Re: [PATCH v2 1/2] Documentation: dt-bindings: k3-r5f-rproc: Add new compatible for AM62 SoC family

From: Devarsh Thakkar
Date: Wed Dec 21 2022 - 02:42:50 EST


Hi Krzysztof,

Thanks for the review. Please find my response inline.

On 30/11/22 20:33, Krzysztof Kozlowski wrote:
> On 30/11/2022 14:40, Devarsh Thakkar wrote:
>> AM62 family of devices don't have a R5F cluster, instead
>> they have single core DM R5F.
>> Add new compatible string ti,am62-r5fss to support this scenario.
>>
>> When this new compatible is used don't allow cluster-mode
>> property usage in device-tree as this implies that there
>> is no R5F cluster available and only single R5F core
>> is present.
>>
>> Signed-off-by: Devarsh Thakkar <devarsht@xxxxxx>
>> ---
>> V2: Avoid acronyms, use "Device Manager" instead of "DM"
>
> Use subject prefixes matching the subsystem (git log --oneline -- ...).
Agreed, I will update the prefix as dt-bindings: remoteproc: k3-r5f: in V3.
>
>> ---
>> .../bindings/remoteproc/ti,k3-r5f-rproc.yaml | 48 +++++++++++++------
>> 1 file changed, 34 insertions(+), 14 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml b/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
>> index fb9605f0655b..91357635025a 100644
>> --- a/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
>> +++ b/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
>> @@ -21,6 +21,9 @@ description: |
>> called "Single-CPU" mode, where only Core0 is used, but with ability to use
>> Core1's TCMs as well.
>>
>> + AM62 SoC family support a single R5F core only which runs Device Manager
>> + firmware and can also be used as a remote processor with IPC communication.
>> +
>> Each Dual-Core R5F sub-system is represented as a single DTS node
>> representing the cluster, with a pair of child DT nodes representing
>> the individual R5F cores. Each node has a number of required or optional
>> @@ -28,6 +31,9 @@ description: |
>> the device management of the remote processor and to communicate with the
>> remote processor.
>>
>> + Since AM62 SoC family only support a single core, there is no cluster-mode
>> + property setting required for it.
>> +
>> properties:
>> $nodename:
>> pattern: "^r5fss(@.*)?"
>> @@ -38,6 +44,7 @@ properties:
>> - ti,j721e-r5fss
>> - ti,j7200-r5fss
>> - ti,am64-r5fss
>> + - ti,am62-r5fss
>
> Some order? Alphabetical, so before am64? Same in other places.
Agreed, I will update in V3 accordingly.
>
>
>> - ti,j721s2-r5fss
>>
>> power-domains:
>> @@ -80,7 +87,8 @@ patternProperties:
>> node representing a TI instantiation of the Arm Cortex R5F core. There
>> are some specific integration differences for the IP like the usage of
>> a Region Address Translator (RAT) for translating the larger SoC bus
>> - addresses into a 32-bit address space for the processor.
>> + addresses into a 32-bit address space for the processor. For AM62x,
>> + should only define one R5F child node as it has only one core available.
>>
>> Each R5F core has an associated 64 KB of Tightly-Coupled Memory (TCM)
>> internal memories split between two banks - TCMA and TCMB (further
>> @@ -104,6 +112,7 @@ patternProperties:
>> - ti,j721e-r5f
>> - ti,j7200-r5f
>> - ti,am64-r5f
>> + - ti,am62-r5f
>> - ti,j721s2-r5f
>>
>> reg:
>> @@ -207,20 +216,31 @@ patternProperties:
>> - firmware-name
>>
>> unevaluatedProperties: false
>
> Blank line.
Agreed, I will remove it in V3.
>
>> +allOf:
>> + - if:
>> + properties:
>> + compatible:
>> + enum:
>> + - ti,am64-r5fss
>> + then:
>> + properties:
>> + ti,cluster-mode:
>> + enum: [0, 2]
>> +
>> + else:
>> + properties:
>> + ti,cluster-mode:
>
> It's not really valid anymore for ti,am62-r5fss, so this cannot be
> simple "else". Instead you need to list all compatibles.
I agree that the else block is not valid for am62x, but my understanding is that since all the blocks under allOf are checked for validity,
I thought to add a separate if block only for am62x to set cluster-mode to false [1], which I believe would negate the effect of above else condition for am62x,
so that we don't have to list all compatibles under separate if blocks.

Just to verify this, I deliberately set cluster-mode=1 in am62x devicetree and then ran a dtbs-check and got below log :
"linux-next/arch/arm64/boot/dts/ti/k3-am625-sk.dtb: r5fss@78000000: ti,cluster-mode: False schema does not allow [[1]]"

and above warning log goes away when i remove the cluster-mode node in am62x devicetree.
But please do let me know if I am missing something here or there is a better/more proper way to do this.

Best Regards,
Devarsh

>
>> + enum: [0, 1]
>> +
[1]
>> + - if:
>> + properties:
>> + compatible:
>> + enum:
>> + - ti,am62-r5fss
>> + then:
>> + properties:
>> + ti,cluster-mode: false
>>
>> -if:
>> - properties:
>> - compatible:
>> - enum:
>> - - ti,am64-r5fss
>> -then:
>> - properties:
>> - ti,cluster-mode:
>> - enum: [0, 2]
>> -else:
>> - properties:
>> - ti,cluster-mode:
>> - enum: [0, 1]
>>
>> required:
>> - compatible
>
> Best regards,
> Krzysztof
>