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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Real Time Clock interface for Linux on Atmel AT91RM9200
4 *
5 * Copyright (C) 2002 Rick Bronson
6 *
7 * Converted to RTC class model by Andrew Victor
8 *
9 * Ported to Linux 2.6 by Steven Scholz
10 * Based on s3c2410-rtc.c Simtec Electronics
11 *
12 * Based on sa1100-rtc.c by Nils Faerber
13 * Based on rtc.c by Paul Gortmaker
14 */
15
16#include <linux/bcd.h>
17#include <linux/bitfield.h>
18#include <linux/clk.h>
19#include <linux/completion.h>
20#include <linux/interrupt.h>
21#include <linux/ioctl.h>
22#include <linux/io.h>
23#include <linux/kernel.h>
24#include <linux/module.h>
25#include <linux/of_device.h>
26#include <linux/of.h>
27#include <linux/platform_device.h>
28#include <linux/rtc.h>
29#include <linux/spinlock.h>
30#include <linux/suspend.h>
31#include <linux/time.h>
32#include <linux/uaccess.h>
33
34#define AT91_RTC_CR 0x00 /* Control Register */
35#define AT91_RTC_UPDTIM BIT(0) /* Update Request Time Register */
36#define AT91_RTC_UPDCAL BIT(1) /* Update Request Calendar Register */
37
38#define AT91_RTC_MR 0x04 /* Mode Register */
39
40#define AT91_RTC_TIMR 0x08 /* Time Register */
41#define AT91_RTC_SEC GENMASK(6, 0) /* Current Second */
42#define AT91_RTC_MIN GENMASK(14, 8) /* Current Minute */
43#define AT91_RTC_HOUR GENMASK(21, 16) /* Current Hour */
44#define AT91_RTC_AMPM BIT(22) /* Ante Meridiem Post Meridiem Indicator */
45
46#define AT91_RTC_CALR 0x0c /* Calendar Register */
47#define AT91_RTC_CENT GENMASK(6, 0) /* Current Century */
48#define AT91_RTC_YEAR GENMASK(15, 8) /* Current Year */
49#define AT91_RTC_MONTH GENMASK(20, 16) /* Current Month */
50#define AT91_RTC_DAY GENMASK(23, 21) /* Current Day */
51#define AT91_RTC_DATE GENMASK(29, 24) /* Current Date */
52
53#define AT91_RTC_TIMALR 0x10 /* Time Alarm Register */
54#define AT91_RTC_SECEN BIT(7) /* Second Alarm Enable */
55#define AT91_RTC_MINEN BIT(15) /* Minute Alarm Enable */
56#define AT91_RTC_HOUREN BIT(23) /* Hour Alarm Enable */
57
58#define AT91_RTC_CALALR 0x14 /* Calendar Alarm Register */
59#define AT91_RTC_MTHEN BIT(23) /* Month Alarm Enable */
60#define AT91_RTC_DATEEN BIT(31) /* Date Alarm Enable */
61
62#define AT91_RTC_SR 0x18 /* Status Register */
63#define AT91_RTC_ACKUPD BIT(0) /* Acknowledge for Update */
64#define AT91_RTC_ALARM BIT(1) /* Alarm Flag */
65#define AT91_RTC_SECEV BIT(2) /* Second Event */
66#define AT91_RTC_TIMEV BIT(3) /* Time Event */
67#define AT91_RTC_CALEV BIT(4) /* Calendar Event */
68
69#define AT91_RTC_SCCR 0x1c /* Status Clear Command Register */
70#define AT91_RTC_IER 0x20 /* Interrupt Enable Register */
71#define AT91_RTC_IDR 0x24 /* Interrupt Disable Register */
72#define AT91_RTC_IMR 0x28 /* Interrupt Mask Register */
73
74#define AT91_RTC_VER 0x2c /* Valid Entry Register */
75#define AT91_RTC_NVTIM BIT(0) /* Non valid Time */
76#define AT91_RTC_NVCAL BIT(1) /* Non valid Calendar */
77#define AT91_RTC_NVTIMALR BIT(2) /* Non valid Time Alarm */
78#define AT91_RTC_NVCALALR BIT(3) /* Non valid Calendar Alarm */
79
80#define at91_rtc_read(field) \
81 readl_relaxed(at91_rtc_regs + field)
82#define at91_rtc_write(field, val) \
83 writel_relaxed((val), at91_rtc_regs + field)
84
85struct at91_rtc_config {
86 bool use_shadow_imr;
87};
88
89static const struct at91_rtc_config *at91_rtc_config;
90static DECLARE_COMPLETION(at91_rtc_updated);
91static DECLARE_COMPLETION(at91_rtc_upd_rdy);
92static void __iomem *at91_rtc_regs;
93static int irq;
94static DEFINE_SPINLOCK(at91_rtc_lock);
95static u32 at91_rtc_shadow_imr;
96static bool suspended;
97static DEFINE_SPINLOCK(suspended_lock);
98static unsigned long cached_events;
99static u32 at91_rtc_imr;
100static struct clk *sclk;
101
102static void at91_rtc_write_ier(u32 mask)
103{
104 unsigned long flags;
105
106 spin_lock_irqsave(&at91_rtc_lock, flags);
107 at91_rtc_shadow_imr |= mask;
108 at91_rtc_write(AT91_RTC_IER, mask);
109 spin_unlock_irqrestore(&at91_rtc_lock, flags);
110}
111
112static void at91_rtc_write_idr(u32 mask)
113{
114 unsigned long flags;
115
116 spin_lock_irqsave(&at91_rtc_lock, flags);
117 at91_rtc_write(AT91_RTC_IDR, mask);
118 /*
119 * Register read back (of any RTC-register) needed to make sure
120 * IDR-register write has reached the peripheral before updating
121 * shadow mask.
122 *
123 * Note that there is still a possibility that the mask is updated
124 * before interrupts have actually been disabled in hardware. The only
125 * way to be certain would be to poll the IMR-register, which is is
126 * the very register we are trying to emulate. The register read back
127 * is a reasonable heuristic.
128 */
129 at91_rtc_read(AT91_RTC_SR);
130 at91_rtc_shadow_imr &= ~mask;
131 spin_unlock_irqrestore(&at91_rtc_lock, flags);
132}
133
134static u32 at91_rtc_read_imr(void)
135{
136 unsigned long flags;
137 u32 mask;
138
139 if (at91_rtc_config->use_shadow_imr) {
140 spin_lock_irqsave(&at91_rtc_lock, flags);
141 mask = at91_rtc_shadow_imr;
142 spin_unlock_irqrestore(&at91_rtc_lock, flags);
143 } else {
144 mask = at91_rtc_read(AT91_RTC_IMR);
145 }
146
147 return mask;
148}
149
150/*
151 * Decode time/date into rtc_time structure
152 */
153static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg,
154 struct rtc_time *tm)
155{
156 unsigned int time, date;
157
158 /* must read twice in case it changes */
159 do {
160 time = at91_rtc_read(timereg);
161 date = at91_rtc_read(calreg);
162 } while ((time != at91_rtc_read(timereg)) ||
163 (date != at91_rtc_read(calreg)));
164
165 tm->tm_sec = bcd2bin(FIELD_GET(AT91_RTC_SEC, time));
166 tm->tm_min = bcd2bin(FIELD_GET(AT91_RTC_MIN, time));
167 tm->tm_hour = bcd2bin(FIELD_GET(AT91_RTC_HOUR, time));
168
169 /*
170 * The Calendar Alarm register does not have a field for
171 * the year - so these will return an invalid value.
172 */
173 tm->tm_year = bcd2bin(date & AT91_RTC_CENT) * 100; /* century */
174 tm->tm_year += bcd2bin(FIELD_GET(AT91_RTC_YEAR, date)); /* year */
175
176 tm->tm_wday = bcd2bin(FIELD_GET(AT91_RTC_DAY, date)) - 1; /* day of the week [0-6], Sunday=0 */
177 tm->tm_mon = bcd2bin(FIELD_GET(AT91_RTC_MONTH, date)) - 1;
178 tm->tm_mday = bcd2bin(FIELD_GET(AT91_RTC_DATE, date));
179}
180
181/*
182 * Read current time and date in RTC
183 */
184static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
185{
186 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm);
187 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
188 tm->tm_year = tm->tm_year - 1900;
189
190 dev_dbg(dev, "%s(): %ptR\n", __func__, tm);
191
192 return 0;
193}
194
195/*
196 * Set current time and date in RTC
197 */
198static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
199{
200 unsigned long cr;
201
202 dev_dbg(dev, "%s(): %ptR\n", __func__, tm);
203
204 wait_for_completion(&at91_rtc_upd_rdy);
205
206 /* Stop Time/Calendar from counting */
207 cr = at91_rtc_read(AT91_RTC_CR);
208 at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);
209
210 at91_rtc_write_ier(AT91_RTC_ACKUPD);
211 wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */
212 at91_rtc_write_idr(AT91_RTC_ACKUPD);
213
214 at91_rtc_write(AT91_RTC_TIMR,
215 FIELD_PREP(AT91_RTC_SEC, bin2bcd(tm->tm_sec))
216 | FIELD_PREP(AT91_RTC_MIN, bin2bcd(tm->tm_min))
217 | FIELD_PREP(AT91_RTC_HOUR, bin2bcd(tm->tm_hour)));
218
219 at91_rtc_write(AT91_RTC_CALR,
220 FIELD_PREP(AT91_RTC_CENT,
221 bin2bcd((tm->tm_year + 1900) / 100))
222 | FIELD_PREP(AT91_RTC_YEAR, bin2bcd(tm->tm_year % 100))
223 | FIELD_PREP(AT91_RTC_MONTH, bin2bcd(tm->tm_mon + 1))
224 | FIELD_PREP(AT91_RTC_DAY, bin2bcd(tm->tm_wday + 1))
225 | FIELD_PREP(AT91_RTC_DATE, bin2bcd(tm->tm_mday)));
226
227 /* Restart Time/Calendar */
228 cr = at91_rtc_read(AT91_RTC_CR);
229 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_SECEV);
230 at91_rtc_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM));
231 at91_rtc_write_ier(AT91_RTC_SECEV);
232
233 return 0;
234}
235
236/*
237 * Read alarm time and date in RTC
238 */
239static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
240{
241 struct rtc_time *tm = &alrm->time;
242
243 at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm);
244 tm->tm_year = -1;
245
246 alrm->enabled = (at91_rtc_read_imr() & AT91_RTC_ALARM)
247 ? 1 : 0;
248
249 dev_dbg(dev, "%s(): %ptR %sabled\n", __func__, tm,
250 alrm->enabled ? "en" : "dis");
251
252 return 0;
253}
254
255/*
256 * Set alarm time and date in RTC
257 */
258static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
259{
260 struct rtc_time tm = alrm->time;
261
262 at91_rtc_write_idr(AT91_RTC_ALARM);
263 at91_rtc_write(AT91_RTC_TIMALR,
264 FIELD_PREP(AT91_RTC_SEC, bin2bcd(alrm->time.tm_sec))
265 | FIELD_PREP(AT91_RTC_MIN, bin2bcd(alrm->time.tm_min))
266 | FIELD_PREP(AT91_RTC_HOUR, bin2bcd(alrm->time.tm_hour))
267 | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN);
268 at91_rtc_write(AT91_RTC_CALALR,
269 FIELD_PREP(AT91_RTC_MONTH, bin2bcd(alrm->time.tm_mon + 1))
270 | FIELD_PREP(AT91_RTC_DATE, bin2bcd(alrm->time.tm_mday))
271 | AT91_RTC_DATEEN | AT91_RTC_MTHEN);
272
273 if (alrm->enabled) {
274 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
275 at91_rtc_write_ier(AT91_RTC_ALARM);
276 }
277
278 dev_dbg(dev, "%s(): %ptR\n", __func__, &tm);
279
280 return 0;
281}
282
283static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
284{
285 dev_dbg(dev, "%s(): cmd=%08x\n", __func__, enabled);
286
287 if (enabled) {
288 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
289 at91_rtc_write_ier(AT91_RTC_ALARM);
290 } else
291 at91_rtc_write_idr(AT91_RTC_ALARM);
292
293 return 0;
294}
295
296/*
297 * IRQ handler for the RTC
298 */
299static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
300{
301 struct platform_device *pdev = dev_id;
302 struct rtc_device *rtc = platform_get_drvdata(pdev);
303 unsigned int rtsr;
304 unsigned long events = 0;
305 int ret = IRQ_NONE;
306
307 spin_lock(&suspended_lock);
308 rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_read_imr();
309 if (rtsr) { /* this interrupt is shared! Is it ours? */
310 if (rtsr & AT91_RTC_ALARM)
311 events |= (RTC_AF | RTC_IRQF);
312 if (rtsr & AT91_RTC_SECEV) {
313 complete(&at91_rtc_upd_rdy);
314 at91_rtc_write_idr(AT91_RTC_SECEV);
315 }
316 if (rtsr & AT91_RTC_ACKUPD)
317 complete(&at91_rtc_updated);
318
319 at91_rtc_write(AT91_RTC_SCCR, rtsr); /* clear status reg */
320
321 if (!suspended) {
322 rtc_update_irq(rtc, 1, events);
323
324 dev_dbg(&pdev->dev, "%s(): num=%ld, events=0x%02lx\n",
325 __func__, events >> 8, events & 0x000000FF);
326 } else {
327 cached_events |= events;
328 at91_rtc_write_idr(at91_rtc_imr);
329 pm_system_wakeup();
330 }
331
332 ret = IRQ_HANDLED;
333 }
334 spin_unlock(&suspended_lock);
335
336 return ret;
337}
338
339static const struct at91_rtc_config at91rm9200_config = {
340};
341
342static const struct at91_rtc_config at91sam9x5_config = {
343 .use_shadow_imr = true,
344};
345
346static const struct of_device_id at91_rtc_dt_ids[] = {
347 {
348 .compatible = "atmel,at91rm9200-rtc",
349 .data = &at91rm9200_config,
350 }, {
351 .compatible = "atmel,at91sam9x5-rtc",
352 .data = &at91sam9x5_config,
353 }, {
354 .compatible = "atmel,sama5d4-rtc",
355 .data = &at91rm9200_config,
356 }, {
357 .compatible = "atmel,sama5d2-rtc",
358 .data = &at91rm9200_config,
359 }, {
360 /* sentinel */
361 }
362};
363MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids);
364
365static const struct rtc_class_ops at91_rtc_ops = {
366 .read_time = at91_rtc_readtime,
367 .set_time = at91_rtc_settime,
368 .read_alarm = at91_rtc_readalarm,
369 .set_alarm = at91_rtc_setalarm,
370 .alarm_irq_enable = at91_rtc_alarm_irq_enable,
371};
372
373/*
374 * Initialize and install RTC driver
375 */
376static 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 = of_device_get_match_data(&pdev->dev);
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 return -ENXIO;
395
396 at91_rtc_regs = devm_ioremap(&pdev->dev, regs->start,
397 resource_size(regs));
398 if (!at91_rtc_regs) {
399 dev_err(&pdev->dev, "failed to map registers, aborting.\n");
400 return -ENOMEM;
401 }
402
403 rtc = devm_rtc_allocate_device(&pdev->dev);
404 if (IS_ERR(rtc))
405 return PTR_ERR(rtc);
406 platform_set_drvdata(pdev, rtc);
407
408 sclk = devm_clk_get(&pdev->dev, NULL);
409 if (IS_ERR(sclk))
410 return PTR_ERR(sclk);
411
412 ret = clk_prepare_enable(sclk);
413 if (ret) {
414 dev_err(&pdev->dev, "Could not enable slow clock\n");
415 return ret;
416 }
417
418 at91_rtc_write(AT91_RTC_CR, 0);
419 at91_rtc_write(AT91_RTC_MR, 0); /* 24 hour mode */
420
421 /* Disable all interrupts */
422 at91_rtc_write_idr(AT91_RTC_ACKUPD | AT91_RTC_ALARM |
423 AT91_RTC_SECEV | AT91_RTC_TIMEV |
424 AT91_RTC_CALEV);
425
426 ret = devm_request_irq(&pdev->dev, irq, at91_rtc_interrupt,
427 IRQF_SHARED | IRQF_COND_SUSPEND,
428 "at91_rtc", pdev);
429 if (ret) {
430 dev_err(&pdev->dev, "IRQ %d already in use.\n", irq);
431 goto err_clk;
432 }
433
434 /* cpu init code should really have flagged this device as
435 * being wake-capable; if it didn't, do that here.
436 */
437 if (!device_can_wakeup(&pdev->dev))
438 device_init_wakeup(&pdev->dev, 1);
439
440 rtc->ops = &at91_rtc_ops;
441 rtc->range_min = RTC_TIMESTAMP_BEGIN_1900;
442 rtc->range_max = RTC_TIMESTAMP_END_2099;
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
455err_clk:
456 clk_disable_unprepare(sclk);
457
458 return ret;
459}
460
461/*
462 * Disable and remove the RTC driver
463 */
464static 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
476static 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
488static 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
513static 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
539static SIMPLE_DEV_PM_OPS(at91_rtc_pm_ops, at91_rtc_suspend, at91_rtc_resume);
540
541static 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
551module_platform_driver_probe(at91_rtc_driver, at91_rtc_probe);
552
553MODULE_AUTHOR("Rick Bronson");
554MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
555MODULE_LICENSE("GPL");
556MODULE_ALIAS("platform:at91_rtc");
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Real Time Clock interface for Linux on Atmel AT91RM9200
4 *
5 * Copyright (C) 2002 Rick Bronson
6 *
7 * Converted to RTC class model by Andrew Victor
8 *
9 * Ported to Linux 2.6 by Steven Scholz
10 * Based on s3c2410-rtc.c Simtec Electronics
11 *
12 * Based on sa1100-rtc.c by Nils Faerber
13 * Based on rtc.c by Paul Gortmaker
14 */
15
16#include <linux/bcd.h>
17#include <linux/clk.h>
18#include <linux/completion.h>
19#include <linux/interrupt.h>
20#include <linux/ioctl.h>
21#include <linux/io.h>
22#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/of_device.h>
25#include <linux/of.h>
26#include <linux/platform_device.h>
27#include <linux/rtc.h>
28#include <linux/spinlock.h>
29#include <linux/suspend.h>
30#include <linux/time.h>
31#include <linux/uaccess.h>
32
33#include "rtc-at91rm9200.h"
34
35#define at91_rtc_read(field) \
36 readl_relaxed(at91_rtc_regs + field)
37#define at91_rtc_write(field, val) \
38 writel_relaxed((val), at91_rtc_regs + field)
39
40struct at91_rtc_config {
41 bool use_shadow_imr;
42};
43
44static const struct at91_rtc_config *at91_rtc_config;
45static DECLARE_COMPLETION(at91_rtc_updated);
46static DECLARE_COMPLETION(at91_rtc_upd_rdy);
47static void __iomem *at91_rtc_regs;
48static int irq;
49static DEFINE_SPINLOCK(at91_rtc_lock);
50static u32 at91_rtc_shadow_imr;
51static bool suspended;
52static DEFINE_SPINLOCK(suspended_lock);
53static unsigned long cached_events;
54static u32 at91_rtc_imr;
55static struct clk *sclk;
56
57static void at91_rtc_write_ier(u32 mask)
58{
59 unsigned long flags;
60
61 spin_lock_irqsave(&at91_rtc_lock, flags);
62 at91_rtc_shadow_imr |= mask;
63 at91_rtc_write(AT91_RTC_IER, mask);
64 spin_unlock_irqrestore(&at91_rtc_lock, flags);
65}
66
67static void at91_rtc_write_idr(u32 mask)
68{
69 unsigned long flags;
70
71 spin_lock_irqsave(&at91_rtc_lock, flags);
72 at91_rtc_write(AT91_RTC_IDR, mask);
73 /*
74 * Register read back (of any RTC-register) needed to make sure
75 * IDR-register write has reached the peripheral before updating
76 * shadow mask.
77 *
78 * Note that there is still a possibility that the mask is updated
79 * before interrupts have actually been disabled in hardware. The only
80 * way to be certain would be to poll the IMR-register, which is is
81 * the very register we are trying to emulate. The register read back
82 * is a reasonable heuristic.
83 */
84 at91_rtc_read(AT91_RTC_SR);
85 at91_rtc_shadow_imr &= ~mask;
86 spin_unlock_irqrestore(&at91_rtc_lock, flags);
87}
88
89static u32 at91_rtc_read_imr(void)
90{
91 unsigned long flags;
92 u32 mask;
93
94 if (at91_rtc_config->use_shadow_imr) {
95 spin_lock_irqsave(&at91_rtc_lock, flags);
96 mask = at91_rtc_shadow_imr;
97 spin_unlock_irqrestore(&at91_rtc_lock, flags);
98 } else {
99 mask = at91_rtc_read(AT91_RTC_IMR);
100 }
101
102 return mask;
103}
104
105/*
106 * Decode time/date into rtc_time structure
107 */
108static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg,
109 struct rtc_time *tm)
110{
111 unsigned int time, date;
112
113 /* must read twice in case it changes */
114 do {
115 time = at91_rtc_read(timereg);
116 date = at91_rtc_read(calreg);
117 } while ((time != at91_rtc_read(timereg)) ||
118 (date != at91_rtc_read(calreg)));
119
120 tm->tm_sec = bcd2bin((time & AT91_RTC_SEC) >> 0);
121 tm->tm_min = bcd2bin((time & AT91_RTC_MIN) >> 8);
122 tm->tm_hour = bcd2bin((time & AT91_RTC_HOUR) >> 16);
123
124 /*
125 * The Calendar Alarm register does not have a field for
126 * the year - so these will return an invalid value.
127 */
128 tm->tm_year = bcd2bin(date & AT91_RTC_CENT) * 100; /* century */
129 tm->tm_year += bcd2bin((date & AT91_RTC_YEAR) >> 8); /* year */
130
131 tm->tm_wday = bcd2bin((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */
132 tm->tm_mon = bcd2bin((date & AT91_RTC_MONTH) >> 16) - 1;
133 tm->tm_mday = bcd2bin((date & AT91_RTC_DATE) >> 24);
134}
135
136/*
137 * Read current time and date in RTC
138 */
139static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
140{
141 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm);
142 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
143 tm->tm_year = tm->tm_year - 1900;
144
145 dev_dbg(dev, "%s(): %ptR\n", __func__, tm);
146
147 return 0;
148}
149
150/*
151 * Set current time and date in RTC
152 */
153static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
154{
155 unsigned long cr;
156
157 dev_dbg(dev, "%s(): %ptR\n", __func__, tm);
158
159 wait_for_completion(&at91_rtc_upd_rdy);
160
161 /* Stop Time/Calendar from counting */
162 cr = at91_rtc_read(AT91_RTC_CR);
163 at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);
164
165 at91_rtc_write_ier(AT91_RTC_ACKUPD);
166 wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */
167 at91_rtc_write_idr(AT91_RTC_ACKUPD);
168
169 at91_rtc_write(AT91_RTC_TIMR,
170 bin2bcd(tm->tm_sec) << 0
171 | bin2bcd(tm->tm_min) << 8
172 | bin2bcd(tm->tm_hour) << 16);
173
174 at91_rtc_write(AT91_RTC_CALR,
175 bin2bcd((tm->tm_year + 1900) / 100) /* century */
176 | bin2bcd(tm->tm_year % 100) << 8 /* year */
177 | bin2bcd(tm->tm_mon + 1) << 16 /* tm_mon starts at zero */
178 | bin2bcd(tm->tm_wday + 1) << 21 /* day of the week [0-6], Sunday=0 */
179 | bin2bcd(tm->tm_mday) << 24);
180
181 /* Restart Time/Calendar */
182 cr = at91_rtc_read(AT91_RTC_CR);
183 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_SECEV);
184 at91_rtc_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM));
185 at91_rtc_write_ier(AT91_RTC_SECEV);
186
187 return 0;
188}
189
190/*
191 * Read alarm time and date in RTC
192 */
193static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
194{
195 struct rtc_time *tm = &alrm->time;
196
197 at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm);
198 tm->tm_year = -1;
199
200 alrm->enabled = (at91_rtc_read_imr() & AT91_RTC_ALARM)
201 ? 1 : 0;
202
203 dev_dbg(dev, "%s(): %ptR %sabled\n", __func__, tm,
204 alrm->enabled ? "en" : "dis");
205
206 return 0;
207}
208
209/*
210 * Set alarm time and date in RTC
211 */
212static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
213{
214 struct rtc_time tm;
215
216 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm);
217
218 tm.tm_mon = alrm->time.tm_mon;
219 tm.tm_mday = alrm->time.tm_mday;
220 tm.tm_hour = alrm->time.tm_hour;
221 tm.tm_min = alrm->time.tm_min;
222 tm.tm_sec = alrm->time.tm_sec;
223
224 at91_rtc_write_idr(AT91_RTC_ALARM);
225 at91_rtc_write(AT91_RTC_TIMALR,
226 bin2bcd(tm.tm_sec) << 0
227 | bin2bcd(tm.tm_min) << 8
228 | bin2bcd(tm.tm_hour) << 16
229 | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN);
230 at91_rtc_write(AT91_RTC_CALALR,
231 bin2bcd(tm.tm_mon + 1) << 16 /* tm_mon starts at zero */
232 | bin2bcd(tm.tm_mday) << 24
233 | AT91_RTC_DATEEN | AT91_RTC_MTHEN);
234
235 if (alrm->enabled) {
236 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
237 at91_rtc_write_ier(AT91_RTC_ALARM);
238 }
239
240 dev_dbg(dev, "%s(): %ptR\n", __func__, &tm);
241
242 return 0;
243}
244
245static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
246{
247 dev_dbg(dev, "%s(): cmd=%08x\n", __func__, enabled);
248
249 if (enabled) {
250 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
251 at91_rtc_write_ier(AT91_RTC_ALARM);
252 } else
253 at91_rtc_write_idr(AT91_RTC_ALARM);
254
255 return 0;
256}
257/*
258 * Provide additional RTC information in /proc/driver/rtc
259 */
260static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
261{
262 unsigned long imr = at91_rtc_read_imr();
263
264 seq_printf(seq, "update_IRQ\t: %s\n",
265 (imr & AT91_RTC_ACKUPD) ? "yes" : "no");
266 seq_printf(seq, "periodic_IRQ\t: %s\n",
267 (imr & AT91_RTC_SECEV) ? "yes" : "no");
268
269 return 0;
270}
271
272/*
273 * IRQ handler for the RTC
274 */
275static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
276{
277 struct platform_device *pdev = dev_id;
278 struct rtc_device *rtc = platform_get_drvdata(pdev);
279 unsigned int rtsr;
280 unsigned long events = 0;
281 int ret = IRQ_NONE;
282
283 spin_lock(&suspended_lock);
284 rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_read_imr();
285 if (rtsr) { /* this interrupt is shared! Is it ours? */
286 if (rtsr & AT91_RTC_ALARM)
287 events |= (RTC_AF | RTC_IRQF);
288 if (rtsr & AT91_RTC_SECEV) {
289 complete(&at91_rtc_upd_rdy);
290 at91_rtc_write_idr(AT91_RTC_SECEV);
291 }
292 if (rtsr & AT91_RTC_ACKUPD)
293 complete(&at91_rtc_updated);
294
295 at91_rtc_write(AT91_RTC_SCCR, rtsr); /* clear status reg */
296
297 if (!suspended) {
298 rtc_update_irq(rtc, 1, events);
299
300 dev_dbg(&pdev->dev, "%s(): num=%ld, events=0x%02lx\n",
301 __func__, events >> 8, events & 0x000000FF);
302 } else {
303 cached_events |= events;
304 at91_rtc_write_idr(at91_rtc_imr);
305 pm_system_wakeup();
306 }
307
308 ret = IRQ_HANDLED;
309 }
310 spin_unlock(&suspended_lock);
311
312 return ret;
313}
314
315static const struct at91_rtc_config at91rm9200_config = {
316};
317
318static const struct at91_rtc_config at91sam9x5_config = {
319 .use_shadow_imr = true,
320};
321
322#ifdef CONFIG_OF
323static const struct of_device_id at91_rtc_dt_ids[] = {
324 {
325 .compatible = "atmel,at91rm9200-rtc",
326 .data = &at91rm9200_config,
327 }, {
328 .compatible = "atmel,at91sam9x5-rtc",
329 .data = &at91sam9x5_config,
330 }, {
331 /* sentinel */
332 }
333};
334MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids);
335#endif
336
337static const struct at91_rtc_config *
338at91_rtc_get_config(struct platform_device *pdev)
339{
340 const struct of_device_id *match;
341
342 if (pdev->dev.of_node) {
343 match = of_match_node(at91_rtc_dt_ids, pdev->dev.of_node);
344 if (!match)
345 return NULL;
346 return (const struct at91_rtc_config *)match->data;
347 }
348
349 return &at91rm9200_config;
350}
351
352static const struct rtc_class_ops at91_rtc_ops = {
353 .read_time = at91_rtc_readtime,
354 .set_time = at91_rtc_settime,
355 .read_alarm = at91_rtc_readalarm,
356 .set_alarm = at91_rtc_setalarm,
357 .proc = at91_rtc_proc,
358 .alarm_irq_enable = at91_rtc_alarm_irq_enable,
359};
360
361/*
362 * Initialize and install RTC driver
363 */
364static int __init at91_rtc_probe(struct platform_device *pdev)
365{
366 struct rtc_device *rtc;
367 struct resource *regs;
368 int ret = 0;
369
370 at91_rtc_config = at91_rtc_get_config(pdev);
371 if (!at91_rtc_config)
372 return -ENODEV;
373
374 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
375 if (!regs) {
376 dev_err(&pdev->dev, "no mmio resource defined\n");
377 return -ENXIO;
378 }
379
380 irq = platform_get_irq(pdev, 0);
381 if (irq < 0)
382 return -ENXIO;
383
384 at91_rtc_regs = devm_ioremap(&pdev->dev, regs->start,
385 resource_size(regs));
386 if (!at91_rtc_regs) {
387 dev_err(&pdev->dev, "failed to map registers, aborting.\n");
388 return -ENOMEM;
389 }
390
391 rtc = devm_rtc_allocate_device(&pdev->dev);
392 if (IS_ERR(rtc))
393 return PTR_ERR(rtc);
394 platform_set_drvdata(pdev, rtc);
395
396 sclk = devm_clk_get(&pdev->dev, NULL);
397 if (IS_ERR(sclk))
398 return PTR_ERR(sclk);
399
400 ret = clk_prepare_enable(sclk);
401 if (ret) {
402 dev_err(&pdev->dev, "Could not enable slow clock\n");
403 return ret;
404 }
405
406 at91_rtc_write(AT91_RTC_CR, 0);
407 at91_rtc_write(AT91_RTC_MR, 0); /* 24 hour mode */
408
409 /* Disable all interrupts */
410 at91_rtc_write_idr(AT91_RTC_ACKUPD | AT91_RTC_ALARM |
411 AT91_RTC_SECEV | AT91_RTC_TIMEV |
412 AT91_RTC_CALEV);
413
414 ret = devm_request_irq(&pdev->dev, irq, at91_rtc_interrupt,
415 IRQF_SHARED | IRQF_COND_SUSPEND,
416 "at91_rtc", pdev);
417 if (ret) {
418 dev_err(&pdev->dev, "IRQ %d already in use.\n", irq);
419 goto err_clk;
420 }
421
422 /* cpu init code should really have flagged this device as
423 * being wake-capable; if it didn't, do that here.
424 */
425 if (!device_can_wakeup(&pdev->dev))
426 device_init_wakeup(&pdev->dev, 1);
427
428 rtc->ops = &at91_rtc_ops;
429 rtc->range_min = RTC_TIMESTAMP_BEGIN_1900;
430 rtc->range_max = RTC_TIMESTAMP_END_2099;
431 ret = rtc_register_device(rtc);
432 if (ret)
433 goto err_clk;
434
435 /* enable SECEV interrupt in order to initialize at91_rtc_upd_rdy
436 * completion.
437 */
438 at91_rtc_write_ier(AT91_RTC_SECEV);
439
440 dev_info(&pdev->dev, "AT91 Real Time Clock driver.\n");
441 return 0;
442
443err_clk:
444 clk_disable_unprepare(sclk);
445
446 return ret;
447}
448
449/*
450 * Disable and remove the RTC driver
451 */
452static int __exit at91_rtc_remove(struct platform_device *pdev)
453{
454 /* Disable all interrupts */
455 at91_rtc_write_idr(AT91_RTC_ACKUPD | AT91_RTC_ALARM |
456 AT91_RTC_SECEV | AT91_RTC_TIMEV |
457 AT91_RTC_CALEV);
458
459 clk_disable_unprepare(sclk);
460
461 return 0;
462}
463
464static void at91_rtc_shutdown(struct platform_device *pdev)
465{
466 /* Disable all interrupts */
467 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
468 AT91_RTC_SECEV | AT91_RTC_TIMEV |
469 AT91_RTC_CALEV);
470}
471
472#ifdef CONFIG_PM_SLEEP
473
474/* AT91RM9200 RTC Power management control */
475
476static int at91_rtc_suspend(struct device *dev)
477{
478 /* this IRQ is shared with DBGU and other hardware which isn't
479 * necessarily doing PM like we are...
480 */
481 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
482
483 at91_rtc_imr = at91_rtc_read_imr()
484 & (AT91_RTC_ALARM|AT91_RTC_SECEV);
485 if (at91_rtc_imr) {
486 if (device_may_wakeup(dev)) {
487 unsigned long flags;
488
489 enable_irq_wake(irq);
490
491 spin_lock_irqsave(&suspended_lock, flags);
492 suspended = true;
493 spin_unlock_irqrestore(&suspended_lock, flags);
494 } else {
495 at91_rtc_write_idr(at91_rtc_imr);
496 }
497 }
498 return 0;
499}
500
501static int at91_rtc_resume(struct device *dev)
502{
503 struct rtc_device *rtc = dev_get_drvdata(dev);
504
505 if (at91_rtc_imr) {
506 if (device_may_wakeup(dev)) {
507 unsigned long flags;
508
509 spin_lock_irqsave(&suspended_lock, flags);
510
511 if (cached_events) {
512 rtc_update_irq(rtc, 1, cached_events);
513 cached_events = 0;
514 }
515
516 suspended = false;
517 spin_unlock_irqrestore(&suspended_lock, flags);
518
519 disable_irq_wake(irq);
520 }
521 at91_rtc_write_ier(at91_rtc_imr);
522 }
523 return 0;
524}
525#endif
526
527static SIMPLE_DEV_PM_OPS(at91_rtc_pm_ops, at91_rtc_suspend, at91_rtc_resume);
528
529static struct platform_driver at91_rtc_driver = {
530 .remove = __exit_p(at91_rtc_remove),
531 .shutdown = at91_rtc_shutdown,
532 .driver = {
533 .name = "at91_rtc",
534 .pm = &at91_rtc_pm_ops,
535 .of_match_table = of_match_ptr(at91_rtc_dt_ids),
536 },
537};
538
539module_platform_driver_probe(at91_rtc_driver, at91_rtc_probe);
540
541MODULE_AUTHOR("Rick Bronson");
542MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
543MODULE_LICENSE("GPL");
544MODULE_ALIAS("platform:at91_rtc");