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

[Jan Kiszka <jan.kiszka@siemens.com>]

On 14.06.24 18:19, Andrew Davis wrote:
> On 6/14/24 2:44 AM, Jan Kiszka wrote:
>> 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@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@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@910000 {
>>> @@ -81,7 +81,7 @@ serdes1: serdes@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@2800000 {
>>> @@ -485,18 +485,23 @@ scm_conf: scm-conf@100000 {
>>>           serdes0_clk: clock@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@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@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@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@100000/serdes@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@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@100000/serdes@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)
>>
> 
> Thanks for the report, I think I know the issue and can
> send the fix here in a bit. In the mean time, could you
> see if the following fixes the issue (this isn't fully
> correct and will cause a new DTB check warning, but will
> let me verify the issue):
> 
> diff --git a/arch/arm64/boot/dts/ti/k3-am65-main.dtsi
> b/arch/arm64/boot/dts/ti/k3-am65-main.dtsi
> index 1af3dedde1f67..06ed74197f893 100644
> --- a/arch/arm64/boot/dts/ti/k3-am65-main.dtsi
> +++ b/arch/arm64/boot/dts/ti/k3-am65-main.dtsi
> @@ -478,7 +478,7 @@ scm_conf: scm-conf@100000 {
>                 ranges = <0x0 0x0 0x00100000 0x1c000>;
>  
>                 serdes0_clk: clock@4080 {
> -                       compatible = "ti,am654-serdes-ctrl", "syscon";
> +                       compatible = "ti,am654-serdes-ctrl", "syscon",
> "simple-mfd";
>                         reg = <0x4080 0x4>;
>  
>                         serdes0_mux: mux-controller {
> @@ -489,7 +489,7 @@ serdes0_mux: mux-controller {
>                 };
>  
>                 serdes1_clk: clock@4090 {
> -                       compatible = "ti,am654-serdes-ctrl", "syscon";
> +                       compatible = "ti,am654-serdes-ctrl", "syscon",
> "simple-mfd";
>                         reg = <0x4090 0x4>;
>  
>                         serdes1_mux: mux-controller {
> 

Yes, this works.

Jan

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