Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * SuperH Timer Support - TMU
4 *
5 * Copyright (C) 2009 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/ioport.h>
17#include <linux/irq.h>
18#include <linux/module.h>
19#include <linux/of.h>
20#include <linux/platform_device.h>
21#include <linux/pm_domain.h>
22#include <linux/pm_runtime.h>
23#include <linux/sh_timer.h>
24#include <linux/slab.h>
25#include <linux/spinlock.h>
26
27#ifdef CONFIG_SUPERH
28#include <asm/platform_early.h>
29#endif
30
31enum sh_tmu_model {
32 SH_TMU,
33 SH_TMU_SH3,
34};
35
36struct sh_tmu_device;
37
38struct sh_tmu_channel {
39 struct sh_tmu_device *tmu;
40 unsigned int index;
41
42 void __iomem *base;
43 int irq;
44
45 unsigned long periodic;
46 struct clock_event_device ced;
47 struct clocksource cs;
48 bool cs_enabled;
49 unsigned int enable_count;
50};
51
52struct sh_tmu_device {
53 struct platform_device *pdev;
54
55 void __iomem *mapbase;
56 struct clk *clk;
57 unsigned long rate;
58
59 enum sh_tmu_model model;
60
61 raw_spinlock_t lock; /* Protect the shared start/stop register */
62
63 struct sh_tmu_channel *channels;
64 unsigned int num_channels;
65
66 bool has_clockevent;
67 bool has_clocksource;
68};
69
70#define TSTR -1 /* shared register */
71#define TCOR 0 /* channel register */
72#define TCNT 1 /* channel register */
73#define TCR 2 /* channel register */
74
75#define TCR_UNF (1 << 8)
76#define TCR_UNIE (1 << 5)
77#define TCR_TPSC_CLK4 (0 << 0)
78#define TCR_TPSC_CLK16 (1 << 0)
79#define TCR_TPSC_CLK64 (2 << 0)
80#define TCR_TPSC_CLK256 (3 << 0)
81#define TCR_TPSC_CLK1024 (4 << 0)
82#define TCR_TPSC_MASK (7 << 0)
83
84static inline unsigned long sh_tmu_read(struct sh_tmu_channel *ch, int reg_nr)
85{
86 unsigned long offs;
87
88 if (reg_nr == TSTR) {
89 switch (ch->tmu->model) {
90 case SH_TMU_SH3:
91 return ioread8(ch->tmu->mapbase + 2);
92 case SH_TMU:
93 return ioread8(ch->tmu->mapbase + 4);
94 }
95 }
96
97 offs = reg_nr << 2;
98
99 if (reg_nr == TCR)
100 return ioread16(ch->base + offs);
101 else
102 return ioread32(ch->base + offs);
103}
104
105static inline void sh_tmu_write(struct sh_tmu_channel *ch, int reg_nr,
106 unsigned long value)
107{
108 unsigned long offs;
109
110 if (reg_nr == TSTR) {
111 switch (ch->tmu->model) {
112 case SH_TMU_SH3:
113 return iowrite8(value, ch->tmu->mapbase + 2);
114 case SH_TMU:
115 return iowrite8(value, ch->tmu->mapbase + 4);
116 }
117 }
118
119 offs = reg_nr << 2;
120
121 if (reg_nr == TCR)
122 iowrite16(value, ch->base + offs);
123 else
124 iowrite32(value, ch->base + offs);
125}
126
127static void sh_tmu_start_stop_ch(struct sh_tmu_channel *ch, int start)
128{
129 unsigned long flags, value;
130
131 /* start stop register shared by multiple timer channels */
132 raw_spin_lock_irqsave(&ch->tmu->lock, flags);
133 value = sh_tmu_read(ch, TSTR);
134
135 if (start)
136 value |= 1 << ch->index;
137 else
138 value &= ~(1 << ch->index);
139
140 sh_tmu_write(ch, TSTR, value);
141 raw_spin_unlock_irqrestore(&ch->tmu->lock, flags);
142}
143
144static int __sh_tmu_enable(struct sh_tmu_channel *ch)
145{
146 /* make sure channel is disabled */
147 sh_tmu_start_stop_ch(ch, 0);
148
149 /* maximum timeout */
150 sh_tmu_write(ch, TCOR, 0xffffffff);
151 sh_tmu_write(ch, TCNT, 0xffffffff);
152
153 /* configure channel to parent clock / 4, irq off */
154 sh_tmu_write(ch, TCR, TCR_TPSC_CLK4);
155
156 /* enable channel */
157 sh_tmu_start_stop_ch(ch, 1);
158
159 return 0;
160}
161
162static int sh_tmu_enable(struct sh_tmu_channel *ch)
163{
164 if (ch->enable_count++ > 0)
165 return 0;
166
167 dev_pm_syscore_device(&ch->tmu->pdev->dev, true);
168
169 return __sh_tmu_enable(ch);
170}
171
172static void __sh_tmu_disable(struct sh_tmu_channel *ch)
173{
174 /* disable channel */
175 sh_tmu_start_stop_ch(ch, 0);
176
177 /* disable interrupts in TMU block */
178 sh_tmu_write(ch, TCR, TCR_TPSC_CLK4);
179}
180
181static void sh_tmu_disable(struct sh_tmu_channel *ch)
182{
183 if (WARN_ON(ch->enable_count == 0))
184 return;
185
186 if (--ch->enable_count > 0)
187 return;
188
189 __sh_tmu_disable(ch);
190
191 dev_pm_syscore_device(&ch->tmu->pdev->dev, false);
192}
193
194static void sh_tmu_set_next(struct sh_tmu_channel *ch, unsigned long delta,
195 int periodic)
196{
197 /* stop timer */
198 sh_tmu_start_stop_ch(ch, 0);
199
200 /* acknowledge interrupt */
201 sh_tmu_read(ch, TCR);
202
203 /* enable interrupt */
204 sh_tmu_write(ch, TCR, TCR_UNIE | TCR_TPSC_CLK4);
205
206 /* reload delta value in case of periodic timer */
207 if (periodic)
208 sh_tmu_write(ch, TCOR, delta);
209 else
210 sh_tmu_write(ch, TCOR, 0xffffffff);
211
212 sh_tmu_write(ch, TCNT, delta);
213
214 /* start timer */
215 sh_tmu_start_stop_ch(ch, 1);
216}
217
218static irqreturn_t sh_tmu_interrupt(int irq, void *dev_id)
219{
220 struct sh_tmu_channel *ch = dev_id;
221
222 /* disable or acknowledge interrupt */
223 if (clockevent_state_oneshot(&ch->ced))
224 sh_tmu_write(ch, TCR, TCR_TPSC_CLK4);
225 else
226 sh_tmu_write(ch, TCR, TCR_UNIE | TCR_TPSC_CLK4);
227
228 /* notify clockevent layer */
229 ch->ced.event_handler(&ch->ced);
230 return IRQ_HANDLED;
231}
232
233static struct sh_tmu_channel *cs_to_sh_tmu(struct clocksource *cs)
234{
235 return container_of(cs, struct sh_tmu_channel, cs);
236}
237
238static u64 sh_tmu_clocksource_read(struct clocksource *cs)
239{
240 struct sh_tmu_channel *ch = cs_to_sh_tmu(cs);
241
242 return sh_tmu_read(ch, TCNT) ^ 0xffffffff;
243}
244
245static int sh_tmu_clocksource_enable(struct clocksource *cs)
246{
247 struct sh_tmu_channel *ch = cs_to_sh_tmu(cs);
248 int ret;
249
250 if (WARN_ON(ch->cs_enabled))
251 return 0;
252
253 ret = sh_tmu_enable(ch);
254 if (!ret)
255 ch->cs_enabled = true;
256
257 return ret;
258}
259
260static void sh_tmu_clocksource_disable(struct clocksource *cs)
261{
262 struct sh_tmu_channel *ch = cs_to_sh_tmu(cs);
263
264 if (WARN_ON(!ch->cs_enabled))
265 return;
266
267 sh_tmu_disable(ch);
268 ch->cs_enabled = false;
269}
270
271static void sh_tmu_clocksource_suspend(struct clocksource *cs)
272{
273 struct sh_tmu_channel *ch = cs_to_sh_tmu(cs);
274
275 if (!ch->cs_enabled)
276 return;
277
278 if (--ch->enable_count == 0) {
279 __sh_tmu_disable(ch);
280 dev_pm_genpd_suspend(&ch->tmu->pdev->dev);
281 }
282}
283
284static void sh_tmu_clocksource_resume(struct clocksource *cs)
285{
286 struct sh_tmu_channel *ch = cs_to_sh_tmu(cs);
287
288 if (!ch->cs_enabled)
289 return;
290
291 if (ch->enable_count++ == 0) {
292 dev_pm_genpd_resume(&ch->tmu->pdev->dev);
293 __sh_tmu_enable(ch);
294 }
295}
296
297static int sh_tmu_register_clocksource(struct sh_tmu_channel *ch,
298 const char *name)
299{
300 struct clocksource *cs = &ch->cs;
301
302 cs->name = name;
303 cs->rating = 200;
304 cs->read = sh_tmu_clocksource_read;
305 cs->enable = sh_tmu_clocksource_enable;
306 cs->disable = sh_tmu_clocksource_disable;
307 cs->suspend = sh_tmu_clocksource_suspend;
308 cs->resume = sh_tmu_clocksource_resume;
309 cs->mask = CLOCKSOURCE_MASK(32);
310 cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
311
312 dev_info(&ch->tmu->pdev->dev, "ch%u: used as clock source\n",
313 ch->index);
314
315 clocksource_register_hz(cs, ch->tmu->rate);
316 return 0;
317}
318
319static struct sh_tmu_channel *ced_to_sh_tmu(struct clock_event_device *ced)
320{
321 return container_of(ced, struct sh_tmu_channel, ced);
322}
323
324static void sh_tmu_clock_event_start(struct sh_tmu_channel *ch, int periodic)
325{
326 sh_tmu_enable(ch);
327
328 if (periodic) {
329 ch->periodic = (ch->tmu->rate + HZ/2) / HZ;
330 sh_tmu_set_next(ch, ch->periodic, 1);
331 }
332}
333
334static int sh_tmu_clock_event_shutdown(struct clock_event_device *ced)
335{
336 struct sh_tmu_channel *ch = ced_to_sh_tmu(ced);
337
338 if (clockevent_state_oneshot(ced) || clockevent_state_periodic(ced))
339 sh_tmu_disable(ch);
340 return 0;
341}
342
343static int sh_tmu_clock_event_set_state(struct clock_event_device *ced,
344 int periodic)
345{
346 struct sh_tmu_channel *ch = ced_to_sh_tmu(ced);
347
348 /* deal with old setting first */
349 if (clockevent_state_oneshot(ced) || clockevent_state_periodic(ced))
350 sh_tmu_disable(ch);
351
352 dev_info(&ch->tmu->pdev->dev, "ch%u: used for %s clock events\n",
353 ch->index, periodic ? "periodic" : "oneshot");
354 sh_tmu_clock_event_start(ch, periodic);
355 return 0;
356}
357
358static int sh_tmu_clock_event_set_oneshot(struct clock_event_device *ced)
359{
360 return sh_tmu_clock_event_set_state(ced, 0);
361}
362
363static int sh_tmu_clock_event_set_periodic(struct clock_event_device *ced)
364{
365 return sh_tmu_clock_event_set_state(ced, 1);
366}
367
368static int sh_tmu_clock_event_next(unsigned long delta,
369 struct clock_event_device *ced)
370{
371 struct sh_tmu_channel *ch = ced_to_sh_tmu(ced);
372
373 BUG_ON(!clockevent_state_oneshot(ced));
374
375 /* program new delta value */
376 sh_tmu_set_next(ch, delta, 0);
377 return 0;
378}
379
380static void sh_tmu_clock_event_suspend(struct clock_event_device *ced)
381{
382 dev_pm_genpd_suspend(&ced_to_sh_tmu(ced)->tmu->pdev->dev);
383}
384
385static void sh_tmu_clock_event_resume(struct clock_event_device *ced)
386{
387 dev_pm_genpd_resume(&ced_to_sh_tmu(ced)->tmu->pdev->dev);
388}
389
390static void sh_tmu_register_clockevent(struct sh_tmu_channel *ch,
391 const char *name)
392{
393 struct clock_event_device *ced = &ch->ced;
394 int ret;
395
396 ced->name = name;
397 ced->features = CLOCK_EVT_FEAT_PERIODIC;
398 ced->features |= CLOCK_EVT_FEAT_ONESHOT;
399 ced->rating = 200;
400 ced->cpumask = cpu_possible_mask;
401 ced->set_next_event = sh_tmu_clock_event_next;
402 ced->set_state_shutdown = sh_tmu_clock_event_shutdown;
403 ced->set_state_periodic = sh_tmu_clock_event_set_periodic;
404 ced->set_state_oneshot = sh_tmu_clock_event_set_oneshot;
405 ced->suspend = sh_tmu_clock_event_suspend;
406 ced->resume = sh_tmu_clock_event_resume;
407
408 dev_info(&ch->tmu->pdev->dev, "ch%u: used for clock events\n",
409 ch->index);
410
411 clockevents_config_and_register(ced, ch->tmu->rate, 0x300, 0xffffffff);
412
413 ret = request_irq(ch->irq, sh_tmu_interrupt,
414 IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING,
415 dev_name(&ch->tmu->pdev->dev), ch);
416 if (ret) {
417 dev_err(&ch->tmu->pdev->dev, "ch%u: failed to request irq %d\n",
418 ch->index, ch->irq);
419 return;
420 }
421}
422
423static int sh_tmu_register(struct sh_tmu_channel *ch, const char *name,
424 bool clockevent, bool clocksource)
425{
426 if (clockevent) {
427 ch->tmu->has_clockevent = true;
428 sh_tmu_register_clockevent(ch, name);
429 } else if (clocksource) {
430 ch->tmu->has_clocksource = true;
431 sh_tmu_register_clocksource(ch, name);
432 }
433
434 return 0;
435}
436
437static int sh_tmu_channel_setup(struct sh_tmu_channel *ch, unsigned int index,
438 bool clockevent, bool clocksource,
439 struct sh_tmu_device *tmu)
440{
441 /* Skip unused channels. */
442 if (!clockevent && !clocksource)
443 return 0;
444
445 ch->tmu = tmu;
446 ch->index = index;
447
448 if (tmu->model == SH_TMU_SH3)
449 ch->base = tmu->mapbase + 4 + ch->index * 12;
450 else
451 ch->base = tmu->mapbase + 8 + ch->index * 12;
452
453 ch->irq = platform_get_irq(tmu->pdev, index);
454 if (ch->irq < 0)
455 return ch->irq;
456
457 ch->cs_enabled = false;
458 ch->enable_count = 0;
459
460 return sh_tmu_register(ch, dev_name(&tmu->pdev->dev),
461 clockevent, clocksource);
462}
463
464static int sh_tmu_map_memory(struct sh_tmu_device *tmu)
465{
466 struct resource *res;
467
468 res = platform_get_resource(tmu->pdev, IORESOURCE_MEM, 0);
469 if (!res) {
470 dev_err(&tmu->pdev->dev, "failed to get I/O memory\n");
471 return -ENXIO;
472 }
473
474 tmu->mapbase = ioremap(res->start, resource_size(res));
475 if (tmu->mapbase == NULL)
476 return -ENXIO;
477
478 return 0;
479}
480
481static int sh_tmu_parse_dt(struct sh_tmu_device *tmu)
482{
483 struct device_node *np = tmu->pdev->dev.of_node;
484
485 tmu->model = SH_TMU;
486 tmu->num_channels = 3;
487
488 of_property_read_u32(np, "#renesas,channels", &tmu->num_channels);
489
490 if (tmu->num_channels != 2 && tmu->num_channels != 3) {
491 dev_err(&tmu->pdev->dev, "invalid number of channels %u\n",
492 tmu->num_channels);
493 return -EINVAL;
494 }
495
496 return 0;
497}
498
499static int sh_tmu_setup(struct sh_tmu_device *tmu, struct platform_device *pdev)
500{
501 unsigned int i;
502 int ret;
503
504 tmu->pdev = pdev;
505
506 raw_spin_lock_init(&tmu->lock);
507
508 if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node) {
509 ret = sh_tmu_parse_dt(tmu);
510 if (ret < 0)
511 return ret;
512 } else if (pdev->dev.platform_data) {
513 const struct platform_device_id *id = pdev->id_entry;
514 struct sh_timer_config *cfg = pdev->dev.platform_data;
515
516 tmu->model = id->driver_data;
517 tmu->num_channels = hweight8(cfg->channels_mask);
518 } else {
519 dev_err(&tmu->pdev->dev, "missing platform data\n");
520 return -ENXIO;
521 }
522
523 /* Get hold of clock. */
524 tmu->clk = clk_get(&tmu->pdev->dev, "fck");
525 if (IS_ERR(tmu->clk)) {
526 dev_err(&tmu->pdev->dev, "cannot get clock\n");
527 return PTR_ERR(tmu->clk);
528 }
529
530 ret = clk_prepare(tmu->clk);
531 if (ret < 0)
532 goto err_clk_put;
533
534 /* Determine clock rate. */
535 ret = clk_enable(tmu->clk);
536 if (ret < 0)
537 goto err_clk_unprepare;
538
539 tmu->rate = clk_get_rate(tmu->clk) / 4;
540
541 /* Map the memory resource. */
542 ret = sh_tmu_map_memory(tmu);
543 if (ret < 0) {
544 dev_err(&tmu->pdev->dev, "failed to remap I/O memory\n");
545 goto err_clk_unprepare;
546 }
547
548 /* Allocate and setup the channels. */
549 tmu->channels = kzalloc_objs(*tmu->channels, tmu->num_channels);
550 if (tmu->channels == NULL) {
551 ret = -ENOMEM;
552 goto err_unmap;
553 }
554
555 /*
556 * Use the first channel as a clock event device and the second channel
557 * as a clock source.
558 */
559 for (i = 0; i < tmu->num_channels; ++i) {
560 ret = sh_tmu_channel_setup(&tmu->channels[i], i,
561 i == 0, i == 1, tmu);
562 if (ret < 0)
563 goto err_unmap;
564 }
565
566 platform_set_drvdata(pdev, tmu);
567
568 return 0;
569
570err_unmap:
571 kfree(tmu->channels);
572 iounmap(tmu->mapbase);
573err_clk_unprepare:
574 clk_unprepare(tmu->clk);
575err_clk_put:
576 clk_put(tmu->clk);
577 return ret;
578}
579
580static int sh_tmu_probe(struct platform_device *pdev)
581{
582 struct sh_tmu_device *tmu = platform_get_drvdata(pdev);
583 int ret;
584
585 if (!is_sh_early_platform_device(pdev)) {
586 pm_runtime_set_active(&pdev->dev);
587 pm_runtime_enable(&pdev->dev);
588 }
589
590 if (tmu) {
591 dev_info(&pdev->dev, "kept as earlytimer\n");
592 goto out;
593 }
594
595 tmu = kzalloc_obj(*tmu);
596 if (tmu == NULL)
597 return -ENOMEM;
598
599 ret = sh_tmu_setup(tmu, pdev);
600 if (ret) {
601 kfree(tmu);
602 pm_runtime_idle(&pdev->dev);
603 return ret;
604 }
605
606 if (is_sh_early_platform_device(pdev))
607 return 0;
608
609 out:
610 if (tmu->has_clockevent || tmu->has_clocksource)
611 pm_runtime_irq_safe(&pdev->dev);
612
613 return 0;
614}
615
616static const struct platform_device_id sh_tmu_id_table[] = {
617 { "sh-tmu", SH_TMU },
618 { "sh-tmu-sh3", SH_TMU_SH3 },
619 { }
620};
621MODULE_DEVICE_TABLE(platform, sh_tmu_id_table);
622
623static const struct of_device_id sh_tmu_of_table[] __maybe_unused = {
624 { .compatible = "renesas,tmu" },
625 { }
626};
627MODULE_DEVICE_TABLE(of, sh_tmu_of_table);
628
629static struct platform_driver sh_tmu_device_driver = {
630 .probe = sh_tmu_probe,
631 .driver = {
632 .name = "sh_tmu",
633 .of_match_table = of_match_ptr(sh_tmu_of_table),
634 .suppress_bind_attrs = true,
635 },
636 .id_table = sh_tmu_id_table,
637};
638
639static int __init sh_tmu_init(void)
640{
641 return platform_driver_register(&sh_tmu_device_driver);
642}
643
644static void __exit sh_tmu_exit(void)
645{
646 platform_driver_unregister(&sh_tmu_device_driver);
647}
648
649#ifdef CONFIG_SUPERH
650sh_early_platform_init("earlytimer", &sh_tmu_device_driver);
651#endif
652
653subsys_initcall(sh_tmu_init);
654module_exit(sh_tmu_exit);
655
656MODULE_AUTHOR("Magnus Damm");
657MODULE_DESCRIPTION("SuperH TMU Timer Driver");