Based on kernel version 4.15. Page generated on 2018-01-29 10:00 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 * 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 81 Authors: 82 Christophe Gauthron 83 Jean Delvare <email@example.com> 84 85 86 Module 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. 104 105 106 Hardware Interfaces 107 ------------------- 108 109 All the chips supported by this driver are LPC Super-I/O chips, accessed 110 through the LPC bus (ISA-like I/O ports). The IT8712F additionally has an 111 SMBus interface to the hardware monitoring functions. This driver no 112 longer supports this interface though, as it is slower and less reliable 113 than the ISA access, and was only available on a small number of 114 motherboard models. 115 116 117 Description 118 ----------- 119 120 This driver implements support for the IT8603E, IT8620E, IT8623E, IT8628E, 121 IT8705F, IT8712F, IT8716F, IT8718F, IT8720F, IT8721F, IT8726F, IT8728F, IT8732F, 122 IT8758E, IT8771E, IT8772E, IT8781F, IT8782F, IT8783E/F, IT8786E, IT8790E, and 123 SiS950 chips. 124 125 These chips are 'Super I/O chips', supporting floppy disks, infrared ports, 126 joysticks and other miscellaneous stuff. For hardware monitoring, they 127 include an 'environment controller' with 3 temperature sensors, 3 fan 128 rotation speed sensors, 8 voltage sensors, associated alarms, and chassis 129 intrusion detection. 130 131 The IT8712F and IT8716F additionally feature VID inputs, used to report 132 the Vcore voltage of the processor. The early IT8712F have 5 VID pins, 133 the IT8716F and late IT8712F have 6. They are shared with other functions 134 though, so the functionality may not be available on a given system. 135 136 The IT8718F and IT8720F also features VID inputs (up to 8 pins) but the value 137 is stored in the Super-I/O configuration space. Due to technical limitations, 138 this value can currently only be read once at initialization time, so 139 the driver won't notice and report changes in the VID value. The two 140 upper VID bits share their pins with voltage inputs (in5 and in6) so you 141 can't have both on a given board. 142 143 The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E and later IT8712F revisions 144 have support for 2 additional fans. The additional fans are supported by the 145 driver. 146 147 The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E, IT8732F, IT8781F, IT8782F, 148 IT8783E/F, and late IT8712F and IT8705F also have optional 16-bit tachometer 149 counters for fans 1 to 3. This is better (no more fan clock divider mess) but 150 not compatible with the older chips and revisions. The 16-bit tachometer mode 151 is enabled by the driver when one of the above chips is detected. 152 153 The IT8726F is just bit enhanced IT8716F with additional hardware 154 for AMD power sequencing. Therefore the chip will appear as IT8716F 155 to userspace applications. 156 157 The IT8728F, IT8771E, and IT8772E are considered compatible with the IT8721F, 158 until a datasheet becomes available (hopefully.) 159 160 The IT8603E/IT8623E is a custom design, hardware monitoring part is similar to 161 IT8728F. It only supports 3 fans, 16-bit fan mode, and the full speed mode 162 of the fan is not supported (value 0 of pwmX_enable). 163 164 The IT8620E and IT8628E are custom designs, hardware monitoring part is similar 165 to IT8728F. It only supports 16-bit fan mode. Both chips support up to 6 fans. 166 167 The IT8790E supports up to 3 fans. 16-bit fan mode is always enabled. 168 169 The IT8732F supports a closed-loop mode for fan control, but this is not 170 currently implemented by the driver. 171 172 Temperatures are measured in degrees Celsius. An alarm is triggered once 173 when the Overtemperature Shutdown limit is crossed. 174 175 Fan rotation speeds are reported in RPM (rotations per minute). An alarm is 176 triggered if the rotation speed has dropped below a programmable limit. When 177 16-bit tachometer counters aren't used, fan readings can be divided by 178 a programmable divider (1, 2, 4 or 8) to give the readings more range or 179 accuracy. With a divider of 2, the lowest representable value is around 180 2600 RPM. Not all RPM values can accurately be represented, so some rounding 181 is done. 182 183 Voltage sensors (also known as IN sensors) report their values in volts. An 184 alarm is triggered if the voltage has crossed a programmable minimum or 185 maximum limit. Note that minimum in this case always means 'closest to 186 zero'; this is important for negative voltage measurements. On most chips, all 187 voltage inputs can measure voltages between 0 and 4.08 volts, with a resolution 188 of 0.016 volt. IT8603E, IT8721F/IT8758E and IT8728F can measure between 0 and 189 3.06 volts, with a resolution of 0.012 volt. IT8732F can measure between 0 and 190 2.8 volts with a resolution of 0.0109 volt. The battery voltage in8 does not 191 have limit registers. 192 193 On the IT8603E, IT8620E, IT8628E, IT8721F/IT8758E, IT8732F, IT8781F, IT8782F, 194 and 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) 199 The driver handles this transparently so user-space doesn't have to care. 200 201 The VID lines (IT8712F/IT8716F/IT8718F/IT8720F) encode the core voltage value: 202 the voltage level your processor should work with. This is hardcoded by 203 the mainboard and/or processor itself. It is a value in volts. 204 205 If an alarm triggers, it will remain triggered until the hardware register 206 is read at least once. This means that the cause for the alarm may already 207 have disappeared! Note that in the current implementation, all hardware 208 registers are read whenever any data is read (unless it is less than 1.5 209 seconds since the last update). This means that you can easily miss 210 once-only alarms. 211 212 Out-of-limit readings can also result in beeping, if the chip is properly 213 wired and configured. Beeping can be enabled or disabled per sensor type 214 (temperatures, voltages and fans.) 215 216 The IT87xx only updates its values each 1.5 seconds; reading it more often 217 will do no harm, but will return 'old' values. 218 219 To change sensor N to a thermistor, 'echo 4 > tempN_type' where N is 1, 2, 220 or 3. To change sensor N to a thermal diode, 'echo 3 > tempN_type'. 221 Give 0 for unused sensor. Any other value is invalid. To configure this at 222 startup, consult lm_sensors's /etc/sensors.conf. (4 = thermistor; 223 3 = thermal diode) 224 225 226 Fan speed control 227 ----------------- 228 229 The 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 232 pwmN_enable. 233 234 If you are only able to control the fan speed with very small PWM values, 235 try lowering the PWM base frequency (pwm1_freq). Depending on the fan, 236 it may give you a somewhat greater control range. The same frequency is 237 used to drive all fan outputs, which is why pwm2_freq and pwm3_freq are 238 read-only. 239 240 241 Automatic fan speed control (old interface) 242 ------------------------------------------- 243 244 The driver supports the old interface to automatic fan speed control 245 which is implemented by IT8705F chips up to revision F and IT8712F 246 chips up to revision G. 247 248 This interface implements 4 temperature vs. PWM output trip points. 249 The PWM output of trip point 4 is always the maximum value (fan running 250 at full speed) while the PWM output of the other 3 trip points can be 251 freely chosen. The temperature of all 4 trip points can be freely chosen. 252 Additionally, trip point 1 has an hysteresis temperature attached, to 253 prevent fast switching between fan on and off. 254 255 The chip automatically computes the PWM output value based on the input 256 temperature, based on this simple rule: if the temperature value is 257 between trip point N and trip point N+1 then the PWM output value is 258 the one of trip point N. The automatic control mode is less flexible 259 than the manual control mode, but it reacts faster, is more robust and 260 doesn't use CPU cycles. 261 262 Trip points must be set properly before switching to automatic fan speed 263 control mode. The driver will perform basic integrity checks before 264 actually switching to automatic control mode. 265 266 267 Temperature offset attributes 268 ----------------------------- 269 270 The driver supports temp[1-3]_offset sysfs attributes to adjust the reported 271 temperature for thermal diodes or diode-connected thermal transistors. 272 If a temperature sensor is configured for thermistors, the attribute values 273 are ignored. If the thermal sensor type is Intel PECI, the temperature offset 274 must be programmed to the critical CPU temperature.