MidiUSB.cpp

00001 
00002 /*
00003 Copyright (c) 2012 RadioJunkBox
00004 
00005 Permission is hereby granted, free of charge, to any person obtaining a copy
00006 of this software and associated documentation files (the "Software"), to deal
00007 in the Software without restriction, including without limitation the rights
00008 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00009 copies of the Software, and to permit persons to whom the Software is
00010 furnished to do so, subject to the following conditions:
00011 
00012 The above copyright notice and this permission notice shall be included in
00013 all copies or substantial portions of the Software.
00014 
00015 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00016 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00017 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00018 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00019 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00020 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00021 THE SOFTWARE.
00022 */
00023 
00024 #include "mbed.h"
00025 #include "USBHost.h"
00026 #include "Utils.h"
00027 
00028 #define MIDIEVT(_class,_subclass,_protocol) (((_class) << 16) | ((_subclass) << 8) | _protocol)
00029 u8 ms_buf[255];  // MIDI Streaming Buffer
00030 
00031 // Ring Buffer
00032 #define         BUFSIZE             32      // size of ring buffer (ex 4,8,16,32...)
00033 int             gPtr_buf_in, gPtr_buf_out;
00034 unsigned char   gRxBuf[BUFSIZE];
00035 
00036 // Serial MIDI Port
00037 #define         MIDI_RATE           31250   // 31.25kbps
00038 Serial          gMIDI(p9,p10);
00039 Ticker          gTickerMIDI;
00040 
00041 // Transmit to Serial MIDI Port
00042 void TxSerialMidi()
00043 {
00044     unsigned char rb;
00045 
00046     // ring buffer empty?
00047     if(gPtr_buf_in != gPtr_buf_out)
00048     {
00049         // get 1byte from ring buffer
00050         gPtr_buf_out++;
00051         gPtr_buf_out &= (BUFSIZE - 1);
00052         rb = gRxBuf[gPtr_buf_out];
00053         gMIDI.putc(rb);
00054     }      
00055 }
00056 
00057 // Intialize Serial MIDI Port  
00058 void InitSerialMIDI()
00059 {
00060     gPtr_buf_in = gPtr_buf_out = 0;
00061     gMIDI.baud(MIDI_RATE);
00062     gTickerMIDI.attach_us(&TxSerialMidi, 500);  // 500us
00063 }
00064 
00065 //  Received MIDI Steram
00066 void MidiEventCallback(int device, int endpoint, int status, u8* data, int len, void* userData)
00067 {
00068     int i;
00069     int ptr = 0;
00070 
00071     while((data[ptr] != 0) && (ptr < len))
00072     {        
00073         // printf("MIDI %02X %02X %02X",device,status,len);
00074         // printfBytes("",data,4);
00075         for( i = 1; i<4; i++)
00076         {
00077             gPtr_buf_in++;
00078             gPtr_buf_in &= (BUFSIZE - 1);
00079             gRxBuf[gPtr_buf_in] = data[ptr+i];
00080         }
00081         ptr+=4;
00082     }
00083     USBBulkTransfer(device,endpoint,data,len,MidiEventCallback,userData);
00084 }
00085 
00086 //  Add MIDI Interface
00087 void AddMidiInterface(int device, InterfaceDescriptor* id, EndpointDescriptor* ed,int len)
00088 {
00089     if ((ed->bmAttributes & 3) != ENDPOINT_BULK || !(ed->bEndpointAddress & 0x80))
00090         return;
00091     
00092     // Make bulk enpoints for MIDI devices
00093     u32 evt = MIDIEVT(id->bInterfaceClass,id->bInterfaceSubClass,id->bInterfaceProtocol);
00094     u8* dst = ms_buf;
00095 
00096     if(dst)
00097     {
00098         // printf("Add Midi Interface %02X %08X\r\n",ed->bEndpointAddress,evt);
00099         USBBulkTransfer(device,ed->bEndpointAddress,dst,len,MidiEventCallback,(void*)evt);
00100     }
00101 }
00102 
00103 //  Detected Midi Device
00104 int OnMidiInsert(int device)
00105 {
00106     u8 buffer[255];
00107     int err = GetDescriptor(device,DESCRIPTOR_TYPE_CONFIGURATION,0,buffer,255);
00108     if (err < 0)
00109         return err;
00110 
00111     int len = buffer[2] | (buffer[3] << 8);
00112     u8* d = buffer;
00113     u8* end = d + len;
00114 
00115     // printf("OnMidiInsert %02X %02X\r\n",device,len);
00116 
00117     while (d < end)
00118     {
00119         if (d[1] == DESCRIPTOR_TYPE_INTERFACE)
00120         {
00121             InterfaceDescriptor* id = (InterfaceDescriptor*)d;
00122             d += d[0];
00123             while (d < end)
00124             {
00125                     if (d[1] == DESCRIPTOR_TYPE_ENDPOINT)
00126                     {
00127                         // printfBytes("MIDI Endpoint",d,d[0]);
00128                         AddMidiInterface(device,id,(EndpointDescriptor*)d,d[4]);
00129                     }
00130                     d += d[0];
00131             }
00132         }
00133         d += d[0];
00134     }
00135     return 0;
00136 }