Loading...
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
647static int __init rx8025_init(void)
648{
649 return i2c_add_driver(&rx8025_driver);
650}
651
652static void __exit rx8025_exit(void)
653{
654 i2c_del_driver(&rx8025_driver);
655}
656
657MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
658MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
659MODULE_LICENSE("GPL");
660
661module_init(rx8025_init);
662module_exit(rx8025_exit);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Driver for Epson's RTC module RX-8025 SA/NB
4 *
5 * Copyright (C) 2009 Wolfgang Grandegger <wg@grandegger.com>
6 *
7 * Copyright (C) 2005 by Digi International Inc.
8 * All rights reserved.
9 *
10 * Modified by fengjh at rising.com.cn
11 * <lm-sensors@lm-sensors.org>
12 * 2006.11
13 *
14 * Code cleanup by Sergei Poselenov, <sposelenov@emcraft.com>
15 * Converted to new style by Wolfgang Grandegger <wg@grandegger.com>
16 * Alarm and periodic interrupt added by Dmitry Rakhchev <rda@emcraft.com>
17 */
18#include <linux/bcd.h>
19#include <linux/bitops.h>
20#include <linux/i2c.h>
21#include <linux/kernel.h>
22#include <linux/module.h>
23#include <linux/rtc.h>
24
25/* Register definitions */
26#define RX8025_REG_SEC 0x00
27#define RX8025_REG_MIN 0x01
28#define RX8025_REG_HOUR 0x02
29#define RX8025_REG_WDAY 0x03
30#define RX8025_REG_MDAY 0x04
31#define RX8025_REG_MONTH 0x05
32#define RX8025_REG_YEAR 0x06
33#define RX8025_REG_DIGOFF 0x07
34#define RX8025_REG_ALWMIN 0x08
35#define RX8025_REG_ALWHOUR 0x09
36#define RX8025_REG_ALWWDAY 0x0a
37#define RX8025_REG_ALDMIN 0x0b
38#define RX8025_REG_ALDHOUR 0x0c
39/* 0x0d is reserved */
40#define RX8025_REG_CTRL1 0x0e
41#define RX8025_REG_CTRL2 0x0f
42
43#define RX8025_BIT_CTRL1_CT (7 << 0)
44/* 1 Hz periodic level irq */
45#define RX8025_BIT_CTRL1_CT_1HZ 4
46#define RX8025_BIT_CTRL1_TEST BIT(3)
47#define RX8025_BIT_CTRL1_1224 BIT(5)
48#define RX8025_BIT_CTRL1_DALE BIT(6)
49#define RX8025_BIT_CTRL1_WALE BIT(7)
50
51#define RX8025_BIT_CTRL2_DAFG BIT(0)
52#define RX8025_BIT_CTRL2_WAFG BIT(1)
53#define RX8025_BIT_CTRL2_CTFG BIT(2)
54#define RX8025_BIT_CTRL2_PON BIT(4)
55#define RX8025_BIT_CTRL2_XST BIT(5)
56#define RX8025_BIT_CTRL2_VDET BIT(6)
57
58/* Clock precision adjustment */
59#define RX8025_ADJ_RESOLUTION 3050 /* in ppb */
60#define RX8025_ADJ_DATA_MAX 62
61#define RX8025_ADJ_DATA_MIN -62
62
63static const struct i2c_device_id rx8025_id[] = {
64 { "rx8025", 0 },
65 { }
66};
67MODULE_DEVICE_TABLE(i2c, rx8025_id);
68
69struct rx8025_data {
70 struct rtc_device *rtc;
71 u8 ctrl1;
72};
73
74static s32 rx8025_read_reg(const struct i2c_client *client, u8 number)
75{
76 return i2c_smbus_read_byte_data(client, number << 4);
77}
78
79static int rx8025_read_regs(const struct i2c_client *client,
80 u8 number, u8 length, u8 *values)
81{
82 int ret = i2c_smbus_read_i2c_block_data(client, number << 4, length,
83 values);
84 if (ret != length)
85 return ret < 0 ? ret : -EIO;
86
87 return 0;
88}
89
90static s32 rx8025_write_reg(const struct i2c_client *client, u8 number,
91 u8 value)
92{
93 return i2c_smbus_write_byte_data(client, number << 4, value);
94}
95
96static s32 rx8025_write_regs(const struct i2c_client *client,
97 u8 number, u8 length, const u8 *values)
98{
99 return i2c_smbus_write_i2c_block_data(client, number << 4,
100 length, values);
101}
102
103static int rx8025_check_validity(struct device *dev)
104{
105 struct i2c_client *client = to_i2c_client(dev);
106 int ctrl2;
107
108 ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
109 if (ctrl2 < 0)
110 return ctrl2;
111
112 if (ctrl2 & RX8025_BIT_CTRL2_VDET)
113 dev_warn(dev, "power voltage drop detected\n");
114
115 if (ctrl2 & RX8025_BIT_CTRL2_PON) {
116 dev_warn(dev, "power-on reset detected, date is invalid\n");
117 return -EINVAL;
118 }
119
120 if (!(ctrl2 & RX8025_BIT_CTRL2_XST)) {
121 dev_warn(dev, "crystal stopped, date is invalid\n");
122 return -EINVAL;
123 }
124
125 return 0;
126}
127
128static int rx8025_reset_validity(struct i2c_client *client)
129{
130 int ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
131
132 if (ctrl2 < 0)
133 return ctrl2;
134
135 ctrl2 &= ~(RX8025_BIT_CTRL2_PON | RX8025_BIT_CTRL2_VDET);
136
137 return rx8025_write_reg(client, RX8025_REG_CTRL2,
138 ctrl2 | RX8025_BIT_CTRL2_XST);
139}
140
141static irqreturn_t rx8025_handle_irq(int irq, void *dev_id)
142{
143 struct i2c_client *client = dev_id;
144 struct rx8025_data *rx8025 = i2c_get_clientdata(client);
145 int status;
146
147 rtc_lock(rx8025->rtc);
148 status = rx8025_read_reg(client, RX8025_REG_CTRL2);
149 if (status < 0)
150 goto out;
151
152 if (!(status & RX8025_BIT_CTRL2_XST))
153 dev_warn(&client->dev, "Oscillation stop was detected,"
154 "you may have to readjust the clock\n");
155
156 if (status & RX8025_BIT_CTRL2_CTFG) {
157 /* periodic */
158 status &= ~RX8025_BIT_CTRL2_CTFG;
159 rtc_update_irq(rx8025->rtc, 1, RTC_PF | RTC_IRQF);
160 }
161
162 if (status & RX8025_BIT_CTRL2_DAFG) {
163 /* alarm */
164 status &= RX8025_BIT_CTRL2_DAFG;
165 if (rx8025_write_reg(client, RX8025_REG_CTRL1,
166 rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE))
167 goto out;
168 rtc_update_irq(rx8025->rtc, 1, RTC_AF | RTC_IRQF);
169 }
170
171out:
172 rtc_unlock(rx8025->rtc);
173
174 return IRQ_HANDLED;
175}
176
177static int rx8025_get_time(struct device *dev, struct rtc_time *dt)
178{
179 struct i2c_client *client = to_i2c_client(dev);
180 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
181 u8 date[7];
182 int err;
183
184 err = rx8025_check_validity(dev);
185 if (err)
186 return err;
187
188 err = rx8025_read_regs(client, RX8025_REG_SEC, 7, date);
189 if (err)
190 return err;
191
192 dev_dbg(dev, "%s: read %7ph\n", __func__, date);
193
194 dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
195 dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
196 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
197 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);
198 else
199 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12
200 + (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0);
201
202 dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);
203 dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
204 dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]) + 100;
205
206 dev_dbg(dev, "%s: date %ptRr\n", __func__, dt);
207
208 return 0;
209}
210
211static int rx8025_set_time(struct device *dev, struct rtc_time *dt)
212{
213 struct i2c_client *client = to_i2c_client(dev);
214 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
215 u8 date[7];
216 int ret;
217
218 if ((dt->tm_year < 100) || (dt->tm_year > 199))
219 return -EINVAL;
220
221 /*
222 * Here the read-only bits are written as "0". I'm not sure if that
223 * is sound.
224 */
225 date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
226 date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
227 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
228 date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
229 else
230 date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
231 | bin2bcd((dt->tm_hour + 11) % 12 + 1);
232
233 date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
234 date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
235 date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
236 date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year - 100);
237
238 dev_dbg(dev, "%s: write %7ph\n", __func__, date);
239
240 ret = rx8025_write_regs(client, RX8025_REG_SEC, 7, date);
241 if (ret < 0)
242 return ret;
243
244 return rx8025_reset_validity(client);
245}
246
247static int rx8025_init_client(struct i2c_client *client)
248{
249 struct rx8025_data *rx8025 = i2c_get_clientdata(client);
250 u8 ctrl[2], ctrl2;
251 int need_clear = 0;
252 int err;
253
254 err = rx8025_read_regs(client, RX8025_REG_CTRL1, 2, ctrl);
255 if (err)
256 goto out;
257
258 /* Keep test bit zero ! */
259 rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;
260
261 if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG | RX8025_BIT_CTRL2_WAFG)) {
262 dev_warn(&client->dev, "Alarm was detected\n");
263 need_clear = 1;
264 }
265
266 if (ctrl[1] & RX8025_BIT_CTRL2_CTFG)
267 need_clear = 1;
268
269 if (need_clear) {
270 ctrl2 = ctrl[1];
271 ctrl2 &= ~(RX8025_BIT_CTRL2_CTFG | RX8025_BIT_CTRL2_WAFG |
272 RX8025_BIT_CTRL2_DAFG);
273
274 err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
275 }
276out:
277 return err;
278}
279
280/* Alarm support */
281static int rx8025_read_alarm(struct device *dev, struct rtc_wkalrm *t)
282{
283 struct i2c_client *client = to_i2c_client(dev);
284 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
285 u8 ald[2];
286 int ctrl2, err;
287
288 if (client->irq <= 0)
289 return -EINVAL;
290
291 err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);
292 if (err)
293 return err;
294
295 ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
296 if (ctrl2 < 0)
297 return ctrl2;
298
299 dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",
300 __func__, ald[0], ald[1], ctrl2);
301
302 /* Hardware alarms precision is 1 minute! */
303 t->time.tm_sec = 0;
304 t->time.tm_min = bcd2bin(ald[0] & 0x7f);
305 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
306 t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
307 else
308 t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
309 + (ald[1] & 0x20 ? 12 : 0);
310
311 dev_dbg(dev, "%s: date: %ptRr\n", __func__, &t->time);
312 t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
313 t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
314
315 return err;
316}
317
318static int rx8025_set_alarm(struct device *dev, struct rtc_wkalrm *t)
319{
320 struct i2c_client *client = to_i2c_client(dev);
321 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
322 u8 ald[2];
323 int err;
324
325 if (client->irq <= 0)
326 return -EINVAL;
327
328 /*
329 * Hardware alarm precision is 1 minute!
330 * round up to nearest minute
331 */
332 if (t->time.tm_sec) {
333 time64_t alarm_time = rtc_tm_to_time64(&t->time);
334
335 alarm_time += 60 - t->time.tm_sec;
336 rtc_time64_to_tm(alarm_time, &t->time);
337 }
338
339 ald[0] = bin2bcd(t->time.tm_min);
340 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
341 ald[1] = bin2bcd(t->time.tm_hour);
342 else
343 ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
344 | bin2bcd((t->time.tm_hour + 11) % 12 + 1);
345
346 dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);
347
348 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
349 rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
350 err = rx8025_write_reg(client, RX8025_REG_CTRL1,
351 rx8025->ctrl1);
352 if (err)
353 return err;
354 }
355 err = rx8025_write_regs(client, RX8025_REG_ALDMIN, 2, ald);
356 if (err)
357 return err;
358
359 if (t->enabled) {
360 rx8025->ctrl1 |= RX8025_BIT_CTRL1_DALE;
361 err = rx8025_write_reg(client, RX8025_REG_CTRL1,
362 rx8025->ctrl1);
363 if (err)
364 return err;
365 }
366
367 return 0;
368}
369
370static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
371{
372 struct i2c_client *client = to_i2c_client(dev);
373 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
374 u8 ctrl1;
375 int err;
376
377 ctrl1 = rx8025->ctrl1;
378 if (enabled)
379 ctrl1 |= RX8025_BIT_CTRL1_DALE;
380 else
381 ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
382
383 if (ctrl1 != rx8025->ctrl1) {
384 rx8025->ctrl1 = ctrl1;
385 err = rx8025_write_reg(client, RX8025_REG_CTRL1,
386 rx8025->ctrl1);
387 if (err)
388 return err;
389 }
390 return 0;
391}
392
393static const struct rtc_class_ops rx8025_rtc_ops = {
394 .read_time = rx8025_get_time,
395 .set_time = rx8025_set_time,
396 .read_alarm = rx8025_read_alarm,
397 .set_alarm = rx8025_set_alarm,
398 .alarm_irq_enable = rx8025_alarm_irq_enable,
399};
400
401/*
402 * Clock precision adjustment support
403 *
404 * According to the RX8025 SA/NB application manual the frequency and
405 * temperature characteristics can be approximated using the following
406 * equation:
407 *
408 * df = a * (ut - t)**2
409 *
410 * df: Frequency deviation in any temperature
411 * a : Coefficient = (-35 +-5) * 10**-9
412 * ut: Ultimate temperature in degree = +25 +-5 degree
413 * t : Any temperature in degree
414 *
415 * Note that the clock adjustment in ppb must be entered (which is
416 * the negative value of the deviation).
417 */
418static int rx8025_get_clock_adjust(struct device *dev, int *adj)
419{
420 struct i2c_client *client = to_i2c_client(dev);
421 int digoff;
422
423 digoff = rx8025_read_reg(client, RX8025_REG_DIGOFF);
424 if (digoff < 0)
425 return digoff;
426
427 *adj = digoff >= 64 ? digoff - 128 : digoff;
428 if (*adj > 0)
429 (*adj)--;
430 *adj *= -RX8025_ADJ_RESOLUTION;
431
432 return 0;
433}
434
435static int rx8025_set_clock_adjust(struct device *dev, int adj)
436{
437 struct i2c_client *client = to_i2c_client(dev);
438 u8 digoff;
439 int err;
440
441 adj /= -RX8025_ADJ_RESOLUTION;
442 if (adj > RX8025_ADJ_DATA_MAX)
443 adj = RX8025_ADJ_DATA_MAX;
444 else if (adj < RX8025_ADJ_DATA_MIN)
445 adj = RX8025_ADJ_DATA_MIN;
446 else if (adj > 0)
447 adj++;
448 else if (adj < 0)
449 adj += 128;
450 digoff = adj;
451
452 err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
453 if (err)
454 return err;
455
456 dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff);
457
458 return 0;
459}
460
461static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
462 struct device_attribute *attr,
463 char *buf)
464{
465 int err, adj;
466
467 err = rx8025_get_clock_adjust(dev, &adj);
468 if (err)
469 return err;
470
471 return sprintf(buf, "%d\n", adj);
472}
473
474static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
475 struct device_attribute *attr,
476 const char *buf, size_t count)
477{
478 int adj, err;
479
480 if (sscanf(buf, "%i", &adj) != 1)
481 return -EINVAL;
482
483 err = rx8025_set_clock_adjust(dev, adj);
484
485 return err ? err : count;
486}
487
488static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO | S_IWUSR,
489 rx8025_sysfs_show_clock_adjust,
490 rx8025_sysfs_store_clock_adjust);
491
492static int rx8025_sysfs_register(struct device *dev)
493{
494 return device_create_file(dev, &dev_attr_clock_adjust_ppb);
495}
496
497static void rx8025_sysfs_unregister(struct device *dev)
498{
499 device_remove_file(dev, &dev_attr_clock_adjust_ppb);
500}
501
502static int rx8025_probe(struct i2c_client *client,
503 const struct i2c_device_id *id)
504{
505 struct i2c_adapter *adapter = client->adapter;
506 struct rx8025_data *rx8025;
507 int err = 0;
508
509 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
510 | I2C_FUNC_SMBUS_I2C_BLOCK)) {
511 dev_err(&adapter->dev,
512 "doesn't support required functionality\n");
513 return -EIO;
514 }
515
516 rx8025 = devm_kzalloc(&client->dev, sizeof(*rx8025), GFP_KERNEL);
517 if (!rx8025)
518 return -ENOMEM;
519
520 i2c_set_clientdata(client, rx8025);
521
522 err = rx8025_init_client(client);
523 if (err)
524 return err;
525
526 rx8025->rtc = devm_rtc_device_register(&client->dev, client->name,
527 &rx8025_rtc_ops, THIS_MODULE);
528 if (IS_ERR(rx8025->rtc)) {
529 dev_err(&client->dev, "unable to register the class device\n");
530 return PTR_ERR(rx8025->rtc);
531 }
532
533 if (client->irq > 0) {
534 dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
535 err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
536 rx8025_handle_irq,
537 IRQF_ONESHOT,
538 "rx8025", client);
539 if (err) {
540 dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
541 client->irq = 0;
542 }
543 }
544
545 rx8025->rtc->max_user_freq = 1;
546
547 /* the rx8025 alarm only supports a minute accuracy */
548 rx8025->rtc->uie_unsupported = 1;
549
550 err = rx8025_sysfs_register(&client->dev);
551 return err;
552}
553
554static int rx8025_remove(struct i2c_client *client)
555{
556 rx8025_sysfs_unregister(&client->dev);
557 return 0;
558}
559
560static struct i2c_driver rx8025_driver = {
561 .driver = {
562 .name = "rtc-rx8025",
563 },
564 .probe = rx8025_probe,
565 .remove = rx8025_remove,
566 .id_table = rx8025_id,
567};
568
569module_i2c_driver(rx8025_driver);
570
571MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
572MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
573MODULE_LICENSE("GPL");