[PATCH 5/6] dts: sunxi: v3s: enable emac support

[Andre Przywara <andre.przywara@arm.com>]

On Wed, 19 May 2021 21:42:07 +0200
Andreas Rehn <rehn.andreas86@gmail.com> wrote:

Hi,

> h3 and v3s have internal phys and can share the same driver.
> Furthermore sun8i-v3s-emac is not available, use sun8i-h3-emac instead
> - add emac pins
> - enable emac for licheepi-zero-dock as it provides a ethernet port

So first, this is not how we handle DT changes in U-Boot. They would
need to go through the Linux tree first, then can be synced back to
U-Boot. Sorry.

Looking more into the details:

> 
> Signed-off-by: Andreas Rehn <rehn.andreas86@gmail.com>
> ---
>  arch/arm/dts/sun8i-v3s-licheepi-zero-dock.dts | 11 +++++++++++
>  arch/arm/dts/sun8i-v3s.dtsi                   | 10 +++++++++-
>  2 files changed, 20 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm/dts/sun8i-v3s-licheepi-zero-dock.dts b/arch/arm/dts/sun8i-v3s-licheepi-zero-dock.dts
> index db5cd0b857..083ac11b94 100644
> --- a/arch/arm/dts/sun8i-v3s-licheepi-zero-dock.dts
> +++ b/arch/arm/dts/sun8i-v3s-licheepi-zero-dock.dts
> @@ -49,6 +49,10 @@
>  	compatible = "licheepi,licheepi-zero-dock", "licheepi,licheepi-zero",
>  		     "allwinner,sun8i-v3s";
>  
> +	aliases {
> +		ethernet0 = &emac;
> +	};
> +
>  	leds {
>  		/* The LEDs use PG0~2 pins, which conflict with MMC1 */
>  		status = "disabled";
> @@ -94,3 +98,10 @@
>  		voltage = <800000>;
>  	};
>  };
> +
> +&emac {
> +	allwinner,leds-active-low;
> +	status = "okay";
> +	pinctrl-names = "default";
> +	pinctrl-0 = <&emac_rgmii_pins>;

I don't think this is correct. If I understand correctly, the V3s does
not expose any MAC pins, instead relies entirely on the internal PHY.
Those pins are not muxed, so don't need any pinctrl properties.

> +};
> diff --git a/arch/arm/dts/sun8i-v3s.dtsi b/arch/arm/dts/sun8i-v3s.dtsi
> index 0c73416769..35cc4d63f7 100644
> --- a/arch/arm/dts/sun8i-v3s.dtsi
> +++ b/arch/arm/dts/sun8i-v3s.dtsi
> @@ -342,6 +342,14 @@
>  				function = "csi";
>  			};
>  
> +			emac_rgmii_pins: emac-rgmii-pins {
> +				pins = "PD0", "PD1", "PD2", "PD3", "PD4",
> +					   "PD5", "PD7", "PD8", "PD9", "PD10",
> +					   "PD12", "PD13", "PD15", "PD16", "PD17";
> +				function = "emac";
> +				drive-strength = <40>;
> +			};

This is wrong (and not needed): The V3s does not expose MAC pins. If I
understand correctly, the V3 and V3s share the same die, so the pin
controller has those registers, but the whole port is connected nowhere.

>  			i2c0_pins: i2c0-pins {
>  				pins = "PB6", "PB7";
>  				function = "i2c0";
> @@ -468,7 +476,7 @@
>  		};
>  
>  		emac: ethernet at 1c30000 {
> -			compatible = "allwinner,sun8i-v3s-emac";
> +			compatible = "allwinner,sun8i-h3-emac";

You can't just change the compatible string this way, the original one
is there for a reason. In this case the difference is that the V3s does
not support Gigabit Ethernet - because the only MAC pins connected are
the internal MII ones. I believe the MAC itself could probably still
handle GBit, but it can't talk to the outside in this mode.

Instead just add the v3s compatible string to the sun8i-emac driver.
Assign a new type and add this new type wherever you see H3_EMAC, but
not in the RGMII part.

Cheers,
Andre

>  			syscon = <&syscon>;
>  			reg = <0x01c30000 0x10000>;
>  			interrupts = <GIC_SPI 82 IRQ_TYPE_LEVEL_HIGH>;