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
86 enum rv3028_type {
87 rv_3028,
88 };
89
90 struct 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
99 static u16 rv3028_trickle_resistors[] = {3000, 5000, 9000, 15000};
100
timestamp0_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)101 static 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
timestamp0_show(struct device * dev,struct device_attribute * attr,char * buf)113 static 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
148 static DEVICE_ATTR_RW(timestamp0);
149
timestamp0_count_show(struct device * dev,struct device_attribute * attr,char * buf)150 static 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
163 static DEVICE_ATTR_RO(timestamp0_count);
164
165 static struct attribute *rv3028_attrs[] = {
166 &dev_attr_timestamp0.attr,
167 &dev_attr_timestamp0_count.attr,
168 NULL
169 };
170
171 static const struct attribute_group rv3028_attr_group = {
172 .attrs = rv3028_attrs,
173 };
174
rv3028_exit_eerd(struct rv3028_data * rv3028,u32 eerd)175 static 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
rv3028_enter_eerd(struct rv3028_data * rv3028,u32 * eerd)183 static 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
rv3028_update_eeprom(struct rv3028_data * rv3028,u32 eerd)213 static 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
232 exit_eerd:
233 rv3028_exit_eerd(rv3028, eerd);
234
235 return ret;
236 }
237
rv3028_update_cfg(struct rv3028_data * rv3028,unsigned int reg,unsigned int mask,unsigned int val)238 static 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
rv3028_handle_irq(int irq,void * dev_id)257 static 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 if (status & RV3028_STATUS_PORF)
269 dev_warn(&rv3028->rtc->dev, "Voltage low, data loss detected.\n");
270
271 if (status & RV3028_STATUS_TF) {
272 status |= RV3028_STATUS_TF;
273 ctrl |= RV3028_CTRL2_TIE;
274 events |= RTC_PF;
275 }
276
277 if (status & RV3028_STATUS_AF) {
278 status |= RV3028_STATUS_AF;
279 ctrl |= RV3028_CTRL2_AIE;
280 events |= RTC_AF;
281 }
282
283 if (status & RV3028_STATUS_UF) {
284 status |= RV3028_STATUS_UF;
285 ctrl |= RV3028_CTRL2_UIE;
286 events |= RTC_UF;
287 }
288
289 if (events) {
290 rtc_update_irq(rv3028->rtc, 1, events);
291 regmap_update_bits(rv3028->regmap, RV3028_STATUS, status, 0);
292 regmap_update_bits(rv3028->regmap, RV3028_CTRL2, ctrl, 0);
293 }
294
295 if (status & RV3028_STATUS_EVF) {
296 sysfs_notify(&rv3028->rtc->dev.kobj, NULL,
297 dev_attr_timestamp0.attr.name);
298 dev_warn(&rv3028->rtc->dev, "event detected");
299 }
300
301 return IRQ_HANDLED;
302 }
303
rv3028_get_time(struct device * dev,struct rtc_time * tm)304 static int rv3028_get_time(struct device *dev, struct rtc_time *tm)
305 {
306 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
307 u8 date[7];
308 int ret, status;
309
310 ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
311 if (ret < 0)
312 return ret;
313
314 if (status & RV3028_STATUS_PORF) {
315 dev_warn(dev, "Voltage low, data is invalid.\n");
316 return -EINVAL;
317 }
318
319 ret = regmap_bulk_read(rv3028->regmap, RV3028_SEC, date, sizeof(date));
320 if (ret)
321 return ret;
322
323 tm->tm_sec = bcd2bin(date[RV3028_SEC] & 0x7f);
324 tm->tm_min = bcd2bin(date[RV3028_MIN] & 0x7f);
325 tm->tm_hour = bcd2bin(date[RV3028_HOUR] & 0x3f);
326 tm->tm_wday = ilog2(date[RV3028_WDAY] & 0x7f);
327 tm->tm_mday = bcd2bin(date[RV3028_DAY] & 0x3f);
328 tm->tm_mon = bcd2bin(date[RV3028_MONTH] & 0x1f) - 1;
329 tm->tm_year = bcd2bin(date[RV3028_YEAR]) + 100;
330
331 return 0;
332 }
333
rv3028_set_time(struct device * dev,struct rtc_time * tm)334 static int rv3028_set_time(struct device *dev, struct rtc_time *tm)
335 {
336 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
337 u8 date[7];
338 int ret;
339
340 date[RV3028_SEC] = bin2bcd(tm->tm_sec);
341 date[RV3028_MIN] = bin2bcd(tm->tm_min);
342 date[RV3028_HOUR] = bin2bcd(tm->tm_hour);
343 date[RV3028_WDAY] = 1 << (tm->tm_wday);
344 date[RV3028_DAY] = bin2bcd(tm->tm_mday);
345 date[RV3028_MONTH] = bin2bcd(tm->tm_mon + 1);
346 date[RV3028_YEAR] = bin2bcd(tm->tm_year - 100);
347
348 /*
349 * Writing to the Seconds register has the same effect as setting RESET
350 * bit to 1
351 */
352 ret = regmap_bulk_write(rv3028->regmap, RV3028_SEC, date,
353 sizeof(date));
354 if (ret)
355 return ret;
356
357 ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
358 RV3028_STATUS_PORF, 0);
359
360 return ret;
361 }
362
rv3028_get_alarm(struct device * dev,struct rtc_wkalrm * alrm)363 static int rv3028_get_alarm(struct device *dev, struct rtc_wkalrm *alrm)
364 {
365 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
366 u8 alarmvals[3];
367 int status, ctrl, ret;
368
369 ret = regmap_bulk_read(rv3028->regmap, RV3028_ALARM_MIN, alarmvals,
370 sizeof(alarmvals));
371 if (ret)
372 return ret;
373
374 ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
375 if (ret < 0)
376 return ret;
377
378 ret = regmap_read(rv3028->regmap, RV3028_CTRL2, &ctrl);
379 if (ret < 0)
380 return ret;
381
382 alrm->time.tm_sec = 0;
383 alrm->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);
384 alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
385 alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f);
386
387 alrm->enabled = !!(ctrl & RV3028_CTRL2_AIE);
388 alrm->pending = (status & RV3028_STATUS_AF) && alrm->enabled;
389
390 return 0;
391 }
392
rv3028_set_alarm(struct device * dev,struct rtc_wkalrm * alrm)393 static int rv3028_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
394 {
395 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
396 u8 alarmvals[3];
397 u8 ctrl = 0;
398 int ret;
399
400 /* The alarm has no seconds, round up to nearest minute */
401 if (alrm->time.tm_sec) {
402 time64_t alarm_time = rtc_tm_to_time64(&alrm->time);
403
404 alarm_time += 60 - alrm->time.tm_sec;
405 rtc_time64_to_tm(alarm_time, &alrm->time);
406 }
407
408 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
409 RV3028_CTRL2_AIE | RV3028_CTRL2_UIE, 0);
410 if (ret)
411 return ret;
412
413 alarmvals[0] = bin2bcd(alrm->time.tm_min);
414 alarmvals[1] = bin2bcd(alrm->time.tm_hour);
415 alarmvals[2] = bin2bcd(alrm->time.tm_mday);
416
417 ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
418 RV3028_STATUS_AF, 0);
419 if (ret)
420 return ret;
421
422 ret = regmap_bulk_write(rv3028->regmap, RV3028_ALARM_MIN, alarmvals,
423 sizeof(alarmvals));
424 if (ret)
425 return ret;
426
427 if (alrm->enabled) {
428 if (rv3028->rtc->uie_rtctimer.enabled)
429 ctrl |= RV3028_CTRL2_UIE;
430 if (rv3028->rtc->aie_timer.enabled)
431 ctrl |= RV3028_CTRL2_AIE;
432 }
433
434 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
435 RV3028_CTRL2_UIE | RV3028_CTRL2_AIE, ctrl);
436
437 return ret;
438 }
439
rv3028_alarm_irq_enable(struct device * dev,unsigned int enabled)440 static int rv3028_alarm_irq_enable(struct device *dev, unsigned int enabled)
441 {
442 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
443 int ctrl = 0, ret;
444
445 if (enabled) {
446 if (rv3028->rtc->uie_rtctimer.enabled)
447 ctrl |= RV3028_CTRL2_UIE;
448 if (rv3028->rtc->aie_timer.enabled)
449 ctrl |= RV3028_CTRL2_AIE;
450 }
451
452 ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
453 RV3028_STATUS_AF | RV3028_STATUS_UF, 0);
454 if (ret)
455 return ret;
456
457 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
458 RV3028_CTRL2_UIE | RV3028_CTRL2_AIE, ctrl);
459 if (ret)
460 return ret;
461
462 return 0;
463 }
464
rv3028_read_offset(struct device * dev,long * offset)465 static int rv3028_read_offset(struct device *dev, long *offset)
466 {
467 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
468 int ret, value, steps;
469
470 ret = regmap_read(rv3028->regmap, RV3028_OFFSET, &value);
471 if (ret < 0)
472 return ret;
473
474 steps = sign_extend32(value << 1, 8);
475
476 ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &value);
477 if (ret < 0)
478 return ret;
479
480 steps += value >> 7;
481
482 *offset = DIV_ROUND_CLOSEST(steps * OFFSET_STEP_PPT, 1000);
483
484 return 0;
485 }
486
rv3028_set_offset(struct device * dev,long offset)487 static int rv3028_set_offset(struct device *dev, long offset)
488 {
489 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
490 u32 eerd;
491 int ret;
492
493 offset = clamp(offset, -244141L, 243187L) * 1000;
494 offset = DIV_ROUND_CLOSEST(offset, OFFSET_STEP_PPT);
495
496 ret = rv3028_enter_eerd(rv3028, &eerd);
497 if (ret)
498 return ret;
499
500 ret = regmap_write(rv3028->regmap, RV3028_OFFSET, offset >> 1);
501 if (ret < 0)
502 goto exit_eerd;
503
504 ret = regmap_update_bits(rv3028->regmap, RV3028_BACKUP, BIT(7),
505 offset << 7);
506 if (ret < 0)
507 goto exit_eerd;
508
509 return rv3028_update_eeprom(rv3028, eerd);
510
511 exit_eerd:
512 rv3028_exit_eerd(rv3028, eerd);
513
514 return ret;
515
516 }
517
rv3028_ioctl(struct device * dev,unsigned int cmd,unsigned long arg)518 static int rv3028_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
519 {
520 struct rv3028_data *rv3028 = dev_get_drvdata(dev);
521 int status, ret = 0;
522
523 switch (cmd) {
524 case RTC_VL_READ:
525 ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
526 if (ret < 0)
527 return ret;
528
529 status = status & RV3028_STATUS_PORF ? RTC_VL_DATA_INVALID : 0;
530 return put_user(status, (unsigned int __user *)arg);
531
532 default:
533 return -ENOIOCTLCMD;
534 }
535 }
536
rv3028_nvram_write(void * priv,unsigned int offset,void * val,size_t bytes)537 static int rv3028_nvram_write(void *priv, unsigned int offset, void *val,
538 size_t bytes)
539 {
540 return regmap_bulk_write(priv, RV3028_RAM1 + offset, val, bytes);
541 }
542
rv3028_nvram_read(void * priv,unsigned int offset,void * val,size_t bytes)543 static int rv3028_nvram_read(void *priv, unsigned int offset, void *val,
544 size_t bytes)
545 {
546 return regmap_bulk_read(priv, RV3028_RAM1 + offset, val, bytes);
547 }
548
rv3028_eeprom_write(void * priv,unsigned int offset,void * val,size_t bytes)549 static int rv3028_eeprom_write(void *priv, unsigned int offset, void *val,
550 size_t bytes)
551 {
552 struct rv3028_data *rv3028 = priv;
553 u32 status, eerd;
554 int i, ret;
555 u8 *buf = val;
556
557 ret = rv3028_enter_eerd(rv3028, &eerd);
558 if (ret)
559 return ret;
560
561 for (i = 0; i < bytes; i++) {
562 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_ADDR, offset + i);
563 if (ret)
564 goto restore_eerd;
565
566 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_DATA, buf[i]);
567 if (ret)
568 goto restore_eerd;
569
570 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, 0x0);
571 if (ret)
572 goto restore_eerd;
573
574 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD,
575 RV3028_EEPROM_CMD_WRITE);
576 if (ret)
577 goto restore_eerd;
578
579 usleep_range(RV3028_EEBUSY_POLL, RV3028_EEBUSY_TIMEOUT);
580
581 ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status,
582 !(status & RV3028_STATUS_EEBUSY),
583 RV3028_EEBUSY_POLL,
584 RV3028_EEBUSY_TIMEOUT);
585 if (ret)
586 goto restore_eerd;
587 }
588
589 restore_eerd:
590 rv3028_exit_eerd(rv3028, eerd);
591
592 return ret;
593 }
594
rv3028_eeprom_read(void * priv,unsigned int offset,void * val,size_t bytes)595 static int rv3028_eeprom_read(void *priv, unsigned int offset, void *val,
596 size_t bytes)
597 {
598 struct rv3028_data *rv3028 = priv;
599 u32 status, eerd, data;
600 int i, ret;
601 u8 *buf = val;
602
603 ret = rv3028_enter_eerd(rv3028, &eerd);
604 if (ret)
605 return ret;
606
607 for (i = 0; i < bytes; i++) {
608 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_ADDR, offset + i);
609 if (ret)
610 goto restore_eerd;
611
612 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, 0x0);
613 if (ret)
614 goto restore_eerd;
615
616 ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD,
617 RV3028_EEPROM_CMD_READ);
618 if (ret)
619 goto restore_eerd;
620
621 ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status,
622 !(status & RV3028_STATUS_EEBUSY),
623 RV3028_EEBUSY_POLL,
624 RV3028_EEBUSY_TIMEOUT);
625 if (ret)
626 goto restore_eerd;
627
628 ret = regmap_read(rv3028->regmap, RV3028_EEPROM_DATA, &data);
629 if (ret)
630 goto restore_eerd;
631 buf[i] = data;
632 }
633
634 restore_eerd:
635 rv3028_exit_eerd(rv3028, eerd);
636
637 return ret;
638 }
639
640 #ifdef CONFIG_COMMON_CLK
641 #define clkout_hw_to_rv3028(hw) container_of(hw, struct rv3028_data, clkout_hw)
642
643 static int clkout_rates[] = {
644 32768,
645 8192,
646 1024,
647 64,
648 32,
649 1,
650 };
651
rv3028_clkout_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)652 static unsigned long rv3028_clkout_recalc_rate(struct clk_hw *hw,
653 unsigned long parent_rate)
654 {
655 int clkout, ret;
656 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
657
658 ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &clkout);
659 if (ret < 0)
660 return 0;
661
662 clkout &= RV3028_CLKOUT_FD_MASK;
663 return clkout_rates[clkout];
664 }
665
rv3028_clkout_round_rate(struct clk_hw * hw,unsigned long rate,unsigned long * prate)666 static long rv3028_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
667 unsigned long *prate)
668 {
669 int i;
670
671 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
672 if (clkout_rates[i] <= rate)
673 return clkout_rates[i];
674
675 return 0;
676 }
677
rv3028_clkout_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)678 static int rv3028_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
679 unsigned long parent_rate)
680 {
681 int i, ret;
682 u32 enabled;
683 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
684
685 ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &enabled);
686 if (ret < 0)
687 return ret;
688
689 ret = regmap_write(rv3028->regmap, RV3028_CLKOUT, 0x0);
690 if (ret < 0)
691 return ret;
692
693 enabled &= RV3028_CLKOUT_CLKOE;
694
695 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
696 if (clkout_rates[i] == rate)
697 return rv3028_update_cfg(rv3028, RV3028_CLKOUT, 0xff,
698 RV3028_CLKOUT_CLKSY | enabled | i);
699
700 return -EINVAL;
701 }
702
rv3028_clkout_prepare(struct clk_hw * hw)703 static int rv3028_clkout_prepare(struct clk_hw *hw)
704 {
705 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
706
707 return regmap_write(rv3028->regmap, RV3028_CLKOUT,
708 RV3028_CLKOUT_CLKSY | RV3028_CLKOUT_CLKOE);
709 }
710
rv3028_clkout_unprepare(struct clk_hw * hw)711 static void rv3028_clkout_unprepare(struct clk_hw *hw)
712 {
713 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
714
715 regmap_write(rv3028->regmap, RV3028_CLKOUT, 0x0);
716 regmap_update_bits(rv3028->regmap, RV3028_STATUS,
717 RV3028_STATUS_CLKF, 0);
718 }
719
rv3028_clkout_is_prepared(struct clk_hw * hw)720 static int rv3028_clkout_is_prepared(struct clk_hw *hw)
721 {
722 int clkout, ret;
723 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
724
725 ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &clkout);
726 if (ret < 0)
727 return ret;
728
729 return !!(clkout & RV3028_CLKOUT_CLKOE);
730 }
731
732 static const struct clk_ops rv3028_clkout_ops = {
733 .prepare = rv3028_clkout_prepare,
734 .unprepare = rv3028_clkout_unprepare,
735 .is_prepared = rv3028_clkout_is_prepared,
736 .recalc_rate = rv3028_clkout_recalc_rate,
737 .round_rate = rv3028_clkout_round_rate,
738 .set_rate = rv3028_clkout_set_rate,
739 };
740
rv3028_clkout_register_clk(struct rv3028_data * rv3028,struct i2c_client * client)741 static int rv3028_clkout_register_clk(struct rv3028_data *rv3028,
742 struct i2c_client *client)
743 {
744 int ret;
745 struct clk *clk;
746 struct clk_init_data init;
747 struct device_node *node = client->dev.of_node;
748
749 ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
750 RV3028_STATUS_CLKF, 0);
751 if (ret < 0)
752 return ret;
753
754 init.name = "rv3028-clkout";
755 init.ops = &rv3028_clkout_ops;
756 init.flags = 0;
757 init.parent_names = NULL;
758 init.num_parents = 0;
759 rv3028->clkout_hw.init = &init;
760
761 /* optional override of the clockname */
762 of_property_read_string(node, "clock-output-names", &init.name);
763
764 /* register the clock */
765 clk = devm_clk_register(&client->dev, &rv3028->clkout_hw);
766 if (!IS_ERR(clk))
767 of_clk_add_provider(node, of_clk_src_simple_get, clk);
768
769 return 0;
770 }
771 #endif
772
773 static struct rtc_class_ops rv3028_rtc_ops = {
774 .read_time = rv3028_get_time,
775 .set_time = rv3028_set_time,
776 .read_offset = rv3028_read_offset,
777 .set_offset = rv3028_set_offset,
778 .ioctl = rv3028_ioctl,
779 };
780
781 static const struct regmap_config regmap_config = {
782 .reg_bits = 8,
783 .val_bits = 8,
784 .max_register = 0x37,
785 };
786
rv3028_probe(struct i2c_client * client)787 static 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_PORF)
827 dev_warn(&client->dev, "Voltage low, data loss detected.\n");
828
829 if (status & RV3028_STATUS_AF)
830 dev_warn(&client->dev, "An alarm may have been missed.\n");
831
832 rv3028->rtc = devm_rtc_allocate_device(&client->dev);
833 if (IS_ERR(rv3028->rtc))
834 return PTR_ERR(rv3028->rtc);
835
836 if (client->irq > 0) {
837 ret = devm_request_threaded_irq(&client->dev, client->irq,
838 NULL, rv3028_handle_irq,
839 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
840 "rv3028", rv3028);
841 if (ret) {
842 dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
843 client->irq = 0;
844 } else {
845 rv3028_rtc_ops.read_alarm = rv3028_get_alarm;
846 rv3028_rtc_ops.set_alarm = rv3028_set_alarm;
847 rv3028_rtc_ops.alarm_irq_enable = rv3028_alarm_irq_enable;
848 }
849 }
850
851 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL1,
852 RV3028_CTRL1_WADA, RV3028_CTRL1_WADA);
853 if (ret)
854 return ret;
855
856 /* setup timestamping */
857 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
858 RV3028_CTRL2_EIE | RV3028_CTRL2_TSE,
859 RV3028_CTRL2_EIE | RV3028_CTRL2_TSE);
860 if (ret)
861 return ret;
862
863 /* setup trickle charger */
864 if (!device_property_read_u32(&client->dev, "trickle-resistor-ohms",
865 &ohms)) {
866 int i;
867
868 for (i = 0; i < ARRAY_SIZE(rv3028_trickle_resistors); i++)
869 if (ohms == rv3028_trickle_resistors[i])
870 break;
871
872 if (i < ARRAY_SIZE(rv3028_trickle_resistors)) {
873 ret = rv3028_update_cfg(rv3028, RV3028_BACKUP, RV3028_BACKUP_TCE |
874 RV3028_BACKUP_TCR_MASK, RV3028_BACKUP_TCE | i);
875 if (ret)
876 return ret;
877 } else {
878 dev_warn(&client->dev, "invalid trickle resistor value\n");
879 }
880 }
881
882 ret = rtc_add_group(rv3028->rtc, &rv3028_attr_group);
883 if (ret)
884 return ret;
885
886 rv3028->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
887 rv3028->rtc->range_max = RTC_TIMESTAMP_END_2099;
888 rv3028->rtc->ops = &rv3028_rtc_ops;
889 ret = rtc_register_device(rv3028->rtc);
890 if (ret)
891 return ret;
892
893 nvmem_cfg.priv = rv3028->regmap;
894 rtc_nvmem_register(rv3028->rtc, &nvmem_cfg);
895 eeprom_cfg.priv = rv3028;
896 rtc_nvmem_register(rv3028->rtc, &eeprom_cfg);
897
898 rv3028->rtc->max_user_freq = 1;
899
900 #ifdef CONFIG_COMMON_CLK
901 rv3028_clkout_register_clk(rv3028, client);
902 #endif
903 return 0;
904 }
905
906 static const struct of_device_id rv3028_of_match[] = {
907 { .compatible = "microcrystal,rv3028", },
908 { }
909 };
910 MODULE_DEVICE_TABLE(of, rv3028_of_match);
911
912 static struct i2c_driver rv3028_driver = {
913 .driver = {
914 .name = "rtc-rv3028",
915 .of_match_table = of_match_ptr(rv3028_of_match),
916 },
917 .probe_new = rv3028_probe,
918 };
919 module_i2c_driver(rv3028_driver);
920
921 MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
922 MODULE_DESCRIPTION("Micro Crystal RV3028 RTC driver");
923 MODULE_LICENSE("GPL v2");
924