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[linux-2.6.32.60-moxart.git] / drivers / rtc / rtc-ds1511.c
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1 /*
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>
24 #include <linux/io.h>
26 #define DRV_VERSION "0.6"
28 enum ds1511reg {
29 DS1511_SEC = 0x0,
30 DS1511_MIN = 0x1,
31 DS1511_HOUR = 0x2,
32 DS1511_DOW = 0x3,
33 DS1511_DOM = 0x4,
34 DS1511_MONTH = 0x5,
35 DS1511_YEAR = 0x6,
36 DS1511_CENTURY = 0x7,
37 DS1511_AM1_SEC = 0x8,
38 DS1511_AM2_MIN = 0x9,
39 DS1511_AM3_HOUR = 0xa,
40 DS1511_AM4_DATE = 0xb,
41 DS1511_WD_MSEC = 0xc,
42 DS1511_WD_SEC = 0xd,
43 DS1511_CONTROL_A = 0xe,
44 DS1511_CONTROL_B = 0xf,
45 DS1511_RAMADDR_LSB = 0x10,
46 DS1511_RAMDATA = 0x13
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 */
92 int irq;
93 unsigned int irqen;
94 int alrm_sec;
95 int alrm_min;
96 int alrm_hour;
97 int alrm_mday;
100 static DEFINE_SPINLOCK(ds1511_lock);
102 static __iomem char *ds1511_base;
103 static u32 reg_spacing = 1;
105 static noinline void
106 rtc_write(uint8_t val, uint32_t reg)
108 writeb(val, ds1511_base + (reg * reg_spacing));
111 static inline void
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));
123 static inline void
124 rtc_disable_update(void)
126 rtc_write((rtc_read(RTC_CMD) & ~RTC_TE), RTC_CMD);
129 static void
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
146 void
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);
164 void
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);
177 #endif
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;
187 unsigned long flags;
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) {
197 return -EINVAL;
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)) {
209 return -EINVAL;
212 if (day > rtc_month_days(rtc_tm->tm_mon, rtc_tm->tm_year)) {
213 return -EINVAL;
216 if ((hrs >= 24) || (min >= 60) || (sec >= 60)) {
217 return -EINVAL;
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);
241 rtc_enable_update();
242 spin_unlock_irqrestore(&ds1511_lock, flags);
244 return 0;
247 static int ds1511_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
249 unsigned int century;
250 unsigned long flags;
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);
264 rtc_enable_update();
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;
283 rtc_tm->tm_mon--;
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);
289 return 0;
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.
300 static void
301 ds1511_rtc_update_alarm(struct rtc_plat_data *pdata)
303 unsigned long flags;
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,
308 RTC_ALARM_DATE);
309 rtc_write(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ?
310 0x80 : bin2bcd(pdata->alrm_hour) & 0x3f,
311 RTC_ALARM_HOUR);
312 rtc_write(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ?
313 0x80 : bin2bcd(pdata->alrm_min) & 0x7f,
314 RTC_ALARM_MIN);
315 rtc_write(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ?
316 0x80 : bin2bcd(pdata->alrm_sec) & 0x7f,
317 RTC_ALARM_SEC);
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);
323 static int
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)
330 return -EINVAL;
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;
336 if (alrm->enabled) {
337 pdata->irqen |= RTC_AF;
339 ds1511_rtc_update_alarm(pdata);
340 return 0;
343 static int
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)
350 return -EINVAL;
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;
357 return 0;
360 static irqreturn_t
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)) {
371 return IRQ_NONE;
373 if (rtc_read(RTC_ALARM_SEC) & 0x80) {
374 events |= RTC_UF;
375 } else {
376 events |= RTC_AF;
378 rtc_update_irq(pdata->rtc, 1, events);
379 return IRQ_HANDLED;
382 static int
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 */
391 switch (cmd) {
392 case RTC_AIE_OFF:
393 pdata->irqen &= ~RTC_AF;
394 ds1511_rtc_update_alarm(pdata);
395 break;
396 case RTC_AIE_ON:
397 pdata->irqen |= RTC_AF;
398 ds1511_rtc_update_alarm(pdata);
399 break;
400 case RTC_UIE_OFF:
401 pdata->irqen &= ~RTC_UF;
402 ds1511_rtc_update_alarm(pdata);
403 break;
404 case RTC_UIE_ON:
405 pdata->irqen |= RTC_UF;
406 ds1511_rtc_update_alarm(pdata);
407 break;
408 default:
409 return -ENOIOCTLCMD;
411 return 0;
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,
422 static ssize_t
423 ds1511_nvram_read(struct kobject *kobj, struct bin_attribute *ba,
424 char *buf, loff_t pos, size_t size)
426 ssize_t count;
429 * if count is more than one, turn on "burst" mode
430 * turn it off when you're done
432 if (size > 1) {
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);
445 if (count > 1) {
446 rtc_write((rtc_read(RTC_CMD) & ~DS1511_BME), RTC_CMD);
448 return count;
451 static ssize_t
452 ds1511_nvram_write(struct kobject *kobj, struct bin_attribute *bin_attr,
453 char *buf, loff_t pos, size_t size)
455 ssize_t count;
458 * if count is more than one, turn on "burst" mode
459 * turn it off when you're done
461 if (size > 1) {
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);
474 if (count > 1) {
475 rtc_write((rtc_read(RTC_CMD) & ~DS1511_BME), RTC_CMD);
477 return count;
480 static struct bin_attribute ds1511_nvram_attr = {
481 .attr = {
482 .name = "nvram",
483 .mode = S_IRUGO | S_IWUSR,
485 .size = DS1511_RAM_MAX,
486 .read = ds1511_nvram_read,
487 .write = ds1511_nvram_write,
490 static int __devinit
491 ds1511_rtc_probe(struct platform_device *pdev)
493 struct rtc_device *rtc;
494 struct resource *res;
495 struct rtc_plat_data *pdata = NULL;
496 int ret = 0;
498 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
499 if (!res) {
500 return -ENODEV;
502 pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
503 if (!pdata) {
504 return -ENOMEM;
506 pdata->size = res->end - res->start + 1;
507 if (!request_mem_region(res->start, pdata->size, pdev->name)) {
508 ret = -EBUSY;
509 goto out;
511 pdata->baseaddr = res->start;
512 pdata->size = pdata->size;
513 ds1511_base = ioremap(pdata->baseaddr, pdata->size);
514 if (!ds1511_base) {
515 ret = -ENOMEM;
516 goto out;
518 pdata->ioaddr = ds1511_base;
519 pdata->irq = platform_get_irq(pdev, 0);
522 * turn on the clock and the crystal, etc.
524 rtc_write(0, RTC_CMD);
525 rtc_write(0, RTC_CMD1);
527 * clear the wdog counter
529 rtc_write(0, DS1511_WD_MSEC);
530 rtc_write(0, DS1511_WD_SEC);
532 * start the clock
534 rtc_enable_update();
537 * check for a dying bat-tree
539 if (rtc_read(RTC_CMD1) & DS1511_BLF1) {
540 dev_warn(&pdev->dev, "voltage-low detected.\n");
544 * if the platform has an interrupt in mind for this device,
545 * then by all means, set it
547 if (pdata->irq > 0) {
548 rtc_read(RTC_CMD1);
549 if (request_irq(pdata->irq, ds1511_interrupt,
550 IRQF_DISABLED | IRQF_SHARED, pdev->name, pdev) < 0) {
552 dev_warn(&pdev->dev, "interrupt not available.\n");
553 pdata->irq = 0;
557 rtc = rtc_device_register(pdev->name, &pdev->dev, &ds1511_rtc_ops,
558 THIS_MODULE);
559 if (IS_ERR(rtc)) {
560 ret = PTR_ERR(rtc);
561 goto out;
563 pdata->rtc = rtc;
564 platform_set_drvdata(pdev, pdata);
565 ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr);
566 if (ret) {
567 goto out;
569 return 0;
570 out:
571 if (pdata->rtc) {
572 rtc_device_unregister(pdata->rtc);
574 if (pdata->irq > 0) {
575 free_irq(pdata->irq, pdev);
577 if (ds1511_base) {
578 iounmap(ds1511_base);
579 ds1511_base = NULL;
581 if (pdata->baseaddr) {
582 release_mem_region(pdata->baseaddr, pdata->size);
585 kfree(pdata);
586 return ret;
589 static int __devexit
590 ds1511_rtc_remove(struct platform_device *pdev)
592 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
594 sysfs_remove_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr);
595 rtc_device_unregister(pdata->rtc);
596 pdata->rtc = NULL;
597 if (pdata->irq > 0) {
599 * disable the alarm interrupt
601 rtc_write(rtc_read(RTC_CMD) & ~RTC_TIE, RTC_CMD);
602 rtc_read(RTC_CMD1);
603 free_irq(pdata->irq, pdev);
605 iounmap(pdata->ioaddr);
606 ds1511_base = NULL;
607 release_mem_region(pdata->baseaddr, pdata->size);
608 kfree(pdata);
609 return 0;
612 /* work with hotplug and coldplug */
613 MODULE_ALIAS("platform:ds1511");
615 static struct platform_driver ds1511_rtc_driver = {
616 .probe = ds1511_rtc_probe,
617 .remove = __devexit_p(ds1511_rtc_remove),
618 .driver = {
619 .name = "ds1511",
620 .owner = THIS_MODULE,
624 static int __init
625 ds1511_rtc_init(void)
627 return platform_driver_register(&ds1511_rtc_driver);
630 static void __exit
631 ds1511_rtc_exit(void)
633 platform_driver_unregister(&ds1511_rtc_driver);
636 module_init(ds1511_rtc_init);
637 module_exit(ds1511_rtc_exit);
639 MODULE_AUTHOR("Andrew Sharp <andy.sharp@onstor.com>");
640 MODULE_DESCRIPTION("Dallas DS1511 RTC driver");
641 MODULE_LICENSE("GPL");
642 MODULE_VERSION(DRV_VERSION);