1Kernel driver it87 2================== 3 4Supported chips: 5 * IT8603E/IT8623E 6 Prefix: 'it8603' 7 Addresses scanned: from Super I/O config space (8 I/O ports) 8 Datasheet: Not publicly available 9 * IT8705F 10 Prefix: 'it87' 11 Addresses scanned: from Super I/O config space (8 I/O ports) 12 Datasheet: Once publicly available at the ITE website, but no longer 13 * IT8712F 14 Prefix: 'it8712' 15 Addresses scanned: from Super I/O config space (8 I/O ports) 16 Datasheet: Once publicly available at the ITE website, but no longer 17 * IT8716F/IT8726F 18 Prefix: 'it8716' 19 Addresses scanned: from Super I/O config space (8 I/O ports) 20 Datasheet: Once publicly available at the ITE website, but no longer 21 * IT8718F 22 Prefix: 'it8718' 23 Addresses scanned: from Super I/O config space (8 I/O ports) 24 Datasheet: Once publicly available at the ITE website, but no longer 25 * IT8720F 26 Prefix: 'it8720' 27 Addresses scanned: from Super I/O config space (8 I/O ports) 28 Datasheet: Not publicly available 29 * IT8721F/IT8758E 30 Prefix: 'it8721' 31 Addresses scanned: from Super I/O config space (8 I/O ports) 32 Datasheet: Not publicly available 33 * IT8728F 34 Prefix: 'it8728' 35 Addresses scanned: from Super I/O config space (8 I/O ports) 36 Datasheet: Not publicly available 37 * IT8771E 38 Prefix: 'it8771' 39 Addresses scanned: from Super I/O config space (8 I/O ports) 40 Datasheet: Not publicly available 41 * IT8772E 42 Prefix: 'it8772' 43 Addresses scanned: from Super I/O config space (8 I/O ports) 44 Datasheet: Not publicly available 45 * IT8782F 46 Prefix: 'it8782' 47 Addresses scanned: from Super I/O config space (8 I/O ports) 48 Datasheet: Not publicly available 49 * IT8783E/F 50 Prefix: 'it8783' 51 Addresses scanned: from Super I/O config space (8 I/O ports) 52 Datasheet: Not publicly available 53 * SiS950 [clone of IT8705F] 54 Prefix: 'it87' 55 Addresses scanned: from Super I/O config space (8 I/O ports) 56 Datasheet: No longer be available 57 58Authors: 59 Christophe Gauthron 60 Jean Delvare <jdelvare@suse.de> 61 62 63Module Parameters 64----------------- 65 66* update_vbat: int 67 68 0 if vbat should report power on value, 1 if vbat should be updated after 69 each read. Default is 0. On some boards the battery voltage is provided 70 by either the battery or the onboard power supply. Only the first reading 71 at power on will be the actual battery voltage (which the chip does 72 automatically). On other boards the battery voltage is always fed to 73 the chip so can be read at any time. Excessive reading may decrease 74 battery life but no information is given in the datasheet. 75 76* fix_pwm_polarity int 77 78 Force PWM polarity to active high (DANGEROUS). Some chips are 79 misconfigured by BIOS - PWM values would be inverted. This option tries 80 to fix this. Please contact your BIOS manufacturer and ask him for fix. 81 82 83Hardware Interfaces 84------------------- 85 86All the chips supported by this driver are LPC Super-I/O chips, accessed 87through the LPC bus (ISA-like I/O ports). The IT8712F additionally has an 88SMBus interface to the hardware monitoring functions. This driver no 89longer supports this interface though, as it is slower and less reliable 90than the ISA access, and was only available on a small number of 91motherboard models. 92 93 94Description 95----------- 96 97This driver implements support for the IT8603E, IT8623E, IT8705F, IT8712F, 98IT8716F, IT8718F, IT8720F, IT8721F, IT8726F, IT8728F, IT8758E, IT8771E, 99IT8772E, IT8782F, IT8783E/F, and SiS950 chips. 100 101These chips are 'Super I/O chips', supporting floppy disks, infrared ports, 102joysticks and other miscellaneous stuff. For hardware monitoring, they 103include an 'environment controller' with 3 temperature sensors, 3 fan 104rotation speed sensors, 8 voltage sensors, associated alarms, and chassis 105intrusion detection. 106 107The IT8712F and IT8716F additionally feature VID inputs, used to report 108the Vcore voltage of the processor. The early IT8712F have 5 VID pins, 109the IT8716F and late IT8712F have 6. They are shared with other functions 110though, so the functionality may not be available on a given system. 111 112The IT8718F and IT8720F also features VID inputs (up to 8 pins) but the value 113is stored in the Super-I/O configuration space. Due to technical limitations, 114this value can currently only be read once at initialization time, so 115the driver won't notice and report changes in the VID value. The two 116upper VID bits share their pins with voltage inputs (in5 and in6) so you 117can't have both on a given board. 118 119The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E and later IT8712F revisions 120have support for 2 additional fans. The additional fans are supported by the 121driver. 122 123The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E, IT8782F, IT8783E/F, and late 124IT8712F and IT8705F also have optional 16-bit tachometer counters for fans 1 to 1253. This is better (no more fan clock divider mess) but not compatible with the 126older chips and revisions. The 16-bit tachometer mode is enabled by the driver 127when one of the above chips is detected. 128 129The IT8726F is just bit enhanced IT8716F with additional hardware 130for AMD power sequencing. Therefore the chip will appear as IT8716F 131to userspace applications. 132 133The IT8728F, IT8771E, and IT8772E are considered compatible with the IT8721F, 134until a datasheet becomes available (hopefully.) 135 136The IT8603E/IT8623E is a custom design, hardware monitoring part is similar to 137IT8728F. It only supports 16-bit fan mode, the full speed mode of the 138fan is not supported (value 0 of pwmX_enable). 139 140Temperatures are measured in degrees Celsius. An alarm is triggered once 141when the Overtemperature Shutdown limit is crossed. 142 143Fan rotation speeds are reported in RPM (rotations per minute). An alarm is 144triggered if the rotation speed has dropped below a programmable limit. When 14516-bit tachometer counters aren't used, fan readings can be divided by 146a programmable divider (1, 2, 4 or 8) to give the readings more range or 147accuracy. With a divider of 2, the lowest representable value is around 1482600 RPM. Not all RPM values can accurately be represented, so some rounding 149is done. 150 151Voltage sensors (also known as IN sensors) report their values in volts. An 152alarm is triggered if the voltage has crossed a programmable minimum or 153maximum limit. Note that minimum in this case always means 'closest to 154zero'; this is important for negative voltage measurements. All voltage 155inputs can measure voltages between 0 and 4.08 volts, with a resolution of 1560.016 volt (except IT8603E, IT8721F/IT8758E and IT8728F: 0.012 volt.) The 157battery voltage in8 does not have limit registers. 158 159On the IT8603E, IT8721F/IT8758E, IT8782F, and IT8783E/F, some voltage inputs 160are internal and scaled inside the chip: 161* in3 (optional) 162* in7 (optional for IT8782F and IT8783E/F) 163* in8 (always) 164* in9 (relevant for IT8603E only) 165The driver handles this transparently so user-space doesn't have to care. 166 167The VID lines (IT8712F/IT8716F/IT8718F/IT8720F) encode the core voltage value: 168the voltage level your processor should work with. This is hardcoded by 169the mainboard and/or processor itself. It is a value in volts. 170 171If an alarm triggers, it will remain triggered until the hardware register 172is read at least once. This means that the cause for the alarm may already 173have disappeared! Note that in the current implementation, all hardware 174registers are read whenever any data is read (unless it is less than 1.5 175seconds since the last update). This means that you can easily miss 176once-only alarms. 177 178Out-of-limit readings can also result in beeping, if the chip is properly 179wired and configured. Beeping can be enabled or disabled per sensor type 180(temperatures, voltages and fans.) 181 182The IT87xx only updates its values each 1.5 seconds; reading it more often 183will do no harm, but will return 'old' values. 184 185To change sensor N to a thermistor, 'echo 4 > tempN_type' where N is 1, 2, 186or 3. To change sensor N to a thermal diode, 'echo 3 > tempN_type'. 187Give 0 for unused sensor. Any other value is invalid. To configure this at 188startup, consult lm_sensors's /etc/sensors.conf. (4 = thermistor; 1893 = thermal diode) 190 191 192Fan speed control 193----------------- 194 195The fan speed control features are limited to manual PWM mode. Automatic 196"Smart Guardian" mode control handling is only implemented for older chips 197(see below.) However if you want to go for "manual mode" just write 1 to 198pwmN_enable. 199 200If you are only able to control the fan speed with very small PWM values, 201try lowering the PWM base frequency (pwm1_freq). Depending on the fan, 202it may give you a somewhat greater control range. The same frequency is 203used to drive all fan outputs, which is why pwm2_freq and pwm3_freq are 204read-only. 205 206 207Automatic fan speed control (old interface) 208------------------------------------------- 209 210The driver supports the old interface to automatic fan speed control 211which is implemented by IT8705F chips up to revision F and IT8712F 212chips up to revision G. 213 214This interface implements 4 temperature vs. PWM output trip points. 215The PWM output of trip point 4 is always the maximum value (fan running 216at full speed) while the PWM output of the other 3 trip points can be 217freely chosen. The temperature of all 4 trip points can be freely chosen. 218Additionally, trip point 1 has an hysteresis temperature attached, to 219prevent fast switching between fan on and off. 220 221The chip automatically computes the PWM output value based on the input 222temperature, based on this simple rule: if the temperature value is 223between trip point N and trip point N+1 then the PWM output value is 224the one of trip point N. The automatic control mode is less flexible 225than the manual control mode, but it reacts faster, is more robust and 226doesn't use CPU cycles. 227 228Trip points must be set properly before switching to automatic fan speed 229control mode. The driver will perform basic integrity checks before 230actually switching to automatic control mode. 231 232 233Temperature offset attributes 234----------------------------- 235 236The driver supports temp[1-3]_offset sysfs attributes to adjust the reported 237temperature for thermal diodes or diode-connected thermal transistors. 238If a temperature sensor is configured for thermistors, the attribute values 239are ignored. If the thermal sensor type is Intel PECI, the temperature offset 240must be programmed to the critical CPU temperature. 241