Re: [PATCH v2 2/2] sh_eth: add device tree support

[Stephen Warren <swarren@wwwdotorg.org>]

On 09/10/2013 12:01 PM, Sergei Shtylyov wrote:
> Hello.
> 
> On 09/10/2013 07:15 PM, Stephen Warren wrote:
> 
>>>> Do you need any clocks properties, IP block reset signals, power
>>>> domains?
> 
>>>     Currently not.
> 
>> What does "currently" mean? Does that mean that the Linux driver simply
>> doesn't touch those entities at present?
> 
>    There's Ether clock but the driver doesn't manipulate it directly,
> assumingly it does this thru the runtime PM interface. As for the
> others, I simply don't know.

If there's a clock, it should be represented in DT, even if the kernel
somehow gets access to the clock through some means other than parsing DT.

>> If so, that's not enough to say
>> that those entities should not be described in the DT binding. We should
>> strive to make the binding completely describe all aspects of the HW,
>> irrespective of whether a particular driver happens to use that
>> information at present.
> 
>    There's no DT representation for the clocks in SH-Mobile subarch yet.
> The same applies to the other entities you mentioned.

You can still write the binding to say that the appropriate clock
property must be present; the overall format of this property won't be
affected by the representation chosen for the SH-Mobile clocks.

It seems like it'd be best to get the basic resources (like clocks)
represented in DT before trying to build blocks that use them.