Merge git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog
[linux-2.6] / drivers / rtc / rtc-fm3130.c
1 /*
2  * rtc-fm3130.c - RTC driver for Ramtron FM3130 I2C chip.
3  *
4  *  Copyright (C) 2008 Sergey Lapin
5  *  Based on ds1307 driver by James Chapman and 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/i2c.h>
14 #include <linux/rtc.h>
15 #include <linux/bcd.h>
16
17 #define FM3130_RTC_CONTROL      (0x0)
18 #define FM3130_CAL_CONTROL      (0x1)
19 #define FM3130_RTC_SECONDS      (0x2)
20 #define FM3130_RTC_MINUTES      (0x3)
21 #define FM3130_RTC_HOURS        (0x4)
22 #define FM3130_RTC_DAY          (0x5)
23 #define FM3130_RTC_DATE         (0x6)
24 #define FM3130_RTC_MONTHS       (0x7)
25 #define FM3130_RTC_YEARS        (0x8)
26
27 #define FM3130_ALARM_SECONDS    (0x9)
28 #define FM3130_ALARM_MINUTES    (0xa)
29 #define FM3130_ALARM_HOURS      (0xb)
30 #define FM3130_ALARM_DATE       (0xc)
31 #define FM3130_ALARM_MONTHS     (0xd)
32 #define FM3130_ALARM_WP_CONTROL (0xe)
33
34 #define FM3130_CAL_CONTROL_BIT_nOSCEN (1 << 7) /* Osciallator enabled */
35 #define FM3130_RTC_CONTROL_BIT_LB (1 << 7) /* Low battery */
36 #define FM3130_RTC_CONTROL_BIT_AF (1 << 6) /* Alarm flag */
37 #define FM3130_RTC_CONTROL_BIT_CF (1 << 5) /* Century overflow */
38 #define FM3130_RTC_CONTROL_BIT_POR (1 << 4) /* Power on reset */
39 #define FM3130_RTC_CONTROL_BIT_AEN (1 << 3) /* Alarm enable */
40 #define FM3130_RTC_CONTROL_BIT_CAL (1 << 2) /* Calibration mode */
41 #define FM3130_RTC_CONTROL_BIT_WRITE (1 << 1) /* W=1 -> write mode W=0 normal */
42 #define FM3130_RTC_CONTROL_BIT_READ (1 << 0) /* R=1 -> read mode R=0 normal */
43
44 #define FM3130_CLOCK_REGS 7
45 #define FM3130_ALARM_REGS 5
46
47 struct fm3130 {
48         u8                      reg_addr_time;
49         u8                      reg_addr_alarm;
50         u8                      regs[15];
51         struct i2c_msg          msg[4];
52         struct i2c_client       *client;
53         struct rtc_device       *rtc;
54         int                     data_valid;
55         int                     alarm;
56 };
57 static const struct i2c_device_id fm3130_id[] = {
58         { "fm3130", 0 },
59         { }
60 };
61 MODULE_DEVICE_TABLE(i2c, fm3130_id);
62
63 #define FM3130_MODE_NORMAL              0
64 #define FM3130_MODE_WRITE               1
65 #define FM3130_MODE_READ                2
66
67 static void fm3130_rtc_mode(struct device *dev, int mode)
68 {
69         struct fm3130 *fm3130 = dev_get_drvdata(dev);
70
71         fm3130->regs[FM3130_RTC_CONTROL] =
72                 i2c_smbus_read_byte_data(fm3130->client, FM3130_RTC_CONTROL);
73         switch (mode) {
74         case FM3130_MODE_NORMAL:
75                 fm3130->regs[FM3130_RTC_CONTROL] &=
76                         ~(FM3130_RTC_CONTROL_BIT_WRITE |
77                         FM3130_RTC_CONTROL_BIT_READ);
78                 break;
79         case FM3130_MODE_WRITE:
80                 fm3130->regs[FM3130_RTC_CONTROL] |= FM3130_RTC_CONTROL_BIT_WRITE;
81                 break;
82         case FM3130_MODE_READ:
83                 fm3130->regs[FM3130_RTC_CONTROL] |= FM3130_RTC_CONTROL_BIT_READ;
84                 break;
85         default:
86                 dev_dbg(dev, "invalid mode %d\n", mode);
87                 break;
88         }
89         /* Checking for alarm */
90         if (fm3130->regs[FM3130_RTC_CONTROL] & FM3130_RTC_CONTROL_BIT_AF) {
91                 fm3130->alarm = 1;
92                 fm3130->regs[FM3130_RTC_CONTROL] &= ~FM3130_RTC_CONTROL_BIT_AF;
93         }
94         i2c_smbus_write_byte_data(fm3130->client,
95                  FM3130_RTC_CONTROL, fm3130->regs[FM3130_RTC_CONTROL]);
96 }
97
98 static int fm3130_get_time(struct device *dev, struct rtc_time *t)
99 {
100         struct fm3130 *fm3130 = dev_get_drvdata(dev);
101         int             tmp;
102
103         if (!fm3130->data_valid) {
104                 /* We have invalid data in RTC, probably due
105                 to battery faults or other problems. Return EIO
106                 for now, it will allow us to set data later insted
107                 of error during probing which disables device */
108                 return -EIO;
109         }
110         fm3130_rtc_mode(dev, FM3130_MODE_READ);
111
112         /* read the RTC date and time registers all at once */
113         tmp = i2c_transfer(to_i2c_adapter(fm3130->client->dev.parent),
114                         fm3130->msg, 2);
115         if (tmp != 2) {
116                 dev_err(dev, "%s error %d\n", "read", tmp);
117                 return -EIO;
118         }
119
120         fm3130_rtc_mode(dev, FM3130_MODE_NORMAL);
121
122         dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x %02x"
123                         "%02x %02x %02x %02x %02x %02x %02x\n",
124                         "read",
125                         fm3130->regs[0], fm3130->regs[1],
126                         fm3130->regs[2], fm3130->regs[3],
127                         fm3130->regs[4], fm3130->regs[5],
128                         fm3130->regs[6], fm3130->regs[7],
129                         fm3130->regs[8], fm3130->regs[9],
130                         fm3130->regs[0xa], fm3130->regs[0xb],
131                         fm3130->regs[0xc], fm3130->regs[0xd],
132                         fm3130->regs[0xe]);
133
134         t->tm_sec = bcd2bin(fm3130->regs[FM3130_RTC_SECONDS] & 0x7f);
135         t->tm_min = bcd2bin(fm3130->regs[FM3130_RTC_MINUTES] & 0x7f);
136         tmp = fm3130->regs[FM3130_RTC_HOURS] & 0x3f;
137         t->tm_hour = bcd2bin(tmp);
138         t->tm_wday = bcd2bin(fm3130->regs[FM3130_RTC_DAY] & 0x07) - 1;
139         t->tm_mday = bcd2bin(fm3130->regs[FM3130_RTC_DATE] & 0x3f);
140         tmp = fm3130->regs[FM3130_RTC_MONTHS] & 0x1f;
141         t->tm_mon = bcd2bin(tmp) - 1;
142
143         /* assume 20YY not 19YY, and ignore CF bit */
144         t->tm_year = bcd2bin(fm3130->regs[FM3130_RTC_YEARS]) + 100;
145
146         dev_dbg(dev, "%s secs=%d, mins=%d, "
147                 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
148                 "read", t->tm_sec, t->tm_min,
149                 t->tm_hour, t->tm_mday,
150                 t->tm_mon, t->tm_year, t->tm_wday);
151
152         /* initial clock setting can be undefined */
153         return rtc_valid_tm(t);
154 }
155
156
157 static int fm3130_set_time(struct device *dev, struct rtc_time *t)
158 {
159         struct fm3130 *fm3130 = dev_get_drvdata(dev);
160         int             tmp, i;
161         u8              *buf = fm3130->regs;
162
163         dev_dbg(dev, "%s secs=%d, mins=%d, "
164                 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
165                 "write", t->tm_sec, t->tm_min,
166                 t->tm_hour, t->tm_mday,
167                 t->tm_mon, t->tm_year, t->tm_wday);
168
169         /* first register addr */
170         buf[FM3130_RTC_SECONDS] = bin2bcd(t->tm_sec);
171         buf[FM3130_RTC_MINUTES] = bin2bcd(t->tm_min);
172         buf[FM3130_RTC_HOURS] = bin2bcd(t->tm_hour);
173         buf[FM3130_RTC_DAY] = bin2bcd(t->tm_wday + 1);
174         buf[FM3130_RTC_DATE] = bin2bcd(t->tm_mday);
175         buf[FM3130_RTC_MONTHS] = bin2bcd(t->tm_mon + 1);
176
177         /* assume 20YY not 19YY */
178         tmp = t->tm_year - 100;
179         buf[FM3130_RTC_YEARS] = bin2bcd(tmp);
180
181         dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x"
182                 "%02x %02x %02x %02x %02x %02x %02x %02x\n",
183                 "write", buf[0], buf[1], buf[2], buf[3],
184                 buf[4], buf[5], buf[6], buf[7],
185                 buf[8], buf[9], buf[0xa], buf[0xb],
186                 buf[0xc], buf[0xd], buf[0xe]);
187
188         fm3130_rtc_mode(dev, FM3130_MODE_WRITE);
189
190         /* Writing time registers, we don't support multibyte transfers */
191         for (i = 0; i < FM3130_CLOCK_REGS; i++) {
192                 i2c_smbus_write_byte_data(fm3130->client,
193                                         FM3130_RTC_SECONDS + i,
194                                         fm3130->regs[FM3130_RTC_SECONDS + i]);
195         }
196
197         fm3130_rtc_mode(dev, FM3130_MODE_NORMAL);
198
199         /* We assume here that data are valid once written */
200         if (!fm3130->data_valid)
201                 fm3130->data_valid = 1;
202         return 0;
203 }
204
205 static int fm3130_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
206 {
207         struct fm3130 *fm3130 = dev_get_drvdata(dev);
208         int tmp;
209         struct rtc_time *tm = &alrm->time;
210         /* read the RTC alarm registers all at once */
211         tmp = i2c_transfer(to_i2c_adapter(fm3130->client->dev.parent),
212                         &fm3130->msg[2], 2);
213         if (tmp != 2) {
214                 dev_err(dev, "%s error %d\n", "read", tmp);
215                 return -EIO;
216         }
217         dev_dbg(dev, "alarm read %02x %02x %02x %02x %02x\n",
218                         fm3130->regs[FM3130_ALARM_SECONDS],
219                         fm3130->regs[FM3130_ALARM_MINUTES],
220                         fm3130->regs[FM3130_ALARM_HOURS],
221                         fm3130->regs[FM3130_ALARM_DATE],
222                         fm3130->regs[FM3130_ALARM_MONTHS]);
223
224
225         tm->tm_sec      = bcd2bin(fm3130->regs[FM3130_ALARM_SECONDS] & 0x7F);
226         tm->tm_min      = bcd2bin(fm3130->regs[FM3130_ALARM_MINUTES] & 0x7F);
227         tm->tm_hour     = bcd2bin(fm3130->regs[FM3130_ALARM_HOURS] & 0x3F);
228         tm->tm_mday     = bcd2bin(fm3130->regs[FM3130_ALARM_DATE] & 0x3F);
229         tm->tm_mon      = bcd2bin(fm3130->regs[FM3130_ALARM_MONTHS] & 0x1F);
230         if (tm->tm_mon > 0)
231                 tm->tm_mon -= 1; /* RTC is 1-12, tm_mon is 0-11 */
232         dev_dbg(dev, "%s secs=%d, mins=%d, "
233                 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
234                 "read alarm", tm->tm_sec, tm->tm_min,
235                 tm->tm_hour, tm->tm_mday,
236                 tm->tm_mon, tm->tm_year, tm->tm_wday);
237
238         return 0;
239 }
240
241 static int fm3130_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
242 {
243         struct fm3130 *fm3130 = dev_get_drvdata(dev);
244         struct rtc_time *tm = &alrm->time;
245         int i;
246
247         dev_dbg(dev, "%s secs=%d, mins=%d, "
248                 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
249                 "write alarm", tm->tm_sec, tm->tm_min,
250                 tm->tm_hour, tm->tm_mday,
251                 tm->tm_mon, tm->tm_year, tm->tm_wday);
252
253         if (tm->tm_sec != -1)
254                 fm3130->regs[FM3130_ALARM_SECONDS] =
255                         bin2bcd(tm->tm_sec) | 0x80;
256
257         if (tm->tm_min != -1)
258                 fm3130->regs[FM3130_ALARM_MINUTES] =
259                         bin2bcd(tm->tm_min) | 0x80;
260
261         if (tm->tm_hour != -1)
262                 fm3130->regs[FM3130_ALARM_HOURS] =
263                         bin2bcd(tm->tm_hour) | 0x80;
264
265         if (tm->tm_mday != -1)
266                 fm3130->regs[FM3130_ALARM_DATE] =
267                         bin2bcd(tm->tm_mday) | 0x80;
268
269         if (tm->tm_mon != -1)
270                 fm3130->regs[FM3130_ALARM_MONTHS] =
271                         bin2bcd(tm->tm_mon + 1) | 0x80;
272
273         dev_dbg(dev, "alarm write %02x %02x %02x %02x %02x\n",
274                         fm3130->regs[FM3130_ALARM_SECONDS],
275                         fm3130->regs[FM3130_ALARM_MINUTES],
276                         fm3130->regs[FM3130_ALARM_HOURS],
277                         fm3130->regs[FM3130_ALARM_DATE],
278                         fm3130->regs[FM3130_ALARM_MONTHS]);
279         /* Writing time registers, we don't support multibyte transfers */
280         for (i = 0; i < FM3130_ALARM_REGS; i++) {
281                 i2c_smbus_write_byte_data(fm3130->client,
282                                         FM3130_ALARM_SECONDS + i,
283                                         fm3130->regs[FM3130_ALARM_SECONDS + i]);
284         }
285         fm3130->regs[FM3130_RTC_CONTROL] =
286                 i2c_smbus_read_byte_data(fm3130->client, FM3130_RTC_CONTROL);
287         /* Checking for alarm */
288         if (fm3130->regs[FM3130_RTC_CONTROL] & FM3130_RTC_CONTROL_BIT_AF) {
289                 fm3130->alarm = 1;
290                 fm3130->regs[FM3130_RTC_CONTROL] &= ~FM3130_RTC_CONTROL_BIT_AF;
291         }
292         if (alrm->enabled) {
293                 i2c_smbus_write_byte_data(fm3130->client, FM3130_RTC_CONTROL,
294                         (fm3130->regs[FM3130_RTC_CONTROL] &
295                                 ~(FM3130_RTC_CONTROL_BIT_CAL)) |
296                                         FM3130_RTC_CONTROL_BIT_AEN);
297         } else {
298                 i2c_smbus_write_byte_data(fm3130->client, FM3130_RTC_CONTROL,
299                         fm3130->regs[FM3130_RTC_CONTROL] &
300                                 ~(FM3130_RTC_CONTROL_BIT_AEN));
301         }
302         return 0;
303 }
304
305 static const struct rtc_class_ops fm3130_rtc_ops = {
306         .read_time      = fm3130_get_time,
307         .set_time       = fm3130_set_time,
308         .read_alarm     = fm3130_read_alarm,
309         .set_alarm      = fm3130_set_alarm,
310 };
311
312 static struct i2c_driver fm3130_driver;
313
314 static int __devinit fm3130_probe(struct i2c_client *client,
315                                   const struct i2c_device_id *id)
316 {
317         struct fm3130           *fm3130;
318         int                     err = -ENODEV;
319         int                     tmp;
320         struct i2c_adapter      *adapter = to_i2c_adapter(client->dev.parent);
321
322         if (!i2c_check_functionality(adapter,
323                         I2C_FUNC_I2C | I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
324                 return -EIO;
325
326         fm3130 = kzalloc(sizeof(struct fm3130), GFP_KERNEL);
327
328         if (!fm3130)
329                 return -ENOMEM;
330
331         fm3130->client = client;
332         i2c_set_clientdata(client, fm3130);
333         fm3130->reg_addr_time = FM3130_RTC_SECONDS;
334         fm3130->reg_addr_alarm = FM3130_ALARM_SECONDS;
335
336         /* Messages to read time */
337         fm3130->msg[0].addr = client->addr;
338         fm3130->msg[0].flags = 0;
339         fm3130->msg[0].len = 1;
340         fm3130->msg[0].buf = &fm3130->reg_addr_time;
341
342         fm3130->msg[1].addr = client->addr;
343         fm3130->msg[1].flags = I2C_M_RD;
344         fm3130->msg[1].len = FM3130_CLOCK_REGS;
345         fm3130->msg[1].buf = &fm3130->regs[FM3130_RTC_SECONDS];
346
347         /* Messages to read alarm */
348         fm3130->msg[2].addr = client->addr;
349         fm3130->msg[2].flags = 0;
350         fm3130->msg[2].len = 1;
351         fm3130->msg[2].buf = &fm3130->reg_addr_alarm;
352
353         fm3130->msg[3].addr = client->addr;
354         fm3130->msg[3].flags = I2C_M_RD;
355         fm3130->msg[3].len = FM3130_ALARM_REGS;
356         fm3130->msg[3].buf = &fm3130->regs[FM3130_ALARM_SECONDS];
357
358         fm3130->data_valid = 0;
359
360         tmp = i2c_transfer(adapter, fm3130->msg, 4);
361         if (tmp != 4) {
362                 pr_debug("read error %d\n", tmp);
363                 err = -EIO;
364                 goto exit_free;
365         }
366
367         fm3130->regs[FM3130_RTC_CONTROL] =
368                 i2c_smbus_read_byte_data(client, FM3130_RTC_CONTROL);
369         fm3130->regs[FM3130_CAL_CONTROL] =
370                 i2c_smbus_read_byte_data(client, FM3130_CAL_CONTROL);
371
372         /* Checking for alarm */
373         if (fm3130->regs[FM3130_RTC_CONTROL] & FM3130_RTC_CONTROL_BIT_AF) {
374                 fm3130->alarm = 1;
375                 fm3130->regs[FM3130_RTC_CONTROL] &= ~FM3130_RTC_CONTROL_BIT_AF;
376         }
377
378         /* Disabling calibration mode */
379         if (fm3130->regs[FM3130_RTC_CONTROL] & FM3130_RTC_CONTROL_BIT_CAL)
380                 i2c_smbus_write_byte_data(client, FM3130_RTC_CONTROL,
381                         fm3130->regs[FM3130_RTC_CONTROL] &
382                                 ~(FM3130_RTC_CONTROL_BIT_CAL));
383                 dev_warn(&client->dev, "Disabling calibration mode!\n");
384
385         /* Disabling read and write modes */
386         if (fm3130->regs[FM3130_RTC_CONTROL] & FM3130_RTC_CONTROL_BIT_WRITE ||
387             fm3130->regs[FM3130_RTC_CONTROL] & FM3130_RTC_CONTROL_BIT_READ)
388                 i2c_smbus_write_byte_data(client, FM3130_RTC_CONTROL,
389                         fm3130->regs[FM3130_RTC_CONTROL] &
390                                 ~(FM3130_RTC_CONTROL_BIT_READ |
391                                         FM3130_RTC_CONTROL_BIT_WRITE));
392                 dev_warn(&client->dev, "Disabling READ or WRITE mode!\n");
393
394         /* oscillator off?  turn it on, so clock can tick. */
395         if (fm3130->regs[FM3130_CAL_CONTROL] & FM3130_CAL_CONTROL_BIT_nOSCEN)
396                 i2c_smbus_write_byte_data(client, FM3130_CAL_CONTROL,
397                         fm3130->regs[FM3130_CAL_CONTROL] &
398                                 ~(FM3130_CAL_CONTROL_BIT_nOSCEN));
399
400         /* oscillator fault?  clear flag, and warn */
401         if (fm3130->regs[FM3130_RTC_CONTROL] & FM3130_RTC_CONTROL_BIT_LB)
402                 dev_warn(&client->dev, "Low battery!\n");
403
404         /* oscillator fault?  clear flag, and warn */
405         if (fm3130->regs[FM3130_RTC_CONTROL] & FM3130_RTC_CONTROL_BIT_POR) {
406                 i2c_smbus_write_byte_data(client, FM3130_RTC_CONTROL,
407                         fm3130->regs[FM3130_RTC_CONTROL] &
408                                 ~FM3130_RTC_CONTROL_BIT_POR);
409                 dev_warn(&client->dev, "SET TIME!\n");
410         }
411         /* ACS is controlled by alarm */
412         i2c_smbus_write_byte_data(client, FM3130_ALARM_WP_CONTROL, 0x80);
413
414         /* TODO */
415         /* TODO need to sanity check alarm */
416         tmp = fm3130->regs[FM3130_RTC_SECONDS];
417         tmp = bcd2bin(tmp & 0x7f);
418         if (tmp > 60)
419                 goto exit_bad;
420         tmp = bcd2bin(fm3130->regs[FM3130_RTC_MINUTES] & 0x7f);
421         if (tmp > 60)
422                 goto exit_bad;
423
424         tmp = bcd2bin(fm3130->regs[FM3130_RTC_DATE] & 0x3f);
425         if (tmp == 0 || tmp > 31)
426                 goto exit_bad;
427
428         tmp = bcd2bin(fm3130->regs[FM3130_RTC_MONTHS] & 0x1f);
429         if (tmp == 0 || tmp > 12)
430                 goto exit_bad;
431
432         tmp = fm3130->regs[FM3130_RTC_HOURS];
433
434         fm3130->data_valid = 1;
435
436 exit_bad:
437         if (!fm3130->data_valid)
438                 dev_dbg(&client->dev,
439                                 "%s: %02x %02x %02x %02x %02x %02x %02x %02x"
440                                 "%02x %02x %02x %02x %02x %02x %02x\n",
441                         "bogus registers",
442                         fm3130->regs[0], fm3130->regs[1],
443                         fm3130->regs[2], fm3130->regs[3],
444                         fm3130->regs[4], fm3130->regs[5],
445                         fm3130->regs[6], fm3130->regs[7],
446                         fm3130->regs[8], fm3130->regs[9],
447                         fm3130->regs[0xa], fm3130->regs[0xb],
448                         fm3130->regs[0xc], fm3130->regs[0xd],
449                         fm3130->regs[0xe]);
450
451         /* We won't bail out here because we just got invalid data.
452            Time setting from u-boot doesn't work anyway */
453         fm3130->rtc = rtc_device_register(client->name, &client->dev,
454                                 &fm3130_rtc_ops, THIS_MODULE);
455         if (IS_ERR(fm3130->rtc)) {
456                 err = PTR_ERR(fm3130->rtc);
457                 dev_err(&client->dev,
458                         "unable to register the class device\n");
459                 goto exit_free;
460         }
461         return 0;
462 exit_free:
463         kfree(fm3130);
464         return err;
465 }
466
467 static int __devexit fm3130_remove(struct i2c_client *client)
468 {
469         struct fm3130 *fm3130 = i2c_get_clientdata(client);
470
471         rtc_device_unregister(fm3130->rtc);
472         kfree(fm3130);
473         return 0;
474 }
475
476 static struct i2c_driver fm3130_driver = {
477         .driver = {
478                 .name   = "rtc-fm3130",
479                 .owner  = THIS_MODULE,
480         },
481         .probe          = fm3130_probe,
482         .remove         = __devexit_p(fm3130_remove),
483         .id_table       = fm3130_id,
484 };
485
486 static int __init fm3130_init(void)
487 {
488         return i2c_add_driver(&fm3130_driver);
489 }
490 module_init(fm3130_init);
491
492 static void __exit fm3130_exit(void)
493 {
494         i2c_del_driver(&fm3130_driver);
495 }
496 module_exit(fm3130_exit);
497
498 MODULE_DESCRIPTION("RTC driver for FM3130");
499 MODULE_AUTHOR("Sergey Lapin <slapin@ossfans.org>");
500 MODULE_LICENSE("GPL");
501