Re: [PATCH v4 13/18] arm64: allwinner: sun50i-a64: add dwmac-sun8i Ethernet driver

On Mon, Apr 24, 2017 at 8:24 PM, Corentin Labbe
[off-list ref] wrote:

On Wed, Apr 12, 2017 at 02:41:53PM +0200, Maxime Ripard wrote:

quoted

On Wed, Apr 12, 2017 at 01:13:55PM +0200, Corentin Labbe wrote:

quoted

The dwmac-sun8i is an Ethernet MAC that supports 10/100/1000 Mbit
connections. It is very similar to the device found in the Allwinner
H3, but lacks the internal 100 Mbit PHY and its associated control
bits.
This adds the necessary bits to the Allwinner A64 SoC .dtsi, but keeps
it disabled at this level.

Signed-off-by: Corentin Labbe <redacted>
---
 arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi | 37 +++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi b/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
index 0b0f4ab..2569827 100644
--- a/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
+++ b/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi

@@ -287,6 +287,23 @@
                            bias-pull-up;
                    };

+                   rmii_pins: rmii_pins {
+                           pins = "PD10", "PD11", "PD13", "PD14",
+                                           "PD17", "PD18", "PD19", "PD20",
+                                           "PD22", "PD23";

Please align the wrapped lines on the first pin.

OK

quoted

quoted

+                           function = "emac";
+                           drive-strength = <40>;

Do you actually need that for all the boards, or only a few of them?

I have tried to use lower value without success on some boards. (opipc/pine64 in my memory)

FYI we need them for all the boards that use RGMII.
The signals at gigabit speed run at 125 MHz DDR.

For RMII we probably don't need it. Even at 100 Mbps,
it's only 50 MHz SDR. drive-strength = <30> should be
enough.

ChenYu