OMAP3: DSS questions

OMAP3: DSS questions

[Yegor Yefremov]

I'm trying to get my am3517 board working with 4.10 (porting from
2.6.37). An LCD screen is attached to OMAP DSS using 24 bits. Display
config looks like this in [1].

What DTS options reflectes ".acb = 0x0"?

Btw. I just need a frame buffer device and will use it with Embedded
Qt. Should I nevertheless use DRM flavor as it already provides frame
buffer driver?

drivers/gpu/drm/omapdrm/displays/panel-dpi.c performs either platform
or OF initialization. Platform flavor contains data_lines info, OF -
not. As I'm using OF flavor, how do I get proper data_lines info?

[1] https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id™2ee64af66f05e16aa70b475f9ad3047f801185

Yegor

Re: OMAP3: DSS questions

[Tony Lindgren]

* Yegor Yefremov <yegorslists@googlemail.com> [170104 08:27]:
> I'm trying to get my am3517 board working with 4.10 (porting from
> 2.6.37). An LCD screen is attached to OMAP DSS using 24 bits. Display
> config looks like this in [1].
> 
> What DTS options reflectes ".acb = 0x0"?
> 
> Btw. I just need a frame buffer device and will use it with Embedded
> Qt. Should I nevertheless use DRM flavor as it already provides frame
> buffer driver?
> 
> drivers/gpu/drm/omapdrm/displays/panel-dpi.c performs either platform
> or OF initialization. Platform flavor contains data_lines info, OF -
> not. As I'm using OF flavor, how do I get proper data_lines info?

Adding Tomi Valkeinen to Cc.

Tony


> [1] https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id™2ee64af66f05e16aa70b475f9ad3047f801185

Re: OMAP3: DSS questions

[Tomi Valkeinen]

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On 05/01/17 18:49, Tony Lindgren wrote:
> * Yegor Yefremov <yegorslists@googlemail.com> [170104 08:27]:
>> I'm trying to get my am3517 board working with 4.10 (porting from
>> 2.6.37). An LCD screen is attached to OMAP DSS using 24 bits. Display
>> config looks like this in [1].
>>
>> What DTS options reflectes ".acb = 0x0"?

acb was only for passive matrix panels, which have never even been
supported. So you can just ignore acb.

>> Btw. I just need a frame buffer device and will use it with Embedded
>> Qt. Should I nevertheless use DRM flavor as it already provides frame
>> buffer driver?

Depends. If you somehow rely on the custom ioctls from omapfb, then it
might be easiest to use that. However, it's no longer developed, so I
suggest at least trying to use omapdrm first.

>> drivers/gpu/drm/omapdrm/displays/panel-dpi.c performs either platform
>> or OF initialization. Platform flavor contains data_lines info, OF -
>> not. As I'm using OF flavor, how do I get proper data_lines info?

With the endpoint's data-lines property. See, for example,
am437x-gp-evm.dts.

 Tomi


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