usb: dwc3: omap: use runtime API's to enable clocks

Before accessing any register, runtime API's should be invoked to enable
the clocks. runtime API's are added here to prevent abort during register
access.
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/dwc3/dwc3-omap.c

@@ -43,6 +43,7 @@
 #include <linux/spinlock.h>
 #include <linux/platform_device.h>
 #include <linux/platform_data/dwc3-omap.h>
+#include <linux/pm_runtime.h>
 #include <linux/dma-mapping.h>
 #include <linux/ioport.h>
 #include <linux/io.h>
@@ -336,6 +337,13 @@ static int dwc3_omap_probe(struct platform_device *pdev)
 	omap->irq	= irq;
 	omap->base	= base;
 
+	pm_runtime_enable(dev);
+	ret = pm_runtime_get_sync(dev);
+	if (ret < 0) {
+		dev_err(dev, "get_sync failed with err %d\n", ret);
+		return ret;
+	}
+
 	reg = dwc3_omap_readl(omap->base, USBOTGSS_UTMI_OTG_STATUS);
 
 	utmi_mode = of_get_property(node, "utmi-mode", &size);
@@ -416,6 +424,8 @@ static int dwc3_omap_remove(struct platform_device *pdev)
 
 	platform_device_unregister(omap->usb2_phy);
 	platform_device_unregister(omap->usb3_phy);
+	pm_runtime_put_sync(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
 	device_for_each_child(&pdev->dev, NULL, dwc3_omap_remove_core);
 
 	return 0;