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1/*
2 * Driver for Epson's RTC module RX-8025 SA/NB
3 *
4 * Copyright (C) 2009 Wolfgang Grandegger <wg@grandegger.com>
5 *
6 * Copyright (C) 2005 by Digi International Inc.
7 * All rights reserved.
8 *
9 * Modified by fengjh at rising.com.cn
10 * <http://lists.lm-sensors.org/mailman/listinfo/lm-sensors>
11 * 2006.11
12 *
13 * Code cleanup by Sergei Poselenov, <sposelenov@emcraft.com>
14 * Converted to new style by Wolfgang Grandegger <wg@grandegger.com>
15 * Alarm and periodic interrupt added by Dmitry Rakhchev <rda@emcraft.com>
16 *
17 * This program is free software; you can redistribute it and/or
18 * modify it under the terms of the GNU General Public License
19 * version 2 as published by the Free Software Foundation.
20 */
21#include <linux/kernel.h>
22#include <linux/module.h>
23#include <linux/slab.h>
24#include <linux/init.h>
25#include <linux/bcd.h>
26#include <linux/i2c.h>
27#include <linux/list.h>
28#include <linux/rtc.h>
29
30/* Register definitions */
31#define RX8025_REG_SEC 0x00
32#define RX8025_REG_MIN 0x01
33#define RX8025_REG_HOUR 0x02
34#define RX8025_REG_WDAY 0x03
35#define RX8025_REG_MDAY 0x04
36#define RX8025_REG_MONTH 0x05
37#define RX8025_REG_YEAR 0x06
38#define RX8025_REG_DIGOFF 0x07
39#define RX8025_REG_ALWMIN 0x08
40#define RX8025_REG_ALWHOUR 0x09
41#define RX8025_REG_ALWWDAY 0x0a
42#define RX8025_REG_ALDMIN 0x0b
43#define RX8025_REG_ALDHOUR 0x0c
44/* 0x0d is reserved */
45#define RX8025_REG_CTRL1 0x0e
46#define RX8025_REG_CTRL2 0x0f
47
48#define RX8025_BIT_CTRL1_CT (7 << 0)
49/* 1 Hz periodic level irq */
50#define RX8025_BIT_CTRL1_CT_1HZ 4
51#define RX8025_BIT_CTRL1_TEST (1 << 3)
52#define RX8025_BIT_CTRL1_1224 (1 << 5)
53#define RX8025_BIT_CTRL1_DALE (1 << 6)
54#define RX8025_BIT_CTRL1_WALE (1 << 7)
55
56#define RX8025_BIT_CTRL2_DAFG (1 << 0)
57#define RX8025_BIT_CTRL2_WAFG (1 << 1)
58#define RX8025_BIT_CTRL2_CTFG (1 << 2)
59#define RX8025_BIT_CTRL2_PON (1 << 4)
60#define RX8025_BIT_CTRL2_XST (1 << 5)
61#define RX8025_BIT_CTRL2_VDET (1 << 6)
62
63/* Clock precision adjustment */
64#define RX8025_ADJ_RESOLUTION 3050 /* in ppb */
65#define RX8025_ADJ_DATA_MAX 62
66#define RX8025_ADJ_DATA_MIN -62
67
68static const struct i2c_device_id rx8025_id[] = {
69 { "rx8025", 0 },
70 { }
71};
72MODULE_DEVICE_TABLE(i2c, rx8025_id);
73
74struct rx8025_data {
75 struct i2c_client *client;
76 struct rtc_device *rtc;
77 struct work_struct work;
78 u8 ctrl1;
79 unsigned exiting:1;
80};
81
82static int rx8025_read_reg(struct i2c_client *client, int number, u8 *value)
83{
84 int ret = i2c_smbus_read_byte_data(client, (number << 4) | 0x08);
85
86 if (ret < 0) {
87 dev_err(&client->dev, "Unable to read register #%d\n", number);
88 return ret;
89 }
90
91 *value = ret;
92 return 0;
93}
94
95static int rx8025_read_regs(struct i2c_client *client,
96 int number, u8 length, u8 *values)
97{
98 int ret = i2c_smbus_read_i2c_block_data(client, (number << 4) | 0x08,
99 length, values);
100
101 if (ret != length) {
102 dev_err(&client->dev, "Unable to read registers #%d..#%d\n",
103 number, number + length - 1);
104 return ret < 0 ? ret : -EIO;
105 }
106
107 return 0;
108}
109
110static int rx8025_write_reg(struct i2c_client *client, int number, u8 value)
111{
112 int ret = i2c_smbus_write_byte_data(client, number << 4, value);
113
114 if (ret)
115 dev_err(&client->dev, "Unable to write register #%d\n",
116 number);
117
118 return ret;
119}
120
121static int rx8025_write_regs(struct i2c_client *client,
122 int number, u8 length, u8 *values)
123{
124 int ret = i2c_smbus_write_i2c_block_data(client, (number << 4) | 0x08,
125 length, values);
126
127 if (ret)
128 dev_err(&client->dev, "Unable to write registers #%d..#%d\n",
129 number, number + length - 1);
130
131 return ret;
132}
133
134static irqreturn_t rx8025_irq(int irq, void *dev_id)
135{
136 struct i2c_client *client = dev_id;
137 struct rx8025_data *rx8025 = i2c_get_clientdata(client);
138
139 disable_irq_nosync(irq);
140 schedule_work(&rx8025->work);
141 return IRQ_HANDLED;
142}
143
144static void rx8025_work(struct work_struct *work)
145{
146 struct rx8025_data *rx8025 = container_of(work, struct rx8025_data,
147 work);
148 struct i2c_client *client = rx8025->client;
149 struct mutex *lock = &rx8025->rtc->ops_lock;
150 u8 status;
151
152 mutex_lock(lock);
153
154 if (rx8025_read_reg(client, RX8025_REG_CTRL2, &status))
155 goto out;
156
157 if (!(status & RX8025_BIT_CTRL2_XST))
158 dev_warn(&client->dev, "Oscillation stop was detected,"
159 "you may have to readjust the clock\n");
160
161 if (status & RX8025_BIT_CTRL2_CTFG) {
162 /* periodic */
163 status &= ~RX8025_BIT_CTRL2_CTFG;
164 local_irq_disable();
165 rtc_update_irq(rx8025->rtc, 1, RTC_PF | RTC_IRQF);
166 local_irq_enable();
167 }
168
169 if (status & RX8025_BIT_CTRL2_DAFG) {
170 /* alarm */
171 status &= RX8025_BIT_CTRL2_DAFG;
172 if (rx8025_write_reg(client, RX8025_REG_CTRL1,
173 rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE))
174 goto out;
175 local_irq_disable();
176 rtc_update_irq(rx8025->rtc, 1, RTC_AF | RTC_IRQF);
177 local_irq_enable();
178 }
179
180 /* acknowledge IRQ */
181 rx8025_write_reg(client, RX8025_REG_CTRL2,
182 status | RX8025_BIT_CTRL2_XST);
183
184out:
185 if (!rx8025->exiting)
186 enable_irq(client->irq);
187
188 mutex_unlock(lock);
189}
190
191static int rx8025_get_time(struct device *dev, struct rtc_time *dt)
192{
193 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
194 u8 date[7];
195 int err;
196
197 err = rx8025_read_regs(rx8025->client, RX8025_REG_SEC, 7, date);
198 if (err)
199 return err;
200
201 dev_dbg(dev, "%s: read 0x%02x 0x%02x "
202 "0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n", __func__,
203 date[0], date[1], date[2], date[3], date[4],
204 date[5], date[6]);
205
206 dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
207 dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
208 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
209 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);
210 else
211 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12
212 + (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0);
213
214 dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);
215 dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
216 dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]);
217
218 if (dt->tm_year < 70)
219 dt->tm_year += 100;
220
221 dev_dbg(dev, "%s: date %ds %dm %dh %dmd %dm %dy\n", __func__,
222 dt->tm_sec, dt->tm_min, dt->tm_hour,
223 dt->tm_mday, dt->tm_mon, dt->tm_year);
224
225 return rtc_valid_tm(dt);
226}
227
228static int rx8025_set_time(struct device *dev, struct rtc_time *dt)
229{
230 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
231 u8 date[7];
232
233 /*
234 * BUG: The HW assumes every year that is a multiple of 4 to be a leap
235 * year. Next time this is wrong is 2100, which will not be a leap
236 * year.
237 */
238
239 /*
240 * Here the read-only bits are written as "0". I'm not sure if that
241 * is sound.
242 */
243 date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
244 date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
245 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
246 date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
247 else
248 date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
249 | bin2bcd((dt->tm_hour + 11) % 12 + 1);
250
251 date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
252 date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
253 date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
254 date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year % 100);
255
256 dev_dbg(dev,
257 "%s: write 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n",
258 __func__,
259 date[0], date[1], date[2], date[3], date[4], date[5], date[6]);
260
261 return rx8025_write_regs(rx8025->client, RX8025_REG_SEC, 7, date);
262}
263
264static int rx8025_init_client(struct i2c_client *client, int *need_reset)
265{
266 struct rx8025_data *rx8025 = i2c_get_clientdata(client);
267 u8 ctrl[2], ctrl2;
268 int need_clear = 0;
269 int err;
270
271 err = rx8025_read_regs(rx8025->client, RX8025_REG_CTRL1, 2, ctrl);
272 if (err)
273 goto out;
274
275 /* Keep test bit zero ! */
276 rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;
277
278 if (ctrl[1] & RX8025_BIT_CTRL2_PON) {
279 dev_warn(&client->dev, "power-on reset was detected, "
280 "you may have to readjust the clock\n");
281 *need_reset = 1;
282 }
283
284 if (ctrl[1] & RX8025_BIT_CTRL2_VDET) {
285 dev_warn(&client->dev, "a power voltage drop was detected, "
286 "you may have to readjust the clock\n");
287 *need_reset = 1;
288 }
289
290 if (!(ctrl[1] & RX8025_BIT_CTRL2_XST)) {
291 dev_warn(&client->dev, "Oscillation stop was detected,"
292 "you may have to readjust the clock\n");
293 *need_reset = 1;
294 }
295
296 if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG | RX8025_BIT_CTRL2_WAFG)) {
297 dev_warn(&client->dev, "Alarm was detected\n");
298 need_clear = 1;
299 }
300
301 if (!(ctrl[1] & RX8025_BIT_CTRL2_CTFG))
302 need_clear = 1;
303
304 if (*need_reset || need_clear) {
305 ctrl2 = ctrl[0];
306 ctrl2 &= ~(RX8025_BIT_CTRL2_PON | RX8025_BIT_CTRL2_VDET |
307 RX8025_BIT_CTRL2_CTFG | RX8025_BIT_CTRL2_WAFG |
308 RX8025_BIT_CTRL2_DAFG);
309 ctrl2 |= RX8025_BIT_CTRL2_XST;
310
311 err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
312 }
313out:
314 return err;
315}
316
317/* Alarm support */
318static int rx8025_read_alarm(struct device *dev, struct rtc_wkalrm *t)
319{
320 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
321 struct i2c_client *client = rx8025->client;
322 u8 ctrl2, ald[2];
323 int err;
324
325 if (client->irq <= 0)
326 return -EINVAL;
327
328 err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);
329 if (err)
330 return err;
331
332 err = rx8025_read_reg(client, RX8025_REG_CTRL2, &ctrl2);
333 if (err)
334 return err;
335
336 dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",
337 __func__, ald[0], ald[1], ctrl2);
338
339 /* Hardware alarms precision is 1 minute! */
340 t->time.tm_sec = 0;
341 t->time.tm_min = bcd2bin(ald[0] & 0x7f);
342 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
343 t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
344 else
345 t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
346 + (ald[1] & 0x20 ? 12 : 0);
347
348 t->time.tm_wday = -1;
349 t->time.tm_mday = -1;
350 t->time.tm_mon = -1;
351 t->time.tm_year = -1;
352
353 dev_dbg(dev, "%s: date: %ds %dm %dh %dmd %dm %dy\n",
354 __func__,
355 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
356 t->time.tm_mday, t->time.tm_mon, t->time.tm_year);
357 t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
358 t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
359
360 return err;
361}
362
363static int rx8025_set_alarm(struct device *dev, struct rtc_wkalrm *t)
364{
365 struct i2c_client *client = to_i2c_client(dev);
366 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
367 u8 ald[2];
368 int err;
369
370 if (client->irq <= 0)
371 return -EINVAL;
372
373 /* Hardware alarm precision is 1 minute! */
374 ald[0] = bin2bcd(t->time.tm_min);
375 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
376 ald[1] = bin2bcd(t->time.tm_hour);
377 else
378 ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
379 | bin2bcd((t->time.tm_hour + 11) % 12 + 1);
380
381 dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);
382
383 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
384 rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
385 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
386 rx8025->ctrl1);
387 if (err)
388 return err;
389 }
390 err = rx8025_write_regs(rx8025->client, RX8025_REG_ALDMIN, 2, ald);
391 if (err)
392 return err;
393
394 if (t->enabled) {
395 rx8025->ctrl1 |= RX8025_BIT_CTRL1_DALE;
396 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
397 rx8025->ctrl1);
398 if (err)
399 return err;
400 }
401
402 return 0;
403}
404
405static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
406{
407 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
408 u8 ctrl1;
409 int err;
410
411 ctrl1 = rx8025->ctrl1;
412 if (enabled)
413 ctrl1 |= RX8025_BIT_CTRL1_DALE;
414 else
415 ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
416
417 if (ctrl1 != rx8025->ctrl1) {
418 rx8025->ctrl1 = ctrl1;
419 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
420 rx8025->ctrl1);
421 if (err)
422 return err;
423 }
424 return 0;
425}
426
427static struct rtc_class_ops rx8025_rtc_ops = {
428 .read_time = rx8025_get_time,
429 .set_time = rx8025_set_time,
430 .read_alarm = rx8025_read_alarm,
431 .set_alarm = rx8025_set_alarm,
432 .alarm_irq_enable = rx8025_alarm_irq_enable,
433};
434
435/*
436 * Clock precision adjustment support
437 *
438 * According to the RX8025 SA/NB application manual the frequency and
439 * temperature characteristics can be approximated using the following
440 * equation:
441 *
442 * df = a * (ut - t)**2
443 *
444 * df: Frequency deviation in any temperature
445 * a : Coefficient = (-35 +-5) * 10**-9
446 * ut: Ultimate temperature in degree = +25 +-5 degree
447 * t : Any temperature in degree
448 *
449 * Note that the clock adjustment in ppb must be entered (which is
450 * the negative value of the deviation).
451 */
452static int rx8025_get_clock_adjust(struct device *dev, int *adj)
453{
454 struct i2c_client *client = to_i2c_client(dev);
455 u8 digoff;
456 int err;
457
458 err = rx8025_read_reg(client, RX8025_REG_DIGOFF, &digoff);
459 if (err)
460 return err;
461
462 *adj = digoff >= 64 ? digoff - 128 : digoff;
463 if (*adj > 0)
464 (*adj)--;
465 *adj *= -RX8025_ADJ_RESOLUTION;
466
467 return 0;
468}
469
470static int rx8025_set_clock_adjust(struct device *dev, int adj)
471{
472 struct i2c_client *client = to_i2c_client(dev);
473 u8 digoff;
474 int err;
475
476 adj /= -RX8025_ADJ_RESOLUTION;
477 if (adj > RX8025_ADJ_DATA_MAX)
478 adj = RX8025_ADJ_DATA_MAX;
479 else if (adj < RX8025_ADJ_DATA_MIN)
480 adj = RX8025_ADJ_DATA_MIN;
481 else if (adj > 0)
482 adj++;
483 else if (adj < 0)
484 adj += 128;
485 digoff = adj;
486
487 err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
488 if (err)
489 return err;
490
491 dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff);
492
493 return 0;
494}
495
496static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
497 struct device_attribute *attr,
498 char *buf)
499{
500 int err, adj;
501
502 err = rx8025_get_clock_adjust(dev, &adj);
503 if (err)
504 return err;
505
506 return sprintf(buf, "%d\n", adj);
507}
508
509static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
510 struct device_attribute *attr,
511 const char *buf, size_t count)
512{
513 int adj, err;
514
515 if (sscanf(buf, "%i", &adj) != 1)
516 return -EINVAL;
517
518 err = rx8025_set_clock_adjust(dev, adj);
519
520 return err ? err : count;
521}
522
523static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO | S_IWUSR,
524 rx8025_sysfs_show_clock_adjust,
525 rx8025_sysfs_store_clock_adjust);
526
527static int rx8025_sysfs_register(struct device *dev)
528{
529 return device_create_file(dev, &dev_attr_clock_adjust_ppb);
530}
531
532static void rx8025_sysfs_unregister(struct device *dev)
533{
534 device_remove_file(dev, &dev_attr_clock_adjust_ppb);
535}
536
537static int __devinit rx8025_probe(struct i2c_client *client,
538 const struct i2c_device_id *id)
539{
540 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
541 struct rx8025_data *rx8025;
542 int err, need_reset = 0;
543
544 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
545 | I2C_FUNC_SMBUS_I2C_BLOCK)) {
546 dev_err(&adapter->dev,
547 "doesn't support required functionality\n");
548 err = -EIO;
549 goto errout;
550 }
551
552 rx8025 = kzalloc(sizeof(*rx8025), GFP_KERNEL);
553 if (!rx8025) {
554 dev_err(&adapter->dev, "failed to alloc memory\n");
555 err = -ENOMEM;
556 goto errout;
557 }
558
559 rx8025->client = client;
560 i2c_set_clientdata(client, rx8025);
561 INIT_WORK(&rx8025->work, rx8025_work);
562
563 err = rx8025_init_client(client, &need_reset);
564 if (err)
565 goto errout_free;
566
567 if (need_reset) {
568 struct rtc_time tm;
569 dev_info(&client->dev,
570 "bad conditions detected, resetting date\n");
571 rtc_time_to_tm(0, &tm); /* 1970/1/1 */
572 rx8025_set_time(&client->dev, &tm);
573 }
574
575 rx8025->rtc = rtc_device_register(client->name, &client->dev,
576 &rx8025_rtc_ops, THIS_MODULE);
577 if (IS_ERR(rx8025->rtc)) {
578 err = PTR_ERR(rx8025->rtc);
579 dev_err(&client->dev, "unable to register the class device\n");
580 goto errout_free;
581 }
582
583 if (client->irq > 0) {
584 dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
585 err = request_irq(client->irq, rx8025_irq,
586 0, "rx8025", client);
587 if (err) {
588 dev_err(&client->dev, "unable to request IRQ\n");
589 goto errout_reg;
590 }
591 }
592
593 rx8025->rtc->irq_freq = 1;
594 rx8025->rtc->max_user_freq = 1;
595
596 err = rx8025_sysfs_register(&client->dev);
597 if (err)
598 goto errout_irq;
599
600 return 0;
601
602errout_irq:
603 if (client->irq > 0)
604 free_irq(client->irq, client);
605
606errout_reg:
607 rtc_device_unregister(rx8025->rtc);
608
609errout_free:
610 kfree(rx8025);
611
612errout:
613 dev_err(&adapter->dev, "probing for rx8025 failed\n");
614 return err;
615}
616
617static int __devexit rx8025_remove(struct i2c_client *client)
618{
619 struct rx8025_data *rx8025 = i2c_get_clientdata(client);
620 struct mutex *lock = &rx8025->rtc->ops_lock;
621
622 if (client->irq > 0) {
623 mutex_lock(lock);
624 rx8025->exiting = 1;
625 mutex_unlock(lock);
626
627 free_irq(client->irq, client);
628 cancel_work_sync(&rx8025->work);
629 }
630
631 rx8025_sysfs_unregister(&client->dev);
632 rtc_device_unregister(rx8025->rtc);
633 kfree(rx8025);
634 return 0;
635}
636
637static struct i2c_driver rx8025_driver = {
638 .driver = {
639 .name = "rtc-rx8025",
640 .owner = THIS_MODULE,
641 },
642 .probe = rx8025_probe,
643 .remove = __devexit_p(rx8025_remove),
644 .id_table = rx8025_id,
645};
646
647module_i2c_driver(rx8025_driver);
648
649MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
650MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
651MODULE_LICENSE("GPL");
1/*
2 * Driver for Epson's RTC module RX-8025 SA/NB
3 *
4 * Copyright (C) 2009 Wolfgang Grandegger <wg@grandegger.com>
5 *
6 * Copyright (C) 2005 by Digi International Inc.
7 * All rights reserved.
8 *
9 * Modified by fengjh at rising.com.cn
10 * <lm-sensors@lm-sensors.org>
11 * 2006.11
12 *
13 * Code cleanup by Sergei Poselenov, <sposelenov@emcraft.com>
14 * Converted to new style by Wolfgang Grandegger <wg@grandegger.com>
15 * Alarm and periodic interrupt added by Dmitry Rakhchev <rda@emcraft.com>
16 *
17 * This program is free software; you can redistribute it and/or
18 * modify it under the terms of the GNU General Public License
19 * version 2 as published by the Free Software Foundation.
20 */
21#include <linux/bcd.h>
22#include <linux/bitops.h>
23#include <linux/i2c.h>
24#include <linux/kernel.h>
25#include <linux/module.h>
26#include <linux/rtc.h>
27
28/* Register definitions */
29#define RX8025_REG_SEC 0x00
30#define RX8025_REG_MIN 0x01
31#define RX8025_REG_HOUR 0x02
32#define RX8025_REG_WDAY 0x03
33#define RX8025_REG_MDAY 0x04
34#define RX8025_REG_MONTH 0x05
35#define RX8025_REG_YEAR 0x06
36#define RX8025_REG_DIGOFF 0x07
37#define RX8025_REG_ALWMIN 0x08
38#define RX8025_REG_ALWHOUR 0x09
39#define RX8025_REG_ALWWDAY 0x0a
40#define RX8025_REG_ALDMIN 0x0b
41#define RX8025_REG_ALDHOUR 0x0c
42/* 0x0d is reserved */
43#define RX8025_REG_CTRL1 0x0e
44#define RX8025_REG_CTRL2 0x0f
45
46#define RX8025_BIT_CTRL1_CT (7 << 0)
47/* 1 Hz periodic level irq */
48#define RX8025_BIT_CTRL1_CT_1HZ 4
49#define RX8025_BIT_CTRL1_TEST BIT(3)
50#define RX8025_BIT_CTRL1_1224 BIT(5)
51#define RX8025_BIT_CTRL1_DALE BIT(6)
52#define RX8025_BIT_CTRL1_WALE BIT(7)
53
54#define RX8025_BIT_CTRL2_DAFG BIT(0)
55#define RX8025_BIT_CTRL2_WAFG BIT(1)
56#define RX8025_BIT_CTRL2_CTFG BIT(2)
57#define RX8025_BIT_CTRL2_PON BIT(4)
58#define RX8025_BIT_CTRL2_XST BIT(5)
59#define RX8025_BIT_CTRL2_VDET BIT(6)
60
61/* Clock precision adjustment */
62#define RX8025_ADJ_RESOLUTION 3050 /* in ppb */
63#define RX8025_ADJ_DATA_MAX 62
64#define RX8025_ADJ_DATA_MIN -62
65
66static const struct i2c_device_id rx8025_id[] = {
67 { "rx8025", 0 },
68 { }
69};
70MODULE_DEVICE_TABLE(i2c, rx8025_id);
71
72struct rx8025_data {
73 struct i2c_client *client;
74 struct rtc_device *rtc;
75 u8 ctrl1;
76};
77
78static s32 rx8025_read_reg(const struct i2c_client *client, u8 number)
79{
80 return i2c_smbus_read_byte_data(client, number << 4);
81}
82
83static int rx8025_read_regs(const struct i2c_client *client,
84 u8 number, u8 length, u8 *values)
85{
86 int ret = i2c_smbus_read_i2c_block_data(client, number << 4, length,
87 values);
88 if (ret != length)
89 return ret < 0 ? ret : -EIO;
90
91 return 0;
92}
93
94static s32 rx8025_write_reg(const struct i2c_client *client, u8 number,
95 u8 value)
96{
97 return i2c_smbus_write_byte_data(client, number << 4, value);
98}
99
100static s32 rx8025_write_regs(const struct i2c_client *client,
101 u8 number, u8 length, const u8 *values)
102{
103 return i2c_smbus_write_i2c_block_data(client, number << 4,
104 length, values);
105}
106
107static int rx8025_check_validity(struct device *dev)
108{
109 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
110 int ctrl2;
111
112 ctrl2 = rx8025_read_reg(rx8025->client, RX8025_REG_CTRL2);
113 if (ctrl2 < 0)
114 return ctrl2;
115
116 if (ctrl2 & RX8025_BIT_CTRL2_VDET)
117 dev_warn(dev, "power voltage drop detected\n");
118
119 if (ctrl2 & RX8025_BIT_CTRL2_PON) {
120 dev_warn(dev, "power-on reset detected, date is invalid\n");
121 return -EINVAL;
122 }
123
124 if (!(ctrl2 & RX8025_BIT_CTRL2_XST)) {
125 dev_warn(dev, "crystal stopped, date is invalid\n");
126 return -EINVAL;
127 }
128
129 return 0;
130}
131
132static int rx8025_reset_validity(struct i2c_client *client)
133{
134 int ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
135
136 if (ctrl2 < 0)
137 return ctrl2;
138
139 ctrl2 &= ~(RX8025_BIT_CTRL2_PON | RX8025_BIT_CTRL2_VDET);
140
141 return rx8025_write_reg(client, RX8025_REG_CTRL2,
142 ctrl2 | RX8025_BIT_CTRL2_XST);
143}
144
145static irqreturn_t rx8025_handle_irq(int irq, void *dev_id)
146{
147 struct i2c_client *client = dev_id;
148 struct rx8025_data *rx8025 = i2c_get_clientdata(client);
149 struct mutex *lock = &rx8025->rtc->ops_lock;
150 int status;
151
152 mutex_lock(lock);
153 status = rx8025_read_reg(client, RX8025_REG_CTRL2);
154 if (status < 0)
155 goto out;
156
157 if (!(status & RX8025_BIT_CTRL2_XST))
158 dev_warn(&client->dev, "Oscillation stop was detected,"
159 "you may have to readjust the clock\n");
160
161 if (status & RX8025_BIT_CTRL2_CTFG) {
162 /* periodic */
163 status &= ~RX8025_BIT_CTRL2_CTFG;
164 rtc_update_irq(rx8025->rtc, 1, RTC_PF | RTC_IRQF);
165 }
166
167 if (status & RX8025_BIT_CTRL2_DAFG) {
168 /* alarm */
169 status &= RX8025_BIT_CTRL2_DAFG;
170 if (rx8025_write_reg(client, RX8025_REG_CTRL1,
171 rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE))
172 goto out;
173 rtc_update_irq(rx8025->rtc, 1, RTC_AF | RTC_IRQF);
174 }
175
176out:
177 mutex_unlock(lock);
178
179 return IRQ_HANDLED;
180}
181
182static int rx8025_get_time(struct device *dev, struct rtc_time *dt)
183{
184 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
185 u8 date[7];
186 int err;
187
188 err = rx8025_check_validity(dev);
189 if (err)
190 return err;
191
192 err = rx8025_read_regs(rx8025->client, RX8025_REG_SEC, 7, date);
193 if (err)
194 return err;
195
196 dev_dbg(dev, "%s: read 0x%02x 0x%02x "
197 "0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n", __func__,
198 date[0], date[1], date[2], date[3], date[4],
199 date[5], date[6]);
200
201 dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
202 dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
203 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
204 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);
205 else
206 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12
207 + (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0);
208
209 dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);
210 dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
211 dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]) + 100;
212
213 dev_dbg(dev, "%s: date %ds %dm %dh %dmd %dm %dy\n", __func__,
214 dt->tm_sec, dt->tm_min, dt->tm_hour,
215 dt->tm_mday, dt->tm_mon, dt->tm_year);
216
217 return 0;
218}
219
220static int rx8025_set_time(struct device *dev, struct rtc_time *dt)
221{
222 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
223 u8 date[7];
224 int ret;
225
226 if ((dt->tm_year < 100) || (dt->tm_year > 199))
227 return -EINVAL;
228
229 /*
230 * Here the read-only bits are written as "0". I'm not sure if that
231 * is sound.
232 */
233 date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
234 date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
235 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
236 date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
237 else
238 date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
239 | bin2bcd((dt->tm_hour + 11) % 12 + 1);
240
241 date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
242 date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
243 date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
244 date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year - 100);
245
246 dev_dbg(dev,
247 "%s: write 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n",
248 __func__,
249 date[0], date[1], date[2], date[3], date[4], date[5], date[6]);
250
251 ret = rx8025_write_regs(rx8025->client, RX8025_REG_SEC, 7, date);
252 if (ret < 0)
253 return ret;
254
255 return rx8025_reset_validity(rx8025->client);
256}
257
258static int rx8025_init_client(struct i2c_client *client)
259{
260 struct rx8025_data *rx8025 = i2c_get_clientdata(client);
261 u8 ctrl[2], ctrl2;
262 int need_clear = 0;
263 int err;
264
265 err = rx8025_read_regs(rx8025->client, RX8025_REG_CTRL1, 2, ctrl);
266 if (err)
267 goto out;
268
269 /* Keep test bit zero ! */
270 rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;
271
272 if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG | RX8025_BIT_CTRL2_WAFG)) {
273 dev_warn(&client->dev, "Alarm was detected\n");
274 need_clear = 1;
275 }
276
277 if (ctrl[1] & RX8025_BIT_CTRL2_CTFG)
278 need_clear = 1;
279
280 if (need_clear) {
281 ctrl2 = ctrl[1];
282 ctrl2 &= ~(RX8025_BIT_CTRL2_CTFG | RX8025_BIT_CTRL2_WAFG |
283 RX8025_BIT_CTRL2_DAFG);
284
285 err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
286 }
287out:
288 return err;
289}
290
291/* Alarm support */
292static int rx8025_read_alarm(struct device *dev, struct rtc_wkalrm *t)
293{
294 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
295 struct i2c_client *client = rx8025->client;
296 u8 ald[2];
297 int ctrl2, err;
298
299 if (client->irq <= 0)
300 return -EINVAL;
301
302 err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);
303 if (err)
304 return err;
305
306 ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
307 if (ctrl2 < 0)
308 return ctrl2;
309
310 dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",
311 __func__, ald[0], ald[1], ctrl2);
312
313 /* Hardware alarms precision is 1 minute! */
314 t->time.tm_sec = 0;
315 t->time.tm_min = bcd2bin(ald[0] & 0x7f);
316 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
317 t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
318 else
319 t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
320 + (ald[1] & 0x20 ? 12 : 0);
321
322 dev_dbg(dev, "%s: date: %ds %dm %dh %dmd %dm %dy\n",
323 __func__,
324 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
325 t->time.tm_mday, t->time.tm_mon, t->time.tm_year);
326 t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
327 t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
328
329 return err;
330}
331
332static int rx8025_set_alarm(struct device *dev, struct rtc_wkalrm *t)
333{
334 struct i2c_client *client = to_i2c_client(dev);
335 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
336 u8 ald[2];
337 int err;
338
339 if (client->irq <= 0)
340 return -EINVAL;
341
342 /*
343 * Hardware alarm precision is 1 minute!
344 * round up to nearest minute
345 */
346 if (t->time.tm_sec) {
347 time64_t alarm_time = rtc_tm_to_time64(&t->time);
348
349 alarm_time += 60 - t->time.tm_sec;
350 rtc_time64_to_tm(alarm_time, &t->time);
351 }
352
353 ald[0] = bin2bcd(t->time.tm_min);
354 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
355 ald[1] = bin2bcd(t->time.tm_hour);
356 else
357 ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
358 | bin2bcd((t->time.tm_hour + 11) % 12 + 1);
359
360 dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);
361
362 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
363 rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
364 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
365 rx8025->ctrl1);
366 if (err)
367 return err;
368 }
369 err = rx8025_write_regs(rx8025->client, RX8025_REG_ALDMIN, 2, ald);
370 if (err)
371 return err;
372
373 if (t->enabled) {
374 rx8025->ctrl1 |= RX8025_BIT_CTRL1_DALE;
375 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
376 rx8025->ctrl1);
377 if (err)
378 return err;
379 }
380
381 return 0;
382}
383
384static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
385{
386 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
387 u8 ctrl1;
388 int err;
389
390 ctrl1 = rx8025->ctrl1;
391 if (enabled)
392 ctrl1 |= RX8025_BIT_CTRL1_DALE;
393 else
394 ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
395
396 if (ctrl1 != rx8025->ctrl1) {
397 rx8025->ctrl1 = ctrl1;
398 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
399 rx8025->ctrl1);
400 if (err)
401 return err;
402 }
403 return 0;
404}
405
406static const struct rtc_class_ops rx8025_rtc_ops = {
407 .read_time = rx8025_get_time,
408 .set_time = rx8025_set_time,
409 .read_alarm = rx8025_read_alarm,
410 .set_alarm = rx8025_set_alarm,
411 .alarm_irq_enable = rx8025_alarm_irq_enable,
412};
413
414/*
415 * Clock precision adjustment support
416 *
417 * According to the RX8025 SA/NB application manual the frequency and
418 * temperature characteristics can be approximated using the following
419 * equation:
420 *
421 * df = a * (ut - t)**2
422 *
423 * df: Frequency deviation in any temperature
424 * a : Coefficient = (-35 +-5) * 10**-9
425 * ut: Ultimate temperature in degree = +25 +-5 degree
426 * t : Any temperature in degree
427 *
428 * Note that the clock adjustment in ppb must be entered (which is
429 * the negative value of the deviation).
430 */
431static int rx8025_get_clock_adjust(struct device *dev, int *adj)
432{
433 struct i2c_client *client = to_i2c_client(dev);
434 int digoff;
435
436 digoff = rx8025_read_reg(client, RX8025_REG_DIGOFF);
437 if (digoff < 0)
438 return digoff;
439
440 *adj = digoff >= 64 ? digoff - 128 : digoff;
441 if (*adj > 0)
442 (*adj)--;
443 *adj *= -RX8025_ADJ_RESOLUTION;
444
445 return 0;
446}
447
448static int rx8025_set_clock_adjust(struct device *dev, int adj)
449{
450 struct i2c_client *client = to_i2c_client(dev);
451 u8 digoff;
452 int err;
453
454 adj /= -RX8025_ADJ_RESOLUTION;
455 if (adj > RX8025_ADJ_DATA_MAX)
456 adj = RX8025_ADJ_DATA_MAX;
457 else if (adj < RX8025_ADJ_DATA_MIN)
458 adj = RX8025_ADJ_DATA_MIN;
459 else if (adj > 0)
460 adj++;
461 else if (adj < 0)
462 adj += 128;
463 digoff = adj;
464
465 err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
466 if (err)
467 return err;
468
469 dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff);
470
471 return 0;
472}
473
474static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
475 struct device_attribute *attr,
476 char *buf)
477{
478 int err, adj;
479
480 err = rx8025_get_clock_adjust(dev, &adj);
481 if (err)
482 return err;
483
484 return sprintf(buf, "%d\n", adj);
485}
486
487static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
488 struct device_attribute *attr,
489 const char *buf, size_t count)
490{
491 int adj, err;
492
493 if (sscanf(buf, "%i", &adj) != 1)
494 return -EINVAL;
495
496 err = rx8025_set_clock_adjust(dev, adj);
497
498 return err ? err : count;
499}
500
501static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO | S_IWUSR,
502 rx8025_sysfs_show_clock_adjust,
503 rx8025_sysfs_store_clock_adjust);
504
505static int rx8025_sysfs_register(struct device *dev)
506{
507 return device_create_file(dev, &dev_attr_clock_adjust_ppb);
508}
509
510static void rx8025_sysfs_unregister(struct device *dev)
511{
512 device_remove_file(dev, &dev_attr_clock_adjust_ppb);
513}
514
515static int rx8025_probe(struct i2c_client *client,
516 const struct i2c_device_id *id)
517{
518 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
519 struct rx8025_data *rx8025;
520 int err = 0;
521
522 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
523 | I2C_FUNC_SMBUS_I2C_BLOCK)) {
524 dev_err(&adapter->dev,
525 "doesn't support required functionality\n");
526 return -EIO;
527 }
528
529 rx8025 = devm_kzalloc(&client->dev, sizeof(*rx8025), GFP_KERNEL);
530 if (!rx8025)
531 return -ENOMEM;
532
533 rx8025->client = client;
534 i2c_set_clientdata(client, rx8025);
535
536 err = rx8025_init_client(client);
537 if (err)
538 return err;
539
540 rx8025->rtc = devm_rtc_device_register(&client->dev, client->name,
541 &rx8025_rtc_ops, THIS_MODULE);
542 if (IS_ERR(rx8025->rtc)) {
543 dev_err(&client->dev, "unable to register the class device\n");
544 return PTR_ERR(rx8025->rtc);
545 }
546
547 if (client->irq > 0) {
548 dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
549 err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
550 rx8025_handle_irq,
551 IRQF_ONESHOT,
552 "rx8025", client);
553 if (err) {
554 dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
555 client->irq = 0;
556 }
557 }
558
559 rx8025->rtc->max_user_freq = 1;
560
561 /* the rx8025 alarm only supports a minute accuracy */
562 rx8025->rtc->uie_unsupported = 1;
563
564 err = rx8025_sysfs_register(&client->dev);
565 return err;
566}
567
568static int rx8025_remove(struct i2c_client *client)
569{
570 rx8025_sysfs_unregister(&client->dev);
571 return 0;
572}
573
574static struct i2c_driver rx8025_driver = {
575 .driver = {
576 .name = "rtc-rx8025",
577 },
578 .probe = rx8025_probe,
579 .remove = rx8025_remove,
580 .id_table = rx8025_id,
581};
582
583module_i2c_driver(rx8025_driver);
584
585MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
586MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
587MODULE_LICENSE("GPL");