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authorMarc Hulsman <m.hulsman@tudelft.nl>2008-10-17 17:51:17 +0200
committerJean Delvare <khali@mahadeva.delvare>2008-10-17 17:51:17 +0200
commit6495ce184033d5e70dfdf5bb8d149e9e02feaaa9 (patch)
treed1d0d2f2e52363f3c416413c5e554d4e42a61b16 /Documentation
parent6e1ecd9b8f1358ed4d099f0c54434240dc40debe (diff)
downloadlinux-linaro-stable-6495ce184033d5e70dfdf5bb8d149e9e02feaaa9.tar.gz
hwmon: (w83791d) add manual PWM support
Add PWM manual control. Signed-off-by: Marc Hulsman <m.hulsman@tudelft.nl> Acked-by: Hans de Goede <j.w.r.degoede@hhs.nl> Signed-off-by: Jean Delvare <khali@linux-fr.org>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/hwmon/w83791d15
1 files changed, 9 insertions, 6 deletions
diff --git a/Documentation/hwmon/w83791d b/Documentation/hwmon/w83791d
index a67d3b7a7098..49c0e94a118c 100644
--- a/Documentation/hwmon/w83791d
+++ b/Documentation/hwmon/w83791d
@@ -58,29 +58,32 @@ internal state that allows no clean access (Bank with ID register is not
currently selected). If you know the address of the chip, use a 'force'
parameter; this will put it into a more well-behaved state first.
-The driver implements three temperature sensors, five fan rotation speed
-sensors, and ten voltage sensors.
+The driver implements three temperature sensors, ten voltage sensors,
+five fan rotation speed sensors and manual PWM control of each fan.
Temperatures are measured in degrees Celsius and measurement resolution is 1
degC for temp1 and 0.5 degC for temp2 and temp3. An alarm is triggered when
the temperature gets higher than the Overtemperature Shutdown value; it stays
on until the temperature falls below the Hysteresis value.
+Voltage sensors (also known as IN sensors) report their values in millivolts.
+An alarm is triggered if the voltage has crossed a programmable minimum
+or maximum limit.
+
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, 8, 16,
32, 64 or 128 for all fans) to give the readings more range or accuracy.
-Voltage sensors (also known as IN sensors) report their values in millivolts.
-An alarm is triggered if the voltage has crossed a programmable minimum
-or maximum limit.
+Each fan controlled is controlled by PWM. The PWM duty cycle can be read and
+set for each fan separately. Valid values range from 0 (stop) to 255 (full).
The w83791d has a global bit used to enable beeping from the speaker when an
alarm is triggered as well as a bitmask to enable or disable the beep for
specific alarms. You need both the global beep enable bit and the
corresponding beep bit to be on for a triggered alarm to sound a beep.
-The sysfs interface to the gloabal enable is via the sysfs beep_enable file.
+The sysfs interface to the global enable is via the sysfs beep_enable file.
This file is used for both legacy and new code.
The sysfs interface to the beep bitmask has migrated from the original legacy