The EcoNet EN751221 MIPS SoC integrates an MT7530 switch memory-mapped
in the SoC register space. It is similar to the econet,en7528-switch
except that ports 0..3 are 10/100 only, port 4 has a gigabit PHY, and
port 5 has no PHY, but is in some implementations connected to a
downstream MT7530 multi-chip module via a TRGMII link.

The downstream MT7530 is similar to the MT7621 multi-chip module and
has all gigabit ports.

Add the econet,en751221-switch compatible with the same constraints as
the other built-in switches and also add the econet,en751221
multi-chip-module switch whose port 6 is configured as a DSA link port.

Signed-off-by: Caleb James DeLisle <cjd@cjdns.fr>
---
 .../bindings/net/dsa/mediatek,mt7530.yaml     | 43 ++++++++++++++++++-
 1 file changed, 41 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/dsa/mediatek,mt7530.yaml b/Documentation/devicetree/bindings/net/dsa/mediatek,mt7530.yaml
index e29fb8693498..106c4087528d 100644
--- a/Documentation/devicetree/bindings/net/dsa/mediatek,mt7530.yaml
+++ b/Documentation/devicetree/bindings/net/dsa/mediatek,mt7530.yaml
@@ -29,6 +29,12 @@ description: |
   and the switch registers are directly mapped into SoC's memory map rather than
   using MDIO. The DSA driver currently doesn't support MT7620 variants.
 
+  EcoNet EN751221 SoCs have a memory mapped MT7530 with 3x 10/100 PHYs and 1x
+  gigabit PHY. Some EN751221 chips such as EN7513G and EN7526G have a multi-chip
+  module implementation of the MT7530 as well as the on-die switch. In these
+  packages, the multi-chip module is connected to port 5 of the on-die switch
+  via a TRGMII link.
+
   There is only the standalone version of MT7531.
 
   Port 5 on MT7530 supports various configurations:
@@ -111,6 +117,14 @@ properties:
           Built-in switch of the EcoNet EN7528 SoC
         const: econet,en7528-switch
 
+      - description:
+          Built-in switch of EcoNet EN751221 SoC
+        const: econet,en751221-switch
+
+      - description:
+          Multi-chip module MT7530 in EN751221 SoC
+        const: econet,en751221
+
   reg:
     maxItems: 1
 
@@ -160,8 +174,8 @@ properties:
   mediatek,mcm:
     type: boolean
     description:
-      Used for MT7621AT, MT7621DAT, MT7621ST and MT7623AI SoCs which the MT7530
-      switch is a part of the multi-chip module.
+      Used for MT7621AT, MT7621DAT, MT7621ST, MT7623AI and EN751221 SoCs which
+      the MT7530 switch is a part of the multi-chip module.
 
   reset-gpios:
     description: |
@@ -223,6 +237,20 @@ $defs:
                 phy-mode:
                   const: internal
 
+  mt7530-passthrough-dsa-port:
+    patternProperties:
+      "^(ethernet-)?ports$":
+        patternProperties:
+          "^(ethernet-)?port@[0-6]$":
+            if:
+              required: [ link ]
+            then:
+              properties:
+                reg:
+                  const: 6
+                phy-mode:
+                  const: trgmii
+
   mt7530-dsa-port:
     patternProperties:
       "^(ethernet-)?ports$":
@@ -330,6 +358,7 @@ allOf:
             - airoha,en7581-switch
             - airoha,an7583-switch
             - econet,en7528-switch
+            - econet,en751221-switch
     then:
       $ref: "#/$defs/builtin-dsa-port"
       properties:
@@ -337,6 +366,16 @@ allOf:
         mediatek,mcm: false
         reset-names: false
 
+  - if:
+      properties:
+        compatible:
+          enum:
+            - econet,en751221
+    then:
+      $ref: "#/$defs/mt7530-passthrough-dsa-port"
+      required:
+        - mediatek,mcm
+
 unevaluatedProperties: false
 
 examples:
-- 
2.39.5