What are the steps to enable the regular (non-mali) LCD display (lcd0/1) with a Vanilla kernel?

 

I can't find any examples of making the LCD work. What am I missing?

 

Thanks

 

Chris

 

 

I'm trying to organize my thoughts, such as the are, on the topic of the LCD with Armbian. Attached is my "mind map" on it. Details are extremely light. I'm uploading the PDF and the Mind Map document for editing. Oop, I'm "not permitted to upload this kind of file" 'round here.

 

I posted the Mind Map .mup file to pastebin: http://pastebin.com/ZnvXMr0K

 

Hope that helps to illustrate all that I don't know on this topic.

 

What's missing? I have no idea what the syntax is of the boot_args apart from the ones in my copy of boot.cmd, which modules are required to be loaded, what DT entries need to be created to supply the parameters to the modules or kernel .... 

 

The HDMI is coming up, and I can't see how that's happening from the parameters I know about in the boot.cmd and DTB file for the running kernel.

 

I tried enabling framebuffer@2 like this:

 

                framebuffer@2 {

                        compatible = "allwinner,simple-framebuffer", "simple-framebuffer";

                        allwinner,pipeline = "de_fe0-de_be0-lcd0";

                        clocks = <0x2 0x1 0x3 0x24 0x3 0x2c 0x3 0x2e 0x4 0x19 0x4 0x1a>;

                        status = "enabled";

                };

This had no effect AFAIK.

 

Any pointer would be appreciated.

 

Thanks

 

Chris

Armbian-LCD-MM-rev0.pdf

I hope this is readable:

 

ARMBIAN-LCD-MM.pdf

 

Just updated the MM: added modules and compiled-in off the kernel bubble, six likely modules in use now with the working HDMI output, added "Boot Parameters" ahead of boot.cmd, lcd parameters[0..1] to name the LCD parameters in use ... please make suggestions on how to improve the picture.

 

The .mup file is at http://pastebin.com/um49wzFx

 

My object here is to control the LCD parameters for an 800x480 LCD panel I'm trying to activate, and get the output to come out of LCD0's interface (already wired up).

 

Thanks

 

Chris

I just found (again) the lcd module from drivers/video/backlight and added that to the Modules bubble.

 

.mup file at http://pastebin.com/uCWKFLm0

Added X Configuration bubble ...

The rules I'm trying to apply here are:

1. Include nodes that have user supplied parameters that effect the LCD display
2. Include nodes that are "parents" to nodes from rule #1.

So if the "sysfillrect" bubble has no user supplied parameter, it can be deleted. I don't know if that's the case yet, so it will stay for now.

Added boot.ini to Boot Parameters. I don't know if that's the right dependency.

 

I think boot.ini is not relevant - this is just another naming for boot script.

The version of boot.ini is a parameter/value file like:

 

[parameter]

value

 

??? Not quite a boot.cmd script ... or were you referring to another file?

Correction: the boot.ini file is more like:

 

[section-name]

parameter=value

 

The boot.cmd file actually looks like a script.

I don't have u-boot in the map ... where should that go? at the same level as the kernel ?