aboutsummaryrefslogtreecommitdiff
path: root/Documentation
diff options
context:
space:
mode:
authorJean Delvare <khali@linux-fr.org>2010-08-14 21:08:58 +0200
committerJean Delvare <khali@linux-fr.org>2010-08-14 21:08:58 +0200
commit328716bc16b7077ea5f6293c7420247c570d6480 (patch)
treee96b0cf74988b4b3b05c6408d8640ba61e99f63c /Documentation
parent0d22d5835d4c82d1d03399688267f63334efd526 (diff)
downloadlinux-linaro-android-328716bc16b7077ea5f6293c7420247c570d6480.tar.gz
hwmon: (pc87427) Add support for manual fan speed control
Add initial support for PWM outputs of the PC87427 Super-I/O chip. Only mode change and manual fan speed control are supported. Automatic mode configuration isn't supported, and won't be until at least one board is known, which makes uses of the PWM outputs. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Guenter Roeck <guenter.roeck@ericsson.com>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/hwmon/pc8742713
1 files changed, 11 insertions, 2 deletions
diff --git a/Documentation/hwmon/pc87427 b/Documentation/hwmon/pc87427
index db5cc1227a8..3282bf39d67 100644
--- a/Documentation/hwmon/pc87427
+++ b/Documentation/hwmon/pc87427
@@ -20,8 +20,8 @@ The National Semiconductor Super I/O chip includes complete hardware
monitoring capabilities. It can monitor up to 18 voltages, 8 fans and
6 temperature sensors. Only the fans are supported at the moment.
-This chip also has fan controlling features, which are not yet supported
-by this driver either.
+This chip also has fan controlling features (up to 4 PWM outputs),
+which are partly supported by this driver.
The driver assumes that no more than one chip is present, which seems
reasonable.
@@ -36,3 +36,12 @@ signal. Speeds down to 83 RPM can be measured.
An alarm is triggered if the rotation speed drops below a programmable
limit. Another alarm is triggered if the speed is too low to be measured
(including stalled or missing fan).
+
+
+Fan Speed Control
+-----------------
+
+Fan speed can be controlled by PWM outputs. There are 4 possible modes:
+always off, always on, manual and automatic. The latter isn't supported
+by the driver: you can only return to that mode if it was the original
+setting, and the configuration interface is missing.