[U-Boot] [linux-sunxi] Re: [RFC PATCH 0/3] sunxi: video: Add support for HDMI output on H3

[Icenowy Zheng]

14.12.2016, 04:29, "Simon Glass" <sjg at chromium.org>:
> Hi,
>
> On 12 December 2016 at 19:36, Jernej Skrabec <jernej.skrabec at siol.net> wrote:
>>  This patch series add support for HDMI output. Support for other,
>>  newer, SoCs, which also uses DE2 and same or similar HDMI controller
>>  and PHY can be easily added later (A83T/A64/H5/R40). Current driver
>>  can also be easily extended with TV out support, just like video
>>  driver for older Allwinner SoCs.
>>
>>  While driver works, I would like to get few opinions first.
>>  - From what I understand, drivers which supports DT are preferred.
>>    Would it be better to rewrite this driver to support device tree?
>
> Yes I think so, and in fact it should use driver model also.
>
> The rockchip driver provides a reasonable example of how to split the
> driver up as you suggest below. The VIDEO driver provides the
> top-level video interface, DISPLAY drivers provide display output for
> the video, and you have PANEL as well for receiving the display
> output. VIDCONSOLE works automatically to display text.
>
> I actually took a bit of a look at this a few weeks ago so am happy to
> help with review or discussions.

Yes, I think go to Driver Model is also valuable, as Allwinner's display parts
are really in reusable components.

In addition, Driver Model provides the possibility to use EFI GOP, which can
be a more standardized replacement of SimpleFB, especially for OSes other
than Linux. (For example, Windows, if we can really get it running ;-) )

>
>>  - TCON code is currently exactly the same as in driver for older
>>    SoCs. Should I split it out into shared module? Also TV out code
>>    seems to be similar, but I didn't manage to confirm that it works
>>    as-is on H3.
>>  - A80 SoC is mix of older display engine and newer HDMI controller,
>>    so it doesn't really work with either of sunxi video drivers. Two
>>    solutions I see here are either combine both driver into one massive
>>    display driver or, much better, split everything by components
>>    (TCON/DE/DE2/HDMI/TV) and instantiate compatible ones. I guess this
>>    is not much different than adding support for DT in drivers. Note
>>    that I don't have any A80 board, I'm just thinking ahead.
>>
>>  Best regards,
>>  Jernej Skrabec
>>
>>  Jernej Skrabec (3):
>>    sunxi: Add clocks for DE2/HDMI/TCON
>>    sunxi: video: Add video driver for H3 SoC
>>    sunxi: Enable H3 video driver in defconfigs
>>
>>   arch/arm/include/asm/arch-sunxi/clock_sun6i.h | 43 +
>>   arch/arm/include/asm/arch-sunxi/cpu_sun4i.h | 8 +
>>   arch/arm/include/asm/arch-sunxi/display2.h | 377 +++++++++
>>   arch/arm/mach-sunxi/clock_sun6i.c | 28 +
>>   board/sunxi/Kconfig | 4 +-
>>   configs/orangepi_2_defconfig | 1 +
>>   configs/orangepi_lite_defconfig | 1 +
>>   configs/orangepi_one_defconfig | 1 +
>>   configs/orangepi_pc_defconfig | 1 +
>>   configs/orangepi_pc_plus_defconfig | 1 +
>>   configs/orangepi_plus2e_defconfig | 1 +
>>   configs/orangepi_plus_defconfig | 1 +
>>   drivers/video/Makefile | 1 +
>>   drivers/video/sunxi_display2.c | 1037 +++++++++++++++++++++++++
>>   include/configs/sunxi-common.h | 17 +-
>>   scripts/config_whitelist.txt | 1 +
>>   16 files changed, 1516 insertions(+), 7 deletions(-)
>>   create mode 100644 arch/arm/include/asm/arch-sunxi/display2.h
>>   create mode 100644 drivers/video/sunxi_display2.c
>>
>>  --
>>  2.10.2
>
> Regards,
> Simon
>
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