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10#include <linux/bcd.h>
11#include <linux/bitops.h>
12#include <linux/log2.h>
13#include <linux/i2c.h>
14#include <linux/interrupt.h>
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/of_device.h>
18#include <linux/rtc.h>
19
20#define RV8803_I2C_TRY_COUNT 4
21
22#define RV8803_SEC 0x00
23#define RV8803_MIN 0x01
24#define RV8803_HOUR 0x02
25#define RV8803_WEEK 0x03
26#define RV8803_DAY 0x04
27#define RV8803_MONTH 0x05
28#define RV8803_YEAR 0x06
29#define RV8803_RAM 0x07
30#define RV8803_ALARM_MIN 0x08
31#define RV8803_ALARM_HOUR 0x09
32#define RV8803_ALARM_WEEK_OR_DAY 0x0A
33#define RV8803_EXT 0x0D
34#define RV8803_FLAG 0x0E
35#define RV8803_CTRL 0x0F
36
37#define RV8803_EXT_WADA BIT(6)
38
39#define RV8803_FLAG_V1F BIT(0)
40#define RV8803_FLAG_V2F BIT(1)
41#define RV8803_FLAG_AF BIT(3)
42#define RV8803_FLAG_TF BIT(4)
43#define RV8803_FLAG_UF BIT(5)
44
45#define RV8803_CTRL_RESET BIT(0)
46
47#define RV8803_CTRL_EIE BIT(2)
48#define RV8803_CTRL_AIE BIT(3)
49#define RV8803_CTRL_TIE BIT(4)
50#define RV8803_CTRL_UIE BIT(5)
51
52#define RX8900_BACKUP_CTRL 0x18
53#define RX8900_FLAG_SWOFF BIT(2)
54#define RX8900_FLAG_VDETOFF BIT(3)
55
56enum rv8803_type {
57 rv_8803,
58 rx_8900
59};
60
61struct rv8803_data {
62 struct i2c_client *client;
63 struct rtc_device *rtc;
64 struct mutex flags_lock;
65 u8 ctrl;
66 enum rv8803_type type;
67};
68
69static int rv8803_read_reg(const struct i2c_client *client, u8 reg)
70{
71 int try = RV8803_I2C_TRY_COUNT;
72 s32 ret;
73
74
75
76
77
78 do
79 ret = i2c_smbus_read_byte_data(client, reg);
80 while ((ret == -ENXIO || ret == -EIO) && --try);
81 if (ret < 0)
82 dev_err(&client->dev, "Unable to read register 0x%02x\n", reg);
83
84 return ret;
85}
86
87static int rv8803_read_regs(const struct i2c_client *client,
88 u8 reg, u8 count, u8 *values)
89{
90 int try = RV8803_I2C_TRY_COUNT;
91 s32 ret;
92
93 do
94 ret = i2c_smbus_read_i2c_block_data(client, reg, count, values);
95 while ((ret == -ENXIO || ret == -EIO) && --try);
96 if (ret != count) {
97 dev_err(&client->dev,
98 "Unable to read registers 0x%02x..0x%02x\n",
99 reg, reg + count - 1);
100 return ret < 0 ? ret : -EIO;
101 }
102
103 return 0;
104}
105
106static int rv8803_write_reg(const struct i2c_client *client, u8 reg, u8 value)
107{
108 int try = RV8803_I2C_TRY_COUNT;
109 s32 ret;
110
111 do
112 ret = i2c_smbus_write_byte_data(client, reg, value);
113 while ((ret == -ENXIO || ret == -EIO) && --try);
114 if (ret)
115 dev_err(&client->dev, "Unable to write register 0x%02x\n", reg);
116
117 return ret;
118}
119
120static int rv8803_write_regs(const struct i2c_client *client,
121 u8 reg, u8 count, const u8 *values)
122{
123 int try = RV8803_I2C_TRY_COUNT;
124 s32 ret;
125
126 do
127 ret = i2c_smbus_write_i2c_block_data(client, reg, count,
128 values);
129 while ((ret == -ENXIO || ret == -EIO) && --try);
130 if (ret)
131 dev_err(&client->dev,
132 "Unable to write registers 0x%02x..0x%02x\n",
133 reg, reg + count - 1);
134
135 return ret;
136}
137
138static irqreturn_t rv8803_handle_irq(int irq, void *dev_id)
139{
140 struct i2c_client *client = dev_id;
141 struct rv8803_data *rv8803 = i2c_get_clientdata(client);
142 unsigned long events = 0;
143 int flags;
144
145 mutex_lock(&rv8803->flags_lock);
146
147 flags = rv8803_read_reg(client, RV8803_FLAG);
148 if (flags <= 0) {
149 mutex_unlock(&rv8803->flags_lock);
150 return IRQ_NONE;
151 }
152
153 if (flags & RV8803_FLAG_V1F)
154 dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
155
156 if (flags & RV8803_FLAG_V2F)
157 dev_warn(&client->dev, "Voltage low, data loss detected.\n");
158
159 if (flags & RV8803_FLAG_TF) {
160 flags &= ~RV8803_FLAG_TF;
161 rv8803->ctrl &= ~RV8803_CTRL_TIE;
162 events |= RTC_PF;
163 }
164
165 if (flags & RV8803_FLAG_AF) {
166 flags &= ~RV8803_FLAG_AF;
167 rv8803->ctrl &= ~RV8803_CTRL_AIE;
168 events |= RTC_AF;
169 }
170
171 if (flags & RV8803_FLAG_UF) {
172 flags &= ~RV8803_FLAG_UF;
173 rv8803->ctrl &= ~RV8803_CTRL_UIE;
174 events |= RTC_UF;
175 }
176
177 if (events) {
178 rtc_update_irq(rv8803->rtc, 1, events);
179 rv8803_write_reg(client, RV8803_FLAG, flags);
180 rv8803_write_reg(rv8803->client, RV8803_CTRL, rv8803->ctrl);
181 }
182
183 mutex_unlock(&rv8803->flags_lock);
184
185 return IRQ_HANDLED;
186}
187
188static int rv8803_get_time(struct device *dev, struct rtc_time *tm)
189{
190 struct rv8803_data *rv8803 = dev_get_drvdata(dev);
191 u8 date1[7];
192 u8 date2[7];
193 u8 *date = date1;
194 int ret, flags;
195
196 flags = rv8803_read_reg(rv8803->client, RV8803_FLAG);
197 if (flags < 0)
198 return flags;
199
200 if (flags & RV8803_FLAG_V2F) {
201 dev_warn(dev, "Voltage low, data is invalid.\n");
202 return -EINVAL;
203 }
204
205 ret = rv8803_read_regs(rv8803->client, RV8803_SEC, 7, date);
206 if (ret)
207 return ret;
208
209 if ((date1[RV8803_SEC] & 0x7f) == bin2bcd(59)) {
210 ret = rv8803_read_regs(rv8803->client, RV8803_SEC, 7, date2);
211 if (ret)
212 return ret;
213
214 if ((date2[RV8803_SEC] & 0x7f) != bin2bcd(59))
215 date = date2;
216 }
217
218 tm->tm_sec = bcd2bin(date[RV8803_SEC] & 0x7f);
219 tm->tm_min = bcd2bin(date[RV8803_MIN] & 0x7f);
220 tm->tm_hour = bcd2bin(date[RV8803_HOUR] & 0x3f);
221 tm->tm_wday = ilog2(date[RV8803_WEEK] & 0x7f);
222 tm->tm_mday = bcd2bin(date[RV8803_DAY] & 0x3f);
223 tm->tm_mon = bcd2bin(date[RV8803_MONTH] & 0x1f) - 1;
224 tm->tm_year = bcd2bin(date[RV8803_YEAR]) + 100;
225
226 return 0;
227}
228
229static int rv8803_set_time(struct device *dev, struct rtc_time *tm)
230{
231 struct rv8803_data *rv8803 = dev_get_drvdata(dev);
232 u8 date[7];
233 int ctrl, flags, ret;
234
235 ctrl = rv8803_read_reg(rv8803->client, RV8803_CTRL);
236 if (ctrl < 0)
237 return ctrl;
238
239
240 ret = rv8803_write_reg(rv8803->client, RV8803_CTRL,
241 ctrl | RV8803_CTRL_RESET);
242 if (ret)
243 return ret;
244
245 date[RV8803_SEC] = bin2bcd(tm->tm_sec);
246 date[RV8803_MIN] = bin2bcd(tm->tm_min);
247 date[RV8803_HOUR] = bin2bcd(tm->tm_hour);
248 date[RV8803_WEEK] = 1 << (tm->tm_wday);
249 date[RV8803_DAY] = bin2bcd(tm->tm_mday);
250 date[RV8803_MONTH] = bin2bcd(tm->tm_mon + 1);
251 date[RV8803_YEAR] = bin2bcd(tm->tm_year - 100);
252
253 ret = rv8803_write_regs(rv8803->client, RV8803_SEC, 7, date);
254 if (ret)
255 return ret;
256
257
258 ret = rv8803_write_reg(rv8803->client, RV8803_CTRL,
259 ctrl & ~RV8803_CTRL_RESET);
260 if (ret)
261 return ret;
262
263 mutex_lock(&rv8803->flags_lock);
264
265 flags = rv8803_read_reg(rv8803->client, RV8803_FLAG);
266 if (flags < 0) {
267 mutex_unlock(&rv8803->flags_lock);
268 return flags;
269 }
270
271 ret = rv8803_write_reg(rv8803->client, RV8803_FLAG,
272 flags & ~(RV8803_FLAG_V1F | RV8803_FLAG_V2F));
273
274 mutex_unlock(&rv8803->flags_lock);
275
276 return ret;
277}
278
279static int rv8803_get_alarm(struct device *dev, struct rtc_wkalrm *alrm)
280{
281 struct rv8803_data *rv8803 = dev_get_drvdata(dev);
282 struct i2c_client *client = rv8803->client;
283 u8 alarmvals[3];
284 int flags, ret;
285
286 ret = rv8803_read_regs(client, RV8803_ALARM_MIN, 3, alarmvals);
287 if (ret)
288 return ret;
289
290 flags = rv8803_read_reg(client, RV8803_FLAG);
291 if (flags < 0)
292 return flags;
293
294 alrm->time.tm_sec = 0;
295 alrm->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);
296 alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
297 alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f);
298
299 alrm->enabled = !!(rv8803->ctrl & RV8803_CTRL_AIE);
300 alrm->pending = (flags & RV8803_FLAG_AF) && alrm->enabled;
301
302 return 0;
303}
304
305static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
306{
307 struct i2c_client *client = to_i2c_client(dev);
308 struct rv8803_data *rv8803 = dev_get_drvdata(dev);
309 u8 alarmvals[3];
310 u8 ctrl[2];
311 int ret, err;
312
313
314 if (alrm->time.tm_sec) {
315 time64_t alarm_time = rtc_tm_to_time64(&alrm->time);
316
317 alarm_time += 60 - alrm->time.tm_sec;
318 rtc_time64_to_tm(alarm_time, &alrm->time);
319 }
320
321 mutex_lock(&rv8803->flags_lock);
322
323 ret = rv8803_read_regs(client, RV8803_FLAG, 2, ctrl);
324 if (ret) {
325 mutex_unlock(&rv8803->flags_lock);
326 return ret;
327 }
328
329 alarmvals[0] = bin2bcd(alrm->time.tm_min);
330 alarmvals[1] = bin2bcd(alrm->time.tm_hour);
331 alarmvals[2] = bin2bcd(alrm->time.tm_mday);
332
333 if (rv8803->ctrl & (RV8803_CTRL_AIE | RV8803_CTRL_UIE)) {
334 rv8803->ctrl &= ~(RV8803_CTRL_AIE | RV8803_CTRL_UIE);
335 err = rv8803_write_reg(rv8803->client, RV8803_CTRL,
336 rv8803->ctrl);
337 if (err) {
338 mutex_unlock(&rv8803->flags_lock);
339 return err;
340 }
341 }
342
343 ctrl[1] &= ~RV8803_FLAG_AF;
344 err = rv8803_write_reg(rv8803->client, RV8803_FLAG, ctrl[1]);
345 mutex_unlock(&rv8803->flags_lock);
346 if (err)
347 return err;
348
349 err = rv8803_write_regs(rv8803->client, RV8803_ALARM_MIN, 3, alarmvals);
350 if (err)
351 return err;
352
353 if (alrm->enabled) {
354 if (rv8803->rtc->uie_rtctimer.enabled)
355 rv8803->ctrl |= RV8803_CTRL_UIE;
356 if (rv8803->rtc->aie_timer.enabled)
357 rv8803->ctrl |= RV8803_CTRL_AIE;
358
359 err = rv8803_write_reg(rv8803->client, RV8803_CTRL,
360 rv8803->ctrl);
361 if (err)
362 return err;
363 }
364
365 return 0;
366}
367
368static int rv8803_alarm_irq_enable(struct device *dev, unsigned int enabled)
369{
370 struct i2c_client *client = to_i2c_client(dev);
371 struct rv8803_data *rv8803 = dev_get_drvdata(dev);
372 int ctrl, flags, err;
373
374 ctrl = rv8803->ctrl;
375
376 if (enabled) {
377 if (rv8803->rtc->uie_rtctimer.enabled)
378 ctrl |= RV8803_CTRL_UIE;
379 if (rv8803->rtc->aie_timer.enabled)
380 ctrl |= RV8803_CTRL_AIE;
381 } else {
382 if (!rv8803->rtc->uie_rtctimer.enabled)
383 ctrl &= ~RV8803_CTRL_UIE;
384 if (!rv8803->rtc->aie_timer.enabled)
385 ctrl &= ~RV8803_CTRL_AIE;
386 }
387
388 mutex_lock(&rv8803->flags_lock);
389 flags = rv8803_read_reg(client, RV8803_FLAG);
390 if (flags < 0) {
391 mutex_unlock(&rv8803->flags_lock);
392 return flags;
393 }
394 flags &= ~(RV8803_FLAG_AF | RV8803_FLAG_UF);
395 err = rv8803_write_reg(client, RV8803_FLAG, flags);
396 mutex_unlock(&rv8803->flags_lock);
397 if (err)
398 return err;
399
400 if (ctrl != rv8803->ctrl) {
401 rv8803->ctrl = ctrl;
402 err = rv8803_write_reg(client, RV8803_CTRL, rv8803->ctrl);
403 if (err)
404 return err;
405 }
406
407 return 0;
408}
409
410static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
411{
412 struct i2c_client *client = to_i2c_client(dev);
413 struct rv8803_data *rv8803 = dev_get_drvdata(dev);
414 unsigned int vl = 0;
415 int flags, ret = 0;
416
417 switch (cmd) {
418 case RTC_VL_READ:
419 flags = rv8803_read_reg(client, RV8803_FLAG);
420 if (flags < 0)
421 return flags;
422
423 if (flags & RV8803_FLAG_V1F) {
424 dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
425 vl = RTC_VL_ACCURACY_LOW;
426 }
427
428 if (flags & RV8803_FLAG_V2F)
429 vl |= RTC_VL_DATA_INVALID;
430
431 return put_user(vl, (unsigned int __user *)arg);
432
433 case RTC_VL_CLR:
434 mutex_lock(&rv8803->flags_lock);
435 flags = rv8803_read_reg(client, RV8803_FLAG);
436 if (flags < 0) {
437 mutex_unlock(&rv8803->flags_lock);
438 return flags;
439 }
440
441 flags &= ~RV8803_FLAG_V1F;
442 ret = rv8803_write_reg(client, RV8803_FLAG, flags);
443 mutex_unlock(&rv8803->flags_lock);
444 if (ret)
445 return ret;
446
447 return 0;
448
449 default:
450 return -ENOIOCTLCMD;
451 }
452}
453
454static int rv8803_nvram_write(void *priv, unsigned int offset, void *val,
455 size_t bytes)
456{
457 return rv8803_write_reg(priv, RV8803_RAM, *(u8 *)val);
458}
459
460static int rv8803_nvram_read(void *priv, unsigned int offset,
461 void *val, size_t bytes)
462{
463 int ret;
464
465 ret = rv8803_read_reg(priv, RV8803_RAM);
466 if (ret < 0)
467 return ret;
468
469 *(u8 *)val = ret;
470
471 return 0;
472}
473
474static const struct rtc_class_ops rv8803_rtc_ops = {
475 .read_time = rv8803_get_time,
476 .set_time = rv8803_set_time,
477 .ioctl = rv8803_ioctl,
478 .read_alarm = rv8803_get_alarm,
479 .set_alarm = rv8803_set_alarm,
480 .alarm_irq_enable = rv8803_alarm_irq_enable,
481};
482
483static int rx8900_trickle_charger_init(struct rv8803_data *rv8803)
484{
485 struct i2c_client *client = rv8803->client;
486 struct device_node *node = client->dev.of_node;
487 int err;
488 u8 flags;
489
490 if (!node)
491 return 0;
492
493 if (rv8803->type != rx_8900)
494 return 0;
495
496 err = i2c_smbus_read_byte_data(rv8803->client, RX8900_BACKUP_CTRL);
497 if (err < 0)
498 return err;
499
500 flags = ~(RX8900_FLAG_VDETOFF | RX8900_FLAG_SWOFF) & (u8)err;
501
502 if (of_property_read_bool(node, "epson,vdet-disable"))
503 flags |= RX8900_FLAG_VDETOFF;
504
505 if (of_property_read_bool(node, "trickle-diode-disable"))
506 flags |= RX8900_FLAG_SWOFF;
507
508 return i2c_smbus_write_byte_data(rv8803->client, RX8900_BACKUP_CTRL,
509 flags);
510}
511
512static int rv8803_probe(struct i2c_client *client,
513 const struct i2c_device_id *id)
514{
515 struct i2c_adapter *adapter = client->adapter;
516 struct rv8803_data *rv8803;
517 int err, flags;
518 struct nvmem_config nvmem_cfg = {
519 .name = "rv8803_nvram",
520 .word_size = 1,
521 .stride = 1,
522 .size = 1,
523 .reg_read = rv8803_nvram_read,
524 .reg_write = rv8803_nvram_write,
525 .priv = client,
526 };
527
528 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
529 I2C_FUNC_SMBUS_I2C_BLOCK)) {
530 dev_err(&adapter->dev, "doesn't support I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK\n");
531 return -EIO;
532 }
533
534 rv8803 = devm_kzalloc(&client->dev, sizeof(struct rv8803_data),
535 GFP_KERNEL);
536 if (!rv8803)
537 return -ENOMEM;
538
539 mutex_init(&rv8803->flags_lock);
540 rv8803->client = client;
541 if (client->dev.of_node)
542 rv8803->type = (enum rv8803_type)
543 of_device_get_match_data(&client->dev);
544 else
545 rv8803->type = id->driver_data;
546 i2c_set_clientdata(client, rv8803);
547
548 flags = rv8803_read_reg(client, RV8803_FLAG);
549 if (flags < 0)
550 return flags;
551
552 if (flags & RV8803_FLAG_V1F)
553 dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
554
555 if (flags & RV8803_FLAG_V2F)
556 dev_warn(&client->dev, "Voltage low, data loss detected.\n");
557
558 if (flags & RV8803_FLAG_AF)
559 dev_warn(&client->dev, "An alarm maybe have been missed.\n");
560
561 rv8803->rtc = devm_rtc_allocate_device(&client->dev);
562 if (IS_ERR(rv8803->rtc))
563 return PTR_ERR(rv8803->rtc);
564
565 if (client->irq > 0) {
566 err = devm_request_threaded_irq(&client->dev, client->irq,
567 NULL, rv8803_handle_irq,
568 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
569 "rv8803", client);
570 if (err) {
571 dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
572 client->irq = 0;
573 }
574 }
575 if (!client->irq)
576 clear_bit(RTC_FEATURE_ALARM, rv8803->rtc->features);
577
578 err = rv8803_write_reg(rv8803->client, RV8803_EXT, RV8803_EXT_WADA);
579 if (err)
580 return err;
581
582 err = rx8900_trickle_charger_init(rv8803);
583 if (err) {
584 dev_err(&client->dev, "failed to init charger\n");
585 return err;
586 }
587
588 rv8803->rtc->ops = &rv8803_rtc_ops;
589 rv8803->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
590 rv8803->rtc->range_max = RTC_TIMESTAMP_END_2099;
591 err = devm_rtc_register_device(rv8803->rtc);
592 if (err)
593 return err;
594
595 devm_rtc_nvmem_register(rv8803->rtc, &nvmem_cfg);
596
597 rv8803->rtc->max_user_freq = 1;
598
599 return 0;
600}
601
602static const struct i2c_device_id rv8803_id[] = {
603 { "rv8803", rv_8803 },
604 { "rx8803", rv_8803 },
605 { "rx8900", rx_8900 },
606 { }
607};
608MODULE_DEVICE_TABLE(i2c, rv8803_id);
609
610static const __maybe_unused struct of_device_id rv8803_of_match[] = {
611 {
612 .compatible = "microcrystal,rv8803",
613 .data = (void *)rv_8803
614 },
615 {
616 .compatible = "epson,rx8803",
617 .data = (void *)rv_8803
618 },
619 {
620 .compatible = "epson,rx8900",
621 .data = (void *)rx_8900
622 },
623 { }
624};
625MODULE_DEVICE_TABLE(of, rv8803_of_match);
626
627static struct i2c_driver rv8803_driver = {
628 .driver = {
629 .name = "rtc-rv8803",
630 .of_match_table = of_match_ptr(rv8803_of_match),
631 },
632 .probe = rv8803_probe,
633 .id_table = rv8803_id,
634};
635module_i2c_driver(rv8803_driver);
636
637MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
638MODULE_DESCRIPTION("Micro Crystal RV8803 RTC driver");
639MODULE_LICENSE("GPL v2");
640
