Based on kernel version 3.13. Page generated on 2014-01-20 22:03 EST.
1 Kernel driver it87 2 ================== 3 4 Supported chips: 5 * IT8705F 6 Prefix: 'it87' 7 Addresses scanned: from Super I/O config space (8 I/O ports) 8 Datasheet: Once publicly available at the ITE website, but no longer 9 * IT8712F 10 Prefix: 'it8712' 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 * IT8716F/IT8726F 14 Prefix: 'it8716' 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 * IT8718F 18 Prefix: 'it8718' 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 * IT8720F 22 Prefix: 'it8720' 23 Addresses scanned: from Super I/O config space (8 I/O ports) 24 Datasheet: Not publicly available 25 * IT8721F/IT8758E 26 Prefix: 'it8721' 27 Addresses scanned: from Super I/O config space (8 I/O ports) 28 Datasheet: Not publicly available 29 * IT8728F 30 Prefix: 'it8728' 31 Addresses scanned: from Super I/O config space (8 I/O ports) 32 Datasheet: Not publicly available 33 * IT8771E 34 Prefix: 'it8771' 35 Addresses scanned: from Super I/O config space (8 I/O ports) 36 Datasheet: Not publicly available 37 * IT8772E 38 Prefix: 'it8772' 39 Addresses scanned: from Super I/O config space (8 I/O ports) 40 Datasheet: Not publicly available 41 * IT8782F 42 Prefix: 'it8782' 43 Addresses scanned: from Super I/O config space (8 I/O ports) 44 Datasheet: Not publicly available 45 * IT8783E/F 46 Prefix: 'it8783' 47 Addresses scanned: from Super I/O config space (8 I/O ports) 48 Datasheet: Not publicly available 49 * SiS950 [clone of IT8705F] 50 Prefix: 'it87' 51 Addresses scanned: from Super I/O config space (8 I/O ports) 52 Datasheet: No longer be available 53 54 Authors: 55 Christophe Gauthron 56 Jean Delvare <firstname.lastname@example.org> 57 58 59 Module Parameters 60 ----------------- 61 62 * update_vbat: int 63 64 0 if vbat should report power on value, 1 if vbat should be updated after 65 each read. Default is 0. On some boards the battery voltage is provided 66 by either the battery or the onboard power supply. Only the first reading 67 at power on will be the actual battery voltage (which the chip does 68 automatically). On other boards the battery voltage is always fed to 69 the chip so can be read at any time. Excessive reading may decrease 70 battery life but no information is given in the datasheet. 71 72 * fix_pwm_polarity int 73 74 Force PWM polarity to active high (DANGEROUS). Some chips are 75 misconfigured by BIOS - PWM values would be inverted. This option tries 76 to fix this. Please contact your BIOS manufacturer and ask him for fix. 77 78 79 Hardware Interfaces 80 ------------------- 81 82 All the chips supported by this driver are LPC Super-I/O chips, accessed 83 through the LPC bus (ISA-like I/O ports). The IT8712F additionally has an 84 SMBus interface to the hardware monitoring functions. This driver no 85 longer supports this interface though, as it is slower and less reliable 86 than the ISA access, and was only available on a small number of 87 motherboard models. 88 89 90 Description 91 ----------- 92 93 This driver implements support for the IT8705F, IT8712F, IT8716F, 94 IT8718F, IT8720F, IT8721F, IT8726F, IT8728F, IT8758E, IT8771E, IT8772E, 95 IT8782F, IT8783E/F, and SiS950 chips. 96 97 These chips are 'Super I/O chips', supporting floppy disks, infrared ports, 98 joysticks and other miscellaneous stuff. For hardware monitoring, they 99 include an 'environment controller' with 3 temperature sensors, 3 fan 100 rotation speed sensors, 8 voltage sensors, associated alarms, and chassis 101 intrusion detection. 102 103 The IT8712F and IT8716F additionally feature VID inputs, used to report 104 the Vcore voltage of the processor. The early IT8712F have 5 VID pins, 105 the IT8716F and late IT8712F have 6. They are shared with other functions 106 though, so the functionality may not be available on a given system. 107 108 The IT8718F and IT8720F also features VID inputs (up to 8 pins) but the value 109 is stored in the Super-I/O configuration space. Due to technical limitations, 110 this value can currently only be read once at initialization time, so 111 the driver won't notice and report changes in the VID value. The two 112 upper VID bits share their pins with voltage inputs (in5 and in6) so you 113 can't have both on a given board. 114 115 The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E and later IT8712F revisions 116 have support for 2 additional fans. The additional fans are supported by the 117 driver. 118 119 The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E, IT8782F, IT8783E/F, and late 120 IT8712F and IT8705F also have optional 16-bit tachometer counters for fans 1 to 121 3. This is better (no more fan clock divider mess) but not compatible with the 122 older chips and revisions. The 16-bit tachometer mode is enabled by the driver 123 when one of the above chips is detected. 124 125 The IT8726F is just bit enhanced IT8716F with additional hardware 126 for AMD power sequencing. Therefore the chip will appear as IT8716F 127 to userspace applications. 128 129 The IT8728F, IT8771E, and IT8772E are considered compatible with the IT8721F, 130 until a datasheet becomes available (hopefully.) 131 132 Temperatures are measured in degrees Celsius. An alarm is triggered once 133 when the Overtemperature Shutdown limit is crossed. 134 135 Fan rotation speeds are reported in RPM (rotations per minute). An alarm is 136 triggered if the rotation speed has dropped below a programmable limit. When 137 16-bit tachometer counters aren't used, fan readings can be divided by 138 a programmable divider (1, 2, 4 or 8) to give the readings more range or 139 accuracy. With a divider of 2, the lowest representable value is around 140 2600 RPM. Not all RPM values can accurately be represented, so some rounding 141 is done. 142 143 Voltage sensors (also known as IN sensors) report their values in volts. An 144 alarm is triggered if the voltage has crossed a programmable minimum or 145 maximum limit. Note that minimum in this case always means 'closest to 146 zero'; this is important for negative voltage measurements. All voltage 147 inputs can measure voltages between 0 and 4.08 volts, with a resolution of 148 0.016 volt (except IT8721F/IT8758E and IT8728F: 0.012 volt.) The battery 149 voltage in8 does not have limit registers. 150 151 On the IT8721F/IT8758E, IT8782F, and IT8783E/F, some voltage inputs are 152 internal and scaled inside the chip (in7 (optional for IT8782F and IT8783E/F), 153 in8 and optionally in3). The driver handles this transparently so user-space 154 doesn't have to care. 155 156 The VID lines (IT8712F/IT8716F/IT8718F/IT8720F) encode the core voltage value: 157 the voltage level your processor should work with. This is hardcoded by 158 the mainboard and/or processor itself. It is a value in volts. 159 160 If an alarm triggers, it will remain triggered until the hardware register 161 is read at least once. This means that the cause for the alarm may already 162 have disappeared! Note that in the current implementation, all hardware 163 registers are read whenever any data is read (unless it is less than 1.5 164 seconds since the last update). This means that you can easily miss 165 once-only alarms. 166 167 Out-of-limit readings can also result in beeping, if the chip is properly 168 wired and configured. Beeping can be enabled or disabled per sensor type 169 (temperatures, voltages and fans.) 170 171 The IT87xx only updates its values each 1.5 seconds; reading it more often 172 will do no harm, but will return 'old' values. 173 174 To change sensor N to a thermistor, 'echo 4 > tempN_type' where N is 1, 2, 175 or 3. To change sensor N to a thermal diode, 'echo 3 > tempN_type'. 176 Give 0 for unused sensor. Any other value is invalid. To configure this at 177 startup, consult lm_sensors's /etc/sensors.conf. (4 = thermistor; 178 3 = thermal diode) 179 180 181 Fan speed control 182 ----------------- 183 184 The fan speed control features are limited to manual PWM mode. Automatic 185 "Smart Guardian" mode control handling is only implemented for older chips 186 (see below.) However if you want to go for "manual mode" just write 1 to 187 pwmN_enable. 188 189 If you are only able to control the fan speed with very small PWM values, 190 try lowering the PWM base frequency (pwm1_freq). Depending on the fan, 191 it may give you a somewhat greater control range. The same frequency is 192 used to drive all fan outputs, which is why pwm2_freq and pwm3_freq are 193 read-only. 194 195 196 Automatic fan speed control (old interface) 197 ------------------------------------------- 198 199 The driver supports the old interface to automatic fan speed control 200 which is implemented by IT8705F chips up to revision F and IT8712F 201 chips up to revision G. 202 203 This interface implements 4 temperature vs. PWM output trip points. 204 The PWM output of trip point 4 is always the maximum value (fan running 205 at full speed) while the PWM output of the other 3 trip points can be 206 freely chosen. The temperature of all 4 trip points can be freely chosen. 207 Additionally, trip point 1 has an hysteresis temperature attached, to 208 prevent fast switching between fan on and off. 209 210 The chip automatically computes the PWM output value based on the input 211 temperature, based on this simple rule: if the temperature value is 212 between trip point N and trip point N+1 then the PWM output value is 213 the one of trip point N. The automatic control mode is less flexible 214 than the manual control mode, but it reacts faster, is more robust and 215 doesn't use CPU cycles. 216 217 Trip points must be set properly before switching to automatic fan speed 218 control mode. The driver will perform basic integrity checks before 219 actually switching to automatic control mode. 220 221 222 Temperature offset attributes 223 ----------------------------- 224 225 The driver supports temp[1-3]_offset sysfs attributes to adjust the reported 226 temperature for thermal diodes or diode-connected thermal transistors. 227 If a temperature sensor is configured for thermistors, the attribute values 228 are ignored. If the thermal sensor type is Intel PECI, the temperature offset 229 must be programmed to the critical CPU temperature.