Re: [PATCH 07/12] arm64: dts: allwinner: orange-pi-3: Enable ethernet

["Ondřej Jirman" <megous@megous.com>]

On Mon, Apr 08, 2019 at 09:40:42AM +0200, Maxime Ripard wrote:
> On Sat, Apr 06, 2019 at 01:45:09AM +0200, megous@megous.com wrote:
> > From: Ondrej Jirman <megous@megous.com>
> >
> > Orange Pi 3 has two regulators that power the Realtek RTL8211E.
> > According to the phy datasheet, both regulators need to be enabled
> > at the same time, but we can only specify a single phy-supply in
> > the DT.
> >
> > This can be achieved by making one regulator depedning on the
> > other via vin-supply. While it's not a technically correct
> > description of the hardware, it achieves the purpose.
> >
> > All values of RX/TX delay were tested exhaustively and a middle
> > one of the working values was chosen.
> >
> > Signed-off-by: Ondrej Jirman <megous@megous.com>
> > ---
> >  .../dts/allwinner/sun50i-h6-orangepi-3.dts    | 44 +++++++++++++++++++
> >  1 file changed, 44 insertions(+)
> >
> > diff --git a/arch/arm64/boot/dts/allwinner/sun50i-h6-orangepi-3.dts b/arch/arm64/boot/dts/allwinner/sun50i-h6-orangepi-3.dts
> > index 644946749088..5270142527f5 100644
> > --- a/arch/arm64/boot/dts/allwinner/sun50i-h6-orangepi-3.dts
> > +++ b/arch/arm64/boot/dts/allwinner/sun50i-h6-orangepi-3.dts
> > @@ -15,6 +15,7 @@
> >
> >  	aliases {
> >  		serial0 = &uart0;
> > +		ethernet0 = &emac;
> >  	};
> >
> >  	chosen {
> > @@ -64,6 +65,27 @@
> >  		regulator-max-microvolt = <5000000>;
> >  		regulator-always-on;
> >  	};
> > +
> > +	/*
> > +	 * The board uses 2.5V RGMII signalling. Power sequence
> > +	 * to enable the phy is to enable GMAC-2V5 and GMAC-3V3 (aldo2)
> > +	 * power rails at the same time and to wait 100ms.
> > +	 */
> > +	reg_gmac_2v5: gmac-2v5 {
> > +                compatible = "regulator-fixed";
> > +                regulator-name = "gmac-2v5";
> > +                regulator-min-microvolt = <2500000>;
> > +                regulator-max-microvolt = <2500000>;
> > +                startup-delay-us = <100000>;
> > +                enable-active-high;
> > +                gpio = <&pio 3 6 GPIO_ACTIVE_HIGH>; /* PD6 */
> 
> Is enable-active-high still needed? It's redundant with the
> GPIO_ACTIVE_HIGH flag.

Looking at the code, use/non-use of enable-active-high inhibits
flags specified in gpio property. So the GPIO_ACTIVE_HIGH flag
is ignored here (had GPIO_ACTIVE_LOW been used, the kernel would
ignore it too and print a warning).

So enable-active-high is still necessary here.

See comment in gpiolib-of.c where this is handled:

/*
 * The regulator GPIO handles are specified such that the
 * presence or absence of "enable-active-high" solely controls
 * the polarity of the GPIO line. Any phandle flags must
 * be actively ignored.
 */

regards,
	o.

> The indentation is wrong here as well.
> 
> Maxime
> 
> --
> Maxime Ripard, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com