Merge pull request #215 from kaysievers/midi-port-names

MIDI: support port name strings

Author: hathach

examples/MIDI/midi_multi_ports/midi_multi_ports.ino

@@ -0,0 +1,46 @@
+/*********************************************************************
+ Adafruit invests time and resources providing this open source code,
+ please support Adafruit and open-source hardware by purchasing
+ products from Adafruit!
+
+ MIT license, check LICENSE for more information
+ Copyright (c) 2019 Ha Thach for Adafruit Industries
+ All text above, and the splash screen below must be included in
+ any redistribution
+*********************************************************************/
+
+// This sketch is enumerated as USB MIDI device with multiple ports
+// and how to set their name
+
+#include <Arduino.h>
+#include <Adafruit_TinyUSB.h>
+#include <MIDI.h>
+
+// USB MIDI object with 3 ports
+Adafruit_USBD_MIDI usb_midi(3);
+
+void setup()
+{
+  pinMode(LED_BUILTIN, OUTPUT);
+
+#if defined(ARDUINO_ARCH_MBED) && defined(ARDUINO_ARCH_RP2040)
+  // Manual begin() is required on core without built-in support for TinyUSB such as mbed rp2040
+  TinyUSB_Device_Init(0);
+#endif
+
+  // Set name for each cable, must be done before usb_midi.begin()
+  usb_midi.setCableName(1, "Keyboard");
+  usb_midi.setCableName(2, "Drum Pads");
+  usb_midi.setCableName(3, "Lights");
+
+  usb_midi.begin();
+}
+
+void loop()
+{
+  digitalWrite(LED_BUILTIN, HIGH);
+  delay(1000);
+
+  digitalWrite(LED_BUILTIN, LOW);
+  delay(1000);
+}

src/arduino/Adafruit_USBD_Device.cpp

@@ -126,6 +126,18 @@ void Adafruit_USBD_Device::setSerialDescriptor(const char *s) {
   _desc_str_arr[STRID_SERIAL] = s;
 }
 
+// Add a string descriptor to the device's pool
+// Return string index
+uint8_t Adafruit_USBD_Device::addStringDescriptor(const char *s) {
+  if (_desc_str_count >= STRING_DESCRIPTOR_MAX || s == NULL) {
+    return 0;
+  }
+
+  uint8_t index = _desc_str_count++;
+  _desc_str_arr[index] = s;
+  return index;
+}
+
 void Adafruit_USBD_Device::task(void) { tud_task(); }
 
 bool Adafruit_USBD_Device::mounted(void) { return tud_mounted(); }

src/arduino/Adafruit_USBD_Device.h

@@ -34,7 +34,7 @@
 
 class Adafruit_USBD_Device {
 private:
-  enum { STRING_DESCRIPTOR_MAX = 8 };
+  enum { STRING_DESCRIPTOR_MAX = 12 };
 
   // Device descriptor
   tusb_desc_device_t _desc_device __attribute__((aligned(4)));
@@ -88,6 +88,8 @@ class Adafruit_USBD_Device {
   void setSerialDescriptor(const char *s);
   uint8_t getSerialDescriptor(uint16_t *serial_utf16);
 
+  uint8_t addStringDescriptor(const char *s);
+
   //------------- Control -------------//
 
   bool begin(uint8_t rhport = 0);

src/arduino/midi/Adafruit_USBD_MIDI.cpp

@@ -58,6 +58,7 @@ static uint16_t midi_load_descriptor(uint8_t *dst, uint8_t *itf) {
 
 Adafruit_USBD_MIDI::Adafruit_USBD_MIDI(uint8_t n_cables) {
   _n_cables = n_cables;
+  memset(_cable_name_strid, 0, sizeof(_cable_name_strid));
 
 #ifdef ARDUINO_ARCH_ESP32
   // ESP32 requires setup configuration descriptor within constructor
@@ -69,6 +70,17 @@ Adafruit_USBD_MIDI::Adafruit_USBD_MIDI(uint8_t n_cables) {
 
 void Adafruit_USBD_MIDI::setCables(uint8_t n_cables) { _n_cables = n_cables; }
 
+bool Adafruit_USBD_MIDI::setCableName(uint8_t cable_id, const char *str) {
+  if (cable_id == 0 || cable_id > sizeof(_cable_name_strid)) {
+    return false;
+  }
+
+  uint8_t strid = TinyUSBDevice.addStringDescriptor(str);
+  _cable_name_strid[cable_id] = strid;
+
+  return strid > 0;
+}
+
 bool Adafruit_USBD_MIDI::begin(void) {
   if (!TinyUSBDevice.addInterface(*this)) {
     return false;
@@ -105,7 +117,7 @@ uint16_t Adafruit_USBD_MIDI::makeItfDesc(uint8_t itfnum, uint8_t *buf,
 
   // Jack
   for (uint8_t i = 1; i <= _n_cables; i++) {
-    uint8_t jack[] = {TUD_MIDI_DESC_JACK(i)};
+    uint8_t jack[] = {TUD_MIDI_DESC_JACK_DESC(i, _cable_name_strid[i])};
     memcpy(buf + len, jack, sizeof(jack));
     len += sizeof(jack);
   }

src/arduino/midi/Adafruit_USBD_MIDI.h

@@ -34,6 +34,10 @@ class Adafruit_USBD_MIDI : public Stream, public Adafruit_USBD_Interface {
 
   void setCables(uint8_t n_cables);
 
+  // Set the cable number with a USB device descriptor string
+  // Note: per MIDI specs cable_id (or jackid/elementid) starting from 1. 0 is
+  // reserved for undefined ID.
+  bool setCableName(uint8_t cable_id, const char *str);
   bool begin(void);
 
   // for MIDI library
@@ -65,6 +69,7 @@ class Adafruit_USBD_MIDI : public Stream, public Adafruit_USBD_Interface {
 
 private:
   uint8_t _n_cables;
+  uint8_t _cable_name_strid[8];
 };
 
 #endif /* ADAFRUIT_USBD_MIDI_H_ */