diff options
author | Jean Delvare <khali@linux-fr.org> | 2005-07-02 18:52:48 +0200 |
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committer | Greg Kroah-Hartman <gregkh@suse.de> | 2005-07-11 23:47:41 +0200 |
commit | ede7fbdf526c314850c9f32dd8da1753bf8d0ad5 (patch) | |
tree | 2f1fefa6f6df58f5c27bf98bd7df0908e97e44ef /Documentation/hwmon/it87 | |
parent | [PATCH] I2C: Move hwmon drivers (2/3) (diff) | |
download | linux-ede7fbdf526c314850c9f32dd8da1753bf8d0ad5.tar.xz linux-ede7fbdf526c314850c9f32dd8da1753bf8d0ad5.zip |
[PATCH] I2C: Move hwmon drivers (3/3)
Part 3: Move the drivers documentation, plus two general documentation
files.
Note that the patch "adds trailing whitespace", because it does move the
files as-is, and some files happen to have trailing whitespace.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'Documentation/hwmon/it87')
-rw-r--r-- | Documentation/hwmon/it87 | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/Documentation/hwmon/it87 b/Documentation/hwmon/it87 new file mode 100644 index 000000000000..0d0195040d88 --- /dev/null +++ b/Documentation/hwmon/it87 @@ -0,0 +1,96 @@ +Kernel driver it87 +================== + +Supported chips: + * IT8705F + Prefix: 'it87' + Addresses scanned: from Super I/O config space, or default ISA 0x290 (8 I/O ports) + Datasheet: Publicly available at the ITE website + http://www.ite.com.tw/ + * IT8712F + Prefix: 'it8712' + Addresses scanned: I2C 0x28 - 0x2f + from Super I/O config space, or default ISA 0x290 (8 I/O ports) + Datasheet: Publicly available at the ITE website + http://www.ite.com.tw/ + * SiS950 [clone of IT8705F] + Prefix: 'sis950' + Addresses scanned: from Super I/O config space, or default ISA 0x290 (8 I/O ports) + Datasheet: No longer be available + +Author: Christophe Gauthron <chrisg@0-in.com> + + +Module Parameters +----------------- + +* update_vbat: int + + 0 if vbat should report power on value, 1 if vbat should be updated after + each read. Default is 0. On some boards the battery voltage is provided + by either the battery or the onboard power supply. Only the first reading + at power on will be the actual battery voltage (which the chip does + automatically). On other boards the battery voltage is always fed to + the chip so can be read at any time. Excessive reading may decrease + battery life but no information is given in the datasheet. + +* fix_pwm_polarity int + + Force PWM polarity to active high (DANGEROUS). Some chips are + misconfigured by BIOS - PWM values would be inverted. This option tries + to fix this. Please contact your BIOS manufacturer and ask him for fix. + +Description +----------- + +This driver implements support for the IT8705F, IT8712F and SiS950 chips. + +This driver also supports IT8712F, which adds SMBus access, and a VID +input, used to report the Vcore voltage of the Pentium processor. +The IT8712F additionally features VID inputs. + +These chips are 'Super I/O chips', supporting floppy disks, infrared ports, +joysticks and other miscellaneous stuff. For hardware monitoring, they +include an 'environment controller' with 3 temperature sensors, 3 fan +rotation speed sensors, 8 voltage sensors, and associated alarms. + +Temperatures are measured in degrees Celsius. An alarm is triggered once +when the Overtemperature Shutdown limit is crossed. + +Fan rotation speeds are reported in RPM (rotations per minute). An alarm is +triggered if the rotation speed has dropped below a programmable limit. Fan +readings can be divided by a programmable divider (1, 2, 4 or 8) to give the +readings more range or accuracy. Not all RPM values can accurately be +represented, so some rounding is done. With a divider of 2, the lowest +representable value is around 2600 RPM. + +Voltage sensors (also known as IN sensors) report their values in volts. An +alarm is triggered if the voltage has crossed a programmable minimum or +maximum limit. Note that minimum in this case always means 'closest to +zero'; this is important for negative voltage measurements. All voltage +inputs can measure voltages between 0 and 4.08 volts, with a resolution of +0.016 volt. The battery voltage in8 does not have limit registers. + +The VID lines (IT8712F only) encode the core voltage value: the voltage +level your processor should work with. This is hardcoded by the mainboard +and/or processor itself. It is a value in volts. + +If an alarm triggers, it will remain triggered until the hardware register +is read at least once. This means that the cause for the alarm may already +have disappeared! Note that in the current implementation, all hardware +registers are read whenever any data is read (unless it is less than 1.5 +seconds since the last update). This means that you can easily miss +once-only alarms. + +The IT87xx only updates its values each 1.5 seconds; reading it more often +will do no harm, but will return 'old' values. + +To change sensor N to a thermistor, 'echo 2 > tempN_type' where N is 1, 2, +or 3. To change sensor N to a thermal diode, 'echo 3 > tempN_type'. +Give 0 for unused sensor. Any other value is invalid. To configure this at +startup, consult lm_sensors's /etc/sensors.conf. (2 = thermistor; +3 = thermal diode) + +The fan speed control features are limited to manual PWM mode. Automatic +"Smart Guardian" mode control handling is not implemented. However +if you want to go for "manual mode" just write 1 to pwmN_enable. |