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 * IT8628E 13 Prefix: 'it8628' 14 Addresses scanned: from Super I/O config space (8 I/O ports) 15 Datasheet: Not publicly available 16 * IT8705F 17 Prefix: 'it87' 18 Addresses scanned: from Super I/O config space (8 I/O ports) 19 Datasheet: Once publicly available at the ITE website, but no longer 20 * IT8712F 21 Prefix: 'it8712' 22 Addresses scanned: from Super I/O config space (8 I/O ports) 23 Datasheet: Once publicly available at the ITE website, but no longer 24 * IT8716F/IT8726F 25 Prefix: 'it8716' 26 Addresses scanned: from Super I/O config space (8 I/O ports) 27 Datasheet: Once publicly available at the ITE website, but no longer 28 * IT8718F 29 Prefix: 'it8718' 30 Addresses scanned: from Super I/O config space (8 I/O ports) 31 Datasheet: Once publicly available at the ITE website, but no longer 32 * IT8720F 33 Prefix: 'it8720' 34 Addresses scanned: from Super I/O config space (8 I/O ports) 35 Datasheet: Not publicly available 36 * IT8721F/IT8758E 37 Prefix: 'it8721' 38 Addresses scanned: from Super I/O config space (8 I/O ports) 39 Datasheet: Not publicly available 40 * IT8728F 41 Prefix: 'it8728' 42 Addresses scanned: from Super I/O config space (8 I/O ports) 43 Datasheet: Not publicly available 44 * IT8732F 45 Prefix: 'it8732' 46 Addresses scanned: from Super I/O config space (8 I/O ports) 47 Datasheet: Not publicly available 48 * IT8771E 49 Prefix: 'it8771' 50 Addresses scanned: from Super I/O config space (8 I/O ports) 51 Datasheet: Not publicly available 52 * IT8772E 53 Prefix: 'it8772' 54 Addresses scanned: from Super I/O config space (8 I/O ports) 55 Datasheet: Not publicly available 56 * IT8781F 57 Prefix: 'it8781' 58 Addresses scanned: from Super I/O config space (8 I/O ports) 59 Datasheet: Not publicly available 60 * IT8782F 61 Prefix: 'it8782' 62 Addresses scanned: from Super I/O config space (8 I/O ports) 63 Datasheet: Not publicly available 64 * IT8783E/F 65 Prefix: 'it8783' 66 Addresses scanned: from Super I/O config space (8 I/O ports) 67 Datasheet: Not publicly available 68 * IT8786E 69 Prefix: 'it8786' 70 Addresses scanned: from Super I/O config space (8 I/O ports) 71 Datasheet: Not publicly available 72 * IT8790E 73 Prefix: 'it8790' 74 Addresses scanned: from Super I/O config space (8 I/O ports) 75 Datasheet: Not publicly available 76 * SiS950 [clone of IT8705F] 77 Prefix: 'it87' 78 Addresses scanned: from Super I/O config space (8 I/O ports) 79 Datasheet: No longer be available 80 81Authors: 82 Christophe Gauthron 83 Jean Delvare <jdelvare@suse.de> 84 85 86Module Parameters 87----------------- 88 89* update_vbat: int 90 91 0 if vbat should report power on value, 1 if vbat should be updated after 92 each read. Default is 0. On some boards the battery voltage is provided 93 by either the battery or the onboard power supply. Only the first reading 94 at power on will be the actual battery voltage (which the chip does 95 automatically). On other boards the battery voltage is always fed to 96 the chip so can be read at any time. Excessive reading may decrease 97 battery life but no information is given in the datasheet. 98 99* fix_pwm_polarity int 100 101 Force PWM polarity to active high (DANGEROUS). Some chips are 102 misconfigured by BIOS - PWM values would be inverted. This option tries 103 to fix this. Please contact your BIOS manufacturer and ask him for fix. 104 105 106Hardware Interfaces 107------------------- 108 109All the chips supported by this driver are LPC Super-I/O chips, accessed 110through the LPC bus (ISA-like I/O ports). The IT8712F additionally has an 111SMBus interface to the hardware monitoring functions. This driver no 112longer supports this interface though, as it is slower and less reliable 113than the ISA access, and was only available on a small number of 114motherboard models. 115 116 117Description 118----------- 119 120This driver implements support for the IT8603E, IT8620E, IT8623E, IT8628E, 121IT8705F, IT8712F, IT8716F, IT8718F, IT8720F, IT8721F, IT8726F, IT8728F, IT8732F, 122IT8758E, IT8771E, IT8772E, IT8781F, IT8782F, IT8783E/F, IT8786E, IT8790E, and 123SiS950 chips. 124 125These chips are 'Super I/O chips', supporting floppy disks, infrared ports, 126joysticks and other miscellaneous stuff. For hardware monitoring, they 127include an 'environment controller' with 3 temperature sensors, 3 fan 128rotation speed sensors, 8 voltage sensors, associated alarms, and chassis 129intrusion detection. 130 131The IT8712F and IT8716F additionally feature VID inputs, used to report 132the Vcore voltage of the processor. The early IT8712F have 5 VID pins, 133the IT8716F and late IT8712F have 6. They are shared with other functions 134though, so the functionality may not be available on a given system. 135 136The IT8718F and IT8720F also features VID inputs (up to 8 pins) but the value 137is stored in the Super-I/O configuration space. Due to technical limitations, 138this value can currently only be read once at initialization time, so 139the driver won't notice and report changes in the VID value. The two 140upper VID bits share their pins with voltage inputs (in5 and in6) so you 141can't have both on a given board. 142 143The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E and later IT8712F revisions 144have support for 2 additional fans. The additional fans are supported by the 145driver. 146 147The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E, IT8732F, IT8781F, IT8782F, 148IT8783E/F, and late IT8712F and IT8705F also have optional 16-bit tachometer 149counters for fans 1 to 3. This is better (no more fan clock divider mess) but 150not compatible with the older chips and revisions. The 16-bit tachometer mode 151is enabled by the driver when one of the above chips is detected. 152 153The IT8726F is just bit enhanced IT8716F with additional hardware 154for AMD power sequencing. Therefore the chip will appear as IT8716F 155to userspace applications. 156 157The IT8728F, IT8771E, and IT8772E are considered compatible with the IT8721F, 158until a datasheet becomes available (hopefully.) 159 160The IT8603E/IT8623E is a custom design, hardware monitoring part is similar to 161IT8728F. It only supports 3 fans, 16-bit fan mode, and the full speed mode 162of the fan is not supported (value 0 of pwmX_enable). 163 164The IT8620E and IT8628E are custom designs, hardware monitoring part is similar 165to IT8728F. It only supports 16-bit fan mode. Both chips support up to 6 fans. 166 167The IT8790E supports up to 3 fans. 16-bit fan mode is always enabled. 168 169The IT8732F supports a closed-loop mode for fan control, but this is not 170currently implemented by the driver. 171 172Temperatures are measured in degrees Celsius. An alarm is triggered once 173when the Overtemperature Shutdown limit is crossed. 174 175Fan rotation speeds are reported in RPM (rotations per minute). An alarm is 176triggered if the rotation speed has dropped below a programmable limit. When 17716-bit tachometer counters aren't used, fan readings can be divided by 178a programmable divider (1, 2, 4 or 8) to give the readings more range or 179accuracy. With a divider of 2, the lowest representable value is around 1802600 RPM. Not all RPM values can accurately be represented, so some rounding 181is done. 182 183Voltage sensors (also known as IN sensors) report their values in volts. An 184alarm is triggered if the voltage has crossed a programmable minimum or 185maximum limit. Note that minimum in this case always means 'closest to 186zero'; this is important for negative voltage measurements. On most chips, all 187voltage inputs can measure voltages between 0 and 4.08 volts, with a resolution 188of 0.016 volt. IT8603E, IT8721F/IT8758E and IT8728F can measure between 0 and 1893.06 volts, with a resolution of 0.012 volt. IT8732F can measure between 0 and 1902.8 volts with a resolution of 0.0109 volt. The battery voltage in8 does not 191have limit registers. 192 193On the IT8603E, IT8620E, IT8628E, IT8721F/IT8758E, IT8732F, IT8781F, IT8782F, 194and IT8783E/F, some voltage inputs are internal and scaled inside the chip: 195* in3 (optional) 196* in7 (optional for IT8781F, IT8782F, and IT8783E/F) 197* in8 (always) 198* in9 (relevant for IT8603E only) 199The driver handles this transparently so user-space doesn't have to care. 200 201The VID lines (IT8712F/IT8716F/IT8718F/IT8720F) encode the core voltage value: 202the voltage level your processor should work with. This is hardcoded by 203the mainboard and/or processor itself. It is a value in volts. 204 205If an alarm triggers, it will remain triggered until the hardware register 206is read at least once. This means that the cause for the alarm may already 207have disappeared! Note that in the current implementation, all hardware 208registers are read whenever any data is read (unless it is less than 1.5 209seconds since the last update). This means that you can easily miss 210once-only alarms. 211 212Out-of-limit readings can also result in beeping, if the chip is properly 213wired and configured. Beeping can be enabled or disabled per sensor type 214(temperatures, voltages and fans.) 215 216The IT87xx only updates its values each 1.5 seconds; reading it more often 217will do no harm, but will return 'old' values. 218 219To change sensor N to a thermistor, 'echo 4 > tempN_type' where N is 1, 2, 220or 3. To change sensor N to a thermal diode, 'echo 3 > tempN_type'. 221Give 0 for unused sensor. Any other value is invalid. To configure this at 222startup, consult lm_sensors's /etc/sensors.conf. (4 = thermistor; 2233 = thermal diode) 224 225 226Fan speed control 227----------------- 228 229The fan speed control features are limited to manual PWM mode. Automatic 230"Smart Guardian" mode control handling is only implemented for older chips 231(see below.) However if you want to go for "manual mode" just write 1 to 232pwmN_enable. 233 234If you are only able to control the fan speed with very small PWM values, 235try lowering the PWM base frequency (pwm1_freq). Depending on the fan, 236it may give you a somewhat greater control range. The same frequency is 237used to drive all fan outputs, which is why pwm2_freq and pwm3_freq are 238read-only. 239 240 241Automatic fan speed control (old interface) 242------------------------------------------- 243 244The driver supports the old interface to automatic fan speed control 245which is implemented by IT8705F chips up to revision F and IT8712F 246chips up to revision G. 247 248This interface implements 4 temperature vs. PWM output trip points. 249The PWM output of trip point 4 is always the maximum value (fan running 250at full speed) while the PWM output of the other 3 trip points can be 251freely chosen. The temperature of all 4 trip points can be freely chosen. 252Additionally, trip point 1 has an hysteresis temperature attached, to 253prevent fast switching between fan on and off. 254 255The chip automatically computes the PWM output value based on the input 256temperature, based on this simple rule: if the temperature value is 257between trip point N and trip point N+1 then the PWM output value is 258the one of trip point N. The automatic control mode is less flexible 259than the manual control mode, but it reacts faster, is more robust and 260doesn't use CPU cycles. 261 262Trip points must be set properly before switching to automatic fan speed 263control mode. The driver will perform basic integrity checks before 264actually switching to automatic control mode. 265 266 267Temperature offset attributes 268----------------------------- 269 270The driver supports temp[1-3]_offset sysfs attributes to adjust the reported 271temperature for thermal diodes or diode-connected thermal transistors. 272If a temperature sensor is configured for thermistors, the attribute values 273are ignored. If the thermal sensor type is Intel PECI, the temperature offset 274must be programmed to the critical CPU temperature. 275
