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;

}