soundwire: cdns: Add cadence library

Cadence IP implements SoundWire Master. Add base cadence library
initialization and interrupt handling

Signed-off-by: Hardik T Shah <hardik.t.shah@intel.com>
Signed-off-by: Sanyog Kale <sanyog.r.kale@intel.com>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Acked-By: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/soundwire/cadence_master.h

@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+// Copyright(c) 2015-17 Intel Corporation.
+
+#ifndef __SDW_CADENCE_H
+#define __SDW_CADENCE_H
+
+/**
+ * struct sdw_cdns - Cadence driver context
+ * @dev: Linux device
+ * @bus: Bus handle
+ * @instance: instance number
+ * @registers: Cadence registers
+ * @link_up: Link status
+ */
+struct sdw_cdns {
+	struct device *dev;
+	struct sdw_bus bus;
+	unsigned int instance;
+
+	void __iomem *registers;
+
+	bool link_up;
+};
+
+#define bus_to_cdns(_bus) container_of(_bus, struct sdw_cdns, bus)
+
+/* Exported symbols */
+
+irqreturn_t sdw_cdns_irq(int irq, void *dev_id);
+irqreturn_t sdw_cdns_thread(int irq, void *dev_id);
+
+int sdw_cdns_init(struct sdw_cdns *cdns);
+
+#endif /* __SDW_CADENCE_H */