[PATCH 2/2] arm64: dts: ti: k3-am65: Move SerDes mux nodes under the control node

[Jan Kiszka]

On 26.03.24 19:56, Andrew Davis wrote:
> These SerDes lane select muxes use bits from the same register as
> the SerDes clock select mux. Make the lane select mux a child
> of the SerDes control node.
> 
> This removes one more requirement on scm-conf being a syscon node
> which will later be converted to fix a couple DTS check warnings.
> 
> Signed-off-by: Andrew Davis <afd at ti.com>
> ---
>  arch/arm64/boot/dts/ti/k3-am65-main.dtsi | 21 +++++++++++++--------
>  1 file changed, 13 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/ti/k3-am65-main.dtsi b/arch/arm64/boot/dts/ti/k3-am65-main.dtsi
> index 738c5c4acbcd2..5ce67e6a33600 100644
> --- a/arch/arm64/boot/dts/ti/k3-am65-main.dtsi
> +++ b/arch/arm64/boot/dts/ti/k3-am65-main.dtsi
> @@ -66,7 +66,7 @@ serdes0: serdes at 900000 {
>  		assigned-clock-parents = <&k3_clks 153 8>, <&k3_clks 153 4>;
>  		ti,serdes-clk = <&serdes0_clk>;
>  		#clock-cells = <1>;
> -		mux-controls = <&serdes_mux 0>;
> +		mux-controls = <&serdes0_mux 0>;
>  	};
>  
>  	serdes1: serdes at 910000 {
> @@ -81,7 +81,7 @@ serdes1: serdes at 910000 {
>  		assigned-clock-parents = <&k3_clks 154 9>, <&k3_clks 154 5>;
>  		ti,serdes-clk = <&serdes1_clk>;
>  		#clock-cells = <1>;
> -		mux-controls = <&serdes_mux 1>;
> +		mux-controls = <&serdes1_mux 0>;
>  	};
>  
>  	main_uart0: serial at 2800000 {
> @@ -485,18 +485,23 @@ scm_conf: scm-conf at 100000 {
>  		serdes0_clk: clock at 4080 {
>  			compatible = "ti,am654-serdes-ctrl", "syscon";
>  			reg = <0x4080 0x4>;
> +
> +			serdes0_mux: mux-controller {
> +				compatible = "mmio-mux";
> +				#mux-control-cells = <1>;
> +				mux-reg-masks = <0x0 0x3>; /* lane select */
> +			};
>  		};
>  
>  		serdes1_clk: clock at 4090 {
>  			compatible = "ti,am654-serdes-ctrl", "syscon";
>  			reg = <0x4090 0x4>;
> -		};
>  
> -		serdes_mux: mux-controller {
> -			compatible = "mmio-mux";
> -			#mux-control-cells = <1>;
> -			mux-reg-masks = <0x4080 0x3>, /* SERDES0 lane select */
> -					<0x4090 0x3>; /* SERDES1 lane select */
> +			serdes1_mux: mux-controller {
> +				compatible = "mmio-mux";
> +				#mux-control-cells = <1>;
> +				mux-reg-masks = <0x0 0x3>; /* lane select */
> +			};
>  		};
>  
>  		dss_oldi_io_ctrl: dss-oldi-io-ctrl at 41e0 {

This change breaks serdes setup on the IOT2050 SM (k3-am6548-iot2050-
advanced-sm.dts), possibly on more of our devices as well:

platform 5500000.pcie: deferred probe pending: platform: supplier 900000.serdes not ready
platform 900000.serdes: deferred probe pending: (reason unknown)

And PCI remains unavailable. Digging a bit into it, it seems the change 
is causing a circular consumer/provider dependency between serdes0 and 
serdes1:

root at iot2050-debian:~# ls -l /sys/bus/platform/devices/900000.serdes/
total 0
lrwxrwxrwx 1 root root    0 Jun 14 07:10 consumer:platform:5500000.pcie -> ../../../virtual/devlink/platform:900000.serdes--platform:5500000.pcie
lrwxrwxrwx 1 root root    0 Jun 14 07:10 consumer:platform:910000.serdes -> ../../../virtual/devlink/platform:900000.serdes--platform:910000.serdes
-rw-r--r-- 1 root root 4096 Jun 14 07:10 driver_override
-r--r--r-- 1 root root 4096 Jun 14 07:10 modalias
lrwxrwxrwx 1 root root    0 Jun 14 07:10 of_node -> ../../../../firmware/devicetree/base/bus at 100000/serdes at 900000
drwxr-xr-x 2 root root    0 Jun 14 07:10 power
lrwxrwxrwx 1 root root    0 Jun 14 07:00 subsystem -> ../../../../bus/platform
lrwxrwxrwx 1 root root    0 Jun 14 07:10 supplier:platform:44083000.system-controller:clock-controller -> ../../../virtual/devlink/platform:44083000.system-controller:clock-controller--platform:900000.serdes
lrwxrwxrwx 1 root root    0 Jun 14 07:10 supplier:platform:44083000.system-controller:power-controller -> ../../../virtual/devlink/platform:44083000.system-controller:power-controller--platform:900000.serdes
lrwxrwxrwx 1 root root    0 Jun 14 07:10 supplier:platform:910000.serdes -> ../../../virtual/devlink/platform:910000.serdes--platform:900000.serdes
-rw-r--r-- 1 root root 4096 Jun 14 07:00 uevent
-r--r--r-- 1 root root 4096 Jun 14 07:10 waiting_for_supplier
root at iot2050-debian:~# ls -l /sys/bus/platform/devices/910000.serdes/
total 0
lrwxrwxrwx 1 root root    0 Jun 14 07:14 consumer:platform:900000.serdes -> ../../../virtual/devlink/platform:910000.serdes--platform:900000.serdes
-rw-r--r-- 1 root root 4096 Jun 14 07:14 driver_override
-r--r--r-- 1 root root 4096 Jun 14 07:14 modalias
lrwxrwxrwx 1 root root    0 Jun 14 07:14 of_node -> ../../../../firmware/devicetree/base/bus at 100000/serdes at 910000
drwxr-xr-x 2 root root    0 Jun 14 07:14 power
lrwxrwxrwx 1 root root    0 Jun 14 07:00 subsystem -> ../../../../bus/platform
lrwxrwxrwx 1 root root    0 Jun 14 07:14 supplier:platform:44083000.system-controller:clock-controller -> ../../../virtual/devlink/platform:44083000.system-controller:clock-controller--platform:910000.serdes
lrwxrwxrwx 1 root root    0 Jun 14 07:14 supplier:platform:44083000.system-controller:power-controller -> ../../../virtual/devlink/platform:44083000.system-controller:power-controller--platform:910000.serdes
lrwxrwxrwx 1 root root    0 Jun 14 07:14 supplier:platform:900000.serdes -> ../../../virtual/devlink/platform:900000.serdes--platform:910000.serdes
-rw-r--r-- 1 root root 4096 Jun 14 07:00 uevent
-r--r--r-- 1 root root 4096 Jun 14 07:14 waiting_for_supplier

Note that we normally disable serdes1 on this device as it was not 
required so far. Enabling the node does not solve the issue, though:

platform 5500000.pcie: deferred probe pending: platform: supplier 900000.serdes not ready
platform 900000.serdes: deferred probe pending: (reason unknown)
platform 910000.serdes: deferred probe pending: (reason unknown)

Jan

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