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