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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 <alexandre.belloni@bootlin.com>
8 *
9 */
10
11#include <linux/clk-provider.h>
12#include <linux/bcd.h>
13#include <linux/bitops.h>
14#include <linux/i2c.h>
15#include <linux/interrupt.h>
16#include <linux/kernel.h>
17#include <linux/log2.h>
18#include <linux/module.h>
19#include <linux/of_device.h>
20#include <linux/regmap.h>
21#include <linux/rtc.h>
22
23#define RV3028_SEC 0x00
24#define RV3028_MIN 0x01
25#define RV3028_HOUR 0x02
26#define RV3028_WDAY 0x03
27#define RV3028_DAY 0x04
28#define RV3028_MONTH 0x05
29#define RV3028_YEAR 0x06
30#define RV3028_ALARM_MIN 0x07
31#define RV3028_ALARM_HOUR 0x08
32#define RV3028_ALARM_DAY 0x09
33#define RV3028_STATUS 0x0E
34#define RV3028_CTRL1 0x0F
35#define RV3028_CTRL2 0x10
36#define RV3028_EVT_CTRL 0x13
37#define RV3028_TS_COUNT 0x14
38#define RV3028_TS_SEC 0x15
39#define RV3028_RAM1 0x1F
40#define RV3028_EEPROM_ADDR 0x25
41#define RV3028_EEPROM_DATA 0x26
42#define RV3028_EEPROM_CMD 0x27
43#define RV3028_CLKOUT 0x35
44#define RV3028_OFFSET 0x36
45#define RV3028_BACKUP 0x37
46
47#define RV3028_STATUS_PORF BIT(0)
48#define RV3028_STATUS_EVF BIT(1)
49#define RV3028_STATUS_AF BIT(2)
50#define RV3028_STATUS_TF BIT(3)
51#define RV3028_STATUS_UF BIT(4)
52#define RV3028_STATUS_BSF BIT(5)
53#define RV3028_STATUS_CLKF BIT(6)
54#define RV3028_STATUS_EEBUSY BIT(7)
55
56#define RV3028_CLKOUT_FD_MASK GENMASK(2, 0)
57#define RV3028_CLKOUT_PORIE BIT(3)
58#define RV3028_CLKOUT_CLKSY BIT(6)
59#define RV3028_CLKOUT_CLKOE BIT(7)
60
61#define RV3028_CTRL1_EERD BIT(3)
62#define RV3028_CTRL1_WADA BIT(5)
63
64#define RV3028_CTRL2_RESET BIT(0)
65#define RV3028_CTRL2_12_24 BIT(1)
66#define RV3028_CTRL2_EIE BIT(2)
67#define RV3028_CTRL2_AIE BIT(3)
68#define RV3028_CTRL2_TIE BIT(4)
69#define RV3028_CTRL2_UIE BIT(5)
70#define RV3028_CTRL2_TSE BIT(7)
71
72#define RV3028_EVT_CTRL_TSR BIT(2)
73
74#define RV3028_EEPROM_CMD_WRITE 0x21
75#define RV3028_EEPROM_CMD_READ 0x22
76
77#define RV3028_EEBUSY_POLL 10000
78#define RV3028_EEBUSY_TIMEOUT 100000
79
80#define RV3028_BACKUP_TCE BIT(5)
81#define RV3028_BACKUP_TCR_MASK GENMASK(1,0)
82
83#define OFFSET_STEP_PPT 953674
84
85enum rv3028_type {
86 rv_3028,
87};
88
89struct rv3028_data {
90 struct regmap *regmap;
91 struct rtc_device *rtc;
92 enum rv3028_type type;
93#ifdef CONFIG_COMMON_CLK
94 struct clk_hw clkout_hw;
95#endif
96};
97
98static u16 rv3028_trickle_resistors[] = {1000, 3000, 6000, 11000};
99
100static ssize_t timestamp0_store(struct device *dev,
101 struct device_attribute *attr,
102 const char *buf, size_t count)
103{
104 struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent);
105
106 regmap_update_bits(rv3028->regmap, RV3028_EVT_CTRL, RV3028_EVT_CTRL_TSR,
107 RV3028_EVT_CTRL_TSR);
108
109 return count;
110};
111
112static ssize_t timestamp0_show(struct device *dev,
113 struct device_attribute *attr, char *buf)
114{
115 struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent);
116 struct rtc_time tm;
117 int ret, count;
118 u8 date[6];
119
120 ret = regmap_read(rv3028->regmap, RV3028_TS_COUNT, &count);
121 if (ret)
122 return ret;
123
124 if (!count)
125 return 0;
126
127 ret = regmap_bulk_read(rv3028->regmap, RV3028_TS_SEC, date,
128 sizeof(date));
129 if (ret)
130 return ret;
131
132 tm.tm_sec = bcd2bin(date[0]);
133 tm.tm_min = bcd2bin(date[1]);
134 tm.tm_hour = bcd2bin(date[2]);
135 tm.tm_mday = bcd2bin(date[3]);
136 tm.tm_mon = bcd2bin(date[4]) - 1;
137 tm.tm_year = bcd2bin(date[5]) + 100;
138
139 ret = rtc_valid_tm(&tm);
140 if (ret)
141 return ret;
142
143 return sprintf(buf, "%llu\n",
144 (unsigned long long)rtc_tm_to_time64(&tm));
145};
146
147static DEVICE_ATTR_RW(timestamp0);
148
149static ssize_t timestamp0_count_show(struct device *dev,
150 struct device_attribute *attr, char *buf)
151{
152 struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent);
153 int ret, count;
154
155 ret = regmap_read(rv3028->regmap, RV3028_TS_COUNT, &count);
156 if (ret)
157 return ret;
158
159 return sprintf(buf, "%u\n", count);
160};
161
162static DEVICE_ATTR_RO(timestamp0_count);
163
164static struct attribute *rv3028_attrs[] = {
165 &dev_attr_timestamp0.attr,
166 &dev_attr_timestamp0_count.attr,
167 NULL
168};
169
170static const struct attribute_group rv3028_attr_group = {
171 .attrs = rv3028_attrs,
172};
173
174static irqreturn_t rv3028_handle_irq(int irq, void *dev_id)
175{
176 struct rv3028_data *rv3028 = dev_id;
177 unsigned long events = 0;
178 u32 status = 0, ctrl = 0;
179
180 if (regmap_read(rv3028->regmap, RV3028_STATUS, &status) < 0 ||
181 status == 0) {
182 return IRQ_NONE;
183 }
184
185 if (status & RV3028_STATUS_PORF)
186 dev_warn(&rv3028->rtc->dev, "Voltage low, data loss detected.\n");
187
188 if (status & RV3028_STATUS_TF) {
189 status |= RV3028_STATUS_TF;
190 ctrl |= RV3028_CTRL2_TIE;
191 events |= RTC_PF;
192 }
193
194 if (status & RV3028_STATUS_AF) {
195 status |= RV3028_STATUS_AF;
196 ctrl |= RV3028_CTRL2_AIE;
197 events |= RTC_AF;
198 }
199
200 if (status & RV3028_STATUS_UF) {
201 status |= RV3028_STATUS_UF;
202 ctrl |= RV3028_CTRL2_UIE;
203 events |= RTC_UF;
204 }
205
206 if (events) {
207 rtc_update_irq(rv3028->rtc, 1, events);
208 regmap_update_bits(rv3028->regmap, RV3028_STATUS, status, 0);
209 regmap_update_bits(rv3028->regmap, RV3028_CTRL2, ctrl, 0);
210 }
211
212 if (status & RV3028_STATUS_EVF) {
213 sysfs_notify(&rv3028->rtc->dev.kobj, NULL,
214 dev_attr_timestamp0.attr.name);
215 dev_warn(&rv3028->rtc->dev, "event detected");
216 }
217
218 return IRQ_HANDLED;
219}
220
221static int rv3028_get_time(struct device *dev, struct rtc_time *tm)
222{
223 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
224 u8 date[7];
225 int ret, status;
226
227 ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
228 if (ret < 0)
229 return ret;
230
231 if (status & RV3028_STATUS_PORF) {
232 dev_warn(dev, "Voltage low, data is invalid.\n");
233 return -EINVAL;
234 }
235
236 ret = regmap_bulk_read(rv3028->regmap, RV3028_SEC, date, sizeof(date));
237 if (ret)
238 return ret;
239
240 tm->tm_sec = bcd2bin(date[RV3028_SEC] & 0x7f);
241 tm->tm_min = bcd2bin(date[RV3028_MIN] & 0x7f);
242 tm->tm_hour = bcd2bin(date[RV3028_HOUR] & 0x3f);
243 tm->tm_wday = ilog2(date[RV3028_WDAY] & 0x7f);
244 tm->tm_mday = bcd2bin(date[RV3028_DAY] & 0x3f);
245 tm->tm_mon = bcd2bin(date[RV3028_MONTH] & 0x1f) - 1;
246 tm->tm_year = bcd2bin(date[RV3028_YEAR]) + 100;
247
248 return 0;
249}
250
251static int rv3028_set_time(struct device *dev, struct rtc_time *tm)
252{
253 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
254 u8 date[7];
255 int ret;
256
257 date[RV3028_SEC] = bin2bcd(tm->tm_sec);
258 date[RV3028_MIN] = bin2bcd(tm->tm_min);
259 date[RV3028_HOUR] = bin2bcd(tm->tm_hour);
260 date[RV3028_WDAY] = 1 << (tm->tm_wday);
261 date[RV3028_DAY] = bin2bcd(tm->tm_mday);
262 date[RV3028_MONTH] = bin2bcd(tm->tm_mon + 1);
263 date[RV3028_YEAR] = bin2bcd(tm->tm_year - 100);
264
265 /*
266 * Writing to the Seconds register has the same effect as setting RESET
267 * bit to 1
268 */
269 ret = regmap_bulk_write(rv3028->regmap, RV3028_SEC, date,
270 sizeof(date));
271 if (ret)
272 return ret;
273
274 ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
275 RV3028_STATUS_PORF, 0);
276
277 return ret;
278}
279
280static int rv3028_get_alarm(struct device *dev, struct rtc_wkalrm *alrm)
281{
282 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
283 u8 alarmvals[3];
284 int status, ctrl, ret;
285
286 ret = regmap_bulk_read(rv3028->regmap, RV3028_ALARM_MIN, alarmvals,
287 sizeof(alarmvals));
288 if (ret)
289 return ret;
290
291 ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
292 if (ret < 0)
293 return ret;
294
295 ret = regmap_read(rv3028->regmap, RV3028_CTRL2, &ctrl);
296 if (ret < 0)
297 return ret;
298
299 alrm->time.tm_sec = 0;
300 alrm->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);
301 alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
302 alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f);
303
304 alrm->enabled = !!(ctrl & RV3028_CTRL2_AIE);
305 alrm->pending = (status & RV3028_STATUS_AF) && alrm->enabled;
306
307 return 0;
308}
309
310static int rv3028_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
311{
312 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
313 u8 alarmvals[3];
314 u8 ctrl = 0;
315 int ret;
316
317 /* The alarm has no seconds, round up to nearest minute */
318 if (alrm->time.tm_sec) {
319 time64_t alarm_time = rtc_tm_to_time64(&alrm->time);
320
321 alarm_time += 60 - alrm->time.tm_sec;
322 rtc_time64_to_tm(alarm_time, &alrm->time);
323 }
324
325 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
326 RV3028_CTRL2_AIE | RV3028_CTRL2_UIE, 0);
327 if (ret)
328 return ret;
329
330 alarmvals[0] = bin2bcd(alrm->time.tm_min);
331 alarmvals[1] = bin2bcd(alrm->time.tm_hour);
332 alarmvals[2] = bin2bcd(alrm->time.tm_mday);
333
334 ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
335 RV3028_STATUS_AF, 0);
336 if (ret)
337 return ret;
338
339 ret = regmap_bulk_write(rv3028->regmap, RV3028_ALARM_MIN, alarmvals,
340 sizeof(alarmvals));
341 if (ret)
342 return ret;
343
344 if (alrm->enabled) {
345 if (rv3028->rtc->uie_rtctimer.enabled)
346 ctrl |= RV3028_CTRL2_UIE;
347 if (rv3028->rtc->aie_timer.enabled)
348 ctrl |= RV3028_CTRL2_AIE;
349 }
350
351 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
352 RV3028_CTRL2_UIE | RV3028_CTRL2_AIE, ctrl);
353
354 return ret;
355}
356
357static int rv3028_alarm_irq_enable(struct device *dev, unsigned int enabled)
358{
359 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
360 int ctrl = 0, ret;
361
362 if (enabled) {
363 if (rv3028->rtc->uie_rtctimer.enabled)
364 ctrl |= RV3028_CTRL2_UIE;
365 if (rv3028->rtc->aie_timer.enabled)
366 ctrl |= RV3028_CTRL2_AIE;
367 }
368
369 ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
370 RV3028_STATUS_AF | RV3028_STATUS_UF, 0);
371 if (ret)
372 return ret;
373
374 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
375 RV3028_CTRL2_UIE | RV3028_CTRL2_AIE, ctrl);
376 if (ret)
377 return ret;
378
379 return 0;
380}
381
382static int rv3028_read_offset(struct device *dev, long *offset)
383{
384 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
385 int ret, value, steps;
386
387 ret = regmap_read(rv3028->regmap, RV3028_OFFSET, &value);
388 if (ret < 0)
389 return ret;
390
391 steps = sign_extend32(value << 1, 8);
392
393 ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &value);
394 if (ret < 0)
395 return ret;
396
397 steps += value >> 7;
398
399 *offset = DIV_ROUND_CLOSEST(steps * OFFSET_STEP_PPT, 1000);
400
401 return 0;
402}
403
404static int rv3028_set_offset(struct device *dev, long offset)
405{
406 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
407 int ret;
408
409 offset = clamp(offset, -244141L, 243187L) * 1000;
410 offset = DIV_ROUND_CLOSEST(offset, OFFSET_STEP_PPT);
411
412 ret = regmap_write(rv3028->regmap, RV3028_OFFSET, offset >> 1);
413 if (ret < 0)
414 return ret;
415
416 return regmap_update_bits(rv3028->regmap, RV3028_BACKUP, BIT(7),
417 offset << 7);
418}
419
420static int rv3028_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
421{
422 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
423 int status, ret = 0;
424
425 switch (cmd) {
426 case RTC_VL_READ:
427 ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
428 if (ret < 0)
429 return ret;
430
431 status = status & RV3028_STATUS_PORF ? RTC_VL_DATA_INVALID : 0;
432 return put_user(status, (unsigned int __user *)arg);
433
434 default:
435 return -ENOIOCTLCMD;
436 }
437}
438
439static int rv3028_nvram_write(void *priv, unsigned int offset, void *val,
440 size_t bytes)
441{
442 return regmap_bulk_write(priv, RV3028_RAM1 + offset, val, bytes);
443}
444
445static int rv3028_nvram_read(void *priv, unsigned int offset, void *val,
446 size_t bytes)
447{
448 return regmap_bulk_read(priv, RV3028_RAM1 + offset, val, bytes);
449}
450
451static int rv3028_eeprom_write(void *priv, unsigned int offset, void *val,
452 size_t bytes)
453{
454 u32 status, ctrl1;
455 int i, ret, err;
456 u8 *buf = val;
457
458 ret = regmap_read(priv, RV3028_CTRL1, &ctrl1);
459 if (ret)
460 return ret;
461
462 if (!(ctrl1 & RV3028_CTRL1_EERD)) {
463 ret = regmap_update_bits(priv, RV3028_CTRL1,
464 RV3028_CTRL1_EERD, RV3028_CTRL1_EERD);
465 if (ret)
466 return ret;
467
468 ret = regmap_read_poll_timeout(priv, RV3028_STATUS, status,
469 !(status & RV3028_STATUS_EEBUSY),
470 RV3028_EEBUSY_POLL,
471 RV3028_EEBUSY_TIMEOUT);
472 if (ret)
473 goto restore_eerd;
474 }
475
476 for (i = 0; i < bytes; i++) {
477 ret = regmap_write(priv, RV3028_EEPROM_ADDR, offset + i);
478 if (ret)
479 goto restore_eerd;
480
481 ret = regmap_write(priv, RV3028_EEPROM_DATA, buf[i]);
482 if (ret)
483 goto restore_eerd;
484
485 ret = regmap_write(priv, RV3028_EEPROM_CMD, 0x0);
486 if (ret)
487 goto restore_eerd;
488
489 ret = regmap_write(priv, RV3028_EEPROM_CMD,
490 RV3028_EEPROM_CMD_WRITE);
491 if (ret)
492 goto restore_eerd;
493
494 usleep_range(RV3028_EEBUSY_POLL, RV3028_EEBUSY_TIMEOUT);
495
496 ret = regmap_read_poll_timeout(priv, RV3028_STATUS, status,
497 !(status & RV3028_STATUS_EEBUSY),
498 RV3028_EEBUSY_POLL,
499 RV3028_EEBUSY_TIMEOUT);
500 if (ret)
501 goto restore_eerd;
502 }
503
504restore_eerd:
505 if (!(ctrl1 & RV3028_CTRL1_EERD))
506 {
507 err = regmap_update_bits(priv, RV3028_CTRL1, RV3028_CTRL1_EERD,
508 0);
509 if (err && !ret)
510 ret = err;
511 }
512
513 return ret;
514}
515
516static int rv3028_eeprom_read(void *priv, unsigned int offset, void *val,
517 size_t bytes)
518{
519 u32 status, ctrl1, data;
520 int i, ret, err;
521 u8 *buf = val;
522
523 ret = regmap_read(priv, RV3028_CTRL1, &ctrl1);
524 if (ret)
525 return ret;
526
527 if (!(ctrl1 & RV3028_CTRL1_EERD)) {
528 ret = regmap_update_bits(priv, RV3028_CTRL1,
529 RV3028_CTRL1_EERD, RV3028_CTRL1_EERD);
530 if (ret)
531 return ret;
532
533 ret = regmap_read_poll_timeout(priv, RV3028_STATUS, status,
534 !(status & RV3028_STATUS_EEBUSY),
535 RV3028_EEBUSY_POLL,
536 RV3028_EEBUSY_TIMEOUT);
537 if (ret)
538 goto restore_eerd;
539 }
540
541 for (i = 0; i < bytes; i++) {
542 ret = regmap_write(priv, RV3028_EEPROM_ADDR, offset + i);
543 if (ret)
544 goto restore_eerd;
545
546 ret = regmap_write(priv, RV3028_EEPROM_CMD, 0x0);
547 if (ret)
548 goto restore_eerd;
549
550 ret = regmap_write(priv, RV3028_EEPROM_CMD,
551 RV3028_EEPROM_CMD_READ);
552 if (ret)
553 goto restore_eerd;
554
555 ret = regmap_read_poll_timeout(priv, RV3028_STATUS, status,
556 !(status & RV3028_STATUS_EEBUSY),
557 RV3028_EEBUSY_POLL,
558 RV3028_EEBUSY_TIMEOUT);
559 if (ret)
560 goto restore_eerd;
561
562 ret = regmap_read(priv, RV3028_EEPROM_DATA, &data);
563 if (ret)
564 goto restore_eerd;
565 buf[i] = data;
566 }
567
568restore_eerd:
569 if (!(ctrl1 & RV3028_CTRL1_EERD))
570 {
571 err = regmap_update_bits(priv, RV3028_CTRL1, RV3028_CTRL1_EERD,
572 0);
573 if (err && !ret)
574 ret = err;
575 }
576
577 return ret;
578}
579
580#ifdef CONFIG_COMMON_CLK
581#define clkout_hw_to_rv3028(hw) container_of(hw, struct rv3028_data, clkout_hw)
582
583static int clkout_rates[] = {
584 32768,
585 8192,
586 1024,
587 64,
588 32,
589 1,
590};
591
592static unsigned long rv3028_clkout_recalc_rate(struct clk_hw *hw,
593 unsigned long parent_rate)
594{
595 int clkout, ret;
596 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
597
598 ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &clkout);
599 if (ret < 0)
600 return 0;
601
602 clkout &= RV3028_CLKOUT_FD_MASK;
603 return clkout_rates[clkout];
604}
605
606static long rv3028_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
607 unsigned long *prate)
608{
609 int i;
610
611 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
612 if (clkout_rates[i] <= rate)
613 return clkout_rates[i];
614
615 return 0;
616}
617
618static int rv3028_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
619 unsigned long parent_rate)
620{
621 int i, ret;
622 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
623
624 ret = regmap_write(rv3028->regmap, RV3028_CLKOUT, 0x0);
625 if (ret < 0)
626 return ret;
627
628 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++) {
629 if (clkout_rates[i] == rate) {
630 ret = regmap_update_bits(rv3028->regmap,
631 RV3028_CLKOUT,
632 RV3028_CLKOUT_FD_MASK, i);
633 if (ret < 0)
634 return ret;
635
636 return regmap_write(rv3028->regmap, RV3028_CLKOUT,
637 RV3028_CLKOUT_CLKSY | RV3028_CLKOUT_CLKOE);
638 }
639 }
640
641 return -EINVAL;
642}
643
644static int rv3028_clkout_prepare(struct clk_hw *hw)
645{
646 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
647
648 return regmap_write(rv3028->regmap, RV3028_CLKOUT,
649 RV3028_CLKOUT_CLKSY | RV3028_CLKOUT_CLKOE);
650}
651
652static void rv3028_clkout_unprepare(struct clk_hw *hw)
653{
654 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
655
656 regmap_write(rv3028->regmap, RV3028_CLKOUT, 0x0);
657 regmap_update_bits(rv3028->regmap, RV3028_STATUS,
658 RV3028_STATUS_CLKF, 0);
659}
660
661static int rv3028_clkout_is_prepared(struct clk_hw *hw)
662{
663 int clkout, ret;
664 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
665
666 ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &clkout);
667 if (ret < 0)
668 return ret;
669
670 return !!(clkout & RV3028_CLKOUT_CLKOE);
671}
672
673static const struct clk_ops rv3028_clkout_ops = {
674 .prepare = rv3028_clkout_prepare,
675 .unprepare = rv3028_clkout_unprepare,
676 .is_prepared = rv3028_clkout_is_prepared,
677 .recalc_rate = rv3028_clkout_recalc_rate,
678 .round_rate = rv3028_clkout_round_rate,
679 .set_rate = rv3028_clkout_set_rate,
680};
681
682static int rv3028_clkout_register_clk(struct rv3028_data *rv3028,
683 struct i2c_client *client)
684{
685 int ret;
686 struct clk *clk;
687 struct clk_init_data init;
688 struct device_node *node = client->dev.of_node;
689
690 ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
691 RV3028_STATUS_CLKF, 0);
692 if (ret < 0)
693 return ret;
694
695 init.name = "rv3028-clkout";
696 init.ops = &rv3028_clkout_ops;
697 init.flags = 0;
698 init.parent_names = NULL;
699 init.num_parents = 0;
700 rv3028->clkout_hw.init = &init;
701
702 /* optional override of the clockname */
703 of_property_read_string(node, "clock-output-names", &init.name);
704
705 /* register the clock */
706 clk = devm_clk_register(&client->dev, &rv3028->clkout_hw);
707 if (!IS_ERR(clk))
708 of_clk_add_provider(node, of_clk_src_simple_get, clk);
709
710 return 0;
711}
712#endif
713
714static struct rtc_class_ops rv3028_rtc_ops = {
715 .read_time = rv3028_get_time,
716 .set_time = rv3028_set_time,
717 .read_offset = rv3028_read_offset,
718 .set_offset = rv3028_set_offset,
719 .ioctl = rv3028_ioctl,
720};
721
722static const struct regmap_config regmap_config = {
723 .reg_bits = 8,
724 .val_bits = 8,
725 .max_register = 0x37,
726};
727
728static int rv3028_probe(struct i2c_client *client)
729{
730 struct rv3028_data *rv3028;
731 int ret, status;
732 u32 ohms;
733 struct nvmem_config nvmem_cfg = {
734 .name = "rv3028_nvram",
735 .word_size = 1,
736 .stride = 1,
737 .size = 2,
738 .type = NVMEM_TYPE_BATTERY_BACKED,
739 .reg_read = rv3028_nvram_read,
740 .reg_write = rv3028_nvram_write,
741 };
742 struct nvmem_config eeprom_cfg = {
743 .name = "rv3028_eeprom",
744 .word_size = 1,
745 .stride = 1,
746 .size = 43,
747 .type = NVMEM_TYPE_EEPROM,
748 .reg_read = rv3028_eeprom_read,
749 .reg_write = rv3028_eeprom_write,
750 };
751
752 rv3028 = devm_kzalloc(&client->dev, sizeof(struct rv3028_data),
753 GFP_KERNEL);
754 if (!rv3028)
755 return -ENOMEM;
756
757 rv3028->regmap = devm_regmap_init_i2c(client, ®map_config);
758 if (IS_ERR(rv3028->regmap))
759 return PTR_ERR(rv3028->regmap);
760
761 i2c_set_clientdata(client, rv3028);
762
763 ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
764 if (ret < 0)
765 return ret;
766
767 if (status & RV3028_STATUS_PORF)
768 dev_warn(&client->dev, "Voltage low, data loss detected.\n");
769
770 if (status & RV3028_STATUS_AF)
771 dev_warn(&client->dev, "An alarm may have been missed.\n");
772
773 rv3028->rtc = devm_rtc_allocate_device(&client->dev);
774 if (IS_ERR(rv3028->rtc))
775 return PTR_ERR(rv3028->rtc);
776
777 if (client->irq > 0) {
778 ret = devm_request_threaded_irq(&client->dev, client->irq,
779 NULL, rv3028_handle_irq,
780 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
781 "rv3028", rv3028);
782 if (ret) {
783 dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
784 client->irq = 0;
785 } else {
786 rv3028_rtc_ops.read_alarm = rv3028_get_alarm;
787 rv3028_rtc_ops.set_alarm = rv3028_set_alarm;
788 rv3028_rtc_ops.alarm_irq_enable = rv3028_alarm_irq_enable;
789 }
790 }
791
792 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL1,
793 RV3028_CTRL1_WADA, RV3028_CTRL1_WADA);
794 if (ret)
795 return ret;
796
797 /* setup timestamping */
798 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
799 RV3028_CTRL2_EIE | RV3028_CTRL2_TSE,
800 RV3028_CTRL2_EIE | RV3028_CTRL2_TSE);
801 if (ret)
802 return ret;
803
804 /* setup trickle charger */
805 if (!device_property_read_u32(&client->dev, "trickle-resistor-ohms",
806 &ohms)) {
807 int i;
808
809 for (i = 0; i < ARRAY_SIZE(rv3028_trickle_resistors); i++)
810 if (ohms == rv3028_trickle_resistors[i])
811 break;
812
813 if (i < ARRAY_SIZE(rv3028_trickle_resistors)) {
814 ret = regmap_update_bits(rv3028->regmap, RV3028_BACKUP,
815 RV3028_BACKUP_TCE |
816 RV3028_BACKUP_TCR_MASK,
817 RV3028_BACKUP_TCE | i);
818 if (ret)
819 return ret;
820 } else {
821 dev_warn(&client->dev, "invalid trickle resistor value\n");
822 }
823 }
824
825 ret = rtc_add_group(rv3028->rtc, &rv3028_attr_group);
826 if (ret)
827 return ret;
828
829 rv3028->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
830 rv3028->rtc->range_max = RTC_TIMESTAMP_END_2099;
831 rv3028->rtc->ops = &rv3028_rtc_ops;
832 ret = rtc_register_device(rv3028->rtc);
833 if (ret)
834 return ret;
835
836 nvmem_cfg.priv = rv3028->regmap;
837 rtc_nvmem_register(rv3028->rtc, &nvmem_cfg);
838 eeprom_cfg.priv = rv3028->regmap;
839 rtc_nvmem_register(rv3028->rtc, &eeprom_cfg);
840
841 rv3028->rtc->max_user_freq = 1;
842
843#ifdef CONFIG_COMMON_CLK
844 rv3028_clkout_register_clk(rv3028, client);
845#endif
846 return 0;
847}
848
849static const struct of_device_id rv3028_of_match[] = {
850 { .compatible = "microcrystal,rv3028", },
851 { }
852};
853MODULE_DEVICE_TABLE(of, rv3028_of_match);
854
855static struct i2c_driver rv3028_driver = {
856 .driver = {
857 .name = "rtc-rv3028",
858 .of_match_table = of_match_ptr(rv3028_of_match),
859 },
860 .probe_new = rv3028_probe,
861};
862module_i2c_driver(rv3028_driver);
863
864MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
865MODULE_DESCRIPTION("Micro Crystal RV3028 RTC driver");
866MODULE_LICENSE("GPL v2");
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 <alexandre.belloni@bootlin.com>
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 int ret, count;
124 u8 date[6];
125
126 ret = regmap_read(rv3028->regmap, RV3028_TS_COUNT, &count);
127 if (ret)
128 return ret;
129
130 if (!count)
131 return 0;
132
133 ret = regmap_bulk_read(rv3028->regmap, RV3028_TS_SEC, date,
134 sizeof(date));
135 if (ret)
136 return ret;
137
138 tm.tm_sec = bcd2bin(date[0]);
139 tm.tm_min = bcd2bin(date[1]);
140 tm.tm_hour = bcd2bin(date[2]);
141 tm.tm_mday = bcd2bin(date[3]);
142 tm.tm_mon = bcd2bin(date[4]) - 1;
143 tm.tm_year = bcd2bin(date[5]) + 100;
144
145 ret = rtc_valid_tm(&tm);
146 if (ret)
147 return ret;
148
149 return sprintf(buf, "%llu\n",
150 (unsigned long long)rtc_tm_to_time64(&tm));
151};
152
153static DEVICE_ATTR_RW(timestamp0);
154
155static ssize_t timestamp0_count_show(struct device *dev,
156 struct device_attribute *attr, char *buf)
157{
158 struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent);
159 int ret, count;
160
161 ret = regmap_read(rv3028->regmap, RV3028_TS_COUNT, &count);
162 if (ret)
163 return ret;
164
165 return sprintf(buf, "%u\n", count);
166};
167
168static DEVICE_ATTR_RO(timestamp0_count);
169
170static struct attribute *rv3028_attrs[] = {
171 &dev_attr_timestamp0.attr,
172 &dev_attr_timestamp0_count.attr,
173 NULL
174};
175
176static const struct attribute_group rv3028_attr_group = {
177 .attrs = rv3028_attrs,
178};
179
180static int rv3028_exit_eerd(struct rv3028_data *rv3028, u32 eerd)
181{
182 if (eerd)
183 return 0;
184
185 return regmap_update_bits(rv3028->regmap, RV3028_CTRL1, RV3028_CTRL1_EERD, 0);
186}
187
188static int rv3028_enter_eerd(struct rv3028_data *rv3028, u32 *eerd)
189{
190 u32 ctrl1, status;
191 int ret;
192
193 ret = regmap_read(rv3028->regmap, RV3028_CTRL1, &ctrl1);
194 if (ret)
195 return ret;
196
197 *eerd = ctrl1 & RV3028_CTRL1_EERD;
198 if (*eerd)
199 return 0;
200
201 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL1,
202 RV3028_CTRL1_EERD, RV3028_CTRL1_EERD);
203 if (ret)
204 return ret;
205
206 ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status,
207 !(status & RV3028_STATUS_EEBUSY),
208 RV3028_EEBUSY_POLL, RV3028_EEBUSY_TIMEOUT);
209 if (ret) {
210 rv3028_exit_eerd(rv3028, *eerd);
211
212 return ret;
213 }
214
215 return 0;
216}
217
218static int rv3028_update_eeprom(struct rv3028_data *rv3028, u32 eerd)
219{
220 u32 status;
221 int ret;
222
223 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, 0x0);
224 if (ret)
225 goto exit_eerd;
226
227 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, RV3028_EEPROM_CMD_UPDATE);
228 if (ret)
229 goto exit_eerd;
230
231 usleep_range(63000, RV3028_EEBUSY_TIMEOUT);
232
233 ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status,
234 !(status & RV3028_STATUS_EEBUSY),
235 RV3028_EEBUSY_POLL, RV3028_EEBUSY_TIMEOUT);
236
237exit_eerd:
238 rv3028_exit_eerd(rv3028, eerd);
239
240 return ret;
241}
242
243static int rv3028_update_cfg(struct rv3028_data *rv3028, unsigned int reg,
244 unsigned int mask, unsigned int val)
245{
246 u32 eerd;
247 int ret;
248
249 ret = rv3028_enter_eerd(rv3028, &eerd);
250 if (ret)
251 return ret;
252
253 ret = regmap_update_bits(rv3028->regmap, reg, mask, val);
254 if (ret) {
255 rv3028_exit_eerd(rv3028, eerd);
256 return ret;
257 }
258
259 return rv3028_update_eeprom(rv3028, eerd);
260}
261
262static irqreturn_t rv3028_handle_irq(int irq, void *dev_id)
263{
264 struct rv3028_data *rv3028 = dev_id;
265 unsigned long events = 0;
266 u32 status = 0, ctrl = 0;
267
268 if (regmap_read(rv3028->regmap, RV3028_STATUS, &status) < 0 ||
269 status == 0) {
270 return IRQ_NONE;
271 }
272
273 status &= ~RV3028_STATUS_PORF;
274
275 if (status & RV3028_STATUS_TF) {
276 status |= RV3028_STATUS_TF;
277 ctrl |= RV3028_CTRL2_TIE;
278 events |= RTC_PF;
279 }
280
281 if (status & RV3028_STATUS_AF) {
282 status |= RV3028_STATUS_AF;
283 ctrl |= RV3028_CTRL2_AIE;
284 events |= RTC_AF;
285 }
286
287 if (status & RV3028_STATUS_UF) {
288 status |= RV3028_STATUS_UF;
289 ctrl |= RV3028_CTRL2_UIE;
290 events |= RTC_UF;
291 }
292
293 if (events) {
294 rtc_update_irq(rv3028->rtc, 1, events);
295 regmap_update_bits(rv3028->regmap, RV3028_STATUS, status, 0);
296 regmap_update_bits(rv3028->regmap, RV3028_CTRL2, ctrl, 0);
297 }
298
299 if (status & RV3028_STATUS_EVF) {
300 sysfs_notify(&rv3028->rtc->dev.kobj, NULL,
301 dev_attr_timestamp0.attr.name);
302 dev_warn(&rv3028->rtc->dev, "event detected");
303 }
304
305 return IRQ_HANDLED;
306}
307
308static int rv3028_get_time(struct device *dev, struct rtc_time *tm)
309{
310 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
311 u8 date[7];
312 int ret, status;
313
314 ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
315 if (ret < 0)
316 return ret;
317
318 if (status & RV3028_STATUS_PORF)
319 return -EINVAL;
320
321 ret = regmap_bulk_read(rv3028->regmap, RV3028_SEC, date, sizeof(date));
322 if (ret)
323 return ret;
324
325 tm->tm_sec = bcd2bin(date[RV3028_SEC] & 0x7f);
326 tm->tm_min = bcd2bin(date[RV3028_MIN] & 0x7f);
327 tm->tm_hour = bcd2bin(date[RV3028_HOUR] & 0x3f);
328 tm->tm_wday = date[RV3028_WDAY] & 0x7f;
329 tm->tm_mday = bcd2bin(date[RV3028_DAY] & 0x3f);
330 tm->tm_mon = bcd2bin(date[RV3028_MONTH] & 0x1f) - 1;
331 tm->tm_year = bcd2bin(date[RV3028_YEAR]) + 100;
332
333 return 0;
334}
335
336static int rv3028_set_time(struct device *dev, struct rtc_time *tm)
337{
338 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
339 u8 date[7];
340 int ret;
341
342 date[RV3028_SEC] = bin2bcd(tm->tm_sec);
343 date[RV3028_MIN] = bin2bcd(tm->tm_min);
344 date[RV3028_HOUR] = bin2bcd(tm->tm_hour);
345 date[RV3028_WDAY] = tm->tm_wday;
346 date[RV3028_DAY] = bin2bcd(tm->tm_mday);
347 date[RV3028_MONTH] = bin2bcd(tm->tm_mon + 1);
348 date[RV3028_YEAR] = bin2bcd(tm->tm_year - 100);
349
350 /*
351 * Writing to the Seconds register has the same effect as setting RESET
352 * bit to 1
353 */
354 ret = regmap_bulk_write(rv3028->regmap, RV3028_SEC, date,
355 sizeof(date));
356 if (ret)
357 return ret;
358
359 ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
360 RV3028_STATUS_PORF, 0);
361
362 return ret;
363}
364
365static int rv3028_get_alarm(struct device *dev, struct rtc_wkalrm *alrm)
366{
367 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
368 u8 alarmvals[3];
369 int status, ctrl, ret;
370
371 ret = regmap_bulk_read(rv3028->regmap, RV3028_ALARM_MIN, alarmvals,
372 sizeof(alarmvals));
373 if (ret)
374 return ret;
375
376 ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
377 if (ret < 0)
378 return ret;
379
380 ret = regmap_read(rv3028->regmap, RV3028_CTRL2, &ctrl);
381 if (ret < 0)
382 return ret;
383
384 alrm->time.tm_sec = 0;
385 alrm->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);
386 alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
387 alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f);
388
389 alrm->enabled = !!(ctrl & RV3028_CTRL2_AIE);
390 alrm->pending = (status & RV3028_STATUS_AF) && alrm->enabled;
391
392 return 0;
393}
394
395static int rv3028_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
396{
397 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
398 u8 alarmvals[3];
399 u8 ctrl = 0;
400 int ret;
401
402 /* The alarm has no seconds, round up to nearest minute */
403 if (alrm->time.tm_sec) {
404 time64_t alarm_time = rtc_tm_to_time64(&alrm->time);
405
406 alarm_time += 60 - alrm->time.tm_sec;
407 rtc_time64_to_tm(alarm_time, &alrm->time);
408 }
409
410 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
411 RV3028_CTRL2_AIE | RV3028_CTRL2_UIE, 0);
412 if (ret)
413 return ret;
414
415 alarmvals[0] = bin2bcd(alrm->time.tm_min);
416 alarmvals[1] = bin2bcd(alrm->time.tm_hour);
417 alarmvals[2] = bin2bcd(alrm->time.tm_mday);
418
419 ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
420 RV3028_STATUS_AF, 0);
421 if (ret)
422 return ret;
423
424 ret = regmap_bulk_write(rv3028->regmap, RV3028_ALARM_MIN, alarmvals,
425 sizeof(alarmvals));
426 if (ret)
427 return ret;
428
429 if (alrm->enabled) {
430 if (rv3028->rtc->uie_rtctimer.enabled)
431 ctrl |= RV3028_CTRL2_UIE;
432 if (rv3028->rtc->aie_timer.enabled)
433 ctrl |= RV3028_CTRL2_AIE;
434 }
435
436 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
437 RV3028_CTRL2_UIE | RV3028_CTRL2_AIE, ctrl);
438
439 return ret;
440}
441
442static int rv3028_alarm_irq_enable(struct device *dev, unsigned int enabled)
443{
444 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
445 int ctrl = 0, ret;
446
447 if (enabled) {
448 if (rv3028->rtc->uie_rtctimer.enabled)
449 ctrl |= RV3028_CTRL2_UIE;
450 if (rv3028->rtc->aie_timer.enabled)
451 ctrl |= RV3028_CTRL2_AIE;
452 }
453
454 ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
455 RV3028_STATUS_AF | RV3028_STATUS_UF, 0);
456 if (ret)
457 return ret;
458
459 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
460 RV3028_CTRL2_UIE | RV3028_CTRL2_AIE, ctrl);
461 if (ret)
462 return ret;
463
464 return 0;
465}
466
467static int rv3028_read_offset(struct device *dev, long *offset)
468{
469 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
470 int ret, value, steps;
471
472 ret = regmap_read(rv3028->regmap, RV3028_OFFSET, &value);
473 if (ret < 0)
474 return ret;
475
476 steps = sign_extend32(value << 1, 8);
477
478 ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &value);
479 if (ret < 0)
480 return ret;
481
482 steps += value >> 7;
483
484 *offset = DIV_ROUND_CLOSEST(steps * OFFSET_STEP_PPT, 1000);
485
486 return 0;
487}
488
489static int rv3028_set_offset(struct device *dev, long offset)
490{
491 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
492 u32 eerd;
493 int ret;
494
495 offset = clamp(offset, -244141L, 243187L) * 1000;
496 offset = DIV_ROUND_CLOSEST(offset, OFFSET_STEP_PPT);
497
498 ret = rv3028_enter_eerd(rv3028, &eerd);
499 if (ret)
500 return ret;
501
502 ret = regmap_write(rv3028->regmap, RV3028_OFFSET, offset >> 1);
503 if (ret < 0)
504 goto exit_eerd;
505
506 ret = regmap_update_bits(rv3028->regmap, RV3028_BACKUP, BIT(7),
507 offset << 7);
508 if (ret < 0)
509 goto exit_eerd;
510
511 return rv3028_update_eeprom(rv3028, eerd);
512
513exit_eerd:
514 rv3028_exit_eerd(rv3028, eerd);
515
516 return ret;
517
518}
519
520static int rv3028_param_get(struct device *dev, struct rtc_param *param)
521{
522 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
523 int ret;
524 u32 value;
525
526 switch(param->param) {
527 case RTC_PARAM_BACKUP_SWITCH_MODE:
528 ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &value);
529 if (ret < 0)
530 return ret;
531
532 value = FIELD_GET(RV3028_BACKUP_BSM, value);
533
534 switch(value) {
535 case RV3028_BACKUP_BSM_DSM:
536 param->uvalue = RTC_BSM_DIRECT;
537 break;
538 case RV3028_BACKUP_BSM_LSM:
539 param->uvalue = RTC_BSM_LEVEL;
540 break;
541 default:
542 param->uvalue = RTC_BSM_DISABLED;
543 }
544 break;
545
546 default:
547 return -EINVAL;
548 }
549
550 return 0;
551}
552
553static int rv3028_param_set(struct device *dev, struct rtc_param *param)
554{
555 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
556 u8 mode;
557
558 switch(param->param) {
559 case RTC_PARAM_BACKUP_SWITCH_MODE:
560 switch (param->uvalue) {
561 case RTC_BSM_DISABLED:
562 mode = 0;
563 break;
564 case RTC_BSM_DIRECT:
565 mode = RV3028_BACKUP_BSM_DSM;
566 break;
567 case RTC_BSM_LEVEL:
568 mode = RV3028_BACKUP_BSM_LSM;
569 break;
570 default:
571 return -EINVAL;
572 }
573
574 return rv3028_update_cfg(rv3028, RV3028_BACKUP, RV3028_BACKUP_BSM,
575 FIELD_PREP(RV3028_BACKUP_BSM, mode));
576
577 default:
578 return -EINVAL;
579 }
580
581 return 0;
582}
583
584static int rv3028_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
585{
586 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
587 int status, ret = 0;
588
589 switch (cmd) {
590 case RTC_VL_READ:
591 ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
592 if (ret < 0)
593 return ret;
594
595 status = status & RV3028_STATUS_PORF ? RTC_VL_DATA_INVALID : 0;
596 return put_user(status, (unsigned int __user *)arg);
597
598 default:
599 return -ENOIOCTLCMD;
600 }
601}
602
603static int rv3028_nvram_write(void *priv, unsigned int offset, void *val,
604 size_t bytes)
605{
606 return regmap_bulk_write(priv, RV3028_RAM1 + offset, val, bytes);
607}
608
609static int rv3028_nvram_read(void *priv, unsigned int offset, void *val,
610 size_t bytes)
611{
612 return regmap_bulk_read(priv, RV3028_RAM1 + offset, val, bytes);
613}
614
615static int rv3028_eeprom_write(void *priv, unsigned int offset, void *val,
616 size_t bytes)
617{
618 struct rv3028_data *rv3028 = priv;
619 u32 status, eerd;
620 int i, ret;
621 u8 *buf = val;
622
623 ret = rv3028_enter_eerd(rv3028, &eerd);
624 if (ret)
625 return ret;
626
627 for (i = 0; i < bytes; i++) {
628 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_ADDR, offset + i);
629 if (ret)
630 goto restore_eerd;
631
632 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_DATA, buf[i]);
633 if (ret)
634 goto restore_eerd;
635
636 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, 0x0);
637 if (ret)
638 goto restore_eerd;
639
640 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD,
641 RV3028_EEPROM_CMD_WRITE);
642 if (ret)
643 goto restore_eerd;
644
645 usleep_range(RV3028_EEBUSY_POLL, RV3028_EEBUSY_TIMEOUT);
646
647 ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status,
648 !(status & RV3028_STATUS_EEBUSY),
649 RV3028_EEBUSY_POLL,
650 RV3028_EEBUSY_TIMEOUT);
651 if (ret)
652 goto restore_eerd;
653 }
654
655restore_eerd:
656 rv3028_exit_eerd(rv3028, eerd);
657
658 return ret;
659}
660
661static int rv3028_eeprom_read(void *priv, unsigned int offset, void *val,
662 size_t bytes)
663{
664 struct rv3028_data *rv3028 = priv;
665 u32 status, eerd, data;
666 int i, ret;
667 u8 *buf = val;
668
669 ret = rv3028_enter_eerd(rv3028, &eerd);
670 if (ret)
671 return ret;
672
673 for (i = 0; i < bytes; i++) {
674 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_ADDR, offset + i);
675 if (ret)
676 goto restore_eerd;
677
678 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, 0x0);
679 if (ret)
680 goto restore_eerd;
681
682 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD,
683 RV3028_EEPROM_CMD_READ);
684 if (ret)
685 goto restore_eerd;
686
687 ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status,
688 !(status & RV3028_STATUS_EEBUSY),
689 RV3028_EEBUSY_POLL,
690 RV3028_EEBUSY_TIMEOUT);
691 if (ret)
692 goto restore_eerd;
693
694 ret = regmap_read(rv3028->regmap, RV3028_EEPROM_DATA, &data);
695 if (ret)
696 goto restore_eerd;
697 buf[i] = data;
698 }
699
700restore_eerd:
701 rv3028_exit_eerd(rv3028, eerd);
702
703 return ret;
704}
705
706#ifdef CONFIG_COMMON_CLK
707#define clkout_hw_to_rv3028(hw) container_of(hw, struct rv3028_data, clkout_hw)
708
709static int clkout_rates[] = {
710 32768,
711 8192,
712 1024,
713 64,
714 32,
715 1,
716};
717
718static unsigned long rv3028_clkout_recalc_rate(struct clk_hw *hw,
719 unsigned long parent_rate)
720{
721 int clkout, ret;
722 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
723
724 ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &clkout);
725 if (ret < 0)
726 return 0;
727
728 clkout &= RV3028_CLKOUT_FD_MASK;
729 return clkout_rates[clkout];
730}
731
732static long rv3028_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
733 unsigned long *prate)
734{
735 int i;
736
737 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
738 if (clkout_rates[i] <= rate)
739 return clkout_rates[i];
740
741 return 0;
742}
743
744static int rv3028_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
745 unsigned long parent_rate)
746{
747 int i, ret;
748 u32 enabled;
749 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
750
751 ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &enabled);
752 if (ret < 0)
753 return ret;
754
755 ret = regmap_write(rv3028->regmap, RV3028_CLKOUT, 0x0);
756 if (ret < 0)
757 return ret;
758
759 enabled &= RV3028_CLKOUT_CLKOE;
760
761 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
762 if (clkout_rates[i] == rate)
763 return rv3028_update_cfg(rv3028, RV3028_CLKOUT, 0xff,
764 RV3028_CLKOUT_CLKSY | enabled | i);
765
766 return -EINVAL;
767}
768
769static int rv3028_clkout_prepare(struct clk_hw *hw)
770{
771 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
772
773 return regmap_write(rv3028->regmap, RV3028_CLKOUT,
774 RV3028_CLKOUT_CLKSY | RV3028_CLKOUT_CLKOE);
775}
776
777static void rv3028_clkout_unprepare(struct clk_hw *hw)
778{
779 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
780
781 regmap_write(rv3028->regmap, RV3028_CLKOUT, 0x0);
782 regmap_update_bits(rv3028->regmap, RV3028_STATUS,
783 RV3028_STATUS_CLKF, 0);
784}
785
786static int rv3028_clkout_is_prepared(struct clk_hw *hw)
787{
788 int clkout, ret;
789 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
790
791 ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &clkout);
792 if (ret < 0)
793 return ret;
794
795 return !!(clkout & RV3028_CLKOUT_CLKOE);
796}
797
798static const struct clk_ops rv3028_clkout_ops = {
799 .prepare = rv3028_clkout_prepare,
800 .unprepare = rv3028_clkout_unprepare,
801 .is_prepared = rv3028_clkout_is_prepared,
802 .recalc_rate = rv3028_clkout_recalc_rate,
803 .round_rate = rv3028_clkout_round_rate,
804 .set_rate = rv3028_clkout_set_rate,
805};
806
807static int rv3028_clkout_register_clk(struct rv3028_data *rv3028,
808 struct i2c_client *client)
809{
810 int ret;
811 struct clk *clk;
812 struct clk_init_data init;
813 struct device_node *node = client->dev.of_node;
814
815 ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
816 RV3028_STATUS_CLKF, 0);
817 if (ret < 0)
818 return ret;
819
820 init.name = "rv3028-clkout";
821 init.ops = &rv3028_clkout_ops;
822 init.flags = 0;
823 init.parent_names = NULL;
824 init.num_parents = 0;
825 rv3028->clkout_hw.init = &init;
826
827 /* optional override of the clockname */
828 of_property_read_string(node, "clock-output-names", &init.name);
829
830 /* register the clock */
831 clk = devm_clk_register(&client->dev, &rv3028->clkout_hw);
832 if (!IS_ERR(clk))
833 of_clk_add_provider(node, of_clk_src_simple_get, clk);
834
835 return 0;
836}
837#endif
838
839static const struct rtc_class_ops rv3028_rtc_ops = {
840 .read_time = rv3028_get_time,
841 .set_time = rv3028_set_time,
842 .read_alarm = rv3028_get_alarm,
843 .set_alarm = rv3028_set_alarm,
844 .alarm_irq_enable = rv3028_alarm_irq_enable,
845 .read_offset = rv3028_read_offset,
846 .set_offset = rv3028_set_offset,
847 .ioctl = rv3028_ioctl,
848 .param_get = rv3028_param_get,
849 .param_set = rv3028_param_set,
850};
851
852static const struct regmap_config regmap_config = {
853 .reg_bits = 8,
854 .val_bits = 8,
855 .max_register = 0x37,
856};
857
858static u8 rv3028_set_trickle_charger(struct rv3028_data *rv3028,
859 struct i2c_client *client)
860{
861 int ret, val_old, val;
862 u32 ohms, chargeable;
863
864 ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &val_old);
865 if (ret < 0)
866 return ret;
867
868 /* mask out only trickle charger bits */
869 val_old = val_old & (RV3028_BACKUP_TCE | RV3028_BACKUP_TCR_MASK);
870 val = val_old;
871
872 /* setup trickle charger */
873 if (!device_property_read_u32(&client->dev, "trickle-resistor-ohms",
874 &ohms)) {
875 int i;
876
877 for (i = 0; i < ARRAY_SIZE(rv3028_trickle_resistors); i++)
878 if (ohms == rv3028_trickle_resistors[i])
879 break;
880
881 if (i < ARRAY_SIZE(rv3028_trickle_resistors)) {
882 /* enable trickle charger and its resistor */
883 val = RV3028_BACKUP_TCE | i;
884 } else {
885 dev_warn(&client->dev, "invalid trickle resistor value\n");
886 }
887 }
888
889 if (!device_property_read_u32(&client->dev, "aux-voltage-chargeable",
890 &chargeable)) {
891 switch (chargeable) {
892 case 0:
893 val &= ~RV3028_BACKUP_TCE;
894 break;
895 case 1:
896 val |= RV3028_BACKUP_TCE;
897 break;
898 default:
899 dev_warn(&client->dev,
900 "unsupported aux-voltage-chargeable value\n");
901 break;
902 }
903 }
904
905 /* only update EEPROM if changes are necessary */
906 if (val_old != val) {
907 ret = rv3028_update_cfg(rv3028, RV3028_BACKUP, RV3028_BACKUP_TCE |
908 RV3028_BACKUP_TCR_MASK, val);
909 if (ret)
910 return ret;
911 }
912
913 return ret;
914}
915
916static int rv3028_probe(struct i2c_client *client)
917{
918 struct rv3028_data *rv3028;
919 int ret, status;
920 struct nvmem_config nvmem_cfg = {
921 .name = "rv3028_nvram",
922 .word_size = 1,
923 .stride = 1,
924 .size = 2,
925 .type = NVMEM_TYPE_BATTERY_BACKED,
926 .reg_read = rv3028_nvram_read,
927 .reg_write = rv3028_nvram_write,
928 };
929 struct nvmem_config eeprom_cfg = {
930 .name = "rv3028_eeprom",
931 .word_size = 1,
932 .stride = 1,
933 .size = 43,
934 .type = NVMEM_TYPE_EEPROM,
935 .reg_read = rv3028_eeprom_read,
936 .reg_write = rv3028_eeprom_write,
937 };
938
939 rv3028 = devm_kzalloc(&client->dev, sizeof(struct rv3028_data),
940 GFP_KERNEL);
941 if (!rv3028)
942 return -ENOMEM;
943
944 rv3028->regmap = devm_regmap_init_i2c(client, ®map_config);
945 if (IS_ERR(rv3028->regmap))
946 return PTR_ERR(rv3028->regmap);
947
948 i2c_set_clientdata(client, rv3028);
949
950 ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
951 if (ret < 0)
952 return ret;
953
954 if (status & RV3028_STATUS_AF)
955 dev_warn(&client->dev, "An alarm may have been missed.\n");
956
957 rv3028->rtc = devm_rtc_allocate_device(&client->dev);
958 if (IS_ERR(rv3028->rtc))
959 return PTR_ERR(rv3028->rtc);
960
961 if (client->irq > 0) {
962 unsigned long flags;
963
964 /*
965 * If flags = 0, devm_request_threaded_irq() will use IRQ flags
966 * obtained from device tree.
967 */
968 if (dev_fwnode(&client->dev))
969 flags = 0;
970 else
971 flags = IRQF_TRIGGER_LOW;
972
973 ret = devm_request_threaded_irq(&client->dev, client->irq,
974 NULL, rv3028_handle_irq,
975 flags | IRQF_ONESHOT,
976 "rv3028", rv3028);
977 if (ret) {
978 dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
979 client->irq = 0;
980 }
981 }
982 if (!client->irq)
983 clear_bit(RTC_FEATURE_ALARM, rv3028->rtc->features);
984
985 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL1,
986 RV3028_CTRL1_WADA, RV3028_CTRL1_WADA);
987 if (ret)
988 return ret;
989
990 /* setup timestamping */
991 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
992 RV3028_CTRL2_EIE | RV3028_CTRL2_TSE,
993 RV3028_CTRL2_EIE | RV3028_CTRL2_TSE);
994 if (ret)
995 return ret;
996
997 ret = rv3028_set_trickle_charger(rv3028, client);
998 if (ret)
999 return ret;
1000
1001 ret = rtc_add_group(rv3028->rtc, &rv3028_attr_group);
1002 if (ret)
1003 return ret;
1004
1005 set_bit(RTC_FEATURE_BACKUP_SWITCH_MODE, rv3028->rtc->features);
1006
1007 rv3028->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
1008 rv3028->rtc->range_max = RTC_TIMESTAMP_END_2099;
1009 rv3028->rtc->ops = &rv3028_rtc_ops;
1010 ret = devm_rtc_register_device(rv3028->rtc);
1011 if (ret)
1012 return ret;
1013
1014 nvmem_cfg.priv = rv3028->regmap;
1015 devm_rtc_nvmem_register(rv3028->rtc, &nvmem_cfg);
1016 eeprom_cfg.priv = rv3028;
1017 devm_rtc_nvmem_register(rv3028->rtc, &eeprom_cfg);
1018
1019 rv3028->rtc->max_user_freq = 1;
1020
1021#ifdef CONFIG_COMMON_CLK
1022 rv3028_clkout_register_clk(rv3028, client);
1023#endif
1024 return 0;
1025}
1026
1027static const struct acpi_device_id rv3028_i2c_acpi_match[] = {
1028 { "MCRY3028" },
1029 { }
1030};
1031MODULE_DEVICE_TABLE(acpi, rv3028_i2c_acpi_match);
1032
1033static const __maybe_unused struct of_device_id rv3028_of_match[] = {
1034 { .compatible = "microcrystal,rv3028", },
1035 { }
1036};
1037MODULE_DEVICE_TABLE(of, rv3028_of_match);
1038
1039static const struct i2c_device_id rv3028_id_table[] = {
1040 { .name = "rv3028", },
1041 { }
1042};
1043MODULE_DEVICE_TABLE(i2c, rv3028_id_table);
1044
1045static struct i2c_driver rv3028_driver = {
1046 .driver = {
1047 .name = "rtc-rv3028",
1048 .acpi_match_table = rv3028_i2c_acpi_match,
1049 .of_match_table = of_match_ptr(rv3028_of_match),
1050 },
1051 .id_table = rv3028_id_table,
1052 .probe = rv3028_probe,
1053};
1054module_i2c_driver(rv3028_driver);
1055
1056MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
1057MODULE_DESCRIPTION("Micro Crystal RV3028 RTC driver");
1058MODULE_LICENSE("GPL v2");