skylark-qmk/tmk_core/protocol/midi/qmk_midi.c

#include <LUFA/Drivers/USB/USB.h>
#include "qmk_midi.h"
#include "sysex_tools.h"
#include "midi.h"
#include "usb_descriptor.h"
#include "process_midi.h"
#if API_SYSEX_ENABLE
#include "api.h"
#endif

/*******************************************************************************
 * MIDI
 ******************************************************************************/

MidiDevice midi_device;

#define SYSEX_START_OR_CONT 0x40
#define SYSEX_ENDS_IN_1 0x50
#define SYSEX_ENDS_IN_2 0x60
#define SYSEX_ENDS_IN_3 0x70

#define SYS_COMMON_1 0x50
#define SYS_COMMON_2 0x20
#define SYS_COMMON_3 0x30

static void usb_send_func(MidiDevice * device, uint16_t cnt, uint8_t byte0, uint8_t byte1, uint8_t byte2) {
  MIDI_EventPacket_t event;
  event.Data1 = byte0;
  event.Data2 = byte1;
  event.Data3 = byte2;

  uint8_t cable = 0;

  //if the length is undefined we assume it is a SYSEX message
  if (midi_packet_length(byte0) == UNDEFINED) {
    switch(cnt) {
      case 3:
        if (byte2 == SYSEX_END)
          event.Event = MIDI_EVENT(cable, SYSEX_ENDS_IN_3);
        else
          event.Event = MIDI_EVENT(cable, SYSEX_START_OR_CONT);
        break;
      case 2:
        if (byte1 == SYSEX_END)
          event.Event = MIDI_EVENT(cable, SYSEX_ENDS_IN_2);
        else
          event.Event = MIDI_EVENT(cable, SYSEX_START_OR_CONT);
        break;
      case 1:
        if (byte0 == SYSEX_END)
          event.Event = MIDI_EVENT(cable, SYSEX_ENDS_IN_1);
        else
          event.Event = MIDI_EVENT(cable, SYSEX_START_OR_CONT);
        break;
      default:
        return; //invalid cnt
    }
  } else {
    //deal with 'system common' messages
    //TODO are there any more?
    switch(byte0 & 0xF0){
      case MIDI_SONGPOSITION:
        event.Event = MIDI_EVENT(cable, SYS_COMMON_3);
        break;
      case MIDI_SONGSELECT:
      case MIDI_TC_QUARTERFRAME:
        event.Event = MIDI_EVENT(cable, SYS_COMMON_2);
        break;
      default:
        event.Event = MIDI_EVENT(cable, byte0);
        break;
    }
  }

  send_midi_packet(&event);
}

static void usb_get_midi(MidiDevice * device) {
  MIDI_EventPacket_t event;
  while (recv_midi_packet(&event)) {

    midi_packet_length_t length = midi_packet_length(event.Data1);
    uint8_t input[3];
    input[0] = event.Data1;
    input[1] = event.Data2;
    input[2] = event.Data3;
    if (length == UNDEFINED) {
      //sysex
      if (event.Event == MIDI_EVENT(0, SYSEX_START_OR_CONT) || event.Event == MIDI_EVENT(0, SYSEX_ENDS_IN_3)) {
        length = 3;
      } else if (event.Event == MIDI_EVENT(0, SYSEX_ENDS_IN_2)) {
        length = 2;
      } else if(event.Event ==  MIDI_EVENT(0, SYSEX_ENDS_IN_1)) {
        length = 1;
      } else {
        //XXX what to do?
      }
    }

    //pass the data to the device input function
    if (length != UNDEFINED)
      midi_device_input(device, length, input);
  }
}

static void fallthrough_callback(MidiDevice * device,
    uint16_t cnt, uint8_t byte0, uint8_t byte1, uint8_t byte2){

#ifdef AUDIO_ENABLE
  if (cnt == 3) {
    switch (byte0 & 0xF0) {
        case MIDI_NOTEON:
            play_note(((double)261.6)*pow(2.0, -4.0)*pow(2.0,(byte1 & 0x7F)/12.0), (byte2 & 0x7F) / 8);
            break;
        case MIDI_NOTEOFF:
            stop_note(((double)261.6)*pow(2.0, -4.0)*pow(2.0,(byte1 & 0x7F)/12.0));
            break;
    }
  }
  if (byte0 == MIDI_STOP) {
    stop_all_notes();
  }
#endif
}


static void cc_callback(MidiDevice * device,
    uint8_t chan, uint8_t num, uint8_t val) {
  //sending it back on the next channel
  // midi_send_cc(device, (chan + 1) % 16, num, val);
}

#ifdef API_SYSEX_ENABLE
uint8_t midi_buffer[MIDI_SYSEX_BUFFER] = {0};

static void sysex_callback(MidiDevice * device, uint16_t start, uint8_t length, uint8_t * data) {
  // SEND_STRING("\n");
  // send_word(start);
  // SEND_STRING(": ");
  // Don't store the header
  int16_t pos = start - 4;
  for (uint8_t place = 0; place < length; place++) {
      // send_byte(*data);
      if (pos >= 0) {
          if (*data == 0xF7) {
              // SEND_STRING("\nRD: ");
              // for (uint8_t i = 0; i < start + place + 1; i++){
              //     send_byte(midi_buffer[i]);
              // SEND_STRING(" ");
              // }
              const unsigned decoded_length = sysex_decoded_length(pos);
              uint8_t decoded[API_SYSEX_MAX_SIZE];
              sysex_decode(decoded, midi_buffer, pos);
              process_api(decoded_length, decoded);
              return;
          }
          else if (pos >= MIDI_SYSEX_BUFFER) {
              return;
          }
          midi_buffer[pos] = *data;
      }
      // SEND_STRING(" ");
      data++;
      pos++;
  }
}
#endif

void midi_init(void);

void setup_midi(void)
{
#ifdef MIDI_ADVANCED
	midi_init();
#endif
	midi_device_init(&midi_device);
  midi_device_set_send_func(&midi_device, usb_send_func);
  midi_device_set_pre_input_process_func(&midi_device, usb_get_midi);
  midi_register_fallthrough_callback(&midi_device, fallthrough_callback);
  midi_register_cc_callback(&midi_device, cc_callback);
#ifdef API_SYSEX_ENABLE
  midi_register_sysex_callback(&midi_device, sysex_callback);
#endif
}