2 * An I2C driver for the Philips PCF8563 RTC
3 * Copyright 2005-06 Tower Technologies
5 * Author: Alessandro Zummo <a.zummo@towertech.it>
6 * Maintainers: http://www.nslu2-linux.org/
8 * based on the other drivers in this same directory.
10 * http://www.semiconductors.philips.com/acrobat/datasheets/PCF8563-04.pdf
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
17 #include <linux/clk-provider.h>
18 #include <linux/i2c.h>
19 #include <linux/bcd.h>
20 #include <linux/rtc.h>
21 #include <linux/slab.h>
22 #include <linux/module.h>
24 #include <linux/err.h>
26 #define PCF8563_REG_ST1 0x00 /* status */
27 #define PCF8563_REG_ST2 0x01
28 #define PCF8563_BIT_AIE (1 << 1)
29 #define PCF8563_BIT_AF (1 << 3)
30 #define PCF8563_BITS_ST2_N (7 << 5)
32 #define PCF8563_REG_SC 0x02 /* datetime */
33 #define PCF8563_REG_MN 0x03
34 #define PCF8563_REG_HR 0x04
35 #define PCF8563_REG_DM 0x05
36 #define PCF8563_REG_DW 0x06
37 #define PCF8563_REG_MO 0x07
38 #define PCF8563_REG_YR 0x08
40 #define PCF8563_REG_AMN 0x09 /* alarm */
42 #define PCF8563_REG_CLKO 0x0D /* clock out */
43 #define PCF8563_REG_CLKO_FE 0x80 /* clock out enabled */
44 #define PCF8563_REG_CLKO_F_MASK 0x03 /* frequenc mask */
45 #define PCF8563_REG_CLKO_F_32768HZ 0x00
46 #define PCF8563_REG_CLKO_F_1024HZ 0x01
47 #define PCF8563_REG_CLKO_F_32HZ 0x02
48 #define PCF8563_REG_CLKO_F_1HZ 0x03
50 #define PCF8563_REG_TMRC 0x0E /* timer control */
51 #define PCF8563_TMRC_ENABLE BIT(7)
52 #define PCF8563_TMRC_4096 0
53 #define PCF8563_TMRC_64 1
54 #define PCF8563_TMRC_1 2
55 #define PCF8563_TMRC_1_60 3
56 #define PCF8563_TMRC_MASK 3
58 #define PCF8563_REG_TMR 0x0F /* timer */
60 #define PCF8563_SC_LV 0x80 /* low voltage */
61 #define PCF8563_MO_C 0x80 /* century */
63 static struct i2c_driver pcf8563_driver
;
66 struct rtc_device
*rtc
;
68 * The meaning of MO_C bit varies by the chip type.
69 * From PCF8563 datasheet: this bit is toggled when the years
70 * register overflows from 99 to 00
71 * 0 indicates the century is 20xx
72 * 1 indicates the century is 19xx
73 * From RTC8564 datasheet: this bit indicates change of
74 * century. When the year digit data overflows from 99 to 00,
75 * this bit is set. By presetting it to 0 while still in the
76 * 20th century, it will be set in year 2000, ...
77 * There seems no reliable way to know how the system use this
78 * bit. So let's do it heuristically, assuming we are live in
81 int c_polarity
; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
82 int voltage_low
; /* incicates if a low_voltage was detected */
84 struct i2c_client
*client
;
85 #ifdef CONFIG_COMMON_CLK
86 struct clk_hw clkout_hw
;
90 static int pcf8563_read_block_data(struct i2c_client
*client
, unsigned char reg
,
91 unsigned char length
, unsigned char *buf
)
93 struct i2c_msg msgs
[] = {
100 .addr
= client
->addr
,
107 if ((i2c_transfer(client
->adapter
, msgs
, 2)) != 2) {
108 dev_err(&client
->dev
, "%s: read error\n", __func__
);
115 static int pcf8563_write_block_data(struct i2c_client
*client
,
116 unsigned char reg
, unsigned char length
,
121 for (i
= 0; i
< length
; i
++) {
122 unsigned char data
[2] = { reg
+ i
, buf
[i
] };
124 err
= i2c_master_send(client
, data
, sizeof(data
));
125 if (err
!= sizeof(data
)) {
126 dev_err(&client
->dev
,
127 "%s: err=%d addr=%02x, data=%02x\n",
128 __func__
, err
, data
[0], data
[1]);
136 static int pcf8563_set_alarm_mode(struct i2c_client
*client
, bool on
)
141 err
= pcf8563_read_block_data(client
, PCF8563_REG_ST2
, 1, &buf
);
146 buf
|= PCF8563_BIT_AIE
;
148 buf
&= ~PCF8563_BIT_AIE
;
150 buf
&= ~(PCF8563_BIT_AF
| PCF8563_BITS_ST2_N
);
152 err
= pcf8563_write_block_data(client
, PCF8563_REG_ST2
, 1, &buf
);
154 dev_err(&client
->dev
, "%s: write error\n", __func__
);
161 static int pcf8563_get_alarm_mode(struct i2c_client
*client
, unsigned char *en
,
167 err
= pcf8563_read_block_data(client
, PCF8563_REG_ST2
, 1, &buf
);
172 *en
= !!(buf
& PCF8563_BIT_AIE
);
174 *pen
= !!(buf
& PCF8563_BIT_AF
);
179 static irqreturn_t
pcf8563_irq(int irq
, void *dev_id
)
181 struct pcf8563
*pcf8563
= i2c_get_clientdata(dev_id
);
185 err
= pcf8563_get_alarm_mode(pcf8563
->client
, NULL
, &pending
);
190 rtc_update_irq(pcf8563
->rtc
, 1, RTC_IRQF
| RTC_AF
);
191 pcf8563_set_alarm_mode(pcf8563
->client
, 1);
199 * In the routines that deal directly with the pcf8563 hardware, we use
200 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
202 static int pcf8563_get_datetime(struct i2c_client
*client
, struct rtc_time
*tm
)
204 struct pcf8563
*pcf8563
= i2c_get_clientdata(client
);
205 unsigned char buf
[9];
208 err
= pcf8563_read_block_data(client
, PCF8563_REG_ST1
, 9, buf
);
212 if (buf
[PCF8563_REG_SC
] & PCF8563_SC_LV
) {
213 pcf8563
->voltage_low
= 1;
214 dev_err(&client
->dev
,
215 "low voltage detected, date/time is not reliable.\n");
219 dev_dbg(&client
->dev
,
220 "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
221 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
223 buf
[0], buf
[1], buf
[2], buf
[3],
224 buf
[4], buf
[5], buf
[6], buf
[7],
228 tm
->tm_sec
= bcd2bin(buf
[PCF8563_REG_SC
] & 0x7F);
229 tm
->tm_min
= bcd2bin(buf
[PCF8563_REG_MN
] & 0x7F);
230 tm
->tm_hour
= bcd2bin(buf
[PCF8563_REG_HR
] & 0x3F); /* rtc hr 0-23 */
231 tm
->tm_mday
= bcd2bin(buf
[PCF8563_REG_DM
] & 0x3F);
232 tm
->tm_wday
= buf
[PCF8563_REG_DW
] & 0x07;
233 tm
->tm_mon
= bcd2bin(buf
[PCF8563_REG_MO
] & 0x1F) - 1; /* rtc mn 1-12 */
234 tm
->tm_year
= bcd2bin(buf
[PCF8563_REG_YR
]);
235 if (tm
->tm_year
< 70)
236 tm
->tm_year
+= 100; /* assume we are in 1970...2069 */
237 /* detect the polarity heuristically. see note above. */
238 pcf8563
->c_polarity
= (buf
[PCF8563_REG_MO
] & PCF8563_MO_C
) ?
239 (tm
->tm_year
>= 100) : (tm
->tm_year
< 100);
241 dev_dbg(&client
->dev
, "%s: tm is secs=%d, mins=%d, hours=%d, "
242 "mday=%d, mon=%d, year=%d, wday=%d\n",
244 tm
->tm_sec
, tm
->tm_min
, tm
->tm_hour
,
245 tm
->tm_mday
, tm
->tm_mon
, tm
->tm_year
, tm
->tm_wday
);
250 static int pcf8563_set_datetime(struct i2c_client
*client
, struct rtc_time
*tm
)
252 struct pcf8563
*pcf8563
= i2c_get_clientdata(client
);
253 unsigned char buf
[9];
255 dev_dbg(&client
->dev
, "%s: secs=%d, mins=%d, hours=%d, "
256 "mday=%d, mon=%d, year=%d, wday=%d\n",
258 tm
->tm_sec
, tm
->tm_min
, tm
->tm_hour
,
259 tm
->tm_mday
, tm
->tm_mon
, tm
->tm_year
, tm
->tm_wday
);
261 /* hours, minutes and seconds */
262 buf
[PCF8563_REG_SC
] = bin2bcd(tm
->tm_sec
);
263 buf
[PCF8563_REG_MN
] = bin2bcd(tm
->tm_min
);
264 buf
[PCF8563_REG_HR
] = bin2bcd(tm
->tm_hour
);
266 buf
[PCF8563_REG_DM
] = bin2bcd(tm
->tm_mday
);
269 buf
[PCF8563_REG_MO
] = bin2bcd(tm
->tm_mon
+ 1);
271 /* year and century */
272 buf
[PCF8563_REG_YR
] = bin2bcd(tm
->tm_year
% 100);
273 if (pcf8563
->c_polarity
? (tm
->tm_year
>= 100) : (tm
->tm_year
< 100))
274 buf
[PCF8563_REG_MO
] |= PCF8563_MO_C
;
276 buf
[PCF8563_REG_DW
] = tm
->tm_wday
& 0x07;
278 return pcf8563_write_block_data(client
, PCF8563_REG_SC
,
279 9 - PCF8563_REG_SC
, buf
+ PCF8563_REG_SC
);
282 #ifdef CONFIG_RTC_INTF_DEV
283 static int pcf8563_rtc_ioctl(struct device
*dev
, unsigned int cmd
, unsigned long arg
)
285 struct pcf8563
*pcf8563
= i2c_get_clientdata(to_i2c_client(dev
));
290 if (pcf8563
->voltage_low
)
291 dev_info(dev
, "low voltage detected, date/time is not reliable.\n");
293 if (copy_to_user((void __user
*)arg
, &pcf8563
->voltage_low
,
299 * Clear the VL bit in the seconds register in case
300 * the time has not been set already (which would
301 * have cleared it). This does not really matter
302 * because of the cached voltage_low value but do it
303 * anyway for consistency.
305 if (pcf8563_get_datetime(to_i2c_client(dev
), &tm
))
306 pcf8563_set_datetime(to_i2c_client(dev
), &tm
);
308 /* Clear the cached value. */
309 pcf8563
->voltage_low
= 0;
317 #define pcf8563_rtc_ioctl NULL
320 static int pcf8563_rtc_read_time(struct device
*dev
, struct rtc_time
*tm
)
322 return pcf8563_get_datetime(to_i2c_client(dev
), tm
);
325 static int pcf8563_rtc_set_time(struct device
*dev
, struct rtc_time
*tm
)
327 return pcf8563_set_datetime(to_i2c_client(dev
), tm
);
330 static int pcf8563_rtc_read_alarm(struct device
*dev
, struct rtc_wkalrm
*tm
)
332 struct i2c_client
*client
= to_i2c_client(dev
);
333 unsigned char buf
[4];
336 err
= pcf8563_read_block_data(client
, PCF8563_REG_AMN
, 4, buf
);
340 dev_dbg(&client
->dev
,
341 "%s: raw data is min=%02x, hr=%02x, mday=%02x, wday=%02x\n",
342 __func__
, buf
[0], buf
[1], buf
[2], buf
[3]);
345 tm
->time
.tm_min
= bcd2bin(buf
[0] & 0x7F);
346 tm
->time
.tm_hour
= bcd2bin(buf
[1] & 0x3F);
347 tm
->time
.tm_mday
= bcd2bin(buf
[2] & 0x3F);
348 tm
->time
.tm_wday
= bcd2bin(buf
[3] & 0x7);
350 err
= pcf8563_get_alarm_mode(client
, &tm
->enabled
, &tm
->pending
);
354 dev_dbg(&client
->dev
, "%s: tm is mins=%d, hours=%d, mday=%d, wday=%d,"
355 " enabled=%d, pending=%d\n", __func__
, tm
->time
.tm_min
,
356 tm
->time
.tm_hour
, tm
->time
.tm_mday
, tm
->time
.tm_wday
,
357 tm
->enabled
, tm
->pending
);
362 static int pcf8563_rtc_set_alarm(struct device
*dev
, struct rtc_wkalrm
*tm
)
364 struct i2c_client
*client
= to_i2c_client(dev
);
365 unsigned char buf
[4];
368 /* The alarm has no seconds, round up to nearest minute */
369 if (tm
->time
.tm_sec
) {
370 time64_t alarm_time
= rtc_tm_to_time64(&tm
->time
);
372 alarm_time
+= 60 - tm
->time
.tm_sec
;
373 rtc_time64_to_tm(alarm_time
, &tm
->time
);
376 dev_dbg(dev
, "%s, min=%d hour=%d wday=%d mday=%d "
377 "enabled=%d pending=%d\n", __func__
,
378 tm
->time
.tm_min
, tm
->time
.tm_hour
, tm
->time
.tm_wday
,
379 tm
->time
.tm_mday
, tm
->enabled
, tm
->pending
);
381 buf
[0] = bin2bcd(tm
->time
.tm_min
);
382 buf
[1] = bin2bcd(tm
->time
.tm_hour
);
383 buf
[2] = bin2bcd(tm
->time
.tm_mday
);
384 buf
[3] = tm
->time
.tm_wday
& 0x07;
386 err
= pcf8563_write_block_data(client
, PCF8563_REG_AMN
, 4, buf
);
390 return pcf8563_set_alarm_mode(client
, 1);
393 static int pcf8563_irq_enable(struct device
*dev
, unsigned int enabled
)
395 dev_dbg(dev
, "%s: en=%d\n", __func__
, enabled
);
396 return pcf8563_set_alarm_mode(to_i2c_client(dev
), !!enabled
);
399 #ifdef CONFIG_COMMON_CLK
401 * Handling of the clkout
404 #define clkout_hw_to_pcf8563(_hw) container_of(_hw, struct pcf8563, clkout_hw)
406 static int clkout_rates
[] = {
413 static unsigned long pcf8563_clkout_recalc_rate(struct clk_hw
*hw
,
414 unsigned long parent_rate
)
416 struct pcf8563
*pcf8563
= clkout_hw_to_pcf8563(hw
);
417 struct i2c_client
*client
= pcf8563
->client
;
419 int ret
= pcf8563_read_block_data(client
, PCF8563_REG_CLKO
, 1, &buf
);
424 buf
&= PCF8563_REG_CLKO_F_MASK
;
425 return clkout_rates
[buf
];
428 static long pcf8563_clkout_round_rate(struct clk_hw
*hw
, unsigned long rate
,
429 unsigned long *prate
)
433 for (i
= 0; i
< ARRAY_SIZE(clkout_rates
); i
++)
434 if (clkout_rates
[i
] <= rate
)
435 return clkout_rates
[i
];
440 static int pcf8563_clkout_set_rate(struct clk_hw
*hw
, unsigned long rate
,
441 unsigned long parent_rate
)
443 struct pcf8563
*pcf8563
= clkout_hw_to_pcf8563(hw
);
444 struct i2c_client
*client
= pcf8563
->client
;
446 int ret
= pcf8563_read_block_data(client
, PCF8563_REG_CLKO
, 1, &buf
);
452 for (i
= 0; i
< ARRAY_SIZE(clkout_rates
); i
++)
453 if (clkout_rates
[i
] == rate
) {
454 buf
&= ~PCF8563_REG_CLKO_F_MASK
;
456 ret
= pcf8563_write_block_data(client
,
465 static int pcf8563_clkout_control(struct clk_hw
*hw
, bool enable
)
467 struct pcf8563
*pcf8563
= clkout_hw_to_pcf8563(hw
);
468 struct i2c_client
*client
= pcf8563
->client
;
470 int ret
= pcf8563_read_block_data(client
, PCF8563_REG_CLKO
, 1, &buf
);
476 buf
|= PCF8563_REG_CLKO_FE
;
478 buf
&= ~PCF8563_REG_CLKO_FE
;
480 ret
= pcf8563_write_block_data(client
, PCF8563_REG_CLKO
, 1, &buf
);
484 static int pcf8563_clkout_prepare(struct clk_hw
*hw
)
486 return pcf8563_clkout_control(hw
, 1);
489 static void pcf8563_clkout_unprepare(struct clk_hw
*hw
)
491 pcf8563_clkout_control(hw
, 0);
494 static int pcf8563_clkout_is_prepared(struct clk_hw
*hw
)
496 struct pcf8563
*pcf8563
= clkout_hw_to_pcf8563(hw
);
497 struct i2c_client
*client
= pcf8563
->client
;
499 int ret
= pcf8563_read_block_data(client
, PCF8563_REG_CLKO
, 1, &buf
);
504 return !!(buf
& PCF8563_REG_CLKO_FE
);
507 static const struct clk_ops pcf8563_clkout_ops
= {
508 .prepare
= pcf8563_clkout_prepare
,
509 .unprepare
= pcf8563_clkout_unprepare
,
510 .is_prepared
= pcf8563_clkout_is_prepared
,
511 .recalc_rate
= pcf8563_clkout_recalc_rate
,
512 .round_rate
= pcf8563_clkout_round_rate
,
513 .set_rate
= pcf8563_clkout_set_rate
,
516 static struct clk
*pcf8563_clkout_register_clk(struct pcf8563
*pcf8563
)
518 struct i2c_client
*client
= pcf8563
->client
;
519 struct device_node
*node
= client
->dev
.of_node
;
521 struct clk_init_data init
;
525 /* disable the clkout output */
527 ret
= pcf8563_write_block_data(client
, PCF8563_REG_CLKO
, 1, &buf
);
531 init
.name
= "pcf8563-clkout";
532 init
.ops
= &pcf8563_clkout_ops
;
534 init
.parent_names
= NULL
;
535 init
.num_parents
= 0;
536 pcf8563
->clkout_hw
.init
= &init
;
538 /* optional override of the clockname */
539 of_property_read_string(node
, "clock-output-names", &init
.name
);
541 /* register the clock */
542 clk
= devm_clk_register(&client
->dev
, &pcf8563
->clkout_hw
);
545 of_clk_add_provider(node
, of_clk_src_simple_get
, clk
);
551 static const struct rtc_class_ops pcf8563_rtc_ops
= {
552 .ioctl
= pcf8563_rtc_ioctl
,
553 .read_time
= pcf8563_rtc_read_time
,
554 .set_time
= pcf8563_rtc_set_time
,
555 .read_alarm
= pcf8563_rtc_read_alarm
,
556 .set_alarm
= pcf8563_rtc_set_alarm
,
557 .alarm_irq_enable
= pcf8563_irq_enable
,
560 static int pcf8563_probe(struct i2c_client
*client
,
561 const struct i2c_device_id
*id
)
563 struct pcf8563
*pcf8563
;
566 unsigned char alm_pending
;
568 dev_dbg(&client
->dev
, "%s\n", __func__
);
570 if (!i2c_check_functionality(client
->adapter
, I2C_FUNC_I2C
))
573 pcf8563
= devm_kzalloc(&client
->dev
, sizeof(struct pcf8563
),
578 i2c_set_clientdata(client
, pcf8563
);
579 pcf8563
->client
= client
;
580 device_set_wakeup_capable(&client
->dev
, 1);
582 /* Set timer to lowest frequency to save power (ref Haoyu datasheet) */
583 buf
= PCF8563_TMRC_1_60
;
584 err
= pcf8563_write_block_data(client
, PCF8563_REG_TMRC
, 1, &buf
);
586 dev_err(&client
->dev
, "%s: write error\n", __func__
);
590 err
= pcf8563_get_alarm_mode(client
, NULL
, &alm_pending
);
592 dev_err(&client
->dev
, "%s: read error\n", __func__
);
596 pcf8563_set_alarm_mode(client
, 0);
598 pcf8563
->rtc
= devm_rtc_device_register(&client
->dev
,
599 pcf8563_driver
.driver
.name
,
600 &pcf8563_rtc_ops
, THIS_MODULE
);
602 if (IS_ERR(pcf8563
->rtc
))
603 return PTR_ERR(pcf8563
->rtc
);
605 if (client
->irq
> 0) {
606 err
= devm_request_threaded_irq(&client
->dev
, client
->irq
,
608 IRQF_SHARED
|IRQF_ONESHOT
|IRQF_TRIGGER_FALLING
,
609 pcf8563
->rtc
->name
, client
);
611 dev_err(&client
->dev
, "unable to request IRQ %d\n",
618 #ifdef CONFIG_COMMON_CLK
619 /* register clk in common clk framework */
620 pcf8563_clkout_register_clk(pcf8563
);
623 /* the pcf8563 alarm only supports a minute accuracy */
624 pcf8563
->rtc
->uie_unsupported
= 1;
629 static const struct i2c_device_id pcf8563_id
[] = {
634 MODULE_DEVICE_TABLE(i2c
, pcf8563_id
);
637 static const struct of_device_id pcf8563_of_match
[] = {
638 { .compatible
= "nxp,pcf8563" },
641 MODULE_DEVICE_TABLE(of
, pcf8563_of_match
);
644 static struct i2c_driver pcf8563_driver
= {
646 .name
= "rtc-pcf8563",
647 .of_match_table
= of_match_ptr(pcf8563_of_match
),
649 .probe
= pcf8563_probe
,
650 .id_table
= pcf8563_id
,
653 module_i2c_driver(pcf8563_driver
);
655 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
656 MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
657 MODULE_LICENSE("GPL");