7 inch LCD doesn't work in Beaglebone black

Luke Kim

Prodigy 190 points

Hi,

I am porting 7 inch LCD cape onto Beaglebone black refernecing below.

processors.wiki.ti.com/.../Processor_SDK_Linux_LCDC

I am using "Processor SDK Linux 1.00.00.00".

But LCD never worked and no fbdev was created with messages below.

[ 1.495347] tilcdc 4830e000.lcdc: no encoders/connectors found
[ 1.501588] tilcdc 4830e000.lcdc: failed to initialize mode setting

I had copied then compiled dts file from am335x-boneblack-lcd7.zip

Is there anything needed in addition to dtb file to enable LCD interface?

Any help would be greatly appreciated.

Best regards,

Luke

over 10 years ago

0 Biser Gatchev-XID over 10 years ago

TI__Guru**** 393215 points

Hi Luke,

Did you follow this guide: http://processors.wiki.ti.com/index.php/Sitara_Linux_LCDC_Porting_Guide

0 jelliott over 10 years ago

Expert 1510 points

Luke, I think the reason that beaglebone black ld7 dts file doesn't work for you is because it sets up the LCD cape for fbdev driver, as opposed to DRM driver. For Processor SDK 1.00, DRM is now the default driver instead of fbdev. In the LCDC porting guide, notice how there are 2 different entries depending on whether you are using fbdev or DRM. Your best bet would be to take the timing info from that pre-made LCD7 dts from the LCDC page, and try moving the data over into the corresponding DRM entries in modeled in the porting guide. The pin muxing and backlight stuff should be good to go, but I haven't tested them so I don't now for sure.

0 Luke Kim over 10 years ago in reply to Biser Gatchev-XID

Prodigy 190 points

Hi Biser,

Thank you for your help.
I think that guide explains not real LCD but just abstraction with HDMI as for Beaglebone black.
I will try it again referecing that of EVM or StartKit.

Thanks,
Luke

0 Luke Kim over 10 years ago in reply to jelliott

Prodigy 190 points

Hi jelliott,

Thank you very much for your advice.
I will try again as you mentioned.

Thanks,
Luke

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7 inch LCD doesn't work in Beaglebone black