static void enable_fifo() {
/* check if there is a fifo and how deep it is */
uint8_t info = read_iir();
if ((info & IIR_FIFO_ENABLED) == IIR_FIFO_ENABLED) {
fifo_depth = 16;
write_fcr(FCR_TRIGGER_16_1 | FCR_ENABLE);
} else {
fifo_depth = 1;
}
}
static bool clear_iir(void) {
uint8_t iir;
while (! ((iir = read_iir()) & IIR_PENDING)) {
switch(iir & IIR_REASON) {
case IIR_RDA:
case IIR_TIME:
while (read_lsr() & LSR_DATA_READY) {
bool result = handle_char();
if (result) {
return result;
}
}
default:
break;
}
}
return false;
}
static void clear_iir() {
uint8_t iir;
while (! ((iir = read_iir()) & IIR_PENDING)) {
switch(iir & IIR_REASON) {
case IIR_MSR:
read_msr();
break;
case IIR_THR:
break;
case IIR_RDA:
case IIR_TIME:
while (read_lsr() & LSR_DATA_READY) {
handle_char(read_rbr());
}
break;
case IIR_LSR:
read_lsr();
break;
}
}
}
