usb: dwc2/gadget: disable clock when it's not needed

When device is stopped or suspended clock is not needed so we
can disable it for this time.

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/dwc2/gadget.c

@@ -2893,6 +2893,8 @@ static int s3c_hsotg_udc_start(struct usb_gadget *gadget,
 	hsotg->gadget.dev.of_node = hsotg->dev->of_node;
 	hsotg->gadget.speed = USB_SPEED_UNKNOWN;
 
+	clk_enable(hsotg->clk);
+
 	ret = regulator_bulk_enable(ARRAY_SIZE(hsotg->supplies),
 				    hsotg->supplies);
 	if (ret) {
@@ -2941,6 +2943,8 @@ static int s3c_hsotg_udc_stop(struct usb_gadget *gadget,
 
 	regulator_bulk_disable(ARRAY_SIZE(hsotg->supplies), hsotg->supplies);
 
+	clk_disable(hsotg->clk);
+
 	return 0;
 }
 
@@ -2972,8 +2976,10 @@ static int s3c_hsotg_pullup(struct usb_gadget *gadget, int is_on)
 	spin_lock_irqsave(&hsotg->lock, flags);
 	if (is_on) {
 		s3c_hsotg_phy_enable(hsotg);
+		clk_enable(hsotg->clk);
 		s3c_hsotg_core_init(hsotg);
 	} else {
+		clk_disable(hsotg->clk);
 		s3c_hsotg_phy_disable(hsotg);
 	}
 
@@ -3636,6 +3642,7 @@ static int s3c_hsotg_suspend(struct platform_device *pdev, pm_message_t state)
 
 		ret = regulator_bulk_disable(ARRAY_SIZE(hsotg->supplies),
 					     hsotg->supplies);
+		clk_disable(hsotg->clk);
 	}
 
 	return ret;
@@ -3650,6 +3657,8 @@ static int s3c_hsotg_resume(struct platform_device *pdev)
 	if (hsotg->driver) {
 		dev_info(hsotg->dev, "resuming usb gadget %s\n",
 			 hsotg->driver->driver.name);
+
+		clk_enable(hsotg->clk);
 		ret = regulator_bulk_enable(ARRAY_SIZE(hsotg->supplies),
 				      hsotg->supplies);
 	}