[linux-block.git] / Documentation / hwmon / amc6821.rst

Kernel driver amc6821
=====================

Supported chips:

	Texas Instruments AMC6821

	Prefix: 'amc6821'

	Addresses scanned: 0x18, 0x19, 0x1a, 0x2c, 0x2d, 0x2e, 0x4c, 0x4d, 0x4e

	Datasheet: http://focus.ti.com/docs/prod/folders/print/amc6821.html

Authors:
	Tomaz Mertelj <tomaz.mertelj@guest.arnes.si>


Description
-----------

This driver implements support for the Texas Instruments amc6821 chip.
The chip has one on-chip and one remote temperature sensor and one pwm fan
regulator.
The pwm can be controlled either from software or automatically.

The driver provides the following sensor accesses in sysfs:

======================= ==      ===============================================
temp1_input		ro	on-chip temperature
temp1_min		rw	"
temp1_max		rw	"
temp1_crit		rw	"
temp1_min_alarm		ro	"
temp1_max_alarm		ro	"
temp1_crit_alarm	ro	"

temp2_input		ro	remote temperature
temp2_min		rw	"
temp2_max		rw	"
temp2_crit		rw	"
temp2_min_alarm		ro	"
temp2_max_alarm		ro	"
temp2_crit_alarm	ro	"
temp2_fault		ro	"

fan1_input		ro	tachometer speed
fan1_min		rw	"
fan1_max		rw	"
fan1_fault		ro	"
fan1_div		rw	Fan divisor can be either 2 or 4.

pwm1			rw	pwm1
pwm1_enable		rw	regulator mode, 1=open loop, 2=fan controlled
				by remote temperature, 3=fan controlled by
				combination of the on-chip temperature and
				remote-sensor temperature,
pwm1_auto_channels_temp ro	1 if pwm_enable==2, 3 if pwm_enable==3
pwm1_auto_point1_pwm	ro	Hardwired to 0, shared for both
				temperature channels.
pwm1_auto_point2_pwm	rw	This value is shared for both temperature
				channels.
pwm1_auto_point3_pwm	rw	Hardwired to 255, shared for both
				temperature channels.

temp1_auto_point1_temp	ro	Hardwired to temp2_auto_point1_temp
				which is rw. Below this temperature fan stops.
temp1_auto_point2_temp	rw	The low-temperature limit of the proportional
				range. Below this temperature
				pwm1 = pwm1_auto_point2_pwm. It can go from
				0 degree C to 124 degree C in steps of
				4 degree C. Read it out after writing to get
				the actual value.
temp1_auto_point3_temp	rw	Above this temperature fan runs at maximum
				speed. It can go from temp1_auto_point2_temp.
				It can only have certain discrete values
				which depend on temp1_auto_point2_temp and
				pwm1_auto_point2_pwm. Read it out after
				writing to get the actual value.

temp2_auto_point1_temp	rw	Must be between 0 degree C and 63 degree C and
				it defines the passive cooling temperature.
				Below this temperature the fan stops in
				the closed loop mode.
temp2_auto_point2_temp	rw	The low-temperature limit of the proportional
				range. Below this temperature
				pwm1 = pwm1_auto_point2_pwm. It can go from
				0 degree C to 124 degree C in steps
				of 4 degree C.

temp2_auto_point3_temp	rw	Above this temperature fan runs at maximum
				speed. It can only have certain discrete
				values which depend on temp2_auto_point2_temp
				and pwm1_auto_point2_pwm. Read it out after
				writing to get actual value.
======================= ==      ===============================================


Module parameters
-----------------

If your board has a BIOS that initializes the amc6821 correctly, you should
load the module with: init=0.

If your board BIOS doesn't initialize the chip, or you want
different settings, you can set the following parameters:

- init=1,
- pwminv: 0 default pwm output, 1 inverts pwm output.
Commit	Line	Data
b5430a04 TM	1	Kernel driver amc6821
	2	=====================
	3
	4	Supported chips:
b04f2f7d	5
b5430a04	6	Texas Instruments AMC6821
b04f2f7d	7
b5430a04	8	Prefix: 'amc6821'
b04f2f7d	9
b5430a04	10	Addresses scanned: 0x18, 0x19, 0x1a, 0x2c, 0x2d, 0x2e, 0x4c, 0x4d, 0x4e
b04f2f7d	11
b5430a04 TM	12	Datasheet: http://focus.ti.com/docs/prod/folders/print/amc6821.html
	13
	14	Authors:
	15	Tomaz Mertelj <tomaz.mertelj@guest.arnes.si>
	16
	17
	18	Description
	19	-----------
	20
	21	This driver implements support for the Texas Instruments amc6821 chip.
	22	The chip has one on-chip and one remote temperature sensor and one pwm fan
	23	regulator.
	24	The pwm can be controlled either from software or automatically.
	25
	26	The driver provides the following sensor accesses in sysfs:
	27
b04f2f7d	28	======================= == ===============================================
b5430a04 TM	29	temp1_input ro on-chip temperature
	30	temp1_min rw "
	31	temp1_max rw "
b04f2f7d	32	temp1_crit rw "
b5430a04 TM	33	temp1_min_alarm ro "
	34	temp1_max_alarm ro "
	35	temp1_crit_alarm ro "
	36
	37	temp2_input ro remote temperature
	38	temp2_min rw "
	39	temp2_max rw "
b04f2f7d	40	temp2_crit rw "
b5430a04 TM	41	temp2_min_alarm ro "
	42	temp2_max_alarm ro "
	43	temp2_crit_alarm ro "
	44	temp2_fault ro "
	45
b04f2f7d	46	fan1_input ro tachometer speed
b5430a04 TM	47	fan1_min rw "
b5430a04 TM	48	fan1_max rw "
b04f2f7d	49	fan1_fault ro "
b5430a04 TM	50	fan1_div rw Fan divisor can be either 2 or 4.
	51
	52	pwm1 rw pwm1
	53	pwm1_enable rw regulator mode, 1=open loop, 2=fan controlled
	54	by remote temperature, 3=fan controlled by
	55	combination of the on-chip temperature and
	56	remote-sensor temperature,
	57	pwm1_auto_channels_temp ro 1 if pwm_enable==2, 3 if pwm_enable==3
	58	pwm1_auto_point1_pwm ro Hardwired to 0, shared for both
	59	temperature channels.
	60	pwm1_auto_point2_pwm rw This value is shared for both temperature
	61	channels.
	62	pwm1_auto_point3_pwm rw Hardwired to 255, shared for both
	63	temperature channels.
	64
	65	temp1_auto_point1_temp ro Hardwired to temp2_auto_point1_temp
	66	which is rw. Below this temperature fan stops.
	67	temp1_auto_point2_temp rw The low-temperature limit of the proportional
	68	range. Below this temperature
	69	pwm1 = pwm1_auto_point2_pwm. It can go from
	70	0 degree C to 124 degree C in steps of
	71	4 degree C. Read it out after writing to get
	72	the actual value.
	73	temp1_auto_point3_temp rw Above this temperature fan runs at maximum
	74	speed. It can go from temp1_auto_point2_temp.
	75	It can only have certain discrete values
	76	which depend on temp1_auto_point2_temp and
	77	pwm1_auto_point2_pwm. Read it out after
	78	writing to get the actual value.
	79
	80	temp2_auto_point1_temp rw Must be between 0 degree C and 63 degree C and
	81	it defines the passive cooling temperature.
	82	Below this temperature the fan stops in
	83	the closed loop mode.
	84	temp2_auto_point2_temp rw The low-temperature limit of the proportional
	85	range. Below this temperature
	86	pwm1 = pwm1_auto_point2_pwm. It can go from
	87	0 degree C to 124 degree C in steps
	88	of 4 degree C.
	89
	90	temp2_auto_point3_temp rw Above this temperature fan runs at maximum
	91	speed. It can only have certain discrete
	92	values which depend on temp2_auto_point2_temp
	93	and pwm1_auto_point2_pwm. Read it out after
	94	writing to get actual value.
b04f2f7d	95	======================= == ===============================================
b5430a04 TM	96
	97
	98	Module parameters
	99	-----------------
	100
	101	If your board has a BIOS that initializes the amc6821 correctly, you should
	102	load the module with: init=0.
	103
	104	If your board BIOS doesn't initialize the chip, or you want
	105	different settings, you can set the following parameters:
b04f2f7d MCC	106
	107	- init=1,
	108	- pwminv: 0 default pwm output, 1 inverts pwm output.