Re: [PATCH v5 2/3] arm64: dts: rockchip: Add HDMI0 audio output for rk3588 SoC

From: Quentin Schulz <quentin.schulz@cherry.de>
To: Detlev Casanova <detlev.casanova@collabora.com>,
	linux-kernel@vger.kernel.org
Cc: Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Heiko Stuebner <heiko@sntech.de>,
	Andrzej Hajda <andrzej.hajda@intel.com>,
	Neil Armstrong <neil.armstrong@linaro.org>,
	Robert Foss <rfoss@kernel.org>,
	Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
	Jonas Karlman <jonas@kwiboo.se>,
	Jernej Skrabec <jernej.skrabec@gmail.com>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Maxime Ripard <mripard@kernel.org>,
	Thomas Zimmermann <tzimmermann@suse.de>,
	David Airlie <airlied@gmail.com>, Simona Vetter <simona@ffwll.ch>,
	Sebastian Reichel <sebastian.reichel@collabora.com>,
	Alexey Charkov <alchark@gmail.com>,
	Cristian Ciocaltea <cristian.ciocaltea@collabora.com>,
	Dragan Simic <dsimic@manjaro.org>,
	Jianfeng Liu <liujianfeng1994@gmail.com>,
	Niklas Cassel <cassel@kernel.org>,
	FUKAUMI Naoki <naoki@radxa.com>,
	Kever Yang <kever.yang@rock-chips.com>,
	Johan Jonker <jbx6244@gmail.com>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
	Algea Cao <algea.cao@rock-chips.com>,
	Chen-Yu Tsai <wens@csie.org>,
	Sugar Zhang <sugar.zhang@rock-chips.com>,
	devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-rockchip@lists.infradead.org,
	dri-devel@lists.freedesktop.org, kernel@collabora.com
Subject: Re: [PATCH v5 2/3] arm64: dts: rockchip: Add HDMI0 audio output for rk3588 SoC
Date: Tue, 4 Feb 2025 11:14:37 +0100	[thread overview]
Message-ID: <bfe9cb98-12ba-484c-95af-e5842edaab76@cherry.de> (raw)
In-Reply-To: <20250203171925.126309-3-detlev.casanova@collabora.com>

Hi Detlev,

On 2/3/25 6:16 PM, Detlev Casanova wrote:
> Use the simple-audio-card driver with the hdmi0 QP node as CODEC and
> the i2s5 device as CPU.
> 
> The simple-audio-card,mclk-fs value is set to 128 as it is done in
> the downstream driver.
> 
> The #sound-dai-cells value is set to 0 in the hdmi0 node so that it can be
> used as an audio codec node.
> 
> Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>
> ---
>   arch/arm64/boot/dts/rockchip/rk3588-base.dtsi | 17 +++++++++++++++++
>   1 file changed, 17 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/rockchip/rk3588-base.dtsi b/arch/arm64/boot/dts/rockchip/rk3588-base.dtsi
> index 8cfa30837ce72..767bdfc06b7ec 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3588-base.dtsi
> +++ b/arch/arm64/boot/dts/rockchip/rk3588-base.dtsi
> @@ -1369,6 +1369,22 @@ i2s9_8ch: i2s@fddfc000 {
>   		status = "disabled";
>   	};
>   
> +	hdmi0_sound: hdmi0-sound {
> +		compatible = "simple-audio-card";
> +		simple-audio-card,format = "i2s";
> +		simple-audio-card,mclk-fs = <128>;
> +		simple-audio-card,name = "hdmi0";
> +		status = "disabled";
> +
> +		simple-audio-card,codec {
> +			sound-dai = <&hdmi0>;
> +		};
> +
> +		simple-audio-card,cpu {
> +			sound-dai = <&i2s5_8ch>;
> +		};
> +	};
> +

This is an address/bus-less device, so I believe it needs to be put 
among other address/bus-less devices, which for Rockchip SoCs is at the 
top of the DT? c.f. 
https://www.kernel.org/doc/html/latest/devicetree/bindings/dts-coding-style.html

**I** would put it between the firmware and the pmu-a55 nodes.

Tested-by: Quentin Schulz <quentin.schulz@cherry.de> # RK3588 Tiger Haikou

Thanks!
Quentin