size_t cbuf_write_char(cbuf_t *cbuf, char c, bool canreschedule)
{
DEBUG_ASSERT(cbuf);
enter_critical_section();
size_t ret = 0;
if (cbuf_space_avail(cbuf) > 0) {
cbuf->buf[cbuf->head] = c;
cbuf->head = INC_POINTER(cbuf, cbuf->head, 1);
ret = 1;
if (cbuf->head != cbuf->tail)
event_signal(&cbuf->event, canreschedule);
}
exit_critical_section();
return ret;
}
size_t cbuf_write_char(cbuf_t* cbuf, char c) {
DEBUG_ASSERT(cbuf);
size_t ret = 0;
{
AutoSpinLock guard(&cbuf->lock);
if (cbuf_space_avail(cbuf) > 0) {
cbuf->buf[cbuf->head] = c;
cbuf->head = inc_pointer(cbuf, cbuf->head, 1);
ret = 1;
}
}
if (ret > 0) {
event_signal(&cbuf->event, true);
}
return ret;
}
size_t cbuf_write(cbuf_t *cbuf, const void *_buf, size_t len, bool canreschedule)
{
const char *buf = (const char *)_buf;
LTRACEF("len %zd\n", len);
DEBUG_ASSERT(cbuf);
DEBUG_ASSERT(_buf);
DEBUG_ASSERT(len < valpow2(cbuf->len_pow2));
enter_critical_section();
size_t write_len;
size_t pos = 0;
while (pos < len && cbuf_space_avail(cbuf) > 0) {
if (cbuf->head >= cbuf->tail) {
write_len = MIN(valpow2(cbuf->len_pow2) - cbuf->head, len - pos);
} else {
write_len = MIN(cbuf->tail - cbuf->head - 1, len - pos);
}
// if it's full, abort and return how much we've written
if (write_len == 0) {
break;
}
memcpy(cbuf->buf + cbuf->head, buf + pos, write_len);
cbuf->head = INC_POINTER(cbuf, cbuf->head, write_len);
pos += write_len;
}
if (cbuf->head != cbuf->tail)
event_signal(&cbuf->event, canreschedule);
exit_critical_section();
return pos;
}
static interrupt_eoi uart_irq_handler(void* arg) {
/* read interrupt status and mask */
while ((UARTREG(MX8_USR1) & USR1_RRDY)) {
if (cbuf_space_avail(&uart_rx_buf) == 0) {
break;
}
char c = UARTREG(MX8_URXD) & 0xFF;
cbuf_write_char(&uart_rx_buf, c);
}
/* Signal if anyone is waiting to TX */
if (UARTREG(MX8_UCR1) & UCR1_TRDYEN) {
spin_lock(&uart_spinlock);
if (!(UARTREG(MX8_USR2) & UTS_TXFULL)) {
// signal
event_signal(&uart_dputc_event, true);
}
spin_unlock(&uart_spinlock);
}
return IRQ_EOI_DEACTIVATE;
}