/*
* arch/arm64/include/asm/arch_timer.h
*
* Copyright (C) 2012 ARM Ltd.
* Author: Marc Zyngier <[email protected]>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __ASM_ARCH_TIMER_H
#define __ASM_ARCH_TIMER_H

#include <asm/barrier.h>

#include <linux/init.h>
#include <linux/types.h>

#include <clocksource/arm_arch_timer.h>

/*
* 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.
*/
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("msr cntp_ctl_el0, %0" : : "r" (val));
break;
case ARCH_TIMER_REG_TVAL:
asm volatile("msr cntp_tval_el0, %0" : : "r" (val));
break;
}
} else if (access == ARCH_TIMER_VIRT_ACCESS) {
switch (reg) {
case ARCH_TIMER_REG_CTRL:
asm volatile("msr cntv_ctl_el0, %0" : : "r" (val));
break;
case ARCH_TIMER_REG_TVAL:
asm volatile("msr cntv_tval_el0, %0" : : "r" (val));
break;
}
}

isb();
}

static __always_inline
u32 arch_timer_reg_read_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("mrs %0, cntp_ctl_el0" : "=r" (val));
break;
case ARCH_TIMER_REG_TVAL:
asm volatile("mrs %0, cntp_tval_el0" : "=r" (val));
break;
}
} else if (access == ARCH_TIMER_VIRT_ACCESS) {
switch (reg) {
case ARCH_TIMER_REG_CTRL:
asm volatile("mrs %0, cntv_ctl_el0" : "=r" (val));
break;
case ARCH_TIMER_REG_TVAL:
asm volatile("mrs %0, cntv_tval_el0" : "=r" (val));
break;
}
}

return val;
}

static inline u32 arch_timer_get_cntfrq(void)
{
u32 val;
asm volatile("mrs %0, cntfrq_el0" : "=r" (val));
return val;
}

static inline u32 arch_timer_get_cntkctl(void)
{
u32 cntkctl;
asm volatile("mrs %0, cntkctl_el1" : "=r" (cntkctl));
return cntkctl;
}

static inline void arch_timer_set_cntkctl(u32 cntkctl)
{
asm volatile("msr cntkctl_el1, %0" : : "r" (cntkctl));
}

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

/* Disable user access to the timers and the physical counter */
/* 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_PCT_ACCESS_EN);

/* Enable user access to the virtual counter */
cntkctl |= ARCH_TIMER_USR_VCT_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;
#ifdef CONFIG_COMPAT
compat_elf_hwcap |= COMPAT_HWCAP_EVTSTRM;
#endif
}

static inline u64 arch_counter_get_cntvct(void)
{
u64 cval;

isb();
asm volatile("mrs %0, cntvct_el0" : "=r" (cval));

return cval;
}

static inline int arch_timer_arch_init(void)
{
return 0;
}

#endif