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

Arnd Bergmann
2014-05-14T19:10:09Z

On Wednesday 14 May 2014 20:56:29 Sebastian Hesselbarth wrote:
> 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?

A simple bit mask would work fine, but I see your point. Doing
status="disabled" per port sounds nice.

Arnd