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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)
Jean Delvare404a5522010-03-05 22:17:21 +01008 Datasheet: Once publicly available at the ITE website, but no longer
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +00009 * IT8712F
10 Prefix: 'it8712'
Jean Delvare8e9afcb2006-12-12 18:18:28 +010011 Addresses scanned: from Super I/O config space (8 I/O ports)
Jean Delvare404a5522010-03-05 22:17:21 +010012 Datasheet: Once publicly available at the ITE website, but no longer
Rudolf Marek08a8f6e2007-06-09 10:11:16 -040013 * IT8716F/IT8726F
Jean Delvare17d648b2006-08-28 14:23:46 +020014 Prefix: 'it8716'
15 Addresses scanned: from Super I/O config space (8 I/O ports)
Jean Delvare404a5522010-03-05 22:17:21 +010016 Datasheet: Once publicly available at the ITE website, but no longer
Jean Delvare87673dd2006-08-28 14:37:19 +020017 * IT8718F
18 Prefix: 'it8718'
19 Addresses scanned: from Super I/O config space (8 I/O ports)
Jean Delvare404a5522010-03-05 22:17:21 +010020 Datasheet: Once publicly available at the ITE website, but no longer
Jean-Marc Spaggiarib4da93e2009-01-07 16:37:32 +010021 * IT8720F
22 Prefix: 'it8720'
23 Addresses scanned: from Super I/O config space (8 I/O ports)
Jean Delvare404a5522010-03-05 22:17:21 +010024 Datasheet: Not publicly available
Jean Delvare44c1bcd2010-10-28 20:31:51 +020025 * IT8721F/IT8758E
26 Prefix: 'it8721'
27 Addresses scanned: from Super I/O config space (8 I/O ports)
28 Datasheet: Not publicly available
Jean Delvare16b5dda2012-01-16 22:51:48 +010029 * IT8728F
30 Prefix: 'it8728'
31 Addresses scanned: from Super I/O config space (8 I/O ports)
32 Datasheet: Not publicly available
Guenter Roeck0531d982012-03-02 11:46:44 -080033 * IT8782F
34 Prefix: 'it8782'
35 Addresses scanned: from Super I/O config space (8 I/O ports)
36 Datasheet: Not publicly available
37 * IT8783E/F
38 Prefix: 'it8783'
39 Addresses scanned: from Super I/O config space (8 I/O ports)
40 Datasheet: Not publicly available
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +000041 * SiS950 [clone of IT8705F]
Jean Delvare91749992005-10-08 00:10:00 +020042 Prefix: 'it87'
43 Addresses scanned: from Super I/O config space (8 I/O ports)
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +000044 Datasheet: No longer be available
45
Jean Delvareb19367c2006-08-28 14:39:26 +020046Authors:
Jean Delvaref1d8e332007-11-25 16:14:44 +010047 Christophe Gauthron
Jean Delvareb19367c2006-08-28 14:39:26 +020048 Jean Delvare <khali@linux-fr.org>
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +000049
50
51Module Parameters
52-----------------
53
54* update_vbat: int
55
56 0 if vbat should report power on value, 1 if vbat should be updated after
57 each read. Default is 0. On some boards the battery voltage is provided
58 by either the battery or the onboard power supply. Only the first reading
59 at power on will be the actual battery voltage (which the chip does
60 automatically). On other boards the battery voltage is always fed to
61 the chip so can be read at any time. Excessive reading may decrease
62 battery life but no information is given in the datasheet.
63
64* fix_pwm_polarity int
65
66 Force PWM polarity to active high (DANGEROUS). Some chips are
67 misconfigured by BIOS - PWM values would be inverted. This option tries
68 to fix this. Please contact your BIOS manufacturer and ask him for fix.
69
Jean Delvare8e9afcb2006-12-12 18:18:28 +010070
71Hardware Interfaces
72-------------------
73
Masanari Iidac94bed8e2012-04-10 00:22:13 +090074All the chips supported by this driver are LPC Super-I/O chips, accessed
Jean Delvare8e9afcb2006-12-12 18:18:28 +010075through the LPC bus (ISA-like I/O ports). The IT8712F additionally has an
76SMBus interface to the hardware monitoring functions. This driver no
77longer supports this interface though, as it is slower and less reliable
78than the ISA access, and was only available on a small number of
79motherboard models.
80
81
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +000082Description
83-----------
84
Jean Delvare87673dd2006-08-28 14:37:19 +020085This driver implements support for the IT8705F, IT8712F, IT8716F,
Guenter Roeck0531d982012-03-02 11:46:44 -080086IT8718F, IT8720F, IT8721F, IT8726F, IT8728F, IT8758E, IT8781F, IT8782F,
87IT8783E/F, and SiS950 chips.
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +000088
89These chips are 'Super I/O chips', supporting floppy disks, infrared ports,
90joysticks and other miscellaneous stuff. For hardware monitoring, they
91include an 'environment controller' with 3 temperature sensors, 3 fan
Jean Delvare3d30f9e2011-07-25 21:46:10 +020092rotation speed sensors, 8 voltage sensors, associated alarms, and chassis
93intrusion detection.
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +000094
Jean Delvare17d648b2006-08-28 14:23:46 +020095The IT8712F and IT8716F additionally feature VID inputs, used to report
96the Vcore voltage of the processor. The early IT8712F have 5 VID pins,
97the IT8716F and late IT8712F have 6. They are shared with other functions
98though, so the functionality may not be available on a given system.
Jean Delvare17d648b2006-08-28 14:23:46 +020099
Jean-Marc Spaggiarib4da93e2009-01-07 16:37:32 +0100100The IT8718F and IT8720F also features VID inputs (up to 8 pins) but the value
101is stored in the Super-I/O configuration space. Due to technical limitations,
Jean Delvare87673dd2006-08-28 14:37:19 +0200102this value can currently only be read once at initialization time, so
103the driver won't notice and report changes in the VID value. The two
104upper VID bits share their pins with voltage inputs (in5 and in6) so you
105can't have both on a given board.
Jean Delvare17d648b2006-08-28 14:23:46 +0200106
Jean Delvare44c1bcd2010-10-28 20:31:51 +0200107The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E and later IT8712F revisions
108have support for 2 additional fans. The additional fans are supported by the
109driver.
Jean Delvare87673dd2006-08-28 14:37:19 +0200110
Guenter Roeck0531d982012-03-02 11:46:44 -0800111The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E, IT8782F, IT8783E/F, and late
112IT8712F and IT8705F also have optional 16-bit tachometer counters for fans 1 to
1133. This is better (no more fan clock divider mess) but not compatible with the
114older chips and revisions. The 16-bit tachometer mode is enabled by the driver
115when one of the above chips is detected.
Jean Delvare17d648b2006-08-28 14:23:46 +0200116
Rudolf Marek08a8f6e2007-06-09 10:11:16 -0400117The IT8726F is just bit enhanced IT8716F with additional hardware
118for AMD power sequencing. Therefore the chip will appear as IT8716F
119to userspace applications.
120
Jean Delvare16b5dda2012-01-16 22:51:48 +0100121The IT8728F is considered compatible with the IT8721F, until a datasheet
122becomes available (hopefully.)
123
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +0000124Temperatures are measured in degrees Celsius. An alarm is triggered once
125when the Overtemperature Shutdown limit is crossed.
126
127Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
Jean Delvare17d648b2006-08-28 14:23:46 +0200128triggered if the rotation speed has dropped below a programmable limit. When
12916-bit tachometer counters aren't used, fan readings can be divided by
130a programmable divider (1, 2, 4 or 8) to give the readings more range or
131accuracy. With a divider of 2, the lowest representable value is around
1322600 RPM. Not all RPM values can accurately be represented, so some rounding
133is done.
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +0000134
135Voltage sensors (also known as IN sensors) report their values in volts. An
136alarm is triggered if the voltage has crossed a programmable minimum or
137maximum limit. Note that minimum in this case always means 'closest to
138zero'; this is important for negative voltage measurements. All voltage
139inputs can measure voltages between 0 and 4.08 volts, with a resolution of
Jean Delvare16b5dda2012-01-16 22:51:48 +01001400.016 volt (except IT8721F/IT8758E and IT8728F: 0.012 volt.) The battery
141voltage in8 does not have limit registers.
Jean Delvare44c1bcd2010-10-28 20:31:51 +0200142
Guenter Roeck0531d982012-03-02 11:46:44 -0800143On the IT8721F/IT8758E, IT8782F, and IT8783E/F, some voltage inputs are
144internal and scaled inside the chip (in7 (optional for IT8782F and IT8783E/F),
145in8 and optionally in3). The driver handles this transparently so user-space
146doesn't have to care.
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +0000147
Jean-Marc Spaggiarib4da93e2009-01-07 16:37:32 +0100148The VID lines (IT8712F/IT8716F/IT8718F/IT8720F) encode the core voltage value:
Jean Delvare87673dd2006-08-28 14:37:19 +0200149the voltage level your processor should work with. This is hardcoded by
150the mainboard and/or processor itself. It is a value in volts.
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +0000151
152If an alarm triggers, it will remain triggered until the hardware register
153is read at least once. This means that the cause for the alarm may already
154have disappeared! Note that in the current implementation, all hardware
155registers are read whenever any data is read (unless it is less than 1.5
156seconds since the last update). This means that you can easily miss
157once-only alarms.
158
Jean Delvared9b327c2010-03-05 22:17:17 +0100159Out-of-limit readings can also result in beeping, if the chip is properly
160wired and configured. Beeping can be enabled or disabled per sensor type
161(temperatures, voltages and fans.)
162
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +0000163The IT87xx only updates its values each 1.5 seconds; reading it more often
164will do no harm, but will return 'old' values.
165
Jean Delvare4ed10772008-10-17 17:51:16 +0200166To change sensor N to a thermistor, 'echo 4 > tempN_type' where N is 1, 2,
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +0000167or 3. To change sensor N to a thermal diode, 'echo 3 > tempN_type'.
168Give 0 for unused sensor. Any other value is invalid. To configure this at
Jean Delvare4ed10772008-10-17 17:51:16 +0200169startup, consult lm_sensors's /etc/sensors.conf. (4 = thermistor;
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +00001703 = thermal diode)
171
Jean Delvaref8d0c192007-02-14 21:15:02 +0100172
173Fan speed control
174-----------------
175
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +0000176The fan speed control features are limited to manual PWM mode. Automatic
Jean Delvare4f3f51b2010-03-05 22:17:21 +0100177"Smart Guardian" mode control handling is only implemented for older chips
178(see below.) However if you want to go for "manual mode" just write 1 to
179pwmN_enable.
Jean Delvaref8d0c192007-02-14 21:15:02 +0100180
181If you are only able to control the fan speed with very small PWM values,
182try lowering the PWM base frequency (pwm1_freq). Depending on the fan,
183it may give you a somewhat greater control range. The same frequency is
184used to drive all fan outputs, which is why pwm2_freq and pwm3_freq are
185read-only.
Jean Delvare4f3f51b2010-03-05 22:17:21 +0100186
187
188Automatic fan speed control (old interface)
189-------------------------------------------
190
191The driver supports the old interface to automatic fan speed control
192which is implemented by IT8705F chips up to revision F and IT8712F
193chips up to revision G.
194
195This interface implements 4 temperature vs. PWM output trip points.
196The PWM output of trip point 4 is always the maximum value (fan running
197at full speed) while the PWM output of the other 3 trip points can be
198freely chosen. The temperature of all 4 trip points can be freely chosen.
199Additionally, trip point 1 has an hysteresis temperature attached, to
200prevent fast switching between fan on and off.
201
202The chip automatically computes the PWM output value based on the input
203temperature, based on this simple rule: if the temperature value is
204between trip point N and trip point N+1 then the PWM output value is
205the one of trip point N. The automatic control mode is less flexible
206than the manual control mode, but it reacts faster, is more robust and
207doesn't use CPU cycles.
Jean Delvarecccfc9c2010-03-05 22:17:21 +0100208
209Trip points must be set properly before switching to automatic fan speed
210control mode. The driver will perform basic integrity checks before
211actually switching to automatic control mode.
Guenter Roeck161d8982012-12-19 22:17:01 +0100212
213
214Temperature offset attributes
215-----------------------------
216
217The driver supports temp[1-3]_offset sysfs attributes to adjust the reported
218temperature for thermal diodes or diode-connected thermal transistors.
219If a temperature sensor is configured for thermistors, the attribute values
Guenter Roeck5d8d2f22012-12-19 22:17:02 +0100220are ignored. If the thermal sensor type is Intel PECI, the temperature offset
221must be programmed to the critical CPU temperature.