topology2: dmic-generic: add switch for LED control

Add a switch to gain widget for LED control purpose.

Signed-off-by: Brent Lu <[email protected]>

tools/topology/topology2/include/components/gain.conf

@@ -152,6 +152,31 @@ Class.Widget."gain" {
 				}
 			}
 		}
+
+		# mute switch control
+		mixer."2" {
+			## Channel register and shift for Front Left/Right
+			Object.Base.channel.1 {
+				name "fl"
+				reg	2
+				shift	0
+			}
+			Object.Base.channel.2 {
+				name "fr"
+				reg	2
+			}
+
+			Object.Base.ops.1 {
+				name	"ctl"
+				info 	"volsw"
+				## get = 259 binds the mixer control to switch get/put handlers
+				get 	259
+				put 	259
+			}
+
+			#max 1 indicates switch type control
+			max 1
+		}
 	}
 
 	# Default attribute values for gain widget

tools/topology/topology2/platform/intel/dmic-generic.conf

@@ -142,6 +142,12 @@ IncludeByKey.PASSTHROUGH {
 					Object.Control.mixer.1 {
 						name '$DMIC0_PCM_NAME Capture Volume'
 					}
+					Object.Control.mixer.2 {
+						name '$DMIC0_PCM_NAME Capture Switch'
+
+						mute_led_use 		1
+						mute_led_direction	1
+					}
 				}
 
 				Object.Widget.module-copier."2" {