[PATCH 2/9] dt-bindings: memory: mediatek: Add mt8195 smi sub common

[Yong Wu <yong.wu@mediatek.com>]

This patch adds the binding for smi-sub-common. The SMI block diagram
like this:

        IOMMU
         |  |
      smi-common
  ------------------
  |      ....      |
 larb0           larb7   <-max is 8

The smi-common connects with smi-larb and IOMMU. The maximum larbs number
that connects with a smi-common is 8. If the engines number is over 8,
sometimes we use a smi-sub-common which is nearly same with smi-common.
It supports up to 8 input and 1 output(smi-common has 2 output)

Something like:

        IOMMU
         |  |
      smi-common
  ---------------------
  |      |          ...
larb0  sub-common   ...   <-max is 8
      -----------
       |    |    ...   <-max is 8 too.
     larb2 larb5

We don't need extra SW setting for smi-sub-common, only the sub-common has
special clocks need to enable when the engines access dram.

If it is sub-common, it should have a "mediatek,smi" phandle to point to
its smi-common. also, the sub-common only has one gals clock.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
 .../mediatek,smi-common.yaml                  | 25 +++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/Documentation/devicetree/bindings/memory-controllers/mediatek,smi-common.yaml b/Documentation/devicetree/bindings/memory-controllers/mediatek,smi-common.yaml
index 6317025bd203..11515afdfb2e 100644
--- a/Documentation/devicetree/bindings/memory-controllers/mediatek,smi-common.yaml
+++ b/Documentation/devicetree/bindings/memory-controllers/mediatek,smi-common.yaml
@@ -38,6 +38,7 @@ properties:
           - mediatek,mt8192-smi-common
           - mediatek,mt8195-smi-common-vdo
           - mediatek,mt8195-smi-common-vpp
+          - mediatek,mt8195-smi-sub-common
 
       - description: for mt7623
         items:
@@ -69,6 +70,10 @@ properties:
     minItems: 2
     maxItems: 4
 
+  mediatek,smi:
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    description: a phandle to the smi-common node above. Only for sub-common.
+
 required:
   - compatible
   - reg
@@ -95,6 +100,26 @@ allOf:
             - const: smi
             - const: async
 
+  - if:  # only for sub common
+      properties:
+        compatible:
+          contains:
+            enum:
+              - mediatek,mt8195-smi-sub-common
+    then:
+      required:
+        - mediatek,smi
+      properties:
+        clock:
+          items:
+            minItems: 3
+            maxItems: 3
+        clock-names:
+          items:
+            - const: apb
+            - const: smi
+            - const: gals0
+
   - if:  # for gen2 HW that have gals
       properties:
         compatible:
-- 
2.18.0