Loading...
Note: File does not exist in v3.1.
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_UPDATE 0x11
75#define RV3028_EEPROM_CMD_WRITE 0x21
76#define RV3028_EEPROM_CMD_READ 0x22
77
78#define RV3028_EEBUSY_POLL 10000
79#define RV3028_EEBUSY_TIMEOUT 100000
80
81#define RV3028_BACKUP_TCE BIT(5)
82#define RV3028_BACKUP_TCR_MASK GENMASK(1,0)
83
84#define OFFSET_STEP_PPT 953674
85
86enum rv3028_type {
87 rv_3028,
88};
89
90struct rv3028_data {
91 struct regmap *regmap;
92 struct rtc_device *rtc;
93 enum rv3028_type type;
94#ifdef CONFIG_COMMON_CLK
95 struct clk_hw clkout_hw;
96#endif
97};
98
99static u16 rv3028_trickle_resistors[] = {3000, 5000, 9000, 15000};
100
101static ssize_t timestamp0_store(struct device *dev,
102 struct device_attribute *attr,
103 const char *buf, size_t count)
104{
105 struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent);
106
107 regmap_update_bits(rv3028->regmap, RV3028_EVT_CTRL, RV3028_EVT_CTRL_TSR,
108 RV3028_EVT_CTRL_TSR);
109
110 return count;
111};
112
113static ssize_t timestamp0_show(struct device *dev,
114 struct device_attribute *attr, char *buf)
115{
116 struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent);
117 struct rtc_time tm;
118 int ret, count;
119 u8 date[6];
120
121 ret = regmap_read(rv3028->regmap, RV3028_TS_COUNT, &count);
122 if (ret)
123 return ret;
124
125 if (!count)
126 return 0;
127
128 ret = regmap_bulk_read(rv3028->regmap, RV3028_TS_SEC, date,
129 sizeof(date));
130 if (ret)
131 return ret;
132
133 tm.tm_sec = bcd2bin(date[0]);
134 tm.tm_min = bcd2bin(date[1]);
135 tm.tm_hour = bcd2bin(date[2]);
136 tm.tm_mday = bcd2bin(date[3]);
137 tm.tm_mon = bcd2bin(date[4]) - 1;
138 tm.tm_year = bcd2bin(date[5]) + 100;
139
140 ret = rtc_valid_tm(&tm);
141 if (ret)
142 return ret;
143
144 return sprintf(buf, "%llu\n",
145 (unsigned long long)rtc_tm_to_time64(&tm));
146};
147
148static DEVICE_ATTR_RW(timestamp0);
149
150static ssize_t timestamp0_count_show(struct device *dev,
151 struct device_attribute *attr, char *buf)
152{
153 struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent);
154 int ret, count;
155
156 ret = regmap_read(rv3028->regmap, RV3028_TS_COUNT, &count);
157 if (ret)
158 return ret;
159
160 return sprintf(buf, "%u\n", count);
161};
162
163static DEVICE_ATTR_RO(timestamp0_count);
164
165static struct attribute *rv3028_attrs[] = {
166 &dev_attr_timestamp0.attr,
167 &dev_attr_timestamp0_count.attr,
168 NULL
169};
170
171static const struct attribute_group rv3028_attr_group = {
172 .attrs = rv3028_attrs,
173};
174
175static int rv3028_exit_eerd(struct rv3028_data *rv3028, u32 eerd)
176{
177 if (eerd)
178 return 0;
179
180 return regmap_update_bits(rv3028->regmap, RV3028_CTRL1, RV3028_CTRL1_EERD, 0);
181}
182
183static int rv3028_enter_eerd(struct rv3028_data *rv3028, u32 *eerd)
184{
185 u32 ctrl1, status;
186 int ret;
187
188 ret = regmap_read(rv3028->regmap, RV3028_CTRL1, &ctrl1);
189 if (ret)
190 return ret;
191
192 *eerd = ctrl1 & RV3028_CTRL1_EERD;
193 if (*eerd)
194 return 0;
195
196 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL1,
197 RV3028_CTRL1_EERD, RV3028_CTRL1_EERD);
198 if (ret)
199 return ret;
200
201 ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status,
202 !(status & RV3028_STATUS_EEBUSY),
203 RV3028_EEBUSY_POLL, RV3028_EEBUSY_TIMEOUT);
204 if (ret) {
205 rv3028_exit_eerd(rv3028, *eerd);
206
207 return ret;
208 }
209
210 return 0;
211}
212
213static int rv3028_update_eeprom(struct rv3028_data *rv3028, u32 eerd)
214{
215 u32 status;
216 int ret;
217
218 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, 0x0);
219 if (ret)
220 goto exit_eerd;
221
222 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, RV3028_EEPROM_CMD_UPDATE);
223 if (ret)
224 goto exit_eerd;
225
226 usleep_range(63000, RV3028_EEBUSY_TIMEOUT);
227
228 ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status,
229 !(status & RV3028_STATUS_EEBUSY),
230 RV3028_EEBUSY_POLL, RV3028_EEBUSY_TIMEOUT);
231
232exit_eerd:
233 rv3028_exit_eerd(rv3028, eerd);
234
235 return ret;
236}
237
238static int rv3028_update_cfg(struct rv3028_data *rv3028, unsigned int reg,
239 unsigned int mask, unsigned int val)
240{
241 u32 eerd;
242 int ret;
243
244 ret = rv3028_enter_eerd(rv3028, &eerd);
245 if (ret)
246 return ret;
247
248 ret = regmap_update_bits(rv3028->regmap, reg, mask, val);
249 if (ret) {
250 rv3028_exit_eerd(rv3028, eerd);
251 return ret;
252 }
253
254 return rv3028_update_eeprom(rv3028, eerd);
255}
256
257static irqreturn_t rv3028_handle_irq(int irq, void *dev_id)
258{
259 struct rv3028_data *rv3028 = dev_id;
260 unsigned long events = 0;
261 u32 status = 0, ctrl = 0;
262
263 if (regmap_read(rv3028->regmap, RV3028_STATUS, &status) < 0 ||
264 status == 0) {
265 return IRQ_NONE;
266 }
267
268 status &= ~RV3028_STATUS_PORF;
269
270 if (status & RV3028_STATUS_TF) {
271 status |= RV3028_STATUS_TF;
272 ctrl |= RV3028_CTRL2_TIE;
273 events |= RTC_PF;
274 }
275
276 if (status & RV3028_STATUS_AF) {
277 status |= RV3028_STATUS_AF;
278 ctrl |= RV3028_CTRL2_AIE;
279 events |= RTC_AF;
280 }
281
282 if (status & RV3028_STATUS_UF) {
283 status |= RV3028_STATUS_UF;
284 ctrl |= RV3028_CTRL2_UIE;
285 events |= RTC_UF;
286 }
287
288 if (events) {
289 rtc_update_irq(rv3028->rtc, 1, events);
290 regmap_update_bits(rv3028->regmap, RV3028_STATUS, status, 0);
291 regmap_update_bits(rv3028->regmap, RV3028_CTRL2, ctrl, 0);
292 }
293
294 if (status & RV3028_STATUS_EVF) {
295 sysfs_notify(&rv3028->rtc->dev.kobj, NULL,
296 dev_attr_timestamp0.attr.name);
297 dev_warn(&rv3028->rtc->dev, "event detected");
298 }
299
300 return IRQ_HANDLED;
301}
302
303static int rv3028_get_time(struct device *dev, struct rtc_time *tm)
304{
305 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
306 u8 date[7];
307 int ret, status;
308
309 ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
310 if (ret < 0)
311 return ret;
312
313 if (status & RV3028_STATUS_PORF)
314 return -EINVAL;
315
316 ret = regmap_bulk_read(rv3028->regmap, RV3028_SEC, date, sizeof(date));
317 if (ret)
318 return ret;
319
320 tm->tm_sec = bcd2bin(date[RV3028_SEC] & 0x7f);
321 tm->tm_min = bcd2bin(date[RV3028_MIN] & 0x7f);
322 tm->tm_hour = bcd2bin(date[RV3028_HOUR] & 0x3f);
323 tm->tm_wday = date[RV3028_WDAY] & 0x7f;
324 tm->tm_mday = bcd2bin(date[RV3028_DAY] & 0x3f);
325 tm->tm_mon = bcd2bin(date[RV3028_MONTH] & 0x1f) - 1;
326 tm->tm_year = bcd2bin(date[RV3028_YEAR]) + 100;
327
328 return 0;
329}
330
331static int rv3028_set_time(struct device *dev, struct rtc_time *tm)
332{
333 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
334 u8 date[7];
335 int ret;
336
337 date[RV3028_SEC] = bin2bcd(tm->tm_sec);
338 date[RV3028_MIN] = bin2bcd(tm->tm_min);
339 date[RV3028_HOUR] = bin2bcd(tm->tm_hour);
340 date[RV3028_WDAY] = tm->tm_wday;
341 date[RV3028_DAY] = bin2bcd(tm->tm_mday);
342 date[RV3028_MONTH] = bin2bcd(tm->tm_mon + 1);
343 date[RV3028_YEAR] = bin2bcd(tm->tm_year - 100);
344
345 /*
346 * Writing to the Seconds register has the same effect as setting RESET
347 * bit to 1
348 */
349 ret = regmap_bulk_write(rv3028->regmap, RV3028_SEC, date,
350 sizeof(date));
351 if (ret)
352 return ret;
353
354 ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
355 RV3028_STATUS_PORF, 0);
356
357 return ret;
358}
359
360static int rv3028_get_alarm(struct device *dev, struct rtc_wkalrm *alrm)
361{
362 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
363 u8 alarmvals[3];
364 int status, ctrl, ret;
365
366 ret = regmap_bulk_read(rv3028->regmap, RV3028_ALARM_MIN, alarmvals,
367 sizeof(alarmvals));
368 if (ret)
369 return ret;
370
371 ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
372 if (ret < 0)
373 return ret;
374
375 ret = regmap_read(rv3028->regmap, RV3028_CTRL2, &ctrl);
376 if (ret < 0)
377 return ret;
378
379 alrm->time.tm_sec = 0;
380 alrm->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);
381 alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
382 alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f);
383
384 alrm->enabled = !!(ctrl & RV3028_CTRL2_AIE);
385 alrm->pending = (status & RV3028_STATUS_AF) && alrm->enabled;
386
387 return 0;
388}
389
390static int rv3028_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
391{
392 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
393 u8 alarmvals[3];
394 u8 ctrl = 0;
395 int ret;
396
397 /* The alarm has no seconds, round up to nearest minute */
398 if (alrm->time.tm_sec) {
399 time64_t alarm_time = rtc_tm_to_time64(&alrm->time);
400
401 alarm_time += 60 - alrm->time.tm_sec;
402 rtc_time64_to_tm(alarm_time, &alrm->time);
403 }
404
405 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
406 RV3028_CTRL2_AIE | RV3028_CTRL2_UIE, 0);
407 if (ret)
408 return ret;
409
410 alarmvals[0] = bin2bcd(alrm->time.tm_min);
411 alarmvals[1] = bin2bcd(alrm->time.tm_hour);
412 alarmvals[2] = bin2bcd(alrm->time.tm_mday);
413
414 ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
415 RV3028_STATUS_AF, 0);
416 if (ret)
417 return ret;
418
419 ret = regmap_bulk_write(rv3028->regmap, RV3028_ALARM_MIN, alarmvals,
420 sizeof(alarmvals));
421 if (ret)
422 return ret;
423
424 if (alrm->enabled) {
425 if (rv3028->rtc->uie_rtctimer.enabled)
426 ctrl |= RV3028_CTRL2_UIE;
427 if (rv3028->rtc->aie_timer.enabled)
428 ctrl |= RV3028_CTRL2_AIE;
429 }
430
431 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
432 RV3028_CTRL2_UIE | RV3028_CTRL2_AIE, ctrl);
433
434 return ret;
435}
436
437static int rv3028_alarm_irq_enable(struct device *dev, unsigned int enabled)
438{
439 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
440 int ctrl = 0, ret;
441
442 if (enabled) {
443 if (rv3028->rtc->uie_rtctimer.enabled)
444 ctrl |= RV3028_CTRL2_UIE;
445 if (rv3028->rtc->aie_timer.enabled)
446 ctrl |= RV3028_CTRL2_AIE;
447 }
448
449 ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
450 RV3028_STATUS_AF | RV3028_STATUS_UF, 0);
451 if (ret)
452 return ret;
453
454 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
455 RV3028_CTRL2_UIE | RV3028_CTRL2_AIE, ctrl);
456 if (ret)
457 return ret;
458
459 return 0;
460}
461
462static int rv3028_read_offset(struct device *dev, long *offset)
463{
464 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
465 int ret, value, steps;
466
467 ret = regmap_read(rv3028->regmap, RV3028_OFFSET, &value);
468 if (ret < 0)
469 return ret;
470
471 steps = sign_extend32(value << 1, 8);
472
473 ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &value);
474 if (ret < 0)
475 return ret;
476
477 steps += value >> 7;
478
479 *offset = DIV_ROUND_CLOSEST(steps * OFFSET_STEP_PPT, 1000);
480
481 return 0;
482}
483
484static int rv3028_set_offset(struct device *dev, long offset)
485{
486 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
487 u32 eerd;
488 int ret;
489
490 offset = clamp(offset, -244141L, 243187L) * 1000;
491 offset = DIV_ROUND_CLOSEST(offset, OFFSET_STEP_PPT);
492
493 ret = rv3028_enter_eerd(rv3028, &eerd);
494 if (ret)
495 return ret;
496
497 ret = regmap_write(rv3028->regmap, RV3028_OFFSET, offset >> 1);
498 if (ret < 0)
499 goto exit_eerd;
500
501 ret = regmap_update_bits(rv3028->regmap, RV3028_BACKUP, BIT(7),
502 offset << 7);
503 if (ret < 0)
504 goto exit_eerd;
505
506 return rv3028_update_eeprom(rv3028, eerd);
507
508exit_eerd:
509 rv3028_exit_eerd(rv3028, eerd);
510
511 return ret;
512
513}
514
515static int rv3028_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
516{
517 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
518 int status, ret = 0;
519
520 switch (cmd) {
521 case RTC_VL_READ:
522 ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
523 if (ret < 0)
524 return ret;
525
526 status = status & RV3028_STATUS_PORF ? RTC_VL_DATA_INVALID : 0;
527 return put_user(status, (unsigned int __user *)arg);
528
529 default:
530 return -ENOIOCTLCMD;
531 }
532}
533
534static int rv3028_nvram_write(void *priv, unsigned int offset, void *val,
535 size_t bytes)
536{
537 return regmap_bulk_write(priv, RV3028_RAM1 + offset, val, bytes);
538}
539
540static int rv3028_nvram_read(void *priv, unsigned int offset, void *val,
541 size_t bytes)
542{
543 return regmap_bulk_read(priv, RV3028_RAM1 + offset, val, bytes);
544}
545
546static int rv3028_eeprom_write(void *priv, unsigned int offset, void *val,
547 size_t bytes)
548{
549 struct rv3028_data *rv3028 = priv;
550 u32 status, eerd;
551 int i, ret;
552 u8 *buf = val;
553
554 ret = rv3028_enter_eerd(rv3028, &eerd);
555 if (ret)
556 return ret;
557
558 for (i = 0; i < bytes; i++) {
559 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_ADDR, offset + i);
560 if (ret)
561 goto restore_eerd;
562
563 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_DATA, buf[i]);
564 if (ret)
565 goto restore_eerd;
566
567 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, 0x0);
568 if (ret)
569 goto restore_eerd;
570
571 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD,
572 RV3028_EEPROM_CMD_WRITE);
573 if (ret)
574 goto restore_eerd;
575
576 usleep_range(RV3028_EEBUSY_POLL, RV3028_EEBUSY_TIMEOUT);
577
578 ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status,
579 !(status & RV3028_STATUS_EEBUSY),
580 RV3028_EEBUSY_POLL,
581 RV3028_EEBUSY_TIMEOUT);
582 if (ret)
583 goto restore_eerd;
584 }
585
586restore_eerd:
587 rv3028_exit_eerd(rv3028, eerd);
588
589 return ret;
590}
591
592static int rv3028_eeprom_read(void *priv, unsigned int offset, void *val,
593 size_t bytes)
594{
595 struct rv3028_data *rv3028 = priv;
596 u32 status, eerd, data;
597 int i, ret;
598 u8 *buf = val;
599
600 ret = rv3028_enter_eerd(rv3028, &eerd);
601 if (ret)
602 return ret;
603
604 for (i = 0; i < bytes; i++) {
605 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_ADDR, offset + i);
606 if (ret)
607 goto restore_eerd;
608
609 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, 0x0);
610 if (ret)
611 goto restore_eerd;
612
613 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD,
614 RV3028_EEPROM_CMD_READ);
615 if (ret)
616 goto restore_eerd;
617
618 ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status,
619 !(status & RV3028_STATUS_EEBUSY),
620 RV3028_EEBUSY_POLL,
621 RV3028_EEBUSY_TIMEOUT);
622 if (ret)
623 goto restore_eerd;
624
625 ret = regmap_read(rv3028->regmap, RV3028_EEPROM_DATA, &data);
626 if (ret)
627 goto restore_eerd;
628 buf[i] = data;
629 }
630
631restore_eerd:
632 rv3028_exit_eerd(rv3028, eerd);
633
634 return ret;
635}
636
637#ifdef CONFIG_COMMON_CLK
638#define clkout_hw_to_rv3028(hw) container_of(hw, struct rv3028_data, clkout_hw)
639
640static int clkout_rates[] = {
641 32768,
642 8192,
643 1024,
644 64,
645 32,
646 1,
647};
648
649static unsigned long rv3028_clkout_recalc_rate(struct clk_hw *hw,
650 unsigned long parent_rate)
651{
652 int clkout, ret;
653 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
654
655 ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &clkout);
656 if (ret < 0)
657 return 0;
658
659 clkout &= RV3028_CLKOUT_FD_MASK;
660 return clkout_rates[clkout];
661}
662
663static long rv3028_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
664 unsigned long *prate)
665{
666 int i;
667
668 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
669 if (clkout_rates[i] <= rate)
670 return clkout_rates[i];
671
672 return 0;
673}
674
675static int rv3028_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
676 unsigned long parent_rate)
677{
678 int i, ret;
679 u32 enabled;
680 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
681
682 ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &enabled);
683 if (ret < 0)
684 return ret;
685
686 ret = regmap_write(rv3028->regmap, RV3028_CLKOUT, 0x0);
687 if (ret < 0)
688 return ret;
689
690 enabled &= RV3028_CLKOUT_CLKOE;
691
692 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
693 if (clkout_rates[i] == rate)
694 return rv3028_update_cfg(rv3028, RV3028_CLKOUT, 0xff,
695 RV3028_CLKOUT_CLKSY | enabled | i);
696
697 return -EINVAL;
698}
699
700static int rv3028_clkout_prepare(struct clk_hw *hw)
701{
702 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
703
704 return regmap_write(rv3028->regmap, RV3028_CLKOUT,
705 RV3028_CLKOUT_CLKSY | RV3028_CLKOUT_CLKOE);
706}
707
708static void rv3028_clkout_unprepare(struct clk_hw *hw)
709{
710 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
711
712 regmap_write(rv3028->regmap, RV3028_CLKOUT, 0x0);
713 regmap_update_bits(rv3028->regmap, RV3028_STATUS,
714 RV3028_STATUS_CLKF, 0);
715}
716
717static int rv3028_clkout_is_prepared(struct clk_hw *hw)
718{
719 int clkout, ret;
720 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
721
722 ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &clkout);
723 if (ret < 0)
724 return ret;
725
726 return !!(clkout & RV3028_CLKOUT_CLKOE);
727}
728
729static const struct clk_ops rv3028_clkout_ops = {
730 .prepare = rv3028_clkout_prepare,
731 .unprepare = rv3028_clkout_unprepare,
732 .is_prepared = rv3028_clkout_is_prepared,
733 .recalc_rate = rv3028_clkout_recalc_rate,
734 .round_rate = rv3028_clkout_round_rate,
735 .set_rate = rv3028_clkout_set_rate,
736};
737
738static int rv3028_clkout_register_clk(struct rv3028_data *rv3028,
739 struct i2c_client *client)
740{
741 int ret;
742 struct clk *clk;
743 struct clk_init_data init;
744 struct device_node *node = client->dev.of_node;
745
746 ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
747 RV3028_STATUS_CLKF, 0);
748 if (ret < 0)
749 return ret;
750
751 init.name = "rv3028-clkout";
752 init.ops = &rv3028_clkout_ops;
753 init.flags = 0;
754 init.parent_names = NULL;
755 init.num_parents = 0;
756 rv3028->clkout_hw.init = &init;
757
758 /* optional override of the clockname */
759 of_property_read_string(node, "clock-output-names", &init.name);
760
761 /* register the clock */
762 clk = devm_clk_register(&client->dev, &rv3028->clkout_hw);
763 if (!IS_ERR(clk))
764 of_clk_add_provider(node, of_clk_src_simple_get, clk);
765
766 return 0;
767}
768#endif
769
770static const struct rtc_class_ops rv3028_rtc_ops = {
771 .read_time = rv3028_get_time,
772 .set_time = rv3028_set_time,
773 .read_alarm = rv3028_get_alarm,
774 .set_alarm = rv3028_set_alarm,
775 .alarm_irq_enable = rv3028_alarm_irq_enable,
776 .read_offset = rv3028_read_offset,
777 .set_offset = rv3028_set_offset,
778 .ioctl = rv3028_ioctl,
779};
780
781static const struct regmap_config regmap_config = {
782 .reg_bits = 8,
783 .val_bits = 8,
784 .max_register = 0x37,
785};
786
787static int rv3028_probe(struct i2c_client *client)
788{
789 struct rv3028_data *rv3028;
790 int ret, status;
791 u32 ohms;
792 struct nvmem_config nvmem_cfg = {
793 .name = "rv3028_nvram",
794 .word_size = 1,
795 .stride = 1,
796 .size = 2,
797 .type = NVMEM_TYPE_BATTERY_BACKED,
798 .reg_read = rv3028_nvram_read,
799 .reg_write = rv3028_nvram_write,
800 };
801 struct nvmem_config eeprom_cfg = {
802 .name = "rv3028_eeprom",
803 .word_size = 1,
804 .stride = 1,
805 .size = 43,
806 .type = NVMEM_TYPE_EEPROM,
807 .reg_read = rv3028_eeprom_read,
808 .reg_write = rv3028_eeprom_write,
809 };
810
811 rv3028 = devm_kzalloc(&client->dev, sizeof(struct rv3028_data),
812 GFP_KERNEL);
813 if (!rv3028)
814 return -ENOMEM;
815
816 rv3028->regmap = devm_regmap_init_i2c(client, ®map_config);
817 if (IS_ERR(rv3028->regmap))
818 return PTR_ERR(rv3028->regmap);
819
820 i2c_set_clientdata(client, rv3028);
821
822 ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
823 if (ret < 0)
824 return ret;
825
826 if (status & RV3028_STATUS_AF)
827 dev_warn(&client->dev, "An alarm may have been missed.\n");
828
829 rv3028->rtc = devm_rtc_allocate_device(&client->dev);
830 if (IS_ERR(rv3028->rtc))
831 return PTR_ERR(rv3028->rtc);
832
833 if (client->irq > 0) {
834 ret = devm_request_threaded_irq(&client->dev, client->irq,
835 NULL, rv3028_handle_irq,
836 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
837 "rv3028", rv3028);
838 if (ret) {
839 dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
840 client->irq = 0;
841 }
842 }
843 if (!client->irq)
844 clear_bit(RTC_FEATURE_ALARM, rv3028->rtc->features);
845
846 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL1,
847 RV3028_CTRL1_WADA, RV3028_CTRL1_WADA);
848 if (ret)
849 return ret;
850
851 /* setup timestamping */
852 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
853 RV3028_CTRL2_EIE | RV3028_CTRL2_TSE,
854 RV3028_CTRL2_EIE | RV3028_CTRL2_TSE);
855 if (ret)
856 return ret;
857
858 /* setup trickle charger */
859 if (!device_property_read_u32(&client->dev, "trickle-resistor-ohms",
860 &ohms)) {
861 int i;
862
863 for (i = 0; i < ARRAY_SIZE(rv3028_trickle_resistors); i++)
864 if (ohms == rv3028_trickle_resistors[i])
865 break;
866
867 if (i < ARRAY_SIZE(rv3028_trickle_resistors)) {
868 ret = rv3028_update_cfg(rv3028, RV3028_BACKUP, RV3028_BACKUP_TCE |
869 RV3028_BACKUP_TCR_MASK, RV3028_BACKUP_TCE | i);
870 if (ret)
871 return ret;
872 } else {
873 dev_warn(&client->dev, "invalid trickle resistor value\n");
874 }
875 }
876
877 ret = rtc_add_group(rv3028->rtc, &rv3028_attr_group);
878 if (ret)
879 return ret;
880
881 rv3028->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
882 rv3028->rtc->range_max = RTC_TIMESTAMP_END_2099;
883 rv3028->rtc->ops = &rv3028_rtc_ops;
884 ret = devm_rtc_register_device(rv3028->rtc);
885 if (ret)
886 return ret;
887
888 nvmem_cfg.priv = rv3028->regmap;
889 devm_rtc_nvmem_register(rv3028->rtc, &nvmem_cfg);
890 eeprom_cfg.priv = rv3028;
891 devm_rtc_nvmem_register(rv3028->rtc, &eeprom_cfg);
892
893 rv3028->rtc->max_user_freq = 1;
894
895#ifdef CONFIG_COMMON_CLK
896 rv3028_clkout_register_clk(rv3028, client);
897#endif
898 return 0;
899}
900
901static const __maybe_unused struct of_device_id rv3028_of_match[] = {
902 { .compatible = "microcrystal,rv3028", },
903 { }
904};
905MODULE_DEVICE_TABLE(of, rv3028_of_match);
906
907static struct i2c_driver rv3028_driver = {
908 .driver = {
909 .name = "rtc-rv3028",
910 .of_match_table = of_match_ptr(rv3028_of_match),
911 },
912 .probe_new = rv3028_probe,
913};
914module_i2c_driver(rv3028_driver);
915
916MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
917MODULE_DESCRIPTION("Micro Crystal RV3028 RTC driver");
918MODULE_LICENSE("GPL v2");