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 kobject *kobj, struct bin_attribute *ba,
427 char *buf, loff_t pos, size_t size)
432 * if count is more than one, turn on "burst" mode
433 * turn it off when you're done
436 rtc_write((rtc_read(RTC_CMD) | DS1511_BME), RTC_CMD);
438 if (pos > DS1511_RAM_MAX) {
439 pos = DS1511_RAM_MAX;
441 if (size + pos > DS1511_RAM_MAX + 1) {
442 size = DS1511_RAM_MAX - pos + 1;
444 rtc_write(pos, DS1511_RAMADDR_LSB);
445 for (count = 0; size > 0; count++, size--) {
446 *buf++ = rtc_read(DS1511_RAMDATA);
449 rtc_write((rtc_read(RTC_CMD) & ~DS1511_BME), RTC_CMD);
455 ds1511_nvram_write(struct kobject *kobj, struct bin_attribute *bin_attr,
456 char *buf, loff_t pos, size_t size)
461 * if count is more than one, turn on "burst" mode
462 * turn it off when you're done
465 rtc_write((rtc_read(RTC_CMD) | DS1511_BME), RTC_CMD);
467 if (pos > DS1511_RAM_MAX) {
468 pos = DS1511_RAM_MAX;
470 if (size + pos > DS1511_RAM_MAX + 1) {
471 size = DS1511_RAM_MAX - pos + 1;
473 rtc_write(pos, DS1511_RAMADDR_LSB);
474 for (count = 0; size > 0; count++, size--) {
475 rtc_write(*buf++, DS1511_RAMDATA);
478 rtc_write((rtc_read(RTC_CMD) & ~DS1511_BME), RTC_CMD);
483 static struct bin_attribute ds1511_nvram_attr = {
486 .mode = S_IRUGO | S_IWUGO,
488 .size = DS1511_RAM_MAX,
489 .read = ds1511_nvram_read,
490 .write = ds1511_nvram_write,
494 ds1511_rtc_probe(struct platform_device *pdev)
496 struct rtc_device *rtc;
497 struct resource *res;
498 struct rtc_plat_data *pdata;
501 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
505 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
508 pdata->size = res->end - res->start + 1;
509 if (!devm_request_mem_region(&pdev->dev, res->start, pdata->size,
512 ds1511_base = devm_ioremap(&pdev->dev, res->start, pdata->size);
515 pdata->ioaddr = ds1511_base;
516 pdata->irq = platform_get_irq(pdev, 0);
519 * turn on the clock and the crystal, etc.
521 rtc_write(0, RTC_CMD);
522 rtc_write(0, RTC_CMD1);
524 * clear the wdog counter
526 rtc_write(0, DS1511_WD_MSEC);
527 rtc_write(0, DS1511_WD_SEC);
534 * check for a dying bat-tree
536 if (rtc_read(RTC_CMD1) & DS1511_BLF1) {
537 dev_warn(&pdev->dev, "voltage-low detected.\n");
540 spin_lock_init(&pdata->lock);
541 platform_set_drvdata(pdev, pdata);
543 * if the platform has an interrupt in mind for this device,
544 * then by all means, set it
546 if (pdata->irq > 0) {
548 if (devm_request_irq(&pdev->dev, pdata->irq, ds1511_interrupt,
549 IRQF_DISABLED | IRQF_SHARED, pdev->name, pdev) < 0) {
551 dev_warn(&pdev->dev, "interrupt not available.\n");
556 rtc = rtc_device_register(pdev->name, &pdev->dev, &ds1511_rtc_ops,
562 ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr);
564 rtc_device_unregister(pdata->rtc);
569 ds1511_rtc_remove(struct platform_device *pdev)
571 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
573 sysfs_remove_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr);
574 rtc_device_unregister(pdata->rtc);
575 if (pdata->irq > 0) {
577 * disable the alarm interrupt
579 rtc_write(rtc_read(RTC_CMD) & ~RTC_TIE, RTC_CMD);
585 /* work with hotplug and coldplug */
586 MODULE_ALIAS("platform:ds1511");
588 static struct platform_driver ds1511_rtc_driver = {
589 .probe = ds1511_rtc_probe,
590 .remove = __devexit_p(ds1511_rtc_remove),
593 .owner = THIS_MODULE,
598 ds1511_rtc_init(void)
600 return platform_driver_register(&ds1511_rtc_driver);
604 ds1511_rtc_exit(void)
606 platform_driver_unregister(&ds1511_rtc_driver);
609 module_init(ds1511_rtc_init);
610 module_exit(ds1511_rtc_exit);
612 MODULE_AUTHOR("Andrew Sharp <andy.sharp@lsi.com>");
613 MODULE_DESCRIPTION("Dallas DS1511 RTC driver");
614 MODULE_LICENSE("GPL");
615 MODULE_VERSION(DRV_VERSION);