mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-11 23:16:43 +07:00
107 lines
2.4 KiB
C
107 lines
2.4 KiB
C
/*
|
|
* arch/arm/plat-iop/time.c
|
|
*
|
|
* Timer code for IOP32x and IOP33x based systems
|
|
*
|
|
* Author: Deepak Saxena <dsaxena@mvista.com>
|
|
*
|
|
* Copyright 2002-2003 MontaVista Software Inc.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License as published by the
|
|
* Free Software Foundation; either version 2 of the License, or (at your
|
|
* option) any later version.
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/time.h>
|
|
#include <linux/init.h>
|
|
#include <linux/timex.h>
|
|
#include <linux/io.h>
|
|
#include <mach/hardware.h>
|
|
#include <asm/irq.h>
|
|
#include <asm/uaccess.h>
|
|
#include <asm/mach/irq.h>
|
|
#include <asm/mach/time.h>
|
|
#include <mach/time.h>
|
|
|
|
static unsigned long ticks_per_jiffy;
|
|
static unsigned long ticks_per_usec;
|
|
static unsigned long next_jiffy_time;
|
|
|
|
unsigned long iop_gettimeoffset(void)
|
|
{
|
|
unsigned long offset, temp;
|
|
|
|
/* enable cp6, if necessary, to avoid taking the overhead of an
|
|
* undefined instruction trap
|
|
*/
|
|
asm volatile (
|
|
"mrc p15, 0, %0, c15, c1, 0\n\t"
|
|
"tst %0, #(1 << 6)\n\t"
|
|
"orreq %0, %0, #(1 << 6)\n\t"
|
|
"mcreq p15, 0, %0, c15, c1, 0\n\t"
|
|
#ifdef CONFIG_CPU_XSCALE
|
|
"mrceq p15, 0, %0, c15, c1, 0\n\t"
|
|
"moveq %0, %0\n\t"
|
|
"subeq pc, pc, #4\n\t"
|
|
#endif
|
|
: "=r"(temp) : : "cc");
|
|
|
|
offset = next_jiffy_time - read_tcr1();
|
|
|
|
return offset / ticks_per_usec;
|
|
}
|
|
|
|
static irqreturn_t
|
|
iop_timer_interrupt(int irq, void *dev_id)
|
|
{
|
|
write_tisr(1);
|
|
|
|
while ((signed long)(next_jiffy_time - read_tcr1())
|
|
>= ticks_per_jiffy) {
|
|
timer_tick();
|
|
next_jiffy_time -= ticks_per_jiffy;
|
|
}
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static struct irqaction iop_timer_irq = {
|
|
.name = "IOP Timer Tick",
|
|
.handler = iop_timer_interrupt,
|
|
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
|
|
};
|
|
|
|
static unsigned long iop_tick_rate;
|
|
unsigned long get_iop_tick_rate(void)
|
|
{
|
|
return iop_tick_rate;
|
|
}
|
|
EXPORT_SYMBOL(get_iop_tick_rate);
|
|
|
|
void __init iop_init_time(unsigned long tick_rate)
|
|
{
|
|
u32 timer_ctl;
|
|
|
|
ticks_per_jiffy = (tick_rate + HZ/2) / HZ;
|
|
ticks_per_usec = tick_rate / 1000000;
|
|
next_jiffy_time = 0xffffffff;
|
|
iop_tick_rate = tick_rate;
|
|
|
|
timer_ctl = IOP_TMR_EN | IOP_TMR_PRIVILEGED |
|
|
IOP_TMR_RELOAD | IOP_TMR_RATIO_1_1;
|
|
|
|
/*
|
|
* We use timer 0 for our timer interrupt, and timer 1 as
|
|
* monotonic counter for tracking missed jiffies.
|
|
*/
|
|
write_trr0(ticks_per_jiffy - 1);
|
|
write_tmr0(timer_ctl);
|
|
write_trr1(0xffffffff);
|
|
write_tmr1(timer_ctl);
|
|
|
|
setup_irq(IRQ_IOP_TIMER0, &iop_timer_irq);
|
|
}
|