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1/*
2 * SuperH Timer Support - CMT
3 *
4 * Copyright (C) 2008 Magnus Damm
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20#include <linux/init.h>
21#include <linux/platform_device.h>
22#include <linux/spinlock.h>
23#include <linux/interrupt.h>
24#include <linux/ioport.h>
25#include <linux/io.h>
26#include <linux/clk.h>
27#include <linux/irq.h>
28#include <linux/err.h>
29#include <linux/delay.h>
30#include <linux/clocksource.h>
31#include <linux/clockchips.h>
32#include <linux/sh_timer.h>
33#include <linux/slab.h>
34#include <linux/module.h>
35#include <linux/pm_domain.h>
36
37struct sh_cmt_priv {
38 void __iomem *mapbase;
39 struct clk *clk;
40 unsigned long width; /* 16 or 32 bit version of hardware block */
41 unsigned long overflow_bit;
42 unsigned long clear_bits;
43 struct irqaction irqaction;
44 struct platform_device *pdev;
45
46 unsigned long flags;
47 unsigned long match_value;
48 unsigned long next_match_value;
49 unsigned long max_match_value;
50 unsigned long rate;
51 raw_spinlock_t lock;
52 struct clock_event_device ced;
53 struct clocksource cs;
54 unsigned long total_cycles;
55};
56
57static DEFINE_RAW_SPINLOCK(sh_cmt_lock);
58
59#define CMSTR -1 /* shared register */
60#define CMCSR 0 /* channel register */
61#define CMCNT 1 /* channel register */
62#define CMCOR 2 /* channel register */
63
64static inline unsigned long sh_cmt_read(struct sh_cmt_priv *p, int reg_nr)
65{
66 struct sh_timer_config *cfg = p->pdev->dev.platform_data;
67 void __iomem *base = p->mapbase;
68 unsigned long offs;
69
70 if (reg_nr == CMSTR) {
71 offs = 0;
72 base -= cfg->channel_offset;
73 } else
74 offs = reg_nr;
75
76 if (p->width == 16)
77 offs <<= 1;
78 else {
79 offs <<= 2;
80 if ((reg_nr == CMCNT) || (reg_nr == CMCOR))
81 return ioread32(base + offs);
82 }
83
84 return ioread16(base + offs);
85}
86
87static inline void sh_cmt_write(struct sh_cmt_priv *p, int reg_nr,
88 unsigned long value)
89{
90 struct sh_timer_config *cfg = p->pdev->dev.platform_data;
91 void __iomem *base = p->mapbase;
92 unsigned long offs;
93
94 if (reg_nr == CMSTR) {
95 offs = 0;
96 base -= cfg->channel_offset;
97 } else
98 offs = reg_nr;
99
100 if (p->width == 16)
101 offs <<= 1;
102 else {
103 offs <<= 2;
104 if ((reg_nr == CMCNT) || (reg_nr == CMCOR)) {
105 iowrite32(value, base + offs);
106 return;
107 }
108 }
109
110 iowrite16(value, base + offs);
111}
112
113static unsigned long sh_cmt_get_counter(struct sh_cmt_priv *p,
114 int *has_wrapped)
115{
116 unsigned long v1, v2, v3;
117 int o1, o2;
118
119 o1 = sh_cmt_read(p, CMCSR) & p->overflow_bit;
120
121 /* Make sure the timer value is stable. Stolen from acpi_pm.c */
122 do {
123 o2 = o1;
124 v1 = sh_cmt_read(p, CMCNT);
125 v2 = sh_cmt_read(p, CMCNT);
126 v3 = sh_cmt_read(p, CMCNT);
127 o1 = sh_cmt_read(p, CMCSR) & p->overflow_bit;
128 } while (unlikely((o1 != o2) || (v1 > v2 && v1 < v3)
129 || (v2 > v3 && v2 < v1) || (v3 > v1 && v3 < v2)));
130
131 *has_wrapped = o1;
132 return v2;
133}
134
135
136static void sh_cmt_start_stop_ch(struct sh_cmt_priv *p, int start)
137{
138 struct sh_timer_config *cfg = p->pdev->dev.platform_data;
139 unsigned long flags, value;
140
141 /* start stop register shared by multiple timer channels */
142 raw_spin_lock_irqsave(&sh_cmt_lock, flags);
143 value = sh_cmt_read(p, CMSTR);
144
145 if (start)
146 value |= 1 << cfg->timer_bit;
147 else
148 value &= ~(1 << cfg->timer_bit);
149
150 sh_cmt_write(p, CMSTR, value);
151 raw_spin_unlock_irqrestore(&sh_cmt_lock, flags);
152}
153
154static int sh_cmt_enable(struct sh_cmt_priv *p, unsigned long *rate)
155{
156 int k, ret;
157
158 /* enable clock */
159 ret = clk_enable(p->clk);
160 if (ret) {
161 dev_err(&p->pdev->dev, "cannot enable clock\n");
162 goto err0;
163 }
164
165 /* make sure channel is disabled */
166 sh_cmt_start_stop_ch(p, 0);
167
168 /* configure channel, periodic mode and maximum timeout */
169 if (p->width == 16) {
170 *rate = clk_get_rate(p->clk) / 512;
171 sh_cmt_write(p, CMCSR, 0x43);
172 } else {
173 *rate = clk_get_rate(p->clk) / 8;
174 sh_cmt_write(p, CMCSR, 0x01a4);
175 }
176
177 sh_cmt_write(p, CMCOR, 0xffffffff);
178 sh_cmt_write(p, CMCNT, 0);
179
180 /*
181 * According to the sh73a0 user's manual, as CMCNT can be operated
182 * only by the RCLK (Pseudo 32 KHz), there's one restriction on
183 * modifying CMCNT register; two RCLK cycles are necessary before
184 * this register is either read or any modification of the value
185 * it holds is reflected in the LSI's actual operation.
186 *
187 * While at it, we're supposed to clear out the CMCNT as of this
188 * moment, so make sure it's processed properly here. This will
189 * take RCLKx2 at maximum.
190 */
191 for (k = 0; k < 100; k++) {
192 if (!sh_cmt_read(p, CMCNT))
193 break;
194 udelay(1);
195 }
196
197 if (sh_cmt_read(p, CMCNT)) {
198 dev_err(&p->pdev->dev, "cannot clear CMCNT\n");
199 ret = -ETIMEDOUT;
200 goto err1;
201 }
202
203 /* enable channel */
204 sh_cmt_start_stop_ch(p, 1);
205 return 0;
206 err1:
207 /* stop clock */
208 clk_disable(p->clk);
209
210 err0:
211 return ret;
212}
213
214static void sh_cmt_disable(struct sh_cmt_priv *p)
215{
216 /* disable channel */
217 sh_cmt_start_stop_ch(p, 0);
218
219 /* disable interrupts in CMT block */
220 sh_cmt_write(p, CMCSR, 0);
221
222 /* stop clock */
223 clk_disable(p->clk);
224}
225
226/* private flags */
227#define FLAG_CLOCKEVENT (1 << 0)
228#define FLAG_CLOCKSOURCE (1 << 1)
229#define FLAG_REPROGRAM (1 << 2)
230#define FLAG_SKIPEVENT (1 << 3)
231#define FLAG_IRQCONTEXT (1 << 4)
232
233static void sh_cmt_clock_event_program_verify(struct sh_cmt_priv *p,
234 int absolute)
235{
236 unsigned long new_match;
237 unsigned long value = p->next_match_value;
238 unsigned long delay = 0;
239 unsigned long now = 0;
240 int has_wrapped;
241
242 now = sh_cmt_get_counter(p, &has_wrapped);
243 p->flags |= FLAG_REPROGRAM; /* force reprogram */
244
245 if (has_wrapped) {
246 /* we're competing with the interrupt handler.
247 * -> let the interrupt handler reprogram the timer.
248 * -> interrupt number two handles the event.
249 */
250 p->flags |= FLAG_SKIPEVENT;
251 return;
252 }
253
254 if (absolute)
255 now = 0;
256
257 do {
258 /* reprogram the timer hardware,
259 * but don't save the new match value yet.
260 */
261 new_match = now + value + delay;
262 if (new_match > p->max_match_value)
263 new_match = p->max_match_value;
264
265 sh_cmt_write(p, CMCOR, new_match);
266
267 now = sh_cmt_get_counter(p, &has_wrapped);
268 if (has_wrapped && (new_match > p->match_value)) {
269 /* we are changing to a greater match value,
270 * so this wrap must be caused by the counter
271 * matching the old value.
272 * -> first interrupt reprograms the timer.
273 * -> interrupt number two handles the event.
274 */
275 p->flags |= FLAG_SKIPEVENT;
276 break;
277 }
278
279 if (has_wrapped) {
280 /* we are changing to a smaller match value,
281 * so the wrap must be caused by the counter
282 * matching the new value.
283 * -> save programmed match value.
284 * -> let isr handle the event.
285 */
286 p->match_value = new_match;
287 break;
288 }
289
290 /* be safe: verify hardware settings */
291 if (now < new_match) {
292 /* timer value is below match value, all good.
293 * this makes sure we won't miss any match events.
294 * -> save programmed match value.
295 * -> let isr handle the event.
296 */
297 p->match_value = new_match;
298 break;
299 }
300
301 /* the counter has reached a value greater
302 * than our new match value. and since the
303 * has_wrapped flag isn't set we must have
304 * programmed a too close event.
305 * -> increase delay and retry.
306 */
307 if (delay)
308 delay <<= 1;
309 else
310 delay = 1;
311
312 if (!delay)
313 dev_warn(&p->pdev->dev, "too long delay\n");
314
315 } while (delay);
316}
317
318static void __sh_cmt_set_next(struct sh_cmt_priv *p, unsigned long delta)
319{
320 if (delta > p->max_match_value)
321 dev_warn(&p->pdev->dev, "delta out of range\n");
322
323 p->next_match_value = delta;
324 sh_cmt_clock_event_program_verify(p, 0);
325}
326
327static void sh_cmt_set_next(struct sh_cmt_priv *p, unsigned long delta)
328{
329 unsigned long flags;
330
331 raw_spin_lock_irqsave(&p->lock, flags);
332 __sh_cmt_set_next(p, delta);
333 raw_spin_unlock_irqrestore(&p->lock, flags);
334}
335
336static irqreturn_t sh_cmt_interrupt(int irq, void *dev_id)
337{
338 struct sh_cmt_priv *p = dev_id;
339
340 /* clear flags */
341 sh_cmt_write(p, CMCSR, sh_cmt_read(p, CMCSR) & p->clear_bits);
342
343 /* update clock source counter to begin with if enabled
344 * the wrap flag should be cleared by the timer specific
345 * isr before we end up here.
346 */
347 if (p->flags & FLAG_CLOCKSOURCE)
348 p->total_cycles += p->match_value + 1;
349
350 if (!(p->flags & FLAG_REPROGRAM))
351 p->next_match_value = p->max_match_value;
352
353 p->flags |= FLAG_IRQCONTEXT;
354
355 if (p->flags & FLAG_CLOCKEVENT) {
356 if (!(p->flags & FLAG_SKIPEVENT)) {
357 if (p->ced.mode == CLOCK_EVT_MODE_ONESHOT) {
358 p->next_match_value = p->max_match_value;
359 p->flags |= FLAG_REPROGRAM;
360 }
361
362 p->ced.event_handler(&p->ced);
363 }
364 }
365
366 p->flags &= ~FLAG_SKIPEVENT;
367
368 if (p->flags & FLAG_REPROGRAM) {
369 p->flags &= ~FLAG_REPROGRAM;
370 sh_cmt_clock_event_program_verify(p, 1);
371
372 if (p->flags & FLAG_CLOCKEVENT)
373 if ((p->ced.mode == CLOCK_EVT_MODE_SHUTDOWN)
374 || (p->match_value == p->next_match_value))
375 p->flags &= ~FLAG_REPROGRAM;
376 }
377
378 p->flags &= ~FLAG_IRQCONTEXT;
379
380 return IRQ_HANDLED;
381}
382
383static int sh_cmt_start(struct sh_cmt_priv *p, unsigned long flag)
384{
385 int ret = 0;
386 unsigned long flags;
387
388 raw_spin_lock_irqsave(&p->lock, flags);
389
390 if (!(p->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE)))
391 ret = sh_cmt_enable(p, &p->rate);
392
393 if (ret)
394 goto out;
395 p->flags |= flag;
396
397 /* setup timeout if no clockevent */
398 if ((flag == FLAG_CLOCKSOURCE) && (!(p->flags & FLAG_CLOCKEVENT)))
399 __sh_cmt_set_next(p, p->max_match_value);
400 out:
401 raw_spin_unlock_irqrestore(&p->lock, flags);
402
403 return ret;
404}
405
406static void sh_cmt_stop(struct sh_cmt_priv *p, unsigned long flag)
407{
408 unsigned long flags;
409 unsigned long f;
410
411 raw_spin_lock_irqsave(&p->lock, flags);
412
413 f = p->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE);
414 p->flags &= ~flag;
415
416 if (f && !(p->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE)))
417 sh_cmt_disable(p);
418
419 /* adjust the timeout to maximum if only clocksource left */
420 if ((flag == FLAG_CLOCKEVENT) && (p->flags & FLAG_CLOCKSOURCE))
421 __sh_cmt_set_next(p, p->max_match_value);
422
423 raw_spin_unlock_irqrestore(&p->lock, flags);
424}
425
426static struct sh_cmt_priv *cs_to_sh_cmt(struct clocksource *cs)
427{
428 return container_of(cs, struct sh_cmt_priv, cs);
429}
430
431static cycle_t sh_cmt_clocksource_read(struct clocksource *cs)
432{
433 struct sh_cmt_priv *p = cs_to_sh_cmt(cs);
434 unsigned long flags, raw;
435 unsigned long value;
436 int has_wrapped;
437
438 raw_spin_lock_irqsave(&p->lock, flags);
439 value = p->total_cycles;
440 raw = sh_cmt_get_counter(p, &has_wrapped);
441
442 if (unlikely(has_wrapped))
443 raw += p->match_value + 1;
444 raw_spin_unlock_irqrestore(&p->lock, flags);
445
446 return value + raw;
447}
448
449static int sh_cmt_clocksource_enable(struct clocksource *cs)
450{
451 int ret;
452 struct sh_cmt_priv *p = cs_to_sh_cmt(cs);
453
454 p->total_cycles = 0;
455
456 ret = sh_cmt_start(p, FLAG_CLOCKSOURCE);
457 if (!ret)
458 __clocksource_updatefreq_hz(cs, p->rate);
459 return ret;
460}
461
462static void sh_cmt_clocksource_disable(struct clocksource *cs)
463{
464 sh_cmt_stop(cs_to_sh_cmt(cs), FLAG_CLOCKSOURCE);
465}
466
467static void sh_cmt_clocksource_resume(struct clocksource *cs)
468{
469 sh_cmt_start(cs_to_sh_cmt(cs), FLAG_CLOCKSOURCE);
470}
471
472static int sh_cmt_register_clocksource(struct sh_cmt_priv *p,
473 char *name, unsigned long rating)
474{
475 struct clocksource *cs = &p->cs;
476
477 cs->name = name;
478 cs->rating = rating;
479 cs->read = sh_cmt_clocksource_read;
480 cs->enable = sh_cmt_clocksource_enable;
481 cs->disable = sh_cmt_clocksource_disable;
482 cs->suspend = sh_cmt_clocksource_disable;
483 cs->resume = sh_cmt_clocksource_resume;
484 cs->mask = CLOCKSOURCE_MASK(sizeof(unsigned long) * 8);
485 cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
486
487 dev_info(&p->pdev->dev, "used as clock source\n");
488
489 /* Register with dummy 1 Hz value, gets updated in ->enable() */
490 clocksource_register_hz(cs, 1);
491 return 0;
492}
493
494static struct sh_cmt_priv *ced_to_sh_cmt(struct clock_event_device *ced)
495{
496 return container_of(ced, struct sh_cmt_priv, ced);
497}
498
499static void sh_cmt_clock_event_start(struct sh_cmt_priv *p, int periodic)
500{
501 struct clock_event_device *ced = &p->ced;
502
503 sh_cmt_start(p, FLAG_CLOCKEVENT);
504
505 /* TODO: calculate good shift from rate and counter bit width */
506
507 ced->shift = 32;
508 ced->mult = div_sc(p->rate, NSEC_PER_SEC, ced->shift);
509 ced->max_delta_ns = clockevent_delta2ns(p->max_match_value, ced);
510 ced->min_delta_ns = clockevent_delta2ns(0x1f, ced);
511
512 if (periodic)
513 sh_cmt_set_next(p, ((p->rate + HZ/2) / HZ) - 1);
514 else
515 sh_cmt_set_next(p, p->max_match_value);
516}
517
518static void sh_cmt_clock_event_mode(enum clock_event_mode mode,
519 struct clock_event_device *ced)
520{
521 struct sh_cmt_priv *p = ced_to_sh_cmt(ced);
522
523 /* deal with old setting first */
524 switch (ced->mode) {
525 case CLOCK_EVT_MODE_PERIODIC:
526 case CLOCK_EVT_MODE_ONESHOT:
527 sh_cmt_stop(p, FLAG_CLOCKEVENT);
528 break;
529 default:
530 break;
531 }
532
533 switch (mode) {
534 case CLOCK_EVT_MODE_PERIODIC:
535 dev_info(&p->pdev->dev, "used for periodic clock events\n");
536 sh_cmt_clock_event_start(p, 1);
537 break;
538 case CLOCK_EVT_MODE_ONESHOT:
539 dev_info(&p->pdev->dev, "used for oneshot clock events\n");
540 sh_cmt_clock_event_start(p, 0);
541 break;
542 case CLOCK_EVT_MODE_SHUTDOWN:
543 case CLOCK_EVT_MODE_UNUSED:
544 sh_cmt_stop(p, FLAG_CLOCKEVENT);
545 break;
546 default:
547 break;
548 }
549}
550
551static int sh_cmt_clock_event_next(unsigned long delta,
552 struct clock_event_device *ced)
553{
554 struct sh_cmt_priv *p = ced_to_sh_cmt(ced);
555
556 BUG_ON(ced->mode != CLOCK_EVT_MODE_ONESHOT);
557 if (likely(p->flags & FLAG_IRQCONTEXT))
558 p->next_match_value = delta - 1;
559 else
560 sh_cmt_set_next(p, delta - 1);
561
562 return 0;
563}
564
565static void sh_cmt_register_clockevent(struct sh_cmt_priv *p,
566 char *name, unsigned long rating)
567{
568 struct clock_event_device *ced = &p->ced;
569
570 memset(ced, 0, sizeof(*ced));
571
572 ced->name = name;
573 ced->features = CLOCK_EVT_FEAT_PERIODIC;
574 ced->features |= CLOCK_EVT_FEAT_ONESHOT;
575 ced->rating = rating;
576 ced->cpumask = cpumask_of(0);
577 ced->set_next_event = sh_cmt_clock_event_next;
578 ced->set_mode = sh_cmt_clock_event_mode;
579
580 dev_info(&p->pdev->dev, "used for clock events\n");
581 clockevents_register_device(ced);
582}
583
584static int sh_cmt_register(struct sh_cmt_priv *p, char *name,
585 unsigned long clockevent_rating,
586 unsigned long clocksource_rating)
587{
588 if (p->width == (sizeof(p->max_match_value) * 8))
589 p->max_match_value = ~0;
590 else
591 p->max_match_value = (1 << p->width) - 1;
592
593 p->match_value = p->max_match_value;
594 raw_spin_lock_init(&p->lock);
595
596 if (clockevent_rating)
597 sh_cmt_register_clockevent(p, name, clockevent_rating);
598
599 if (clocksource_rating)
600 sh_cmt_register_clocksource(p, name, clocksource_rating);
601
602 return 0;
603}
604
605static int sh_cmt_setup(struct sh_cmt_priv *p, struct platform_device *pdev)
606{
607 struct sh_timer_config *cfg = pdev->dev.platform_data;
608 struct resource *res;
609 int irq, ret;
610 ret = -ENXIO;
611
612 memset(p, 0, sizeof(*p));
613 p->pdev = pdev;
614
615 if (!cfg) {
616 dev_err(&p->pdev->dev, "missing platform data\n");
617 goto err0;
618 }
619
620 platform_set_drvdata(pdev, p);
621
622 res = platform_get_resource(p->pdev, IORESOURCE_MEM, 0);
623 if (!res) {
624 dev_err(&p->pdev->dev, "failed to get I/O memory\n");
625 goto err0;
626 }
627
628 irq = platform_get_irq(p->pdev, 0);
629 if (irq < 0) {
630 dev_err(&p->pdev->dev, "failed to get irq\n");
631 goto err0;
632 }
633
634 /* map memory, let mapbase point to our channel */
635 p->mapbase = ioremap_nocache(res->start, resource_size(res));
636 if (p->mapbase == NULL) {
637 dev_err(&p->pdev->dev, "failed to remap I/O memory\n");
638 goto err0;
639 }
640
641 /* request irq using setup_irq() (too early for request_irq()) */
642 p->irqaction.name = dev_name(&p->pdev->dev);
643 p->irqaction.handler = sh_cmt_interrupt;
644 p->irqaction.dev_id = p;
645 p->irqaction.flags = IRQF_DISABLED | IRQF_TIMER | \
646 IRQF_IRQPOLL | IRQF_NOBALANCING;
647
648 /* get hold of clock */
649 p->clk = clk_get(&p->pdev->dev, "cmt_fck");
650 if (IS_ERR(p->clk)) {
651 dev_err(&p->pdev->dev, "cannot get clock\n");
652 ret = PTR_ERR(p->clk);
653 goto err1;
654 }
655
656 if (resource_size(res) == 6) {
657 p->width = 16;
658 p->overflow_bit = 0x80;
659 p->clear_bits = ~0x80;
660 } else {
661 p->width = 32;
662 p->overflow_bit = 0x8000;
663 p->clear_bits = ~0xc000;
664 }
665
666 ret = sh_cmt_register(p, (char *)dev_name(&p->pdev->dev),
667 cfg->clockevent_rating,
668 cfg->clocksource_rating);
669 if (ret) {
670 dev_err(&p->pdev->dev, "registration failed\n");
671 goto err1;
672 }
673
674 ret = setup_irq(irq, &p->irqaction);
675 if (ret) {
676 dev_err(&p->pdev->dev, "failed to request irq %d\n", irq);
677 goto err1;
678 }
679
680 return 0;
681
682err1:
683 iounmap(p->mapbase);
684err0:
685 return ret;
686}
687
688static int __devinit sh_cmt_probe(struct platform_device *pdev)
689{
690 struct sh_cmt_priv *p = platform_get_drvdata(pdev);
691 int ret;
692
693 if (!is_early_platform_device(pdev))
694 pm_genpd_dev_always_on(&pdev->dev, true);
695
696 if (p) {
697 dev_info(&pdev->dev, "kept as earlytimer\n");
698 return 0;
699 }
700
701 p = kmalloc(sizeof(*p), GFP_KERNEL);
702 if (p == NULL) {
703 dev_err(&pdev->dev, "failed to allocate driver data\n");
704 return -ENOMEM;
705 }
706
707 ret = sh_cmt_setup(p, pdev);
708 if (ret) {
709 kfree(p);
710 platform_set_drvdata(pdev, NULL);
711 }
712 return ret;
713}
714
715static int __devexit sh_cmt_remove(struct platform_device *pdev)
716{
717 return -EBUSY; /* cannot unregister clockevent and clocksource */
718}
719
720static struct platform_driver sh_cmt_device_driver = {
721 .probe = sh_cmt_probe,
722 .remove = __devexit_p(sh_cmt_remove),
723 .driver = {
724 .name = "sh_cmt",
725 }
726};
727
728static int __init sh_cmt_init(void)
729{
730 return platform_driver_register(&sh_cmt_device_driver);
731}
732
733static void __exit sh_cmt_exit(void)
734{
735 platform_driver_unregister(&sh_cmt_device_driver);
736}
737
738early_platform_init("earlytimer", &sh_cmt_device_driver);
739module_init(sh_cmt_init);
740module_exit(sh_cmt_exit);
741
742MODULE_AUTHOR("Magnus Damm");
743MODULE_DESCRIPTION("SuperH CMT Timer Driver");
744MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * SuperH Timer Support - CMT
4 *
5 * Copyright (C) 2008 Magnus Damm
6 */
7
8#include <linux/clk.h>
9#include <linux/clockchips.h>
10#include <linux/clocksource.h>
11#include <linux/delay.h>
12#include <linux/err.h>
13#include <linux/init.h>
14#include <linux/interrupt.h>
15#include <linux/io.h>
16#include <linux/iopoll.h>
17#include <linux/ioport.h>
18#include <linux/irq.h>
19#include <linux/module.h>
20#include <linux/of.h>
21#include <linux/platform_device.h>
22#include <linux/pm_domain.h>
23#include <linux/pm_runtime.h>
24#include <linux/sh_timer.h>
25#include <linux/slab.h>
26#include <linux/spinlock.h>
27
28#ifdef CONFIG_SUPERH
29#include <asm/platform_early.h>
30#endif
31
32struct sh_cmt_device;
33
34/*
35 * The CMT comes in 5 different identified flavours, depending not only on the
36 * SoC but also on the particular instance. The following table lists the main
37 * characteristics of those flavours.
38 *
39 * 16B 32B 32B-F 48B R-Car Gen2
40 * -----------------------------------------------------------------------------
41 * Channels 2 1/4 1 6 2/8
42 * Control Width 16 16 16 16 32
43 * Counter Width 16 32 32 32/48 32/48
44 * Shared Start/Stop Y Y Y Y N
45 *
46 * The r8a73a4 / R-Car Gen2 version has a per-channel start/stop register
47 * located in the channel registers block. All other versions have a shared
48 * start/stop register located in the global space.
49 *
50 * Channels are indexed from 0 to N-1 in the documentation. The channel index
51 * infers the start/stop bit position in the control register and the channel
52 * registers block address. Some CMT instances have a subset of channels
53 * available, in which case the index in the documentation doesn't match the
54 * "real" index as implemented in hardware. This is for instance the case with
55 * CMT0 on r8a7740, which is a 32-bit variant with a single channel numbered 0
56 * in the documentation but using start/stop bit 5 and having its registers
57 * block at 0x60.
58 *
59 * Similarly CMT0 on r8a73a4, r8a7790 and r8a7791, while implementing 32-bit
60 * channels only, is a 48-bit gen2 CMT with the 48-bit channels unavailable.
61 */
62
63enum sh_cmt_model {
64 SH_CMT_16BIT,
65 SH_CMT_32BIT,
66 SH_CMT_48BIT,
67 SH_CMT0_RCAR_GEN2,
68 SH_CMT1_RCAR_GEN2,
69};
70
71struct sh_cmt_info {
72 enum sh_cmt_model model;
73
74 unsigned int channels_mask;
75
76 unsigned long width; /* 16 or 32 bit version of hardware block */
77 u32 overflow_bit;
78 u32 clear_bits;
79
80 /* callbacks for CMSTR and CMCSR access */
81 u32 (*read_control)(void __iomem *base, unsigned long offs);
82 void (*write_control)(void __iomem *base, unsigned long offs,
83 u32 value);
84
85 /* callbacks for CMCNT and CMCOR access */
86 u32 (*read_count)(void __iomem *base, unsigned long offs);
87 void (*write_count)(void __iomem *base, unsigned long offs, u32 value);
88};
89
90struct sh_cmt_channel {
91 struct sh_cmt_device *cmt;
92
93 unsigned int index; /* Index in the documentation */
94 unsigned int hwidx; /* Real hardware index */
95
96 void __iomem *iostart;
97 void __iomem *ioctrl;
98
99 unsigned int timer_bit;
100 unsigned long flags;
101 u32 match_value;
102 u32 next_match_value;
103 u32 max_match_value;
104 raw_spinlock_t lock;
105 struct clock_event_device ced;
106 struct clocksource cs;
107 u64 total_cycles;
108 bool cs_enabled;
109};
110
111struct sh_cmt_device {
112 struct platform_device *pdev;
113
114 const struct sh_cmt_info *info;
115
116 void __iomem *mapbase;
117 struct clk *clk;
118 unsigned long rate;
119 unsigned int reg_delay;
120
121 raw_spinlock_t lock; /* Protect the shared start/stop register */
122
123 struct sh_cmt_channel *channels;
124 unsigned int num_channels;
125 unsigned int hw_channels;
126
127 bool has_clockevent;
128 bool has_clocksource;
129};
130
131#define SH_CMT16_CMCSR_CMF (1 << 7)
132#define SH_CMT16_CMCSR_CMIE (1 << 6)
133#define SH_CMT16_CMCSR_CKS8 (0 << 0)
134#define SH_CMT16_CMCSR_CKS32 (1 << 0)
135#define SH_CMT16_CMCSR_CKS128 (2 << 0)
136#define SH_CMT16_CMCSR_CKS512 (3 << 0)
137#define SH_CMT16_CMCSR_CKS_MASK (3 << 0)
138
139#define SH_CMT32_CMCSR_CMF (1 << 15)
140#define SH_CMT32_CMCSR_OVF (1 << 14)
141#define SH_CMT32_CMCSR_WRFLG (1 << 13)
142#define SH_CMT32_CMCSR_STTF (1 << 12)
143#define SH_CMT32_CMCSR_STPF (1 << 11)
144#define SH_CMT32_CMCSR_SSIE (1 << 10)
145#define SH_CMT32_CMCSR_CMS (1 << 9)
146#define SH_CMT32_CMCSR_CMM (1 << 8)
147#define SH_CMT32_CMCSR_CMTOUT_IE (1 << 7)
148#define SH_CMT32_CMCSR_CMR_NONE (0 << 4)
149#define SH_CMT32_CMCSR_CMR_DMA (1 << 4)
150#define SH_CMT32_CMCSR_CMR_IRQ (2 << 4)
151#define SH_CMT32_CMCSR_CMR_MASK (3 << 4)
152#define SH_CMT32_CMCSR_DBGIVD (1 << 3)
153#define SH_CMT32_CMCSR_CKS_RCLK8 (4 << 0)
154#define SH_CMT32_CMCSR_CKS_RCLK32 (5 << 0)
155#define SH_CMT32_CMCSR_CKS_RCLK128 (6 << 0)
156#define SH_CMT32_CMCSR_CKS_RCLK1 (7 << 0)
157#define SH_CMT32_CMCSR_CKS_MASK (7 << 0)
158
159static u32 sh_cmt_read16(void __iomem *base, unsigned long offs)
160{
161 return ioread16(base + (offs << 1));
162}
163
164static u32 sh_cmt_read32(void __iomem *base, unsigned long offs)
165{
166 return ioread32(base + (offs << 2));
167}
168
169static void sh_cmt_write16(void __iomem *base, unsigned long offs, u32 value)
170{
171 iowrite16(value, base + (offs << 1));
172}
173
174static void sh_cmt_write32(void __iomem *base, unsigned long offs, u32 value)
175{
176 iowrite32(value, base + (offs << 2));
177}
178
179static const struct sh_cmt_info sh_cmt_info[] = {
180 [SH_CMT_16BIT] = {
181 .model = SH_CMT_16BIT,
182 .width = 16,
183 .overflow_bit = SH_CMT16_CMCSR_CMF,
184 .clear_bits = ~SH_CMT16_CMCSR_CMF,
185 .read_control = sh_cmt_read16,
186 .write_control = sh_cmt_write16,
187 .read_count = sh_cmt_read16,
188 .write_count = sh_cmt_write16,
189 },
190 [SH_CMT_32BIT] = {
191 .model = SH_CMT_32BIT,
192 .width = 32,
193 .overflow_bit = SH_CMT32_CMCSR_CMF,
194 .clear_bits = ~(SH_CMT32_CMCSR_CMF | SH_CMT32_CMCSR_OVF),
195 .read_control = sh_cmt_read16,
196 .write_control = sh_cmt_write16,
197 .read_count = sh_cmt_read32,
198 .write_count = sh_cmt_write32,
199 },
200 [SH_CMT_48BIT] = {
201 .model = SH_CMT_48BIT,
202 .channels_mask = 0x3f,
203 .width = 32,
204 .overflow_bit = SH_CMT32_CMCSR_CMF,
205 .clear_bits = ~(SH_CMT32_CMCSR_CMF | SH_CMT32_CMCSR_OVF),
206 .read_control = sh_cmt_read32,
207 .write_control = sh_cmt_write32,
208 .read_count = sh_cmt_read32,
209 .write_count = sh_cmt_write32,
210 },
211 [SH_CMT0_RCAR_GEN2] = {
212 .model = SH_CMT0_RCAR_GEN2,
213 .channels_mask = 0x60,
214 .width = 32,
215 .overflow_bit = SH_CMT32_CMCSR_CMF,
216 .clear_bits = ~(SH_CMT32_CMCSR_CMF | SH_CMT32_CMCSR_OVF),
217 .read_control = sh_cmt_read32,
218 .write_control = sh_cmt_write32,
219 .read_count = sh_cmt_read32,
220 .write_count = sh_cmt_write32,
221 },
222 [SH_CMT1_RCAR_GEN2] = {
223 .model = SH_CMT1_RCAR_GEN2,
224 .channels_mask = 0xff,
225 .width = 32,
226 .overflow_bit = SH_CMT32_CMCSR_CMF,
227 .clear_bits = ~(SH_CMT32_CMCSR_CMF | SH_CMT32_CMCSR_OVF),
228 .read_control = sh_cmt_read32,
229 .write_control = sh_cmt_write32,
230 .read_count = sh_cmt_read32,
231 .write_count = sh_cmt_write32,
232 },
233};
234
235#define CMCSR 0 /* channel register */
236#define CMCNT 1 /* channel register */
237#define CMCOR 2 /* channel register */
238
239#define CMCLKE 0x1000 /* CLK Enable Register (R-Car Gen2) */
240
241static inline u32 sh_cmt_read_cmstr(struct sh_cmt_channel *ch)
242{
243 if (ch->iostart)
244 return ch->cmt->info->read_control(ch->iostart, 0);
245 else
246 return ch->cmt->info->read_control(ch->cmt->mapbase, 0);
247}
248
249static inline void sh_cmt_write_cmstr(struct sh_cmt_channel *ch, u32 value)
250{
251 u32 old_value = sh_cmt_read_cmstr(ch);
252
253 if (value != old_value) {
254 if (ch->iostart) {
255 ch->cmt->info->write_control(ch->iostart, 0, value);
256 udelay(ch->cmt->reg_delay);
257 } else {
258 ch->cmt->info->write_control(ch->cmt->mapbase, 0, value);
259 udelay(ch->cmt->reg_delay);
260 }
261 }
262}
263
264static inline u32 sh_cmt_read_cmcsr(struct sh_cmt_channel *ch)
265{
266 return ch->cmt->info->read_control(ch->ioctrl, CMCSR);
267}
268
269static inline void sh_cmt_write_cmcsr(struct sh_cmt_channel *ch, u32 value)
270{
271 u32 old_value = sh_cmt_read_cmcsr(ch);
272
273 if (value != old_value) {
274 ch->cmt->info->write_control(ch->ioctrl, CMCSR, value);
275 udelay(ch->cmt->reg_delay);
276 }
277}
278
279static inline u32 sh_cmt_read_cmcnt(struct sh_cmt_channel *ch)
280{
281 return ch->cmt->info->read_count(ch->ioctrl, CMCNT);
282}
283
284static inline int sh_cmt_write_cmcnt(struct sh_cmt_channel *ch, u32 value)
285{
286 /* Tests showed that we need to wait 3 clocks here */
287 unsigned int cmcnt_delay = DIV_ROUND_UP(3 * ch->cmt->reg_delay, 2);
288 u32 reg;
289
290 if (ch->cmt->info->model > SH_CMT_16BIT) {
291 int ret = read_poll_timeout_atomic(sh_cmt_read_cmcsr, reg,
292 !(reg & SH_CMT32_CMCSR_WRFLG),
293 1, cmcnt_delay, false, ch);
294 if (ret < 0)
295 return ret;
296 }
297
298 ch->cmt->info->write_count(ch->ioctrl, CMCNT, value);
299 udelay(cmcnt_delay);
300 return 0;
301}
302
303static inline void sh_cmt_write_cmcor(struct sh_cmt_channel *ch, u32 value)
304{
305 u32 old_value = ch->cmt->info->read_count(ch->ioctrl, CMCOR);
306
307 if (value != old_value) {
308 ch->cmt->info->write_count(ch->ioctrl, CMCOR, value);
309 udelay(ch->cmt->reg_delay);
310 }
311}
312
313static u32 sh_cmt_get_counter(struct sh_cmt_channel *ch, u32 *has_wrapped)
314{
315 u32 v1, v2, v3;
316 u32 o1, o2;
317
318 o1 = sh_cmt_read_cmcsr(ch) & ch->cmt->info->overflow_bit;
319
320 /* Make sure the timer value is stable. Stolen from acpi_pm.c */
321 do {
322 o2 = o1;
323 v1 = sh_cmt_read_cmcnt(ch);
324 v2 = sh_cmt_read_cmcnt(ch);
325 v3 = sh_cmt_read_cmcnt(ch);
326 o1 = sh_cmt_read_cmcsr(ch) & ch->cmt->info->overflow_bit;
327 } while (unlikely((o1 != o2) || (v1 > v2 && v1 < v3)
328 || (v2 > v3 && v2 < v1) || (v3 > v1 && v3 < v2)));
329
330 *has_wrapped = o1;
331 return v2;
332}
333
334static void sh_cmt_start_stop_ch(struct sh_cmt_channel *ch, int start)
335{
336 unsigned long flags;
337 u32 value;
338
339 /* start stop register shared by multiple timer channels */
340 raw_spin_lock_irqsave(&ch->cmt->lock, flags);
341 value = sh_cmt_read_cmstr(ch);
342
343 if (start)
344 value |= 1 << ch->timer_bit;
345 else
346 value &= ~(1 << ch->timer_bit);
347
348 sh_cmt_write_cmstr(ch, value);
349 raw_spin_unlock_irqrestore(&ch->cmt->lock, flags);
350}
351
352static int sh_cmt_enable(struct sh_cmt_channel *ch)
353{
354 int ret;
355
356 dev_pm_syscore_device(&ch->cmt->pdev->dev, true);
357
358 /* enable clock */
359 ret = clk_enable(ch->cmt->clk);
360 if (ret) {
361 dev_err(&ch->cmt->pdev->dev, "ch%u: cannot enable clock\n",
362 ch->index);
363 goto err0;
364 }
365
366 /* make sure channel is disabled */
367 sh_cmt_start_stop_ch(ch, 0);
368
369 /* configure channel, periodic mode and maximum timeout */
370 if (ch->cmt->info->width == 16) {
371 sh_cmt_write_cmcsr(ch, SH_CMT16_CMCSR_CMIE |
372 SH_CMT16_CMCSR_CKS512);
373 } else {
374 u32 cmtout = ch->cmt->info->model <= SH_CMT_48BIT ?
375 SH_CMT32_CMCSR_CMTOUT_IE : 0;
376 sh_cmt_write_cmcsr(ch, cmtout | SH_CMT32_CMCSR_CMM |
377 SH_CMT32_CMCSR_CMR_IRQ |
378 SH_CMT32_CMCSR_CKS_RCLK8);
379 }
380
381 sh_cmt_write_cmcor(ch, 0xffffffff);
382 ret = sh_cmt_write_cmcnt(ch, 0);
383
384 if (ret || sh_cmt_read_cmcnt(ch)) {
385 dev_err(&ch->cmt->pdev->dev, "ch%u: cannot clear CMCNT\n",
386 ch->index);
387 ret = -ETIMEDOUT;
388 goto err1;
389 }
390
391 /* enable channel */
392 sh_cmt_start_stop_ch(ch, 1);
393 return 0;
394 err1:
395 /* stop clock */
396 clk_disable(ch->cmt->clk);
397
398 err0:
399 return ret;
400}
401
402static void sh_cmt_disable(struct sh_cmt_channel *ch)
403{
404 /* disable channel */
405 sh_cmt_start_stop_ch(ch, 0);
406
407 /* disable interrupts in CMT block */
408 sh_cmt_write_cmcsr(ch, 0);
409
410 /* stop clock */
411 clk_disable(ch->cmt->clk);
412
413 dev_pm_syscore_device(&ch->cmt->pdev->dev, false);
414}
415
416/* private flags */
417#define FLAG_CLOCKEVENT (1 << 0)
418#define FLAG_CLOCKSOURCE (1 << 1)
419#define FLAG_REPROGRAM (1 << 2)
420#define FLAG_SKIPEVENT (1 << 3)
421#define FLAG_IRQCONTEXT (1 << 4)
422
423static void sh_cmt_clock_event_program_verify(struct sh_cmt_channel *ch,
424 int absolute)
425{
426 u32 value = ch->next_match_value;
427 u32 new_match;
428 u32 delay = 0;
429 u32 now = 0;
430 u32 has_wrapped;
431
432 now = sh_cmt_get_counter(ch, &has_wrapped);
433 ch->flags |= FLAG_REPROGRAM; /* force reprogram */
434
435 if (has_wrapped) {
436 /* we're competing with the interrupt handler.
437 * -> let the interrupt handler reprogram the timer.
438 * -> interrupt number two handles the event.
439 */
440 ch->flags |= FLAG_SKIPEVENT;
441 return;
442 }
443
444 if (absolute)
445 now = 0;
446
447 do {
448 /* reprogram the timer hardware,
449 * but don't save the new match value yet.
450 */
451 new_match = now + value + delay;
452 if (new_match > ch->max_match_value)
453 new_match = ch->max_match_value;
454
455 sh_cmt_write_cmcor(ch, new_match);
456
457 now = sh_cmt_get_counter(ch, &has_wrapped);
458 if (has_wrapped && (new_match > ch->match_value)) {
459 /* we are changing to a greater match value,
460 * so this wrap must be caused by the counter
461 * matching the old value.
462 * -> first interrupt reprograms the timer.
463 * -> interrupt number two handles the event.
464 */
465 ch->flags |= FLAG_SKIPEVENT;
466 break;
467 }
468
469 if (has_wrapped) {
470 /* we are changing to a smaller match value,
471 * so the wrap must be caused by the counter
472 * matching the new value.
473 * -> save programmed match value.
474 * -> let isr handle the event.
475 */
476 ch->match_value = new_match;
477 break;
478 }
479
480 /* be safe: verify hardware settings */
481 if (now < new_match) {
482 /* timer value is below match value, all good.
483 * this makes sure we won't miss any match events.
484 * -> save programmed match value.
485 * -> let isr handle the event.
486 */
487 ch->match_value = new_match;
488 break;
489 }
490
491 /* the counter has reached a value greater
492 * than our new match value. and since the
493 * has_wrapped flag isn't set we must have
494 * programmed a too close event.
495 * -> increase delay and retry.
496 */
497 if (delay)
498 delay <<= 1;
499 else
500 delay = 1;
501
502 if (!delay)
503 dev_warn(&ch->cmt->pdev->dev, "ch%u: too long delay\n",
504 ch->index);
505
506 } while (delay);
507}
508
509static void __sh_cmt_set_next(struct sh_cmt_channel *ch, unsigned long delta)
510{
511 if (delta > ch->max_match_value)
512 dev_warn(&ch->cmt->pdev->dev, "ch%u: delta out of range\n",
513 ch->index);
514
515 ch->next_match_value = delta;
516 sh_cmt_clock_event_program_verify(ch, 0);
517}
518
519static void sh_cmt_set_next(struct sh_cmt_channel *ch, unsigned long delta)
520{
521 unsigned long flags;
522
523 raw_spin_lock_irqsave(&ch->lock, flags);
524 __sh_cmt_set_next(ch, delta);
525 raw_spin_unlock_irqrestore(&ch->lock, flags);
526}
527
528static irqreturn_t sh_cmt_interrupt(int irq, void *dev_id)
529{
530 struct sh_cmt_channel *ch = dev_id;
531 unsigned long flags;
532
533 /* clear flags */
534 sh_cmt_write_cmcsr(ch, sh_cmt_read_cmcsr(ch) &
535 ch->cmt->info->clear_bits);
536
537 /* update clock source counter to begin with if enabled
538 * the wrap flag should be cleared by the timer specific
539 * isr before we end up here.
540 */
541 if (ch->flags & FLAG_CLOCKSOURCE)
542 ch->total_cycles += ch->match_value + 1;
543
544 if (!(ch->flags & FLAG_REPROGRAM))
545 ch->next_match_value = ch->max_match_value;
546
547 ch->flags |= FLAG_IRQCONTEXT;
548
549 if (ch->flags & FLAG_CLOCKEVENT) {
550 if (!(ch->flags & FLAG_SKIPEVENT)) {
551 if (clockevent_state_oneshot(&ch->ced)) {
552 ch->next_match_value = ch->max_match_value;
553 ch->flags |= FLAG_REPROGRAM;
554 }
555
556 ch->ced.event_handler(&ch->ced);
557 }
558 }
559
560 ch->flags &= ~FLAG_SKIPEVENT;
561
562 raw_spin_lock_irqsave(&ch->lock, flags);
563
564 if (ch->flags & FLAG_REPROGRAM) {
565 ch->flags &= ~FLAG_REPROGRAM;
566 sh_cmt_clock_event_program_verify(ch, 1);
567
568 if (ch->flags & FLAG_CLOCKEVENT)
569 if ((clockevent_state_shutdown(&ch->ced))
570 || (ch->match_value == ch->next_match_value))
571 ch->flags &= ~FLAG_REPROGRAM;
572 }
573
574 ch->flags &= ~FLAG_IRQCONTEXT;
575
576 raw_spin_unlock_irqrestore(&ch->lock, flags);
577
578 return IRQ_HANDLED;
579}
580
581static int sh_cmt_start(struct sh_cmt_channel *ch, unsigned long flag)
582{
583 int ret = 0;
584 unsigned long flags;
585
586 if (flag & FLAG_CLOCKSOURCE)
587 pm_runtime_get_sync(&ch->cmt->pdev->dev);
588
589 raw_spin_lock_irqsave(&ch->lock, flags);
590
591 if (!(ch->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE))) {
592 if (flag & FLAG_CLOCKEVENT)
593 pm_runtime_get_sync(&ch->cmt->pdev->dev);
594 ret = sh_cmt_enable(ch);
595 }
596
597 if (ret)
598 goto out;
599 ch->flags |= flag;
600
601 /* setup timeout if no clockevent */
602 if (ch->cmt->num_channels == 1 &&
603 flag == FLAG_CLOCKSOURCE && (!(ch->flags & FLAG_CLOCKEVENT)))
604 __sh_cmt_set_next(ch, ch->max_match_value);
605 out:
606 raw_spin_unlock_irqrestore(&ch->lock, flags);
607
608 return ret;
609}
610
611static void sh_cmt_stop(struct sh_cmt_channel *ch, unsigned long flag)
612{
613 unsigned long flags;
614 unsigned long f;
615
616 raw_spin_lock_irqsave(&ch->lock, flags);
617
618 f = ch->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE);
619 ch->flags &= ~flag;
620
621 if (f && !(ch->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE))) {
622 sh_cmt_disable(ch);
623 if (flag & FLAG_CLOCKEVENT)
624 pm_runtime_put(&ch->cmt->pdev->dev);
625 }
626
627 /* adjust the timeout to maximum if only clocksource left */
628 if ((flag == FLAG_CLOCKEVENT) && (ch->flags & FLAG_CLOCKSOURCE))
629 __sh_cmt_set_next(ch, ch->max_match_value);
630
631 raw_spin_unlock_irqrestore(&ch->lock, flags);
632
633 if (flag & FLAG_CLOCKSOURCE)
634 pm_runtime_put(&ch->cmt->pdev->dev);
635}
636
637static struct sh_cmt_channel *cs_to_sh_cmt(struct clocksource *cs)
638{
639 return container_of(cs, struct sh_cmt_channel, cs);
640}
641
642static u64 sh_cmt_clocksource_read(struct clocksource *cs)
643{
644 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs);
645 u32 has_wrapped;
646
647 if (ch->cmt->num_channels == 1) {
648 unsigned long flags;
649 u64 value;
650 u32 raw;
651
652 raw_spin_lock_irqsave(&ch->lock, flags);
653 value = ch->total_cycles;
654 raw = sh_cmt_get_counter(ch, &has_wrapped);
655
656 if (unlikely(has_wrapped))
657 raw += ch->match_value + 1;
658 raw_spin_unlock_irqrestore(&ch->lock, flags);
659
660 return value + raw;
661 }
662
663 return sh_cmt_get_counter(ch, &has_wrapped);
664}
665
666static int sh_cmt_clocksource_enable(struct clocksource *cs)
667{
668 int ret;
669 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs);
670
671 WARN_ON(ch->cs_enabled);
672
673 ch->total_cycles = 0;
674
675 ret = sh_cmt_start(ch, FLAG_CLOCKSOURCE);
676 if (!ret)
677 ch->cs_enabled = true;
678
679 return ret;
680}
681
682static void sh_cmt_clocksource_disable(struct clocksource *cs)
683{
684 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs);
685
686 WARN_ON(!ch->cs_enabled);
687
688 sh_cmt_stop(ch, FLAG_CLOCKSOURCE);
689 ch->cs_enabled = false;
690}
691
692static void sh_cmt_clocksource_suspend(struct clocksource *cs)
693{
694 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs);
695
696 if (!ch->cs_enabled)
697 return;
698
699 sh_cmt_stop(ch, FLAG_CLOCKSOURCE);
700 dev_pm_genpd_suspend(&ch->cmt->pdev->dev);
701}
702
703static void sh_cmt_clocksource_resume(struct clocksource *cs)
704{
705 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs);
706
707 if (!ch->cs_enabled)
708 return;
709
710 dev_pm_genpd_resume(&ch->cmt->pdev->dev);
711 sh_cmt_start(ch, FLAG_CLOCKSOURCE);
712}
713
714static int sh_cmt_register_clocksource(struct sh_cmt_channel *ch,
715 const char *name)
716{
717 struct clocksource *cs = &ch->cs;
718
719 cs->name = name;
720 cs->rating = 125;
721 cs->read = sh_cmt_clocksource_read;
722 cs->enable = sh_cmt_clocksource_enable;
723 cs->disable = sh_cmt_clocksource_disable;
724 cs->suspend = sh_cmt_clocksource_suspend;
725 cs->resume = sh_cmt_clocksource_resume;
726 cs->mask = CLOCKSOURCE_MASK(ch->cmt->info->width);
727 cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
728
729 dev_info(&ch->cmt->pdev->dev, "ch%u: used as clock source\n",
730 ch->index);
731
732 clocksource_register_hz(cs, ch->cmt->rate);
733 return 0;
734}
735
736static struct sh_cmt_channel *ced_to_sh_cmt(struct clock_event_device *ced)
737{
738 return container_of(ced, struct sh_cmt_channel, ced);
739}
740
741static void sh_cmt_clock_event_start(struct sh_cmt_channel *ch, int periodic)
742{
743 sh_cmt_start(ch, FLAG_CLOCKEVENT);
744
745 if (periodic)
746 sh_cmt_set_next(ch, ((ch->cmt->rate + HZ/2) / HZ) - 1);
747 else
748 sh_cmt_set_next(ch, ch->max_match_value);
749}
750
751static int sh_cmt_clock_event_shutdown(struct clock_event_device *ced)
752{
753 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced);
754
755 sh_cmt_stop(ch, FLAG_CLOCKEVENT);
756 return 0;
757}
758
759static int sh_cmt_clock_event_set_state(struct clock_event_device *ced,
760 int periodic)
761{
762 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced);
763
764 /* deal with old setting first */
765 if (clockevent_state_oneshot(ced) || clockevent_state_periodic(ced))
766 sh_cmt_stop(ch, FLAG_CLOCKEVENT);
767
768 dev_info(&ch->cmt->pdev->dev, "ch%u: used for %s clock events\n",
769 ch->index, periodic ? "periodic" : "oneshot");
770 sh_cmt_clock_event_start(ch, periodic);
771 return 0;
772}
773
774static int sh_cmt_clock_event_set_oneshot(struct clock_event_device *ced)
775{
776 return sh_cmt_clock_event_set_state(ced, 0);
777}
778
779static int sh_cmt_clock_event_set_periodic(struct clock_event_device *ced)
780{
781 return sh_cmt_clock_event_set_state(ced, 1);
782}
783
784static int sh_cmt_clock_event_next(unsigned long delta,
785 struct clock_event_device *ced)
786{
787 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced);
788 unsigned long flags;
789
790 BUG_ON(!clockevent_state_oneshot(ced));
791
792 raw_spin_lock_irqsave(&ch->lock, flags);
793
794 if (likely(ch->flags & FLAG_IRQCONTEXT))
795 ch->next_match_value = delta - 1;
796 else
797 __sh_cmt_set_next(ch, delta - 1);
798
799 raw_spin_unlock_irqrestore(&ch->lock, flags);
800
801 return 0;
802}
803
804static void sh_cmt_clock_event_suspend(struct clock_event_device *ced)
805{
806 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced);
807
808 dev_pm_genpd_suspend(&ch->cmt->pdev->dev);
809 clk_unprepare(ch->cmt->clk);
810}
811
812static void sh_cmt_clock_event_resume(struct clock_event_device *ced)
813{
814 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced);
815
816 clk_prepare(ch->cmt->clk);
817 dev_pm_genpd_resume(&ch->cmt->pdev->dev);
818}
819
820static int sh_cmt_register_clockevent(struct sh_cmt_channel *ch,
821 const char *name)
822{
823 struct clock_event_device *ced = &ch->ced;
824 int irq;
825 int ret;
826
827 irq = platform_get_irq(ch->cmt->pdev, ch->index);
828 if (irq < 0)
829 return irq;
830
831 ret = request_irq(irq, sh_cmt_interrupt,
832 IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING,
833 dev_name(&ch->cmt->pdev->dev), ch);
834 if (ret) {
835 dev_err(&ch->cmt->pdev->dev, "ch%u: failed to request irq %d\n",
836 ch->index, irq);
837 return ret;
838 }
839
840 ced->name = name;
841 ced->features = CLOCK_EVT_FEAT_PERIODIC;
842 ced->features |= CLOCK_EVT_FEAT_ONESHOT;
843 ced->rating = 125;
844 ced->cpumask = cpu_possible_mask;
845 ced->set_next_event = sh_cmt_clock_event_next;
846 ced->set_state_shutdown = sh_cmt_clock_event_shutdown;
847 ced->set_state_periodic = sh_cmt_clock_event_set_periodic;
848 ced->set_state_oneshot = sh_cmt_clock_event_set_oneshot;
849 ced->suspend = sh_cmt_clock_event_suspend;
850 ced->resume = sh_cmt_clock_event_resume;
851
852 /* TODO: calculate good shift from rate and counter bit width */
853 ced->shift = 32;
854 ced->mult = div_sc(ch->cmt->rate, NSEC_PER_SEC, ced->shift);
855 ced->max_delta_ns = clockevent_delta2ns(ch->max_match_value, ced);
856 ced->max_delta_ticks = ch->max_match_value;
857 ced->min_delta_ns = clockevent_delta2ns(0x1f, ced);
858 ced->min_delta_ticks = 0x1f;
859
860 dev_info(&ch->cmt->pdev->dev, "ch%u: used for clock events\n",
861 ch->index);
862 clockevents_register_device(ced);
863
864 return 0;
865}
866
867static int sh_cmt_register(struct sh_cmt_channel *ch, const char *name,
868 bool clockevent, bool clocksource)
869{
870 int ret;
871
872 if (clockevent) {
873 ch->cmt->has_clockevent = true;
874 ret = sh_cmt_register_clockevent(ch, name);
875 if (ret < 0)
876 return ret;
877 }
878
879 if (clocksource) {
880 ch->cmt->has_clocksource = true;
881 sh_cmt_register_clocksource(ch, name);
882 }
883
884 return 0;
885}
886
887static int sh_cmt_setup_channel(struct sh_cmt_channel *ch, unsigned int index,
888 unsigned int hwidx, bool clockevent,
889 bool clocksource, struct sh_cmt_device *cmt)
890{
891 u32 value;
892 int ret;
893
894 /* Skip unused channels. */
895 if (!clockevent && !clocksource)
896 return 0;
897
898 ch->cmt = cmt;
899 ch->index = index;
900 ch->hwidx = hwidx;
901 ch->timer_bit = hwidx;
902
903 /*
904 * Compute the address of the channel control register block. For the
905 * timers with a per-channel start/stop register, compute its address
906 * as well.
907 */
908 switch (cmt->info->model) {
909 case SH_CMT_16BIT:
910 ch->ioctrl = cmt->mapbase + 2 + ch->hwidx * 6;
911 break;
912 case SH_CMT_32BIT:
913 case SH_CMT_48BIT:
914 ch->ioctrl = cmt->mapbase + 0x10 + ch->hwidx * 0x10;
915 break;
916 case SH_CMT0_RCAR_GEN2:
917 case SH_CMT1_RCAR_GEN2:
918 ch->iostart = cmt->mapbase + ch->hwidx * 0x100;
919 ch->ioctrl = ch->iostart + 0x10;
920 ch->timer_bit = 0;
921
922 /* Enable the clock supply to the channel */
923 value = ioread32(cmt->mapbase + CMCLKE);
924 value |= BIT(hwidx);
925 iowrite32(value, cmt->mapbase + CMCLKE);
926 break;
927 }
928
929 if (cmt->info->width == (sizeof(ch->max_match_value) * 8))
930 ch->max_match_value = ~0;
931 else
932 ch->max_match_value = (1 << cmt->info->width) - 1;
933
934 ch->match_value = ch->max_match_value;
935 raw_spin_lock_init(&ch->lock);
936
937 ret = sh_cmt_register(ch, dev_name(&cmt->pdev->dev),
938 clockevent, clocksource);
939 if (ret) {
940 dev_err(&cmt->pdev->dev, "ch%u: registration failed\n",
941 ch->index);
942 return ret;
943 }
944 ch->cs_enabled = false;
945
946 return 0;
947}
948
949static int sh_cmt_map_memory(struct sh_cmt_device *cmt)
950{
951 struct resource *mem;
952
953 mem = platform_get_resource(cmt->pdev, IORESOURCE_MEM, 0);
954 if (!mem) {
955 dev_err(&cmt->pdev->dev, "failed to get I/O memory\n");
956 return -ENXIO;
957 }
958
959 cmt->mapbase = ioremap(mem->start, resource_size(mem));
960 if (cmt->mapbase == NULL) {
961 dev_err(&cmt->pdev->dev, "failed to remap I/O memory\n");
962 return -ENXIO;
963 }
964
965 return 0;
966}
967
968static const struct platform_device_id sh_cmt_id_table[] = {
969 { "sh-cmt-16", (kernel_ulong_t)&sh_cmt_info[SH_CMT_16BIT] },
970 { "sh-cmt-32", (kernel_ulong_t)&sh_cmt_info[SH_CMT_32BIT] },
971 { }
972};
973MODULE_DEVICE_TABLE(platform, sh_cmt_id_table);
974
975static const struct of_device_id sh_cmt_of_table[] __maybe_unused = {
976 {
977 /* deprecated, preserved for backward compatibility */
978 .compatible = "renesas,cmt-48",
979 .data = &sh_cmt_info[SH_CMT_48BIT]
980 },
981 {
982 /* deprecated, preserved for backward compatibility */
983 .compatible = "renesas,cmt-48-gen2",
984 .data = &sh_cmt_info[SH_CMT0_RCAR_GEN2]
985 },
986 {
987 .compatible = "renesas,r8a7740-cmt1",
988 .data = &sh_cmt_info[SH_CMT_48BIT]
989 },
990 {
991 .compatible = "renesas,sh73a0-cmt1",
992 .data = &sh_cmt_info[SH_CMT_48BIT]
993 },
994 {
995 .compatible = "renesas,rcar-gen2-cmt0",
996 .data = &sh_cmt_info[SH_CMT0_RCAR_GEN2]
997 },
998 {
999 .compatible = "renesas,rcar-gen2-cmt1",
1000 .data = &sh_cmt_info[SH_CMT1_RCAR_GEN2]
1001 },
1002 {
1003 .compatible = "renesas,rcar-gen3-cmt0",
1004 .data = &sh_cmt_info[SH_CMT0_RCAR_GEN2]
1005 },
1006 {
1007 .compatible = "renesas,rcar-gen3-cmt1",
1008 .data = &sh_cmt_info[SH_CMT1_RCAR_GEN2]
1009 },
1010 {
1011 .compatible = "renesas,rcar-gen4-cmt0",
1012 .data = &sh_cmt_info[SH_CMT0_RCAR_GEN2]
1013 },
1014 {
1015 .compatible = "renesas,rcar-gen4-cmt1",
1016 .data = &sh_cmt_info[SH_CMT1_RCAR_GEN2]
1017 },
1018 { }
1019};
1020MODULE_DEVICE_TABLE(of, sh_cmt_of_table);
1021
1022static int sh_cmt_setup(struct sh_cmt_device *cmt, struct platform_device *pdev)
1023{
1024 unsigned int mask, i;
1025 unsigned long rate;
1026 int ret;
1027
1028 cmt->pdev = pdev;
1029 raw_spin_lock_init(&cmt->lock);
1030
1031 if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node) {
1032 cmt->info = of_device_get_match_data(&pdev->dev);
1033 cmt->hw_channels = cmt->info->channels_mask;
1034 } else if (pdev->dev.platform_data) {
1035 struct sh_timer_config *cfg = pdev->dev.platform_data;
1036 const struct platform_device_id *id = pdev->id_entry;
1037
1038 cmt->info = (const struct sh_cmt_info *)id->driver_data;
1039 cmt->hw_channels = cfg->channels_mask;
1040 } else {
1041 dev_err(&cmt->pdev->dev, "missing platform data\n");
1042 return -ENXIO;
1043 }
1044
1045 /* Get hold of clock. */
1046 cmt->clk = clk_get(&cmt->pdev->dev, "fck");
1047 if (IS_ERR(cmt->clk)) {
1048 dev_err(&cmt->pdev->dev, "cannot get clock\n");
1049 return PTR_ERR(cmt->clk);
1050 }
1051
1052 ret = clk_prepare(cmt->clk);
1053 if (ret < 0)
1054 goto err_clk_put;
1055
1056 /* Determine clock rate. */
1057 ret = clk_enable(cmt->clk);
1058 if (ret < 0)
1059 goto err_clk_unprepare;
1060
1061 rate = clk_get_rate(cmt->clk);
1062 if (!rate) {
1063 ret = -EINVAL;
1064 goto err_clk_disable;
1065 }
1066
1067 /* We shall wait 2 input clks after register writes */
1068 if (cmt->info->model >= SH_CMT_48BIT)
1069 cmt->reg_delay = DIV_ROUND_UP(2UL * USEC_PER_SEC, rate);
1070 cmt->rate = rate / (cmt->info->width == 16 ? 512 : 8);
1071
1072 /* Map the memory resource(s). */
1073 ret = sh_cmt_map_memory(cmt);
1074 if (ret < 0)
1075 goto err_clk_disable;
1076
1077 /* Allocate and setup the channels. */
1078 cmt->num_channels = hweight8(cmt->hw_channels);
1079 cmt->channels = kcalloc(cmt->num_channels, sizeof(*cmt->channels),
1080 GFP_KERNEL);
1081 if (cmt->channels == NULL) {
1082 ret = -ENOMEM;
1083 goto err_unmap;
1084 }
1085
1086 /*
1087 * Use the first channel as a clock event device and the second channel
1088 * as a clock source. If only one channel is available use it for both.
1089 */
1090 for (i = 0, mask = cmt->hw_channels; i < cmt->num_channels; ++i) {
1091 unsigned int hwidx = ffs(mask) - 1;
1092 bool clocksource = i == 1 || cmt->num_channels == 1;
1093 bool clockevent = i == 0;
1094
1095 ret = sh_cmt_setup_channel(&cmt->channels[i], i, hwidx,
1096 clockevent, clocksource, cmt);
1097 if (ret < 0)
1098 goto err_unmap;
1099
1100 mask &= ~(1 << hwidx);
1101 }
1102
1103 clk_disable(cmt->clk);
1104
1105 platform_set_drvdata(pdev, cmt);
1106
1107 return 0;
1108
1109err_unmap:
1110 kfree(cmt->channels);
1111 iounmap(cmt->mapbase);
1112err_clk_disable:
1113 clk_disable(cmt->clk);
1114err_clk_unprepare:
1115 clk_unprepare(cmt->clk);
1116err_clk_put:
1117 clk_put(cmt->clk);
1118 return ret;
1119}
1120
1121static int sh_cmt_probe(struct platform_device *pdev)
1122{
1123 struct sh_cmt_device *cmt = platform_get_drvdata(pdev);
1124 int ret;
1125
1126 if (!is_sh_early_platform_device(pdev)) {
1127 pm_runtime_set_active(&pdev->dev);
1128 pm_runtime_enable(&pdev->dev);
1129 }
1130
1131 if (cmt) {
1132 dev_info(&pdev->dev, "kept as earlytimer\n");
1133 goto out;
1134 }
1135
1136 cmt = kzalloc(sizeof(*cmt), GFP_KERNEL);
1137 if (cmt == NULL)
1138 return -ENOMEM;
1139
1140 ret = sh_cmt_setup(cmt, pdev);
1141 if (ret) {
1142 kfree(cmt);
1143 pm_runtime_idle(&pdev->dev);
1144 return ret;
1145 }
1146 if (is_sh_early_platform_device(pdev))
1147 return 0;
1148
1149 out:
1150 if (cmt->has_clockevent || cmt->has_clocksource)
1151 pm_runtime_irq_safe(&pdev->dev);
1152 else
1153 pm_runtime_idle(&pdev->dev);
1154
1155 return 0;
1156}
1157
1158static struct platform_driver sh_cmt_device_driver = {
1159 .probe = sh_cmt_probe,
1160 .driver = {
1161 .name = "sh_cmt",
1162 .of_match_table = of_match_ptr(sh_cmt_of_table),
1163 .suppress_bind_attrs = true,
1164 },
1165 .id_table = sh_cmt_id_table,
1166};
1167
1168static int __init sh_cmt_init(void)
1169{
1170 return platform_driver_register(&sh_cmt_device_driver);
1171}
1172
1173static void __exit sh_cmt_exit(void)
1174{
1175 platform_driver_unregister(&sh_cmt_device_driver);
1176}
1177
1178#ifdef CONFIG_SUPERH
1179sh_early_platform_init("earlytimer", &sh_cmt_device_driver);
1180#endif
1181
1182subsys_initcall(sh_cmt_init);
1183module_exit(sh_cmt_exit);
1184
1185MODULE_AUTHOR("Magnus Damm");
1186MODULE_DESCRIPTION("SuperH CMT Timer Driver");