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Diffstat (limited to 'kernel/Documentation/hwmon/f71805f')
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diff --git a/kernel/Documentation/hwmon/f71805f b/kernel/Documentation/hwmon/f71805f new file mode 100644 index 000000000..48a356084 --- /dev/null +++ b/kernel/Documentation/hwmon/f71805f @@ -0,0 +1,167 @@ +Kernel driver f71805f +===================== + +Supported chips: + * Fintek F71805F/FG + Prefix: 'f71805f' + Addresses scanned: none, address read from Super I/O config space + Datasheet: Available from the Fintek website + * Fintek F71806F/FG + Prefix: 'f71872f' + Addresses scanned: none, address read from Super I/O config space + Datasheet: Available from the Fintek website + * Fintek F71872F/FG + Prefix: 'f71872f' + Addresses scanned: none, address read from Super I/O config space + Datasheet: Available from the Fintek website + +Author: Jean Delvare <jdelvare@suse.de> + +Thanks to Denis Kieft from Barracuda Networks for the donation of a +test system (custom Jetway K8M8MS motherboard, with CPU and RAM) and +for providing initial documentation. + +Thanks to Kris Chen and Aaron Huang from Fintek for answering technical +questions and providing additional documentation. + +Thanks to Chris Lin from Jetway for providing wiring schematics and +answering technical questions. + + +Description +----------- + +The Fintek F71805F/FG Super I/O chip includes complete hardware monitoring +capabilities. It can monitor up to 9 voltages (counting its own power +source), 3 fans and 3 temperature sensors. + +This chip also has fan controlling features, using either DC or PWM, in +three different modes (one manual, two automatic). + +The Fintek F71872F/FG Super I/O chip is almost the same, with two +additional internal voltages monitored (VSB and battery). It also features +6 VID inputs. The VID inputs are not yet supported by this driver. + +The Fintek F71806F/FG Super-I/O chip is essentially the same as the +F71872F/FG, and is undistinguishable therefrom. + +The driver assumes that no more than one chip is present, which seems +reasonable. + + +Voltage Monitoring +------------------ + +Voltages are sampled by an 8-bit ADC with a LSB of 8 mV. The supported +range is thus from 0 to 2.040 V. Voltage values outside of this range +need external resistors. An exception is in0, which is used to monitor +the chip's own power source (+3.3V), and is divided internally by a +factor 2. For the F71872F/FG, in9 (VSB) and in10 (battery) are also +divided internally by a factor 2. + +The two LSB of the voltage limit registers are not used (always 0), so +you can only set the limits in steps of 32 mV (before scaling). + +The wirings and resistor values suggested by Fintek are as follow: + + pin expected + name use R1 R2 divider raw val. + +in0 VCC VCC3.3V int. int. 2.00 1.65 V +in1 VIN1 VTT1.2V 10K - 1.00 1.20 V +in2 VIN2 VRAM 100K 100K 2.00 ~1.25 V (1) +in3 VIN3 VCHIPSET 47K 100K 1.47 2.24 V (2) +in4 VIN4 VCC5V 200K 47K 5.25 0.95 V +in5 VIN5 +12V 200K 20K 11.00 1.05 V +in6 VIN6 VCC1.5V 10K - 1.00 1.50 V +in7 VIN7 VCORE 10K - 1.00 ~1.40 V (1) +in8 VIN8 VSB5V 200K 47K 1.00 0.95 V +in10 VSB VSB3.3V int. int. 2.00 1.65 V (3) +in9 VBAT VBATTERY int. int. 2.00 1.50 V (3) + +(1) Depends on your hardware setup. +(2) Obviously not correct, swapping R1 and R2 would make more sense. +(3) F71872F/FG only. + +These values can be used as hints at best, as motherboard manufacturers +are free to use a completely different setup. As a matter of fact, the +Jetway K8M8MS uses a significantly different setup. You will have to +find out documentation about your own motherboard, and edit sensors.conf +accordingly. + +Each voltage measured has associated low and high limits, each of which +triggers an alarm when crossed. + + +Fan Monitoring +-------------- + +Fan rotation speeds are reported as 12-bit values from a gated clock +signal. Speeds down to 366 RPM can be measured. There is no theoretical +high limit, but values over 6000 RPM seem to cause problem. The effective +resolution is much lower than you would expect, the step between different +register values being 10 rather than 1. + +The chip assumes 2 pulse-per-revolution fans. + +An alarm is triggered if the rotation speed drops below a programmable +limit or is too low to be measured. + + +Temperature Monitoring +---------------------- + +Temperatures are reported in degrees Celsius. Each temperature measured +has a high limit, those crossing triggers an alarm. There is an associated +hysteresis value, below which the temperature has to drop before the +alarm is cleared. + +All temperature channels are external, there is no embedded temperature +sensor. Each channel can be used for connecting either a thermal diode +or a thermistor. The driver reports the currently selected mode, but +doesn't allow changing it. In theory, the BIOS should have configured +everything properly. + + +Fan Control +----------- + +Both PWM (pulse-width modulation) and DC fan speed control methods are +supported. The right one to use depends on external circuitry on the +motherboard, so the driver assumes that the BIOS set the method +properly. The driver will report the method, but won't let you change +it. + +When the PWM method is used, you can select the operating frequency, +from 187.5 kHz (default) to 31 Hz. The best frequency depends on the +fan model. As a rule of thumb, lower frequencies seem to give better +control, but may generate annoying high-pitch noise. So a frequency just +above the audible range, such as 25 kHz, may be a good choice; if this +doesn't give you good linear control, try reducing it. Fintek recommends +not going below 1 kHz, as the fan tachometers get confused by lower +frequencies as well. + +When the DC method is used, Fintek recommends not going below 5 V, which +corresponds to a pwm value of 106 for the driver. The driver doesn't +enforce this limit though. + +Three different fan control modes are supported; the mode number is written +to the pwm<n>_enable file. + +* 1: Manual mode + You ask for a specific PWM duty cycle or DC voltage by writing to the + pwm<n> file. + +* 2: Temperature mode + You define 3 temperature/fan speed trip points using the + pwm<n>_auto_point<m>_temp and _fan files. These define a staircase + relationship between temperature and fan speed with two additional points + interpolated between the values that you define. When the temperature + is below auto_point1_temp the fan is switched off. + +* 3: Fan speed mode + You ask for a specific fan speed by writing to the fan<n>_target file. + +Both of the automatic modes require that pwm1 corresponds to fan1, pwm2 to +fan2 and pwm3 to fan3. Temperature mode also requires that temp1 corresponds +to pwm1 and fan1, etc. |