[PATCH RFC 4/6] dt-bindings: rtc: isl1208: Document built-in RTC device on PMIC RAA215300

[Biju Das <biju.das.jz@xxxxxxxxxxxxxx>]

The Built-in RTC device found on PMIC RAA215300 is similar to the isl1208
IP. However, RTC is enabled by PMIC RAA215300 and the polarity of the
external oscillator is determined by the PMIC revision.

Document renesas,raa215300-isl1208 compatible and renesas,raa215300-pmic
property to handle these differences.

Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
---
 .../devicetree/bindings/rtc/isil,isl1208.yaml       | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/Documentation/devicetree/bindings/rtc/isil,isl1208.yaml b/Documentation/devicetree/bindings/rtc/isil,isl1208.yaml
index 04d51887855f..888a832ed1db 100644
--- a/Documentation/devicetree/bindings/rtc/isil,isl1208.yaml
+++ b/Documentation/devicetree/bindings/rtc/isil,isl1208.yaml
@@ -18,6 +18,7 @@ properties:
           - isil,isl1209
           - isil,isl1218
           - isil,isl1219
+          - renesas,raa215300-isl1208
 
   reg:
     maxItems: 1
@@ -40,6 +41,10 @@ properties:
         <0> : Enable internal pull-up
         <1> : Disable internal pull-up
 
+  renesas,raa215300-pmic:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description: phandle to the pmic device with isl1208 built-in RTC.
+
 required:
   - compatible
   - reg
@@ -58,6 +63,14 @@ allOf:
         - interrupts-extended
         - interrupt-names
         - isil,ev-evienb
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: renesas,raa215300-isl1208
+    then:
+      required:
+        - renesas,raa215300-pmic
 
 unevaluatedProperties: false
 
-- 
2.25.1