dt-bindings: mfd: dlg,da9063: document voltage monitoring

Document that the da9063 only provides under- *and* over-voltage
monitoring in one, and therefore requires both to be configured with the
same severity and value. Add an example for clarification.
Signed-off-by: Benjamin Bara <benjamin.bara@skidata.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Adam Ward <DLG-Adam.Ward.opensource@dm.renesas.com>
Link: https://lore.kernel.org/r/20230403-da9063-disable-unused-v3-3-cc4dc698864c@skidata.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/mfd/dlg,da9063.yaml

@@ -12,6 +12,11 @@ maintainers:
 description: |
   For device-tree bindings of other sub-modules refer to the binding documents
   under the respective sub-system directories.
+  Using regulator-{uv,ov}-{warn,error,protection}-microvolt requires special
+  handling: First, when GP_FB2 is used, it must be ensured that there is no
+  moment where all voltage monitors are disabled. Next, as da9063 only supports
+  UV *and* OV monitoring, both must be set to the same severity and value
+  (0: disable, 1: enable).
 
 properties:
   compatible:
@@ -121,11 +126,19 @@ examples:
             regulator-max-microamp = <2000000>;
             regulator-boot-on;
           };
+          ldo6 {
+            /* UNUSED */
+            regulator-name = "LDO_6";
+            regulator-uv-protection-microvolt = <0>;
+            regulator-ov-protection-microvolt = <0>;
+          };
           ldo11 {
             regulator-name = "LDO_11";
             regulator-min-microvolt = <900000>;
-            regulator-max-microvolt = <3600000>;
-            regulator-boot-on;
+            regulator-max-microvolt = <900000>;
+            regulator-uv-protection-microvolt = <1>;
+            regulator-ov-protection-microvolt = <1>;
+            regulator-always-on;
           };
         };
       };