Loading...
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 struct mutex *lock = &rx8025->rtc->ops_lock;
146 int status;
147
148 mutex_lock(lock);
149 status = rx8025_read_reg(client, RX8025_REG_CTRL2);
150 if (status < 0)
151 goto out;
152
153 if (!(status & RX8025_BIT_CTRL2_XST))
154 dev_warn(&client->dev, "Oscillation stop was detected,"
155 "you may have to readjust the clock\n");
156
157 if (status & RX8025_BIT_CTRL2_CTFG) {
158 /* periodic */
159 status &= ~RX8025_BIT_CTRL2_CTFG;
160 rtc_update_irq(rx8025->rtc, 1, RTC_PF | RTC_IRQF);
161 }
162
163 if (status & RX8025_BIT_CTRL2_DAFG) {
164 /* alarm */
165 status &= RX8025_BIT_CTRL2_DAFG;
166 if (rx8025_write_reg(client, RX8025_REG_CTRL1,
167 rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE))
168 goto out;
169 rtc_update_irq(rx8025->rtc, 1, RTC_AF | RTC_IRQF);
170 }
171
172out:
173 mutex_unlock(lock);
174
175 return IRQ_HANDLED;
176}
177
178static int rx8025_get_time(struct device *dev, struct rtc_time *dt)
179{
180 struct i2c_client *client = to_i2c_client(dev);
181 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
182 u8 date[7];
183 int err;
184
185 err = rx8025_check_validity(dev);
186 if (err)
187 return err;
188
189 err = rx8025_read_regs(client, RX8025_REG_SEC, 7, date);
190 if (err)
191 return err;
192
193 dev_dbg(dev, "%s: read %7ph\n", __func__, date);
194
195 dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
196 dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
197 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
198 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);
199 else
200 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12
201 + (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0);
202
203 dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);
204 dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
205 dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]) + 100;
206
207 dev_dbg(dev, "%s: date %ptRr\n", __func__, dt);
208
209 return 0;
210}
211
212static int rx8025_set_time(struct device *dev, struct rtc_time *dt)
213{
214 struct i2c_client *client = to_i2c_client(dev);
215 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
216 u8 date[7];
217 int ret;
218
219 if ((dt->tm_year < 100) || (dt->tm_year > 199))
220 return -EINVAL;
221
222 /*
223 * Here the read-only bits are written as "0". I'm not sure if that
224 * is sound.
225 */
226 date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
227 date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
228 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
229 date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
230 else
231 date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
232 | bin2bcd((dt->tm_hour + 11) % 12 + 1);
233
234 date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
235 date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
236 date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
237 date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year - 100);
238
239 dev_dbg(dev, "%s: write %7ph\n", __func__, date);
240
241 ret = rx8025_write_regs(client, RX8025_REG_SEC, 7, date);
242 if (ret < 0)
243 return ret;
244
245 return rx8025_reset_validity(client);
246}
247
248static int rx8025_init_client(struct i2c_client *client)
249{
250 struct rx8025_data *rx8025 = i2c_get_clientdata(client);
251 u8 ctrl[2], ctrl2;
252 int need_clear = 0;
253 int err;
254
255 err = rx8025_read_regs(client, RX8025_REG_CTRL1, 2, ctrl);
256 if (err)
257 goto out;
258
259 /* Keep test bit zero ! */
260 rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;
261
262 if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG | RX8025_BIT_CTRL2_WAFG)) {
263 dev_warn(&client->dev, "Alarm was detected\n");
264 need_clear = 1;
265 }
266
267 if (ctrl[1] & RX8025_BIT_CTRL2_CTFG)
268 need_clear = 1;
269
270 if (need_clear) {
271 ctrl2 = ctrl[1];
272 ctrl2 &= ~(RX8025_BIT_CTRL2_CTFG | RX8025_BIT_CTRL2_WAFG |
273 RX8025_BIT_CTRL2_DAFG);
274
275 err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
276 }
277out:
278 return err;
279}
280
281/* Alarm support */
282static int rx8025_read_alarm(struct device *dev, struct rtc_wkalrm *t)
283{
284 struct i2c_client *client = to_i2c_client(dev);
285 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
286 u8 ald[2];
287 int ctrl2, err;
288
289 if (client->irq <= 0)
290 return -EINVAL;
291
292 err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);
293 if (err)
294 return err;
295
296 ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
297 if (ctrl2 < 0)
298 return ctrl2;
299
300 dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",
301 __func__, ald[0], ald[1], ctrl2);
302
303 /* Hardware alarms precision is 1 minute! */
304 t->time.tm_sec = 0;
305 t->time.tm_min = bcd2bin(ald[0] & 0x7f);
306 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
307 t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
308 else
309 t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
310 + (ald[1] & 0x20 ? 12 : 0);
311
312 dev_dbg(dev, "%s: date: %ptRr\n", __func__, &t->time);
313 t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
314 t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
315
316 return err;
317}
318
319static int rx8025_set_alarm(struct device *dev, struct rtc_wkalrm *t)
320{
321 struct i2c_client *client = to_i2c_client(dev);
322 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
323 u8 ald[2];
324 int err;
325
326 if (client->irq <= 0)
327 return -EINVAL;
328
329 /*
330 * Hardware alarm precision is 1 minute!
331 * round up to nearest minute
332 */
333 if (t->time.tm_sec) {
334 time64_t alarm_time = rtc_tm_to_time64(&t->time);
335
336 alarm_time += 60 - t->time.tm_sec;
337 rtc_time64_to_tm(alarm_time, &t->time);
338 }
339
340 ald[0] = bin2bcd(t->time.tm_min);
341 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
342 ald[1] = bin2bcd(t->time.tm_hour);
343 else
344 ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
345 | bin2bcd((t->time.tm_hour + 11) % 12 + 1);
346
347 dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);
348
349 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
350 rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
351 err = rx8025_write_reg(client, RX8025_REG_CTRL1,
352 rx8025->ctrl1);
353 if (err)
354 return err;
355 }
356 err = rx8025_write_regs(client, RX8025_REG_ALDMIN, 2, ald);
357 if (err)
358 return err;
359
360 if (t->enabled) {
361 rx8025->ctrl1 |= RX8025_BIT_CTRL1_DALE;
362 err = rx8025_write_reg(client, RX8025_REG_CTRL1,
363 rx8025->ctrl1);
364 if (err)
365 return err;
366 }
367
368 return 0;
369}
370
371static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
372{
373 struct i2c_client *client = to_i2c_client(dev);
374 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
375 u8 ctrl1;
376 int err;
377
378 ctrl1 = rx8025->ctrl1;
379 if (enabled)
380 ctrl1 |= RX8025_BIT_CTRL1_DALE;
381 else
382 ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
383
384 if (ctrl1 != rx8025->ctrl1) {
385 rx8025->ctrl1 = ctrl1;
386 err = rx8025_write_reg(client, RX8025_REG_CTRL1,
387 rx8025->ctrl1);
388 if (err)
389 return err;
390 }
391 return 0;
392}
393
394static const struct rtc_class_ops rx8025_rtc_ops = {
395 .read_time = rx8025_get_time,
396 .set_time = rx8025_set_time,
397 .read_alarm = rx8025_read_alarm,
398 .set_alarm = rx8025_set_alarm,
399 .alarm_irq_enable = rx8025_alarm_irq_enable,
400};
401
402/*
403 * Clock precision adjustment support
404 *
405 * According to the RX8025 SA/NB application manual the frequency and
406 * temperature characteristics can be approximated using the following
407 * equation:
408 *
409 * df = a * (ut - t)**2
410 *
411 * df: Frequency deviation in any temperature
412 * a : Coefficient = (-35 +-5) * 10**-9
413 * ut: Ultimate temperature in degree = +25 +-5 degree
414 * t : Any temperature in degree
415 *
416 * Note that the clock adjustment in ppb must be entered (which is
417 * the negative value of the deviation).
418 */
419static int rx8025_get_clock_adjust(struct device *dev, int *adj)
420{
421 struct i2c_client *client = to_i2c_client(dev);
422 int digoff;
423
424 digoff = rx8025_read_reg(client, RX8025_REG_DIGOFF);
425 if (digoff < 0)
426 return digoff;
427
428 *adj = digoff >= 64 ? digoff - 128 : digoff;
429 if (*adj > 0)
430 (*adj)--;
431 *adj *= -RX8025_ADJ_RESOLUTION;
432
433 return 0;
434}
435
436static int rx8025_set_clock_adjust(struct device *dev, int adj)
437{
438 struct i2c_client *client = to_i2c_client(dev);
439 u8 digoff;
440 int err;
441
442 adj /= -RX8025_ADJ_RESOLUTION;
443 if (adj > RX8025_ADJ_DATA_MAX)
444 adj = RX8025_ADJ_DATA_MAX;
445 else if (adj < RX8025_ADJ_DATA_MIN)
446 adj = RX8025_ADJ_DATA_MIN;
447 else if (adj > 0)
448 adj++;
449 else if (adj < 0)
450 adj += 128;
451 digoff = adj;
452
453 err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
454 if (err)
455 return err;
456
457 dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff);
458
459 return 0;
460}
461
462static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
463 struct device_attribute *attr,
464 char *buf)
465{
466 int err, adj;
467
468 err = rx8025_get_clock_adjust(dev, &adj);
469 if (err)
470 return err;
471
472 return sprintf(buf, "%d\n", adj);
473}
474
475static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
476 struct device_attribute *attr,
477 const char *buf, size_t count)
478{
479 int adj, err;
480
481 if (sscanf(buf, "%i", &adj) != 1)
482 return -EINVAL;
483
484 err = rx8025_set_clock_adjust(dev, adj);
485
486 return err ? err : count;
487}
488
489static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO | S_IWUSR,
490 rx8025_sysfs_show_clock_adjust,
491 rx8025_sysfs_store_clock_adjust);
492
493static int rx8025_sysfs_register(struct device *dev)
494{
495 return device_create_file(dev, &dev_attr_clock_adjust_ppb);
496}
497
498static void rx8025_sysfs_unregister(struct device *dev)
499{
500 device_remove_file(dev, &dev_attr_clock_adjust_ppb);
501}
502
503static int rx8025_probe(struct i2c_client *client,
504 const struct i2c_device_id *id)
505{
506 struct i2c_adapter *adapter = client->adapter;
507 struct rx8025_data *rx8025;
508 int err = 0;
509
510 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
511 | I2C_FUNC_SMBUS_I2C_BLOCK)) {
512 dev_err(&adapter->dev,
513 "doesn't support required functionality\n");
514 return -EIO;
515 }
516
517 rx8025 = devm_kzalloc(&client->dev, sizeof(*rx8025), GFP_KERNEL);
518 if (!rx8025)
519 return -ENOMEM;
520
521 i2c_set_clientdata(client, rx8025);
522
523 err = rx8025_init_client(client);
524 if (err)
525 return err;
526
527 rx8025->rtc = devm_rtc_device_register(&client->dev, client->name,
528 &rx8025_rtc_ops, THIS_MODULE);
529 if (IS_ERR(rx8025->rtc)) {
530 dev_err(&client->dev, "unable to register the class device\n");
531 return PTR_ERR(rx8025->rtc);
532 }
533
534 if (client->irq > 0) {
535 dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
536 err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
537 rx8025_handle_irq,
538 IRQF_ONESHOT,
539 "rx8025", client);
540 if (err) {
541 dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
542 client->irq = 0;
543 }
544 }
545
546 rx8025->rtc->max_user_freq = 1;
547
548 /* the rx8025 alarm only supports a minute accuracy */
549 rx8025->rtc->uie_unsupported = 1;
550
551 err = rx8025_sysfs_register(&client->dev);
552 return err;
553}
554
555static int rx8025_remove(struct i2c_client *client)
556{
557 rx8025_sysfs_unregister(&client->dev);
558 return 0;
559}
560
561static struct i2c_driver rx8025_driver = {
562 .driver = {
563 .name = "rtc-rx8025",
564 },
565 .probe = rx8025_probe,
566 .remove = rx8025_remove,
567 .id_table = rx8025_id,
568};
569
570module_i2c_driver(rx8025_driver);
571
572MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
573MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
574MODULE_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 * <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 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 = devm_kzalloc(&client->dev, sizeof(*rx8025), GFP_KERNEL);
553 if (!rx8025) {
554 err = -ENOMEM;
555 goto errout;
556 }
557
558 rx8025->client = client;
559 i2c_set_clientdata(client, rx8025);
560 INIT_WORK(&rx8025->work, rx8025_work);
561
562 err = rx8025_init_client(client, &need_reset);
563 if (err)
564 goto errout;
565
566 if (need_reset) {
567 struct rtc_time tm;
568 dev_info(&client->dev,
569 "bad conditions detected, resetting date\n");
570 rtc_time_to_tm(0, &tm); /* 1970/1/1 */
571 rx8025_set_time(&client->dev, &tm);
572 }
573
574 rx8025->rtc = devm_rtc_device_register(&client->dev, client->name,
575 &rx8025_rtc_ops, THIS_MODULE);
576 if (IS_ERR(rx8025->rtc)) {
577 err = PTR_ERR(rx8025->rtc);
578 dev_err(&client->dev, "unable to register the class device\n");
579 goto errout;
580 }
581
582 if (client->irq > 0) {
583 dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
584 err = request_irq(client->irq, rx8025_irq,
585 0, "rx8025", client);
586 if (err) {
587 dev_err(&client->dev, "unable to request IRQ\n");
588 goto errout;
589 }
590 }
591
592 rx8025->rtc->irq_freq = 1;
593 rx8025->rtc->max_user_freq = 1;
594
595 err = rx8025_sysfs_register(&client->dev);
596 if (err)
597 goto errout_irq;
598
599 return 0;
600
601errout_irq:
602 if (client->irq > 0)
603 free_irq(client->irq, client);
604
605errout:
606 dev_err(&adapter->dev, "probing for rx8025 failed\n");
607 return err;
608}
609
610static int rx8025_remove(struct i2c_client *client)
611{
612 struct rx8025_data *rx8025 = i2c_get_clientdata(client);
613 struct mutex *lock = &rx8025->rtc->ops_lock;
614
615 if (client->irq > 0) {
616 mutex_lock(lock);
617 rx8025->exiting = 1;
618 mutex_unlock(lock);
619
620 free_irq(client->irq, client);
621 cancel_work_sync(&rx8025->work);
622 }
623
624 rx8025_sysfs_unregister(&client->dev);
625 return 0;
626}
627
628static struct i2c_driver rx8025_driver = {
629 .driver = {
630 .name = "rtc-rx8025",
631 .owner = THIS_MODULE,
632 },
633 .probe = rx8025_probe,
634 .remove = rx8025_remove,
635 .id_table = rx8025_id,
636};
637
638module_i2c_driver(rx8025_driver);
639
640MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
641MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
642MODULE_LICENSE("GPL");