1Kernel driver amc6821 2===================== 3 4Supported chips: 5 6 Texas Instruments AMC6821 7 8 Prefix: 'amc6821' 9 10 Addresses scanned: 0x18, 0x19, 0x1a, 0x2c, 0x2d, 0x2e, 0x4c, 0x4d, 0x4e 11 12 Datasheet: http://focus.ti.com/docs/prod/folders/print/amc6821.html 13 14Authors: 15 Tomaz Mertelj <tomaz.mertelj@guest.arnes.si> 16 17 18Description 19----------- 20 21This driver implements support for the Texas Instruments amc6821 chip. 22The chip has one on-chip and one remote temperature sensor and one pwm fan 23regulator. 24The pwm can be controlled either from software or automatically. 25 26The driver provides the following sensor accesses in sysfs: 27 28======================= == =============================================== 29temp1_input ro on-chip temperature 30temp1_min rw " 31temp1_max rw " 32temp1_crit rw " 33temp1_min_alarm ro " 34temp1_max_alarm ro " 35temp1_crit_alarm ro " 36 37temp2_input ro remote temperature 38temp2_min rw " 39temp2_max rw " 40temp2_crit rw " 41temp2_min_alarm ro " 42temp2_max_alarm ro " 43temp2_crit_alarm ro " 44temp2_fault ro " 45 46fan1_input ro tachometer speed 47fan1_min rw " 48fan1_max rw " 49fan1_fault ro " 50fan1_div rw Fan divisor can be either 2 or 4. 51 52pwm1 rw pwm1 53pwm1_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, 57pwm1_auto_channels_temp ro 1 if pwm_enable==2, 3 if pwm_enable==3 58pwm1_auto_point1_pwm ro Hardwired to 0, shared for both 59 temperature channels. 60pwm1_auto_point2_pwm rw This value is shared for both temperature 61 channels. 62pwm1_auto_point3_pwm rw Hardwired to 255, shared for both 63 temperature channels. 64 65temp1_auto_point1_temp ro Hardwired to temp2_auto_point1_temp 66 which is rw. Below this temperature fan stops. 67temp1_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. 73temp1_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 80temp2_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. 84temp2_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 90temp2_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. 95======================= == =============================================== 96 97 98Module parameters 99----------------- 100 101If your board has a BIOS that initializes the amc6821 correctly, you should 102load the module with: init=0. 103 104If your board BIOS doesn't initialize the chip, or you want 105different settings, you can set the following parameters: 106 107- init=1, 108- pwminv: 0 default pwm output, 1 inverts pwm output. 109