BB-CAPE-DISP-CT43 source files/drivers?

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John Adamson

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Feb 13, 2017, 10:15:25 AM2/13/17
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Hi,

{Apologies if posting here and at Element14 is considered cross-posting, I was given the impression that it is two different communities}

I'm trying to bring up the BB-CAPE-DISP-CT43.  There's a 4GB distribution image that supports the display and touch screen, but I'd really like to get it working under my own Yocto distribution to merge it with other work.  I'm trying to reverse-engineer the 4GB image, but if anyone can point me to dts files, driver source, or anything else that might be needed for the touch controller, it would be greatly appreciated.  I'm migrating from a resistive touch screen (this is cap touch), and the display itself apparently maps transparently (it works).  But nothing from the touch screen, and my attempt to include a driver in the kernel build hasn't gotten me anywhere.

Thanks!

John

Robert Nelson

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Feb 13, 2017, 10:33:41 AM2/13/17
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John Adamson

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Feb 13, 2017, 10:52:26 AM2/13/17
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Thanks, Robert.  I needed to add the am335x-bbw-bbb-base.h board file and I'm getting syntax errors on the dts file compile (krogoth, 4.4.11 kernel), but it's a good start.  Thanks!

Robert Nelson

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Feb 13, 2017, 10:55:46 AM2/13/17
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> Thanks, Robert. I needed to add the am335x-bbw-bbb-base.h board file and
> I'm getting syntax errors on the dts file compile (krogoth, 4.4.11 kernel),
> but it's a good start. Thanks!

If you are using mainline dtc, add:

DTC_FLAGS += -Wno-unit_address_vs_reg

I haven't fully pushed mainline dtc over our patched dtc for jessie
users, so i don't have that flag enabled by default (yet)..

John Adamson

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Feb 15, 2017, 11:16:33 AM2/15/17
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Tried this, and then am335x-boneblack.dtb threw errors...but I did get it working.

In the unlikely event that someone else wants to get this display working under Yocto (krogoth)...my first advice is don't.  You're probably better off moving to a more recent Yocto and using Robert's file.  But I'm under pressure to get this working, and my past experience is that changing to a new Yocto/kernel version would be another week's work IF there aren't any show stoppers.   What I did was 1) translate the dts file into a format recognized by krogoth...I think the key issue was that it didn't like fragments...and 2) since touchscreen-swapped-x-y apparently wasn't supported, I had to swap the x and y sizes in the dts file, and hack the driver source to do the swapping.  Oh, and the driver apparently had to be compiled into the kernel source, not loaded as a module.  

I don't think it makes sense to share my (already obsolete) dts file or driver hack, but if someone wants it, I'll be happy to post.

John

 

Robert Nelson

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Feb 15, 2017, 11:48:10 AM2/15/17
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zane...@gmail.com

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Aug 8, 2020, 3:57:15 PM8/8/20
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Does anyone have a link to the 4GB distribution image? Thanks.
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