Re: DSS2 questions

[Gary Thomas <gary@mlbassoc.com>]

Tomi Valkeinen wrote:
> Hi,
> 
> ext Gary Thomas wrote:
>>>> Second question; I've set up my system much the same as the
>>>> boards you are working on, with an LCD and TV outputs.  I'm
>>>> a bit confused as to how I configure the overlays and managers
>>>> to be able to send YUV data directly through to either the
>>>> LCD or TV.  Can you explain this?
>>> You need to change the framebuffer to YUV color mode. And YUV only works
>>> on video overlays, so you need to setup video overlay to be shown on the
>>> LCD or TV.
>>>
>>> If you have fb1 as a video overlay, you can do for example:
>>>
>>> fbset -fb /dev/fb1 -nonstd 1
>>>
>>> which sets fb1 to YUV422 mode. 8 would be YUY422. Those numbers come
>>> from omapfb.h, enum omapfb_color_format.
>>>
>>> Check also Documentation/arm/OMAP/DSS, if you haven't already done so.
>>>
>>
>> Still a bit fuzzy on this.  I'm sure that document helps, if
>> one already knows how all the overlays and managers and ...
>> are wired together.  I'm new at this game :-)
>>
>> I tried to set my TV to be video/uyv422 via the attached script.
>> I was trying to leave fb0 alone (running on the LCD) and use fb1
>> to display the YUV422 data. Alas, 'fbset' gives me "Bad video mode"?
>> Any pointers?
>>
> 
> You need to allocate memory for the framebuffer.
> 
> Try adding for example this:
> 
> mem=$((w*h*4))
> echo $mem > $fb1/size
> 
> Also, you are trying to connect video2 overlay to fb1, but by default
> DSS connects video2 to fb2. So if you really want to do that, you first
> need to detach video1 from fb1, video2 from fb2, and then attach video2
> to fb1. I suggest you use fb2 which is already attached to video2.

That helped, thanks.  'fbset' no longer complains and I now have
a lovely green screen on my TV.

Now, to figure out how to send some YUV422 data to it.  I have Vaibhav's
V4L2 support in my tree - will this work with your DSS2 devices?

-- 
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Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
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