hwmon: Add tachometer pulses per fan revolution to sysfs ABI
Some fan control chips support a configuration register to set the number of
tachometer pulses per fan revolution. Add an ABI attribute to support this
configuration register.
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
diff --git a/Documentation/hwmon/sysfs-interface b/Documentation/hwmon/sysfs-interface
index c6559f1..83a6987 100644
--- a/Documentation/hwmon/sysfs-interface
+++ b/Documentation/hwmon/sysfs-interface
@@ -187,6 +187,17 @@
Note that this is actually an internal clock divisor, which
affects the measurable speed range, not the read value.
+fan[1-*]_pulses Number of tachometer pulses per fan revolution.
+ Integer value, typically between 1 and 4.
+ RW
+ This value is a characteristic of the fan connected to the
+ device's input, so it has to be set in accordance with the fan
+ model.
+ Should only be created if the chip has a register to configure
+ the number of pulses. In the absence of such a register (and
+ thus attribute) the value assumed by all devices is 2 pulses
+ per fan revolution.
+
fan[1-*]_target
Desired fan speed
Unit: revolution/min (RPM)