midi work with esp32

Author: hathach

src/arduino/midi/Adafruit_USBD_MIDI.cpp

@@ -35,42 +35,83 @@
 #define EPIN 0x80
 #define EPSIZE 64
 
-Adafruit_USBD_MIDI::Adafruit_USBD_MIDI(void) : _n_cables(1) {}
+// TODO multiple instances
+static Adafruit_USBD_MIDI *_midi_dev = NULL;
+
+
+#ifdef ARDUINO_ARCH_ESP32
+static uint16_t midi_load_descriptor(uint8_t * dst, uint8_t * itf)
+{
+  // uint8_t str_index = tinyusb_add_string_descriptor("TinyUSB HID");
+  uint8_t str_index = 0;
+
+  uint8_t ep_in = tinyusb_get_free_in_endpoint();
+  uint8_t ep_out = tinyusb_get_free_out_endpoint();
+  TU_VERIFY (ep_in && ep_out);
+  ep_in |= 0x80;
+
+  uint16_t desc_len = _midi_dev->getInterfaceDescriptor(0, NULL, 0);
+
+  desc_len = _midi_dev->makeItfDesc(*itf, dst, desc_len, ep_in, ep_out);
+
+  *itf+=2;
+  return desc_len;
+}
+#endif
+
+Adafruit_USBD_MIDI::Adafruit_USBD_MIDI(uint8_t n_cables){
+  _n_cables = n_cables;
+
+#ifdef ARDUINO_ARCH_ESP32
+  // ESP32 requires setup configuration descriptor within constructor
+  _midi_dev = this;
+  uint16_t const desc_len = getInterfaceDescriptor(0, NULL, 0);
+  tinyusb_enable_interface(USB_INTERFACE_MIDI, desc_len, midi_load_descriptor);
+#endif
+}
 
 void Adafruit_USBD_MIDI::setCables(uint8_t n_cables) { _n_cables = n_cables; }
 
 bool Adafruit_USBD_MIDI::begin(void) {
-  if (!TinyUSBDevice.addInterface(*this))
+  if (!TinyUSBDevice.addInterface(*this)) {
     return false;
+  }
 
+  _midi_dev = this;
   return true;
 }
 
-uint16_t Adafruit_USBD_MIDI::getInterfaceDescriptor(uint8_t itfnum,
-                                                    uint8_t *buf,
-                                                    uint16_t bufsize) {
-  uint16_t len = 0;
+uint16_t Adafruit_USBD_MIDI::makeItfDesc(uint8_t itfnum, uint8_t *buf, uint16_t bufsize, uint8_t ep_in, uint8_t ep_out) {
+  uint16_t const desc_len = TUD_MIDI_DESC_HEAD_LEN + TUD_MIDI_DESC_JACK_LEN * _n_cables + 2 * TUD_MIDI_DESC_EP_LEN(_n_cables);
+
+  // null buf is for length only
+  if (!buf) {
+    return desc_len;
+  }
 
-  if (bufsize < TUD_MIDI_DESC_HEAD_LEN + TUD_MIDI_DESC_JACK_LEN * _n_cables +
-                    TUD_MIDI_DESC_EP_LEN(_n_cables) * 2)
+  if (bufsize < desc_len) {
     return 0;
+  }
 
+  uint16_t len = 0;
+
+  // Header
   {
     uint8_t desc[] = {TUD_MIDI_DESC_HEAD(itfnum, 0, _n_cables)};
     memcpy(buf + len, desc, sizeof(desc));
     len += sizeof(desc);
   }
 
+  // Jack
   for (uint8_t i = 1; i <= _n_cables; i++) {
     uint8_t jack[] = {TUD_MIDI_DESC_JACK(i)};
     memcpy(buf + len, jack, sizeof(jack));
     len += sizeof(jack);
   }
 
-  // Endpoint OUT + jack mapping - usb core will automatically update endpoint
-  // number
+  // Endpoint OUT + jack mapping
   {
-    uint8_t desc[] = {TUD_MIDI_DESC_EP(EPOUT, EPSIZE, _n_cables)};
+    uint8_t desc[] = {TUD_MIDI_DESC_EP(ep_out, EPSIZE, _n_cables)};
     memcpy(buf + len, desc, sizeof(desc));
     len += sizeof(desc);
   }
@@ -81,10 +122,9 @@ uint16_t Adafruit_USBD_MIDI::getInterfaceDescriptor(uint8_t itfnum,
     len += sizeof(jack);
   }
 
-  // Endpoint IN + jack mapping - usb core will automatically update endpoint
-  // number
+  // Endpoint IN + jack mapping
   {
-    uint8_t desc[] = {TUD_MIDI_DESC_EP(EPIN, EPSIZE, _n_cables)};
+    uint8_t desc[] = {TUD_MIDI_DESC_EP(ep_in, EPSIZE, _n_cables)};
     memcpy(buf + len, desc, sizeof(desc));
     len += sizeof(desc);
   }
@@ -95,7 +135,18 @@ uint16_t Adafruit_USBD_MIDI::getInterfaceDescriptor(uint8_t itfnum,
     len += sizeof(jack);
   }
 
-  return len;
+  if ( len != desc_len ) {
+    // TODO should throw an error message
+    return 0;
+  }
+
+  return desc_len;
+}
+
+uint16_t Adafruit_USBD_MIDI::getInterfaceDescriptor(uint8_t itfnum,
+                                                    uint8_t *buf,
+                                                    uint16_t bufsize) {
+  return makeItfDesc(itfnum, buf, bufsize, EPIN, EPOUT);
 }
 
 int Adafruit_USBD_MIDI::read(void) {

src/arduino/midi/Adafruit_USBD_MIDI.h

@@ -30,7 +30,9 @@
 
 class Adafruit_USBD_MIDI : public Stream, public Adafruit_USBD_Interface {
 public:
-  Adafruit_USBD_MIDI(void);
+  Adafruit_USBD_MIDI(uint8_t n_cables = 1);
+
+  void setCables(uint8_t n_cables);
 
   bool begin(void);
 
@@ -57,7 +59,8 @@ class Adafruit_USBD_MIDI : public Stream, public Adafruit_USBD_Interface {
   virtual uint16_t getInterfaceDescriptor(uint8_t itfnum, uint8_t *buf,
                                           uint16_t bufsize);
 
-  void setCables(uint8_t n_cables);
+  // internal use only
+  uint16_t makeItfDesc(uint8_t itfnum, uint8_t *buf, uint16_t bufsize, uint8_t ep_in, uint8_t ep_out);
 
 private:
   uint8_t _n_cables;