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authorAndrzej Pietrasiewicz <andrzej.p@samsung.com>2014-12-16 13:56:33 (GMT)
committerFelipe Balbi <balbi@ti.com>2015-01-12 18:13:25 (GMT)
commit0d6be59a1d8a93086cd81e1c59f8d60ba35b40a2 (patch)
treec81c6f24028f20955daa629408964622d25beb57 /Documentation/usb
parentcdbe287d271637cb90f239d6a826e2aed555c1d7 (diff)
Documentation: usb: MIDI function testing
Summary of how to test MIDI function of USB gadget. Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com> Signed-off-by: Felipe Balbi <balbi@ti.com>
Diffstat (limited to 'Documentation/usb')
-rw-r--r--Documentation/usb/gadget-testing.txt84
1 files changed, 84 insertions, 0 deletions
diff --git a/Documentation/usb/gadget-testing.txt b/Documentation/usb/gadget-testing.txt
index 01b9ffe..c2f148d 100644
--- a/Documentation/usb/gadget-testing.txt
+++ b/Documentation/usb/gadget-testing.txt
@@ -9,6 +9,7 @@ provided by gadgets.
6. HID function
7. LOOPBACK function
8. MASS STORAGE function
+9. MIDI function
1. ACM function
@@ -282,3 +283,86 @@ Testing the MASS STORAGE function
device: connect the gadget, enable it
host: dmesg, see the USB drives appear (if system configured to automatically
mount)
+
+9. MIDI function
+================
+
+The function is provided by usb_f_midi.ko module.
+
+Function-specific configfs interface
+------------------------------------
+
+The function name to use when creating the function directory is "midi".
+The MIDI function provides these attributes in its function directory:
+
+ buflen - MIDI buffer length
+ id - ID string for the USB MIDI adapter
+ in_ports - number of MIDI input ports
+ index - index value for the USB MIDI adapter
+ out_ports - number of MIDI output ports
+ qlen - USB read request queue length
+
+Testing the MIDI function
+-------------------------
+
+There are two cases: playing a mid from the gadget to
+the host and playing a mid from the host to the gadget.
+
+1) Playing a mid from the gadget to the host
+host)
+
+$ arecordmidi -l
+ Port Client name Port name
+ 14:0 Midi Through Midi Through Port-0
+ 24:0 MIDI Gadget MIDI Gadget MIDI 1
+$ arecordmidi -p 24:0 from_gadget.mid
+
+gadget)
+
+$ aplaymidi -l
+ Port Client name Port name
+ 20:0 f_midi f_midi
+
+$ aplaymidi -p 20:0 to_host.mid
+
+2) Playing a mid from the host to the gadget
+gadget)
+
+$ arecordmidi -l
+ Port Client name Port name
+ 20:0 f_midi f_midi
+
+$ arecordmidi -p 20:0 from_host.mid
+
+host)
+
+$ aplaymidi -l
+ Port Client name Port name
+ 14:0 Midi Through Midi Through Port-0
+ 24:0 MIDI Gadget MIDI Gadget MIDI 1
+
+$ aplaymidi -p24:0 to_gadget.mid
+
+The from_gadget.mid should sound identical to the to_host.mid.
+The from_host.id should sound identical to the to_gadget.mid.
+
+MIDI files can be played to speakers/headphones with e.g. timidity installed
+
+$ aplaymidi -l
+ Port Client name Port name
+ 14:0 Midi Through Midi Through Port-0
+ 24:0 MIDI Gadget MIDI Gadget MIDI 1
+128:0 TiMidity TiMidity port 0
+128:1 TiMidity TiMidity port 1
+128:2 TiMidity TiMidity port 2
+128:3 TiMidity TiMidity port 3
+
+$ aplaymidi -p 128:0 file.mid
+
+MIDI ports can be logically connected using the aconnect utility, e.g.:
+
+$ aconnect 24:0 128:0 # try it on the host
+
+After the gadget's MIDI port is connected to timidity's MIDI port,
+whatever is played at the gadget side with aplaymidi -l is audible
+in host's speakers/headphones.

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