[Lenny400] Slightly later kernel/distro version

Paul Boddie paul at boddie.org.uk
Fri Sep 1 13:53:17 CEST 2017

On Friday 1. September 2017 12.13.38 H. Nikolaus Schaller wrote:


> Maybe it is possible to simply turn it on by gpio-pinmux...

I'm not sure where to start with that, but given that there is a generic PWM 
backlight device, I suppose that a usable driver combined with that device 
should be enough to start with.


> Yes, the original jzchar driver did a lot of magic which should be done
> completely different with modern kernels.

David mentioned some odd "encoded" character driver stuff that I haven't 
investigated yet.

[Device tree]

> If you have a newer version, I can simply add it so that we can show it
> around...

I can include that with my patches, sure.


> IMHO, the RTC is simply an nxp,pcf8563 which has a modern driver:
> http://elixir.free-electrons.com/linux/v4.13-rc7/source/drivers/rtc/rtc-pcf
> 8563.c
> So having a SoC I2C master driver is the limitation.

Right. I'll try and look at what the 2.6 kernel does with the RTC via I2C.


> What I am no longer finding is the nice documentation of the gpios on
> kwaak... Do you have a link to that? Then I could set up something from
> documentation (schematics).

There are archived versions of these documents which I can link to from the 
projects area. I might create some separate pages or update any that already 

I also noted down some things about clocks and pins which might be useful, if 
I've understood the existing code correctly.


> Fine! Then I can try to integrate them into the Letux kernel tree.

So, I'll try and tidy up the patches and send them here, then.


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