[PATCH v3 1/6] phy: add a driver for the Berlin SATA PHY

Sebastian Hesselbarth sebastian.hesselbarth at gmail.com
Wed May 14 11:56:29 PDT 2014


On 05/14/2014 08:51 PM, Arnd Bergmann wrote:
> On Wednesday 14 May 2014 20:42:16 Sebastian Hesselbarth wrote:
>>>> For the driver, Antoine then would have to squeeze all PHY register
>>>> mangling in phy-berlin2.c and see how to make ahci-platform aware of
>>>> individual port nodes (I haven't looked up if it already exists, sorry)
>>>> and announce only enabled port child nodes, right?
>>>
>>> I've been thinking some more about this aspect. I don't actually have
>>> a strong opinion on whether it's better to use the generic ahci-platform
>>> driver, or to keep the multi-phy support as a special variant for
>>> berlin. If we do the latter, it would however be good to define the
>>> binding in a way that lets us later merge things into the generic phy
>>> driver in case we get more of the same.
>>
>> Hmm, IMHO multi-phy support is orthogonal to ahci-platform, isn't it?
>> ahci-platform needs to know about the phy property and calls some
>> helper that deals with the phy-specifier?
>>
>> About a generic _phy_ driver, I am not so sure if berlin is the best
>> template right now 
>>
>> So, my call would be:
>> - make ahci-platform aware of port sub-nodes and phy properties
>> - have a berlin specific PHY driver
> 
> I'm not sure if we need sub-nodes per port, it should be enough
> to have an array of phys, plus a way to match them up with the
> ports.

Actually, I'd love to see sub-nodes per port as it will allow to
disabled unused ports on a per-board basis.

I have this in mind for a long time for Kirkwood's SATA node already:
Consider a board where you have the one available SATA plug connected
to port 1. How would that work out with status = "disabled"/"okay" that
doesn't allow array of strings obviously?

Sebastian




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