Add System API to enable / disable a logical modem.

Bug: 122926141
Test: unittest
Change-Id: Ifeb3b135ba9ecba8982a911f369fa266468d2e45

api/system-current.txt

@@ -6827,6 +6827,7 @@ package android.telephony {
     method public void dial(java.lang.String);
     method public boolean disableDataConnectivity();
     method public boolean enableDataConnectivity();
+    method public boolean enableModemForSlot(int, boolean);
     method public void enableVideoCalling(boolean);
     method public java.lang.String getAidForAppType(int);
     method public java.util.List<android.service.carrier.CarrierIdentifier> getAllowedCarriers(int);

telephony/java/android/telephony/TelephonyManager.java

@@ -9972,4 +9972,33 @@ public class TelephonyManager {
         }
         return ret;
     }
+
+    /**
+     * Enable or disable a logical modem stack. When a logical modem is disabled, the corresponding
+     * SIM will still be visible to the user but its mapping modem will not have any radio activity.
+     * For example, we will disable a modem when user or system believes the corresponding SIM
+     * is temporarily not needed (e.g. out of coverage), and will enable it back on when needed.
+     *
+     * Requires that the calling app has permission
+     * {@link android.Manifest.permission#MODIFY_PHONE_STATE MODIFY_PHONE_STATE}.
+     * @param slotIndex which corresponding modem will operate on.
+     * @param enable whether to enable or disable the modem stack.
+     * @return whether the operation is successful.
+     *
+     * @hide
+     */
+    @SystemApi
+    @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE)
+    public boolean enableModemForSlot(int slotIndex, boolean enable) {
+        boolean ret = false;
+        try {
+            ITelephony telephony = getITelephony();
+            if (telephony != null) {
+                ret = telephony.enableModemForSlot(slotIndex, enable);
+            }
+        } catch (RemoteException ex) {
+            Log.e(TAG, "enableModem RemoteException", ex);
+        }
+        return ret;
+    }
 }

telephony/java/com/android/internal/telephony/ITelephony.aidl

@@ -1787,4 +1787,9 @@ interface ITelephony {
      * Get the full emergency number list for Test Mode.
      */
     List<String> getEmergencyNumberListTestMode();
+
+    /**
+     * Enable or disable a logical modem stack associated with the slotIndex.
+     */
+    boolean enableModemForSlot(int slotIndex, boolean enable);
 }

telephony/java/com/android/internal/telephony/RILConstants.java

@@ -489,6 +489,7 @@ public interface RILConstants {
     int RIL_REQUEST_STOP_NETWORK_SCAN = 143;
     int RIL_REQUEST_START_KEEPALIVE = 144;
     int RIL_REQUEST_STOP_KEEPALIVE = 145;
+    int RIL_REQUEST_ENABLE_MODEM = 146;
 
     /* The following requests are not defined in RIL.h */
     int RIL_REQUEST_HAL_NON_RIL_BASE = 200;