[Buildroot] [RFC v2] linux: add fbtft kernel extension

[Yann E. MORIN]

Peter, All,

On 2014-12-30 20:58 +0100, Peter Seiderer spake thusly:
> ... sorry for the resend, file linux/linux-ext-fbtft.mk was missing.

No problem, I've marked the first iteration as "Syuperseded" in our
Patchwork.

> First draft of a patch adding fbtft framebuffer drivers to buildroot.

Thanks! :-)

> My first attempt was using the out of tree kernel modules compile
> (as suggested by Yann E. MORIN [1]) which is already (partly)
> supported by the fbtft source, but I failed to enable some
> needed kernel configurations e.g FB_DEFERRED_IO (did not survive
> the oldconfig/silentoldconfig step when not referenced in tree,
> workaround is to enable a built in feature with the same
> preferences [2]).

OK, I'll be looking at it, to see why it fails. Don't expect much before
next week-end (actually, that will be next year, too! :-) ) because,
well, New Year celebrations, boring stuff like that, which I'm socially
obliged to attend... ;-)

Regards,
Yann E. MORIN.

> The second attempt is the linux-ext approach (as presented here).
> 
> I am unsure if the enabling of CONFIG_SPI_BCM2708 belongs into
> linux.mk or should go into raspberrypi_defconfig or belongs into
> the appropriate Readme?
> 
> The second question is about the 25 submodules of fbtft
> (at the moment only FB_TFT_ILI9340 and FB_TFT_ILI9341 are
> enabled). Should every submodule be configurable or should all
> submodules be enabled by default?
> 
> There is an adafruit fork of the fbtft repository [4] with some
> adfruit specific enhancements...
> 
> Regards,
> Peter
> 
> Tested with RaspberryPi B+ and PiTFT Mini Kit - 320x240 2.8" TFT
> (see [5] and [6]) and the following configuration changes:
> 
> - cmdline.txt: add 'fbcon=map:10 fbcon=font:VGA8x8'
> - add /etc/modules-load.d/fbtft.conf with 'fbtft_device'
> - add /etc/modprobe.d/00-fbtft.conf with 'options fbtft_device name=adafruit28 rotate=90 gpios=dc:25'
> 
> [1] http://lists.busybox.net/pipermail/buildroot/2014-December/115770.html
> [2] https://github.com/notro/fbtft/issues/209#issuecomment-68191514
> [3] http://www.adafruit.com/products/1983
> [4] https://github.com/adafruit/adafruit-rpi-fbtft
> [5] http://h65951.serverkompetenz.net/PeterSeiderer/upload/PiTFT_2_8_ct/Image9893.jpg
> [6] http://h65951.serverkompetenz.net/PeterSeiderer/upload/PiTFT_2_8_ct/Image9897.jpg
> 
> Peter Seiderer (1):
>   linux: add fbtft kernel extension
> 
>  linux/Config.ext.in      | 10 ++++++++++
>  linux/linux-ext-fbtft.mk | 25 +++++++++++++++++++++++++
>  linux/linux.mk           |  9 +++++++++
>  package/Config.in        |  1 +
>  package/fbtft/Config.in  | 13 +++++++++++++
>  package/fbtft/fbtft.mk   | 11 +++++++++++
>  6 files changed, 69 insertions(+)
>  create mode 100644 linux/linux-ext-fbtft.mk
>  create mode 100644 package/fbtft/Config.in
>  create mode 100644 package/fbtft/fbtft.mk
> 
> -- 
> 2.1.2
> 

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