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usb: gadget: udc: core: Document the relation between usb_ep_queue() and completion...
[linux/fpc-iii.git] / drivers / rtc / rtc-at91rm9200.c
blobde81ecedd571d8e0a1ff5ba1f5df59673d5efc60
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 struct at91_rtc_config {
46 bool use_shadow_imr;
47 };
48
49 static const struct at91_rtc_config *at91_rtc_config;
50 static DECLARE_COMPLETION(at91_rtc_updated);
51 static DECLARE_COMPLETION(at91_rtc_upd_rdy);
52 static void __iomem *at91_rtc_regs;
53 static int irq;
54 static DEFINE_SPINLOCK(at91_rtc_lock);
55 static u32 at91_rtc_shadow_imr;
56 static bool suspended;
57 static DEFINE_SPINLOCK(suspended_lock);
58 static unsigned long cached_events;
59 static u32 at91_rtc_imr;
60 static struct clk *sclk;
61
62 static void at91_rtc_write_ier(u32 mask)
63 {
64 unsigned long flags;
65
66 spin_lock_irqsave(&at91_rtc_lock, flags);
67 at91_rtc_shadow_imr |= mask;
68 at91_rtc_write(AT91_RTC_IER, mask);
69 spin_unlock_irqrestore(&at91_rtc_lock, flags);
70 }
71
72 static void at91_rtc_write_idr(u32 mask)
73 {
74 unsigned long flags;
75
76 spin_lock_irqsave(&at91_rtc_lock, flags);
77 at91_rtc_write(AT91_RTC_IDR, mask);
78 /*
79 * Register read back (of any RTC-register) needed to make sure
80 * IDR-register write has reached the peripheral before updating
81 * shadow mask.
82 *
83 * Note that there is still a possibility that the mask is updated
84 * before interrupts have actually been disabled in hardware. The only
85 * way to be certain would be to poll the IMR-register, which is is
86 * the very register we are trying to emulate. The register read back
87 * is a reasonable heuristic.
88 */
89 at91_rtc_read(AT91_RTC_SR);
90 at91_rtc_shadow_imr &= ~mask;
91 spin_unlock_irqrestore(&at91_rtc_lock, flags);
92 }
93
94 static u32 at91_rtc_read_imr(void)
95 {
96 unsigned long flags;
97 u32 mask;
98
99 if (at91_rtc_config->use_shadow_imr) {
100 spin_lock_irqsave(&at91_rtc_lock, flags);
101 mask = at91_rtc_shadow_imr;
102 spin_unlock_irqrestore(&at91_rtc_lock, flags);
103 } else {
104 mask = at91_rtc_read(AT91_RTC_IMR);
105 }
106
107 return mask;
108 }
109
110 /*
111 * Decode time/date into rtc_time structure
112 */
113 static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg,
114 struct rtc_time *tm)
115 {
116 unsigned int time, date;
117
118 /* must read twice in case it changes */
119 do {
120 time = at91_rtc_read(timereg);
121 date = at91_rtc_read(calreg);
122 } while ((time != at91_rtc_read(timereg)) ||
123 (date != at91_rtc_read(calreg)));
124
125 tm->tm_sec = bcd2bin((time & AT91_RTC_SEC) >> 0);
126 tm->tm_min = bcd2bin((time & AT91_RTC_MIN) >> 8);
127 tm->tm_hour = bcd2bin((time & AT91_RTC_HOUR) >> 16);
128
129 /*
130 * The Calendar Alarm register does not have a field for
131 * the year - so these will return an invalid value.
132 */
133 tm->tm_year = bcd2bin(date & AT91_RTC_CENT) * 100; /* century */
134 tm->tm_year += bcd2bin((date & AT91_RTC_YEAR) >> 8); /* year */
135
136 tm->tm_wday = bcd2bin((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */
137 tm->tm_mon = bcd2bin((date & AT91_RTC_MONTH) >> 16) - 1;
138 tm->tm_mday = bcd2bin((date & AT91_RTC_DATE) >> 24);
139 }
140
141 /*
142 * Read current time and date in RTC
143 */
144 static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
145 {
146 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm);
147 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
148 tm->tm_year = tm->tm_year - 1900;
149
150 dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
151 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
152 tm->tm_hour, tm->tm_min, tm->tm_sec);
153
154 return 0;
155 }
156
157 /*
158 * Set current time and date in RTC
159 */
160 static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
161 {
162 unsigned long cr;
163
164 dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
165 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
166 tm->tm_hour, tm->tm_min, tm->tm_sec);
167
168 wait_for_completion(&at91_rtc_upd_rdy);
169
170 /* Stop Time/Calendar from counting */
171 cr = at91_rtc_read(AT91_RTC_CR);
172 at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);
173
174 at91_rtc_write_ier(AT91_RTC_ACKUPD);
175 wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */
176 at91_rtc_write_idr(AT91_RTC_ACKUPD);
177
178 at91_rtc_write(AT91_RTC_TIMR,
179 bin2bcd(tm->tm_sec) << 0
180 | bin2bcd(tm->tm_min) << 8
181 | bin2bcd(tm->tm_hour) << 16);
182
183 at91_rtc_write(AT91_RTC_CALR,
184 bin2bcd((tm->tm_year + 1900) / 100) /* century */
185 | bin2bcd(tm->tm_year % 100) << 8 /* year */
186 | bin2bcd(tm->tm_mon + 1) << 16 /* tm_mon starts at zero */
187 | bin2bcd(tm->tm_wday + 1) << 21 /* day of the week [0-6], Sunday=0 */
188 | bin2bcd(tm->tm_mday) << 24);
189
190 /* Restart Time/Calendar */
191 cr = at91_rtc_read(AT91_RTC_CR);
192 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_SECEV);
193 at91_rtc_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM));
194 at91_rtc_write_ier(AT91_RTC_SECEV);
195
196 return 0;
197 }
198
199 /*
200 * Read alarm time and date in RTC
201 */
202 static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
203 {
204 struct rtc_time *tm = &alrm->time;
205
206 at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm);
207 tm->tm_year = -1;
208
209 alrm->enabled = (at91_rtc_read_imr() & AT91_RTC_ALARM)
210 ? 1 : 0;
211
212 dev_dbg(dev, "%s(): %02d-%02d %02d:%02d:%02d %sabled\n", __func__,
213 tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec,
214 alrm->enabled ? "en" : "dis");
215
216 return 0;
217 }
218
219 /*
220 * Set alarm time and date in RTC
221 */
222 static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
223 {
224 struct rtc_time tm;
225
226 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm);
227
228 tm.tm_mon = alrm->time.tm_mon;
229 tm.tm_mday = alrm->time.tm_mday;
230 tm.tm_hour = alrm->time.tm_hour;
231 tm.tm_min = alrm->time.tm_min;
232 tm.tm_sec = alrm->time.tm_sec;
233
234 at91_rtc_write_idr(AT91_RTC_ALARM);
235 at91_rtc_write(AT91_RTC_TIMALR,
236 bin2bcd(tm.tm_sec) << 0
237 | bin2bcd(tm.tm_min) << 8
238 | bin2bcd(tm.tm_hour) << 16
239 | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN);
240 at91_rtc_write(AT91_RTC_CALALR,
241 bin2bcd(tm.tm_mon + 1) << 16 /* tm_mon starts at zero */
242 | bin2bcd(tm.tm_mday) << 24
243 | AT91_RTC_DATEEN | AT91_RTC_MTHEN);
244
245 if (alrm->enabled) {
246 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
247 at91_rtc_write_ier(AT91_RTC_ALARM);
248 }
249
250 dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
251 tm.tm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour,
252 tm.tm_min, tm.tm_sec);
253
254 return 0;
255 }
256
257 static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
258 {
259 dev_dbg(dev, "%s(): cmd=%08x\n", __func__, enabled);
260
261 if (enabled) {
262 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
263 at91_rtc_write_ier(AT91_RTC_ALARM);
264 } else
265 at91_rtc_write_idr(AT91_RTC_ALARM);
266
267 return 0;
268 }
269 /*
270 * Provide additional RTC information in /proc/driver/rtc
271 */
272 static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
273 {
274 unsigned long imr = at91_rtc_read_imr();
275
276 seq_printf(seq, "update_IRQ\t: %s\n",
277 (imr & AT91_RTC_ACKUPD) ? "yes" : "no");
278 seq_printf(seq, "periodic_IRQ\t: %s\n",
279 (imr & AT91_RTC_SECEV) ? "yes" : "no");
280
281 return 0;
282 }
283
284 /*
285 * IRQ handler for the RTC
286 */
287 static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
288 {
289 struct platform_device *pdev = dev_id;
290 struct rtc_device *rtc = platform_get_drvdata(pdev);
291 unsigned int rtsr;
292 unsigned long events = 0;
293 int ret = IRQ_NONE;
294
295 spin_lock(&suspended_lock);
296 rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_read_imr();
297 if (rtsr) { /* this interrupt is shared! Is it ours? */
298 if (rtsr & AT91_RTC_ALARM)
299 events |= (RTC_AF | RTC_IRQF);
300 if (rtsr & AT91_RTC_SECEV) {
301 complete(&at91_rtc_upd_rdy);
302 at91_rtc_write_idr(AT91_RTC_SECEV);
303 }
304 if (rtsr & AT91_RTC_ACKUPD)
305 complete(&at91_rtc_updated);
306
307 at91_rtc_write(AT91_RTC_SCCR, rtsr); /* clear status reg */
308
309 if (!suspended) {
310 rtc_update_irq(rtc, 1, events);
311
312 dev_dbg(&pdev->dev, "%s(): num=%ld, events=0x%02lx\n",
313 __func__, events >> 8, events & 0x000000FF);
314 } else {
315 cached_events |= events;
316 at91_rtc_write_idr(at91_rtc_imr);
317 pm_system_wakeup();
318 }
319
320 ret = IRQ_HANDLED;
321 }
322 spin_unlock(&suspended_lock);
323
324 return ret;
325 }
326
327 static const struct at91_rtc_config at91rm9200_config = {
328 };
329
330 static const struct at91_rtc_config at91sam9x5_config = {
331 .use_shadow_imr = true,
332 };
333
334 #ifdef CONFIG_OF
335 static const struct of_device_id at91_rtc_dt_ids[] = {
336 {
337 .compatible = "atmel,at91rm9200-rtc",
338 .data = &at91rm9200_config,
339 }, {
340 .compatible = "atmel,at91sam9x5-rtc",
341 .data = &at91sam9x5_config,
342 }, {
343 /* sentinel */
344 }
345 };
346 MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids);
347 #endif
348
349 static const struct at91_rtc_config *
350 at91_rtc_get_config(struct platform_device *pdev)
351 {
352 const struct of_device_id *match;
353
354 if (pdev->dev.of_node) {
355 match = of_match_node(at91_rtc_dt_ids, pdev->dev.of_node);
356 if (!match)
357 return NULL;
358 return (const struct at91_rtc_config *)match->data;
359 }
360
361 return &at91rm9200_config;
362 }
363
364 static const struct rtc_class_ops at91_rtc_ops = {
365 .read_time = at91_rtc_readtime,
366 .set_time = at91_rtc_settime,
367 .read_alarm = at91_rtc_readalarm,
368 .set_alarm = at91_rtc_setalarm,
369 .proc = at91_rtc_proc,
370 .alarm_irq_enable = at91_rtc_alarm_irq_enable,
371 };
372
373 /*
374 * Initialize and install RTC driver
375 */
376 static int __init at91_rtc_probe(struct platform_device *pdev)
377 {
378 struct rtc_device *rtc;
379 struct resource *regs;
380 int ret = 0;
381
382 at91_rtc_config = at91_rtc_get_config(pdev);
383 if (!at91_rtc_config)
384 return -ENODEV;
385
386 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
387 if (!regs) {
388 dev_err(&pdev->dev, "no mmio resource defined\n");
389 return -ENXIO;
390 }
391
392 irq = platform_get_irq(pdev, 0);
393 if (irq < 0) {
394 dev_err(&pdev->dev, "no irq resource defined\n");
395 return -ENXIO;
396 }
397
398 at91_rtc_regs = devm_ioremap(&pdev->dev, regs->start,
399 resource_size(regs));
400 if (!at91_rtc_regs) {
401 dev_err(&pdev->dev, "failed to map registers, aborting.\n");
402 return -ENOMEM;
403 }
404
405 rtc = devm_rtc_allocate_device(&pdev->dev);
406 if (IS_ERR(rtc))
407 return PTR_ERR(rtc);
408 platform_set_drvdata(pdev, rtc);
409
410 sclk = devm_clk_get(&pdev->dev, NULL);
411 if (IS_ERR(sclk))
412 return PTR_ERR(sclk);
413
414 ret = clk_prepare_enable(sclk);
415 if (ret) {
416 dev_err(&pdev->dev, "Could not enable slow clock\n");
417 return ret;
418 }
419
420 at91_rtc_write(AT91_RTC_CR, 0);
421 at91_rtc_write(AT91_RTC_MR, 0); /* 24 hour mode */
422
423 /* Disable all interrupts */
424 at91_rtc_write_idr(AT91_RTC_ACKUPD | AT91_RTC_ALARM |
425 AT91_RTC_SECEV | AT91_RTC_TIMEV |
426 AT91_RTC_CALEV);
427
428 ret = devm_request_irq(&pdev->dev, irq, at91_rtc_interrupt,
429 IRQF_SHARED | IRQF_COND_SUSPEND,
430 "at91_rtc", pdev);
431 if (ret) {
432 dev_err(&pdev->dev, "IRQ %d already in use.\n", irq);
433 goto err_clk;
434 }
435
436 /* cpu init code should really have flagged this device as
437 * being wake-capable; if it didn't, do that here.
438 */
439 if (!device_can_wakeup(&pdev->dev))
440 device_init_wakeup(&pdev->dev, 1);
441
442 rtc->ops = &at91_rtc_ops;
443 ret = rtc_register_device(rtc);
444 if (ret)
445 goto err_clk;
446
447 /* enable SECEV interrupt in order to initialize at91_rtc_upd_rdy
448 * completion.
449 */
450 at91_rtc_write_ier(AT91_RTC_SECEV);
451
452 dev_info(&pdev->dev, "AT91 Real Time Clock driver.\n");
453 return 0;
454
455 err_clk:
456 clk_disable_unprepare(sclk);
457
458 return ret;
459 }
460
461 /*
462 * Disable and remove the RTC driver
463 */
464 static int __exit at91_rtc_remove(struct platform_device *pdev)
465 {
466 /* Disable all interrupts */
467 at91_rtc_write_idr(AT91_RTC_ACKUPD | AT91_RTC_ALARM |
468 AT91_RTC_SECEV | AT91_RTC_TIMEV |
469 AT91_RTC_CALEV);
470
471 clk_disable_unprepare(sclk);
472
473 return 0;
474 }
475
476 static void at91_rtc_shutdown(struct platform_device *pdev)
477 {
478 /* Disable all interrupts */
479 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
480 AT91_RTC_SECEV | AT91_RTC_TIMEV |
481 AT91_RTC_CALEV);
482 }
483
484 #ifdef CONFIG_PM_SLEEP
485
486 /* AT91RM9200 RTC Power management control */
487
488 static int at91_rtc_suspend(struct device *dev)
489 {
490 /* this IRQ is shared with DBGU and other hardware which isn't
491 * necessarily doing PM like we are...
492 */
493 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
494
495 at91_rtc_imr = at91_rtc_read_imr()
496 & (AT91_RTC_ALARM|AT91_RTC_SECEV);
497 if (at91_rtc_imr) {
498 if (device_may_wakeup(dev)) {
499 unsigned long flags;
500
501 enable_irq_wake(irq);
502
503 spin_lock_irqsave(&suspended_lock, flags);
504 suspended = true;
505 spin_unlock_irqrestore(&suspended_lock, flags);
506 } else {
507 at91_rtc_write_idr(at91_rtc_imr);
508 }
509 }
510 return 0;
511 }
512
513 static int at91_rtc_resume(struct device *dev)
514 {
515 struct rtc_device *rtc = dev_get_drvdata(dev);
516
517 if (at91_rtc_imr) {
518 if (device_may_wakeup(dev)) {
519 unsigned long flags;
520
521 spin_lock_irqsave(&suspended_lock, flags);
522
523 if (cached_events) {
524 rtc_update_irq(rtc, 1, cached_events);
525 cached_events = 0;
526 }
527
528 suspended = false;
529 spin_unlock_irqrestore(&suspended_lock, flags);
530
531 disable_irq_wake(irq);
532 }
533 at91_rtc_write_ier(at91_rtc_imr);
534 }
535 return 0;
536 }
537 #endif
538
539 static SIMPLE_DEV_PM_OPS(at91_rtc_pm_ops, at91_rtc_suspend, at91_rtc_resume);
540
541 static struct platform_driver at91_rtc_driver = {
542 .remove = __exit_p(at91_rtc_remove),
543 .shutdown = at91_rtc_shutdown,
544 .driver = {
545 .name = "at91_rtc",
546 .pm = &at91_rtc_pm_ops,
547 .of_match_table = of_match_ptr(at91_rtc_dt_ids),
548 },
549 };
550
551 module_platform_driver_probe(at91_rtc_driver, at91_rtc_probe);
552
553 MODULE_AUTHOR("Rick Bronson");
554 MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
555 MODULE_LICENSE("GPL");
556 MODULE_ALIAS("platform:at91_rtc");
Linux with added FPC-III support