Add bFrameIndex as a UVCG_FRAME_ATTR for each frame size.
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.
Note that this still requires the gadget to be configured with unique
bFrameIndexes for each frameSize of each format through configfs. An
alternative might be to automatically assign ascending indices when the
format is linked into the streaming header, but the user space gadget
would need a way to check or predict the indices so that it can properly
interpret to PROBE/COMMIT CONTROL requests
v2: Add the new attribute to both MJPEG and uncompressedframe descriptos
in Documentation/ABI, with note that it was added only in a later
kernel version
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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