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-control.c b/drivers/usb/phy/phy-am335x-control.c
index 22cf07d..0fac976 100644
--- a/drivers/usb/phy/phy-am335x-control.c
+++ b/drivers/usb/phy/phy-am335x-control.c
@@ -26,6 +26,41 @@
 #define USBPHY_OTGVDET_EN	(1 << 19)
 #define USBPHY_OTGSESSEND_EN	(1 << 20)
 
+#define AM335X_PHY0_WK_EN	(1 << 0)
+#define AM335X_PHY1_WK_EN	(1 << 8)
+
+static void am335x_phy_wkup(struct  phy_control *phy_ctrl, u32 id, bool on)
+{
+	struct am335x_control_usb *usb_ctrl;
+	u32 val;
+	u32 reg;
+
+	usb_ctrl = container_of(phy_ctrl, struct am335x_control_usb, phy_ctrl);
+
+	switch (id) {
+	case 0:
+		reg = AM335X_PHY0_WK_EN;
+		break;
+	case 1:
+		reg = AM335X_PHY1_WK_EN;
+		break;
+	default:
+		WARN_ON(1);
+		return;
+	}
+
+	spin_lock(&usb_ctrl->lock);
+	val = readl(usb_ctrl->wkup);
+
+	if (on)
+		val |= reg;
+	else
+		val &= ~reg;
+
+	writel(val, usb_ctrl->wkup);
+	spin_unlock(&usb_ctrl->lock);
+}
+
 static void am335x_phy_power(struct phy_control *phy_ctrl, u32 id, bool on)
 {
 	struct am335x_control_usb *usb_ctrl;
@@ -59,6 +94,7 @@
 
 static const struct phy_control ctrl_am335x = {
 	.phy_power = am335x_phy_power,
+	.phy_wkup = am335x_phy_wkup,
 };
 
 static const struct of_device_id omap_control_usb_id_table[] = {
@@ -117,6 +153,12 @@
 	ctrl_usb->phy_reg = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(ctrl_usb->phy_reg))
 		return PTR_ERR(ctrl_usb->phy_reg);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "wakeup");
+	ctrl_usb->wkup = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(ctrl_usb->wkup))
+		return PTR_ERR(ctrl_usb->wkup);
+
 	spin_lock_init(&ctrl_usb->lock);
 	ctrl_usb->phy_ctrl = *phy_ctrl;