mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-24 22:36:57 +07:00
ccf988b66d
Convert each file at I2C subsystem, renaming them to .rst and adding to the driver-api book. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Wolfram Sang <wsa@the-dreams.de> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
154 lines
4.5 KiB
ReStructuredText
154 lines
4.5 KiB
ReStructuredText
Kernel driver adm1021
|
|
=====================
|
|
|
|
Supported chips:
|
|
|
|
* Analog Devices ADM1021
|
|
|
|
Prefix: 'adm1021'
|
|
|
|
Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
|
|
|
|
Datasheet: Publicly available at the Analog Devices website
|
|
|
|
* Analog Devices ADM1021A/ADM1023
|
|
|
|
Prefix: 'adm1023'
|
|
|
|
Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
|
|
|
|
Datasheet: Publicly available at the Analog Devices website
|
|
|
|
* Genesys Logic GL523SM
|
|
|
|
Prefix: 'gl523sm'
|
|
|
|
Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
|
|
|
|
Datasheet:
|
|
|
|
* Maxim MAX1617
|
|
|
|
Prefix: 'max1617'
|
|
|
|
Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
|
|
|
|
Datasheet: Publicly available at the Maxim website
|
|
|
|
* Maxim MAX1617A
|
|
|
|
Prefix: 'max1617a'
|
|
|
|
Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
|
|
|
|
Datasheet: Publicly available at the Maxim website
|
|
|
|
* National Semiconductor LM84
|
|
|
|
Prefix: 'lm84'
|
|
|
|
Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
|
|
|
|
Datasheet: Publicly available at the National Semiconductor website
|
|
|
|
* Philips NE1617
|
|
|
|
Prefix: 'max1617' (probably detected as a max1617)
|
|
|
|
Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
|
|
|
|
Datasheet: Publicly available at the Philips website
|
|
|
|
* Philips NE1617A
|
|
|
|
Prefix: 'max1617' (probably detected as a max1617)
|
|
|
|
Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
|
|
|
|
Datasheet: Publicly available at the Philips website
|
|
|
|
* TI THMC10
|
|
|
|
Prefix: 'thmc10'
|
|
|
|
Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
|
|
|
|
Datasheet: Publicly available at the TI website
|
|
|
|
* Onsemi MC1066
|
|
|
|
Prefix: 'mc1066'
|
|
|
|
Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
|
|
|
|
Datasheet: Publicly available at the Onsemi website
|
|
|
|
|
|
Authors:
|
|
- Frodo Looijaard <frodol@dds.nl>,
|
|
- Philip Edelbrock <phil@netroedge.com>
|
|
|
|
Module Parameters
|
|
-----------------
|
|
|
|
* read_only: int
|
|
Don't set any values, read only mode
|
|
|
|
|
|
Description
|
|
-----------
|
|
|
|
The chips supported by this driver are very similar. The Maxim MAX1617 is
|
|
the oldest; it has the problem that it is not very well detectable. The
|
|
MAX1617A solves that. The ADM1021 is a straight clone of the MAX1617A.
|
|
Ditto for the THMC10. From here on, we will refer to all these chips as
|
|
ADM1021-clones.
|
|
|
|
The ADM1021 and MAX1617A reports a die code, which is a sort of revision
|
|
code. This can help us pinpoint problems; it is not very useful
|
|
otherwise.
|
|
|
|
ADM1021-clones implement two temperature sensors. One of them is internal,
|
|
and measures the temperature of the chip itself; the other is external and
|
|
is realised in the form of a transistor-like device. A special alarm
|
|
indicates whether the remote sensor is connected.
|
|
|
|
Each sensor has its own low and high limits. When they are crossed, the
|
|
corresponding alarm is set and remains on as long as the temperature stays
|
|
out of range. Temperatures are measured in degrees Celsius. Measurements
|
|
are possible between -65 and +127 degrees, with a resolution of one degree.
|
|
|
|
If an alarm triggers, it will remain triggered until the hardware register
|
|
is read at least once. This means that the cause for the alarm may already
|
|
have disappeared!
|
|
|
|
This driver only updates its values each 1.5 seconds; reading it more often
|
|
will do no harm, but will return 'old' values. It is possible to make
|
|
ADM1021-clones do faster measurements, but there is really no good reason
|
|
for that.
|
|
|
|
|
|
Netburst-based Xeon support
|
|
---------------------------
|
|
|
|
Some Xeon processors based on the Netburst (early Pentium 4, from 2001 to
|
|
2003) microarchitecture had real MAX1617, ADM1021, or compatible chips
|
|
within them, with two temperature sensors. Other Xeon processors of this
|
|
era (with 400 MHz FSB) had chips with only one temperature sensor.
|
|
|
|
If you have such an old Xeon, and you get two valid temperatures when
|
|
loading the adm1021 module, then things are good.
|
|
|
|
If nothing happens when loading the adm1021 module, and you are certain
|
|
that your specific Xeon processor model includes compatible sensors, you
|
|
will have to explicitly instantiate the sensor chips from user-space. See
|
|
method 4 in Documentation/i2c/instantiating-devices.rst. Possible slave
|
|
addresses are 0x18, 0x1a, 0x29, 0x2b, 0x4c, or 0x4e. It is likely that
|
|
only temp2 will be correct and temp1 will have to be ignored.
|
|
|
|
Previous generations of the Xeon processor (based on Pentium II/III)
|
|
didn't have these sensors. Next generations of Xeon processors (533 MHz
|
|
FSB and faster) lost them, until the Core-based generation which
|
|
introduced integrated digital thermal sensors. These are supported by
|
|
the coretemp driver.
|