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 * IT8620E 10 Prefix: 'it8620' 11 Addresses scanned: from Super I/O config space (8 I/O ports) 12 Datasheet: Not publicly available 13 * IT8705F 14 Prefix: 'it87' 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 * IT8712F 18 Prefix: 'it8712' 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 * IT8716F/IT8726F 22 Prefix: 'it8716' 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 * IT8718F 26 Prefix: 'it8718' 27 Addresses scanned: from Super I/O config space (8 I/O ports) 28 Datasheet: Once publicly available at the ITE website, but no longer 29 * IT8720F 30 Prefix: 'it8720' 31 Addresses scanned: from Super I/O config space (8 I/O ports) 32 Datasheet: Not publicly available 33 * IT8721F/IT8758E 34 Prefix: 'it8721' 35 Addresses scanned: from Super I/O config space (8 I/O ports) 36 Datasheet: Not publicly available 37 * IT8728F 38 Prefix: 'it8728' 39 Addresses scanned: from Super I/O config space (8 I/O ports) 40 Datasheet: Not publicly available 41 * IT8771E 42 Prefix: 'it8771' 43 Addresses scanned: from Super I/O config space (8 I/O ports) 44 Datasheet: Not publicly available 45 * IT8772E 46 Prefix: 'it8772' 47 Addresses scanned: from Super I/O config space (8 I/O ports) 48 Datasheet: Not publicly available 49 * IT8781F 50 Prefix: 'it8781' 51 Addresses scanned: from Super I/O config space (8 I/O ports) 52 Datasheet: Not publicly available 53 * IT8782F 54 Prefix: 'it8782' 55 Addresses scanned: from Super I/O config space (8 I/O ports) 56 Datasheet: Not publicly available 57 * IT8783E/F 58 Prefix: 'it8783' 59 Addresses scanned: from Super I/O config space (8 I/O ports) 60 Datasheet: Not publicly available 61 * IT8786E 62 Prefix: 'it8786' 63 Addresses scanned: from Super I/O config space (8 I/O ports) 64 Datasheet: Not publicly available 65 * IT8790E 66 Prefix: 'it8790' 67 Addresses scanned: from Super I/O config space (8 I/O ports) 68 Datasheet: Not publicly available 69 * SiS950 [clone of IT8705F] 70 Prefix: 'it87' 71 Addresses scanned: from Super I/O config space (8 I/O ports) 72 Datasheet: No longer be available 73 74Authors: 75 Christophe Gauthron 76 Jean Delvare <jdelvare@suse.de> 77 78 79Module Parameters 80----------------- 81 82* update_vbat: int 83 84 0 if vbat should report power on value, 1 if vbat should be updated after 85 each read. Default is 0. On some boards the battery voltage is provided 86 by either the battery or the onboard power supply. Only the first reading 87 at power on will be the actual battery voltage (which the chip does 88 automatically). On other boards the battery voltage is always fed to 89 the chip so can be read at any time. Excessive reading may decrease 90 battery life but no information is given in the datasheet. 91 92* fix_pwm_polarity int 93 94 Force PWM polarity to active high (DANGEROUS). Some chips are 95 misconfigured by BIOS - PWM values would be inverted. This option tries 96 to fix this. Please contact your BIOS manufacturer and ask him for fix. 97 98 99Hardware Interfaces 100------------------- 101 102All the chips supported by this driver are LPC Super-I/O chips, accessed 103through the LPC bus (ISA-like I/O ports). The IT8712F additionally has an 104SMBus interface to the hardware monitoring functions. This driver no 105longer supports this interface though, as it is slower and less reliable 106than the ISA access, and was only available on a small number of 107motherboard models. 108 109 110Description 111----------- 112 113This driver implements support for the IT8603E, IT8620E, IT8623E, IT8705F, 114IT8712F, IT8716F, IT8718F, IT8720F, IT8721F, IT8726F, IT8728F, IT8758E, 115IT8771E, IT8772E, IT8781F, IT8782F, IT8783E/F, IT8786E, IT8790E, and SiS950 116chips. 117 118These chips are 'Super I/O chips', supporting floppy disks, infrared ports, 119joysticks and other miscellaneous stuff. For hardware monitoring, they 120include an 'environment controller' with 3 temperature sensors, 3 fan 121rotation speed sensors, 8 voltage sensors, associated alarms, and chassis 122intrusion detection. 123 124The IT8712F and IT8716F additionally feature VID inputs, used to report 125the Vcore voltage of the processor. The early IT8712F have 5 VID pins, 126the IT8716F and late IT8712F have 6. They are shared with other functions 127though, so the functionality may not be available on a given system. 128 129The IT8718F and IT8720F also features VID inputs (up to 8 pins) but the value 130is stored in the Super-I/O configuration space. Due to technical limitations, 131this value can currently only be read once at initialization time, so 132the driver won't notice and report changes in the VID value. The two 133upper VID bits share their pins with voltage inputs (in5 and in6) so you 134can't have both on a given board. 135 136The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E and later IT8712F revisions 137have support for 2 additional fans. The additional fans are supported by the 138driver. 139 140The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E, IT8781F, IT8782F, IT8783E/F, 141and late IT8712F and IT8705F also have optional 16-bit tachometer counters 142for fans 1 to 3. This is better (no more fan clock divider mess) but not 143compatible with the older chips and revisions. The 16-bit tachometer mode 144is enabled by the driver when one of the above chips is detected. 145 146The IT8726F is just bit enhanced IT8716F with additional hardware 147for AMD power sequencing. Therefore the chip will appear as IT8716F 148to userspace applications. 149 150The IT8728F, IT8771E, and IT8772E are considered compatible with the IT8721F, 151until a datasheet becomes available (hopefully.) 152 153The IT8603E/IT8623E is a custom design, hardware monitoring part is similar to 154IT8728F. It only supports 3 fans, 16-bit fan mode, and the full speed mode 155of the fan is not supported (value 0 of pwmX_enable). 156 157The IT8620E is another custom design, hardware monitoring part is similar to 158IT8728F. It only supports 16-bit fan mode. 159 160The IT8790E supports up to 3 fans. 16-bit fan mode is always enabled. 161 162Temperatures are measured in degrees Celsius. An alarm is triggered once 163when the Overtemperature Shutdown limit is crossed. 164 165Fan rotation speeds are reported in RPM (rotations per minute). An alarm is 166triggered if the rotation speed has dropped below a programmable limit. When 16716-bit tachometer counters aren't used, fan readings can be divided by 168a programmable divider (1, 2, 4 or 8) to give the readings more range or 169accuracy. With a divider of 2, the lowest representable value is around 1702600 RPM. Not all RPM values can accurately be represented, so some rounding 171is done. 172 173Voltage sensors (also known as IN sensors) report their values in volts. An 174alarm is triggered if the voltage has crossed a programmable minimum or 175maximum limit. Note that minimum in this case always means 'closest to 176zero'; this is important for negative voltage measurements. All voltage 177inputs can measure voltages between 0 and 4.08 volts, with a resolution of 1780.016 volt (except IT8603E, IT8721F/IT8758E and IT8728F: 0.012 volt.) The 179battery voltage in8 does not have limit registers. 180 181On the IT8603E, IT8721F/IT8758E, IT8781F, IT8782F, and IT8783E/F, some 182voltage inputs are internal and scaled inside the chip: 183* in3 (optional) 184* in7 (optional for IT8781F, IT8782F, and IT8783E/F) 185* in8 (always) 186* in9 (relevant for IT8603E only) 187The driver handles this transparently so user-space doesn't have to care. 188 189The VID lines (IT8712F/IT8716F/IT8718F/IT8720F) encode the core voltage value: 190the voltage level your processor should work with. This is hardcoded by 191the mainboard and/or processor itself. It is a value in volts. 192 193If an alarm triggers, it will remain triggered until the hardware register 194is read at least once. This means that the cause for the alarm may already 195have disappeared! Note that in the current implementation, all hardware 196registers are read whenever any data is read (unless it is less than 1.5 197seconds since the last update). This means that you can easily miss 198once-only alarms. 199 200Out-of-limit readings can also result in beeping, if the chip is properly 201wired and configured. Beeping can be enabled or disabled per sensor type 202(temperatures, voltages and fans.) 203 204The IT87xx only updates its values each 1.5 seconds; reading it more often 205will do no harm, but will return 'old' values. 206 207To change sensor N to a thermistor, 'echo 4 > tempN_type' where N is 1, 2, 208or 3. To change sensor N to a thermal diode, 'echo 3 > tempN_type'. 209Give 0 for unused sensor. Any other value is invalid. To configure this at 210startup, consult lm_sensors's /etc/sensors.conf. (4 = thermistor; 2113 = thermal diode) 212 213 214Fan speed control 215----------------- 216 217The fan speed control features are limited to manual PWM mode. Automatic 218"Smart Guardian" mode control handling is only implemented for older chips 219(see below.) However if you want to go for "manual mode" just write 1 to 220pwmN_enable. 221 222If you are only able to control the fan speed with very small PWM values, 223try lowering the PWM base frequency (pwm1_freq). Depending on the fan, 224it may give you a somewhat greater control range. The same frequency is 225used to drive all fan outputs, which is why pwm2_freq and pwm3_freq are 226read-only. 227 228 229Automatic fan speed control (old interface) 230------------------------------------------- 231 232The driver supports the old interface to automatic fan speed control 233which is implemented by IT8705F chips up to revision F and IT8712F 234chips up to revision G. 235 236This interface implements 4 temperature vs. PWM output trip points. 237The PWM output of trip point 4 is always the maximum value (fan running 238at full speed) while the PWM output of the other 3 trip points can be 239freely chosen. The temperature of all 4 trip points can be freely chosen. 240Additionally, trip point 1 has an hysteresis temperature attached, to 241prevent fast switching between fan on and off. 242 243The chip automatically computes the PWM output value based on the input 244temperature, based on this simple rule: if the temperature value is 245between trip point N and trip point N+1 then the PWM output value is 246the one of trip point N. The automatic control mode is less flexible 247than the manual control mode, but it reacts faster, is more robust and 248doesn't use CPU cycles. 249 250Trip points must be set properly before switching to automatic fan speed 251control mode. The driver will perform basic integrity checks before 252actually switching to automatic control mode. 253 254 255Temperature offset attributes 256----------------------------- 257 258The driver supports temp[1-3]_offset sysfs attributes to adjust the reported 259temperature for thermal diodes or diode-connected thermal transistors. 260If a temperature sensor is configured for thermistors, the attribute values 261are ignored. If the thermal sensor type is Intel PECI, the temperature offset 262must be programmed to the critical CPU temperature. 263