35 lines
		
	
	
	
		
			1.3 KiB
			
		
	
	
	
		
			Text
		
	
	
	
	
	
		
		
			
		
	
	
			35 lines
		
	
	
	
		
			1.3 KiB
			
		
	
	
	
		
			Text
		
	
	
	
	
	
|   | Kernel driver ds620 | ||
|  | =================== | ||
|  | 
 | ||
|  | Supported chips: | ||
|  |   * Dallas Semiconductor DS620 | ||
|  |     Prefix: 'ds620' | ||
|  |     Datasheet: Publicly available at the Dallas Semiconductor website | ||
|  |                http://www.dalsemi.com/ | ||
|  | 
 | ||
|  | Authors: | ||
|  |         Roland Stigge <stigge@antcom.de> | ||
|  |         based on ds1621.c by | ||
|  |         Christian W. Zuckschwerdt <zany@triq.net> | ||
|  | 
 | ||
|  | Description | ||
|  | ----------- | ||
|  | 
 | ||
|  | The DS620 is a (one instance) digital thermometer and thermostat. It has both | ||
|  | high and low temperature limits which can be user defined (i.e.  programmed | ||
|  | into non-volatile on-chip registers). Temperature range is -55 degree Celsius | ||
|  | to +125. Between 0 and 70 degree Celsius, accuracy is 0.5 Kelvin. The value | ||
|  | returned via sysfs displays post decimal positions. | ||
|  | 
 | ||
|  | The thermostat function works as follows: When configured via platform_data | ||
|  | (struct ds620_platform_data) .pomode == 0 (default), the thermostat output pin | ||
|  | PO is always low. If .pomode == 1, the thermostat is in PO_LOW mode. I.e., the | ||
|  | output pin PO becomes active when the temperature falls below temp1_min and | ||
|  | stays active until the temperature goes above temp1_max. | ||
|  | 
 | ||
|  | Likewise, with .pomode == 2, the thermostat is in PO_HIGH mode. I.e., the PO | ||
|  | output pin becomes active when the temperature goes above temp1_max and stays | ||
|  | active until the temperature falls below temp1_min. | ||
|  | 
 | ||
|  | The PO output pin of the DS620 operates active-low. |