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rtc: ds1307: refactor chip_desc table
[deliverable/linux.git] / drivers / rtc / rtc-ds1307.c
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 mcp7941x,
38 rx_8025,
39 last_ds_type /* always last */
40 // rs5c372 too? different address...
41 };
42
43
44 /* RTC registers don't differ much, except for the century flag */
45 #define DS1307_REG_SECS 0x00 /* 00-59 */
46 # define DS1307_BIT_CH 0x80
47 # define DS1340_BIT_nEOSC 0x80
48 # define MCP7941X_BIT_ST 0x80
49 #define DS1307_REG_MIN 0x01 /* 00-59 */
50 #define DS1307_REG_HOUR 0x02 /* 00-23, or 1-12{am,pm} */
51 # define DS1307_BIT_12HR 0x40 /* in REG_HOUR */
52 # define DS1307_BIT_PM 0x20 /* in REG_HOUR */
53 # define DS1340_BIT_CENTURY_EN 0x80 /* in REG_HOUR */
54 # define DS1340_BIT_CENTURY 0x40 /* in REG_HOUR */
55 #define DS1307_REG_WDAY 0x03 /* 01-07 */
56 # define MCP7941X_BIT_VBATEN 0x08
57 #define DS1307_REG_MDAY 0x04 /* 01-31 */
58 #define DS1307_REG_MONTH 0x05 /* 01-12 */
59 # define DS1337_BIT_CENTURY 0x80 /* in REG_MONTH */
60 #define DS1307_REG_YEAR 0x06 /* 00-99 */
61
62 /* Other registers (control, status, alarms, trickle charge, NVRAM, etc)
63 * start at 7, and they differ a LOT. Only control and status matter for
64 * basic RTC date and time functionality; be careful using them.
65 */
66 #define DS1307_REG_CONTROL 0x07 /* or ds1338 */
67 # define DS1307_BIT_OUT 0x80
68 # define DS1338_BIT_OSF 0x20
69 # define DS1307_BIT_SQWE 0x10
70 # define DS1307_BIT_RS1 0x02
71 # define DS1307_BIT_RS0 0x01
72 #define DS1337_REG_CONTROL 0x0e
73 # define DS1337_BIT_nEOSC 0x80
74 # define DS1339_BIT_BBSQI 0x20
75 # define DS3231_BIT_BBSQW 0x40 /* same as BBSQI */
76 # define DS1337_BIT_RS2 0x10
77 # define DS1337_BIT_RS1 0x08
78 # define DS1337_BIT_INTCN 0x04
79 # define DS1337_BIT_A2IE 0x02
80 # define DS1337_BIT_A1IE 0x01
81 #define DS1340_REG_CONTROL 0x07
82 # define DS1340_BIT_OUT 0x80
83 # define DS1340_BIT_FT 0x40
84 # define DS1340_BIT_CALIB_SIGN 0x20
85 # define DS1340_M_CALIBRATION 0x1f
86 #define DS1340_REG_FLAG 0x09
87 # define DS1340_BIT_OSF 0x80
88 #define DS1337_REG_STATUS 0x0f
89 # define DS1337_BIT_OSF 0x80
90 # define DS1337_BIT_A2I 0x02
91 # define DS1337_BIT_A1I 0x01
92 #define DS1339_REG_ALARM1_SECS 0x07
93 #define DS1339_REG_TRICKLE 0x10
94
95 #define RX8025_REG_CTRL1 0x0e
96 # define RX8025_BIT_2412 0x20
97 #define RX8025_REG_CTRL2 0x0f
98 # define RX8025_BIT_PON 0x10
99 # define RX8025_BIT_VDET 0x40
100 # define RX8025_BIT_XST 0x20
101
102
103 struct ds1307 {
104 u8 offset; /* register's offset */
105 u8 regs[11];
106 enum ds_type type;
107 unsigned long flags;
108 #define HAS_NVRAM 0 /* bit 0 == sysfs file active */
109 #define HAS_ALARM 1 /* bit 1 == irq claimed */
110 struct i2c_client *client;
111 struct rtc_device *rtc;
112 struct work_struct work;
113 s32 (*read_block_data)(const struct i2c_client *client, u8 command,
114 u8 length, u8 *values);
115 s32 (*write_block_data)(const struct i2c_client *client, u8 command,
116 u8 length, const u8 *values);
117 };
118
119 struct chip_desc {
120 unsigned nvram56:1;
121 unsigned alarm:1;
122 };
123
124 static const struct chip_desc chips[last_ds_type] = {
125 [ds_1307] = {
126 .nvram56 = 1,
127 },
128 [ds_1337] = {
129 .alarm = 1,
130 },
131 [ds_1338] = {
132 .nvram56 = 1,
133 },
134 [ds_1339] = {
135 .alarm = 1,
136 },
137 [ds_3231] = {
138 .alarm = 1,
139 },
140 };
141
142 static const struct i2c_device_id ds1307_id[] = {
143 { "ds1307", ds_1307 },
144 { "ds1337", ds_1337 },
145 { "ds1338", ds_1338 },
146 { "ds1339", ds_1339 },
147 { "ds1388", ds_1388 },
148 { "ds1340", ds_1340 },
149 { "ds3231", ds_3231 },
150 { "m41t00", m41t00 },
151 { "mcp7941x", mcp7941x },
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 case mcp7941x:
369 buf[DS1307_REG_SECS] |= MCP7941X_BIT_ST;
370 buf[DS1307_REG_WDAY] |= MCP7941X_BIT_VBATEN;
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_alarm_irq_enable(struct device *dev, unsigned int enabled)
504 {
505 struct i2c_client *client = to_i2c_client(dev);
506 struct ds1307 *ds1307 = i2c_get_clientdata(client);
507 int ret;
508
509 if (!test_bit(HAS_ALARM, &ds1307->flags))
510 return -ENOTTY;
511
512 ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
513 if (ret < 0)
514 return ret;
515
516 if (enabled)
517 ret |= DS1337_BIT_A1IE;
518 else
519 ret &= ~DS1337_BIT_A1IE;
520
521 ret = i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, ret);
522 if (ret < 0)
523 return ret;
524
525 return 0;
526 }
527
528 static const struct rtc_class_ops ds13xx_rtc_ops = {
529 .read_time = ds1307_get_time,
530 .set_time = ds1307_set_time,
531 .read_alarm = ds1337_read_alarm,
532 .set_alarm = ds1337_set_alarm,
533 .alarm_irq_enable = ds1307_alarm_irq_enable,
534 };
535
536 /*----------------------------------------------------------------------*/
537
538 #define NVRAM_SIZE 56
539
540 static ssize_t
541 ds1307_nvram_read(struct file *filp, struct kobject *kobj,
542 struct bin_attribute *attr,
543 char *buf, loff_t off, size_t count)
544 {
545 struct i2c_client *client;
546 struct ds1307 *ds1307;
547 int result;
548
549 client = kobj_to_i2c_client(kobj);
550 ds1307 = i2c_get_clientdata(client);
551
552 if (unlikely(off >= NVRAM_SIZE))
553 return 0;
554 if ((off + count) > NVRAM_SIZE)
555 count = NVRAM_SIZE - off;
556 if (unlikely(!count))
557 return count;
558
559 result = ds1307->read_block_data(client, 8 + off, count, buf);
560 if (result < 0)
561 dev_err(&client->dev, "%s error %d\n", "nvram read", result);
562 return result;
563 }
564
565 static ssize_t
566 ds1307_nvram_write(struct file *filp, struct kobject *kobj,
567 struct bin_attribute *attr,
568 char *buf, loff_t off, size_t count)
569 {
570 struct i2c_client *client;
571 struct ds1307 *ds1307;
572 int result;
573
574 client = kobj_to_i2c_client(kobj);
575 ds1307 = i2c_get_clientdata(client);
576
577 if (unlikely(off >= NVRAM_SIZE))
578 return -EFBIG;
579 if ((off + count) > NVRAM_SIZE)
580 count = NVRAM_SIZE - off;
581 if (unlikely(!count))
582 return count;
583
584 result = ds1307->write_block_data(client, 8 + off, count, buf);
585 if (result < 0) {
586 dev_err(&client->dev, "%s error %d\n", "nvram write", result);
587 return result;
588 }
589 return count;
590 }
591
592 static struct bin_attribute nvram = {
593 .attr = {
594 .name = "nvram",
595 .mode = S_IRUGO | S_IWUSR,
596 },
597
598 .read = ds1307_nvram_read,
599 .write = ds1307_nvram_write,
600 .size = NVRAM_SIZE,
601 };
602
603 /*----------------------------------------------------------------------*/
604
605 static struct i2c_driver ds1307_driver;
606
607 static int __devinit ds1307_probe(struct i2c_client *client,
608 const struct i2c_device_id *id)
609 {
610 struct ds1307 *ds1307;
611 int err = -ENODEV;
612 int tmp;
613 const struct chip_desc *chip = &chips[id->driver_data];
614 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
615 int want_irq = false;
616 unsigned char *buf;
617 static const int bbsqi_bitpos[] = {
618 [ds_1337] = 0,
619 [ds_1339] = DS1339_BIT_BBSQI,
620 [ds_3231] = DS3231_BIT_BBSQW,
621 };
622
623 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)
624 && !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
625 return -EIO;
626
627 if (!(ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL)))
628 return -ENOMEM;
629
630 i2c_set_clientdata(client, ds1307);
631
632 ds1307->client = client;
633 ds1307->type = id->driver_data;
634 ds1307->offset = 0;
635
636 buf = ds1307->regs;
637 if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) {
638 ds1307->read_block_data = i2c_smbus_read_i2c_block_data;
639 ds1307->write_block_data = i2c_smbus_write_i2c_block_data;
640 } else {
641 ds1307->read_block_data = ds1307_read_block_data;
642 ds1307->write_block_data = ds1307_write_block_data;
643 }
644
645 switch (ds1307->type) {
646 case ds_1337:
647 case ds_1339:
648 case ds_3231:
649 /* has IRQ? */
650 if (ds1307->client->irq > 0 && chip->alarm) {
651 INIT_WORK(&ds1307->work, ds1307_work);
652 want_irq = true;
653 }
654 /* get registers that the "rtc" read below won't read... */
655 tmp = ds1307->read_block_data(ds1307->client,
656 DS1337_REG_CONTROL, 2, buf);
657 if (tmp != 2) {
658 pr_debug("read error %d\n", tmp);
659 err = -EIO;
660 goto exit_free;
661 }
662
663 /* oscillator off? turn it on, so clock can tick. */
664 if (ds1307->regs[0] & DS1337_BIT_nEOSC)
665 ds1307->regs[0] &= ~DS1337_BIT_nEOSC;
666
667 /* Using IRQ? Disable the square wave and both alarms.
668 * For some variants, be sure alarms can trigger when we're
669 * running on Vbackup (BBSQI/BBSQW)
670 */
671 if (want_irq) {
672 ds1307->regs[0] |= DS1337_BIT_INTCN
673 | bbsqi_bitpos[ds1307->type];
674 ds1307->regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
675 }
676
677 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL,
678 ds1307->regs[0]);
679
680 /* oscillator fault? clear flag, and warn */
681 if (ds1307->regs[1] & DS1337_BIT_OSF) {
682 i2c_smbus_write_byte_data(client, DS1337_REG_STATUS,
683 ds1307->regs[1] & ~DS1337_BIT_OSF);
684 dev_warn(&client->dev, "SET TIME!\n");
685 }
686 break;
687
688 case rx_8025:
689 tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
690 RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
691 if (tmp != 2) {
692 pr_debug("read error %d\n", tmp);
693 err = -EIO;
694 goto exit_free;
695 }
696
697 /* oscillator off? turn it on, so clock can tick. */
698 if (!(ds1307->regs[1] & RX8025_BIT_XST)) {
699 ds1307->regs[1] |= RX8025_BIT_XST;
700 i2c_smbus_write_byte_data(client,
701 RX8025_REG_CTRL2 << 4 | 0x08,
702 ds1307->regs[1]);
703 dev_warn(&client->dev,
704 "oscillator stop detected - SET TIME!\n");
705 }
706
707 if (ds1307->regs[1] & RX8025_BIT_PON) {
708 ds1307->regs[1] &= ~RX8025_BIT_PON;
709 i2c_smbus_write_byte_data(client,
710 RX8025_REG_CTRL2 << 4 | 0x08,
711 ds1307->regs[1]);
712 dev_warn(&client->dev, "power-on detected\n");
713 }
714
715 if (ds1307->regs[1] & RX8025_BIT_VDET) {
716 ds1307->regs[1] &= ~RX8025_BIT_VDET;
717 i2c_smbus_write_byte_data(client,
718 RX8025_REG_CTRL2 << 4 | 0x08,
719 ds1307->regs[1]);
720 dev_warn(&client->dev, "voltage drop detected\n");
721 }
722
723 /* make sure we are running in 24hour mode */
724 if (!(ds1307->regs[0] & RX8025_BIT_2412)) {
725 u8 hour;
726
727 /* switch to 24 hour mode */
728 i2c_smbus_write_byte_data(client,
729 RX8025_REG_CTRL1 << 4 | 0x08,
730 ds1307->regs[0] |
731 RX8025_BIT_2412);
732
733 tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
734 RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
735 if (tmp != 2) {
736 pr_debug("read error %d\n", tmp);
737 err = -EIO;
738 goto exit_free;
739 }
740
741 /* correct hour */
742 hour = bcd2bin(ds1307->regs[DS1307_REG_HOUR]);
743 if (hour == 12)
744 hour = 0;
745 if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
746 hour += 12;
747
748 i2c_smbus_write_byte_data(client,
749 DS1307_REG_HOUR << 4 | 0x08,
750 hour);
751 }
752 break;
753 case ds_1388:
754 ds1307->offset = 1; /* Seconds starts at 1 */
755 break;
756 default:
757 break;
758 }
759
760 read_rtc:
761 /* read RTC registers */
762 tmp = ds1307->read_block_data(ds1307->client, ds1307->offset, 8, buf);
763 if (tmp != 8) {
764 pr_debug("read error %d\n", tmp);
765 err = -EIO;
766 goto exit_free;
767 }
768
769 /* minimal sanity checking; some chips (like DS1340) don't
770 * specify the extra bits as must-be-zero, but there are
771 * still a few values that are clearly out-of-range.
772 */
773 tmp = ds1307->regs[DS1307_REG_SECS];
774 switch (ds1307->type) {
775 case ds_1307:
776 case m41t00:
777 /* clock halted? turn it on, so clock can tick. */
778 if (tmp & DS1307_BIT_CH) {
779 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
780 dev_warn(&client->dev, "SET TIME!\n");
781 goto read_rtc;
782 }
783 break;
784 case ds_1338:
785 /* clock halted? turn it on, so clock can tick. */
786 if (tmp & DS1307_BIT_CH)
787 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
788
789 /* oscillator fault? clear flag, and warn */
790 if (ds1307->regs[DS1307_REG_CONTROL] & DS1338_BIT_OSF) {
791 i2c_smbus_write_byte_data(client, DS1307_REG_CONTROL,
792 ds1307->regs[DS1307_REG_CONTROL]
793 & ~DS1338_BIT_OSF);
794 dev_warn(&client->dev, "SET TIME!\n");
795 goto read_rtc;
796 }
797 break;
798 case ds_1340:
799 /* clock halted? turn it on, so clock can tick. */
800 if (tmp & DS1340_BIT_nEOSC)
801 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
802
803 tmp = i2c_smbus_read_byte_data(client, DS1340_REG_FLAG);
804 if (tmp < 0) {
805 pr_debug("read error %d\n", tmp);
806 err = -EIO;
807 goto exit_free;
808 }
809
810 /* oscillator fault? clear flag, and warn */
811 if (tmp & DS1340_BIT_OSF) {
812 i2c_smbus_write_byte_data(client, DS1340_REG_FLAG, 0);
813 dev_warn(&client->dev, "SET TIME!\n");
814 }
815 break;
816 case mcp7941x:
817 /* make sure that the backup battery is enabled */
818 if (!(ds1307->regs[DS1307_REG_WDAY] & MCP7941X_BIT_VBATEN)) {
819 i2c_smbus_write_byte_data(client, DS1307_REG_WDAY,
820 ds1307->regs[DS1307_REG_WDAY]
821 | MCP7941X_BIT_VBATEN);
822 }
823
824 /* clock halted? turn it on, so clock can tick. */
825 if (!(tmp & MCP7941X_BIT_ST)) {
826 i2c_smbus_write_byte_data(client, DS1307_REG_SECS,
827 MCP7941X_BIT_ST);
828 dev_warn(&client->dev, "SET TIME!\n");
829 goto read_rtc;
830 }
831
832 break;
833 default:
834 break;
835 }
836
837 tmp = ds1307->regs[DS1307_REG_HOUR];
838 switch (ds1307->type) {
839 case ds_1340:
840 case m41t00:
841 /* NOTE: ignores century bits; fix before deploying
842 * systems that will run through year 2100.
843 */
844 break;
845 case rx_8025:
846 break;
847 default:
848 if (!(tmp & DS1307_BIT_12HR))
849 break;
850
851 /* Be sure we're in 24 hour mode. Multi-master systems
852 * take note...
853 */
854 tmp = bcd2bin(tmp & 0x1f);
855 if (tmp == 12)
856 tmp = 0;
857 if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
858 tmp += 12;
859 i2c_smbus_write_byte_data(client,
860 ds1307->offset + DS1307_REG_HOUR,
861 bin2bcd(tmp));
862 }
863
864 ds1307->rtc = rtc_device_register(client->name, &client->dev,
865 &ds13xx_rtc_ops, THIS_MODULE);
866 if (IS_ERR(ds1307->rtc)) {
867 err = PTR_ERR(ds1307->rtc);
868 dev_err(&client->dev,
869 "unable to register the class device\n");
870 goto exit_free;
871 }
872
873 if (want_irq) {
874 err = request_irq(client->irq, ds1307_irq, IRQF_SHARED,
875 ds1307->rtc->name, client);
876 if (err) {
877 dev_err(&client->dev,
878 "unable to request IRQ!\n");
879 goto exit_irq;
880 }
881
882 device_set_wakeup_capable(&client->dev, 1);
883 set_bit(HAS_ALARM, &ds1307->flags);
884 dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
885 }
886
887 if (chip->nvram56) {
888 err = sysfs_create_bin_file(&client->dev.kobj, &nvram);
889 if (err == 0) {
890 set_bit(HAS_NVRAM, &ds1307->flags);
891 dev_info(&client->dev, "56 bytes nvram\n");
892 }
893 }
894
895 return 0;
896
897 exit_irq:
898 rtc_device_unregister(ds1307->rtc);
899 exit_free:
900 kfree(ds1307);
901 return err;
902 }
903
904 static int __devexit ds1307_remove(struct i2c_client *client)
905 {
906 struct ds1307 *ds1307 = i2c_get_clientdata(client);
907
908 if (test_and_clear_bit(HAS_ALARM, &ds1307->flags)) {
909 free_irq(client->irq, client);
910 cancel_work_sync(&ds1307->work);
911 }
912
913 if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags))
914 sysfs_remove_bin_file(&client->dev.kobj, &nvram);
915
916 rtc_device_unregister(ds1307->rtc);
917 kfree(ds1307);
918 return 0;
919 }
920
921 static struct i2c_driver ds1307_driver = {
922 .driver = {
923 .name = "rtc-ds1307",
924 .owner = THIS_MODULE,
925 },
926 .probe = ds1307_probe,
927 .remove = __devexit_p(ds1307_remove),
928 .id_table = ds1307_id,
929 };
930
931 module_i2c_driver(ds1307_driver);
932
933 MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
934 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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