[PATCH 3/3] arm64: dts: rockchip: Add HDMI PHY PLL clock source to VOP2 on rk3576

[Detlev Casanova]

Hi Cristian,

On Wednesday, 11 June 2025 17:47:49 EDT Cristian Ciocaltea wrote:
> Since commit c871a311edf0 ("phy: rockchip: samsung-hdptx: Setup TMDS
> char rate via phy_configure_opts_hdmi"), the workaround of passing the
> rate from DW HDMI QP bridge driver via phy_set_bus_width() became
> partially broken, as it cannot reliably handle mode switches anymore.
> 
> Attempting to fix this up at PHY level would not only introduce
> additional hacks, but it would also fail to adequately resolve the
> display issues that are a consequence of the system CRU limitations.
> 
> Instead, proceed with the solution already implemented for RK3588: make
> use of the HDMI PHY PLL as a better suited DCLK source for VOP2. This
> will not only address the aforementioned problem, but it should also
> facilitate the proper operation of display modes up to 4K at 60Hz.
> 
> It's worth noting that anything above 4K at 30Hz still requires high TMDS
> clock ratio and scrambling support, which hasn't been mainlined yet.
> 
> Fixes: d74b842cab08 ("arm64: dts: rockchip: Add vop for rk3576")
> Cc: stable at vger.kernel.org
> Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea at collabora.com>
> ---
>  arch/arm64/boot/dts/rockchip/rk3576.dtsi | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/rockchip/rk3576.dtsi
> b/arch/arm64/boot/dts/rockchip/rk3576.dtsi index
> 6a13fe0c3513fb2ff7cd535aa70e3386c37696e4..b1ac23035dd789f0478bf10c78c74ef16
> 7d94904 100644 --- a/arch/arm64/boot/dts/rockchip/rk3576.dtsi
> +++ b/arch/arm64/boot/dts/rockchip/rk3576.dtsi
> @@ -1155,12 +1155,14 @@ vop: vop at 27d00000 {
>  				 <&cru HCLK_VOP>,
>  				 <&cru DCLK_VP0>,
>  				 <&cru DCLK_VP1>,
> -				 <&cru DCLK_VP2>;
> +				 <&cru DCLK_VP2>,
> +				 <&hdptxphy>;
>  			clock-names = "aclk",
>  				      "hclk",
>  				      "dclk_vp0",
>  				      "dclk_vp1",
> -				      "dclk_vp2";
> +				      "dclk_vp2",
> +				      "pll_hdmiphy0";
>  			iommus = <&vop_mmu>;
>  			power-domains = <&power RK3576_PD_VOP>;
>  			rockchip,grf = <&sys_grf>;

I tested this on the ROCK 4D and can confirm that:
 - New modes like 2K are now working
 - Mode changes is now correctly supported

So,
Tested-By: Detlev Casanova <detlev.casanova at collabora.com>

Regards,

Detlev.