Based on kernel version 4.0. Page generated on 2015-04-14 21:24 EST.
1 Kernel driver it87 2 ================== 3 4 Supported 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 58 Authors: 59 Christophe Gauthron 60 Jean Delvare <firstname.lastname@example.org> 61 62 63 Module 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 83 Hardware Interfaces 84 ------------------- 85 86 All the chips supported by this driver are LPC Super-I/O chips, accessed 87 through the LPC bus (ISA-like I/O ports). The IT8712F additionally has an 88 SMBus interface to the hardware monitoring functions. This driver no 89 longer supports this interface though, as it is slower and less reliable 90 than the ISA access, and was only available on a small number of 91 motherboard models. 92 93 94 Description 95 ----------- 96 97 This driver implements support for the IT8603E, IT8623E, IT8705F, IT8712F, 98 IT8716F, IT8718F, IT8720F, IT8721F, IT8726F, IT8728F, IT8758E, IT8771E, 99 IT8772E, IT8782F, IT8783E/F, and SiS950 chips. 100 101 These chips are 'Super I/O chips', supporting floppy disks, infrared ports, 102 joysticks and other miscellaneous stuff. For hardware monitoring, they 103 include an 'environment controller' with 3 temperature sensors, 3 fan 104 rotation speed sensors, 8 voltage sensors, associated alarms, and chassis 105 intrusion detection. 106 107 The IT8712F and IT8716F additionally feature VID inputs, used to report 108 the Vcore voltage of the processor. The early IT8712F have 5 VID pins, 109 the IT8716F and late IT8712F have 6. They are shared with other functions 110 though, so the functionality may not be available on a given system. 111 112 The IT8718F and IT8720F also features VID inputs (up to 8 pins) but the value 113 is stored in the Super-I/O configuration space. Due to technical limitations, 114 this value can currently only be read once at initialization time, so 115 the driver won't notice and report changes in the VID value. The two 116 upper VID bits share their pins with voltage inputs (in5 and in6) so you 117 can't have both on a given board. 118 119 The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E and later IT8712F revisions 120 have support for 2 additional fans. The additional fans are supported by the 121 driver. 122 123 The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E, IT8782F, IT8783E/F, and late 124 IT8712F and IT8705F also have optional 16-bit tachometer counters for fans 1 to 125 3. This is better (no more fan clock divider mess) but not compatible with the 126 older chips and revisions. The 16-bit tachometer mode is enabled by the driver 127 when one of the above chips is detected. 128 129 The IT8726F is just bit enhanced IT8716F with additional hardware 130 for AMD power sequencing. Therefore the chip will appear as IT8716F 131 to userspace applications. 132 133 The IT8728F, IT8771E, and IT8772E are considered compatible with the IT8721F, 134 until a datasheet becomes available (hopefully.) 135 136 The IT8603E/IT8623E is a custom design, hardware monitoring part is similar to 137 IT8728F. It only supports 16-bit fan mode, the full speed mode of the 138 fan is not supported (value 0 of pwmX_enable). 139 140 Temperatures are measured in degrees Celsius. An alarm is triggered once 141 when the Overtemperature Shutdown limit is crossed. 142 143 Fan rotation speeds are reported in RPM (rotations per minute). An alarm is 144 triggered if the rotation speed has dropped below a programmable limit. When 145 16-bit tachometer counters aren't used, fan readings can be divided by 146 a programmable divider (1, 2, 4 or 8) to give the readings more range or 147 accuracy. With a divider of 2, the lowest representable value is around 148 2600 RPM. Not all RPM values can accurately be represented, so some rounding 149 is done. 150 151 Voltage sensors (also known as IN sensors) report their values in volts. An 152 alarm is triggered if the voltage has crossed a programmable minimum or 153 maximum limit. Note that minimum in this case always means 'closest to 154 zero'; this is important for negative voltage measurements. All voltage 155 inputs can measure voltages between 0 and 4.08 volts, with a resolution of 156 0.016 volt (except IT8603E, IT8721F/IT8758E and IT8728F: 0.012 volt.) The 157 battery voltage in8 does not have limit registers. 158 159 On the IT8603E, IT8721F/IT8758E, IT8782F, and IT8783E/F, some voltage inputs 160 are 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) 165 The driver handles this transparently so user-space doesn't have to care. 166 167 The VID lines (IT8712F/IT8716F/IT8718F/IT8720F) encode the core voltage value: 168 the voltage level your processor should work with. This is hardcoded by 169 the mainboard and/or processor itself. It is a value in volts. 170 171 If an alarm triggers, it will remain triggered until the hardware register 172 is read at least once. This means that the cause for the alarm may already 173 have disappeared! Note that in the current implementation, all hardware 174 registers are read whenever any data is read (unless it is less than 1.5 175 seconds since the last update). This means that you can easily miss 176 once-only alarms. 177 178 Out-of-limit readings can also result in beeping, if the chip is properly 179 wired and configured. Beeping can be enabled or disabled per sensor type 180 (temperatures, voltages and fans.) 181 182 The IT87xx only updates its values each 1.5 seconds; reading it more often 183 will do no harm, but will return 'old' values. 184 185 To change sensor N to a thermistor, 'echo 4 > tempN_type' where N is 1, 2, 186 or 3. To change sensor N to a thermal diode, 'echo 3 > tempN_type'. 187 Give 0 for unused sensor. Any other value is invalid. To configure this at 188 startup, consult lm_sensors's /etc/sensors.conf. (4 = thermistor; 189 3 = thermal diode) 190 191 192 Fan speed control 193 ----------------- 194 195 The 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 198 pwmN_enable. 199 200 If you are only able to control the fan speed with very small PWM values, 201 try lowering the PWM base frequency (pwm1_freq). Depending on the fan, 202 it may give you a somewhat greater control range. The same frequency is 203 used to drive all fan outputs, which is why pwm2_freq and pwm3_freq are 204 read-only. 205 206 207 Automatic fan speed control (old interface) 208 ------------------------------------------- 209 210 The driver supports the old interface to automatic fan speed control 211 which is implemented by IT8705F chips up to revision F and IT8712F 212 chips up to revision G. 213 214 This interface implements 4 temperature vs. PWM output trip points. 215 The PWM output of trip point 4 is always the maximum value (fan running 216 at full speed) while the PWM output of the other 3 trip points can be 217 freely chosen. The temperature of all 4 trip points can be freely chosen. 218 Additionally, trip point 1 has an hysteresis temperature attached, to 219 prevent fast switching between fan on and off. 220 221 The chip automatically computes the PWM output value based on the input 222 temperature, based on this simple rule: if the temperature value is 223 between trip point N and trip point N+1 then the PWM output value is 224 the one of trip point N. The automatic control mode is less flexible 225 than the manual control mode, but it reacts faster, is more robust and 226 doesn't use CPU cycles. 227 228 Trip points must be set properly before switching to automatic fan speed 229 control mode. The driver will perform basic integrity checks before 230 actually switching to automatic control mode. 231 232 233 Temperature offset attributes 234 ----------------------------- 235 236 The driver supports temp[1-3]_offset sysfs attributes to adjust the reported 237 temperature for thermal diodes or diode-connected thermal transistors. 238 If a temperature sensor is configured for thermistors, the attribute values 239 are ignored. If the thermal sensor type is Intel PECI, the temperature offset 240 must be programmed to the critical CPU temperature.