tinygo/src/machine/usb/adc/midi/midi.go

106 строки
1,7 КиБ
Go

package midi
import (
"machine"
"machine/usb"
"machine/usb/descriptor"
)
const (
midiEndpointOut = usb.MIDI_ENDPOINT_OUT // from PC
midiEndpointIn = usb.MIDI_ENDPOINT_IN // to PC
)
var Midi *midi
type midi struct {
msg [4]byte
buf *RingBuffer
rxHandler func([]byte)
waitTxc bool
}
func init() {
if Midi == nil {
Midi = newMidi()
}
}
// New returns the USB MIDI port.
// Deprecated, better to just use Port()
func New() *midi {
return Port()
}
// Port returns the USB midi port.
func Port() *midi {
return Midi
}
func newMidi() *midi {
m := &midi{
buf: NewRingBuffer(),
}
machine.ConfigureUSBEndpoint(descriptor.CDCMIDI,
[]usb.EndpointConfig{
{
Index: usb.MIDI_ENDPOINT_OUT,
IsIn: false,
Type: usb.ENDPOINT_TYPE_BULK,
RxHandler: m.RxHandler,
},
{
Index: usb.MIDI_ENDPOINT_IN,
IsIn: true,
Type: usb.ENDPOINT_TYPE_BULK,
TxHandler: m.Handler,
},
},
[]usb.SetupConfig{},
)
return m
}
func (m *midi) SetHandler(rxHandler func([]byte)) {
m.rxHandler = rxHandler
}
func (m *midi) Write(b []byte) (n int, err error) {
i := 0
for i = 0; i < len(b); i += 4 {
m.tx(b[i : i+4])
}
return i, nil
}
// sendUSBPacket sends a MIDIPacket.
func (m *midi) sendUSBPacket(b []byte) {
machine.SendUSBInPacket(midiEndpointIn, b)
}
// from BulkIn
func (m *midi) Handler() {
m.waitTxc = false
if b, ok := m.buf.Get(); ok {
m.waitTxc = true
m.sendUSBPacket(b)
}
}
func (m *midi) tx(b []byte) {
if machine.USBDev.InitEndpointComplete {
if m.waitTxc {
m.buf.Put(b)
} else {
m.waitTxc = true
m.sendUSBPacket(b)
}
}
}
// from BulkOut
func (m *midi) RxHandler(b []byte) {
if m.rxHandler != nil {
m.rxHandler(b)
}
}