w1: new netlink commands, add/remove/list slaves

Introduce new commands to add, remove, and list slave devices through
the netlink interface.  This can be useful to skip the search on a
static network.  They could previously only be added or removed
through automatic search or sysfs, and this allows a program to only
use netlink.

Only allocate memory when needed, so move kzalloc into w1_get_slaves
where it was used.

Signed-off-by: David Fries <David@Fries.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/w1/w1_netlink.h b/drivers/w1/w1_netlink.h
index b0922dc..ea9f3e4 100644
--- a/drivers/w1/w1_netlink.h
+++ b/drivers/w1/w1_netlink.h
@@ -27,6 +27,17 @@
 
 #include "w1.h"
 
+/** enum w1_netlink_message_types - message type
+ *
+ * @W1_SLAVE_ADD: notification that a slave device was added
+ * @W1_SLAVE_REMOVE: notification that a slave device was removed
+ * @W1_MASTER_ADD: notification that a new bus master was added
+ * @W1_MASTER_REMOVE: notification that a bus masterwas removed
+ * @W1_MASTER_CMD: initiate operations on a specific master
+ * @W1_SLAVE_CMD: sends reset, selects the slave, then does a read/write/touch
+ * operation
+ * @W1_LIST_MASTERS: used to determine the bus master identifiers
+ */
 enum w1_netlink_message_types {
 	W1_SLAVE_ADD = 0,
 	W1_SLAVE_REMOVE,
@@ -52,6 +63,21 @@
 	__u8				data[0];
 };
 
+/** enum w1_commands - commands available for master or slave operations
+ * @W1_CMD_READ: read len bytes
+ * @W1_CMD_WRITE: write len bytes
+ * @W1_CMD_SEARCH: initiate a standard search, returns only the slave
+ * devices found during that search
+ * @W1_CMD_ALARM_SEARCH: search for devices that are currently alarming
+ * @W1_CMD_TOUCH: Touches a series of bytes.
+ * @W1_CMD_RESET: sends a bus reset on the given master
+ * @W1_CMD_SLAVE_ADD: adds a slave to the given master,
+ * 8 byte slave id at data[0]
+ * @W1_CMD_SLAVE_REMOVE: removes a slave to the given master,
+ * 8 byte slave id at data[0]
+ * @W1_CMD_LIST_SLAVES: list of slaves registered on this master
+ * @W1_CMD_MAX: number of available commands
+ */
 enum w1_commands {
 	W1_CMD_READ = 0,
 	W1_CMD_WRITE,
@@ -59,7 +85,10 @@
 	W1_CMD_ALARM_SEARCH,
 	W1_CMD_TOUCH,
 	W1_CMD_RESET,
-	W1_CMD_MAX,
+	W1_CMD_SLAVE_ADD,
+	W1_CMD_SLAVE_REMOVE,
+	W1_CMD_LIST_SLAVES,
+	W1_CMD_MAX
 };
 
 struct w1_netlink_cmd