[sdiy] USB Midi??

[Thorsten Klose]

There is no need for writing an own driver, because Windows/Mac OSX/
Linux already comes with an integrated MIDI USB solution which 
is based on the specification that can be found under www.usb.org

Here an example setup which works (as you can notice, I had to
tweak the descriptors for Windows, since the M$ driver isn't
compatible at all)

;; for incompatible WinME/WinXP Driver
#define MICRO_WORKAROUND 1       

#define FAKE_MIDI      
1

;;-----------------------------------------------------------------------------
;; Global
Variables
;;-----------------------------------------------------------------------------
;; Note: This segment must be located in on-part memory.
		rseg DSCR		;; locate the descriptor table anywhere below 8K
DeviceDscr:	db	deviceDscrEnd-DeviceDscr		;; Descriptor length
		db	DSCR_DEVICE	;; Decriptor type
		db	0x10, 0x01	;; Specification Version (BCD)
		db	00H  		;; Device class
		db	00H		;; Device sub-class
		db	00H		;; Device sub-sub-class
		db	64		;; Maximum packet size
#if FAKE_MIDI == 1
		dw	4705H		;; Vendor ID
		dw	0210H		;; Product ID - set to default example ID
		dw	0100H		;; Product version ID
#else
		dw	1112H		;; Vendor ID
		dw	2222H		;; Product ID
		db	0x01, 0x00	;; Product version ID
#endif
		db	1		;; Manufacturer string index
		db	2		;; Product string index
		db	0		;; Serial number string index
		db	1		;; Number of configurations
deviceDscrEnd:

ConfigDscr:	db	ConfigDscrEnd-ConfigDscr		;; Descriptor length
		db	DSCR_CONFIG	;; Descriptor type
		db	LOW(StringDscr-ConfigDscr)   ;; Config + End Points length (LSB)
		db	HIGH(StringDscr-ConfigDscr)  ;; Config + End Points length (MSB)
#if MICRO_WORKAROUND == 0
		db	2		;; Number of interfaces
#else
		db	1		;; Number of interfaces
#endif
		db	1		;; Interface number
		db	3		;; Configuration string
		db	10000000b	;; Attributes (b7 - buspwr, b6 - selfpwr, b5 - rwu)
		db	0x10		;; Power requirement (div 2 ma)
ConfigDscrEnd:

#if MICRO_WORKAROUND == 0
AudioCtrlIntrfcDscr:
		db	AudioCtrlIntrfcDscrEnd-AudioCtrlIntrfcDscr	;; Descriptor length
		db	DSCR_INTRFC	;; Descriptor type
		db	0		;; Zero-based index of this interface
		db	0		;; Alternate setting
		db	0		;; Number of end points 
#if FAKE_MIDI == 1
		db	0ffH		;; Interface class
		db	00H		;; Interface sub class
		db	00H		;; Interface sub sub class
#else
		db	01H		;; Interface class  (AUDIO)
		db	01H		;; Interface sub class  (AUDIO_CONTROL)
		db	00H		;; Interface sub sub class
#endif
		db	3		;; Interface descriptor string index
AudioCtrlIntrfcDscrEnd:

AudioControlClassIntrfcDscr:
		db	AudioControlClassIntrfcDscrEnd-AudioControlClassIntrfcDscr	;;
Descriptor length
		db	0x24		;; Descriptor type (CS_INTERFACE)
		db	0x01		;; HEADER subtype
		db	0x00, 0x01	;; Revision of class specification - 1.0
		db	LOW(ClassLength);; Total size of specific descriptors
		db	HIGH(ClassLength)
		db	0x01		;; number of streaming interfaces
		db	0x01		;; MIDI streaming interface 1 belongs to this AudioControl
interface
AudioControlClassIntrfcDscrEnd:
ClassLength	EQU	$-AudioControlClassIntrfcDscr
#endif

AudioStreamIntrfcDscr:
		db	AudioStreamIntrfcDscrEnd-AudioStreamIntrfcDscr	;; Descriptor length
		db	DSCR_INTRFC	;; Descriptor type
#if MICROSHIT == 0
		db	1		;; Zero-based index of this interface
#else
		db	0		;; Zero-based index of this interface
#endif
		db	0		;; Alternate setting
		db	2		;; Number of end points 
		db	01H		;; Interface class  (AUDIO)
		db	03H		;; Interface sub class  (MIDISTREAMING)
		db	00H		;; Interface sub sub class
		db	2		;; Interface descriptor string index
AudioStreamIntrfcDscrEnd:

MSCIntrfcDscr:
		db	MSCIntrfcDscrEnd-MSCIntrfcDscr		;; Descriptor length
		db	0x24		;; Descriptor type
		db	1		;; Zero-based index of this interface
		db	0x00, 0x01	;; revision of this class specification
		db	LOW(MSCClassSize);; Total size of class-specific descriptors
		db	HIGH(MSCClassSize)
MSCIntrfcDscrEnd:

MIDIInEmDscr:
		db	MIDIInEmDscrEnd-MIDIInEmDscr		;; Descriptor length
		db	0x24		;; Descriptor type (CS_INTERFACE)
		db	0x02		;; MIDI_IN_JACK subtype
		db	0x01		;; EMBEDDED
		db	0x01		;; ID of this jack
		db	00H		;; unused
MIDIInEmDscrEnd:

MIDIInExDscr:
		db	MIDIInExDscrEnd-MIDIInExDscr		;; Descriptor length
		db	0x24		;; Descriptor type (CS_INTERFACE)
		db	0x02		;; MIDI_IN_JACK subtype
		db	0x02		;; EXTERNAL
		db	0x02		;; ID of this jack
		db	00H		;; unused
MIDIInExDscrEnd:

MIDIOutEmDscr:
		db	MIDIOutEmDscrEnd-MIDIOutEmDscr		;; Descriptor length
		db	0x24		;; Descriptor type (CS_INTERFACE)
		db	0x03		;; MIDI_OUT_JACK subtype
		db	0x01		;; EMBEDDED
		db	0x03		;; ID of this jack
		db	0x01		;; number of input pins of this jack
		db	0x02		;; ID of the entity to which this pin is connected
		db	0x01		;; Output Pin number of the entity to which this input pin is
connected
		db	00H		;; unused
MIDIOutEmDscrEnd:

MIDIOutExDscr:
		db	MIDIOutExDscrEnd-MIDIOutExDscr		;; Descriptor length
		db	0x24		;; Descriptor type (CS_INTERFACE)
		db	0x03		;; MIDI_OUT_JACK subtype
		db	0x02		;; EXTERNAL
		db	0x04		;; ID of this jack
		db	0x01		;; number of input pins of this jack
		db	0x01		;; ID of the entity to which this pin is connected
		db	0x01		;; Output Pin number of the entity to which this input pin is
connected
		db	00H		;; unused
MIDIOutExDscrEnd:

StdBulkOutEPDscr:
		db	StdBulkOutEPDscrEnd-StdBulkOutEPDscr	;; Descriptor length
		db	DSCR_ENDPNT	;; Descriptor type
		db	0x02		;; Out Endpoint 2
		db	0x02		;; Bulk, not shared
		db	0x04, 0x00	;; 4 bytes per packet
		db	0x00		;; ignore for bulk
		db	0x00		;; unused
		db	0x00		;; unused
StdBulkOutEPDscrEnd:

StdBulkInEPDscr:
		db	StdBulkInEPDscrEnd-StdBulkInEPDscr	;; Descriptor length
		db	DSCR_ENDPNT	;; Descriptor type
		db	0x82		;; In Endpoint 2
		db	0x02		;; Bulk, not shared
		db	0x04, 0x00	;; 4 bytes per packet
		db	0x00		;; ignore for bulk
		db	0x00		;; unused
		db	0x00		;; unused
StdBulkInEPDscrEnd:

MSBulkOutEPDscr:
		db	MSBulkOutEPDscrEnd-MSBulkOutEPDscr	;; Descriptor length
		db	0x25		;; Descriptor type (CS_ENDPOINT)
		db	0x01		;; MS_GENERAL
		db	0x01		;; number of embedded MIDI IN Jacks
		db	0x01		;; ID of embedded MIDI In Jack
MSBulkOutEPDscrEnd:

MSBulkInEPDscr:
		db	MSBulkInEPDscrEnd-MSBulkInEPDscr	;; Descriptor length
		db	0x25		;; Descriptor type (CS_ENDPOINT)
		db	0x01		;; MS_GENERAL
		db	0x01		;; number of embedded MIDI Out Jacks
		db	0x03		;; ID of embedded MIDI Out Jack
MSBulkInEPDscrEnd:

MSCClassSize	EQU	$-MSCIntrfcDscr

StringDscr:
StringDscr0:
		db	StringDscr0End-StringDscr0		;; String descriptor length
		db	DSCR_STRING
		db	09H,04H
StringDscr0End:

StringDscr1:	
		db	StringDscr1End-StringDscr1		;; String descriptor length
		db	DSCR_STRING
		db	'A',00
StringDscr1End:

StringDscr2:	
		db	StringDscr2End-StringDscr2		;; Descriptor length
		db	DSCR_STRING
		db	'B',00
StringDscr2End:

StringDscr3:	
		db	StringDscr3End-StringDscr3		;; Descriptor length
		db	DSCR_STRING
		db	'C',00
StringDscr3End:

UserDscr:		
		dw	0000H
		end