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R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +00001Kernel driver it87
2==================
3
4Supported chips:
5 * IT8705F
6 Prefix: 'it87'
Jean Delvare91749992005-10-08 00:10:00 +02007 Addresses scanned: from Super I/O config space (8 I/O ports)
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +00008 Datasheet: Publicly available at the ITE website
9 http://www.ite.com.tw/
10 * IT8712F
11 Prefix: 'it8712'
Jean Delvare8e9afcb2006-12-12 18:18:28 +010012 Addresses scanned: from Super I/O config space (8 I/O ports)
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +000013 Datasheet: Publicly available at the ITE website
14 http://www.ite.com.tw/
Jean Delvare17d648b2006-08-28 14:23:46 +020015 * IT8716F
16 Prefix: 'it8716'
17 Addresses scanned: from Super I/O config space (8 I/O ports)
18 Datasheet: Publicly available at the ITE website
19 http://www.ite.com.tw/product_info/file/pc/IT8716F_V0.3.ZIP
Jean Delvare87673dd2006-08-28 14:37:19 +020020 * IT8718F
21 Prefix: 'it8718'
22 Addresses scanned: from Super I/O config space (8 I/O ports)
23 Datasheet: Publicly available at the ITE website
24 http://www.ite.com.tw/product_info/file/pc/IT8718F_V0.2.zip
25 http://www.ite.com.tw/product_info/file/pc/IT8718F_V0%203_(for%20C%20version).zip
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +000026 * SiS950 [clone of IT8705F]
Jean Delvare91749992005-10-08 00:10:00 +020027 Prefix: 'it87'
28 Addresses scanned: from Super I/O config space (8 I/O ports)
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +000029 Datasheet: No longer be available
30
Jean Delvareb19367c2006-08-28 14:39:26 +020031Authors:
32 Christophe Gauthron <chrisg@0-in.com>
33 Jean Delvare <khali@linux-fr.org>
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +000034
35
36Module Parameters
37-----------------
38
39* update_vbat: int
40
41 0 if vbat should report power on value, 1 if vbat should be updated after
42 each read. Default is 0. On some boards the battery voltage is provided
43 by either the battery or the onboard power supply. Only the first reading
44 at power on will be the actual battery voltage (which the chip does
45 automatically). On other boards the battery voltage is always fed to
46 the chip so can be read at any time. Excessive reading may decrease
47 battery life but no information is given in the datasheet.
48
49* fix_pwm_polarity int
50
51 Force PWM polarity to active high (DANGEROUS). Some chips are
52 misconfigured by BIOS - PWM values would be inverted. This option tries
53 to fix this. Please contact your BIOS manufacturer and ask him for fix.
54
Jean Delvare8e9afcb2006-12-12 18:18:28 +010055
56Hardware Interfaces
57-------------------
58
59All the chips suported by this driver are LPC Super-I/O chips, accessed
60through the LPC bus (ISA-like I/O ports). The IT8712F additionally has an
61SMBus interface to the hardware monitoring functions. This driver no
62longer supports this interface though, as it is slower and less reliable
63than the ISA access, and was only available on a small number of
64motherboard models.
65
66
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +000067Description
68-----------
69
Jean Delvare87673dd2006-08-28 14:37:19 +020070This driver implements support for the IT8705F, IT8712F, IT8716F,
71IT8718F and SiS950 chips.
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +000072
73These chips are 'Super I/O chips', supporting floppy disks, infrared ports,
74joysticks and other miscellaneous stuff. For hardware monitoring, they
75include an 'environment controller' with 3 temperature sensors, 3 fan
76rotation speed sensors, 8 voltage sensors, and associated alarms.
77
Jean Delvare17d648b2006-08-28 14:23:46 +020078The IT8712F and IT8716F additionally feature VID inputs, used to report
79the Vcore voltage of the processor. The early IT8712F have 5 VID pins,
80the IT8716F and late IT8712F have 6. They are shared with other functions
81though, so the functionality may not be available on a given system.
82The driver dumbly assume it is there.
83
Jean Delvare87673dd2006-08-28 14:37:19 +020084The IT8718F also features VID inputs (up to 8 pins) but the value is
85stored in the Super-I/O configuration space. Due to technical limitations,
86this value can currently only be read once at initialization time, so
87the driver won't notice and report changes in the VID value. The two
88upper VID bits share their pins with voltage inputs (in5 and in6) so you
89can't have both on a given board.
Jean Delvare17d648b2006-08-28 14:23:46 +020090
Jean Delvare87673dd2006-08-28 14:37:19 +020091The IT8716F, IT8718F and later IT8712F revisions have support for
922 additional fans. They are not yet supported by the driver.
93
94The IT8716F and IT8718F, and late IT8712F and IT8705F also have optional
9516-bit tachometer counters for fans 1 to 3. This is better (no more fan
Jean Delvare17d648b2006-08-28 14:23:46 +020096clock divider mess) but not compatible with the older chips and
97revisions. For now, the driver only uses the 16-bit mode on the
Jean Delvare87673dd2006-08-28 14:37:19 +020098IT8716F and IT8718F.
Jean Delvare17d648b2006-08-28 14:23:46 +020099
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +0000100Temperatures are measured in degrees Celsius. An alarm is triggered once
101when the Overtemperature Shutdown limit is crossed.
102
103Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
Jean Delvare17d648b2006-08-28 14:23:46 +0200104triggered if the rotation speed has dropped below a programmable limit. When
10516-bit tachometer counters aren't used, fan readings can be divided by
106a programmable divider (1, 2, 4 or 8) to give the readings more range or
107accuracy. With a divider of 2, the lowest representable value is around
1082600 RPM. Not all RPM values can accurately be represented, so some rounding
109is done.
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +0000110
111Voltage sensors (also known as IN sensors) report their values in volts. An
112alarm is triggered if the voltage has crossed a programmable minimum or
113maximum limit. Note that minimum in this case always means 'closest to
114zero'; this is important for negative voltage measurements. All voltage
115inputs can measure voltages between 0 and 4.08 volts, with a resolution of
1160.016 volt. The battery voltage in8 does not have limit registers.
117
Jean Delvare87673dd2006-08-28 14:37:19 +0200118The VID lines (IT8712F/IT8716F/IT8718F) encode the core voltage value:
119the voltage level your processor should work with. This is hardcoded by
120the mainboard and/or processor itself. It is a value in volts.
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +0000121
122If an alarm triggers, it will remain triggered until the hardware register
123is read at least once. This means that the cause for the alarm may already
124have disappeared! Note that in the current implementation, all hardware
125registers are read whenever any data is read (unless it is less than 1.5
126seconds since the last update). This means that you can easily miss
127once-only alarms.
128
129The IT87xx only updates its values each 1.5 seconds; reading it more often
130will do no harm, but will return 'old' values.
131
132To change sensor N to a thermistor, 'echo 2 > tempN_type' where N is 1, 2,
133or 3. To change sensor N to a thermal diode, 'echo 3 > tempN_type'.
134Give 0 for unused sensor. Any other value is invalid. To configure this at
135startup, consult lm_sensors's /etc/sensors.conf. (2 = thermistor;
1363 = thermal diode)
137
Jean Delvaref8d0c192007-02-14 21:15:02 +0100138
139Fan speed control
140-----------------
141
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +0000142The fan speed control features are limited to manual PWM mode. Automatic
143"Smart Guardian" mode control handling is not implemented. However
144if you want to go for "manual mode" just write 1 to pwmN_enable.
Jean Delvaref8d0c192007-02-14 21:15:02 +0100145
146If you are only able to control the fan speed with very small PWM values,
147try lowering the PWM base frequency (pwm1_freq). Depending on the fan,
148it may give you a somewhat greater control range. The same frequency is
149used to drive all fan outputs, which is why pwm2_freq and pwm3_freq are
150read-only.