> Hi Hans,
>
> On Monday 13 September 2010 19:06:20 Hans Verkuil wrote:
>> On Monday, September 13, 2010 17:27:52 Sakari Ailus wrote:
>> > Aguirre, Sergio wrote:
>> > > I was wondering if there exists a current standard way to query a
>> > > Imaging sensor driver for knowing things like the signal vert/horz
>> > > blanking time.
>> > >
>> > > In an old TI custom driver, we used to have a private IOCTL in the
>> > > sensor Driver we interfaced with the omap3 ISP, which was basically
>> > > reporting:
>> > >
>> > > - Active resolution (Actual image size)
>> > > - Full resolution (Above size + dummy pixel columns/rows
>> representing
>> > > blanking times)
>> > >
>> > > However I resist to keep importing that custom interface, since I
>> think
>> > > its Something that could be already part of an standard API.
>> >
>> > The N900 sensor drivers currently use private controls for this
>> purpose.
>> > That is an issue which should be resolved. I agree there should be a
>> > uniform, standard way to access this information.
>> >
>> > What we currently have is this, not in upstream:
>> >
>> > ---
>> > /* SMIA-type sensor information */
>> > #define V4L2_CID_MODE_CLASS_BASE (V4L2_CTRL_CLASS_MODE |
>> 0x900)
>> > #define V4L2_CID_MODE_CLASS (V4L2_CTRL_CLASS_MODE | 1)
>> > #define V4L2_CID_MODE_FRAME_WIDTH
>> (V4L2_CID_MODE_CLASS_BASE+1)
>> > #define V4L2_CID_MODE_FRAME_HEIGHT
>> (V4L2_CID_MODE_CLASS_BASE+2)
>> > #define V4L2_CID_MODE_VISIBLE_WIDTH
>> (V4L2_CID_MODE_CLASS_BASE+3)
>> > #define V4L2_CID_MODE_VISIBLE_HEIGHT
>> (V4L2_CID_MODE_CLASS_BASE+4)
>> > #define V4L2_CID_MODE_PIXELCLOCK
>> (V4L2_CID_MODE_CLASS_BASE+5)
>> > #define V4L2_CID_MODE_SENSITIVITY
>> (V4L2_CID_MODE_CLASS_BASE+6)
> ---
>> >
>> > The pixel clock is read-only but some of the others should likely be
>> > changeable.
>>
>> It is very similar to the VIDIOC_G/S_DV_TIMINGS ioctls. I think we
>> should
>> look into adding an e.g. V4L2_DV_SMIA_SENSOR type or something along
>> those
>> lines.
>
> I'm not sure if sensivity would fit in there. The rest probably would.
>
>> I'm no sensor expert, so I don't know what sort of timing information is
>> needed for the various sensor types. But I'm sure there are other people
>> who have this knowledge. It would be useful if someone can list the
>> information that you need from the various sensor types. Based on that
>> we
>> can see if this ioctl is a good fit.
>
> Another possibility could be to report the information using the media
> controller framework and an upcoming MEDIA_IOC_ENTITY_INFO ioctl.
Are you talking about timing information? That doesn't belong in the media
framework. But I think I didn't quite understood what you meant here.
Regards,
Hans
>
> --
> Regards,
>
> Laurent Pinchart
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--
Hans Verkuil - video4linux developer - sponsored by TANDBERG, part of Cisco
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