Documentation/hwmon/asc7621.rst

20 Andigilog has both the PECI and pre-PECI versions of the Heceta-6, as
21 Intel calls them. Heceta-6e has high frequency PWM and Heceta-6p has
23 Heceta-6e part and aSC7621 is the Heceta-6p part. They are both in
28 have used registers below 20h for vendor-specific functions in addition
29 to those in the Intel-specified vendor range.
32 The fan speed control uses this finer value to produce a "step-less" fan
33 PWM output. These two bytes are "read-locked" to guarantee that once a
34 high or low byte is read, the other byte is locked-in until after the
37 sheet says 10-bits of resolution, although you may find the lower bits
42 data sheet. Our temperature reports and fan PWM outputs are very smooth
44 temperature reports. The smoother PWM output does not require user
47 We offer GPIO features on the former VID pins. These are open-drain
55 Since there is a fan to zone assignment that allows for the "hotter" of
56 a set of zones to control the PWM of an individual fan, but there is no
58 is currently controlling the PWM for a given fan. This is in register
63 PWM may be offset for system calibration purposes.
69 Intel configuration. This would be useful in multi-CPU systems with
70 individual fans on each that would benefit from individual fan control.
74 fan types. We can also support pulse-stretched PWM so that 3-wire fans
81 --------------------------------------------------------------------------
87 Using a 10-bit ADC, the aSC7621 measures the temperature of two remote diode
91 Using temperature information from these four zones, an automatic fan speed
95 To set fan speed, the aSC7621 has three independent pulse width modulation
96 (PWM) outputs that are controlled by one, or a combination of three,
97 temperature zones. Both high- and low-frequency PWM ranges are supported.
100 temperature readings for better control of fan speed and minimum acoustic
103 The aSC7621 has tachometer inputs to measure fan speed on up to four fans.
112 --------
114 - Supports PECI interface and monitors internal and remote thermal diodes
115 - 2-wire, SMBus 2.0 compliant, serial interface
116 - 10-bit ADC
117 - Monitors VCCP, 2.5V, 3.3V, 5.0V, and 12V motherboard/processor supplies
118 - Programmable autonomous fan control based on temperature readings
119 - Noise filtering of temperature reading for fan speed control
120 - 0.25C digital temperature sensor resolution
121 - 3 PWM fan speed control outputs for 2-, 3- or 4-wire fans and up to 4 fan
123 - Enhanced measured temperature to Temperature Zone assignment.
124 - Provides high and low PWM frequency ranges
125 - 3 GPIO pins for custom use
126 - 24-Lead QSOP package
132 the standards defined in "sysfs-interface".
184 temp[1-4]_smoothing_enable / temp[1-4]_smoothing_time
197 temp[1-4]_crit
199 	ALL pwm outputs will got to 100%.
201 temp[5-8]_input / temp[5-8]_enable
207 pwm[1-3]_enable
209 	0		Fan off.
210 	1		Fan on manual control.
211 	2		Fan on automatic control and will run at the minimum pwm
213 	3		Fan on automatic control but will be off if the
215 	4-254		Ignored.
216 	255		Fan on full.
219 pwm[1-3]_auto_channels
220 	Bitmap as described in sysctl-interface with the following
238 	  16		Fan on manual control.
239 	  31		Fan on full.
243 pwm[1-3]_invert
244 	When set, inverts the meaning of pwm[1-3].
245 	i.e.  when pwm = 0, the fan will be on full and
246 	when pwm = 255 the fan will be off.
248 pwm[1-3]_freq
249 	PWM frequency in Hz