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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 int flags, ret = 0;
415
416 switch (cmd) {
417 case RTC_VL_READ:
418 flags = rv8803_read_reg(client, RV8803_FLAG);
419 if (flags < 0)
420 return flags;
421
422 if (flags & RV8803_FLAG_V1F)
423 dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
424
425 if (flags & RV8803_FLAG_V2F)
426 dev_warn(&client->dev, "Voltage low, data loss detected.\n");
427
428 flags &= RV8803_FLAG_V1F | RV8803_FLAG_V2F;
429
430 if (copy_to_user((void __user *)arg, &flags, sizeof(int)))
431 return -EFAULT;
432
433 return 0;
434
435 case RTC_VL_CLR:
436 mutex_lock(&rv8803->flags_lock);
437 flags = rv8803_read_reg(client, RV8803_FLAG);
438 if (flags < 0) {
439 mutex_unlock(&rv8803->flags_lock);
440 return flags;
441 }
442
443 flags &= ~(RV8803_FLAG_V1F | RV8803_FLAG_V2F);
444 ret = rv8803_write_reg(client, RV8803_FLAG, flags);
445 mutex_unlock(&rv8803->flags_lock);
446 if (ret)
447 return ret;
448
449 return 0;
450
451 default:
452 return -ENOIOCTLCMD;
453 }
454}
455
456static int rv8803_nvram_write(void *priv, unsigned int offset, void *val,
457 size_t bytes)
458{
459 int ret;
460
461 ret = rv8803_write_reg(priv, RV8803_RAM, *(u8 *)val);
462 if (ret)
463 return ret;
464
465 return 0;
466}
467
468static int rv8803_nvram_read(void *priv, unsigned int offset,
469 void *val, size_t bytes)
470{
471 int ret;
472
473 ret = rv8803_read_reg(priv, RV8803_RAM);
474 if (ret < 0)
475 return ret;
476
477 *(u8 *)val = ret;
478
479 return 0;
480}
481
482static struct rtc_class_ops rv8803_rtc_ops = {
483 .read_time = rv8803_get_time,
484 .set_time = rv8803_set_time,
485 .ioctl = rv8803_ioctl,
486};
487
488static int rx8900_trickle_charger_init(struct rv8803_data *rv8803)
489{
490 struct i2c_client *client = rv8803->client;
491 struct device_node *node = client->dev.of_node;
492 int err;
493 u8 flags;
494
495 if (!node)
496 return 0;
497
498 if (rv8803->type != rx_8900)
499 return 0;
500
501 err = i2c_smbus_read_byte_data(rv8803->client, RX8900_BACKUP_CTRL);
502 if (err < 0)
503 return err;
504
505 flags = ~(RX8900_FLAG_VDETOFF | RX8900_FLAG_SWOFF) & (u8)err;
506
507 if (of_property_read_bool(node, "epson,vdet-disable"))
508 flags |= RX8900_FLAG_VDETOFF;
509
510 if (of_property_read_bool(node, "trickle-diode-disable"))
511 flags |= RX8900_FLAG_SWOFF;
512
513 return i2c_smbus_write_byte_data(rv8803->client, RX8900_BACKUP_CTRL,
514 flags);
515}
516
517static int rv8803_probe(struct i2c_client *client,
518 const struct i2c_device_id *id)
519{
520 struct i2c_adapter *adapter = client->adapter;
521 struct rv8803_data *rv8803;
522 int err, flags;
523 struct nvmem_config nvmem_cfg = {
524 .name = "rv8803_nvram",
525 .word_size = 1,
526 .stride = 1,
527 .size = 1,
528 .reg_read = rv8803_nvram_read,
529 .reg_write = rv8803_nvram_write,
530 .priv = client,
531 };
532
533 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
534 I2C_FUNC_SMBUS_I2C_BLOCK)) {
535 dev_err(&adapter->dev, "doesn't support I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK\n");
536 return -EIO;
537 }
538
539 rv8803 = devm_kzalloc(&client->dev, sizeof(struct rv8803_data),
540 GFP_KERNEL);
541 if (!rv8803)
542 return -ENOMEM;
543
544 mutex_init(&rv8803->flags_lock);
545 rv8803->client = client;
546 if (client->dev.of_node)
547 rv8803->type = (enum rv8803_type)
548 of_device_get_match_data(&client->dev);
549 else
550 rv8803->type = id->driver_data;
551 i2c_set_clientdata(client, rv8803);
552
553 flags = rv8803_read_reg(client, RV8803_FLAG);
554 if (flags < 0)
555 return flags;
556
557 if (flags & RV8803_FLAG_V1F)
558 dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
559
560 if (flags & RV8803_FLAG_V2F)
561 dev_warn(&client->dev, "Voltage low, data loss detected.\n");
562
563 if (flags & RV8803_FLAG_AF)
564 dev_warn(&client->dev, "An alarm maybe have been missed.\n");
565
566 rv8803->rtc = devm_rtc_allocate_device(&client->dev);
567 if (IS_ERR(rv8803->rtc)) {
568 return PTR_ERR(rv8803->rtc);
569 }
570
571 if (client->irq > 0) {
572 err = devm_request_threaded_irq(&client->dev, client->irq,
573 NULL, rv8803_handle_irq,
574 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
575 "rv8803", client);
576 if (err) {
577 dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
578 client->irq = 0;
579 } else {
580 rv8803_rtc_ops.read_alarm = rv8803_get_alarm;
581 rv8803_rtc_ops.set_alarm = rv8803_set_alarm;
582 rv8803_rtc_ops.alarm_irq_enable = rv8803_alarm_irq_enable;
583 }
584 }
585
586 err = rv8803_write_reg(rv8803->client, RV8803_EXT, RV8803_EXT_WADA);
587 if (err)
588 return err;
589
590 err = rx8900_trickle_charger_init(rv8803);
591 if (err) {
592 dev_err(&client->dev, "failed to init charger\n");
593 return err;
594 }
595
596 rv8803->rtc->ops = &rv8803_rtc_ops;
597 rv8803->rtc->nvram_old_abi = true;
598 rv8803->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
599 rv8803->rtc->range_max = RTC_TIMESTAMP_END_2099;
600 err = rtc_register_device(rv8803->rtc);
601 if (err)
602 return err;
603
604 rtc_nvmem_register(rv8803->rtc, &nvmem_cfg);
605
606 rv8803->rtc->max_user_freq = 1;
607
608 return 0;
609}
610
611static const struct i2c_device_id rv8803_id[] = {
612 { "rv8803", rv_8803 },
613 { "rx8803", rv_8803 },
614 { "rx8900", rx_8900 },
615 { }
616};
617MODULE_DEVICE_TABLE(i2c, rv8803_id);
618
619static const struct of_device_id rv8803_of_match[] = {
620 {
621 .compatible = "microcrystal,rv8803",
622 .data = (void *)rv_8803
623 },
624 {
625 .compatible = "epson,rx8803",
626 .data = (void *)rv_8803
627 },
628 {
629 .compatible = "epson,rx8900",
630 .data = (void *)rx_8900
631 },
632 { }
633};
634MODULE_DEVICE_TABLE(of, rv8803_of_match);
635
636static struct i2c_driver rv8803_driver = {
637 .driver = {
638 .name = "rtc-rv8803",
639 .of_match_table = of_match_ptr(rv8803_of_match),
640 },
641 .probe = rv8803_probe,
642 .id_table = rv8803_id,
643};
644module_i2c_driver(rv8803_driver);
645
646MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
647MODULE_DESCRIPTION("Micro Crystal RV8803 RTC driver");
648MODULE_LICENSE("GPL v2");
649
