phy: helpers for USB ULPI PHY registering

ULPI PHYs need to be bound to their controllers with a
lookup. This adds helpers that the ULPI drivers can use to
do both, the registration of the PHY and the lookup, at the
same time.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: David Cohen <david.a.cohen@linux.intel.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/phy/ulpi_phy.h

+#include <linux/phy/phy.h>
+
+/**
+ * Helper that registers PHY for a ULPI device and adds a lookup for binding it
+ * and it's controller, which is always the parent.
+ */
+static inline struct phy
+*ulpi_phy_create(struct ulpi *ulpi, struct phy_ops *ops)
+{
+	struct phy *phy;
+	int ret;
+
+	phy = phy_create(&ulpi->dev, NULL, ops);
+	if (IS_ERR(phy))
+		return phy;
+
+	ret = phy_create_lookup(phy, "usb2-phy", dev_name(ulpi->dev.parent));
+	if (ret) {
+		phy_destroy(phy);
+		return ERR_PTR(ret);
+	}
+
+	return phy;
+}
+
+/* Remove a PHY that was created with ulpi_phy_create() and it's lookup. */
+static inline void ulpi_phy_destroy(struct ulpi *ulpi, struct phy *phy)
+{
+	phy_remove_lookup(phy, "usb2-phy", dev_name(ulpi->dev.parent));
+	phy_destroy(phy);
+}