]> git.kernelconcepts.de Git - karo-tx-linux.git/blob - drivers/clocksource/sh_tmu.c
Merge tag 'fscrypt_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso...
[karo-tx-linux.git] / drivers / clocksource / sh_tmu.c
1 /*
2  * SuperH Timer Support - TMU
3  *
4  *  Copyright (C) 2009 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
16 #include <linux/clk.h>
17 #include <linux/clockchips.h>
18 #include <linux/clocksource.h>
19 #include <linux/delay.h>
20 #include <linux/err.h>
21 #include <linux/init.h>
22 #include <linux/interrupt.h>
23 #include <linux/io.h>
24 #include <linux/ioport.h>
25 #include <linux/irq.h>
26 #include <linux/module.h>
27 #include <linux/of.h>
28 #include <linux/platform_device.h>
29 #include <linux/pm_domain.h>
30 #include <linux/pm_runtime.h>
31 #include <linux/sh_timer.h>
32 #include <linux/slab.h>
33 #include <linux/spinlock.h>
34
35 enum sh_tmu_model {
36         SH_TMU,
37         SH_TMU_SH3,
38 };
39
40 struct sh_tmu_device;
41
42 struct sh_tmu_channel {
43         struct sh_tmu_device *tmu;
44         unsigned int index;
45
46         void __iomem *base;
47         int irq;
48
49         unsigned long periodic;
50         struct clock_event_device ced;
51         struct clocksource cs;
52         bool cs_enabled;
53         unsigned int enable_count;
54 };
55
56 struct sh_tmu_device {
57         struct platform_device *pdev;
58
59         void __iomem *mapbase;
60         struct clk *clk;
61         unsigned long rate;
62
63         enum sh_tmu_model model;
64
65         raw_spinlock_t lock; /* Protect the shared start/stop register */
66
67         struct sh_tmu_channel *channels;
68         unsigned int num_channels;
69
70         bool has_clockevent;
71         bool has_clocksource;
72 };
73
74 #define TSTR -1 /* shared register */
75 #define TCOR  0 /* channel register */
76 #define TCNT 1 /* channel register */
77 #define TCR 2 /* channel register */
78
79 #define TCR_UNF                 (1 << 8)
80 #define TCR_UNIE                (1 << 5)
81 #define TCR_TPSC_CLK4           (0 << 0)
82 #define TCR_TPSC_CLK16          (1 << 0)
83 #define TCR_TPSC_CLK64          (2 << 0)
84 #define TCR_TPSC_CLK256         (3 << 0)
85 #define TCR_TPSC_CLK1024        (4 << 0)
86 #define TCR_TPSC_MASK           (7 << 0)
87
88 static inline unsigned long sh_tmu_read(struct sh_tmu_channel *ch, int reg_nr)
89 {
90         unsigned long offs;
91
92         if (reg_nr == TSTR) {
93                 switch (ch->tmu->model) {
94                 case SH_TMU_SH3:
95                         return ioread8(ch->tmu->mapbase + 2);
96                 case SH_TMU:
97                         return ioread8(ch->tmu->mapbase + 4);
98                 }
99         }
100
101         offs = reg_nr << 2;
102
103         if (reg_nr == TCR)
104                 return ioread16(ch->base + offs);
105         else
106                 return ioread32(ch->base + offs);
107 }
108
109 static inline void sh_tmu_write(struct sh_tmu_channel *ch, int reg_nr,
110                                 unsigned long value)
111 {
112         unsigned long offs;
113
114         if (reg_nr == TSTR) {
115                 switch (ch->tmu->model) {
116                 case SH_TMU_SH3:
117                         return iowrite8(value, ch->tmu->mapbase + 2);
118                 case SH_TMU:
119                         return iowrite8(value, ch->tmu->mapbase + 4);
120                 }
121         }
122
123         offs = reg_nr << 2;
124
125         if (reg_nr == TCR)
126                 iowrite16(value, ch->base + offs);
127         else
128                 iowrite32(value, ch->base + offs);
129 }
130
131 static void sh_tmu_start_stop_ch(struct sh_tmu_channel *ch, int start)
132 {
133         unsigned long flags, value;
134
135         /* start stop register shared by multiple timer channels */
136         raw_spin_lock_irqsave(&ch->tmu->lock, flags);
137         value = sh_tmu_read(ch, TSTR);
138
139         if (start)
140                 value |= 1 << ch->index;
141         else
142                 value &= ~(1 << ch->index);
143
144         sh_tmu_write(ch, TSTR, value);
145         raw_spin_unlock_irqrestore(&ch->tmu->lock, flags);
146 }
147
148 static int __sh_tmu_enable(struct sh_tmu_channel *ch)
149 {
150         int ret;
151
152         /* enable clock */
153         ret = clk_enable(ch->tmu->clk);
154         if (ret) {
155                 dev_err(&ch->tmu->pdev->dev, "ch%u: cannot enable clock\n",
156                         ch->index);
157                 return ret;
158         }
159
160         /* make sure channel is disabled */
161         sh_tmu_start_stop_ch(ch, 0);
162
163         /* maximum timeout */
164         sh_tmu_write(ch, TCOR, 0xffffffff);
165         sh_tmu_write(ch, TCNT, 0xffffffff);
166
167         /* configure channel to parent clock / 4, irq off */
168         sh_tmu_write(ch, TCR, TCR_TPSC_CLK4);
169
170         /* enable channel */
171         sh_tmu_start_stop_ch(ch, 1);
172
173         return 0;
174 }
175
176 static int sh_tmu_enable(struct sh_tmu_channel *ch)
177 {
178         if (ch->enable_count++ > 0)
179                 return 0;
180
181         pm_runtime_get_sync(&ch->tmu->pdev->dev);
182         dev_pm_syscore_device(&ch->tmu->pdev->dev, true);
183
184         return __sh_tmu_enable(ch);
185 }
186
187 static void __sh_tmu_disable(struct sh_tmu_channel *ch)
188 {
189         /* disable channel */
190         sh_tmu_start_stop_ch(ch, 0);
191
192         /* disable interrupts in TMU block */
193         sh_tmu_write(ch, TCR, TCR_TPSC_CLK4);
194
195         /* stop clock */
196         clk_disable(ch->tmu->clk);
197 }
198
199 static void sh_tmu_disable(struct sh_tmu_channel *ch)
200 {
201         if (WARN_ON(ch->enable_count == 0))
202                 return;
203
204         if (--ch->enable_count > 0)
205                 return;
206
207         __sh_tmu_disable(ch);
208
209         dev_pm_syscore_device(&ch->tmu->pdev->dev, false);
210         pm_runtime_put(&ch->tmu->pdev->dev);
211 }
212
213 static void sh_tmu_set_next(struct sh_tmu_channel *ch, unsigned long delta,
214                             int periodic)
215 {
216         /* stop timer */
217         sh_tmu_start_stop_ch(ch, 0);
218
219         /* acknowledge interrupt */
220         sh_tmu_read(ch, TCR);
221
222         /* enable interrupt */
223         sh_tmu_write(ch, TCR, TCR_UNIE | TCR_TPSC_CLK4);
224
225         /* reload delta value in case of periodic timer */
226         if (periodic)
227                 sh_tmu_write(ch, TCOR, delta);
228         else
229                 sh_tmu_write(ch, TCOR, 0xffffffff);
230
231         sh_tmu_write(ch, TCNT, delta);
232
233         /* start timer */
234         sh_tmu_start_stop_ch(ch, 1);
235 }
236
237 static irqreturn_t sh_tmu_interrupt(int irq, void *dev_id)
238 {
239         struct sh_tmu_channel *ch = dev_id;
240
241         /* disable or acknowledge interrupt */
242         if (clockevent_state_oneshot(&ch->ced))
243                 sh_tmu_write(ch, TCR, TCR_TPSC_CLK4);
244         else
245                 sh_tmu_write(ch, TCR, TCR_UNIE | TCR_TPSC_CLK4);
246
247         /* notify clockevent layer */
248         ch->ced.event_handler(&ch->ced);
249         return IRQ_HANDLED;
250 }
251
252 static struct sh_tmu_channel *cs_to_sh_tmu(struct clocksource *cs)
253 {
254         return container_of(cs, struct sh_tmu_channel, cs);
255 }
256
257 static u64 sh_tmu_clocksource_read(struct clocksource *cs)
258 {
259         struct sh_tmu_channel *ch = cs_to_sh_tmu(cs);
260
261         return sh_tmu_read(ch, TCNT) ^ 0xffffffff;
262 }
263
264 static int sh_tmu_clocksource_enable(struct clocksource *cs)
265 {
266         struct sh_tmu_channel *ch = cs_to_sh_tmu(cs);
267         int ret;
268
269         if (WARN_ON(ch->cs_enabled))
270                 return 0;
271
272         ret = sh_tmu_enable(ch);
273         if (!ret)
274                 ch->cs_enabled = true;
275
276         return ret;
277 }
278
279 static void sh_tmu_clocksource_disable(struct clocksource *cs)
280 {
281         struct sh_tmu_channel *ch = cs_to_sh_tmu(cs);
282
283         if (WARN_ON(!ch->cs_enabled))
284                 return;
285
286         sh_tmu_disable(ch);
287         ch->cs_enabled = false;
288 }
289
290 static void sh_tmu_clocksource_suspend(struct clocksource *cs)
291 {
292         struct sh_tmu_channel *ch = cs_to_sh_tmu(cs);
293
294         if (!ch->cs_enabled)
295                 return;
296
297         if (--ch->enable_count == 0) {
298                 __sh_tmu_disable(ch);
299                 pm_genpd_syscore_poweroff(&ch->tmu->pdev->dev);
300         }
301 }
302
303 static void sh_tmu_clocksource_resume(struct clocksource *cs)
304 {
305         struct sh_tmu_channel *ch = cs_to_sh_tmu(cs);
306
307         if (!ch->cs_enabled)
308                 return;
309
310         if (ch->enable_count++ == 0) {
311                 pm_genpd_syscore_poweron(&ch->tmu->pdev->dev);
312                 __sh_tmu_enable(ch);
313         }
314 }
315
316 static int sh_tmu_register_clocksource(struct sh_tmu_channel *ch,
317                                        const char *name)
318 {
319         struct clocksource *cs = &ch->cs;
320
321         cs->name = name;
322         cs->rating = 200;
323         cs->read = sh_tmu_clocksource_read;
324         cs->enable = sh_tmu_clocksource_enable;
325         cs->disable = sh_tmu_clocksource_disable;
326         cs->suspend = sh_tmu_clocksource_suspend;
327         cs->resume = sh_tmu_clocksource_resume;
328         cs->mask = CLOCKSOURCE_MASK(32);
329         cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
330
331         dev_info(&ch->tmu->pdev->dev, "ch%u: used as clock source\n",
332                  ch->index);
333
334         clocksource_register_hz(cs, ch->tmu->rate);
335         return 0;
336 }
337
338 static struct sh_tmu_channel *ced_to_sh_tmu(struct clock_event_device *ced)
339 {
340         return container_of(ced, struct sh_tmu_channel, ced);
341 }
342
343 static void sh_tmu_clock_event_start(struct sh_tmu_channel *ch, int periodic)
344 {
345         sh_tmu_enable(ch);
346
347         if (periodic) {
348                 ch->periodic = (ch->tmu->rate + HZ/2) / HZ;
349                 sh_tmu_set_next(ch, ch->periodic, 1);
350         }
351 }
352
353 static int sh_tmu_clock_event_shutdown(struct clock_event_device *ced)
354 {
355         struct sh_tmu_channel *ch = ced_to_sh_tmu(ced);
356
357         if (clockevent_state_oneshot(ced) || clockevent_state_periodic(ced))
358                 sh_tmu_disable(ch);
359         return 0;
360 }
361
362 static int sh_tmu_clock_event_set_state(struct clock_event_device *ced,
363                                         int periodic)
364 {
365         struct sh_tmu_channel *ch = ced_to_sh_tmu(ced);
366
367         /* deal with old setting first */
368         if (clockevent_state_oneshot(ced) || clockevent_state_periodic(ced))
369                 sh_tmu_disable(ch);
370
371         dev_info(&ch->tmu->pdev->dev, "ch%u: used for %s clock events\n",
372                  ch->index, periodic ? "periodic" : "oneshot");
373         sh_tmu_clock_event_start(ch, periodic);
374         return 0;
375 }
376
377 static int sh_tmu_clock_event_set_oneshot(struct clock_event_device *ced)
378 {
379         return sh_tmu_clock_event_set_state(ced, 0);
380 }
381
382 static int sh_tmu_clock_event_set_periodic(struct clock_event_device *ced)
383 {
384         return sh_tmu_clock_event_set_state(ced, 1);
385 }
386
387 static int sh_tmu_clock_event_next(unsigned long delta,
388                                    struct clock_event_device *ced)
389 {
390         struct sh_tmu_channel *ch = ced_to_sh_tmu(ced);
391
392         BUG_ON(!clockevent_state_oneshot(ced));
393
394         /* program new delta value */
395         sh_tmu_set_next(ch, delta, 0);
396         return 0;
397 }
398
399 static void sh_tmu_clock_event_suspend(struct clock_event_device *ced)
400 {
401         pm_genpd_syscore_poweroff(&ced_to_sh_tmu(ced)->tmu->pdev->dev);
402 }
403
404 static void sh_tmu_clock_event_resume(struct clock_event_device *ced)
405 {
406         pm_genpd_syscore_poweron(&ced_to_sh_tmu(ced)->tmu->pdev->dev);
407 }
408
409 static void sh_tmu_register_clockevent(struct sh_tmu_channel *ch,
410                                        const char *name)
411 {
412         struct clock_event_device *ced = &ch->ced;
413         int ret;
414
415         ced->name = name;
416         ced->features = CLOCK_EVT_FEAT_PERIODIC;
417         ced->features |= CLOCK_EVT_FEAT_ONESHOT;
418         ced->rating = 200;
419         ced->cpumask = cpu_possible_mask;
420         ced->set_next_event = sh_tmu_clock_event_next;
421         ced->set_state_shutdown = sh_tmu_clock_event_shutdown;
422         ced->set_state_periodic = sh_tmu_clock_event_set_periodic;
423         ced->set_state_oneshot = sh_tmu_clock_event_set_oneshot;
424         ced->suspend = sh_tmu_clock_event_suspend;
425         ced->resume = sh_tmu_clock_event_resume;
426
427         dev_info(&ch->tmu->pdev->dev, "ch%u: used for clock events\n",
428                  ch->index);
429
430         clockevents_config_and_register(ced, ch->tmu->rate, 0x300, 0xffffffff);
431
432         ret = request_irq(ch->irq, sh_tmu_interrupt,
433                           IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING,
434                           dev_name(&ch->tmu->pdev->dev), ch);
435         if (ret) {
436                 dev_err(&ch->tmu->pdev->dev, "ch%u: failed to request irq %d\n",
437                         ch->index, ch->irq);
438                 return;
439         }
440 }
441
442 static int sh_tmu_register(struct sh_tmu_channel *ch, const char *name,
443                            bool clockevent, bool clocksource)
444 {
445         if (clockevent) {
446                 ch->tmu->has_clockevent = true;
447                 sh_tmu_register_clockevent(ch, name);
448         } else if (clocksource) {
449                 ch->tmu->has_clocksource = true;
450                 sh_tmu_register_clocksource(ch, name);
451         }
452
453         return 0;
454 }
455
456 static int sh_tmu_channel_setup(struct sh_tmu_channel *ch, unsigned int index,
457                                 bool clockevent, bool clocksource,
458                                 struct sh_tmu_device *tmu)
459 {
460         /* Skip unused channels. */
461         if (!clockevent && !clocksource)
462                 return 0;
463
464         ch->tmu = tmu;
465         ch->index = index;
466
467         if (tmu->model == SH_TMU_SH3)
468                 ch->base = tmu->mapbase + 4 + ch->index * 12;
469         else
470                 ch->base = tmu->mapbase + 8 + ch->index * 12;
471
472         ch->irq = platform_get_irq(tmu->pdev, index);
473         if (ch->irq < 0) {
474                 dev_err(&tmu->pdev->dev, "ch%u: failed to get irq\n",
475                         ch->index);
476                 return ch->irq;
477         }
478
479         ch->cs_enabled = false;
480         ch->enable_count = 0;
481
482         return sh_tmu_register(ch, dev_name(&tmu->pdev->dev),
483                                clockevent, clocksource);
484 }
485
486 static int sh_tmu_map_memory(struct sh_tmu_device *tmu)
487 {
488         struct resource *res;
489
490         res = platform_get_resource(tmu->pdev, IORESOURCE_MEM, 0);
491         if (!res) {
492                 dev_err(&tmu->pdev->dev, "failed to get I/O memory\n");
493                 return -ENXIO;
494         }
495
496         tmu->mapbase = ioremap_nocache(res->start, resource_size(res));
497         if (tmu->mapbase == NULL)
498                 return -ENXIO;
499
500         return 0;
501 }
502
503 static int sh_tmu_parse_dt(struct sh_tmu_device *tmu)
504 {
505         struct device_node *np = tmu->pdev->dev.of_node;
506
507         tmu->model = SH_TMU;
508         tmu->num_channels = 3;
509
510         of_property_read_u32(np, "#renesas,channels", &tmu->num_channels);
511
512         if (tmu->num_channels != 2 && tmu->num_channels != 3) {
513                 dev_err(&tmu->pdev->dev, "invalid number of channels %u\n",
514                         tmu->num_channels);
515                 return -EINVAL;
516         }
517
518         return 0;
519 }
520
521 static int sh_tmu_setup(struct sh_tmu_device *tmu, struct platform_device *pdev)
522 {
523         unsigned int i;
524         int ret;
525
526         tmu->pdev = pdev;
527
528         raw_spin_lock_init(&tmu->lock);
529
530         if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node) {
531                 ret = sh_tmu_parse_dt(tmu);
532                 if (ret < 0)
533                         return ret;
534         } else if (pdev->dev.platform_data) {
535                 const struct platform_device_id *id = pdev->id_entry;
536                 struct sh_timer_config *cfg = pdev->dev.platform_data;
537
538                 tmu->model = id->driver_data;
539                 tmu->num_channels = hweight8(cfg->channels_mask);
540         } else {
541                 dev_err(&tmu->pdev->dev, "missing platform data\n");
542                 return -ENXIO;
543         }
544
545         /* Get hold of clock. */
546         tmu->clk = clk_get(&tmu->pdev->dev, "fck");
547         if (IS_ERR(tmu->clk)) {
548                 dev_err(&tmu->pdev->dev, "cannot get clock\n");
549                 return PTR_ERR(tmu->clk);
550         }
551
552         ret = clk_prepare(tmu->clk);
553         if (ret < 0)
554                 goto err_clk_put;
555
556         /* Determine clock rate. */
557         ret = clk_enable(tmu->clk);
558         if (ret < 0)
559                 goto err_clk_unprepare;
560
561         tmu->rate = clk_get_rate(tmu->clk) / 4;
562         clk_disable(tmu->clk);
563
564         /* Map the memory resource. */
565         ret = sh_tmu_map_memory(tmu);
566         if (ret < 0) {
567                 dev_err(&tmu->pdev->dev, "failed to remap I/O memory\n");
568                 goto err_clk_unprepare;
569         }
570
571         /* Allocate and setup the channels. */
572         tmu->channels = kzalloc(sizeof(*tmu->channels) * tmu->num_channels,
573                                 GFP_KERNEL);
574         if (tmu->channels == NULL) {
575                 ret = -ENOMEM;
576                 goto err_unmap;
577         }
578
579         /*
580          * Use the first channel as a clock event device and the second channel
581          * as a clock source.
582          */
583         for (i = 0; i < tmu->num_channels; ++i) {
584                 ret = sh_tmu_channel_setup(&tmu->channels[i], i,
585                                            i == 0, i == 1, tmu);
586                 if (ret < 0)
587                         goto err_unmap;
588         }
589
590         platform_set_drvdata(pdev, tmu);
591
592         return 0;
593
594 err_unmap:
595         kfree(tmu->channels);
596         iounmap(tmu->mapbase);
597 err_clk_unprepare:
598         clk_unprepare(tmu->clk);
599 err_clk_put:
600         clk_put(tmu->clk);
601         return ret;
602 }
603
604 static int sh_tmu_probe(struct platform_device *pdev)
605 {
606         struct sh_tmu_device *tmu = platform_get_drvdata(pdev);
607         int ret;
608
609         if (!is_early_platform_device(pdev)) {
610                 pm_runtime_set_active(&pdev->dev);
611                 pm_runtime_enable(&pdev->dev);
612         }
613
614         if (tmu) {
615                 dev_info(&pdev->dev, "kept as earlytimer\n");
616                 goto out;
617         }
618
619         tmu = kzalloc(sizeof(*tmu), GFP_KERNEL);
620         if (tmu == NULL)
621                 return -ENOMEM;
622
623         ret = sh_tmu_setup(tmu, pdev);
624         if (ret) {
625                 kfree(tmu);
626                 pm_runtime_idle(&pdev->dev);
627                 return ret;
628         }
629         if (is_early_platform_device(pdev))
630                 return 0;
631
632  out:
633         if (tmu->has_clockevent || tmu->has_clocksource)
634                 pm_runtime_irq_safe(&pdev->dev);
635         else
636                 pm_runtime_idle(&pdev->dev);
637
638         return 0;
639 }
640
641 static int sh_tmu_remove(struct platform_device *pdev)
642 {
643         return -EBUSY; /* cannot unregister clockevent and clocksource */
644 }
645
646 static const struct platform_device_id sh_tmu_id_table[] = {
647         { "sh-tmu", SH_TMU },
648         { "sh-tmu-sh3", SH_TMU_SH3 },
649         { }
650 };
651 MODULE_DEVICE_TABLE(platform, sh_tmu_id_table);
652
653 static const struct of_device_id sh_tmu_of_table[] __maybe_unused = {
654         { .compatible = "renesas,tmu" },
655         { }
656 };
657 MODULE_DEVICE_TABLE(of, sh_tmu_of_table);
658
659 static struct platform_driver sh_tmu_device_driver = {
660         .probe          = sh_tmu_probe,
661         .remove         = sh_tmu_remove,
662         .driver         = {
663                 .name   = "sh_tmu",
664                 .of_match_table = of_match_ptr(sh_tmu_of_table),
665         },
666         .id_table       = sh_tmu_id_table,
667 };
668
669 static int __init sh_tmu_init(void)
670 {
671         return platform_driver_register(&sh_tmu_device_driver);
672 }
673
674 static void __exit sh_tmu_exit(void)
675 {
676         platform_driver_unregister(&sh_tmu_device_driver);
677 }
678
679 early_platform_init("earlytimer", &sh_tmu_device_driver);
680 subsys_initcall(sh_tmu_init);
681 module_exit(sh_tmu_exit);
682
683 MODULE_AUTHOR("Magnus Damm");
684 MODULE_DESCRIPTION("SuperH TMU Timer Driver");
685 MODULE_LICENSE("GPL v2");