mirror of https://gitee.com/openkylin/linux.git
118 lines
2.5 KiB
C
118 lines
2.5 KiB
C
/*
|
|
* This file is subject to the terms and conditions of the GNU General Public
|
|
* License. See the file "COPYING" in the main directory of this archive
|
|
* for more details.
|
|
*
|
|
* Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved.
|
|
*/
|
|
#include <linux/init.h>
|
|
|
|
#include <asm/setup.h>
|
|
#include <asm/time.h>
|
|
#include <asm/irq.h>
|
|
#include <asm/mips-boards/generic.h>
|
|
#include <asm/mips-boards/prom.h>
|
|
|
|
unsigned long cpu_khz;
|
|
|
|
static int mips_cpu_timer_irq;
|
|
static int mips_cpu_perf_irq;
|
|
|
|
static void mips_timer_dispatch(void)
|
|
{
|
|
do_IRQ(mips_cpu_timer_irq);
|
|
}
|
|
|
|
static void mips_perf_dispatch(void)
|
|
{
|
|
do_IRQ(mips_cpu_perf_irq);
|
|
}
|
|
|
|
static void __iomem *status_reg = (void __iomem *)0xbf000410;
|
|
|
|
/*
|
|
* Estimate CPU frequency. Sets mips_hpt_frequency as a side-effect.
|
|
*/
|
|
static unsigned int __init estimate_cpu_frequency(void)
|
|
{
|
|
unsigned int prid = read_c0_prid() & 0xffff00;
|
|
unsigned int tick = 0;
|
|
unsigned int freq;
|
|
unsigned int orig;
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
|
|
orig = readl(status_reg) & 0x2; /* get original sample */
|
|
/* wait for transition */
|
|
while ((readl(status_reg) & 0x2) == orig)
|
|
;
|
|
orig = orig ^ 0x2; /* flip the bit */
|
|
|
|
write_c0_count(0);
|
|
|
|
/* wait 1 second (the sampling clock transitions every 10ms) */
|
|
while (tick < 100) {
|
|
/* wait for transition */
|
|
while ((readl(status_reg) & 0x2) == orig)
|
|
;
|
|
orig = orig ^ 0x2; /* flip the bit */
|
|
tick++;
|
|
}
|
|
|
|
freq = read_c0_count();
|
|
|
|
local_irq_restore(flags);
|
|
|
|
mips_hpt_frequency = freq;
|
|
|
|
/* Adjust for processor */
|
|
if ((prid != (PRID_COMP_MIPS | PRID_IMP_20KC)) &&
|
|
(prid != (PRID_COMP_MIPS | PRID_IMP_25KF)))
|
|
freq *= 2;
|
|
|
|
freq += 5000; /* rounding */
|
|
freq -= freq%10000;
|
|
|
|
return freq ;
|
|
}
|
|
|
|
void read_persistent_clock(struct timespec *ts)
|
|
{
|
|
ts->tv_sec = 0;
|
|
ts->tv_nsec = 0;
|
|
}
|
|
|
|
static void __init plat_perf_setup(void)
|
|
{
|
|
if (cp0_perfcount_irq >= 0) {
|
|
if (cpu_has_vint)
|
|
set_vi_handler(cp0_perfcount_irq, mips_perf_dispatch);
|
|
mips_cpu_perf_irq = MIPS_CPU_IRQ_BASE + cp0_perfcount_irq;
|
|
}
|
|
}
|
|
|
|
unsigned int __cpuinit get_c0_compare_int(void)
|
|
{
|
|
if (cpu_has_vint)
|
|
set_vi_handler(cp0_compare_irq, mips_timer_dispatch);
|
|
mips_cpu_timer_irq = MIPS_CPU_IRQ_BASE + cp0_compare_irq;
|
|
return mips_cpu_timer_irq;
|
|
}
|
|
|
|
void __init plat_time_init(void)
|
|
{
|
|
unsigned int est_freq;
|
|
|
|
est_freq = estimate_cpu_frequency();
|
|
|
|
pr_debug("CPU frequency %d.%02d MHz\n", (est_freq / 1000000),
|
|
(est_freq % 1000000) * 100 / 1000000);
|
|
|
|
cpu_khz = est_freq / 1000;
|
|
|
|
mips_scroll_message();
|
|
|
|
plat_perf_setup();
|
|
}
|