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/*
* Carsten Langgaard, carstenl@mips.com
* Copyright (C) 1999,2000 MIPS Technologies, Inc. All rights reserved.
*
* This program is free software; you can distribute 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 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, write to the Free Software Foundation, Inc.,
* 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
*
* Setting up the clock on the MIPS boards.
*/
#include <linux/types.h>
#include <linux/init.h>
#include <linux/kernel_stat.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/mc146818rtc.h>
#include <asm/mipsregs.h>
#include <asm/mipsmtregs.h>
#include <asm/hardirq.h>
#include <asm/i8253.h>
#include <asm/irq.h>
#include <asm/div64.h>
#include <asm/cpu.h>
#include <asm/time.h>
#include <asm/mc146818-time.h>
#include <asm/msc01_ic.h>
#include <asm/mips-boards/generic.h>
#include <asm/mips-boards/prom.h>
#ifdef CONFIG_MIPS_ATLAS
#include <asm/mips-boards/atlasint.h>
#endif
#ifdef CONFIG_MIPS_MALTA
#include <asm/mips-boards/maltaint.h>
#endif
#ifdef CONFIG_MIPS_SEAD
#include <asm/mips-boards/seadint.h>
#endif
unsigned long cpu_khz;
static int mips_cpu_timer_irq;
static int mips_cpu_perf_irq;
extern int cp0_perfcount_irq;
DEFINE_PER_CPU(unsigned int, tickcount);
#define tickcount_this_cpu __get_cpu_var(tickcount)
static unsigned long ledbitmask;
static void mips_timer_dispatch(void)
{
#if defined(CONFIG_MIPS_MALTA) || defined(CONFIG_MIPS_ATLAS)
/*
* Yes, this is very tacky, won't work as expected with SMTC and
* dyntick will break it,
* but it gives me a nice warm feeling during debug
*/
#define LEDBAR 0xbf000408
if (tickcount_this_cpu++ >= HZ) {
tickcount_this_cpu = 0;
change_bit(smp_processor_id(), &ledbitmask);
smp_wmb(); /* Make sure every one else sees the change */
/* This will pick up any recent changes made by other CPU's */
*(unsigned int *)LEDBAR = ledbitmask;
}
#endif
do_IRQ(mips_cpu_timer_irq);
}
static void mips_perf_dispatch(void)
{
do_IRQ(mips_cpu_perf_irq);
}
/*
* 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 count;
#if defined(CONFIG_MIPS_SEAD) || defined(CONFIG_MIPS_SIM)
/*
* The SEAD board doesn't have a real time clock, so we can't
* really calculate the timer frequency
* For now we hardwire the SEAD board frequency to 12MHz.
*/
if ((prid == (PRID_COMP_MIPS | PRID_IMP_20KC)) ||
(prid == (PRID_COMP_MIPS | PRID_IMP_25KF)))
count = 12000000;
else
count = 6000000;
#endif
#if defined(CONFIG_MIPS_ATLAS) || defined(CONFIG_MIPS_MALTA)
unsigned long flags;
unsigned int start;
local_irq_save(flags);
/* Start counter exactly on falling edge of update flag */
while (CMOS_READ(RTC_REG_A) & RTC_UIP);
while (!(CMOS_READ(RTC_REG_A) & RTC_UIP));
/* Start r4k counter. */
start = read_c0_count();
/* Read counter exactly on falling edge of update flag */
while (CMOS_READ(RTC_REG_A) & RTC_UIP);
while (!(CMOS_READ(RTC_REG_A) & RTC_UIP));
count = read_c0_count() - start;
/* restore interrupts */
local_irq_restore(flags);
#endif
mips_hpt_frequency = count;
if ((prid != (PRID_COMP_MIPS | PRID_IMP_20KC)) &&
(prid != (PRID_COMP_MIPS | PRID_IMP_25KF)))
count *= 2;
count += 5000; /* round */
count -= count%10000;
return count;
}
unsigned long read_persistent_clock(void)
{
return mc146818_get_cmos_time();
}
static void __init plat_perf_setup(void)
{
#ifdef MSC01E_INT_BASE
if (cpu_has_veic) {
set_vi_handler(MSC01E_INT_PERFCTR, mips_perf_dispatch);
mips_cpu_perf_irq = MSC01E_INT_BASE + MSC01E_INT_PERFCTR;
} else
#endif
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;
#ifdef CONFIG_SMP
set_irq_handler(mips_cpu_perf_irq, handle_percpu_irq);
#endif
}
}
unsigned int __cpuinit get_c0_compare_int(void)
{
#ifdef MSC01E_INT_BASE
if (cpu_has_veic) {
set_vi_handler(MSC01E_INT_CPUCTR, mips_timer_dispatch);
mips_cpu_timer_irq = MSC01E_INT_BASE + MSC01E_INT_CPUCTR;
} else
#endif
{
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;
/* Set Data mode - binary. */
CMOS_WRITE(CMOS_READ(RTC_CONTROL) | RTC_DM_BINARY, RTC_CONTROL);
est_freq = estimate_cpu_frequency();
printk("CPU frequency %d.%02d MHz\n", est_freq/1000000,
(est_freq%1000000)*100/1000000);
cpu_khz = est_freq / 1000;
mips_scroll_message();
#ifdef CONFIG_I8253 /* Only Malta has a PIT */
setup_pit_timer();
#endif
plat_perf_setup();
}
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