2 * An rtc driver for the Dallas DS1511
4 * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
5 * Copyright (C) 2007 Andrew Sharp <andy.sharp@lsi.com>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 * Real time clock driver for the Dallas 1511 chip, which also
12 * contains a watchdog timer. There is a tiny amount of code that
13 * platform code could use to mess with the watchdog device a little
14 * bit, but not a full watchdog driver.
17 #include <linux/bcd.h>
18 #include <linux/init.h>
19 #include <linux/kernel.h>
20 #include <linux/delay.h>
21 #include <linux/interrupt.h>
22 #include <linux/rtc.h>
23 #include <linux/platform_device.h>
26 #define DRV_VERSION "0.6"
39 DS1511_AM3_HOUR
= 0xa,
40 DS1511_AM4_DATE
= 0xb,
43 DS1511_CONTROL_A
= 0xe,
44 DS1511_CONTROL_B
= 0xf,
45 DS1511_RAMADDR_LSB
= 0x10,
49 #define DS1511_BLF1 0x80
50 #define DS1511_BLF2 0x40
51 #define DS1511_PRS 0x20
52 #define DS1511_PAB 0x10
53 #define DS1511_TDF 0x08
54 #define DS1511_KSF 0x04
55 #define DS1511_WDF 0x02
56 #define DS1511_IRQF 0x01
57 #define DS1511_TE 0x80
58 #define DS1511_CS 0x40
59 #define DS1511_BME 0x20
60 #define DS1511_TPE 0x10
61 #define DS1511_TIE 0x08
62 #define DS1511_KIE 0x04
63 #define DS1511_WDE 0x02
64 #define DS1511_WDS 0x01
65 #define DS1511_RAM_MAX 0xff
67 #define RTC_CMD DS1511_CONTROL_B
68 #define RTC_CMD1 DS1511_CONTROL_A
70 #define RTC_ALARM_SEC DS1511_AM1_SEC
71 #define RTC_ALARM_MIN DS1511_AM2_MIN
72 #define RTC_ALARM_HOUR DS1511_AM3_HOUR
73 #define RTC_ALARM_DATE DS1511_AM4_DATE
75 #define RTC_SEC DS1511_SEC
76 #define RTC_MIN DS1511_MIN
77 #define RTC_HOUR DS1511_HOUR
78 #define RTC_DOW DS1511_DOW
79 #define RTC_DOM DS1511_DOM
80 #define RTC_MON DS1511_MONTH
81 #define RTC_YEAR DS1511_YEAR
82 #define RTC_CENTURY DS1511_CENTURY
84 #define RTC_TIE DS1511_TIE
85 #define RTC_TE DS1511_TE
87 struct rtc_plat_data
{
88 struct rtc_device
*rtc
;
89 void __iomem
*ioaddr
; /* virtual base address */
90 int size
; /* amount of memory mapped */
100 static DEFINE_SPINLOCK(ds1511_lock
);
102 static __iomem
char *ds1511_base
;
103 static u32 reg_spacing
= 1;
106 rtc_write(uint8_t val
, uint32_t reg
)
108 writeb(val
, ds1511_base
+ (reg
* reg_spacing
));
112 rtc_write_alarm(uint8_t val
, enum ds1511reg reg
)
114 rtc_write((val
| 0x80), reg
);
117 static noinline
uint8_t
118 rtc_read(enum ds1511reg reg
)
120 return readb(ds1511_base
+ (reg
* reg_spacing
));
124 rtc_disable_update(void)
126 rtc_write((rtc_read(RTC_CMD
) & ~RTC_TE
), RTC_CMD
);
130 rtc_enable_update(void)
132 rtc_write((rtc_read(RTC_CMD
) | RTC_TE
), RTC_CMD
);
136 * #define DS1511_WDOG_RESET_SUPPORT
138 * Uncomment this if you want to use these routines in
139 * some platform code.
141 #ifdef DS1511_WDOG_RESET_SUPPORT
143 * just enough code to set the watchdog timer so that it
144 * will reboot the system
147 ds1511_wdog_set(unsigned long deciseconds
)
150 * the wdog timer can take 99.99 seconds
152 deciseconds
%= 10000;
154 * set the wdog values in the wdog registers
156 rtc_write(bin2bcd(deciseconds
% 100), DS1511_WD_MSEC
);
157 rtc_write(bin2bcd(deciseconds
/ 100), DS1511_WD_SEC
);
159 * set wdog enable and wdog 'steering' bit to issue a reset
161 rtc_write(DS1511_WDE
| DS1511_WDS
, RTC_CMD
);
165 ds1511_wdog_disable(void)
168 * clear wdog enable and wdog 'steering' bits
170 rtc_write(rtc_read(RTC_CMD
) & ~(DS1511_WDE
| DS1511_WDS
), RTC_CMD
);
172 * clear the wdog counter
174 rtc_write(0, DS1511_WD_MSEC
);
175 rtc_write(0, DS1511_WD_SEC
);
180 * set the rtc chip's idea of the time.
181 * stupidly, some callers call with year unmolested;
182 * and some call with year = year - 1900. thanks.
184 static int ds1511_rtc_set_time(struct device
*dev
, struct rtc_time
*rtc_tm
)
186 u8 mon
, day
, dow
, hrs
, min
, sec
, yrs
, cen
;
190 * won't have to change this for a while
192 if (rtc_tm
->tm_year
< 1900) {
193 rtc_tm
->tm_year
+= 1900;
196 if (rtc_tm
->tm_year
< 1970) {
199 yrs
= rtc_tm
->tm_year
% 100;
200 cen
= rtc_tm
->tm_year
/ 100;
201 mon
= rtc_tm
->tm_mon
+ 1; /* tm_mon starts at zero */
202 day
= rtc_tm
->tm_mday
;
203 dow
= rtc_tm
->tm_wday
& 0x7; /* automatic BCD */
204 hrs
= rtc_tm
->tm_hour
;
205 min
= rtc_tm
->tm_min
;
206 sec
= rtc_tm
->tm_sec
;
208 if ((mon
> 12) || (day
== 0)) {
212 if (day
> rtc_month_days(rtc_tm
->tm_mon
, rtc_tm
->tm_year
)) {
216 if ((hrs
>= 24) || (min
>= 60) || (sec
>= 60)) {
221 * each register is a different number of valid bits
223 sec
= bin2bcd(sec
) & 0x7f;
224 min
= bin2bcd(min
) & 0x7f;
225 hrs
= bin2bcd(hrs
) & 0x3f;
226 day
= bin2bcd(day
) & 0x3f;
227 mon
= bin2bcd(mon
) & 0x1f;
228 yrs
= bin2bcd(yrs
) & 0xff;
229 cen
= bin2bcd(cen
) & 0xff;
231 spin_lock_irqsave(&ds1511_lock
, flags
);
232 rtc_disable_update();
233 rtc_write(cen
, RTC_CENTURY
);
234 rtc_write(yrs
, RTC_YEAR
);
235 rtc_write((rtc_read(RTC_MON
) & 0xe0) | mon
, RTC_MON
);
236 rtc_write(day
, RTC_DOM
);
237 rtc_write(hrs
, RTC_HOUR
);
238 rtc_write(min
, RTC_MIN
);
239 rtc_write(sec
, RTC_SEC
);
240 rtc_write(dow
, RTC_DOW
);
242 spin_unlock_irqrestore(&ds1511_lock
, flags
);
247 static int ds1511_rtc_read_time(struct device
*dev
, struct rtc_time
*rtc_tm
)
249 unsigned int century
;
252 spin_lock_irqsave(&ds1511_lock
, flags
);
253 rtc_disable_update();
255 rtc_tm
->tm_sec
= rtc_read(RTC_SEC
) & 0x7f;
256 rtc_tm
->tm_min
= rtc_read(RTC_MIN
) & 0x7f;
257 rtc_tm
->tm_hour
= rtc_read(RTC_HOUR
) & 0x3f;
258 rtc_tm
->tm_mday
= rtc_read(RTC_DOM
) & 0x3f;
259 rtc_tm
->tm_wday
= rtc_read(RTC_DOW
) & 0x7;
260 rtc_tm
->tm_mon
= rtc_read(RTC_MON
) & 0x1f;
261 rtc_tm
->tm_year
= rtc_read(RTC_YEAR
) & 0x7f;
262 century
= rtc_read(RTC_CENTURY
);
265 spin_unlock_irqrestore(&ds1511_lock
, flags
);
267 rtc_tm
->tm_sec
= bcd2bin(rtc_tm
->tm_sec
);
268 rtc_tm
->tm_min
= bcd2bin(rtc_tm
->tm_min
);
269 rtc_tm
->tm_hour
= bcd2bin(rtc_tm
->tm_hour
);
270 rtc_tm
->tm_mday
= bcd2bin(rtc_tm
->tm_mday
);
271 rtc_tm
->tm_wday
= bcd2bin(rtc_tm
->tm_wday
);
272 rtc_tm
->tm_mon
= bcd2bin(rtc_tm
->tm_mon
);
273 rtc_tm
->tm_year
= bcd2bin(rtc_tm
->tm_year
);
274 century
= bcd2bin(century
) * 100;
277 * Account for differences between how the RTC uses the values
278 * and how they are defined in a struct rtc_time;
280 century
+= rtc_tm
->tm_year
;
281 rtc_tm
->tm_year
= century
- 1900;
285 if (rtc_valid_tm(rtc_tm
) < 0) {
286 dev_err(dev
, "retrieved date/time is not valid.\n");
287 rtc_time_to_tm(0, rtc_tm
);
293 * write the alarm register settings
295 * we only have the use to interrupt every second, otherwise
296 * known as the update interrupt, or the interrupt if the whole
297 * date/hours/mins/secs matches. the ds1511 has many more
298 * permutations, but the kernel doesn't.
301 ds1511_rtc_update_alarm(struct rtc_plat_data
*pdata
)
305 spin_lock_irqsave(&pdata
->lock
, flags
);
306 rtc_write(pdata
->alrm_mday
< 0 || (pdata
->irqen
& RTC_UF
) ?
307 0x80 : bin2bcd(pdata
->alrm_mday
) & 0x3f,
309 rtc_write(pdata
->alrm_hour
< 0 || (pdata
->irqen
& RTC_UF
) ?
310 0x80 : bin2bcd(pdata
->alrm_hour
) & 0x3f,
312 rtc_write(pdata
->alrm_min
< 0 || (pdata
->irqen
& RTC_UF
) ?
313 0x80 : bin2bcd(pdata
->alrm_min
) & 0x7f,
315 rtc_write(pdata
->alrm_sec
< 0 || (pdata
->irqen
& RTC_UF
) ?
316 0x80 : bin2bcd(pdata
->alrm_sec
) & 0x7f,
318 rtc_write(rtc_read(RTC_CMD
) | (pdata
->irqen
? RTC_TIE
: 0), RTC_CMD
);
319 rtc_read(RTC_CMD1
); /* clear interrupts */
320 spin_unlock_irqrestore(&pdata
->lock
, flags
);
324 ds1511_rtc_set_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
326 struct platform_device
*pdev
= to_platform_device(dev
);
327 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
332 pdata
->alrm_mday
= alrm
->time
.tm_mday
;
333 pdata
->alrm_hour
= alrm
->time
.tm_hour
;
334 pdata
->alrm_min
= alrm
->time
.tm_min
;
335 pdata
->alrm_sec
= alrm
->time
.tm_sec
;
337 pdata
->irqen
|= RTC_AF
;
339 ds1511_rtc_update_alarm(pdata
);
344 ds1511_rtc_read_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
346 struct platform_device
*pdev
= to_platform_device(dev
);
347 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
352 alrm
->time
.tm_mday
= pdata
->alrm_mday
< 0 ? 0 : pdata
->alrm_mday
;
353 alrm
->time
.tm_hour
= pdata
->alrm_hour
< 0 ? 0 : pdata
->alrm_hour
;
354 alrm
->time
.tm_min
= pdata
->alrm_min
< 0 ? 0 : pdata
->alrm_min
;
355 alrm
->time
.tm_sec
= pdata
->alrm_sec
< 0 ? 0 : pdata
->alrm_sec
;
356 alrm
->enabled
= (pdata
->irqen
& RTC_AF
) ? 1 : 0;
361 ds1511_interrupt(int irq
, void *dev_id
)
363 struct platform_device
*pdev
= dev_id
;
364 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
365 unsigned long events
= 0;
367 spin_lock(&pdata
->lock
);
369 * read and clear interrupt
371 if (rtc_read(RTC_CMD1
) & DS1511_IRQF
) {
373 if (rtc_read(RTC_ALARM_SEC
) & 0x80)
377 if (likely(pdata
->rtc
))
378 rtc_update_irq(pdata
->rtc
, 1, events
);
380 spin_unlock(&pdata
->lock
);
381 return events
? IRQ_HANDLED
: IRQ_NONE
;
384 static int ds1511_rtc_alarm_irq_enable(struct device
*dev
, unsigned int enabled
)
386 struct platform_device
*pdev
= to_platform_device(dev
);
387 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
392 pdata
->irqen
|= RTC_AF
;
394 pdata
->irqen
&= ~RTC_AF
;
395 ds1511_rtc_update_alarm(pdata
);
399 static int ds1511_rtc_update_irq_enable(struct device
*dev
,
400 unsigned int enabled
)
402 struct platform_device
*pdev
= to_platform_device(dev
);
403 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
408 pdata
->irqen
|= RTC_UF
;
410 pdata
->irqen
&= ~RTC_UF
;
411 ds1511_rtc_update_alarm(pdata
);
415 static const struct rtc_class_ops ds1511_rtc_ops
= {
416 .read_time
= ds1511_rtc_read_time
,
417 .set_time
= ds1511_rtc_set_time
,
418 .read_alarm
= ds1511_rtc_read_alarm
,
419 .set_alarm
= ds1511_rtc_set_alarm
,
420 .alarm_irq_enable
= ds1511_rtc_alarm_irq_enable
,
421 .update_irq_enable
= ds1511_rtc_update_irq_enable
,
425 ds1511_nvram_read(struct kobject
*kobj
, struct bin_attribute
*ba
,
426 char *buf
, loff_t pos
, size_t size
)
431 * if count is more than one, turn on "burst" mode
432 * turn it off when you're done
435 rtc_write((rtc_read(RTC_CMD
) | DS1511_BME
), RTC_CMD
);
437 if (pos
> DS1511_RAM_MAX
) {
438 pos
= DS1511_RAM_MAX
;
440 if (size
+ pos
> DS1511_RAM_MAX
+ 1) {
441 size
= DS1511_RAM_MAX
- pos
+ 1;
443 rtc_write(pos
, DS1511_RAMADDR_LSB
);
444 for (count
= 0; size
> 0; count
++, size
--) {
445 *buf
++ = rtc_read(DS1511_RAMDATA
);
448 rtc_write((rtc_read(RTC_CMD
) & ~DS1511_BME
), RTC_CMD
);
454 ds1511_nvram_write(struct kobject
*kobj
, struct bin_attribute
*bin_attr
,
455 char *buf
, loff_t pos
, size_t size
)
460 * if count is more than one, turn on "burst" mode
461 * turn it off when you're done
464 rtc_write((rtc_read(RTC_CMD
) | DS1511_BME
), RTC_CMD
);
466 if (pos
> DS1511_RAM_MAX
) {
467 pos
= DS1511_RAM_MAX
;
469 if (size
+ pos
> DS1511_RAM_MAX
+ 1) {
470 size
= DS1511_RAM_MAX
- pos
+ 1;
472 rtc_write(pos
, DS1511_RAMADDR_LSB
);
473 for (count
= 0; size
> 0; count
++, size
--) {
474 rtc_write(*buf
++, DS1511_RAMDATA
);
477 rtc_write((rtc_read(RTC_CMD
) & ~DS1511_BME
), RTC_CMD
);
482 static struct bin_attribute ds1511_nvram_attr
= {
485 .mode
= S_IRUGO
| S_IWUGO
,
487 .size
= DS1511_RAM_MAX
,
488 .read
= ds1511_nvram_read
,
489 .write
= ds1511_nvram_write
,
493 ds1511_rtc_probe(struct platform_device
*pdev
)
495 struct rtc_device
*rtc
;
496 struct resource
*res
;
497 struct rtc_plat_data
*pdata
;
500 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
504 pdata
= devm_kzalloc(&pdev
->dev
, sizeof(*pdata
), GFP_KERNEL
);
507 pdata
->size
= res
->end
- res
->start
+ 1;
508 if (!devm_request_mem_region(&pdev
->dev
, res
->start
, pdata
->size
,
511 ds1511_base
= devm_ioremap(&pdev
->dev
, res
->start
, pdata
->size
);
514 pdata
->ioaddr
= ds1511_base
;
515 pdata
->irq
= platform_get_irq(pdev
, 0);
518 * turn on the clock and the crystal, etc.
520 rtc_write(0, RTC_CMD
);
521 rtc_write(0, RTC_CMD1
);
523 * clear the wdog counter
525 rtc_write(0, DS1511_WD_MSEC
);
526 rtc_write(0, DS1511_WD_SEC
);
533 * check for a dying bat-tree
535 if (rtc_read(RTC_CMD1
) & DS1511_BLF1
) {
536 dev_warn(&pdev
->dev
, "voltage-low detected.\n");
539 spin_lock_init(&pdata
->lock
);
540 platform_set_drvdata(pdev
, pdata
);
542 * if the platform has an interrupt in mind for this device,
543 * then by all means, set it
545 if (pdata
->irq
> 0) {
547 if (devm_request_irq(&pdev
->dev
, pdata
->irq
, ds1511_interrupt
,
548 IRQF_DISABLED
| IRQF_SHARED
, pdev
->name
, pdev
) < 0) {
550 dev_warn(&pdev
->dev
, "interrupt not available.\n");
555 rtc
= rtc_device_register(pdev
->name
, &pdev
->dev
, &ds1511_rtc_ops
,
561 ret
= sysfs_create_bin_file(&pdev
->dev
.kobj
, &ds1511_nvram_attr
);
563 rtc_device_unregister(pdata
->rtc
);
568 ds1511_rtc_remove(struct platform_device
*pdev
)
570 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
572 sysfs_remove_bin_file(&pdev
->dev
.kobj
, &ds1511_nvram_attr
);
573 rtc_device_unregister(pdata
->rtc
);
574 if (pdata
->irq
> 0) {
576 * disable the alarm interrupt
578 rtc_write(rtc_read(RTC_CMD
) & ~RTC_TIE
, RTC_CMD
);
584 /* work with hotplug and coldplug */
585 MODULE_ALIAS("platform:ds1511");
587 static struct platform_driver ds1511_rtc_driver
= {
588 .probe
= ds1511_rtc_probe
,
589 .remove
= __devexit_p(ds1511_rtc_remove
),
592 .owner
= THIS_MODULE
,
597 ds1511_rtc_init(void)
599 return platform_driver_register(&ds1511_rtc_driver
);
603 ds1511_rtc_exit(void)
605 platform_driver_unregister(&ds1511_rtc_driver
);
608 module_init(ds1511_rtc_init
);
609 module_exit(ds1511_rtc_exit
);
611 MODULE_AUTHOR("Andrew Sharp <andy.sharp@lsi.com>");
612 MODULE_DESCRIPTION("Dallas DS1511 RTC driver");
613 MODULE_LICENSE("GPL");
614 MODULE_VERSION(DRV_VERSION
);