leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

media: v4l2-subdev: add VIDIOC_SUBDEV_QUERYCAP ioctl

Browse Source 
While normal video/radio/vbi/swradio nodes have a proper QUERYCAP ioctl
that apps can call to determine that it is indeed a V4L2 device, there
is currently no equivalent for v4l-subdev nodes. Adding this ioctl will
solve that, and it will allow utilities like v4l2-compliance to be used
with these devices as well.

SUBDEV_QUERYCAP currently returns the version and capabilities of the
subdevice. Define a capability flag to report if the subdevice is
registered in read-only mode.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
This commit is contained in:
Hans Verkuil 2020-05-07 17:12:52 +02:00 committed by Mauro Carvalho Chehab
parent fb15db8c00
commit 6446ec6cbf
2 changed files with 27 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
drivers/media/v4l2-core/v4l2-subdev.c
View File

@ -15,6 +15,7 @@
#include <linux/types.h>
#include <linux/videodev2.h>
#include <linux/export.h>
#include <linux/version.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-device.h>
@ -344,6 +345,16 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg)
int rval;
switch (cmd) {
case VIDIOC_SUBDEV_QUERYCAP: {
struct v4l2_subdev_capability *cap = arg;
memset(cap->reserved, 0, sizeof(cap->reserved));
cap->version = LINUX_VERSION_CODE;
cap->capabilities = ro_subdev ? V4L2_SUBDEV_CAP_RO_SUBDEV : 0;
return 0;
}
case VIDIOC_QUERYCTRL:
/*
* TODO: this really should be folded into v4l2_queryctrl (this

16
include/uapi/linux/v4l2-subdev.h
View File

@ -155,9 +155,25 @@ struct v4l2_subdev_selection {
__u32 reserved[8];
};
/**
* struct v4l2_subdev_capability - subdev capabilities
* @version: the driver versioning number
* @capabilities: the subdev capabilities, see V4L2_SUBDEV_CAP_*
* @reserved: for future use, set to zero for now
*/
struct v4l2_subdev_capability {
__u32 version;
__u32 capabilities;
__u32 reserved[14];
};
/* The v4l2 sub-device video device node is registered in read-only mode. */
#define V4L2_SUBDEV_CAP_RO_SUBDEV BIT(0)
/* Backwards compatibility define --- to be removed */
#define v4l2_subdev_edid v4l2_edid
#define VIDIOC_SUBDEV_QUERYCAP _IOR('V', 0, struct v4l2_subdev_capability)
#define VIDIOC_SUBDEV_G_FMT _IOWR('V', 4, struct v4l2_subdev_format)
#define VIDIOC_SUBDEV_S_FMT _IOWR('V', 5, struct v4l2_subdev_format)
#define VIDIOC_SUBDEV_G_FRAME_INTERVAL _IOWR('V', 21, struct v4l2_subdev_frame_interval)