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
91 enum rv3028_type {
92 rv_3028,
93 };
94
95 struct 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
104 static u16 rv3028_trickle_resistors[] = {3000, 5000, 9000, 15000};
105
timestamp0_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)106 static 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
timestamp0_show(struct device * dev,struct device_attribute * attr,char * buf)118 static 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
153 static DEVICE_ATTR_RW(timestamp0);
154
timestamp0_count_show(struct device * dev,struct device_attribute * attr,char * buf)155 static 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
168 static DEVICE_ATTR_RO(timestamp0_count);
169
170 static struct attribute *rv3028_attrs[] = {
171 &dev_attr_timestamp0.attr,
172 &dev_attr_timestamp0_count.attr,
173 NULL
174 };
175
176 static const struct attribute_group rv3028_attr_group = {
177 .attrs = rv3028_attrs,
178 };
179
rv3028_exit_eerd(struct rv3028_data * rv3028,u32 eerd)180 static 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
rv3028_enter_eerd(struct rv3028_data * rv3028,u32 * eerd)188 static 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
rv3028_update_eeprom(struct rv3028_data * rv3028,u32 eerd)218 static 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
237 exit_eerd:
238 rv3028_exit_eerd(rv3028, eerd);
239
240 return ret;
241 }
242
rv3028_update_cfg(struct rv3028_data * rv3028,unsigned int reg,unsigned int mask,unsigned int val)243 static 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
rv3028_handle_irq(int irq,void * dev_id)262 static 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
rv3028_get_time(struct device * dev,struct rtc_time * tm)308 static 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
rv3028_set_time(struct device * dev,struct rtc_time * tm)336 static 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
rv3028_get_alarm(struct device * dev,struct rtc_wkalrm * alrm)365 static 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
rv3028_set_alarm(struct device * dev,struct rtc_wkalrm * alrm)395 static 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
rv3028_alarm_irq_enable(struct device * dev,unsigned int enabled)442 static 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
rv3028_read_offset(struct device * dev,long * offset)467 static 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
rv3028_set_offset(struct device * dev,long offset)489 static 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
513 exit_eerd:
514 rv3028_exit_eerd(rv3028, eerd);
515
516 return ret;
517
518 }
519
rv3028_param_get(struct device * dev,struct rtc_param * param)520 static 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
rv3028_param_set(struct device * dev,struct rtc_param * param)553 static 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
rv3028_ioctl(struct device * dev,unsigned int cmd,unsigned long arg)584 static 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
rv3028_nvram_write(void * priv,unsigned int offset,void * val,size_t bytes)603 static 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
rv3028_nvram_read(void * priv,unsigned int offset,void * val,size_t bytes)609 static 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
rv3028_eeprom_write(void * priv,unsigned int offset,void * val,size_t bytes)615 static 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
655 restore_eerd:
656 rv3028_exit_eerd(rv3028, eerd);
657
658 return ret;
659 }
660
rv3028_eeprom_read(void * priv,unsigned int offset,void * val,size_t bytes)661 static 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
700 restore_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
709 static int clkout_rates[] = {
710 32768,
711 8192,
712 1024,
713 64,
714 32,
715 1,
716 };
717
rv3028_clkout_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)718 static 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
rv3028_clkout_round_rate(struct clk_hw * hw,unsigned long rate,unsigned long * prate)732 static 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
rv3028_clkout_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)744 static 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
rv3028_clkout_prepare(struct clk_hw * hw)769 static 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
rv3028_clkout_unprepare(struct clk_hw * hw)777 static 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
rv3028_clkout_is_prepared(struct clk_hw * hw)786 static 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
798 static 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
rv3028_clkout_register_clk(struct rv3028_data * rv3028,struct i2c_client * client)807 static 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
839 static 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
852 static const struct regmap_config regmap_config = {
853 .reg_bits = 8,
854 .val_bits = 8,
855 .max_register = 0x37,
856 };
857
rv3028_set_trickle_charger(struct rv3028_data * rv3028,struct i2c_client * client)858 static 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
rv3028_probe(struct i2c_client * client)916 static 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
1027 static const struct acpi_device_id rv3028_i2c_acpi_match[] = {
1028 { "MCRY3028" },
1029 { }
1030 };
1031 MODULE_DEVICE_TABLE(acpi, rv3028_i2c_acpi_match);
1032
1033 static const __maybe_unused struct of_device_id rv3028_of_match[] = {
1034 { .compatible = "microcrystal,rv3028", },
1035 { }
1036 };
1037 MODULE_DEVICE_TABLE(of, rv3028_of_match);
1038
1039 static const struct i2c_device_id rv3028_id_table[] = {
1040 { .name = "rv3028", },
1041 { }
1042 };
1043 MODULE_DEVICE_TABLE(i2c, rv3028_id_table);
1044
1045 static 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 };
1054 module_i2c_driver(rv3028_driver);
1055
1056 MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
1057 MODULE_DESCRIPTION("Micro Crystal RV3028 RTC driver");
1058 MODULE_LICENSE("GPL v2");
1059