1#include <linux/types.h>
  2#include <linux/init.h>
  3#include <linux/kernel_stat.h>
  4#include <linux/sched.h>
  5#include <linux/spinlock.h>
  6#include <linux/interrupt.h>
  7#include <linux/mc146818rtc.h>
  8#include <linux/smp.h>
  9#include <linux/timex.h>
 10
 11#include <asm/hardirq.h>
 12#include <asm/div64.h>
 13#include <asm/cpu.h>
 14#include <asm/setup.h>
 15#include <asm/time.h>
 16#include <asm/irq.h>
 17#include <asm/mc146818-time.h>
 18#include <asm/msc01_ic.h>
 19
 20#include <asm/mips-boards/generic.h>
 21#include <asm/mips-boards/prom.h>
 22#include <asm/mips-boards/simint.h>
 23
 24
 25unsigned long cpu_khz;
 26
 27/*
 28 * Estimate CPU frequency.  Sets mips_hpt_frequency as a side-effect
 29 */
 30static unsigned int __init estimate_cpu_frequency(void)
 31{
 32	unsigned int prid = read_c0_prid() & 0xffff00;
 33	unsigned int count;
 34
 35#if 1
 36	/*
 37	 * hardwire the board frequency to 12MHz.
 38	 */
 39
 40	if ((prid == (PRID_COMP_MIPS | PRID_IMP_20KC)) ||
 41	    (prid == (PRID_COMP_MIPS | PRID_IMP_25KF)))
 42		count = 12000000;
 43	else
 44		count =  6000000;
 45#else
 46	unsigned int flags;
 47
 48	local_irq_save(flags);
 49
 50	/* Start counter exactly on falling edge of update flag */
 51	while (CMOS_READ(RTC_REG_A) & RTC_UIP);
 52	while (!(CMOS_READ(RTC_REG_A) & RTC_UIP));
 53
 54	/* Start r4k counter. */
 55	write_c0_count(0);
 56
 57	/* Read counter exactly on falling edge of update flag */
 58	while (CMOS_READ(RTC_REG_A) & RTC_UIP);
 59	while (!(CMOS_READ(RTC_REG_A) & RTC_UIP));
 60
 61	count = read_c0_count();
 62
 63	/* restore interrupts */
 64	local_irq_restore(flags);
 65#endif
 66
 67	mips_hpt_frequency = count;
 68
 69	if ((prid != (PRID_COMP_MIPS | PRID_IMP_20KC)) &&
 70	    (prid != (PRID_COMP_MIPS | PRID_IMP_25KF)))
 71		count *= 2;
 72
 73	count += 5000;    /* round */
 74	count -= count%10000;
 75
 76	return count;
 77}
 78
 79static int mips_cpu_timer_irq;
 80
 81static void mips_timer_dispatch(void)
 82{
 83	do_IRQ(mips_cpu_timer_irq);
 84}
 85
 86
 87unsigned __cpuinit get_c0_compare_int(void)
 88{
 89#ifdef MSC01E_INT_BASE
 90	if (cpu_has_veic) {
 91		set_vi_handler(MSC01E_INT_CPUCTR, mips_timer_dispatch);
 92		mips_cpu_timer_irq = MSC01E_INT_BASE + MSC01E_INT_CPUCTR;
 93
 94		return mips_cpu_timer_irq;
 95	}
 96#endif
 97	if (cpu_has_vint)
 98		set_vi_handler(cp0_compare_irq, mips_timer_dispatch);
 99	mips_cpu_timer_irq = MIPS_CPU_IRQ_BASE + cp0_compare_irq;
100
101	return mips_cpu_timer_irq;
102}
103
104void __init plat_time_init(void)
105{
106	unsigned int est_freq;
107
108	/* Set Data mode - binary. */
109	CMOS_WRITE(CMOS_READ(RTC_CONTROL) | RTC_DM_BINARY, RTC_CONTROL);
110
111	est_freq = estimate_cpu_frequency();
112
113	printk(KERN_INFO "CPU frequency %d.%02d MHz\n", est_freq / 1000000,
114	       (est_freq % 1000000) * 100 / 1000000);
115
116	cpu_khz = est_freq / 1000;
117}