[linux.git] / Documentation / hwmon / ds620.rst

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 <[email protected]>
	based on ds1621.c by
	Christian W. Zuckschwerdt <[email protected]>

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:
b04f2f7d	5
60994698	6	* Dallas Semiconductor DS620
b04f2f7d	7
60994698	8	Prefix: 'ds620'
b04f2f7d	9
60994698	10	Datasheet: Publicly available at the Dallas Semiconductor website
b04f2f7d MCC	11
b04f2f7d MCC	12	http://www.dalsemi.com/
60994698 RS	13
60994698 RS	14	Authors:
b04f2f7d MCC	15	Roland Stigge <[email protected]>
	16	based on ds1621.c by
	17	Christian W. Zuckschwerdt <[email protected]>
60994698 RS	18
	19	Description
	20	-----------
	21
	22	The DS620 is a (one instance) digital thermometer and thermostat. It has both
	23	high and low temperature limits which can be user defined (i.e. programmed
	24	into non-volatile on-chip registers). Temperature range is -55 degree Celsius
	25	to +125. Between 0 and 70 degree Celsius, accuracy is 0.5 Kelvin. The value
	26	returned via sysfs displays post decimal positions.
	27
	28	The thermostat function works as follows: When configured via platform_data
	29	(struct ds620_platform_data) .pomode == 0 (default), the thermostat output pin
	30	PO is always low. If .pomode == 1, the thermostat is in PO_LOW mode. I.e., the
	31	output pin PO becomes active when the temperature falls below temp1_min and
	32	stays active until the temperature goes above temp1_max.
	33
	34	Likewise, with .pomode == 2, the thermostat is in PO_HIGH mode. I.e., the PO
	35	output pin becomes active when the temperature goes above temp1_max and stays
	36	active until the temperature falls below temp1_min.
	37
	38	The PO output pin of the DS620 operates active-low.