w1: core: match sub-nodes of bus masters in devicetree

Once a new slave device is detected, match it against all sub-nodes of the
master bus controller. If a match is found, set the slave device's of_node
pointer.

Signed-off-by: Daniel Mack <daniel@zonque.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

drivers/w1/w1.c

@@ -26,6 +26,7 @@
 #include <linux/kthread.h>
 #include <linux/freezer.h>
 #include <linux/hwmon.h>
+#include <linux/of.h>
 
 #include <linux/atomic.h>
 
@@ -686,6 +687,8 @@ static int __w1_attach_slave_device(struct w1_slave *sl)
 	sl->dev.bus = &w1_bus_type;
 	sl->dev.release = &w1_slave_release;
 	sl->dev.groups = w1_slave_groups;
+	sl->dev.of_node = of_find_matching_node(sl->master->dev.of_node,
+						sl->family->of_match_table);
 
 	dev_set_name(&sl->dev, "%02x-%012llx",
 		 (unsigned int) sl->reg_num.family,

include/linux/w1.h

@@ -274,6 +274,8 @@ struct w1_family {
 
 	struct w1_family_ops	*fops;
 
+	const struct of_device_id *of_match_table;
+
 	atomic_t		refcnt;
 };