W1: Document add, remove, search_count, and pullup.

Document w1_master_add, w1_master_remove, search_count, and pullup.
Signed-off-by: NDavid Fries <david@fries.net>
Signed-off-by: NEvgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Documentation/w1/w1.generic

@@ -79,10 +79,13 @@ w1 master sysfs interface
 <xx-xxxxxxxxxxxxx> - a directory for a found device. The format is family-serial
 bus                - (standard) symlink to the w1 bus
 driver             - (standard) symlink to the w1 driver
+w1_master_add      - Manually register a slave device
 w1_master_attempts - the number of times a search was attempted
 w1_master_max_slave_count
                    - the maximum slaves that may be attached to a master
 w1_master_name     - the name of the device (w1_bus_masterX)
+w1_master_pullup   - 5V strong pullup 0 enabled, 1 disabled
+w1_master_remove   - Manually remove a slave device
 w1_master_search   - the number of searches left to do, -1=continual (default)
 w1_master_slave_count
                    - the number of slaves found
@@ -90,7 +93,13 @@ w1_master_slaves   - the names of the slaves, one per line
 w1_master_timeout  - the delay in seconds between searches
 
 If you have a w1 bus that never changes (you don't add or remove devices),
-you can set w1_master_search to a positive value to disable searches.
+you can set the module parameter search_count to a small positive number
+for an initially small number of bus searches.  Alternatively it could be
+set to zero, then manually add the slave device serial numbers by
+w1_master_add device file.  The w1_master_add and w1_master_remove files
+generally only make sense when searching is disabled, as a search will
+redetect manually removed devices that are present and timeout manually
+added devices that aren't on the bus.
 
 
 w1 slave sysfs interface