[PATCH net-next RFC v2 6/6] dt-bindings: net: Introduce the phy-port description

[Maxime Chevallier <maxime.chevallier@bootlin.com>]

The ability to describe the physical ports of Ethernet devices is useful
to describe multi-port devices, as well as to remove any ambiguity with
regard to the nature of the port.

Moreover, describing ports allows for a better description of features
that are tied to connectors, such as PoE through the PSE-PD devices.

Introduce a binding to allow describing the ports, for now with 2
attributes :

 - The number of lanes, which is a quite generic property that allows
   differentating between multiple similar technologies such as BaseT1
   and "regular" BaseT (which usually means BaseT4).

 - The media that can be used on that port, such as BaseT for Twisted
   Copper, BaseC for coax copper, BaseS/L for Fiber, BaseK for backplane
   ethernet, etc. This allows defining the nature of the port, and
   therefore avoids the need for vendor-specific properties such as
   "micrel,fiber-mode" or "ti,fiber-mode".

The port description lives in its own file, as it is intended in the
future to allow describing the ports for phy-less devices.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
RFC V2: New patch

 .../devicetree/bindings/net/ethernet-phy.yaml | 18 +++++++
 .../bindings/net/ethernet-port.yaml           | 47 +++++++++++++++++++
 2 files changed, 65 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/ethernet-port.yaml

diff --git a/Documentation/devicetree/bindings/net/ethernet-phy.yaml b/Documentation/devicetree/bindings/net/ethernet-phy.yaml
index 2c71454ae8e3..950fdacfd27d 100644
--- a/Documentation/devicetree/bindings/net/ethernet-phy.yaml
+++ b/Documentation/devicetree/bindings/net/ethernet-phy.yaml
@@ -261,6 +261,17 @@ properties:
 
     additionalProperties: false
 
+  mdi:
+    type: object
+
+    patternProperties:
+      '^port-[a-f0-9]+$':
+        $ref: /schemas/net/ethernet-port.yaml#
+
+        unevaluatedProperties: false
+
+    additionalProperties: false
+
 required:
   - reg
 
@@ -297,5 +308,12 @@ examples:
                     default-state = "keep";
                 };
             };
+
+            mdi {
+              port-0 {
+                lanes = <2>;
+                media = "BaseT";
+              };
+            };
         };
     };
diff --git a/Documentation/devicetree/bindings/net/ethernet-port.yaml b/Documentation/devicetree/bindings/net/ethernet-port.yaml
new file mode 100644
index 000000000000..bf0f64f1b0aa
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/ethernet-port.yaml
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/ethernet-port.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Generic Ethernet Port
+
+maintainers:
+  - Maxime Chevallier <maxime.chevallier@bootlin.com>
+
+description:
+  An Ethernet port represents an output, such as a connector, of a network
+  component such as a PHY, an Ethernet controller with no PHY, or an SFP module.
+
+properties:
+
+  lanes:
+    description:
+      Defines the number of lanes on the port, that is the number of physical
+      channels used to convey the data with the link partner.
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  media:
+    description:
+      The mediums, as defined in 802.3, that can be used on the port.
+    items:
+      enum:
+        - BaseT
+        - BaseK
+        - BaseS
+        - BaseC
+        - BaseL
+        - BaseD
+        - BaseE
+        - BaseF
+        - BaseV
+        - BaseMLD
+        - BaseX
+
+required:
+  - lanes
+  - media
+
+additionalProperties: true
+
+...
-- 
2.48.1