test-case: add lib file for test-mic-privacy

The file is added in the separate PR 1280:
#1280

Signed-off-by: Artur Wilczak <arturx.wilczak@intel.com>

Author: arikgreen

case-lib/relay.sh

@@ -0,0 +1,49 @@
+#!/bin/bash
+
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright(c) 2021-2025 Intel Corporation. All rights reserved.
+
+# needs usbrelay package: https://github.com/darrylb123/usbrelay
+# param1: --debug | switch name
+# param2: switch state
+usbrelay_switch()
+{
+    if [[ "$1" == "--debug" ]]; then
+        dlogi "Debug mode: Current status of all relays:"
+        usbrelay || {
+            die "Failed to get usbrelay status.
+            The usbrelay hw module is not responding or no relays detected.
+            Check hardware connection."
+        }
+    fi
+
+    # Declare a constant for the relay settle time
+    local USBRELAY_SETTLE_TIME=0.5
+
+    local switch_name=$1
+    local state=$2
+
+    dlogi "Setting usbrelay switch $switch_name to $state."
+    usbrelay "$switch_name=$state" --quiet || {
+        die "Failed to set usbrelay switch $switch_name to $state.
+        The usbrelay hw module is not responding or no relays detected.
+        Check hardware connection."
+    }
+
+    # wait for the switch to settle
+    sleep "$USBRELAY_SETTLE_TIME"
+
+    # Display current state of the switch
+    current_state=$(usbrelay | awk -F= -v name="$switch_name" '$1 == name { print $2 }')
+
+    # Check if current_state is equal to the requested state
+    [[ "$current_state" == "$state" ]] || {
+        die "usbrelay switch $switch_name failed to set to $state (current: $current_state)"
+    }
+
+    case "$current_state" in
+        '1') dlogi "Current state of $switch_name is: on";;
+        '0') dlogi "Current state of $switch_name is: off";;
+        *) die "Invalid state for $switch_name: $current_state";;
+    esac
+}