On Thu, Aug 15, 2019 at 03:02:45PM +0200, Jacopo Mondi wrote:
> Hi Laurent,
>
> On Thu, Aug 15, 2019 at 01:53:53AM +0300, Laurent Pinchart wrote:
> > Hi Jacopo,
> >
> > Thank you for the patch.
> >
> > On Wed, Aug 14, 2019 at 10:28:13PM +0200, Jacopo Mondi wrote:
> > > Add support for the newly defined V4L2_CID_LOCATION read-only control
> > > used to report the camera device mounting position.
> > >
> > > Signed-off-by: Jacopo Mondi <jac...@jmondi.org>
> > > ---
> > > drivers/media/v4l2-core/v4l2-ctrls.c | 7 +++++++
> > > include/uapi/linux/v4l2-controls.h | 4 ++++
> > > 2 files changed, 11 insertions(+)
> > >
> > > diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c
> > > b/drivers/media/v4l2-core/v4l2-ctrls.c
> > > index 7d3a33258748..8ab0857df59a 100644
> > > --- a/drivers/media/v4l2-core/v4l2-ctrls.c
> > > +++ b/drivers/media/v4l2-core/v4l2-ctrls.c
> > > @@ -943,6 +943,7 @@ const char *v4l2_ctrl_get_name(u32 id)
> > > case V4L2_CID_AUTO_FOCUS_RANGE: return "Auto Focus, Range";
> > > case V4L2_CID_PAN_SPEED: return "Pan, Speed";
> > > case V4L2_CID_TILT_SPEED: return "Tilt, Speed";
> > > + case V4L2_CID_LOCATION: return "Location";
> >
> > Depending on what we decide to name the control (see review of 2/5), you
> > should adjust the description accordingly.
> >
> > >
> > > /* FM Radio Modulator controls */
> > > /* Keep the order of the 'case's the same as in v4l2-controls.h! */
> > > @@ -1300,6 +1301,12 @@ void v4l2_ctrl_fill(u32 id, const char **name,
> > > enum v4l2_ctrl_type *type,
> > > break;
> > > case V4L2_CID_MPEG_VIDEO_FWHT_PARAMS:
> > > *type = V4L2_CTRL_TYPE_FWHT_PARAMS;
> > > + case V4L2_CID_LOCATION:
> > > + *type = V4L2_CTRL_TYPE_INTEGER;
> > > + *flags |= V4L2_CTRL_FLAG_READ_ONLY;
> > > + *min = V4L2_LOCATION_FRONT;
> > > + *max = V4L2_LOCATION_BACK;
> >
> > I don't think the control should have a min and a max different than the
> > current value, as it's a fully static control. I'd drop those two lines
> > here, and drivers will have to set value = min = max = V4L2_LOCATION_xxx
> > when creating the control. That why you should be able to collapse this
> > with V4L2_CID_MIN_BUFFERS_FOR_OUTPUT.
> >
>
> Ah, I thought min/max should report the actual control values limits.
> Anyway, if we move this to be an integer menu control with an helper
> to parse the DT property and register the control on behalf of
> drivers, this will change.
>
> > > + *step = 1;
> > > break;
> > > default:
> > > *type = V4L2_CTRL_TYPE_INTEGER;
> > > diff --git a/include/uapi/linux/v4l2-controls.h
> > > b/include/uapi/linux/v4l2-controls.h
> > > index 37807f23231e..5c4c7b245921 100644
> > > --- a/include/uapi/linux/v4l2-controls.h
> > > +++ b/include/uapi/linux/v4l2-controls.h
> > > @@ -889,6 +889,10 @@ enum v4l2_auto_focus_range {
> > > #define V4L2_CID_PAN_SPEED
> > > (V4L2_CID_CAMERA_CLASS_BASE+32)
> > > #define V4L2_CID_TILT_SPEED
> > > (V4L2_CID_CAMERA_CLASS_BASE+33)
> > >
> > > +#define V4L2_CID_LOCATION
> > > (V4L2_CID_CAMERA_CLASS_BASE+34)
> > > +#define V4L2_LOCATION_FRONT (0 << 0)
> > > +#define V4L2_LOCATION_BACK (1 << 0)
> >
> > Why not just 0 and 1 ?
>
> Or why not BIT().
No, BIT(0) == (0 << 0) but BIT(1) != (1 << 0).
> I saw that the (1 << x) style is the mostly used one in this header
> file when defining macros like this one so I went for consistency with
> the existing code.
That's when you need a bitmask, which isn't the case here.
> > > +
> > > /* FM Modulator class control IDs */
> > >
> > > #define V4L2_CID_FM_TX_CLASS_BASE (V4L2_CTRL_CLASS_FM_TX
> > > | 0x900)
--
Regards,
Laurent Pinchart
