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Linux 3.11-rc3
[cris-mirror.git] / drivers / clocksource / exynos_mct.c
blobb2bbc415f12055886a53288d1cca2d11a91a304c
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/platform_device.h>
20 #include <linux/delay.h>
21 #include <linux/percpu.h>
22 #include <linux/of.h>
23 #include <linux/of_irq.h>
24 #include <linux/of_address.h>
25 #include <linux/clocksource.h>
26
27 #include <asm/localtimer.h>
28 #include <asm/mach/time.h>
29
30 #define EXYNOS4_MCTREG(x) (x)
31 #define EXYNOS4_MCT_G_CNT_L EXYNOS4_MCTREG(0x100)
32 #define EXYNOS4_MCT_G_CNT_U EXYNOS4_MCTREG(0x104)
33 #define EXYNOS4_MCT_G_CNT_WSTAT EXYNOS4_MCTREG(0x110)
34 #define EXYNOS4_MCT_G_COMP0_L EXYNOS4_MCTREG(0x200)
35 #define EXYNOS4_MCT_G_COMP0_U EXYNOS4_MCTREG(0x204)
36 #define EXYNOS4_MCT_G_COMP0_ADD_INCR EXYNOS4_MCTREG(0x208)
37 #define EXYNOS4_MCT_G_TCON EXYNOS4_MCTREG(0x240)
38 #define EXYNOS4_MCT_G_INT_CSTAT EXYNOS4_MCTREG(0x244)
39 #define EXYNOS4_MCT_G_INT_ENB EXYNOS4_MCTREG(0x248)
40 #define EXYNOS4_MCT_G_WSTAT EXYNOS4_MCTREG(0x24C)
41 #define _EXYNOS4_MCT_L_BASE EXYNOS4_MCTREG(0x300)
42 #define EXYNOS4_MCT_L_BASE(x) (_EXYNOS4_MCT_L_BASE + (0x100 * x))
43 #define EXYNOS4_MCT_L_MASK (0xffffff00)
44
45 #define MCT_L_TCNTB_OFFSET (0x00)
46 #define MCT_L_ICNTB_OFFSET (0x08)
47 #define MCT_L_TCON_OFFSET (0x20)
48 #define MCT_L_INT_CSTAT_OFFSET (0x30)
49 #define MCT_L_INT_ENB_OFFSET (0x34)
50 #define MCT_L_WSTAT_OFFSET (0x40)
51 #define MCT_G_TCON_START (1 << 8)
52 #define MCT_G_TCON_COMP0_AUTO_INC (1 << 1)
53 #define MCT_G_TCON_COMP0_ENABLE (1 << 0)
54 #define MCT_L_TCON_INTERVAL_MODE (1 << 2)
55 #define MCT_L_TCON_INT_START (1 << 1)
56 #define MCT_L_TCON_TIMER_START (1 << 0)
57
58 #define TICK_BASE_CNT 1
59
60 enum {
61 MCT_INT_SPI,
62 MCT_INT_PPI
63 };
64
65 enum {
66 MCT_G0_IRQ,
67 MCT_G1_IRQ,
68 MCT_G2_IRQ,
69 MCT_G3_IRQ,
70 MCT_L0_IRQ,
71 MCT_L1_IRQ,
72 MCT_L2_IRQ,
73 MCT_L3_IRQ,
74 MCT_NR_IRQS,
75 };
76
77 static void __iomem *reg_base;
78 static unsigned long clk_rate;
79 static unsigned int mct_int_type;
80 static int mct_irqs[MCT_NR_IRQS];
81
82 struct mct_clock_event_device {
83 struct clock_event_device *evt;
84 unsigned long base;
85 char name[10];
86 };
87
88 static void exynos4_mct_write(unsigned int value, unsigned long offset)
89 {
90 unsigned long stat_addr;
91 u32 mask;
92 u32 i;
93
94 __raw_writel(value, reg_base + offset);
95
96 if (likely(offset >= EXYNOS4_MCT_L_BASE(0))) {
97 stat_addr = (offset & ~EXYNOS4_MCT_L_MASK) + MCT_L_WSTAT_OFFSET;
98 switch (offset & EXYNOS4_MCT_L_MASK) {
99 case MCT_L_TCON_OFFSET:
100 mask = 1 << 3; /* L_TCON write status */
101 break;
102 case MCT_L_ICNTB_OFFSET:
103 mask = 1 << 1; /* L_ICNTB write status */
104 break;
105 case MCT_L_TCNTB_OFFSET:
106 mask = 1 << 0; /* L_TCNTB write status */
107 break;
108 default:
109 return;
110 }
111 } else {
112 switch (offset) {
113 case EXYNOS4_MCT_G_TCON:
114 stat_addr = EXYNOS4_MCT_G_WSTAT;
115 mask = 1 << 16; /* G_TCON write status */
116 break;
117 case EXYNOS4_MCT_G_COMP0_L:
118 stat_addr = EXYNOS4_MCT_G_WSTAT;
119 mask = 1 << 0; /* G_COMP0_L write status */
120 break;
121 case EXYNOS4_MCT_G_COMP0_U:
122 stat_addr = EXYNOS4_MCT_G_WSTAT;
123 mask = 1 << 1; /* G_COMP0_U write status */
124 break;
125 case EXYNOS4_MCT_G_COMP0_ADD_INCR:
126 stat_addr = EXYNOS4_MCT_G_WSTAT;
127 mask = 1 << 2; /* G_COMP0_ADD_INCR w status */
128 break;
129 case EXYNOS4_MCT_G_CNT_L:
130 stat_addr = EXYNOS4_MCT_G_CNT_WSTAT;
131 mask = 1 << 0; /* G_CNT_L write status */
132 break;
133 case EXYNOS4_MCT_G_CNT_U:
134 stat_addr = EXYNOS4_MCT_G_CNT_WSTAT;
135 mask = 1 << 1; /* G_CNT_U write status */
136 break;
137 default:
138 return;
139 }
140 }
141
142 /* Wait maximum 1 ms until written values are applied */
143 for (i = 0; i < loops_per_jiffy / 1000 * HZ; i++)
144 if (__raw_readl(reg_base + stat_addr) & mask) {
145 __raw_writel(mask, reg_base + stat_addr);
146 return;
147 }
148
149 panic("MCT hangs after writing %d (offset:0x%lx)\n", value, offset);
150 }
151
152 /* Clocksource handling */
153 static void exynos4_mct_frc_start(u32 hi, u32 lo)
154 {
155 u32 reg;
156
157 exynos4_mct_write(lo, EXYNOS4_MCT_G_CNT_L);
158 exynos4_mct_write(hi, EXYNOS4_MCT_G_CNT_U);
159
160 reg = __raw_readl(reg_base + EXYNOS4_MCT_G_TCON);
161 reg |= MCT_G_TCON_START;
162 exynos4_mct_write(reg, EXYNOS4_MCT_G_TCON);
163 }
164
165 static cycle_t exynos4_frc_read(struct clocksource *cs)
166 {
167 unsigned int lo, hi;
168 u32 hi2 = __raw_readl(reg_base + EXYNOS4_MCT_G_CNT_U);
169
170 do {
171 hi = hi2;
172 lo = __raw_readl(reg_base + EXYNOS4_MCT_G_CNT_L);
173 hi2 = __raw_readl(reg_base + EXYNOS4_MCT_G_CNT_U);
174 } while (hi != hi2);
175
176 return ((cycle_t)hi << 32) | lo;
177 }
178
179 static void exynos4_frc_resume(struct clocksource *cs)
180 {
181 exynos4_mct_frc_start(0, 0);
182 }
183
184 struct clocksource mct_frc = {
185 .name = "mct-frc",
186 .rating = 400,
187 .read = exynos4_frc_read,
188 .mask = CLOCKSOURCE_MASK(64),
189 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
190 .resume = exynos4_frc_resume,
191 };
192
193 static void __init exynos4_clocksource_init(void)
194 {
195 exynos4_mct_frc_start(0, 0);
196
197 if (clocksource_register_hz(&mct_frc, clk_rate))
198 panic("%s: can't register clocksource\n", mct_frc.name);
199 }
200
201 static void exynos4_mct_comp0_stop(void)
202 {
203 unsigned int tcon;
204
205 tcon = __raw_readl(reg_base + EXYNOS4_MCT_G_TCON);
206 tcon &= ~(MCT_G_TCON_COMP0_ENABLE | MCT_G_TCON_COMP0_AUTO_INC);
207
208 exynos4_mct_write(tcon, EXYNOS4_MCT_G_TCON);
209 exynos4_mct_write(0, EXYNOS4_MCT_G_INT_ENB);
210 }
211
212 static void exynos4_mct_comp0_start(enum clock_event_mode mode,
213 unsigned long cycles)
214 {
215 unsigned int tcon;
216 cycle_t comp_cycle;
217
218 tcon = __raw_readl(reg_base + EXYNOS4_MCT_G_TCON);
219
220 if (mode == CLOCK_EVT_MODE_PERIODIC) {
221 tcon |= MCT_G_TCON_COMP0_AUTO_INC;
222 exynos4_mct_write(cycles, EXYNOS4_MCT_G_COMP0_ADD_INCR);
223 }
224
225 comp_cycle = exynos4_frc_read(&mct_frc) + cycles;
226 exynos4_mct_write((u32)comp_cycle, EXYNOS4_MCT_G_COMP0_L);
227 exynos4_mct_write((u32)(comp_cycle >> 32), EXYNOS4_MCT_G_COMP0_U);
228
229 exynos4_mct_write(0x1, EXYNOS4_MCT_G_INT_ENB);
230
231 tcon |= MCT_G_TCON_COMP0_ENABLE;
232 exynos4_mct_write(tcon , EXYNOS4_MCT_G_TCON);
233 }
234
235 static int exynos4_comp_set_next_event(unsigned long cycles,
236 struct clock_event_device *evt)
237 {
238 exynos4_mct_comp0_start(evt->mode, cycles);
239
240 return 0;
241 }
242
243 static void exynos4_comp_set_mode(enum clock_event_mode mode,
244 struct clock_event_device *evt)
245 {
246 unsigned long cycles_per_jiffy;
247 exynos4_mct_comp0_stop();
248
249 switch (mode) {
250 case CLOCK_EVT_MODE_PERIODIC:
251 cycles_per_jiffy =
252 (((unsigned long long) NSEC_PER_SEC / HZ * evt->mult) >> evt->shift);
253 exynos4_mct_comp0_start(mode, cycles_per_jiffy);
254 break;
255
256 case CLOCK_EVT_MODE_ONESHOT:
257 case CLOCK_EVT_MODE_UNUSED:
258 case CLOCK_EVT_MODE_SHUTDOWN:
259 case CLOCK_EVT_MODE_RESUME:
260 break;
261 }
262 }
263
264 static struct clock_event_device mct_comp_device = {
265 .name = "mct-comp",
266 .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
267 .rating = 250,
268 .set_next_event = exynos4_comp_set_next_event,
269 .set_mode = exynos4_comp_set_mode,
270 };
271
272 static irqreturn_t exynos4_mct_comp_isr(int irq, void *dev_id)
273 {
274 struct clock_event_device *evt = dev_id;
275
276 exynos4_mct_write(0x1, EXYNOS4_MCT_G_INT_CSTAT);
277
278 evt->event_handler(evt);
279
280 return IRQ_HANDLED;
281 }
282
283 static struct irqaction mct_comp_event_irq = {
284 .name = "mct_comp_irq",
285 .flags = IRQF_TIMER | IRQF_IRQPOLL,
286 .handler = exynos4_mct_comp_isr,
287 .dev_id = &mct_comp_device,
288 };
289
290 static void exynos4_clockevent_init(void)
291 {
292 mct_comp_device.cpumask = cpumask_of(0);
293 clockevents_config_and_register(&mct_comp_device, clk_rate,
294 0xf, 0xffffffff);
295 setup_irq(mct_irqs[MCT_G0_IRQ], &mct_comp_event_irq);
296 }
297
298 #ifdef CONFIG_LOCAL_TIMERS
299
300 static DEFINE_PER_CPU(struct mct_clock_event_device, percpu_mct_tick);
301
302 /* Clock event handling */
303 static void exynos4_mct_tick_stop(struct mct_clock_event_device *mevt)
304 {
305 unsigned long tmp;
306 unsigned long mask = MCT_L_TCON_INT_START | MCT_L_TCON_TIMER_START;
307 unsigned long offset = mevt->base + MCT_L_TCON_OFFSET;
308
309 tmp = __raw_readl(reg_base + offset);
310 if (tmp & mask) {
311 tmp &= ~mask;
312 exynos4_mct_write(tmp, offset);
313 }
314 }
315
316 static void exynos4_mct_tick_start(unsigned long cycles,
317 struct mct_clock_event_device *mevt)
318 {
319 unsigned long tmp;
320
321 exynos4_mct_tick_stop(mevt);
322
323 tmp = (1 << 31) | cycles; /* MCT_L_UPDATE_ICNTB */
324
325 /* update interrupt count buffer */
326 exynos4_mct_write(tmp, mevt->base + MCT_L_ICNTB_OFFSET);
327
328 /* enable MCT tick interrupt */
329 exynos4_mct_write(0x1, mevt->base + MCT_L_INT_ENB_OFFSET);
330
331 tmp = __raw_readl(reg_base + mevt->base + MCT_L_TCON_OFFSET);
332 tmp |= MCT_L_TCON_INT_START | MCT_L_TCON_TIMER_START |
333 MCT_L_TCON_INTERVAL_MODE;
334 exynos4_mct_write(tmp, mevt->base + MCT_L_TCON_OFFSET);
335 }
336
337 static int exynos4_tick_set_next_event(unsigned long cycles,
338 struct clock_event_device *evt)
339 {
340 struct mct_clock_event_device *mevt = this_cpu_ptr(&percpu_mct_tick);
341
342 exynos4_mct_tick_start(cycles, mevt);
343
344 return 0;
345 }
346
347 static inline void exynos4_tick_set_mode(enum clock_event_mode mode,
348 struct clock_event_device *evt)
349 {
350 struct mct_clock_event_device *mevt = this_cpu_ptr(&percpu_mct_tick);
351 unsigned long cycles_per_jiffy;
352
353 exynos4_mct_tick_stop(mevt);
354
355 switch (mode) {
356 case CLOCK_EVT_MODE_PERIODIC:
357 cycles_per_jiffy =
358 (((unsigned long long) NSEC_PER_SEC / HZ * evt->mult) >> evt->shift);
359 exynos4_mct_tick_start(cycles_per_jiffy, mevt);
360 break;
361
362 case CLOCK_EVT_MODE_ONESHOT:
363 case CLOCK_EVT_MODE_UNUSED:
364 case CLOCK_EVT_MODE_SHUTDOWN:
365 case CLOCK_EVT_MODE_RESUME:
366 break;
367 }
368 }
369
370 static int exynos4_mct_tick_clear(struct mct_clock_event_device *mevt)
371 {
372 struct clock_event_device *evt = mevt->evt;
373
374 /*
375 * This is for supporting oneshot mode.
376 * Mct would generate interrupt periodically
377 * without explicit stopping.
378 */
379 if (evt->mode != CLOCK_EVT_MODE_PERIODIC)
380 exynos4_mct_tick_stop(mevt);
381
382 /* Clear the MCT tick interrupt */
383 if (__raw_readl(reg_base + mevt->base + MCT_L_INT_CSTAT_OFFSET) & 1) {
384 exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET);
385 return 1;
386 } else {
387 return 0;
388 }
389 }
390
391 static irqreturn_t exynos4_mct_tick_isr(int irq, void *dev_id)
392 {
393 struct mct_clock_event_device *mevt = dev_id;
394 struct clock_event_device *evt = mevt->evt;
395
396 exynos4_mct_tick_clear(mevt);
397
398 evt->event_handler(evt);
399
400 return IRQ_HANDLED;
401 }
402
403 static int exynos4_local_timer_setup(struct clock_event_device *evt)
404 {
405 struct mct_clock_event_device *mevt;
406 unsigned int cpu = smp_processor_id();
407
408 mevt = this_cpu_ptr(&percpu_mct_tick);
409 mevt->evt = evt;
410
411 mevt->base = EXYNOS4_MCT_L_BASE(cpu);
412 sprintf(mevt->name, "mct_tick%d", cpu);
413
414 evt->name = mevt->name;
415 evt->cpumask = cpumask_of(cpu);
416 evt->set_next_event = exynos4_tick_set_next_event;
417 evt->set_mode = exynos4_tick_set_mode;
418 evt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
419 evt->rating = 450;
420 clockevents_config_and_register(evt, clk_rate / (TICK_BASE_CNT + 1),
421 0xf, 0x7fffffff);
422
423 exynos4_mct_write(TICK_BASE_CNT, mevt->base + MCT_L_TCNTB_OFFSET);
424
425 if (mct_int_type == MCT_INT_SPI) {
426 evt->irq = mct_irqs[MCT_L0_IRQ + cpu];
427 if (request_irq(evt->irq, exynos4_mct_tick_isr,
428 IRQF_TIMER | IRQF_NOBALANCING,
429 evt->name, mevt)) {
430 pr_err("exynos-mct: cannot register IRQ %d\n",
431 evt->irq);
432 return -EIO;
433 }
434 irq_set_affinity(evt->irq, cpumask_of(cpu));
435 } else {
436 enable_percpu_irq(mct_irqs[MCT_L0_IRQ], 0);
437 }
438
439 return 0;
440 }
441
442 static void exynos4_local_timer_stop(struct clock_event_device *evt)
443 {
444 evt->set_mode(CLOCK_EVT_MODE_UNUSED, evt);
445 if (mct_int_type == MCT_INT_SPI)
446 free_irq(evt->irq, this_cpu_ptr(&percpu_mct_tick));
447 else
448 disable_percpu_irq(mct_irqs[MCT_L0_IRQ]);
449 }
450
451 static struct local_timer_ops exynos4_mct_tick_ops = {
452 .setup = exynos4_local_timer_setup,
453 .stop = exynos4_local_timer_stop,
454 };
455 #endif /* CONFIG_LOCAL_TIMERS */
456
457 static void __init exynos4_timer_resources(struct device_node *np, void __iomem *base)
458 {
459 struct clk *mct_clk, *tick_clk;
460
461 tick_clk = np ? of_clk_get_by_name(np, "fin_pll") :
462 clk_get(NULL, "fin_pll");
463 if (IS_ERR(tick_clk))
464 panic("%s: unable to determine tick clock rate\n", __func__);
465 clk_rate = clk_get_rate(tick_clk);
466
467 mct_clk = np ? of_clk_get_by_name(np, "mct") : clk_get(NULL, "mct");
468 if (IS_ERR(mct_clk))
469 panic("%s: unable to retrieve mct clock instance\n", __func__);
470 clk_prepare_enable(mct_clk);
471
472 reg_base = base;
473 if (!reg_base)
474 panic("%s: unable to ioremap mct address space\n", __func__);
475
476 #ifdef CONFIG_LOCAL_TIMERS
477 if (mct_int_type == MCT_INT_PPI) {
478 int err;
479
480 err = request_percpu_irq(mct_irqs[MCT_L0_IRQ],
481 exynos4_mct_tick_isr, "MCT",
482 &percpu_mct_tick);
483 WARN(err, "MCT: can't request IRQ %d (%d)\n",
484 mct_irqs[MCT_L0_IRQ], err);
485 }
486
487 local_timer_register(&exynos4_mct_tick_ops);
488 #endif /* CONFIG_LOCAL_TIMERS */
489 }
490
491 void __init mct_init(void __iomem *base, int irq_g0, int irq_l0, int irq_l1)
492 {
493 mct_irqs[MCT_G0_IRQ] = irq_g0;
494 mct_irqs[MCT_L0_IRQ] = irq_l0;
495 mct_irqs[MCT_L1_IRQ] = irq_l1;
496 mct_int_type = MCT_INT_SPI;
497
498 exynos4_timer_resources(NULL, base);
499 exynos4_clocksource_init();
500 exynos4_clockevent_init();
501 }
502
503 static void __init mct_init_dt(struct device_node *np, unsigned int int_type)
504 {
505 u32 nr_irqs, i;
506
507 mct_int_type = int_type;
508
509 /* This driver uses only one global timer interrupt */
510 mct_irqs[MCT_G0_IRQ] = irq_of_parse_and_map(np, MCT_G0_IRQ);
511
512 /*
513 * Find out the number of local irqs specified. The local
514 * timer irqs are specified after the four global timer
515 * irqs are specified.
516 */
517 #ifdef CONFIG_OF
518 nr_irqs = of_irq_count(np);
519 #else
520 nr_irqs = 0;
521 #endif
522 for (i = MCT_L0_IRQ; i < nr_irqs; i++)
523 mct_irqs[i] = irq_of_parse_and_map(np, i);
524
525 exynos4_timer_resources(np, of_iomap(np, 0));
526 exynos4_clocksource_init();
527 exynos4_clockevent_init();
528 }
529
530
531 static void __init mct_init_spi(struct device_node *np)
532 {
533 return mct_init_dt(np, MCT_INT_SPI);
534 }
535
536 static void __init mct_init_ppi(struct device_node *np)
537 {
538 return mct_init_dt(np, MCT_INT_PPI);
539 }
540 CLOCKSOURCE_OF_DECLARE(exynos4210, "samsung,exynos4210-mct", mct_init_spi);
541 CLOCKSOURCE_OF_DECLARE(exynos4412, "samsung,exynos4412-mct", mct_init_ppi);
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