[linux-2.6-block.git] / Documentation / hwmon / sis5595.rst

Kernel driver sis5595
=====================

Supported chips:

  * 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.


Authors:

      - Kyösti Mälkki <kmalkki@cc.hut.fi>,
      - Mark D. Studebaker <mdsxyz123@yahoo.com>,
      - Aurelien Jarno <aurelien@aurel32.net> 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
   =================== =============== ================


Module Parameters
-----------------

======================= =====================================================
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'
======================= =====================================================


Description
-----------

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
temperature sensor.

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
0.016 volt.

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
once-only alarms.

The SiS5595 only updates its values each 1.5 seconds; reading it more often
will do no harm, but will return 'old' values.

Problems
--------
Some chips refuse to be enabled. We don't know why.
The driver will recognize this and print a message in dmesg.
Commit	Line	Data
7f15b664 M	1	Kernel driver sis5595
	2	=====================
	3
	4	Supported chips:
b04f2f7d	5
7f15b664	6	* Silicon Integrated Systems Corp. SiS5595 Southbridge Hardware Monitor
b04f2f7d	7
7f15b664	8	Prefix: 'sis5595'
b04f2f7d	9
7f15b664	10	Addresses scanned: ISA in PCI-space encoded address
b04f2f7d	11
7f15b664 M	12	Datasheet: Publicly available at the Silicon Integrated Systems Corp. site.
7f15b664 M	13
b04f2f7d MCC	14
b04f2f7d MCC	15
7f15b664	16	Authors:
b04f2f7d MCC	17
	18	- Kyösti Mälkki <kmalkki@cc.hut.fi>,
	19	- Mark D. Studebaker <mdsxyz123@yahoo.com>,
	20	- Aurelien Jarno <aurelien@aurel32.net> 2.6 port
7f15b664 M	21
	22	SiS southbridge has a LM78-like chip integrated on the same IC.
	23	This driver is a customized copy of lm78.c
	24
	25	Supports following revisions:
b04f2f7d MCC	26
b04f2f7d MCC	27	=============== =============== ==============
7f15b664	28	Version PCI ID PCI Revision
b04f2f7d	29	=============== =============== ==============
7f15b664 M	30	1 1039/0008 AF or less
7f15b664 M	31	2 1039/0008 B0 or greater
b04f2f7d	32	=============== =============== ==============
7f15b664 M	33
7f15b664 M	34	Note: these chips contain a 0008 device which is incompatible with the
b04f2f7d MCC	35	5595. We recognize these by the presence of the listed
b04f2f7d MCC	36	"blacklist" PCI ID and refuse to load.
7f15b664	37
b04f2f7d	38	=================== =============== ================
7f15b664	39	NOT SUPPORTED PCI ID BLACKLIST PCI ID
b04f2f7d MCC	40	=================== =============== ================
	41	540 0008 0540
	42	550 0008 0550
7f15b664 M	43	5513 0008 5511
	44	5581 0008 5597
	45	5582 0008 5597
	46	5597 0008 5597
b04f2f7d MCC	47	630 0008 0630
	48	645 0008 0645
	49	730 0008 0730
	50	735 0008 0735
	51	=================== =============== ================
7f15b664 M	52
	53
	54	Module Parameters
	55	-----------------
b04f2f7d MCC	56
b04f2f7d MCC	57	======================= =====================================================
7f15b664 M	58	force_addr=0xaddr Set the I/O base address. Useful for boards
	59	that don't set the address in the BIOS. Does not do a
	60	PCI force; the device must still be present in lspci.
	61	Don't use this unless the driver complains that the
	62	base address is not set.
b04f2f7d	63
7f15b664	64	Example: 'modprobe sis5595 force_addr=0x290'
b04f2f7d	65	======================= =====================================================
7f15b664 M	66
	67
	68	Description
	69	-----------
	70
	71	The SiS5595 southbridge has integrated hardware monitor functions. It also
	72	has an I2C bus, but this driver only supports the hardware monitor. For the
	73	I2C bus driver see i2c-sis5595.
	74
	75	The SiS5595 implements zero or one temperature sensor, two fan speed
	76	sensors, four or five voltage sensors, and alarms.
	77
	78	On the first version of the chip, there are four voltage sensors and one
	79	temperature sensor.
	80
	81	On the second version of the chip, the temperature sensor (temp) and the
	82	fifth voltage sensor (in4) share a pin which is configurable, but not
	83	through the driver. Sorry. The driver senses the configuration of the pin,
	84	which was hopefully set by the BIOS.
	85
	86	Temperatures are measured in degrees Celsius. An alarm is triggered once
	87	when the max is crossed; it is also triggered when it drops below the min
	88	value. Measurements are guaranteed between -55 and +125 degrees, with a
	89	resolution of 1 degree.
	90
	91	Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
	92	triggered if the rotation speed has dropped below a programmable limit. Fan
	93	readings can be divided by a programmable divider (1, 2, 4 or 8) to give
	94	the readings more range or accuracy. Not all RPM values can accurately be
	95	represented, so some rounding is done. With a divider of 2, the lowest
	96	representable value is around 2600 RPM.
	97
	98	Voltage sensors (also known as IN sensors) report their values in volts. An
	99	alarm is triggered if the voltage has crossed a programmable minimum or
	100	maximum limit. Note that minimum in this case always means 'closest to
	101	zero'; this is important for negative voltage measurements. All voltage
	102	inputs can measure voltages between 0 and 4.08 volts, with a resolution of
	103	0.016 volt.
	104
	105	In addition to the alarms described above, there is a BTI alarm, which gets
	106	triggered when an external chip has crossed its limits. Usually, this is
	107	connected to some LM75-like chip; if at least one crosses its limits, this
	108	bit gets set.
	109
	110	If an alarm triggers, it will remain triggered until the hardware register
	111	is read at least once. This means that the cause for the alarm may already
	112	have disappeared! Note that in the current implementation, all hardware
	113	registers are read whenever any data is read (unless it is less than 1.5
	114	seconds since the last update). This means that you can easily miss
	115	once-only alarms.
	116
	117	The SiS5595 only updates its values each 1.5 seconds; reading it more often
	118	will do no harm, but will return 'old' values.
	119
	120	Problems
	121	--------
	122	Some chips refuse to be enabled. We don't know why.
	123	The driver will recognize this and print a message in dmesg.