- 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 framesize of the gadget).
After the negotiation the host driver will set the user or application
selected framesize, while the gadget is actually set to the first
framesize.
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 configsfs attribute in each frame descriptor item.
v2: Add the new attribute to both MJPEG and uncompressed frame descriptors
in Documentation/ABI, with note that it was added only in a later
kernel version
v3: Changed from simply allowing user to set the value for bFrameIndex to
automatically assigning correct distinct frame indexes. Changed
bFrameIndex from RW to RO
Signed-off-by: Joel Pepper <joel.pepper@xxxxxxxxxxxxxx>
---
Documentation/ABI/testing/configfs-usb-gadget-uvc | 17 +++++++++++++++++
drivers/usb/gadget/function/uvc_configfs.c | 3 +++
2 files changed, 20 insertions(+)
diff --git a/Documentation/ABI/testing/configfs-usb-gadget-uvc b/Documentation/ABI/testing/configfs-usb-gadget-uvc
index 1ba0d0f..d435cf7 100644
--- a/Documentation/ABI/testing/configfs-usb-gadget-uvc
+++ b/Documentation/ABI/testing/configfs-usb-gadget-uvc
@@ -194,6 +194,14 @@ Description: Specific MJPEG frame descriptors
bmCapabilities - still image support, fixed frame-rate
support
+Date: Mar 2018
+KernelVersion: 4.16
+
+ bFrameIndex - unique id for this framedescriptor;
+ if using multiple framedescriptors for
+ same format, user needs to set distinct
+ value for each frame descriptor
+
What: /config/usb-gadget/gadget/functions/uvc.name/streaming/uncompressed
Date: Dec 2014
KernelVersion: 4.0
@@ -241,6 +249,15 @@ Description: Specific uncompressed frame descriptors
bmCapabilities - still image support, fixed frame-rate
support
+Date: Mar 2018
+KernelVersion: 4.16
+
+ bFrameIndex - unique id for this framedescriptor;
+ if using multiple framedescriptors for
+ same format, user needs to set distinct
+ value for each frame descriptor
+
+
What: /config/usb-gadget/gadget/functions/uvc.name/streaming/header
Date: Dec 2014
KernelVersion: 4.0
diff --git a/drivers/usb/gadget/function/uvc_configfs.c b/drivers/usb/gadget/function/uvc_configfs.c
index c9b8cc4a..5966d65 100644
--- a/drivers/usb/gadget/function/uvc_configfs.c
+++ b/drivers/usb/gadget/function/uvc_configfs.c
@@ -992,6 +992,8 @@ UVC_ATTR(uvcg_frame_, cname, aname);
UVCG_FRAME_ATTR(bm_capabilities, bmCapabilities, noop_conversion,
noop_conversion, 8);
+UVCG_FRAME_ATTR(b_frame_index, bFrameIndex, noop_conversion,
+ noop_conversion, 8);
UVCG_FRAME_ATTR(w_width, wWidth, le16_to_cpu, cpu_to_le16, 16);
UVCG_FRAME_ATTR(w_height, wHeight, le16_to_cpu, cpu_to_le16, 16);
UVCG_FRAME_ATTR(dw_min_bit_rate, dwMinBitRate, le32_to_cpu, cpu_to_le32, 32);
@@ -1137,6 +1139,7 @@ UVC_ATTR(uvcg_frame_, dw_frame_interval, dwFrameInterval);
static struct configfs_attribute *uvcg_frame_attrs[] = {
&uvcg_frame_attr_bm_capabilities,
+ &uvcg_frame_attr_b_frame_index,
&uvcg_frame_attr_w_width,
&uvcg_frame_attr_w_height,
&uvcg_frame_attr_dw_min_bit_rate,
--
2.1.4
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