#include	"u.h"#include	"../port/lib.h"#include	"mem.h"#include	"dat.h"#include	"fns.h"#include	"io.h"#include	"ureg.h"#include	"../port/error.h" typedef struct OSTimer{	ulong		osmr[4];	/* match registers */	volatile ulong	oscr;		/* counter register */	ulong		ossr;		/* status register */	ulong		ower;	/* watchdog enable register */	ulong		oier;		/* timer interrupt enable register */} OSTimer; OSTimer *timerregs = (OSTimer*)OSTIMERREGS;static int clockinited; static void		clockintr(Ureg*, void*);static uvlong	when;	/* scheduled time of next interrupt */ long	timeradjust; enum{	Minfreq = ClockFreq/HZ,		/* At least one interrupt per HZ (50 ms) */	Maxfreq = ClockFreq/10000,	/* At most one interrupt every 100 µs */}; voidclockpower(int on){ 	if (on){		timerregs->ossr |= 1<<0;		timerregs->oier = 1<<0;		timerregs->osmr[0] = timerregs->oscr + Minfreq;	}	clockinited = on;} voidclockinit(void){	ulong x;	ulong id; 	/* map the clock registers */	timerregs = mapspecial(OSTIMERREGS, 32); 	/* enable interrupts on match register 0, turn off all others */	timerregs->ossr |= 1<<0;	intrenable(IRQ, IRQtimer0, clockintr, nil, "clock");	timerregs->oier = 1<<0; 	/* figure out processor frequency */	x = powerregs->ppcr & 0x1f;	conf.hz = ClockFreq*(x*4+16);	conf.mhz = (conf.hz+499999)/1000000; 	/* get processor type */	id = getcpuid(); 	print("%lud MHZ ARM, ver %lux/part %lux/step %lud\n", conf.mhz,		(id>>16)&0xff, (id>>4)&0xfff, id&0xf); 	/* post interrupt 1/HZ secs from now */	when = timerregs->oscr + Minfreq;	timerregs->osmr[0] = when; 	timersinit(); 	clockinited = 1;} /*  turn 32 bit counter into a 64 bit one.  since todfix calls *  us at least once a second and we overflow once every 1165 *  seconds, we won't miss an overflow. */uvlongfastticks(uvlong *hz){	static uvlong high;	static ulong last;	ulong x; 	if(hz != nil)		*hz = ClockFreq;	x = timerregs->oscr;	if(x < last)		high += 1LL<<32;	last = x;	return high+x;} voidtimerset(uvlong v){	ulong next, tics;	/* Must be unsigned! */	static int count; 	next = v; 	/* post next interrupt: calculate # of tics from now */	tics = next - timerregs->oscr - Maxfreq;	if (tics > Minfreq){		timeradjust++;		next = timerregs->oscr + Maxfreq;	}	timerregs->osmr[0] = next;} static voidclockintr(Ureg *ureg, void*){	/* reset previous interrupt */	timerregs->ossr |= 1<<0;	when += Minfreq;	timerregs->osmr[0] = when;	/* insurance */ 	timerintr(ureg, when);} voiddelay(int ms){	ulong start;	int i; 	if(clockinited){		while(ms-- > 0){			start = timerregs->oscr;			while(timerregs->oscr-start < ClockFreq/1000)				;		}	} else {		while(ms-- > 0){			for(i = 0; i < 1000; i++)				;		}	}} voidµdelay(ulong µs){	ulong start;	int i; 	µs++;	if(clockinited){		start = timerregs->oscr;		while(timerregs->oscr - start < 1UL+(µs*ClockFreq)/1000000UL)			;	} else {		while(µs-- > 0){			for(i = 0; i < 10; i++)				;		}	}} ulongTK2MS(ulong ticks){	uvlong t, hz; 	t = ticks;	hz = HZ;	t *= 1000L;	t = t/hz;	ticks = t;	return ticks;}