soundwire: add helper macros for devID fields

Move bit extractors to macros, so that the definitions can be used by
other drivers parsing the MIPI definitions extracted from firmware
tables (ACPI or DT).
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200225170041.23644-4-pierre-louis.bossart@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/soundwire/bus.c

@@ -504,22 +504,11 @@ void sdw_extract_slave_id(struct sdw_bus *bus,
 {
 	dev_dbg(bus->dev, "SDW Slave Addr: %llx\n", addr);
 
-	/*
-	 * Spec definition
-	 *   Register		Bit	Contents
-	 *   DevId_0 [7:4]	47:44	sdw_version
-	 *   DevId_0 [3:0]	43:40	unique_id
-	 *   DevId_1		39:32	mfg_id [15:8]
-	 *   DevId_2		31:24	mfg_id [7:0]
-	 *   DevId_3		23:16	part_id [15:8]
-	 *   DevId_4		15:08	part_id [7:0]
-	 *   DevId_5		07:00	class_id
-	 */
-	id->sdw_version = (addr >> 44) & GENMASK(3, 0);
-	id->unique_id = (addr >> 40) & GENMASK(3, 0);
-	id->mfg_id = (addr >> 24) & GENMASK(15, 0);
-	id->part_id = (addr >> 8) & GENMASK(15, 0);
-	id->class_id = addr & GENMASK(7, 0);
+	id->sdw_version = SDW_VERSION(addr);
+	id->unique_id = SDW_UNIQUE_ID(addr);
+	id->mfg_id = SDW_MFG_ID(addr);
+	id->part_id = SDW_PART_ID(addr);
+	id->class_id = SDW_CLASS_ID(addr);
 
 	dev_dbg(bus->dev,
 		"SDW Slave class_id %x, part_id %x, mfg_id %x, unique_id %x, version %x\n",

include/linux/soundwire/sdw.h

@@ -424,6 +424,29 @@ struct sdw_slave_id {
 	__u8 sdw_version:4;
 };
 
+/*
+ * Helper macros to extract the MIPI-defined IDs
+ *
+ * Spec definition
+ *   Register		Bit	Contents
+ *   DevId_0 [7:4]	47:44	sdw_version
+ *   DevId_0 [3:0]	43:40	unique_id
+ *   DevId_1		39:32	mfg_id [15:8]
+ *   DevId_2		31:24	mfg_id [7:0]
+ *   DevId_3		23:16	part_id [15:8]
+ *   DevId_4		15:08	part_id [7:0]
+ *   DevId_5		07:00	class_id
+ *
+ * The MIPI DisCo for SoundWire defines in addition the link_id as bits 51:48
+ */
+
+#define SDW_DISCO_LINK_ID(adr)	(((adr) >> 48) & GENMASK(3, 0))
+#define SDW_VERSION(adr)	(((adr) >> 44) & GENMASK(3, 0))
+#define SDW_UNIQUE_ID(adr)	(((adr) >> 40) & GENMASK(3, 0))
+#define SDW_MFG_ID(adr)		(((adr) >> 24) & GENMASK(15, 0))
+#define SDW_PART_ID(adr)	(((adr) >> 8) & GENMASK(15, 0))
+#define SDW_CLASS_ID(adr)	((adr) & GENMASK(7, 0))
+
 /**
  * struct sdw_slave_intr_status - Slave interrupt status
  * @control_port: control port status