oleavr-rgl-a500-mini-linux-3.10/arch/arm/include/asm/arch_timer.h

#ifndef __ASMARM_ARCH_TIMER_H
#define __ASMARM_ARCH_TIMER_H

#include <asm/barrier.h>
#include <asm/errno.h>
#include <linux/clocksource.h>
#include <linux/init.h>
#include <linux/types.h>

#include <clocksource/arm_arch_timer.h>

#ifdef CONFIG_ARM_ARCH_TIMER
int arch_timer_arch_init(void);

/*
 * These register accessors are marked inline so the compiler can
 * nicely work out which register we want, and chuck away the rest of
 * the code. At least it does so with a recent GCC (4.6.3).
 */
static __always_inline
void arch_timer_reg_write_cp15(int access, enum arch_timer_reg reg, u32 val)
{
	if (access == ARCH_TIMER_PHYS_ACCESS) {
		switch (reg) {
		case ARCH_TIMER_REG_CTRL:
			asm volatile("mcr p15, 0, %0, c14, c2, 1" : : "r" (val));
			break;
		case ARCH_TIMER_REG_TVAL:
			asm volatile("mcr p15, 0, %0, c14, c2, 0" : : "r" (val));
			break;
		}
	} else if (access == ARCH_TIMER_VIRT_ACCESS) {
		switch (reg) {
		case ARCH_TIMER_REG_CTRL:
			asm volatile("mcr p15, 0, %0, c14, c3, 1" : : "r" (val));
			break;
		case ARCH_TIMER_REG_TVAL:
			asm volatile("mcr p15, 0, %0, c14, c3, 0" : : "r" (val));
			break;
		}
	}

	isb();
}

static __always_inline
u32 arch_timer_reg_read_cp15(int access, enum arch_timer_reg reg)
{
	u32 val = 0;

	if (access == ARCH_TIMER_PHYS_ACCESS) {
		switch (reg) {
		case ARCH_TIMER_REG_CTRL:
			asm volatile("mrc p15, 0, %0, c14, c2, 1" : "=r" (val));
			break;
		case ARCH_TIMER_REG_TVAL:
			asm volatile("mrc p15, 0, %0, c14, c2, 0" : "=r" (val));
			break;
		}
	} else if (access == ARCH_TIMER_VIRT_ACCESS) {
		switch (reg) {
		case ARCH_TIMER_REG_CTRL:
			asm volatile("mrc p15, 0, %0, c14, c3, 1" : "=r" (val));
			break;
		case ARCH_TIMER_REG_TVAL:
			asm volatile("mrc p15, 0, %0, c14, c3, 0" : "=r" (val));
			break;
		}
	}

	return val;
}

static __always_inline
u64 arch_timer_reg_read_cval(int access)
{
	u64 cval;

	if (access == ARCH_TIMER_PHYS_ACCESS)
		asm volatile("mrrc p15, 2, %Q0, %R0, c14" : "=r" (cval));
	else if (access == ARCH_TIMER_VIRT_ACCESS)
		asm volatile("mrrc p15, 3, %Q0, %R0, c14" : "=r" (cval));
	else
		cval = 0;

	return cval;
}

static inline u32 arch_timer_get_cntfrq(void)
{
	u32 val;
	asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (val));
	return val;
}

#ifdef CONFIG_ARCH_SUN50I
#define ARCH_PCNT_TRY_MAX_TIME (12)
#define ARCH_PCNT_MAX_DELTA    (8)
static inline u64 arch_counter_get_cntpct(void)
{
	u64 pct0;
	u64 pct1;
	u64 delta;
	u32 retry = 0;

	/* sun50i vcnt maybe imprecise,
	 * we should try to fix this.
	 */
	while (retry < ARCH_PCNT_TRY_MAX_TIME) {
		isb();
		asm volatile("mrrc p15, 0, %Q0, %R0, c14" : "=r" (pct0));
		isb();
		asm volatile("mrrc p15, 0, %Q0, %R0, c14" : "=r" (pct1));
		delta = pct1 - pct0;
		if ((pct1 >= pct0) && (delta < ARCH_PCNT_MAX_DELTA)) {
			/* read valid vcnt */
			return pct1;
		}
		/* vcnt value error, try again */
		retry++;
	}
	/* Do not warry for this, just return the last time vcnt.
	 * arm64 have enabled CONFIG_CLOCKSOURCE_VALIDATE_LAST_CYCLE.
	 */
	return pct1;
}
#else
static inline u64 arch_counter_get_cntpct(void)
{
	u64 cval;

	isb();
	asm volatile("mrrc p15, 0, %Q0, %R0, c14" : "=r" (cval));
	return cval;
}
#endif /* CONFIG_ARCH_SUN50I */

#ifdef CONFIG_ARCH_SUN50I
#define ARCH_VCNT_TRY_MAX_TIME (12)
#define ARCH_VCNT_MAX_DELTA    (8)
static inline u64 arch_counter_get_cntvct(void)
{
	u64 vct0;
	u64 vct1;
	u64 delta;
	u32 retry = 0;

	/* sun50i vcnt maybe imprecise,
	 * we should try to fix this.
	 */
	while (retry < ARCH_VCNT_TRY_MAX_TIME) {
		isb();
		asm volatile("mrrc p15, 1, %Q0, %R0, c14" : "=r" (vct0));
		isb();
		asm volatile("mrrc p15, 1, %Q0, %R0, c14" : "=r" (vct1));
		delta = vct1 - vct0;
		if ((vct1 >= vct0) && (delta < ARCH_VCNT_MAX_DELTA)) {
			/* read valid vcnt */
			return vct1;
		}
		/* vcnt value error, try again */
		retry++;
	}
	/* Do not warry for this, just return the last time vcnt.
	 * arm64 have enabled CONFIG_CLOCKSOURCE_VALIDATE_LAST_CYCLE.
	 */
	return vct1;
}
#else
static inline u64 arch_counter_get_cntvct(void)
{
	u64 cval;

	isb();
	asm volatile("mrrc p15, 1, %Q0, %R0, c14" : "=r" (cval));
	return cval;
}
#endif /* CONFIG_ARCH_SUN50I */

static inline u32 arch_timer_get_cntkctl(void)
{
	u32 cntkctl;
	asm volatile("mrc p15, 0, %0, c14, c1, 0" : "=r" (cntkctl));
	return cntkctl;
}

static inline void arch_timer_set_cntkctl(u32 cntkctl)
{
	asm volatile("mcr p15, 0, %0, c14, c1, 0" : : "r" (cntkctl));
}

static inline void __cpuinit arch_counter_set_user_access(void)
{
	u32 cntkctl = arch_timer_get_cntkctl();

	/* Disable user access to both physical/virtual counters/timers */
	/* Also disable virtual event stream */
	cntkctl &= ~(ARCH_TIMER_USR_PT_ACCESS_EN
			| ARCH_TIMER_USR_VT_ACCESS_EN
			| ARCH_TIMER_VIRT_EVT_EN
			| ARCH_TIMER_USR_VCT_ACCESS_EN
			| ARCH_TIMER_USR_PCT_ACCESS_EN);
	arch_timer_set_cntkctl(cntkctl);
}

static inline void arch_timer_evtstrm_enable(int divider)
{
	u32 cntkctl = arch_timer_get_cntkctl();
	cntkctl &= ~ARCH_TIMER_EVT_TRIGGER_MASK;
	/* Set the divider and enable virtual event stream */
	cntkctl |= (divider << ARCH_TIMER_EVT_TRIGGER_SHIFT)
			| ARCH_TIMER_VIRT_EVT_EN;
	arch_timer_set_cntkctl(cntkctl);
	elf_hwcap |= HWCAP_EVTSTRM;
}

#endif

#endif