int
sync_tlock(lock_t* p, const char *wname, int timeout){
if(!wname) wname = "lock";
while(1){
asleep( (void*)p, wname );
if( !sync_lockedp(p) && sync_try_lock(p) ){
aunsleep();
return 1;
}
int t = await( -1, timeout );
if( t ) break; /* time out */
}
return 0;
}
/* output a char */
int
serial_putchar(FILE *f, char ch){
/* outputs a char over the serial line */
int i;
struct Com *p;
int plx;
p = (struct Com*)f->d;
USART_TypeDef *addr = p->addr;
#ifdef USE_PROC
if( f->flags & F_NONBLOCK ){
while(1){
plx = spltty();
if( addr->ISR & SR_TXE ) break;
}
}else{
while(1){
plx = splproc();
asleep( addr, "com/o" );
if( addr->ISR & SR_TXE ) break;
addr->CR1 |= 0x80; /* enable TXE irq */
await( -1, 100000 );
if( addr->ISR & SR_TXE ) break;
}
aunsleep();
}
#else
while(1){
plx = spltty();
if( addr->ISR & SR_TXE ) break;
}
#endif
addr->TDR = ch;
splx(plx);
return 1;
}