Re: [PATCH 3/6] dt-bindings: mips: brcm: Document mips-cbr-reg property

Florian Fainelli
2024-05-03T20:06:18Z

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On 5/3/24 12:33, Christian Marangi wrote:
> On Fri, May 03, 2024 at 05:21:41PM +0100, Conor Dooley wrote:
>> On Fri, May 03, 2024 at 03:54:03PM +0200, Christian Marangi wrote:
>>> Document mips-cbr-reg and mips-broken-cbr-reg property.
>>>
>>> Some SoC suffer from a BUG where read_c0_brcm_cbr() might return 0
>>> if called from TP1. The CBR address is always the same on the SoC
>>> hence it can be provided in DT to handle broken case where bootloader
>>> doesn't init it or SMP where read_c0_brcm_cbr() returns 0 from TP1.
>>>
>>> Usage of this property is to give an address also in these broken
>>> configuration/bootloader.
>>>
>>> If the SoC/Bootloader ALWAYS provide a broken CBR address the property
>>> "mips-broken-cbr-reg" can be used to ignore any value already set in the
>>> registers for CBR address.
>>>
>>> Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
>>> ---
>>> .../devicetree/bindings/mips/brcm/soc.yaml | 32 +++++++++++++++++++
>>> 1 file changed, 32 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/mips/brcm/soc.yaml b/Documentation/devicetree/bindings/mips/brcm/soc.yaml
>>> index 975945ca2888..12d394b7e011 100644
>>> --- a/Documentation/devicetree/bindings/mips/brcm/soc.yaml
>>> +++ b/Documentation/devicetree/bindings/mips/brcm/soc.yaml
>>> @@ -55,6 +55,21 @@ properties:
>>> under the "cpus" node.
>>> $ref: /schemas/types.yaml#/definitions/uint32
>>>
>>> + mips-broken-cbr-reg:
>>> + description: Declare that the Bootloader init a broken
>>> + CBR address in the registers and the one provided from
>>> + DT should always be used.
>>
>> Why is this property even needed, is it not sufficient to just add the
>> mips-cbr-reg property to the DT for SoCs that need it and use the
>> property when present?
>>
>
> I described this in the cover letter. CBR might be set by the Bootloader
> and might be not 0. In that case the value is ignored as an extra
> precaution and the broken propetry is needed.
>
>>> + type: boolean
>>> +
>>> + mips-cbr-reg:
>>
>> Missing a vendor prefix.
>>
>
> I will change this to bmips,cbr-reg hope it's O.K.

brcm,bmips-cbr-reg please.
--
Florian

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