mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-24 16:40:59 +07:00
185 lines
7.5 KiB
Plaintext
185 lines
7.5 KiB
Plaintext
Kernel driver pc87360
|
|
=====================
|
|
|
|
Supported chips:
|
|
* National Semiconductor PC87360, PC87363, PC87364, PC87365 and PC87366
|
|
Prefixes: 'pc87360', 'pc87363', 'pc87364', 'pc87365', 'pc87366'
|
|
Addresses scanned: none, address read from Super I/O config space
|
|
Datasheets: No longer available
|
|
|
|
Authors: Jean Delvare <jdelvare@suse.de>
|
|
|
|
Thanks to Sandeep Mehta, Tonko de Rooy and Daniel Ceregatti for testing.
|
|
Thanks to Rudolf Marek for helping me investigate conversion issues.
|
|
|
|
|
|
Module Parameters
|
|
-----------------
|
|
|
|
* init int
|
|
Chip initialization level:
|
|
0: None
|
|
*1: Forcibly enable internal voltage and temperature channels, except in9
|
|
2: Forcibly enable all voltage and temperature channels, except in9
|
|
3: Forcibly enable all voltage and temperature channels, including in9
|
|
|
|
Note that this parameter has no effect for the PC87360, PC87363 and PC87364
|
|
chips.
|
|
|
|
Also note that for the PC87366, initialization levels 2 and 3 don't enable
|
|
all temperature channels, because some of them share pins with each other,
|
|
so they can't be used at the same time.
|
|
|
|
|
|
Description
|
|
-----------
|
|
|
|
The National Semiconductor PC87360 Super I/O chip contains monitoring and
|
|
PWM control circuitry for two fans. The PC87363 chip is similar, and the
|
|
PC87364 chip has monitoring and PWM control for a third fan.
|
|
|
|
The National Semiconductor PC87365 and PC87366 Super I/O chips are complete
|
|
hardware monitoring chipsets, not only controlling and monitoring three fans,
|
|
but also monitoring eleven voltage inputs and two (PC87365) or up to four
|
|
(PC87366) temperatures.
|
|
|
|
Chip #vin #fan #pwm #temp devid
|
|
|
|
PC87360 - 2 2 - 0xE1
|
|
PC87363 - 2 2 - 0xE8
|
|
PC87364 - 3 3 - 0xE4
|
|
PC87365 11 3 3 2 0xE5
|
|
PC87366 11 3 3 3-4 0xE9
|
|
|
|
The driver assumes that no more than one chip is present, and one of the
|
|
standard Super I/O addresses is used (0x2E/0x2F or 0x4E/0x4F)
|
|
|
|
Fan Monitoring
|
|
--------------
|
|
|
|
Fan rotation speeds are reported in RPM (revolutions per minute). An alarm
|
|
is triggered if the rotation speed has dropped below a programmable limit.
|
|
A different alarm is triggered if the fan speed is too low to be measured.
|
|
|
|
Fan readings are affected by a programmable clock divider, giving the
|
|
readings more range or accuracy. Usually, users have to learn how it works,
|
|
but this driver implements dynamic clock divider selection, so you don't
|
|
have to care no more.
|
|
|
|
For reference, here are a few values about clock dividers:
|
|
|
|
slowest accuracy highest
|
|
measurable around 3000 accurate
|
|
divider speed (RPM) RPM (RPM) speed (RPM)
|
|
1 1882 18 6928
|
|
2 941 37 4898
|
|
4 470 74 3464
|
|
8 235 150 2449
|
|
|
|
For the curious, here is how the values above were computed:
|
|
* slowest measurable speed: clock/(255*divider)
|
|
* accuracy around 3000 RPM: 3000^2/clock
|
|
* highest accurate speed: sqrt(clock*100)
|
|
The clock speed for the PC87360 family is 480 kHz. I arbitrarily chose 100
|
|
RPM as the lowest acceptable accuracy.
|
|
|
|
As mentioned above, you don't have to care about this no more.
|
|
|
|
Note that not all RPM values can be represented, even when the best clock
|
|
divider is selected. This is not only true for the measured speeds, but
|
|
also for the programmable low limits, so don't be surprised if you try to
|
|
set, say, fan1_min to 2900 and it finally reads 2909.
|
|
|
|
|
|
Fan Control
|
|
-----------
|
|
|
|
PWM (pulse width modulation) values range from 0 to 255, with 0 meaning
|
|
that the fan is stopped, and 255 meaning that the fan goes at full speed.
|
|
|
|
Be extremely careful when changing PWM values. Low PWM values, even
|
|
non-zero, can stop the fan, which may cause irreversible damage to your
|
|
hardware if temperature increases too much. When changing PWM values, go
|
|
step by step and keep an eye on temperatures.
|
|
|
|
One user reported problems with PWM. Changing PWM values would break fan
|
|
speed readings. No explanation nor fix could be found.
|
|
|
|
|
|
Temperature Monitoring
|
|
----------------------
|
|
|
|
Temperatures are reported in degrees Celsius. Each temperature measured has
|
|
associated low, high and overtemperature limits, each of which triggers an
|
|
alarm when crossed.
|
|
|
|
The first two temperature channels are external. The third one (PC87366
|
|
only) is internal.
|
|
|
|
The PC87366 has three additional temperature channels, based on
|
|
thermistors (as opposed to thermal diodes for the first three temperature
|
|
channels). For technical reasons, these channels are held by the VLM
|
|
(voltage level monitor) logical device, not the TMS (temperature
|
|
measurement) one. As a consequence, these temperatures are exported as
|
|
voltages, and converted into temperatures in user-space.
|
|
|
|
Note that these three additional channels share their pins with the
|
|
external thermal diode channels, so you (physically) can't use them all at
|
|
the same time. Although it should be possible to mix the two sensor types,
|
|
the documents from National Semiconductor suggest that motherboard
|
|
manufacturers should choose one type and stick to it. So you will more
|
|
likely have either channels 1 to 3 (thermal diodes) or 3 to 6 (internal
|
|
thermal diode, and thermistors).
|
|
|
|
|
|
Voltage Monitoring
|
|
------------------
|
|
|
|
Voltages are reported relatively to a reference voltage, either internal or
|
|
external. Some of them (in7:Vsb, in8:Vdd and in10:AVdd) are divided by two
|
|
internally, you will have to compensate in sensors.conf. Others (in0 to in6)
|
|
are likely to be divided externally. The meaning of each of these inputs as
|
|
well as the values of the resistors used for division is left to the
|
|
motherboard manufacturers, so you will have to document yourself and edit
|
|
sensors.conf accordingly. National Semiconductor has a document with
|
|
recommended resistor values for some voltages, but this still leaves much
|
|
room for per motherboard specificities, unfortunately. Even worse,
|
|
motherboard manufacturers don't seem to care about National Semiconductor's
|
|
recommendations.
|
|
|
|
Each voltage measured has associated low and high limits, each of which
|
|
triggers an alarm when crossed.
|
|
|
|
When available, VID inputs are used to provide the nominal CPU Core voltage.
|
|
The driver will default to VRM 9.0, but this can be changed from user-space.
|
|
The chipsets can handle two sets of VID inputs (on dual-CPU systems), but
|
|
the driver will only export one for now. This may change later if there is
|
|
a need.
|
|
|
|
|
|
General Remarks
|
|
---------------
|
|
|
|
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! Note that all hardware registers are read whenever any
|
|
data is read (unless it is less than 2 seconds since the last update, in
|
|
which case cached values are returned instead). As a consequence, when
|
|
a once-only alarm triggers, it may take 2 seconds for it to show, and 2
|
|
more seconds for it to disappear.
|
|
|
|
Monitoring of in9 isn't enabled at lower init levels (<3) because that
|
|
channel measures the battery voltage (Vbat). It is a known fact that
|
|
repeatedly sampling the battery voltage reduces its lifetime. National
|
|
Semiconductor smartly designed their chipset so that in9 is sampled only
|
|
once every 1024 sampling cycles (that is every 34 minutes at the default
|
|
sampling rate), so the effect is attenuated, but still present.
|
|
|
|
|
|
Limitations
|
|
-----------
|
|
|
|
The datasheets suggests that some values (fan mins, fan dividers)
|
|
shouldn't be changed once the monitoring has started, but we ignore that
|
|
recommendation. We'll reconsider if it actually causes trouble.
|