Commit c36364db authored by Jean Delvare's avatar Jean Delvare Committed by Jean Delvare

hwmon: (lm85) Document the ADT7468 as supported

Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
Cc: Darrick J. Wong <djwong@us.ibm.com>
Acked-by: default avatarGuenter Roeck <guenter.roeck@ericsson.com>
parent fa7a5797
......@@ -14,6 +14,10 @@ Supported chips:
Prefix: 'adt7463'
Addresses scanned: I2C 0x2c, 0x2d, 0x2e
Datasheet: http://www.onsemi.com/PowerSolutions/product.do?id=ADT7463
* Analog Devices ADT7468
Prefix: 'adt7468'
Addresses scanned: I2C 0x2c, 0x2d, 0x2e
Datasheet: http://www.onsemi.com/PowerSolutions/product.do?id=ADT7468
* SMSC EMC6D100, SMSC EMC6D101
Prefix: 'emc6d100'
Addresses scanned: I2C 0x2c, 0x2d, 0x2e
......@@ -34,7 +38,7 @@ Description
-----------
This driver implements support for the National Semiconductor LM85 and
compatible chips including the Analog Devices ADM1027, ADT7463 and
compatible chips including the Analog Devices ADM1027, ADT7463, ADT7468 and
SMSC EMC6D10x chips family.
The LM85 uses the 2-wire interface compatible with the SMBUS 2.0
......@@ -87,14 +91,15 @@ To smooth the response of fans to changes in temperature, the LM85 has an
optional filter for smoothing temperatures. The ADM1027 has the same
config option but uses it to rate limit the changes to fan speed instead.
The ADM1027 and ADT7463 have a 10-bit ADC and can therefore measure
temperatures with 0.25 degC resolution. They also provide an offset to the
temperature readings that is automatically applied during measurement.
This offset can be used to zero out any errors due to traces and placement.
The documentation says that the offset is in 0.25 degC steps, but in
initial testing of the ADM1027 it was 1.00 degC steps. Analog Devices has
confirmed this "bug". The ADT7463 is reported to work as described in the
documentation. The current lm85 driver does not show the offset register.
The ADM1027, ADT7463 and ADT7468 have a 10-bit ADC and can therefore
measure temperatures with 0.25 degC resolution. They also provide an offset
to the temperature readings that is automatically applied during
measurement. This offset can be used to zero out any errors due to traces
and placement. The documentation says that the offset is in 0.25 degC
steps, but in initial testing of the ADM1027 it was 1.00 degC steps. Analog
Devices has confirmed this "bug". The ADT7463 is reported to work as
described in the documentation. The current lm85 driver does not show the
offset register.
See the vendor datasheets for more information. There is application note
from National (AN-1260) with some additional information about the LM85.
......@@ -125,17 +130,17 @@ datasheet for a complete description of the differences. Other than
identifying the chip, the driver behaves no differently with regard to
these two chips. The LM85B is recommended for new designs.
The ADM1027 and ADT7463 chips have an optional SMBALERT output that can be
used to signal the chipset in case a limit is exceeded or the temperature
sensors fail. Individual sensor interrupts can be masked so they won't
trigger SMBALERT. The SMBALERT output if configured replaces one of the other
functions (PWM2 or IN0). This functionality is not implemented in current
driver.
The ADM1027, ADT7463 and ADT7468 chips have an optional SMBALERT output
that can be used to signal the chipset in case a limit is exceeded or the
temperature sensors fail. Individual sensor interrupts can be masked so
they won't trigger SMBALERT. The SMBALERT output if configured replaces one
of the other functions (PWM2 or IN0). This functionality is not implemented
in current driver.
The ADT7463 also has an optional THERM output/input which can be connected
to the processor PROC_HOT output. If available, the autofan control
dynamic Tmin feature can be enabled to keep the system temperature within
spec (just?!) with the least possible fan noise.
The ADT7463 and ADT7468 also have an optional THERM output/input which can
be connected to the processor PROC_HOT output. If available, the autofan
control dynamic Tmin feature can be enabled to keep the system temperature
within spec (just?!) with the least possible fan noise.
Configuration Notes
-------------------
......@@ -201,8 +206,8 @@ the temperatures to compensate for systemic errors in the
measurements. These features are not currently supported by the lm85
driver.
In addition to the ADM1027 features, the ADT7463 also has Tmin control
and THERM asserted counts. Automatic Tmin control acts to adjust the
Tmin value to maintain the measured temperature sensor at a specified
temperature. There isn't much documentation on this feature in the
ADT7463 data sheet. This is not supported by current driver.
In addition to the ADM1027 features, the ADT7463 and ADT7468 also have
Tmin control and THERM asserted counts. Automatic Tmin control acts to
adjust the Tmin value to maintain the measured temperature sensor at a
specified temperature. There isn't much documentation on this feature in
the ADT7463 data sheet. This is not supported by current driver.
......@@ -565,7 +565,8 @@ config SENSORS_LM85
select HWMON_VID
help
If you say yes here you get support for National Semiconductor LM85
sensor chips and clones: ADT7463, EMC6D100, EMC6D102 and ADM1027.
sensor chips and clones: ADM1027, ADT7463, ADT7468, EMC6D100,
EMC6D101 and EMC6D102.
This driver can also be built as a module. If so, the module
will be called lm85.
......
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