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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * RTC driver for the Micro Crystal RV3028
4 *
5 * Copyright (C) 2019 Micro Crystal SA
6 *
7 * Alexandre Belloni <[email protected]>
8 *
9 */
10
11#include <linux/clk-provider.h>
12#include <linux/bcd.h>
13#include <linux/bitfield.h>
14#include <linux/bitops.h>
15#include <linux/i2c.h>
16#include <linux/interrupt.h>
17#include <linux/kernel.h>
18#include <linux/log2.h>
19#include <linux/module.h>
20#include <linux/of.h>
21#include <linux/regmap.h>
22#include <linux/rtc.h>
23
24#define RV3028_SEC 0x00
25#define RV3028_MIN 0x01
26#define RV3028_HOUR 0x02
27#define RV3028_WDAY 0x03
28#define RV3028_DAY 0x04
29#define RV3028_MONTH 0x05
30#define RV3028_YEAR 0x06
31#define RV3028_ALARM_MIN 0x07
32#define RV3028_ALARM_HOUR 0x08
33#define RV3028_ALARM_DAY 0x09
34#define RV3028_STATUS 0x0E
35#define RV3028_CTRL1 0x0F
36#define RV3028_CTRL2 0x10
37#define RV3028_EVT_CTRL 0x13
38#define RV3028_TS_COUNT 0x14
39#define RV3028_TS_SEC 0x15
40#define RV3028_RAM1 0x1F
41#define RV3028_EEPROM_ADDR 0x25
42#define RV3028_EEPROM_DATA 0x26
43#define RV3028_EEPROM_CMD 0x27
44#define RV3028_CLKOUT 0x35
45#define RV3028_OFFSET 0x36
46#define RV3028_BACKUP 0x37
47
48#define RV3028_STATUS_PORF BIT(0)
49#define RV3028_STATUS_EVF BIT(1)
50#define RV3028_STATUS_AF BIT(2)
51#define RV3028_STATUS_TF BIT(3)
52#define RV3028_STATUS_UF BIT(4)
53#define RV3028_STATUS_BSF BIT(5)
54#define RV3028_STATUS_CLKF BIT(6)
55#define RV3028_STATUS_EEBUSY BIT(7)
56
57#define RV3028_CLKOUT_FD_MASK GENMASK(2, 0)
58#define RV3028_CLKOUT_PORIE BIT(3)
59#define RV3028_CLKOUT_CLKSY BIT(6)
60#define RV3028_CLKOUT_CLKOE BIT(7)
61
62#define RV3028_CTRL1_EERD BIT(3)
63#define RV3028_CTRL1_WADA BIT(5)
64
65#define RV3028_CTRL2_RESET BIT(0)
66#define RV3028_CTRL2_12_24 BIT(1)
67#define RV3028_CTRL2_EIE BIT(2)
68#define RV3028_CTRL2_AIE BIT(3)
69#define RV3028_CTRL2_TIE BIT(4)
70#define RV3028_CTRL2_UIE BIT(5)
71#define RV3028_CTRL2_TSE BIT(7)
72
73#define RV3028_EVT_CTRL_TSR BIT(2)
74
75#define RV3028_EEPROM_CMD_UPDATE 0x11
76#define RV3028_EEPROM_CMD_WRITE 0x21
77#define RV3028_EEPROM_CMD_READ 0x22
78
79#define RV3028_EEBUSY_POLL 10000
80#define RV3028_EEBUSY_TIMEOUT 100000
81
82#define RV3028_BACKUP_TCE BIT(5)
83#define RV3028_BACKUP_TCR_MASK GENMASK(1,0)
84#define RV3028_BACKUP_BSM GENMASK(3,2)
85
86#define RV3028_BACKUP_BSM_DSM 0x1
87#define RV3028_BACKUP_BSM_LSM 0x3
88
89#define OFFSET_STEP_PPT 953674
90
91enum rv3028_type {
92 rv_3028,
93};
94
95struct rv3028_data {
96 struct regmap *regmap;
97 struct rtc_device *rtc;
98 enum rv3028_type type;
99#ifdef CONFIG_COMMON_CLK
100 struct clk_hw clkout_hw;
101#endif
102};
103
104static u16 rv3028_trickle_resistors[] = {3000, 5000, 9000, 15000};
105
106static ssize_t timestamp0_store(struct device *dev,
107 struct device_attribute *attr,
108 const char *buf, size_t count)
109{
110 struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent);
111
112 regmap_update_bits(rv3028->regmap, RV3028_EVT_CTRL, RV3028_EVT_CTRL_TSR,
113 RV3028_EVT_CTRL_TSR);
114
115 return count;
116};
117
118static ssize_t timestamp0_show(struct device *dev,
119 struct device_attribute *attr, char *buf)
120{
121 struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent);
122 struct rtc_time tm;
123 unsigned int count;
124 u8 date[6];
125 int ret;
126
127 ret = regmap_read(rv3028->regmap, RV3028_TS_COUNT, &count);
128 if (ret)
129 return ret;
130
131 if (!count)
132 return 0;
133
134 ret = regmap_bulk_read(rv3028->regmap, RV3028_TS_SEC, date,
135 sizeof(date));
136 if (ret)
137 return ret;
138
139 tm.tm_sec = bcd2bin(date[0]);
140 tm.tm_min = bcd2bin(date[1]);
141 tm.tm_hour = bcd2bin(date[2]);
142 tm.tm_mday = bcd2bin(date[3]);
143 tm.tm_mon = bcd2bin(date[4]) - 1;
144 tm.tm_year = bcd2bin(date[5]) + 100;
145
146 ret = rtc_valid_tm(&tm);
147 if (ret)
148 return ret;
149
150 return sprintf(buf, "%llu\n",
151 (unsigned long long)rtc_tm_to_time64(&tm));
152};
153
154static DEVICE_ATTR_RW(timestamp0);
155
156static ssize_t timestamp0_count_show(struct device *dev,
157 struct device_attribute *attr, char *buf)
158{
159 struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent);
160 unsigned int count;
161 int ret;
162
163 ret = regmap_read(rv3028->regmap, RV3028_TS_COUNT, &count);
164 if (ret)
165 return ret;
166
167 return sprintf(buf, "%u\n", count);
168};
169
170static DEVICE_ATTR_RO(timestamp0_count);
171
172static struct attribute *rv3028_attrs[] = {
173 &dev_attr_timestamp0.attr,
174 &dev_attr_timestamp0_count.attr,
175 NULL
176};
177
178static const struct attribute_group rv3028_attr_group = {
179 .attrs = rv3028_attrs,
180};
181
182static int rv3028_exit_eerd(struct rv3028_data *rv3028, u32 eerd)
183{
184 if (eerd)
185 return 0;
186
187 return regmap_update_bits(rv3028->regmap, RV3028_CTRL1, RV3028_CTRL1_EERD, 0);
188}
189
190static int rv3028_enter_eerd(struct rv3028_data *rv3028, u32 *eerd)
191{
192 u32 ctrl1, status;
193 int ret;
194
195 ret = regmap_read(rv3028->regmap, RV3028_CTRL1, &ctrl1);
196 if (ret)
197 return ret;
198
199 *eerd = ctrl1 & RV3028_CTRL1_EERD;
200 if (*eerd)
201 return 0;
202
203 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL1,
204 RV3028_CTRL1_EERD, RV3028_CTRL1_EERD);
205 if (ret)
206 return ret;
207
208 ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status,
209 !(status & RV3028_STATUS_EEBUSY),
210 RV3028_EEBUSY_POLL, RV3028_EEBUSY_TIMEOUT);
211 if (ret) {
212 rv3028_exit_eerd(rv3028, *eerd);
213
214 return ret;
215 }
216
217 return 0;
218}
219
220static int rv3028_update_eeprom(struct rv3028_data *rv3028, u32 eerd)
221{
222 u32 status;
223 int ret;
224
225 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, 0x0);
226 if (ret)
227 goto exit_eerd;
228
229 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, RV3028_EEPROM_CMD_UPDATE);
230 if (ret)
231 goto exit_eerd;
232
233 usleep_range(63000, RV3028_EEBUSY_TIMEOUT);
234
235 ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status,
236 !(status & RV3028_STATUS_EEBUSY),
237 RV3028_EEBUSY_POLL, RV3028_EEBUSY_TIMEOUT);
238
239exit_eerd:
240 rv3028_exit_eerd(rv3028, eerd);
241
242 return ret;
243}
244
245static int rv3028_update_cfg(struct rv3028_data *rv3028, unsigned int reg,
246 unsigned int mask, unsigned int val)
247{
248 u32 eerd;
249 int ret;
250
251 ret = rv3028_enter_eerd(rv3028, &eerd);
252 if (ret)
253 return ret;
254
255 ret = regmap_update_bits(rv3028->regmap, reg, mask, val);
256 if (ret) {
257 rv3028_exit_eerd(rv3028, eerd);
258 return ret;
259 }
260
261 return rv3028_update_eeprom(rv3028, eerd);
262}
263
264static irqreturn_t rv3028_handle_irq(int irq, void *dev_id)
265{
266 struct rv3028_data *rv3028 = dev_id;
267 unsigned long events = 0;
268 u32 status = 0, ctrl = 0;
269
270 if (regmap_read(rv3028->regmap, RV3028_STATUS, &status) < 0 ||
271 status == 0) {
272 return IRQ_NONE;
273 }
274
275 status &= ~RV3028_STATUS_PORF;
276
277 if (status & RV3028_STATUS_TF) {
278 status |= RV3028_STATUS_TF;
279 ctrl |= RV3028_CTRL2_TIE;
280 events |= RTC_PF;
281 }
282
283 if (status & RV3028_STATUS_AF) {
284 status |= RV3028_STATUS_AF;
285 ctrl |= RV3028_CTRL2_AIE;
286 events |= RTC_AF;
287 }
288
289 if (status & RV3028_STATUS_UF) {
290 status |= RV3028_STATUS_UF;
291 ctrl |= RV3028_CTRL2_UIE;
292 events |= RTC_UF;
293 }
294
295 if (events) {
296 rtc_update_irq(rv3028->rtc, 1, events);
297 regmap_update_bits(rv3028->regmap, RV3028_STATUS, status, 0);
298 regmap_update_bits(rv3028->regmap, RV3028_CTRL2, ctrl, 0);
299 }
300
301 if (status & RV3028_STATUS_EVF) {
302 sysfs_notify(&rv3028->rtc->dev.kobj, NULL,
303 dev_attr_timestamp0.attr.name);
304 dev_warn(&rv3028->rtc->dev, "event detected");
305 }
306
307 return IRQ_HANDLED;
308}
309
310static int rv3028_get_time(struct device *dev, struct rtc_time *tm)
311{
312 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
313 u8 date[7];
314 int ret, status;
315
316 ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
317 if (ret < 0)
318 return ret;
319
320 if (status & RV3028_STATUS_PORF)
321 return -EINVAL;
322
323 ret = regmap_bulk_read(rv3028->regmap, RV3028_SEC, date, sizeof(date));
324 if (ret)
325 return ret;
326
327 tm->tm_sec = bcd2bin(date[RV3028_SEC] & 0x7f);
328 tm->tm_min = bcd2bin(date[RV3028_MIN] & 0x7f);
329 tm->tm_hour = bcd2bin(date[RV3028_HOUR] & 0x3f);
330 tm->tm_wday = date[RV3028_WDAY] & 0x7f;
331 tm->tm_mday = bcd2bin(date[RV3028_DAY] & 0x3f);
332 tm->tm_mon = bcd2bin(date[RV3028_MONTH] & 0x1f) - 1;
333 tm->tm_year = bcd2bin(date[RV3028_YEAR]) + 100;
334
335 return 0;
336}
337
338static int rv3028_set_time(struct device *dev, struct rtc_time *tm)
339{
340 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
341 u8 date[7];
342 int ret;
343
344 date[RV3028_SEC] = bin2bcd(tm->tm_sec);
345 date[RV3028_MIN] = bin2bcd(tm->tm_min);
346 date[RV3028_HOUR] = bin2bcd(tm->tm_hour);
347 date[RV3028_WDAY] = tm->tm_wday;
348 date[RV3028_DAY] = bin2bcd(tm->tm_mday);
349 date[RV3028_MONTH] = bin2bcd(tm->tm_mon + 1);
350 date[RV3028_YEAR] = bin2bcd(tm->tm_year - 100);
351
352 /*
353 * Writing to the Seconds register has the same effect as setting RESET
354 * bit to 1
355 */
356 ret = regmap_bulk_write(rv3028->regmap, RV3028_SEC, date,
357 sizeof(date));
358 if (ret)
359 return ret;
360
361 ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
362 RV3028_STATUS_PORF, 0);
363
364 return ret;
365}
366
367static int rv3028_get_alarm(struct device *dev, struct rtc_wkalrm *alrm)
368{
369 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
370 u8 alarmvals[3];
371 int status, ctrl, ret;
372
373 ret = regmap_bulk_read(rv3028->regmap, RV3028_ALARM_MIN, alarmvals,
374 sizeof(alarmvals));
375 if (ret)
376 return ret;
377
378 ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
379 if (ret < 0)
380 return ret;
381
382 ret = regmap_read(rv3028->regmap, RV3028_CTRL2, &ctrl);
383 if (ret < 0)
384 return ret;
385
386 alrm->time.tm_sec = 0;
387 alrm->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);
388 alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
389 alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f);
390
391 alrm->enabled = !!(ctrl & RV3028_CTRL2_AIE);
392 alrm->pending = (status & RV3028_STATUS_AF) && alrm->enabled;
393
394 return 0;
395}
396
397static int rv3028_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
398{
399 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
400 u8 alarmvals[3];
401 u8 ctrl = 0;
402 int ret;
403
404 /* The alarm has no seconds, round up to nearest minute */
405 if (alrm->time.tm_sec) {
406 time64_t alarm_time = rtc_tm_to_time64(&alrm->time);
407
408 alarm_time += 60 - alrm->time.tm_sec;
409 rtc_time64_to_tm(alarm_time, &alrm->time);
410 }
411
412 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
413 RV3028_CTRL2_AIE | RV3028_CTRL2_UIE, 0);
414 if (ret)
415 return ret;
416
417 alarmvals[0] = bin2bcd(alrm->time.tm_min);
418 alarmvals[1] = bin2bcd(alrm->time.tm_hour);
419 alarmvals[2] = bin2bcd(alrm->time.tm_mday);
420
421 ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
422 RV3028_STATUS_AF, 0);
423 if (ret)
424 return ret;
425
426 ret = regmap_bulk_write(rv3028->regmap, RV3028_ALARM_MIN, alarmvals,
427 sizeof(alarmvals));
428 if (ret)
429 return ret;
430
431 if (alrm->enabled) {
432 if (rv3028->rtc->uie_rtctimer.enabled)
433 ctrl |= RV3028_CTRL2_UIE;
434 if (rv3028->rtc->aie_timer.enabled)
435 ctrl |= RV3028_CTRL2_AIE;
436 }
437
438 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
439 RV3028_CTRL2_UIE | RV3028_CTRL2_AIE, ctrl);
440
441 return ret;
442}
443
444static int rv3028_alarm_irq_enable(struct device *dev, unsigned int enabled)
445{
446 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
447 int ctrl = 0, ret;
448
449 if (enabled) {
450 if (rv3028->rtc->uie_rtctimer.enabled)
451 ctrl |= RV3028_CTRL2_UIE;
452 if (rv3028->rtc->aie_timer.enabled)
453 ctrl |= RV3028_CTRL2_AIE;
454 }
455
456 ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
457 RV3028_STATUS_AF | RV3028_STATUS_UF, 0);
458 if (ret)
459 return ret;
460
461 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
462 RV3028_CTRL2_UIE | RV3028_CTRL2_AIE, ctrl);
463 if (ret)
464 return ret;
465
466 return 0;
467}
468
469static int rv3028_read_offset(struct device *dev, long *offset)
470{
471 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
472 int ret, value, steps;
473
474 ret = regmap_read(rv3028->regmap, RV3028_OFFSET, &value);
475 if (ret < 0)
476 return ret;
477
478 steps = sign_extend32(value << 1, 8);
479
480 ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &value);
481 if (ret < 0)
482 return ret;
483
484 steps += value >> 7;
485
486 *offset = DIV_ROUND_CLOSEST(steps * OFFSET_STEP_PPT, 1000);
487
488 return 0;
489}
490
491static int rv3028_set_offset(struct device *dev, long offset)
492{
493 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
494 u32 eerd;
495 int ret;
496
497 offset = clamp(offset, -244141L, 243187L) * 1000;
498 offset = DIV_ROUND_CLOSEST(offset, OFFSET_STEP_PPT);
499
500 ret = rv3028_enter_eerd(rv3028, &eerd);
501 if (ret)
502 return ret;
503
504 ret = regmap_write(rv3028->regmap, RV3028_OFFSET, offset >> 1);
505 if (ret < 0)
506 goto exit_eerd;
507
508 ret = regmap_update_bits(rv3028->regmap, RV3028_BACKUP, BIT(7),
509 offset << 7);
510 if (ret < 0)
511 goto exit_eerd;
512
513 return rv3028_update_eeprom(rv3028, eerd);
514
515exit_eerd:
516 rv3028_exit_eerd(rv3028, eerd);
517
518 return ret;
519
520}
521
522static int rv3028_param_get(struct device *dev, struct rtc_param *param)
523{
524 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
525 int ret;
526 u32 value;
527
528 switch(param->param) {
529 case RTC_PARAM_BACKUP_SWITCH_MODE:
530 ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &value);
531 if (ret < 0)
532 return ret;
533
534 value = FIELD_GET(RV3028_BACKUP_BSM, value);
535
536 switch(value) {
537 case RV3028_BACKUP_BSM_DSM:
538 param->uvalue = RTC_BSM_DIRECT;
539 break;
540 case RV3028_BACKUP_BSM_LSM:
541 param->uvalue = RTC_BSM_LEVEL;
542 break;
543 default:
544 param->uvalue = RTC_BSM_DISABLED;
545 }
546 break;
547
548 default:
549 return -EINVAL;
550 }
551
552 return 0;
553}
554
555static int rv3028_param_set(struct device *dev, struct rtc_param *param)
556{
557 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
558 u8 mode;
559
560 switch(param->param) {
561 case RTC_PARAM_BACKUP_SWITCH_MODE:
562 switch (param->uvalue) {
563 case RTC_BSM_DISABLED:
564 mode = 0;
565 break;
566 case RTC_BSM_DIRECT:
567 mode = RV3028_BACKUP_BSM_DSM;
568 break;
569 case RTC_BSM_LEVEL:
570 mode = RV3028_BACKUP_BSM_LSM;
571 break;
572 default:
573 return -EINVAL;
574 }
575
576 return rv3028_update_cfg(rv3028, RV3028_BACKUP, RV3028_BACKUP_BSM,
577 FIELD_PREP(RV3028_BACKUP_BSM, mode));
578
579 default:
580 return -EINVAL;
581 }
582
583 return 0;
584}
585
586static int rv3028_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
587{
588 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
589 int status, ret = 0;
590
591 switch (cmd) {
592 case RTC_VL_READ:
593 ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
594 if (ret < 0)
595 return ret;
596
597 status = status & RV3028_STATUS_PORF ? RTC_VL_DATA_INVALID : 0;
598 return put_user(status, (unsigned int __user *)arg);
599
600 default:
601 return -ENOIOCTLCMD;
602 }
603}
604
605static int rv3028_nvram_write(void *priv, unsigned int offset, void *val,
606 size_t bytes)
607{
608 return regmap_bulk_write(priv, RV3028_RAM1 + offset, val, bytes);
609}
610
611static int rv3028_nvram_read(void *priv, unsigned int offset, void *val,
612 size_t bytes)
613{
614 return regmap_bulk_read(priv, RV3028_RAM1 + offset, val, bytes);
615}
616
617static int rv3028_eeprom_write(void *priv, unsigned int offset, void *val,
618 size_t bytes)
619{
620 struct rv3028_data *rv3028 = priv;
621 u32 status, eerd;
622 int i, ret;
623 u8 *buf = val;
624
625 ret = rv3028_enter_eerd(rv3028, &eerd);
626 if (ret)
627 return ret;
628
629 for (i = 0; i < bytes; i++) {
630 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_ADDR, offset + i);
631 if (ret)
632 goto restore_eerd;
633
634 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_DATA, buf[i]);
635 if (ret)
636 goto restore_eerd;
637
638 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, 0x0);
639 if (ret)
640 goto restore_eerd;
641
642 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD,
643 RV3028_EEPROM_CMD_WRITE);
644 if (ret)
645 goto restore_eerd;
646
647 usleep_range(RV3028_EEBUSY_POLL, RV3028_EEBUSY_TIMEOUT);
648
649 ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status,
650 !(status & RV3028_STATUS_EEBUSY),
651 RV3028_EEBUSY_POLL,
652 RV3028_EEBUSY_TIMEOUT);
653 if (ret)
654 goto restore_eerd;
655 }
656
657restore_eerd:
658 rv3028_exit_eerd(rv3028, eerd);
659
660 return ret;
661}
662
663static int rv3028_eeprom_read(void *priv, unsigned int offset, void *val,
664 size_t bytes)
665{
666 struct rv3028_data *rv3028 = priv;
667 u32 status, eerd, data;
668 int i, ret;
669 u8 *buf = val;
670
671 ret = rv3028_enter_eerd(rv3028, &eerd);
672 if (ret)
673 return ret;
674
675 for (i = 0; i < bytes; i++) {
676 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_ADDR, offset + i);
677 if (ret)
678 goto restore_eerd;
679
680 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, 0x0);
681 if (ret)
682 goto restore_eerd;
683
684 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD,
685 RV3028_EEPROM_CMD_READ);
686 if (ret)
687 goto restore_eerd;
688
689 ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status,
690 !(status & RV3028_STATUS_EEBUSY),
691 RV3028_EEBUSY_POLL,
692 RV3028_EEBUSY_TIMEOUT);
693 if (ret)
694 goto restore_eerd;
695
696 ret = regmap_read(rv3028->regmap, RV3028_EEPROM_DATA, &data);
697 if (ret)
698 goto restore_eerd;
699 buf[i] = data;
700 }
701
702restore_eerd:
703 rv3028_exit_eerd(rv3028, eerd);
704
705 return ret;
706}
707
708#ifdef CONFIG_COMMON_CLK
709#define clkout_hw_to_rv3028(hw) container_of(hw, struct rv3028_data, clkout_hw)
710
711static int clkout_rates[] = {
712 32768,
713 8192,
714 1024,
715 64,
716 32,
717 1,
718};
719
720static unsigned long rv3028_clkout_recalc_rate(struct clk_hw *hw,
721 unsigned long parent_rate)
722{
723 int clkout, ret;
724 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
725
726 ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &clkout);
727 if (ret < 0)
728 return 0;
729
730 clkout &= RV3028_CLKOUT_FD_MASK;
731 return clkout_rates[clkout];
732}
733
734static int rv3028_clkout_determine_rate(struct clk_hw *hw,
735 struct clk_rate_request *req)
736{
737 int i;
738
739 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
740 if (clkout_rates[i] <= req->rate) {
741 req->rate = clkout_rates[i];
742
743 return 0;
744 }
745
746 req->rate = clkout_rates[0];
747
748 return 0;
749}
750
751static int rv3028_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
752 unsigned long parent_rate)
753{
754 int i, ret;
755 u32 enabled;
756 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
757
758 ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &enabled);
759 if (ret < 0)
760 return ret;
761
762 ret = regmap_write(rv3028->regmap, RV3028_CLKOUT, 0x0);
763 if (ret < 0)
764 return ret;
765
766 enabled &= RV3028_CLKOUT_CLKOE;
767
768 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
769 if (clkout_rates[i] == rate)
770 return rv3028_update_cfg(rv3028, RV3028_CLKOUT, 0xff,
771 RV3028_CLKOUT_CLKSY | enabled | i);
772
773 return -EINVAL;
774}
775
776static int rv3028_clkout_prepare(struct clk_hw *hw)
777{
778 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
779
780 return regmap_write(rv3028->regmap, RV3028_CLKOUT,
781 RV3028_CLKOUT_CLKSY | RV3028_CLKOUT_CLKOE);
782}
783
784static void rv3028_clkout_unprepare(struct clk_hw *hw)
785{
786 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
787
788 regmap_write(rv3028->regmap, RV3028_CLKOUT, 0x0);
789 regmap_update_bits(rv3028->regmap, RV3028_STATUS,
790 RV3028_STATUS_CLKF, 0);
791}
792
793static int rv3028_clkout_is_prepared(struct clk_hw *hw)
794{
795 int clkout, ret;
796 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
797
798 ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &clkout);
799 if (ret < 0)
800 return ret;
801
802 return !!(clkout & RV3028_CLKOUT_CLKOE);
803}
804
805static const struct clk_ops rv3028_clkout_ops = {
806 .prepare = rv3028_clkout_prepare,
807 .unprepare = rv3028_clkout_unprepare,
808 .is_prepared = rv3028_clkout_is_prepared,
809 .recalc_rate = rv3028_clkout_recalc_rate,
810 .determine_rate = rv3028_clkout_determine_rate,
811 .set_rate = rv3028_clkout_set_rate,
812};
813
814static int rv3028_clkout_register_clk(struct rv3028_data *rv3028,
815 struct i2c_client *client)
816{
817 int ret;
818 struct clk *clk;
819 struct clk_init_data init = {};
820 struct device_node *node = client->dev.of_node;
821
822 ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
823 RV3028_STATUS_CLKF, 0);
824 if (ret < 0)
825 return ret;
826
827 init.name = "rv3028-clkout";
828 init.ops = &rv3028_clkout_ops;
829 init.flags = 0;
830 init.parent_names = NULL;
831 init.num_parents = 0;
832 rv3028->clkout_hw.init = &init;
833
834 /* optional override of the clockname */
835 of_property_read_string(node, "clock-output-names", &init.name);
836
837 /* register the clock */
838 clk = devm_clk_register(&client->dev, &rv3028->clkout_hw);
839 if (!IS_ERR(clk))
840 of_clk_add_provider(node, of_clk_src_simple_get, clk);
841
842 return 0;
843}
844#endif
845
846static const struct rtc_class_ops rv3028_rtc_ops = {
847 .read_time = rv3028_get_time,
848 .set_time = rv3028_set_time,
849 .read_alarm = rv3028_get_alarm,
850 .set_alarm = rv3028_set_alarm,
851 .alarm_irq_enable = rv3028_alarm_irq_enable,
852 .read_offset = rv3028_read_offset,
853 .set_offset = rv3028_set_offset,
854 .ioctl = rv3028_ioctl,
855 .param_get = rv3028_param_get,
856 .param_set = rv3028_param_set,
857};
858
859static const struct regmap_config regmap_config = {
860 .reg_bits = 8,
861 .val_bits = 8,
862 .max_register = 0x37,
863};
864
865static u8 rv3028_set_trickle_charger(struct rv3028_data *rv3028,
866 struct i2c_client *client)
867{
868 int ret, val_old, val;
869 u32 ohms, chargeable;
870
871 ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &val_old);
872 if (ret < 0)
873 return ret;
874
875 /* mask out only trickle charger bits */
876 val_old = val_old & (RV3028_BACKUP_TCE | RV3028_BACKUP_TCR_MASK);
877 val = val_old;
878
879 /* setup trickle charger */
880 if (!device_property_read_u32(&client->dev, "trickle-resistor-ohms",
881 &ohms)) {
882 int i;
883
884 for (i = 0; i < ARRAY_SIZE(rv3028_trickle_resistors); i++)
885 if (ohms == rv3028_trickle_resistors[i])
886 break;
887
888 if (i < ARRAY_SIZE(rv3028_trickle_resistors)) {
889 /* enable trickle charger and its resistor */
890 val = RV3028_BACKUP_TCE | i;
891 } else {
892 dev_warn(&client->dev, "invalid trickle resistor value\n");
893 }
894 }
895
896 if (!device_property_read_u32(&client->dev, "aux-voltage-chargeable",
897 &chargeable)) {
898 switch (chargeable) {
899 case 0:
900 val &= ~RV3028_BACKUP_TCE;
901 break;
902 case 1:
903 val |= RV3028_BACKUP_TCE;
904 break;
905 default:
906 dev_warn(&client->dev,
907 "unsupported aux-voltage-chargeable value\n");
908 break;
909 }
910 }
911
912 /* only update EEPROM if changes are necessary */
913 if (val_old != val) {
914 ret = rv3028_update_cfg(rv3028, RV3028_BACKUP, RV3028_BACKUP_TCE |
915 RV3028_BACKUP_TCR_MASK, val);
916 if (ret)
917 return ret;
918 }
919
920 return ret;
921}
922
923static int rv3028_probe(struct i2c_client *client)
924{
925 struct rv3028_data *rv3028;
926 int ret, status;
927 struct nvmem_config nvmem_cfg = {
928 .name = "rv3028_nvram",
929 .word_size = 1,
930 .stride = 1,
931 .size = 2,
932 .type = NVMEM_TYPE_BATTERY_BACKED,
933 .reg_read = rv3028_nvram_read,
934 .reg_write = rv3028_nvram_write,
935 };
936 struct nvmem_config eeprom_cfg = {
937 .name = "rv3028_eeprom",
938 .word_size = 1,
939 .stride = 1,
940 .size = 43,
941 .type = NVMEM_TYPE_EEPROM,
942 .reg_read = rv3028_eeprom_read,
943 .reg_write = rv3028_eeprom_write,
944 };
945
946 rv3028 = devm_kzalloc(&client->dev, sizeof(struct rv3028_data),
947 GFP_KERNEL);
948 if (!rv3028)
949 return -ENOMEM;
950
951 rv3028->regmap = devm_regmap_init_i2c(client, &regmap_config);
952 if (IS_ERR(rv3028->regmap))
953 return PTR_ERR(rv3028->regmap);
954
955 i2c_set_clientdata(client, rv3028);
956
957 ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
958 if (ret < 0)
959 return ret;
960
961 if (status & RV3028_STATUS_AF)
962 dev_warn(&client->dev, "An alarm may have been missed.\n");
963
964 rv3028->rtc = devm_rtc_allocate_device(&client->dev);
965 if (IS_ERR(rv3028->rtc))
966 return PTR_ERR(rv3028->rtc);
967
968 if (client->irq > 0) {
969 unsigned long flags;
970
971 /*
972 * If flags = 0, devm_request_threaded_irq() will use IRQ flags
973 * obtained from device tree.
974 */
975 if (dev_fwnode(&client->dev))
976 flags = 0;
977 else
978 flags = IRQF_TRIGGER_LOW;
979
980 ret = devm_request_threaded_irq(&client->dev, client->irq,
981 NULL, rv3028_handle_irq,
982 flags | IRQF_ONESHOT,
983 "rv3028", rv3028);
984 if (ret) {
985 dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
986 client->irq = 0;
987 }
988 }
989 if (!client->irq)
990 clear_bit(RTC_FEATURE_ALARM, rv3028->rtc->features);
991
992 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL1,
993 RV3028_CTRL1_WADA, RV3028_CTRL1_WADA);
994 if (ret)
995 return ret;
996
997 /* setup timestamping */
998 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
999 RV3028_CTRL2_EIE | RV3028_CTRL2_TSE,
1000 RV3028_CTRL2_EIE | RV3028_CTRL2_TSE);
1001 if (ret)
1002 return ret;
1003
1004 ret = rv3028_set_trickle_charger(rv3028, client);
1005 if (ret)
1006 return ret;
1007
1008 ret = rtc_add_group(rv3028->rtc, &rv3028_attr_group);
1009 if (ret)
1010 return ret;
1011
1012 set_bit(RTC_FEATURE_BACKUP_SWITCH_MODE, rv3028->rtc->features);
1013
1014 rv3028->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
1015 rv3028->rtc->range_max = RTC_TIMESTAMP_END_2099;
1016 rv3028->rtc->ops = &rv3028_rtc_ops;
1017 ret = devm_rtc_register_device(rv3028->rtc);
1018 if (ret)
1019 return ret;
1020
1021 nvmem_cfg.priv = rv3028->regmap;
1022 devm_rtc_nvmem_register(rv3028->rtc, &nvmem_cfg);
1023 eeprom_cfg.priv = rv3028;
1024 devm_rtc_nvmem_register(rv3028->rtc, &eeprom_cfg);
1025
1026#ifdef CONFIG_COMMON_CLK
1027 rv3028_clkout_register_clk(rv3028, client);
1028#endif
1029 return 0;
1030}
1031
1032static const struct acpi_device_id rv3028_i2c_acpi_match[] = {
1033 { "MCRY3028" },
1034 { }
1035};
1036MODULE_DEVICE_TABLE(acpi, rv3028_i2c_acpi_match);
1037
1038static const __maybe_unused struct of_device_id rv3028_of_match[] = {
1039 { .compatible = "microcrystal,rv3028", },
1040 { }
1041};
1042MODULE_DEVICE_TABLE(of, rv3028_of_match);
1043
1044static const struct i2c_device_id rv3028_id_table[] = {
1045 { .name = "rv3028", },
1046 { }
1047};
1048MODULE_DEVICE_TABLE(i2c, rv3028_id_table);
1049
1050static struct i2c_driver rv3028_driver = {
1051 .driver = {
1052 .name = "rtc-rv3028",
1053 .acpi_match_table = rv3028_i2c_acpi_match,
1054 .of_match_table = of_match_ptr(rv3028_of_match),
1055 },
1056 .id_table = rv3028_id_table,
1057 .probe = rv3028_probe,
1058};
1059module_i2c_driver(rv3028_driver);
1060
1061MODULE_AUTHOR("Alexandre Belloni <[email protected]>");
1062MODULE_DESCRIPTION("Micro Crystal RV3028 RTC driver");
1063MODULE_LICENSE("GPL v2");