dt-bindings: mmc: sdhci-of-dwcmhsc: Add Sophgo SG2042 support

SG2042 use Synopsys dwcnshc IP for SD/eMMC controllers.

SG2042 defines 3 clocks for SD/eMMC controllers.
- EMMC_100M/SD_100M for cclk(Card clocks in DWC_mshc), so reuse
  existing "core".
- AXI_EMMC/AXI_SD for aclk/hclk(Bus interface clocks in DWC_mshc)
  and blck(Core Base Clock in DWC_mshc), these 3 clocks share one
  source, so reuse existing "bus".
- 100K_EMMC/100K_SD for cqetmclk(Timer clocks in DWC_mshc), so reuse
  existing "timer" which was added for rockchip specified.

Signed-off-by: Chen Wang <unicorn_wang@outlook.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/9ca450097e5389a38bcd7d8ddf863766df4cea10.1722847198.git.unicorn_wang@outlook.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Documentation/devicetree/bindings/mmc/snps,dwcmshc-sdhci.yaml

@@ -10,9 +10,6 @@ maintainers:
   - Ulf Hansson <ulf.hansson@linaro.org>
   - Jisheng Zhang <Jisheng.Zhang@synaptics.com>
 
-allOf:
-  - $ref: mmc-controller.yaml#
-
 properties:
   compatible:
     enum:
@@ -21,6 +18,7 @@ properties:
       - snps,dwcmshc-sdhci
       - sophgo,cv1800b-dwcmshc
       - sophgo,sg2002-dwcmshc
+      - sophgo,sg2042-dwcmshc
       - thead,th1520-dwcmshc
 
   reg:
@@ -31,22 +29,11 @@ properties:
 
   clocks:
     minItems: 1
-    items:
-      - description: core clock
-      - description: bus clock for optional
-      - description: axi clock for rockchip specified
-      - description: block clock for rockchip specified
-      - description: timer clock for rockchip specified
-
+    maxItems: 5
 
   clock-names:
     minItems: 1
-    items:
-      - const: core
-      - const: bus
-      - const: axi
-      - const: block
-      - const: timer
+    maxItems: 5
 
   resets:
     maxItems: 5
@@ -63,7 +50,6 @@ properties:
     description: Specify the number of delay for tx sampling.
     $ref: /schemas/types.yaml#/definitions/uint8
 
-
 required:
   - compatible
   - reg
@@ -71,6 +57,46 @@ required:
   - clocks
   - clock-names
 
+allOf:
+  - $ref: mmc-controller.yaml#
+
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: sophgo,sg2042-dwcmshc
+
+    then:
+      properties:
+        clocks:
+          items:
+            - description: core clock
+            - description: bus clock
+            - description: timer clock
+        clock-names:
+          items:
+            - const: core
+            - const: bus
+            - const: timer
+    else:
+      properties:
+        clocks:
+          minItems: 1
+          items:
+            - description: core clock
+            - description: bus clock for optional
+            - description: axi clock for rockchip specified
+            - description: block clock for rockchip specified
+            - description: timer clock for rockchip specified
+        clock-names:
+          minItems: 1
+          items:
+            - const: core
+            - const: bus
+            - const: axi
+            - const: block
+            - const: timer
+
 unevaluatedProperties: false
 
 examples: