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Merge tag 'block-5.11-2021-01-10' of git://git.kernel.dk/linux-block
[linux/fpc-iii.git] / drivers / clocksource / sh_cmt.c
blobe258230d432c00029acf930bc4dbd803b948e04a
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/ioport.h>
17 #include <linux/irq.h>
18 #include <linux/module.h>
19 #include <linux/of.h>
20 #include <linux/of_device.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
32 struct 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
63 enum 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
71 struct 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
90 struct 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
111 struct 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
120 raw_spinlock_t lock; /* Protect the shared start/stop register */
121
122 struct sh_cmt_channel *channels;
123 unsigned int num_channels;
124 unsigned int hw_channels;
125
126 bool has_clockevent;
127 bool has_clocksource;
128 };
129
130 #define SH_CMT16_CMCSR_CMF (1 << 7)
131 #define SH_CMT16_CMCSR_CMIE (1 << 6)
132 #define SH_CMT16_CMCSR_CKS8 (0 << 0)
133 #define SH_CMT16_CMCSR_CKS32 (1 << 0)
134 #define SH_CMT16_CMCSR_CKS128 (2 << 0)
135 #define SH_CMT16_CMCSR_CKS512 (3 << 0)
136 #define SH_CMT16_CMCSR_CKS_MASK (3 << 0)
137
138 #define SH_CMT32_CMCSR_CMF (1 << 15)
139 #define SH_CMT32_CMCSR_OVF (1 << 14)
140 #define SH_CMT32_CMCSR_WRFLG (1 << 13)
141 #define SH_CMT32_CMCSR_STTF (1 << 12)
142 #define SH_CMT32_CMCSR_STPF (1 << 11)
143 #define SH_CMT32_CMCSR_SSIE (1 << 10)
144 #define SH_CMT32_CMCSR_CMS (1 << 9)
145 #define SH_CMT32_CMCSR_CMM (1 << 8)
146 #define SH_CMT32_CMCSR_CMTOUT_IE (1 << 7)
147 #define SH_CMT32_CMCSR_CMR_NONE (0 << 4)
148 #define SH_CMT32_CMCSR_CMR_DMA (1 << 4)
149 #define SH_CMT32_CMCSR_CMR_IRQ (2 << 4)
150 #define SH_CMT32_CMCSR_CMR_MASK (3 << 4)
151 #define SH_CMT32_CMCSR_DBGIVD (1 << 3)
152 #define SH_CMT32_CMCSR_CKS_RCLK8 (4 << 0)
153 #define SH_CMT32_CMCSR_CKS_RCLK32 (5 << 0)
154 #define SH_CMT32_CMCSR_CKS_RCLK128 (6 << 0)
155 #define SH_CMT32_CMCSR_CKS_RCLK1 (7 << 0)
156 #define SH_CMT32_CMCSR_CKS_MASK (7 << 0)
157
158 static u32 sh_cmt_read16(void __iomem *base, unsigned long offs)
159 {
160 return ioread16(base + (offs << 1));
161 }
162
163 static u32 sh_cmt_read32(void __iomem *base, unsigned long offs)
164 {
165 return ioread32(base + (offs << 2));
166 }
167
168 static void sh_cmt_write16(void __iomem *base, unsigned long offs, u32 value)
169 {
170 iowrite16(value, base + (offs << 1));
171 }
172
173 static void sh_cmt_write32(void __iomem *base, unsigned long offs, u32 value)
174 {
175 iowrite32(value, base + (offs << 2));
176 }
177
178 static const struct sh_cmt_info sh_cmt_info[] = {
179 [SH_CMT_16BIT] = {
180 .model = SH_CMT_16BIT,
181 .width = 16,
182 .overflow_bit = SH_CMT16_CMCSR_CMF,
183 .clear_bits = ~SH_CMT16_CMCSR_CMF,
184 .read_control = sh_cmt_read16,
185 .write_control = sh_cmt_write16,
186 .read_count = sh_cmt_read16,
187 .write_count = sh_cmt_write16,
188 },
189 [SH_CMT_32BIT] = {
190 .model = SH_CMT_32BIT,
191 .width = 32,
192 .overflow_bit = SH_CMT32_CMCSR_CMF,
193 .clear_bits = ~(SH_CMT32_CMCSR_CMF | SH_CMT32_CMCSR_OVF),
194 .read_control = sh_cmt_read16,
195 .write_control = sh_cmt_write16,
196 .read_count = sh_cmt_read32,
197 .write_count = sh_cmt_write32,
198 },
199 [SH_CMT_48BIT] = {
200 .model = SH_CMT_48BIT,
201 .channels_mask = 0x3f,
202 .width = 32,
203 .overflow_bit = SH_CMT32_CMCSR_CMF,
204 .clear_bits = ~(SH_CMT32_CMCSR_CMF | SH_CMT32_CMCSR_OVF),
205 .read_control = sh_cmt_read32,
206 .write_control = sh_cmt_write32,
207 .read_count = sh_cmt_read32,
208 .write_count = sh_cmt_write32,
209 },
210 [SH_CMT0_RCAR_GEN2] = {
211 .model = SH_CMT0_RCAR_GEN2,
212 .channels_mask = 0x60,
213 .width = 32,
214 .overflow_bit = SH_CMT32_CMCSR_CMF,
215 .clear_bits = ~(SH_CMT32_CMCSR_CMF | SH_CMT32_CMCSR_OVF),
216 .read_control = sh_cmt_read32,
217 .write_control = sh_cmt_write32,
218 .read_count = sh_cmt_read32,
219 .write_count = sh_cmt_write32,
220 },
221 [SH_CMT1_RCAR_GEN2] = {
222 .model = SH_CMT1_RCAR_GEN2,
223 .channels_mask = 0xff,
224 .width = 32,
225 .overflow_bit = SH_CMT32_CMCSR_CMF,
226 .clear_bits = ~(SH_CMT32_CMCSR_CMF | SH_CMT32_CMCSR_OVF),
227 .read_control = sh_cmt_read32,
228 .write_control = sh_cmt_write32,
229 .read_count = sh_cmt_read32,
230 .write_count = sh_cmt_write32,
231 },
232 };
233
234 #define CMCSR 0 /* channel register */
235 #define CMCNT 1 /* channel register */
236 #define CMCOR 2 /* channel register */
237
238 static inline u32 sh_cmt_read_cmstr(struct sh_cmt_channel *ch)
239 {
240 if (ch->iostart)
241 return ch->cmt->info->read_control(ch->iostart, 0);
242 else
243 return ch->cmt->info->read_control(ch->cmt->mapbase, 0);
244 }
245
246 static inline void sh_cmt_write_cmstr(struct sh_cmt_channel *ch, u32 value)
247 {
248 if (ch->iostart)
249 ch->cmt->info->write_control(ch->iostart, 0, value);
250 else
251 ch->cmt->info->write_control(ch->cmt->mapbase, 0, value);
252 }
253
254 static inline u32 sh_cmt_read_cmcsr(struct sh_cmt_channel *ch)
255 {
256 return ch->cmt->info->read_control(ch->ioctrl, CMCSR);
257 }
258
259 static inline void sh_cmt_write_cmcsr(struct sh_cmt_channel *ch, u32 value)
260 {
261 ch->cmt->info->write_control(ch->ioctrl, CMCSR, value);
262 }
263
264 static inline u32 sh_cmt_read_cmcnt(struct sh_cmt_channel *ch)
265 {
266 return ch->cmt->info->read_count(ch->ioctrl, CMCNT);
267 }
268
269 static inline void sh_cmt_write_cmcnt(struct sh_cmt_channel *ch, u32 value)
270 {
271 ch->cmt->info->write_count(ch->ioctrl, CMCNT, value);
272 }
273
274 static inline void sh_cmt_write_cmcor(struct sh_cmt_channel *ch, u32 value)
275 {
276 ch->cmt->info->write_count(ch->ioctrl, CMCOR, value);
277 }
278
279 static u32 sh_cmt_get_counter(struct sh_cmt_channel *ch, u32 *has_wrapped)
280 {
281 u32 v1, v2, v3;
282 u32 o1, o2;
283
284 o1 = sh_cmt_read_cmcsr(ch) & ch->cmt->info->overflow_bit;
285
286 /* Make sure the timer value is stable. Stolen from acpi_pm.c */
287 do {
288 o2 = o1;
289 v1 = sh_cmt_read_cmcnt(ch);
290 v2 = sh_cmt_read_cmcnt(ch);
291 v3 = sh_cmt_read_cmcnt(ch);
292 o1 = sh_cmt_read_cmcsr(ch) & ch->cmt->info->overflow_bit;
293 } while (unlikely((o1 != o2) || (v1 > v2 && v1 < v3)
294 || (v2 > v3 && v2 < v1) || (v3 > v1 && v3 < v2)));
295
296 *has_wrapped = o1;
297 return v2;
298 }
299
300 static void sh_cmt_start_stop_ch(struct sh_cmt_channel *ch, int start)
301 {
302 unsigned long flags;
303 u32 value;
304
305 /* start stop register shared by multiple timer channels */
306 raw_spin_lock_irqsave(&ch->cmt->lock, flags);
307 value = sh_cmt_read_cmstr(ch);
308
309 if (start)
310 value |= 1 << ch->timer_bit;
311 else
312 value &= ~(1 << ch->timer_bit);
313
314 sh_cmt_write_cmstr(ch, value);
315 raw_spin_unlock_irqrestore(&ch->cmt->lock, flags);
316 }
317
318 static int sh_cmt_enable(struct sh_cmt_channel *ch)
319 {
320 int k, ret;
321
322 dev_pm_syscore_device(&ch->cmt->pdev->dev, true);
323
324 /* enable clock */
325 ret = clk_enable(ch->cmt->clk);
326 if (ret) {
327 dev_err(&ch->cmt->pdev->dev, "ch%u: cannot enable clock\n",
328 ch->index);
329 goto err0;
330 }
331
332 /* make sure channel is disabled */
333 sh_cmt_start_stop_ch(ch, 0);
334
335 /* configure channel, periodic mode and maximum timeout */
336 if (ch->cmt->info->width == 16) {
337 sh_cmt_write_cmcsr(ch, SH_CMT16_CMCSR_CMIE |
338 SH_CMT16_CMCSR_CKS512);
339 } else {
340 sh_cmt_write_cmcsr(ch, SH_CMT32_CMCSR_CMM |
341 SH_CMT32_CMCSR_CMTOUT_IE |
342 SH_CMT32_CMCSR_CMR_IRQ |
343 SH_CMT32_CMCSR_CKS_RCLK8);
344 }
345
346 sh_cmt_write_cmcor(ch, 0xffffffff);
347 sh_cmt_write_cmcnt(ch, 0);
348
349 /*
350 * According to the sh73a0 user's manual, as CMCNT can be operated
351 * only by the RCLK (Pseudo 32 kHz), there's one restriction on
352 * modifying CMCNT register; two RCLK cycles are necessary before
353 * this register is either read or any modification of the value
354 * it holds is reflected in the LSI's actual operation.
355 *
356 * While at it, we're supposed to clear out the CMCNT as of this
357 * moment, so make sure it's processed properly here. This will
358 * take RCLKx2 at maximum.
359 */
360 for (k = 0; k < 100; k++) {
361 if (!sh_cmt_read_cmcnt(ch))
362 break;
363 udelay(1);
364 }
365
366 if (sh_cmt_read_cmcnt(ch)) {
367 dev_err(&ch->cmt->pdev->dev, "ch%u: cannot clear CMCNT\n",
368 ch->index);
369 ret = -ETIMEDOUT;
370 goto err1;
371 }
372
373 /* enable channel */
374 sh_cmt_start_stop_ch(ch, 1);
375 return 0;
376 err1:
377 /* stop clock */
378 clk_disable(ch->cmt->clk);
379
380 err0:
381 return ret;
382 }
383
384 static void sh_cmt_disable(struct sh_cmt_channel *ch)
385 {
386 /* disable channel */
387 sh_cmt_start_stop_ch(ch, 0);
388
389 /* disable interrupts in CMT block */
390 sh_cmt_write_cmcsr(ch, 0);
391
392 /* stop clock */
393 clk_disable(ch->cmt->clk);
394
395 dev_pm_syscore_device(&ch->cmt->pdev->dev, 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
405 static 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);
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, new_match);
438
439 now = sh_cmt_get_counter(ch, &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
491 static 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, 0);
499 }
500
501 static 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
510 static irqreturn_t sh_cmt_interrupt(int irq, void *dev_id)
511 {
512 struct sh_cmt_channel *ch = dev_id;
513
514 /* clear flags */
515 sh_cmt_write_cmcsr(ch, sh_cmt_read_cmcsr(ch) &
516 ch->cmt->info->clear_bits);
517
518 /* update clock source counter to begin with if enabled
519 * the wrap flag should be cleared by the timer specific
520 * isr before we end up here.
521 */
522 if (ch->flags & FLAG_CLOCKSOURCE)
523 ch->total_cycles += ch->match_value + 1;
524
525 if (!(ch->flags & FLAG_REPROGRAM))
526 ch->next_match_value = ch->max_match_value;
527
528 ch->flags |= FLAG_IRQCONTEXT;
529
530 if (ch->flags & FLAG_CLOCKEVENT) {
531 if (!(ch->flags & FLAG_SKIPEVENT)) {
532 if (clockevent_state_oneshot(&ch->ced)) {
533 ch->next_match_value = ch->max_match_value;
534 ch->flags |= FLAG_REPROGRAM;
535 }
536
537 ch->ced.event_handler(&ch->ced);
538 }
539 }
540
541 ch->flags &= ~FLAG_SKIPEVENT;
542
543 if (ch->flags & FLAG_REPROGRAM) {
544 ch->flags &= ~FLAG_REPROGRAM;
545 sh_cmt_clock_event_program_verify(ch, 1);
546
547 if (ch->flags & FLAG_CLOCKEVENT)
548 if ((clockevent_state_shutdown(&ch->ced))
549 || (ch->match_value == ch->next_match_value))
550 ch->flags &= ~FLAG_REPROGRAM;
551 }
552
553 ch->flags &= ~FLAG_IRQCONTEXT;
554
555 return IRQ_HANDLED;
556 }
557
558 static int sh_cmt_start(struct sh_cmt_channel *ch, unsigned long flag)
559 {
560 int ret = 0;
561 unsigned long flags;
562
563 if (flag & FLAG_CLOCKSOURCE)
564 pm_runtime_get_sync(&ch->cmt->pdev->dev);
565
566 raw_spin_lock_irqsave(&ch->lock, flags);
567
568 if (!(ch->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE))) {
569 if (flag & FLAG_CLOCKEVENT)
570 pm_runtime_get_sync(&ch->cmt->pdev->dev);
571 ret = sh_cmt_enable(ch);
572 }
573
574 if (ret)
575 goto out;
576 ch->flags |= flag;
577
578 /* setup timeout if no clockevent */
579 if ((flag == FLAG_CLOCKSOURCE) && (!(ch->flags & FLAG_CLOCKEVENT)))
580 __sh_cmt_set_next(ch, ch->max_match_value);
581 out:
582 raw_spin_unlock_irqrestore(&ch->lock, flags);
583
584 return ret;
585 }
586
587 static void sh_cmt_stop(struct sh_cmt_channel *ch, unsigned long flag)
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 ch->flags &= ~flag;
596
597 if (f && !(ch->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE))) {
598 sh_cmt_disable(ch);
599 if (flag & FLAG_CLOCKEVENT)
600 pm_runtime_put(&ch->cmt->pdev->dev);
601 }
602
603 /* adjust the timeout to maximum if only clocksource left */
604 if ((flag == FLAG_CLOCKEVENT) && (ch->flags & FLAG_CLOCKSOURCE))
605 __sh_cmt_set_next(ch, ch->max_match_value);
606
607 raw_spin_unlock_irqrestore(&ch->lock, flags);
608
609 if (flag & FLAG_CLOCKSOURCE)
610 pm_runtime_put(&ch->cmt->pdev->dev);
611 }
612
613 static struct sh_cmt_channel *cs_to_sh_cmt(struct clocksource *cs)
614 {
615 return container_of(cs, struct sh_cmt_channel, cs);
616 }
617
618 static u64 sh_cmt_clocksource_read(struct clocksource *cs)
619 {
620 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs);
621 unsigned long flags;
622 u32 has_wrapped;
623 u64 value;
624 u32 raw;
625
626 raw_spin_lock_irqsave(&ch->lock, flags);
627 value = ch->total_cycles;
628 raw = sh_cmt_get_counter(ch, &has_wrapped);
629
630 if (unlikely(has_wrapped))
631 raw += ch->match_value + 1;
632 raw_spin_unlock_irqrestore(&ch->lock, flags);
633
634 return value + raw;
635 }
636
637 static int sh_cmt_clocksource_enable(struct clocksource *cs)
638 {
639 int ret;
640 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs);
641
642 WARN_ON(ch->cs_enabled);
643
644 ch->total_cycles = 0;
645
646 ret = sh_cmt_start(ch, FLAG_CLOCKSOURCE);
647 if (!ret)
648 ch->cs_enabled = true;
649
650 return ret;
651 }
652
653 static void sh_cmt_clocksource_disable(struct clocksource *cs)
654 {
655 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs);
656
657 WARN_ON(!ch->cs_enabled);
658
659 sh_cmt_stop(ch, FLAG_CLOCKSOURCE);
660 ch->cs_enabled = false;
661 }
662
663 static void sh_cmt_clocksource_suspend(struct clocksource *cs)
664 {
665 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs);
666
667 if (!ch->cs_enabled)
668 return;
669
670 sh_cmt_stop(ch, FLAG_CLOCKSOURCE);
671 dev_pm_genpd_suspend(&ch->cmt->pdev->dev);
672 }
673
674 static void sh_cmt_clocksource_resume(struct clocksource *cs)
675 {
676 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs);
677
678 if (!ch->cs_enabled)
679 return;
680
681 dev_pm_genpd_resume(&ch->cmt->pdev->dev);
682 sh_cmt_start(ch, FLAG_CLOCKSOURCE);
683 }
684
685 static int sh_cmt_register_clocksource(struct sh_cmt_channel *ch,
686 const char *name)
687 {
688 struct clocksource *cs = &ch->cs;
689
690 cs->name = name;
691 cs->rating = 125;
692 cs->read = sh_cmt_clocksource_read;
693 cs->enable = sh_cmt_clocksource_enable;
694 cs->disable = sh_cmt_clocksource_disable;
695 cs->suspend = sh_cmt_clocksource_suspend;
696 cs->resume = sh_cmt_clocksource_resume;
697 cs->mask = CLOCKSOURCE_MASK(sizeof(u64) * 8);
698 cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
699
700 dev_info(&ch->cmt->pdev->dev, "ch%u: used as clock source\n",
701 ch->index);
702
703 clocksource_register_hz(cs, ch->cmt->rate);
704 return 0;
705 }
706
707 static struct sh_cmt_channel *ced_to_sh_cmt(struct clock_event_device *ced)
708 {
709 return container_of(ced, struct sh_cmt_channel, ced);
710 }
711
712 static void sh_cmt_clock_event_start(struct sh_cmt_channel *ch, int periodic)
713 {
714 sh_cmt_start(ch, FLAG_CLOCKEVENT);
715
716 if (periodic)
717 sh_cmt_set_next(ch, ((ch->cmt->rate + HZ/2) / HZ) - 1);
718 else
719 sh_cmt_set_next(ch, ch->max_match_value);
720 }
721
722 static int sh_cmt_clock_event_shutdown(struct clock_event_device *ced)
723 {
724 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced);
725
726 sh_cmt_stop(ch, FLAG_CLOCKEVENT);
727 return 0;
728 }
729
730 static int sh_cmt_clock_event_set_state(struct clock_event_device *ced,
731 int periodic)
732 {
733 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced);
734
735 /* deal with old setting first */
736 if (clockevent_state_oneshot(ced) || clockevent_state_periodic(ced))
737 sh_cmt_stop(ch, FLAG_CLOCKEVENT);
738
739 dev_info(&ch->cmt->pdev->dev, "ch%u: used for %s clock events\n",
740 ch->index, periodic ? "periodic" : "oneshot");
741 sh_cmt_clock_event_start(ch, periodic);
742 return 0;
743 }
744
745 static int sh_cmt_clock_event_set_oneshot(struct clock_event_device *ced)
746 {
747 return sh_cmt_clock_event_set_state(ced, 0);
748 }
749
750 static int sh_cmt_clock_event_set_periodic(struct clock_event_device *ced)
751 {
752 return sh_cmt_clock_event_set_state(ced, 1);
753 }
754
755 static int sh_cmt_clock_event_next(unsigned long delta,
756 struct clock_event_device *ced)
757 {
758 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced);
759
760 BUG_ON(!clockevent_state_oneshot(ced));
761 if (likely(ch->flags & FLAG_IRQCONTEXT))
762 ch->next_match_value = delta - 1;
763 else
764 sh_cmt_set_next(ch, delta - 1);
765
766 return 0;
767 }
768
769 static void sh_cmt_clock_event_suspend(struct clock_event_device *ced)
770 {
771 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced);
772
773 dev_pm_genpd_suspend(&ch->cmt->pdev->dev);
774 clk_unprepare(ch->cmt->clk);
775 }
776
777 static void sh_cmt_clock_event_resume(struct clock_event_device *ced)
778 {
779 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced);
780
781 clk_prepare(ch->cmt->clk);
782 dev_pm_genpd_resume(&ch->cmt->pdev->dev);
783 }
784
785 static int sh_cmt_register_clockevent(struct sh_cmt_channel *ch,
786 const char *name)
787 {
788 struct clock_event_device *ced = &ch->ced;
789 int irq;
790 int ret;
791
792 irq = platform_get_irq(ch->cmt->pdev, ch->index);
793 if (irq < 0)
794 return irq;
795
796 ret = request_irq(irq, sh_cmt_interrupt,
797 IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING,
798 dev_name(&ch->cmt->pdev->dev), ch);
799 if (ret) {
800 dev_err(&ch->cmt->pdev->dev, "ch%u: failed to request irq %d\n",
801 ch->index, irq);
802 return ret;
803 }
804
805 ced->name = name;
806 ced->features = CLOCK_EVT_FEAT_PERIODIC;
807 ced->features |= CLOCK_EVT_FEAT_ONESHOT;
808 ced->rating = 125;
809 ced->cpumask = cpu_possible_mask;
810 ced->set_next_event = sh_cmt_clock_event_next;
811 ced->set_state_shutdown = sh_cmt_clock_event_shutdown;
812 ced->set_state_periodic = sh_cmt_clock_event_set_periodic;
813 ced->set_state_oneshot = sh_cmt_clock_event_set_oneshot;
814 ced->suspend = sh_cmt_clock_event_suspend;
815 ced->resume = sh_cmt_clock_event_resume;
816
817 /* TODO: calculate good shift from rate and counter bit width */
818 ced->shift = 32;
819 ced->mult = div_sc(ch->cmt->rate, NSEC_PER_SEC, ced->shift);
820 ced->max_delta_ns = clockevent_delta2ns(ch->max_match_value, ced);
821 ced->max_delta_ticks = ch->max_match_value;
822 ced->min_delta_ns = clockevent_delta2ns(0x1f, ced);
823 ced->min_delta_ticks = 0x1f;
824
825 dev_info(&ch->cmt->pdev->dev, "ch%u: used for clock events\n",
826 ch->index);
827 clockevents_register_device(ced);
828
829 return 0;
830 }
831
832 static int sh_cmt_register(struct sh_cmt_channel *ch, const char *name,
833 bool clockevent, bool clocksource)
834 {
835 int ret;
836
837 if (clockevent) {
838 ch->cmt->has_clockevent = true;
839 ret = sh_cmt_register_clockevent(ch, name);
840 if (ret < 0)
841 return ret;
842 }
843
844 if (clocksource) {
845 ch->cmt->has_clocksource = true;
846 sh_cmt_register_clocksource(ch, name);
847 }
848
849 return 0;
850 }
851
852 static int sh_cmt_setup_channel(struct sh_cmt_channel *ch, unsigned int index,
853 unsigned int hwidx, bool clockevent,
854 bool clocksource, struct sh_cmt_device *cmt)
855 {
856 int ret;
857
858 /* Skip unused channels. */
859 if (!clockevent && !clocksource)
860 return 0;
861
862 ch->cmt = cmt;
863 ch->index = index;
864 ch->hwidx = hwidx;
865 ch->timer_bit = hwidx;
866
867 /*
868 * Compute the address of the channel control register block. For the
869 * timers with a per-channel start/stop register, compute its address
870 * as well.
871 */
872 switch (cmt->info->model) {
873 case SH_CMT_16BIT:
874 ch->ioctrl = cmt->mapbase + 2 + ch->hwidx * 6;
875 break;
876 case SH_CMT_32BIT:
877 case SH_CMT_48BIT:
878 ch->ioctrl = cmt->mapbase + 0x10 + ch->hwidx * 0x10;
879 break;
880 case SH_CMT0_RCAR_GEN2:
881 case SH_CMT1_RCAR_GEN2:
882 ch->iostart = cmt->mapbase + ch->hwidx * 0x100;
883 ch->ioctrl = ch->iostart + 0x10;
884 ch->timer_bit = 0;
885 break;
886 }
887
888 if (cmt->info->width == (sizeof(ch->max_match_value) * 8))
889 ch->max_match_value = ~0;
890 else
891 ch->max_match_value = (1 << cmt->info->width) - 1;
892
893 ch->match_value = ch->max_match_value;
894 raw_spin_lock_init(&ch->lock);
895
896 ret = sh_cmt_register(ch, dev_name(&cmt->pdev->dev),
897 clockevent, clocksource);
898 if (ret) {
899 dev_err(&cmt->pdev->dev, "ch%u: registration failed\n",
900 ch->index);
901 return ret;
902 }
903 ch->cs_enabled = false;
904
905 return 0;
906 }
907
908 static int sh_cmt_map_memory(struct sh_cmt_device *cmt)
909 {
910 struct resource *mem;
911
912 mem = platform_get_resource(cmt->pdev, IORESOURCE_MEM, 0);
913 if (!mem) {
914 dev_err(&cmt->pdev->dev, "failed to get I/O memory\n");
915 return -ENXIO;
916 }
917
918 cmt->mapbase = ioremap(mem->start, resource_size(mem));
919 if (cmt->mapbase == NULL) {
920 dev_err(&cmt->pdev->dev, "failed to remap I/O memory\n");
921 return -ENXIO;
922 }
923
924 return 0;
925 }
926
927 static const struct platform_device_id sh_cmt_id_table[] = {
928 { "sh-cmt-16", (kernel_ulong_t)&sh_cmt_info[SH_CMT_16BIT] },
929 { "sh-cmt-32", (kernel_ulong_t)&sh_cmt_info[SH_CMT_32BIT] },
930 { }
931 };
932 MODULE_DEVICE_TABLE(platform, sh_cmt_id_table);
933
934 static const struct of_device_id sh_cmt_of_table[] __maybe_unused = {
935 {
936 /* deprecated, preserved for backward compatibility */
937 .compatible = "renesas,cmt-48",
938 .data = &sh_cmt_info[SH_CMT_48BIT]
939 },
940 {
941 /* deprecated, preserved for backward compatibility */
942 .compatible = "renesas,cmt-48-gen2",
943 .data = &sh_cmt_info[SH_CMT0_RCAR_GEN2]
944 },
945 {
946 .compatible = "renesas,r8a7740-cmt1",
947 .data = &sh_cmt_info[SH_CMT_48BIT]
948 },
949 {
950 .compatible = "renesas,sh73a0-cmt1",
951 .data = &sh_cmt_info[SH_CMT_48BIT]
952 },
953 {
954 .compatible = "renesas,rcar-gen2-cmt0",
955 .data = &sh_cmt_info[SH_CMT0_RCAR_GEN2]
956 },
957 {
958 .compatible = "renesas,rcar-gen2-cmt1",
959 .data = &sh_cmt_info[SH_CMT1_RCAR_GEN2]
960 },
961 {
962 .compatible = "renesas,rcar-gen3-cmt0",
963 .data = &sh_cmt_info[SH_CMT0_RCAR_GEN2]
964 },
965 {
966 .compatible = "renesas,rcar-gen3-cmt1",
967 .data = &sh_cmt_info[SH_CMT1_RCAR_GEN2]
968 },
969 { }
970 };
971 MODULE_DEVICE_TABLE(of, sh_cmt_of_table);
972
973 static int sh_cmt_setup(struct sh_cmt_device *cmt, struct platform_device *pdev)
974 {
975 unsigned int mask;
976 unsigned int i;
977 int ret;
978
979 cmt->pdev = pdev;
980 raw_spin_lock_init(&cmt->lock);
981
982 if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node) {
983 cmt->info = of_device_get_match_data(&pdev->dev);
984 cmt->hw_channels = cmt->info->channels_mask;
985 } else if (pdev->dev.platform_data) {
986 struct sh_timer_config *cfg = pdev->dev.platform_data;
987 const struct platform_device_id *id = pdev->id_entry;
988
989 cmt->info = (const struct sh_cmt_info *)id->driver_data;
990 cmt->hw_channels = cfg->channels_mask;
991 } else {
992 dev_err(&cmt->pdev->dev, "missing platform data\n");
993 return -ENXIO;
994 }
995
996 /* Get hold of clock. */
997 cmt->clk = clk_get(&cmt->pdev->dev, "fck");
998 if (IS_ERR(cmt->clk)) {
999 dev_err(&cmt->pdev->dev, "cannot get clock\n");
1000 return PTR_ERR(cmt->clk);
1001 }
1002
1003 ret = clk_prepare(cmt->clk);
1004 if (ret < 0)
1005 goto err_clk_put;
1006
1007 /* Determine clock rate. */
1008 ret = clk_enable(cmt->clk);
1009 if (ret < 0)
1010 goto err_clk_unprepare;
1011
1012 if (cmt->info->width == 16)
1013 cmt->rate = clk_get_rate(cmt->clk) / 512;
1014 else
1015 cmt->rate = clk_get_rate(cmt->clk) / 8;
1016
1017 clk_disable(cmt->clk);
1018
1019 /* Map the memory resource(s). */
1020 ret = sh_cmt_map_memory(cmt);
1021 if (ret < 0)
1022 goto err_clk_unprepare;
1023
1024 /* Allocate and setup the channels. */
1025 cmt->num_channels = hweight8(cmt->hw_channels);
1026 cmt->channels = kcalloc(cmt->num_channels, sizeof(*cmt->channels),
1027 GFP_KERNEL);
1028 if (cmt->channels == NULL) {
1029 ret = -ENOMEM;
1030 goto err_unmap;
1031 }
1032
1033 /*
1034 * Use the first channel as a clock event device and the second channel
1035 * as a clock source. If only one channel is available use it for both.
1036 */
1037 for (i = 0, mask = cmt->hw_channels; i < cmt->num_channels; ++i) {
1038 unsigned int hwidx = ffs(mask) - 1;
1039 bool clocksource = i == 1 || cmt->num_channels == 1;
1040 bool clockevent = i == 0;
1041
1042 ret = sh_cmt_setup_channel(&cmt->channels[i], i, hwidx,
1043 clockevent, clocksource, cmt);
1044 if (ret < 0)
1045 goto err_unmap;
1046
1047 mask &= ~(1 << hwidx);
1048 }
1049
1050 platform_set_drvdata(pdev, cmt);
1051
1052 return 0;
1053
1054 err_unmap:
1055 kfree(cmt->channels);
1056 iounmap(cmt->mapbase);
1057 err_clk_unprepare:
1058 clk_unprepare(cmt->clk);
1059 err_clk_put:
1060 clk_put(cmt->clk);
1061 return ret;
1062 }
1063
1064 static int sh_cmt_probe(struct platform_device *pdev)
1065 {
1066 struct sh_cmt_device *cmt = platform_get_drvdata(pdev);
1067 int ret;
1068
1069 if (!is_sh_early_platform_device(pdev)) {
1070 pm_runtime_set_active(&pdev->dev);
1071 pm_runtime_enable(&pdev->dev);
1072 }
1073
1074 if (cmt) {
1075 dev_info(&pdev->dev, "kept as earlytimer\n");
1076 goto out;
1077 }
1078
1079 cmt = kzalloc(sizeof(*cmt), GFP_KERNEL);
1080 if (cmt == NULL)
1081 return -ENOMEM;
1082
1083 ret = sh_cmt_setup(cmt, pdev);
1084 if (ret) {
1085 kfree(cmt);
1086 pm_runtime_idle(&pdev->dev);
1087 return ret;
1088 }
1089 if (is_sh_early_platform_device(pdev))
1090 return 0;
1091
1092 out:
1093 if (cmt->has_clockevent || cmt->has_clocksource)
1094 pm_runtime_irq_safe(&pdev->dev);
1095 else
1096 pm_runtime_idle(&pdev->dev);
1097
1098 return 0;
1099 }
1100
1101 static int sh_cmt_remove(struct platform_device *pdev)
1102 {
1103 return -EBUSY; /* cannot unregister clockevent and clocksource */
1104 }
1105
1106 static struct platform_driver sh_cmt_device_driver = {
1107 .probe = sh_cmt_probe,
1108 .remove = sh_cmt_remove,
1109 .driver = {
1110 .name = "sh_cmt",
1111 .of_match_table = of_match_ptr(sh_cmt_of_table),
1112 },
1113 .id_table = sh_cmt_id_table,
1114 };
1115
1116 static int __init sh_cmt_init(void)
1117 {
1118 return platform_driver_register(&sh_cmt_device_driver);
1119 }
1120
1121 static void __exit sh_cmt_exit(void)
1122 {
1123 platform_driver_unregister(&sh_cmt_device_driver);
1124 }
1125
1126 #ifdef CONFIG_SUPERH
1127 sh_early_platform_init("earlytimer", &sh_cmt_device_driver);
1128 #endif
1129
1130 subsys_initcall(sh_cmt_init);
1131 module_exit(sh_cmt_exit);
1132
1133 MODULE_AUTHOR("Magnus Damm");
1134 MODULE_DESCRIPTION("SuperH CMT Timer Driver");
1135 MODULE_LICENSE("GPL v2");
Linux with added FPC-III support