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/rtc.h>
23 #define RV8803_I2C_TRY_COUNT 4
25 #define RV8803_SEC 0x00
26 #define RV8803_MIN 0x01
27 #define RV8803_HOUR 0x02
28 #define RV8803_WEEK 0x03
29 #define RV8803_DAY 0x04
30 #define RV8803_MONTH 0x05
31 #define RV8803_YEAR 0x06
32 #define RV8803_RAM 0x07
33 #define RV8803_ALARM_MIN 0x08
34 #define RV8803_ALARM_HOUR 0x09
35 #define RV8803_ALARM_WEEK_OR_DAY 0x0A
36 #define RV8803_EXT 0x0D
37 #define RV8803_FLAG 0x0E
38 #define RV8803_CTRL 0x0F
40 #define RV8803_EXT_WADA BIT(6)
42 #define RV8803_FLAG_V1F BIT(0)
43 #define RV8803_FLAG_V2F BIT(1)
44 #define RV8803_FLAG_AF BIT(3)
45 #define RV8803_FLAG_TF BIT(4)
46 #define RV8803_FLAG_UF BIT(5)
48 #define RV8803_CTRL_RESET BIT(0)
50 #define RV8803_CTRL_EIE BIT(2)
51 #define RV8803_CTRL_AIE BIT(3)
52 #define RV8803_CTRL_TIE BIT(4)
53 #define RV8803_CTRL_UIE BIT(5)
55 #define RX8900_BACKUP_CTRL 0x18
56 #define RX8900_FLAG_SWOFF BIT(2)
57 #define RX8900_FLAG_VDETOFF BIT(3)
65 struct i2c_client
*client
;
66 struct rtc_device
*rtc
;
67 struct mutex flags_lock
;
69 enum rv8803_type type
;
72 static int rv8803_read_reg(const struct i2c_client
*client
, u8 reg
)
74 int try = RV8803_I2C_TRY_COUNT
;
78 * There is a 61µs window during which the RTC does not acknowledge I2C
79 * transfers. In that case, ensure that there are multiple attempts.
82 ret
= i2c_smbus_read_byte_data(client
, reg
);
83 while ((ret
== -ENXIO
|| ret
== -EIO
) && --try);
85 dev_err(&client
->dev
, "Unable to read register 0x%02x\n", reg
);
90 static int rv8803_read_regs(const struct i2c_client
*client
,
91 u8 reg
, u8 count
, u8
*values
)
93 int try = RV8803_I2C_TRY_COUNT
;
97 ret
= i2c_smbus_read_i2c_block_data(client
, reg
, count
, values
);
98 while ((ret
== -ENXIO
|| ret
== -EIO
) && --try);
100 dev_err(&client
->dev
,
101 "Unable to read registers 0x%02x..0x%02x\n",
102 reg
, reg
+ count
- 1);
103 return ret
< 0 ? ret
: -EIO
;
109 static int rv8803_write_reg(const struct i2c_client
*client
, u8 reg
, u8 value
)
111 int try = RV8803_I2C_TRY_COUNT
;
115 ret
= i2c_smbus_write_byte_data(client
, reg
, value
);
116 while ((ret
== -ENXIO
|| ret
== -EIO
) && --try);
118 dev_err(&client
->dev
, "Unable to write register 0x%02x\n", reg
);
123 static int rv8803_write_regs(const struct i2c_client
*client
,
124 u8 reg
, u8 count
, const u8
*values
)
126 int try = RV8803_I2C_TRY_COUNT
;
130 ret
= i2c_smbus_write_i2c_block_data(client
, reg
, count
,
132 while ((ret
== -ENXIO
|| ret
== -EIO
) && --try);
134 dev_err(&client
->dev
,
135 "Unable to write registers 0x%02x..0x%02x\n",
136 reg
, reg
+ count
- 1);
141 static irqreturn_t
rv8803_handle_irq(int irq
, void *dev_id
)
143 struct i2c_client
*client
= dev_id
;
144 struct rv8803_data
*rv8803
= i2c_get_clientdata(client
);
145 unsigned long events
= 0;
148 mutex_lock(&rv8803
->flags_lock
);
150 flags
= rv8803_read_reg(client
, RV8803_FLAG
);
152 mutex_unlock(&rv8803
->flags_lock
);
156 if (flags
& RV8803_FLAG_V1F
)
157 dev_warn(&client
->dev
, "Voltage low, temperature compensation stopped.\n");
159 if (flags
& RV8803_FLAG_V2F
)
160 dev_warn(&client
->dev
, "Voltage low, data loss detected.\n");
162 if (flags
& RV8803_FLAG_TF
) {
163 flags
&= ~RV8803_FLAG_TF
;
164 rv8803
->ctrl
&= ~RV8803_CTRL_TIE
;
168 if (flags
& RV8803_FLAG_AF
) {
169 flags
&= ~RV8803_FLAG_AF
;
170 rv8803
->ctrl
&= ~RV8803_CTRL_AIE
;
174 if (flags
& RV8803_FLAG_UF
) {
175 flags
&= ~RV8803_FLAG_UF
;
176 rv8803
->ctrl
&= ~RV8803_CTRL_UIE
;
181 rtc_update_irq(rv8803
->rtc
, 1, events
);
182 rv8803_write_reg(client
, RV8803_FLAG
, flags
);
183 rv8803_write_reg(rv8803
->client
, RV8803_CTRL
, rv8803
->ctrl
);
186 mutex_unlock(&rv8803
->flags_lock
);
191 static int rv8803_get_time(struct device
*dev
, struct rtc_time
*tm
)
193 struct rv8803_data
*rv8803
= dev_get_drvdata(dev
);
199 flags
= rv8803_read_reg(rv8803
->client
, RV8803_FLAG
);
203 if (flags
& RV8803_FLAG_V2F
) {
204 dev_warn(dev
, "Voltage low, data is invalid.\n");
208 ret
= rv8803_read_regs(rv8803
->client
, RV8803_SEC
, 7, date
);
212 if ((date1
[RV8803_SEC
] & 0x7f) == bin2bcd(59)) {
213 ret
= rv8803_read_regs(rv8803
->client
, RV8803_SEC
, 7, date2
);
217 if ((date2
[RV8803_SEC
] & 0x7f) != bin2bcd(59))
221 tm
->tm_sec
= bcd2bin(date
[RV8803_SEC
] & 0x7f);
222 tm
->tm_min
= bcd2bin(date
[RV8803_MIN
] & 0x7f);
223 tm
->tm_hour
= bcd2bin(date
[RV8803_HOUR
] & 0x3f);
224 tm
->tm_wday
= ilog2(date
[RV8803_WEEK
] & 0x7f);
225 tm
->tm_mday
= bcd2bin(date
[RV8803_DAY
] & 0x3f);
226 tm
->tm_mon
= bcd2bin(date
[RV8803_MONTH
] & 0x1f) - 1;
227 tm
->tm_year
= bcd2bin(date
[RV8803_YEAR
]) + 100;
232 static int rv8803_set_time(struct device
*dev
, struct rtc_time
*tm
)
234 struct rv8803_data
*rv8803
= dev_get_drvdata(dev
);
236 int ctrl
, flags
, ret
;
238 if ((tm
->tm_year
< 100) || (tm
->tm_year
> 199))
241 ctrl
= rv8803_read_reg(rv8803
->client
, RV8803_CTRL
);
246 ret
= rv8803_write_reg(rv8803
->client
, RV8803_CTRL
,
247 ctrl
| RV8803_CTRL_RESET
);
251 date
[RV8803_SEC
] = bin2bcd(tm
->tm_sec
);
252 date
[RV8803_MIN
] = bin2bcd(tm
->tm_min
);
253 date
[RV8803_HOUR
] = bin2bcd(tm
->tm_hour
);
254 date
[RV8803_WEEK
] = 1 << (tm
->tm_wday
);
255 date
[RV8803_DAY
] = bin2bcd(tm
->tm_mday
);
256 date
[RV8803_MONTH
] = bin2bcd(tm
->tm_mon
+ 1);
257 date
[RV8803_YEAR
] = bin2bcd(tm
->tm_year
- 100);
259 ret
= rv8803_write_regs(rv8803
->client
, RV8803_SEC
, 7, date
);
263 /* Restart the clock */
264 ret
= rv8803_write_reg(rv8803
->client
, RV8803_CTRL
,
265 ctrl
& ~RV8803_CTRL_RESET
);
269 mutex_lock(&rv8803
->flags_lock
);
271 flags
= rv8803_read_reg(rv8803
->client
, RV8803_FLAG
);
273 mutex_unlock(&rv8803
->flags_lock
);
277 ret
= rv8803_write_reg(rv8803
->client
, RV8803_FLAG
,
278 flags
& ~(RV8803_FLAG_V1F
| RV8803_FLAG_V2F
));
280 mutex_unlock(&rv8803
->flags_lock
);
285 static int rv8803_get_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
287 struct rv8803_data
*rv8803
= dev_get_drvdata(dev
);
288 struct i2c_client
*client
= rv8803
->client
;
292 ret
= rv8803_read_regs(client
, RV8803_ALARM_MIN
, 3, alarmvals
);
296 flags
= rv8803_read_reg(client
, RV8803_FLAG
);
300 alrm
->time
.tm_sec
= 0;
301 alrm
->time
.tm_min
= bcd2bin(alarmvals
[0] & 0x7f);
302 alrm
->time
.tm_hour
= bcd2bin(alarmvals
[1] & 0x3f);
303 alrm
->time
.tm_mday
= bcd2bin(alarmvals
[2] & 0x3f);
305 alrm
->enabled
= !!(rv8803
->ctrl
& RV8803_CTRL_AIE
);
306 alrm
->pending
= (flags
& RV8803_FLAG_AF
) && alrm
->enabled
;
311 static int rv8803_set_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
313 struct i2c_client
*client
= to_i2c_client(dev
);
314 struct rv8803_data
*rv8803
= dev_get_drvdata(dev
);
319 /* The alarm has no seconds, round up to nearest minute */
320 if (alrm
->time
.tm_sec
) {
321 time64_t alarm_time
= rtc_tm_to_time64(&alrm
->time
);
323 alarm_time
+= 60 - alrm
->time
.tm_sec
;
324 rtc_time64_to_tm(alarm_time
, &alrm
->time
);
327 mutex_lock(&rv8803
->flags_lock
);
329 ret
= rv8803_read_regs(client
, RV8803_FLAG
, 2, ctrl
);
331 mutex_unlock(&rv8803
->flags_lock
);
335 alarmvals
[0] = bin2bcd(alrm
->time
.tm_min
);
336 alarmvals
[1] = bin2bcd(alrm
->time
.tm_hour
);
337 alarmvals
[2] = bin2bcd(alrm
->time
.tm_mday
);
339 if (rv8803
->ctrl
& (RV8803_CTRL_AIE
| RV8803_CTRL_UIE
)) {
340 rv8803
->ctrl
&= ~(RV8803_CTRL_AIE
| RV8803_CTRL_UIE
);
341 err
= rv8803_write_reg(rv8803
->client
, RV8803_CTRL
,
344 mutex_unlock(&rv8803
->flags_lock
);
349 ctrl
[1] &= ~RV8803_FLAG_AF
;
350 err
= rv8803_write_reg(rv8803
->client
, RV8803_FLAG
, ctrl
[1]);
351 mutex_unlock(&rv8803
->flags_lock
);
355 err
= rv8803_write_regs(rv8803
->client
, RV8803_ALARM_MIN
, 3, alarmvals
);
360 if (rv8803
->rtc
->uie_rtctimer
.enabled
)
361 rv8803
->ctrl
|= RV8803_CTRL_UIE
;
362 if (rv8803
->rtc
->aie_timer
.enabled
)
363 rv8803
->ctrl
|= RV8803_CTRL_AIE
;
365 err
= rv8803_write_reg(rv8803
->client
, RV8803_CTRL
,
374 static int rv8803_alarm_irq_enable(struct device
*dev
, unsigned int enabled
)
376 struct i2c_client
*client
= to_i2c_client(dev
);
377 struct rv8803_data
*rv8803
= dev_get_drvdata(dev
);
378 int ctrl
, flags
, err
;
383 if (rv8803
->rtc
->uie_rtctimer
.enabled
)
384 ctrl
|= RV8803_CTRL_UIE
;
385 if (rv8803
->rtc
->aie_timer
.enabled
)
386 ctrl
|= RV8803_CTRL_AIE
;
388 if (!rv8803
->rtc
->uie_rtctimer
.enabled
)
389 ctrl
&= ~RV8803_CTRL_UIE
;
390 if (!rv8803
->rtc
->aie_timer
.enabled
)
391 ctrl
&= ~RV8803_CTRL_AIE
;
394 mutex_lock(&rv8803
->flags_lock
);
395 flags
= rv8803_read_reg(client
, RV8803_FLAG
);
397 mutex_unlock(&rv8803
->flags_lock
);
400 flags
&= ~(RV8803_FLAG_AF
| RV8803_FLAG_UF
);
401 err
= rv8803_write_reg(client
, RV8803_FLAG
, flags
);
402 mutex_unlock(&rv8803
->flags_lock
);
406 if (ctrl
!= rv8803
->ctrl
) {
408 err
= rv8803_write_reg(client
, RV8803_CTRL
, rv8803
->ctrl
);
416 static int rv8803_ioctl(struct device
*dev
, unsigned int cmd
, unsigned long arg
)
418 struct i2c_client
*client
= to_i2c_client(dev
);
419 struct rv8803_data
*rv8803
= dev_get_drvdata(dev
);
424 flags
= rv8803_read_reg(client
, RV8803_FLAG
);
428 if (flags
& RV8803_FLAG_V1F
)
429 dev_warn(&client
->dev
, "Voltage low, temperature compensation stopped.\n");
431 if (flags
& RV8803_FLAG_V2F
)
432 dev_warn(&client
->dev
, "Voltage low, data loss detected.\n");
434 flags
&= RV8803_FLAG_V1F
| RV8803_FLAG_V2F
;
436 if (copy_to_user((void __user
*)arg
, &flags
, sizeof(int)))
442 mutex_lock(&rv8803
->flags_lock
);
443 flags
= rv8803_read_reg(client
, RV8803_FLAG
);
445 mutex_unlock(&rv8803
->flags_lock
);
449 flags
&= ~(RV8803_FLAG_V1F
| RV8803_FLAG_V2F
);
450 ret
= rv8803_write_reg(client
, RV8803_FLAG
, flags
);
451 mutex_unlock(&rv8803
->flags_lock
);
462 static ssize_t
rv8803_nvram_write(struct file
*filp
, struct kobject
*kobj
,
463 struct bin_attribute
*attr
,
464 char *buf
, loff_t off
, size_t count
)
466 struct device
*dev
= kobj_to_dev(kobj
);
467 struct i2c_client
*client
= to_i2c_client(dev
);
470 ret
= rv8803_write_reg(client
, RV8803_RAM
, buf
[0]);
477 static ssize_t
rv8803_nvram_read(struct file
*filp
, struct kobject
*kobj
,
478 struct bin_attribute
*attr
,
479 char *buf
, loff_t off
, size_t count
)
481 struct device
*dev
= kobj_to_dev(kobj
);
482 struct i2c_client
*client
= to_i2c_client(dev
);
485 ret
= rv8803_read_reg(client
, RV8803_RAM
);
494 static struct bin_attribute rv8803_nvram_attr
= {
497 .mode
= S_IRUGO
| S_IWUSR
,
500 .read
= rv8803_nvram_read
,
501 .write
= rv8803_nvram_write
,
504 static struct rtc_class_ops rv8803_rtc_ops
= {
505 .read_time
= rv8803_get_time
,
506 .set_time
= rv8803_set_time
,
507 .ioctl
= rv8803_ioctl
,
510 static int rx8900_trickle_charger_init(struct rv8803_data
*rv8803
)
512 struct i2c_client
*client
= rv8803
->client
;
513 struct device_node
*node
= client
->dev
.of_node
;
520 if (rv8803
->type
!= rx_8900
)
523 err
= i2c_smbus_read_byte_data(rv8803
->client
, RX8900_BACKUP_CTRL
);
527 flags
= ~(RX8900_FLAG_VDETOFF
| RX8900_FLAG_SWOFF
) & (u8
)err
;
529 if (of_property_read_bool(node
, "epson,vdet-disable"))
530 flags
|= RX8900_FLAG_VDETOFF
;
532 if (of_property_read_bool(node
, "trickle-diode-disable"))
533 flags
|= RX8900_FLAG_SWOFF
;
535 return i2c_smbus_write_byte_data(rv8803
->client
, RX8900_BACKUP_CTRL
,
539 static int rv8803_probe(struct i2c_client
*client
,
540 const struct i2c_device_id
*id
)
542 struct i2c_adapter
*adapter
= to_i2c_adapter(client
->dev
.parent
);
543 struct rv8803_data
*rv8803
;
546 if (!i2c_check_functionality(adapter
, I2C_FUNC_SMBUS_BYTE_DATA
|
547 I2C_FUNC_SMBUS_I2C_BLOCK
)) {
548 dev_err(&adapter
->dev
, "doesn't support I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK\n");
552 rv8803
= devm_kzalloc(&client
->dev
, sizeof(struct rv8803_data
),
557 mutex_init(&rv8803
->flags_lock
);
558 rv8803
->client
= client
;
559 rv8803
->type
= id
->driver_data
;
560 i2c_set_clientdata(client
, rv8803
);
562 flags
= rv8803_read_reg(client
, RV8803_FLAG
);
566 if (flags
& RV8803_FLAG_V1F
)
567 dev_warn(&client
->dev
, "Voltage low, temperature compensation stopped.\n");
569 if (flags
& RV8803_FLAG_V2F
)
570 dev_warn(&client
->dev
, "Voltage low, data loss detected.\n");
572 if (flags
& RV8803_FLAG_AF
)
573 dev_warn(&client
->dev
, "An alarm maybe have been missed.\n");
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 rv8803
->rtc
= devm_rtc_device_register(&client
->dev
, client
->name
,
591 &rv8803_rtc_ops
, THIS_MODULE
);
592 if (IS_ERR(rv8803
->rtc
)) {
593 dev_err(&client
->dev
, "unable to register the class device\n");
594 return PTR_ERR(rv8803
->rtc
);
597 err
= rv8803_write_reg(rv8803
->client
, RV8803_EXT
, RV8803_EXT_WADA
);
601 err
= rx8900_trickle_charger_init(rv8803
);
603 dev_err(&client
->dev
, "failed to init charger\n");
607 err
= device_create_bin_file(&client
->dev
, &rv8803_nvram_attr
);
611 rv8803
->rtc
->max_user_freq
= 1;
616 static int rv8803_remove(struct i2c_client
*client
)
618 device_remove_bin_file(&client
->dev
, &rv8803_nvram_attr
);
623 static const struct i2c_device_id rv8803_id
[] = {
624 { "rv8803", rv_8803
},
625 { "rx8900", rx_8900
},
628 MODULE_DEVICE_TABLE(i2c
, rv8803_id
);
630 static struct i2c_driver rv8803_driver
= {
632 .name
= "rtc-rv8803",
634 .probe
= rv8803_probe
,
635 .remove
= rv8803_remove
,
636 .id_table
= rv8803_id
,
638 module_i2c_driver(rv8803_driver
);
640 MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>");
641 MODULE_DESCRIPTION("Micro Crystal RV8803 RTC driver");
642 MODULE_LICENSE("GPL v2");