| 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_pulses rw Pulses per revolution can be either 2 or 4. |
| fan1_target rw Target fan speed, to be used with pwm1_enable |
| mode 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, |
| 4=fan controlled by target rpm set with |
| fan1_target attribute. |
| pwm1_mode rw Fan duty control mode (0=DC, 1=PWM) |
| 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. |
