linux-kernel - Re: Should regulator core support parsing OF based fwnode?

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Message-ID: <20191004174233.GF4866@sirena.co.uk>
Date:   Fri, 4 Oct 2019 18:42:33 +0100
From:   Mark Brown <broonie@...nel.org>
To:     Jean-Jacques Hiblot <jjhiblot@...com>
Cc:     mark.rutland@....com, daniel.thompson@...aro.org,
        Liam Girdwood <lgirdwood@...il.com>, tomi.valkeinen@...com,
        Sebastian Reichel <sebastian.reichel@...labora.com>,
        dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
        robh+dt@...nel.org, Jacek Anaszewski <jacek.anaszewski@...il.com>,
        pavel@....cz, lee.jones@...aro.org, linux-leds@...r.kernel.org,
        dmurphy@...com
Subject: Re: Should regulator core support parsing OF based fwnode?

On Fri, Oct 04, 2019 at 06:12:52PM +0200, Jean-Jacques Hiblot wrote:
> On 04/10/2019 17:58, Mark Brown wrote:

> > Regulator supplies are supposed to be defined at the chip level rather
> > than subfunctions with names corresponding to the names on the chip.

...

> > good chance that they come up with the same mapping.  The supply_alias
> > interface is there to allow mapping these through to subfunctions if
> > needed, it looks like the LED framework should be using this.

> In case of current-sink LED drivers, each LED can be powered by a different
> regulator, because the driver is only a switch between the LED cathod and
> the ground.

Sure, it's common for devices to have supplies that are only needed by
one part of the chip which is why we have the supply_alias interface for
mapping things through.

> > That said if you are doing the above and the LEDs are appearing as
> > devices it's extremely surprising that their of_node might not be
> > initialized.

> That is because this is usually done by the platform core which is not
> involved here.

The surprise is more that it got instantiated from the DT without
keeping the node around than how it happened.

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