| Kernel driver it87 | 
 | ================== | 
 |  | 
 | Supported chips: | 
 |  | 
 |   * IT8603E/IT8623E | 
 |  | 
 |     Prefix: 'it8603' | 
 |  | 
 |     Addresses scanned: from Super I/O config space (8 I/O ports) | 
 |  | 
 |     Datasheet: Not publicly available | 
 |  | 
 |   * IT8620E | 
 |  | 
 |     Prefix: 'it8620' | 
 |  | 
 |     Addresses scanned: from Super I/O config space (8 I/O ports) | 
 |  | 
 |   * IT8628E | 
 |  | 
 |     Prefix: 'it8628' | 
 |  | 
 |     Addresses scanned: from Super I/O config space (8 I/O ports) | 
 |  | 
 |     Datasheet: Not publicly available | 
 |  | 
 |   * IT8705F | 
 |  | 
 |     Prefix: 'it87' | 
 |  | 
 |     Addresses scanned: from Super I/O config space (8 I/O ports) | 
 |  | 
 |     Datasheet: Once publicly available at the ITE website, but no longer | 
 |  | 
 |   * IT8712F | 
 |  | 
 |     Prefix: 'it8712' | 
 |  | 
 |     Addresses scanned: from Super I/O config space (8 I/O ports) | 
 |  | 
 |     Datasheet: Once publicly available at the ITE website, but no longer | 
 |  | 
 |   * IT8716F/IT8726F | 
 |  | 
 |     Prefix: 'it8716' | 
 |  | 
 |     Addresses scanned: from Super I/O config space (8 I/O ports) | 
 |  | 
 |     Datasheet: Once publicly available at the ITE website, but no longer | 
 |  | 
 |   * IT8718F | 
 |  | 
 |     Prefix: 'it8718' | 
 |  | 
 |     Addresses scanned: from Super I/O config space (8 I/O ports) | 
 |  | 
 |     Datasheet: Once publicly available at the ITE website, but no longer | 
 |  | 
 |   * IT8720F | 
 |  | 
 |     Prefix: 'it8720' | 
 |  | 
 |     Addresses scanned: from Super I/O config space (8 I/O ports) | 
 |  | 
 |     Datasheet: Not publicly available | 
 |  | 
 |   * IT8721F/IT8758E | 
 |  | 
 |     Prefix: 'it8721' | 
 |  | 
 |     Addresses scanned: from Super I/O config space (8 I/O ports) | 
 |  | 
 |     Datasheet: Not publicly available | 
 |  | 
 |   * IT8728F | 
 |  | 
 |     Prefix: 'it8728' | 
 |  | 
 |     Addresses scanned: from Super I/O config space (8 I/O ports) | 
 |  | 
 |     Datasheet: Not publicly available | 
 |  | 
 |   * IT8732F | 
 |  | 
 |     Prefix: 'it8732' | 
 |  | 
 |     Addresses scanned: from Super I/O config space (8 I/O ports) | 
 |  | 
 |     Datasheet: Not publicly available | 
 |  | 
 |   * IT8771E | 
 |  | 
 |     Prefix: 'it8771' | 
 |  | 
 |     Addresses scanned: from Super I/O config space (8 I/O ports) | 
 |  | 
 |     Datasheet: Not publicly available | 
 |  | 
 |   * IT8772E | 
 |  | 
 |     Prefix: 'it8772' | 
 |  | 
 |     Addresses scanned: from Super I/O config space (8 I/O ports) | 
 |  | 
 |     Datasheet: Not publicly available | 
 |  | 
 |   * IT8781F | 
 |  | 
 |     Prefix: 'it8781' | 
 |  | 
 |     Addresses scanned: from Super I/O config space (8 I/O ports) | 
 |  | 
 |     Datasheet: Not publicly available | 
 |  | 
 |   * IT8782F | 
 |  | 
 |     Prefix: 'it8782' | 
 |  | 
 |     Addresses scanned: from Super I/O config space (8 I/O ports) | 
 |  | 
 |     Datasheet: Not publicly available | 
 |  | 
 |   * IT8783E/F | 
 |  | 
 |     Prefix: 'it8783' | 
 |  | 
 |     Addresses scanned: from Super I/O config space (8 I/O ports) | 
 |  | 
 |     Datasheet: Not publicly available | 
 |  | 
 |   * IT8786E | 
 |  | 
 |     Prefix: 'it8786' | 
 |  | 
 |     Addresses scanned: from Super I/O config space (8 I/O ports) | 
 |  | 
 |     Datasheet: Not publicly available | 
 |  | 
 |   * IT8790E | 
 |  | 
 |     Prefix: 'it8790' | 
 |  | 
 |     Addresses scanned: from Super I/O config space (8 I/O ports) | 
 |  | 
 |     Datasheet: Not publicly available | 
 |  | 
 |   * SiS950   [clone of IT8705F] | 
 |  | 
 |     Prefix: 'it87' | 
 |  | 
 |     Addresses scanned: from Super I/O config space (8 I/O ports) | 
 |  | 
 |     Datasheet: No longer be available | 
 |  | 
 |  | 
 | Authors: | 
 |     - Christophe Gauthron | 
 |     - Jean Delvare <jdelvare@suse.de> | 
 |  | 
 |  | 
 | Module Parameters | 
 | ----------------- | 
 |  | 
 | * update_vbat: int | 
 |     0 if vbat should report power on value, 1 if vbat should be updated after | 
 |     each read. Default is 0. On some boards the battery voltage is provided | 
 |     by either the battery or the onboard power supply. Only the first reading | 
 |     at power on will be the actual battery voltage (which the chip does | 
 |     automatically). On other boards the battery voltage is always fed to | 
 |     the chip so can be read at any time. Excessive reading may decrease | 
 |     battery life but no information is given in the datasheet. | 
 |  | 
 | * fix_pwm_polarity int | 
 |     Force PWM polarity to active high (DANGEROUS). Some chips are | 
 |     misconfigured by BIOS - PWM values would be inverted. This option tries | 
 |     to fix this. Please contact your BIOS manufacturer and ask him for fix. | 
 |  | 
 |  | 
 | Hardware Interfaces | 
 | ------------------- | 
 |  | 
 | All the chips supported by this driver are LPC Super-I/O chips, accessed | 
 | through the LPC bus (ISA-like I/O ports). The IT8712F additionally has an | 
 | SMBus interface to the hardware monitoring functions. This driver no | 
 | longer supports this interface though, as it is slower and less reliable | 
 | than the ISA access, and was only available on a small number of | 
 | motherboard models. | 
 |  | 
 |  | 
 | Description | 
 | ----------- | 
 |  | 
 | This driver implements support for the IT8603E, IT8620E, IT8623E, IT8628E, | 
 | IT8705F, IT8712F, IT8716F, IT8718F, IT8720F, IT8721F, IT8726F, IT8728F, IT8732F, | 
 | IT8758E, IT8771E, IT8772E, IT8781F, IT8782F, IT8783E/F, IT8786E, IT8790E, and | 
 | SiS950 chips. | 
 |  | 
 | These chips are 'Super I/O chips', supporting floppy disks, infrared ports, | 
 | joysticks and other miscellaneous stuff. For hardware monitoring, they | 
 | include an 'environment controller' with 3 temperature sensors, 3 fan | 
 | rotation speed sensors, 8 voltage sensors, associated alarms, and chassis | 
 | intrusion detection. | 
 |  | 
 | The IT8712F and IT8716F additionally feature VID inputs, used to report | 
 | the Vcore voltage of the processor. The early IT8712F have 5 VID pins, | 
 | the IT8716F and late IT8712F have 6. They are shared with other functions | 
 | though, so the functionality may not be available on a given system. | 
 |  | 
 | The IT8718F and IT8720F also features VID inputs (up to 8 pins) but the value | 
 | is stored in the Super-I/O configuration space. Due to technical limitations, | 
 | this value can currently only be read once at initialization time, so | 
 | the driver won't notice and report changes in the VID value. The two | 
 | upper VID bits share their pins with voltage inputs (in5 and in6) so you | 
 | can't have both on a given board. | 
 |  | 
 | The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E and later IT8712F revisions | 
 | have support for 2 additional fans. The additional fans are supported by the | 
 | driver. | 
 |  | 
 | The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E, IT8732F, IT8781F, IT8782F, | 
 | IT8783E/F, and late IT8712F and IT8705F also have optional 16-bit tachometer | 
 | counters for fans 1 to 3. This is better (no more fan clock divider mess) but | 
 | not compatible with the older chips and revisions. The 16-bit tachometer mode | 
 | is enabled by the driver when one of the above chips is detected. | 
 |  | 
 | The IT8726F is just bit enhanced IT8716F with additional hardware | 
 | for AMD power sequencing. Therefore the chip will appear as IT8716F | 
 | to userspace applications. | 
 |  | 
 | The IT8728F, IT8771E, and IT8772E are considered compatible with the IT8721F, | 
 | until a datasheet becomes available (hopefully.) | 
 |  | 
 | The IT8603E/IT8623E is a custom design, hardware monitoring part is similar to | 
 | IT8728F. It only supports 3 fans, 16-bit fan mode, and the full speed mode | 
 | of the fan is not supported (value 0 of pwmX_enable). | 
 |  | 
 | The IT8620E and IT8628E are custom designs, hardware monitoring part is similar | 
 | to IT8728F. It only supports 16-bit fan mode. Both chips support up to 6 fans. | 
 |  | 
 | The IT8790E supports up to 3 fans. 16-bit fan mode is always enabled. | 
 |  | 
 | The IT8732F supports a closed-loop mode for fan control, but this is not | 
 | currently implemented by the driver. | 
 |  | 
 | Temperatures are measured in degrees Celsius. An alarm is triggered once | 
 | when the Overtemperature Shutdown limit is crossed. | 
 |  | 
 | Fan rotation speeds are reported in RPM (rotations per minute). An alarm is | 
 | triggered if the rotation speed has dropped below a programmable limit. When | 
 | 16-bit tachometer counters aren't used, fan readings can be divided by | 
 | a programmable divider (1, 2, 4 or 8) to give the readings more range or | 
 | accuracy. With a divider of 2, the lowest representable value is around | 
 | 2600 RPM. Not all RPM values can accurately be represented, so some rounding | 
 | is done. | 
 |  | 
 | Voltage sensors (also known as IN sensors) report their values in volts. An | 
 | alarm is triggered if the voltage has crossed a programmable minimum or | 
 | maximum limit. Note that minimum in this case always means 'closest to | 
 | zero'; this is important for negative voltage measurements. On most chips, all | 
 | voltage inputs can measure voltages between 0 and 4.08 volts, with a resolution | 
 | of 0.016 volt.  IT8603E, IT8721F/IT8758E and IT8728F can measure between 0 and | 
 | 3.06 volts, with a resolution of 0.012 volt.  IT8732F can measure between 0 and | 
 | 2.8 volts with a resolution of 0.0109 volt.  The battery voltage in8 does not | 
 | have limit registers. | 
 |  | 
 | On the IT8603E, IT8620E, IT8628E, IT8721F/IT8758E, IT8732F, IT8781F, IT8782F, | 
 | and IT8783E/F, some voltage inputs are internal and scaled inside the chip: | 
 | * in3 (optional) | 
 | * in7 (optional for IT8781F, IT8782F, and IT8783E/F) | 
 | * in8 (always) | 
 | * in9 (relevant for IT8603E only) | 
 | The driver handles this transparently so user-space doesn't have to care. | 
 |  | 
 | The VID lines (IT8712F/IT8716F/IT8718F/IT8720F) encode the core voltage value: | 
 | the voltage level your processor should work with. This is hardcoded by | 
 | the mainboard and/or processor itself. It is a value in volts. | 
 |  | 
 | 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 in the current implementation, all hardware | 
 | registers are read whenever any data is read (unless it is less than 1.5 | 
 | seconds since the last update). This means that you can easily miss | 
 | once-only alarms. | 
 |  | 
 | Out-of-limit readings can also result in beeping, if the chip is properly | 
 | wired and configured. Beeping can be enabled or disabled per sensor type | 
 | (temperatures, voltages and fans.) | 
 |  | 
 | The IT87xx only updates its values each 1.5 seconds; reading it more often | 
 | will do no harm, but will return 'old' values. | 
 |  | 
 | To change sensor N to a thermistor, 'echo 4 > tempN_type' where N is 1, 2, | 
 | or 3. To change sensor N to a thermal diode, 'echo 3 > tempN_type'. | 
 | Give 0 for unused sensor. Any other value is invalid. To configure this at | 
 | startup, consult lm_sensors's /etc/sensors.conf. (4 = thermistor; | 
 | 3 = thermal diode) | 
 |  | 
 |  | 
 | Fan speed control | 
 | ----------------- | 
 |  | 
 | The fan speed control features are limited to manual PWM mode. Automatic | 
 | "Smart Guardian" mode control handling is only implemented for older chips | 
 | (see below.) However if you want to go for "manual mode" just write 1 to | 
 | pwmN_enable. | 
 |  | 
 | If you are only able to control the fan speed with very small PWM values, | 
 | try lowering the PWM base frequency (pwm1_freq). Depending on the fan, | 
 | it may give you a somewhat greater control range. The same frequency is | 
 | used to drive all fan outputs, which is why pwm2_freq and pwm3_freq are | 
 | read-only. | 
 |  | 
 |  | 
 | Automatic fan speed control (old interface) | 
 | ------------------------------------------- | 
 |  | 
 | The driver supports the old interface to automatic fan speed control | 
 | which is implemented by IT8705F chips up to revision F and IT8712F | 
 | chips up to revision G. | 
 |  | 
 | This interface implements 4 temperature vs. PWM output trip points. | 
 | The PWM output of trip point 4 is always the maximum value (fan running | 
 | at full speed) while the PWM output of the other 3 trip points can be | 
 | freely chosen. The temperature of all 4 trip points can be freely chosen. | 
 | Additionally, trip point 1 has an hysteresis temperature attached, to | 
 | prevent fast switching between fan on and off. | 
 |  | 
 | The chip automatically computes the PWM output value based on the input | 
 | temperature, based on this simple rule: if the temperature value is | 
 | between trip point N and trip point N+1 then the PWM output value is | 
 | the one of trip point N. The automatic control mode is less flexible | 
 | than the manual control mode, but it reacts faster, is more robust and | 
 | doesn't use CPU cycles. | 
 |  | 
 | Trip points must be set properly before switching to automatic fan speed | 
 | control mode. The driver will perform basic integrity checks before | 
 | actually switching to automatic control mode. | 
 |  | 
 |  | 
 | Temperature offset attributes | 
 | ----------------------------- | 
 |  | 
 | The driver supports temp[1-3]_offset sysfs attributes to adjust the reported | 
 | temperature for thermal diodes or diode-connected thermal transistors. | 
 | If a temperature sensor is configured for thermistors, the attribute values | 
 | are ignored. If the thermal sensor type is Intel PECI, the temperature offset | 
 | must be programmed to the critical CPU temperature. |