Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

#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/mc146818rtc.h>
#include <linux/smp.h>
#include <linux/timex.h>
 
#include <asm/hardirq.h>
#include <asm/div64.h>
#include <asm/cpu.h>
#include <asm/time.h>
#include <asm/irq.h>
#include <asm/mc146818-time.h>
#include <asm/msc01_ic.h>
 
#include <asm/mips-boards/generic.h>
#include <asm/mips-boards/prom.h>
#include <asm/mips-boards/simint.h>
 
 
unsigned long cpu_khz;
 
/*
 * 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 1
	/*
	 * hardwire the board frequency to 12MHz.
	 */
 
	if ((prid == (PRID_COMP_MIPS | PRID_IMP_20KC)) ||
	    (prid == (PRID_COMP_MIPS | PRID_IMP_25KF)))
		count = 12000000;
	else
		count =  6000000;
#else
	unsigned int flags;
 
	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. */
	write_c0_count(0);
 
	/* 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();
 
	/* 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;
}
 
static int mips_cpu_timer_irq;
 
static void mips_timer_dispatch(void)
{
	do_IRQ(mips_cpu_timer_irq);
}
 
 
unsigned __init 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(KERN_INFO "CPU frequency %d.%02d MHz\n", est_freq / 1000000,
	       (est_freq % 1000000) * 100 / 1000000);
 
	cpu_khz = est_freq / 1000;
}