[U-Boot] [PATCH 0/8] video: Add support for SSD2828 (parallel LCD to MIPI bridge)

[Hans de Goede]

Hi,

On 09-01-15 11:01, Siarhei Siamashka wrote:
> Hello,
>
> This patchset adds support for the Solomon Systech SSD2828 bridge chip,
> which is used to convert parallel LCD interface into MIPI DSI interface
> and drive MIPI LCD display in some tablets. In particular, this allows
> to have a working LCD display in my Allwinner A31s based MSI Primo81 tablet.
>
> The core of the SSD2828 support code is generic and should work with
> any SoC (as long as the hardware supports the standard u-boot GPIO API).
> It also does not have any hardcoded assumptions about the MSI Primo81
> display and should be able to drive any MIPI LCD panel (as long as the
> number of data lanes and the bitrate per lane is provided in the
> config struct). The code tries to follow the standard power-up sequence
> described in the SSD2828 datasheet. However it has been tested only
> on my MSI Primo81 tablet so far.
>
> The sunxi specific part includes a small glue code in the sunxi display
> driver and the defconfig update for the MSI Primo81 tablet.
>
> This can be applied after
>      http://lists.denx.de/pipermail/u-boot/2015-January/200753.html
> 'sunxi: video: Add lvds support' patchset to the 'next' branch
> in the u-boot-sunxi repository.
>
> And here is a bonus picture :-)
>      http://linux-sunxi.org/File:MSI_Primo81_and_LCD_support_in_u-boot.jpg

Cool :)


> Siarhei Siamashka (8):
>    sunxi: axp221: Add ELDO[1-3] support
>    include: Add header file with MIPI DSI constants from the Linux kernel
>    video: Add support for SSD2828 (parallel LCD to MIPI bridge)
>    video: sunxi: Hook up SSD2828 with the sunxi video driver
>    sun6i: Add LCD display support for MSI Primo81 tablet
>    video: ssd2828: Allow using 'pclk' as the PLL clock source
>    video: sunxi: Switch from 'tx_clk' to 'pclk' for SSD2828
>    video: ssd2828: Use MIPI DCS commands to retrieve the LCD panel id

Thanks for working on this!

Overall this looks good. Looks like you did a better job then I did with
the Hitachi tx18d42vm LCD panel support, esp. wrt making things generic
rather then sunxi specific.

So assuming the Ian will ack v2 of my lvds patch I suggest that we merge
my lvds patch, then your patches (pending an ack from Anatolij) and then I
respin my "Hitachi tx18d42vm LCD panel" patch following your patches as an
example.

I've also reviewed all of your patches. I've one change request, can you
please move all of the board/sunxi/Kconfig changes except for the last
hunk to drivers/video/Kconfig, if we go the generic route we should also
make the Kconfig stuff generic. This also means dropping the
"select VIDEO_LCD_IF_PARALLEL" from "config VIDEO_LCD_SSD2828" and adding
it to "config VIDEO_LCD_PANEL_MIPI_4_LANE_513_MBPS_VIA_SSD2828", as that
option is the only one which will stay in board/sunxi/Kconfig and
VIDEO_LCD_IF_PARALLEL is sunxi specific.

The changes to drivers/video/Kconfig should then become part of the
"video: Add support for SSD2828 (parallel LCD to MIPI bridge)" commit.

With that changed patches 1-7 are:

Acked-by: Hans de Goede <hdegoede at redhat.com>

I'm not 100% sure about patch 8, I can see this being useful for
debugging but not for normal use, and as you said it may (theoretically)
be unsafe with some panels. Maybe keep the patch, but #ifdef DEBUG the
entire code block it adds ?

Regards,

Hans