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authorJoel Pepper <joel.pepper@rwth-aachen.de>2018-05-29 21:02:13 +0200
committerLaurent Pinchart <laurent.pinchart@ideasonboard.com>2018-09-24 18:00:35 +0200
commitb206548be6459ea5ffa82b9f1175915b225a89a1 (patch)
treea4829236755de0f970f8bae416cad8ee5742dbe6 /Documentation/ABI
parentusb: gadget: uvc: configfs: Add bFormatIndex attributes (diff)
downloadlinux-b206548be6459ea5ffa82b9f1175915b225a89a1.tar.xz
linux-b206548be6459ea5ffa82b9f1175915b225a89a1.zip
usb: gadget: uvc: configfs: Add bFrameIndex attributes
- Add bFrameIndex as a UVCG_FRAME_ATTR_RO for each frame size. - Automatically assign ascending bFrameIndex to each frame in a format. Before all "bFrameindex" attributes were set to "1" with no way to configure the gadget otherwise. This resulted in the host always negotiating for bFrameIndex 1 (i.e. the first frame size of the gadget). After the negotiation the host driver will set the user or application selected frame size, while the gadget is actually set to the first frame size. Now, when the containing format is linked into the streaming header, iterate over all child frame descriptors and assign ascending indices. The automatically assigned indices can be read from the new read only bFrameIndex configfs attribute in each frame descriptor item. Signed-off-by: Joel Pepper <joel.pepper@rwth-aachen.de> [Simplified documentation, renamed function, blank space update] Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Diffstat (limited to 'Documentation/ABI')
-rw-r--r--Documentation/ABI/testing/configfs-usb-gadget-uvc8
1 files changed, 8 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/configfs-usb-gadget-uvc b/Documentation/ABI/testing/configfs-usb-gadget-uvc
index a6cc8d6d398e..809765bd9573 100644
--- a/Documentation/ABI/testing/configfs-usb-gadget-uvc
+++ b/Documentation/ABI/testing/configfs-usb-gadget-uvc
@@ -189,6 +189,10 @@ Date: Dec 2014
KernelVersion: 4.0
Description: Specific MJPEG frame descriptors
+ bFrameIndex - unique id for this framedescriptor;
+ only defined after parent format is
+ linked into the streaming header;
+ read-only
dwFrameInterval - indicates how frame interval can be
programmed; a number of values
separated by newline can be specified
@@ -240,6 +244,10 @@ Date: Dec 2014
KernelVersion: 4.0
Description: Specific uncompressed frame descriptors
+ bFrameIndex - unique id for this framedescriptor;
+ only defined after parent format is
+ linked into the streaming header;
+ read-only
dwFrameInterval - indicates how frame interval can be
programmed; a number of values
separated by newline can be specified