linux-kernel - Re: [PATCH v3 2/2] regulator: pwm: Prevent falling too fast

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Date:   Thu, 1 Sep 2016 20:51:06 +0100
From:   Mark Brown <broonie@...nel.org>
To:     Douglas Anderson <dianders@...omium.org>
Cc:     lgirdwood@...il.com, mka@...omium.org, briannorris@...omium.org,
        javier@...hile0.org, linux-rockchip@...ts.infradead.org,
        robh+dt@...nel.org, mark.rutland@....com,
        linux-kernel@...r.kernel.org, devicetree@...r.kernel.org
Subject: Re: [PATCH v3 2/2] regulator: pwm: Prevent falling too fast

On Tue, Aug 30, 2016 at 09:21:16PM -0700, Douglas Anderson wrote:

> In this patch we actually block returning from the set_voltage() call
> until we've finished delaying.  A future patch atop this one might
> choose to return more immediately and let the voltages fall in the
> background.  That would possibly to allow us to cancel a slow downward
> decay if there was a request to go back up.

We already have mechanisms in the core for drivers to tell the core how
long a ramp they need for a given voltage transition - you should extend
them (probably needs a set_voltage_time() operation adding) so that
anything like this can be done in the core rather than open coded in
drivers.

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