diff options
Diffstat (limited to 'Documentation/i2c/chips/pc87360')
| -rw-r--r-- | Documentation/i2c/chips/pc87360 | 189 |
1 files changed, 0 insertions, 189 deletions
diff --git a/Documentation/i2c/chips/pc87360 b/Documentation/i2c/chips/pc87360 deleted file mode 100644 index 89a8fcfa78df..000000000000 --- a/Documentation/i2c/chips/pc87360 +++ /dev/null @@ -1,189 +0,0 @@ -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: - http://www.national.com/pf/PC/PC87360.html - http://www.national.com/pf/PC/PC87363.html - http://www.national.com/pf/PC/PC87364.html - http://www.national.com/pf/PC/PC87365.html - http://www.national.com/pf/PC/PC87366.html - -Authors: Jean Delvare <khali@linux-fr.org> - -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. |