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1/*
2 * An i2c driver for the Xicor/Intersil X1205 RTC
3 * Copyright 2004 Karen Spearel
4 * Copyright 2005 Alessandro Zummo
5 *
6 * please send all reports to:
7 * Karen Spearel <kas111 at gmail dot com>
8 * Alessandro Zummo <a.zummo@towertech.it>
9 *
10 * based on a lot of other RTC drivers.
11 *
12 * Information and datasheet:
13 * http://www.intersil.com/cda/deviceinfo/0,1477,X1205,00.html
14 *
15 * This program is free software; you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License version 2 as
17 * published by the Free Software Foundation.
18 */
19
20#include <linux/i2c.h>
21#include <linux/bcd.h>
22#include <linux/rtc.h>
23#include <linux/delay.h>
24#include <linux/module.h>
25
26#define DRV_VERSION "1.0.8"
27
28/* offsets into CCR area */
29
30#define CCR_SEC 0
31#define CCR_MIN 1
32#define CCR_HOUR 2
33#define CCR_MDAY 3
34#define CCR_MONTH 4
35#define CCR_YEAR 5
36#define CCR_WDAY 6
37#define CCR_Y2K 7
38
39#define X1205_REG_SR 0x3F /* status register */
40#define X1205_REG_Y2K 0x37
41#define X1205_REG_DW 0x36
42#define X1205_REG_YR 0x35
43#define X1205_REG_MO 0x34
44#define X1205_REG_DT 0x33
45#define X1205_REG_HR 0x32
46#define X1205_REG_MN 0x31
47#define X1205_REG_SC 0x30
48#define X1205_REG_DTR 0x13
49#define X1205_REG_ATR 0x12
50#define X1205_REG_INT 0x11
51#define X1205_REG_0 0x10
52#define X1205_REG_Y2K1 0x0F
53#define X1205_REG_DWA1 0x0E
54#define X1205_REG_YRA1 0x0D
55#define X1205_REG_MOA1 0x0C
56#define X1205_REG_DTA1 0x0B
57#define X1205_REG_HRA1 0x0A
58#define X1205_REG_MNA1 0x09
59#define X1205_REG_SCA1 0x08
60#define X1205_REG_Y2K0 0x07
61#define X1205_REG_DWA0 0x06
62#define X1205_REG_YRA0 0x05
63#define X1205_REG_MOA0 0x04
64#define X1205_REG_DTA0 0x03
65#define X1205_REG_HRA0 0x02
66#define X1205_REG_MNA0 0x01
67#define X1205_REG_SCA0 0x00
68
69#define X1205_CCR_BASE 0x30 /* Base address of CCR */
70#define X1205_ALM0_BASE 0x00 /* Base address of ALARM0 */
71
72#define X1205_SR_RTCF 0x01 /* Clock failure */
73#define X1205_SR_WEL 0x02 /* Write Enable Latch */
74#define X1205_SR_RWEL 0x04 /* Register Write Enable */
75#define X1205_SR_AL0 0x20 /* Alarm 0 match */
76
77#define X1205_DTR_DTR0 0x01
78#define X1205_DTR_DTR1 0x02
79#define X1205_DTR_DTR2 0x04
80
81#define X1205_HR_MIL 0x80 /* Set in ccr.hour for 24 hr mode */
82
83#define X1205_INT_AL0E 0x20 /* Alarm 0 enable */
84
85static struct i2c_driver x1205_driver;
86
87/*
88 * In the routines that deal directly with the x1205 hardware, we use
89 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch
90 * Epoch is initialized as 2000. Time is set to UTC.
91 */
92static int x1205_get_datetime(struct i2c_client *client, struct rtc_time *tm,
93 unsigned char reg_base)
94{
95 unsigned char dt_addr[2] = { 0, reg_base };
96 unsigned char buf[8];
97 int i;
98
99 struct i2c_msg msgs[] = {
100 { client->addr, 0, 2, dt_addr }, /* setup read ptr */
101 { client->addr, I2C_M_RD, 8, buf }, /* read date */
102 };
103
104 /* read date registers */
105 if (i2c_transfer(client->adapter, &msgs[0], 2) != 2) {
106 dev_err(&client->dev, "%s: read error\n", __func__);
107 return -EIO;
108 }
109
110 dev_dbg(&client->dev,
111 "%s: raw read data - sec=%02x, min=%02x, hr=%02x, "
112 "mday=%02x, mon=%02x, year=%02x, wday=%02x, y2k=%02x\n",
113 __func__,
114 buf[0], buf[1], buf[2], buf[3],
115 buf[4], buf[5], buf[6], buf[7]);
116
117 /* Mask out the enable bits if these are alarm registers */
118 if (reg_base < X1205_CCR_BASE)
119 for (i = 0; i <= 4; i++)
120 buf[i] &= 0x7F;
121
122 tm->tm_sec = bcd2bin(buf[CCR_SEC]);
123 tm->tm_min = bcd2bin(buf[CCR_MIN]);
124 tm->tm_hour = bcd2bin(buf[CCR_HOUR] & 0x3F); /* hr is 0-23 */
125 tm->tm_mday = bcd2bin(buf[CCR_MDAY]);
126 tm->tm_mon = bcd2bin(buf[CCR_MONTH]) - 1; /* mon is 0-11 */
127 tm->tm_year = bcd2bin(buf[CCR_YEAR])
128 + (bcd2bin(buf[CCR_Y2K]) * 100) - 1900;
129 tm->tm_wday = buf[CCR_WDAY];
130
131 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
132 "mday=%d, mon=%d, year=%d, wday=%d\n",
133 __func__,
134 tm->tm_sec, tm->tm_min, tm->tm_hour,
135 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
136
137 return 0;
138}
139
140static int x1205_get_status(struct i2c_client *client, unsigned char *sr)
141{
142 static unsigned char sr_addr[2] = { 0, X1205_REG_SR };
143
144 struct i2c_msg msgs[] = {
145 { client->addr, 0, 2, sr_addr }, /* setup read ptr */
146 { client->addr, I2C_M_RD, 1, sr }, /* read status */
147 };
148
149 /* read status register */
150 if (i2c_transfer(client->adapter, &msgs[0], 2) != 2) {
151 dev_err(&client->dev, "%s: read error\n", __func__);
152 return -EIO;
153 }
154
155 return 0;
156}
157
158static int x1205_set_datetime(struct i2c_client *client, struct rtc_time *tm,
159 u8 reg_base, unsigned char alm_enable)
160{
161 int i, xfer;
162 unsigned char rdata[10] = { 0, reg_base };
163 unsigned char *buf = rdata + 2;
164
165 static const unsigned char wel[3] = { 0, X1205_REG_SR,
166 X1205_SR_WEL };
167
168 static const unsigned char rwel[3] = { 0, X1205_REG_SR,
169 X1205_SR_WEL | X1205_SR_RWEL };
170
171 static const unsigned char diswe[3] = { 0, X1205_REG_SR, 0 };
172
173 dev_dbg(&client->dev,
174 "%s: sec=%d min=%d hour=%d mday=%d mon=%d year=%d wday=%d\n",
175 __func__, tm->tm_sec, tm->tm_min, tm->tm_hour, tm->tm_mday,
176 tm->tm_mon, tm->tm_year, tm->tm_wday);
177
178 buf[CCR_SEC] = bin2bcd(tm->tm_sec);
179 buf[CCR_MIN] = bin2bcd(tm->tm_min);
180
181 /* set hour and 24hr bit */
182 buf[CCR_HOUR] = bin2bcd(tm->tm_hour) | X1205_HR_MIL;
183
184 buf[CCR_MDAY] = bin2bcd(tm->tm_mday);
185
186 /* month, 1 - 12 */
187 buf[CCR_MONTH] = bin2bcd(tm->tm_mon + 1);
188
189 /* year, since the rtc epoch*/
190 buf[CCR_YEAR] = bin2bcd(tm->tm_year % 100);
191 buf[CCR_WDAY] = tm->tm_wday & 0x07;
192 buf[CCR_Y2K] = bin2bcd((tm->tm_year + 1900) / 100);
193
194 /* If writing alarm registers, set compare bits on registers 0-4 */
195 if (reg_base < X1205_CCR_BASE)
196 for (i = 0; i <= 4; i++)
197 buf[i] |= 0x80;
198
199 /* this sequence is required to unlock the chip */
200 if ((xfer = i2c_master_send(client, wel, 3)) != 3) {
201 dev_err(&client->dev, "%s: wel - %d\n", __func__, xfer);
202 return -EIO;
203 }
204
205 if ((xfer = i2c_master_send(client, rwel, 3)) != 3) {
206 dev_err(&client->dev, "%s: rwel - %d\n", __func__, xfer);
207 return -EIO;
208 }
209
210 xfer = i2c_master_send(client, rdata, sizeof(rdata));
211 if (xfer != sizeof(rdata)) {
212 dev_err(&client->dev,
213 "%s: result=%d addr=%02x, data=%02x\n",
214 __func__,
215 xfer, rdata[1], rdata[2]);
216 return -EIO;
217 }
218
219 /* If we wrote to the nonvolatile region, wait 10msec for write cycle*/
220 if (reg_base < X1205_CCR_BASE) {
221 unsigned char al0e[3] = { 0, X1205_REG_INT, 0 };
222
223 msleep(10);
224
225 /* ...and set or clear the AL0E bit in the INT register */
226
227 /* Need to set RWEL again as the write has cleared it */
228 xfer = i2c_master_send(client, rwel, 3);
229 if (xfer != 3) {
230 dev_err(&client->dev,
231 "%s: aloe rwel - %d\n",
232 __func__,
233 xfer);
234 return -EIO;
235 }
236
237 if (alm_enable)
238 al0e[2] = X1205_INT_AL0E;
239
240 xfer = i2c_master_send(client, al0e, 3);
241 if (xfer != 3) {
242 dev_err(&client->dev,
243 "%s: al0e - %d\n",
244 __func__,
245 xfer);
246 return -EIO;
247 }
248
249 /* and wait 10msec again for this write to complete */
250 msleep(10);
251 }
252
253 /* disable further writes */
254 if ((xfer = i2c_master_send(client, diswe, 3)) != 3) {
255 dev_err(&client->dev, "%s: diswe - %d\n", __func__, xfer);
256 return -EIO;
257 }
258
259 return 0;
260}
261
262static int x1205_fix_osc(struct i2c_client *client)
263{
264 int err;
265 struct rtc_time tm;
266
267 memset(&tm, 0, sizeof(tm));
268
269 err = x1205_set_datetime(client, &tm, X1205_CCR_BASE, 0);
270 if (err < 0)
271 dev_err(&client->dev, "unable to restart the oscillator\n");
272
273 return err;
274}
275
276static int x1205_get_dtrim(struct i2c_client *client, int *trim)
277{
278 unsigned char dtr;
279 static unsigned char dtr_addr[2] = { 0, X1205_REG_DTR };
280
281 struct i2c_msg msgs[] = {
282 { client->addr, 0, 2, dtr_addr }, /* setup read ptr */
283 { client->addr, I2C_M_RD, 1, &dtr }, /* read dtr */
284 };
285
286 /* read dtr register */
287 if (i2c_transfer(client->adapter, &msgs[0], 2) != 2) {
288 dev_err(&client->dev, "%s: read error\n", __func__);
289 return -EIO;
290 }
291
292 dev_dbg(&client->dev, "%s: raw dtr=%x\n", __func__, dtr);
293
294 *trim = 0;
295
296 if (dtr & X1205_DTR_DTR0)
297 *trim += 20;
298
299 if (dtr & X1205_DTR_DTR1)
300 *trim += 10;
301
302 if (dtr & X1205_DTR_DTR2)
303 *trim = -*trim;
304
305 return 0;
306}
307
308static int x1205_get_atrim(struct i2c_client *client, int *trim)
309{
310 s8 atr;
311 static unsigned char atr_addr[2] = { 0, X1205_REG_ATR };
312
313 struct i2c_msg msgs[] = {
314 { client->addr, 0, 2, atr_addr }, /* setup read ptr */
315 { client->addr, I2C_M_RD, 1, &atr }, /* read atr */
316 };
317
318 /* read atr register */
319 if (i2c_transfer(client->adapter, &msgs[0], 2) != 2) {
320 dev_err(&client->dev, "%s: read error\n", __func__);
321 return -EIO;
322 }
323
324 dev_dbg(&client->dev, "%s: raw atr=%x\n", __func__, atr);
325
326 /* atr is a two's complement value on 6 bits,
327 * perform sign extension. The formula is
328 * Catr = (atr * 0.25pF) + 11.00pF.
329 */
330 if (atr & 0x20)
331 atr |= 0xC0;
332
333 dev_dbg(&client->dev, "%s: raw atr=%x (%d)\n", __func__, atr, atr);
334
335 *trim = (atr * 250) + 11000;
336
337 dev_dbg(&client->dev, "%s: real=%d\n", __func__, *trim);
338
339 return 0;
340}
341
342struct x1205_limit
343{
344 unsigned char reg, mask, min, max;
345};
346
347static int x1205_validate_client(struct i2c_client *client)
348{
349 int i, xfer;
350
351 /* Probe array. We will read the register at the specified
352 * address and check if the given bits are zero.
353 */
354 static const unsigned char probe_zero_pattern[] = {
355 /* register, mask */
356 X1205_REG_SR, 0x18,
357 X1205_REG_DTR, 0xF8,
358 X1205_REG_ATR, 0xC0,
359 X1205_REG_INT, 0x18,
360 X1205_REG_0, 0xFF,
361 };
362
363 static const struct x1205_limit probe_limits_pattern[] = {
364 /* register, mask, min, max */
365 { X1205_REG_Y2K, 0xFF, 19, 20 },
366 { X1205_REG_DW, 0xFF, 0, 6 },
367 { X1205_REG_YR, 0xFF, 0, 99 },
368 { X1205_REG_MO, 0xFF, 0, 12 },
369 { X1205_REG_DT, 0xFF, 0, 31 },
370 { X1205_REG_HR, 0x7F, 0, 23 },
371 { X1205_REG_MN, 0xFF, 0, 59 },
372 { X1205_REG_SC, 0xFF, 0, 59 },
373 { X1205_REG_Y2K1, 0xFF, 19, 20 },
374 { X1205_REG_Y2K0, 0xFF, 19, 20 },
375 };
376
377 /* check that registers have bits a 0 where expected */
378 for (i = 0; i < ARRAY_SIZE(probe_zero_pattern); i += 2) {
379 unsigned char buf;
380
381 unsigned char addr[2] = { 0, probe_zero_pattern[i] };
382
383 struct i2c_msg msgs[2] = {
384 { client->addr, 0, 2, addr },
385 { client->addr, I2C_M_RD, 1, &buf },
386 };
387
388 if ((xfer = i2c_transfer(client->adapter, msgs, 2)) != 2) {
389 dev_err(&client->dev,
390 "%s: could not read register %x\n",
391 __func__, probe_zero_pattern[i]);
392
393 return -EIO;
394 }
395
396 if ((buf & probe_zero_pattern[i+1]) != 0) {
397 dev_err(&client->dev,
398 "%s: register=%02x, zero pattern=%d, value=%x\n",
399 __func__, probe_zero_pattern[i], i, buf);
400
401 return -ENODEV;
402 }
403 }
404
405 /* check limits (only registers with bcd values) */
406 for (i = 0; i < ARRAY_SIZE(probe_limits_pattern); i++) {
407 unsigned char reg, value;
408
409 unsigned char addr[2] = { 0, probe_limits_pattern[i].reg };
410
411 struct i2c_msg msgs[2] = {
412 { client->addr, 0, 2, addr },
413 { client->addr, I2C_M_RD, 1, ® },
414 };
415
416 if ((xfer = i2c_transfer(client->adapter, msgs, 2)) != 2) {
417 dev_err(&client->dev,
418 "%s: could not read register %x\n",
419 __func__, probe_limits_pattern[i].reg);
420
421 return -EIO;
422 }
423
424 value = bcd2bin(reg & probe_limits_pattern[i].mask);
425
426 if (value > probe_limits_pattern[i].max ||
427 value < probe_limits_pattern[i].min) {
428 dev_dbg(&client->dev,
429 "%s: register=%x, lim pattern=%d, value=%d\n",
430 __func__, probe_limits_pattern[i].reg,
431 i, value);
432
433 return -ENODEV;
434 }
435 }
436
437 return 0;
438}
439
440static int x1205_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
441{
442 int err;
443 unsigned char intreg, status;
444 static unsigned char int_addr[2] = { 0, X1205_REG_INT };
445 struct i2c_client *client = to_i2c_client(dev);
446 struct i2c_msg msgs[] = {
447 { client->addr, 0, 2, int_addr }, /* setup read ptr */
448 { client->addr, I2C_M_RD, 1, &intreg }, /* read INT register */
449 };
450
451 /* read interrupt register and status register */
452 if (i2c_transfer(client->adapter, &msgs[0], 2) != 2) {
453 dev_err(&client->dev, "%s: read error\n", __func__);
454 return -EIO;
455 }
456 err = x1205_get_status(client, &status);
457 if (err == 0) {
458 alrm->pending = (status & X1205_SR_AL0) ? 1 : 0;
459 alrm->enabled = (intreg & X1205_INT_AL0E) ? 1 : 0;
460 err = x1205_get_datetime(client, &alrm->time, X1205_ALM0_BASE);
461 }
462 return err;
463}
464
465static int x1205_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
466{
467 return x1205_set_datetime(to_i2c_client(dev),
468 &alrm->time, X1205_ALM0_BASE, alrm->enabled);
469}
470
471static int x1205_rtc_read_time(struct device *dev, struct rtc_time *tm)
472{
473 return x1205_get_datetime(to_i2c_client(dev),
474 tm, X1205_CCR_BASE);
475}
476
477static int x1205_rtc_set_time(struct device *dev, struct rtc_time *tm)
478{
479 return x1205_set_datetime(to_i2c_client(dev),
480 tm, X1205_CCR_BASE, 0);
481}
482
483static int x1205_rtc_proc(struct device *dev, struct seq_file *seq)
484{
485 int err, dtrim, atrim;
486
487 if ((err = x1205_get_dtrim(to_i2c_client(dev), &dtrim)) == 0)
488 seq_printf(seq, "digital_trim\t: %d ppm\n", dtrim);
489
490 if ((err = x1205_get_atrim(to_i2c_client(dev), &atrim)) == 0)
491 seq_printf(seq, "analog_trim\t: %d.%02d pF\n",
492 atrim / 1000, atrim % 1000);
493 return 0;
494}
495
496static const struct rtc_class_ops x1205_rtc_ops = {
497 .proc = x1205_rtc_proc,
498 .read_time = x1205_rtc_read_time,
499 .set_time = x1205_rtc_set_time,
500 .read_alarm = x1205_rtc_read_alarm,
501 .set_alarm = x1205_rtc_set_alarm,
502};
503
504static ssize_t x1205_sysfs_show_atrim(struct device *dev,
505 struct device_attribute *attr, char *buf)
506{
507 int err, atrim;
508
509 err = x1205_get_atrim(to_i2c_client(dev), &atrim);
510 if (err)
511 return err;
512
513 return sprintf(buf, "%d.%02d pF\n", atrim / 1000, atrim % 1000);
514}
515static DEVICE_ATTR(atrim, S_IRUGO, x1205_sysfs_show_atrim, NULL);
516
517static ssize_t x1205_sysfs_show_dtrim(struct device *dev,
518 struct device_attribute *attr, char *buf)
519{
520 int err, dtrim;
521
522 err = x1205_get_dtrim(to_i2c_client(dev), &dtrim);
523 if (err)
524 return err;
525
526 return sprintf(buf, "%d ppm\n", dtrim);
527}
528static DEVICE_ATTR(dtrim, S_IRUGO, x1205_sysfs_show_dtrim, NULL);
529
530static int x1205_sysfs_register(struct device *dev)
531{
532 int err;
533
534 err = device_create_file(dev, &dev_attr_atrim);
535 if (err)
536 return err;
537
538 err = device_create_file(dev, &dev_attr_dtrim);
539 if (err)
540 device_remove_file(dev, &dev_attr_atrim);
541
542 return err;
543}
544
545static void x1205_sysfs_unregister(struct device *dev)
546{
547 device_remove_file(dev, &dev_attr_atrim);
548 device_remove_file(dev, &dev_attr_dtrim);
549}
550
551
552static int x1205_probe(struct i2c_client *client,
553 const struct i2c_device_id *id)
554{
555 int err = 0;
556 unsigned char sr;
557 struct rtc_device *rtc;
558
559 dev_dbg(&client->dev, "%s\n", __func__);
560
561 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
562 return -ENODEV;
563
564 if (x1205_validate_client(client) < 0)
565 return -ENODEV;
566
567 dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
568
569 rtc = rtc_device_register(x1205_driver.driver.name, &client->dev,
570 &x1205_rtc_ops, THIS_MODULE);
571
572 if (IS_ERR(rtc))
573 return PTR_ERR(rtc);
574
575 i2c_set_clientdata(client, rtc);
576
577 /* Check for power failures and eventually enable the osc */
578 if ((err = x1205_get_status(client, &sr)) == 0) {
579 if (sr & X1205_SR_RTCF) {
580 dev_err(&client->dev,
581 "power failure detected, "
582 "please set the clock\n");
583 udelay(50);
584 x1205_fix_osc(client);
585 }
586 }
587 else
588 dev_err(&client->dev, "couldn't read status\n");
589
590 err = x1205_sysfs_register(&client->dev);
591 if (err)
592 goto exit_devreg;
593
594 return 0;
595
596exit_devreg:
597 rtc_device_unregister(rtc);
598
599 return err;
600}
601
602static int x1205_remove(struct i2c_client *client)
603{
604 struct rtc_device *rtc = i2c_get_clientdata(client);
605
606 rtc_device_unregister(rtc);
607 x1205_sysfs_unregister(&client->dev);
608 return 0;
609}
610
611static const struct i2c_device_id x1205_id[] = {
612 { "x1205", 0 },
613 { }
614};
615MODULE_DEVICE_TABLE(i2c, x1205_id);
616
617static struct i2c_driver x1205_driver = {
618 .driver = {
619 .name = "rtc-x1205",
620 },
621 .probe = x1205_probe,
622 .remove = x1205_remove,
623 .id_table = x1205_id,
624};
625
626module_i2c_driver(x1205_driver);
627
628MODULE_AUTHOR(
629 "Karen Spearel <kas111 at gmail dot com>, "
630 "Alessandro Zummo <a.zummo@towertech.it>");
631MODULE_DESCRIPTION("Xicor/Intersil X1205 RTC driver");
632MODULE_LICENSE("GPL");
633MODULE_VERSION(DRV_VERSION);
1/*
2 * An i2c driver for the Xicor/Intersil X1205 RTC
3 * Copyright 2004 Karen Spearel
4 * Copyright 2005 Alessandro Zummo
5 *
6 * please send all reports to:
7 * Karen Spearel <kas111 at gmail dot com>
8 * Alessandro Zummo <a.zummo@towertech.it>
9 *
10 * based on a lot of other RTC drivers.
11 *
12 * Information and datasheet:
13 * http://www.intersil.com/cda/deviceinfo/0,1477,X1205,00.html
14 *
15 * This program is free software; you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License version 2 as
17 * published by the Free Software Foundation.
18 */
19
20#include <linux/i2c.h>
21#include <linux/bcd.h>
22#include <linux/rtc.h>
23#include <linux/delay.h>
24#include <linux/module.h>
25
26#define DRV_VERSION "1.0.8"
27
28/* offsets into CCR area */
29
30#define CCR_SEC 0
31#define CCR_MIN 1
32#define CCR_HOUR 2
33#define CCR_MDAY 3
34#define CCR_MONTH 4
35#define CCR_YEAR 5
36#define CCR_WDAY 6
37#define CCR_Y2K 7
38
39#define X1205_REG_SR 0x3F /* status register */
40#define X1205_REG_Y2K 0x37
41#define X1205_REG_DW 0x36
42#define X1205_REG_YR 0x35
43#define X1205_REG_MO 0x34
44#define X1205_REG_DT 0x33
45#define X1205_REG_HR 0x32
46#define X1205_REG_MN 0x31
47#define X1205_REG_SC 0x30
48#define X1205_REG_DTR 0x13
49#define X1205_REG_ATR 0x12
50#define X1205_REG_INT 0x11
51#define X1205_REG_0 0x10
52#define X1205_REG_Y2K1 0x0F
53#define X1205_REG_DWA1 0x0E
54#define X1205_REG_YRA1 0x0D
55#define X1205_REG_MOA1 0x0C
56#define X1205_REG_DTA1 0x0B
57#define X1205_REG_HRA1 0x0A
58#define X1205_REG_MNA1 0x09
59#define X1205_REG_SCA1 0x08
60#define X1205_REG_Y2K0 0x07
61#define X1205_REG_DWA0 0x06
62#define X1205_REG_YRA0 0x05
63#define X1205_REG_MOA0 0x04
64#define X1205_REG_DTA0 0x03
65#define X1205_REG_HRA0 0x02
66#define X1205_REG_MNA0 0x01
67#define X1205_REG_SCA0 0x00
68
69#define X1205_CCR_BASE 0x30 /* Base address of CCR */
70#define X1205_ALM0_BASE 0x00 /* Base address of ALARM0 */
71
72#define X1205_SR_RTCF 0x01 /* Clock failure */
73#define X1205_SR_WEL 0x02 /* Write Enable Latch */
74#define X1205_SR_RWEL 0x04 /* Register Write Enable */
75#define X1205_SR_AL0 0x20 /* Alarm 0 match */
76
77#define X1205_DTR_DTR0 0x01
78#define X1205_DTR_DTR1 0x02
79#define X1205_DTR_DTR2 0x04
80
81#define X1205_HR_MIL 0x80 /* Set in ccr.hour for 24 hr mode */
82
83#define X1205_INT_AL0E 0x20 /* Alarm 0 enable */
84
85static struct i2c_driver x1205_driver;
86
87/*
88 * In the routines that deal directly with the x1205 hardware, we use
89 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch
90 * Epoch is initialized as 2000. Time is set to UTC.
91 */
92static int x1205_get_datetime(struct i2c_client *client, struct rtc_time *tm,
93 unsigned char reg_base)
94{
95 unsigned char dt_addr[2] = { 0, reg_base };
96 unsigned char buf[8];
97 int i;
98
99 struct i2c_msg msgs[] = {
100 {/* setup read ptr */
101 .addr = client->addr,
102 .len = 2,
103 .buf = dt_addr
104 },
105 {/* read date */
106 .addr = client->addr,
107 .flags = I2C_M_RD,
108 .len = 8,
109 .buf = buf
110 },
111 };
112
113 /* read date registers */
114 if (i2c_transfer(client->adapter, &msgs[0], 2) != 2) {
115 dev_err(&client->dev, "%s: read error\n", __func__);
116 return -EIO;
117 }
118
119 dev_dbg(&client->dev,
120 "%s: raw read data - sec=%02x, min=%02x, hr=%02x, "
121 "mday=%02x, mon=%02x, year=%02x, wday=%02x, y2k=%02x\n",
122 __func__,
123 buf[0], buf[1], buf[2], buf[3],
124 buf[4], buf[5], buf[6], buf[7]);
125
126 /* Mask out the enable bits if these are alarm registers */
127 if (reg_base < X1205_CCR_BASE)
128 for (i = 0; i <= 4; i++)
129 buf[i] &= 0x7F;
130
131 tm->tm_sec = bcd2bin(buf[CCR_SEC]);
132 tm->tm_min = bcd2bin(buf[CCR_MIN]);
133 tm->tm_hour = bcd2bin(buf[CCR_HOUR] & 0x3F); /* hr is 0-23 */
134 tm->tm_mday = bcd2bin(buf[CCR_MDAY]);
135 tm->tm_mon = bcd2bin(buf[CCR_MONTH]) - 1; /* mon is 0-11 */
136 tm->tm_year = bcd2bin(buf[CCR_YEAR])
137 + (bcd2bin(buf[CCR_Y2K]) * 100) - 1900;
138 tm->tm_wday = buf[CCR_WDAY];
139
140 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
141 "mday=%d, mon=%d, year=%d, wday=%d\n",
142 __func__,
143 tm->tm_sec, tm->tm_min, tm->tm_hour,
144 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
145
146 return 0;
147}
148
149static int x1205_get_status(struct i2c_client *client, unsigned char *sr)
150{
151 static unsigned char sr_addr[2] = { 0, X1205_REG_SR };
152
153 struct i2c_msg msgs[] = {
154 { /* setup read ptr */
155 .addr = client->addr,
156 .len = 2,
157 .buf = sr_addr
158 },
159 { /* read status */
160 .addr = client->addr,
161 .flags = I2C_M_RD,
162 .len = 1,
163 .buf = sr
164 },
165 };
166
167 /* read status register */
168 if (i2c_transfer(client->adapter, &msgs[0], 2) != 2) {
169 dev_err(&client->dev, "%s: read error\n", __func__);
170 return -EIO;
171 }
172
173 return 0;
174}
175
176static int x1205_set_datetime(struct i2c_client *client, struct rtc_time *tm,
177 u8 reg_base, unsigned char alm_enable)
178{
179 int i, xfer;
180 unsigned char rdata[10] = { 0, reg_base };
181 unsigned char *buf = rdata + 2;
182
183 static const unsigned char wel[3] = { 0, X1205_REG_SR,
184 X1205_SR_WEL };
185
186 static const unsigned char rwel[3] = { 0, X1205_REG_SR,
187 X1205_SR_WEL | X1205_SR_RWEL };
188
189 static const unsigned char diswe[3] = { 0, X1205_REG_SR, 0 };
190
191 dev_dbg(&client->dev,
192 "%s: sec=%d min=%d hour=%d mday=%d mon=%d year=%d wday=%d\n",
193 __func__, tm->tm_sec, tm->tm_min, tm->tm_hour, tm->tm_mday,
194 tm->tm_mon, tm->tm_year, tm->tm_wday);
195
196 buf[CCR_SEC] = bin2bcd(tm->tm_sec);
197 buf[CCR_MIN] = bin2bcd(tm->tm_min);
198
199 /* set hour and 24hr bit */
200 buf[CCR_HOUR] = bin2bcd(tm->tm_hour) | X1205_HR_MIL;
201
202 buf[CCR_MDAY] = bin2bcd(tm->tm_mday);
203
204 /* month, 1 - 12 */
205 buf[CCR_MONTH] = bin2bcd(tm->tm_mon + 1);
206
207 /* year, since the rtc epoch*/
208 buf[CCR_YEAR] = bin2bcd(tm->tm_year % 100);
209 buf[CCR_WDAY] = tm->tm_wday & 0x07;
210 buf[CCR_Y2K] = bin2bcd((tm->tm_year + 1900) / 100);
211
212 /* If writing alarm registers, set compare bits on registers 0-4 */
213 if (reg_base < X1205_CCR_BASE)
214 for (i = 0; i <= 4; i++)
215 buf[i] |= 0x80;
216
217 /* this sequence is required to unlock the chip */
218 xfer = i2c_master_send(client, wel, 3);
219 if (xfer != 3) {
220 dev_err(&client->dev, "%s: wel - %d\n", __func__, xfer);
221 return -EIO;
222 }
223
224 xfer = i2c_master_send(client, rwel, 3);
225 if (xfer != 3) {
226 dev_err(&client->dev, "%s: rwel - %d\n", __func__, xfer);
227 return -EIO;
228 }
229
230 xfer = i2c_master_send(client, rdata, sizeof(rdata));
231 if (xfer != sizeof(rdata)) {
232 dev_err(&client->dev,
233 "%s: result=%d addr=%02x, data=%02x\n",
234 __func__,
235 xfer, rdata[1], rdata[2]);
236 return -EIO;
237 }
238
239 /* If we wrote to the nonvolatile region, wait 10msec for write cycle*/
240 if (reg_base < X1205_CCR_BASE) {
241 unsigned char al0e[3] = { 0, X1205_REG_INT, 0 };
242
243 msleep(10);
244
245 /* ...and set or clear the AL0E bit in the INT register */
246
247 /* Need to set RWEL again as the write has cleared it */
248 xfer = i2c_master_send(client, rwel, 3);
249 if (xfer != 3) {
250 dev_err(&client->dev,
251 "%s: aloe rwel - %d\n",
252 __func__,
253 xfer);
254 return -EIO;
255 }
256
257 if (alm_enable)
258 al0e[2] = X1205_INT_AL0E;
259
260 xfer = i2c_master_send(client, al0e, 3);
261 if (xfer != 3) {
262 dev_err(&client->dev,
263 "%s: al0e - %d\n",
264 __func__,
265 xfer);
266 return -EIO;
267 }
268
269 /* and wait 10msec again for this write to complete */
270 msleep(10);
271 }
272
273 /* disable further writes */
274 xfer = i2c_master_send(client, diswe, 3);
275 if (xfer != 3) {
276 dev_err(&client->dev, "%s: diswe - %d\n", __func__, xfer);
277 return -EIO;
278 }
279
280 return 0;
281}
282
283static int x1205_fix_osc(struct i2c_client *client)
284{
285 int err;
286 struct rtc_time tm;
287
288 memset(&tm, 0, sizeof(tm));
289
290 err = x1205_set_datetime(client, &tm, X1205_CCR_BASE, 0);
291 if (err < 0)
292 dev_err(&client->dev, "unable to restart the oscillator\n");
293
294 return err;
295}
296
297static int x1205_get_dtrim(struct i2c_client *client, int *trim)
298{
299 unsigned char dtr;
300 static unsigned char dtr_addr[2] = { 0, X1205_REG_DTR };
301
302 struct i2c_msg msgs[] = {
303 { /* setup read ptr */
304 .addr = client->addr,
305 .len = 2,
306 .buf = dtr_addr
307 },
308 { /* read dtr */
309 .addr = client->addr,
310 .flags = I2C_M_RD,
311 .len = 1,
312 .buf = &dtr
313 },
314 };
315
316 /* read dtr register */
317 if (i2c_transfer(client->adapter, &msgs[0], 2) != 2) {
318 dev_err(&client->dev, "%s: read error\n", __func__);
319 return -EIO;
320 }
321
322 dev_dbg(&client->dev, "%s: raw dtr=%x\n", __func__, dtr);
323
324 *trim = 0;
325
326 if (dtr & X1205_DTR_DTR0)
327 *trim += 20;
328
329 if (dtr & X1205_DTR_DTR1)
330 *trim += 10;
331
332 if (dtr & X1205_DTR_DTR2)
333 *trim = -*trim;
334
335 return 0;
336}
337
338static int x1205_get_atrim(struct i2c_client *client, int *trim)
339{
340 s8 atr;
341 static unsigned char atr_addr[2] = { 0, X1205_REG_ATR };
342
343 struct i2c_msg msgs[] = {
344 {/* setup read ptr */
345 .addr = client->addr,
346 .len = 2,
347 .buf = atr_addr
348 },
349 {/* read atr */
350 .addr = client->addr,
351 .flags = I2C_M_RD,
352 .len = 1,
353 .buf = &atr
354 },
355 };
356
357 /* read atr register */
358 if (i2c_transfer(client->adapter, &msgs[0], 2) != 2) {
359 dev_err(&client->dev, "%s: read error\n", __func__);
360 return -EIO;
361 }
362
363 dev_dbg(&client->dev, "%s: raw atr=%x\n", __func__, atr);
364
365 /* atr is a two's complement value on 6 bits,
366 * perform sign extension. The formula is
367 * Catr = (atr * 0.25pF) + 11.00pF.
368 */
369 if (atr & 0x20)
370 atr |= 0xC0;
371
372 dev_dbg(&client->dev, "%s: raw atr=%x (%d)\n", __func__, atr, atr);
373
374 *trim = (atr * 250) + 11000;
375
376 dev_dbg(&client->dev, "%s: real=%d\n", __func__, *trim);
377
378 return 0;
379}
380
381struct x1205_limit {
382 unsigned char reg, mask, min, max;
383};
384
385static int x1205_validate_client(struct i2c_client *client)
386{
387 int i, xfer;
388
389 /* Probe array. We will read the register at the specified
390 * address and check if the given bits are zero.
391 */
392 static const unsigned char probe_zero_pattern[] = {
393 /* register, mask */
394 X1205_REG_SR, 0x18,
395 X1205_REG_DTR, 0xF8,
396 X1205_REG_ATR, 0xC0,
397 X1205_REG_INT, 0x18,
398 X1205_REG_0, 0xFF,
399 };
400
401 static const struct x1205_limit probe_limits_pattern[] = {
402 /* register, mask, min, max */
403 { X1205_REG_Y2K, 0xFF, 19, 20 },
404 { X1205_REG_DW, 0xFF, 0, 6 },
405 { X1205_REG_YR, 0xFF, 0, 99 },
406 { X1205_REG_MO, 0xFF, 0, 12 },
407 { X1205_REG_DT, 0xFF, 0, 31 },
408 { X1205_REG_HR, 0x7F, 0, 23 },
409 { X1205_REG_MN, 0xFF, 0, 59 },
410 { X1205_REG_SC, 0xFF, 0, 59 },
411 { X1205_REG_Y2K1, 0xFF, 19, 20 },
412 { X1205_REG_Y2K0, 0xFF, 19, 20 },
413 };
414
415 /* check that registers have bits a 0 where expected */
416 for (i = 0; i < ARRAY_SIZE(probe_zero_pattern); i += 2) {
417 unsigned char buf;
418
419 unsigned char addr[2] = { 0, probe_zero_pattern[i] };
420
421 struct i2c_msg msgs[2] = {
422 {
423 .addr = client->addr,
424 .len = 2,
425 .buf = addr
426 },
427 {
428 .addr = client->addr,
429 .flags = I2C_M_RD,
430 .len = 1,
431 .buf = &buf
432 },
433 };
434
435 xfer = i2c_transfer(client->adapter, msgs, 2);
436 if (xfer != 2) {
437 dev_err(&client->dev,
438 "%s: could not read register %x\n",
439 __func__, probe_zero_pattern[i]);
440
441 return -EIO;
442 }
443
444 if ((buf & probe_zero_pattern[i+1]) != 0) {
445 dev_err(&client->dev,
446 "%s: register=%02x, zero pattern=%d, value=%x\n",
447 __func__, probe_zero_pattern[i], i, buf);
448
449 return -ENODEV;
450 }
451 }
452
453 /* check limits (only registers with bcd values) */
454 for (i = 0; i < ARRAY_SIZE(probe_limits_pattern); i++) {
455 unsigned char reg, value;
456
457 unsigned char addr[2] = { 0, probe_limits_pattern[i].reg };
458
459 struct i2c_msg msgs[2] = {
460 {
461 .addr = client->addr,
462 .len = 2,
463 .buf = addr
464 },
465 {
466 .addr = client->addr,
467 .flags = I2C_M_RD,
468 .len = 1,
469 .buf = ®
470 },
471 };
472
473 xfer = i2c_transfer(client->adapter, msgs, 2);
474 if (xfer != 2) {
475 dev_err(&client->dev,
476 "%s: could not read register %x\n",
477 __func__, probe_limits_pattern[i].reg);
478
479 return -EIO;
480 }
481
482 value = bcd2bin(reg & probe_limits_pattern[i].mask);
483
484 if (value > probe_limits_pattern[i].max ||
485 value < probe_limits_pattern[i].min) {
486 dev_dbg(&client->dev,
487 "%s: register=%x, lim pattern=%d, value=%d\n",
488 __func__, probe_limits_pattern[i].reg,
489 i, value);
490
491 return -ENODEV;
492 }
493 }
494
495 return 0;
496}
497
498static int x1205_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
499{
500 int err;
501 unsigned char intreg, status;
502 static unsigned char int_addr[2] = { 0, X1205_REG_INT };
503 struct i2c_client *client = to_i2c_client(dev);
504 struct i2c_msg msgs[] = {
505 { /* setup read ptr */
506 .addr = client->addr,
507 .len = 2,
508 .buf = int_addr
509 },
510 {/* read INT register */
511
512 .addr = client->addr,
513 .flags = I2C_M_RD,
514 .len = 1,
515 .buf = &intreg
516 },
517 };
518
519 /* read interrupt register and status register */
520 if (i2c_transfer(client->adapter, &msgs[0], 2) != 2) {
521 dev_err(&client->dev, "%s: read error\n", __func__);
522 return -EIO;
523 }
524 err = x1205_get_status(client, &status);
525 if (err == 0) {
526 alrm->pending = (status & X1205_SR_AL0) ? 1 : 0;
527 alrm->enabled = (intreg & X1205_INT_AL0E) ? 1 : 0;
528 err = x1205_get_datetime(client, &alrm->time, X1205_ALM0_BASE);
529 }
530 return err;
531}
532
533static int x1205_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
534{
535 return x1205_set_datetime(to_i2c_client(dev),
536 &alrm->time, X1205_ALM0_BASE, alrm->enabled);
537}
538
539static int x1205_rtc_read_time(struct device *dev, struct rtc_time *tm)
540{
541 return x1205_get_datetime(to_i2c_client(dev),
542 tm, X1205_CCR_BASE);
543}
544
545static int x1205_rtc_set_time(struct device *dev, struct rtc_time *tm)
546{
547 return x1205_set_datetime(to_i2c_client(dev),
548 tm, X1205_CCR_BASE, 0);
549}
550
551static int x1205_rtc_proc(struct device *dev, struct seq_file *seq)
552{
553 int err, dtrim, atrim;
554
555 err = x1205_get_dtrim(to_i2c_client(dev), &dtrim);
556 if (!err)
557 seq_printf(seq, "digital_trim\t: %d ppm\n", dtrim);
558
559 err = x1205_get_atrim(to_i2c_client(dev), &atrim);
560 if (!err)
561 seq_printf(seq, "analog_trim\t: %d.%02d pF\n",
562 atrim / 1000, atrim % 1000);
563 return 0;
564}
565
566static const struct rtc_class_ops x1205_rtc_ops = {
567 .proc = x1205_rtc_proc,
568 .read_time = x1205_rtc_read_time,
569 .set_time = x1205_rtc_set_time,
570 .read_alarm = x1205_rtc_read_alarm,
571 .set_alarm = x1205_rtc_set_alarm,
572};
573
574static ssize_t x1205_sysfs_show_atrim(struct device *dev,
575 struct device_attribute *attr, char *buf)
576{
577 int err, atrim;
578
579 err = x1205_get_atrim(to_i2c_client(dev), &atrim);
580 if (err)
581 return err;
582
583 return sprintf(buf, "%d.%02d pF\n", atrim / 1000, atrim % 1000);
584}
585static DEVICE_ATTR(atrim, S_IRUGO, x1205_sysfs_show_atrim, NULL);
586
587static ssize_t x1205_sysfs_show_dtrim(struct device *dev,
588 struct device_attribute *attr, char *buf)
589{
590 int err, dtrim;
591
592 err = x1205_get_dtrim(to_i2c_client(dev), &dtrim);
593 if (err)
594 return err;
595
596 return sprintf(buf, "%d ppm\n", dtrim);
597}
598static DEVICE_ATTR(dtrim, S_IRUGO, x1205_sysfs_show_dtrim, NULL);
599
600static int x1205_sysfs_register(struct device *dev)
601{
602 int err;
603
604 err = device_create_file(dev, &dev_attr_atrim);
605 if (err)
606 return err;
607
608 err = device_create_file(dev, &dev_attr_dtrim);
609 if (err)
610 device_remove_file(dev, &dev_attr_atrim);
611
612 return err;
613}
614
615static void x1205_sysfs_unregister(struct device *dev)
616{
617 device_remove_file(dev, &dev_attr_atrim);
618 device_remove_file(dev, &dev_attr_dtrim);
619}
620
621
622static int x1205_probe(struct i2c_client *client,
623 const struct i2c_device_id *id)
624{
625 int err = 0;
626 unsigned char sr;
627 struct rtc_device *rtc;
628
629 dev_dbg(&client->dev, "%s\n", __func__);
630
631 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
632 return -ENODEV;
633
634 if (x1205_validate_client(client) < 0)
635 return -ENODEV;
636
637 dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
638
639 rtc = devm_rtc_device_register(&client->dev, x1205_driver.driver.name,
640 &x1205_rtc_ops, THIS_MODULE);
641
642 if (IS_ERR(rtc))
643 return PTR_ERR(rtc);
644
645 i2c_set_clientdata(client, rtc);
646
647 /* Check for power failures and eventually enable the osc */
648 err = x1205_get_status(client, &sr);
649 if (!err) {
650 if (sr & X1205_SR_RTCF) {
651 dev_err(&client->dev,
652 "power failure detected, "
653 "please set the clock\n");
654 udelay(50);
655 x1205_fix_osc(client);
656 }
657 } else {
658 dev_err(&client->dev, "couldn't read status\n");
659 }
660
661 err = x1205_sysfs_register(&client->dev);
662 if (err)
663 dev_err(&client->dev, "Unable to create sysfs entries\n");
664
665 return 0;
666}
667
668static int x1205_remove(struct i2c_client *client)
669{
670 x1205_sysfs_unregister(&client->dev);
671 return 0;
672}
673
674static const struct i2c_device_id x1205_id[] = {
675 { "x1205", 0 },
676 { }
677};
678MODULE_DEVICE_TABLE(i2c, x1205_id);
679
680static struct i2c_driver x1205_driver = {
681 .driver = {
682 .name = "rtc-x1205",
683 },
684 .probe = x1205_probe,
685 .remove = x1205_remove,
686 .id_table = x1205_id,
687};
688
689module_i2c_driver(x1205_driver);
690
691MODULE_AUTHOR(
692 "Karen Spearel <kas111 at gmail dot com>, "
693 "Alessandro Zummo <a.zummo@towertech.it>");
694MODULE_DESCRIPTION("Xicor/Intersil X1205 RTC driver");
695MODULE_LICENSE("GPL");
696MODULE_VERSION(DRV_VERSION);