ext2: support statx syscall
[linux/fpc-iii.git] / drivers / rtc / rtc-rv8803.c
blob450a0b831a2da8a2366a57c7e6ac0c3ee5c0c98c
1 /*
2 * RTC driver for the Micro Crystal RV8803
4 * Copyright (C) 2015 Micro Crystal SA
6 * Alexandre Belloni <alexandre.belloni@free-electrons.com>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
14 #include <linux/bcd.h>
15 #include <linux/bitops.h>
16 #include <linux/log2.h>
17 #include <linux/i2c.h>
18 #include <linux/interrupt.h>
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/of_device.h>
22 #include <linux/rtc.h>
24 #define RV8803_I2C_TRY_COUNT 4
26 #define RV8803_SEC 0x00
27 #define RV8803_MIN 0x01
28 #define RV8803_HOUR 0x02
29 #define RV8803_WEEK 0x03
30 #define RV8803_DAY 0x04
31 #define RV8803_MONTH 0x05
32 #define RV8803_YEAR 0x06
33 #define RV8803_RAM 0x07
34 #define RV8803_ALARM_MIN 0x08
35 #define RV8803_ALARM_HOUR 0x09
36 #define RV8803_ALARM_WEEK_OR_DAY 0x0A
37 #define RV8803_EXT 0x0D
38 #define RV8803_FLAG 0x0E
39 #define RV8803_CTRL 0x0F
41 #define RV8803_EXT_WADA BIT(6)
43 #define RV8803_FLAG_V1F BIT(0)
44 #define RV8803_FLAG_V2F BIT(1)
45 #define RV8803_FLAG_AF BIT(3)
46 #define RV8803_FLAG_TF BIT(4)
47 #define RV8803_FLAG_UF BIT(5)
49 #define RV8803_CTRL_RESET BIT(0)
51 #define RV8803_CTRL_EIE BIT(2)
52 #define RV8803_CTRL_AIE BIT(3)
53 #define RV8803_CTRL_TIE BIT(4)
54 #define RV8803_CTRL_UIE BIT(5)
56 #define RX8900_BACKUP_CTRL 0x18
57 #define RX8900_FLAG_SWOFF BIT(2)
58 #define RX8900_FLAG_VDETOFF BIT(3)
60 enum rv8803_type {
61 rv_8803,
62 rx_8900
65 struct rv8803_data {
66 struct i2c_client *client;
67 struct rtc_device *rtc;
68 struct mutex flags_lock;
69 u8 ctrl;
70 enum rv8803_type type;
73 static int rv8803_read_reg(const struct i2c_client *client, u8 reg)
75 int try = RV8803_I2C_TRY_COUNT;
76 s32 ret;
79 * There is a 61µs window during which the RTC does not acknowledge I2C
80 * transfers. In that case, ensure that there are multiple attempts.
83 ret = i2c_smbus_read_byte_data(client, reg);
84 while ((ret == -ENXIO || ret == -EIO) && --try);
85 if (ret < 0)
86 dev_err(&client->dev, "Unable to read register 0x%02x\n", reg);
88 return ret;
91 static int rv8803_read_regs(const struct i2c_client *client,
92 u8 reg, u8 count, u8 *values)
94 int try = RV8803_I2C_TRY_COUNT;
95 s32 ret;
98 ret = i2c_smbus_read_i2c_block_data(client, reg, count, values);
99 while ((ret == -ENXIO || ret == -EIO) && --try);
100 if (ret != count) {
101 dev_err(&client->dev,
102 "Unable to read registers 0x%02x..0x%02x\n",
103 reg, reg + count - 1);
104 return ret < 0 ? ret : -EIO;
107 return 0;
110 static int rv8803_write_reg(const struct i2c_client *client, u8 reg, u8 value)
112 int try = RV8803_I2C_TRY_COUNT;
113 s32 ret;
116 ret = i2c_smbus_write_byte_data(client, reg, value);
117 while ((ret == -ENXIO || ret == -EIO) && --try);
118 if (ret)
119 dev_err(&client->dev, "Unable to write register 0x%02x\n", reg);
121 return ret;
124 static int rv8803_write_regs(const struct i2c_client *client,
125 u8 reg, u8 count, const u8 *values)
127 int try = RV8803_I2C_TRY_COUNT;
128 s32 ret;
131 ret = i2c_smbus_write_i2c_block_data(client, reg, count,
132 values);
133 while ((ret == -ENXIO || ret == -EIO) && --try);
134 if (ret)
135 dev_err(&client->dev,
136 "Unable to write registers 0x%02x..0x%02x\n",
137 reg, reg + count - 1);
139 return ret;
142 static irqreturn_t rv8803_handle_irq(int irq, void *dev_id)
144 struct i2c_client *client = dev_id;
145 struct rv8803_data *rv8803 = i2c_get_clientdata(client);
146 unsigned long events = 0;
147 int flags;
149 mutex_lock(&rv8803->flags_lock);
151 flags = rv8803_read_reg(client, RV8803_FLAG);
152 if (flags <= 0) {
153 mutex_unlock(&rv8803->flags_lock);
154 return IRQ_NONE;
157 if (flags & RV8803_FLAG_V1F)
158 dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
160 if (flags & RV8803_FLAG_V2F)
161 dev_warn(&client->dev, "Voltage low, data loss detected.\n");
163 if (flags & RV8803_FLAG_TF) {
164 flags &= ~RV8803_FLAG_TF;
165 rv8803->ctrl &= ~RV8803_CTRL_TIE;
166 events |= RTC_PF;
169 if (flags & RV8803_FLAG_AF) {
170 flags &= ~RV8803_FLAG_AF;
171 rv8803->ctrl &= ~RV8803_CTRL_AIE;
172 events |= RTC_AF;
175 if (flags & RV8803_FLAG_UF) {
176 flags &= ~RV8803_FLAG_UF;
177 rv8803->ctrl &= ~RV8803_CTRL_UIE;
178 events |= RTC_UF;
181 if (events) {
182 rtc_update_irq(rv8803->rtc, 1, events);
183 rv8803_write_reg(client, RV8803_FLAG, flags);
184 rv8803_write_reg(rv8803->client, RV8803_CTRL, rv8803->ctrl);
187 mutex_unlock(&rv8803->flags_lock);
189 return IRQ_HANDLED;
192 static int rv8803_get_time(struct device *dev, struct rtc_time *tm)
194 struct rv8803_data *rv8803 = dev_get_drvdata(dev);
195 u8 date1[7];
196 u8 date2[7];
197 u8 *date = date1;
198 int ret, flags;
200 flags = rv8803_read_reg(rv8803->client, RV8803_FLAG);
201 if (flags < 0)
202 return flags;
204 if (flags & RV8803_FLAG_V2F) {
205 dev_warn(dev, "Voltage low, data is invalid.\n");
206 return -EINVAL;
209 ret = rv8803_read_regs(rv8803->client, RV8803_SEC, 7, date);
210 if (ret)
211 return ret;
213 if ((date1[RV8803_SEC] & 0x7f) == bin2bcd(59)) {
214 ret = rv8803_read_regs(rv8803->client, RV8803_SEC, 7, date2);
215 if (ret)
216 return ret;
218 if ((date2[RV8803_SEC] & 0x7f) != bin2bcd(59))
219 date = date2;
222 tm->tm_sec = bcd2bin(date[RV8803_SEC] & 0x7f);
223 tm->tm_min = bcd2bin(date[RV8803_MIN] & 0x7f);
224 tm->tm_hour = bcd2bin(date[RV8803_HOUR] & 0x3f);
225 tm->tm_wday = ilog2(date[RV8803_WEEK] & 0x7f);
226 tm->tm_mday = bcd2bin(date[RV8803_DAY] & 0x3f);
227 tm->tm_mon = bcd2bin(date[RV8803_MONTH] & 0x1f) - 1;
228 tm->tm_year = bcd2bin(date[RV8803_YEAR]) + 100;
230 return 0;
233 static int rv8803_set_time(struct device *dev, struct rtc_time *tm)
235 struct rv8803_data *rv8803 = dev_get_drvdata(dev);
236 u8 date[7];
237 int ctrl, flags, ret;
239 if ((tm->tm_year < 100) || (tm->tm_year > 199))
240 return -EINVAL;
242 ctrl = rv8803_read_reg(rv8803->client, RV8803_CTRL);
243 if (ctrl < 0)
244 return ctrl;
246 /* Stop the clock */
247 ret = rv8803_write_reg(rv8803->client, RV8803_CTRL,
248 ctrl | RV8803_CTRL_RESET);
249 if (ret)
250 return ret;
252 date[RV8803_SEC] = bin2bcd(tm->tm_sec);
253 date[RV8803_MIN] = bin2bcd(tm->tm_min);
254 date[RV8803_HOUR] = bin2bcd(tm->tm_hour);
255 date[RV8803_WEEK] = 1 << (tm->tm_wday);
256 date[RV8803_DAY] = bin2bcd(tm->tm_mday);
257 date[RV8803_MONTH] = bin2bcd(tm->tm_mon + 1);
258 date[RV8803_YEAR] = bin2bcd(tm->tm_year - 100);
260 ret = rv8803_write_regs(rv8803->client, RV8803_SEC, 7, date);
261 if (ret)
262 return ret;
264 /* Restart the clock */
265 ret = rv8803_write_reg(rv8803->client, RV8803_CTRL,
266 ctrl & ~RV8803_CTRL_RESET);
267 if (ret)
268 return ret;
270 mutex_lock(&rv8803->flags_lock);
272 flags = rv8803_read_reg(rv8803->client, RV8803_FLAG);
273 if (flags < 0) {
274 mutex_unlock(&rv8803->flags_lock);
275 return flags;
278 ret = rv8803_write_reg(rv8803->client, RV8803_FLAG,
279 flags & ~(RV8803_FLAG_V1F | RV8803_FLAG_V2F));
281 mutex_unlock(&rv8803->flags_lock);
283 return ret;
286 static int rv8803_get_alarm(struct device *dev, struct rtc_wkalrm *alrm)
288 struct rv8803_data *rv8803 = dev_get_drvdata(dev);
289 struct i2c_client *client = rv8803->client;
290 u8 alarmvals[3];
291 int flags, ret;
293 ret = rv8803_read_regs(client, RV8803_ALARM_MIN, 3, alarmvals);
294 if (ret)
295 return ret;
297 flags = rv8803_read_reg(client, RV8803_FLAG);
298 if (flags < 0)
299 return flags;
301 alrm->time.tm_sec = 0;
302 alrm->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);
303 alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
304 alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f);
306 alrm->enabled = !!(rv8803->ctrl & RV8803_CTRL_AIE);
307 alrm->pending = (flags & RV8803_FLAG_AF) && alrm->enabled;
309 return 0;
312 static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
314 struct i2c_client *client = to_i2c_client(dev);
315 struct rv8803_data *rv8803 = dev_get_drvdata(dev);
316 u8 alarmvals[3];
317 u8 ctrl[2];
318 int ret, err;
320 /* The alarm has no seconds, round up to nearest minute */
321 if (alrm->time.tm_sec) {
322 time64_t alarm_time = rtc_tm_to_time64(&alrm->time);
324 alarm_time += 60 - alrm->time.tm_sec;
325 rtc_time64_to_tm(alarm_time, &alrm->time);
328 mutex_lock(&rv8803->flags_lock);
330 ret = rv8803_read_regs(client, RV8803_FLAG, 2, ctrl);
331 if (ret) {
332 mutex_unlock(&rv8803->flags_lock);
333 return ret;
336 alarmvals[0] = bin2bcd(alrm->time.tm_min);
337 alarmvals[1] = bin2bcd(alrm->time.tm_hour);
338 alarmvals[2] = bin2bcd(alrm->time.tm_mday);
340 if (rv8803->ctrl & (RV8803_CTRL_AIE | RV8803_CTRL_UIE)) {
341 rv8803->ctrl &= ~(RV8803_CTRL_AIE | RV8803_CTRL_UIE);
342 err = rv8803_write_reg(rv8803->client, RV8803_CTRL,
343 rv8803->ctrl);
344 if (err) {
345 mutex_unlock(&rv8803->flags_lock);
346 return err;
350 ctrl[1] &= ~RV8803_FLAG_AF;
351 err = rv8803_write_reg(rv8803->client, RV8803_FLAG, ctrl[1]);
352 mutex_unlock(&rv8803->flags_lock);
353 if (err)
354 return err;
356 err = rv8803_write_regs(rv8803->client, RV8803_ALARM_MIN, 3, alarmvals);
357 if (err)
358 return err;
360 if (alrm->enabled) {
361 if (rv8803->rtc->uie_rtctimer.enabled)
362 rv8803->ctrl |= RV8803_CTRL_UIE;
363 if (rv8803->rtc->aie_timer.enabled)
364 rv8803->ctrl |= RV8803_CTRL_AIE;
366 err = rv8803_write_reg(rv8803->client, RV8803_CTRL,
367 rv8803->ctrl);
368 if (err)
369 return err;
372 return 0;
375 static int rv8803_alarm_irq_enable(struct device *dev, unsigned int enabled)
377 struct i2c_client *client = to_i2c_client(dev);
378 struct rv8803_data *rv8803 = dev_get_drvdata(dev);
379 int ctrl, flags, err;
381 ctrl = rv8803->ctrl;
383 if (enabled) {
384 if (rv8803->rtc->uie_rtctimer.enabled)
385 ctrl |= RV8803_CTRL_UIE;
386 if (rv8803->rtc->aie_timer.enabled)
387 ctrl |= RV8803_CTRL_AIE;
388 } else {
389 if (!rv8803->rtc->uie_rtctimer.enabled)
390 ctrl &= ~RV8803_CTRL_UIE;
391 if (!rv8803->rtc->aie_timer.enabled)
392 ctrl &= ~RV8803_CTRL_AIE;
395 mutex_lock(&rv8803->flags_lock);
396 flags = rv8803_read_reg(client, RV8803_FLAG);
397 if (flags < 0) {
398 mutex_unlock(&rv8803->flags_lock);
399 return flags;
401 flags &= ~(RV8803_FLAG_AF | RV8803_FLAG_UF);
402 err = rv8803_write_reg(client, RV8803_FLAG, flags);
403 mutex_unlock(&rv8803->flags_lock);
404 if (err)
405 return err;
407 if (ctrl != rv8803->ctrl) {
408 rv8803->ctrl = ctrl;
409 err = rv8803_write_reg(client, RV8803_CTRL, rv8803->ctrl);
410 if (err)
411 return err;
414 return 0;
417 static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
419 struct i2c_client *client = to_i2c_client(dev);
420 struct rv8803_data *rv8803 = dev_get_drvdata(dev);
421 int flags, ret = 0;
423 switch (cmd) {
424 case RTC_VL_READ:
425 flags = rv8803_read_reg(client, RV8803_FLAG);
426 if (flags < 0)
427 return flags;
429 if (flags & RV8803_FLAG_V1F)
430 dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
432 if (flags & RV8803_FLAG_V2F)
433 dev_warn(&client->dev, "Voltage low, data loss detected.\n");
435 flags &= RV8803_FLAG_V1F | RV8803_FLAG_V2F;
437 if (copy_to_user((void __user *)arg, &flags, sizeof(int)))
438 return -EFAULT;
440 return 0;
442 case RTC_VL_CLR:
443 mutex_lock(&rv8803->flags_lock);
444 flags = rv8803_read_reg(client, RV8803_FLAG);
445 if (flags < 0) {
446 mutex_unlock(&rv8803->flags_lock);
447 return flags;
450 flags &= ~(RV8803_FLAG_V1F | RV8803_FLAG_V2F);
451 ret = rv8803_write_reg(client, RV8803_FLAG, flags);
452 mutex_unlock(&rv8803->flags_lock);
453 if (ret)
454 return ret;
456 return 0;
458 default:
459 return -ENOIOCTLCMD;
463 static int rv8803_nvram_write(void *priv, unsigned int offset, void *val,
464 size_t bytes)
466 int ret;
468 ret = rv8803_write_reg(priv, RV8803_RAM, *(u8 *)val);
469 if (ret)
470 return ret;
472 return 0;
475 static int rv8803_nvram_read(void *priv, unsigned int offset,
476 void *val, size_t bytes)
478 int ret;
480 ret = rv8803_read_reg(priv, RV8803_RAM);
481 if (ret < 0)
482 return ret;
484 *(u8 *)val = ret;
486 return 0;
489 static struct rtc_class_ops rv8803_rtc_ops = {
490 .read_time = rv8803_get_time,
491 .set_time = rv8803_set_time,
492 .ioctl = rv8803_ioctl,
495 static int rx8900_trickle_charger_init(struct rv8803_data *rv8803)
497 struct i2c_client *client = rv8803->client;
498 struct device_node *node = client->dev.of_node;
499 int err;
500 u8 flags;
502 if (!node)
503 return 0;
505 if (rv8803->type != rx_8900)
506 return 0;
508 err = i2c_smbus_read_byte_data(rv8803->client, RX8900_BACKUP_CTRL);
509 if (err < 0)
510 return err;
512 flags = ~(RX8900_FLAG_VDETOFF | RX8900_FLAG_SWOFF) & (u8)err;
514 if (of_property_read_bool(node, "epson,vdet-disable"))
515 flags |= RX8900_FLAG_VDETOFF;
517 if (of_property_read_bool(node, "trickle-diode-disable"))
518 flags |= RX8900_FLAG_SWOFF;
520 return i2c_smbus_write_byte_data(rv8803->client, RX8900_BACKUP_CTRL,
521 flags);
524 static int rv8803_probe(struct i2c_client *client,
525 const struct i2c_device_id *id)
527 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
528 struct rv8803_data *rv8803;
529 int err, flags;
530 struct nvmem_config nvmem_cfg = {
531 .name = "rv8803_nvram",
532 .word_size = 1,
533 .stride = 1,
534 .size = 1,
535 .reg_read = rv8803_nvram_read,
536 .reg_write = rv8803_nvram_write,
537 .priv = client,
540 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
541 I2C_FUNC_SMBUS_I2C_BLOCK)) {
542 dev_err(&adapter->dev, "doesn't support I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK\n");
543 return -EIO;
546 rv8803 = devm_kzalloc(&client->dev, sizeof(struct rv8803_data),
547 GFP_KERNEL);
548 if (!rv8803)
549 return -ENOMEM;
551 mutex_init(&rv8803->flags_lock);
552 rv8803->client = client;
553 if (client->dev.of_node)
554 rv8803->type = (enum rv8803_type)
555 of_device_get_match_data(&client->dev);
556 else
557 rv8803->type = id->driver_data;
558 i2c_set_clientdata(client, rv8803);
560 flags = rv8803_read_reg(client, RV8803_FLAG);
561 if (flags < 0)
562 return flags;
564 if (flags & RV8803_FLAG_V1F)
565 dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
567 if (flags & RV8803_FLAG_V2F)
568 dev_warn(&client->dev, "Voltage low, data loss detected.\n");
570 if (flags & RV8803_FLAG_AF)
571 dev_warn(&client->dev, "An alarm maybe have been missed.\n");
573 rv8803->rtc = devm_rtc_allocate_device(&client->dev);
574 if (IS_ERR(rv8803->rtc)) {
575 return PTR_ERR(rv8803->rtc);
578 if (client->irq > 0) {
579 err = devm_request_threaded_irq(&client->dev, client->irq,
580 NULL, rv8803_handle_irq,
581 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
582 "rv8803", client);
583 if (err) {
584 dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
585 client->irq = 0;
586 } else {
587 rv8803_rtc_ops.read_alarm = rv8803_get_alarm;
588 rv8803_rtc_ops.set_alarm = rv8803_set_alarm;
589 rv8803_rtc_ops.alarm_irq_enable = rv8803_alarm_irq_enable;
593 err = rv8803_write_reg(rv8803->client, RV8803_EXT, RV8803_EXT_WADA);
594 if (err)
595 return err;
597 err = rx8900_trickle_charger_init(rv8803);
598 if (err) {
599 dev_err(&client->dev, "failed to init charger\n");
600 return err;
603 rv8803->rtc->ops = &rv8803_rtc_ops;
604 rv8803->rtc->nvram_old_abi = true;
605 err = rtc_register_device(rv8803->rtc);
606 if (err)
607 return err;
609 rtc_nvmem_register(rv8803->rtc, &nvmem_cfg);
611 rv8803->rtc->max_user_freq = 1;
613 return 0;
616 static const struct i2c_device_id rv8803_id[] = {
617 { "rv8803", rv_8803 },
618 { "rx8803", rv_8803 },
619 { "rx8900", rx_8900 },
622 MODULE_DEVICE_TABLE(i2c, rv8803_id);
624 static const struct of_device_id rv8803_of_match[] = {
626 .compatible = "microcrystal,rv8803",
627 .data = (void *)rv_8803
630 .compatible = "epson,rx8803",
631 .data = (void *)rv_8803
634 .compatible = "epson,rx8900",
635 .data = (void *)rx_8900
639 MODULE_DEVICE_TABLE(of, rv8803_of_match);
641 static struct i2c_driver rv8803_driver = {
642 .driver = {
643 .name = "rtc-rv8803",
644 .of_match_table = of_match_ptr(rv8803_of_match),
646 .probe = rv8803_probe,
647 .id_table = rv8803_id,
649 module_i2c_driver(rv8803_driver);
651 MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>");
652 MODULE_DESCRIPTION("Micro Crystal RV8803 RTC driver");
653 MODULE_LICENSE("GPL v2");