linux-kernel - Re: [PATCH RESEND] ARM: dts: qcom: msm8974-hammerhead: add device tree bindings for vibrator

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Message-ID: <20190522082348.GA15793@basecamp>
Date:   Wed, 22 May 2019 04:23:48 -0400
From:   Brian Masney <masneyb@...tation.org>
To:     Stephen Boyd <sboyd@...nel.org>
Cc:     agross@...nel.org, david.brown@...aro.org,
        bjorn.andersson@...aro.org, robh+dt@...nel.org,
        mark.rutland@....com, linux-arm-msm@...r.kernel.org,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH RESEND] ARM: dts: qcom: msm8974-hammerhead: add device
 tree bindings for vibrator

Hi Stephen,

On Mon, May 20, 2019 at 07:21:49AM -0700, Stephen Boyd wrote:
> Quoting Brian Masney (2019-05-16 01:50:18)
> > @@ -306,6 +307,36 @@
> >                                 input-enable;
> >                         };
> >                 };
> > +
> > +               vibrator_pin: vibrator {
> > +                       pwm {
> > +                               pins = "gpio27";
> > +                               function = "gp1_clk";
> > +
> > +                               drive-strength = <6>;
> > +                               bias-disable;
> > +                       };
> > +
> > +                       enable {
> > +                               pins = "gpio60";
> > +                               function = "gpio";
> > +                       };
> > +               };
> > +       };
> > +
> > +       vibrator@...c3450 {
> > +               compatible = "qcom,msm8974-vibrator";
> > +               reg = <0xfd8c3450 0x400>;
> 
> This is inside the multimedia clk controller. The resource reservation
> mechanism should be complaining loudly here. Is the driver writing
> directly into clk controller registers to adjust a duty cycle of the
> camera's general purpose clk?
> 
> Can you add support for duty cycle to the qcom clk driver's RCGs and
> then write a generic clk duty cycle vibrator driver that adjusts the
> duty cycle of the clk? That would be better than reaching into the clk
> controller registers to do this.

I don't see any complaints in dmesg about this, however I'll work on a
new clk duty cycle vibrator driver.

Brian