uint32 usb_midi_tx(const uint32* buf, uint32 packets) {
uint32 bytes=packets*4;
/* Last transmission hasn't finished, so abort. */
if (usb_midi_is_transmitting()) {
/* Copy to TxBuffer */
return 0; /* return len */
}
/* We can only put USB_MIDI_TX_EPSIZE bytes in the buffer. */
if (bytes > USB_MIDI_TX_EPSIZE) {
bytes = USB_MIDI_TX_EPSIZE;
packets=bytes/4;
}
/* Queue bytes for sending. */
if (packets) {
usb_copy_to_pma((uint8 *)buf, bytes, USB_MIDI_TX_ADDR);
}
// We still need to wait for the interrupt, even if we're sending
// zero bytes. (Sending zero-size packets is useful for flushing
// host-side buffers.)
usb_set_ep_tx_count(USB_MIDI_TX_ENDP, bytes);
n_unsent_packets = packets;
transmitting = 1;
usb_set_ep_tx_stat(USB_MIDI_TX_ENDP, USB_EP_STAT_TX_VALID);
return packets;
}
void USBMidi::writePackets(const void *buf, uint32 len) {
if (!this->isConnected() || !buf) {
return;
}
uint32 txed = 0;
uint32 old_txed = 0;
uint32 start = millis();
uint32 sent = 0;
while (txed < len && (millis() - start < USB_TIMEOUT)) {
sent = usb_midi_tx((const uint32*)buf + txed, len - txed);
txed += sent;
if (old_txed != txed) {
start = millis();
}
old_txed = txed;
}
if (sent == USB_MIDI_TX_EPSIZE) {
while (usb_midi_is_transmitting() != 0) {
}
/* flush out to avoid having the pc wait for more data */
usb_midi_tx(NULL, 0);
}
}
uint32 usb_midi_tx(const uint32* buf, uint32 packets) {
int count = 0;
locktxbuffer = 1;
if (locktxbuffer)
{
int bpos = 0;
count = USB_MIDI_TX_EPSIZE/4 - tx_offset;
if (packets < count) count = packets;
while (bpos < count) {
midiBufferTx[tx_offset++] = buf[bpos++];
}
/* Disable USB EP interrupts */
USB_BASE->CNTR = USB_ISR_MSK&~USB_CNTR_CTRM;
if (!usb_midi_is_transmitting())
{
usb_midi_tx_send_buffer();
}
locktxbuffer = 0;
/* Reenable USB EP interrupts */
USB_BASE->CNTR = USB_ISR_MSK&~USB_CNTR_CTRM;
}
locktxbuffer = 0;
return count;
}
