* JEDEC JC 42.4 compliant temperature sensor chips
Prefix: 'jc42'
Addresses scanned: I2C 0x18 - 0x1f
- Datasheet: -
+ Datasheet:
+ http://www.jedec.org/sites/default/files/docs/4_01_04R19.pdf
Author:
Guenter Roeck <guenter.roeck@ericsson.com>
Description
-----------
-This driver implements support for JEDEC JC 42.4 compliant temperature sensors.
+This driver implements support for JEDEC JC 42.4 compliant temperature sensors,
+which are used on many DDR3 memory modules for mobile devices and servers. Some
+systems use the sensor to prevent memory overheating by automatically throttling
+the memory controller.
+
The driver auto-detects the chips listed above, but can be manually instantiated
to support other JC 42.4 compliant chips.
which applies to all limits. This register can be written by writing into
temp1_crit_hyst. Other hysteresis attributes are read-only.
+If the BIOS has configured the sensor for automatic temperature management, it
+is likely that it has locked the registers, i.e., that the temperature limits
+cannot be changed.
+
Sysfs entries
-------------
temp1_input Temperature (RO)
-temp1_min Minimum temperature (RW)
-temp1_max Maximum temperature (RW)
-temp1_crit Critical high temperature (RW)
+temp1_min Minimum temperature (RO or RW)
+temp1_max Maximum temperature (RO or RW)
+temp1_crit Critical high temperature (RO or RW)
-temp1_crit_hyst Critical hysteresis temperature (RW)
+temp1_crit_hyst Critical hysteresis temperature (RO or RW)
temp1_max_hyst Maximum hysteresis temperature (RO)
temp1_min_alarm Temperature low alarm