Re: [PATCH] LED control

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 09/05/2010 10:56 AM, Jean-Francois Moine wrote:
> On Sun, 05 Sep 2010 09:56:54 +0200
> Hans de Goede<hdegoede@redhat.com>  wrote:
>
>> I think that using one control for both status leds (which is what we
>> are usually talking about) and illuminator(s) is a bad idea. I'm fine
>> with standardizing these, but can we please have 2 CID's one for
>> status lights and one for the led. Esp, as I can easily see us
>> supporting a microscope in the future where the microscope itself or
>> other devices with the same bridge will have a status led, so then we
>> will need 2 separate controls anyways.
>
> Hi Hans,
>
> I was not thinking about the status light (I do not see any other usage
> for it), but well about illuminators which I saw only in microscopes.
>

Ah, ok thanks for clarifying. For some more on this see p.s. below.

> So, which is the better name? V4L2_CID_LAMPS? V4L2_CID_ILLUMINATORS?

I think that V4L2_CID_ILLUMINATORS together with a comment in the .h
and explanation in the spec that this specifically applies to microscopes
would be good.

Regards,

Hans

p.s.

I think it would be good to have a V4L2_CID_STATUS_LED too. In many drivers
we are explicitly controlling the led by register writes. Some people may very
well prefer the led to always be off. I know that uvc logitech cameras have
controls for the status led through the extended uvc controls. Once we have
a standardized LED control, we can move the logitech uvc cams over from
using their own private one to this one.

Once this is in place I would like to build some framework in to gspca
for supporting this control in gspca (the control would be handled by the core,
and sub drivers would have an sd_set_led function).

While at it could you write a proposal / patch for adding this control to the
spec as well ?