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SubjectRe: [PATCH v2 1/2] dt-bindings: display: rockchip: Add compatible for rk3568 HDMI
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Hi Michael,

Am Dienstag, 13. Juli 2021, 10:44:00 CEST schrieb Michael Riesch:
> The HDMI TX block in the RK3568 requires two power supplies, which have
> to be enabled in some cases (at least on the RK3568 EVB1 the voltages
> VDDA0V9_IMAGE and VCCA1V8_IMAGE are disabled by default). It would be
> great if this was considered by the driver and the device tree binding.
> I am not sure, though, whether this is a RK3568 specific or
> rockchip_dw_hdmi specific thing. Maybe it can even enter the Synopsis DW
> HDMI driver.

I do remember that this discussion happened many years back already.
And yes the supplies are needed for all but back then there was opposition
as these are supposedly phy-related supplies, not for the dw-hdmi itself.
[There are variants with an external phy, like on the rk3328]

See discussion on [0]

[0] https://dri-devel.freedesktop.narkive.com/pen2zWo1/patch-v3-1-2-drm-bridge-dw-hdmi-support-optional-supply-regulators



> On 7/7/21 2:03 PM, Benjamin Gaignard wrote:
> > Define a new compatible for rk3568 HDMI.
> > This version of HDMI hardware block needs two new clocks hclk_vio and hclk
> > to provide phy reference clocks.
> >
> > Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
> > ---
> > version 2:
> > - Add the clocks needed for the phy.
> >
> > .../bindings/display/rockchip/rockchip,dw-hdmi.yaml | 6 +++++-
> > 1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/Documentation/devicetree/bindings/display/rockchip/rockchip,dw-hdmi.yaml b/Documentation/devicetree/bindings/display/rockchip/rockchip,dw-hdmi.yaml
> > index 75cd9c686e985..cb8643b3a8b84 100644
> > --- a/Documentation/devicetree/bindings/display/rockchip/rockchip,dw-hdmi.yaml
> > +++ b/Documentation/devicetree/bindings/display/rockchip/rockchip,dw-hdmi.yaml
> > @@ -23,6 +23,7 @@ properties:
> > - rockchip,rk3288-dw-hdmi
> > - rockchip,rk3328-dw-hdmi
> > - rockchip,rk3399-dw-hdmi
> > + - rockchip,rk3568-dw-hdmi
> >
> > reg-io-width:
> > const: 4
> > @@ -51,8 +52,11 @@ properties:
> > - vpll
> > - enum:
> > - grf
> > + - hclk_vio
> > + - vpll
> > + - enum:
> > + - hclk
> > - vpll
> > - - const: vpll
>
> The description and documentation of the clocks are somewhat misleading
> IMHO. This is not caused by your patches, of course. But maybe this is a
> chance to clean them up a bit.
>
> It seems that the CEC clock is an optional clock of the dw-hdmi driver.
> Shouldn't it be documented in the synopsys,dw-hdmi.yaml?
>
> Also, it would be nice if the clocks hclk_vio and hclk featured a
> description in the binding.
>
> BTW, I am not too familiar with the syntax here, but shouldn't items in
> clocks and items in clock-names be aligned (currently, there is a plain
> list vs. an enum structure)?
>
> Best regards,
> Michael
>
> >
> > ddc-i2c-bus:
> > $ref: /schemas/types.yaml#/definitions/phandle
> >
>




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