Re: [RFC PATCH v2 3/4] drm: rockchip: hdmi: add RK3229 HDMI support

Hi Yakir,

Am Donnerstag, den 07.01.2016, 18:15 +0800 schrieb Yakir Yang:

Hi Philipp,

Thanks for your fast respond :)

On 01/07/2016 06:04 PM, Philipp Zabel wrote:

quoted

Am Donnerstag, den 07.01.2016, 17:02 +0800 schrieb Yakir Yang:

quoted

RK3229 integrate an DesignedWare HDMI2.0 controller and an INNO HDMI2.0 phy,
the max output resolution is 4K.

Signed-off-by: Yakir Yang <redacted>

It sounds like the INNO HDMI2.0 phy is not necessarily specific to
RK3229 but might also appear in other SoCs? If so, I think this should
be implemented in a separate phy driver and be used by dw_hdmi-rockchip.

Do you mean I should create a new phy driver that place in "driver/phy" 
directly ?

Possibly, yes. The exynos video phys are already there. I have kept the
mediatek dsi/hdmi phys together with the DRM driver, but I suppose I
could move them there, too.

I have think about this idea, and it would make things much clean. But 
INNO PHY
driver need the target pixel clock in drm_display_mode, I didn't find a 
good way
to pass this variable to separate phy driver. Do you have some idea ?

We'd need to extend the PHY API for this. For the mediatek phys we have
side-stepped the issue by wiring up the PLL output to the common clock
framework.
I expect besides the pixel clock frequency, it might also be necessary
to inform the PHY about cycles per pixel for deep color modes.

regards
Philipp

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