Based on kernel version 4.3. Page generated on 2015-11-02 12:49 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 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 * IT8732F 42 Prefix: 'it8732' 43 Addresses scanned: from Super I/O config space (8 I/O ports) 44 Datasheet: Not publicly available 45 * IT8771E 46 Prefix: 'it8771' 47 Addresses scanned: from Super I/O config space (8 I/O ports) 48 Datasheet: Not publicly available 49 * IT8772E 50 Prefix: 'it8772' 51 Addresses scanned: from Super I/O config space (8 I/O ports) 52 Datasheet: Not publicly available 53 * IT8781F 54 Prefix: 'it8781' 55 Addresses scanned: from Super I/O config space (8 I/O ports) 56 Datasheet: Not publicly available 57 * IT8782F 58 Prefix: 'it8782' 59 Addresses scanned: from Super I/O config space (8 I/O ports) 60 Datasheet: Not publicly available 61 * IT8783E/F 62 Prefix: 'it8783' 63 Addresses scanned: from Super I/O config space (8 I/O ports) 64 Datasheet: Not publicly available 65 * IT8786E 66 Prefix: 'it8786' 67 Addresses scanned: from Super I/O config space (8 I/O ports) 68 Datasheet: Not publicly available 69 * IT8790E 70 Prefix: 'it8790' 71 Addresses scanned: from Super I/O config space (8 I/O ports) 72 Datasheet: Not publicly available 73 * SiS950 [clone of IT8705F] 74 Prefix: 'it87' 75 Addresses scanned: from Super I/O config space (8 I/O ports) 76 Datasheet: No longer be available 77 78 Authors: 79 Christophe Gauthron 80 Jean Delvare <firstname.lastname@example.org> 81 82 83 Module Parameters 84 ----------------- 85 86 * update_vbat: int 87 88 0 if vbat should report power on value, 1 if vbat should be updated after 89 each read. Default is 0. On some boards the battery voltage is provided 90 by either the battery or the onboard power supply. Only the first reading 91 at power on will be the actual battery voltage (which the chip does 92 automatically). On other boards the battery voltage is always fed to 93 the chip so can be read at any time. Excessive reading may decrease 94 battery life but no information is given in the datasheet. 95 96 * fix_pwm_polarity int 97 98 Force PWM polarity to active high (DANGEROUS). Some chips are 99 misconfigured by BIOS - PWM values would be inverted. This option tries 100 to fix this. Please contact your BIOS manufacturer and ask him for fix. 101 102 103 Hardware Interfaces 104 ------------------- 105 106 All the chips supported by this driver are LPC Super-I/O chips, accessed 107 through the LPC bus (ISA-like I/O ports). The IT8712F additionally has an 108 SMBus interface to the hardware monitoring functions. This driver no 109 longer supports this interface though, as it is slower and less reliable 110 than the ISA access, and was only available on a small number of 111 motherboard models. 112 113 114 Description 115 ----------- 116 117 This driver implements support for the IT8603E, IT8620E, IT8623E, IT8705F, 118 IT8712F, IT8716F, IT8718F, IT8720F, IT8721F, IT8726F, IT8728F, IT8732F, 119 IT8758E, IT8771E, IT8772E, IT8781F, IT8782F, IT8783E/F, IT8786E, IT8790E, and 120 SiS950 chips. 121 122 These chips are 'Super I/O chips', supporting floppy disks, infrared ports, 123 joysticks and other miscellaneous stuff. For hardware monitoring, they 124 include an 'environment controller' with 3 temperature sensors, 3 fan 125 rotation speed sensors, 8 voltage sensors, associated alarms, and chassis 126 intrusion detection. 127 128 The IT8712F and IT8716F additionally feature VID inputs, used to report 129 the Vcore voltage of the processor. The early IT8712F have 5 VID pins, 130 the IT8716F and late IT8712F have 6. They are shared with other functions 131 though, so the functionality may not be available on a given system. 132 133 The IT8718F and IT8720F also features VID inputs (up to 8 pins) but the value 134 is stored in the Super-I/O configuration space. Due to technical limitations, 135 this value can currently only be read once at initialization time, so 136 the driver won't notice and report changes in the VID value. The two 137 upper VID bits share their pins with voltage inputs (in5 and in6) so you 138 can't have both on a given board. 139 140 The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E and later IT8712F revisions 141 have support for 2 additional fans. The additional fans are supported by the 142 driver. 143 144 The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E, IT8732F, IT8781F, IT8782F, 145 IT8783E/F, and late IT8712F and IT8705F also have optional 16-bit tachometer 146 counters for fans 1 to 3. This is better (no more fan clock divider mess) but 147 not compatible with the older chips and revisions. The 16-bit tachometer mode 148 is enabled by the driver when one of the above chips is detected. 149 150 The IT8726F is just bit enhanced IT8716F with additional hardware 151 for AMD power sequencing. Therefore the chip will appear as IT8716F 152 to userspace applications. 153 154 The IT8728F, IT8771E, and IT8772E are considered compatible with the IT8721F, 155 until a datasheet becomes available (hopefully.) 156 157 The IT8603E/IT8623E is a custom design, hardware monitoring part is similar to 158 IT8728F. It only supports 3 fans, 16-bit fan mode, and the full speed mode 159 of the fan is not supported (value 0 of pwmX_enable). 160 161 The IT8620E is another custom design, hardware monitoring part is similar to 162 IT8728F. It only supports 16-bit fan mode. 163 164 The IT8790E supports up to 3 fans. 16-bit fan mode is always enabled. 165 166 The IT8732F supports a closed-loop mode for fan control, but this is not 167 currently implemented by the driver. 168 169 Temperatures are measured in degrees Celsius. An alarm is triggered once 170 when the Overtemperature Shutdown limit is crossed. 171 172 Fan rotation speeds are reported in RPM (rotations per minute). An alarm is 173 triggered if the rotation speed has dropped below a programmable limit. When 174 16-bit tachometer counters aren't used, fan readings can be divided by 175 a programmable divider (1, 2, 4 or 8) to give the readings more range or 176 accuracy. With a divider of 2, the lowest representable value is around 177 2600 RPM. Not all RPM values can accurately be represented, so some rounding 178 is done. 179 180 Voltage sensors (also known as IN sensors) report their values in volts. An 181 alarm is triggered if the voltage has crossed a programmable minimum or 182 maximum limit. Note that minimum in this case always means 'closest to 183 zero'; this is important for negative voltage measurements. On most chips, all 184 voltage inputs can measure voltages between 0 and 4.08 volts, with a resolution 185 of 0.016 volt. IT8603E, IT8721F/IT8758E and IT8728F can measure between 0 and 186 3.06 volts, with a resolution of 0.012 volt. IT8732F can measure between 0 and 187 2.8 volts with a resolution of 0.0109 volt. The battery voltage in8 does not 188 have limit registers. 189 190 On the IT8603E, IT8721F/IT8758E, IT8732F, IT8781F, IT8782F, and IT8783E/F, some 191 voltage inputs are internal and scaled inside the chip: 192 * in3 (optional) 193 * in7 (optional for IT8781F, IT8782F, and IT8783E/F) 194 * in8 (always) 195 * in9 (relevant for IT8603E only) 196 The driver handles this transparently so user-space doesn't have to care. 197 198 The VID lines (IT8712F/IT8716F/IT8718F/IT8720F) encode the core voltage value: 199 the voltage level your processor should work with. This is hardcoded by 200 the mainboard and/or processor itself. It is a value in volts. 201 202 If an alarm triggers, it will remain triggered until the hardware register 203 is read at least once. This means that the cause for the alarm may already 204 have disappeared! Note that in the current implementation, all hardware 205 registers are read whenever any data is read (unless it is less than 1.5 206 seconds since the last update). This means that you can easily miss 207 once-only alarms. 208 209 Out-of-limit readings can also result in beeping, if the chip is properly 210 wired and configured. Beeping can be enabled or disabled per sensor type 211 (temperatures, voltages and fans.) 212 213 The IT87xx only updates its values each 1.5 seconds; reading it more often 214 will do no harm, but will return 'old' values. 215 216 To change sensor N to a thermistor, 'echo 4 > tempN_type' where N is 1, 2, 217 or 3. To change sensor N to a thermal diode, 'echo 3 > tempN_type'. 218 Give 0 for unused sensor. Any other value is invalid. To configure this at 219 startup, consult lm_sensors's /etc/sensors.conf. (4 = thermistor; 220 3 = thermal diode) 221 222 223 Fan speed control 224 ----------------- 225 226 The fan speed control features are limited to manual PWM mode. Automatic 227 "Smart Guardian" mode control handling is only implemented for older chips 228 (see below.) However if you want to go for "manual mode" just write 1 to 229 pwmN_enable. 230 231 If you are only able to control the fan speed with very small PWM values, 232 try lowering the PWM base frequency (pwm1_freq). Depending on the fan, 233 it may give you a somewhat greater control range. The same frequency is 234 used to drive all fan outputs, which is why pwm2_freq and pwm3_freq are 235 read-only. 236 237 238 Automatic fan speed control (old interface) 239 ------------------------------------------- 240 241 The driver supports the old interface to automatic fan speed control 242 which is implemented by IT8705F chips up to revision F and IT8712F 243 chips up to revision G. 244 245 This interface implements 4 temperature vs. PWM output trip points. 246 The PWM output of trip point 4 is always the maximum value (fan running 247 at full speed) while the PWM output of the other 3 trip points can be 248 freely chosen. The temperature of all 4 trip points can be freely chosen. 249 Additionally, trip point 1 has an hysteresis temperature attached, to 250 prevent fast switching between fan on and off. 251 252 The chip automatically computes the PWM output value based on the input 253 temperature, based on this simple rule: if the temperature value is 254 between trip point N and trip point N+1 then the PWM output value is 255 the one of trip point N. The automatic control mode is less flexible 256 than the manual control mode, but it reacts faster, is more robust and 257 doesn't use CPU cycles. 258 259 Trip points must be set properly before switching to automatic fan speed 260 control mode. The driver will perform basic integrity checks before 261 actually switching to automatic control mode. 262 263 264 Temperature offset attributes 265 ----------------------------- 266 267 The driver supports temp[1-3]_offset sysfs attributes to adjust the reported 268 temperature for thermal diodes or diode-connected thermal transistors. 269 If a temperature sensor is configured for thermistors, the attribute values 270 are ignored. If the thermal sensor type is Intel PECI, the temperature offset 271 must be programmed to the critical CPU temperature.