Re: [PATCH] arm: dts: vexpress: Move mcc node back into motherboard node

[Guenter Roeck <linux@roeck-us.net>]

On Wed, Jun 03, 2020 at 05:22:37PM +0100, Andre Przywara wrote:
> Commit 	d9258898ad49 ("arm64: dts: arm: vexpress: Move fixed devices
> out of bus node") moved the "mcc" DT node into the root node, because
> it does not have any children using "reg" properties, so does violate
> some dtc checks about "simple-bus" nodes.
> However this broke the vexpress config-bus code, which walks up the
> device tree to find the first node with an "arm,vexpress,site" property.
> This gave the wrong result (matching the root node instead of the
> motherboard node), so broke the clocks and some other devices for
> VExpress boards.
> 
> Move the whole node back into its original position. This re-introduces
> the dtc warning, but is conceptually the right thing to do. The dtc
> warning seems to be overzealous here, there are discussions on fixing or
> relaxing this check instead.
> 
> Fixes: 	d9258898ad49 ("arm64: dts: arm: vexpress: Move fixed devices out of bus node")
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>

Tested-by: Guenter Roeck <linux@roeck-us.net>

> ---
> P.S. The broken commit has not reached mainline yet, but is already in
> arm-soc/arm/dt.
> 
>  arch/arm/boot/dts/vexpress-v2m-rs1.dtsi | 146 ++++++++++++------------
>  1 file changed, 73 insertions(+), 73 deletions(-)
> 
> diff --git a/arch/arm/boot/dts/vexpress-v2m-rs1.dtsi b/arch/arm/boot/dts/vexpress-v2m-rs1.dtsi
> index e6308fb76183..a88ee5294d35 100644
> --- a/arch/arm/boot/dts/vexpress-v2m-rs1.dtsi
> +++ b/arch/arm/boot/dts/vexpress-v2m-rs1.dtsi
> @@ -100,79 +100,6 @@
>  		};
>  	};
>  
> -	mcc {
> -		compatible = "arm,vexpress,config-bus";
> -		arm,vexpress,config-bridge = <&v2m_sysreg>;
> -
> -		oscclk0 {
> -			/* MCC static memory clock */
> -			compatible = "arm,vexpress-osc";
> -			arm,vexpress-sysreg,func = <1 0>;
> -			freq-range = <25000000 60000000>;
> -			#clock-cells = <0>;
> -			clock-output-names = "v2m:oscclk0";
> -		};
> -
> -		v2m_oscclk1: oscclk1 {
> -			/* CLCD clock */
> -			compatible = "arm,vexpress-osc";
> -			arm,vexpress-sysreg,func = <1 1>;
> -			freq-range = <23750000 65000000>;
> -			#clock-cells = <0>;
> -			clock-output-names = "v2m:oscclk1";
> -		};
> -
> -		v2m_oscclk2: oscclk2 {
> -			/* IO FPGA peripheral clock */
> -			compatible = "arm,vexpress-osc";
> -			arm,vexpress-sysreg,func = <1 2>;
> -			freq-range = <24000000 24000000>;
> -			#clock-cells = <0>;
> -			clock-output-names = "v2m:oscclk2";
> -		};
> -
> -		volt-vio {
> -			/* Logic level voltage */
> -			compatible = "arm,vexpress-volt";
> -			arm,vexpress-sysreg,func = <2 0>;
> -			regulator-name = "VIO";
> -			regulator-always-on;
> -			label = "VIO";
> -		};
> -
> -		temp-mcc {
> -			/* MCC internal operating temperature */
> -			compatible = "arm,vexpress-temp";
> -			arm,vexpress-sysreg,func = <4 0>;
> -			label = "MCC";
> -		};
> -
> -		reset {
> -			compatible = "arm,vexpress-reset";
> -			arm,vexpress-sysreg,func = <5 0>;
> -		};
> -
> -		muxfpga {
> -			compatible = "arm,vexpress-muxfpga";
> -			arm,vexpress-sysreg,func = <7 0>;
> -		};
> -
> -		shutdown {
> -			compatible = "arm,vexpress-shutdown";
> -			arm,vexpress-sysreg,func = <8 0>;
> -		};
> -
> -		reboot {
> -			compatible = "arm,vexpress-reboot";
> -			arm,vexpress-sysreg,func = <9 0>;
> -		};
> -
> -		dvimode {
> -			compatible = "arm,vexpress-dvimode";
> -			arm,vexpress-sysreg,func = <11 0>;
> -		};
> -	};
> -
>  	bus@8000000 {
>  		motherboard-bus {
>  			model = "V2M-P1";
> @@ -435,6 +362,79 @@
>  						};
>  					};
>  				};
> +
> +				mcc {
> +					compatible = "arm,vexpress,config-bus";
> +					arm,vexpress,config-bridge = <&v2m_sysreg>;
> +
> +					oscclk0 {
> +						/* MCC static memory clock */
> +						compatible = "arm,vexpress-osc";
> +						arm,vexpress-sysreg,func = <1 0>;
> +						freq-range = <25000000 60000000>;
> +						#clock-cells = <0>;
> +						clock-output-names = "v2m:oscclk0";
> +					};
> +
> +					v2m_oscclk1: oscclk1 {
> +						/* CLCD clock */
> +						compatible = "arm,vexpress-osc";
> +						arm,vexpress-sysreg,func = <1 1>;
> +						freq-range = <23750000 65000000>;
> +						#clock-cells = <0>;
> +						clock-output-names = "v2m:oscclk1";
> +					};
> +
> +					v2m_oscclk2: oscclk2 {
> +						/* IO FPGA peripheral clock */
> +						compatible = "arm,vexpress-osc";
> +						arm,vexpress-sysreg,func = <1 2>;
> +						freq-range = <24000000 24000000>;
> +						#clock-cells = <0>;
> +						clock-output-names = "v2m:oscclk2";
> +					};
> +
> +					volt-vio {
> +						/* Logic level voltage */
> +						compatible = "arm,vexpress-volt";
> +						arm,vexpress-sysreg,func = <2 0>;
> +						regulator-name = "VIO";
> +						regulator-always-on;
> +						label = "VIO";
> +					};
> +
> +					temp-mcc {
> +						/* MCC internal operating temperature */
> +						compatible = "arm,vexpress-temp";
> +						arm,vexpress-sysreg,func = <4 0>;
> +						label = "MCC";
> +					};
> +
> +					reset {
> +						compatible = "arm,vexpress-reset";
> +						arm,vexpress-sysreg,func = <5 0>;
> +					};
> +
> +					muxfpga {
> +						compatible = "arm,vexpress-muxfpga";
> +						arm,vexpress-sysreg,func = <7 0>;
> +					};
> +
> +					shutdown {
> +						compatible = "arm,vexpress-shutdown";
> +						arm,vexpress-sysreg,func = <8 0>;
> +					};
> +
> +					reboot {
> +						compatible = "arm,vexpress-reboot";
> +						arm,vexpress-sysreg,func = <9 0>;
> +					};
> +
> +					dvimode {
> +						compatible = "arm,vexpress-dvimode";
> +						arm,vexpress-sysreg,func = <11 0>;
> +					};
> +				};
>  			};
>  		};
>  	};
> -- 
> 2.17.1
>