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+Kernel driver sis5595
+ * Silicon Integrated Systems Corp. SiS5595 Southbridge Hardware Monitor
+ Prefix: 'sis5595'
+ Addresses scanned: ISA in PCI-space encoded address
+ Datasheet: Publicly available at the Silicon Integrated Systems Corp. site.
+ Kyösti Mälkki <email@example.com>,
+ Mark D. Studebaker <firstname.lastname@example.org>,
+ Aurelien Jarno <email@example.com> 2.6 port
+ SiS southbridge has a LM78-like chip integrated on the same IC.
+ This driver is a customized copy of lm78.c
+ Supports following revisions:
+ Version PCI ID PCI Revision
+ 1 1039/0008 AF or less
+ 2 1039/0008 B0 or greater
+ Note: these chips contain a 0008 device which is incompatible with the
+ 5595. We recognize these by the presence of the listed
+ "blacklist" PCI ID and refuse to load.
+ NOT SUPPORTED PCI ID BLACKLIST PCI ID
+ 540 0008 0540
+ 550 0008 0550
+ 5513 0008 5511
+ 5581 0008 5597
+ 5582 0008 5597
+ 5597 0008 5597
+ 630 0008 0630
+ 645 0008 0645
+ 730 0008 0730
+ 735 0008 0735
+force_addr=0xaddr Set the I/O base address. Useful for boards
+ that don't set the address in the BIOS. Does not do a
+ PCI force; the device must still be present in lspci.
+ Don't use this unless the driver complains that the
+ base address is not set.
+ Example: 'modprobe sis5595 force_addr=0x290'
+The SiS5595 southbridge has integrated hardware monitor functions. It also
+has an I2C bus, but this driver only supports the hardware monitor. For the
+I2C bus driver see i2c-sis5595.
+The SiS5595 implements zero or one temperature sensor, two fan speed
+sensors, four or five voltage sensors, and alarms.
+On the first version of the chip, there are four voltage sensors and one
+On the second version of the chip, the temperature sensor (temp) and the
+fifth voltage sensor (in4) share a pin which is configurable, but not
+through the driver. Sorry. The driver senses the configuration of the pin,
+which was hopefully set by the BIOS.
+Temperatures are measured in degrees Celsius. An alarm is triggered once
+when the max is crossed; it is also triggered when it drops below the min
+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
+In addition to the alarms described above, there is a BTI alarm, which gets
+triggered when an external chip has crossed its limits. Usually, this is
+connected to some LM75-like chip; if at least one crosses its limits, this
+bit gets set.
+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
+The SiS5595 only updates its values each 1.5 seconds; reading it more often
+will do no harm, but will return 'old' values.
+Some chips refuse to be enabled. We don't know why.
+The driver will recognize this and print a message in dmesg.