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Date: Wed, 25 Mar 2015 15:49:21 -0700
From: Dmitry Torokhov <dtor@google.com>
To: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Arun Ramamurthy <arun.ramamurthy@broadcom.com>,
        Rob Herring <robh+dt@kernel.org>, Pawel Moll <pawel.moll@arm.com>,
        Mark Rutland <mark.rutland@arm.com>,
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        Anatol Pomazau <anatol@google.com>,
        Jonathan Richardson <jonathar@broadcom.com>,
        Scott Branden <sbranden@broadcom.com>, Ray Jui <rjui@broadcom.com>
Subject: Re: [PATCH v1 1/3] phy: phy-core: allow specifying supply at port
 level
Message-ID: <20150325224921.GB16950@dtor-ws>
References: <1426886727-537-1-git-send-email-arun.ramamurthy@broadcom.com>
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On Thu, Mar 26, 2015 at 04:09:23AM +0530, Kishon Vijay Abraham I wrote:
> Hi,
> 
> On Thursday 26 March 2015 03:47 AM, Dmitry Torokhov wrote:
> > On Wed, Mar 25, 2015 at 3:11 PM, Kishon Vijay Abraham I <kishon@ti.com> wrote:
> >> Hi,
> >>
> >> On Saturday 21 March 2015 02:55 AM, Arun Ramamurthy wrote:
> >>> Multi-port phy's may have per-port power supplies. Let's change phy core
> >>> to first attempt to look up the supply at the port level, and then, if
> >>> not found, check parent device.
> >>
> >> Why not just have every port provide the power supply if it needs?
> >> I don't think checking for parent device should be present in the phy-core at
> >> all.
> > 
> > We need to do that if we want to keep compatibility with the current
> > DTSes: before this patch the supply would be always looked up on
> > device and not port level.
> 
> ah okay.
> so just using regulator_get_optional(&phy->dev, "phy"); should be sufficient

This is for regulators specified at port level (&phy->dev represents
port).

> right? Why do we need regulator_get_optional(phy->dev.parent, "phy");?
> 

This is for compatibility with old multi-port bindings where supply is
specified at parent device level and phy_create() is called with dev and
node that is not NULL and not the same as dev->of_node. I have no idea
if such bindings exist in wild, but wanted to keep them working given
stated DT stability rules.

Thanks.

-- 
Dmitry