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-rw-r--r--Documentation/w1/slaves/w1_therm11
-rw-r--r--Documentation/w1/w1.generic30
2 files changed, 29 insertions, 12 deletions
diff --git a/Documentation/w1/slaves/w1_therm b/Documentation/w1/slaves/w1_therm
index cc62a95e4..13411fe52 100644
--- a/Documentation/w1/slaves/w1_therm
+++ b/Documentation/w1/slaves/w1_therm
@@ -11,12 +11,14 @@ Author: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Description
-----------
-w1_therm provides basic temperature conversion for ds18*20 devices.
+w1_therm provides basic temperature conversion for ds18*20 devices, and the
+ds28ea00 device.
supported family codes:
W1_THERM_DS18S20 0x10
W1_THERM_DS1822 0x22
W1_THERM_DS18B20 0x28
W1_THERM_DS1825 0x3B
+W1_THERM_DS28EA00 0x42
Support is provided through the sysfs w1_slave file. Each open and
read sequence will initiate a temperature conversion then provide two
@@ -48,3 +50,10 @@ resistor). The DS18b20 temperature sensor specification lists a
maximum current draw of 1.5mA and that a 5k pullup resistor is not
sufficient. The strong pullup is designed to provide the additional
current required.
+
+The DS28EA00 provides an additional two pins for implementing a sequence
+detection algorithm. This feature allows you to determine the physical
+location of the chip in the 1-wire bus without needing pre-existing
+knowledge of the bus ordering. Support is provided through the sysfs
+w1_seq file. The file will contain a single line with an integer value
+representing the device index in the bus starting at 0.
diff --git a/Documentation/w1/w1.generic b/Documentation/w1/w1.generic
index b2033c64c..b3ffaf8cf 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
------------------------------------------------------------------