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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
46
47struct at91_rtc_config {
48 bool use_shadow_imr;
49};
50
51static const struct at91_rtc_config *at91_rtc_config;
52static DECLARE_COMPLETION(at91_rtc_updated);
53static DECLARE_COMPLETION(at91_rtc_upd_rdy);
54static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
55static void __iomem *at91_rtc_regs;
56static int irq;
57static DEFINE_SPINLOCK(at91_rtc_lock);
58static u32 at91_rtc_shadow_imr;
59static bool suspended;
60static DEFINE_SPINLOCK(suspended_lock);
61static unsigned long cached_events;
62static u32 at91_rtc_imr;
63static struct clk *sclk;
64
65static 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
75static 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
83
84
85
86
87
88
89
90
91
92 at91_rtc_read(AT91_RTC_SR);
93 at91_rtc_shadow_imr &= ~mask;
94 spin_unlock_irqrestore(&at91_rtc_lock, flags);
95}
96
97static 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
115
116static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg,
117 struct rtc_time *tm)
118{
119 unsigned int time, date;
120
121
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
134
135
136
137 tm->tm_year = bcd2bin(date & AT91_RTC_CENT) * 100;
138 tm->tm_year += bcd2bin((date & AT91_RTC_YEAR) >> 8);
139
140 tm->tm_wday = bcd2bin((date & AT91_RTC_DAY) >> 21) - 1;
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
147
148static 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
163
164static 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
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);
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)
189 | bin2bcd(tm->tm_year % 100) << 8
190 | bin2bcd(tm->tm_mon + 1) << 16
191 | bin2bcd(tm->tm_wday + 1) << 21
192 | bin2bcd(tm->tm_mday) << 24);
193
194
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
205
206static 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
226
227static 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
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
264static 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
278
279static 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
293
294static 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) {
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);
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
334static const struct at91_rtc_config at91rm9200_config = {
335};
336
337static const struct at91_rtc_config at91sam9x5_config = {
338 .use_shadow_imr = true,
339};
340
341#ifdef CONFIG_OF
342static 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
351 }
352};
353MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids);
354#endif
355
356static const struct at91_rtc_config *
357at91_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
371static 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
382
383static 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 rtc = devm_rtc_allocate_device(&pdev->dev);
413 if (IS_ERR(rtc))
414 return PTR_ERR(rtc);
415 platform_set_drvdata(pdev, rtc);
416
417 sclk = devm_clk_get(&pdev->dev, NULL);
418 if (IS_ERR(sclk))
419 return PTR_ERR(sclk);
420
421 ret = clk_prepare_enable(sclk);
422 if (ret) {
423 dev_err(&pdev->dev, "Could not enable slow clock\n");
424 return ret;
425 }
426
427 at91_rtc_write(AT91_RTC_CR, 0);
428 at91_rtc_write(AT91_RTC_MR, 0);
429
430
431 at91_rtc_write_idr(AT91_RTC_ACKUPD | AT91_RTC_ALARM |
432 AT91_RTC_SECEV | AT91_RTC_TIMEV |
433 AT91_RTC_CALEV);
434
435 ret = devm_request_irq(&pdev->dev, irq, at91_rtc_interrupt,
436 IRQF_SHARED | IRQF_COND_SUSPEND,
437 "at91_rtc", pdev);
438 if (ret) {
439 dev_err(&pdev->dev, "IRQ %d already in use.\n", irq);
440 goto err_clk;
441 }
442
443
444
445
446 if (!device_can_wakeup(&pdev->dev))
447 device_init_wakeup(&pdev->dev, 1);
448
449 rtc->ops = &at91_rtc_ops;
450 ret = rtc_register_device(rtc);
451 if (ret)
452 goto err_clk;
453
454
455
456
457 at91_rtc_write_ier(AT91_RTC_SECEV);
458
459 dev_info(&pdev->dev, "AT91 Real Time Clock driver.\n");
460 return 0;
461
462err_clk:
463 clk_disable_unprepare(sclk);
464
465 return ret;
466}
467
468
469
470
471static int __exit at91_rtc_remove(struct platform_device *pdev)
472{
473
474 at91_rtc_write_idr(AT91_RTC_ACKUPD | AT91_RTC_ALARM |
475 AT91_RTC_SECEV | AT91_RTC_TIMEV |
476 AT91_RTC_CALEV);
477
478 clk_disable_unprepare(sclk);
479
480 return 0;
481}
482
483static void at91_rtc_shutdown(struct platform_device *pdev)
484{
485
486 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
487 AT91_RTC_SECEV | AT91_RTC_TIMEV |
488 AT91_RTC_CALEV);
489}
490
491#ifdef CONFIG_PM_SLEEP
492
493
494
495static int at91_rtc_suspend(struct device *dev)
496{
497
498
499
500 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
501
502 at91_rtc_imr = at91_rtc_read_imr()
503 & (AT91_RTC_ALARM|AT91_RTC_SECEV);
504 if (at91_rtc_imr) {
505 if (device_may_wakeup(dev)) {
506 unsigned long flags;
507
508 enable_irq_wake(irq);
509
510 spin_lock_irqsave(&suspended_lock, flags);
511 suspended = true;
512 spin_unlock_irqrestore(&suspended_lock, flags);
513 } else {
514 at91_rtc_write_idr(at91_rtc_imr);
515 }
516 }
517 return 0;
518}
519
520static int at91_rtc_resume(struct device *dev)
521{
522 struct rtc_device *rtc = dev_get_drvdata(dev);
523
524 if (at91_rtc_imr) {
525 if (device_may_wakeup(dev)) {
526 unsigned long flags;
527
528 spin_lock_irqsave(&suspended_lock, flags);
529
530 if (cached_events) {
531 rtc_update_irq(rtc, 1, cached_events);
532 cached_events = 0;
533 }
534
535 suspended = false;
536 spin_unlock_irqrestore(&suspended_lock, flags);
537
538 disable_irq_wake(irq);
539 }
540 at91_rtc_write_ier(at91_rtc_imr);
541 }
542 return 0;
543}
544#endif
545
546static SIMPLE_DEV_PM_OPS(at91_rtc_pm_ops, at91_rtc_suspend, at91_rtc_resume);
547
548static struct platform_driver at91_rtc_driver = {
549 .remove = __exit_p(at91_rtc_remove),
550 .shutdown = at91_rtc_shutdown,
551 .driver = {
552 .name = "at91_rtc",
553 .pm = &at91_rtc_pm_ops,
554 .of_match_table = of_match_ptr(at91_rtc_dt_ids),
555 },
556};
557
558module_platform_driver_probe(at91_rtc_driver, at91_rtc_probe);
559
560MODULE_AUTHOR("Rick Bronson");
561MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
562MODULE_LICENSE("GPL");
563MODULE_ALIAS("platform:at91_rtc");
564
