DSS2: Simultaneous DSI and DPI panels

DSS2: Simultaneous DSI and DPI panels

[Juha Kuikka]

Hello,

I was wondering if it would be possible to run DPI and DSI interfaces
simultaneously with OMAP3 (DM3730).

Limitations:
- DSI would have to be in video mode (data to DSI phy through video
port with H/VSYNC signaling, OMAP_DSS_PARALLELMODE_BYPASS)
- DSI PLL would need to be used for clock source
- Both the DPI and DSI panels would have to accept identical clocking
(PCLK, blanking intervals etc).
- Data lane # must match.
- And of course same data would go to both

I realize the current SW does not support this, but I'm more wondering
if it is possible from the HW point of view because it seems to me
that data out from DISPC is pretty much identical in both cases.

 - Juha

Re: DSS2: Simultaneous DSI and DPI panels

[Archit Taneja]

Hi,

On Friday 13 May 2011 12:46 AM, Juha Kuikka wrote:
> Hello,
>
> I was wondering if it would be possible to run DPI and DSI interfaces
> simultaneously with OMAP3 (DM3730).
>
> Limitations:
> - DSI would have to be in video mode (data to DSI phy through video
> port with H/VSYNC signaling, OMAP_DSS_PARALLELMODE_BYPASS)
> - DSI PLL would need to be used for clock source
> - Both the DPI and DSI panels would have to accept identical clocking
> (PCLK, blanking intervals etc).
> - Data lane # must match.
> - And of course same data would go to both
>
> I realize the current SW does not support this, but I'm more wondering
> if it is possible from the HW point of view because it seems to me
> that data out from DISPC is pretty much identical in both cases.

I don't think this is possible on OMAP3, there is one LCD manager in 
OMAP3 which can either feed pixels to DPI or DSI.

The only way you could run 2 panels is by routing LCD manager's content 
to DPI, and use DSI's capability to do a system DMA directly and send 
the data to the panel(bypassing DISPC), I don't think the system DMA 
method will work with a video mode panel, only command mode panels will 
do here.

Archit
>
>   - Juha
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Re: DSS2: Simultaneous DSI and DPI panels

[Tomi Valkeinen]

On Fri, 2011-05-13 at 16:14 +0530, Archit Taneja wrote:
> Hi,
> 
> On Friday 13 May 2011 12:46 AM, Juha Kuikka wrote:
> > Hello,
> >
> > I was wondering if it would be possible to run DPI and DSI interfaces
> > simultaneously with OMAP3 (DM3730).
> >
> > Limitations:
> > - DSI would have to be in video mode (data to DSI phy through video
> > port with H/VSYNC signaling, OMAP_DSS_PARALLELMODE_BYPASS)
> > - DSI PLL would need to be used for clock source
> > - Both the DPI and DSI panels would have to accept identical clocking
> > (PCLK, blanking intervals etc).
> > - Data lane # must match.
> > - And of course same data would go to both
> >
> > I realize the current SW does not support this, but I'm more wondering
> > if it is possible from the HW point of view because it seems to me
> > that data out from DISPC is pretty much identical in both cases.
> 
> I don't think this is possible on OMAP3, there is one LCD manager in 
> OMAP3 which can either feed pixels to DPI or DSI.
> 
> The only way you could run 2 panels is by routing LCD manager's content 
> to DPI, and use DSI's capability to do a system DMA directly and send 
> the data to the panel(bypassing DISPC), I don't think the system DMA 
> method will work with a video mode panel, only command mode panels will 
> do here.

Yes, that is correct. DPI + DSI command mode would work, although in
that case the DSI panel would be driven by CPU or sDMA, both of which
are not very good at the job.

 Tomi