ASoC: cs35l41: Document CS35l41 External Boost

Document internal and external boost feature for ASoC CS35L41.
For internal boost the following properties are required:
- cirrus,boost-peak-milliamp
- cirrus,boost-ind-nanohenry
- cirrus,boost-cap-microfarad

For external boost, the GPIO1 must be configured as output,
so the following properties are required:
- cirrus,gpio1-src-select = <1>
- cirrus,gpio1-output-enable

Signed-off-by: David Rhodes <drhodes@opensource.cirrus.com>
Signed-off-by: Lucas Tanure <tanureal@opensource.cirrus.com>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220413083728.10730-16-tanureal@opensource.cirrus.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Documentation/devicetree/bindings/sound/cirrus,cs35l41.yaml

@@ -75,6 +75,19 @@ properties:
     maximum: 3
     default: 2
 
+  cirrus,boost-type:
+    description:
+      Configures the type of Boost being used.
+      Internal boost requires boost-peak-milliamp, boost-ind-nanohenry and
+      boost-cap-microfarad.
+      External Boost must have GPIO1 as GPIO output. GPIO1 will be set high to
+      enable boost voltage.
+      0 = Internal Boost
+      1 = External Boost
+    $ref: "/schemas/types.yaml#/definitions/uint32"
+    minimum: 0
+    maximum: 1
+
   cirrus,gpio1-polarity-invert:
     description:
       Boolean which specifies whether the GPIO1
@@ -131,9 +144,32 @@ required:
   - compatible
   - reg
   - "#sound-dai-cells"
-  - cirrus,boost-peak-milliamp
-  - cirrus,boost-ind-nanohenry
-  - cirrus,boost-cap-microfarad
+
+allOf:
+  - if:
+      properties:
+        cirrus,boost-type:
+          const: 0
+    then:
+      required:
+        - cirrus,boost-peak-milliamp
+        - cirrus,boost-ind-nanohenry
+        - cirrus,boost-cap-microfarad
+    else:
+      if:
+        properties:
+          cirrus,boost-type:
+            const: 1
+      then:
+        required:
+          - cirrus,gpio1-output-enable
+          - cirrus,gpio1-src-select
+        properties:
+          cirrus,boost-peak-milliamp: false
+          cirrus,boost-ind-nanohenry: false
+          cirrus,boost-cap-microfarad: false
+          cirrus,gpio1-src-select:
+            enum: [1]
 
 additionalProperties: false
 
@@ -150,6 +186,8 @@ examples:
           VA-supply = <&dummy_vreg>;
           VP-supply = <&dummy_vreg>;
           reset-gpios = <&gpio 110 0>;
+
+          cirrus,boost-type = <0>;
           cirrus,boost-peak-milliamp = <4500>;
           cirrus,boost-ind-nanohenry = <1000>;
           cirrus,boost-cap-microfarad = <15>;