[PATCH 0/3] add mie driver for exynos

[Stéphane Marchesin]

On Mon, Dec 10, 2012 at 1:27 AM, Inki Dae <inki.dae at samsung.com> wrote:
>
>
> 2012/12/10 Stéphane Marchesin <stephane.marchesin at gmail.com>
>>
>> On Sun, Dec 9, 2012 at 10:26 PM, Inki Dae <inki.dae at samsung.com> wrote:
>> >
>> >
>> > 2012/12/6 R. Chandrasekar <rcsekar at samsung.com>
>> >
>> >> From: "R. Chandrasekar" <rcsekar at samsung.com>
>> >>
>> >> this patch set adds the driver support for the dithering functionality
>> >> of
>> >> the
>> >> mobile image enhancement (mie) module.
>> >>
>> >> device tree support is added for mie.
>> >>
>> >> fimd adds the mie module as plugin and calls the dithering function.
>> >> dithere is
>> >> required when the panels bpp is less then fimd output.
>> >>
>> >> though mie mie has other functionalities, current system uses only
>> >> dithereing.
>> >>
>> >
>> > Please, move mie module into drivers/video/exynos. The mie is a
>> > interface
>> > between fimd and lcd panel(or mipi-dsi, eDP) to enhance image to be
>> > displayed. And it seems like that this doesn't need drm
>> > framework-relevant
>> > interfaces, such as gem.
>>
>> Well, if you want to support it from the DRM, it should live in
>> drivers/gpu/drm, and I don't think you should add another platform
>> driver in the first place. The profusion of platform drivers in exynos
>> makes it really difficult to support suspend/resume and initialization
>> properly as many devices which operate separately need to sync through
>> global variables.
>>
>
> MIE could be used by linux framebuffer-based specific driver(s3c-fb) also.

Yes, but it is a DRM driver we're talking about here. Again it is
really difficult to work with it across suspend-resume. I don't think
the DRM was ever meant to be a collection of independent platform
drivers.

> If linux framebuffer-based driver want to use this mie module, should the
> mie module be placed in drivers/video coping it? I think it's not good so
> it's better way to use this mie module commonly without duplicated codes.
> And mipi-dsi and eDP drivers also have their own platform device/driver and
> are being used by exynos drm driver or s3c-fb driver. Of course, for some
> IPs such as mie between display controller and lcd panel, It seems like that
> there should be proper framework or interfaces in drivers/video/exynos or
> somewhere so that other frameworks can use it commonly. And drm and linux
> framebuffer drivers should call the interfaces.

For the short term, I think it's fine to duplicate the code.

For the longer term, I think framebuffer support should be provided by
the drm framebuffer compat layer, and s3c-fb should disappear. This is
what has been done with all the other DRM drivers.

Stéphane


>
> Thanks,
> Inki Dae
>
>> Stéphane
>>
>>
>> >
>> > And also, please refer to the below link, Common Display Framework, for
>> > more
>> > generic way.
>> >
>> >
>> > http://lists.freedesktop.org/archives/dri-devel/2012-November/030888.html
>> >
>> > Thanks,
>> > Inki Dae
>> >
>> >>
>> >> R. Chandrasekar (3):
>> >>   DTS: exynos: add device tree support for exynos mie
>> >>   drm: fimd: add mie plugin support for dithering
>> >>   drm: mie: add mie driver for exynos
>> >>
>> >>  arch/arm/boot/dts/exynos5250.dtsi               |    7 +-
>> >>  drivers/gpu/drm/exynos/Kconfig                  |    7 +
>> >>  drivers/gpu/drm/exynos/Makefile                 |    1 +
>> >>  drivers/gpu/drm/exynos/exynos_drm_fimd.c        |   58 +++++-
>> >>  drivers/gpu/drm/exynos/exynos_drm_fimd_common.h |   20 ++
>> >>  drivers/gpu/drm/exynos/exynos_drm_mie.c         |  250
>> >> +++++++++++++++++++++++
>> >>  drivers/gpu/drm/exynos/exynos_drm_mie.h         |   50 +++++
>> >>  drivers/gpu/drm/exynos/exynos_regs-mie.h        |   75 +++++++
>> >>  8 files changed, 465 insertions(+), 3 deletions(-)
>> >>  create mode 100644 drivers/gpu/drm/exynos/exynos_drm_fimd_common.h
>> >>  create mode 100644 drivers/gpu/drm/exynos/exynos_drm_mie.c
>> >>  create mode 100644 drivers/gpu/drm/exynos/exynos_drm_mie.h
>> >>  create mode 100644 drivers/gpu/drm/exynos/exynos_regs-mie.h
>> >>
>> >> --
>> >> 1.7.9.5
>> >>
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