Re: [PATCHv3 RESEND 1/3] Documentation: dt: memory: ti-emif: add edac support under emif

[Tero Kristo <t-kristo@ti.com>]

On 27/12/17 00:48, Rob Herring wrote:
> On Fri, Dec 22, 2017 at 06:23:54PM +0200, Tero Kristo wrote:
>> Certain revisions of the TI EMIF IP contain ECC support in them. Reflect
>> this in the DT binding.
> 
> "dt-bindings: edac: ..." is the preferred subject prefix.

 >Err, I mean "dt-bindings: memory-controllers: ..."

I'll fix this.

> 
>>
>> Signed-off-by: Tero Kristo <t-kristo@ti.com>
>> Cc: Tony Lindgren <tony@atomide.com>
>> Cc: Rob Herring <robh+dt@kernel.org>
>> ---
>> Just resending this patch, missed adding devicetree list on this previously
>> and it got lost.
>>
>>   .../devicetree/bindings/memory-controllers/ti/emif.txt   | 16 +++++++++++++++-
>>   1 file changed, 15 insertions(+), 1 deletion(-)
>>
>> diff --git a/Documentation/devicetree/bindings/memory-controllers/ti/emif.txt b/Documentation/devicetree/bindings/memory-controllers/ti/emif.txt
>> index 0db6047..f56a347 100644
>> --- a/Documentation/devicetree/bindings/memory-controllers/ti/emif.txt
>> +++ b/Documentation/devicetree/bindings/memory-controllers/ti/emif.txt
>> @@ -3,12 +3,16 @@
>>   EMIF - External Memory Interface - is an SDRAM controller used in
>>   TI SoCs. EMIF supports, based on the IP revision, one or more of
>>   DDR2/DDR3/LPDDR2 protocols. This binding describes a given instance
>> -of the EMIF IP and memory parts attached to it.
>> +of the EMIF IP and memory parts attached to it. Certain revisions
>> +of the EMIF IP controller also contain optional ECC support, which
>> +corrects one bit errors and detects two bit errors.
>>   
>>   Required properties:
>>   - compatible	: Should be of the form "ti,emif-<ip-rev>" where <ip-rev>
>>     is the IP revision of the specific EMIF instance.
>>   		  For am437x should be ti,emif-am4372.
>> +		  For dra7xx should be ti,emif-dra7xx.
>> +		  For k2x family, should be ti,emif-keystone.
>>   
>>   - phy-type	: <u32> indicating the DDR phy type. Following are the
>>     allowed values
>> @@ -42,6 +46,10 @@ Optional properties:
>>   - hw-caps-temp-alert	: Have this property if the controller
>>     has capability for generating SDRAM temperature alerts
>>   
>> +- interrupts		: A list of interrupt specifiers for memory
>> +  controller interrupts, if available. Required for EMIF instances
>> +  that support ECC.
> 
> Be explicit as to which compatibles have an interrupt. Is it really
> optional for for those controllers? The interrupt is in the h/w whether
> you use ECC or not.

It seems the interrupt property is actually required also for omap4, 
omap5 emif based on the driver implementation, they use it for high temp 
alert as the main feature. The interrupt exists on am3/am4 also but it 
is not used at all there right now.

Would it be better just to make this a required property from binding 
point of view and ignore the fact that am3/am4 do not really use it?

-Tero

> 
>> +
>>   Example:
>>   
>>   emif1: emif@0x4c000000 {
>> @@ -54,3 +62,9 @@ emif1: emif@0x4c000000 {
>>   	hw-caps-ll-interface;
>>   	hw-caps-temp-alert;
>>   };
>> +
>> +emif1: emif@4c000000 {
>> +	compatible = "ti,emif-dra7";
>> +	reg = <0x4c000000 0x200>;
>> +	interrupts = <GIC_SPI 105 IRQ_TYPE_LEVEL_HIGH>;
>> +};
>> -- 
>> 1.9.1
>>
>> --

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