Skip to content

Commit

Permalink
usb: gadget: uvc: add framebased stream support
Browse files Browse the repository at this point in the history 
Currently the uvc gadget can't support H264/HEVC transport, After
adding framebased stream support, the driver can support them.

Framebased stream is a little different from uncompressed stream.
So we can support framebased stream on the basis of uncompressed stream.

Here are the differences:

1. For the format, framebased format has a extra member (
__u8 bVariableSize) than uncompressed format.

2. For the frame, the layout of last three members of framebased frame
is different from uncompressed frame.
a. Last three members of uncompressed frame are:
  u32	dw_max_video_frame_buffer_size;
  u32	dw_default_frame_interval;
  u8	b_frame_interval_type;
b. Last three members of framebased frame are:
  u32	dw_default_frame_interval;
  u8	b_frame_interval_type;
  u32	dw_bytes_perline;

Here is an example of configuring H264:

cd /sys/kernel/config/usb_gadget/g1
ndir=functions/uvc.usb0/streaming/uncompressed/$NAME
mkdir -p $ndir
echo -n "H264" > $ndir/guidFormat  # H264 or HEVC
echo 0 > $ndir/bBitsPerPixel
echo 1 > $ndir/bVariableSize
wdir=functions/uvc.usb0/streaming/uncompressed/$NAME/${HEIGHT}p
mkdir -p $wdir
echo 0 > $wdir/dwBytesPerLine
echo $WIDTH  > $wdir/wWidth
echo $HEIGHT > $wdir/wHeight
echo 29491200 > $wdir/dwMinBitRate
echo 29491200 > $wdir/dwMaxBitRate
cat <<EOF > $wdir/dwFrameInterval
$INTERVAL
EOF

Signed-off-by: Jing Leng <jleng@ambarella.com>
  • Loading branch information
@intel-lab-lkp
Jing Leng authored and intel-lab-lkp committed Feb 16, 2022
1 parent 9902951 commit 475fba6
Show file tree
Hide file tree
Showing 4 changed files with 81 additions and 9 deletions.
13 changes: 10 additions & 3 deletions Documentation/ABI/testing/configfs-usb-gadget-uvc
View file
Expand Up @@ -243,7 +243,7 @@ Description: Uncompressed format descriptors
What: /config/usb-gadget/gadget/functions/uvc.name/streaming/uncompressed/name
Date: Dec 2014
KernelVersion: 4.0
Description: Specific uncompressed format descriptors
Description: Specific uncompressed/framebased format descriptors

================== =======================================
bFormatIndex unique id for this format descriptor;
Expand All @@ -264,12 +264,15 @@ Description: Specific uncompressed format descriptors
frame
guidFormat globally unique id used to identify
stream-encoding format
bVariableSize whether the data within the frame is of
variable length from frame to frame (
only for framebased format)
================== =======================================

What: /config/usb-gadget/gadget/functions/uvc.name/streaming/uncompressed/name/name
Date: Dec 2014
KernelVersion: 4.0
Description: Specific uncompressed frame descriptors
Description: Specific uncompressed/framebased frame descriptors

========================= =====================================
bFrameIndex unique id for this framedescriptor;
Expand All @@ -283,7 +286,11 @@ Description: Specific uncompressed frame descriptors
like to use as default
dwMaxVideoFrameBufferSize the maximum number of bytes the
compressor will produce for a video
frame or still image
frame or still image (only for
uncompressed frame)
dwBytesPerLine the per-line bytes of the framebased
frame, e.g. H264 or HEVC (only for
framebased frame)
dwMaxBitRate the maximum bit rate at the shortest
frame interval in bps
dwMinBitRate the minimum bit rate at the longest
Expand Down
72 changes: 66 additions & 6 deletions drivers/usb/gadget/function/uvc_configfs.c
View file
Expand Up @@ -11,6 +11,7 @@
*/

#include <linux/sort.h>
#include <linux/videodev2.h>

#include "u_uvc.h"
#include "uvc_configfs.h"
Expand Down Expand Up @@ -782,6 +783,8 @@ struct uvcg_format {
__u8 bmaControls[UVCG_STREAMING_CONTROL_SIZE];
};

static u8 uvcg_uncompressed_subtype(struct uvcg_format *fmt);

static struct uvcg_format *to_uvcg_format(struct config_item *item)
{
return container_of(to_config_group(item), struct uvcg_format, group);
Expand Down Expand Up @@ -1072,7 +1075,23 @@ struct uvcg_frame {
u16 w_height;
u32 dw_min_bit_rate;
u32 dw_max_bit_rate;
u32 dw_max_video_frame_buffer_size;

/*
* The layout of last three members of framebased frame
* is different from uncompressed frame.
* Last three members of uncompressed frame are:
* u32 dw_max_video_frame_buffer_size;
* u32 dw_default_frame_interval;
* u8 b_frame_interval_type;
* Last three members of framebased frame are:
* u32 dw_default_frame_interval;
* u8 b_frame_interval_type;
* u32 dw_bytes_perline;
*/
union {
u32 dw_max_video_frame_buffer_size;
u32 dw_bytes_perline;
};
u32 dw_default_frame_interval;
u8 b_frame_interval_type;
} __attribute__((packed)) frame;
Expand Down Expand Up @@ -1185,6 +1204,7 @@ UVCG_FRAME_ATTR(dw_min_bit_rate, dwMinBitRate, 32);
UVCG_FRAME_ATTR(dw_max_bit_rate, dwMaxBitRate, 32);
UVCG_FRAME_ATTR(dw_max_video_frame_buffer_size, dwMaxVideoFrameBufferSize, 32);
UVCG_FRAME_ATTR(dw_default_frame_interval, dwDefaultFrameInterval, 32);
UVCG_FRAME_ATTR(dw_bytes_perline, dwBytesPerLine, 32);

#undef UVCG_FRAME_ATTR

Expand Down Expand Up @@ -1329,6 +1349,7 @@ static struct configfs_attribute *uvcg_frame_attrs[] = {
&uvcg_frame_attr_dw_max_video_frame_buffer_size,
&uvcg_frame_attr_dw_default_frame_interval,
&uvcg_frame_attr_dw_frame_interval,
&uvcg_frame_attr_dw_bytes_perline,
NULL,
};

Expand Down Expand Up @@ -1365,7 +1386,12 @@ static struct config_item *uvcg_frame_make(struct config_group *group,
mutex_lock(&opts->lock);
fmt = to_uvcg_format(&group->cg_item);
if (fmt->type == UVCG_UNCOMPRESSED) {
h->frame.b_descriptor_subtype = UVC_VS_FRAME_UNCOMPRESSED;
if (uvcg_uncompressed_subtype(fmt) == UVC_VS_FORMAT_UNCOMPRESSED) {
h->frame.b_descriptor_subtype = UVC_VS_FRAME_UNCOMPRESSED;
} else {
h->frame.b_descriptor_subtype = UVC_VS_FRAME_FRAME_BASED;
h->frame.dw_bytes_perline = 0;
}
h->fmt_type = UVCG_UNCOMPRESSED;
} else if (fmt->type == UVCG_MJPEG) {
h->frame.b_descriptor_subtype = UVC_VS_FRAME_MJPEG;
Expand Down Expand Up @@ -1425,6 +1451,14 @@ struct uvcg_uncompressed {
struct uvc_format_uncompressed desc;
};

static u8 uvcg_uncompressed_subtype(struct uvcg_format *fmt)
{
struct uvcg_uncompressed *ch = container_of(fmt,
struct uvcg_uncompressed, fmt);

return ch->desc.bDescriptorSubType;
}

static struct uvcg_uncompressed *to_uvcg_uncompressed(struct config_item *item)
{
return container_of(
Expand Down Expand Up @@ -1466,6 +1500,7 @@ static ssize_t uvcg_uncompressed_guid_format_store(struct config_item *item,
struct f_uvc_opts *opts;
struct config_item *opts_item;
struct mutex *su_mutex = &ch->fmt.group.cg_subsys->su_mutex;
u32 fcc = 0;
int ret;

mutex_lock(su_mutex); /* for navigating configfs hierarchy */
Expand All @@ -1481,7 +1516,17 @@ static ssize_t uvcg_uncompressed_guid_format_store(struct config_item *item,

memcpy(ch->desc.guidFormat, page,
min(sizeof(ch->desc.guidFormat), len));
ret = sizeof(ch->desc.guidFormat);
ret = len;

fcc = v4l2_fourcc(ch->desc.guidFormat[0], ch->desc.guidFormat[1],
ch->desc.guidFormat[2], ch->desc.guidFormat[3]);
if (fcc == V4L2_PIX_FMT_H264 || fcc == V4L2_PIX_FMT_HEVC) {
ch->desc.bLength = UVC_DT_FORMAT_FRAMEBASED_SIZE;
ch->desc.bDescriptorSubType = UVC_VS_FORMAT_FRAME_BASED;
} else {
ch->desc.bLength = UVC_DT_FORMAT_UNCOMPRESSED_SIZE;
ch->desc.bDescriptorSubType = UVC_VS_FORMAT_UNCOMPRESSED;
}

end:
mutex_unlock(&opts->lock);
Expand Down Expand Up @@ -1581,6 +1626,7 @@ UVCG_UNCOMPRESSED_ATTR(b_default_frame_index, bDefaultFrameIndex, 8);
UVCG_UNCOMPRESSED_ATTR_RO(b_aspect_ratio_x, bAspectRatioX, 8);
UVCG_UNCOMPRESSED_ATTR_RO(b_aspect_ratio_y, bAspectRatioY, 8);
UVCG_UNCOMPRESSED_ATTR_RO(bm_interface_flags, bmInterfaceFlags, 8);
UVCG_UNCOMPRESSED_ATTR(b_variable_size, bVariableSize, 8);

#undef UVCG_UNCOMPRESSED_ATTR
#undef UVCG_UNCOMPRESSED_ATTR_RO
Expand Down Expand Up @@ -1611,6 +1657,7 @@ static struct configfs_attribute *uvcg_uncompressed_attrs[] = {
&uvcg_uncompressed_attr_b_aspect_ratio_y,
&uvcg_uncompressed_attr_bm_interface_flags,
&uvcg_uncompressed_attr_bma_controls,
&uvcg_uncompressed_attr_b_variable_size,
NULL,
};

Expand Down Expand Up @@ -1644,6 +1691,7 @@ static struct config_group *uvcg_uncompressed_make(struct config_group *group,
h->desc.bAspectRatioY = 0;
h->desc.bmInterfaceFlags = 0;
h->desc.bCopyProtect = 0;
h->desc.bVariableSize = 0;

h->fmt.type = UVCG_UNCOMPRESSED;
config_group_init_type_name(&h->fmt.group, name,
Expand Down Expand Up @@ -2038,7 +2086,7 @@ static int __uvcg_cnt_strm(void *priv1, void *priv2, void *priv3, int n,
container_of(fmt, struct uvcg_uncompressed,
fmt);

*size += sizeof(u->desc);
*size += u->desc.bLength;
} else if (fmt->type == UVCG_MJPEG) {
struct uvcg_mjpeg *m =
container_of(fmt, struct uvcg_mjpeg, fmt);
Expand Down Expand Up @@ -2108,8 +2156,8 @@ static int __uvcg_fill_strm(void *priv1, void *priv2, void *priv3, int n,

u->desc.bFormatIndex = n + 1;
u->desc.bNumFrameDescriptors = fmt->num_frames;
memcpy(*dest, &u->desc, sizeof(u->desc));
*dest += sizeof(u->desc);
memcpy(*dest, &u->desc, u->desc.bLength);
*dest += u->desc.bLength;
} else if (fmt->type == UVCG_MJPEG) {
struct uvcg_mjpeg *m =
container_of(fmt, struct uvcg_mjpeg, fmt);
Expand All @@ -2129,6 +2177,18 @@ static int __uvcg_fill_strm(void *priv1, void *priv2, void *priv3, int n,

sz = sizeof(frm->frame);
memcpy(*dest, &frm->frame, sz);
/*
* Reorder the frame struct layout due to the difference
* between uncompressed frame and framebased frame.
*/
if (frm->frame.b_descriptor_subtype == UVC_VS_FRAME_FRAME_BASED) {
u8 *data = (u8 *)*dest;

memcpy(data + 17, &frm->frame.dw_default_frame_interval, 4);
memcpy(data + 21, &frm->frame.b_frame_interval_type, 1);
memcpy(data + 22, &frm->frame.dw_bytes_perline, 4);
}

*dest += sz;
sz = frm->frame.b_frame_interval_type *
sizeof(*frm->dw_frame_interval);
Expand Down
2 changes: 2 additions & 0 deletions drivers/usb/gadget/function/uvc_v4l2.c
View file
Expand Up @@ -58,6 +58,8 @@ struct uvc_format {
static struct uvc_format uvc_formats[] = {
{ 16, V4L2_PIX_FMT_YUYV },
{ 0, V4L2_PIX_FMT_MJPEG },
{ 0, V4L2_PIX_FMT_H264 },
{ 0, V4L2_PIX_FMT_HEVC },
};

static int
Expand Down
3 changes: 3 additions & 0 deletions include/uapi/linux/usb/video.h
View file
Expand Up @@ -468,9 +468,12 @@ struct uvc_format_uncompressed {
__u8 bAspectRatioY;
__u8 bmInterfaceFlags;
__u8 bCopyProtect;
/* bVariableSize is only for framebased format. */
__u8 bVariableSize;
} __attribute__((__packed__));

#define UVC_DT_FORMAT_UNCOMPRESSED_SIZE 27
#define UVC_DT_FORMAT_FRAMEBASED_SIZE 28

/* Uncompressed Payload - 3.1.2. Uncompressed Video Frame Descriptor */
struct uvc_frame_uncompressed {
Expand Down

0 comments on commit 475fba6

Please sign in to comment.