dt-bindings: net: Document support for Aeonsemi PHYs

Add Aeonsemi PHYs and the requirement of a firmware to correctly work.
Also document the max number of LEDs supported and what PHY ID expose
when no firmware is loaded.

Supported PHYs AS21011JB1, AS21011PB1, AS21010JB1, AS21010PB1,
AS21511JB1, AS21511PB1, AS21510JB1, AS21510PB1, AS21210JB1,
AS21210PB1 that all register with the PHY ID 0x7500 0x9410 on C45
registers before the firmware is loaded.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Link: https://patch.msgid.link/20250517201353.5137-7-ansuelsmth@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

2 files changed, 123 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/net/aeonsemi,as21xxx.yaml b/Documentation/devicetree/bindings/net/aeonsemi,as21xxx.yaml
new file mode 100644
index 000000000000..69eb29dc4d7b
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/aeonsemi,as21xxx.yaml
@@ -0,0 +1,122 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/aeonsemi,as21xxx.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Aeonsemi AS21XXX Ethernet PHY
+
+maintainers:
+  - Christian Marangi <ansuelsmth@gmail.com>
+
+description: |
+  Aeonsemi AS21xxx Ethernet PHYs requires a firmware to be loaded to actually
+  work. The same firmware is compatible with various PHYs of the same family.
+
+  A PHY with not firmware loaded will be exposed on the MDIO bus with ID
+  0x7500 0x7500 or 0x7500 0x9410 on C45 registers.
+
+  This can be done and is implemented by OEM in 2 different way:
+    - Attached SPI flash directly to the PHY with the firmware. The PHY
+      will self load the firmware in the presence of this configuration.
+    - Manually provided firmware loaded from a file in the filesystem.
+
+  Each PHY can support up to 5 LEDs.
+
+  AS2xxx PHY Name logic:
+
+  AS21x1xxB1
+      ^ ^^
+      | |J: Supports SyncE/PTP
+      | |P: No SyncE/PTP support
+      | 1: Supports 2nd Serdes
+      | 2: Not 2nd Serdes support
+      0: 10G, 5G, 2.5G
+      5: 5G, 2.5G
+      2: 2.5G
+
+allOf:
+  - $ref: ethernet-phy.yaml#
+
+select:
+  properties:
+    compatible:
+      contains:
+        enum:
+          - ethernet-phy-id7500.9410
+          - ethernet-phy-id7500.9402
+          - ethernet-phy-id7500.9412
+          - ethernet-phy-id7500.9422
+          - ethernet-phy-id7500.9432
+          - ethernet-phy-id7500.9442
+          - ethernet-phy-id7500.9452
+          - ethernet-phy-id7500.9462
+          - ethernet-phy-id7500.9472
+          - ethernet-phy-id7500.9482
+          - ethernet-phy-id7500.9492
+  required:
+    - compatible
+
+properties:
+  reg:
+    maxItems: 1
+
+  firmware-name:
+    description: specify the name of PHY firmware to load
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+if:
+  properties:
+    compatible:
+      contains:
+        const: ethernet-phy-id7500.9410
+then:
+  required:
+    - firmware-name
+else:
+  properties:
+    firmware-name: false
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/leds/common.h>
+
+    mdio {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        ethernet-phy@1f {
+            compatible = "ethernet-phy-id7500.9410",
+                         "ethernet-phy-ieee802.3-c45";
+
+            reg = <31>;
+            firmware-name = "as21x1x_fw.bin";
+
+            leds {
+                #address-cells = <1>;
+                #size-cells = <0>;
+
+                led@0 {
+                    reg = <0>;
+                    color = <LED_COLOR_ID_GREEN>;
+                    function = LED_FUNCTION_LAN;
+                    function-enumerator = <0>;
+                    default-state = "keep";
+                };
+
+                led@1 {
+                    reg = <1>;
+                    color = <LED_COLOR_ID_GREEN>;
+                    function = LED_FUNCTION_LAN;
+                    function-enumerator = <1>;
+                    default-state = "keep";
+                };
+            };
+        };
+    };
diff --git a/MAINTAINERS b/MAINTAINERS
index 88b878fcfd3d..b0509db13c4d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -650,6 +650,7 @@ AEONSEMI PHY DRIVER
 M:	Christian Marangi <ansuelsmth@gmail.com>
 L:	netdev@vger.kernel.org
 S:	Maintained
+F:	Documentation/devicetree/bindings/net/aeonsemi,as21xxx.yaml
 F:	drivers/net/phy/as21xxx.c
 
 AF8133J THREE-AXIS MAGNETOMETER DRIVER