Wednesday, April 8, 2009

N 6100 linux framebuffer driver


I finally sorted out the underlying spi master/slave setup issues and were able to start working on a linux framebuffer driver.
The first version can be downloaded from the link below. It is a fairly standard framebuffer driver, based on the skeletonfb sample module. After the module is loaded it should create the /dev/fb0 device node. The node can then be used to send data (image data mostly) to te screen.
(mmap-ed write access is not supported right now, the write() function can be used to send image data to the screen in a similar fashion.)
If the fbcon driver is built into the kernel, it can also use this driver and turn the lcd into a small console screen (see image on the right).
More information about rebuilding the driver and module parameters can be found in the README.txt file in the archive.

Download : n6100fb-0.01.tar.gz

5 comments:

Alexander said...

Hi Zsolt. I have a working version of the driver which supports mmap from a user space, tested with nano-x and minigui.
http://www.at91.com/samphpbb/viewtopic.php?f=12&t=5103&sid=90a754e99893272129ac0bc08174a401

Zsolt said...

Hi, I see, a thread keeps the buffer synchronized with the screen. I thought about something like that, but haven't added it yet.
First I just wanted to have something that fbcon can use, so I can easily use it for text output. And fbcon doesn't need the mmap() access, so I didn't really worry about it.
I see you have the Phillips compatible controller. My driver is supposed to be able to support both, selectable with a module parameter. But I only have one screen, with an Epson compatible controller, so that's the only way I was able to test it. I doubt that it works with a Phillips controlled variant right now.
Maybe someone can give it a try and send some feedback.

Alexander said...

Unfortunately I do not work any more with it lcd and not have it, the screen size is too small.

flameman said...

i am trying to develop an usb framebuffer, i have coded the most and i have a textconsole using fbiterm (pretty hacked to work without a VT term), unfortunately my driver is not working with fbcon ... the screen is blank and no char is displayed at all

if i do cat image.bin > /dev/fb0
and then echo "hello" > /dev/tty0

i can see something at the first line: that means there is something wrong with font or such a stuff ...

any idea ? how are you modprobing fbcon ? which parameters are you passing ?

Carlo Pisani said...

me too