projects / deliverable / linux.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Merge branch 'drm-fixes-4.0' of git://people.freedesktop.org/~agd5f/linux into drm...
[deliverable/linux.git] / drivers / clocksource / arm_arch_timer.c
1 /*
2 * linux/drivers/clocksource/arm_arch_timer.c
3 *
4 * Copyright (C) 2011 ARM Ltd.
5 * All Rights Reserved
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11 #include <linux/init.h>
12 #include <linux/kernel.h>
13 #include <linux/device.h>
14 #include <linux/smp.h>
15 #include <linux/cpu.h>
16 #include <linux/cpu_pm.h>
17 #include <linux/clockchips.h>
18 #include <linux/clocksource.h>
19 #include <linux/interrupt.h>
20 #include <linux/of_irq.h>
21 #include <linux/of_address.h>
22 #include <linux/io.h>
23 #include <linux/slab.h>
24 #include <linux/sched_clock.h>
25
26 #include <asm/arch_timer.h>
27 #include <asm/virt.h>
28
29 #include <clocksource/arm_arch_timer.h>
30
31 #define CNTTIDR 0x08
32 #define CNTTIDR_VIRT(n) (BIT(1) << ((n) * 4))
33
34 #define CNTVCT_LO 0x08
35 #define CNTVCT_HI 0x0c
36 #define CNTFRQ 0x10
37 #define CNTP_TVAL 0x28
38 #define CNTP_CTL 0x2c
39 #define CNTV_TVAL 0x38
40 #define CNTV_CTL 0x3c
41
42 #define ARCH_CP15_TIMER BIT(0)
43 #define ARCH_MEM_TIMER BIT(1)
44 static unsigned arch_timers_present __initdata;
45
46 static void __iomem *arch_counter_base;
47
48 struct arch_timer {
49 void __iomem *base;
50 struct clock_event_device evt;
51 };
52
53 #define to_arch_timer(e) container_of(e, struct arch_timer, evt)
54
55 static u32 arch_timer_rate;
56
57 enum ppi_nr {
58 PHYS_SECURE_PPI,
59 PHYS_NONSECURE_PPI,
60 VIRT_PPI,
61 HYP_PPI,
62 MAX_TIMER_PPI
63 };
64
65 static int arch_timer_ppi[MAX_TIMER_PPI];
66
67 static struct clock_event_device __percpu *arch_timer_evt;
68
69 static bool arch_timer_use_virtual = true;
70 static bool arch_timer_c3stop;
71 static bool arch_timer_mem_use_virtual;
72
73 /*
74 * Architected system timer support.
75 */
76
77 static __always_inline
78 void arch_timer_reg_write(int access, enum arch_timer_reg reg, u32 val,
79 struct clock_event_device *clk)
80 {
81 if (access == ARCH_TIMER_MEM_PHYS_ACCESS) {
82 struct arch_timer *timer = to_arch_timer(clk);
83 switch (reg) {
84 case ARCH_TIMER_REG_CTRL:
85 writel_relaxed(val, timer->base + CNTP_CTL);
86 break;
87 case ARCH_TIMER_REG_TVAL:
88 writel_relaxed(val, timer->base + CNTP_TVAL);
89 break;
90 }
91 } else if (access == ARCH_TIMER_MEM_VIRT_ACCESS) {
92 struct arch_timer *timer = to_arch_timer(clk);
93 switch (reg) {
94 case ARCH_TIMER_REG_CTRL:
95 writel_relaxed(val, timer->base + CNTV_CTL);
96 break;
97 case ARCH_TIMER_REG_TVAL:
98 writel_relaxed(val, timer->base + CNTV_TVAL);
99 break;
100 }
101 } else {
102 arch_timer_reg_write_cp15(access, reg, val);
103 }
104 }
105
106 static __always_inline
107 u32 arch_timer_reg_read(int access, enum arch_timer_reg reg,
108 struct clock_event_device *clk)
109 {
110 u32 val;
111
112 if (access == ARCH_TIMER_MEM_PHYS_ACCESS) {
113 struct arch_timer *timer = to_arch_timer(clk);
114 switch (reg) {
115 case ARCH_TIMER_REG_CTRL:
116 val = readl_relaxed(timer->base + CNTP_CTL);
117 break;
118 case ARCH_TIMER_REG_TVAL:
119 val = readl_relaxed(timer->base + CNTP_TVAL);
120 break;
121 }
122 } else if (access == ARCH_TIMER_MEM_VIRT_ACCESS) {
123 struct arch_timer *timer = to_arch_timer(clk);
124 switch (reg) {
125 case ARCH_TIMER_REG_CTRL:
126 val = readl_relaxed(timer->base + CNTV_CTL);
127 break;
128 case ARCH_TIMER_REG_TVAL:
129 val = readl_relaxed(timer->base + CNTV_TVAL);
130 break;
131 }
132 } else {
133 val = arch_timer_reg_read_cp15(access, reg);
134 }
135
136 return val;
137 }
138
139 static __always_inline irqreturn_t timer_handler(const int access,
140 struct clock_event_device *evt)
141 {
142 unsigned long ctrl;
143
144 ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, evt);
145 if (ctrl & ARCH_TIMER_CTRL_IT_STAT) {
146 ctrl |= ARCH_TIMER_CTRL_IT_MASK;
147 arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, evt);
148 evt->event_handler(evt);
149 return IRQ_HANDLED;
150 }
151
152 return IRQ_NONE;
153 }
154
155 static irqreturn_t arch_timer_handler_virt(int irq, void *dev_id)
156 {
157 struct clock_event_device *evt = dev_id;
158
159 return timer_handler(ARCH_TIMER_VIRT_ACCESS, evt);
160 }
161
162 static irqreturn_t arch_timer_handler_phys(int irq, void *dev_id)
163 {
164 struct clock_event_device *evt = dev_id;
165
166 return timer_handler(ARCH_TIMER_PHYS_ACCESS, evt);
167 }
168
169 static irqreturn_t arch_timer_handler_phys_mem(int irq, void *dev_id)
170 {
171 struct clock_event_device *evt = dev_id;
172
173 return timer_handler(ARCH_TIMER_MEM_PHYS_ACCESS, evt);
174 }
175
176 static irqreturn_t arch_timer_handler_virt_mem(int irq, void *dev_id)
177 {
178 struct clock_event_device *evt = dev_id;
179
180 return timer_handler(ARCH_TIMER_MEM_VIRT_ACCESS, evt);
181 }
182
183 static __always_inline void timer_set_mode(const int access, int mode,
184 struct clock_event_device *clk)
185 {
186 unsigned long ctrl;
187 switch (mode) {
188 case CLOCK_EVT_MODE_UNUSED:
189 case CLOCK_EVT_MODE_SHUTDOWN:
190 ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, clk);
191 ctrl &= ~ARCH_TIMER_CTRL_ENABLE;
192 arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
193 break;
194 default:
195 break;
196 }
197 }
198
199 static void arch_timer_set_mode_virt(enum clock_event_mode mode,
200 struct clock_event_device *clk)
201 {
202 timer_set_mode(ARCH_TIMER_VIRT_ACCESS, mode, clk);
203 }
204
205 static void arch_timer_set_mode_phys(enum clock_event_mode mode,
206 struct clock_event_device *clk)
207 {
208 timer_set_mode(ARCH_TIMER_PHYS_ACCESS, mode, clk);
209 }
210
211 static void arch_timer_set_mode_virt_mem(enum clock_event_mode mode,
212 struct clock_event_device *clk)
213 {
214 timer_set_mode(ARCH_TIMER_MEM_VIRT_ACCESS, mode, clk);
215 }
216
217 static void arch_timer_set_mode_phys_mem(enum clock_event_mode mode,
218 struct clock_event_device *clk)
219 {
220 timer_set_mode(ARCH_TIMER_MEM_PHYS_ACCESS, mode, clk);
221 }
222
223 static __always_inline void set_next_event(const int access, unsigned long evt,
224 struct clock_event_device *clk)
225 {
226 unsigned long ctrl;
227 ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, clk);
228 ctrl |= ARCH_TIMER_CTRL_ENABLE;
229 ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;
230 arch_timer_reg_write(access, ARCH_TIMER_REG_TVAL, evt, clk);
231 arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
232 }
233
234 static int arch_timer_set_next_event_virt(unsigned long evt,
235 struct clock_event_device *clk)
236 {
237 set_next_event(ARCH_TIMER_VIRT_ACCESS, evt, clk);
238 return 0;
239 }
240
241 static int arch_timer_set_next_event_phys(unsigned long evt,
242 struct clock_event_device *clk)
243 {
244 set_next_event(ARCH_TIMER_PHYS_ACCESS, evt, clk);
245 return 0;
246 }
247
248 static int arch_timer_set_next_event_virt_mem(unsigned long evt,
249 struct clock_event_device *clk)
250 {
251 set_next_event(ARCH_TIMER_MEM_VIRT_ACCESS, evt, clk);
252 return 0;
253 }
254
255 static int arch_timer_set_next_event_phys_mem(unsigned long evt,
256 struct clock_event_device *clk)
257 {
258 set_next_event(ARCH_TIMER_MEM_PHYS_ACCESS, evt, clk);
259 return 0;
260 }
261
262 static void __arch_timer_setup(unsigned type,
263 struct clock_event_device *clk)
264 {
265 clk->features = CLOCK_EVT_FEAT_ONESHOT;
266
267 if (type == ARCH_CP15_TIMER) {
268 if (arch_timer_c3stop)
269 clk->features |= CLOCK_EVT_FEAT_C3STOP;
270 clk->name = "arch_sys_timer";
271 clk->rating = 450;
272 clk->cpumask = cpumask_of(smp_processor_id());
273 if (arch_timer_use_virtual) {
274 clk->irq = arch_timer_ppi[VIRT_PPI];
275 clk->set_mode = arch_timer_set_mode_virt;
276 clk->set_next_event = arch_timer_set_next_event_virt;
277 } else {
278 clk->irq = arch_timer_ppi[PHYS_SECURE_PPI];
279 clk->set_mode = arch_timer_set_mode_phys;
280 clk->set_next_event = arch_timer_set_next_event_phys;
281 }
282 } else {
283 clk->features |= CLOCK_EVT_FEAT_DYNIRQ;
284 clk->name = "arch_mem_timer";
285 clk->rating = 400;
286 clk->cpumask = cpu_all_mask;
287 if (arch_timer_mem_use_virtual) {
288 clk->set_mode = arch_timer_set_mode_virt_mem;
289 clk->set_next_event =
290 arch_timer_set_next_event_virt_mem;
291 } else {
292 clk->set_mode = arch_timer_set_mode_phys_mem;
293 clk->set_next_event =
294 arch_timer_set_next_event_phys_mem;
295 }
296 }
297
298 clk->set_mode(CLOCK_EVT_MODE_SHUTDOWN, clk);
299
300 clockevents_config_and_register(clk, arch_timer_rate, 0xf, 0x7fffffff);
301 }
302
303 static void arch_timer_evtstrm_enable(int divider)
304 {
305 u32 cntkctl = arch_timer_get_cntkctl();
306
307 cntkctl &= ~ARCH_TIMER_EVT_TRIGGER_MASK;
308 /* Set the divider and enable virtual event stream */
309 cntkctl |= (divider << ARCH_TIMER_EVT_TRIGGER_SHIFT)
310 | ARCH_TIMER_VIRT_EVT_EN;
311 arch_timer_set_cntkctl(cntkctl);
312 elf_hwcap |= HWCAP_EVTSTRM;
313 #ifdef CONFIG_COMPAT
314 compat_elf_hwcap |= COMPAT_HWCAP_EVTSTRM;
315 #endif
316 }
317
318 static void arch_timer_configure_evtstream(void)
319 {
320 int evt_stream_div, pos;
321
322 /* Find the closest power of two to the divisor */
323 evt_stream_div = arch_timer_rate / ARCH_TIMER_EVT_STREAM_FREQ;
324 pos = fls(evt_stream_div);
325 if (pos > 1 && !(evt_stream_div & (1 << (pos - 2))))
326 pos--;
327 /* enable event stream */
328 arch_timer_evtstrm_enable(min(pos, 15));
329 }
330
331 static void arch_counter_set_user_access(void)
332 {
333 u32 cntkctl = arch_timer_get_cntkctl();
334
335 /* Disable user access to the timers and the physical counter */
336 /* Also disable virtual event stream */
337 cntkctl &= ~(ARCH_TIMER_USR_PT_ACCESS_EN
338 | ARCH_TIMER_USR_VT_ACCESS_EN
339 | ARCH_TIMER_VIRT_EVT_EN
340 | ARCH_TIMER_USR_PCT_ACCESS_EN);
341
342 /* Enable user access to the virtual counter */
343 cntkctl |= ARCH_TIMER_USR_VCT_ACCESS_EN;
344
345 arch_timer_set_cntkctl(cntkctl);
346 }
347
348 static int arch_timer_setup(struct clock_event_device *clk)
349 {
350 __arch_timer_setup(ARCH_CP15_TIMER, clk);
351
352 if (arch_timer_use_virtual)
353 enable_percpu_irq(arch_timer_ppi[VIRT_PPI], 0);
354 else {
355 enable_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI], 0);
356 if (arch_timer_ppi[PHYS_NONSECURE_PPI])
357 enable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI], 0);
358 }
359
360 arch_counter_set_user_access();
361 if (IS_ENABLED(CONFIG_ARM_ARCH_TIMER_EVTSTREAM))
362 arch_timer_configure_evtstream();
363
364 return 0;
365 }
366
367 static void
368 arch_timer_detect_rate(void __iomem *cntbase, struct device_node *np)
369 {
370 /* Who has more than one independent system counter? */
371 if (arch_timer_rate)
372 return;
373
374 /* Try to determine the frequency from the device tree or CNTFRQ */
375 if (of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) {
376 if (cntbase)
377 arch_timer_rate = readl_relaxed(cntbase + CNTFRQ);
378 else
379 arch_timer_rate = arch_timer_get_cntfrq();
380 }
381
382 /* Check the timer frequency. */
383 if (arch_timer_rate == 0)
384 pr_warn("Architected timer frequency not available\n");
385 }
386
387 static void arch_timer_banner(unsigned type)
388 {
389 pr_info("Architected %s%s%s timer(s) running at %lu.%02luMHz (%s%s%s).\n",
390 type & ARCH_CP15_TIMER ? "cp15" : "",
391 type == (ARCH_CP15_TIMER | ARCH_MEM_TIMER) ? " and " : "",
392 type & ARCH_MEM_TIMER ? "mmio" : "",
393 (unsigned long)arch_timer_rate / 1000000,
394 (unsigned long)(arch_timer_rate / 10000) % 100,
395 type & ARCH_CP15_TIMER ?
396 arch_timer_use_virtual ? "virt" : "phys" :
397 "",
398 type == (ARCH_CP15_TIMER | ARCH_MEM_TIMER) ? "/" : "",
399 type & ARCH_MEM_TIMER ?
400 arch_timer_mem_use_virtual ? "virt" : "phys" :
401 "");
402 }
403
404 u32 arch_timer_get_rate(void)
405 {
406 return arch_timer_rate;
407 }
408
409 static u64 arch_counter_get_cntvct_mem(void)
410 {
411 u32 vct_lo, vct_hi, tmp_hi;
412
413 do {
414 vct_hi = readl_relaxed(arch_counter_base + CNTVCT_HI);
415 vct_lo = readl_relaxed(arch_counter_base + CNTVCT_LO);
416 tmp_hi = readl_relaxed(arch_counter_base + CNTVCT_HI);
417 } while (vct_hi != tmp_hi);
418
419 return ((u64) vct_hi << 32) | vct_lo;
420 }
421
422 /*
423 * Default to cp15 based access because arm64 uses this function for
424 * sched_clock() before DT is probed and the cp15 method is guaranteed
425 * to exist on arm64. arm doesn't use this before DT is probed so even
426 * if we don't have the cp15 accessors we won't have a problem.
427 */
428 u64 (*arch_timer_read_counter)(void) = arch_counter_get_cntvct;
429
430 static cycle_t arch_counter_read(struct clocksource *cs)
431 {
432 return arch_timer_read_counter();
433 }
434
435 static cycle_t arch_counter_read_cc(const struct cyclecounter *cc)
436 {
437 return arch_timer_read_counter();
438 }
439
440 static struct clocksource clocksource_counter = {
441 .name = "arch_sys_counter",
442 .rating = 400,
443 .read = arch_counter_read,
444 .mask = CLOCKSOURCE_MASK(56),
445 .flags = CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_SUSPEND_NONSTOP,
446 };
447
448 static struct cyclecounter cyclecounter = {
449 .read = arch_counter_read_cc,
450 .mask = CLOCKSOURCE_MASK(56),
451 };
452
453 static struct timecounter timecounter;
454
455 struct timecounter *arch_timer_get_timecounter(void)
456 {
457 return &timecounter;
458 }
459
460 static void __init arch_counter_register(unsigned type)
461 {
462 u64 start_count;
463
464 /* Register the CP15 based counter if we have one */
465 if (type & ARCH_CP15_TIMER) {
466 if (IS_ENABLED(CONFIG_ARM64) || arch_timer_use_virtual)
467 arch_timer_read_counter = arch_counter_get_cntvct;
468 else
469 arch_timer_read_counter = arch_counter_get_cntpct;
470 } else {
471 arch_timer_read_counter = arch_counter_get_cntvct_mem;
472
473 /* If the clocksource name is "arch_sys_counter" the
474 * VDSO will attempt to read the CP15-based counter.
475 * Ensure this does not happen when CP15-based
476 * counter is not available.
477 */
478 clocksource_counter.name = "arch_mem_counter";
479 }
480
481 start_count = arch_timer_read_counter();
482 clocksource_register_hz(&clocksource_counter, arch_timer_rate);
483 cyclecounter.mult = clocksource_counter.mult;
484 cyclecounter.shift = clocksource_counter.shift;
485 timecounter_init(&timecounter, &cyclecounter, start_count);
486
487 /* 56 bits minimum, so we assume worst case rollover */
488 sched_clock_register(arch_timer_read_counter, 56, arch_timer_rate);
489 }
490
491 static void arch_timer_stop(struct clock_event_device *clk)
492 {
493 pr_debug("arch_timer_teardown disable IRQ%d cpu #%d\n",
494 clk->irq, smp_processor_id());
495
496 if (arch_timer_use_virtual)
497 disable_percpu_irq(arch_timer_ppi[VIRT_PPI]);
498 else {
499 disable_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI]);
500 if (arch_timer_ppi[PHYS_NONSECURE_PPI])
501 disable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI]);
502 }
503
504 clk->set_mode(CLOCK_EVT_MODE_UNUSED, clk);
505 }
506
507 static int arch_timer_cpu_notify(struct notifier_block *self,
508 unsigned long action, void *hcpu)
509 {
510 /*
511 * Grab cpu pointer in each case to avoid spurious
512 * preemptible warnings
513 */
514 switch (action & ~CPU_TASKS_FROZEN) {
515 case CPU_STARTING:
516 arch_timer_setup(this_cpu_ptr(arch_timer_evt));
517 break;
518 case CPU_DYING:
519 arch_timer_stop(this_cpu_ptr(arch_timer_evt));
520 break;
521 }
522
523 return NOTIFY_OK;
524 }
525
526 static struct notifier_block arch_timer_cpu_nb = {
527 .notifier_call = arch_timer_cpu_notify,
528 };
529
530 #ifdef CONFIG_CPU_PM
531 static unsigned int saved_cntkctl;
532 static int arch_timer_cpu_pm_notify(struct notifier_block *self,
533 unsigned long action, void *hcpu)
534 {
535 if (action == CPU_PM_ENTER)
536 saved_cntkctl = arch_timer_get_cntkctl();
537 else if (action == CPU_PM_ENTER_FAILED || action == CPU_PM_EXIT)
538 arch_timer_set_cntkctl(saved_cntkctl);
539 return NOTIFY_OK;
540 }
541
542 static struct notifier_block arch_timer_cpu_pm_notifier = {
543 .notifier_call = arch_timer_cpu_pm_notify,
544 };
545
546 static int __init arch_timer_cpu_pm_init(void)
547 {
548 return cpu_pm_register_notifier(&arch_timer_cpu_pm_notifier);
549 }
550 #else
551 static int __init arch_timer_cpu_pm_init(void)
552 {
553 return 0;
554 }
555 #endif
556
557 static int __init arch_timer_register(void)
558 {
559 int err;
560 int ppi;
561
562 arch_timer_evt = alloc_percpu(struct clock_event_device);
563 if (!arch_timer_evt) {
564 err = -ENOMEM;
565 goto out;
566 }
567
568 if (arch_timer_use_virtual) {
569 ppi = arch_timer_ppi[VIRT_PPI];
570 err = request_percpu_irq(ppi, arch_timer_handler_virt,
571 "arch_timer", arch_timer_evt);
572 } else {
573 ppi = arch_timer_ppi[PHYS_SECURE_PPI];
574 err = request_percpu_irq(ppi, arch_timer_handler_phys,
575 "arch_timer", arch_timer_evt);
576 if (!err && arch_timer_ppi[PHYS_NONSECURE_PPI]) {
577 ppi = arch_timer_ppi[PHYS_NONSECURE_PPI];
578 err = request_percpu_irq(ppi, arch_timer_handler_phys,
579 "arch_timer", arch_timer_evt);
580 if (err)
581 free_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI],
582 arch_timer_evt);
583 }
584 }
585
586 if (err) {
587 pr_err("arch_timer: can't register interrupt %d (%d)\n",
588 ppi, err);
589 goto out_free;
590 }
591
592 err = register_cpu_notifier(&arch_timer_cpu_nb);
593 if (err)
594 goto out_free_irq;
595
596 err = arch_timer_cpu_pm_init();
597 if (err)
598 goto out_unreg_notify;
599
600 /* Immediately configure the timer on the boot CPU */
601 arch_timer_setup(this_cpu_ptr(arch_timer_evt));
602
603 return 0;
604
605 out_unreg_notify:
606 unregister_cpu_notifier(&arch_timer_cpu_nb);
607 out_free_irq:
608 if (arch_timer_use_virtual)
609 free_percpu_irq(arch_timer_ppi[VIRT_PPI], arch_timer_evt);
610 else {
611 free_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI],
612 arch_timer_evt);
613 if (arch_timer_ppi[PHYS_NONSECURE_PPI])
614 free_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI],
615 arch_timer_evt);
616 }
617
618 out_free:
619 free_percpu(arch_timer_evt);
620 out:
621 return err;
622 }
623
624 static int __init arch_timer_mem_register(void __iomem *base, unsigned int irq)
625 {
626 int ret;
627 irq_handler_t func;
628 struct arch_timer *t;
629
630 t = kzalloc(sizeof(*t), GFP_KERNEL);
631 if (!t)
632 return -ENOMEM;
633
634 t->base = base;
635 t->evt.irq = irq;
636 __arch_timer_setup(ARCH_MEM_TIMER, &t->evt);
637
638 if (arch_timer_mem_use_virtual)
639 func = arch_timer_handler_virt_mem;
640 else
641 func = arch_timer_handler_phys_mem;
642
643 ret = request_irq(irq, func, IRQF_TIMER, "arch_mem_timer", &t->evt);
644 if (ret) {
645 pr_err("arch_timer: Failed to request mem timer irq\n");
646 kfree(t);
647 }
648
649 return ret;
650 }
651
652 static const struct of_device_id arch_timer_of_match[] __initconst = {
653 { .compatible = "arm,armv7-timer", },
654 { .compatible = "arm,armv8-timer", },
655 {},
656 };
657
658 static const struct of_device_id arch_timer_mem_of_match[] __initconst = {
659 { .compatible = "arm,armv7-timer-mem", },
660 {},
661 };
662
663 static bool __init
664 arch_timer_probed(int type, const struct of_device_id *matches)
665 {
666 struct device_node *dn;
667 bool probed = true;
668
669 dn = of_find_matching_node(NULL, matches);
670 if (dn && of_device_is_available(dn) && !(arch_timers_present & type))
671 probed = false;
672 of_node_put(dn);
673
674 return probed;
675 }
676
677 static void __init arch_timer_common_init(void)
678 {
679 unsigned mask = ARCH_CP15_TIMER | ARCH_MEM_TIMER;
680
681 /* Wait until both nodes are probed if we have two timers */
682 if ((arch_timers_present & mask) != mask) {
683 if (!arch_timer_probed(ARCH_MEM_TIMER, arch_timer_mem_of_match))
684 return;
685 if (!arch_timer_probed(ARCH_CP15_TIMER, arch_timer_of_match))
686 return;
687 }
688
689 arch_timer_banner(arch_timers_present);
690 arch_counter_register(arch_timers_present);
691 arch_timer_arch_init();
692 }
693
694 static void __init arch_timer_init(struct device_node *np)
695 {
696 int i;
697
698 if (arch_timers_present & ARCH_CP15_TIMER) {
699 pr_warn("arch_timer: multiple nodes in dt, skipping\n");
700 return;
701 }
702
703 arch_timers_present |= ARCH_CP15_TIMER;
704 for (i = PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++)
705 arch_timer_ppi[i] = irq_of_parse_and_map(np, i);
706 arch_timer_detect_rate(NULL, np);
707
708 /*
709 * If we cannot rely on firmware initializing the timer registers then
710 * we should use the physical timers instead.
711 */
712 if (IS_ENABLED(CONFIG_ARM) &&
713 of_property_read_bool(np, "arm,cpu-registers-not-fw-configured"))
714 arch_timer_use_virtual = false;
715
716 /*
717 * If HYP mode is available, we know that the physical timer
718 * has been configured to be accessible from PL1. Use it, so
719 * that a guest can use the virtual timer instead.
720 *
721 * If no interrupt provided for virtual timer, we'll have to
722 * stick to the physical timer. It'd better be accessible...
723 */
724 if (is_hyp_mode_available() || !arch_timer_ppi[VIRT_PPI]) {
725 arch_timer_use_virtual = false;
726
727 if (!arch_timer_ppi[PHYS_SECURE_PPI] ||
728 !arch_timer_ppi[PHYS_NONSECURE_PPI]) {
729 pr_warn("arch_timer: No interrupt available, giving up\n");
730 return;
731 }
732 }
733
734 arch_timer_c3stop = !of_property_read_bool(np, "always-on");
735
736 arch_timer_register();
737 arch_timer_common_init();
738 }
739 CLOCKSOURCE_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer", arch_timer_init);
740 CLOCKSOURCE_OF_DECLARE(armv8_arch_timer, "arm,armv8-timer", arch_timer_init);
741
742 static void __init arch_timer_mem_init(struct device_node *np)
743 {
744 struct device_node *frame, *best_frame = NULL;
745 void __iomem *cntctlbase, *base;
746 unsigned int irq;
747 u32 cnttidr;
748
749 arch_timers_present |= ARCH_MEM_TIMER;
750 cntctlbase = of_iomap(np, 0);
751 if (!cntctlbase) {
752 pr_err("arch_timer: Can't find CNTCTLBase\n");
753 return;
754 }
755
756 cnttidr = readl_relaxed(cntctlbase + CNTTIDR);
757 iounmap(cntctlbase);
758
759 /*
760 * Try to find a virtual capable frame. Otherwise fall back to a
761 * physical capable frame.
762 */
763 for_each_available_child_of_node(np, frame) {
764 int n;
765
766 if (of_property_read_u32(frame, "frame-number", &n)) {
767 pr_err("arch_timer: Missing frame-number\n");
768 of_node_put(best_frame);
769 of_node_put(frame);
770 return;
771 }
772
773 if (cnttidr & CNTTIDR_VIRT(n)) {
774 of_node_put(best_frame);
775 best_frame = frame;
776 arch_timer_mem_use_virtual = true;
777 break;
778 }
779 of_node_put(best_frame);
780 best_frame = of_node_get(frame);
781 }
782
783 base = arch_counter_base = of_iomap(best_frame, 0);
784 if (!base) {
785 pr_err("arch_timer: Can't map frame's registers\n");
786 of_node_put(best_frame);
787 return;
788 }
789
790 if (arch_timer_mem_use_virtual)
791 irq = irq_of_parse_and_map(best_frame, 1);
792 else
793 irq = irq_of_parse_and_map(best_frame, 0);
794 of_node_put(best_frame);
795 if (!irq) {
796 pr_err("arch_timer: Frame missing %s irq",
797 arch_timer_mem_use_virtual ? "virt" : "phys");
798 return;
799 }
800
801 arch_timer_detect_rate(base, np);
802 arch_timer_mem_register(base, irq);
803 arch_timer_common_init();
804 }
805 CLOCKSOURCE_OF_DECLARE(armv7_arch_timer_mem, "arm,armv7-timer-mem",
806 arch_timer_mem_init);
Linux kernel - Deliverables
This page took 0.071404 seconds and 5 git commands to generate.