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#include <u.h>
#include <libc.h>
#include <thread.h>
#include "dat.h"
#include "fns.h"
typedef struct {
u16int *cnt;
Event;
u16int val;
int clock;
u8int i, sh, snd;
} Timer;
typedef struct fifo fifo;
struct fifo {
u32int d[8];
u8int head, level, headpos;
};
fifo sndfifo[2];
Event *elist;
Timer timers[4];
Event evhblank;
extern Event evsamp;
Event *events[NEVENT] = {&timers[0].Event, &timers[1].Event, &timers[2].Event, &timers[3].Event, &evhblank, &evsamp};
Var evvars[] = {
VAR(clock),
ARR(sndfifo[0].d), VAR(sndfifo[0].head), VAR(sndfifo[0].level), VAR(sndfifo[0].headpos),
ARR(sndfifo[1].d), VAR(sndfifo[1].head), VAR(sndfifo[1].level), VAR(sndfifo[1].headpos),
VAR(timers[0].val), VAR(timers[0].clock), VAR(timers[0].sh), VAR(timers[0].snd),
VAR(timers[1].val), VAR(timers[1].clock), VAR(timers[1].sh), VAR(timers[1].snd),
VAR(timers[2].val), VAR(timers[2].clock), VAR(timers[2].sh), VAR(timers[2].snd),
VAR(timers[3].val), VAR(timers[3].clock), VAR(timers[3].sh), VAR(timers[3].snd),
{nil, 0, 0},
};
void
addevent(Event *ev, int time)
{
Event **p, *e;
int t;
t = time;
for(p = &elist; (e = *p) != nil; p = &e->next){
if(t < e->time){
e->time -= t;
break;
}
t -= e->time;
}
ev->next = e;
ev->time = t;
*p = ev;
}
void
delevent(Event *ev)
{
Event **p, *e;
for(p = &elist; (e = *p) != nil; p = &e->next)
if(e == ev){
*p = e->next;
if(e->next != nil)
e->next->time += e->time;
return;
}
}
void
popevent(void)
{
Event *e;
int t;
do{
e = elist;
t = e->time;
elist = e->next;
e->f(e->aux);
}while((elist->time += t) <= 0);
}
void
fifoput(int i, u32int s)
{
fifo *f;
f = sndfifo + i;
if(f->level < 8)
f->d[(f->head + f->level++) & 7] = s;
}
void
fifotimer(int b, int n)
{
fifo *f;
int i, j;
extern s8int snddma[2];
for(i = 0; i < 2; i++){
if((b & 1<<i) == 0)
continue;
f = &sndfifo[i];
for(j = 0; j < n && f->level > 0; j++){
snddma[i] = f->d[f->head] & 0xff;
f->d[f->head] >>= 8;
if(++f->headpos == 4){
f->head = (f->head + 1) & 7;
f->level--;
f->headpos = 0;
}
}
if(f->level <= 4)
dmastart(DMASOUND);
}
}
void
soundcnth(u16int v)
{
timers[0].snd = 0;
timers[1].snd = 0;
if((v & 3<<8) != 0)
timers[(v >> 10) & 1].snd |= 1;
if((v & 3<<12) != 0)
timers[(v >> 14) & 1].snd |= 2;
if((v & 1<<11) != 0){
sndfifo[0].level = 0;
sndfifo[0].head = 0;
sndfifo[0].headpos = 0;
}
if((v & 1<<15) != 0){
sndfifo[1].level = 0;
sndfifo[1].head = 0;
sndfifo[1].headpos = 0;
}
}
u16int
timerget(int i)
{
Timer *t;
t = &timers[i];
if((*t->cnt & (COUNTUP|TIMERON)) != TIMERON)
return t->val;
return t->val + (clock - t->clock >> t->sh);
}
void
timerset(int i, u16int nc)
{
u32int v;
u16int oc;
Timer *t;
t = &timers[i];
oc = *t->cnt;
if((oc & (PRESC|COUNTUP|TIMERON)) == (nc & (PRESC|COUNTUP|TIMERON)))
return;
if((oc & (COUNTUP|TIMERON)) == TIMERON){
v = t->val + (clock - t->clock >> t->sh);
delevent(t);
}else
v = t->val;
if((oc & TIMERON) == 0 && (nc & TIMERON) != 0)
v = t->cnt[-1];
if((nc & 3) != 0)
t->sh = 4 + (nc & 3) * 2;
else
t->sh = 0;
t->val = v;
t->clock = clock & -(1 << t->sh);
if((nc & (COUNTUP|TIMERON)) == TIMERON)
addevent(t, (0x10000 - t->val << t->sh) + (-clock & (1 << t->sh) - 1));
}
void
timertick(void *aux)
{
Timer *t;
u32int v;
int to;
ulong clock0;
t = aux;
clock0 = clock + t->time;
t->clock = clock0 & -(1 << t->sh);
t->val = -t->time >> t->sh;
do{
to = 0;
do{
t->val = v = t->val + t->cnt[-1];
to++;
}while(v >= 0x10000);
if(t == aux)
addevent(t, (0x10000 - t->val << t->sh) + (-clock0 & (1 << t->sh) - 1));
if((*t->cnt & TIMERIRQ) != 0)
setif(IRQTIM0 << t->i);
if(t->snd)
fifotimer(t->snd, to);
if(++t >= timers + 4 || (*t->cnt & (COUNTUP | TIMERON)) != (COUNTUP|TIMERON))
break;
t->val = v = t->val + to;
}while(v >= 0x10000);
}
void
eventinit(void)
{
int i;
extern void hblanktick(void *);
for(i = 0; i < 4; i++){
timers[i].f = timertick;
timers[i].aux = &timers[i];
timers[i].i = i;
timers[i].cnt = ®[TM0CNTH + i * 2];
}
evhblank.f = hblanktick;
addevent(&evhblank, 240*4);
}
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