On 09/17/2018 09:47 AM, Wang, Dongsheng wrote:

On 9/17/2018 10:50 PM, Andrew Lunn wrote:

quoted

On Mon, Sep 17, 2018 at 04:53:29PM +0800, Wang Dongsheng wrote:

quoted

This property copy from "ibm,emac.txt" to describe a shared MIDO bus.
Since emac include MDIO, so If the motherboard has more than one PHY
connected to an MDIO bus, this property will point to the MAC device
that has the MDIO bus.

Signed-off-by: Wang Dongsheng <redacted>
---
V2: s/Since QDF2400 emac/Since emac/
---
 Documentation/devicetree/bindings/net/qcom-emac.txt | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/qcom-emac.txt b/Documentation/devicetree/bindings/net/qcom-emac.txt
index 346e6c7f47b7..50db71771358 100644
--- a/Documentation/devicetree/bindings/net/qcom-emac.txt
+++ b/Documentation/devicetree/bindings/net/qcom-emac.txt

@@ -24,6 +24,9 @@ Internal PHY node:
 The external phy child node:
 - reg : The phy address
 
+Optional properties:
+- mdio-device : Shared MIDO bus.

Hi Dongsheng

I don't see why you need this property. The ethernet interface has a
phy-handle which points to a PHY. That is all you need to find the PHY.

phy-handle is description PHY address. This property is describing an
MDIO controller.
Each QCOM emac include an MDIO controller, normally each emac only
connect one
PHY device, but when all of the PHY devices mdio lines connect one MDIO
controller
that is included in EMAC, we need to share this MDIO controller for
others EMAC.

If you want to describe the MDIO controller, then you embed a mdio
subnode into your Ethernet MAC node:

 emac0: ethernet@feb20000 {
	mdio {
		#address-cells = <1>;
		#size-cells = <0>;

		phy0: ethernet-phy@0 {
			reg = <0>;
		};
	};
};

And then each Ethernet MAC controller refers to their appropriate PHY
device tree node using a phy-handle property to point to either their
own MDIO controller, or another MAC's MDIO controller.

The IBM Emac is a old (not to say bad) example and it does not use the
PHY library and the standard Device Tree node property, please don't use
it as a reference.
-- 
Florian