Documentation/hwmon/lm93.rst

10     Addresses scanned: I2C 0x2c-0x2e
18     Addresses scanned: I2C 0x2c-0x2e
24 	- Mark M. Hoffman <mhoffman@lightlink.com>
25 	- Ported to 2.6 by Eric J. Bowersox <ericb@aspsys.com>
26 	- Adapted to 2.6.20 by Carsten Emde <ce@osadl.org>
27 	- Modified for mainline integration by Hans J. Koch <hjk@hansjkoch.de>
30 -----------------
33   Set to non-zero to force some initializations (default is 0).
38   Configures in7 and in8 limit type, where 0 means absolute and non-zero
54 --------------------
59 SMBus 2.0. Using an 8-bit ADC, the LM93 measures the temperature of two remote
62 controlled by up to four temperature zones. The fancontrol algorithm is lookup
63 table based. The LM93 includes a digital filter that can be invoked to smooth
64 temperature readings for better control of fan speed. The LM93 has four
77 --------------
88 exponential moving average (but not quite - check the datasheet). Note
90 from 0-255 where 0 indicates no throttling, and 255 indicates > 99.6%.
104 assert #P2_PROCHOT, and vice-versa.  This mode is enabled by writing a
105 non-zero integer to the sysfs file prochot_short.
125 files are read-only.
129 	If a fan is driven using a low-side drive PWM, the tachometer
144 are still some conditions that will override even this mode - see section
148 and pwm2 are used to set the manual duty cycle; each is an integer (0-255)
175 The eight control sources are: temp1-temp4 (aka "zones" in the datasheet),
191 The function y = f(x) takes a source temperature x to a PWM output y.  This
192 function of the LM93 is derived from a base temperature and a table of 12
193 temperature offsets.  The base temperature is expressed in degrees C in the
195 degrees C, with the value of offset <i> for temperature value <n> being
196 contained in the file temp<n>_auto_offset<i>.  E.g. if the base temperature
202 	 1		0		-		 25.00%
203 	 2		0		-		 28.57%
204 	 3		1		40C - 41C	 32.14%
205 	 4		1		41C - 42C	 35.71%
206 	 5		2		42C - 44C	 39.29%
207 	 6		2		44C - 46C	 42.86%
208 	 7		2		48C - 50C	 46.43%
209 	 8		2		50C - 52C	 50.00%
210 	 9		2		52C - 54C	 53.57%
211 	10		2		54C - 56C	 57.14%
212 	11		2		56C - 58C	 71.43%
213 	12		2		58C - 60C	 85.71%
214 	-		-		> 60C		100.00%
219 There is an independent base temperature for each temperature channel. Note,
224 The LM93 can also apply hysteresis to the offset table, to prevent unwanted
225 oscillation between two steps in the offsets table.  These values are found in
229 If a temperature reading falls below the base value for that channel, the LM93
235 PWM Spin-Up Cycle
238 A spin-up cycle occurs when a PWM output is commanded from 0% duty cycle to
239 some value > 0%.  The LM93 supports a minimum duty cycle during spin-up.  These
242 duration of the spin-up cycle is also configurable.  These values are found in
244 the spin-up time in seconds.  The available spin-up times are constrained by
248 Spin-up Durations:
267 For each temperature channel, there is a boost temperature: if the channel
270 There is also a hysteresis temperature for this function: after the boost
271 limit is reached, the temperature channel must drop below this value before
272 the boost function is disabled.  This temperature is also expressed in degrees
279 four tach input pins.  GPIO0-GPIO3 correspond to (fan) tach 1-4, respectively.
285 -----------------------
301 pwm<n>_auto_spinup_min	    minimum duty cycle during spin-up
302 pwm<n>_auto_spinup_time	    duration of spin-up
305 temp<n>_auto_base	    temperature channel base
306 temp<n>_auto_offset[1-12]   temperature channel offsets
307 temp<n>_auto_offset_hyst    temperature channel offset hysteresis
308 temp<n>_auto_boost	    temperature channel boost (PWMs to 100%)
310 temp<n>_auto_boost_hyst     temperature channel boost hysteresis
311 gpio			    input state of 8 GPIO pins; read-only