diff options
| author | Phil Endecott <kernel@chezphil.org> | 2007-06-29 11:19:14 +0400 |
|---|---|---|
| committer | Mark M. Hoffman <mhoffman@lightlink.com> | 2007-07-19 22:22:15 +0400 |
| commit | aba5073d3f4c928c89c483d85f8cff7cc9aa3312 (patch) | |
| tree | c966ca4de6e14d4edbb7232b3dcef3fb7e114b7f /Documentation/hwmon | |
| parent | 158ce07564b68d4215b9560213a089d6f7c5a4ea (diff) | |
| download | linux-aba5073d3f4c928c89c483d85f8cff7cc9aa3312.tar.xz | |
hwmon/f71805f: Add temperature-tracking fan control mode
Add support for the "temperature mode" fan speed control. In this mode,
the user can define 3 temperature/speed trip points, and the chip will
set the speed automatically according to the temperature changes.
Signed-off-by: Phil Endecott <kernel@chezphil.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>
Diffstat (limited to 'Documentation/hwmon')
| -rw-r--r-- | Documentation/hwmon/f71805f | 35 |
1 files changed, 22 insertions, 13 deletions
diff --git a/Documentation/hwmon/f71805f b/Documentation/hwmon/f71805f index bfd0f154959c..94e0d2cbd3d2 100644 --- a/Documentation/hwmon/f71805f +++ b/Documentation/hwmon/f71805f @@ -5,11 +5,11 @@ Supported chips: * Fintek F71805F/FG Prefix: 'f71805f' Addresses scanned: none, address read from Super I/O config space - Datasheet: Provided by Fintek on request + Datasheet: Available from the Fintek website * Fintek F71872F/FG Prefix: 'f71872f' Addresses scanned: none, address read from Super I/O config space - Datasheet: Provided by Fintek on request + Datasheet: Available from the Fintek website Author: Jean Delvare <khali@linux-fr.org> @@ -128,7 +128,9 @@ 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. Fintek recommends +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. @@ -136,16 +138,23 @@ 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: +Three different fan control modes are supported; the mode number is written +to the pwm<n>_enable file. -* Manual mode - You ask for a specific PWM duty cycle or DC voltage. +* 1: Manual mode + You ask for a specific PWM duty cycle or DC voltage by writing to the + pwm<n> file. -* Fan speed mode - You ask for a specific fan speed. This mode assumes that pwm1 - corresponds to fan1, pwm2 to fan2 and pwm3 to fan3. +* 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. -* Temperature mode - You define 3 temperature/fan speed trip points, and the fan speed is - adjusted depending on the measured temperature, using interpolation. - This mode is not yet supported by the driver. +* 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. |