driver: net: ti: introduce common mdio support library

All existing TI SoCs network HW have similar MDIO implementation, so
introduce common mdio support library which can be reused by TI networking
drivers.

Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/drivers/net/ti/cpsw_mdio.h b/drivers/net/ti/cpsw_mdio.h
new file mode 100644
index 0000000..4a76d4e
--- /dev/null
+++ b/drivers/net/ti/cpsw_mdio.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * CPSW MDIO generic driver API for TI AMxx/K2x/EMAC devices.
+ *
+ * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
+ */
+
+#ifndef CPSW_MDIO_H_
+#define CPSW_MDIO_H_
+
+struct cpsw_mdio;
+
+struct mii_dev *cpsw_mdio_init(const char *name, u32 mdio_base,
+			       u32 bus_freq, int fck_freq);
+void cpsw_mdio_free(struct mii_dev *bus);
+u32 cpsw_mdio_get_alive(struct mii_dev *bus);
+
+#endif /* CPSW_MDIO_H_ */