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authorDmitry Khromov <dk@icelogic.net>2015-05-12 22:29:44 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-05-24 12:08:59 -0700
commitc3098356927254be270e5dc186a2ca144b64463b (patch)
tree940a4cbc322141f72c57507bc9867cf1489466a9 /Documentation
parent99b7e93c95c78952724a9783de6c78def8fbfc3f (diff)
downloadtalos-obmc-linux-c3098356927254be270e5dc186a2ca144b64463b.tar.gz
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w1: introduce an ability to specify microseconds bus scanning intervals
Some of 1-Wire devices commonly associated with physical access control systems are attached/generate presence for as short as 100 ms - hence the tens-to-hundreds milliseconds scan intervals are required. Signed-off-by: Dmitry Khromov <dk@icelogic.net> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/ABI/stable/sysfs-bus-w111
-rw-r--r--Documentation/w1/w1.generic30
2 files changed, 30 insertions, 11 deletions
diff --git a/Documentation/ABI/stable/sysfs-bus-w1 b/Documentation/ABI/stable/sysfs-bus-w1
new file mode 100644
index 000000000000..140d85b4ae92
--- /dev/null
+++ b/Documentation/ABI/stable/sysfs-bus-w1
@@ -0,0 +1,11 @@
+What: /sys/bus/w1/devices/.../w1_master_timeout_us
+Date: April 2015
+Contact: Dmitry Khromov <dk@icelogic.net>
+Description: Bus scanning interval, microseconds component.
+ Some of 1-Wire devices commonly associated with physical access
+ control systems are attached/generate presence for as short as
+ 100 ms - hence the tens-to-hundreds milliseconds scan intervals
+ are required.
+ see Documentation/w1/w1.generic for detailed information.
+Users: any user space application which wants to know bus scanning
+ interval
diff --git a/Documentation/w1/w1.generic b/Documentation/w1/w1.generic
index b2033c64c7da..b3ffaf8cfab2 100644
--- a/Documentation/w1/w1.generic
+++ b/Documentation/w1/w1.generic
@@ -76,21 +76,24 @@ See struct w1_bus_master definition in w1.h for details.
w1 master sysfs interface
------------------------------------------------------------------
-<xx-xxxxxxxxxxxxx> - a directory for a found device. The format is family-serial
+<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_add - (rw) manually register a slave device
+w1_master_attempts - (ro) the number of times a search was attempted
w1_master_max_slave_count
- - maximum number of slaves to search for at a time
-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)
+ - (rw) maximum number of slaves to search for at a time
+w1_master_name - (ro) the name of the device (w1_bus_masterX)
+w1_master_pullup - (rw) 5V strong pullup 0 enabled, 1 disabled
+w1_master_remove - (rw) manually remove a slave device
+w1_master_search - (rw) the number of searches left to do,
+ -1=continual (default)
w1_master_slave_count
- - the number of slaves found
-w1_master_slaves - the names of the slaves, one per line
-w1_master_timeout - the delay in seconds between searches
+ - (ro) the number of slaves found
+w1_master_slaves - (ro) the names of the slaves, one per line
+w1_master_timeout - (ro) the delay in seconds between searches
+w1_master_timeout_us
+ - (ro) the delay in microseconds beetwen searches
If you have a w1 bus that never changes (you don't add or remove devices),
you can set the module parameter search_count to a small positive number
@@ -101,6 +104,11 @@ 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.
+Bus searches occur at an interval, specified as a summ of timeout and
+timeout_us module parameters (either of which may be 0) for as long as
+w1_master_search remains greater than 0 or is -1. Each search attempt
+decrements w1_master_search by 1 (down to 0) and increments
+w1_master_attempts by 1.
w1 slave sysfs interface
------------------------------------------------------------------
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