dt-bindings: iio: adc: renesas,rzg2l-adc: Document RZ/G3S SoC

Document the ADC IP available on the RZ/G3S SoC. The ADC IP on the RZ/G3S
differs slightly from the one found on the RZ/G2L. The identified
differences are as follows:
- different number of channels (one being used for temperature conversion);
  consequently, various registers differ; the temperature channel
  support was not available for the RZ/G2L variant; the #io-channel-cells
  property was added to be able to request the temperature channel from
  the thermal driver
- different default sampling periods
- the RZ/G3S variant lacks the ADVIC register.

Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Link: https://patch.msgid.link/20241206111337.726244-13-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/iio/adc/renesas,rzg2l-adc.yaml

@@ -17,12 +17,15 @@ description: |
 
 properties:
   compatible:
-    items:
-      - enum:
-          - renesas,r9a07g043-adc   # RZ/G2UL and RZ/Five
-          - renesas,r9a07g044-adc   # RZ/G2L
-          - renesas,r9a07g054-adc   # RZ/V2L
-      - const: renesas,rzg2l-adc
+    oneOf:
+      - items:
+          - enum:
+              - renesas,r9a07g043-adc   # RZ/G2UL and RZ/Five
+              - renesas,r9a07g044-adc   # RZ/G2L
+              - renesas,r9a07g054-adc   # RZ/V2L
+          - const: renesas,rzg2l-adc
+      - items:
+          - const: renesas,r9a08g045-adc  # RZ/G3S
 
   reg:
     maxItems: 1
@@ -57,6 +60,9 @@ properties:
   '#size-cells':
     const: 0
 
+  "#io-channel-cells":
+    const: 1
+
 required:
   - compatible
   - reg
@@ -68,7 +74,7 @@ required:
   - reset-names
 
 patternProperties:
-  "^channel@[0-7]$":
+  "^channel@[0-8]$":
     $ref: adc.yaml
     type: object
     description: |
@@ -78,6 +84,8 @@ patternProperties:
       reg:
         description: |
           The channel number.
+        minimum: 0
+        maximum: 8
 
     required:
       - reg
@@ -92,18 +100,25 @@ allOf:
             const: renesas,r9a07g043-adc
     then:
       patternProperties:
-        "^channel@[2-7]$": false
+        "^channel@[2-8]$": false
         "^channel@[0-1]$":
           properties:
             reg:
-              minimum: 0
               maximum: 1
-    else:
+
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - renesas,r9a07g044-adc
+              - renesas,r9a07g054-adc
+    then:
       patternProperties:
+        "^channel@[8]$": false
         "^channel@[0-7]$":
           properties:
             reg:
-              minimum: 0
               maximum: 7
 
 additionalProperties: false