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Message-ID: <2528be71-ca3f-566b-4769-36063c98ee0e@ti.com>
Date:   Fri, 22 Apr 2022 14:10:52 -0500
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Subject: Re: [PATCH 1/6] dt-bindings: ti,sci: Add ti,ctx-memory-region
 property
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To:     Andrew Davis <afd@ti.com>, Rob Herring <robh+dt@kernel.org>,
        Santosh Shilimkar <ssantosh@kernel.org>,
        Krzysztof Kozlowski <krzk+dt@kernel.org>,
        Tero Kristo <kristo@kernel.org>, Nishanth Menon <nm@ti.com>
CC:     <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, <devicetree@vger.kernel.org>,
        Vignesh Raghavendra <vigneshr@ti.com>
References: <20220421203659.27853-1-d-gerlach@ti.com>
 <20220421203659.27853-2-d-gerlach@ti.com>
 <ad47db06-7f5c-399f-0ad0-81f720e6f035@ti.com>
From:   Dave Gerlach <d-gerlach@ti.com>
In-Reply-To: <ad47db06-7f5c-399f-0ad0-81f720e6f035@ti.com>
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Hi,

On 4/22/22 14:02, Andrew Davis wrote:
> On 4/21/22 3:36 PM, Dave Gerlach wrote:
>> Add documentation for the ti,ctx-memory-region property which is a
>> phandle to a reserved-memory carveout to be used by the ti_sci driver
>> storage of low power mode memory context. This is optional for normal
>> system operation but required to enabled suspend-to-mem usage of Deep
>> Sleep state.
>>
>> Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
>> ---
>>   .../devicetree/bindings/arm/keystone/ti,sci.yaml         | 9 +++++++++
>>   1 file changed, 9 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/arm/keystone/ti,sci.yaml b/Documentation/devicetree/bindings/arm/keystone/ti,sci.yaml
>> index 34f5f877d444..ec88aa88a2a0 100644
>> --- a/Documentation/devicetree/bindings/arm/keystone/ti,sci.yaml
>> +++ b/Documentation/devicetree/bindings/arm/keystone/ti,sci.yaml
>> @@ -61,6 +61,15 @@ properties:
>>     mboxes:
>>       minItems: 2
>>   
>> +  ti,ctx-memory-region:
>> +    description:
>> +      Phandle to the reserved memory node to be associated with the
>> +      ti-sci device, to be used for saving low power context. The
>> +      reserved memory node should be a carveout node, and should
>> +      be defined as per the bindings in
>> +      Documentation/devicetree/bindings/reserved-memory/reserved-memory.yaml
>> +    $ref: /schemas/types.yaml#/definitions/string
>> +
> 
> 
> Why does this have to be yet another reserved carveout region,
> should be dynamically allocated.
> 

This must be a fixed address in order to support other low power modes
which have not yet been introduced.

Regards,
Dave

> Andrew
> 
> 
>>     ti,system-reboot-controller:
>>       description: Determines If system reboot can be triggered by SoC reboot
>>       type: boolean