diff options
Diffstat (limited to 'Documentation/hwmon/amc6821.rst')
| -rw-r--r-- | Documentation/hwmon/amc6821.rst | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/Documentation/hwmon/amc6821.rst b/Documentation/hwmon/amc6821.rst new file mode 100644 index 000000000000..5ddb2849da90 --- /dev/null +++ b/Documentation/hwmon/amc6821.rst @@ -0,0 +1,108 @@ +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. |