BIT_PON) {
704 ds1307->regs[1] &= ~RX8025_BIT_PON;
705 i2c_smbus_write_byte_data(client,
706 RX8025_REG_CTRL2 << 4 | 0x08,
707 ds1307->regs[1]);
708 dev_warn(&client->dev, "power-on detected\n");
709 }
710
711 if (ds1307->regs[1] & RX8025_BIT_VDET) {
712 ds1307->regs[1] &= ~RX8025_BIT_VDET;
713 i2c_smbus_write_byte_data(client,
714 RX8025_REG_CTRL2 << 4 | 0x08,
715 ds1307->regs[1]);
716 dev_warn(&client->dev, "voltage drop detected\n");
717 }
718
719 /* make sure we are running in 24hour mode */
720 if (!(ds1307->regs[0] & RX8025_BIT_2412)) {
721 u8 hour;
722
723 /* switch to 24 hour mode */
724 i2c_smbus_write_byte_data(client,
725 RX8025_REG_CTRL1 << 4 | 0x08,
726 ds1307->regs[0] |
727 RX8025_BIT_2412);
728
729 tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
730 RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
731 if (tmp != 2) {
732 pr_debug("read error %d\n", tmp);
733 err = -EIO;
734 goto exit_free;
735 }
736
737 /* correct hour */
738 hour = bcd2bin(ds1307->regs[DS1307_REG_HOUR]);
739 if (hour == 12)
740 hour = 0;
741 if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
742 hour += 12;
743
744 i2c_smbus_write_byte_data(client,
745 DS1307_REG_HOUR << 4 | 0x08,
746 hour);
747 }
748 break;
749 case ds_1388:
750 ds1307->offset = 1; /* Seconds starts at 1 */
751 break;
752 default:
753 break;
754 }
755
756 read_rtc:
757 /* read RTC registers */
758 tmp = ds1307->read_block_data(ds1307->client, ds1307->offset, 8, buf);
759 if (tmp != 8) {
760 pr_debug("read error %d\n", tmp);
761 err = -EIO;
762 goto exit_free;
763 }
764
765 /* minimal sanity checking; some chips (like DS1340) don't
766 * specify the extra bits as must-be-zero, but there are
767 * still a few values that are clearly out-of-range.
768 */
769 tmp = ds1307->regs[DS1307_REG_SECS];
770 switch (ds1307->type) {
771 case ds_1307:
772 case m41t00:
773 /* clock halted? turn it on, so clock can tick. */
774 if (tmp & DS1307_BIT_CH) {
775 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
776 dev_warn(&client->dev, "SET TIME!\n");
777 goto read_rtc;
778 }
779 break;
780 case ds_1338:
781 /* clock halted? turn it on, so clock can tick. */
782 if (tmp & DS1307_BIT_CH)
783 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
784
785 /* oscillator fault? clear flag, and warn */
786 if (ds1307->regs[DS1307_REG_CONTROL] & DS1338_BIT_OSF) {
787 i2c_smbus_write_byte_data(client, DS1307_REG_CONTROL,
788 ds1307->regs[DS1307_REG_CONTROL]
789 & ~DS1338_BIT_OSF);
790 dev_warn(&client->dev, "SET TIME!\n");
791 goto read_rtc;
792 }
793 break;
794 case ds_1340:
795 /* clock halted? turn it on, so clock can tick. */
796 if (tmp & DS1340_BIT_nEOSC)
797 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
798
799 tmp = i2c_smbus_read_byte_data(client, DS1340_REG_FLAG);
800 if (tmp < 0) {
801 pr_debug("read error %d\n", tmp);
802 err = -EIO;
803 goto exit_free;
804 }
805
806 /* oscillator fault? clear flag, and warn */
807 if (tmp & DS1340_BIT_OSF) {
808 i2c_smbus_write_byte_data(client, DS1340_REG_FLAG, 0);
809 dev_warn(&client->dev, "SET TIME!\n");
810 }
811 break;
812 case rx_8025:
813 case ds_1337:
814 case ds_1339:
815 case ds_1388:
816 case ds_3231:
817 break;
818 }
819
820 tmp = ds1307->regs[DS1307_REG_HOUR];
821 switch (ds1307->type) {
822 case ds_1340:
823 case m41t00:
824 /* NOTE: ignores century bits; fix before deploying
825 * systems that will run through year 2100.
826 */
827 break;
828 case rx_8025:
829 break;
830 default:
831 if (!(tmp & DS1307_BIT_12HR))
832 break;
833
834 /* Be sure we're in 24 hour mode. Multi-master systems
835 * take note...
836 */
837 tmp = bcd2bin(tmp & 0x1f);
838 if (tmp == 12)
839 tmp = 0;
840 if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
841 tmp += 12;
842 i2c_smbus_write_byte_data(client,
843 ds1307->offset + DS1307_REG_HOUR,
844 bin2bcd(tmp));
845 }
846
847 ds1307->rtc = rtc_device_register(client->name, &client->dev,
848 &ds13xx_rtc_ops, THIS_MODULE);
849 if (IS_ERR(ds1307->rtc)) {
850 err = PTR_ERR(ds1307->rtc);
851 dev_err(&client->dev,
852 "unable to register the class device\n");
853 goto exit_free;
854 }
855
856 if (want_irq) {
857 err = request_irq(client->irq, ds1307_irq, IRQF_SHARED,
858 ds1307->rtc->name, client);
859 if (err) {
860 dev_err(&client->dev,
861 "unable to request IRQ!\n");
862 goto exit_irq;
863 }
864
865 device_set_wakeup_capable(&client->dev, 1);
866 set_bit(HAS_ALARM, &ds1307->flags);
867 dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
868 }
869
870 if (chip->nvram56) {
871 err = sysfs_create_bin_file(&client->dev.kobj, &nvram);
872 if (err == 0) {
873 set_bit(HAS_NVRAM, &ds1307->flags);
874 dev_info(&client->dev, "56 bytes nvram\n");
875 }
876 }
877
878 return 0;
879
880 exit_irq:
881 rtc_device_unregister(ds1307->rtc);
882 exit_free:
883 kfree(ds1307);
884 return err;
885 }
886
887 static int __devexit ds1307_remove(struct i2c_client *client)
888 {
889 struct ds1307 *ds1307 = i2c_get_clientdata(client);
890
891 if (test_and_clear_bit(HAS_ALARM, &ds1307->flags)) {
892 free_irq(client->irq, client);
893 cancel_work_sync(&ds1307->work);
894 }
895
896 if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags))
897 sysfs_remove_bin_file(&client->dev.kobj, &nvram);
898
899 rtc_device_unregister(ds1307->rtc);
900 kfree(ds1307);
901 return 0;
902 }
903
904 static struct i2c_driver ds1307_driver = {
905 .driver = {
906 .name = "rtc-ds1307",
907 .owner = THIS_MODULE,
908 },
909 .probe = ds1307_probe,
910 .remove = __devexit_p(ds1307_remove),
911 .id_table = ds1307_id,
912 };
913
914 static int __init ds1307_init(void)
915 {
916 return i2c_add_driver(&ds1307_driver);
917 }
918 module_init(ds1307_init);
919
920 static void __exit ds1307_exit(void)
921 {
922 i2c_del_driver(&ds1307_driver);
923 }
924 module_exit(ds1307_exit);
925
926 MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
927 MODULE_LICENSE("GPL");
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