[PATCH v4 1/2] ASoC: dt-bindings: nau8821: Add DMIC slew rate.

[Seven Lee <wtli@nuvoton.com>]

Add input with DMIC slew rate controls.

Signed-off-by: Seven Lee <wtli@nuvoton.com>
---
 .../devicetree/bindings/sound/nuvoton,nau8821.yaml       | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Documentation/devicetree/bindings/sound/nuvoton,nau8821.yaml b/Documentation/devicetree/bindings/sound/nuvoton,nau8821.yaml
index 3e54abd4ca74..3380b6aa9542 100644
--- a/Documentation/devicetree/bindings/sound/nuvoton,nau8821.yaml
+++ b/Documentation/devicetree/bindings/sound/nuvoton,nau8821.yaml
@@ -89,6 +89,14 @@ properties:
     $ref: /schemas/types.yaml#/definitions/uint32
     default: 3072000
 
+  nuvoton,dmic-slew-rate:
+    description: The range 0 to 7 represents the speed of DMIC slew rate.
+        The lowest value 0 means the slowest rate and the highest value
+        7 means the fastest rate.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    maximum: 7
+    default: 0
+
   nuvoton,left-input-single-end:
     description: Enable left input with single-ended settings if set.
         For the headset mic application, the single-ended control is
@@ -127,6 +135,7 @@ examples:
             nuvoton,jack-insert-debounce = <7>;
             nuvoton,jack-eject-debounce = <0>;
             nuvoton,dmic-clk-threshold = <3072000>;
+            nuvoton,dmic-slew-rate= <0>;
             #sound-dai-cells = <0>;
         };
     };
-- 
2.25.1