ref: 09d11c64e5014a64dbc7b807899b3dd2581fe26f
dir: /os/pxa/clock.c/
#include "u.h"
#include "../port/lib.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "io.h"
#include "ureg.h"
static ulong timer_incr[4] = { 0, 0, 0, -1 };
typedef struct Clock0link Clock0link;
typedef struct Clock0link {
void (*clock)(void);
Clock0link* link;
} Clock0link;
static Clock0link *clock0link;
static Lock clock0lock;
static void (*prof_fcn)(Ureg *, int);
Timer*
addclock0link(void (*clock)(void), int)
{
Clock0link *lp;
if((lp = malloc(sizeof(Clock0link))) == 0){
print("addclock0link: too many links\n");
return nil;
}
ilock(&clock0lock);
lp->clock = clock;
lp->link = clock0link;
clock0link = lp;
iunlock(&clock0lock);
return nil;
}
static void
profintr(Ureg *ur, void*)
{
OstmrReg *ost = OSTMRREG;
int t;
if((ost->osmr[3] - ost->oscr) < 2*CLOCKFREQ) {
/* less than 2 seconds before reset, say something */
setpanic();
clockpoll();
dumpregs(ur);
panic("Watchdog timer will expire");
}
/* advance the profile clock tick */
ost->osmr[2] += timer_incr[2];
ost->ossr = (1 << 2); /* Clear the SR */
t = 1;
while((ost->osmr[2] - ost->oscr) > 0x80000000) {
ost->osmr[2] += timer_incr[2];
t++;
}
if(prof_fcn)
prof_fcn(ur, t);
}
static void
clockintr(Ureg*, void*)
{
Clock0link *lp;
int losttick = 0;
OstmrReg *ost = OSTMRREG;
{static int tag, led; if(++tag >= HZ){ledset(led ^= 1);tag=0;}}
m->ticks++;
// ost->osmr[3] = ost->oscr + timer_incr[3]; /* restart the watchdog */
ost->osmr[0] += timer_incr[0]; /* advance the clock tick */
ost->ossr = (1<<0); /* Clear the SR */
while((ost->osmr[0] - ost->oscr) >= 0x80000000) {
ost->osmr[0] += timer_incr[0];
losttick++;
m->ticks++;
}
checkalarms();
if(canlock(&clock0lock)){
for(lp = clock0link; lp; lp = lp->link)
if(lp->clock)
lp->clock();
unlock(&clock0lock);
}
/* round robin time slice is done by trap.c and proc.c */
}
void
timerenable( int timer, int Hz, void (*f)(Ureg *, void*), void* a)
{
OstmrReg *ost = OSTMRREG;
char name[KNAMELEN];
if(timer < 0 || timer > 3)
return;
timer_incr[timer] = CLOCKFREQ/Hz; /* set up freq */
ost->osmr[timer] = ost->oscr+timer_incr[timer];
snprint(name, sizeof(name), "timer%d", timer);
intrenable(IRQ, IRQtimer0+timer, f, a, name);
ost->ossr = (1 << timer); /* clear any pending interrupt */
ost->oier |= (1 << timer); /* enable interrupt */
}
void
timerdisable( int timer )
{
OstmrReg *ost = OSTMRREG;
if(timer < 0 || timer > 3)
return;
ost->osmr[timer] = 0; /* clear freq */
ost->oier &= ~(1 << timer); /* disable interrupt */
}
void
installprof(void (*pf)(Ureg *, int))
{
int s;
s = splfhi();
prof_fcn = pf;
timerenable( 2, HZ+1, profintr, 0);
timer_incr[2] = timer_incr[0]+63; /* fine tuning */
splx(s);
}
void
clockinit(void)
{
OstmrReg *ost = OSTMRREG;
m->ticks = 0;
/* Set up timer registers */
ost->ossr = 0xf; /* clear all four OSSR trigger bits */
ost->oier = 0;
ost->osmr[0] = 0;
ost->osmr[1] = 0;
ost->osmr[2] = 0;
// ost->osmr[3] = 0;
timerenable( 0, HZ, clockintr, 0);
// timer_incr[3] = CLOCKFREQ*10; /* 10 second watchdog */
// timer_setwatchdog(timer_incr[3]);
// timerenable( 2, 1, profintr, 0); /* watch the watchdog */
}
void
clockpoll(void)
{
OstmrReg *ost = OSTMRREG;
// ost->osmr[3] = ost->oscr + timer_incr[3]; /* restart the watchdog */
}
void
clockcheck(void)
{
OstmrReg *ost = OSTMRREG;
if((ost->osmr[3] - ost->oscr) < CLOCKFREQ) {
setpanic();
clockpoll();
dumpstack();
panic("Watchdog timer will expire");
}
}
// macros for fixed-point math
ulong _mularsv(ulong m0, ulong m1, ulong a, ulong s);
/* truncated: */
#define FXDPTDIV(a,b,n) ((ulong)(((uvlong)(a) << (n)) / (b)))
#define MAXMUL(a,n) ((ulong)((((uvlong)1<<(n))-1)/(a)))
#define MULDIV(x,a,b,n) (((x)*FXDPTDIV(a,b,n)) >> (n))
#define MULDIV64(x,a,b,n) ((ulong)_mularsv(x, FXDPTDIV(a,b,n), 0, (n)))
/* rounded: */
#define FXDPTDIVR(a,b,n) ((ulong)((((uvlong)(a) << (n))+((b)/2)) / (b)))
#define MAXMULR(a,n) ((ulong)((((uvlong)1<<(n))-1)/(a)))
#define MULDIVR(x,a,b,n) (((x)*FXDPTDIVR(a,b,n)+(1<<((n)-1))) >> (n))
#define MULDIVR64(x,a,b,n) ((ulong)_mularsv(x, FXDPTDIVR(a,b,n), 1<<((n)-1), (n)))
// these routines are all limited to a maximum of 1165 seconds,
// due to the wrap-around of the OSTIMER
ulong
timer_start(void)
{
return OSTMRREG->oscr;
}
ulong
timer_ticks(ulong t0)
{
return OSTMRREG->oscr - t0;
}
int
timer_devwait(ulong *adr, ulong mask, ulong val, int ost)
{
int i;
ulong t0 = timer_start();
while((*adr & mask) != val)
if(timer_ticks(t0) > ost)
return ((*adr & mask) == val) ? 0 : -1;
else
for(i = 0; i < 10; i++); /* don't pound OSCR too hard! (why not?) */
return 0;
}
void
timer_setwatchdog(int t)
{
OstmrReg *ost = OSTMRREG;
ost->osmr[3] = ost->oscr + t;
if(t) {
ost->ossr = (1<<3);
ost->oier |= (1<<3);
ost->ower = 1;
} else
ost->oier &= ~(1<<3);
}
void
timer_delay(int t)
{
ulong t0 = timer_start();
while(timer_ticks(t0) < t)
;
}
ulong
us2tmr(int us)
{
return MULDIV64(us, CLOCKFREQ, 1000000, 24);
}
int
tmr2us(ulong t)
{
return MULDIV64(t, 1000000, CLOCKFREQ, 24);
}
void
microdelay(int us)
{
ulong t0 = timer_start();
ulong t = us2tmr(us);
while(timer_ticks(t0) <= t)
;
}
ulong
ms2tmr(int ms)
{
return MULDIV64(ms, CLOCKFREQ, 1000, 20);
}
int
tmr2ms(ulong t)
{
return MULDIV64(t, 1000, CLOCKFREQ, 32);
}
void
delay(int ms)
{
ulong t0 = timer_start();
ulong t = ms2tmr(ms);
while(timer_ticks(t0) <= t)
clockpoll();
}
/*
* for devbench.c
*/
vlong
archrdtsc(void)
{
return OSTMRREG->oscr;
}
ulong
archrdtsc32(void)
{
return OSTMRREG->oscr;
}
/*
* for devkprof.c
*/
long
archkprofmicrosecondspertick(void)
{
return MS2HZ*1000;
}
void
archkprofenable(int)
{
/* TO DO */
}
uvlong
fastticks(uvlong *hz)
{
if(hz)
*hz = HZ;
return m->ticks;
}