Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/soundwire/slave.c b/drivers/soundwire/slave.c
index ac103bd..6473fa6 100644
--- a/drivers/soundwire/slave.c
+++ b/drivers/soundwire/slave.c
@@ -2,6 +2,7 @@
 // Copyright(c) 2015-17 Intel Corporation.
 
 #include <linux/acpi.h>
+#include <linux/of.h>
 #include <linux/soundwire/sdw.h>
 #include <linux/soundwire/sdw_type.h>
 #include "bus.h"
@@ -14,7 +15,7 @@
 }
 
 static int sdw_slave_add(struct sdw_bus *bus,
-		struct sdw_slave_id *id, struct fwnode_handle *fwnode)
+			 struct sdw_slave_id *id, struct fwnode_handle *fwnode)
 {
 	struct sdw_slave *slave;
 	int ret;
@@ -30,11 +31,12 @@
 
 	/* name shall be sdw:link:mfg:part:class:unique */
 	dev_set_name(&slave->dev, "sdw:%x:%x:%x:%x:%x",
-			bus->link_id, id->mfg_id, id->part_id,
-			id->class_id, id->unique_id);
+		     bus->link_id, id->mfg_id, id->part_id,
+		     id->class_id, id->unique_id);
 
 	slave->dev.release = sdw_slave_release;
 	slave->dev.bus = &sdw_bus_type;
+	slave->dev.of_node = of_node_get(to_of_node(fwnode));
 	slave->bus = bus;
 	slave->status = SDW_SLAVE_UNATTACHED;
 	slave->dev_num = 0;
@@ -56,6 +58,7 @@
 		mutex_unlock(&bus->bus_lock);
 		put_device(&slave->dev);
 	}
+	sdw_slave_debugfs_init(slave);
 
 	return ret;
 }
@@ -84,11 +87,11 @@
 		acpi_status status;
 
 		status = acpi_evaluate_integer(adev->handle,
-					METHOD_NAME__ADR, NULL, &addr);
+					       METHOD_NAME__ADR, NULL, &addr);
 
 		if (ACPI_FAILURE(status)) {
 			dev_err(bus->dev, "_ADR resolution failed: %x\n",
-							status);
+				status);
 			return status;
 		}
 
@@ -112,3 +115,54 @@
 }
 
 #endif
+
+/*
+ * sdw_of_find_slaves() - Find Slave devices in master device tree node
+ * @bus: SDW bus instance
+ *
+ * Scans Master DT node for SDW child Slave devices and registers it.
+ */
+int sdw_of_find_slaves(struct sdw_bus *bus)
+{
+	struct device *dev = bus->dev;
+	struct device_node *node;
+
+	for_each_child_of_node(bus->dev->of_node, node) {
+		int link_id, ret, len;
+		unsigned int sdw_version;
+		const char *compat = NULL;
+		struct sdw_slave_id id;
+		const __be32 *addr;
+
+		compat = of_get_property(node, "compatible", NULL);
+		if (!compat)
+			continue;
+
+		ret = sscanf(compat, "sdw%01x%04hx%04hx%02hhx", &sdw_version,
+			     &id.mfg_id, &id.part_id, &id.class_id);
+
+		if (ret != 4) {
+			dev_err(dev, "Invalid compatible string found %s\n",
+				compat);
+			continue;
+		}
+
+		addr = of_get_property(node, "reg", &len);
+		if (!addr || (len < 2 * sizeof(u32))) {
+			dev_err(dev, "Invalid Link and Instance ID\n");
+			continue;
+		}
+
+		link_id = be32_to_cpup(addr++);
+		id.unique_id = be32_to_cpup(addr);
+		id.sdw_version = sdw_version;
+
+		/* Check for link_id match */
+		if (link_id != bus->link_id)
+			continue;
+
+		sdw_slave_add(bus, &id, of_fwnode_handle(node));
+	}
+
+	return 0;
+}