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@onstor.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 unsigned long baseaddr
; /* physical base address */
91 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
->rtc
->irq_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
->rtc
->irq_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
);
329 if (pdata
->irq
< 0) {
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
);
349 if (pdata
->irq
< 0) {
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
= RTC_IRQF
;
368 * read and clear interrupt
370 if (!(rtc_read(RTC_CMD1
) & DS1511_IRQF
)) {
373 if (rtc_read(RTC_ALARM_SEC
) & 0x80) {
378 rtc_update_irq(pdata
->rtc
, 1, events
);
383 ds1511_rtc_ioctl(struct device
*dev
, unsigned int cmd
, unsigned long arg
)
385 struct platform_device
*pdev
= to_platform_device(dev
);
386 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
388 if (pdata
->irq
< 0) {
389 return -ENOIOCTLCMD
; /* fall back into rtc-dev's emulation */
393 pdata
->irqen
&= ~RTC_AF
;
394 ds1511_rtc_update_alarm(pdata
);
397 pdata
->irqen
|= RTC_AF
;
398 ds1511_rtc_update_alarm(pdata
);
401 pdata
->irqen
&= ~RTC_UF
;
402 ds1511_rtc_update_alarm(pdata
);
405 pdata
->irqen
|= RTC_UF
;
406 ds1511_rtc_update_alarm(pdata
);
414 static const struct rtc_class_ops ds1511_rtc_ops
= {
415 .read_time
= ds1511_rtc_read_time
,
416 .set_time
= ds1511_rtc_set_time
,
417 .read_alarm
= ds1511_rtc_read_alarm
,
418 .set_alarm
= ds1511_rtc_set_alarm
,
419 .ioctl
= ds1511_rtc_ioctl
,
423 ds1511_nvram_read(struct kobject
*kobj
, struct bin_attribute
*ba
,
424 char *buf
, loff_t pos
, size_t size
)
429 * if count is more than one, turn on "burst" mode
430 * turn it off when you're done
433 rtc_write((rtc_read(RTC_CMD
) | DS1511_BME
), RTC_CMD
);
435 if (pos
> DS1511_RAM_MAX
) {
436 pos
= DS1511_RAM_MAX
;
438 if (size
+ pos
> DS1511_RAM_MAX
+ 1) {
439 size
= DS1511_RAM_MAX
- pos
+ 1;
441 rtc_write(pos
, DS1511_RAMADDR_LSB
);
442 for (count
= 0; size
> 0; count
++, size
--) {
443 *buf
++ = rtc_read(DS1511_RAMDATA
);
446 rtc_write((rtc_read(RTC_CMD
) & ~DS1511_BME
), RTC_CMD
);
452 ds1511_nvram_write(struct kobject
*kobj
, struct bin_attribute
*bin_attr
,
453 char *buf
, loff_t pos
, size_t size
)
458 * if count is more than one, turn on "burst" mode
459 * turn it off when you're done
462 rtc_write((rtc_read(RTC_CMD
) | DS1511_BME
), RTC_CMD
);
464 if (pos
> DS1511_RAM_MAX
) {
465 pos
= DS1511_RAM_MAX
;
467 if (size
+ pos
> DS1511_RAM_MAX
+ 1) {
468 size
= DS1511_RAM_MAX
- pos
+ 1;
470 rtc_write(pos
, DS1511_RAMADDR_LSB
);
471 for (count
= 0; size
> 0; count
++, size
--) {
472 rtc_write(*buf
++, DS1511_RAMDATA
);
475 rtc_write((rtc_read(RTC_CMD
) & ~DS1511_BME
), RTC_CMD
);
480 static struct bin_attribute ds1511_nvram_attr
= {
483 .mode
= S_IRUGO
| S_IWUGO
,
485 .size
= DS1511_RAM_MAX
,
486 .read
= ds1511_nvram_read
,
487 .write
= ds1511_nvram_write
,
491 ds1511_rtc_probe(struct platform_device
*pdev
)
493 struct rtc_device
*rtc
;
494 struct resource
*res
;
495 struct rtc_plat_data
*pdata
= NULL
;
498 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
502 pdata
= kzalloc(sizeof(*pdata
), GFP_KERNEL
);
507 pdata
->size
= res
->end
- res
->start
+ 1;
508 if (!request_mem_region(res
->start
, pdata
->size
, pdev
->name
)) {
512 pdata
->baseaddr
= res
->start
;
513 pdata
->size
= pdata
->size
;
514 ds1511_base
= ioremap(pdata
->baseaddr
, pdata
->size
);
519 pdata
->ioaddr
= ds1511_base
;
520 pdata
->irq
= platform_get_irq(pdev
, 0);
523 * turn on the clock and the crystal, etc.
525 rtc_write(0, RTC_CMD
);
526 rtc_write(0, RTC_CMD1
);
528 * clear the wdog counter
530 rtc_write(0, DS1511_WD_MSEC
);
531 rtc_write(0, DS1511_WD_SEC
);
538 * check for a dying bat-tree
540 if (rtc_read(RTC_CMD1
) & DS1511_BLF1
) {
541 dev_warn(&pdev
->dev
, "voltage-low detected.\n");
545 * if the platform has an interrupt in mind for this device,
546 * then by all means, set it
548 if (pdata
->irq
>= 0) {
550 if (request_irq(pdata
->irq
, ds1511_interrupt
,
551 IRQF_DISABLED
| IRQF_SHARED
, pdev
->name
, pdev
) < 0) {
553 dev_warn(&pdev
->dev
, "interrupt not available.\n");
558 rtc
= rtc_device_register(pdev
->name
, &pdev
->dev
, &ds1511_rtc_ops
,
565 platform_set_drvdata(pdev
, pdata
);
566 ret
= sysfs_create_bin_file(&pdev
->dev
.kobj
, &ds1511_nvram_attr
);
573 rtc_device_unregister(pdata
->rtc
);
575 if (pdata
->irq
>= 0) {
576 free_irq(pdata
->irq
, pdev
);
579 iounmap(ds1511_base
);
582 if (pdata
->baseaddr
) {
583 release_mem_region(pdata
->baseaddr
, pdata
->size
);
591 ds1511_rtc_remove(struct platform_device
*pdev
)
593 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
595 sysfs_remove_bin_file(&pdev
->dev
.kobj
, &ds1511_nvram_attr
);
596 rtc_device_unregister(pdata
->rtc
);
598 if (pdata
->irq
>= 0) {
600 * disable the alarm interrupt
602 rtc_write(rtc_read(RTC_CMD
) & ~RTC_TIE
, RTC_CMD
);
604 free_irq(pdata
->irq
, pdev
);
606 iounmap(pdata
->ioaddr
);
608 release_mem_region(pdata
->baseaddr
, pdata
->size
);
613 /* work with hotplug and coldplug */
614 MODULE_ALIAS("platform:ds1511");
616 static struct platform_driver ds1511_rtc_driver
= {
617 .probe
= ds1511_rtc_probe
,
618 .remove
= __devexit_p(ds1511_rtc_remove
),
621 .owner
= THIS_MODULE
,
626 ds1511_rtc_init(void)
628 return platform_driver_register(&ds1511_rtc_driver
);
632 ds1511_rtc_exit(void)
634 return platform_driver_unregister(&ds1511_rtc_driver
);
637 module_init(ds1511_rtc_init
);
638 module_exit(ds1511_rtc_exit
);
640 MODULE_AUTHOR("Andrew Sharp <andy.sharp@onstor.com>");
641 MODULE_DESCRIPTION("Dallas DS1511 RTC driver");
642 MODULE_LICENSE("GPL");
643 MODULE_VERSION(DRV_VERSION
);