Input: xpad - Poweroff XBOX360W on mode button long press

Newer gamepads turn themselves off when the mode button is held down.
For XBOX360W gamepads we must do this this in the driver.

xpad.c

@@ -603,11 +603,13 @@ struct usb_xpad {
 	int pad_nr;			/* the order x360 pads were attached */
 	const char *name;		/* name of the device */
 	struct work_struct work;	/* init/remove device from callback */
+	time64_t mode_btn_down_ts;
 };
 
 static int xpad_init_input(struct usb_xpad *xpad);
 static void xpad_deinit_input(struct usb_xpad *xpad);
 static void xpadone_ack_mode_report(struct usb_xpad *xpad, u8 seq_num);
+static void xpad360w_poweroff_controller(struct usb_xpad *xpad);
 
 /*
  *	xpad_process_packet
@@ -759,6 +761,23 @@ static void xpad360_process_packet(struct usb_xpad *xpad, struct input_dev *dev,
 	}
 
 	input_sync(dev);
+
+	/* XBOX360W controllers can't be turned off without driver assistance */
+	if (xpad->xtype == XTYPE_XBOX360W) {
+		if (xpad->mode_btn_down_ts > 0
+		&& xpad->pad_present
+		&& (ktime_get_seconds() - xpad->mode_btn_down_ts) >= 5) {
+			xpad360w_poweroff_controller(xpad);
+			xpad->mode_btn_down_ts = 0;
+			return;
+		}
+
+		/* mode button down/up */
+		if (data[3] & 0x04)
+			xpad->mode_btn_down_ts = ktime_get_seconds();
+		else
+			xpad->mode_btn_down_ts = 0;
+	}
 }
 
 static void xpad_presence_work(struct work_struct *work)