rtc ds1307: ds_1340 change init
[linux-2.6.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  *
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  * This is currently a simple no-alarms driver.  If your board has the
28  * alarm irq wired up on a ds1337 or ds1339, and you want to use that,
29  * then look at the rtc-rs5c372 driver for code to steal...
30  */
31 enum ds_type {
32         ds_1307,
33         ds_1337,
34         ds_1338,
35         ds_1339,
36         ds_1340,
37         m41t00,
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 DS1337_BIT_RS2           0x10
71 #       define DS1337_BIT_RS1           0x08
72 #       define DS1337_BIT_INTCN         0x04
73 #       define DS1337_BIT_A2IE          0x02
74 #       define DS1337_BIT_A1IE          0x01
75 #define DS1340_REG_CONTROL      0x07
76 #       define DS1340_BIT_OUT           0x80
77 #       define DS1340_BIT_FT            0x40
78 #       define DS1340_BIT_CALIB_SIGN    0x20
79 #       define DS1340_M_CALIBRATION     0x1f
80 #define DS1340_REG_FLAG         0x09
81 #       define DS1340_BIT_OSF           0x80
82 #define DS1337_REG_STATUS       0x0f
83 #       define DS1337_BIT_OSF           0x80
84 #       define DS1337_BIT_A2I           0x02
85 #       define DS1337_BIT_A1I           0x01
86 #define DS1339_REG_TRICKLE      0x10
87
88
89
90 struct ds1307 {
91         u8                      reg_addr;
92         bool                    has_nvram;
93         u8                      regs[8];
94         enum ds_type            type;
95         struct i2c_msg          msg[2];
96         struct i2c_client       *client;
97         struct i2c_client       dev;
98         struct rtc_device       *rtc;
99 };
100
101 struct chip_desc {
102         char                    name[9];
103         unsigned                nvram56:1;
104         unsigned                alarm:1;
105         enum ds_type            type;
106 };
107
108 static const struct chip_desc chips[] = { {
109         .name           = "ds1307",
110         .type           = ds_1307,
111         .nvram56        = 1,
112 }, {
113         .name           = "ds1337",
114         .type           = ds_1337,
115         .alarm          = 1,
116 }, {
117         .name           = "ds1338",
118         .type           = ds_1338,
119         .nvram56        = 1,
120 }, {
121         .name           = "ds1339",
122         .type           = ds_1339,
123         .alarm          = 1,
124 }, {
125         .name           = "ds1340",
126         .type           = ds_1340,
127 }, {
128         .name           = "m41t00",
129         .type           = m41t00,
130 }, };
131
132 static inline const struct chip_desc *find_chip(const char *s)
133 {
134         unsigned i;
135
136         for (i = 0; i < ARRAY_SIZE(chips); i++)
137                 if (strnicmp(s, chips[i].name, sizeof chips[i].name) == 0)
138                         return &chips[i];
139         return NULL;
140 }
141
142 static int ds1307_get_time(struct device *dev, struct rtc_time *t)
143 {
144         struct ds1307   *ds1307 = dev_get_drvdata(dev);
145         int             tmp;
146
147         /* read the RTC date and time registers all at once */
148         ds1307->msg[1].flags = I2C_M_RD;
149         ds1307->msg[1].len = 7;
150
151         tmp = i2c_transfer(to_i2c_adapter(ds1307->client->dev.parent),
152                         ds1307->msg, 2);
153         if (tmp != 2) {
154                 dev_err(dev, "%s error %d\n", "read", tmp);
155                 return -EIO;
156         }
157
158         dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
159                         "read",
160                         ds1307->regs[0], ds1307->regs[1],
161                         ds1307->regs[2], ds1307->regs[3],
162                         ds1307->regs[4], ds1307->regs[5],
163                         ds1307->regs[6]);
164
165         t->tm_sec = BCD2BIN(ds1307->regs[DS1307_REG_SECS] & 0x7f);
166         t->tm_min = BCD2BIN(ds1307->regs[DS1307_REG_MIN] & 0x7f);
167         tmp = ds1307->regs[DS1307_REG_HOUR] & 0x3f;
168         t->tm_hour = BCD2BIN(tmp);
169         t->tm_wday = BCD2BIN(ds1307->regs[DS1307_REG_WDAY] & 0x07) - 1;
170         t->tm_mday = BCD2BIN(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
171         tmp = ds1307->regs[DS1307_REG_MONTH] & 0x1f;
172         t->tm_mon = BCD2BIN(tmp) - 1;
173
174         /* assume 20YY not 19YY, and ignore DS1337_BIT_CENTURY */
175         t->tm_year = BCD2BIN(ds1307->regs[DS1307_REG_YEAR]) + 100;
176
177         dev_dbg(dev, "%s secs=%d, mins=%d, "
178                 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
179                 "read", t->tm_sec, t->tm_min,
180                 t->tm_hour, t->tm_mday,
181                 t->tm_mon, t->tm_year, t->tm_wday);
182
183         /* initial clock setting can be undefined */
184         return rtc_valid_tm(t);
185 }
186
187 static int ds1307_set_time(struct device *dev, struct rtc_time *t)
188 {
189         struct ds1307   *ds1307 = dev_get_drvdata(dev);
190         int             result;
191         int             tmp;
192         u8              *buf = ds1307->regs;
193
194         dev_dbg(dev, "%s secs=%d, mins=%d, "
195                 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
196                 "write", t->tm_sec, t->tm_min,
197                 t->tm_hour, t->tm_mday,
198                 t->tm_mon, t->tm_year, t->tm_wday);
199
200         *buf++ = 0;             /* first register addr */
201         buf[DS1307_REG_SECS] = BIN2BCD(t->tm_sec);
202         buf[DS1307_REG_MIN] = BIN2BCD(t->tm_min);
203         buf[DS1307_REG_HOUR] = BIN2BCD(t->tm_hour);
204         buf[DS1307_REG_WDAY] = BIN2BCD(t->tm_wday + 1);
205         buf[DS1307_REG_MDAY] = BIN2BCD(t->tm_mday);
206         buf[DS1307_REG_MONTH] = BIN2BCD(t->tm_mon + 1);
207
208         /* assume 20YY not 19YY */
209         tmp = t->tm_year - 100;
210         buf[DS1307_REG_YEAR] = BIN2BCD(tmp);
211
212         switch (ds1307->type) {
213         case ds_1337:
214         case ds_1339:
215                 buf[DS1307_REG_MONTH] |= DS1337_BIT_CENTURY;
216                 break;
217         case ds_1340:
218                 buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN
219                                 | DS1340_BIT_CENTURY;
220                 break;
221         default:
222                 break;
223         }
224
225         ds1307->msg[1].flags = 0;
226         ds1307->msg[1].len = 8;
227
228         dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
229                 "write", buf[0], buf[1], buf[2], buf[3],
230                 buf[4], buf[5], buf[6]);
231
232         result = i2c_transfer(to_i2c_adapter(ds1307->client->dev.parent),
233                         &ds1307->msg[1], 1);
234         if (result != 1) {
235                 dev_err(dev, "%s error %d\n", "write", tmp);
236                 return -EIO;
237         }
238         return 0;
239 }
240
241 static const struct rtc_class_ops ds13xx_rtc_ops = {
242         .read_time      = ds1307_get_time,
243         .set_time       = ds1307_set_time,
244 };
245
246 /*----------------------------------------------------------------------*/
247
248 #define NVRAM_SIZE      56
249
250 static ssize_t
251 ds1307_nvram_read(struct kobject *kobj, struct bin_attribute *attr,
252                 char *buf, loff_t off, size_t count)
253 {
254         struct i2c_client       *client;
255         struct ds1307           *ds1307;
256         struct i2c_msg          msg[2];
257         int                     result;
258
259         client = kobj_to_i2c_client(kobj);
260         ds1307 = i2c_get_clientdata(client);
261
262         if (unlikely(off >= NVRAM_SIZE))
263                 return 0;
264         if ((off + count) > NVRAM_SIZE)
265                 count = NVRAM_SIZE - off;
266         if (unlikely(!count))
267                 return count;
268
269         msg[0].addr = client->addr;
270         msg[0].flags = 0;
271         msg[0].len = 1;
272         msg[0].buf = buf;
273
274         buf[0] = 8 + off;
275
276         msg[1].addr = client->addr;
277         msg[1].flags = I2C_M_RD;
278         msg[1].len = count;
279         msg[1].buf = buf;
280
281         result = i2c_transfer(to_i2c_adapter(client->dev.parent), msg, 2);
282         if (result != 2) {
283                 dev_err(&client->dev, "%s error %d\n", "nvram read", result);
284                 return -EIO;
285         }
286         return count;
287 }
288
289 static ssize_t
290 ds1307_nvram_write(struct kobject *kobj, struct bin_attribute *attr,
291                 char *buf, loff_t off, size_t count)
292 {
293         struct i2c_client       *client;
294         u8                      buffer[NVRAM_SIZE + 1];
295         int                     ret;
296
297         client = kobj_to_i2c_client(kobj);
298
299         if (unlikely(off >= NVRAM_SIZE))
300                 return -EFBIG;
301         if ((off + count) > NVRAM_SIZE)
302                 count = NVRAM_SIZE - off;
303         if (unlikely(!count))
304                 return count;
305
306         buffer[0] = 8 + off;
307         memcpy(buffer + 1, buf, count);
308
309         ret = i2c_master_send(client, buffer, count + 1);
310         return (ret < 0) ? ret : (ret - 1);
311 }
312
313 static struct bin_attribute nvram = {
314         .attr = {
315                 .name   = "nvram",
316                 .mode   = S_IRUGO | S_IWUSR,
317                 .owner  = THIS_MODULE,
318         },
319
320         .read   = ds1307_nvram_read,
321         .write  = ds1307_nvram_write,
322         .size   = NVRAM_SIZE,
323 };
324
325 /*----------------------------------------------------------------------*/
326
327 static struct i2c_driver ds1307_driver;
328
329 static int __devinit ds1307_probe(struct i2c_client *client)
330 {
331         struct ds1307           *ds1307;
332         int                     err = -ENODEV;
333         int                     tmp;
334         const struct chip_desc  *chip;
335         struct i2c_adapter      *adapter = to_i2c_adapter(client->dev.parent);
336
337         chip = find_chip(client->name);
338         if (!chip) {
339                 dev_err(&client->dev, "unknown chip type '%s'\n",
340                                 client->name);
341                 return -ENODEV;
342         }
343
344         if (!i2c_check_functionality(adapter,
345                         I2C_FUNC_I2C | I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
346                 return -EIO;
347
348         if (!(ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL)))
349                 return -ENOMEM;
350
351         ds1307->client = client;
352         i2c_set_clientdata(client, ds1307);
353
354         ds1307->msg[0].addr = client->addr;
355         ds1307->msg[0].flags = 0;
356         ds1307->msg[0].len = 1;
357         ds1307->msg[0].buf = &ds1307->reg_addr;
358
359         ds1307->msg[1].addr = client->addr;
360         ds1307->msg[1].flags = I2C_M_RD;
361         ds1307->msg[1].len = sizeof(ds1307->regs);
362         ds1307->msg[1].buf = ds1307->regs;
363
364         ds1307->type = chip->type;
365
366         switch (ds1307->type) {
367         case ds_1337:
368         case ds_1339:
369                 ds1307->reg_addr = DS1337_REG_CONTROL;
370                 ds1307->msg[1].len = 2;
371
372                 /* get registers that the "rtc" read below won't read... */
373                 tmp = i2c_transfer(adapter, ds1307->msg, 2);
374                 if (tmp != 2) {
375                         pr_debug("read error %d\n", tmp);
376                         err = -EIO;
377                         goto exit_free;
378                 }
379
380                 ds1307->reg_addr = 0;
381                 ds1307->msg[1].len = sizeof(ds1307->regs);
382
383                 /* oscillator off?  turn it on, so clock can tick. */
384                 if (ds1307->regs[0] & DS1337_BIT_nEOSC)
385                         i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL,
386                                 ds1307->regs[0] & ~DS1337_BIT_nEOSC);
387
388                 /* oscillator fault?  clear flag, and warn */
389                 if (ds1307->regs[1] & DS1337_BIT_OSF) {
390                         i2c_smbus_write_byte_data(client, DS1337_REG_STATUS,
391                                 ds1307->regs[1] & ~DS1337_BIT_OSF);
392                         dev_warn(&client->dev, "SET TIME!\n");
393                 }
394                 break;
395         default:
396                 break;
397         }
398
399 read_rtc:
400         /* read RTC registers */
401
402         tmp = i2c_transfer(adapter, ds1307->msg, 2);
403         if (tmp != 2) {
404                 pr_debug("read error %d\n", tmp);
405                 err = -EIO;
406                 goto exit_free;
407         }
408
409         /* minimal sanity checking; some chips (like DS1340) don't
410          * specify the extra bits as must-be-zero, but there are
411          * still a few values that are clearly out-of-range.
412          */
413         tmp = ds1307->regs[DS1307_REG_SECS];
414         switch (ds1307->type) {
415         case ds_1307:
416         case m41t00:
417                 /* clock halted?  turn it on, so clock can tick. */
418                 if (tmp & DS1307_BIT_CH) {
419                         i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
420                         dev_warn(&client->dev, "SET TIME!\n");
421                         goto read_rtc;
422                 }
423                 break;
424         case ds_1338:
425                 /* clock halted?  turn it on, so clock can tick. */
426                 if (tmp & DS1307_BIT_CH)
427                         i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
428
429                 /* oscillator fault?  clear flag, and warn */
430                 if (ds1307->regs[DS1307_REG_CONTROL] & DS1338_BIT_OSF) {
431                         i2c_smbus_write_byte_data(client, DS1307_REG_CONTROL,
432                                         ds1307->regs[DS1307_REG_CONTROL]
433                                         & ~DS1338_BIT_OSF);
434                         dev_warn(&client->dev, "SET TIME!\n");
435                         goto read_rtc;
436                 }
437                 break;
438         case ds_1340:
439                 /* clock halted?  turn it on, so clock can tick. */
440                 if (tmp & DS1340_BIT_nEOSC)
441                         i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
442
443                 tmp = i2c_smbus_read_byte_data(client, DS1340_REG_FLAG);
444                 if (tmp < 0) {
445                         pr_debug("read error %d\n", tmp);
446                         err = -EIO;
447                         goto exit_free;
448                 }
449
450                 /* oscillator fault?  clear flag, and warn */
451                 if (tmp & DS1340_BIT_OSF) {
452                         i2c_smbus_write_byte_data(client, DS1340_REG_FLAG, 0);
453                         dev_warn(&client->dev, "SET TIME!\n");
454                 }
455                 break;
456         case ds_1337:
457         case ds_1339:
458                 break;
459         }
460
461         tmp = ds1307->regs[DS1307_REG_SECS];
462         tmp = BCD2BIN(tmp & 0x7f);
463         if (tmp > 60)
464                 goto exit_bad;
465         tmp = BCD2BIN(ds1307->regs[DS1307_REG_MIN] & 0x7f);
466         if (tmp > 60)
467                 goto exit_bad;
468
469         tmp = BCD2BIN(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
470         if (tmp == 0 || tmp > 31)
471                 goto exit_bad;
472
473         tmp = BCD2BIN(ds1307->regs[DS1307_REG_MONTH] & 0x1f);
474         if (tmp == 0 || tmp > 12)
475                 goto exit_bad;
476
477         tmp = ds1307->regs[DS1307_REG_HOUR];
478         switch (ds1307->type) {
479         case ds_1340:
480         case m41t00:
481                 /* NOTE: ignores century bits; fix before deploying
482                  * systems that will run through year 2100.
483                  */
484                 break;
485         default:
486                 if (!(tmp & DS1307_BIT_12HR))
487                         break;
488
489                 /* Be sure we're in 24 hour mode.  Multi-master systems
490                  * take note...
491                  */
492                 tmp = BCD2BIN(tmp & 0x1f);
493                 if (tmp == 12)
494                         tmp = 0;
495                 if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
496                         tmp += 12;
497                 i2c_smbus_write_byte_data(client,
498                                 DS1307_REG_HOUR,
499                                 BIN2BCD(tmp));
500         }
501
502         ds1307->rtc = rtc_device_register(client->name, &client->dev,
503                                 &ds13xx_rtc_ops, THIS_MODULE);
504         if (IS_ERR(ds1307->rtc)) {
505                 err = PTR_ERR(ds1307->rtc);
506                 dev_err(&client->dev,
507                         "unable to register the class device\n");
508                 goto exit_free;
509         }
510
511         if (chip->nvram56) {
512                 err = sysfs_create_bin_file(&client->dev.kobj, &nvram);
513                 if (err == 0) {
514                         ds1307->has_nvram = true;
515                         dev_info(&client->dev, "56 bytes nvram\n");
516                 }
517         }
518
519         return 0;
520
521 exit_bad:
522         dev_dbg(&client->dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
523                         "bogus register",
524                         ds1307->regs[0], ds1307->regs[1],
525                         ds1307->regs[2], ds1307->regs[3],
526                         ds1307->regs[4], ds1307->regs[5],
527                         ds1307->regs[6]);
528
529 exit_free:
530         kfree(ds1307);
531         return err;
532 }
533
534 static int __devexit ds1307_remove(struct i2c_client *client)
535 {
536         struct ds1307   *ds1307 = i2c_get_clientdata(client);
537
538         if (ds1307->has_nvram)
539                 sysfs_remove_bin_file(&client->dev.kobj, &nvram);
540
541         rtc_device_unregister(ds1307->rtc);
542         kfree(ds1307);
543         return 0;
544 }
545
546 static struct i2c_driver ds1307_driver = {
547         .driver = {
548                 .name   = "rtc-ds1307",
549                 .owner  = THIS_MODULE,
550         },
551         .probe          = ds1307_probe,
552         .remove         = __devexit_p(ds1307_remove),
553 };
554
555 static int __init ds1307_init(void)
556 {
557         return i2c_add_driver(&ds1307_driver);
558 }
559 module_init(ds1307_init);
560
561 static void __exit ds1307_exit(void)
562 {
563         i2c_del_driver(&ds1307_driver);
564 }
565 module_exit(ds1307_exit);
566
567 MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
568 MODULE_LICENSE("GPL");