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Based on kernel version 4.8. Page generated on 2016-10-06 23:16 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	  * IT8628E
13	    Prefix: 'it8628'
14	    Addresses scanned: from Super I/O config space (8 I/O ports)
15	    Datasheet: Not publicly available
16	  * IT8705F
17	    Prefix: 'it87'
18	    Addresses scanned: from Super I/O config space (8 I/O ports)
19	    Datasheet: Once publicly available at the ITE website, but no longer
20	  * IT8712F
21	    Prefix: 'it8712'
22	    Addresses scanned: from Super I/O config space (8 I/O ports)
23	    Datasheet: Once publicly available at the ITE website, but no longer
24	  * IT8716F/IT8726F
25	    Prefix: 'it8716'
26	    Addresses scanned: from Super I/O config space (8 I/O ports)
27	    Datasheet: Once publicly available at the ITE website, but no longer
28	  * IT8718F
29	    Prefix: 'it8718'
30	    Addresses scanned: from Super I/O config space (8 I/O ports)
31	    Datasheet: Once publicly available at the ITE website, but no longer
32	  * IT8720F
33	    Prefix: 'it8720'
34	    Addresses scanned: from Super I/O config space (8 I/O ports)
35	    Datasheet: Not publicly available
36	  * IT8721F/IT8758E
37	    Prefix: 'it8721'
38	    Addresses scanned: from Super I/O config space (8 I/O ports)
39	    Datasheet: Not publicly available
40	  * IT8728F
41	    Prefix: 'it8728'
42	    Addresses scanned: from Super I/O config space (8 I/O ports)
43	    Datasheet: Not publicly available
44	  * IT8732F
45	    Prefix: 'it8732'
46	    Addresses scanned: from Super I/O config space (8 I/O ports)
47	    Datasheet: Not publicly available
48	  * IT8771E
49	    Prefix: 'it8771'
50	    Addresses scanned: from Super I/O config space (8 I/O ports)
51	    Datasheet: Not publicly available
52	  * IT8772E
53	    Prefix: 'it8772'
54	    Addresses scanned: from Super I/O config space (8 I/O ports)
55	    Datasheet: Not publicly available
56	  * IT8781F
57	    Prefix: 'it8781'
58	    Addresses scanned: from Super I/O config space (8 I/O ports)
59	    Datasheet: Not publicly available
60	  * IT8782F
61	    Prefix: 'it8782'
62	    Addresses scanned: from Super I/O config space (8 I/O ports)
63	    Datasheet: Not publicly available
64	  * IT8783E/F
65	    Prefix: 'it8783'
66	    Addresses scanned: from Super I/O config space (8 I/O ports)
67	    Datasheet: Not publicly available
68	  * IT8786E
69	    Prefix: 'it8786'
70	    Addresses scanned: from Super I/O config space (8 I/O ports)
71	    Datasheet: Not publicly available
72	  * IT8790E
73	    Prefix: 'it8790'
74	    Addresses scanned: from Super I/O config space (8 I/O ports)
75	    Datasheet: Not publicly available
76	  * SiS950   [clone of IT8705F]
77	    Prefix: 'it87'
78	    Addresses scanned: from Super I/O config space (8 I/O ports)
79	    Datasheet: No longer be available
80	
81	Authors:
82	    Christophe Gauthron
83	    Jean Delvare <jdelvare@suse.de>
84	
85	
86	Module Parameters
87	-----------------
88	
89	* update_vbat: int
90	
91	  0 if vbat should report power on value, 1 if vbat should be updated after
92	  each read. Default is 0. On some boards the battery voltage is provided
93	  by either the battery or the onboard power supply. Only the first reading
94	  at power on will be the actual battery voltage (which the chip does
95	  automatically). On other boards the battery voltage is always fed to
96	  the chip so can be read at any time. Excessive reading may decrease
97	  battery life but no information is given in the datasheet.
98	
99	* fix_pwm_polarity int
100	
101	  Force PWM polarity to active high (DANGEROUS). Some chips are
102	  misconfigured by BIOS - PWM values would be inverted. This option tries
103	  to fix this. Please contact your BIOS manufacturer and ask him for fix.
104	
105	
106	Hardware Interfaces
107	-------------------
108	
109	All the chips supported by this driver are LPC Super-I/O chips, accessed
110	through the LPC bus (ISA-like I/O ports). The IT8712F additionally has an
111	SMBus interface to the hardware monitoring functions. This driver no
112	longer supports this interface though, as it is slower and less reliable
113	than the ISA access, and was only available on a small number of
114	motherboard models.
115	
116	
117	Description
118	-----------
119	
120	This driver implements support for the IT8603E, IT8620E, IT8623E, IT8628E,
121	IT8705F, IT8712F, IT8716F, IT8718F, IT8720F, IT8721F, IT8726F, IT8728F, IT8732F,
122	IT8758E, IT8771E, IT8772E, IT8781F, IT8782F, IT8783E/F, IT8786E, IT8790E, and
123	SiS950 chips.
124	
125	These chips are 'Super I/O chips', supporting floppy disks, infrared ports,
126	joysticks and other miscellaneous stuff. For hardware monitoring, they
127	include an 'environment controller' with 3 temperature sensors, 3 fan
128	rotation speed sensors, 8 voltage sensors, associated alarms, and chassis
129	intrusion detection.
130	
131	The IT8712F and IT8716F additionally feature VID inputs, used to report
132	the Vcore voltage of the processor. The early IT8712F have 5 VID pins,
133	the IT8716F and late IT8712F have 6. They are shared with other functions
134	though, so the functionality may not be available on a given system.
135	
136	The IT8718F and IT8720F also features VID inputs (up to 8 pins) but the value
137	is stored in the Super-I/O configuration space. Due to technical limitations,
138	this value can currently only be read once at initialization time, so
139	the driver won't notice and report changes in the VID value. The two
140	upper VID bits share their pins with voltage inputs (in5 and in6) so you
141	can't have both on a given board.
142	
143	The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E and later IT8712F revisions
144	have support for 2 additional fans. The additional fans are supported by the
145	driver.
146	
147	The IT8716F, IT8718F, IT8720F, IT8721F/IT8758E, IT8732F, IT8781F, IT8782F,
148	IT8783E/F, and late IT8712F and IT8705F also have optional 16-bit tachometer
149	counters for fans 1 to 3. This is better (no more fan clock divider mess) but
150	not compatible with the older chips and revisions. The 16-bit tachometer mode
151	is enabled by the driver when one of the above chips is detected.
152	
153	The IT8726F is just bit enhanced IT8716F with additional hardware
154	for AMD power sequencing. Therefore the chip will appear as IT8716F
155	to userspace applications.
156	
157	The IT8728F, IT8771E, and IT8772E are considered compatible with the IT8721F,
158	until a datasheet becomes available (hopefully.)
159	
160	The IT8603E/IT8623E is a custom design, hardware monitoring part is similar to
161	IT8728F. It only supports 3 fans, 16-bit fan mode, and the full speed mode
162	of the fan is not supported (value 0 of pwmX_enable).
163	
164	The IT8620E and IT8628E are custom designs, hardware monitoring part is similar
165	to IT8728F. It only supports 16-bit fan mode. Both chips support up to 6 fans.
166	
167	The IT8790E supports up to 3 fans. 16-bit fan mode is always enabled.
168	
169	The IT8732F supports a closed-loop mode for fan control, but this is not
170	currently implemented by the driver.
171	
172	Temperatures are measured in degrees Celsius. An alarm is triggered once
173	when the Overtemperature Shutdown limit is crossed.
174	
175	Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
176	triggered if the rotation speed has dropped below a programmable limit. When
177	16-bit tachometer counters aren't used, fan readings can be divided by
178	a programmable divider (1, 2, 4 or 8) to give the readings more range or
179	accuracy. With a divider of 2, the lowest representable value is around
180	2600 RPM. Not all RPM values can accurately be represented, so some rounding
181	is done.
182	
183	Voltage sensors (also known as IN sensors) report their values in volts. An
184	alarm is triggered if the voltage has crossed a programmable minimum or
185	maximum limit. Note that minimum in this case always means 'closest to
186	zero'; this is important for negative voltage measurements. On most chips, all
187	voltage inputs can measure voltages between 0 and 4.08 volts, with a resolution
188	of 0.016 volt.  IT8603E, IT8721F/IT8758E and IT8728F can measure between 0 and
189	3.06 volts, with a resolution of 0.012 volt.  IT8732F can measure between 0 and
190	2.8 volts with a resolution of 0.0109 volt.  The battery voltage in8 does not
191	have limit registers.
192	
193	On the IT8603E, IT8620E, IT8628E, IT8721F/IT8758E, IT8732F, IT8781F, IT8782F,
194	and IT8783E/F, some voltage inputs are internal and scaled inside the chip:
195	* in3 (optional)
196	* in7 (optional for IT8781F, IT8782F, and IT8783E/F)
197	* in8 (always)
198	* in9 (relevant for IT8603E only)
199	The driver handles this transparently so user-space doesn't have to care.
200	
201	The VID lines (IT8712F/IT8716F/IT8718F/IT8720F) encode the core voltage value:
202	the voltage level your processor should work with. This is hardcoded by
203	the mainboard and/or processor itself. It is a value in volts.
204	
205	If an alarm triggers, it will remain triggered until the hardware register
206	is read at least once. This means that the cause for the alarm may already
207	have disappeared! Note that in the current implementation, all hardware
208	registers are read whenever any data is read (unless it is less than 1.5
209	seconds since the last update). This means that you can easily miss
210	once-only alarms.
211	
212	Out-of-limit readings can also result in beeping, if the chip is properly
213	wired and configured. Beeping can be enabled or disabled per sensor type
214	(temperatures, voltages and fans.)
215	
216	The IT87xx only updates its values each 1.5 seconds; reading it more often
217	will do no harm, but will return 'old' values.
218	
219	To change sensor N to a thermistor, 'echo 4 > tempN_type' where N is 1, 2,
220	or 3. To change sensor N to a thermal diode, 'echo 3 > tempN_type'.
221	Give 0 for unused sensor. Any other value is invalid. To configure this at
222	startup, consult lm_sensors's /etc/sensors.conf. (4 = thermistor;
223	3 = thermal diode)
224	
225	
226	Fan speed control
227	-----------------
228	
229	The fan speed control features are limited to manual PWM mode. Automatic
230	"Smart Guardian" mode control handling is only implemented for older chips
231	(see below.) However if you want to go for "manual mode" just write 1 to
232	pwmN_enable.
233	
234	If you are only able to control the fan speed with very small PWM values,
235	try lowering the PWM base frequency (pwm1_freq). Depending on the fan,
236	it may give you a somewhat greater control range. The same frequency is
237	used to drive all fan outputs, which is why pwm2_freq and pwm3_freq are
238	read-only.
239	
240	
241	Automatic fan speed control (old interface)
242	-------------------------------------------
243	
244	The driver supports the old interface to automatic fan speed control
245	which is implemented by IT8705F chips up to revision F and IT8712F
246	chips up to revision G.
247	
248	This interface implements 4 temperature vs. PWM output trip points.
249	The PWM output of trip point 4 is always the maximum value (fan running
250	at full speed) while the PWM output of the other 3 trip points can be
251	freely chosen. The temperature of all 4 trip points can be freely chosen.
252	Additionally, trip point 1 has an hysteresis temperature attached, to
253	prevent fast switching between fan on and off.
254	
255	The chip automatically computes the PWM output value based on the input
256	temperature, based on this simple rule: if the temperature value is
257	between trip point N and trip point N+1 then the PWM output value is
258	the one of trip point N. The automatic control mode is less flexible
259	than the manual control mode, but it reacts faster, is more robust and
260	doesn't use CPU cycles.
261	
262	Trip points must be set properly before switching to automatic fan speed
263	control mode. The driver will perform basic integrity checks before
264	actually switching to automatic control mode.
265	
266	
267	Temperature offset attributes
268	-----------------------------
269	
270	The driver supports temp[1-3]_offset sysfs attributes to adjust the reported
271	temperature for thermal diodes or diode-connected thermal transistors.
272	If a temperature sensor is configured for thermistors, the attribute values
273	are ignored. If the thermal sensor type is Intel PECI, the temperature offset
274	must be programmed to the critical CPU temperature.
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