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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 * <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 rtc_valid_tm(dt);
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 t->time.tm_wday = -1;
323 t->time.tm_mday = -1;
324 t->time.tm_mon = -1;
325 t->time.tm_year = -1;
326
327 dev_dbg(dev, "%s: date: %ds %dm %dh %dmd %dm %dy\n",
328 __func__,
329 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
330 t->time.tm_mday, t->time.tm_mon, t->time.tm_year);
331 t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
332 t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
333
334 return err;
335}
336
337static int rx8025_set_alarm(struct device *dev, struct rtc_wkalrm *t)
338{
339 struct i2c_client *client = to_i2c_client(dev);
340 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
341 u8 ald[2];
342 int err;
343
344 if (client->irq <= 0)
345 return -EINVAL;
346
347 /*
348 * Hardware alarm precision is 1 minute!
349 * round up to nearest minute
350 */
351 if (t->time.tm_sec) {
352 time64_t alarm_time = rtc_tm_to_time64(&t->time);
353
354 alarm_time += 60 - t->time.tm_sec;
355 rtc_time64_to_tm(alarm_time, &t->time);
356 }
357
358 ald[0] = bin2bcd(t->time.tm_min);
359 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
360 ald[1] = bin2bcd(t->time.tm_hour);
361 else
362 ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
363 | bin2bcd((t->time.tm_hour + 11) % 12 + 1);
364
365 dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);
366
367 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
368 rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
369 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
370 rx8025->ctrl1);
371 if (err)
372 return err;
373 }
374 err = rx8025_write_regs(rx8025->client, RX8025_REG_ALDMIN, 2, ald);
375 if (err)
376 return err;
377
378 if (t->enabled) {
379 rx8025->ctrl1 |= RX8025_BIT_CTRL1_DALE;
380 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
381 rx8025->ctrl1);
382 if (err)
383 return err;
384 }
385
386 return 0;
387}
388
389static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
390{
391 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
392 u8 ctrl1;
393 int err;
394
395 ctrl1 = rx8025->ctrl1;
396 if (enabled)
397 ctrl1 |= RX8025_BIT_CTRL1_DALE;
398 else
399 ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
400
401 if (ctrl1 != rx8025->ctrl1) {
402 rx8025->ctrl1 = ctrl1;
403 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
404 rx8025->ctrl1);
405 if (err)
406 return err;
407 }
408 return 0;
409}
410
411static struct rtc_class_ops rx8025_rtc_ops = {
412 .read_time = rx8025_get_time,
413 .set_time = rx8025_set_time,
414 .read_alarm = rx8025_read_alarm,
415 .set_alarm = rx8025_set_alarm,
416 .alarm_irq_enable = rx8025_alarm_irq_enable,
417};
418
419/*
420 * Clock precision adjustment support
421 *
422 * According to the RX8025 SA/NB application manual the frequency and
423 * temperature characteristics can be approximated using the following
424 * equation:
425 *
426 * df = a * (ut - t)**2
427 *
428 * df: Frequency deviation in any temperature
429 * a : Coefficient = (-35 +-5) * 10**-9
430 * ut: Ultimate temperature in degree = +25 +-5 degree
431 * t : Any temperature in degree
432 *
433 * Note that the clock adjustment in ppb must be entered (which is
434 * the negative value of the deviation).
435 */
436static int rx8025_get_clock_adjust(struct device *dev, int *adj)
437{
438 struct i2c_client *client = to_i2c_client(dev);
439 int digoff;
440
441 digoff = rx8025_read_reg(client, RX8025_REG_DIGOFF);
442 if (digoff < 0)
443 return digoff;
444
445 *adj = digoff >= 64 ? digoff - 128 : digoff;
446 if (*adj > 0)
447 (*adj)--;
448 *adj *= -RX8025_ADJ_RESOLUTION;
449
450 return 0;
451}
452
453static int rx8025_set_clock_adjust(struct device *dev, int adj)
454{
455 struct i2c_client *client = to_i2c_client(dev);
456 u8 digoff;
457 int err;
458
459 adj /= -RX8025_ADJ_RESOLUTION;
460 if (adj > RX8025_ADJ_DATA_MAX)
461 adj = RX8025_ADJ_DATA_MAX;
462 else if (adj < RX8025_ADJ_DATA_MIN)
463 adj = RX8025_ADJ_DATA_MIN;
464 else if (adj > 0)
465 adj++;
466 else if (adj < 0)
467 adj += 128;
468 digoff = adj;
469
470 err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
471 if (err)
472 return err;
473
474 dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff);
475
476 return 0;
477}
478
479static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
480 struct device_attribute *attr,
481 char *buf)
482{
483 int err, adj;
484
485 err = rx8025_get_clock_adjust(dev, &adj);
486 if (err)
487 return err;
488
489 return sprintf(buf, "%d\n", adj);
490}
491
492static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
493 struct device_attribute *attr,
494 const char *buf, size_t count)
495{
496 int adj, err;
497
498 if (sscanf(buf, "%i", &adj) != 1)
499 return -EINVAL;
500
501 err = rx8025_set_clock_adjust(dev, adj);
502
503 return err ? err : count;
504}
505
506static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO | S_IWUSR,
507 rx8025_sysfs_show_clock_adjust,
508 rx8025_sysfs_store_clock_adjust);
509
510static int rx8025_sysfs_register(struct device *dev)
511{
512 return device_create_file(dev, &dev_attr_clock_adjust_ppb);
513}
514
515static void rx8025_sysfs_unregister(struct device *dev)
516{
517 device_remove_file(dev, &dev_attr_clock_adjust_ppb);
518}
519
520static int rx8025_probe(struct i2c_client *client,
521 const struct i2c_device_id *id)
522{
523 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
524 struct rx8025_data *rx8025;
525 int err = 0;
526
527 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
528 | I2C_FUNC_SMBUS_I2C_BLOCK)) {
529 dev_err(&adapter->dev,
530 "doesn't support required functionality\n");
531 return -EIO;
532 }
533
534 rx8025 = devm_kzalloc(&client->dev, sizeof(*rx8025), GFP_KERNEL);
535 if (!rx8025)
536 return -ENOMEM;
537
538 rx8025->client = client;
539 i2c_set_clientdata(client, rx8025);
540
541 err = rx8025_init_client(client);
542 if (err)
543 return err;
544
545 rx8025->rtc = devm_rtc_device_register(&client->dev, client->name,
546 &rx8025_rtc_ops, THIS_MODULE);
547 if (IS_ERR(rx8025->rtc)) {
548 dev_err(&client->dev, "unable to register the class device\n");
549 return PTR_ERR(rx8025->rtc);
550 }
551
552 if (client->irq > 0) {
553 dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
554 err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
555 rx8025_handle_irq,
556 IRQF_ONESHOT,
557 "rx8025", client);
558 if (err) {
559 dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
560 client->irq = 0;
561 }
562 }
563
564 rx8025->rtc->max_user_freq = 1;
565
566 /* the rx8025 alarm only supports a minute accuracy */
567 rx8025->rtc->uie_unsupported = 1;
568
569 err = rx8025_sysfs_register(&client->dev);
570 return err;
571}
572
573static int rx8025_remove(struct i2c_client *client)
574{
575 rx8025_sysfs_unregister(&client->dev);
576 return 0;
577}
578
579static struct i2c_driver rx8025_driver = {
580 .driver = {
581 .name = "rtc-rx8025",
582 },
583 .probe = rx8025_probe,
584 .remove = rx8025_remove,
585 .id_table = rx8025_id,
586};
587
588module_i2c_driver(rx8025_driver);
589
590MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
591MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
592MODULE_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 rtc_valid_tm(dt);
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");