1// SPDX-License-Identifier: GPL-2.0-only
2/* linux/arch/arm/mach-exynos4/mct.c
3 *
4 * Copyright (c) 2011 Samsung Electronics Co., Ltd.
5 * http://www.samsung.com
6 *
7 * Exynos4 MCT(Multi-Core Timer) support
8*/
9
10#include <linux/interrupt.h>
11#include <linux/irq.h>
12#include <linux/err.h>
13#include <linux/clk.h>
14#include <linux/clockchips.h>
15#include <linux/cpu.h>
16#include <linux/delay.h>
17#include <linux/percpu.h>
18#include <linux/of.h>
19#include <linux/of_irq.h>
20#include <linux/of_address.h>
21#include <linux/clocksource.h>
22#include <linux/sched_clock.h>
23
24#define EXYNOS4_MCTREG(x) (x)
25#define EXYNOS4_MCT_G_CNT_L EXYNOS4_MCTREG(0x100)
26#define EXYNOS4_MCT_G_CNT_U EXYNOS4_MCTREG(0x104)
27#define EXYNOS4_MCT_G_CNT_WSTAT EXYNOS4_MCTREG(0x110)
28#define EXYNOS4_MCT_G_COMP0_L EXYNOS4_MCTREG(0x200)
29#define EXYNOS4_MCT_G_COMP0_U EXYNOS4_MCTREG(0x204)
30#define EXYNOS4_MCT_G_COMP0_ADD_INCR EXYNOS4_MCTREG(0x208)
31#define EXYNOS4_MCT_G_TCON EXYNOS4_MCTREG(0x240)
32#define EXYNOS4_MCT_G_INT_CSTAT EXYNOS4_MCTREG(0x244)
33#define EXYNOS4_MCT_G_INT_ENB EXYNOS4_MCTREG(0x248)
34#define EXYNOS4_MCT_G_WSTAT EXYNOS4_MCTREG(0x24C)
35#define _EXYNOS4_MCT_L_BASE EXYNOS4_MCTREG(0x300)
36#define EXYNOS4_MCT_L_BASE(x) (_EXYNOS4_MCT_L_BASE + (0x100 * (x)))
37#define EXYNOS4_MCT_L_MASK (0xffffff00)
38
39#define MCT_L_TCNTB_OFFSET (0x00)
40#define MCT_L_ICNTB_OFFSET (0x08)
41#define MCT_L_TCON_OFFSET (0x20)
42#define MCT_L_INT_CSTAT_OFFSET (0x30)
43#define MCT_L_INT_ENB_OFFSET (0x34)
44#define MCT_L_WSTAT_OFFSET (0x40)
45#define MCT_G_TCON_START (1 << 8)
46#define MCT_G_TCON_COMP0_AUTO_INC (1 << 1)
47#define MCT_G_TCON_COMP0_ENABLE (1 << 0)
48#define MCT_L_TCON_INTERVAL_MODE (1 << 2)
49#define MCT_L_TCON_INT_START (1 << 1)
50#define MCT_L_TCON_TIMER_START (1 << 0)
51
52#define TICK_BASE_CNT 1
53
54#ifdef CONFIG_ARM
55/* Use values higher than ARM arch timer. See 6282edb72bed. */
56#define MCT_CLKSOURCE_RATING 450
57#define MCT_CLKEVENTS_RATING 500
58#else
59#define MCT_CLKSOURCE_RATING 350
60#define MCT_CLKEVENTS_RATING 350
61#endif
62
63/* There are four Global timers starting with 0 offset */
64#define MCT_G0_IRQ 0
65/* Local timers count starts after global timer count */
66#define MCT_L0_IRQ 4
67/* Max number of IRQ as per DT binding document */
68#define MCT_NR_IRQS 20
69/* Max number of local timers */
70#define MCT_NR_LOCAL (MCT_NR_IRQS - MCT_L0_IRQ)
71
72enum {
73 MCT_INT_SPI,
74 MCT_INT_PPI
75};
76
77static void __iomem *reg_base;
78static unsigned long clk_rate;
79static unsigned int mct_int_type;
80static int mct_irqs[MCT_NR_IRQS];
81
82struct mct_clock_event_device {
83 struct clock_event_device evt;
84 unsigned long base;
85 /**
86 * The length of the name must be adjusted if number of
87 * local timer interrupts grow over two digits
88 */
89 char name[11];
90};
91
92static void exynos4_mct_write(unsigned int value, unsigned long offset)
93{
94 unsigned long stat_addr;
95 u32 mask;
96 u32 i;
97
98 writel_relaxed(value, reg_base + offset);
99
100 if (likely(offset >= EXYNOS4_MCT_L_BASE(0))) {
101 stat_addr = (offset & EXYNOS4_MCT_L_MASK) + MCT_L_WSTAT_OFFSET;
102 switch (offset & ~EXYNOS4_MCT_L_MASK) {
103 case MCT_L_TCON_OFFSET:
104 mask = 1 << 3; /* L_TCON write status */
105 break;
106 case MCT_L_ICNTB_OFFSET:
107 mask = 1 << 1; /* L_ICNTB write status */
108 break;
109 case MCT_L_TCNTB_OFFSET:
110 mask = 1 << 0; /* L_TCNTB write status */
111 break;
112 default:
113 return;
114 }
115 } else {
116 switch (offset) {
117 case EXYNOS4_MCT_G_TCON:
118 stat_addr = EXYNOS4_MCT_G_WSTAT;
119 mask = 1 << 16; /* G_TCON write status */
120 break;
121 case EXYNOS4_MCT_G_COMP0_L:
122 stat_addr = EXYNOS4_MCT_G_WSTAT;
123 mask = 1 << 0; /* G_COMP0_L write status */
124 break;
125 case EXYNOS4_MCT_G_COMP0_U:
126 stat_addr = EXYNOS4_MCT_G_WSTAT;
127 mask = 1 << 1; /* G_COMP0_U write status */
128 break;
129 case EXYNOS4_MCT_G_COMP0_ADD_INCR:
130 stat_addr = EXYNOS4_MCT_G_WSTAT;
131 mask = 1 << 2; /* G_COMP0_ADD_INCR w status */
132 break;
133 case EXYNOS4_MCT_G_CNT_L:
134 stat_addr = EXYNOS4_MCT_G_CNT_WSTAT;
135 mask = 1 << 0; /* G_CNT_L write status */
136 break;
137 case EXYNOS4_MCT_G_CNT_U:
138 stat_addr = EXYNOS4_MCT_G_CNT_WSTAT;
139 mask = 1 << 1; /* G_CNT_U write status */
140 break;
141 default:
142 return;
143 }
144 }
145
146 /* Wait maximum 1 ms until written values are applied */
147 for (i = 0; i < loops_per_jiffy / 1000 * HZ; i++)
148 if (readl_relaxed(reg_base + stat_addr) & mask) {
149 writel_relaxed(mask, reg_base + stat_addr);
150 return;
151 }
152
153 panic(fmt: "MCT hangs after writing %d (offset:0x%lx)\n", value, offset);
154}
155
156/* Clocksource handling */
157static void exynos4_mct_frc_start(void)
158{
159 u32 reg;
160
161 reg = readl_relaxed(reg_base + EXYNOS4_MCT_G_TCON);
162 reg |= MCT_G_TCON_START;
163 exynos4_mct_write(value: reg, EXYNOS4_MCT_G_TCON);
164}
165
166/**
167 * exynos4_read_count_64 - Read all 64-bits of the global counter
168 *
169 * This will read all 64-bits of the global counter taking care to make sure
170 * that the upper and lower half match. Note that reading the MCT can be quite
171 * slow (hundreds of nanoseconds) so you should use the 32-bit (lower half
172 * only) version when possible.
173 *
174 * Returns the number of cycles in the global counter.
175 */
176static u64 exynos4_read_count_64(void)
177{
178 unsigned int lo, hi;
179 u32 hi2 = readl_relaxed(reg_base + EXYNOS4_MCT_G_CNT_U);
180
181 do {
182 hi = hi2;
183 lo = readl_relaxed(reg_base + EXYNOS4_MCT_G_CNT_L);
184 hi2 = readl_relaxed(reg_base + EXYNOS4_MCT_G_CNT_U);
185 } while (hi != hi2);
186
187 return ((u64)hi << 32) | lo;
188}
189
190/**
191 * exynos4_read_count_32 - Read the lower 32-bits of the global counter
192 *
193 * This will read just the lower 32-bits of the global counter. This is marked
194 * as notrace so it can be used by the scheduler clock.
195 *
196 * Returns the number of cycles in the global counter (lower 32 bits).
197 */
198static u32 notrace exynos4_read_count_32(void)
199{
200 return readl_relaxed(reg_base + EXYNOS4_MCT_G_CNT_L);
201}
202
203static u64 exynos4_frc_read(struct clocksource *cs)
204{
205 return exynos4_read_count_32();
206}
207
208static void exynos4_frc_resume(struct clocksource *cs)
209{
210 exynos4_mct_frc_start();
211}
212
213static struct clocksource mct_frc = {
214 .name = "mct-frc",
215 .rating = MCT_CLKSOURCE_RATING,
216 .read = exynos4_frc_read,
217 .mask = CLOCKSOURCE_MASK(32),
218 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
219 .resume = exynos4_frc_resume,
220};
221
222static u64 notrace exynos4_read_sched_clock(void)
223{
224 return exynos4_read_count_32();
225}
226
227#if defined(CONFIG_ARM)
228static struct delay_timer exynos4_delay_timer;
229
230static cycles_t exynos4_read_current_timer(void)
231{
232 BUILD_BUG_ON_MSG(sizeof(cycles_t) != sizeof(u32),
233 "cycles_t needs to move to 32-bit for ARM64 usage");
234 return exynos4_read_count_32();
235}
236#endif
237
238static int __init exynos4_clocksource_init(bool frc_shared)
239{
240 /*
241 * When the frc is shared, the main processor should have already
242 * turned it on and we shouldn't be writing to TCON.
243 */
244 if (frc_shared)
245 mct_frc.resume = NULL;
246 else
247 exynos4_mct_frc_start();
248
249#if defined(CONFIG_ARM)
250 exynos4_delay_timer.read_current_timer = &exynos4_read_current_timer;
251 exynos4_delay_timer.freq = clk_rate;
252 register_current_timer_delay(&exynos4_delay_timer);
253#endif
254
255 if (clocksource_register_hz(cs: &mct_frc, hz: clk_rate))
256 panic(fmt: "%s: can't register clocksource\n", mct_frc.name);
257
258 sched_clock_register(read: exynos4_read_sched_clock, bits: 32, rate: clk_rate);
259
260 return 0;
261}
262
263static void exynos4_mct_comp0_stop(void)
264{
265 unsigned int tcon;
266
267 tcon = readl_relaxed(reg_base + EXYNOS4_MCT_G_TCON);
268 tcon &= ~(MCT_G_TCON_COMP0_ENABLE | MCT_G_TCON_COMP0_AUTO_INC);
269
270 exynos4_mct_write(value: tcon, EXYNOS4_MCT_G_TCON);
271 exynos4_mct_write(value: 0, EXYNOS4_MCT_G_INT_ENB);
272}
273
274static void exynos4_mct_comp0_start(bool periodic, unsigned long cycles)
275{
276 unsigned int tcon;
277 u64 comp_cycle;
278
279 tcon = readl_relaxed(reg_base + EXYNOS4_MCT_G_TCON);
280
281 if (periodic) {
282 tcon |= MCT_G_TCON_COMP0_AUTO_INC;
283 exynos4_mct_write(value: cycles, EXYNOS4_MCT_G_COMP0_ADD_INCR);
284 }
285
286 comp_cycle = exynos4_read_count_64() + cycles;
287 exynos4_mct_write(value: (u32)comp_cycle, EXYNOS4_MCT_G_COMP0_L);
288 exynos4_mct_write(value: (u32)(comp_cycle >> 32), EXYNOS4_MCT_G_COMP0_U);
289
290 exynos4_mct_write(value: 0x1, EXYNOS4_MCT_G_INT_ENB);
291
292 tcon |= MCT_G_TCON_COMP0_ENABLE;
293 exynos4_mct_write(value: tcon , EXYNOS4_MCT_G_TCON);
294}
295
296static int exynos4_comp_set_next_event(unsigned long cycles,
297 struct clock_event_device *evt)
298{
299 exynos4_mct_comp0_start(periodic: false, cycles);
300
301 return 0;
302}
303
304static int mct_set_state_shutdown(struct clock_event_device *evt)
305{
306 exynos4_mct_comp0_stop();
307 return 0;
308}
309
310static int mct_set_state_periodic(struct clock_event_device *evt)
311{
312 unsigned long cycles_per_jiffy;
313
314 cycles_per_jiffy = (((unsigned long long)NSEC_PER_SEC / HZ * evt->mult)
315 >> evt->shift);
316 exynos4_mct_comp0_stop();
317 exynos4_mct_comp0_start(periodic: true, cycles: cycles_per_jiffy);
318 return 0;
319}
320
321static struct clock_event_device mct_comp_device = {
322 .name = "mct-comp",
323 .features = CLOCK_EVT_FEAT_PERIODIC |
324 CLOCK_EVT_FEAT_ONESHOT,
325 .rating = 250,
326 .set_next_event = exynos4_comp_set_next_event,
327 .set_state_periodic = mct_set_state_periodic,
328 .set_state_shutdown = mct_set_state_shutdown,
329 .set_state_oneshot = mct_set_state_shutdown,
330 .set_state_oneshot_stopped = mct_set_state_shutdown,
331 .tick_resume = mct_set_state_shutdown,
332};
333
334static irqreturn_t exynos4_mct_comp_isr(int irq, void *dev_id)
335{
336 struct clock_event_device *evt = dev_id;
337
338 exynos4_mct_write(value: 0x1, EXYNOS4_MCT_G_INT_CSTAT);
339
340 evt->event_handler(evt);
341
342 return IRQ_HANDLED;
343}
344
345static int exynos4_clockevent_init(void)
346{
347 mct_comp_device.cpumask = cpumask_of(0);
348 clockevents_config_and_register(dev: &mct_comp_device, freq: clk_rate,
349 min_delta: 0xf, max_delta: 0xffffffff);
350 if (request_irq(irq: mct_irqs[MCT_G0_IRQ], handler: exynos4_mct_comp_isr,
351 IRQF_TIMER | IRQF_IRQPOLL, name: "mct_comp_irq",
352 dev: &mct_comp_device))
353 pr_err("%s: request_irq() failed\n", "mct_comp_irq");
354
355 return 0;
356}
357
358static DEFINE_PER_CPU(struct mct_clock_event_device, percpu_mct_tick);
359
360/* Clock event handling */
361static void exynos4_mct_tick_stop(struct mct_clock_event_device *mevt)
362{
363 unsigned long tmp;
364 unsigned long mask = MCT_L_TCON_INT_START | MCT_L_TCON_TIMER_START;
365 unsigned long offset = mevt->base + MCT_L_TCON_OFFSET;
366
367 tmp = readl_relaxed(reg_base + offset);
368 if (tmp & mask) {
369 tmp &= ~mask;
370 exynos4_mct_write(value: tmp, offset);
371 }
372}
373
374static void exynos4_mct_tick_start(unsigned long cycles,
375 struct mct_clock_event_device *mevt)
376{
377 unsigned long tmp;
378
379 exynos4_mct_tick_stop(mevt);
380
381 tmp = (1 << 31) | cycles; /* MCT_L_UPDATE_ICNTB */
382
383 /* update interrupt count buffer */
384 exynos4_mct_write(value: tmp, offset: mevt->base + MCT_L_ICNTB_OFFSET);
385
386 /* enable MCT tick interrupt */
387 exynos4_mct_write(value: 0x1, offset: mevt->base + MCT_L_INT_ENB_OFFSET);
388
389 tmp = readl_relaxed(reg_base + mevt->base + MCT_L_TCON_OFFSET);
390 tmp |= MCT_L_TCON_INT_START | MCT_L_TCON_TIMER_START |
391 MCT_L_TCON_INTERVAL_MODE;
392 exynos4_mct_write(value: tmp, offset: mevt->base + MCT_L_TCON_OFFSET);
393}
394
395static void exynos4_mct_tick_clear(struct mct_clock_event_device *mevt)
396{
397 /* Clear the MCT tick interrupt */
398 if (readl_relaxed(reg_base + mevt->base + MCT_L_INT_CSTAT_OFFSET) & 1)
399 exynos4_mct_write(value: 0x1, offset: mevt->base + MCT_L_INT_CSTAT_OFFSET);
400}
401
402static int exynos4_tick_set_next_event(unsigned long cycles,
403 struct clock_event_device *evt)
404{
405 struct mct_clock_event_device *mevt;
406
407 mevt = container_of(evt, struct mct_clock_event_device, evt);
408 exynos4_mct_tick_start(cycles, mevt);
409 return 0;
410}
411
412static int set_state_shutdown(struct clock_event_device *evt)
413{
414 struct mct_clock_event_device *mevt;
415
416 mevt = container_of(evt, struct mct_clock_event_device, evt);
417 exynos4_mct_tick_stop(mevt);
418 exynos4_mct_tick_clear(mevt);
419 return 0;
420}
421
422static int set_state_periodic(struct clock_event_device *evt)
423{
424 struct mct_clock_event_device *mevt;
425 unsigned long cycles_per_jiffy;
426
427 mevt = container_of(evt, struct mct_clock_event_device, evt);
428 cycles_per_jiffy = (((unsigned long long)NSEC_PER_SEC / HZ * evt->mult)
429 >> evt->shift);
430 exynos4_mct_tick_stop(mevt);
431 exynos4_mct_tick_start(cycles: cycles_per_jiffy, mevt);
432 return 0;
433}
434
435static irqreturn_t exynos4_mct_tick_isr(int irq, void *dev_id)
436{
437 struct mct_clock_event_device *mevt = dev_id;
438 struct clock_event_device *evt = &mevt->evt;
439
440 /*
441 * This is for supporting oneshot mode.
442 * Mct would generate interrupt periodically
443 * without explicit stopping.
444 */
445 if (!clockevent_state_periodic(dev: &mevt->evt))
446 exynos4_mct_tick_stop(mevt);
447
448 exynos4_mct_tick_clear(mevt);
449
450 evt->event_handler(evt);
451
452 return IRQ_HANDLED;
453}
454
455static int exynos4_mct_starting_cpu(unsigned int cpu)
456{
457 struct mct_clock_event_device *mevt =
458 per_cpu_ptr(&percpu_mct_tick, cpu);
459 struct clock_event_device *evt = &mevt->evt;
460
461 snprintf(buf: mevt->name, size: sizeof(mevt->name), fmt: "mct_tick%d", cpu);
462
463 evt->name = mevt->name;
464 evt->cpumask = cpumask_of(cpu);
465 evt->set_next_event = exynos4_tick_set_next_event;
466 evt->set_state_periodic = set_state_periodic;
467 evt->set_state_shutdown = set_state_shutdown;
468 evt->set_state_oneshot = set_state_shutdown;
469 evt->set_state_oneshot_stopped = set_state_shutdown;
470 evt->tick_resume = set_state_shutdown;
471 evt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT |
472 CLOCK_EVT_FEAT_PERCPU;
473 evt->rating = MCT_CLKEVENTS_RATING;
474
475 exynos4_mct_write(TICK_BASE_CNT, offset: mevt->base + MCT_L_TCNTB_OFFSET);
476
477 if (mct_int_type == MCT_INT_SPI) {
478
479 if (evt->irq == -1)
480 return -EIO;
481
482 irq_force_affinity(irq: evt->irq, cpumask_of(cpu));
483 enable_irq(irq: evt->irq);
484 } else {
485 enable_percpu_irq(irq: mct_irqs[MCT_L0_IRQ], type: 0);
486 }
487 clockevents_config_and_register(dev: evt, freq: clk_rate / (TICK_BASE_CNT + 1),
488 min_delta: 0xf, max_delta: 0x7fffffff);
489
490 return 0;
491}
492
493static int exynos4_mct_dying_cpu(unsigned int cpu)
494{
495 struct mct_clock_event_device *mevt =
496 per_cpu_ptr(&percpu_mct_tick, cpu);
497 struct clock_event_device *evt = &mevt->evt;
498
499 if (mct_int_type == MCT_INT_SPI) {
500 if (evt->irq != -1)
501 disable_irq_nosync(irq: evt->irq);
502 exynos4_mct_write(value: 0x1, offset: mevt->base + MCT_L_INT_CSTAT_OFFSET);
503 } else {
504 disable_percpu_irq(irq: mct_irqs[MCT_L0_IRQ]);
505 }
506 return 0;
507}
508
509static int __init exynos4_timer_resources(struct device_node *np)
510{
511 struct clk *mct_clk, *tick_clk;
512
513 reg_base = of_iomap(node: np, index: 0);
514 if (!reg_base)
515 panic(fmt: "%s: unable to ioremap mct address space\n", __func__);
516
517 tick_clk = of_clk_get_by_name(np, name: "fin_pll");
518 if (IS_ERR(ptr: tick_clk))
519 panic(fmt: "%s: unable to determine tick clock rate\n", __func__);
520 clk_rate = clk_get_rate(clk: tick_clk);
521
522 mct_clk = of_clk_get_by_name(np, name: "mct");
523 if (IS_ERR(ptr: mct_clk))
524 panic(fmt: "%s: unable to retrieve mct clock instance\n", __func__);
525 clk_prepare_enable(clk: mct_clk);
526
527 return 0;
528}
529
530/**
531 * exynos4_timer_interrupts - initialize MCT interrupts
532 * @np: device node for MCT
533 * @int_type: interrupt type, MCT_INT_PPI or MCT_INT_SPI
534 * @local_idx: array mapping CPU numbers to local timer indices
535 * @nr_local: size of @local_idx array
536 */
537static int __init exynos4_timer_interrupts(struct device_node *np,
538 unsigned int int_type,
539 const u32 *local_idx,
540 size_t nr_local)
541{
542 int nr_irqs, i, err, cpu;
543
544 mct_int_type = int_type;
545
546 /* This driver uses only one global timer interrupt */
547 mct_irqs[MCT_G0_IRQ] = irq_of_parse_and_map(node: np, MCT_G0_IRQ);
548
549 /*
550 * Find out the number of local irqs specified. The local
551 * timer irqs are specified after the four global timer
552 * irqs are specified.
553 */
554 nr_irqs = of_irq_count(dev: np);
555 if (nr_irqs > ARRAY_SIZE(mct_irqs)) {
556 pr_err("exynos-mct: too many (%d) interrupts configured in DT\n",
557 nr_irqs);
558 nr_irqs = ARRAY_SIZE(mct_irqs);
559 }
560 for (i = MCT_L0_IRQ; i < nr_irqs; i++)
561 mct_irqs[i] = irq_of_parse_and_map(node: np, index: i);
562
563 if (mct_int_type == MCT_INT_PPI) {
564
565 err = request_percpu_irq(irq: mct_irqs[MCT_L0_IRQ],
566 handler: exynos4_mct_tick_isr, devname: "MCT",
567 percpu_dev_id: &percpu_mct_tick);
568 WARN(err, "MCT: can't request IRQ %d (%d)\n",
569 mct_irqs[MCT_L0_IRQ], err);
570 } else {
571 for_each_possible_cpu(cpu) {
572 int mct_irq;
573 unsigned int irq_idx;
574 struct mct_clock_event_device *pcpu_mevt =
575 per_cpu_ptr(&percpu_mct_tick, cpu);
576
577 if (cpu >= nr_local) {
578 err = -EINVAL;
579 goto out_irq;
580 }
581
582 irq_idx = MCT_L0_IRQ + local_idx[cpu];
583
584 pcpu_mevt->evt.irq = -1;
585 if (irq_idx >= ARRAY_SIZE(mct_irqs))
586 break;
587 mct_irq = mct_irqs[irq_idx];
588
589 irq_set_status_flags(irq: mct_irq, set: IRQ_NOAUTOEN);
590 if (request_irq(irq: mct_irq,
591 handler: exynos4_mct_tick_isr,
592 IRQF_TIMER | IRQF_NOBALANCING,
593 name: pcpu_mevt->name, dev: pcpu_mevt)) {
594 pr_err("exynos-mct: cannot register IRQ (cpu%d)\n",
595 cpu);
596
597 continue;
598 }
599 pcpu_mevt->evt.irq = mct_irq;
600 }
601 }
602
603 for_each_possible_cpu(cpu) {
604 struct mct_clock_event_device *mevt = per_cpu_ptr(&percpu_mct_tick, cpu);
605
606 if (cpu >= nr_local) {
607 err = -EINVAL;
608 goto out_irq;
609 }
610
611 mevt->base = EXYNOS4_MCT_L_BASE(local_idx[cpu]);
612 }
613
614 /* Install hotplug callbacks which configure the timer on this CPU */
615 err = cpuhp_setup_state(state: CPUHP_AP_EXYNOS4_MCT_TIMER_STARTING,
616 name: "clockevents/exynos4/mct_timer:starting",
617 startup: exynos4_mct_starting_cpu,
618 teardown: exynos4_mct_dying_cpu);
619 if (err)
620 goto out_irq;
621
622 return 0;
623
624out_irq:
625 if (mct_int_type == MCT_INT_PPI) {
626 free_percpu_irq(mct_irqs[MCT_L0_IRQ], &percpu_mct_tick);
627 } else {
628 for_each_possible_cpu(cpu) {
629 struct mct_clock_event_device *pcpu_mevt =
630 per_cpu_ptr(&percpu_mct_tick, cpu);
631
632 if (pcpu_mevt->evt.irq != -1) {
633 free_irq(pcpu_mevt->evt.irq, pcpu_mevt);
634 pcpu_mevt->evt.irq = -1;
635 }
636 }
637 }
638 return err;
639}
640
641static int __init mct_init_dt(struct device_node *np, unsigned int int_type)
642{
643 bool frc_shared = of_property_read_bool(np, propname: "samsung,frc-shared");
644 u32 local_idx[MCT_NR_LOCAL] = {0};
645 int nr_local;
646 int ret;
647
648 nr_local = of_property_count_u32_elems(np, propname: "samsung,local-timers");
649 if (nr_local == 0)
650 return -EINVAL;
651 if (nr_local > 0) {
652 if (nr_local > ARRAY_SIZE(local_idx))
653 return -EINVAL;
654
655 ret = of_property_read_u32_array(np, propname: "samsung,local-timers",
656 out_values: local_idx, sz: nr_local);
657 if (ret)
658 return ret;
659 } else {
660 int i;
661
662 nr_local = ARRAY_SIZE(local_idx);
663 for (i = 0; i < nr_local; i++)
664 local_idx[i] = i;
665 }
666
667 ret = exynos4_timer_resources(np);
668 if (ret)
669 return ret;
670
671 ret = exynos4_timer_interrupts(np, int_type, local_idx, nr_local);
672 if (ret)
673 return ret;
674
675 ret = exynos4_clocksource_init(frc_shared);
676 if (ret)
677 return ret;
678
679 /*
680 * When the FRC is shared with a main processor, this secondary
681 * processor cannot use the global comparator.
682 */
683 if (frc_shared)
684 return 0;
685
686 return exynos4_clockevent_init();
687}
688
689
690static int __init mct_init_spi(struct device_node *np)
691{
692 return mct_init_dt(np, int_type: MCT_INT_SPI);
693}
694
695static int __init mct_init_ppi(struct device_node *np)
696{
697 return mct_init_dt(np, int_type: MCT_INT_PPI);
698}
699TIMER_OF_DECLARE(exynos4210, "samsung,exynos4210-mct", mct_init_spi);
700TIMER_OF_DECLARE(exynos4412, "samsung,exynos4412-mct", mct_init_ppi);
701

source code of linux/drivers/clocksource/exynos_mct.c