usb: phy: am335x: add wakeup support

This is based on George Cherian's patch which added power & wakeup
support to am335x and does no longer apply since I took some if the code
apart in favor of the multi instance support.
This compiles and I boots and later it detects a device after I plug it in :)
Could somebody please test it so it does what it should?

Cc: George Cherian <george.cherian@ti.com>
Reviewed-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/phy/phy-am335x.c b/drivers/usb/phy/phy-am335x.c
index f836dc6..f3478a8 100644
--- a/drivers/usb/phy/phy-am335x.c
+++ b/drivers/usb/phy/phy-am335x.c
@@ -78,6 +78,40 @@
 	return 0;
 }
 
+#ifdef CONFIG_PM_RUNTIME
+
+static int am335x_phy_runtime_suspend(struct device *dev)
+{
+	struct platform_device	*pdev = to_platform_device(dev);
+	struct am335x_phy *am_phy = platform_get_drvdata(pdev);
+
+	if (device_may_wakeup(dev))
+		phy_ctrl_wkup(am_phy->phy_ctrl, am_phy->id, true);
+	phy_ctrl_power(am_phy->phy_ctrl, am_phy->id, false);
+	return 0;
+}
+
+static int am335x_phy_runtime_resume(struct device *dev)
+{
+	struct platform_device	*pdev = to_platform_device(dev);
+	struct am335x_phy	*am_phy = platform_get_drvdata(pdev);
+
+	phy_ctrl_power(am_phy->phy_ctrl, am_phy->id, true);
+	if (device_may_wakeup(dev))
+		phy_ctrl_wkup(am_phy->phy_ctrl, am_phy->id, false);
+	return 0;
+}
+
+static const struct dev_pm_ops am335x_pm_ops = {
+	SET_RUNTIME_PM_OPS(am335x_phy_runtime_suspend,
+			am335x_phy_runtime_resume, NULL)
+};
+
+#define DEV_PM_OPS	(&am335x_pm_ops)
+#else
+#define DEV_PM_OPS	NULL
+#endif
+
 static const struct of_device_id am335x_phy_ids[] = {
 	{ .compatible = "ti,am335x-usb-phy" },
 	{ }
@@ -90,6 +124,7 @@
 	.driver         = {
 		.name   = "am335x-phy-driver",
 		.owner  = THIS_MODULE,
+		.pm = DEV_PM_OPS,
 		.of_match_table = of_match_ptr(am335x_phy_ids),
 	},
 };