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14#include <linux/clk.h>
15#include <linux/interrupt.h>
16#include <linux/ioctl.h>
17#include <linux/io.h>
18#include <linux/kernel.h>
19#include <linux/mfd/syscon.h>
20#include <linux/module.h>
21#include <linux/of.h>
22#include <linux/platform_device.h>
23#include <linux/regmap.h>
24#include <linux/rtc.h>
25#include <linux/slab.h>
26#include <linux/suspend.h>
27#include <linux/time.h>
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49
50#define AT91_RTT_MR 0x00
51#define AT91_RTT_RTPRES (0xffff << 0)
52#define AT91_RTT_ALMIEN (1 << 16)
53#define AT91_RTT_RTTINCIEN (1 << 17)
54#define AT91_RTT_RTTRST (1 << 18)
55
56#define AT91_RTT_AR 0x04
57#define AT91_RTT_ALMV (0xffffffff)
58
59#define AT91_RTT_VR 0x08
60#define AT91_RTT_CRTV (0xffffffff)
61
62#define AT91_RTT_SR 0x0c
63#define AT91_RTT_ALMS (1 << 0)
64#define AT91_RTT_RTTINC (1 << 1)
65
66
67
68
69
70#define ALARM_DISABLED ((u32)~0)
71
72
73struct sam9_rtc {
74 void __iomem *rtt;
75 struct rtc_device *rtcdev;
76 u32 imr;
77 struct regmap *gpbr;
78 unsigned int gpbr_offset;
79 int irq;
80 struct clk *sclk;
81 bool suspended;
82 unsigned long events;
83 spinlock_t lock;
84};
85
86#define rtt_readl(rtc, field) \
87 readl((rtc)->rtt + AT91_RTT_ ## field)
88#define rtt_writel(rtc, field, val) \
89 writel((val), (rtc)->rtt + AT91_RTT_ ## field)
90
91static inline unsigned int gpbr_readl(struct sam9_rtc *rtc)
92{
93 unsigned int val;
94
95 regmap_read(rtc->gpbr, rtc->gpbr_offset, &val);
96
97 return val;
98}
99
100static inline void gpbr_writel(struct sam9_rtc *rtc, unsigned int val)
101{
102 regmap_write(rtc->gpbr, rtc->gpbr_offset, val);
103}
104
105
106
107
108static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
109{
110 struct sam9_rtc *rtc = dev_get_drvdata(dev);
111 u32 secs, secs2;
112 u32 offset;
113
114
115 offset = gpbr_readl(rtc);
116 if (offset == 0)
117 return -EILSEQ;
118
119
120 secs = rtt_readl(rtc, VR);
121 secs2 = rtt_readl(rtc, VR);
122 if (secs != secs2)
123 secs = rtt_readl(rtc, VR);
124
125 rtc_time_to_tm(offset + secs, tm);
126
127 dev_dbg(dev, "%s: %ptR\n", __func__, tm);
128
129 return 0;
130}
131
132
133
134
135static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
136{
137 struct sam9_rtc *rtc = dev_get_drvdata(dev);
138 int err;
139 u32 offset, alarm, mr;
140 unsigned long secs;
141
142 dev_dbg(dev, "%s: %ptR\n", __func__, tm);
143
144 err = rtc_tm_to_time(tm, &secs);
145 if (err != 0)
146 return err;
147
148 mr = rtt_readl(rtc, MR);
149
150
151 rtt_writel(rtc, MR, mr & ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN));
152
153
154 offset = gpbr_readl(rtc);
155
156
157 secs += 1;
158 gpbr_writel(rtc, secs);
159
160
161 alarm = rtt_readl(rtc, AR);
162 if (alarm != ALARM_DISABLED) {
163 if (offset > secs) {
164
165 alarm += (offset - secs);
166 } else if ((alarm + offset) > secs) {
167
168 alarm -= (secs - offset);
169 } else {
170
171 alarm = ALARM_DISABLED;
172 mr &= ~AT91_RTT_ALMIEN;
173 }
174 rtt_writel(rtc, AR, alarm);
175 }
176
177
178 rtt_writel(rtc, MR, mr | AT91_RTT_RTTRST);
179
180 return 0;
181}
182
183static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
184{
185 struct sam9_rtc *rtc = dev_get_drvdata(dev);
186 struct rtc_time *tm = &alrm->time;
187 u32 alarm = rtt_readl(rtc, AR);
188 u32 offset;
189
190 offset = gpbr_readl(rtc);
191 if (offset == 0)
192 return -EILSEQ;
193
194 memset(alrm, 0, sizeof(*alrm));
195 if (alarm != ALARM_DISABLED && offset != 0) {
196 rtc_time_to_tm(offset + alarm, tm);
197
198 dev_dbg(dev, "%s: %ptR\n", __func__, tm);
199
200 if (rtt_readl(rtc, MR) & AT91_RTT_ALMIEN)
201 alrm->enabled = 1;
202 }
203
204 return 0;
205}
206
207static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
208{
209 struct sam9_rtc *rtc = dev_get_drvdata(dev);
210 struct rtc_time *tm = &alrm->time;
211 unsigned long secs;
212 u32 offset;
213 u32 mr;
214 int err;
215
216 err = rtc_tm_to_time(tm, &secs);
217 if (err != 0)
218 return err;
219
220 offset = gpbr_readl(rtc);
221 if (offset == 0) {
222
223 return -EILSEQ;
224 }
225 mr = rtt_readl(rtc, MR);
226 rtt_writel(rtc, MR, mr & ~AT91_RTT_ALMIEN);
227
228
229 if (secs <= offset) {
230 rtt_writel(rtc, AR, ALARM_DISABLED);
231 return 0;
232 }
233
234
235 rtt_writel(rtc, AR, secs - offset);
236 if (alrm->enabled)
237 rtt_writel(rtc, MR, mr | AT91_RTT_ALMIEN);
238
239 dev_dbg(dev, "%s: %ptR\n", __func__, tm);
240
241 return 0;
242}
243
244static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
245{
246 struct sam9_rtc *rtc = dev_get_drvdata(dev);
247 u32 mr = rtt_readl(rtc, MR);
248
249 dev_dbg(dev, "alarm_irq_enable: enabled=%08x, mr %08x\n", enabled, mr);
250 if (enabled)
251 rtt_writel(rtc, MR, mr | AT91_RTT_ALMIEN);
252 else
253 rtt_writel(rtc, MR, mr & ~AT91_RTT_ALMIEN);
254 return 0;
255}
256
257
258
259
260static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
261{
262 struct sam9_rtc *rtc = dev_get_drvdata(dev);
263 u32 mr = rtt_readl(rtc, MR);
264
265 seq_printf(seq, "update_IRQ\t: %s\n",
266 (mr & AT91_RTT_RTTINCIEN) ? "yes" : "no");
267 return 0;
268}
269
270static irqreturn_t at91_rtc_cache_events(struct sam9_rtc *rtc)
271{
272 u32 sr, mr;
273
274
275
276
277 mr = rtt_readl(rtc, MR) & (AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN);
278 sr = rtt_readl(rtc, SR) & (mr >> 16);
279 if (!sr)
280 return IRQ_NONE;
281
282
283 if (sr & AT91_RTT_ALMS)
284 rtc->events |= (RTC_AF | RTC_IRQF);
285
286
287 if (sr & AT91_RTT_RTTINC)
288 rtc->events |= (RTC_UF | RTC_IRQF);
289
290 return IRQ_HANDLED;
291}
292
293static void at91_rtc_flush_events(struct sam9_rtc *rtc)
294{
295 if (!rtc->events)
296 return;
297
298 rtc_update_irq(rtc->rtcdev, 1, rtc->events);
299 rtc->events = 0;
300
301 pr_debug("%s: num=%ld, events=0x%02lx\n", __func__,
302 rtc->events >> 8, rtc->events & 0x000000FF);
303}
304
305
306
307
308static irqreturn_t at91_rtc_interrupt(int irq, void *_rtc)
309{
310 struct sam9_rtc *rtc = _rtc;
311 int ret;
312
313 spin_lock(&rtc->lock);
314
315 ret = at91_rtc_cache_events(rtc);
316
317
318 if (rtc->suspended) {
319
320 rtt_writel(rtc, MR,
321 rtt_readl(rtc, MR) &
322 ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN));
323
324 pm_system_wakeup();
325 } else {
326 at91_rtc_flush_events(rtc);
327 }
328
329 spin_unlock(&rtc->lock);
330
331 return ret;
332}
333
334static const struct rtc_class_ops at91_rtc_ops = {
335 .read_time = at91_rtc_readtime,
336 .set_time = at91_rtc_settime,
337 .read_alarm = at91_rtc_readalarm,
338 .set_alarm = at91_rtc_setalarm,
339 .proc = at91_rtc_proc,
340 .alarm_irq_enable = at91_rtc_alarm_irq_enable,
341};
342
343static const struct regmap_config gpbr_regmap_config = {
344 .name = "gpbr",
345 .reg_bits = 32,
346 .val_bits = 32,
347 .reg_stride = 4,
348};
349
350
351
352
353static int at91_rtc_probe(struct platform_device *pdev)
354{
355 struct resource *r;
356 struct sam9_rtc *rtc;
357 int ret, irq;
358 u32 mr;
359 unsigned int sclk_rate;
360
361 irq = platform_get_irq(pdev, 0);
362 if (irq < 0) {
363 dev_err(&pdev->dev, "failed to get interrupt resource\n");
364 return irq;
365 }
366
367 rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
368 if (!rtc)
369 return -ENOMEM;
370
371 spin_lock_init(&rtc->lock);
372 rtc->irq = irq;
373
374
375 if (!device_can_wakeup(&pdev->dev))
376 device_init_wakeup(&pdev->dev, 1);
377
378 platform_set_drvdata(pdev, rtc);
379
380 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
381 rtc->rtt = devm_ioremap_resource(&pdev->dev, r);
382 if (IS_ERR(rtc->rtt))
383 return PTR_ERR(rtc->rtt);
384
385 if (!pdev->dev.of_node) {
386
387
388
389
390
391 void __iomem *gpbr;
392
393 r = platform_get_resource(pdev, IORESOURCE_MEM, 1);
394 gpbr = devm_ioremap_resource(&pdev->dev, r);
395 if (IS_ERR(gpbr))
396 return PTR_ERR(gpbr);
397
398 rtc->gpbr = regmap_init_mmio(NULL, gpbr,
399 &gpbr_regmap_config);
400 } else {
401 struct of_phandle_args args;
402
403 ret = of_parse_phandle_with_fixed_args(pdev->dev.of_node,
404 "atmel,rtt-rtc-time-reg", 1, 0,
405 &args);
406 if (ret)
407 return ret;
408
409 rtc->gpbr = syscon_node_to_regmap(args.np);
410 rtc->gpbr_offset = args.args[0];
411 }
412
413 if (IS_ERR(rtc->gpbr)) {
414 dev_err(&pdev->dev, "failed to retrieve gpbr regmap, aborting.\n");
415 return -ENOMEM;
416 }
417
418 rtc->sclk = devm_clk_get(&pdev->dev, NULL);
419 if (IS_ERR(rtc->sclk))
420 return PTR_ERR(rtc->sclk);
421
422 ret = clk_prepare_enable(rtc->sclk);
423 if (ret) {
424 dev_err(&pdev->dev, "Could not enable slow clock\n");
425 return ret;
426 }
427
428 sclk_rate = clk_get_rate(rtc->sclk);
429 if (!sclk_rate || sclk_rate > AT91_RTT_RTPRES) {
430 dev_err(&pdev->dev, "Invalid slow clock rate\n");
431 ret = -EINVAL;
432 goto err_clk;
433 }
434
435 mr = rtt_readl(rtc, MR);
436
437
438 if ((mr & AT91_RTT_RTPRES) != sclk_rate) {
439 mr = AT91_RTT_RTTRST | (sclk_rate & AT91_RTT_RTPRES);
440 gpbr_writel(rtc, 0);
441 }
442
443
444 mr &= ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN);
445 rtt_writel(rtc, MR, mr);
446
447 rtc->rtcdev = devm_rtc_device_register(&pdev->dev, pdev->name,
448 &at91_rtc_ops, THIS_MODULE);
449 if (IS_ERR(rtc->rtcdev)) {
450 ret = PTR_ERR(rtc->rtcdev);
451 goto err_clk;
452 }
453
454
455 ret = devm_request_irq(&pdev->dev, rtc->irq, at91_rtc_interrupt,
456 IRQF_SHARED | IRQF_COND_SUSPEND,
457 dev_name(&rtc->rtcdev->dev), rtc);
458 if (ret) {
459 dev_dbg(&pdev->dev, "can't share IRQ %d?\n", rtc->irq);
460 goto err_clk;
461 }
462
463
464
465
466
467
468
469 if (gpbr_readl(rtc) == 0)
470 dev_warn(&pdev->dev, "%s: SET TIME!\n",
471 dev_name(&rtc->rtcdev->dev));
472
473 return 0;
474
475err_clk:
476 clk_disable_unprepare(rtc->sclk);
477
478 return ret;
479}
480
481
482
483
484static int at91_rtc_remove(struct platform_device *pdev)
485{
486 struct sam9_rtc *rtc = platform_get_drvdata(pdev);
487 u32 mr = rtt_readl(rtc, MR);
488
489
490 rtt_writel(rtc, MR, mr & ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN));
491
492 clk_disable_unprepare(rtc->sclk);
493
494 return 0;
495}
496
497static void at91_rtc_shutdown(struct platform_device *pdev)
498{
499 struct sam9_rtc *rtc = platform_get_drvdata(pdev);
500 u32 mr = rtt_readl(rtc, MR);
501
502 rtc->imr = mr & (AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN);
503 rtt_writel(rtc, MR, mr & ~rtc->imr);
504}
505
506#ifdef CONFIG_PM_SLEEP
507
508
509
510static int at91_rtc_suspend(struct device *dev)
511{
512 struct sam9_rtc *rtc = dev_get_drvdata(dev);
513 u32 mr = rtt_readl(rtc, MR);
514
515
516
517
518
519 rtc->imr = mr & (AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN);
520 if (rtc->imr) {
521 if (device_may_wakeup(dev) && (mr & AT91_RTT_ALMIEN)) {
522 unsigned long flags;
523
524 enable_irq_wake(rtc->irq);
525 spin_lock_irqsave(&rtc->lock, flags);
526 rtc->suspended = true;
527 spin_unlock_irqrestore(&rtc->lock, flags);
528
529 if (mr & AT91_RTT_RTTINCIEN)
530 rtt_writel(rtc, MR, mr & ~AT91_RTT_RTTINCIEN);
531 } else
532 rtt_writel(rtc, MR, mr & ~rtc->imr);
533 }
534
535 return 0;
536}
537
538static int at91_rtc_resume(struct device *dev)
539{
540 struct sam9_rtc *rtc = dev_get_drvdata(dev);
541 u32 mr;
542
543 if (rtc->imr) {
544 unsigned long flags;
545
546 if (device_may_wakeup(dev))
547 disable_irq_wake(rtc->irq);
548 mr = rtt_readl(rtc, MR);
549 rtt_writel(rtc, MR, mr | rtc->imr);
550
551 spin_lock_irqsave(&rtc->lock, flags);
552 rtc->suspended = false;
553 at91_rtc_cache_events(rtc);
554 at91_rtc_flush_events(rtc);
555 spin_unlock_irqrestore(&rtc->lock, flags);
556 }
557
558 return 0;
559}
560#endif
561
562static SIMPLE_DEV_PM_OPS(at91_rtc_pm_ops, at91_rtc_suspend, at91_rtc_resume);
563
564#ifdef CONFIG_OF
565static const struct of_device_id at91_rtc_dt_ids[] = {
566 { .compatible = "atmel,at91sam9260-rtt" },
567 { }
568};
569MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids);
570#endif
571
572static struct platform_driver at91_rtc_driver = {
573 .probe = at91_rtc_probe,
574 .remove = at91_rtc_remove,
575 .shutdown = at91_rtc_shutdown,
576 .driver = {
577 .name = "rtc-at91sam9",
578 .pm = &at91_rtc_pm_ops,
579 .of_match_table = of_match_ptr(at91_rtc_dt_ids),
580 },
581};
582
583module_platform_driver(at91_rtc_driver);
584
585MODULE_AUTHOR("Michel Benoit");
586MODULE_DESCRIPTION("RTC driver for Atmel AT91SAM9x");
587MODULE_LICENSE("GPL");
588