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/gfp.h>
21 #include <linux/delay.h>
22 #include <linux/interrupt.h>
23 #include <linux/rtc.h>
24 #include <linux/platform_device.h>
27 #define DRV_VERSION "0.6"
40 DS1511_AM3_HOUR
= 0xa,
41 DS1511_AM4_DATE
= 0xb,
44 DS1511_CONTROL_A
= 0xe,
45 DS1511_CONTROL_B
= 0xf,
46 DS1511_RAMADDR_LSB
= 0x10,
50 #define DS1511_BLF1 0x80
51 #define DS1511_BLF2 0x40
52 #define DS1511_PRS 0x20
53 #define DS1511_PAB 0x10
54 #define DS1511_TDF 0x08
55 #define DS1511_KSF 0x04
56 #define DS1511_WDF 0x02
57 #define DS1511_IRQF 0x01
58 #define DS1511_TE 0x80
59 #define DS1511_CS 0x40
60 #define DS1511_BME 0x20
61 #define DS1511_TPE 0x10
62 #define DS1511_TIE 0x08
63 #define DS1511_KIE 0x04
64 #define DS1511_WDE 0x02
65 #define DS1511_WDS 0x01
66 #define DS1511_RAM_MAX 0xff
68 #define RTC_CMD DS1511_CONTROL_B
69 #define RTC_CMD1 DS1511_CONTROL_A
71 #define RTC_ALARM_SEC DS1511_AM1_SEC
72 #define RTC_ALARM_MIN DS1511_AM2_MIN
73 #define RTC_ALARM_HOUR DS1511_AM3_HOUR
74 #define RTC_ALARM_DATE DS1511_AM4_DATE
76 #define RTC_SEC DS1511_SEC
77 #define RTC_MIN DS1511_MIN
78 #define RTC_HOUR DS1511_HOUR
79 #define RTC_DOW DS1511_DOW
80 #define RTC_DOM DS1511_DOM
81 #define RTC_MON DS1511_MONTH
82 #define RTC_YEAR DS1511_YEAR
83 #define RTC_CENTURY DS1511_CENTURY
85 #define RTC_TIE DS1511_TIE
86 #define RTC_TE DS1511_TE
88 struct rtc_plat_data
{
89 struct rtc_device
*rtc
;
90 void __iomem
*ioaddr
; /* virtual base address */
91 int size
; /* amount of memory mapped */
101 static DEFINE_SPINLOCK(ds1511_lock
);
103 static __iomem
char *ds1511_base
;
104 static u32 reg_spacing
= 1;
107 rtc_write(uint8_t val
, uint32_t reg
)
109 writeb(val
, ds1511_base
+ (reg
* reg_spacing
));
113 rtc_write_alarm(uint8_t val
, enum ds1511reg reg
)
115 rtc_write((val
| 0x80), reg
);
118 static noinline
uint8_t
119 rtc_read(enum ds1511reg reg
)
121 return readb(ds1511_base
+ (reg
* reg_spacing
));
125 rtc_disable_update(void)
127 rtc_write((rtc_read(RTC_CMD
) & ~RTC_TE
), RTC_CMD
);
131 rtc_enable_update(void)
133 rtc_write((rtc_read(RTC_CMD
) | RTC_TE
), RTC_CMD
);
137 * #define DS1511_WDOG_RESET_SUPPORT
139 * Uncomment this if you want to use these routines in
140 * some platform code.
142 #ifdef DS1511_WDOG_RESET_SUPPORT
144 * just enough code to set the watchdog timer so that it
145 * will reboot the system
148 ds1511_wdog_set(unsigned long deciseconds
)
151 * the wdog timer can take 99.99 seconds
153 deciseconds
%= 10000;
155 * set the wdog values in the wdog registers
157 rtc_write(bin2bcd(deciseconds
% 100), DS1511_WD_MSEC
);
158 rtc_write(bin2bcd(deciseconds
/ 100), DS1511_WD_SEC
);
160 * set wdog enable and wdog 'steering' bit to issue a reset
162 rtc_write(DS1511_WDE
| DS1511_WDS
, RTC_CMD
);
166 ds1511_wdog_disable(void)
169 * clear wdog enable and wdog 'steering' bits
171 rtc_write(rtc_read(RTC_CMD
) & ~(DS1511_WDE
| DS1511_WDS
), RTC_CMD
);
173 * clear the wdog counter
175 rtc_write(0, DS1511_WD_MSEC
);
176 rtc_write(0, DS1511_WD_SEC
);
181 * set the rtc chip's idea of the time.
182 * stupidly, some callers call with year unmolested;
183 * and some call with year = year - 1900. thanks.
185 static int ds1511_rtc_set_time(struct device
*dev
, struct rtc_time
*rtc_tm
)
187 u8 mon
, day
, dow
, hrs
, min
, sec
, yrs
, cen
;
191 * won't have to change this for a while
193 if (rtc_tm
->tm_year
< 1900) {
194 rtc_tm
->tm_year
+= 1900;
197 if (rtc_tm
->tm_year
< 1970) {
200 yrs
= rtc_tm
->tm_year
% 100;
201 cen
= rtc_tm
->tm_year
/ 100;
202 mon
= rtc_tm
->tm_mon
+ 1; /* tm_mon starts at zero */
203 day
= rtc_tm
->tm_mday
;
204 dow
= rtc_tm
->tm_wday
& 0x7; /* automatic BCD */
205 hrs
= rtc_tm
->tm_hour
;
206 min
= rtc_tm
->tm_min
;
207 sec
= rtc_tm
->tm_sec
;
209 if ((mon
> 12) || (day
== 0)) {
213 if (day
> rtc_month_days(rtc_tm
->tm_mon
, rtc_tm
->tm_year
)) {
217 if ((hrs
>= 24) || (min
>= 60) || (sec
>= 60)) {
222 * each register is a different number of valid bits
224 sec
= bin2bcd(sec
) & 0x7f;
225 min
= bin2bcd(min
) & 0x7f;
226 hrs
= bin2bcd(hrs
) & 0x3f;
227 day
= bin2bcd(day
) & 0x3f;
228 mon
= bin2bcd(mon
) & 0x1f;
229 yrs
= bin2bcd(yrs
) & 0xff;
230 cen
= bin2bcd(cen
) & 0xff;
232 spin_lock_irqsave(&ds1511_lock
, flags
);
233 rtc_disable_update();
234 rtc_write(cen
, RTC_CENTURY
);
235 rtc_write(yrs
, RTC_YEAR
);
236 rtc_write((rtc_read(RTC_MON
) & 0xe0) | mon
, RTC_MON
);
237 rtc_write(day
, RTC_DOM
);
238 rtc_write(hrs
, RTC_HOUR
);
239 rtc_write(min
, RTC_MIN
);
240 rtc_write(sec
, RTC_SEC
);
241 rtc_write(dow
, RTC_DOW
);
243 spin_unlock_irqrestore(&ds1511_lock
, flags
);
248 static int ds1511_rtc_read_time(struct device
*dev
, struct rtc_time
*rtc_tm
)
250 unsigned int century
;
253 spin_lock_irqsave(&ds1511_lock
, flags
);
254 rtc_disable_update();
256 rtc_tm
->tm_sec
= rtc_read(RTC_SEC
) & 0x7f;
257 rtc_tm
->tm_min
= rtc_read(RTC_MIN
) & 0x7f;
258 rtc_tm
->tm_hour
= rtc_read(RTC_HOUR
) & 0x3f;
259 rtc_tm
->tm_mday
= rtc_read(RTC_DOM
) & 0x3f;
260 rtc_tm
->tm_wday
= rtc_read(RTC_DOW
) & 0x7;
261 rtc_tm
->tm_mon
= rtc_read(RTC_MON
) & 0x1f;
262 rtc_tm
->tm_year
= rtc_read(RTC_YEAR
) & 0x7f;
263 century
= rtc_read(RTC_CENTURY
);
266 spin_unlock_irqrestore(&ds1511_lock
, flags
);
268 rtc_tm
->tm_sec
= bcd2bin(rtc_tm
->tm_sec
);
269 rtc_tm
->tm_min
= bcd2bin(rtc_tm
->tm_min
);
270 rtc_tm
->tm_hour
= bcd2bin(rtc_tm
->tm_hour
);
271 rtc_tm
->tm_mday
= bcd2bin(rtc_tm
->tm_mday
);
272 rtc_tm
->tm_wday
= bcd2bin(rtc_tm
->tm_wday
);
273 rtc_tm
->tm_mon
= bcd2bin(rtc_tm
->tm_mon
);
274 rtc_tm
->tm_year
= bcd2bin(rtc_tm
->tm_year
);
275 century
= bcd2bin(century
) * 100;
278 * Account for differences between how the RTC uses the values
279 * and how they are defined in a struct rtc_time;
281 century
+= rtc_tm
->tm_year
;
282 rtc_tm
->tm_year
= century
- 1900;
286 if (rtc_valid_tm(rtc_tm
) < 0) {
287 dev_err(dev
, "retrieved date/time is not valid.\n");
288 rtc_time_to_tm(0, rtc_tm
);
294 * write the alarm register settings
296 * we only have the use to interrupt every second, otherwise
297 * known as the update interrupt, or the interrupt if the whole
298 * date/hours/mins/secs matches. the ds1511 has many more
299 * permutations, but the kernel doesn't.
302 ds1511_rtc_update_alarm(struct rtc_plat_data
*pdata
)
306 spin_lock_irqsave(&pdata
->lock
, flags
);
307 rtc_write(pdata
->alrm_mday
< 0 || (pdata
->irqen
& RTC_UF
) ?
308 0x80 : bin2bcd(pdata
->alrm_mday
) & 0x3f,
310 rtc_write(pdata
->alrm_hour
< 0 || (pdata
->irqen
& RTC_UF
) ?
311 0x80 : bin2bcd(pdata
->alrm_hour
) & 0x3f,
313 rtc_write(pdata
->alrm_min
< 0 || (pdata
->irqen
& RTC_UF
) ?
314 0x80 : bin2bcd(pdata
->alrm_min
) & 0x7f,
316 rtc_write(pdata
->alrm_sec
< 0 || (pdata
->irqen
& RTC_UF
) ?
317 0x80 : bin2bcd(pdata
->alrm_sec
) & 0x7f,
319 rtc_write(rtc_read(RTC_CMD
) | (pdata
->irqen
? RTC_TIE
: 0), RTC_CMD
);
320 rtc_read(RTC_CMD1
); /* clear interrupts */
321 spin_unlock_irqrestore(&pdata
->lock
, flags
);
325 ds1511_rtc_set_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
327 struct platform_device
*pdev
= to_platform_device(dev
);
328 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
333 pdata
->alrm_mday
= alrm
->time
.tm_mday
;
334 pdata
->alrm_hour
= alrm
->time
.tm_hour
;
335 pdata
->alrm_min
= alrm
->time
.tm_min
;
336 pdata
->alrm_sec
= alrm
->time
.tm_sec
;
338 pdata
->irqen
|= RTC_AF
;
340 ds1511_rtc_update_alarm(pdata
);
345 ds1511_rtc_read_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
347 struct platform_device
*pdev
= to_platform_device(dev
);
348 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
353 alrm
->time
.tm_mday
= pdata
->alrm_mday
< 0 ? 0 : pdata
->alrm_mday
;
354 alrm
->time
.tm_hour
= pdata
->alrm_hour
< 0 ? 0 : pdata
->alrm_hour
;
355 alrm
->time
.tm_min
= pdata
->alrm_min
< 0 ? 0 : pdata
->alrm_min
;
356 alrm
->time
.tm_sec
= pdata
->alrm_sec
< 0 ? 0 : pdata
->alrm_sec
;
357 alrm
->enabled
= (pdata
->irqen
& RTC_AF
) ? 1 : 0;
362 ds1511_interrupt(int irq
, void *dev_id
)
364 struct platform_device
*pdev
= dev_id
;
365 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
366 unsigned long events
= 0;
368 spin_lock(&pdata
->lock
);
370 * read and clear interrupt
372 if (rtc_read(RTC_CMD1
) & DS1511_IRQF
) {
374 if (rtc_read(RTC_ALARM_SEC
) & 0x80)
378 if (likely(pdata
->rtc
))
379 rtc_update_irq(pdata
->rtc
, 1, events
);
381 spin_unlock(&pdata
->lock
);
382 return events
? IRQ_HANDLED
: IRQ_NONE
;
385 static int ds1511_rtc_alarm_irq_enable(struct device
*dev
, unsigned int enabled
)
387 struct platform_device
*pdev
= to_platform_device(dev
);
388 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
393 pdata
->irqen
|= RTC_AF
;
395 pdata
->irqen
&= ~RTC_AF
;
396 ds1511_rtc_update_alarm(pdata
);
400 static int ds1511_rtc_update_irq_enable(struct device
*dev
,
401 unsigned int enabled
)
403 struct platform_device
*pdev
= to_platform_device(dev
);
404 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
409 pdata
->irqen
|= RTC_UF
;
411 pdata
->irqen
&= ~RTC_UF
;
412 ds1511_rtc_update_alarm(pdata
);
416 static const struct rtc_class_ops ds1511_rtc_ops
= {
417 .read_time
= ds1511_rtc_read_time
,
418 .set_time
= ds1511_rtc_set_time
,
419 .read_alarm
= ds1511_rtc_read_alarm
,
420 .set_alarm
= ds1511_rtc_set_alarm
,
421 .alarm_irq_enable
= ds1511_rtc_alarm_irq_enable
,
422 .update_irq_enable
= ds1511_rtc_update_irq_enable
,
426 ds1511_nvram_read(struct file
*filp
, struct kobject
*kobj
,
427 struct bin_attribute
*ba
,
428 char *buf
, loff_t pos
, size_t size
)
433 * if count is more than one, turn on "burst" mode
434 * turn it off when you're done
437 rtc_write((rtc_read(RTC_CMD
) | DS1511_BME
), RTC_CMD
);
439 if (pos
> DS1511_RAM_MAX
) {
440 pos
= DS1511_RAM_MAX
;
442 if (size
+ pos
> DS1511_RAM_MAX
+ 1) {
443 size
= DS1511_RAM_MAX
- pos
+ 1;
445 rtc_write(pos
, DS1511_RAMADDR_LSB
);
446 for (count
= 0; size
> 0; count
++, size
--) {
447 *buf
++ = rtc_read(DS1511_RAMDATA
);
450 rtc_write((rtc_read(RTC_CMD
) & ~DS1511_BME
), RTC_CMD
);
456 ds1511_nvram_write(struct file
*filp
, struct kobject
*kobj
,
457 struct bin_attribute
*bin_attr
,
458 char *buf
, loff_t pos
, size_t size
)
463 * if count is more than one, turn on "burst" mode
464 * turn it off when you're done
467 rtc_write((rtc_read(RTC_CMD
) | DS1511_BME
), RTC_CMD
);
469 if (pos
> DS1511_RAM_MAX
) {
470 pos
= DS1511_RAM_MAX
;
472 if (size
+ pos
> DS1511_RAM_MAX
+ 1) {
473 size
= DS1511_RAM_MAX
- pos
+ 1;
475 rtc_write(pos
, DS1511_RAMADDR_LSB
);
476 for (count
= 0; size
> 0; count
++, size
--) {
477 rtc_write(*buf
++, DS1511_RAMDATA
);
480 rtc_write((rtc_read(RTC_CMD
) & ~DS1511_BME
), RTC_CMD
);
485 static struct bin_attribute ds1511_nvram_attr
= {
488 .mode
= S_IRUGO
| S_IWUSR
,
490 .size
= DS1511_RAM_MAX
,
491 .read
= ds1511_nvram_read
,
492 .write
= ds1511_nvram_write
,
496 ds1511_rtc_probe(struct platform_device
*pdev
)
498 struct rtc_device
*rtc
;
499 struct resource
*res
;
500 struct rtc_plat_data
*pdata
;
503 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
507 pdata
= devm_kzalloc(&pdev
->dev
, sizeof(*pdata
), GFP_KERNEL
);
510 pdata
->size
= res
->end
- res
->start
+ 1;
511 if (!devm_request_mem_region(&pdev
->dev
, res
->start
, pdata
->size
,
514 ds1511_base
= devm_ioremap(&pdev
->dev
, res
->start
, pdata
->size
);
517 pdata
->ioaddr
= ds1511_base
;
518 pdata
->irq
= platform_get_irq(pdev
, 0);
521 * turn on the clock and the crystal, etc.
523 rtc_write(0, RTC_CMD
);
524 rtc_write(0, RTC_CMD1
);
526 * clear the wdog counter
528 rtc_write(0, DS1511_WD_MSEC
);
529 rtc_write(0, DS1511_WD_SEC
);
536 * check for a dying bat-tree
538 if (rtc_read(RTC_CMD1
) & DS1511_BLF1
) {
539 dev_warn(&pdev
->dev
, "voltage-low detected.\n");
542 spin_lock_init(&pdata
->lock
);
543 platform_set_drvdata(pdev
, pdata
);
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 (devm_request_irq(&pdev
->dev
, 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
,
564 ret
= sysfs_create_bin_file(&pdev
->dev
.kobj
, &ds1511_nvram_attr
);
566 rtc_device_unregister(pdata
->rtc
);
571 ds1511_rtc_remove(struct platform_device
*pdev
)
573 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
575 sysfs_remove_bin_file(&pdev
->dev
.kobj
, &ds1511_nvram_attr
);
576 rtc_device_unregister(pdata
->rtc
);
577 if (pdata
->irq
> 0) {
579 * disable the alarm interrupt
581 rtc_write(rtc_read(RTC_CMD
) & ~RTC_TIE
, RTC_CMD
);
587 /* work with hotplug and coldplug */
588 MODULE_ALIAS("platform:ds1511");
590 static struct platform_driver ds1511_rtc_driver
= {
591 .probe
= ds1511_rtc_probe
,
592 .remove
= __devexit_p(ds1511_rtc_remove
),
595 .owner
= THIS_MODULE
,
600 ds1511_rtc_init(void)
602 return platform_driver_register(&ds1511_rtc_driver
);
606 ds1511_rtc_exit(void)
608 platform_driver_unregister(&ds1511_rtc_driver
);
611 module_init(ds1511_rtc_init
);
612 module_exit(ds1511_rtc_exit
);
614 MODULE_AUTHOR("Andrew Sharp <andy.sharp@lsi.com>");
615 MODULE_DESCRIPTION("Dallas DS1511 RTC driver");
616 MODULE_LICENSE("GPL");
617 MODULE_VERSION(DRV_VERSION
);