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
61 voltages. To set fan speed, the LM93 has two PWM outputs that are each
64 temperature readings for better control of fan speed. The LM93 has four
65 tachometer inputs to measure fan speed. Limit and status registers for all
68 (i.e. smart tachometer mode). It also adds measurement and control support
72 LM94 is also supported in LM93 compatible mode. Extra sensors and features of
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.
107 The LM93 can also override the #PROCHOT pins by driving a PWM signal onto
125 files are read-only.
127 Smart Tach Mode (from the datasheet)::
129 	If a fan is driven using a low-side drive PWM, the tachometer
130 	output of the fan is corrupted. The LM93 includes smart tachometer
132 	achieved despite the signal corruption.  In smart tach mode all
135 Smart tach mode is enabled by the driver by writing 1 or 2 (associating the
136 fan tachometer with a pwm) to the sysfs file fan<n>_smart_tach.  A zero
137 will disable the function for that fan.  Note that Smart tach mode cannot be
143 The LM93 has a fixed or override mode for the two PWM outputs (although, there
144 are still some conditions that will override even this mode - see section
146 and pwm2_override are used to enable this mode; each is a boolean integer
147 where 0 disables and 1 enables the manual control mode.  The sysfs files pwm1
148 and pwm2 are used to set the manual duty cycle; each is an integer (0-255)
152 PWM mode is disabled, the value of pwm1 and pwm2 indicates the current duty
162 that this parameter has implications for the Smart Tach Mode (see above).
170 The LM93 is capable of complex automatic fan control, with many different
175 The eight control sources are: temp1-temp4 (aka "zones" in the datasheet),
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%
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:
264 Fan Boost
279 four tach input pins.  GPIO0-GPIO3 correspond to (fan) tach 1-4, respectively.
285 -----------------------
299 fan<n>_smart_tach	    enable or disable smart tach mode
301 pwm<n>_auto_spinup_min	    minimum duty cycle during spin-up
302 pwm<n>_auto_spinup_time	    duration of spin-up
306 temp<n>_auto_offset[1-12]   temperature channel offsets
311 gpio			    input state of 8 GPIO pins; read-only