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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
59enum {
60 MCT_INT_SPI,
61 MCT_INT_PPI
62};
63
64enum {
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
80static void __iomem *reg_base;
81static unsigned long clk_rate;
82static unsigned int mct_int_type;
83static int mct_irqs[MCT_NR_IRQS];
84
85struct mct_clock_event_device {
86 struct clock_event_device evt;
87 unsigned long base;
88 char name[10];
89};
90
91static 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;
104 break;
105 case MCT_L_ICNTB_OFFSET:
106 mask = 1 << 1;
107 break;
108 case MCT_L_TCNTB_OFFSET:
109 mask = 1 << 0;
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;
119 break;
120 case EXYNOS4_MCT_G_COMP0_L:
121 stat_addr = EXYNOS4_MCT_G_WSTAT;
122 mask = 1 << 0;
123 break;
124 case EXYNOS4_MCT_G_COMP0_U:
125 stat_addr = EXYNOS4_MCT_G_WSTAT;
126 mask = 1 << 1;
127 break;
128 case EXYNOS4_MCT_G_COMP0_ADD_INCR:
129 stat_addr = EXYNOS4_MCT_G_WSTAT;
130 mask = 1 << 2;
131 break;
132 case EXYNOS4_MCT_G_CNT_L:
133 stat_addr = EXYNOS4_MCT_G_CNT_WSTAT;
134 mask = 1 << 0;
135 break;
136 case EXYNOS4_MCT_G_CNT_U:
137 stat_addr = EXYNOS4_MCT_G_CNT_WSTAT;
138 mask = 1 << 1;
139 break;
140 default:
141 return;
142 }
143 }
144
145
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
156static 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
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167
168
169
170
171
172
173
174
175static 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
191
192
193
194
195
196
197static u32 notrace exynos4_read_count_32(void)
198{
199 return readl_relaxed(reg_base + EXYNOS4_MCT_G_CNT_L);
200}
201
202static cycle_t exynos4_frc_read(struct clocksource *cs)
203{
204 return exynos4_read_count_32();
205}
206
207static void exynos4_frc_resume(struct clocksource *cs)
208{
209 exynos4_mct_frc_start();
210}
211
212struct 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
221static u64 notrace exynos4_read_sched_clock(void)
222{
223 return exynos4_read_count_32();
224}
225
226static struct delay_timer exynos4_delay_timer;
227
228static 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
235static 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
249static 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
260static 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
283static 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
291static 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
312static 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
320static 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
331static 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
338static 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
346static DEFINE_PER_CPU(struct mct_clock_event_device, percpu_mct_tick);
347
348
349static 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
362static 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;
370
371
372 exynos4_mct_write(tmp, mevt->base + MCT_L_ICNTB_OFFSET);
373
374
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
383static 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
393static 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
416static int exynos4_mct_tick_clear(struct mct_clock_event_device *mevt)
417{
418 struct clock_event_device *evt = &mevt->evt;
419
420
421
422
423
424
425 if (evt->mode != CLOCK_EVT_MODE_PERIODIC)
426 exynos4_mct_tick_stop(mevt);
427
428
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 return 1;
432 } else {
433 return 0;
434 }
435}
436
437static irqreturn_t exynos4_mct_tick_isr(int irq, void *dev_id)
438{
439 struct mct_clock_event_device *mevt = dev_id;
440 struct clock_event_device *evt = &mevt->evt;
441
442 exynos4_mct_tick_clear(mevt);
443
444 evt->event_handler(evt);
445
446 return IRQ_HANDLED;
447}
448
449static int exynos4_local_timer_setup(struct clock_event_device *evt)
450{
451 struct mct_clock_event_device *mevt;
452 unsigned int cpu = smp_processor_id();
453
454 mevt = container_of(evt, struct mct_clock_event_device, evt);
455
456 mevt->base = EXYNOS4_MCT_L_BASE(cpu);
457 snprintf(mevt->name, sizeof(mevt->name), "mct_tick%d", cpu);
458
459 evt->name = mevt->name;
460 evt->cpumask = cpumask_of(cpu);
461 evt->set_next_event = exynos4_tick_set_next_event;
462 evt->set_mode = exynos4_tick_set_mode;
463 evt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
464 evt->rating = 450;
465
466 exynos4_mct_write(TICK_BASE_CNT, mevt->base + MCT_L_TCNTB_OFFSET);
467
468 if (mct_int_type == MCT_INT_SPI) {
469 evt->irq = mct_irqs[MCT_L0_IRQ + cpu];
470 if (request_irq(evt->irq, exynos4_mct_tick_isr,
471 IRQF_TIMER | IRQF_NOBALANCING,
472 evt->name, mevt)) {
473 pr_err("exynos-mct: cannot register IRQ %d\n",
474 evt->irq);
475 return -EIO;
476 }
477 irq_force_affinity(mct_irqs[MCT_L0_IRQ + cpu], cpumask_of(cpu));
478 } else {
479 enable_percpu_irq(mct_irqs[MCT_L0_IRQ], 0);
480 }
481 clockevents_config_and_register(evt, clk_rate / (TICK_BASE_CNT + 1),
482 0xf, 0x7fffffff);
483
484 return 0;
485}
486
487static void exynos4_local_timer_stop(struct clock_event_device *evt)
488{
489 evt->set_mode(CLOCK_EVT_MODE_UNUSED, evt);
490 if (mct_int_type == MCT_INT_SPI)
491 free_irq(evt->irq, this_cpu_ptr(&percpu_mct_tick));
492 else
493 disable_percpu_irq(mct_irqs[MCT_L0_IRQ]);
494}
495
496static int exynos4_mct_cpu_notify(struct notifier_block *self,
497 unsigned long action, void *hcpu)
498{
499 struct mct_clock_event_device *mevt;
500
501
502
503
504
505 switch (action & ~CPU_TASKS_FROZEN) {
506 case CPU_STARTING:
507 mevt = this_cpu_ptr(&percpu_mct_tick);
508 exynos4_local_timer_setup(&mevt->evt);
509 break;
510 case CPU_DYING:
511 mevt = this_cpu_ptr(&percpu_mct_tick);
512 exynos4_local_timer_stop(&mevt->evt);
513 break;
514 }
515
516 return NOTIFY_OK;
517}
518
519static struct notifier_block exynos4_mct_cpu_nb = {
520 .notifier_call = exynos4_mct_cpu_notify,
521};
522
523static void __init exynos4_timer_resources(struct device_node *np, void __iomem *base)
524{
525 int err;
526 struct mct_clock_event_device *mevt = this_cpu_ptr(&percpu_mct_tick);
527 struct clk *mct_clk, *tick_clk;
528
529 tick_clk = np ? of_clk_get_by_name(np, "fin_pll") :
530 clk_get(NULL, "fin_pll");
531 if (IS_ERR(tick_clk))
532 panic("%s: unable to determine tick clock rate\n", __func__);
533 clk_rate = clk_get_rate(tick_clk);
534
535 mct_clk = np ? of_clk_get_by_name(np, "mct") : clk_get(NULL, "mct");
536 if (IS_ERR(mct_clk))
537 panic("%s: unable to retrieve mct clock instance\n", __func__);
538 clk_prepare_enable(mct_clk);
539
540 reg_base = base;
541 if (!reg_base)
542 panic("%s: unable to ioremap mct address space\n", __func__);
543
544 if (mct_int_type == MCT_INT_PPI) {
545
546 err = request_percpu_irq(mct_irqs[MCT_L0_IRQ],
547 exynos4_mct_tick_isr, "MCT",
548 &percpu_mct_tick);
549 WARN(err, "MCT: can't request IRQ %d (%d)\n",
550 mct_irqs[MCT_L0_IRQ], err);
551 } else {
552 irq_set_affinity(mct_irqs[MCT_L0_IRQ], cpumask_of(0));
553 }
554
555 err = register_cpu_notifier(&exynos4_mct_cpu_nb);
556 if (err)
557 goto out_irq;
558
559
560 exynos4_local_timer_setup(&mevt->evt);
561 return;
562
563out_irq:
564 free_percpu_irq(mct_irqs[MCT_L0_IRQ], &percpu_mct_tick);
565}
566
567void __init mct_init(void __iomem *base, int irq_g0, int irq_l0, int irq_l1)
568{
569 mct_irqs[MCT_G0_IRQ] = irq_g0;
570 mct_irqs[MCT_L0_IRQ] = irq_l0;
571 mct_irqs[MCT_L1_IRQ] = irq_l1;
572 mct_int_type = MCT_INT_SPI;
573
574 exynos4_timer_resources(NULL, base);
575 exynos4_clocksource_init();
576 exynos4_clockevent_init();
577}
578
579static void __init mct_init_dt(struct device_node *np, unsigned int int_type)
580{
581 u32 nr_irqs, i;
582
583 mct_int_type = int_type;
584
585
586 mct_irqs[MCT_G0_IRQ] = irq_of_parse_and_map(np, MCT_G0_IRQ);
587
588
589
590
591
592
593#ifdef CONFIG_OF
594 nr_irqs = of_irq_count(np);
595#else
596 nr_irqs = 0;
597#endif
598 for (i = MCT_L0_IRQ; i < nr_irqs; i++)
599 mct_irqs[i] = irq_of_parse_and_map(np, i);
600
601 exynos4_timer_resources(np, of_iomap(np, 0));
602 exynos4_clocksource_init();
603 exynos4_clockevent_init();
604}
605
606
607static void __init mct_init_spi(struct device_node *np)
608{
609 return mct_init_dt(np, MCT_INT_SPI);
610}
611
612static void __init mct_init_ppi(struct device_node *np)
613{
614 return mct_init_dt(np, MCT_INT_PPI);
615}
616CLOCKSOURCE_OF_DECLARE(exynos4210, "samsung,exynos4210-mct", mct_init_spi);
617CLOCKSOURCE_OF_DECLARE(exynos4412, "samsung,exynos4412-mct", mct_init_ppi);
618
