Linux/AM5718: Progressive and Interlace Display Outputs

SENTHILKUMAR RAMAN

Intellectual 335 points

Part Number: AM5718
Other Parts Discussed in Thread: SN65LVDS93

Tool/software: Linux

Hi,

In our AM5718 based custom board; I have a following doubts in linux device driver support for DSS,

The custom design supports two display output ports,
- LCD Port1: LCD output -> Flatlink Rx (SN65LVDS93) -> LVDS output
- LCD Port2: LCD output -> Video DAC (ADV7393) -> Y/C Analog output
Our requirement is to have Progressive output on LCD Port1 (LVDS output) and Interlace output on LCD Port2 (Y/C Analog output)
Through TI docs, I came to know that interlace is not supported for LCD port and only the HDMI port supports the interlace output.
Please confirm us the same, and also please let us know whether is it possible to modify the driver to have the interlace support on LCD port.

With Thanks and Regards,

Senthilkumar R

over 6 years ago

0 Margarita Gashova over 6 years ago

TI__Guru* 80190 points

Hello,

Please, refer the below guide about DSS:
software-dl.ti.com/.../Foundational_Components_Kernel_Drivers.html
"Unsupported Features/Limitations" chapter.
Please check this answer also:
e2e.ti.com/.../2694947

Hope this helps.

BR
Margarita

0 SENTHILKUMAR RAMAN over 6 years ago in reply to Margarita Gashova

Intellectual 335 points

Hi,

Thanks for your response, i would like to know whether it is (Interlaced - unsupported feature for LCD port) is a hardware limitation or the device driver limitation.
If it is device driver limitation, i would like to know whether is it possible to modify the device driver to support interlace outport on LCD port.

Thanks in Advance.
Senthilkumar R

0 Margarita Gashova over 6 years ago in reply to SENTHILKUMAR RAMAN

TI__Guru* 80190 points

Hello,

"Interlace feature has DSS IP level limitation for LCD but for HDMI, it’s driver level limitation."

BR
Margarita

0 SENTHILKUMAR RAMAN over 6 years ago in reply to Margarita Gashova

Intellectual 335 points

Hi Margarita,

Thank you for your response.

0 SENTHILKUMAR RAMAN over 6 years ago in reply to SENTHILKUMAR RAMAN

Intellectual 335 points

Hi Margarita,

For ‘Interlace Display support on HDMI port’; from TI forum ( http://e2e.ti.com/support/processors/f/791/t/520838), I came to know that it is a simple change in the HDMI driver by enable a macro.

Driver file: drivers/video/fbdev/omap2/omapfb/displays/connector-hdmi.c

Macro to be done:

static const struct omap_video_timings hdmic_default_timings = {

…………

.interlace = false,

};

Please confirm me whether by changing the ‘.interlace’ macro in ‘connector-hdmi.c’ is sufficient to have a interace video output on HDMI port or much more changes is required in the HDMI driver.

Thanks in Advance,

Senthilkumar R

0 SENTHILKUMAR RAMAN over 6 years ago in reply to Margarita Gashova

Intellectual 335 points

Hi Margarita,

For ‘Interlace Display support on HDMI port’; from TI forum ( e2e.ti.com/.../520838), I came to know that it is a simple change in the HDMI driver by enable a macro.

Driver file: drivers/video/fbdev/omap2/omapfb/displays/connector-hdmi.c

Macro to be done:

static const struct omap_video_timings hdmic_default_timings = {

…………

…………

.interlace = false,

};

Please confirm me whether by changing the ‘.interlace’ macro in ‘connector-hdmi.c’ is sufficient to have a interace video output on HDMI port or much more changes is required in the HDMI driver.

Thanks in Advance,

Senthilkumar R

0 Margarita Gashova over 6 years ago in reply to SENTHILKUMAR RAMAN

TI__Guru* 80190 points

Hello,

This thread is very old (> 2 years). Omapfb is no longer supported.
Please refer below guide:
software-dl.ti.com/.../Foundational_Components_Kernel_Drivers.html
"Driver Architecture" chapter.
I see that you are already discussing this in here:
e2e.ti.com/.../736233
So I will close this one.

BR
Margarita

Processors

Processors forum

Linux/AM5718: Progressive and Interlace Display Outputs