Re: [PATCH 5/10] dt: bindings: Add bindings for Marvell Xenon SD Host Controller

From: Marcin Wojtas
Date: Thu Nov 24 2016 - 04:49:30 EST


Hi Gregory,

2016-11-24 10:44 GMT+01:00 Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>:
> Hi Arnd,
>
> On jeu., nov. 24 2016, Arnd Bergmann <arnd@xxxxxxxx> wrote:
>
>> On Thursday, November 24, 2016 10:22:31 AM CET Gregory CLEMENT wrote:
>>>
>>> I don't have an option for mmc in general, but using child node do not
>>> fit at all the xenon controller.
>>>
>>> For this controller each slot has its own set of register, so there is
>>> no common ressource to share so no advantage to use it. Using child node
>>> in our case will just make the code more complex for no benefit.
>>
>> If every slot has its own registers, what is it that makes up the
>> 'controller'? It sounds to me that you just have to adjust the terminology
>> and talk about multiple controllers then, with one slot per controller.
>>
>
> I agree and actually there were some words about in at the begining of
> the binding:
>
> "A single Xenon IP can support multiple slots.
> Each slot acts as an independent SDHC. It owns independent resources, such
> as register sets clock and PHY.
> Each slot should have an independent device tree node."
>
> All the confusion came from the fact that we still need to identify a
> slot ID. For an obscure reason the hardware can't guess the slot ID from
> the address register."
>

How about to avoid confusion, by simply renaming this number to
port-id/xenon-id or anything else but slot? I guess this may allow to
avoid some misunderstandings.

Best regards,
Marcin