[PATCH] w1: Cleans up usage of touch_bit/w1_read_bit/w1_write_bit.

Cleans up usage of touch_bit/w1_read_bit/w1_write_bit.

Signed-off-by: Ben Gardner <bgardner@wabtec.com>
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/w1/w1_int.c b/drivers/w1/w1_int.c
index ce24e3b..280f140 100644
--- a/drivers/w1/w1_int.c
+++ b/drivers/w1/w1_int.c
@@ -121,6 +121,14 @@
 	int retval = 0;
 	struct w1_netlink_msg msg;
 
+        /* validate minimum functionality */
+        if (!(master->touch_bit && master->reset_bus) &&
+            !(master->write_bit && master->read_bit))
+        {
+           printk(KERN_ERR "w1_add_master_device: invalid function set\n");
+           return(-EINVAL);
+        }
+
 	dev = w1_alloc_dev(w1_ids++, w1_max_slave_count, w1_max_slave_ttl, &w1_driver, &w1_device);
 	if (!dev)
 		return -ENOMEM;