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1/*
2 * An rtc driver for the Dallas DS1511
3 *
4 * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
5 * Copyright (C) 2007 Andrew Sharp <andy.sharp@lsi.com>
6 *
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.
10 *
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.
15 */
16
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>
26#include <linux/module.h>
27
28#define DRV_VERSION "0.6"
29
30enum ds1511reg {
31 DS1511_SEC = 0x0,
32 DS1511_MIN = 0x1,
33 DS1511_HOUR = 0x2,
34 DS1511_DOW = 0x3,
35 DS1511_DOM = 0x4,
36 DS1511_MONTH = 0x5,
37 DS1511_YEAR = 0x6,
38 DS1511_CENTURY = 0x7,
39 DS1511_AM1_SEC = 0x8,
40 DS1511_AM2_MIN = 0x9,
41 DS1511_AM3_HOUR = 0xa,
42 DS1511_AM4_DATE = 0xb,
43 DS1511_WD_MSEC = 0xc,
44 DS1511_WD_SEC = 0xd,
45 DS1511_CONTROL_A = 0xe,
46 DS1511_CONTROL_B = 0xf,
47 DS1511_RAMADDR_LSB = 0x10,
48 DS1511_RAMDATA = 0x13
49};
50
51#define DS1511_BLF1 0x80
52#define DS1511_BLF2 0x40
53#define DS1511_PRS 0x20
54#define DS1511_PAB 0x10
55#define DS1511_TDF 0x08
56#define DS1511_KSF 0x04
57#define DS1511_WDF 0x02
58#define DS1511_IRQF 0x01
59#define DS1511_TE 0x80
60#define DS1511_CS 0x40
61#define DS1511_BME 0x20
62#define DS1511_TPE 0x10
63#define DS1511_TIE 0x08
64#define DS1511_KIE 0x04
65#define DS1511_WDE 0x02
66#define DS1511_WDS 0x01
67#define DS1511_RAM_MAX 0xff
68
69#define RTC_CMD DS1511_CONTROL_B
70#define RTC_CMD1 DS1511_CONTROL_A
71
72#define RTC_ALARM_SEC DS1511_AM1_SEC
73#define RTC_ALARM_MIN DS1511_AM2_MIN
74#define RTC_ALARM_HOUR DS1511_AM3_HOUR
75#define RTC_ALARM_DATE DS1511_AM4_DATE
76
77#define RTC_SEC DS1511_SEC
78#define RTC_MIN DS1511_MIN
79#define RTC_HOUR DS1511_HOUR
80#define RTC_DOW DS1511_DOW
81#define RTC_DOM DS1511_DOM
82#define RTC_MON DS1511_MONTH
83#define RTC_YEAR DS1511_YEAR
84#define RTC_CENTURY DS1511_CENTURY
85
86#define RTC_TIE DS1511_TIE
87#define RTC_TE DS1511_TE
88
89struct rtc_plat_data {
90 struct rtc_device *rtc;
91 void __iomem *ioaddr; /* virtual base address */
92 int size; /* amount of memory mapped */
93 int irq;
94 unsigned int irqen;
95 int alrm_sec;
96 int alrm_min;
97 int alrm_hour;
98 int alrm_mday;
99 spinlock_t lock;
100};
101
102static DEFINE_SPINLOCK(ds1511_lock);
103
104static __iomem char *ds1511_base;
105static u32 reg_spacing = 1;
106
107 static noinline void
108rtc_write(uint8_t val, uint32_t reg)
109{
110 writeb(val, ds1511_base + (reg * reg_spacing));
111}
112
113 static inline void
114rtc_write_alarm(uint8_t val, enum ds1511reg reg)
115{
116 rtc_write((val | 0x80), reg);
117}
118
119 static noinline uint8_t
120rtc_read(enum ds1511reg reg)
121{
122 return readb(ds1511_base + (reg * reg_spacing));
123}
124
125 static inline void
126rtc_disable_update(void)
127{
128 rtc_write((rtc_read(RTC_CMD) & ~RTC_TE), RTC_CMD);
129}
130
131 static void
132rtc_enable_update(void)
133{
134 rtc_write((rtc_read(RTC_CMD) | RTC_TE), RTC_CMD);
135}
136
137/*
138 * #define DS1511_WDOG_RESET_SUPPORT
139 *
140 * Uncomment this if you want to use these routines in
141 * some platform code.
142 */
143#ifdef DS1511_WDOG_RESET_SUPPORT
144/*
145 * just enough code to set the watchdog timer so that it
146 * will reboot the system
147 */
148 void
149ds1511_wdog_set(unsigned long deciseconds)
150{
151 /*
152 * the wdog timer can take 99.99 seconds
153 */
154 deciseconds %= 10000;
155 /*
156 * set the wdog values in the wdog registers
157 */
158 rtc_write(bin2bcd(deciseconds % 100), DS1511_WD_MSEC);
159 rtc_write(bin2bcd(deciseconds / 100), DS1511_WD_SEC);
160 /*
161 * set wdog enable and wdog 'steering' bit to issue a reset
162 */
163 rtc_write(DS1511_WDE | DS1511_WDS, RTC_CMD);
164}
165
166 void
167ds1511_wdog_disable(void)
168{
169 /*
170 * clear wdog enable and wdog 'steering' bits
171 */
172 rtc_write(rtc_read(RTC_CMD) & ~(DS1511_WDE | DS1511_WDS), RTC_CMD);
173 /*
174 * clear the wdog counter
175 */
176 rtc_write(0, DS1511_WD_MSEC);
177 rtc_write(0, DS1511_WD_SEC);
178}
179#endif
180
181/*
182 * set the rtc chip's idea of the time.
183 * stupidly, some callers call with year unmolested;
184 * and some call with year = year - 1900. thanks.
185 */
186static int ds1511_rtc_set_time(struct device *dev, struct rtc_time *rtc_tm)
187{
188 u8 mon, day, dow, hrs, min, sec, yrs, cen;
189 unsigned long flags;
190
191 /*
192 * won't have to change this for a while
193 */
194 if (rtc_tm->tm_year < 1900) {
195 rtc_tm->tm_year += 1900;
196 }
197
198 if (rtc_tm->tm_year < 1970) {
199 return -EINVAL;
200 }
201 yrs = rtc_tm->tm_year % 100;
202 cen = rtc_tm->tm_year / 100;
203 mon = rtc_tm->tm_mon + 1; /* tm_mon starts at zero */
204 day = rtc_tm->tm_mday;
205 dow = rtc_tm->tm_wday & 0x7; /* automatic BCD */
206 hrs = rtc_tm->tm_hour;
207 min = rtc_tm->tm_min;
208 sec = rtc_tm->tm_sec;
209
210 if ((mon > 12) || (day == 0)) {
211 return -EINVAL;
212 }
213
214 if (day > rtc_month_days(rtc_tm->tm_mon, rtc_tm->tm_year)) {
215 return -EINVAL;
216 }
217
218 if ((hrs >= 24) || (min >= 60) || (sec >= 60)) {
219 return -EINVAL;
220 }
221
222 /*
223 * each register is a different number of valid bits
224 */
225 sec = bin2bcd(sec) & 0x7f;
226 min = bin2bcd(min) & 0x7f;
227 hrs = bin2bcd(hrs) & 0x3f;
228 day = bin2bcd(day) & 0x3f;
229 mon = bin2bcd(mon) & 0x1f;
230 yrs = bin2bcd(yrs) & 0xff;
231 cen = bin2bcd(cen) & 0xff;
232
233 spin_lock_irqsave(&ds1511_lock, flags);
234 rtc_disable_update();
235 rtc_write(cen, RTC_CENTURY);
236 rtc_write(yrs, RTC_YEAR);
237 rtc_write((rtc_read(RTC_MON) & 0xe0) | mon, RTC_MON);
238 rtc_write(day, RTC_DOM);
239 rtc_write(hrs, RTC_HOUR);
240 rtc_write(min, RTC_MIN);
241 rtc_write(sec, RTC_SEC);
242 rtc_write(dow, RTC_DOW);
243 rtc_enable_update();
244 spin_unlock_irqrestore(&ds1511_lock, flags);
245
246 return 0;
247}
248
249static int ds1511_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
250{
251 unsigned int century;
252 unsigned long flags;
253
254 spin_lock_irqsave(&ds1511_lock, flags);
255 rtc_disable_update();
256
257 rtc_tm->tm_sec = rtc_read(RTC_SEC) & 0x7f;
258 rtc_tm->tm_min = rtc_read(RTC_MIN) & 0x7f;
259 rtc_tm->tm_hour = rtc_read(RTC_HOUR) & 0x3f;
260 rtc_tm->tm_mday = rtc_read(RTC_DOM) & 0x3f;
261 rtc_tm->tm_wday = rtc_read(RTC_DOW) & 0x7;
262 rtc_tm->tm_mon = rtc_read(RTC_MON) & 0x1f;
263 rtc_tm->tm_year = rtc_read(RTC_YEAR) & 0x7f;
264 century = rtc_read(RTC_CENTURY);
265
266 rtc_enable_update();
267 spin_unlock_irqrestore(&ds1511_lock, flags);
268
269 rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
270 rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
271 rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
272 rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
273 rtc_tm->tm_wday = bcd2bin(rtc_tm->tm_wday);
274 rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
275 rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
276 century = bcd2bin(century) * 100;
277
278 /*
279 * Account for differences between how the RTC uses the values
280 * and how they are defined in a struct rtc_time;
281 */
282 century += rtc_tm->tm_year;
283 rtc_tm->tm_year = century - 1900;
284
285 rtc_tm->tm_mon--;
286
287 if (rtc_valid_tm(rtc_tm) < 0) {
288 dev_err(dev, "retrieved date/time is not valid.\n");
289 rtc_time_to_tm(0, rtc_tm);
290 }
291 return 0;
292}
293
294/*
295 * write the alarm register settings
296 *
297 * we only have the use to interrupt every second, otherwise
298 * known as the update interrupt, or the interrupt if the whole
299 * date/hours/mins/secs matches. the ds1511 has many more
300 * permutations, but the kernel doesn't.
301 */
302 static void
303ds1511_rtc_update_alarm(struct rtc_plat_data *pdata)
304{
305 unsigned long flags;
306
307 spin_lock_irqsave(&pdata->lock, flags);
308 rtc_write(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ?
309 0x80 : bin2bcd(pdata->alrm_mday) & 0x3f,
310 RTC_ALARM_DATE);
311 rtc_write(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ?
312 0x80 : bin2bcd(pdata->alrm_hour) & 0x3f,
313 RTC_ALARM_HOUR);
314 rtc_write(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ?
315 0x80 : bin2bcd(pdata->alrm_min) & 0x7f,
316 RTC_ALARM_MIN);
317 rtc_write(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ?
318 0x80 : bin2bcd(pdata->alrm_sec) & 0x7f,
319 RTC_ALARM_SEC);
320 rtc_write(rtc_read(RTC_CMD) | (pdata->irqen ? RTC_TIE : 0), RTC_CMD);
321 rtc_read(RTC_CMD1); /* clear interrupts */
322 spin_unlock_irqrestore(&pdata->lock, flags);
323}
324
325 static int
326ds1511_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
327{
328 struct platform_device *pdev = to_platform_device(dev);
329 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
330
331 if (pdata->irq <= 0)
332 return -EINVAL;
333
334 pdata->alrm_mday = alrm->time.tm_mday;
335 pdata->alrm_hour = alrm->time.tm_hour;
336 pdata->alrm_min = alrm->time.tm_min;
337 pdata->alrm_sec = alrm->time.tm_sec;
338 if (alrm->enabled) {
339 pdata->irqen |= RTC_AF;
340 }
341 ds1511_rtc_update_alarm(pdata);
342 return 0;
343}
344
345 static int
346ds1511_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
347{
348 struct platform_device *pdev = to_platform_device(dev);
349 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
350
351 if (pdata->irq <= 0)
352 return -EINVAL;
353
354 alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
355 alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
356 alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
357 alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
358 alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
359 return 0;
360}
361
362 static irqreturn_t
363ds1511_interrupt(int irq, void *dev_id)
364{
365 struct platform_device *pdev = dev_id;
366 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
367 unsigned long events = 0;
368
369 spin_lock(&pdata->lock);
370 /*
371 * read and clear interrupt
372 */
373 if (rtc_read(RTC_CMD1) & DS1511_IRQF) {
374 events = RTC_IRQF;
375 if (rtc_read(RTC_ALARM_SEC) & 0x80)
376 events |= RTC_UF;
377 else
378 events |= RTC_AF;
379 if (likely(pdata->rtc))
380 rtc_update_irq(pdata->rtc, 1, events);
381 }
382 spin_unlock(&pdata->lock);
383 return events ? IRQ_HANDLED : IRQ_NONE;
384}
385
386static int ds1511_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
387{
388 struct platform_device *pdev = to_platform_device(dev);
389 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
390
391 if (pdata->irq <= 0)
392 return -EINVAL;
393 if (enabled)
394 pdata->irqen |= RTC_AF;
395 else
396 pdata->irqen &= ~RTC_AF;
397 ds1511_rtc_update_alarm(pdata);
398 return 0;
399}
400
401static const struct rtc_class_ops ds1511_rtc_ops = {
402 .read_time = ds1511_rtc_read_time,
403 .set_time = ds1511_rtc_set_time,
404 .read_alarm = ds1511_rtc_read_alarm,
405 .set_alarm = ds1511_rtc_set_alarm,
406 .alarm_irq_enable = ds1511_rtc_alarm_irq_enable,
407};
408
409 static ssize_t
410ds1511_nvram_read(struct file *filp, struct kobject *kobj,
411 struct bin_attribute *ba,
412 char *buf, loff_t pos, size_t size)
413{
414 ssize_t count;
415
416 /*
417 * if count is more than one, turn on "burst" mode
418 * turn it off when you're done
419 */
420 if (size > 1) {
421 rtc_write((rtc_read(RTC_CMD) | DS1511_BME), RTC_CMD);
422 }
423 if (pos > DS1511_RAM_MAX) {
424 pos = DS1511_RAM_MAX;
425 }
426 if (size + pos > DS1511_RAM_MAX + 1) {
427 size = DS1511_RAM_MAX - pos + 1;
428 }
429 rtc_write(pos, DS1511_RAMADDR_LSB);
430 for (count = 0; size > 0; count++, size--) {
431 *buf++ = rtc_read(DS1511_RAMDATA);
432 }
433 if (count > 1) {
434 rtc_write((rtc_read(RTC_CMD) & ~DS1511_BME), RTC_CMD);
435 }
436 return count;
437}
438
439 static ssize_t
440ds1511_nvram_write(struct file *filp, struct kobject *kobj,
441 struct bin_attribute *bin_attr,
442 char *buf, loff_t pos, size_t size)
443{
444 ssize_t count;
445
446 /*
447 * if count is more than one, turn on "burst" mode
448 * turn it off when you're done
449 */
450 if (size > 1) {
451 rtc_write((rtc_read(RTC_CMD) | DS1511_BME), RTC_CMD);
452 }
453 if (pos > DS1511_RAM_MAX) {
454 pos = DS1511_RAM_MAX;
455 }
456 if (size + pos > DS1511_RAM_MAX + 1) {
457 size = DS1511_RAM_MAX - pos + 1;
458 }
459 rtc_write(pos, DS1511_RAMADDR_LSB);
460 for (count = 0; size > 0; count++, size--) {
461 rtc_write(*buf++, DS1511_RAMDATA);
462 }
463 if (count > 1) {
464 rtc_write((rtc_read(RTC_CMD) & ~DS1511_BME), RTC_CMD);
465 }
466 return count;
467}
468
469static struct bin_attribute ds1511_nvram_attr = {
470 .attr = {
471 .name = "nvram",
472 .mode = S_IRUGO | S_IWUSR,
473 },
474 .size = DS1511_RAM_MAX,
475 .read = ds1511_nvram_read,
476 .write = ds1511_nvram_write,
477};
478
479 static int __devinit
480ds1511_rtc_probe(struct platform_device *pdev)
481{
482 struct rtc_device *rtc;
483 struct resource *res;
484 struct rtc_plat_data *pdata;
485 int ret = 0;
486
487 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
488 if (!res) {
489 return -ENODEV;
490 }
491 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
492 if (!pdata)
493 return -ENOMEM;
494 pdata->size = resource_size(res);
495 if (!devm_request_mem_region(&pdev->dev, res->start, pdata->size,
496 pdev->name))
497 return -EBUSY;
498 ds1511_base = devm_ioremap(&pdev->dev, res->start, pdata->size);
499 if (!ds1511_base)
500 return -ENOMEM;
501 pdata->ioaddr = ds1511_base;
502 pdata->irq = platform_get_irq(pdev, 0);
503
504 /*
505 * turn on the clock and the crystal, etc.
506 */
507 rtc_write(0, RTC_CMD);
508 rtc_write(0, RTC_CMD1);
509 /*
510 * clear the wdog counter
511 */
512 rtc_write(0, DS1511_WD_MSEC);
513 rtc_write(0, DS1511_WD_SEC);
514 /*
515 * start the clock
516 */
517 rtc_enable_update();
518
519 /*
520 * check for a dying bat-tree
521 */
522 if (rtc_read(RTC_CMD1) & DS1511_BLF1) {
523 dev_warn(&pdev->dev, "voltage-low detected.\n");
524 }
525
526 spin_lock_init(&pdata->lock);
527 platform_set_drvdata(pdev, pdata);
528 /*
529 * if the platform has an interrupt in mind for this device,
530 * then by all means, set it
531 */
532 if (pdata->irq > 0) {
533 rtc_read(RTC_CMD1);
534 if (devm_request_irq(&pdev->dev, pdata->irq, ds1511_interrupt,
535 IRQF_SHARED, pdev->name, pdev) < 0) {
536
537 dev_warn(&pdev->dev, "interrupt not available.\n");
538 pdata->irq = 0;
539 }
540 }
541
542 rtc = rtc_device_register(pdev->name, &pdev->dev, &ds1511_rtc_ops,
543 THIS_MODULE);
544 if (IS_ERR(rtc))
545 return PTR_ERR(rtc);
546 pdata->rtc = rtc;
547
548 ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr);
549 if (ret)
550 rtc_device_unregister(pdata->rtc);
551 return ret;
552}
553
554 static int __devexit
555ds1511_rtc_remove(struct platform_device *pdev)
556{
557 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
558
559 sysfs_remove_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr);
560 rtc_device_unregister(pdata->rtc);
561 if (pdata->irq > 0) {
562 /*
563 * disable the alarm interrupt
564 */
565 rtc_write(rtc_read(RTC_CMD) & ~RTC_TIE, RTC_CMD);
566 rtc_read(RTC_CMD1);
567 }
568 return 0;
569}
570
571/* work with hotplug and coldplug */
572MODULE_ALIAS("platform:ds1511");
573
574static struct platform_driver ds1511_rtc_driver = {
575 .probe = ds1511_rtc_probe,
576 .remove = __devexit_p(ds1511_rtc_remove),
577 .driver = {
578 .name = "ds1511",
579 .owner = THIS_MODULE,
580 },
581};
582
583module_platform_driver(ds1511_rtc_driver);
584
585MODULE_AUTHOR("Andrew Sharp <andy.sharp@lsi.com>");
586MODULE_DESCRIPTION("Dallas DS1511 RTC driver");
587MODULE_LICENSE("GPL");
588MODULE_VERSION(DRV_VERSION);
1/*
2 * An rtc driver for the Dallas DS1511
3 *
4 * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
5 * Copyright (C) 2007 Andrew Sharp <andy.sharp@lsi.com>
6 *
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.
10 *
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.
15 */
16
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>
26#include <linux/module.h>
27
28enum 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
47};
48
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 0x100
66
67#define RTC_CMD DS1511_CONTROL_B
68#define RTC_CMD1 DS1511_CONTROL_A
69
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
74
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
83
84#define RTC_TIE DS1511_TIE
85#define RTC_TE DS1511_TE
86
87struct rtc_plat_data {
88 struct rtc_device *rtc;
89 void __iomem *ioaddr; /* virtual base address */
90 int irq;
91 unsigned int irqen;
92 int alrm_sec;
93 int alrm_min;
94 int alrm_hour;
95 int alrm_mday;
96 spinlock_t lock;
97};
98
99static DEFINE_SPINLOCK(ds1511_lock);
100
101static __iomem char *ds1511_base;
102static u32 reg_spacing = 1;
103
104static noinline void
105rtc_write(uint8_t val, uint32_t reg)
106{
107 writeb(val, ds1511_base + (reg * reg_spacing));
108}
109
110static inline void
111rtc_write_alarm(uint8_t val, enum ds1511reg reg)
112{
113 rtc_write((val | 0x80), reg);
114}
115
116static noinline uint8_t
117rtc_read(enum ds1511reg reg)
118{
119 return readb(ds1511_base + (reg * reg_spacing));
120}
121
122static inline void
123rtc_disable_update(void)
124{
125 rtc_write((rtc_read(RTC_CMD) & ~RTC_TE), RTC_CMD);
126}
127
128static void
129rtc_enable_update(void)
130{
131 rtc_write((rtc_read(RTC_CMD) | RTC_TE), RTC_CMD);
132}
133
134/*
135 * #define DS1511_WDOG_RESET_SUPPORT
136 *
137 * Uncomment this if you want to use these routines in
138 * some platform code.
139 */
140#ifdef DS1511_WDOG_RESET_SUPPORT
141/*
142 * just enough code to set the watchdog timer so that it
143 * will reboot the system
144 */
145void
146ds1511_wdog_set(unsigned long deciseconds)
147{
148 /*
149 * the wdog timer can take 99.99 seconds
150 */
151 deciseconds %= 10000;
152 /*
153 * set the wdog values in the wdog registers
154 */
155 rtc_write(bin2bcd(deciseconds % 100), DS1511_WD_MSEC);
156 rtc_write(bin2bcd(deciseconds / 100), DS1511_WD_SEC);
157 /*
158 * set wdog enable and wdog 'steering' bit to issue a reset
159 */
160 rtc_write(rtc_read(RTC_CMD) | DS1511_WDE | DS1511_WDS, RTC_CMD);
161}
162
163void
164ds1511_wdog_disable(void)
165{
166 /*
167 * clear wdog enable and wdog 'steering' bits
168 */
169 rtc_write(rtc_read(RTC_CMD) & ~(DS1511_WDE | DS1511_WDS), RTC_CMD);
170 /*
171 * clear the wdog counter
172 */
173 rtc_write(0, DS1511_WD_MSEC);
174 rtc_write(0, DS1511_WD_SEC);
175}
176#endif
177
178/*
179 * set the rtc chip's idea of the time.
180 * stupidly, some callers call with year unmolested;
181 * and some call with year = year - 1900. thanks.
182 */
183static int ds1511_rtc_set_time(struct device *dev, struct rtc_time *rtc_tm)
184{
185 u8 mon, day, dow, hrs, min, sec, yrs, cen;
186 unsigned long flags;
187
188 /*
189 * won't have to change this for a while
190 */
191 if (rtc_tm->tm_year < 1900)
192 rtc_tm->tm_year += 1900;
193
194 if (rtc_tm->tm_year < 1970)
195 return -EINVAL;
196
197 yrs = rtc_tm->tm_year % 100;
198 cen = rtc_tm->tm_year / 100;
199 mon = rtc_tm->tm_mon + 1; /* tm_mon starts at zero */
200 day = rtc_tm->tm_mday;
201 dow = rtc_tm->tm_wday & 0x7; /* automatic BCD */
202 hrs = rtc_tm->tm_hour;
203 min = rtc_tm->tm_min;
204 sec = rtc_tm->tm_sec;
205
206 if ((mon > 12) || (day == 0))
207 return -EINVAL;
208
209 if (day > rtc_month_days(rtc_tm->tm_mon, rtc_tm->tm_year))
210 return -EINVAL;
211
212 if ((hrs >= 24) || (min >= 60) || (sec >= 60))
213 return -EINVAL;
214
215 /*
216 * each register is a different number of valid bits
217 */
218 sec = bin2bcd(sec) & 0x7f;
219 min = bin2bcd(min) & 0x7f;
220 hrs = bin2bcd(hrs) & 0x3f;
221 day = bin2bcd(day) & 0x3f;
222 mon = bin2bcd(mon) & 0x1f;
223 yrs = bin2bcd(yrs) & 0xff;
224 cen = bin2bcd(cen) & 0xff;
225
226 spin_lock_irqsave(&ds1511_lock, flags);
227 rtc_disable_update();
228 rtc_write(cen, RTC_CENTURY);
229 rtc_write(yrs, RTC_YEAR);
230 rtc_write((rtc_read(RTC_MON) & 0xe0) | mon, RTC_MON);
231 rtc_write(day, RTC_DOM);
232 rtc_write(hrs, RTC_HOUR);
233 rtc_write(min, RTC_MIN);
234 rtc_write(sec, RTC_SEC);
235 rtc_write(dow, RTC_DOW);
236 rtc_enable_update();
237 spin_unlock_irqrestore(&ds1511_lock, flags);
238
239 return 0;
240}
241
242static int ds1511_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
243{
244 unsigned int century;
245 unsigned long flags;
246
247 spin_lock_irqsave(&ds1511_lock, flags);
248 rtc_disable_update();
249
250 rtc_tm->tm_sec = rtc_read(RTC_SEC) & 0x7f;
251 rtc_tm->tm_min = rtc_read(RTC_MIN) & 0x7f;
252 rtc_tm->tm_hour = rtc_read(RTC_HOUR) & 0x3f;
253 rtc_tm->tm_mday = rtc_read(RTC_DOM) & 0x3f;
254 rtc_tm->tm_wday = rtc_read(RTC_DOW) & 0x7;
255 rtc_tm->tm_mon = rtc_read(RTC_MON) & 0x1f;
256 rtc_tm->tm_year = rtc_read(RTC_YEAR) & 0x7f;
257 century = rtc_read(RTC_CENTURY);
258
259 rtc_enable_update();
260 spin_unlock_irqrestore(&ds1511_lock, flags);
261
262 rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
263 rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
264 rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
265 rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
266 rtc_tm->tm_wday = bcd2bin(rtc_tm->tm_wday);
267 rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
268 rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
269 century = bcd2bin(century) * 100;
270
271 /*
272 * Account for differences between how the RTC uses the values
273 * and how they are defined in a struct rtc_time;
274 */
275 century += rtc_tm->tm_year;
276 rtc_tm->tm_year = century - 1900;
277
278 rtc_tm->tm_mon--;
279
280 return 0;
281}
282
283/*
284 * write the alarm register settings
285 *
286 * we only have the use to interrupt every second, otherwise
287 * known as the update interrupt, or the interrupt if the whole
288 * date/hours/mins/secs matches. the ds1511 has many more
289 * permutations, but the kernel doesn't.
290 */
291static void
292ds1511_rtc_update_alarm(struct rtc_plat_data *pdata)
293{
294 unsigned long flags;
295
296 spin_lock_irqsave(&pdata->lock, flags);
297 rtc_write(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ?
298 0x80 : bin2bcd(pdata->alrm_mday) & 0x3f,
299 RTC_ALARM_DATE);
300 rtc_write(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ?
301 0x80 : bin2bcd(pdata->alrm_hour) & 0x3f,
302 RTC_ALARM_HOUR);
303 rtc_write(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ?
304 0x80 : bin2bcd(pdata->alrm_min) & 0x7f,
305 RTC_ALARM_MIN);
306 rtc_write(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ?
307 0x80 : bin2bcd(pdata->alrm_sec) & 0x7f,
308 RTC_ALARM_SEC);
309 rtc_write(rtc_read(RTC_CMD) | (pdata->irqen ? RTC_TIE : 0), RTC_CMD);
310 rtc_read(RTC_CMD1); /* clear interrupts */
311 spin_unlock_irqrestore(&pdata->lock, flags);
312}
313
314static int
315ds1511_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
316{
317 struct platform_device *pdev = to_platform_device(dev);
318 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
319
320 if (pdata->irq <= 0)
321 return -EINVAL;
322
323 pdata->alrm_mday = alrm->time.tm_mday;
324 pdata->alrm_hour = alrm->time.tm_hour;
325 pdata->alrm_min = alrm->time.tm_min;
326 pdata->alrm_sec = alrm->time.tm_sec;
327 if (alrm->enabled)
328 pdata->irqen |= RTC_AF;
329
330 ds1511_rtc_update_alarm(pdata);
331 return 0;
332}
333
334static int
335ds1511_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
336{
337 struct platform_device *pdev = to_platform_device(dev);
338 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
339
340 if (pdata->irq <= 0)
341 return -EINVAL;
342
343 alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
344 alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
345 alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
346 alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
347 alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
348 return 0;
349}
350
351static irqreturn_t
352ds1511_interrupt(int irq, void *dev_id)
353{
354 struct platform_device *pdev = dev_id;
355 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
356 unsigned long events = 0;
357
358 spin_lock(&pdata->lock);
359 /*
360 * read and clear interrupt
361 */
362 if (rtc_read(RTC_CMD1) & DS1511_IRQF) {
363 events = RTC_IRQF;
364 if (rtc_read(RTC_ALARM_SEC) & 0x80)
365 events |= RTC_UF;
366 else
367 events |= RTC_AF;
368 rtc_update_irq(pdata->rtc, 1, events);
369 }
370 spin_unlock(&pdata->lock);
371 return events ? IRQ_HANDLED : IRQ_NONE;
372}
373
374static int ds1511_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
375{
376 struct platform_device *pdev = to_platform_device(dev);
377 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
378
379 if (pdata->irq <= 0)
380 return -EINVAL;
381 if (enabled)
382 pdata->irqen |= RTC_AF;
383 else
384 pdata->irqen &= ~RTC_AF;
385 ds1511_rtc_update_alarm(pdata);
386 return 0;
387}
388
389static const struct rtc_class_ops ds1511_rtc_ops = {
390 .read_time = ds1511_rtc_read_time,
391 .set_time = ds1511_rtc_set_time,
392 .read_alarm = ds1511_rtc_read_alarm,
393 .set_alarm = ds1511_rtc_set_alarm,
394 .alarm_irq_enable = ds1511_rtc_alarm_irq_enable,
395};
396
397static int ds1511_nvram_read(void *priv, unsigned int pos, void *buf,
398 size_t size)
399{
400 int i;
401
402 rtc_write(pos, DS1511_RAMADDR_LSB);
403 for (i = 0; i < size; i++)
404 *(char *)buf++ = rtc_read(DS1511_RAMDATA);
405
406 return 0;
407}
408
409static int ds1511_nvram_write(void *priv, unsigned int pos, void *buf,
410 size_t size)
411{
412 int i;
413
414 rtc_write(pos, DS1511_RAMADDR_LSB);
415 for (i = 0; i < size; i++)
416 rtc_write(*(char *)buf++, DS1511_RAMDATA);
417
418 return 0;
419}
420
421static int ds1511_rtc_probe(struct platform_device *pdev)
422{
423 struct resource *res;
424 struct rtc_plat_data *pdata;
425 int ret = 0;
426 struct nvmem_config ds1511_nvmem_cfg = {
427 .name = "ds1511_nvram",
428 .word_size = 1,
429 .stride = 1,
430 .size = DS1511_RAM_MAX,
431 .reg_read = ds1511_nvram_read,
432 .reg_write = ds1511_nvram_write,
433 .priv = &pdev->dev,
434 };
435
436 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
437 if (!pdata)
438 return -ENOMEM;
439
440 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
441 ds1511_base = devm_ioremap_resource(&pdev->dev, res);
442 if (IS_ERR(ds1511_base))
443 return PTR_ERR(ds1511_base);
444 pdata->ioaddr = ds1511_base;
445 pdata->irq = platform_get_irq(pdev, 0);
446
447 /*
448 * turn on the clock and the crystal, etc.
449 */
450 rtc_write(DS1511_BME, RTC_CMD);
451 rtc_write(0, RTC_CMD1);
452 /*
453 * clear the wdog counter
454 */
455 rtc_write(0, DS1511_WD_MSEC);
456 rtc_write(0, DS1511_WD_SEC);
457 /*
458 * start the clock
459 */
460 rtc_enable_update();
461
462 /*
463 * check for a dying bat-tree
464 */
465 if (rtc_read(RTC_CMD1) & DS1511_BLF1)
466 dev_warn(&pdev->dev, "voltage-low detected.\n");
467
468 spin_lock_init(&pdata->lock);
469 platform_set_drvdata(pdev, pdata);
470
471 pdata->rtc = devm_rtc_allocate_device(&pdev->dev);
472 if (IS_ERR(pdata->rtc))
473 return PTR_ERR(pdata->rtc);
474
475 pdata->rtc->ops = &ds1511_rtc_ops;
476
477 pdata->rtc->nvram_old_abi = true;
478
479 ret = rtc_register_device(pdata->rtc);
480 if (ret)
481 return ret;
482
483 rtc_nvmem_register(pdata->rtc, &ds1511_nvmem_cfg);
484
485 /*
486 * if the platform has an interrupt in mind for this device,
487 * then by all means, set it
488 */
489 if (pdata->irq > 0) {
490 rtc_read(RTC_CMD1);
491 if (devm_request_irq(&pdev->dev, pdata->irq, ds1511_interrupt,
492 IRQF_SHARED, pdev->name, pdev) < 0) {
493
494 dev_warn(&pdev->dev, "interrupt not available.\n");
495 pdata->irq = 0;
496 }
497 }
498
499 return 0;
500}
501
502/* work with hotplug and coldplug */
503MODULE_ALIAS("platform:ds1511");
504
505static struct platform_driver ds1511_rtc_driver = {
506 .probe = ds1511_rtc_probe,
507 .driver = {
508 .name = "ds1511",
509 },
510};
511
512module_platform_driver(ds1511_rtc_driver);
513
514MODULE_AUTHOR("Andrew Sharp <andy.sharp@lsi.com>");
515MODULE_DESCRIPTION("Dallas DS1511 RTC driver");
516MODULE_LICENSE("GPL");