[mirror_ubuntu-artful-kernel.git] / Documentation / hwmon / ds620

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.
Commit	Line	Data
60994698 RS	1	Kernel driver ds620
	2	===================
	3
	4	Supported chips:
	5	* Dallas Semiconductor DS620
	6	Prefix: 'ds620'
	7	Datasheet: Publicly available at the Dallas Semiconductor website
	8	http://www.dalsemi.com/
	9
	10	Authors:
	11	Roland Stigge <stigge@antcom.de>
	12	based on ds1621.c by
	13	Christian W. Zuckschwerdt <zany@triq.net>
	14
	15	Description
	16	-----------
	17
	18	The DS620 is a (one instance) digital thermometer and thermostat. It has both
	19	high and low temperature limits which can be user defined (i.e. programmed
	20	into non-volatile on-chip registers). Temperature range is -55 degree Celsius
	21	to +125. Between 0 and 70 degree Celsius, accuracy is 0.5 Kelvin. The value
	22	returned via sysfs displays post decimal positions.
	23
	24	The thermostat function works as follows: When configured via platform_data
	25	(struct ds620_platform_data) .pomode == 0 (default), the thermostat output pin
	26	PO is always low. If .pomode == 1, the thermostat is in PO_LOW mode. I.e., the
	27	output pin PO becomes active when the temperature falls below temp1_min and
	28	stays active until the temperature goes above temp1_max.
	29
	30	Likewise, with .pomode == 2, the thermostat is in PO_HIGH mode. I.e., the PO
	31	output pin becomes active when the temperature goes above temp1_max and stays
	32	active until the temperature falls below temp1_min.
	33
	34	The PO output pin of the DS620 operates active-low.