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(usec: ch->cmt->reg_delay);
257 } else {
258 ch->cmt->info->write_control(ch->cmt->mapbase, 0, value);
259 udelay(usec: 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(usec: 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(usec: 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(usec: 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(dev: &ch->cmt->pdev->dev, val: true);
357
358 /* make sure channel is disabled */
359 sh_cmt_start_stop_ch(ch, start: 0);
360
361 /* configure channel, periodic mode and maximum timeout */
362 if (ch->cmt->info->width == 16) {
363 sh_cmt_write_cmcsr(ch, SH_CMT16_CMCSR_CMIE |
364 SH_CMT16_CMCSR_CKS512);
365 } else {
366 u32 cmtout = ch->cmt->info->model <= SH_CMT_48BIT ?
367 SH_CMT32_CMCSR_CMTOUT_IE : 0;
368 sh_cmt_write_cmcsr(ch, value: cmtout | SH_CMT32_CMCSR_CMM |
369 SH_CMT32_CMCSR_CMR_IRQ |
370 SH_CMT32_CMCSR_CKS_RCLK8);
371 }
372
373 sh_cmt_write_cmcor(ch, value: 0xffffffff);
374 ret = sh_cmt_write_cmcnt(ch, value: 0);
375
376 if (ret || sh_cmt_read_cmcnt(ch)) {
377 dev_err(&ch->cmt->pdev->dev, "ch%u: cannot clear CMCNT\n",
378 ch->index);
379 return -ETIMEDOUT;
380 }
381
382 /* enable channel */
383 sh_cmt_start_stop_ch(ch, start: 1);
384 return 0;
385}
386
387static void sh_cmt_disable(struct sh_cmt_channel *ch)
388{
389 /* disable channel */
390 sh_cmt_start_stop_ch(ch, start: 0);
391
392 /* disable interrupts in CMT block */
393 sh_cmt_write_cmcsr(ch, value: 0);
394
395 dev_pm_syscore_device(dev: &ch->cmt->pdev->dev, val: false);
396}
397
398/* private flags */
399#define FLAG_CLOCKEVENT (1 << 0)
400#define FLAG_CLOCKSOURCE (1 << 1)
401#define FLAG_REPROGRAM (1 << 2)
402#define FLAG_SKIPEVENT (1 << 3)
403#define FLAG_IRQCONTEXT (1 << 4)
404
405static void sh_cmt_clock_event_program_verify(struct sh_cmt_channel *ch,
406 int absolute)
407{
408 u32 value = ch->next_match_value;
409 u32 new_match;
410 u32 delay = 0;
411 u32 now = 0;
412 u32 has_wrapped;
413
414 now = sh_cmt_get_counter(ch, has_wrapped: &has_wrapped);
415 ch->flags |= FLAG_REPROGRAM; /* force reprogram */
416
417 if (has_wrapped) {
418 /* we're competing with the interrupt handler.
419 * -> let the interrupt handler reprogram the timer.
420 * -> interrupt number two handles the event.
421 */
422 ch->flags |= FLAG_SKIPEVENT;
423 return;
424 }
425
426 if (absolute)
427 now = 0;
428
429 do {
430 /* reprogram the timer hardware,
431 * but don't save the new match value yet.
432 */
433 new_match = now + value + delay;
434 if (new_match > ch->max_match_value)
435 new_match = ch->max_match_value;
436
437 sh_cmt_write_cmcor(ch, value: new_match);
438
439 now = sh_cmt_get_counter(ch, has_wrapped: &has_wrapped);
440 if (has_wrapped && (new_match > ch->match_value)) {
441 /* we are changing to a greater match value,
442 * so this wrap must be caused by the counter
443 * matching the old value.
444 * -> first interrupt reprograms the timer.
445 * -> interrupt number two handles the event.
446 */
447 ch->flags |= FLAG_SKIPEVENT;
448 break;
449 }
450
451 if (has_wrapped) {
452 /* we are changing to a smaller match value,
453 * so the wrap must be caused by the counter
454 * matching the new value.
455 * -> save programmed match value.
456 * -> let isr handle the event.
457 */
458 ch->match_value = new_match;
459 break;
460 }
461
462 /* be safe: verify hardware settings */
463 if (now < new_match) {
464 /* timer value is below match value, all good.
465 * this makes sure we won't miss any match events.
466 * -> save programmed match value.
467 * -> let isr handle the event.
468 */
469 ch->match_value = new_match;
470 break;
471 }
472
473 /* the counter has reached a value greater
474 * than our new match value. and since the
475 * has_wrapped flag isn't set we must have
476 * programmed a too close event.
477 * -> increase delay and retry.
478 */
479 if (delay)
480 delay <<= 1;
481 else
482 delay = 1;
483
484 if (!delay)
485 dev_warn(&ch->cmt->pdev->dev, "ch%u: too long delay\n",
486 ch->index);
487
488 } while (delay);
489}
490
491static void __sh_cmt_set_next(struct sh_cmt_channel *ch, unsigned long delta)
492{
493 if (delta > ch->max_match_value)
494 dev_warn(&ch->cmt->pdev->dev, "ch%u: delta out of range\n",
495 ch->index);
496
497 ch->next_match_value = delta;
498 sh_cmt_clock_event_program_verify(ch, absolute: 0);
499}
500
501static void sh_cmt_set_next(struct sh_cmt_channel *ch, unsigned long delta)
502{
503 unsigned long flags;
504
505 raw_spin_lock_irqsave(&ch->lock, flags);
506 __sh_cmt_set_next(ch, delta);
507 raw_spin_unlock_irqrestore(&ch->lock, flags);
508}
509
510static irqreturn_t sh_cmt_interrupt(int irq, void *dev_id)
511{
512 struct sh_cmt_channel *ch = dev_id;
513 unsigned long flags;
514
515 /* clear flags */
516 sh_cmt_write_cmcsr(ch, value: sh_cmt_read_cmcsr(ch) &
517 ch->cmt->info->clear_bits);
518
519 /* update clock source counter to begin with if enabled
520 * the wrap flag should be cleared by the timer specific
521 * isr before we end up here.
522 */
523 if (ch->flags & FLAG_CLOCKSOURCE)
524 ch->total_cycles += ch->match_value + 1;
525
526 if (!(ch->flags & FLAG_REPROGRAM))
527 ch->next_match_value = ch->max_match_value;
528
529 ch->flags |= FLAG_IRQCONTEXT;
530
531 if (ch->flags & FLAG_CLOCKEVENT) {
532 if (!(ch->flags & FLAG_SKIPEVENT)) {
533 if (clockevent_state_oneshot(dev: &ch->ced)) {
534 ch->next_match_value = ch->max_match_value;
535 ch->flags |= FLAG_REPROGRAM;
536 }
537
538 ch->ced.event_handler(&ch->ced);
539 }
540 }
541
542 ch->flags &= ~FLAG_SKIPEVENT;
543
544 raw_spin_lock_irqsave(&ch->lock, flags);
545
546 if (ch->flags & FLAG_REPROGRAM) {
547 ch->flags &= ~FLAG_REPROGRAM;
548 sh_cmt_clock_event_program_verify(ch, absolute: 1);
549
550 if (ch->flags & FLAG_CLOCKEVENT)
551 if ((clockevent_state_shutdown(dev: &ch->ced))
552 || (ch->match_value == ch->next_match_value))
553 ch->flags &= ~FLAG_REPROGRAM;
554 }
555
556 ch->flags &= ~FLAG_IRQCONTEXT;
557
558 raw_spin_unlock_irqrestore(&ch->lock, flags);
559
560 return IRQ_HANDLED;
561}
562
563static int sh_cmt_start_clocksource(struct sh_cmt_channel *ch)
564{
565 int ret = 0;
566 unsigned long flags;
567
568 raw_spin_lock_irqsave(&ch->lock, flags);
569
570 if (!(ch->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE)))
571 ret = sh_cmt_enable(ch);
572
573 if (ret)
574 goto out;
575
576 ch->flags |= FLAG_CLOCKSOURCE;
577
578 /* setup timeout if no clockevent */
579 if (ch->cmt->num_channels == 1 && !(ch->flags & FLAG_CLOCKEVENT))
580 __sh_cmt_set_next(ch, delta: ch->max_match_value);
581out:
582 raw_spin_unlock_irqrestore(&ch->lock, flags);
583
584 return ret;
585}
586
587static void sh_cmt_stop_clocksource(struct sh_cmt_channel *ch)
588{
589 unsigned long flags;
590 unsigned long f;
591
592 raw_spin_lock_irqsave(&ch->lock, flags);
593
594 f = ch->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE);
595
596 ch->flags &= ~FLAG_CLOCKSOURCE;
597
598 if (f && !(ch->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE)))
599 sh_cmt_disable(ch);
600
601 raw_spin_unlock_irqrestore(&ch->lock, flags);
602}
603
604static int sh_cmt_start_clockevent(struct sh_cmt_channel *ch)
605{
606 int ret = 0;
607 unsigned long flags;
608
609 raw_spin_lock_irqsave(&ch->lock, flags);
610
611 if (!(ch->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE)))
612 ret = sh_cmt_enable(ch);
613
614 if (ret)
615 goto out;
616
617 ch->flags |= FLAG_CLOCKEVENT;
618 out:
619 raw_spin_unlock_irqrestore(&ch->lock, flags);
620
621 return ret;
622}
623
624static void sh_cmt_stop_clockevent(struct sh_cmt_channel *ch)
625{
626 unsigned long flags;
627 unsigned long f;
628
629 raw_spin_lock_irqsave(&ch->lock, flags);
630
631 f = ch->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE);
632
633 ch->flags &= ~FLAG_CLOCKEVENT;
634
635 if (f && !(ch->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE)))
636 sh_cmt_disable(ch);
637
638 /* adjust the timeout to maximum if only clocksource left */
639 if (ch->flags & FLAG_CLOCKSOURCE)
640 __sh_cmt_set_next(ch, delta: ch->max_match_value);
641
642 raw_spin_unlock_irqrestore(&ch->lock, flags);
643}
644
645static struct sh_cmt_channel *cs_to_sh_cmt(struct clocksource *cs)
646{
647 return container_of(cs, struct sh_cmt_channel, cs);
648}
649
650static u64 sh_cmt_clocksource_read(struct clocksource *cs)
651{
652 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs);
653 u32 has_wrapped;
654
655 if (ch->cmt->num_channels == 1) {
656 unsigned long flags;
657 u64 value;
658 u32 raw;
659
660 raw_spin_lock_irqsave(&ch->lock, flags);
661 value = ch->total_cycles;
662 raw = sh_cmt_get_counter(ch, has_wrapped: &has_wrapped);
663
664 if (unlikely(has_wrapped))
665 raw += ch->match_value + 1;
666 raw_spin_unlock_irqrestore(&ch->lock, flags);
667
668 return value + raw;
669 }
670
671 return sh_cmt_get_counter(ch, has_wrapped: &has_wrapped);
672}
673
674static int sh_cmt_clocksource_enable(struct clocksource *cs)
675{
676 int ret;
677 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs);
678
679 WARN_ON(ch->cs_enabled);
680
681 ch->total_cycles = 0;
682
683 ret = sh_cmt_start_clocksource(ch);
684 if (!ret)
685 ch->cs_enabled = true;
686
687 return ret;
688}
689
690static void sh_cmt_clocksource_disable(struct clocksource *cs)
691{
692 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs);
693
694 WARN_ON(!ch->cs_enabled);
695
696 sh_cmt_stop_clocksource(ch);
697 ch->cs_enabled = false;
698}
699
700static void sh_cmt_clocksource_suspend(struct clocksource *cs)
701{
702 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs);
703
704 if (!ch->cs_enabled)
705 return;
706
707 sh_cmt_stop_clocksource(ch);
708 dev_pm_genpd_suspend(dev: &ch->cmt->pdev->dev);
709}
710
711static void sh_cmt_clocksource_resume(struct clocksource *cs)
712{
713 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs);
714
715 if (!ch->cs_enabled)
716 return;
717
718 dev_pm_genpd_resume(dev: &ch->cmt->pdev->dev);
719 sh_cmt_start_clocksource(ch);
720}
721
722static int sh_cmt_register_clocksource(struct sh_cmt_channel *ch,
723 const char *name)
724{
725 struct clocksource *cs = &ch->cs;
726
727 cs->name = name;
728 cs->rating = 125;
729 cs->read = sh_cmt_clocksource_read;
730 cs->enable = sh_cmt_clocksource_enable;
731 cs->disable = sh_cmt_clocksource_disable;
732 cs->suspend = sh_cmt_clocksource_suspend;
733 cs->resume = sh_cmt_clocksource_resume;
734 cs->mask = CLOCKSOURCE_MASK(ch->cmt->info->width);
735 cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
736
737 dev_info(&ch->cmt->pdev->dev, "ch%u: used as clock source\n",
738 ch->index);
739
740 clocksource_register_hz(cs, hz: ch->cmt->rate);
741 return 0;
742}
743
744static struct sh_cmt_channel *ced_to_sh_cmt(struct clock_event_device *ced)
745{
746 return container_of(ced, struct sh_cmt_channel, ced);
747}
748
749static void sh_cmt_clock_event_start(struct sh_cmt_channel *ch, int periodic)
750{
751 sh_cmt_start_clockevent(ch);
752
753 if (periodic)
754 sh_cmt_set_next(ch, delta: ((ch->cmt->rate + HZ/2) / HZ) - 1);
755 else
756 sh_cmt_set_next(ch, delta: ch->max_match_value);
757}
758
759static int sh_cmt_clock_event_shutdown(struct clock_event_device *ced)
760{
761 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced);
762
763 sh_cmt_stop_clockevent(ch);
764 return 0;
765}
766
767static int sh_cmt_clock_event_set_state(struct clock_event_device *ced,
768 int periodic)
769{
770 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced);
771
772 /* deal with old setting first */
773 if (clockevent_state_oneshot(dev: ced) || clockevent_state_periodic(dev: ced))
774 sh_cmt_stop_clockevent(ch);
775
776 dev_info(&ch->cmt->pdev->dev, "ch%u: used for %s clock events\n",
777 ch->index, periodic ? "periodic" : "oneshot");
778 sh_cmt_clock_event_start(ch, periodic);
779 return 0;
780}
781
782static int sh_cmt_clock_event_set_oneshot(struct clock_event_device *ced)
783{
784 return sh_cmt_clock_event_set_state(ced, periodic: 0);
785}
786
787static int sh_cmt_clock_event_set_periodic(struct clock_event_device *ced)
788{
789 return sh_cmt_clock_event_set_state(ced, periodic: 1);
790}
791
792static int sh_cmt_clock_event_next(unsigned long delta,
793 struct clock_event_device *ced)
794{
795 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced);
796 unsigned long flags;
797
798 BUG_ON(!clockevent_state_oneshot(ced));
799
800 raw_spin_lock_irqsave(&ch->lock, flags);
801
802 if (likely(ch->flags & FLAG_IRQCONTEXT))
803 ch->next_match_value = delta - 1;
804 else
805 __sh_cmt_set_next(ch, delta: delta - 1);
806
807 raw_spin_unlock_irqrestore(&ch->lock, flags);
808
809 return 0;
810}
811
812static void sh_cmt_clock_event_suspend(struct clock_event_device *ced)
813{
814 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced);
815
816 dev_pm_genpd_suspend(dev: &ch->cmt->pdev->dev);
817 clk_unprepare(clk: ch->cmt->clk);
818}
819
820static void sh_cmt_clock_event_resume(struct clock_event_device *ced)
821{
822 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced);
823
824 clk_prepare(clk: ch->cmt->clk);
825 dev_pm_genpd_resume(dev: &ch->cmt->pdev->dev);
826}
827
828static int sh_cmt_register_clockevent(struct sh_cmt_channel *ch,
829 const char *name)
830{
831 struct clock_event_device *ced = &ch->ced;
832 int irq;
833 int ret;
834
835 irq = platform_get_irq(ch->cmt->pdev, ch->index);
836 if (irq < 0)
837 return irq;
838
839 ret = request_irq(irq, handler: sh_cmt_interrupt,
840 IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING,
841 name: dev_name(dev: &ch->cmt->pdev->dev), dev: ch);
842 if (ret) {
843 dev_err(&ch->cmt->pdev->dev, "ch%u: failed to request irq %d\n",
844 ch->index, irq);
845 return ret;
846 }
847
848 ced->name = name;
849 ced->features = CLOCK_EVT_FEAT_PERIODIC;
850 ced->features |= CLOCK_EVT_FEAT_ONESHOT;
851 ced->rating = 125;
852 ced->cpumask = cpu_possible_mask;
853 ced->set_next_event = sh_cmt_clock_event_next;
854 ced->set_state_shutdown = sh_cmt_clock_event_shutdown;
855 ced->set_state_periodic = sh_cmt_clock_event_set_periodic;
856 ced->set_state_oneshot = sh_cmt_clock_event_set_oneshot;
857 ced->suspend = sh_cmt_clock_event_suspend;
858 ced->resume = sh_cmt_clock_event_resume;
859
860 /* TODO: calculate good shift from rate and counter bit width */
861 ced->shift = 32;
862 ced->mult = div_sc(ticks: ch->cmt->rate, NSEC_PER_SEC, shift: ced->shift);
863 ced->max_delta_ns = clockevent_delta2ns(latch: ch->max_match_value, evt: ced);
864 ced->max_delta_ticks = ch->max_match_value;
865 ced->min_delta_ns = clockevent_delta2ns(latch: 0x1f, evt: ced);
866 ced->min_delta_ticks = 0x1f;
867
868 dev_info(&ch->cmt->pdev->dev, "ch%u: used for clock events\n",
869 ch->index);
870 clockevents_register_device(dev: ced);
871
872 return 0;
873}
874
875static int sh_cmt_register(struct sh_cmt_channel *ch, const char *name,
876 bool clockevent, bool clocksource)
877{
878 int ret;
879
880 if (clockevent) {
881 ch->cmt->has_clockevent = true;
882 ret = sh_cmt_register_clockevent(ch, name);
883 if (ret < 0)
884 return ret;
885 }
886
887 if (clocksource) {
888 ch->cmt->has_clocksource = true;
889 sh_cmt_register_clocksource(ch, name);
890 }
891
892 return 0;
893}
894
895static int sh_cmt_setup_channel(struct sh_cmt_channel *ch, unsigned int index,
896 unsigned int hwidx, bool clockevent,
897 bool clocksource, struct sh_cmt_device *cmt)
898{
899 u32 value;
900 int ret;
901
902 /* Skip unused channels. */
903 if (!clockevent && !clocksource)
904 return 0;
905
906 ch->cmt = cmt;
907 ch->index = index;
908 ch->hwidx = hwidx;
909 ch->timer_bit = hwidx;
910
911 /*
912 * Compute the address of the channel control register block. For the
913 * timers with a per-channel start/stop register, compute its address
914 * as well.
915 */
916 switch (cmt->info->model) {
917 case SH_CMT_16BIT:
918 ch->ioctrl = cmt->mapbase + 2 + ch->hwidx * 6;
919 break;
920 case SH_CMT_32BIT:
921 case SH_CMT_48BIT:
922 ch->ioctrl = cmt->mapbase + 0x10 + ch->hwidx * 0x10;
923 break;
924 case SH_CMT0_RCAR_GEN2:
925 case SH_CMT1_RCAR_GEN2:
926 ch->iostart = cmt->mapbase + ch->hwidx * 0x100;
927 ch->ioctrl = ch->iostart + 0x10;
928 ch->timer_bit = 0;
929
930 /* Enable the clock supply to the channel */
931 value = ioread32(cmt->mapbase + CMCLKE);
932 value |= BIT(hwidx);
933 iowrite32(value, cmt->mapbase + CMCLKE);
934 break;
935 }
936
937 if (cmt->info->width == (sizeof(ch->max_match_value) * 8))
938 ch->max_match_value = ~0;
939 else
940 ch->max_match_value = (1 << cmt->info->width) - 1;
941
942 ch->match_value = ch->max_match_value;
943 raw_spin_lock_init(&ch->lock);
944
945 ret = sh_cmt_register(ch, name: dev_name(dev: &cmt->pdev->dev),
946 clockevent, clocksource);
947 if (ret) {
948 dev_err(&cmt->pdev->dev, "ch%u: registration failed\n",
949 ch->index);
950 return ret;
951 }
952 ch->cs_enabled = false;
953
954 return 0;
955}
956
957static int sh_cmt_map_memory(struct sh_cmt_device *cmt)
958{
959 struct resource *mem;
960
961 mem = platform_get_resource(cmt->pdev, IORESOURCE_MEM, 0);
962 if (!mem) {
963 dev_err(&cmt->pdev->dev, "failed to get I/O memory\n");
964 return -ENXIO;
965 }
966
967 cmt->mapbase = ioremap(offset: mem->start, size: resource_size(res: mem));
968 if (cmt->mapbase == NULL) {
969 dev_err(&cmt->pdev->dev, "failed to remap I/O memory\n");
970 return -ENXIO;
971 }
972
973 return 0;
974}
975
976static const struct platform_device_id sh_cmt_id_table[] = {
977 { "sh-cmt-16", (kernel_ulong_t)&sh_cmt_info[SH_CMT_16BIT] },
978 { "sh-cmt-32", (kernel_ulong_t)&sh_cmt_info[SH_CMT_32BIT] },
979 { }
980};
981MODULE_DEVICE_TABLE(platform, sh_cmt_id_table);
982
983static const struct of_device_id sh_cmt_of_table[] __maybe_unused = {
984 {
985 /* deprecated, preserved for backward compatibility */
986 .compatible = "renesas,cmt-48",
987 .data = &sh_cmt_info[SH_CMT_48BIT]
988 },
989 {
990 /* deprecated, preserved for backward compatibility */
991 .compatible = "renesas,cmt-48-gen2",
992 .data = &sh_cmt_info[SH_CMT0_RCAR_GEN2]
993 },
994 {
995 .compatible = "renesas,r8a7740-cmt1",
996 .data = &sh_cmt_info[SH_CMT_48BIT]
997 },
998 {
999 .compatible = "renesas,sh73a0-cmt1",
1000 .data = &sh_cmt_info[SH_CMT_48BIT]
1001 },
1002 {
1003 .compatible = "renesas,rcar-gen2-cmt0",
1004 .data = &sh_cmt_info[SH_CMT0_RCAR_GEN2]
1005 },
1006 {
1007 .compatible = "renesas,rcar-gen2-cmt1",
1008 .data = &sh_cmt_info[SH_CMT1_RCAR_GEN2]
1009 },
1010 {
1011 .compatible = "renesas,rcar-gen3-cmt0",
1012 .data = &sh_cmt_info[SH_CMT0_RCAR_GEN2]
1013 },
1014 {
1015 .compatible = "renesas,rcar-gen3-cmt1",
1016 .data = &sh_cmt_info[SH_CMT1_RCAR_GEN2]
1017 },
1018 {
1019 .compatible = "renesas,rcar-gen4-cmt0",
1020 .data = &sh_cmt_info[SH_CMT0_RCAR_GEN2]
1021 },
1022 {
1023 .compatible = "renesas,rcar-gen4-cmt1",
1024 .data = &sh_cmt_info[SH_CMT1_RCAR_GEN2]
1025 },
1026 { }
1027};
1028MODULE_DEVICE_TABLE(of, sh_cmt_of_table);
1029
1030static int sh_cmt_setup(struct sh_cmt_device *cmt, struct platform_device *pdev)
1031{
1032 unsigned int mask, i;
1033 unsigned long rate;
1034 int ret;
1035
1036 cmt->pdev = pdev;
1037 raw_spin_lock_init(&cmt->lock);
1038
1039 if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node) {
1040 cmt->info = of_device_get_match_data(dev: &pdev->dev);
1041 cmt->hw_channels = cmt->info->channels_mask;
1042 } else if (pdev->dev.platform_data) {
1043 struct sh_timer_config *cfg = pdev->dev.platform_data;
1044 const struct platform_device_id *id = pdev->id_entry;
1045
1046 cmt->info = (const struct sh_cmt_info *)id->driver_data;
1047 cmt->hw_channels = cfg->channels_mask;
1048 } else {
1049 dev_err(&cmt->pdev->dev, "missing platform data\n");
1050 return -ENXIO;
1051 }
1052
1053 /* Get hold of clock. */
1054 cmt->clk = clk_get(dev: &cmt->pdev->dev, id: "fck");
1055 if (IS_ERR(ptr: cmt->clk)) {
1056 dev_err(&cmt->pdev->dev, "cannot get clock\n");
1057 return PTR_ERR(ptr: cmt->clk);
1058 }
1059
1060 ret = clk_prepare(clk: cmt->clk);
1061 if (ret < 0)
1062 goto err_clk_put;
1063
1064 /* Determine clock rate. */
1065 ret = clk_enable(clk: cmt->clk);
1066 if (ret < 0)
1067 goto err_clk_unprepare;
1068
1069 rate = clk_get_rate(clk: cmt->clk);
1070 if (!rate) {
1071 ret = -EINVAL;
1072 goto err_clk_disable;
1073 }
1074
1075 /* We shall wait 2 input clks after register writes */
1076 if (cmt->info->model >= SH_CMT_48BIT)
1077 cmt->reg_delay = DIV_ROUND_UP(2UL * USEC_PER_SEC, rate);
1078 cmt->rate = rate / (cmt->info->width == 16 ? 512 : 8);
1079
1080 /* Map the memory resource(s). */
1081 ret = sh_cmt_map_memory(cmt);
1082 if (ret < 0)
1083 goto err_clk_disable;
1084
1085 /* Allocate and setup the channels. */
1086 cmt->num_channels = hweight8(cmt->hw_channels);
1087 cmt->channels = kcalloc(cmt->num_channels, sizeof(*cmt->channels),
1088 GFP_KERNEL);
1089 if (cmt->channels == NULL) {
1090 ret = -ENOMEM;
1091 goto err_unmap;
1092 }
1093
1094 /*
1095 * Use the first channel as a clock event device and the second channel
1096 * as a clock source. If only one channel is available use it for both.
1097 */
1098 for (i = 0, mask = cmt->hw_channels; i < cmt->num_channels; ++i) {
1099 unsigned int hwidx = ffs(mask) - 1;
1100 bool clocksource = i == 1 || cmt->num_channels == 1;
1101 bool clockevent = i == 0;
1102
1103 ret = sh_cmt_setup_channel(ch: &cmt->channels[i], index: i, hwidx,
1104 clockevent, clocksource, cmt);
1105 if (ret < 0)
1106 goto err_unmap;
1107
1108 mask &= ~(1 << hwidx);
1109 }
1110
1111 platform_set_drvdata(pdev, data: cmt);
1112
1113 return 0;
1114
1115err_unmap:
1116 kfree(objp: cmt->channels);
1117 iounmap(addr: cmt->mapbase);
1118err_clk_disable:
1119 clk_disable(clk: cmt->clk);
1120err_clk_unprepare:
1121 clk_unprepare(clk: cmt->clk);
1122err_clk_put:
1123 clk_put(clk: cmt->clk);
1124 return ret;
1125}
1126
1127static int sh_cmt_probe(struct platform_device *pdev)
1128{
1129 struct sh_cmt_device *cmt = platform_get_drvdata(pdev);
1130 int ret;
1131
1132 if (!is_sh_early_platform_device(pdev)) {
1133 pm_runtime_set_active(dev: &pdev->dev);
1134 pm_runtime_enable(dev: &pdev->dev);
1135 }
1136
1137 if (cmt) {
1138 dev_info(&pdev->dev, "kept as earlytimer\n");
1139 goto out;
1140 }
1141
1142 cmt = kzalloc(sizeof(*cmt), GFP_KERNEL);
1143 if (cmt == NULL)
1144 return -ENOMEM;
1145
1146 ret = sh_cmt_setup(cmt, pdev);
1147 if (ret) {
1148 kfree(objp: cmt);
1149 pm_runtime_idle(dev: &pdev->dev);
1150 return ret;
1151 }
1152 if (is_sh_early_platform_device(pdev))
1153 return 0;
1154
1155 out:
1156 if (cmt->has_clockevent || cmt->has_clocksource)
1157 pm_runtime_irq_safe(dev: &pdev->dev);
1158
1159 return 0;
1160}
1161
1162static struct platform_driver sh_cmt_device_driver = {
1163 .probe = sh_cmt_probe,
1164 .driver = {
1165 .name = "sh_cmt",
1166 .of_match_table = of_match_ptr(sh_cmt_of_table),
1167 .suppress_bind_attrs = true,
1168 },
1169 .id_table = sh_cmt_id_table,
1170};
1171
1172static int __init sh_cmt_init(void)
1173{
1174 return platform_driver_register(&sh_cmt_device_driver);
1175}
1176
1177static void __exit sh_cmt_exit(void)
1178{
1179 platform_driver_unregister(&sh_cmt_device_driver);
1180}
1181
1182#ifdef CONFIG_SUPERH
1183sh_early_platform_init("earlytimer", &sh_cmt_device_driver);
1184#endif
1185
1186subsys_initcall(sh_cmt_init);
1187module_exit(sh_cmt_exit);
1188
1189MODULE_AUTHOR("Magnus Damm");
1190MODULE_DESCRIPTION("SuperH CMT Timer Driver");
1191

source code of linux/drivers/clocksource/sh_cmt.c