Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target...
[linux-btrfs-devel.git] / drivers / rtc / rtc-ds1511.c
blob568ad30617e7dad58f38f7a6583b8c73630a4aa7
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@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>
25 #include <linux/io.h>
27 #define DRV_VERSION "0.6"
29 enum ds1511reg {
30 DS1511_SEC = 0x0,
31 DS1511_MIN = 0x1,
32 DS1511_HOUR = 0x2,
33 DS1511_DOW = 0x3,
34 DS1511_DOM = 0x4,
35 DS1511_MONTH = 0x5,
36 DS1511_YEAR = 0x6,
37 DS1511_CENTURY = 0x7,
38 DS1511_AM1_SEC = 0x8,
39 DS1511_AM2_MIN = 0x9,
40 DS1511_AM3_HOUR = 0xa,
41 DS1511_AM4_DATE = 0xb,
42 DS1511_WD_MSEC = 0xc,
43 DS1511_WD_SEC = 0xd,
44 DS1511_CONTROL_A = 0xe,
45 DS1511_CONTROL_B = 0xf,
46 DS1511_RAMADDR_LSB = 0x10,
47 DS1511_RAMDATA = 0x13
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 */
92 int irq;
93 unsigned int irqen;
94 int alrm_sec;
95 int alrm_min;
96 int alrm_hour;
97 int alrm_mday;
98 spinlock_t lock;
101 static DEFINE_SPINLOCK(ds1511_lock);
103 static __iomem char *ds1511_base;
104 static u32 reg_spacing = 1;
106 static noinline void
107 rtc_write(uint8_t val, uint32_t reg)
109 writeb(val, ds1511_base + (reg * reg_spacing));
112 static inline void
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));
124 static inline void
125 rtc_disable_update(void)
127 rtc_write((rtc_read(RTC_CMD) & ~RTC_TE), RTC_CMD);
130 static void
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
147 void
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);
165 void
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);
178 #endif
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;
188 unsigned long flags;
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) {
198 return -EINVAL;
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)) {
210 return -EINVAL;
213 if (day > rtc_month_days(rtc_tm->tm_mon, rtc_tm->tm_year)) {
214 return -EINVAL;
217 if ((hrs >= 24) || (min >= 60) || (sec >= 60)) {
218 return -EINVAL;
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);
242 rtc_enable_update();
243 spin_unlock_irqrestore(&ds1511_lock, flags);
245 return 0;
248 static int ds1511_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
250 unsigned int century;
251 unsigned long flags;
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);
265 rtc_enable_update();
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;
284 rtc_tm->tm_mon--;
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);
290 return 0;
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.
301 static void
302 ds1511_rtc_update_alarm(struct rtc_plat_data *pdata)
304 unsigned long flags;
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,
309 RTC_ALARM_DATE);
310 rtc_write(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ?
311 0x80 : bin2bcd(pdata->alrm_hour) & 0x3f,
312 RTC_ALARM_HOUR);
313 rtc_write(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ?
314 0x80 : bin2bcd(pdata->alrm_min) & 0x7f,
315 RTC_ALARM_MIN);
316 rtc_write(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ?
317 0x80 : bin2bcd(pdata->alrm_sec) & 0x7f,
318 RTC_ALARM_SEC);
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);
324 static int
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);
330 if (pdata->irq <= 0)
331 return -EINVAL;
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;
337 if (alrm->enabled) {
338 pdata->irqen |= RTC_AF;
340 ds1511_rtc_update_alarm(pdata);
341 return 0;
344 static int
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);
350 if (pdata->irq <= 0)
351 return -EINVAL;
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;
358 return 0;
361 static irqreturn_t
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) {
373 events = RTC_IRQF;
374 if (rtc_read(RTC_ALARM_SEC) & 0x80)
375 events |= RTC_UF;
376 else
377 events |= RTC_AF;
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);
390 if (pdata->irq <= 0)
391 return -EINVAL;
392 if (enabled)
393 pdata->irqen |= RTC_AF;
394 else
395 pdata->irqen &= ~RTC_AF;
396 ds1511_rtc_update_alarm(pdata);
397 return 0;
400 static const struct rtc_class_ops ds1511_rtc_ops = {
401 .read_time = ds1511_rtc_read_time,
402 .set_time = ds1511_rtc_set_time,
403 .read_alarm = ds1511_rtc_read_alarm,
404 .set_alarm = ds1511_rtc_set_alarm,
405 .alarm_irq_enable = ds1511_rtc_alarm_irq_enable,
408 static ssize_t
409 ds1511_nvram_read(struct file *filp, struct kobject *kobj,
410 struct bin_attribute *ba,
411 char *buf, loff_t pos, size_t size)
413 ssize_t count;
416 * if count is more than one, turn on "burst" mode
417 * turn it off when you're done
419 if (size > 1) {
420 rtc_write((rtc_read(RTC_CMD) | DS1511_BME), RTC_CMD);
422 if (pos > DS1511_RAM_MAX) {
423 pos = DS1511_RAM_MAX;
425 if (size + pos > DS1511_RAM_MAX + 1) {
426 size = DS1511_RAM_MAX - pos + 1;
428 rtc_write(pos, DS1511_RAMADDR_LSB);
429 for (count = 0; size > 0; count++, size--) {
430 *buf++ = rtc_read(DS1511_RAMDATA);
432 if (count > 1) {
433 rtc_write((rtc_read(RTC_CMD) & ~DS1511_BME), RTC_CMD);
435 return count;
438 static ssize_t
439 ds1511_nvram_write(struct file *filp, struct kobject *kobj,
440 struct bin_attribute *bin_attr,
441 char *buf, loff_t pos, size_t size)
443 ssize_t count;
446 * if count is more than one, turn on "burst" mode
447 * turn it off when you're done
449 if (size > 1) {
450 rtc_write((rtc_read(RTC_CMD) | DS1511_BME), RTC_CMD);
452 if (pos > DS1511_RAM_MAX) {
453 pos = DS1511_RAM_MAX;
455 if (size + pos > DS1511_RAM_MAX + 1) {
456 size = DS1511_RAM_MAX - pos + 1;
458 rtc_write(pos, DS1511_RAMADDR_LSB);
459 for (count = 0; size > 0; count++, size--) {
460 rtc_write(*buf++, DS1511_RAMDATA);
462 if (count > 1) {
463 rtc_write((rtc_read(RTC_CMD) & ~DS1511_BME), RTC_CMD);
465 return count;
468 static struct bin_attribute ds1511_nvram_attr = {
469 .attr = {
470 .name = "nvram",
471 .mode = S_IRUGO | S_IWUSR,
473 .size = DS1511_RAM_MAX,
474 .read = ds1511_nvram_read,
475 .write = ds1511_nvram_write,
478 static int __devinit
479 ds1511_rtc_probe(struct platform_device *pdev)
481 struct rtc_device *rtc;
482 struct resource *res;
483 struct rtc_plat_data *pdata;
484 int ret = 0;
486 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
487 if (!res) {
488 return -ENODEV;
490 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
491 if (!pdata)
492 return -ENOMEM;
493 pdata->size = resource_size(res);
494 if (!devm_request_mem_region(&pdev->dev, res->start, pdata->size,
495 pdev->name))
496 return -EBUSY;
497 ds1511_base = devm_ioremap(&pdev->dev, res->start, pdata->size);
498 if (!ds1511_base)
499 return -ENOMEM;
500 pdata->ioaddr = ds1511_base;
501 pdata->irq = platform_get_irq(pdev, 0);
504 * turn on the clock and the crystal, etc.
506 rtc_write(0, RTC_CMD);
507 rtc_write(0, RTC_CMD1);
509 * clear the wdog counter
511 rtc_write(0, DS1511_WD_MSEC);
512 rtc_write(0, DS1511_WD_SEC);
514 * start the clock
516 rtc_enable_update();
519 * check for a dying bat-tree
521 if (rtc_read(RTC_CMD1) & DS1511_BLF1) {
522 dev_warn(&pdev->dev, "voltage-low detected.\n");
525 spin_lock_init(&pdata->lock);
526 platform_set_drvdata(pdev, pdata);
528 * if the platform has an interrupt in mind for this device,
529 * then by all means, set it
531 if (pdata->irq > 0) {
532 rtc_read(RTC_CMD1);
533 if (devm_request_irq(&pdev->dev, pdata->irq, ds1511_interrupt,
534 IRQF_DISABLED | IRQF_SHARED, pdev->name, pdev) < 0) {
536 dev_warn(&pdev->dev, "interrupt not available.\n");
537 pdata->irq = 0;
541 rtc = rtc_device_register(pdev->name, &pdev->dev, &ds1511_rtc_ops,
542 THIS_MODULE);
543 if (IS_ERR(rtc))
544 return PTR_ERR(rtc);
545 pdata->rtc = rtc;
547 ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr);
548 if (ret)
549 rtc_device_unregister(pdata->rtc);
550 return ret;
553 static int __devexit
554 ds1511_rtc_remove(struct platform_device *pdev)
556 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
558 sysfs_remove_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr);
559 rtc_device_unregister(pdata->rtc);
560 if (pdata->irq > 0) {
562 * disable the alarm interrupt
564 rtc_write(rtc_read(RTC_CMD) & ~RTC_TIE, RTC_CMD);
565 rtc_read(RTC_CMD1);
567 return 0;
570 /* work with hotplug and coldplug */
571 MODULE_ALIAS("platform:ds1511");
573 static struct platform_driver ds1511_rtc_driver = {
574 .probe = ds1511_rtc_probe,
575 .remove = __devexit_p(ds1511_rtc_remove),
576 .driver = {
577 .name = "ds1511",
578 .owner = THIS_MODULE,
582 static int __init
583 ds1511_rtc_init(void)
585 return platform_driver_register(&ds1511_rtc_driver);
588 static void __exit
589 ds1511_rtc_exit(void)
591 platform_driver_unregister(&ds1511_rtc_driver);
594 module_init(ds1511_rtc_init);
595 module_exit(ds1511_rtc_exit);
597 MODULE_AUTHOR("Andrew Sharp <andy.sharp@lsi.com>");
598 MODULE_DESCRIPTION("Dallas DS1511 RTC driver");
599 MODULE_LICENSE("GPL");
600 MODULE_VERSION(DRV_VERSION);