1 // SPDX-License-Identifier: GPL-2.0-only
3 * An I2C driver for the Philips PCF8563 RTC
4 * Copyright 2005-06 Tower Technologies
6 * Author: Alessandro Zummo <a.zummo@towertech.it>
7 * Maintainers: http://www.nslu2-linux.org/
9 * based on the other drivers in this same directory.
11 * http://www.semiconductors.philips.com/acrobat/datasheets/PCF8563-04.pdf
14 #include <linux/clk-provider.h>
15 #include <linux/i2c.h>
16 #include <linux/bcd.h>
17 #include <linux/rtc.h>
18 #include <linux/slab.h>
19 #include <linux/module.h>
21 #include <linux/err.h>
23 #define PCF8563_REG_ST1 0x00 /* status */
24 #define PCF8563_REG_ST2 0x01
25 #define PCF8563_BIT_AIE (1 << 1)
26 #define PCF8563_BIT_AF (1 << 3)
27 #define PCF8563_BITS_ST2_N (7 << 5)
29 #define PCF8563_REG_SC 0x02 /* datetime */
30 #define PCF8563_REG_MN 0x03
31 #define PCF8563_REG_HR 0x04
32 #define PCF8563_REG_DM 0x05
33 #define PCF8563_REG_DW 0x06
34 #define PCF8563_REG_MO 0x07
35 #define PCF8563_REG_YR 0x08
37 #define PCF8563_REG_AMN 0x09 /* alarm */
39 #define PCF8563_REG_CLKO 0x0D /* clock out */
40 #define PCF8563_REG_CLKO_FE 0x80 /* clock out enabled */
41 #define PCF8563_REG_CLKO_F_MASK 0x03 /* frequenc mask */
42 #define PCF8563_REG_CLKO_F_32768HZ 0x00
43 #define PCF8563_REG_CLKO_F_1024HZ 0x01
44 #define PCF8563_REG_CLKO_F_32HZ 0x02
45 #define PCF8563_REG_CLKO_F_1HZ 0x03
47 #define PCF8563_REG_TMRC 0x0E /* timer control */
48 #define PCF8563_TMRC_ENABLE BIT(7)
49 #define PCF8563_TMRC_4096 0
50 #define PCF8563_TMRC_64 1
51 #define PCF8563_TMRC_1 2
52 #define PCF8563_TMRC_1_60 3
53 #define PCF8563_TMRC_MASK 3
55 #define PCF8563_REG_TMR 0x0F /* timer */
57 #define PCF8563_SC_LV 0x80 /* low voltage */
58 #define PCF8563_MO_C 0x80 /* century */
60 static struct i2c_driver pcf8563_driver
;
63 struct rtc_device
*rtc
;
65 * The meaning of MO_C bit varies by the chip type.
66 * From PCF8563 datasheet: this bit is toggled when the years
67 * register overflows from 99 to 00
68 * 0 indicates the century is 20xx
69 * 1 indicates the century is 19xx
70 * From RTC8564 datasheet: this bit indicates change of
71 * century. When the year digit data overflows from 99 to 00,
72 * this bit is set. By presetting it to 0 while still in the
73 * 20th century, it will be set in year 2000, ...
74 * There seems no reliable way to know how the system use this
75 * bit. So let's do it heuristically, assuming we are live in
78 int c_polarity
; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
79 int voltage_low
; /* incicates if a low_voltage was detected */
81 struct i2c_client
*client
;
82 #ifdef CONFIG_COMMON_CLK
83 struct clk_hw clkout_hw
;
87 static int pcf8563_read_block_data(struct i2c_client
*client
, unsigned char reg
,
88 unsigned char length
, unsigned char *buf
)
90 struct i2c_msg msgs
[] = {
104 if ((i2c_transfer(client
->adapter
, msgs
, 2)) != 2) {
105 dev_err(&client
->dev
, "%s: read error\n", __func__
);
112 static int pcf8563_write_block_data(struct i2c_client
*client
,
113 unsigned char reg
, unsigned char length
,
118 for (i
= 0; i
< length
; i
++) {
119 unsigned char data
[2] = { reg
+ i
, buf
[i
] };
121 err
= i2c_master_send(client
, data
, sizeof(data
));
122 if (err
!= sizeof(data
)) {
123 dev_err(&client
->dev
,
124 "%s: err=%d addr=%02x, data=%02x\n",
125 __func__
, err
, data
[0], data
[1]);
133 static int pcf8563_set_alarm_mode(struct i2c_client
*client
, bool on
)
138 err
= pcf8563_read_block_data(client
, PCF8563_REG_ST2
, 1, &buf
);
143 buf
|= PCF8563_BIT_AIE
;
145 buf
&= ~PCF8563_BIT_AIE
;
147 buf
&= ~(PCF8563_BIT_AF
| PCF8563_BITS_ST2_N
);
149 err
= pcf8563_write_block_data(client
, PCF8563_REG_ST2
, 1, &buf
);
151 dev_err(&client
->dev
, "%s: write error\n", __func__
);
158 static int pcf8563_get_alarm_mode(struct i2c_client
*client
, unsigned char *en
,
164 err
= pcf8563_read_block_data(client
, PCF8563_REG_ST2
, 1, &buf
);
169 *en
= !!(buf
& PCF8563_BIT_AIE
);
171 *pen
= !!(buf
& PCF8563_BIT_AF
);
176 static irqreturn_t
pcf8563_irq(int irq
, void *dev_id
)
178 struct pcf8563
*pcf8563
= i2c_get_clientdata(dev_id
);
182 err
= pcf8563_get_alarm_mode(pcf8563
->client
, NULL
, &pending
);
187 rtc_update_irq(pcf8563
->rtc
, 1, RTC_IRQF
| RTC_AF
);
188 pcf8563_set_alarm_mode(pcf8563
->client
, 1);
196 * In the routines that deal directly with the pcf8563 hardware, we use
197 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
199 static int pcf8563_rtc_read_time(struct device
*dev
, struct rtc_time
*tm
)
201 struct i2c_client
*client
= to_i2c_client(dev
);
202 struct pcf8563
*pcf8563
= i2c_get_clientdata(client
);
203 unsigned char buf
[9];
206 err
= pcf8563_read_block_data(client
, PCF8563_REG_ST1
, 9, buf
);
210 if (buf
[PCF8563_REG_SC
] & PCF8563_SC_LV
) {
211 pcf8563
->voltage_low
= 1;
212 dev_err(&client
->dev
,
213 "low voltage detected, date/time is not reliable.\n");
217 dev_dbg(&client
->dev
,
218 "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
219 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
221 buf
[0], buf
[1], buf
[2], buf
[3],
222 buf
[4], buf
[5], buf
[6], buf
[7],
226 tm
->tm_sec
= bcd2bin(buf
[PCF8563_REG_SC
] & 0x7F);
227 tm
->tm_min
= bcd2bin(buf
[PCF8563_REG_MN
] & 0x7F);
228 tm
->tm_hour
= bcd2bin(buf
[PCF8563_REG_HR
] & 0x3F); /* rtc hr 0-23 */
229 tm
->tm_mday
= bcd2bin(buf
[PCF8563_REG_DM
] & 0x3F);
230 tm
->tm_wday
= buf
[PCF8563_REG_DW
] & 0x07;
231 tm
->tm_mon
= bcd2bin(buf
[PCF8563_REG_MO
] & 0x1F) - 1; /* rtc mn 1-12 */
232 tm
->tm_year
= bcd2bin(buf
[PCF8563_REG_YR
]) + 100;
233 /* detect the polarity heuristically. see note above. */
234 pcf8563
->c_polarity
= (buf
[PCF8563_REG_MO
] & PCF8563_MO_C
) ?
235 (tm
->tm_year
>= 100) : (tm
->tm_year
< 100);
237 dev_dbg(&client
->dev
, "%s: tm is secs=%d, mins=%d, hours=%d, "
238 "mday=%d, mon=%d, year=%d, wday=%d\n",
240 tm
->tm_sec
, tm
->tm_min
, tm
->tm_hour
,
241 tm
->tm_mday
, tm
->tm_mon
, tm
->tm_year
, tm
->tm_wday
);
246 static int pcf8563_rtc_set_time(struct device
*dev
, struct rtc_time
*tm
)
248 struct i2c_client
*client
= to_i2c_client(dev
);
249 struct pcf8563
*pcf8563
= i2c_get_clientdata(client
);
250 unsigned char buf
[9];
252 dev_dbg(&client
->dev
, "%s: secs=%d, mins=%d, hours=%d, "
253 "mday=%d, mon=%d, year=%d, wday=%d\n",
255 tm
->tm_sec
, tm
->tm_min
, tm
->tm_hour
,
256 tm
->tm_mday
, tm
->tm_mon
, tm
->tm_year
, tm
->tm_wday
);
258 /* hours, minutes and seconds */
259 buf
[PCF8563_REG_SC
] = bin2bcd(tm
->tm_sec
);
260 buf
[PCF8563_REG_MN
] = bin2bcd(tm
->tm_min
);
261 buf
[PCF8563_REG_HR
] = bin2bcd(tm
->tm_hour
);
263 buf
[PCF8563_REG_DM
] = bin2bcd(tm
->tm_mday
);
266 buf
[PCF8563_REG_MO
] = bin2bcd(tm
->tm_mon
+ 1);
268 /* year and century */
269 buf
[PCF8563_REG_YR
] = bin2bcd(tm
->tm_year
- 100);
270 if (pcf8563
->c_polarity
? (tm
->tm_year
>= 100) : (tm
->tm_year
< 100))
271 buf
[PCF8563_REG_MO
] |= PCF8563_MO_C
;
273 buf
[PCF8563_REG_DW
] = tm
->tm_wday
& 0x07;
275 return pcf8563_write_block_data(client
, PCF8563_REG_SC
,
276 9 - PCF8563_REG_SC
, buf
+ PCF8563_REG_SC
);
279 #ifdef CONFIG_RTC_INTF_DEV
280 static int pcf8563_rtc_ioctl(struct device
*dev
, unsigned int cmd
, unsigned long arg
)
282 struct pcf8563
*pcf8563
= i2c_get_clientdata(to_i2c_client(dev
));
287 if (pcf8563
->voltage_low
)
288 dev_info(dev
, "low voltage detected, date/time is not reliable.\n");
290 if (copy_to_user((void __user
*)arg
, &pcf8563
->voltage_low
,
296 * Clear the VL bit in the seconds register in case
297 * the time has not been set already (which would
298 * have cleared it). This does not really matter
299 * because of the cached voltage_low value but do it
300 * anyway for consistency.
302 if (pcf8563_rtc_read_time(dev
, &tm
))
303 pcf8563_rtc_set_time(dev
, &tm
);
305 /* Clear the cached value. */
306 pcf8563
->voltage_low
= 0;
314 #define pcf8563_rtc_ioctl NULL
317 static int pcf8563_rtc_read_alarm(struct device
*dev
, struct rtc_wkalrm
*tm
)
319 struct i2c_client
*client
= to_i2c_client(dev
);
320 unsigned char buf
[4];
323 err
= pcf8563_read_block_data(client
, PCF8563_REG_AMN
, 4, buf
);
327 dev_dbg(&client
->dev
,
328 "%s: raw data is min=%02x, hr=%02x, mday=%02x, wday=%02x\n",
329 __func__
, buf
[0], buf
[1], buf
[2], buf
[3]);
332 tm
->time
.tm_min
= bcd2bin(buf
[0] & 0x7F);
333 tm
->time
.tm_hour
= bcd2bin(buf
[1] & 0x3F);
334 tm
->time
.tm_mday
= bcd2bin(buf
[2] & 0x3F);
335 tm
->time
.tm_wday
= bcd2bin(buf
[3] & 0x7);
337 err
= pcf8563_get_alarm_mode(client
, &tm
->enabled
, &tm
->pending
);
341 dev_dbg(&client
->dev
, "%s: tm is mins=%d, hours=%d, mday=%d, wday=%d,"
342 " enabled=%d, pending=%d\n", __func__
, tm
->time
.tm_min
,
343 tm
->time
.tm_hour
, tm
->time
.tm_mday
, tm
->time
.tm_wday
,
344 tm
->enabled
, tm
->pending
);
349 static int pcf8563_rtc_set_alarm(struct device
*dev
, struct rtc_wkalrm
*tm
)
351 struct i2c_client
*client
= to_i2c_client(dev
);
352 unsigned char buf
[4];
355 /* The alarm has no seconds, round up to nearest minute */
356 if (tm
->time
.tm_sec
) {
357 time64_t alarm_time
= rtc_tm_to_time64(&tm
->time
);
359 alarm_time
+= 60 - tm
->time
.tm_sec
;
360 rtc_time64_to_tm(alarm_time
, &tm
->time
);
363 dev_dbg(dev
, "%s, min=%d hour=%d wday=%d mday=%d "
364 "enabled=%d pending=%d\n", __func__
,
365 tm
->time
.tm_min
, tm
->time
.tm_hour
, tm
->time
.tm_wday
,
366 tm
->time
.tm_mday
, tm
->enabled
, tm
->pending
);
368 buf
[0] = bin2bcd(tm
->time
.tm_min
);
369 buf
[1] = bin2bcd(tm
->time
.tm_hour
);
370 buf
[2] = bin2bcd(tm
->time
.tm_mday
);
371 buf
[3] = tm
->time
.tm_wday
& 0x07;
373 err
= pcf8563_write_block_data(client
, PCF8563_REG_AMN
, 4, buf
);
377 return pcf8563_set_alarm_mode(client
, !!tm
->enabled
);
380 static int pcf8563_irq_enable(struct device
*dev
, unsigned int enabled
)
382 dev_dbg(dev
, "%s: en=%d\n", __func__
, enabled
);
383 return pcf8563_set_alarm_mode(to_i2c_client(dev
), !!enabled
);
386 #ifdef CONFIG_COMMON_CLK
388 * Handling of the clkout
391 #define clkout_hw_to_pcf8563(_hw) container_of(_hw, struct pcf8563, clkout_hw)
393 static const int clkout_rates
[] = {
400 static unsigned long pcf8563_clkout_recalc_rate(struct clk_hw
*hw
,
401 unsigned long parent_rate
)
403 struct pcf8563
*pcf8563
= clkout_hw_to_pcf8563(hw
);
404 struct i2c_client
*client
= pcf8563
->client
;
406 int ret
= pcf8563_read_block_data(client
, PCF8563_REG_CLKO
, 1, &buf
);
411 buf
&= PCF8563_REG_CLKO_F_MASK
;
412 return clkout_rates
[buf
];
415 static long pcf8563_clkout_round_rate(struct clk_hw
*hw
, unsigned long rate
,
416 unsigned long *prate
)
420 for (i
= 0; i
< ARRAY_SIZE(clkout_rates
); i
++)
421 if (clkout_rates
[i
] <= rate
)
422 return clkout_rates
[i
];
427 static int pcf8563_clkout_set_rate(struct clk_hw
*hw
, unsigned long rate
,
428 unsigned long parent_rate
)
430 struct pcf8563
*pcf8563
= clkout_hw_to_pcf8563(hw
);
431 struct i2c_client
*client
= pcf8563
->client
;
433 int ret
= pcf8563_read_block_data(client
, PCF8563_REG_CLKO
, 1, &buf
);
439 for (i
= 0; i
< ARRAY_SIZE(clkout_rates
); i
++)
440 if (clkout_rates
[i
] == rate
) {
441 buf
&= ~PCF8563_REG_CLKO_F_MASK
;
443 ret
= pcf8563_write_block_data(client
,
452 static int pcf8563_clkout_control(struct clk_hw
*hw
, bool enable
)
454 struct pcf8563
*pcf8563
= clkout_hw_to_pcf8563(hw
);
455 struct i2c_client
*client
= pcf8563
->client
;
457 int ret
= pcf8563_read_block_data(client
, PCF8563_REG_CLKO
, 1, &buf
);
463 buf
|= PCF8563_REG_CLKO_FE
;
465 buf
&= ~PCF8563_REG_CLKO_FE
;
467 ret
= pcf8563_write_block_data(client
, PCF8563_REG_CLKO
, 1, &buf
);
471 static int pcf8563_clkout_prepare(struct clk_hw
*hw
)
473 return pcf8563_clkout_control(hw
, 1);
476 static void pcf8563_clkout_unprepare(struct clk_hw
*hw
)
478 pcf8563_clkout_control(hw
, 0);
481 static int pcf8563_clkout_is_prepared(struct clk_hw
*hw
)
483 struct pcf8563
*pcf8563
= clkout_hw_to_pcf8563(hw
);
484 struct i2c_client
*client
= pcf8563
->client
;
486 int ret
= pcf8563_read_block_data(client
, PCF8563_REG_CLKO
, 1, &buf
);
491 return !!(buf
& PCF8563_REG_CLKO_FE
);
494 static const struct clk_ops pcf8563_clkout_ops
= {
495 .prepare
= pcf8563_clkout_prepare
,
496 .unprepare
= pcf8563_clkout_unprepare
,
497 .is_prepared
= pcf8563_clkout_is_prepared
,
498 .recalc_rate
= pcf8563_clkout_recalc_rate
,
499 .round_rate
= pcf8563_clkout_round_rate
,
500 .set_rate
= pcf8563_clkout_set_rate
,
503 static struct clk
*pcf8563_clkout_register_clk(struct pcf8563
*pcf8563
)
505 struct i2c_client
*client
= pcf8563
->client
;
506 struct device_node
*node
= client
->dev
.of_node
;
508 struct clk_init_data init
;
512 /* disable the clkout output */
514 ret
= pcf8563_write_block_data(client
, PCF8563_REG_CLKO
, 1, &buf
);
518 init
.name
= "pcf8563-clkout";
519 init
.ops
= &pcf8563_clkout_ops
;
521 init
.parent_names
= NULL
;
522 init
.num_parents
= 0;
523 pcf8563
->clkout_hw
.init
= &init
;
525 /* optional override of the clockname */
526 of_property_read_string(node
, "clock-output-names", &init
.name
);
528 /* register the clock */
529 clk
= devm_clk_register(&client
->dev
, &pcf8563
->clkout_hw
);
532 of_clk_add_provider(node
, of_clk_src_simple_get
, clk
);
538 static const struct rtc_class_ops pcf8563_rtc_ops
= {
539 .ioctl
= pcf8563_rtc_ioctl
,
540 .read_time
= pcf8563_rtc_read_time
,
541 .set_time
= pcf8563_rtc_set_time
,
542 .read_alarm
= pcf8563_rtc_read_alarm
,
543 .set_alarm
= pcf8563_rtc_set_alarm
,
544 .alarm_irq_enable
= pcf8563_irq_enable
,
547 static int pcf8563_probe(struct i2c_client
*client
,
548 const struct i2c_device_id
*id
)
550 struct pcf8563
*pcf8563
;
554 dev_dbg(&client
->dev
, "%s\n", __func__
);
556 if (!i2c_check_functionality(client
->adapter
, I2C_FUNC_I2C
))
559 pcf8563
= devm_kzalloc(&client
->dev
, sizeof(struct pcf8563
),
564 i2c_set_clientdata(client
, pcf8563
);
565 pcf8563
->client
= client
;
566 device_set_wakeup_capable(&client
->dev
, 1);
568 /* Set timer to lowest frequency to save power (ref Haoyu datasheet) */
569 buf
= PCF8563_TMRC_1_60
;
570 err
= pcf8563_write_block_data(client
, PCF8563_REG_TMRC
, 1, &buf
);
572 dev_err(&client
->dev
, "%s: write error\n", __func__
);
576 /* Clear flags and disable interrupts */
578 err
= pcf8563_write_block_data(client
, PCF8563_REG_ST2
, 1, &buf
);
580 dev_err(&client
->dev
, "%s: write error\n", __func__
);
584 pcf8563
->rtc
= devm_rtc_allocate_device(&client
->dev
);
585 if (IS_ERR(pcf8563
->rtc
))
586 return PTR_ERR(pcf8563
->rtc
);
588 pcf8563
->rtc
->ops
= &pcf8563_rtc_ops
;
589 /* the pcf8563 alarm only supports a minute accuracy */
590 pcf8563
->rtc
->uie_unsupported
= 1;
591 pcf8563
->rtc
->range_min
= RTC_TIMESTAMP_BEGIN_2000
;
592 pcf8563
->rtc
->range_max
= RTC_TIMESTAMP_END_2099
;
593 pcf8563
->rtc
->set_start_time
= true;
595 if (client
->irq
> 0) {
596 err
= devm_request_threaded_irq(&client
->dev
, client
->irq
,
598 IRQF_SHARED
| IRQF_ONESHOT
| IRQF_TRIGGER_LOW
,
599 pcf8563_driver
.driver
.name
, client
);
601 dev_err(&client
->dev
, "unable to request IRQ %d\n",
607 err
= rtc_register_device(pcf8563
->rtc
);
611 #ifdef CONFIG_COMMON_CLK
612 /* register clk in common clk framework */
613 pcf8563_clkout_register_clk(pcf8563
);
619 static const struct i2c_device_id pcf8563_id
[] = {
624 MODULE_DEVICE_TABLE(i2c
, pcf8563_id
);
627 static const struct of_device_id pcf8563_of_match
[] = {
628 { .compatible
= "nxp,pcf8563" },
629 { .compatible
= "epson,rtc8564" },
630 { .compatible
= "microcrystal,rv8564" },
633 MODULE_DEVICE_TABLE(of
, pcf8563_of_match
);
636 static struct i2c_driver pcf8563_driver
= {
638 .name
= "rtc-pcf8563",
639 .of_match_table
= of_match_ptr(pcf8563_of_match
),
641 .probe
= pcf8563_probe
,
642 .id_table
= pcf8563_id
,
645 module_i2c_driver(pcf8563_driver
);
647 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
648 MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
649 MODULE_LICENSE("GPL");