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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/kstrtox.h>
23#include <linux/module.h>
24#include <linux/rtc.h>
25
26/* Register definitions */
27#define RX8025_REG_SEC 0x00
28#define RX8025_REG_MIN 0x01
29#define RX8025_REG_HOUR 0x02
30#define RX8025_REG_WDAY 0x03
31#define RX8025_REG_MDAY 0x04
32#define RX8025_REG_MONTH 0x05
33#define RX8025_REG_YEAR 0x06
34#define RX8025_REG_DIGOFF 0x07
35#define RX8025_REG_ALWMIN 0x08
36#define RX8025_REG_ALWHOUR 0x09
37#define RX8025_REG_ALWWDAY 0x0a
38#define RX8025_REG_ALDMIN 0x0b
39#define RX8025_REG_ALDHOUR 0x0c
40/* 0x0d is reserved */
41#define RX8025_REG_CTRL1 0x0e
42#define RX8025_REG_CTRL2 0x0f
43
44#define RX8025_BIT_CTRL1_CT (7 << 0)
45/* 1 Hz periodic level irq */
46#define RX8025_BIT_CTRL1_CT_1HZ 4
47#define RX8025_BIT_CTRL1_TEST BIT(3)
48#define RX8025_BIT_CTRL1_1224 BIT(5)
49#define RX8025_BIT_CTRL1_DALE BIT(6)
50#define RX8025_BIT_CTRL1_WALE BIT(7)
51
52#define RX8025_BIT_CTRL2_DAFG BIT(0)
53#define RX8025_BIT_CTRL2_WAFG BIT(1)
54#define RX8025_BIT_CTRL2_CTFG BIT(2)
55#define RX8025_BIT_CTRL2_PON BIT(4)
56#define RX8025_BIT_CTRL2_XST BIT(5)
57#define RX8025_BIT_CTRL2_VDET BIT(6)
58
59#define RX8035_BIT_HOUR_1224 BIT(7)
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
66enum rx_model {
67 model_rx_unknown,
68 model_rx_8025,
69 model_rx_8035,
70 model_last
71};
72
73static const struct i2c_device_id rx8025_id[] = {
74 { "rx8025", model_rx_8025 },
75 { "rx8035", model_rx_8035 },
76 { }
77};
78MODULE_DEVICE_TABLE(i2c, rx8025_id);
79
80struct rx8025_data {
81 struct rtc_device *rtc;
82 enum rx_model model;
83 u8 ctrl1;
84 int is_24;
85};
86
87static s32 rx8025_read_reg(const struct i2c_client *client, u8 number)
88{
89 return i2c_smbus_read_byte_data(client, number << 4);
90}
91
92static int rx8025_read_regs(const struct i2c_client *client,
93 u8 number, u8 length, u8 *values)
94{
95 int ret = i2c_smbus_read_i2c_block_data(client, number << 4, length,
96 values);
97 if (ret != length)
98 return ret < 0 ? ret : -EIO;
99
100 return 0;
101}
102
103static s32 rx8025_write_reg(const struct i2c_client *client, u8 number,
104 u8 value)
105{
106 return i2c_smbus_write_byte_data(client, number << 4, value);
107}
108
109static s32 rx8025_write_regs(const struct i2c_client *client,
110 u8 number, u8 length, const u8 *values)
111{
112 return i2c_smbus_write_i2c_block_data(client, number << 4,
113 length, values);
114}
115
116static int rx8025_is_osc_stopped(enum rx_model model, int ctrl2)
117{
118 int xstp = ctrl2 & RX8025_BIT_CTRL2_XST;
119 /* XSTP bit has different polarity on RX-8025 vs RX-8035.
120 * RX-8025: 0 == oscillator stopped
121 * RX-8035: 1 == oscillator stopped
122 */
123
124 if (model == model_rx_8025)
125 xstp = !xstp;
126
127 return xstp;
128}
129
130static int rx8025_check_validity(struct device *dev)
131{
132 struct i2c_client *client = to_i2c_client(dev);
133 struct rx8025_data *drvdata = dev_get_drvdata(dev);
134 int ctrl2;
135 int xstp;
136
137 ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
138 if (ctrl2 < 0)
139 return ctrl2;
140
141 if (ctrl2 & RX8025_BIT_CTRL2_VDET)
142 dev_warn(dev, "power voltage drop detected\n");
143
144 if (ctrl2 & RX8025_BIT_CTRL2_PON) {
145 dev_warn(dev, "power-on reset detected, date is invalid\n");
146 return -EINVAL;
147 }
148
149 xstp = rx8025_is_osc_stopped(drvdata->model, ctrl2);
150 if (xstp) {
151 dev_warn(dev, "crystal stopped, date is invalid\n");
152 return -EINVAL;
153 }
154
155 return 0;
156}
157
158static int rx8025_reset_validity(struct i2c_client *client)
159{
160 struct rx8025_data *drvdata = i2c_get_clientdata(client);
161 int ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
162
163 if (ctrl2 < 0)
164 return ctrl2;
165
166 ctrl2 &= ~(RX8025_BIT_CTRL2_PON | RX8025_BIT_CTRL2_VDET);
167
168 if (drvdata->model == model_rx_8025)
169 ctrl2 |= RX8025_BIT_CTRL2_XST;
170 else
171 ctrl2 &= ~(RX8025_BIT_CTRL2_XST);
172
173 return rx8025_write_reg(client, RX8025_REG_CTRL2,
174 ctrl2);
175}
176
177static irqreturn_t rx8025_handle_irq(int irq, void *dev_id)
178{
179 struct i2c_client *client = dev_id;
180 struct rx8025_data *rx8025 = i2c_get_clientdata(client);
181 int status, xstp;
182
183 rtc_lock(rx8025->rtc);
184 status = rx8025_read_reg(client, RX8025_REG_CTRL2);
185 if (status < 0)
186 goto out;
187
188 xstp = rx8025_is_osc_stopped(rx8025->model, status);
189 if (xstp)
190 dev_warn(&client->dev, "Oscillation stop was detected,"
191 "you may have to readjust the clock\n");
192
193 if (status & RX8025_BIT_CTRL2_CTFG) {
194 /* periodic */
195 status &= ~RX8025_BIT_CTRL2_CTFG;
196 rtc_update_irq(rx8025->rtc, 1, RTC_PF | RTC_IRQF);
197 }
198
199 if (status & RX8025_BIT_CTRL2_DAFG) {
200 /* alarm */
201 status &= RX8025_BIT_CTRL2_DAFG;
202 if (rx8025_write_reg(client, RX8025_REG_CTRL1,
203 rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE))
204 goto out;
205 rtc_update_irq(rx8025->rtc, 1, RTC_AF | RTC_IRQF);
206 }
207
208out:
209 rtc_unlock(rx8025->rtc);
210
211 return IRQ_HANDLED;
212}
213
214static int rx8025_get_time(struct device *dev, struct rtc_time *dt)
215{
216 struct i2c_client *client = to_i2c_client(dev);
217 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
218 u8 date[7];
219 int err;
220
221 err = rx8025_check_validity(dev);
222 if (err)
223 return err;
224
225 err = rx8025_read_regs(client, RX8025_REG_SEC, 7, date);
226 if (err)
227 return err;
228
229 dev_dbg(dev, "%s: read %7ph\n", __func__, date);
230
231 dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
232 dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
233 if (rx8025->is_24)
234 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);
235 else
236 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12
237 + (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0);
238
239 dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);
240 dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
241 dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]) + 100;
242
243 dev_dbg(dev, "%s: date %ptRr\n", __func__, dt);
244
245 return 0;
246}
247
248static int rx8025_set_time(struct device *dev, struct rtc_time *dt)
249{
250 struct i2c_client *client = to_i2c_client(dev);
251 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
252 u8 date[7];
253 int ret;
254
255 /*
256 * Here the read-only bits are written as "0". I'm not sure if that
257 * is sound.
258 */
259 date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
260 date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
261 if (rx8025->is_24)
262 date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
263 else
264 date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
265 | bin2bcd((dt->tm_hour + 11) % 12 + 1);
266
267 date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
268 date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
269 date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
270 date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year - 100);
271
272 dev_dbg(dev, "%s: write %7ph\n", __func__, date);
273
274 ret = rx8025_write_regs(client, RX8025_REG_SEC, 7, date);
275 if (ret < 0)
276 return ret;
277
278 return rx8025_reset_validity(client);
279}
280
281static int rx8025_init_client(struct i2c_client *client)
282{
283 struct rx8025_data *rx8025 = i2c_get_clientdata(client);
284 u8 ctrl[2], ctrl2;
285 int need_clear = 0;
286 int hour_reg;
287 int err;
288
289 err = rx8025_read_regs(client, RX8025_REG_CTRL1, 2, ctrl);
290 if (err)
291 goto out;
292
293 /* Keep test bit zero ! */
294 rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;
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_clear) {
305 ctrl2 = ctrl[1];
306 ctrl2 &= ~(RX8025_BIT_CTRL2_CTFG | RX8025_BIT_CTRL2_WAFG |
307 RX8025_BIT_CTRL2_DAFG);
308
309 err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
310 }
311
312 if (rx8025->model == model_rx_8035) {
313 /* In RX-8035, 12/24 flag is in the hour register */
314 hour_reg = rx8025_read_reg(client, RX8025_REG_HOUR);
315 if (hour_reg < 0)
316 return hour_reg;
317 rx8025->is_24 = (hour_reg & RX8035_BIT_HOUR_1224);
318 } else {
319 rx8025->is_24 = (ctrl[1] & RX8025_BIT_CTRL1_1224);
320 }
321out:
322 return err;
323}
324
325/* Alarm support */
326static int rx8025_read_alarm(struct device *dev, struct rtc_wkalrm *t)
327{
328 struct i2c_client *client = to_i2c_client(dev);
329 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
330 u8 ald[2];
331 int ctrl2, err;
332
333 err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);
334 if (err)
335 return err;
336
337 ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
338 if (ctrl2 < 0)
339 return ctrl2;
340
341 dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",
342 __func__, ald[0], ald[1], ctrl2);
343
344 /* Hardware alarms precision is 1 minute! */
345 t->time.tm_sec = 0;
346 t->time.tm_min = bcd2bin(ald[0] & 0x7f);
347 if (rx8025->is_24)
348 t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
349 else
350 t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
351 + (ald[1] & 0x20 ? 12 : 0);
352
353 dev_dbg(dev, "%s: date: %ptRr\n", __func__, &t->time);
354 t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
355 t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
356
357 return err;
358}
359
360static int rx8025_set_alarm(struct device *dev, struct rtc_wkalrm *t)
361{
362 struct i2c_client *client = to_i2c_client(dev);
363 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
364 u8 ald[2];
365 int err;
366
367 ald[0] = bin2bcd(t->time.tm_min);
368 if (rx8025->is_24)
369 ald[1] = bin2bcd(t->time.tm_hour);
370 else
371 ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
372 | bin2bcd((t->time.tm_hour + 11) % 12 + 1);
373
374 dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);
375
376 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
377 rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
378 err = rx8025_write_reg(client, RX8025_REG_CTRL1,
379 rx8025->ctrl1);
380 if (err)
381 return err;
382 }
383 err = rx8025_write_regs(client, RX8025_REG_ALDMIN, 2, ald);
384 if (err)
385 return err;
386
387 if (t->enabled) {
388 rx8025->ctrl1 |= RX8025_BIT_CTRL1_DALE;
389 err = rx8025_write_reg(client, RX8025_REG_CTRL1,
390 rx8025->ctrl1);
391 if (err)
392 return err;
393 }
394
395 return 0;
396}
397
398static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
399{
400 struct i2c_client *client = to_i2c_client(dev);
401 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
402 u8 ctrl1;
403 int err;
404
405 ctrl1 = rx8025->ctrl1;
406 if (enabled)
407 ctrl1 |= RX8025_BIT_CTRL1_DALE;
408 else
409 ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
410
411 if (ctrl1 != rx8025->ctrl1) {
412 rx8025->ctrl1 = ctrl1;
413 err = rx8025_write_reg(client, RX8025_REG_CTRL1,
414 rx8025->ctrl1);
415 if (err)
416 return err;
417 }
418 return 0;
419}
420
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 */
433static int rx8025_read_offset(struct device *dev, long *offset)
434{
435 struct i2c_client *client = to_i2c_client(dev);
436 int digoff;
437
438 digoff = rx8025_read_reg(client, RX8025_REG_DIGOFF);
439 if (digoff < 0)
440 return digoff;
441
442 *offset = digoff >= 64 ? digoff - 128 : digoff;
443 if (*offset > 0)
444 (*offset)--;
445 *offset *= RX8025_ADJ_RESOLUTION;
446
447 return 0;
448}
449
450static int rx8025_set_offset(struct device *dev, long offset)
451{
452 struct i2c_client *client = to_i2c_client(dev);
453 u8 digoff;
454
455 offset /= RX8025_ADJ_RESOLUTION;
456 if (offset > RX8025_ADJ_DATA_MAX)
457 offset = RX8025_ADJ_DATA_MAX;
458 else if (offset < RX8025_ADJ_DATA_MIN)
459 offset = RX8025_ADJ_DATA_MIN;
460 else if (offset > 0)
461 offset++;
462 else if (offset < 0)
463 offset += 128;
464 digoff = offset;
465
466 return rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
467}
468
469static const struct rtc_class_ops rx8025_rtc_ops = {
470 .read_time = rx8025_get_time,
471 .set_time = rx8025_set_time,
472 .read_alarm = rx8025_read_alarm,
473 .set_alarm = rx8025_set_alarm,
474 .alarm_irq_enable = rx8025_alarm_irq_enable,
475 .read_offset = rx8025_read_offset,
476 .set_offset = rx8025_set_offset,
477};
478
479static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
480 struct device_attribute *attr,
481 char *buf)
482{
483 long adj;
484 int err;
485
486 dev_warn_once(dev, "clock_adjust_ppb is deprecated, use offset\n");
487 err = rx8025_read_offset(dev, &adj);
488 if (err)
489 return err;
490
491 return sprintf(buf, "%ld\n", -adj);
492}
493
494static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
495 struct device_attribute *attr,
496 const char *buf, size_t count)
497{
498 long adj;
499 int err;
500
501 dev_warn_once(dev, "clock_adjust_ppb is deprecated, use offset\n");
502 if (kstrtol(buf, 10, &adj) != 0)
503 return -EINVAL;
504
505 err = rx8025_set_offset(dev, -adj);
506
507 return err ? err : count;
508}
509
510static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO | S_IWUSR,
511 rx8025_sysfs_show_clock_adjust,
512 rx8025_sysfs_store_clock_adjust);
513
514static struct attribute *rx8025_attrs[] = {
515 &dev_attr_clock_adjust_ppb.attr,
516 NULL
517};
518
519static const struct attribute_group rx8025_attr_group = {
520 .attrs = rx8025_attrs,
521};
522
523static int rx8025_probe(struct i2c_client *client)
524{
525 const struct i2c_device_id *id = i2c_match_id(rx8025_id, client);
526 struct i2c_adapter *adapter = client->adapter;
527 struct rx8025_data *rx8025;
528 int err = 0;
529
530 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
531 | I2C_FUNC_SMBUS_I2C_BLOCK)) {
532 dev_err(&adapter->dev,
533 "doesn't support required functionality\n");
534 return -EIO;
535 }
536
537 rx8025 = devm_kzalloc(&client->dev, sizeof(*rx8025), GFP_KERNEL);
538 if (!rx8025)
539 return -ENOMEM;
540
541 i2c_set_clientdata(client, rx8025);
542
543 if (id)
544 rx8025->model = id->driver_data;
545
546 err = rx8025_init_client(client);
547 if (err)
548 return err;
549
550 rx8025->rtc = devm_rtc_allocate_device(&client->dev);
551 if (IS_ERR(rx8025->rtc))
552 return PTR_ERR(rx8025->rtc);
553
554 rx8025->rtc->ops = &rx8025_rtc_ops;
555 rx8025->rtc->range_min = RTC_TIMESTAMP_BEGIN_1900;
556 rx8025->rtc->range_max = RTC_TIMESTAMP_END_2099;
557
558 if (client->irq > 0) {
559 dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
560 err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
561 rx8025_handle_irq,
562 IRQF_ONESHOT,
563 "rx8025", client);
564 if (err)
565 clear_bit(RTC_FEATURE_ALARM, rx8025->rtc->features);
566 }
567
568 rx8025->rtc->max_user_freq = 1;
569
570 set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rx8025->rtc->features);
571 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rx8025->rtc->features);
572
573 err = rtc_add_group(rx8025->rtc, &rx8025_attr_group);
574 if (err)
575 return err;
576
577 return devm_rtc_register_device(rx8025->rtc);
578}
579
580static struct i2c_driver rx8025_driver = {
581 .driver = {
582 .name = "rtc-rx8025",
583 },
584 .probe = rx8025_probe,
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// 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 i2c_client *client;
71 struct rtc_device *rtc;
72 u8 ctrl1;
73};
74
75static s32 rx8025_read_reg(const struct i2c_client *client, u8 number)
76{
77 return i2c_smbus_read_byte_data(client, number << 4);
78}
79
80static int rx8025_read_regs(const struct i2c_client *client,
81 u8 number, u8 length, u8 *values)
82{
83 int ret = i2c_smbus_read_i2c_block_data(client, number << 4, length,
84 values);
85 if (ret != length)
86 return ret < 0 ? ret : -EIO;
87
88 return 0;
89}
90
91static s32 rx8025_write_reg(const struct i2c_client *client, u8 number,
92 u8 value)
93{
94 return i2c_smbus_write_byte_data(client, number << 4, value);
95}
96
97static s32 rx8025_write_regs(const struct i2c_client *client,
98 u8 number, u8 length, const u8 *values)
99{
100 return i2c_smbus_write_i2c_block_data(client, number << 4,
101 length, values);
102}
103
104static int rx8025_check_validity(struct device *dev)
105{
106 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
107 int ctrl2;
108
109 ctrl2 = rx8025_read_reg(rx8025->client, RX8025_REG_CTRL2);
110 if (ctrl2 < 0)
111 return ctrl2;
112
113 if (ctrl2 & RX8025_BIT_CTRL2_VDET)
114 dev_warn(dev, "power voltage drop detected\n");
115
116 if (ctrl2 & RX8025_BIT_CTRL2_PON) {
117 dev_warn(dev, "power-on reset detected, date is invalid\n");
118 return -EINVAL;
119 }
120
121 if (!(ctrl2 & RX8025_BIT_CTRL2_XST)) {
122 dev_warn(dev, "crystal stopped, date is invalid\n");
123 return -EINVAL;
124 }
125
126 return 0;
127}
128
129static int rx8025_reset_validity(struct i2c_client *client)
130{
131 int ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
132
133 if (ctrl2 < 0)
134 return ctrl2;
135
136 ctrl2 &= ~(RX8025_BIT_CTRL2_PON | RX8025_BIT_CTRL2_VDET);
137
138 return rx8025_write_reg(client, RX8025_REG_CTRL2,
139 ctrl2 | RX8025_BIT_CTRL2_XST);
140}
141
142static irqreturn_t rx8025_handle_irq(int irq, void *dev_id)
143{
144 struct i2c_client *client = dev_id;
145 struct rx8025_data *rx8025 = i2c_get_clientdata(client);
146 struct mutex *lock = &rx8025->rtc->ops_lock;
147 int status;
148
149 mutex_lock(lock);
150 status = rx8025_read_reg(client, RX8025_REG_CTRL2);
151 if (status < 0)
152 goto out;
153
154 if (!(status & RX8025_BIT_CTRL2_XST))
155 dev_warn(&client->dev, "Oscillation stop was detected,"
156 "you may have to readjust the clock\n");
157
158 if (status & RX8025_BIT_CTRL2_CTFG) {
159 /* periodic */
160 status &= ~RX8025_BIT_CTRL2_CTFG;
161 rtc_update_irq(rx8025->rtc, 1, RTC_PF | RTC_IRQF);
162 }
163
164 if (status & RX8025_BIT_CTRL2_DAFG) {
165 /* alarm */
166 status &= RX8025_BIT_CTRL2_DAFG;
167 if (rx8025_write_reg(client, RX8025_REG_CTRL1,
168 rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE))
169 goto out;
170 rtc_update_irq(rx8025->rtc, 1, RTC_AF | RTC_IRQF);
171 }
172
173out:
174 mutex_unlock(lock);
175
176 return IRQ_HANDLED;
177}
178
179static int rx8025_get_time(struct device *dev, struct rtc_time *dt)
180{
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(rx8025->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 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(rx8025->client, RX8025_REG_SEC, 7, date);
241 if (ret < 0)
242 return ret;
243
244 return rx8025_reset_validity(rx8025->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(rx8025->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 rx8025_data *rx8025 = dev_get_drvdata(dev);
284 struct i2c_client *client = rx8025->client;
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(rx8025->client, RX8025_REG_CTRL1,
351 rx8025->ctrl1);
352 if (err)
353 return err;
354 }
355 err = rx8025_write_regs(rx8025->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(rx8025->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 rx8025_data *rx8025 = dev_get_drvdata(dev);
373 u8 ctrl1;
374 int err;
375
376 ctrl1 = rx8025->ctrl1;
377 if (enabled)
378 ctrl1 |= RX8025_BIT_CTRL1_DALE;
379 else
380 ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
381
382 if (ctrl1 != rx8025->ctrl1) {
383 rx8025->ctrl1 = ctrl1;
384 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
385 rx8025->ctrl1);
386 if (err)
387 return err;
388 }
389 return 0;
390}
391
392static const struct rtc_class_ops rx8025_rtc_ops = {
393 .read_time = rx8025_get_time,
394 .set_time = rx8025_set_time,
395 .read_alarm = rx8025_read_alarm,
396 .set_alarm = rx8025_set_alarm,
397 .alarm_irq_enable = rx8025_alarm_irq_enable,
398};
399
400/*
401 * Clock precision adjustment support
402 *
403 * According to the RX8025 SA/NB application manual the frequency and
404 * temperature characteristics can be approximated using the following
405 * equation:
406 *
407 * df = a * (ut - t)**2
408 *
409 * df: Frequency deviation in any temperature
410 * a : Coefficient = (-35 +-5) * 10**-9
411 * ut: Ultimate temperature in degree = +25 +-5 degree
412 * t : Any temperature in degree
413 *
414 * Note that the clock adjustment in ppb must be entered (which is
415 * the negative value of the deviation).
416 */
417static int rx8025_get_clock_adjust(struct device *dev, int *adj)
418{
419 struct i2c_client *client = to_i2c_client(dev);
420 int digoff;
421
422 digoff = rx8025_read_reg(client, RX8025_REG_DIGOFF);
423 if (digoff < 0)
424 return digoff;
425
426 *adj = digoff >= 64 ? digoff - 128 : digoff;
427 if (*adj > 0)
428 (*adj)--;
429 *adj *= -RX8025_ADJ_RESOLUTION;
430
431 return 0;
432}
433
434static int rx8025_set_clock_adjust(struct device *dev, int adj)
435{
436 struct i2c_client *client = to_i2c_client(dev);
437 u8 digoff;
438 int err;
439
440 adj /= -RX8025_ADJ_RESOLUTION;
441 if (adj > RX8025_ADJ_DATA_MAX)
442 adj = RX8025_ADJ_DATA_MAX;
443 else if (adj < RX8025_ADJ_DATA_MIN)
444 adj = RX8025_ADJ_DATA_MIN;
445 else if (adj > 0)
446 adj++;
447 else if (adj < 0)
448 adj += 128;
449 digoff = adj;
450
451 err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
452 if (err)
453 return err;
454
455 dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff);
456
457 return 0;
458}
459
460static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
461 struct device_attribute *attr,
462 char *buf)
463{
464 int err, adj;
465
466 err = rx8025_get_clock_adjust(dev, &adj);
467 if (err)
468 return err;
469
470 return sprintf(buf, "%d\n", adj);
471}
472
473static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
474 struct device_attribute *attr,
475 const char *buf, size_t count)
476{
477 int adj, err;
478
479 if (sscanf(buf, "%i", &adj) != 1)
480 return -EINVAL;
481
482 err = rx8025_set_clock_adjust(dev, adj);
483
484 return err ? err : count;
485}
486
487static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO | S_IWUSR,
488 rx8025_sysfs_show_clock_adjust,
489 rx8025_sysfs_store_clock_adjust);
490
491static int rx8025_sysfs_register(struct device *dev)
492{
493 return device_create_file(dev, &dev_attr_clock_adjust_ppb);
494}
495
496static void rx8025_sysfs_unregister(struct device *dev)
497{
498 device_remove_file(dev, &dev_attr_clock_adjust_ppb);
499}
500
501static int rx8025_probe(struct i2c_client *client,
502 const struct i2c_device_id *id)
503{
504 struct i2c_adapter *adapter = client->adapter;
505 struct rx8025_data *rx8025;
506 int err = 0;
507
508 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
509 | I2C_FUNC_SMBUS_I2C_BLOCK)) {
510 dev_err(&adapter->dev,
511 "doesn't support required functionality\n");
512 return -EIO;
513 }
514
515 rx8025 = devm_kzalloc(&client->dev, sizeof(*rx8025), GFP_KERNEL);
516 if (!rx8025)
517 return -ENOMEM;
518
519 rx8025->client = client;
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");