Re: [PATCH v6 31/36] dt-bindings: nds32 CPU Bindings

[Greentime Hu]

2018-01-19 23:29 GMT+08:00 Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>:
> Hi Greentime,
>
> On Fri, Jan 19, 2018 at 4:18 PM, Greentime Hu <green.hu@xxxxxxxxx> wrote:
>> 2018-01-19 22:52 GMT+08:00 Arnd Bergmann <arnd@xxxxxxxx>:
>>> On Fri, Jan 19, 2018 at 3:32 PM, Greentime Hu <green.hu@xxxxxxxxx> wrote:
>>>> 2018-01-18 19:02 GMT+08:00 Arnd Bergmann <arnd@xxxxxxxx>:
>>>>> On Mon, Jan 15, 2018 at 6:53 AM, Greentime Hu <green.hu@xxxxxxxxx> wrote:
>>>>>> From: Greentime Hu <greentime@xxxxxxxxxxxxx>
>>>>>>
>>>>>> This patch adds nds32 CPU binding documents.
>>>>>>
>>>>>> Signed-off-by: Vincent Chen <vincentc@xxxxxxxxxxxxx>
>>>>>> Signed-off-by: Rick Chen <rick@xxxxxxxxxxxxx>
>>>>>> Signed-off-by: Zong Li <zong@xxxxxxxxxxxxx>
>>>>>> Signed-off-by: Greentime Hu <greentime@xxxxxxxxxxxxx>
>>>>>> Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
>>>>>> ---
>>>>>>  Documentation/devicetree/bindings/nds32/cpus.txt |   37 ++++++++++++++++++++++
>>>>>>  1 file changed, 37 insertions(+)
>>>>>>  create mode 100644 Documentation/devicetree/bindings/nds32/cpus.txt
>>>>>>
>>>>>> diff --git a/Documentation/devicetree/bindings/nds32/cpus.txt b/Documentation/devicetree/bindings/nds32/cpus.txt
>>>>>> new file mode 100644
>>>>>> index 0000000..9a52937
>>>>>> --- /dev/null
>>>>>> +++ b/Documentation/devicetree/bindings/nds32/cpus.txt
>>>>>> @@ -0,0 +1,37 @@
>>>>>> +* Andestech Processor Binding
>>>>>> +
>>>>>> +This binding specifies what properties must be available in the device tree
>>>>>> +representation of a Andestech Processor Core, which is the root node in the
>>>>>> +tree.
>>>>>> +
>>>>>> +Required properties:
>>>>>> +
>>>>>> +       - compatible:
>>>>>> +               Usage: required
>>>>>> +               Value type: <string>
>>>>>> +               Definition: should be one of:
>>>>>> +                       "andestech,n13"
>>>>>> +                       "andestech,n15"
>>>>>> +                       "andestech,d15"
>>>>>> +                       "andestech,n10"
>>>>>> +                       "andestech,d10"
>>>>>> +                       "andestech,nds32v3"
>>>>>
>>>>> Based on https://lkml.org/lkml/2017/11/27/1290, this should say that
>>>>> the device tree should always list 'andestech,nds32v3' as the most
>>>>> generic 'compatible' value and list exactly one of the others in
>>>>> addition.
>>>
>>>> I will remove the others and just left "andestech,nds32v3" in here.
>>>
>>> No, is not what we want here, the CPU node should list exactly which core
>>> is used, what we need in the description is a clarification that
>>> andestech,nds32v3 must be used in addition to the more specific
>>> string.
>>
>> Hi, Arnd:
>>
>> Sorry I still don't get your point. Do you mean we should always use
>> compatible = "andestech,n13", "andestech,nds32v3";
>> instead of
>> compatible = "andestech,n13";
>
> Exactly. The first value is a device-specific compatible value, the second is
> a generic fallback.
>
>> And I need to add the description in this document.
>
> Indeed. See for example
> Documentation/devicetree/bindings/power/renesas,apmu.txt
>
> Thanks!

Hi, Geert:

Thank you and your example.
I get it. I will update this document like this.
- compatible: Should be "andestech,<core_name>", "andestech,nds32v3"
as fallback.