diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/configfs-usb-gadget-uvc | 4 | ||||
| -rw-r--r-- | Documentation/usb/gadget_uvc.rst | 28 |
2 files changed, 30 insertions, 2 deletions
diff --git a/Documentation/ABI/testing/configfs-usb-gadget-uvc b/Documentation/ABI/testing/configfs-usb-gadget-uvc index 80b98a4a4d0f..4feb692c4c1d 100644 --- a/Documentation/ABI/testing/configfs-usb-gadget-uvc +++ b/Documentation/ABI/testing/configfs-usb-gadget-uvc @@ -76,7 +76,7 @@ Date: Dec 2014 KernelVersion: 4.0 Description: Default camera terminal descriptors - All attributes read only: + All attributes read only except bmControls, which is read/write: ======================== ==================================== bmControls bitmap specifying which controls are @@ -101,7 +101,7 @@ Date: Dec 2014 KernelVersion: 4.0 Description: Default processing unit descriptors - All attributes read only: + All attributes read only except bmControls, which is read/write: =============== ======================================== iProcessing index of string descriptor diff --git a/Documentation/usb/gadget_uvc.rst b/Documentation/usb/gadget_uvc.rst index 6d22faceb1a0..62bd81ba3dd1 100644 --- a/Documentation/usb/gadget_uvc.rst +++ b/Documentation/usb/gadget_uvc.rst @@ -275,6 +275,34 @@ out with 0x00, for example: bNrInPins and baSourceID function in the same way. +Configuring Supported Controls for Camera Terminal and Processing Unit +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +The Camera Terminal and Processing Units in the UVC chain also have bmControls +attributes which function similarly to the same field in an Extension Unit. +Unlike XUs however, the meaning of the bitflag for these units is defined in +the UVC specification; you should consult the "Camera Terminal Descriptor" and +"Processing Unit Descriptor" sections for an enumeration of the flags. + +.. code-block:: bash + + # Set the Processing Unit's bmControls, flagging Brightness, Contrast + # and Hue as available controls: + echo 0x05 > $FUNCTION/control/processing/default/bmControls + + # Set the Camera Terminal's bmControls, flagging Focus Absolute and + # Focus Relative as available controls: + echo 0x60 > $FUNCTION/control/terminal/camera/default/bmControls + +If you do not set these fields then by default the Auto-Exposure Mode control +for the Camera Terminal and the Brightness control for the Processing Unit will +be flagged as available; if they are not supported you should set the field to +0x00. + +Note that the size of the bmControls field for a Camera Terminal or Processing +Unit is fixed by the UVC specification, and so the bControlSize attribute is +read-only here. + Custom Strings Support ~~~~~~~~~~~~~~~~~~~~~~ |