/************************************************************* * File: lib/tmr1.c * Purpose: clock using tmr1 on the 4102 * Author: Phil Bunce (pjb@carmel.com) * Revision History: *	981014	Moved from lib/c4102.c *	981106	Works with "-board bdmr4102". *//* This module can only be used on the 4102, because the 4101, 4001 etc * did not allow tmr1 to generate interrupts. */#ifndef LR4102#define LR4102#endif#include <mips.h>#include <utypes.h>#define inw(a)		(*((volatile Ulong *)(a)))#define outw(a,v)	(*((volatile Ulong *)(a))=(v))/* 4102 cpu 32-bit timer */#define TMRI    (M_TMR4001+O_TIC1)  /* initial value */#define TMRC    (M_TMR4001+O_TCC1)  /* current value */#define TMODE   (M_TMR4001+O_TMODE) /* control */#define TSTAT   (M_TMR4001+O_TSTAT) /* status */static Ulong _time,_ticks;/**************************************************************/static int clkfunc(int op,long value){switch (op) {    case 1 : _time = value; return(value);    case 2 : return(_time);    case 3 : return(_time*1000000)+(_ticks*10000);    }}/**************************************************************/static clkisr(){outw(TSTAT,inw(TSTAT)&~TSTAT_IN1); /* ack timer int */_ticks++;if (_ticks >= 100) {	_time++;	_ticks=0;	}return(1);}/**************************************************************/Func *clkinit_tmr1_4102(){Ulong t8,t0,t1,intmask,msk,tmode,tstat;int i,intnum,cf;t8 = mfc0(C0_SR);mtc0(C0_SR,t8&~SR_IEC); /* disable ints in SR *//* disable clkints */tmode = inw(TMODE)&~TMODE_MASK1;outw(TMODE,tmode); /* stop timer */tstat = inw(TSTAT)&~TSTAT_MASK1;outw(TSTAT,tstat); /* no ints */outw(M_SCR2,inw(M_SCR2)&~SCR2_TMRIE1);t0 = mfc0(C0_CAUSE); /* pre-intr cause value *//* program timer for short period */outw(TMODE,tmode|TMODE_I1);  /* invert */outw(M_SCR2,inw(M_SCR2)|SCR2_TMRIE1);outw(TMRI,3);outw(TSTAT,tstat|TSTAT_IE1); /* int enable */outw(TMODE,tmode|TMODE_I1|TMODE_E1);  /* invert+enable */for (i=0;i<100000;i++) { /* timeout value */	t1 = mfc0(C0_CAUSE); /* new cause value */	if (t1 != t0) break;	}intmask = SR_IMASK&(t0^t1);for (intnum=0,msk=0x100;intnum<8;intnum++,msk<<=1) if (intmask&msk) break;if (intnum > 7) {	mtc0(C0_SR,t8);	return(0);	}outw(M_SCR2,inw(M_SCR2)&~SCR2_TMRIE1);outw(TMODE,tmode); /* stop timer */outw(TSTAT,tstat); /* no ints *//* attach isr */IRQInstall(intnum,clkisr);/* reprogram timer for 10ms */sscanf(getMonEnv("clkfreq"),"%d",&cf);cf *= 1000000;outw(TMRI,cf/100); /* 10ms based on CPU clock frequency */outw(TMODE,tmode|TMODE_I1);  /* invert */outw(M_SCR2,inw(M_SCR2)|SCR2_TMRIE1);outw(TSTAT,tstat|TSTAT_IE1); /* int enable */outw(TMODE,tmode|TMODE_I1|TMODE_E1);  /* invert+enable */return(clkfunc);}