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.
|
