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hwmon: (adt7475) fan stall prevention
[linux/fpc-iii.git] / drivers / rtc / rtc-at91rm9200.c
blobb60fd477778f7fed1e8c1a510d80646f47d8373f
1 /*
2 * Real Time Clock interface for Linux on Atmel AT91RM9200
3 *
4 * Copyright (C) 2002 Rick Bronson
5 *
6 * Converted to RTC class model by Andrew Victor
7 *
8 * Ported to Linux 2.6 by Steven Scholz
9 * Based on s3c2410-rtc.c Simtec Electronics
10 *
11 * Based on sa1100-rtc.c by Nils Faerber
12 * Based on rtc.c by Paul Gortmaker
13 *
14 * This program is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU General Public License
16 * as published by the Free Software Foundation; either version
17 * 2 of the License, or (at your option) any later version.
18 *
19 */
20
21 #include <linux/bcd.h>
22 #include <linux/clk.h>
23 #include <linux/completion.h>
24 #include <linux/interrupt.h>
25 #include <linux/ioctl.h>
26 #include <linux/io.h>
27 #include <linux/kernel.h>
28 #include <linux/module.h>
29 #include <linux/of_device.h>
30 #include <linux/of.h>
31 #include <linux/platform_device.h>
32 #include <linux/rtc.h>
33 #include <linux/spinlock.h>
34 #include <linux/suspend.h>
35 #include <linux/time.h>
36 #include <linux/uaccess.h>
37
38 #include "rtc-at91rm9200.h"
39
40 #define at91_rtc_read(field) \
41 readl_relaxed(at91_rtc_regs + field)
42 #define at91_rtc_write(field, val) \
43 writel_relaxed((val), at91_rtc_regs + field)
44
45 #define AT91_RTC_EPOCH 1900UL /* just like arch/arm/common/rtctime.c */
46
47 struct at91_rtc_config {
48 bool use_shadow_imr;
49 };
50
51 static const struct at91_rtc_config *at91_rtc_config;
52 static DECLARE_COMPLETION(at91_rtc_updated);
53 static DECLARE_COMPLETION(at91_rtc_upd_rdy);
54 static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
55 static void __iomem *at91_rtc_regs;
56 static int irq;
57 static DEFINE_SPINLOCK(at91_rtc_lock);
58 static u32 at91_rtc_shadow_imr;
59 static bool suspended;
60 static DEFINE_SPINLOCK(suspended_lock);
61 static unsigned long cached_events;
62 static u32 at91_rtc_imr;
63 static struct clk *sclk;
64
65 static void at91_rtc_write_ier(u32 mask)
66 {
67 unsigned long flags;
68
69 spin_lock_irqsave(&at91_rtc_lock, flags);
70 at91_rtc_shadow_imr |= mask;
71 at91_rtc_write(AT91_RTC_IER, mask);
72 spin_unlock_irqrestore(&at91_rtc_lock, flags);
73 }
74
75 static void at91_rtc_write_idr(u32 mask)
76 {
77 unsigned long flags;
78
79 spin_lock_irqsave(&at91_rtc_lock, flags);
80 at91_rtc_write(AT91_RTC_IDR, mask);
81 /*
82 * Register read back (of any RTC-register) needed to make sure
83 * IDR-register write has reached the peripheral before updating
84 * shadow mask.
85 *
86 * Note that there is still a possibility that the mask is updated
87 * before interrupts have actually been disabled in hardware. The only
88 * way to be certain would be to poll the IMR-register, which is is
89 * the very register we are trying to emulate. The register read back
90 * is a reasonable heuristic.
91 */
92 at91_rtc_read(AT91_RTC_SR);
93 at91_rtc_shadow_imr &= ~mask;
94 spin_unlock_irqrestore(&at91_rtc_lock, flags);
95 }
96
97 static u32 at91_rtc_read_imr(void)
98 {
99 unsigned long flags;
100 u32 mask;
101
102 if (at91_rtc_config->use_shadow_imr) {
103 spin_lock_irqsave(&at91_rtc_lock, flags);
104 mask = at91_rtc_shadow_imr;
105 spin_unlock_irqrestore(&at91_rtc_lock, flags);
106 } else {
107 mask = at91_rtc_read(AT91_RTC_IMR);
108 }
109
110 return mask;
111 }
112
113 /*
114 * Decode time/date into rtc_time structure
115 */
116 static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg,
117 struct rtc_time *tm)
118 {
119 unsigned int time, date;
120
121 /* must read twice in case it changes */
122 do {
123 time = at91_rtc_read(timereg);
124 date = at91_rtc_read(calreg);
125 } while ((time != at91_rtc_read(timereg)) ||
126 (date != at91_rtc_read(calreg)));
127
128 tm->tm_sec = bcd2bin((time & AT91_RTC_SEC) >> 0);
129 tm->tm_min = bcd2bin((time & AT91_RTC_MIN) >> 8);
130 tm->tm_hour = bcd2bin((time & AT91_RTC_HOUR) >> 16);
131
132 /*
133 * The Calendar Alarm register does not have a field for
134 * the year - so these will return an invalid value. When an
135 * alarm is set, at91_alarm_year will store the current year.
136 */
137 tm->tm_year = bcd2bin(date & AT91_RTC_CENT) * 100; /* century */
138 tm->tm_year += bcd2bin((date & AT91_RTC_YEAR) >> 8); /* year */
139
140 tm->tm_wday = bcd2bin((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */
141 tm->tm_mon = bcd2bin((date & AT91_RTC_MONTH) >> 16) - 1;
142 tm->tm_mday = bcd2bin((date & AT91_RTC_DATE) >> 24);
143 }
144
145 /*
146 * Read current time and date in RTC
147 */
148 static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
149 {
150 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm);
151 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
152 tm->tm_year = tm->tm_year - 1900;
153
154 dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
155 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
156 tm->tm_hour, tm->tm_min, tm->tm_sec);
157
158 return 0;
159 }
160
161 /*
162 * Set current time and date in RTC
163 */
164 static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
165 {
166 unsigned long cr;
167
168 dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
169 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
170 tm->tm_hour, tm->tm_min, tm->tm_sec);
171
172 wait_for_completion(&at91_rtc_upd_rdy);
173
174 /* Stop Time/Calendar from counting */
175 cr = at91_rtc_read(AT91_RTC_CR);
176 at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);
177
178 at91_rtc_write_ier(AT91_RTC_ACKUPD);
179 wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */
180 at91_rtc_write_idr(AT91_RTC_ACKUPD);
181
182 at91_rtc_write(AT91_RTC_TIMR,
183 bin2bcd(tm->tm_sec) << 0
184 | bin2bcd(tm->tm_min) << 8
185 | bin2bcd(tm->tm_hour) << 16);
186
187 at91_rtc_write(AT91_RTC_CALR,
188 bin2bcd((tm->tm_year + 1900) / 100) /* century */
189 | bin2bcd(tm->tm_year % 100) << 8 /* year */
190 | bin2bcd(tm->tm_mon + 1) << 16 /* tm_mon starts at zero */
191 | bin2bcd(tm->tm_wday + 1) << 21 /* day of the week [0-6], Sunday=0 */
192 | bin2bcd(tm->tm_mday) << 24);
193
194 /* Restart Time/Calendar */
195 cr = at91_rtc_read(AT91_RTC_CR);
196 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_SECEV);
197 at91_rtc_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM));
198 at91_rtc_write_ier(AT91_RTC_SECEV);
199
200 return 0;
201 }
202
203 /*
204 * Read alarm time and date in RTC
205 */
206 static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
207 {
208 struct rtc_time *tm = &alrm->time;
209
210 at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm);
211 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
212 tm->tm_year = at91_alarm_year - 1900;
213
214 alrm->enabled = (at91_rtc_read_imr() & AT91_RTC_ALARM)
215 ? 1 : 0;
216
217 dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
218 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
219 tm->tm_hour, tm->tm_min, tm->tm_sec);
220
221 return 0;
222 }
223
224 /*
225 * Set alarm time and date in RTC
226 */
227 static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
228 {
229 struct rtc_time tm;
230
231 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm);
232
233 at91_alarm_year = tm.tm_year;
234
235 tm.tm_mon = alrm->time.tm_mon;
236 tm.tm_mday = alrm->time.tm_mday;
237 tm.tm_hour = alrm->time.tm_hour;
238 tm.tm_min = alrm->time.tm_min;
239 tm.tm_sec = alrm->time.tm_sec;
240
241 at91_rtc_write_idr(AT91_RTC_ALARM);
242 at91_rtc_write(AT91_RTC_TIMALR,
243 bin2bcd(tm.tm_sec) << 0
244 | bin2bcd(tm.tm_min) << 8
245 | bin2bcd(tm.tm_hour) << 16
246 | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN);
247 at91_rtc_write(AT91_RTC_CALALR,
248 bin2bcd(tm.tm_mon + 1) << 16 /* tm_mon starts at zero */
249 | bin2bcd(tm.tm_mday) << 24
250 | AT91_RTC_DATEEN | AT91_RTC_MTHEN);
251
252 if (alrm->enabled) {
253 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
254 at91_rtc_write_ier(AT91_RTC_ALARM);
255 }
256
257 dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
258 at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour,
259 tm.tm_min, tm.tm_sec);
260
261 return 0;
262 }
263
264 static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
265 {
266 dev_dbg(dev, "%s(): cmd=%08x\n", __func__, enabled);
267
268 if (enabled) {
269 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
270 at91_rtc_write_ier(AT91_RTC_ALARM);
271 } else
272 at91_rtc_write_idr(AT91_RTC_ALARM);
273
274 return 0;
275 }
276 /*
277 * Provide additional RTC information in /proc/driver/rtc
278 */
279 static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
280 {
281 unsigned long imr = at91_rtc_read_imr();
282
283 seq_printf(seq, "update_IRQ\t: %s\n",
284 (imr & AT91_RTC_ACKUPD) ? "yes" : "no");
285 seq_printf(seq, "periodic_IRQ\t: %s\n",
286 (imr & AT91_RTC_SECEV) ? "yes" : "no");
287
288 return 0;
289 }
290
291 /*
292 * IRQ handler for the RTC
293 */
294 static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
295 {
296 struct platform_device *pdev = dev_id;
297 struct rtc_device *rtc = platform_get_drvdata(pdev);
298 unsigned int rtsr;
299 unsigned long events = 0;
300 int ret = IRQ_NONE;
301
302 spin_lock(&suspended_lock);
303 rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_read_imr();
304 if (rtsr) { /* this interrupt is shared! Is it ours? */
305 if (rtsr & AT91_RTC_ALARM)
306 events |= (RTC_AF | RTC_IRQF);
307 if (rtsr & AT91_RTC_SECEV) {
308 complete(&at91_rtc_upd_rdy);
309 at91_rtc_write_idr(AT91_RTC_SECEV);
310 }
311 if (rtsr & AT91_RTC_ACKUPD)
312 complete(&at91_rtc_updated);
313
314 at91_rtc_write(AT91_RTC_SCCR, rtsr); /* clear status reg */
315
316 if (!suspended) {
317 rtc_update_irq(rtc, 1, events);
318
319 dev_dbg(&pdev->dev, "%s(): num=%ld, events=0x%02lx\n",
320 __func__, events >> 8, events & 0x000000FF);
321 } else {
322 cached_events |= events;
323 at91_rtc_write_idr(at91_rtc_imr);
324 pm_system_wakeup();
325 }
326
327 ret = IRQ_HANDLED;
328 }
329 spin_unlock(&suspended_lock);
330
331 return ret;
332 }
333
334 static const struct at91_rtc_config at91rm9200_config = {
335 };
336
337 static const struct at91_rtc_config at91sam9x5_config = {
338 .use_shadow_imr = true,
339 };
340
341 #ifdef CONFIG_OF
342 static const struct of_device_id at91_rtc_dt_ids[] = {
343 {
344 .compatible = "atmel,at91rm9200-rtc",
345 .data = &at91rm9200_config,
346 }, {
347 .compatible = "atmel,at91sam9x5-rtc",
348 .data = &at91sam9x5_config,
349 }, {
350 /* sentinel */
351 }
352 };
353 MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids);
354 #endif
355
356 static const struct at91_rtc_config *
357 at91_rtc_get_config(struct platform_device *pdev)
358 {
359 const struct of_device_id *match;
360
361 if (pdev->dev.of_node) {
362 match = of_match_node(at91_rtc_dt_ids, pdev->dev.of_node);
363 if (!match)
364 return NULL;
365 return (const struct at91_rtc_config *)match->data;
366 }
367
368 return &at91rm9200_config;
369 }
370
371 static const struct rtc_class_ops at91_rtc_ops = {
372 .read_time = at91_rtc_readtime,
373 .set_time = at91_rtc_settime,
374 .read_alarm = at91_rtc_readalarm,
375 .set_alarm = at91_rtc_setalarm,
376 .proc = at91_rtc_proc,
377 .alarm_irq_enable = at91_rtc_alarm_irq_enable,
378 };
379
380 /*
381 * Initialize and install RTC driver
382 */
383 static int __init at91_rtc_probe(struct platform_device *pdev)
384 {
385 struct rtc_device *rtc;
386 struct resource *regs;
387 int ret = 0;
388
389 at91_rtc_config = at91_rtc_get_config(pdev);
390 if (!at91_rtc_config)
391 return -ENODEV;
392
393 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
394 if (!regs) {
395 dev_err(&pdev->dev, "no mmio resource defined\n");
396 return -ENXIO;
397 }
398
399 irq = platform_get_irq(pdev, 0);
400 if (irq < 0) {
401 dev_err(&pdev->dev, "no irq resource defined\n");
402 return -ENXIO;
403 }
404
405 at91_rtc_regs = devm_ioremap(&pdev->dev, regs->start,
406 resource_size(regs));
407 if (!at91_rtc_regs) {
408 dev_err(&pdev->dev, "failed to map registers, aborting.\n");
409 return -ENOMEM;
410 }
411
412 sclk = devm_clk_get(&pdev->dev, NULL);
413 if (IS_ERR(sclk))
414 return PTR_ERR(sclk);
415
416 ret = clk_prepare_enable(sclk);
417 if (ret) {
418 dev_err(&pdev->dev, "Could not enable slow clock\n");
419 return ret;
420 }
421
422 at91_rtc_write(AT91_RTC_CR, 0);
423 at91_rtc_write(AT91_RTC_MR, 0); /* 24 hour mode */
424
425 /* Disable all interrupts */
426 at91_rtc_write_idr(AT91_RTC_ACKUPD | AT91_RTC_ALARM |
427 AT91_RTC_SECEV | AT91_RTC_TIMEV |
428 AT91_RTC_CALEV);
429
430 ret = devm_request_irq(&pdev->dev, irq, at91_rtc_interrupt,
431 IRQF_SHARED | IRQF_COND_SUSPEND,
432 "at91_rtc", pdev);
433 if (ret) {
434 dev_err(&pdev->dev, "IRQ %d already in use.\n", irq);
435 goto err_clk;
436 }
437
438 /* cpu init code should really have flagged this device as
439 * being wake-capable; if it didn't, do that here.
440 */
441 if (!device_can_wakeup(&pdev->dev))
442 device_init_wakeup(&pdev->dev, 1);
443
444 rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
445 &at91_rtc_ops, THIS_MODULE);
446 if (IS_ERR(rtc)) {
447 ret = PTR_ERR(rtc);
448 goto err_clk;
449 }
450 platform_set_drvdata(pdev, rtc);
451
452 /* enable SECEV interrupt in order to initialize at91_rtc_upd_rdy
453 * completion.
454 */
455 at91_rtc_write_ier(AT91_RTC_SECEV);
456
457 dev_info(&pdev->dev, "AT91 Real Time Clock driver.\n");
458 return 0;
459
460 err_clk:
461 clk_disable_unprepare(sclk);
462
463 return ret;
464 }
465
466 /*
467 * Disable and remove the RTC driver
468 */
469 static int __exit at91_rtc_remove(struct platform_device *pdev)
470 {
471 /* Disable all interrupts */
472 at91_rtc_write_idr(AT91_RTC_ACKUPD | AT91_RTC_ALARM |
473 AT91_RTC_SECEV | AT91_RTC_TIMEV |
474 AT91_RTC_CALEV);
475
476 clk_disable_unprepare(sclk);
477
478 return 0;
479 }
480
481 static void at91_rtc_shutdown(struct platform_device *pdev)
482 {
483 /* Disable all interrupts */
484 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
485 AT91_RTC_SECEV | AT91_RTC_TIMEV |
486 AT91_RTC_CALEV);
487 }
488
489 #ifdef CONFIG_PM_SLEEP
490
491 /* AT91RM9200 RTC Power management control */
492
493 static int at91_rtc_suspend(struct device *dev)
494 {
495 /* this IRQ is shared with DBGU and other hardware which isn't
496 * necessarily doing PM like we are...
497 */
498 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
499
500 at91_rtc_imr = at91_rtc_read_imr()
501 & (AT91_RTC_ALARM|AT91_RTC_SECEV);
502 if (at91_rtc_imr) {
503 if (device_may_wakeup(dev)) {
504 unsigned long flags;
505
506 enable_irq_wake(irq);
507
508 spin_lock_irqsave(&suspended_lock, flags);
509 suspended = true;
510 spin_unlock_irqrestore(&suspended_lock, flags);
511 } else {
512 at91_rtc_write_idr(at91_rtc_imr);
513 }
514 }
515 return 0;
516 }
517
518 static int at91_rtc_resume(struct device *dev)
519 {
520 struct rtc_device *rtc = dev_get_drvdata(dev);
521
522 if (at91_rtc_imr) {
523 if (device_may_wakeup(dev)) {
524 unsigned long flags;
525
526 spin_lock_irqsave(&suspended_lock, flags);
527
528 if (cached_events) {
529 rtc_update_irq(rtc, 1, cached_events);
530 cached_events = 0;
531 }
532
533 suspended = false;
534 spin_unlock_irqrestore(&suspended_lock, flags);
535
536 disable_irq_wake(irq);
537 }
538 at91_rtc_write_ier(at91_rtc_imr);
539 }
540 return 0;
541 }
542 #endif
543
544 static SIMPLE_DEV_PM_OPS(at91_rtc_pm_ops, at91_rtc_suspend, at91_rtc_resume);
545
546 static struct platform_driver at91_rtc_driver = {
547 .remove = __exit_p(at91_rtc_remove),
548 .shutdown = at91_rtc_shutdown,
549 .driver = {
550 .name = "at91_rtc",
551 .pm = &at91_rtc_pm_ops,
552 .of_match_table = of_match_ptr(at91_rtc_dt_ids),
553 },
554 };
555
556 module_platform_driver_probe(at91_rtc_driver, at91_rtc_probe);
557
558 MODULE_AUTHOR("Rick Bronson");
559 MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
560 MODULE_LICENSE("GPL");
561 MODULE_ALIAS("platform:at91_rtc");
Linux with added FPC-III support