Linux Audio

Check our new training course

Loading...
v6.8
  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("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(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 processer 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(&mct_frc, clk_rate))
256		panic("%s: can't register clocksource\n", mct_frc.name);
257
258	sched_clock_register(exynos4_read_sched_clock, 32, 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(tcon, EXYNOS4_MCT_G_TCON);
271	exynos4_mct_write(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(cycles, EXYNOS4_MCT_G_COMP0_ADD_INCR);
284	}
285
286	comp_cycle = exynos4_read_count_64() + cycles;
287	exynos4_mct_write((u32)comp_cycle, EXYNOS4_MCT_G_COMP0_L);
288	exynos4_mct_write((u32)(comp_cycle >> 32), EXYNOS4_MCT_G_COMP0_U);
289
290	exynos4_mct_write(0x1, EXYNOS4_MCT_G_INT_ENB);
291
292	tcon |= MCT_G_TCON_COMP0_ENABLE;
293	exynos4_mct_write(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(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(true, 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(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(&mct_comp_device, clk_rate,
349					0xf, 0xffffffff);
350	if (request_irq(mct_irqs[MCT_G0_IRQ], exynos4_mct_comp_isr,
351			IRQF_TIMER | IRQF_IRQPOLL, "mct_comp_irq",
352			&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(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(tmp, mevt->base + MCT_L_ICNTB_OFFSET);
385
386	/* enable MCT tick interrupt */
387	exynos4_mct_write(0x1, 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(tmp, 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(0x1, 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_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(&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(mevt->name, sizeof(mevt->name), "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, 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(evt->irq, cpumask_of(cpu));
483		enable_irq(evt->irq);
484	} else {
485		enable_percpu_irq(mct_irqs[MCT_L0_IRQ], 0);
486	}
487	clockevents_config_and_register(evt, clk_rate / (TICK_BASE_CNT + 1),
488					0xf, 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	evt->set_state_shutdown(evt);
500	if (mct_int_type == MCT_INT_SPI) {
501		if (evt->irq != -1)
502			disable_irq_nosync(evt->irq);
503		exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET);
504	} else {
505		disable_percpu_irq(mct_irqs[MCT_L0_IRQ]);
506	}
507	return 0;
508}
509
510static int __init exynos4_timer_resources(struct device_node *np)
511{
 
512	struct clk *mct_clk, *tick_clk;
513
514	reg_base = of_iomap(np, 0);
515	if (!reg_base)
516		panic("%s: unable to ioremap mct address space\n", __func__);
517
518	tick_clk = of_clk_get_by_name(np, "fin_pll");
519	if (IS_ERR(tick_clk))
520		panic("%s: unable to determine tick clock rate\n", __func__);
521	clk_rate = clk_get_rate(tick_clk);
522
523	mct_clk = of_clk_get_by_name(np, "mct");
524	if (IS_ERR(mct_clk))
525		panic("%s: unable to retrieve mct clock instance\n", __func__);
526	clk_prepare_enable(mct_clk);
527
528	return 0;
529}
530
531/**
532 * exynos4_timer_interrupts - initialize MCT interrupts
533 * @np: device node for MCT
534 * @int_type: interrupt type, MCT_INT_PPI or MCT_INT_SPI
535 * @local_idx: array mapping CPU numbers to local timer indices
536 * @nr_local: size of @local_idx array
537 */
538static int __init exynos4_timer_interrupts(struct device_node *np,
539					   unsigned int int_type,
540					   const u32 *local_idx,
541					   size_t nr_local)
542{
543	int nr_irqs, i, err, cpu;
544
545	mct_int_type = int_type;
546
547	/* This driver uses only one global timer interrupt */
548	mct_irqs[MCT_G0_IRQ] = irq_of_parse_and_map(np, MCT_G0_IRQ);
549
550	/*
551	 * Find out the number of local irqs specified. The local
552	 * timer irqs are specified after the four global timer
553	 * irqs are specified.
554	 */
555	nr_irqs = of_irq_count(np);
556	if (nr_irqs > ARRAY_SIZE(mct_irqs)) {
557		pr_err("exynos-mct: too many (%d) interrupts configured in DT\n",
558			nr_irqs);
559		nr_irqs = ARRAY_SIZE(mct_irqs);
560	}
561	for (i = MCT_L0_IRQ; i < nr_irqs; i++)
562		mct_irqs[i] = irq_of_parse_and_map(np, i);
563
564	if (mct_int_type == MCT_INT_PPI) {
565
566		err = request_percpu_irq(mct_irqs[MCT_L0_IRQ],
567					 exynos4_mct_tick_isr, "MCT",
568					 &percpu_mct_tick);
569		WARN(err, "MCT: can't request IRQ %d (%d)\n",
570		     mct_irqs[MCT_L0_IRQ], err);
571	} else {
572		for_each_possible_cpu(cpu) {
573			int mct_irq;
574			unsigned int irq_idx;
575			struct mct_clock_event_device *pcpu_mevt =
576				per_cpu_ptr(&percpu_mct_tick, cpu);
577
578			if (cpu >= nr_local) {
579				err = -EINVAL;
580				goto out_irq;
581			}
582
583			irq_idx = MCT_L0_IRQ + local_idx[cpu];
584
585			pcpu_mevt->evt.irq = -1;
586			if (irq_idx >= ARRAY_SIZE(mct_irqs))
587				break;
588			mct_irq = mct_irqs[irq_idx];
589
590			irq_set_status_flags(mct_irq, IRQ_NOAUTOEN);
591			if (request_irq(mct_irq,
592					exynos4_mct_tick_isr,
593					IRQF_TIMER | IRQF_NOBALANCING,
594					pcpu_mevt->name, pcpu_mevt)) {
595				pr_err("exynos-mct: cannot register IRQ (cpu%d)\n",
596									cpu);
597
598				continue;
599			}
600			pcpu_mevt->evt.irq = mct_irq;
601		}
602	}
603
604	for_each_possible_cpu(cpu) {
605		struct mct_clock_event_device *mevt = per_cpu_ptr(&percpu_mct_tick, cpu);
606
607		if (cpu >= nr_local) {
608			err = -EINVAL;
609			goto out_irq;
610		}
611
612		mevt->base = EXYNOS4_MCT_L_BASE(local_idx[cpu]);
613	}
614
615	/* Install hotplug callbacks which configure the timer on this CPU */
616	err = cpuhp_setup_state(CPUHP_AP_EXYNOS4_MCT_TIMER_STARTING,
617				"clockevents/exynos4/mct_timer:starting",
618				exynos4_mct_starting_cpu,
619				exynos4_mct_dying_cpu);
620	if (err)
621		goto out_irq;
622
623	return 0;
624
625out_irq:
626	if (mct_int_type == MCT_INT_PPI) {
627		free_percpu_irq(mct_irqs[MCT_L0_IRQ], &percpu_mct_tick);
628	} else {
629		for_each_possible_cpu(cpu) {
630			struct mct_clock_event_device *pcpu_mevt =
631				per_cpu_ptr(&percpu_mct_tick, cpu);
632
633			if (pcpu_mevt->evt.irq != -1) {
634				free_irq(pcpu_mevt->evt.irq, pcpu_mevt);
635				pcpu_mevt->evt.irq = -1;
636			}
637		}
638	}
639	return err;
640}
641
642static int __init mct_init_dt(struct device_node *np, unsigned int int_type)
643{
644	bool frc_shared = of_property_read_bool(np, "samsung,frc-shared");
645	u32 local_idx[MCT_NR_LOCAL] = {0};
646	int nr_local;
647	int ret;
648
649	nr_local = of_property_count_u32_elems(np, "samsung,local-timers");
650	if (nr_local == 0)
651		return -EINVAL;
652	if (nr_local > 0) {
653		if (nr_local > ARRAY_SIZE(local_idx))
654			return -EINVAL;
655
656		ret = of_property_read_u32_array(np, "samsung,local-timers",
657						 local_idx, nr_local);
658		if (ret)
659			return ret;
660	} else {
661		int i;
662
663		nr_local = ARRAY_SIZE(local_idx);
664		for (i = 0; i < nr_local; i++)
665			local_idx[i] = i;
666	}
667
668	ret = exynos4_timer_resources(np);
669	if (ret)
670		return ret;
 
 
 
 
 
671
672	ret = exynos4_timer_interrupts(np, int_type, local_idx, nr_local);
673	if (ret)
674		return ret;
675
676	ret = exynos4_clocksource_init(frc_shared);
677	if (ret)
678		return ret;
679
680	/*
681	 * When the FRC is shared with a main processor, this secondary
682	 * processor cannot use the global comparator.
683	 */
684	if (frc_shared)
685		return 0;
686
687	return exynos4_clockevent_init();
688}
689
690
691static int __init mct_init_spi(struct device_node *np)
692{
693	return mct_init_dt(np, MCT_INT_SPI);
694}
695
696static int __init mct_init_ppi(struct device_node *np)
697{
698	return mct_init_dt(np, MCT_INT_PPI);
699}
700TIMER_OF_DECLARE(exynos4210, "samsung,exynos4210-mct", mct_init_spi);
701TIMER_OF_DECLARE(exynos4412, "samsung,exynos4412-mct", mct_init_ppi);
v5.4
  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
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 54enum {
 55	MCT_INT_SPI,
 56	MCT_INT_PPI
 57};
 58
 59enum {
 60	MCT_G0_IRQ,
 61	MCT_G1_IRQ,
 62	MCT_G2_IRQ,
 63	MCT_G3_IRQ,
 64	MCT_L0_IRQ,
 65	MCT_L1_IRQ,
 66	MCT_L2_IRQ,
 67	MCT_L3_IRQ,
 68	MCT_L4_IRQ,
 69	MCT_L5_IRQ,
 70	MCT_L6_IRQ,
 71	MCT_L7_IRQ,
 72	MCT_NR_IRQS,
 73};
 74
 75static void __iomem *reg_base;
 76static unsigned long clk_rate;
 77static unsigned int mct_int_type;
 78static int mct_irqs[MCT_NR_IRQS];
 79
 80struct mct_clock_event_device {
 81	struct clock_event_device evt;
 82	unsigned long base;
 83	char name[10];
 
 
 
 
 84};
 85
 86static void exynos4_mct_write(unsigned int value, unsigned long offset)
 87{
 88	unsigned long stat_addr;
 89	u32 mask;
 90	u32 i;
 91
 92	writel_relaxed(value, reg_base + offset);
 93
 94	if (likely(offset >= EXYNOS4_MCT_L_BASE(0))) {
 95		stat_addr = (offset & EXYNOS4_MCT_L_MASK) + MCT_L_WSTAT_OFFSET;
 96		switch (offset & ~EXYNOS4_MCT_L_MASK) {
 97		case MCT_L_TCON_OFFSET:
 98			mask = 1 << 3;		/* L_TCON write status */
 99			break;
100		case MCT_L_ICNTB_OFFSET:
101			mask = 1 << 1;		/* L_ICNTB write status */
102			break;
103		case MCT_L_TCNTB_OFFSET:
104			mask = 1 << 0;		/* L_TCNTB write status */
105			break;
106		default:
107			return;
108		}
109	} else {
110		switch (offset) {
111		case EXYNOS4_MCT_G_TCON:
112			stat_addr = EXYNOS4_MCT_G_WSTAT;
113			mask = 1 << 16;		/* G_TCON write status */
114			break;
115		case EXYNOS4_MCT_G_COMP0_L:
116			stat_addr = EXYNOS4_MCT_G_WSTAT;
117			mask = 1 << 0;		/* G_COMP0_L write status */
118			break;
119		case EXYNOS4_MCT_G_COMP0_U:
120			stat_addr = EXYNOS4_MCT_G_WSTAT;
121			mask = 1 << 1;		/* G_COMP0_U write status */
122			break;
123		case EXYNOS4_MCT_G_COMP0_ADD_INCR:
124			stat_addr = EXYNOS4_MCT_G_WSTAT;
125			mask = 1 << 2;		/* G_COMP0_ADD_INCR w status */
126			break;
127		case EXYNOS4_MCT_G_CNT_L:
128			stat_addr = EXYNOS4_MCT_G_CNT_WSTAT;
129			mask = 1 << 0;		/* G_CNT_L write status */
130			break;
131		case EXYNOS4_MCT_G_CNT_U:
132			stat_addr = EXYNOS4_MCT_G_CNT_WSTAT;
133			mask = 1 << 1;		/* G_CNT_U write status */
134			break;
135		default:
136			return;
137		}
138	}
139
140	/* Wait maximum 1 ms until written values are applied */
141	for (i = 0; i < loops_per_jiffy / 1000 * HZ; i++)
142		if (readl_relaxed(reg_base + stat_addr) & mask) {
143			writel_relaxed(mask, reg_base + stat_addr);
144			return;
145		}
146
147	panic("MCT hangs after writing %d (offset:0x%lx)\n", value, offset);
148}
149
150/* Clocksource handling */
151static void exynos4_mct_frc_start(void)
152{
153	u32 reg;
154
155	reg = readl_relaxed(reg_base + EXYNOS4_MCT_G_TCON);
156	reg |= MCT_G_TCON_START;
157	exynos4_mct_write(reg, EXYNOS4_MCT_G_TCON);
158}
159
160/**
161 * exynos4_read_count_64 - Read all 64-bits of the global counter
162 *
163 * This will read all 64-bits of the global counter taking care to make sure
164 * that the upper and lower half match.  Note that reading the MCT can be quite
165 * slow (hundreds of nanoseconds) so you should use the 32-bit (lower half
166 * only) version when possible.
167 *
168 * Returns the number of cycles in the global counter.
169 */
170static u64 exynos4_read_count_64(void)
171{
172	unsigned int lo, hi;
173	u32 hi2 = readl_relaxed(reg_base + EXYNOS4_MCT_G_CNT_U);
174
175	do {
176		hi = hi2;
177		lo = readl_relaxed(reg_base + EXYNOS4_MCT_G_CNT_L);
178		hi2 = readl_relaxed(reg_base + EXYNOS4_MCT_G_CNT_U);
179	} while (hi != hi2);
180
181	return ((u64)hi << 32) | lo;
182}
183
184/**
185 * exynos4_read_count_32 - Read the lower 32-bits of the global counter
186 *
187 * This will read just the lower 32-bits of the global counter.  This is marked
188 * as notrace so it can be used by the scheduler clock.
189 *
190 * Returns the number of cycles in the global counter (lower 32 bits).
191 */
192static u32 notrace exynos4_read_count_32(void)
193{
194	return readl_relaxed(reg_base + EXYNOS4_MCT_G_CNT_L);
195}
196
197static u64 exynos4_frc_read(struct clocksource *cs)
198{
199	return exynos4_read_count_32();
200}
201
202static void exynos4_frc_resume(struct clocksource *cs)
203{
204	exynos4_mct_frc_start();
205}
206
207static struct clocksource mct_frc = {
208	.name		= "mct-frc",
209	.rating		= 450,	/* use value higher than ARM arch timer */
210	.read		= exynos4_frc_read,
211	.mask		= CLOCKSOURCE_MASK(32),
212	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
213	.resume		= exynos4_frc_resume,
214};
215
216static u64 notrace exynos4_read_sched_clock(void)
217{
218	return exynos4_read_count_32();
219}
220
221#if defined(CONFIG_ARM)
222static struct delay_timer exynos4_delay_timer;
223
224static cycles_t exynos4_read_current_timer(void)
225{
226	BUILD_BUG_ON_MSG(sizeof(cycles_t) != sizeof(u32),
227			 "cycles_t needs to move to 32-bit for ARM64 usage");
228	return exynos4_read_count_32();
229}
230#endif
231
232static int __init exynos4_clocksource_init(void)
233{
234	exynos4_mct_frc_start();
 
 
 
 
 
 
 
235
236#if defined(CONFIG_ARM)
237	exynos4_delay_timer.read_current_timer = &exynos4_read_current_timer;
238	exynos4_delay_timer.freq = clk_rate;
239	register_current_timer_delay(&exynos4_delay_timer);
240#endif
241
242	if (clocksource_register_hz(&mct_frc, clk_rate))
243		panic("%s: can't register clocksource\n", mct_frc.name);
244
245	sched_clock_register(exynos4_read_sched_clock, 32, clk_rate);
246
247	return 0;
248}
249
250static void exynos4_mct_comp0_stop(void)
251{
252	unsigned int tcon;
253
254	tcon = readl_relaxed(reg_base + EXYNOS4_MCT_G_TCON);
255	tcon &= ~(MCT_G_TCON_COMP0_ENABLE | MCT_G_TCON_COMP0_AUTO_INC);
256
257	exynos4_mct_write(tcon, EXYNOS4_MCT_G_TCON);
258	exynos4_mct_write(0, EXYNOS4_MCT_G_INT_ENB);
259}
260
261static void exynos4_mct_comp0_start(bool periodic, unsigned long cycles)
262{
263	unsigned int tcon;
264	u64 comp_cycle;
265
266	tcon = readl_relaxed(reg_base + EXYNOS4_MCT_G_TCON);
267
268	if (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(false, cycles);
287
288	return 0;
289}
290
291static int mct_set_state_shutdown(struct clock_event_device *evt)
292{
293	exynos4_mct_comp0_stop();
294	return 0;
295}
296
297static int mct_set_state_periodic(struct clock_event_device *evt)
298{
299	unsigned long cycles_per_jiffy;
300
301	cycles_per_jiffy = (((unsigned long long)NSEC_PER_SEC / HZ * evt->mult)
302			    >> evt->shift);
303	exynos4_mct_comp0_stop();
304	exynos4_mct_comp0_start(true, cycles_per_jiffy);
305	return 0;
306}
307
308static struct clock_event_device mct_comp_device = {
309	.name			= "mct-comp",
310	.features		= CLOCK_EVT_FEAT_PERIODIC |
311				  CLOCK_EVT_FEAT_ONESHOT,
312	.rating			= 250,
313	.set_next_event		= exynos4_comp_set_next_event,
314	.set_state_periodic	= mct_set_state_periodic,
315	.set_state_shutdown	= mct_set_state_shutdown,
316	.set_state_oneshot	= mct_set_state_shutdown,
317	.set_state_oneshot_stopped = mct_set_state_shutdown,
318	.tick_resume		= mct_set_state_shutdown,
319};
320
321static irqreturn_t exynos4_mct_comp_isr(int irq, void *dev_id)
322{
323	struct clock_event_device *evt = dev_id;
324
325	exynos4_mct_write(0x1, EXYNOS4_MCT_G_INT_CSTAT);
326
327	evt->event_handler(evt);
328
329	return IRQ_HANDLED;
330}
331
332static struct irqaction mct_comp_event_irq = {
333	.name		= "mct_comp_irq",
334	.flags		= IRQF_TIMER | IRQF_IRQPOLL,
335	.handler	= exynos4_mct_comp_isr,
336	.dev_id		= &mct_comp_device,
337};
338
339static int exynos4_clockevent_init(void)
340{
341	mct_comp_device.cpumask = cpumask_of(0);
342	clockevents_config_and_register(&mct_comp_device, clk_rate,
343					0xf, 0xffffffff);
344	setup_irq(mct_irqs[MCT_G0_IRQ], &mct_comp_event_irq);
 
 
 
345
346	return 0;
347}
348
349static DEFINE_PER_CPU(struct mct_clock_event_device, percpu_mct_tick);
350
351/* Clock event handling */
352static void exynos4_mct_tick_stop(struct mct_clock_event_device *mevt)
353{
354	unsigned long tmp;
355	unsigned long mask = MCT_L_TCON_INT_START | MCT_L_TCON_TIMER_START;
356	unsigned long offset = mevt->base + MCT_L_TCON_OFFSET;
357
358	tmp = readl_relaxed(reg_base + offset);
359	if (tmp & mask) {
360		tmp &= ~mask;
361		exynos4_mct_write(tmp, offset);
362	}
363}
364
365static void exynos4_mct_tick_start(unsigned long cycles,
366				   struct mct_clock_event_device *mevt)
367{
368	unsigned long tmp;
369
370	exynos4_mct_tick_stop(mevt);
371
372	tmp = (1 << 31) | cycles;	/* MCT_L_UPDATE_ICNTB */
373
374	/* update interrupt count buffer */
375	exynos4_mct_write(tmp, mevt->base + MCT_L_ICNTB_OFFSET);
376
377	/* enable MCT tick interrupt */
378	exynos4_mct_write(0x1, mevt->base + MCT_L_INT_ENB_OFFSET);
379
380	tmp = readl_relaxed(reg_base + mevt->base + MCT_L_TCON_OFFSET);
381	tmp |= MCT_L_TCON_INT_START | MCT_L_TCON_TIMER_START |
382	       MCT_L_TCON_INTERVAL_MODE;
383	exynos4_mct_write(tmp, mevt->base + MCT_L_TCON_OFFSET);
384}
385
386static void exynos4_mct_tick_clear(struct mct_clock_event_device *mevt)
387{
388	/* Clear the MCT tick interrupt */
389	if (readl_relaxed(reg_base + mevt->base + MCT_L_INT_CSTAT_OFFSET) & 1)
390		exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET);
391}
392
393static int exynos4_tick_set_next_event(unsigned long cycles,
394				       struct clock_event_device *evt)
395{
396	struct mct_clock_event_device *mevt;
397
398	mevt = container_of(evt, struct mct_clock_event_device, evt);
399	exynos4_mct_tick_start(cycles, mevt);
400	return 0;
401}
402
403static int set_state_shutdown(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_stop(mevt);
409	exynos4_mct_tick_clear(mevt);
410	return 0;
411}
412
413static int set_state_periodic(struct clock_event_device *evt)
414{
415	struct mct_clock_event_device *mevt;
416	unsigned long cycles_per_jiffy;
417
418	mevt = container_of(evt, struct mct_clock_event_device, evt);
419	cycles_per_jiffy = (((unsigned long long)NSEC_PER_SEC / HZ * evt->mult)
420			    >> evt->shift);
421	exynos4_mct_tick_stop(mevt);
422	exynos4_mct_tick_start(cycles_per_jiffy, mevt);
423	return 0;
424}
425
426static irqreturn_t exynos4_mct_tick_isr(int irq, void *dev_id)
427{
428	struct mct_clock_event_device *mevt = dev_id;
429	struct clock_event_device *evt = &mevt->evt;
430
431	/*
432	 * This is for supporting oneshot mode.
433	 * Mct would generate interrupt periodically
434	 * without explicit stopping.
435	 */
436	if (!clockevent_state_periodic(&mevt->evt))
437		exynos4_mct_tick_stop(mevt);
438
439	exynos4_mct_tick_clear(mevt);
440
441	evt->event_handler(evt);
442
443	return IRQ_HANDLED;
444}
445
446static int exynos4_mct_starting_cpu(unsigned int cpu)
447{
448	struct mct_clock_event_device *mevt =
449		per_cpu_ptr(&percpu_mct_tick, cpu);
450	struct clock_event_device *evt = &mevt->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_state_periodic = set_state_periodic;
459	evt->set_state_shutdown = set_state_shutdown;
460	evt->set_state_oneshot = set_state_shutdown;
461	evt->set_state_oneshot_stopped = set_state_shutdown;
462	evt->tick_resume = set_state_shutdown;
463	evt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
464	evt->rating = 500;	/* use value higher than ARM arch timer */
 
465
466	exynos4_mct_write(TICK_BASE_CNT, mevt->base + MCT_L_TCNTB_OFFSET);
467
468	if (mct_int_type == MCT_INT_SPI) {
469
470		if (evt->irq == -1)
471			return -EIO;
472
473		irq_force_affinity(evt->irq, cpumask_of(cpu));
474		enable_irq(evt->irq);
475	} else {
476		enable_percpu_irq(mct_irqs[MCT_L0_IRQ], 0);
477	}
478	clockevents_config_and_register(evt, clk_rate / (TICK_BASE_CNT + 1),
479					0xf, 0x7fffffff);
480
481	return 0;
482}
483
484static int exynos4_mct_dying_cpu(unsigned int cpu)
485{
486	struct mct_clock_event_device *mevt =
487		per_cpu_ptr(&percpu_mct_tick, cpu);
488	struct clock_event_device *evt = &mevt->evt;
489
490	evt->set_state_shutdown(evt);
491	if (mct_int_type == MCT_INT_SPI) {
492		if (evt->irq != -1)
493			disable_irq_nosync(evt->irq);
494		exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET);
495	} else {
496		disable_percpu_irq(mct_irqs[MCT_L0_IRQ]);
497	}
498	return 0;
499}
500
501static int __init exynos4_timer_resources(struct device_node *np, void __iomem *base)
502{
503	int err, cpu;
504	struct clk *mct_clk, *tick_clk;
505
 
 
 
 
506	tick_clk = of_clk_get_by_name(np, "fin_pll");
507	if (IS_ERR(tick_clk))
508		panic("%s: unable to determine tick clock rate\n", __func__);
509	clk_rate = clk_get_rate(tick_clk);
510
511	mct_clk = of_clk_get_by_name(np, "mct");
512	if (IS_ERR(mct_clk))
513		panic("%s: unable to retrieve mct clock instance\n", __func__);
514	clk_prepare_enable(mct_clk);
515
516	reg_base = base;
517	if (!reg_base)
518		panic("%s: unable to ioremap mct address space\n", __func__);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
519
520	if (mct_int_type == MCT_INT_PPI) {
521
522		err = request_percpu_irq(mct_irqs[MCT_L0_IRQ],
523					 exynos4_mct_tick_isr, "MCT",
524					 &percpu_mct_tick);
525		WARN(err, "MCT: can't request IRQ %d (%d)\n",
526		     mct_irqs[MCT_L0_IRQ], err);
527	} else {
528		for_each_possible_cpu(cpu) {
529			int mct_irq = mct_irqs[MCT_L0_IRQ + cpu];
 
530			struct mct_clock_event_device *pcpu_mevt =
531				per_cpu_ptr(&percpu_mct_tick, cpu);
532
 
 
 
 
 
 
 
533			pcpu_mevt->evt.irq = -1;
 
 
 
534
535			irq_set_status_flags(mct_irq, IRQ_NOAUTOEN);
536			if (request_irq(mct_irq,
537					exynos4_mct_tick_isr,
538					IRQF_TIMER | IRQF_NOBALANCING,
539					pcpu_mevt->name, pcpu_mevt)) {
540				pr_err("exynos-mct: cannot register IRQ (cpu%d)\n",
541									cpu);
542
543				continue;
544			}
545			pcpu_mevt->evt.irq = mct_irq;
546		}
547	}
548
 
 
 
 
 
 
 
 
 
 
 
549	/* Install hotplug callbacks which configure the timer on this CPU */
550	err = cpuhp_setup_state(CPUHP_AP_EXYNOS4_MCT_TIMER_STARTING,
551				"clockevents/exynos4/mct_timer:starting",
552				exynos4_mct_starting_cpu,
553				exynos4_mct_dying_cpu);
554	if (err)
555		goto out_irq;
556
557	return 0;
558
559out_irq:
560	if (mct_int_type == MCT_INT_PPI) {
561		free_percpu_irq(mct_irqs[MCT_L0_IRQ], &percpu_mct_tick);
562	} else {
563		for_each_possible_cpu(cpu) {
564			struct mct_clock_event_device *pcpu_mevt =
565				per_cpu_ptr(&percpu_mct_tick, cpu);
566
567			if (pcpu_mevt->evt.irq != -1) {
568				free_irq(pcpu_mevt->evt.irq, pcpu_mevt);
569				pcpu_mevt->evt.irq = -1;
570			}
571		}
572	}
573	return err;
574}
575
576static int __init mct_init_dt(struct device_node *np, unsigned int int_type)
577{
578	u32 nr_irqs, i;
 
 
579	int ret;
580
581	mct_int_type = int_type;
 
 
 
 
 
 
 
 
 
 
 
 
582
583	/* This driver uses only one global timer interrupt */
584	mct_irqs[MCT_G0_IRQ] = irq_of_parse_and_map(np, MCT_G0_IRQ);
 
 
585
586	/*
587	 * Find out the number of local irqs specified. The local
588	 * timer irqs are specified after the four global timer
589	 * irqs are specified.
590	 */
591	nr_irqs = of_irq_count(np);
592	for (i = MCT_L0_IRQ; i < nr_irqs; i++)
593		mct_irqs[i] = irq_of_parse_and_map(np, i);
594
595	ret = exynos4_timer_resources(np, of_iomap(np, 0));
596	if (ret)
597		return ret;
598
599	ret = exynos4_clocksource_init();
600	if (ret)
601		return ret;
 
 
 
 
 
 
 
602
603	return exynos4_clockevent_init();
604}
605
606
607static int __init mct_init_spi(struct device_node *np)
608{
609	return mct_init_dt(np, MCT_INT_SPI);
610}
611
612static int __init mct_init_ppi(struct device_node *np)
613{
614	return mct_init_dt(np, MCT_INT_PPI);
615}
616TIMER_OF_DECLARE(exynos4210, "samsung,exynos4210-mct", mct_init_spi);
617TIMER_OF_DECLARE(exynos4412, "samsung,exynos4412-mct", mct_init_ppi);