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)
66 struct i2c_client *client;
67 struct rtc_device *rtc;
68 struct mutex flags_lock;
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;
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);
86 dev_err(&client->dev, "Unable to read register 0x%02x\n", reg);
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;
98 ret = i2c_smbus_read_i2c_block_data(client, reg, count, values);
99 while ((ret == -ENXIO || ret == -EIO) && --try);
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;
110 static int rv8803_write_reg(const struct i2c_client *client, u8 reg, u8 value)
112 int try = RV8803_I2C_TRY_COUNT;
116 ret = i2c_smbus_write_byte_data(client, reg, value);
117 while ((ret == -ENXIO || ret == -EIO) && --try);
119 dev_err(&client->dev, "Unable to write register 0x%02x\n", reg);
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;
131 ret = i2c_smbus_write_i2c_block_data(client, reg, count,
133 while ((ret == -ENXIO || ret == -EIO) && --try);
135 dev_err(&client->dev,
136 "Unable to write registers 0x%02x..0x%02x\n",
137 reg, reg + count - 1);
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;
149 mutex_lock(&rv8803->flags_lock);
151 flags = rv8803_read_reg(client, RV8803_FLAG);
153 mutex_unlock(&rv8803->flags_lock);
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;
169 if (flags & RV8803_FLAG_AF) {
170 flags &= ~RV8803_FLAG_AF;
171 rv8803->ctrl &= ~RV8803_CTRL_AIE;
175 if (flags & RV8803_FLAG_UF) {
176 flags &= ~RV8803_FLAG_UF;
177 rv8803->ctrl &= ~RV8803_CTRL_UIE;
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);
192 static int rv8803_get_time(struct device *dev, struct rtc_time *tm)
194 struct rv8803_data *rv8803 = dev_get_drvdata(dev);
200 flags = rv8803_read_reg(rv8803->client, RV8803_FLAG);
204 if (flags & RV8803_FLAG_V2F) {
205 dev_warn(dev, "Voltage low, data is invalid.\n");
209 ret = rv8803_read_regs(rv8803->client, RV8803_SEC, 7, date);
213 if ((date1[RV8803_SEC] & 0x7f) == bin2bcd(59)) {
214 ret = rv8803_read_regs(rv8803->client, RV8803_SEC, 7, date2);
218 if ((date2[RV8803_SEC] & 0x7f) != bin2bcd(59))
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;
233 static int rv8803_set_time(struct device *dev, struct rtc_time *tm)
235 struct rv8803_data *rv8803 = dev_get_drvdata(dev);
237 int ctrl, flags, ret;
239 ctrl = rv8803_read_reg(rv8803->client, RV8803_CTRL);
244 ret = rv8803_write_reg(rv8803->client, RV8803_CTRL,
245 ctrl | RV8803_CTRL_RESET);
249 date[RV8803_SEC] = bin2bcd(tm->tm_sec);
250 date[RV8803_MIN] = bin2bcd(tm->tm_min);
251 date[RV8803_HOUR] = bin2bcd(tm->tm_hour);
252 date[RV8803_WEEK] = 1 << (tm->tm_wday);
253 date[RV8803_DAY] = bin2bcd(tm->tm_mday);
254 date[RV8803_MONTH] = bin2bcd(tm->tm_mon + 1);
255 date[RV8803_YEAR] = bin2bcd(tm->tm_year - 100);
257 ret = rv8803_write_regs(rv8803->client, RV8803_SEC, 7, date);
261 /* Restart the clock */
262 ret = rv8803_write_reg(rv8803->client, RV8803_CTRL,
263 ctrl & ~RV8803_CTRL_RESET);
267 mutex_lock(&rv8803->flags_lock);
269 flags = rv8803_read_reg(rv8803->client, RV8803_FLAG);
271 mutex_unlock(&rv8803->flags_lock);
275 ret = rv8803_write_reg(rv8803->client, RV8803_FLAG,
276 flags & ~(RV8803_FLAG_V1F | RV8803_FLAG_V2F));
278 mutex_unlock(&rv8803->flags_lock);
283 static int rv8803_get_alarm(struct device *dev, struct rtc_wkalrm *alrm)
285 struct rv8803_data *rv8803 = dev_get_drvdata(dev);
286 struct i2c_client *client = rv8803->client;
290 ret = rv8803_read_regs(client, RV8803_ALARM_MIN, 3, alarmvals);
294 flags = rv8803_read_reg(client, RV8803_FLAG);
298 alrm->time.tm_sec = 0;
299 alrm->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);
300 alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
301 alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f);
303 alrm->enabled = !!(rv8803->ctrl & RV8803_CTRL_AIE);
304 alrm->pending = (flags & RV8803_FLAG_AF) && alrm->enabled;
309 static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
311 struct i2c_client *client = to_i2c_client(dev);
312 struct rv8803_data *rv8803 = dev_get_drvdata(dev);
317 /* The alarm has no seconds, round up to nearest minute */
318 if (alrm->time.tm_sec) {
319 time64_t alarm_time = rtc_tm_to_time64(&alrm->time);
321 alarm_time += 60 - alrm->time.tm_sec;
322 rtc_time64_to_tm(alarm_time, &alrm->time);
325 mutex_lock(&rv8803->flags_lock);
327 ret = rv8803_read_regs(client, RV8803_FLAG, 2, ctrl);
329 mutex_unlock(&rv8803->flags_lock);
333 alarmvals[0] = bin2bcd(alrm->time.tm_min);
334 alarmvals[1] = bin2bcd(alrm->time.tm_hour);
335 alarmvals[2] = bin2bcd(alrm->time.tm_mday);
337 if (rv8803->ctrl & (RV8803_CTRL_AIE | RV8803_CTRL_UIE)) {
338 rv8803->ctrl &= ~(RV8803_CTRL_AIE | RV8803_CTRL_UIE);
339 err = rv8803_write_reg(rv8803->client, RV8803_CTRL,
342 mutex_unlock(&rv8803->flags_lock);
347 ctrl[1] &= ~RV8803_FLAG_AF;
348 err = rv8803_write_reg(rv8803->client, RV8803_FLAG, ctrl[1]);
349 mutex_unlock(&rv8803->flags_lock);
353 err = rv8803_write_regs(rv8803->client, RV8803_ALARM_MIN, 3, alarmvals);
358 if (rv8803->rtc->uie_rtctimer.enabled)
359 rv8803->ctrl |= RV8803_CTRL_UIE;
360 if (rv8803->rtc->aie_timer.enabled)
361 rv8803->ctrl |= RV8803_CTRL_AIE;
363 err = rv8803_write_reg(rv8803->client, RV8803_CTRL,
372 static int rv8803_alarm_irq_enable(struct device *dev, unsigned int enabled)
374 struct i2c_client *client = to_i2c_client(dev);
375 struct rv8803_data *rv8803 = dev_get_drvdata(dev);
376 int ctrl, flags, err;
381 if (rv8803->rtc->uie_rtctimer.enabled)
382 ctrl |= RV8803_CTRL_UIE;
383 if (rv8803->rtc->aie_timer.enabled)
384 ctrl |= RV8803_CTRL_AIE;
386 if (!rv8803->rtc->uie_rtctimer.enabled)
387 ctrl &= ~RV8803_CTRL_UIE;
388 if (!rv8803->rtc->aie_timer.enabled)
389 ctrl &= ~RV8803_CTRL_AIE;
392 mutex_lock(&rv8803->flags_lock);
393 flags = rv8803_read_reg(client, RV8803_FLAG);
395 mutex_unlock(&rv8803->flags_lock);
398 flags &= ~(RV8803_FLAG_AF | RV8803_FLAG_UF);
399 err = rv8803_write_reg(client, RV8803_FLAG, flags);
400 mutex_unlock(&rv8803->flags_lock);
404 if (ctrl != rv8803->ctrl) {
406 err = rv8803_write_reg(client, RV8803_CTRL, rv8803->ctrl);
414 static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
416 struct i2c_client *client = to_i2c_client(dev);
417 struct rv8803_data *rv8803 = dev_get_drvdata(dev);
422 flags = rv8803_read_reg(client, RV8803_FLAG);
426 if (flags & RV8803_FLAG_V1F)
427 dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
429 if (flags & RV8803_FLAG_V2F)
430 dev_warn(&client->dev, "Voltage low, data loss detected.\n");
432 flags &= RV8803_FLAG_V1F | RV8803_FLAG_V2F;
434 if (copy_to_user((void __user *)arg, &flags, sizeof(int)))
440 mutex_lock(&rv8803->flags_lock);
441 flags = rv8803_read_reg(client, RV8803_FLAG);
443 mutex_unlock(&rv8803->flags_lock);
447 flags &= ~(RV8803_FLAG_V1F | RV8803_FLAG_V2F);
448 ret = rv8803_write_reg(client, RV8803_FLAG, flags);
449 mutex_unlock(&rv8803->flags_lock);
460 static int rv8803_nvram_write(void *priv, unsigned int offset, void *val,
465 ret = rv8803_write_reg(priv, RV8803_RAM, *(u8 *)val);
472 static int rv8803_nvram_read(void *priv, unsigned int offset,
473 void *val, size_t bytes)
477 ret = rv8803_read_reg(priv, RV8803_RAM);
486 static struct rtc_class_ops rv8803_rtc_ops = {
487 .read_time = rv8803_get_time,
488 .set_time = rv8803_set_time,
489 .ioctl = rv8803_ioctl,
492 static int rx8900_trickle_charger_init(struct rv8803_data *rv8803)
494 struct i2c_client *client = rv8803->client;
495 struct device_node *node = client->dev.of_node;
502 if (rv8803->type != rx_8900)
505 err = i2c_smbus_read_byte_data(rv8803->client, RX8900_BACKUP_CTRL);
509 flags = ~(RX8900_FLAG_VDETOFF | RX8900_FLAG_SWOFF) & (u8)err;
511 if (of_property_read_bool(node, "epson,vdet-disable"))
512 flags |= RX8900_FLAG_VDETOFF;
514 if (of_property_read_bool(node, "trickle-diode-disable"))
515 flags |= RX8900_FLAG_SWOFF;
517 return i2c_smbus_write_byte_data(rv8803->client, RX8900_BACKUP_CTRL,
521 static int rv8803_probe(struct i2c_client *client,
522 const struct i2c_device_id *id)
524 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
525 struct rv8803_data *rv8803;
527 struct nvmem_config nvmem_cfg = {
528 .name = "rv8803_nvram",
532 .reg_read = rv8803_nvram_read,
533 .reg_write = rv8803_nvram_write,
537 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
538 I2C_FUNC_SMBUS_I2C_BLOCK)) {
539 dev_err(&adapter->dev, "doesn't support I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK\n");
543 rv8803 = devm_kzalloc(&client->dev, sizeof(struct rv8803_data),
548 mutex_init(&rv8803->flags_lock);
549 rv8803->client = client;
550 if (client->dev.of_node)
551 rv8803->type = (enum rv8803_type)
552 of_device_get_match_data(&client->dev);
554 rv8803->type = id->driver_data;
555 i2c_set_clientdata(client, rv8803);
557 flags = rv8803_read_reg(client, RV8803_FLAG);
561 if (flags & RV8803_FLAG_V1F)
562 dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
564 if (flags & RV8803_FLAG_V2F)
565 dev_warn(&client->dev, "Voltage low, data loss detected.\n");
567 if (flags & RV8803_FLAG_AF)
568 dev_warn(&client->dev, "An alarm maybe have been missed.\n");
570 rv8803->rtc = devm_rtc_allocate_device(&client->dev);
571 if (IS_ERR(rv8803->rtc)) {
572 return PTR_ERR(rv8803->rtc);
575 if (client->irq > 0) {
576 err = devm_request_threaded_irq(&client->dev, client->irq,
577 NULL, rv8803_handle_irq,
578 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
581 dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
584 rv8803_rtc_ops.read_alarm = rv8803_get_alarm;
585 rv8803_rtc_ops.set_alarm = rv8803_set_alarm;
586 rv8803_rtc_ops.alarm_irq_enable = rv8803_alarm_irq_enable;
590 err = rv8803_write_reg(rv8803->client, RV8803_EXT, RV8803_EXT_WADA);
594 err = rx8900_trickle_charger_init(rv8803);
596 dev_err(&client->dev, "failed to init charger\n");
600 rv8803->rtc->ops = &rv8803_rtc_ops;
601 rv8803->rtc->nvram_old_abi = true;
602 rv8803->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
603 rv8803->rtc->range_max = RTC_TIMESTAMP_END_2099;
604 err = rtc_register_device(rv8803->rtc);
608 rtc_nvmem_register(rv8803->rtc, &nvmem_cfg);
610 rv8803->rtc->max_user_freq = 1;
615 static const struct i2c_device_id rv8803_id[] = {
616 { "rv8803", rv_8803 },
617 { "rx8803", rv_8803 },
618 { "rx8900", rx_8900 },
621 MODULE_DEVICE_TABLE(i2c, rv8803_id);
623 static const struct of_device_id rv8803_of_match[] = {
625 .compatible = "microcrystal,rv8803",
626 .data = (void *)rv_8803
629 .compatible = "epson,rx8803",
630 .data = (void *)rv_8803
633 .compatible = "epson,rx8900",
634 .data = (void *)rx_8900
638 MODULE_DEVICE_TABLE(of, rv8803_of_match);
640 static struct i2c_driver rv8803_driver = {
642 .name = "rtc-rv8803",
643 .of_match_table = of_match_ptr(rv8803_of_match),
645 .probe = rv8803_probe,
646 .id_table = rv8803_id,
648 module_i2c_driver(rv8803_driver);
650 MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>");
651 MODULE_DESCRIPTION("Micro Crystal RV8803 RTC driver");
652 MODULE_LICENSE("GPL v2");