summaryrefslogtreecommitdiffstats
path: root/Documentation/usb/gadget-testing.txt
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/usb/gadget-testing.txt')
-rw-r--r--Documentation/usb/gadget-testing.txt53
1 files changed, 49 insertions, 4 deletions
diff --git a/Documentation/usb/gadget-testing.txt b/Documentation/usb/gadget-testing.txt
index fb0cc4df1765..fbc397d17e98 100644
--- a/Documentation/usb/gadget-testing.txt
+++ b/Documentation/usb/gadget-testing.txt
@@ -16,10 +16,11 @@ provided by gadgets.
13. RNDIS function
14. SERIAL function
15. SOURCESINK function
-16. UAC1 function
+16. UAC1 function (legacy implementation)
17. UAC2 function
18. UVC function
19. PRINTER function
+20. UAC1 function (new API)
1. ACM function
@@ -589,15 +590,16 @@ device: run the gadget
host: test-usb (tools/usb/testusb.c)
-16. UAC1 function
+16. UAC1 function (legacy implementation)
=================
-The function is provided by usb_f_uac1.ko module.
+The function is provided by usb_f_uac1_legacy.ko module.
Function-specific configfs interface
------------------------------------
-The function name to use when creating the function directory is "uac1".
+The function name to use when creating the function directory
+is "uac1_legacy".
The uac1 function provides these attributes in its function directory:
audio_buf_size - audio buffer size
@@ -772,3 +774,46 @@ host:
More advanced testing can be done with the prn_example
described in Documentation/usb/gadget-printer.txt.
+
+
+20. UAC1 function (virtual ALSA card, using u_audio API)
+=================
+
+The function is provided by usb_f_uac1.ko module.
+It will create a virtual ALSA card and the audio streams are simply
+sinked to and sourced from it.
+
+Function-specific configfs interface
+------------------------------------
+
+The function name to use when creating the function directory is "uac1".
+The uac1 function provides these attributes in its function directory:
+
+ c_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)
+ req_number - the number of pre-allocated request for both capture
+ and playback
+
+The attributes have sane default values.
+
+Testing the UAC1 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=UAC1Gadget,DEV=0 | \
+aplay -D default:CARD=OdroidU3