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| -rw-r--r-- | Documentation/usb/gadget-testing.txt | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/Documentation/usb/gadget-testing.txt b/Documentation/usb/gadget-testing.txt index 40d22d82cc5a..5ac9dc702c0e 100644 --- a/Documentation/usb/gadget-testing.txt +++ b/Documentation/usb/gadget-testing.txt @@ -17,6 +17,7 @@ provided by gadgets. 14. SERIAL function 15. SOURCESINK function 16. UAC1 function +17. UAC2 function 1. ACM function @@ -614,3 +615,41 @@ Testing the UAC1 function device: run the gadget host: aplay -l # should list our USB Audio Gadget + +17. UAC2 function +================= + +The function is provided by usb_f_uac2.ko module. + +Function-specific configfs interface +------------------------------------ + +The function name to use when creating the function directory is "uac2". +The uac2 function provides these attributes in its function directory: + + chmask - capture channel mask + c_srate - capture sampling rate + c_ssize - capture sample size (bytes) + p_chmask - playback channel mask + p_srate - playback sampling rate + p_ssize - playback sample size (bytes) + +The attributes have sane default values. + +Testing the UAC2 function +------------------------- + +device: run the gadget +host: aplay -l # should list our USB Audio Gadget + +This function does not require real hardware support, it just +sends a stream of audio data to/from the host. In order to +actually hear something at the device side, a command similar +to this must be used at the device side: + +$ arecord -f dat -t wav -D hw:2,0 | aplay -D hw:0,0 & + +e.g.: + +$ arecord -f dat -t wav -D hw:CARD=UAC2Gadget,DEV=0 | \ +aplay -D default:CARD=OdroidU3 |