Added hidMergeSingleJoyAsDualJoy().

nx/include/switch/services/hid.h

@@ -596,12 +596,16 @@ bool hidGetHandheldMode(void);
 /// When used, both joy-cons in a pair should be used with this (CONTROLLER_PLAYER_1 and CONTROLLER_PLAYER_2 for example).
 /// id must be CONTROLLER_PLAYER_*.
 Result hidSetNpadJoyAssignmentModeSingleByDefault(HidControllerID id);
+
 /// Use this if you want to use a pair of joy-cons as a single CONTROLLER_PLAYER_*. Only necessary if you want to use this mode in your application after \ref hidSetNpadJoyAssignmentModeSingleByDefault was used with this pair of joy-cons.
 /// Used automatically during app startup/exit for all controllers.
 /// When used, both joy-cons in a pair should be used with this (CONTROLLER_PLAYER_1 and CONTROLLER_PLAYER_2 for example).
 /// id must be CONTROLLER_PLAYER_*.
 Result hidSetNpadJoyAssignmentModeDual(HidControllerID id);
 
+/// Merge two single joy-cons into a dual-mode controller. Use this after \ref hidSetNpadJoyAssignmentModeDual, when \ref hidSetNpadJoyAssignmentModeSingleByDefault was previously used (this includes using this manually at application exit).
+Result hidMergeSingleJoyAsDualJoy(HidControllerID id0, HidControllerID id1);
+
 Result hidInitializeVibrationDevices(u32 *VibrationDeviceHandles, size_t total_handles, HidControllerID id, HidControllerType type);
 
 /// Gets HidVibrationDeviceInfo for the specified VibrationDeviceHandle.

nx/source/services/hid.c

@@ -563,6 +563,51 @@ Result hidSetNpadJoyAssignmentModeDual(HidControllerID id) {
     return rc;
 }
 
+Result hidMergeSingleJoyAsDualJoy(HidControllerID id0, HidControllerID id1) {
+    Result rc;
+    u64 AppletResourceUserId;
+
+    rc = appletGetAppletResourceUserId(&AppletResourceUserId);
+    if (R_FAILED(rc))
+        return rc;
+
+    IpcCommand c;
+    ipcInitialize(&c);
+
+    struct {
+        u64 magic;
+        u64 cmd_id;
+        u32 id0, id1;
+        u64 AppletResourceUserId;
+    } *raw;
+
+    ipcSendPid(&c);
+
+    raw = ipcPrepareHeader(&c, sizeof(*raw));
+
+    raw->magic = SFCI_MAGIC;
+    raw->cmd_id = 125;
+    raw->id0 = id0;
+    raw->id1 = id1;
+    raw->AppletResourceUserId = AppletResourceUserId;
+
+    rc = serviceIpcDispatch(&g_hidSrv);
+
+    if (R_SUCCEEDED(rc)) {
+        IpcParsedCommand r;
+        ipcParse(&r);
+
+        struct {
+            u64 magic;
+            u64 result;
+        } *resp = r.Raw;
+
+        rc = resp->result;
+    }
+
+    return rc;
+}
+
 static Result _hidCreateActiveVibrationDeviceList(Service* srv_out) {
     IpcCommand c;
     ipcInitialize(&c);