From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/Documentation/hwmon/lm78 | 68 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) create mode 100644 kernel/Documentation/hwmon/lm78 (limited to 'kernel/Documentation/hwmon/lm78') diff --git a/kernel/Documentation/hwmon/lm78 b/kernel/Documentation/hwmon/lm78 new file mode 100644 index 000000000..4dd477317 --- /dev/null +++ b/kernel/Documentation/hwmon/lm78 @@ -0,0 +1,68 @@ +Kernel driver lm78 +================== + +Supported chips: + * National Semiconductor LM78 / LM78-J + Prefix: 'lm78' + Addresses scanned: I2C 0x28 - 0x2f, ISA 0x290 (8 I/O ports) + Datasheet: Publicly available at the National Semiconductor website + http://www.national.com/ + * National Semiconductor LM79 + Prefix: 'lm79' + Addresses scanned: I2C 0x28 - 0x2f, ISA 0x290 (8 I/O ports) + Datasheet: Publicly available at the National Semiconductor website + http://www.national.com/ + +Authors: Frodo Looijaard + Jean Delvare + +Description +----------- + +This driver implements support for the National Semiconductor LM78, LM78-J +and LM79. They are described as 'Microprocessor System Hardware Monitors'. + +There is almost no difference between the three supported chips. Functionally, +the LM78 and LM78-J are exactly identical. The LM79 has one more VID line, +which is used to report the lower voltages newer Pentium processors use. +From here on, LM7* means either of these three types. + +The LM7* implements one temperature sensor, three fan rotation speed sensors, +seven voltage sensors, VID lines, alarms, and some miscellaneous stuff. + +Temperatures are measured in degrees Celsius. An alarm is triggered once +when the Overtemperature Shutdown limit is crossed; it is triggered again +as soon as it drops below the Hysteresis value. A more useful behavior +can be found by setting the Hysteresis value to +127 degrees Celsius; in +this case, alarms are issued during all the time when the actual temperature +is above the Overtemperature Shutdown value. Measurements are guaranteed +between -55 and +125 degrees, with a resolution of 1 degree. + +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. + +Voltage sensors (also known as IN sensors) report their values in volts. +An alarm is triggered if the voltage has crossed a programmable minimum +or maximum limit. Note that minimum in this case always means 'closest to +zero'; this is important for negative voltage measurements. All voltage +inputs can measure voltages between 0 and 4.08 volts, with a resolution +of 0.016 volt. + +The VID lines encode the core voltage value: the voltage level your processor +should work with. This is hardcoded by the mainboard and/or processor itself. +It is a value in volts. When it is unconnected, you will often find the +value 3.50 V here. + +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 LM7* only updates its values each 1.5 seconds; reading it more often +will do no harm, but will return 'old' values. -- cgit 1.2.3-korg