[PATCH v7 3/5] Documentation: Add documentation for the APM X-Gene SoC EDAC DTS binding

[Loc Ho]

Hi Rob,

>>
>>>> > Similar comments for the rest. I would define memory controller
>>>> > bindings and EDAC driver, then worry about the rest.
>>>>
>>>> Okay.. As comment in following emails, I will break up the driver into
>>>> multiple drivers and focus only on the memory controller driver first.
>>>
>>> Please no multiple EDAC drivers. Or do you mean something else here?
>>
>> We will have the following:
>>
>> xgene-edac-mc.c
>> xgene-edac-pmd.c
>> xgene-edac-l3.c
>> xgene-edac-soc.c
>>
>> Or what would you suggest. There are the following HW:
>>
>> 1. 4 DDR controller with one shared top level interrupt, two shared
>> memory bridges
>
> And ECC registers are in the DDR controllers?
>

Yes... ECC registers are with each DDR controller. That's why I leave
the reg property.


> I would expect the DT to have 4 DDR controller nodes and probably 2
> bridges. The memory bridges have control registers?

Mustang DT does have 4 individual DT nodes for memory controllers. The
2 bridges are used to only determine if the memory controller is
active or not. If not, it just skips the initialization during probe.

>
>> 2. 4 CPU's domain with one shared top level interrupt, shared L2 for
>> two CPU's, and individual L1
>> 3. 1 L3 with one shared top level interrupt
>
> Presumably the registers for ECC are wired to some other block and not
> CPU registers?

Yes... The bus has dedicated 64K block for L2, L1, and L3. That's why
the reg property still there and not shared.

>
>> 4. One SoC memory parity block with one shared top level interupt
>
> Shared interrupts are easily supported, but implicit in the DT.
> Otherwise, it seems this block is independent from the rest, correct?

Interrupts are shared and the status registers are also shared. Yes...
the actual error module is independent. The shared blocks are:

1. Interrupt status (PCP block) - Needed for all subblock IP's
2. CSW, MCB A and MCB B - Needed for each individual memory controller
to determine whether it is active
3. efuse block - used to determine if an CPU domain is disabled
(non-existed in HW)

Anything else need clarification?

-Loc