| This describes the interface for the ADT7475 driver: | 
 |  | 
 | (there are 4 fans, numbered fan1 to fan4): | 
 |  | 
 | fanX_input		Read the current speed of the fan (in RPMs) | 
 | fanX_min		Read/write the minimum speed of the fan.  Dropping | 
 | 			below this sets an alarm. | 
 |  | 
 | (there are three PWMs, numbered pwm1 to pwm3): | 
 |  | 
 | pwmX			Read/write the current duty cycle of the PWM.  Writes | 
 | 			only have effect when auto mode is turned off (see | 
 | 			below).  Range is 0 - 255. | 
 |  | 
 | pwmX_enable		Fan speed control method: | 
 |  | 
 | 			0 - No control (fan at full speed) | 
 | 			1 - Manual fan speed control (using pwm[1-*]) | 
 | 			2 - Automatic fan speed control | 
 |  | 
 | pwmX_auto_channels_temp	Select which channels affect this PWM | 
 |  | 
 | 			1 - TEMP1 controls PWM | 
 | 			2 - TEMP2 controls PWM | 
 | 			4 - TEMP3 controls PWM | 
 | 			6 - TEMP2 and TEMP3 control PWM | 
 | 			7 - All three inputs control PWM | 
 |  | 
 | pwmX_freq		Read/write the PWM frequency in Hz. The number | 
 | 			should be one of the following: | 
 |  | 
 | 			11 Hz | 
 | 			14 Hz | 
 | 			22 Hz | 
 | 			29 Hz | 
 | 			35 Hz | 
 | 			44 Hz | 
 | 			58 Hz | 
 | 			88 Hz | 
 |  | 
 | pwmX_auto_point1_pwm	Read/write the minimum PWM duty cycle in automatic mode | 
 |  | 
 | pwmX_auto_point2_pwm	Read/write the maximum PWM duty cycle in automatic mode | 
 |  | 
 | (there are three temperature settings numbered temp1 to temp3): | 
 |  | 
 | tempX_input		Read the current temperature.  The value is in milli | 
 | 			degrees of Celsius. | 
 |  | 
 | tempX_max		Read/write the upper temperature limit - exceeding this | 
 | 			will cause an alarm. | 
 |  | 
 | tempX_min		Read/write the lower temperature limit - exceeding this | 
 | 			will cause an alarm. | 
 |  | 
 | tempX_offset		Read/write the temperature adjustment offset | 
 |  | 
 | tempX_crit		Read/write the THERM limit for remote1. | 
 |  | 
 | tempX_crit_hyst		Set the temperature value below crit where the | 
 | 			fans will stay on - this helps drive the temperature | 
 | 			low enough so it doesn't stay near the edge and | 
 | 			cause THERM to keep tripping. | 
 |  | 
 | tempX_auto_point1_temp	Read/write the minimum temperature where the fans will | 
 | 			turn on in automatic mode. | 
 |  | 
 | tempX_auto_point2_temp	Read/write the maximum temperature over which the fans | 
 | 			will run in automatic mode.  tempX_auto_point1_temp | 
 | 			and tempX_auto_point2_temp together define the | 
 | 			range of automatic control. | 
 |  | 
 | tempX_alarm		Read a 1 if the max/min alarm is set | 
 | tempX_fault		Read a 1 if either temp1 or temp3 diode has a fault | 
 |  | 
 | (There are two voltage settings, in1 and in2): | 
 |  | 
 | inX_input		Read the current voltage on VCC.  Value is in | 
 | 			millivolts. | 
 |  | 
 | inX_min			read/write the minimum voltage limit. | 
 | 			Dropping below this causes an alarm. | 
 |  | 
 | inX_max			read/write the maximum voltage limit. | 
 | 			Exceeding this causes an alarm. | 
 |  | 
 | inX_alarm		Read a 1 if the max/min alarm is set. |