From da97896fae6a977564c11a019e9f6973a8722b42 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Fri, 4 Jul 2003 21:31:08 +0000 Subject: [PATCH] Documentation for the lm83 driver. git-svn-id: http://lm-sensors.org/svn/lm-sensors/trunk@1855 7894878c-1315-0410-8ee3-d5d059ff63e0 --- doc/chips/lm83 | 115 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 115 insertions(+) create mode 100644 doc/chips/lm83 diff --git a/doc/chips/lm83 b/doc/chips/lm83 new file mode 100644 index 00000000..dd04055d --- /dev/null +++ b/doc/chips/lm83 @@ -0,0 +1,115 @@ +Kernel driver `lm83.o' +===================== + +Status: Incomplete and untested + +Supported chips: + * National Semiconductor LM83 + Prefix: `lm83' + Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e (inclusive) + Datasheet: Publicly available at the National Semiconductor website + http://www.national.com/pf/LM/LM83.html + + +Author: Jean Delvare + +License: GPL + + +Module Parameters +----------------- + +* force: short array (min = 1, max = 48) + List of adapter,address pairs to boldly assume to be present +* force_lm83: short array (min = 1, max = 48) + List of adapter,address pairs which are unquestionably assumed to contain + a `lm83' chip +* probe: short array (min = 1, max = 48) + List of adapter,address pairs to scan additionally +* probe_range: short array (min = 1, max = 48) + List of adapter,start-addr,end-addr triples to scan additionally +* ignore: short array (min = 1, max = 48) + List of adapter,address pairs not to scan +* ignore_range: short array (min = 1, max = 48) + List of adapter,start-addr,end-addr triples not to scan + + +Description +----------- + +The LM83 is a digital temperature sensor. It senses its own temperature as +well as the temperature of up to three external diodes. It is compatible +with many other devices such as the LM84 and all other ADM1021 clones. +The main difference between the LM83 and the LM84 in that the later can +only sense the temperature of one external diode. + +Using the adm1021 driver for a LM83 should work, but only two temperatures +will be reported instead of four. + +Alarms and critical temperature (common to all four temperature readings) +are not handled by this driver yet, but should be someday. + +The LM83 is only found on a handful of motherboards. An unconfirmed list +follows. If you can confirm or infirm the fact that any of these +motherboards do actually have an LM83, please contact us. + + Gigabyte GA-7VAX + Gigabyte GA-7VRXP (rev 2.0) + Gigabyte GA-8IK1100 + Iwill MPX2 + Soltek SL-75DRV5 + +Note that the driver is untested so far. We really want testers! If you +want to help, please contact us. + +The fact that the LM83 is only scarcely used can be easily explained. +Most motherboards come with more than just temperature sensors for +health monitoring. They also have voltage and fan rotation speed +sensors. This means that temperature-only chips are usually used as +secondary chips coupled with another chip such as an IT87 or similar +chip, which provides more features. Since systems usually need three +temperature sensors (motherboard, processor, power supply) and primary +chips provide some temperature sensors, the secondary chip, if needed, +won't have to handle more than two temperatures. Thus, ADM1021 clones +are sufficent, and there is no need for a four temperatures sensor +chip such as the LM83. The only case where using an LM83 would make +sense is on SMP systems, such as the above-mentioned Iwill MPX2, +because you want an additional temperature sensor for each additional +CPU. + +All temperature values are given in degrees Celcius. Local temperature +is given within a range of 0 to +85 degrees. Remote temperatures are +given within a range of 0 to +125 degrees. Resolution is 1.0 degree, +accuracy is guaranteed to 3.0 degrees (see the datasheet for more +details). + +Each sensor has its own high limit. There is no hysteresis mechanism as +found on most recent temperature sensors. + + +Chip Features +------------- + +Chip 'lm83' + +LABEL LABEL CLASS COMPUTE CLASS MODE MAGN +local_temp - - R- 0 +local_temp_high local_temp local_temp RW 0 +remote1_temp - - R- 0 +remote1_temp_high remote1_temp remote1_temp RW 0 +remote2_temp - - R- 0 +remote2_temp_high remote2_temp remote2_temp RW 0 +remote3_temp - - R- 0 +remote3_temp_high remote3_temp remote3_temp RW 0 + +LABEL FEATURE SYMBOL SYSCTL FILE:N +local_temp SENSORS_LM83_LOCAL_TEMP temp1:2 +local_temp_high SENSORS_LM83_LOCAL_HIGH temp1:1 +remote1_temp SENSORS_LM83_REMOTE1_TEMP temp2:2 +remote1_temp_high SENSORS_LM83_REMOTE1_HIGH temp2:1 +remote2_temp SENSORS_LM83_REMOTE2_TEMP temp3:2 +remote2_temp_high SENSORS_LM83_REMOTE2_HIGH temp3:1 +remote3_temp SENSORS_LM83_REMOTE3_TEMP temp4:2 +remote3_temp_high SENSORS_LM83_REMOTE3_HIGH temp4:1 + +