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Based on kernel version 4.3. Page generated on 2015-11-02 12:49 EST.

1	Kernel driver it87
2	==================
3	
4	Supported chips:
5	  * IT8603E/IT8623E
6	    Prefix: 'it8603'
7	    Addresses scanned: from Super I/O config space (8 I/O ports)
8	    Datasheet: Not publicly available
9	  * IT8620E
10	    Prefix: 'it8620'
11	    Addresses scanned: from Super I/O config space (8 I/O ports)
12	    Datasheet: Not publicly available
13	  * IT8705F
14	    Prefix: 'it87'
15	    Addresses scanned: from Super I/O config space (8 I/O ports)
16	    Datasheet: Once publicly available at the ITE website, but no longer
17	  * IT8712F
18	    Prefix: 'it8712'
19	    Addresses scanned: from Super I/O config space (8 I/O ports)
20	    Datasheet: Once publicly available at the ITE website, but no longer
21	  * IT8716F/IT8726F
22	    Prefix: 'it8716'
23	    Addresses scanned: from Super I/O config space (8 I/O ports)
24	    Datasheet: Once publicly available at the ITE website, but no longer
25	  * IT8718F
26	    Prefix: 'it8718'
27	    Addresses scanned: from Super I/O config space (8 I/O ports)
28	    Datasheet: Once publicly available at the ITE website, but no longer
29	  * IT8720F
30	    Prefix: 'it8720'
31	    Addresses scanned: from Super I/O config space (8 I/O ports)
32	    Datasheet: Not publicly available
33	  * IT8721F/IT8758E
34	    Prefix: 'it8721'
35	    Addresses scanned: from Super I/O config space (8 I/O ports)
36	    Datasheet: Not publicly available
37	  * IT8728F
38	    Prefix: 'it8728'
39	    Addresses scanned: from Super I/O config space (8 I/O ports)
40	    Datasheet: Not publicly available
41	  * IT8732F
42	    Prefix: 'it8732'
43	    Addresses scanned: from Super I/O config space (8 I/O ports)
44	    Datasheet: Not publicly available
45	  * IT8771E
46	    Prefix: 'it8771'
47	    Addresses scanned: from Super I/O config space (8 I/O ports)
48	    Datasheet: Not publicly available
49	  * IT8772E
50	    Prefix: 'it8772'
51	    Addresses scanned: from Super I/O config space (8 I/O ports)
52	    Datasheet: Not publicly available
53	  * IT8781F
54	    Prefix: 'it8781'
55	    Addresses scanned: from Super I/O config space (8 I/O ports)
56	    Datasheet: Not publicly available
57	  * IT8782F
58	    Prefix: 'it8782'
59	    Addresses scanned: from Super I/O config space (8 I/O ports)
60	    Datasheet: Not publicly available
61	  * IT8783E/F
62	    Prefix: 'it8783'
63	    Addresses scanned: from Super I/O config space (8 I/O ports)
64	    Datasheet: Not publicly available
65	  * IT8786E
66	    Prefix: 'it8786'
67	    Addresses scanned: from Super I/O config space (8 I/O ports)
68	    Datasheet: Not publicly available
69	  * IT8790E
70	    Prefix: 'it8790'
71	    Addresses scanned: from Super I/O config space (8 I/O ports)
72	    Datasheet: Not publicly available
73	  * SiS950   [clone of IT8705F]
74	    Prefix: 'it87'
75	    Addresses scanned: from Super I/O config space (8 I/O ports)
76	    Datasheet: No longer be available
77	
78	Authors:
79	    Christophe Gauthron
80	    Jean Delvare <jdelvare@suse.de>
81	
82	
83	Module Parameters
84	-----------------
85	
86	* update_vbat: int
87	
88	  0 if vbat should report power on value, 1 if vbat should be updated after
89	  each read. Default is 0. On some boards the battery voltage is provided
90	  by either the battery or the onboard power supply. Only the first reading
91	  at power on will be the actual battery voltage (which the chip does
92	  automatically). On other boards the battery voltage is always fed to
93	  the chip so can be read at any time. Excessive reading may decrease
94	  battery life but no information is given in the datasheet.
95	
96	* fix_pwm_polarity int
97	
98	  Force PWM polarity to active high (DANGEROUS). Some chips are
99	  misconfigured by BIOS - PWM values would be inverted. This option tries
100	  to fix this. Please contact your BIOS manufacturer and ask him for fix.
101	
102	
103	Hardware Interfaces
104	-------------------
105	
106	All the chips supported by this driver are LPC Super-I/O chips, accessed
107	through the LPC bus (ISA-like I/O ports). The IT8712F additionally has an
108	SMBus interface to the hardware monitoring functions. This driver no
109	longer supports this interface though, as it is slower and less reliable
110	than the ISA access, and was only available on a small number of
111	motherboard models.
112	
113	
114	Description
115	-----------
116	
117	This driver implements support for the IT8603E, IT8620E, IT8623E, IT8705F,
118	IT8712F, IT8716F, IT8718F, IT8720F, IT8721F, IT8726F, IT8728F, IT8732F,
119	IT8758E, IT8771E, IT8772E, IT8781F, IT8782F, IT8783E/F, IT8786E, IT8790E, and
120	SiS950 chips.
121	
122	These chips are 'Super I/O chips', supporting floppy disks, infrared ports,
123	joysticks and other miscellaneous stuff. For hardware monitoring, they
124	include an 'environment controller' with 3 temperature sensors, 3 fan
125	rotation speed sensors, 8 voltage sensors, associated alarms, and chassis
126	intrusion detection.
127	
128	The IT8712F and IT8716F additionally feature VID inputs, used to report
129	the Vcore voltage of the processor. The early IT8712F have 5 VID pins,
130	the IT8716F and late IT8712F have 6. They are shared with other functions
131	though, so the functionality may not be available on a given system.
132	
133	The IT8718F and IT8720F also features VID inputs (up to 8 pins) but the value
134	is stored in the Super-I/O configuration space. Due to technical limitations,
135	this value can currently only be read once at initialization time, so
136	the driver won't notice and report changes in the VID value. The two
137	upper VID bits share their pins with voltage inputs (in5 and in6) so you
138	can't have both on a given board.
139	
140	The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E and later IT8712F revisions
141	have support for 2 additional fans. The additional fans are supported by the
142	driver.
143	
144	The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E, IT8732F, IT8781F, IT8782F,
145	IT8783E/F, and late IT8712F and IT8705F also have optional 16-bit tachometer
146	counters for fans 1 to 3. This is better (no more fan clock divider mess) but
147	not compatible with the older chips and revisions. The 16-bit tachometer mode
148	is enabled by the driver when one of the above chips is detected.
149	
150	The IT8726F is just bit enhanced IT8716F with additional hardware
151	for AMD power sequencing. Therefore the chip will appear as IT8716F
152	to userspace applications.
153	
154	The IT8728F, IT8771E, and IT8772E are considered compatible with the IT8721F,
155	until a datasheet becomes available (hopefully.)
156	
157	The IT8603E/IT8623E is a custom design, hardware monitoring part is similar to
158	IT8728F. It only supports 3 fans, 16-bit fan mode, and the full speed mode
159	of the fan is not supported (value 0 of pwmX_enable).
160	
161	The IT8620E is another custom design, hardware monitoring part is similar to
162	IT8728F. It only supports 16-bit fan mode.
163	
164	The IT8790E supports up to 3 fans. 16-bit fan mode is always enabled.
165	
166	The IT8732F supports a closed-loop mode for fan control, but this is not
167	currently implemented by the driver.
168	
169	Temperatures are measured in degrees Celsius. An alarm is triggered once
170	when the Overtemperature Shutdown limit is crossed.
171	
172	Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
173	triggered if the rotation speed has dropped below a programmable limit. When
174	16-bit tachometer counters aren't used, fan readings can be divided by
175	a programmable divider (1, 2, 4 or 8) to give the readings more range or
176	accuracy. With a divider of 2, the lowest representable value is around
177	2600 RPM. Not all RPM values can accurately be represented, so some rounding
178	is done.
179	
180	Voltage sensors (also known as IN sensors) report their values in volts. An
181	alarm is triggered if the voltage has crossed a programmable minimum or
182	maximum limit. Note that minimum in this case always means 'closest to
183	zero'; this is important for negative voltage measurements. On most chips, all
184	voltage inputs can measure voltages between 0 and 4.08 volts, with a resolution
185	of 0.016 volt.  IT8603E, IT8721F/IT8758E and IT8728F can measure between 0 and
186	3.06 volts, with a resolution of 0.012 volt.  IT8732F can measure between 0 and
187	2.8 volts with a resolution of 0.0109 volt.  The battery voltage in8 does not
188	have limit registers.
189	
190	On the IT8603E, IT8721F/IT8758E, IT8732F, IT8781F, IT8782F, and IT8783E/F, some
191	voltage inputs are internal and scaled inside the chip:
192	* in3 (optional)
193	* in7 (optional for IT8781F, IT8782F, and IT8783E/F)
194	* in8 (always)
195	* in9 (relevant for IT8603E only)
196	The driver handles this transparently so user-space doesn't have to care.
197	
198	The VID lines (IT8712F/IT8716F/IT8718F/IT8720F) encode the core voltage value:
199	the voltage level your processor should work with. This is hardcoded by
200	the mainboard and/or processor itself. It is a value in volts.
201	
202	If an alarm triggers, it will remain triggered until the hardware register
203	is read at least once. This means that the cause for the alarm may already
204	have disappeared! Note that in the current implementation, all hardware
205	registers are read whenever any data is read (unless it is less than 1.5
206	seconds since the last update). This means that you can easily miss
207	once-only alarms.
208	
209	Out-of-limit readings can also result in beeping, if the chip is properly
210	wired and configured. Beeping can be enabled or disabled per sensor type
211	(temperatures, voltages and fans.)
212	
213	The IT87xx only updates its values each 1.5 seconds; reading it more often
214	will do no harm, but will return 'old' values.
215	
216	To change sensor N to a thermistor, 'echo 4 > tempN_type' where N is 1, 2,
217	or 3. To change sensor N to a thermal diode, 'echo 3 > tempN_type'.
218	Give 0 for unused sensor. Any other value is invalid. To configure this at
219	startup, consult lm_sensors's /etc/sensors.conf. (4 = thermistor;
220	3 = thermal diode)
221	
222	
223	Fan speed control
224	-----------------
225	
226	The fan speed control features are limited to manual PWM mode. Automatic
227	"Smart Guardian" mode control handling is only implemented for older chips
228	(see below.) However if you want to go for "manual mode" just write 1 to
229	pwmN_enable.
230	
231	If you are only able to control the fan speed with very small PWM values,
232	try lowering the PWM base frequency (pwm1_freq). Depending on the fan,
233	it may give you a somewhat greater control range. The same frequency is
234	used to drive all fan outputs, which is why pwm2_freq and pwm3_freq are
235	read-only.
236	
237	
238	Automatic fan speed control (old interface)
239	-------------------------------------------
240	
241	The driver supports the old interface to automatic fan speed control
242	which is implemented by IT8705F chips up to revision F and IT8712F
243	chips up to revision G.
244	
245	This interface implements 4 temperature vs. PWM output trip points.
246	The PWM output of trip point 4 is always the maximum value (fan running
247	at full speed) while the PWM output of the other 3 trip points can be
248	freely chosen. The temperature of all 4 trip points can be freely chosen.
249	Additionally, trip point 1 has an hysteresis temperature attached, to
250	prevent fast switching between fan on and off.
251	
252	The chip automatically computes the PWM output value based on the input
253	temperature, based on this simple rule: if the temperature value is
254	between trip point N and trip point N+1 then the PWM output value is
255	the one of trip point N. The automatic control mode is less flexible
256	than the manual control mode, but it reacts faster, is more robust and
257	doesn't use CPU cycles.
258	
259	Trip points must be set properly before switching to automatic fan speed
260	control mode. The driver will perform basic integrity checks before
261	actually switching to automatic control mode.
262	
263	
264	Temperature offset attributes
265	-----------------------------
266	
267	The driver supports temp[1-3]_offset sysfs attributes to adjust the reported
268	temperature for thermal diodes or diode-connected thermal transistors.
269	If a temperature sensor is configured for thermistors, the attribute values
270	are ignored. If the thermal sensor type is Intel PECI, the temperature offset
271	must be programmed to the critical CPU temperature.
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