Hi Hans,
On Friday 31 Mar 2017 10:29:04 Hans Verkuil wrote:
> On 30/03/17 18:02, Helen Koike wrote:
> > Add V4L2_INPUT_TYPE_DEFAULT and helpers functions for input ioctls to be
> > used when no inputs are available in the device
> >
> > Signed-off-by: Helen Koike <helen.koike@xxxxxxxxxxxxx>
> > ---
> >
> > drivers/media/v4l2-core/v4l2-ioctl.c | 27 +++++++++++++++++++++++++++
> > include/media/v4l2-ioctl.h | 26 ++++++++++++++++++++++++++
> > include/uapi/linux/videodev2.h | 1 +
> > 3 files changed, 54 insertions(+)
> >
> > diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c
> > b/drivers/media/v4l2-core/v4l2-ioctl.c index 0c3f238..ccaf04b 100644
> > --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> > +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> > @@ -2573,6 +2573,33 @@ struct mutex *v4l2_ioctl_get_lock(struct
> > video_device *vdev, unsigned cmd)>
> > return vdev->lock;
> >
> > }
> >
> > +int v4l2_ioctl_enum_input_default(struct file *file, void *priv,
> > + struct v4l2_input *i)
> > +{
> > + if (i->index > 0)
> > + return -EINVAL;
> > +
> > + memset(i, 0, sizeof(*i));
> > + i->type = V4L2_INPUT_TYPE_DEFAULT;
> > + strlcpy(i->name, "Default", sizeof(i->name));
> > +
> > + return 0;
> > +}
> > +EXPORT_SYMBOL(v4l2_ioctl_enum_input_default);
> > +
> > +int v4l2_ioctl_g_input_default(struct file *file, void *priv, unsigned
> > int *i)
> > +{
> > + *i = 0;
> > + return 0;
> > +}
> > +EXPORT_SYMBOL(v4l2_ioctl_g_input_default);
> > +
> > +int v4l2_ioctl_s_input_default(struct file *file, void *priv, unsigned
> > int i)
> > +{
> > + return i ? -EINVAL : 0;
> > +}
> > +EXPORT_SYMBOL(v4l2_ioctl_s_input_default);
> > +
> > /* Common ioctl debug function. This function can be used by
> > external ioctl messages as well as internal V4L ioctl */
> > void v4l_printk_ioctl(const char *prefix, unsigned int cmd)
> > diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h
> > index 6cd94e5..accc470 100644
> > --- a/include/media/v4l2-ioctl.h
> > +++ b/include/media/v4l2-ioctl.h
> > @@ -652,6 +652,32 @@ struct video_device;
> > */
> >
> > struct mutex *v4l2_ioctl_get_lock(struct video_device *vdev, unsigned int
> > cmd);
> > +
> > +/**
> > + * v4l2_ioctl_enum_input_default - v4l2 ioctl helper for
> > VIDIOC_ENUM_INPUT ioctl + *
> > + * Plug this function in vidioc_enum_input field of the struct
> > v4l2_ioctl_ops to + * enumerate a single input as V4L2_INPUT_TYPE_DEFAULT
> > + */
> > +int v4l2_ioctl_enum_input_default(struct file *file, void *priv,
> > + struct v4l2_input *i);
> > +
> > +/**
> > + * v4l2_ioctl_g_input_default - v4l2 ioctl helper for VIDIOC_G_INPUT
> > ioctl
> > + *
> > + * Plug this function in vidioc_g_input field of the struct
> > v4l2_ioctl_ops
> > + * when using v4l2_ioctl_enum_input_default
> > + */
> > +int v4l2_ioctl_g_input_default(struct file *file, void *priv, unsigned
> > int *i); +
> > +/**
> > + * v4l2_ioctl_s_input_default - v4l2 ioctl helper for VIDIOC_S_INPUT
> > ioctl
> > + *
> > + * Plug this function in vidioc_s_input field of the struct
> > v4l2_ioctl_ops
> > + * when using v4l2_ioctl_enum_input_default
> > + */
> > +int v4l2_ioctl_s_input_default(struct file *file, void *priv, unsigned
> > int i); +
> >
> > /* names for fancy debug output */
> > extern const char *v4l2_field_names[];
> > extern const char *v4l2_type_names[];
> >
> > diff --git a/include/uapi/linux/videodev2.h
> > b/include/uapi/linux/videodev2.h index 316be62..c10bbde 100644
> > --- a/include/uapi/linux/videodev2.h
> > +++ b/include/uapi/linux/videodev2.h
> > @@ -1477,6 +1477,7 @@ struct v4l2_input {
> >
> > };
> >
> > /* Values for the 'type' field */
> >
> > +#define V4L2_INPUT_TYPE_DEFAULT 0
>
> I don't think we should add a new type here. The whole point of this
> exercise is to allow existing apps to work, and existing apps expect a
> TYPE_CAMERA.
>
> BTW, don't read to much in the term 'CAMERA': it's really a catch all for
> any video stream, whether it is from a sensor, composite input, HDMI, etc.
>
> The description for V4L2_INPUT_TYPE_CAMERA in the spec is hopelessly out of
> date :-(
>
> Rather than creating a new type I would add a new V4L2_IN_CAP_MC capability
> that indicates that this input is controlled via the media controller. That
> makes much more sense and it wouldn't potentially break applications.
>
> Exactly the same can be done for outputs as well: add V4L2_OUT_CAP_MC and
> use V4L2_OUTPUT_TYPE_ANALOG as the output type (again, a horrible outdated
> name and the spec is again out of date).
What would those capabilities be used for ? Applications can already know
whether the MC API is used by a driver. Furthermore, if we really need such a
flag, I wouldn't add it at the input/output level but as a video node
capability flag.
> Regarding the name: should we use the name stored in struct video_device
> instead? That might be more descriptive. Alternatively use something like
> "Media Controller Input".
>
> More helpful (perhaps) than just "Default" or "Unknown".
If the purpose of the name field is to be displayed as-is to the end-user,
then "Media Controller Input" is as useless as "Unknown". "Default" would be
slightly better.
> I'll make a patch to update the input/output type description in the spec.
>
> > #define V4L2_INPUT_TYPE_TUNER 1
> > #define V4L2_INPUT_TYPE_CAMERA 2
> > #define V4L2_INPUT_TYPE_TOUCH 3
--
Regards,
Laurent Pinchart
