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From:   Linus Walleij <linus.walleij@linaro.org>
Date:   Thu, 15 Aug 2019 10:22:45 +0200
Message-ID: <CACRpkdYdQa+FVfpSjLi0SsBMDT4QC667z1P1dnapz7PXgRoB5Q@mail.gmail.com>
Subject: Re: [PATCH RFC 06/11] drm/bridge: analogix-anx78xx: add support for
 avdd33 regulator
To:     Brian Masney <masneyb@onstation.org>
Cc:     Bjorn Andersson <bjorn.andersson@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Andy Gross <agross@kernel.org>,
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        Dave Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Mark Rutland <mark.rutland@arm.com>,
        Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
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        Jernej Skrabec <jernej.skrabec@siol.net>,
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On Thu, Aug 15, 2019 at 2:49 AM Brian Masney <masneyb@onstation.org> wrote:

> Add support for the avdd33 regulator to the analogix-anx78xx driver.
> Note that the regulator is currently enabled during driver probe and
> disabled when the driver is removed. This is currently how the
> downstream MSM kernel sources do this.
>
> Let's not merge this upstream for the mean time until I get the external
> display fully working on the Nexus 5 and then I can submit proper
> support then that powers down this regulator in the power off function.
>
> Signed-off-by: Brian Masney <masneyb@onstation.org>

> +static void anx78xx_disable_regulator_action(void *_data)
> +{
> +       struct anx78xx_platform_data *pdata = _data;
> +
> +       regulator_disable(pdata->avdd33);
> +}
(...)
> +       err = devm_add_action(dev, anx78xx_disable_regulator_action,
> +                             pdata);

Clever idea. Good for initial support, probably later on it would
need to be reworked using runtime PM so it's not constantly
powered up.

See for example how I try to push down power dissipation
of sensors in 3d838118c6aa.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij