1 files changed, 116 insertions, 0 deletions

diff --git a/arch/mips/mipssim/sim_time.c b/arch/mips/mipssim/sim_time.c
new file mode 100644
index 00000000000..5492c42f765
--- /dev/null
+++ b/arch/mips/mipssim/sim_time.c
@@ -0,0 +1,116 @@
+#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 __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;
+
+                return mips_cpu_timer_irq;
+        }
+#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;
+}