?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
perf intel-pt: Factor out intel_pt_8b_tsc()
[linux/fpc-iii.git] / drivers / rtc / rtc-at91rm9200.c
blob82a54e93ff04af0ed75237fa476da828d762e6ba
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
40 struct at91_rtc_config {
41 bool use_shadow_imr;
42 };
43
44 static const struct at91_rtc_config *at91_rtc_config;
45 static DECLARE_COMPLETION(at91_rtc_updated);
46 static DECLARE_COMPLETION(at91_rtc_upd_rdy);
47 static void __iomem *at91_rtc_regs;
48 static int irq;
49 static DEFINE_SPINLOCK(at91_rtc_lock);
50 static u32 at91_rtc_shadow_imr;
51 static bool suspended;
52 static DEFINE_SPINLOCK(suspended_lock);
53 static unsigned long cached_events;
54 static u32 at91_rtc_imr;
55 static struct clk *sclk;
56
57 static 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
67 static 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
89 static 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 */
108 static 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 */
139 static 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 */
153 static 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 */
193 static 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 */
212 static 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
245 static 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 */
260 static 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 */
275 static 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
315 static const struct at91_rtc_config at91rm9200_config = {
316 };
317
318 static const struct at91_rtc_config at91sam9x5_config = {
319 .use_shadow_imr = true,
320 };
321
322 #ifdef CONFIG_OF
323 static 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 };
334 MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids);
335 #endif
336
337 static const struct at91_rtc_config *
338 at91_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
352 static 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 */
364 static 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 dev_err(&pdev->dev, "no irq resource defined\n");
383 return -ENXIO;
384 }
385
386 at91_rtc_regs = devm_ioremap(&pdev->dev, regs->start,
387 resource_size(regs));
388 if (!at91_rtc_regs) {
389 dev_err(&pdev->dev, "failed to map registers, aborting.\n");
390 return -ENOMEM;
391 }
392
393 rtc = devm_rtc_allocate_device(&pdev->dev);
394 if (IS_ERR(rtc))
395 return PTR_ERR(rtc);
396 platform_set_drvdata(pdev, rtc);
397
398 sclk = devm_clk_get(&pdev->dev, NULL);
399 if (IS_ERR(sclk))
400 return PTR_ERR(sclk);
401
402 ret = clk_prepare_enable(sclk);
403 if (ret) {
404 dev_err(&pdev->dev, "Could not enable slow clock\n");
405 return ret;
406 }
407
408 at91_rtc_write(AT91_RTC_CR, 0);
409 at91_rtc_write(AT91_RTC_MR, 0); /* 24 hour mode */
410
411 /* Disable all interrupts */
412 at91_rtc_write_idr(AT91_RTC_ACKUPD | AT91_RTC_ALARM |
413 AT91_RTC_SECEV | AT91_RTC_TIMEV |
414 AT91_RTC_CALEV);
415
416 ret = devm_request_irq(&pdev->dev, irq, at91_rtc_interrupt,
417 IRQF_SHARED | IRQF_COND_SUSPEND,
418 "at91_rtc", pdev);
419 if (ret) {
420 dev_err(&pdev->dev, "IRQ %d already in use.\n", irq);
421 goto err_clk;
422 }
423
424 /* cpu init code should really have flagged this device as
425 * being wake-capable; if it didn't, do that here.
426 */
427 if (!device_can_wakeup(&pdev->dev))
428 device_init_wakeup(&pdev->dev, 1);
429
430 rtc->ops = &at91_rtc_ops;
431 rtc->range_min = RTC_TIMESTAMP_BEGIN_1900;
432 rtc->range_max = RTC_TIMESTAMP_END_2099;
433 ret = rtc_register_device(rtc);
434 if (ret)
435 goto err_clk;
436
437 /* enable SECEV interrupt in order to initialize at91_rtc_upd_rdy
438 * completion.
439 */
440 at91_rtc_write_ier(AT91_RTC_SECEV);
441
442 dev_info(&pdev->dev, "AT91 Real Time Clock driver.\n");
443 return 0;
444
445 err_clk:
446 clk_disable_unprepare(sclk);
447
448 return ret;
449 }
450
451 /*
452 * Disable and remove the RTC driver
453 */
454 static int __exit at91_rtc_remove(struct platform_device *pdev)
455 {
456 /* Disable all interrupts */
457 at91_rtc_write_idr(AT91_RTC_ACKUPD | AT91_RTC_ALARM |
458 AT91_RTC_SECEV | AT91_RTC_TIMEV |
459 AT91_RTC_CALEV);
460
461 clk_disable_unprepare(sclk);
462
463 return 0;
464 }
465
466 static void at91_rtc_shutdown(struct platform_device *pdev)
467 {
468 /* Disable all interrupts */
469 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
470 AT91_RTC_SECEV | AT91_RTC_TIMEV |
471 AT91_RTC_CALEV);
472 }
473
474 #ifdef CONFIG_PM_SLEEP
475
476 /* AT91RM9200 RTC Power management control */
477
478 static int at91_rtc_suspend(struct device *dev)
479 {
480 /* this IRQ is shared with DBGU and other hardware which isn't
481 * necessarily doing PM like we are...
482 */
483 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
484
485 at91_rtc_imr = at91_rtc_read_imr()
486 & (AT91_RTC_ALARM|AT91_RTC_SECEV);
487 if (at91_rtc_imr) {
488 if (device_may_wakeup(dev)) {
489 unsigned long flags;
490
491 enable_irq_wake(irq);
492
493 spin_lock_irqsave(&suspended_lock, flags);
494 suspended = true;
495 spin_unlock_irqrestore(&suspended_lock, flags);
496 } else {
497 at91_rtc_write_idr(at91_rtc_imr);
498 }
499 }
500 return 0;
501 }
502
503 static int at91_rtc_resume(struct device *dev)
504 {
505 struct rtc_device *rtc = dev_get_drvdata(dev);
506
507 if (at91_rtc_imr) {
508 if (device_may_wakeup(dev)) {
509 unsigned long flags;
510
511 spin_lock_irqsave(&suspended_lock, flags);
512
513 if (cached_events) {
514 rtc_update_irq(rtc, 1, cached_events);
515 cached_events = 0;
516 }
517
518 suspended = false;
519 spin_unlock_irqrestore(&suspended_lock, flags);
520
521 disable_irq_wake(irq);
522 }
523 at91_rtc_write_ier(at91_rtc_imr);
524 }
525 return 0;
526 }
527 #endif
528
529 static SIMPLE_DEV_PM_OPS(at91_rtc_pm_ops, at91_rtc_suspend, at91_rtc_resume);
530
531 static struct platform_driver at91_rtc_driver = {
532 .remove = __exit_p(at91_rtc_remove),
533 .shutdown = at91_rtc_shutdown,
534 .driver = {
535 .name = "at91_rtc",
536 .pm = &at91_rtc_pm_ops,
537 .of_match_table = of_match_ptr(at91_rtc_dt_ids),
538 },
539 };
540
541 module_platform_driver_probe(at91_rtc_driver, at91_rtc_probe);
542
543 MODULE_AUTHOR("Rick Bronson");
544 MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
545 MODULE_LICENSE("GPL");
546 MODULE_ALIAS("platform:at91_rtc");
Linux with added FPC-III support