Hi Hans,
On Tuesday 07 September 2010 23:14:10 Hans de Goede wrote:
> On 09/07/2010 05:30 PM, Hans Verkuil wrote:
[snip]
> Also note that at least with the uvc driver that due to how extension
> unit controls are working (the uvcvideo driver gets told about these
> vendor specific controls from a userspace helper), the menu index is
> the value which gets written to the hardware! So one cannot simply
> make this match some random enum.
That's not correct. The UVC driver maps the menu index to the hardware value,
so there shouldn't be any problem here.
[snip]
> > This looks pretty decent IMHO:
> >
> > enum v4l2_illuminator {
> >
> > V4L2_ILLUMINATOR_OFF = 0,
> > V4L2_ILLUMINATOR_ON = 1,
> >
> > };
> > #define V4L2_CID_ILLUMINATOR_0 (V4L2_CID_BASE+37)
> > #define V4L2_CID_ILLUMINATOR_1 (V4L2_CID_BASE+38)
>
> I don't like this, as explained before most microscopes have a top
> and a bottom light, and you want to switch between them, or to
> all off, or to all on. So having a menu with 4 options for this
> makes a lot more sense then having 2 separate controls. Defining
> these values as standard values would take away the option for drivers
> to do something other then a simple on / off control here. Again
> what is wrong with with not defining standard meanings for standard
> controls with a menu type. This means less stuff in videodev2.h
> and more flexibility wrt using these control ids.
>
> I think we should not even define a type for this one. If we
> get microscopes with pwm control for the lights we will want this
> to be an integer using one control per light.
LED dimming using PWM is something we can surely expect in the future, if not
already available in existing devices.
--
Regards,
Laurent Pinchart
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