Diffstat (limited to 'Documentation/hwmon/smsc47m1')
1 files changed, 52 insertions, 0 deletions
diff --git a/Documentation/hwmon/smsc47m1 b/Documentation/hwmon/smsc47m1
new file mode 100644
@@ -0,0 +1,52 @@
+Kernel driver smsc47m1
+ * SMSC LPC47B27x, LPC47M10x, LPC47M13x, LPC47M14x, LPC47M15x and LPC47M192
+ Addresses scanned: none, address read from Super I/O config space
+ Prefix: 'smsc47m1'
+ Mark D. Studebaker <firstname.lastname@example.org>,
+ With assistance from Bruce Allen <email@example.com>, and his
+ fan.c program: http://www.lsc-group.phys.uwm.edu/%7Eballen/driver/
+ Gabriele Gorla <firstname.lastname@example.org>,
+ Jean Delvare <email@example.com>
+The Standard Microsystems Corporation (SMSC) 47M1xx Super I/O chips
+contain monitoring and PWM control circuitry for two fans.
+The 47M15x and 47M192 chips contain a full 'hardware monitoring block'
+in addition to the fan monitoring and control. The hardware monitoring
+block is not supported by the driver.
+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.
+PWM values are from 0 to 255.
+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 lm_sensors project gratefully acknowledges the support of
+Intel in the development of this driver.