| Kernel driver it87 | |
| ================== | |
| Supported chips: | |
| * 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 | |
| * 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 | |
| * 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 | |
| * 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 <khali@linux-fr.org> | |
| 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 IT8705F, IT8712F, IT8716F, | |
| IT8718F, IT8720F, IT8721F, IT8726F, IT8728F, IT8758E, IT8771E, IT8772E, | |
| IT8782F, IT8783E/F, 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, 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.) | |
| 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. All voltage | |
| inputs can measure voltages between 0 and 4.08 volts, with a resolution of | |
| 0.016 volt (except IT8721F/IT8758E and IT8728F: 0.012 volt.) The battery | |
| voltage in8 does not have limit registers. | |
| On the IT8721F/IT8758E, IT8782F, and IT8783E/F, some voltage inputs are | |
| internal and scaled inside the chip (in7 (optional for IT8782F and IT8783E/F), | |
| in8 and optionally in3). 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. |