[ADV7393] DRM Encoder Slave or DRM Bridge

[Tomi Valkeinen]

On 26/09/16 15:34, Vikas Patil wrote:

> Will check once I get display working, for time being I think it shows
> connected with the hack I mentioned. I was taking about supporting
> "interlace" via LCD here.

Ah, sorry, I didn't check the context =).

I don't know if adding interlace to LCD output is easy. It might be. To
answer that, one needs to read the relevant parts of the TRM and the
driver and see how difficult it is. I cannot give you step to step
instructions on how to do it.

>>>> If I read the above snippet right, to use progressive input, the DISPC
>>>> needs to output at double refresh rate. So probably what you would have
>>>> to do is in ADV driver, you have your set_timings function, where you
>>>> should double the pix clock before you pass the timings forward to the
>>>> DISPC's DPI driver.
>>>>
>>>
>>> I have configured ADV7393 chip in following mode with the timing below
>>> in connector-analog.tv.c. With this I am seeing continuous flicker
>>> with nothing on display (black screen) and sometime could see the
>>> kmscube but it seems it renders in four quadrant(i.e. once in each
>>> quadrant). I have also tried doubling the pixel clock from 27MHz to
>>> 54MHz in timing for non-interlaced mode of ADV7393 but with it also
>>> nothing on display and continuous flicker.
>>>
>>> Do you know what might be going wrong? What should I look for to fix this?
>>>
>>> ** ADV config:
>>> - 16-bit SD RGB input
>>> - NTSC mode
>>> - YPrPb component output (CVBS)
>>> - non-interlaced mode
>>>
>>> ** Timing configured in in connector-analog.tv.c
>>>
>>> static const struct omap_video_timings harman_ntsc_timings = {
>>>         .x_res          = 720,
>>>         .y_res          = 480,
>>>         .pixelclock     = 270000000,
>>
>> That's 270MHz.
>>
> 
> It was a typo. I have confirmed it is 27Mhz.

Ok.

Well, I'm not familiar with ADV7393 so it's very difficult to say
anything. If you're certain that the video mode you give above should
work with ADV7393 with the configuration you have done to it, then you
might want to check the HW. Is ADV7393 connected correctly? Perhaps
probe the lines to make sure the signal is correct?

And if that's correct, then you'd need to do the same for the output.

 Tomi

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