Re: [PATCH v13 2/4] arm64: dts: fsl: librem5: Add a device tree for the Librem5 devkit

[Angus Ainslie]

Hi Pavel,


On 2019-05-23 12:19, Pavel Machek wrote:
> Hi!
>
> > This is for the development kit board for the Librem 5. The current 
> > level
> > of support yields a working console and is able to boot userspace from
> > the network or eMMC.
> >
> > Additional subsystems that are active :
>
> > - haptic motor
>
> Haptic motor is not a LED. It should be controlled by input subsystem.
>
> > +	pwmleds {
> > +		compatible = "pwm-leds";
> > +
> > +		haptic {
> > +			label = "librem5::haptic";
> > +			pwms = <&pwm2 0 200000>;
> > +			active-low;
> > +			max-brightness = <255>;
> > +			power-supply = <&reg_3v3_p>;
> > +		};
> > +	};
>
> You can take a look at N900, that has reasonable interface.

I wanted to control the haptic with the pwm-vibra driver but 
"fsl,imx27-pwm" doesn't seem to respect the PWM_POLARITY_INVERTED flag 
so when I start the system the vibrator is full on.

I could use gpio-vibrator but that seemed like a waste when the device 
is connected to pwm.

I figured the using the pwm-leds interface was a reasonable compromise 
until I had an opportunity to make changes the the imx27-pwm driver.

Thanks
Angus


> Thanks,
> 										Pavel