usb: dwc2: Add exit clock gating before removing driver

When dwc2 core is in clock gating mode loading driver
again causes driver fail. Because in that mode
registers are not accessible.

Added a flow of exiting clock gating mode
to avoid the driver reload failure.
Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com>
Link: https://lore.kernel.org/r/20210413073731.3C81BA022E@mailhost.synopsys.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/dwc2/platform.c

@@ -326,6 +326,15 @@ static int dwc2_driver_remove(struct platform_device *dev)
 				"exit partial_power_down failed\n");
 	}
 
+	/* Exit clock gating when driver is removed. */
+	if (hsotg->params.power_down == DWC2_POWER_DOWN_PARAM_NONE &&
+	    hsotg->bus_suspended) {
+		if (dwc2_is_device_mode(hsotg))
+			dwc2_gadget_exit_clock_gating(hsotg, 0);
+		else
+			dwc2_host_exit_clock_gating(hsotg, 0);
+	}
+
 	dwc2_debugfs_exit(hsotg);
 	if (hsotg->hcd_enabled)
 		dwc2_hcd_remove(hsotg);