Merge tag 'trace-v4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux...
[deliverable/linux.git] / drivers / clocksource / exynos_mct.c
1 /* linux/arch/arm/mach-exynos4/mct.c
2 *
3 * Copyright (c) 2011 Samsung Electronics Co., Ltd.
4 * http://www.samsung.com
5 *
6 * EXYNOS4 MCT(Multi-Core Timer) support
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13 #include <linux/sched.h>
14 #include <linux/interrupt.h>
15 #include <linux/irq.h>
16 #include <linux/err.h>
17 #include <linux/clk.h>
18 #include <linux/clockchips.h>
19 #include <linux/cpu.h>
20 #include <linux/platform_device.h>
21 #include <linux/delay.h>
22 #include <linux/percpu.h>
23 #include <linux/of.h>
24 #include <linux/of_irq.h>
25 #include <linux/of_address.h>
26 #include <linux/clocksource.h>
27 #include <linux/sched_clock.h>
28
29 #define EXYNOS4_MCTREG(x) (x)
30 #define EXYNOS4_MCT_G_CNT_L EXYNOS4_MCTREG(0x100)
31 #define EXYNOS4_MCT_G_CNT_U EXYNOS4_MCTREG(0x104)
32 #define EXYNOS4_MCT_G_CNT_WSTAT EXYNOS4_MCTREG(0x110)
33 #define EXYNOS4_MCT_G_COMP0_L EXYNOS4_MCTREG(0x200)
34 #define EXYNOS4_MCT_G_COMP0_U EXYNOS4_MCTREG(0x204)
35 #define EXYNOS4_MCT_G_COMP0_ADD_INCR EXYNOS4_MCTREG(0x208)
36 #define EXYNOS4_MCT_G_TCON EXYNOS4_MCTREG(0x240)
37 #define EXYNOS4_MCT_G_INT_CSTAT EXYNOS4_MCTREG(0x244)
38 #define EXYNOS4_MCT_G_INT_ENB EXYNOS4_MCTREG(0x248)
39 #define EXYNOS4_MCT_G_WSTAT EXYNOS4_MCTREG(0x24C)
40 #define _EXYNOS4_MCT_L_BASE EXYNOS4_MCTREG(0x300)
41 #define EXYNOS4_MCT_L_BASE(x) (_EXYNOS4_MCT_L_BASE + (0x100 * x))
42 #define EXYNOS4_MCT_L_MASK (0xffffff00)
43
44 #define MCT_L_TCNTB_OFFSET (0x00)
45 #define MCT_L_ICNTB_OFFSET (0x08)
46 #define MCT_L_TCON_OFFSET (0x20)
47 #define MCT_L_INT_CSTAT_OFFSET (0x30)
48 #define MCT_L_INT_ENB_OFFSET (0x34)
49 #define MCT_L_WSTAT_OFFSET (0x40)
50 #define MCT_G_TCON_START (1 << 8)
51 #define MCT_G_TCON_COMP0_AUTO_INC (1 << 1)
52 #define MCT_G_TCON_COMP0_ENABLE (1 << 0)
53 #define MCT_L_TCON_INTERVAL_MODE (1 << 2)
54 #define MCT_L_TCON_INT_START (1 << 1)
55 #define MCT_L_TCON_TIMER_START (1 << 0)
56
57 #define TICK_BASE_CNT 1
58
59 enum {
60 MCT_INT_SPI,
61 MCT_INT_PPI
62 };
63
64 enum {
65 MCT_G0_IRQ,
66 MCT_G1_IRQ,
67 MCT_G2_IRQ,
68 MCT_G3_IRQ,
69 MCT_L0_IRQ,
70 MCT_L1_IRQ,
71 MCT_L2_IRQ,
72 MCT_L3_IRQ,
73 MCT_L4_IRQ,
74 MCT_L5_IRQ,
75 MCT_L6_IRQ,
76 MCT_L7_IRQ,
77 MCT_NR_IRQS,
78 };
79
80 static void __iomem *reg_base;
81 static unsigned long clk_rate;
82 static unsigned int mct_int_type;
83 static int mct_irqs[MCT_NR_IRQS];
84
85 struct mct_clock_event_device {
86 struct clock_event_device evt;
87 unsigned long base;
88 char name[10];
89 };
90
91 static void exynos4_mct_write(unsigned int value, unsigned long offset)
92 {
93 unsigned long stat_addr;
94 u32 mask;
95 u32 i;
96
97 writel_relaxed(value, reg_base + offset);
98
99 if (likely(offset >= EXYNOS4_MCT_L_BASE(0))) {
100 stat_addr = (offset & EXYNOS4_MCT_L_MASK) + MCT_L_WSTAT_OFFSET;
101 switch (offset & ~EXYNOS4_MCT_L_MASK) {
102 case MCT_L_TCON_OFFSET:
103 mask = 1 << 3; /* L_TCON write status */
104 break;
105 case MCT_L_ICNTB_OFFSET:
106 mask = 1 << 1; /* L_ICNTB write status */
107 break;
108 case MCT_L_TCNTB_OFFSET:
109 mask = 1 << 0; /* L_TCNTB write status */
110 break;
111 default:
112 return;
113 }
114 } else {
115 switch (offset) {
116 case EXYNOS4_MCT_G_TCON:
117 stat_addr = EXYNOS4_MCT_G_WSTAT;
118 mask = 1 << 16; /* G_TCON write status */
119 break;
120 case EXYNOS4_MCT_G_COMP0_L:
121 stat_addr = EXYNOS4_MCT_G_WSTAT;
122 mask = 1 << 0; /* G_COMP0_L write status */
123 break;
124 case EXYNOS4_MCT_G_COMP0_U:
125 stat_addr = EXYNOS4_MCT_G_WSTAT;
126 mask = 1 << 1; /* G_COMP0_U write status */
127 break;
128 case EXYNOS4_MCT_G_COMP0_ADD_INCR:
129 stat_addr = EXYNOS4_MCT_G_WSTAT;
130 mask = 1 << 2; /* G_COMP0_ADD_INCR w status */
131 break;
132 case EXYNOS4_MCT_G_CNT_L:
133 stat_addr = EXYNOS4_MCT_G_CNT_WSTAT;
134 mask = 1 << 0; /* G_CNT_L write status */
135 break;
136 case EXYNOS4_MCT_G_CNT_U:
137 stat_addr = EXYNOS4_MCT_G_CNT_WSTAT;
138 mask = 1 << 1; /* G_CNT_U write status */
139 break;
140 default:
141 return;
142 }
143 }
144
145 /* Wait maximum 1 ms until written values are applied */
146 for (i = 0; i < loops_per_jiffy / 1000 * HZ; i++)
147 if (readl_relaxed(reg_base + stat_addr) & mask) {
148 writel_relaxed(mask, reg_base + stat_addr);
149 return;
150 }
151
152 panic("MCT hangs after writing %d (offset:0x%lx)\n", value, offset);
153 }
154
155 /* Clocksource handling */
156 static void exynos4_mct_frc_start(void)
157 {
158 u32 reg;
159
160 reg = readl_relaxed(reg_base + EXYNOS4_MCT_G_TCON);
161 reg |= MCT_G_TCON_START;
162 exynos4_mct_write(reg, EXYNOS4_MCT_G_TCON);
163 }
164
165 /**
166 * exynos4_read_count_64 - Read all 64-bits of the global counter
167 *
168 * This will read all 64-bits of the global counter taking care to make sure
169 * that the upper and lower half match. Note that reading the MCT can be quite
170 * slow (hundreds of nanoseconds) so you should use the 32-bit (lower half
171 * only) version when possible.
172 *
173 * Returns the number of cycles in the global counter.
174 */
175 static u64 exynos4_read_count_64(void)
176 {
177 unsigned int lo, hi;
178 u32 hi2 = readl_relaxed(reg_base + EXYNOS4_MCT_G_CNT_U);
179
180 do {
181 hi = hi2;
182 lo = readl_relaxed(reg_base + EXYNOS4_MCT_G_CNT_L);
183 hi2 = readl_relaxed(reg_base + EXYNOS4_MCT_G_CNT_U);
184 } while (hi != hi2);
185
186 return ((cycle_t)hi << 32) | lo;
187 }
188
189 /**
190 * exynos4_read_count_32 - Read the lower 32-bits of the global counter
191 *
192 * This will read just the lower 32-bits of the global counter. This is marked
193 * as notrace so it can be used by the scheduler clock.
194 *
195 * Returns the number of cycles in the global counter (lower 32 bits).
196 */
197 static u32 notrace exynos4_read_count_32(void)
198 {
199 return readl_relaxed(reg_base + EXYNOS4_MCT_G_CNT_L);
200 }
201
202 static cycle_t exynos4_frc_read(struct clocksource *cs)
203 {
204 return exynos4_read_count_32();
205 }
206
207 static void exynos4_frc_resume(struct clocksource *cs)
208 {
209 exynos4_mct_frc_start();
210 }
211
212 static struct clocksource mct_frc = {
213 .name = "mct-frc",
214 .rating = 400,
215 .read = exynos4_frc_read,
216 .mask = CLOCKSOURCE_MASK(32),
217 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
218 .resume = exynos4_frc_resume,
219 };
220
221 static u64 notrace exynos4_read_sched_clock(void)
222 {
223 return exynos4_read_count_32();
224 }
225
226 static struct delay_timer exynos4_delay_timer;
227
228 static cycles_t exynos4_read_current_timer(void)
229 {
230 BUILD_BUG_ON_MSG(sizeof(cycles_t) != sizeof(u32),
231 "cycles_t needs to move to 32-bit for ARM64 usage");
232 return exynos4_read_count_32();
233 }
234
235 static void __init exynos4_clocksource_init(void)
236 {
237 exynos4_mct_frc_start();
238
239 exynos4_delay_timer.read_current_timer = &exynos4_read_current_timer;
240 exynos4_delay_timer.freq = clk_rate;
241 register_current_timer_delay(&exynos4_delay_timer);
242
243 if (clocksource_register_hz(&mct_frc, clk_rate))
244 panic("%s: can't register clocksource\n", mct_frc.name);
245
246 sched_clock_register(exynos4_read_sched_clock, 32, clk_rate);
247 }
248
249 static void exynos4_mct_comp0_stop(void)
250 {
251 unsigned int tcon;
252
253 tcon = readl_relaxed(reg_base + EXYNOS4_MCT_G_TCON);
254 tcon &= ~(MCT_G_TCON_COMP0_ENABLE | MCT_G_TCON_COMP0_AUTO_INC);
255
256 exynos4_mct_write(tcon, EXYNOS4_MCT_G_TCON);
257 exynos4_mct_write(0, EXYNOS4_MCT_G_INT_ENB);
258 }
259
260 static void exynos4_mct_comp0_start(enum clock_event_mode mode,
261 unsigned long cycles)
262 {
263 unsigned int tcon;
264 cycle_t comp_cycle;
265
266 tcon = readl_relaxed(reg_base + EXYNOS4_MCT_G_TCON);
267
268 if (mode == CLOCK_EVT_MODE_PERIODIC) {
269 tcon |= MCT_G_TCON_COMP0_AUTO_INC;
270 exynos4_mct_write(cycles, EXYNOS4_MCT_G_COMP0_ADD_INCR);
271 }
272
273 comp_cycle = exynos4_read_count_64() + cycles;
274 exynos4_mct_write((u32)comp_cycle, EXYNOS4_MCT_G_COMP0_L);
275 exynos4_mct_write((u32)(comp_cycle >> 32), EXYNOS4_MCT_G_COMP0_U);
276
277 exynos4_mct_write(0x1, EXYNOS4_MCT_G_INT_ENB);
278
279 tcon |= MCT_G_TCON_COMP0_ENABLE;
280 exynos4_mct_write(tcon , EXYNOS4_MCT_G_TCON);
281 }
282
283 static int exynos4_comp_set_next_event(unsigned long cycles,
284 struct clock_event_device *evt)
285 {
286 exynos4_mct_comp0_start(evt->mode, cycles);
287
288 return 0;
289 }
290
291 static void exynos4_comp_set_mode(enum clock_event_mode mode,
292 struct clock_event_device *evt)
293 {
294 unsigned long cycles_per_jiffy;
295 exynos4_mct_comp0_stop();
296
297 switch (mode) {
298 case CLOCK_EVT_MODE_PERIODIC:
299 cycles_per_jiffy =
300 (((unsigned long long) NSEC_PER_SEC / HZ * evt->mult) >> evt->shift);
301 exynos4_mct_comp0_start(mode, cycles_per_jiffy);
302 break;
303
304 case CLOCK_EVT_MODE_ONESHOT:
305 case CLOCK_EVT_MODE_UNUSED:
306 case CLOCK_EVT_MODE_SHUTDOWN:
307 case CLOCK_EVT_MODE_RESUME:
308 break;
309 }
310 }
311
312 static struct clock_event_device mct_comp_device = {
313 .name = "mct-comp",
314 .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
315 .rating = 250,
316 .set_next_event = exynos4_comp_set_next_event,
317 .set_mode = exynos4_comp_set_mode,
318 };
319
320 static irqreturn_t exynos4_mct_comp_isr(int irq, void *dev_id)
321 {
322 struct clock_event_device *evt = dev_id;
323
324 exynos4_mct_write(0x1, EXYNOS4_MCT_G_INT_CSTAT);
325
326 evt->event_handler(evt);
327
328 return IRQ_HANDLED;
329 }
330
331 static struct irqaction mct_comp_event_irq = {
332 .name = "mct_comp_irq",
333 .flags = IRQF_TIMER | IRQF_IRQPOLL,
334 .handler = exynos4_mct_comp_isr,
335 .dev_id = &mct_comp_device,
336 };
337
338 static void exynos4_clockevent_init(void)
339 {
340 mct_comp_device.cpumask = cpumask_of(0);
341 clockevents_config_and_register(&mct_comp_device, clk_rate,
342 0xf, 0xffffffff);
343 setup_irq(mct_irqs[MCT_G0_IRQ], &mct_comp_event_irq);
344 }
345
346 static DEFINE_PER_CPU(struct mct_clock_event_device, percpu_mct_tick);
347
348 /* Clock event handling */
349 static void exynos4_mct_tick_stop(struct mct_clock_event_device *mevt)
350 {
351 unsigned long tmp;
352 unsigned long mask = MCT_L_TCON_INT_START | MCT_L_TCON_TIMER_START;
353 unsigned long offset = mevt->base + MCT_L_TCON_OFFSET;
354
355 tmp = readl_relaxed(reg_base + offset);
356 if (tmp & mask) {
357 tmp &= ~mask;
358 exynos4_mct_write(tmp, offset);
359 }
360 }
361
362 static void exynos4_mct_tick_start(unsigned long cycles,
363 struct mct_clock_event_device *mevt)
364 {
365 unsigned long tmp;
366
367 exynos4_mct_tick_stop(mevt);
368
369 tmp = (1 << 31) | cycles; /* MCT_L_UPDATE_ICNTB */
370
371 /* update interrupt count buffer */
372 exynos4_mct_write(tmp, mevt->base + MCT_L_ICNTB_OFFSET);
373
374 /* enable MCT tick interrupt */
375 exynos4_mct_write(0x1, mevt->base + MCT_L_INT_ENB_OFFSET);
376
377 tmp = readl_relaxed(reg_base + mevt->base + MCT_L_TCON_OFFSET);
378 tmp |= MCT_L_TCON_INT_START | MCT_L_TCON_TIMER_START |
379 MCT_L_TCON_INTERVAL_MODE;
380 exynos4_mct_write(tmp, mevt->base + MCT_L_TCON_OFFSET);
381 }
382
383 static int exynos4_tick_set_next_event(unsigned long cycles,
384 struct clock_event_device *evt)
385 {
386 struct mct_clock_event_device *mevt = this_cpu_ptr(&percpu_mct_tick);
387
388 exynos4_mct_tick_start(cycles, mevt);
389
390 return 0;
391 }
392
393 static inline void exynos4_tick_set_mode(enum clock_event_mode mode,
394 struct clock_event_device *evt)
395 {
396 struct mct_clock_event_device *mevt = this_cpu_ptr(&percpu_mct_tick);
397 unsigned long cycles_per_jiffy;
398
399 exynos4_mct_tick_stop(mevt);
400
401 switch (mode) {
402 case CLOCK_EVT_MODE_PERIODIC:
403 cycles_per_jiffy =
404 (((unsigned long long) NSEC_PER_SEC / HZ * evt->mult) >> evt->shift);
405 exynos4_mct_tick_start(cycles_per_jiffy, mevt);
406 break;
407
408 case CLOCK_EVT_MODE_ONESHOT:
409 case CLOCK_EVT_MODE_UNUSED:
410 case CLOCK_EVT_MODE_SHUTDOWN:
411 case CLOCK_EVT_MODE_RESUME:
412 break;
413 }
414 }
415
416 static void exynos4_mct_tick_clear(struct mct_clock_event_device *mevt)
417 {
418 struct clock_event_device *evt = &mevt->evt;
419
420 /*
421 * This is for supporting oneshot mode.
422 * Mct would generate interrupt periodically
423 * without explicit stopping.
424 */
425 if (evt->mode != CLOCK_EVT_MODE_PERIODIC)
426 exynos4_mct_tick_stop(mevt);
427
428 /* Clear the MCT tick interrupt */
429 if (readl_relaxed(reg_base + mevt->base + MCT_L_INT_CSTAT_OFFSET) & 1)
430 exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET);
431 }
432
433 static irqreturn_t exynos4_mct_tick_isr(int irq, void *dev_id)
434 {
435 struct mct_clock_event_device *mevt = dev_id;
436 struct clock_event_device *evt = &mevt->evt;
437
438 exynos4_mct_tick_clear(mevt);
439
440 evt->event_handler(evt);
441
442 return IRQ_HANDLED;
443 }
444
445 static int exynos4_local_timer_setup(struct clock_event_device *evt)
446 {
447 struct mct_clock_event_device *mevt;
448 unsigned int cpu = smp_processor_id();
449
450 mevt = container_of(evt, struct mct_clock_event_device, evt);
451
452 mevt->base = EXYNOS4_MCT_L_BASE(cpu);
453 snprintf(mevt->name, sizeof(mevt->name), "mct_tick%d", cpu);
454
455 evt->name = mevt->name;
456 evt->cpumask = cpumask_of(cpu);
457 evt->set_next_event = exynos4_tick_set_next_event;
458 evt->set_mode = exynos4_tick_set_mode;
459 evt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
460 evt->rating = 450;
461
462 exynos4_mct_write(TICK_BASE_CNT, mevt->base + MCT_L_TCNTB_OFFSET);
463
464 if (mct_int_type == MCT_INT_SPI) {
465 evt->irq = mct_irqs[MCT_L0_IRQ + cpu];
466 if (request_irq(evt->irq, exynos4_mct_tick_isr,
467 IRQF_TIMER | IRQF_NOBALANCING,
468 evt->name, mevt)) {
469 pr_err("exynos-mct: cannot register IRQ %d\n",
470 evt->irq);
471 return -EIO;
472 }
473 irq_force_affinity(mct_irqs[MCT_L0_IRQ + cpu], cpumask_of(cpu));
474 } else {
475 enable_percpu_irq(mct_irqs[MCT_L0_IRQ], 0);
476 }
477 clockevents_config_and_register(evt, clk_rate / (TICK_BASE_CNT + 1),
478 0xf, 0x7fffffff);
479
480 return 0;
481 }
482
483 static void exynos4_local_timer_stop(struct clock_event_device *evt)
484 {
485 evt->set_mode(CLOCK_EVT_MODE_UNUSED, evt);
486 if (mct_int_type == MCT_INT_SPI)
487 free_irq(evt->irq, this_cpu_ptr(&percpu_mct_tick));
488 else
489 disable_percpu_irq(mct_irqs[MCT_L0_IRQ]);
490 }
491
492 static int exynos4_mct_cpu_notify(struct notifier_block *self,
493 unsigned long action, void *hcpu)
494 {
495 struct mct_clock_event_device *mevt;
496
497 /*
498 * Grab cpu pointer in each case to avoid spurious
499 * preemptible warnings
500 */
501 switch (action & ~CPU_TASKS_FROZEN) {
502 case CPU_STARTING:
503 mevt = this_cpu_ptr(&percpu_mct_tick);
504 exynos4_local_timer_setup(&mevt->evt);
505 break;
506 case CPU_DYING:
507 mevt = this_cpu_ptr(&percpu_mct_tick);
508 exynos4_local_timer_stop(&mevt->evt);
509 break;
510 }
511
512 return NOTIFY_OK;
513 }
514
515 static struct notifier_block exynos4_mct_cpu_nb = {
516 .notifier_call = exynos4_mct_cpu_notify,
517 };
518
519 static void __init exynos4_timer_resources(struct device_node *np, void __iomem *base)
520 {
521 int err;
522 struct mct_clock_event_device *mevt = this_cpu_ptr(&percpu_mct_tick);
523 struct clk *mct_clk, *tick_clk;
524
525 tick_clk = np ? of_clk_get_by_name(np, "fin_pll") :
526 clk_get(NULL, "fin_pll");
527 if (IS_ERR(tick_clk))
528 panic("%s: unable to determine tick clock rate\n", __func__);
529 clk_rate = clk_get_rate(tick_clk);
530
531 mct_clk = np ? of_clk_get_by_name(np, "mct") : clk_get(NULL, "mct");
532 if (IS_ERR(mct_clk))
533 panic("%s: unable to retrieve mct clock instance\n", __func__);
534 clk_prepare_enable(mct_clk);
535
536 reg_base = base;
537 if (!reg_base)
538 panic("%s: unable to ioremap mct address space\n", __func__);
539
540 if (mct_int_type == MCT_INT_PPI) {
541
542 err = request_percpu_irq(mct_irqs[MCT_L0_IRQ],
543 exynos4_mct_tick_isr, "MCT",
544 &percpu_mct_tick);
545 WARN(err, "MCT: can't request IRQ %d (%d)\n",
546 mct_irqs[MCT_L0_IRQ], err);
547 } else {
548 irq_set_affinity(mct_irqs[MCT_L0_IRQ], cpumask_of(0));
549 }
550
551 err = register_cpu_notifier(&exynos4_mct_cpu_nb);
552 if (err)
553 goto out_irq;
554
555 /* Immediately configure the timer on the boot CPU */
556 exynos4_local_timer_setup(&mevt->evt);
557 return;
558
559 out_irq:
560 free_percpu_irq(mct_irqs[MCT_L0_IRQ], &percpu_mct_tick);
561 }
562
563 static void __init mct_init_dt(struct device_node *np, unsigned int int_type)
564 {
565 u32 nr_irqs, i;
566
567 mct_int_type = int_type;
568
569 /* This driver uses only one global timer interrupt */
570 mct_irqs[MCT_G0_IRQ] = irq_of_parse_and_map(np, MCT_G0_IRQ);
571
572 /*
573 * Find out the number of local irqs specified. The local
574 * timer irqs are specified after the four global timer
575 * irqs are specified.
576 */
577 #ifdef CONFIG_OF
578 nr_irqs = of_irq_count(np);
579 #else
580 nr_irqs = 0;
581 #endif
582 for (i = MCT_L0_IRQ; i < nr_irqs; i++)
583 mct_irqs[i] = irq_of_parse_and_map(np, i);
584
585 exynos4_timer_resources(np, of_iomap(np, 0));
586 exynos4_clocksource_init();
587 exynos4_clockevent_init();
588 }
589
590
591 static void __init mct_init_spi(struct device_node *np)
592 {
593 return mct_init_dt(np, MCT_INT_SPI);
594 }
595
596 static void __init mct_init_ppi(struct device_node *np)
597 {
598 return mct_init_dt(np, MCT_INT_PPI);
599 }
600 CLOCKSOURCE_OF_DECLARE(exynos4210, "samsung,exynos4210-mct", mct_init_spi);
601 CLOCKSOURCE_OF_DECLARE(exynos4412, "samsung,exynos4412-mct", mct_init_ppi);
This page took 0.043373 seconds and 5 git commands to generate.