usb: phy: mxs-phy: add set_suspend API

It needs to call set_suspend during USB suspend/resume

Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/otg/mxs-phy.c b/drivers/usb/otg/mxs-phy.c
index 7630272..5158332 100644
--- a/drivers/usb/otg/mxs-phy.c
+++ b/drivers/usb/otg/mxs-phy.c
@@ -76,6 +76,25 @@
 	clk_disable_unprepare(mxs_phy->clk);
 }
 
+static int mxs_phy_suspend(struct usb_phy *x, int suspend)
+{
+	struct mxs_phy *mxs_phy = to_mxs_phy(x);
+
+	if (suspend) {
+		writel_relaxed(0xffffffff, x->io_priv + HW_USBPHY_PWD);
+		writel_relaxed(BM_USBPHY_CTRL_CLKGATE,
+			x->io_priv + HW_USBPHY_CTRL_SET);
+		clk_disable_unprepare(mxs_phy->clk);
+	} else {
+		clk_prepare_enable(mxs_phy->clk);
+		writel_relaxed(BM_USBPHY_CTRL_CLKGATE,
+			x->io_priv + HW_USBPHY_CTRL_CLR);
+		writel_relaxed(0, x->io_priv + HW_USBPHY_PWD);
+	}
+
+	return 0;
+}
+
 static int mxs_phy_on_connect(struct usb_phy *phy,
 		enum usb_device_speed speed)
 {
@@ -137,6 +156,7 @@
 	mxs_phy->phy.label		= DRIVER_NAME;
 	mxs_phy->phy.init		= mxs_phy_init;
 	mxs_phy->phy.shutdown		= mxs_phy_shutdown;
+	mxs_phy->phy.set_suspend	= mxs_phy_suspend;
 	mxs_phy->phy.notify_connect	= mxs_phy_on_connect;
 	mxs_phy->phy.notify_disconnect	= mxs_phy_on_disconnect;