it87.rst (11799B)
1Kernel driver it87 2================== 3 4Supported chips: 5 6 * IT8603E/IT8623E 7 8 Prefix: 'it8603' 9 10 Addresses scanned: from Super I/O config space (8 I/O ports) 11 12 Datasheet: Not publicly available 13 14 * IT8620E 15 16 Prefix: 'it8620' 17 18 Addresses scanned: from Super I/O config space (8 I/O ports) 19 20 * IT8628E 21 22 Prefix: 'it8628' 23 24 Addresses scanned: from Super I/O config space (8 I/O ports) 25 26 Datasheet: Not publicly available 27 28 * IT8705F 29 30 Prefix: 'it87' 31 32 Addresses scanned: from Super I/O config space (8 I/O ports) 33 34 Datasheet: Once publicly available at the ITE website, but no longer 35 36 * IT8712F 37 38 Prefix: 'it8712' 39 40 Addresses scanned: from Super I/O config space (8 I/O ports) 41 42 Datasheet: Once publicly available at the ITE website, but no longer 43 44 * IT8716F/IT8726F 45 46 Prefix: 'it8716' 47 48 Addresses scanned: from Super I/O config space (8 I/O ports) 49 50 Datasheet: Once publicly available at the ITE website, but no longer 51 52 * IT8718F 53 54 Prefix: 'it8718' 55 56 Addresses scanned: from Super I/O config space (8 I/O ports) 57 58 Datasheet: Once publicly available at the ITE website, but no longer 59 60 * IT8720F 61 62 Prefix: 'it8720' 63 64 Addresses scanned: from Super I/O config space (8 I/O ports) 65 66 Datasheet: Not publicly available 67 68 * IT8721F/IT8758E 69 70 Prefix: 'it8721' 71 72 Addresses scanned: from Super I/O config space (8 I/O ports) 73 74 Datasheet: Not publicly available 75 76 * IT8728F 77 78 Prefix: 'it8728' 79 80 Addresses scanned: from Super I/O config space (8 I/O ports) 81 82 Datasheet: Not publicly available 83 84 * IT8732F 85 86 Prefix: 'it8732' 87 88 Addresses scanned: from Super I/O config space (8 I/O ports) 89 90 Datasheet: Not publicly available 91 92 * IT8771E 93 94 Prefix: 'it8771' 95 96 Addresses scanned: from Super I/O config space (8 I/O ports) 97 98 Datasheet: Not publicly available 99 100 * IT8772E 101 102 Prefix: 'it8772' 103 104 Addresses scanned: from Super I/O config space (8 I/O ports) 105 106 Datasheet: Not publicly available 107 108 * IT8781F 109 110 Prefix: 'it8781' 111 112 Addresses scanned: from Super I/O config space (8 I/O ports) 113 114 Datasheet: Not publicly available 115 116 * IT8782F 117 118 Prefix: 'it8782' 119 120 Addresses scanned: from Super I/O config space (8 I/O ports) 121 122 Datasheet: Not publicly available 123 124 * IT8783E/F 125 126 Prefix: 'it8783' 127 128 Addresses scanned: from Super I/O config space (8 I/O ports) 129 130 Datasheet: Not publicly available 131 132 * IT8786E 133 134 Prefix: 'it8786' 135 136 Addresses scanned: from Super I/O config space (8 I/O ports) 137 138 Datasheet: Not publicly available 139 140 * IT8790E 141 142 Prefix: 'it8790' 143 144 Addresses scanned: from Super I/O config space (8 I/O ports) 145 146 Datasheet: Not publicly available 147 148 * SiS950 [clone of IT8705F] 149 150 Prefix: 'it87' 151 152 Addresses scanned: from Super I/O config space (8 I/O ports) 153 154 Datasheet: No longer be available 155 156 157Authors: 158 - Christophe Gauthron 159 - Jean Delvare <jdelvare@suse.de> 160 161 162Module Parameters 163----------------- 164 165* update_vbat: int 166 0 if vbat should report power on value, 1 if vbat should be updated after 167 each read. Default is 0. On some boards the battery voltage is provided 168 by either the battery or the onboard power supply. Only the first reading 169 at power on will be the actual battery voltage (which the chip does 170 automatically). On other boards the battery voltage is always fed to 171 the chip so can be read at any time. Excessive reading may decrease 172 battery life but no information is given in the datasheet. 173 174* fix_pwm_polarity int 175 Force PWM polarity to active high (DANGEROUS). Some chips are 176 misconfigured by BIOS - PWM values would be inverted. This option tries 177 to fix this. Please contact your BIOS manufacturer and ask him for fix. 178 179 180Hardware Interfaces 181------------------- 182 183All the chips supported by this driver are LPC Super-I/O chips, accessed 184through the LPC bus (ISA-like I/O ports). The IT8712F additionally has an 185SMBus interface to the hardware monitoring functions. This driver no 186longer supports this interface though, as it is slower and less reliable 187than the ISA access, and was only available on a small number of 188motherboard models. 189 190 191Description 192----------- 193 194This driver implements support for the IT8603E, IT8620E, IT8623E, IT8628E, 195IT8705F, IT8712F, IT8716F, IT8718F, IT8720F, IT8721F, IT8726F, IT8728F, IT8732F, 196IT8758E, IT8771E, IT8772E, IT8781F, IT8782F, IT8783E/F, IT8786E, IT8790E, and 197SiS950 chips. 198 199These chips are 'Super I/O chips', supporting floppy disks, infrared ports, 200joysticks and other miscellaneous stuff. For hardware monitoring, they 201include an 'environment controller' with 3 temperature sensors, 3 fan 202rotation speed sensors, 8 voltage sensors, associated alarms, and chassis 203intrusion detection. 204 205The IT8712F and IT8716F additionally feature VID inputs, used to report 206the Vcore voltage of the processor. The early IT8712F have 5 VID pins, 207the IT8716F and late IT8712F have 6. They are shared with other functions 208though, so the functionality may not be available on a given system. 209 210The IT8718F and IT8720F also features VID inputs (up to 8 pins) but the value 211is stored in the Super-I/O configuration space. Due to technical limitations, 212this value can currently only be read once at initialization time, so 213the driver won't notice and report changes in the VID value. The two 214upper VID bits share their pins with voltage inputs (in5 and in6) so you 215can't have both on a given board. 216 217The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E and later IT8712F revisions 218have support for 2 additional fans. The additional fans are supported by the 219driver. 220 221The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E, IT8732F, IT8781F, IT8782F, 222IT8783E/F, and late IT8712F and IT8705F also have optional 16-bit tachometer 223counters for fans 1 to 3. This is better (no more fan clock divider mess) but 224not compatible with the older chips and revisions. The 16-bit tachometer mode 225is enabled by the driver when one of the above chips is detected. 226 227The IT8726F is just bit enhanced IT8716F with additional hardware 228for AMD power sequencing. Therefore the chip will appear as IT8716F 229to userspace applications. 230 231The IT8728F, IT8771E, and IT8772E are considered compatible with the IT8721F, 232until a datasheet becomes available (hopefully.) 233 234The IT8603E/IT8623E is a custom design, hardware monitoring part is similar to 235IT8728F. It only supports 3 fans, 16-bit fan mode, and the full speed mode 236of the fan is not supported (value 0 of pwmX_enable). 237 238The IT8620E and IT8628E are custom designs, hardware monitoring part is similar 239to IT8728F. It only supports 16-bit fan mode. Both chips support up to 6 fans. 240 241The IT8790E supports up to 3 fans. 16-bit fan mode is always enabled. 242 243The IT8732F supports a closed-loop mode for fan control, but this is not 244currently implemented by the driver. 245 246Temperatures are measured in degrees Celsius. An alarm is triggered once 247when the Overtemperature Shutdown limit is crossed. 248 249Fan rotation speeds are reported in RPM (rotations per minute). An alarm is 250triggered if the rotation speed has dropped below a programmable limit. When 25116-bit tachometer counters aren't used, fan readings can be divided by 252a programmable divider (1, 2, 4 or 8) to give the readings more range or 253accuracy. With a divider of 2, the lowest representable value is around 2542600 RPM. Not all RPM values can accurately be represented, so some rounding 255is done. 256 257Voltage sensors (also known as IN sensors) report their values in volts. An 258alarm is triggered if the voltage has crossed a programmable minimum or 259maximum limit. Note that minimum in this case always means 'closest to 260zero'; this is important for negative voltage measurements. On most chips, all 261voltage inputs can measure voltages between 0 and 4.08 volts, with a resolution 262of 0.016 volt. IT8603E, IT8721F/IT8758E and IT8728F can measure between 0 and 2633.06 volts, with a resolution of 0.012 volt. IT8732F can measure between 0 and 2642.8 volts with a resolution of 0.0109 volt. The battery voltage in8 does not 265have limit registers. 266 267On the IT8603E, IT8620E, IT8628E, IT8721F/IT8758E, IT8732F, IT8781F, IT8782F, 268and IT8783E/F, some voltage inputs are internal and scaled inside the chip: 269* in3 (optional) 270* in7 (optional for IT8781F, IT8782F, and IT8783E/F) 271* in8 (always) 272* in9 (relevant for IT8603E only) 273The driver handles this transparently so user-space doesn't have to care. 274 275The VID lines (IT8712F/IT8716F/IT8718F/IT8720F) encode the core voltage value: 276the voltage level your processor should work with. This is hardcoded by 277the mainboard and/or processor itself. It is a value in volts. 278 279If an alarm triggers, it will remain triggered until the hardware register 280is read at least once. This means that the cause for the alarm may already 281have disappeared! Note that in the current implementation, all hardware 282registers are read whenever any data is read (unless it is less than 1.5 283seconds since the last update). This means that you can easily miss 284once-only alarms. 285 286Out-of-limit readings can also result in beeping, if the chip is properly 287wired and configured. Beeping can be enabled or disabled per sensor type 288(temperatures, voltages and fans.) 289 290The IT87xx only updates its values each 1.5 seconds; reading it more often 291will do no harm, but will return 'old' values. 292 293To change sensor N to a thermistor, 'echo 4 > tempN_type' where N is 1, 2, 294or 3. To change sensor N to a thermal diode, 'echo 3 > tempN_type'. 295Give 0 for unused sensor. Any other value is invalid. To configure this at 296startup, consult lm_sensors's /etc/sensors.conf. (4 = thermistor; 2973 = thermal diode) 298 299 300Fan speed control 301----------------- 302 303The fan speed control features are limited to manual PWM mode. Automatic 304"Smart Guardian" mode control handling is only implemented for older chips 305(see below.) However if you want to go for "manual mode" just write 1 to 306pwmN_enable. 307 308If you are only able to control the fan speed with very small PWM values, 309try lowering the PWM base frequency (pwm1_freq). Depending on the fan, 310it may give you a somewhat greater control range. The same frequency is 311used to drive all fan outputs, which is why pwm2_freq and pwm3_freq are 312read-only. 313 314 315Automatic fan speed control (old interface) 316------------------------------------------- 317 318The driver supports the old interface to automatic fan speed control 319which is implemented by IT8705F chips up to revision F and IT8712F 320chips up to revision G. 321 322This interface implements 4 temperature vs. PWM output trip points. 323The PWM output of trip point 4 is always the maximum value (fan running 324at full speed) while the PWM output of the other 3 trip points can be 325freely chosen. The temperature of all 4 trip points can be freely chosen. 326Additionally, trip point 1 has an hysteresis temperature attached, to 327prevent fast switching between fan on and off. 328 329The chip automatically computes the PWM output value based on the input 330temperature, based on this simple rule: if the temperature value is 331between trip point N and trip point N+1 then the PWM output value is 332the one of trip point N. The automatic control mode is less flexible 333than the manual control mode, but it reacts faster, is more robust and 334doesn't use CPU cycles. 335 336Trip points must be set properly before switching to automatic fan speed 337control mode. The driver will perform basic integrity checks before 338actually switching to automatic control mode. 339 340 341Temperature offset attributes 342----------------------------- 343 344The driver supports temp[1-3]_offset sysfs attributes to adjust the reported 345temperature for thermal diodes or diode-connected thermal transistors. 346If a temperature sensor is configured for thermistors, the attribute values 347are ignored. If the thermal sensor type is Intel PECI, the temperature offset 348must be programmed to the critical CPU temperature.