Documentation/usb/gadget-testing.rst

18    9. MIDI function
352 9. MIDI function
360 The function name to use when creating the function directory is "midi".
361 The MIDI function provides these attributes in its function directory:
364 	buflen		MIDI buffer length
365 	id		ID string for the USB MIDI adapter
366 	in_ports	number of MIDI input ports
367 	index		index value for the USB MIDI adapter
368 	out_ports	number of MIDI output ports
372 Testing the MIDI function
384    14:0    Midi Through                     Midi Through Port-0
385    24:0    MIDI Gadget                      MIDI Gadget MIDI 1
410    14:0    Midi Through                     Midi Through Port-0
411    24:0    MIDI Gadget                      MIDI Gadget MIDI 1
419 MIDI files can be played to speakers/headphones with e.g. timidity installed::
423    14:0    Midi Through                     Midi Through Port-0
424    24:0    MIDI Gadget                      MIDI Gadget MIDI 1
432 MIDI ports can be logically connected using the aconnect utility, e.g.::
436 After the gadget's MIDI port is connected to timidity's MIDI port,
998 attributes for a UMP Endpoint (which is a pair of USB MIDI Endpoints):
1001 	protocol_caps	MIDI protocol capabilities;
1002 			1: MIDI 1.0, 2: MIDI 2.0, or 3: both protocols
1003 	protocol	Default MIDI protocol (either 1 or 2)
1022 	midi1_first_group	The first UMP Group number for MIDI 1.0 (0-15)
1023 	midi1_num_groups	The number of groups for MIDI 1.0 (0-16)
1026 	midi_ci_verison		Supported MIDI-CI version number (8 bit)
1027 	is_midi1		Legacy MIDI 1.0 device (0-2)
1028 				0: MIDI 2.0 device,
1029 				1: MIDI 1.0 without restriction, or
1030 				2: MIDI 1.0 with low speed
1045 For emulating the old MIDI 2.0 device without UMP v1.1 support, pass 0
1065 UMP MIDI client such as "MIDI 2.0 Gadget".
1070 For testing a MIDI input from the gadget to the host (e.g. emulating a
1071 MIDI keyboard), you can send a MIDI stream like the following.
1077   client 20: 'MIDI 2.0 Gadget' [type=kernel,card=1]
1078       0 'MIDI 2.0        '
1079       1 'Group 1 (MIDI 2.0 Gadget I/O)'
1086   client 24: 'MIDI 2.0 Gadget' [type=kernel,card=2]
1087       0 'MIDI 2.0        '
1088       1 'Group 1 (MIDI 2.0 Gadget I/O)'
1101 For testing a MIDI output to the gadget to the host (e.g. emulating a
1102 MIDI synth), it'll be just other way round.
1112 The access to MIDI 1.0 on altset 0 on the host is supported, and it's
1124 where 0 = unused, 1 = MIDI 1.0 (altset 0), 2 = MIDI 2.0 (altset 1).
1125 The example above shows it's running in 2, i.e. MIDI 2.0.