Based on kernel version 4.2. Page generated on 2015-09-09 12:13 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 * 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 74 Authors: 75 Christophe Gauthron 76 Jean Delvare <firstname.lastname@example.org> 77 78 79 Module 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 99 Hardware Interfaces 100 ------------------- 101 102 All the chips supported by this driver are LPC Super-I/O chips, accessed 103 through the LPC bus (ISA-like I/O ports). The IT8712F additionally has an 104 SMBus interface to the hardware monitoring functions. This driver no 105 longer supports this interface though, as it is slower and less reliable 106 than the ISA access, and was only available on a small number of 107 motherboard models. 108 109 110 Description 111 ----------- 112 113 This driver implements support for the IT8603E, IT8620E, IT8623E, IT8705F, 114 IT8712F, IT8716F, IT8718F, IT8720F, IT8721F, IT8726F, IT8728F, IT8758E, 115 IT8771E, IT8772E, IT8781F, IT8782F, IT8783E/F, IT8786E, IT8790E, and SiS950 116 chips. 117 118 These chips are 'Super I/O chips', supporting floppy disks, infrared ports, 119 joysticks and other miscellaneous stuff. For hardware monitoring, they 120 include an 'environment controller' with 3 temperature sensors, 3 fan 121 rotation speed sensors, 8 voltage sensors, associated alarms, and chassis 122 intrusion detection. 123 124 The IT8712F and IT8716F additionally feature VID inputs, used to report 125 the Vcore voltage of the processor. The early IT8712F have 5 VID pins, 126 the IT8716F and late IT8712F have 6. They are shared with other functions 127 though, so the functionality may not be available on a given system. 128 129 The IT8718F and IT8720F also features VID inputs (up to 8 pins) but the value 130 is stored in the Super-I/O configuration space. Due to technical limitations, 131 this value can currently only be read once at initialization time, so 132 the driver won't notice and report changes in the VID value. The two 133 upper VID bits share their pins with voltage inputs (in5 and in6) so you 134 can't have both on a given board. 135 136 The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E and later IT8712F revisions 137 have support for 2 additional fans. The additional fans are supported by the 138 driver. 139 140 The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E, IT8781F, IT8782F, IT8783E/F, 141 and late IT8712F and IT8705F also have optional 16-bit tachometer counters 142 for fans 1 to 3. This is better (no more fan clock divider mess) but not 143 compatible with the older chips and revisions. The 16-bit tachometer mode 144 is enabled by the driver when one of the above chips is detected. 145 146 The IT8726F is just bit enhanced IT8716F with additional hardware 147 for AMD power sequencing. Therefore the chip will appear as IT8716F 148 to userspace applications. 149 150 The IT8728F, IT8771E, and IT8772E are considered compatible with the IT8721F, 151 until a datasheet becomes available (hopefully.) 152 153 The IT8603E/IT8623E is a custom design, hardware monitoring part is similar to 154 IT8728F. It only supports 3 fans, 16-bit fan mode, and the full speed mode 155 of the fan is not supported (value 0 of pwmX_enable). 156 157 The IT8620E is another custom design, hardware monitoring part is similar to 158 IT8728F. It only supports 16-bit fan mode. 159 160 The IT8790E supports up to 3 fans. 16-bit fan mode is always enabled. 161 162 Temperatures are measured in degrees Celsius. An alarm is triggered once 163 when the Overtemperature Shutdown limit is crossed. 164 165 Fan rotation speeds are reported in RPM (rotations per minute). An alarm is 166 triggered if the rotation speed has dropped below a programmable limit. When 167 16-bit tachometer counters aren't used, fan readings can be divided by 168 a programmable divider (1, 2, 4 or 8) to give the readings more range or 169 accuracy. With a divider of 2, the lowest representable value is around 170 2600 RPM. Not all RPM values can accurately be represented, so some rounding 171 is done. 172 173 Voltage sensors (also known as IN sensors) report their values in volts. An 174 alarm is triggered if the voltage has crossed a programmable minimum or 175 maximum limit. Note that minimum in this case always means 'closest to 176 zero'; this is important for negative voltage measurements. All voltage 177 inputs can measure voltages between 0 and 4.08 volts, with a resolution of 178 0.016 volt (except IT8603E, IT8721F/IT8758E and IT8728F: 0.012 volt.) The 179 battery voltage in8 does not have limit registers. 180 181 On the IT8603E, IT8721F/IT8758E, IT8781F, IT8782F, and IT8783E/F, some 182 voltage 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) 187 The driver handles this transparently so user-space doesn't have to care. 188 189 The VID lines (IT8712F/IT8716F/IT8718F/IT8720F) encode the core voltage value: 190 the voltage level your processor should work with. This is hardcoded by 191 the mainboard and/or processor itself. It is a value in volts. 192 193 If an alarm triggers, it will remain triggered until the hardware register 194 is read at least once. This means that the cause for the alarm may already 195 have disappeared! Note that in the current implementation, all hardware 196 registers are read whenever any data is read (unless it is less than 1.5 197 seconds since the last update). This means that you can easily miss 198 once-only alarms. 199 200 Out-of-limit readings can also result in beeping, if the chip is properly 201 wired and configured. Beeping can be enabled or disabled per sensor type 202 (temperatures, voltages and fans.) 203 204 The IT87xx only updates its values each 1.5 seconds; reading it more often 205 will do no harm, but will return 'old' values. 206 207 To change sensor N to a thermistor, 'echo 4 > tempN_type' where N is 1, 2, 208 or 3. To change sensor N to a thermal diode, 'echo 3 > tempN_type'. 209 Give 0 for unused sensor. Any other value is invalid. To configure this at 210 startup, consult lm_sensors's /etc/sensors.conf. (4 = thermistor; 211 3 = thermal diode) 212 213 214 Fan speed control 215 ----------------- 216 217 The 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 220 pwmN_enable. 221 222 If you are only able to control the fan speed with very small PWM values, 223 try lowering the PWM base frequency (pwm1_freq). Depending on the fan, 224 it may give you a somewhat greater control range. The same frequency is 225 used to drive all fan outputs, which is why pwm2_freq and pwm3_freq are 226 read-only. 227 228 229 Automatic fan speed control (old interface) 230 ------------------------------------------- 231 232 The driver supports the old interface to automatic fan speed control 233 which is implemented by IT8705F chips up to revision F and IT8712F 234 chips up to revision G. 235 236 This interface implements 4 temperature vs. PWM output trip points. 237 The PWM output of trip point 4 is always the maximum value (fan running 238 at full speed) while the PWM output of the other 3 trip points can be 239 freely chosen. The temperature of all 4 trip points can be freely chosen. 240 Additionally, trip point 1 has an hysteresis temperature attached, to 241 prevent fast switching between fan on and off. 242 243 The chip automatically computes the PWM output value based on the input 244 temperature, based on this simple rule: if the temperature value is 245 between trip point N and trip point N+1 then the PWM output value is 246 the one of trip point N. The automatic control mode is less flexible 247 than the manual control mode, but it reacts faster, is more robust and 248 doesn't use CPU cycles. 249 250 Trip points must be set properly before switching to automatic fan speed 251 control mode. The driver will perform basic integrity checks before 252 actually switching to automatic control mode. 253 254 255 Temperature offset attributes 256 ----------------------------- 257 258 The driver supports temp[1-3]_offset sysfs attributes to adjust the reported 259 temperature for thermal diodes or diode-connected thermal transistors. 260 If a temperature sensor is configured for thermistors, the attribute values 261 are ignored. If the thermal sensor type is Intel PECI, the temperature offset 262 must be programmed to the critical CPU temperature.