Re: [PATCH v3 4/4] arm64: dts: rockchip: Add devicetree for Pine64 PineTab2

Manuel Traut
2024-01-26T20:36:29Z

Hello Ondřej,

On Fri, Jan 05, 2024 at 05:48:46PM +0100, Ondřej Jirman wrote:
> On Fri, Jan 05, 2024 at 05:11:03PM +0100, Manuel Traut wrote:
> > On Wed, Jan 03, 2024 at 10:42:54AM +0100, Ondřej Jirman wrote:
> > > Hello Manuel,
> > >
> > > a few more things I noticed:
> > >
> > > On Tue, Jan 02, 2024 at 05:15:47PM +0100, Manuel Traut wrote:
> > > > From: Alexander Warnecke <awarnecke002@hotmail.com>
> > > >
> > > > + leds {
> > > > + compatible = "gpio-leds";
> > > > +
> > > > + pinctrl-names = "default";
> > > > + pinctrl-0 = <&flash_led_en_h>;
> > > > +
> > > > + led-0 {
> > > > + gpios = <&gpio4 RK_PA5 GPIO_ACTIVE_HIGH>;
> > > > + color = <LED_COLOR_ID_WHITE>;
> > > > + function = LED_FUNCTION_FLASH;
> > > > + };
> > >
> > > This LED is supplied by VCC5V_MIDU, so maybe this should be a regulator-led
> > > supplied by gpio (FLASH_LED_EN_H) controlled regulator-fixed named f_led which
> > > is in turn supplied by VCC5V_MIDU.
> > >
> > > https://megous.com/dl/tmp/9bf0d85d78946b5e.png
> >
> > regulator-leds are controlled by turning on or off the regulator. However
> > VCC5V_MIDU is also used by other devices (USB, HDMI, ..) so I guess this is
> > not what we want. I would keep it as is.
>
> It's used by the LED. gpio-leds will not ensure it's on when you enable the LED.
>
> In practice this may only come up if someone tries to save power by unloading
> dwc3 USB driver, when using PT2 outside of the keyboard case. Otherwise
> VCC5V_MIDU will be enabled by DWC3 driver's use of PHY API.
>
> In any case, I'm not saying you should use VCC5V_MIDU directly in regulator-led,
> but as a vin-supply to a new regulator-fixed node (which would be describing
> this "fixed voltage regulator" https://megous.com/dl/tmp/cc65ec81ab9af163.png ).

Sorry for the late response, I was busy with other things in the last weeks.

I changed it to be a regulator led and will post a v4 soon.