| 1 | Kernel driver w83792d |
| 2 | ===================== |
| 3 | |
| 4 | Supported chips: |
| 5 | * Winbond W83792D |
| 6 | Prefix: 'w83792d' |
| 7 | Addresses scanned: I2C 0x2c - 0x2f |
| 8 | Datasheet: http://www.winbond.com.tw |
| 9 | |
| 10 | Author: Chunhao Huang |
| 11 | Contact: DZShen <DZShen@Winbond.com.tw> |
| 12 | |
| 13 | |
| 14 | Module Parameters |
| 15 | ----------------- |
| 16 | |
| 17 | * init int |
| 18 | (default 1) |
| 19 | Use 'init=0' to bypass initializing the chip. |
| 20 | Try this if your computer crashes when you load the module. |
| 21 | |
| 22 | * force_subclients=bus,caddr,saddr,saddr |
| 23 | This is used to force the i2c addresses for subclients of |
| 24 | a certain chip. Example usage is `force_subclients=0,0x2f,0x4a,0x4b' |
| 25 | to force the subclients of chip 0x2f on bus 0 to i2c addresses |
| 26 | 0x4a and 0x4b. |
| 27 | |
| 28 | |
| 29 | Description |
| 30 | ----------- |
| 31 | |
| 32 | This driver implements support for the Winbond W83792AD/D. |
| 33 | |
| 34 | Detection of the chip can sometimes be foiled because it can be in an |
| 35 | internal state that allows no clean access (Bank with ID register is not |
| 36 | currently selected). If you know the address of the chip, use a 'force' |
| 37 | parameter; this will put it into a more well-behaved state first. |
| 38 | |
| 39 | The driver implements three temperature sensors, seven fan rotation speed |
| 40 | sensors, nine voltage sensors, and two automatic fan regulation |
| 41 | strategies called: Smart Fan I (Thermal Cruise mode) and Smart Fan II. |
| 42 | Automatic fan control mode is possible only for fan1-fan3. Fan4-fan7 can run |
| 43 | synchronized with selected fan (fan1-fan3). This functionality and manual PWM |
| 44 | control for fan4-fan7 is not yet implemented. |
| 45 | |
| 46 | Temperatures are measured in degrees Celsius and measurement resolution is 1 |
| 47 | degC for temp1 and 0.5 degC for temp2 and temp3. An alarm is triggered when |
| 48 | the temperature gets higher than the Overtemperature Shutdown value; it stays |
| 49 | on until the temperature falls below the Hysteresis value. |
| 50 | |
| 51 | Fan rotation speeds are reported in RPM (rotations per minute). An alarm is |
| 52 | triggered if the rotation speed has dropped below a programmable limit. Fan |
| 53 | readings can be divided by a programmable divider (1, 2, 4, 8, 16, 32, 64 or |
| 54 | 128) to give the readings more range or accuracy. |
| 55 | |
| 56 | Voltage sensors (also known as IN sensors) report their values in millivolts. |
| 57 | An alarm is triggered if the voltage has crossed a programmable minimum |
| 58 | or maximum limit. |
| 59 | |
| 60 | Alarms are provided as output from "realtime status register". Following bits |
| 61 | are defined: |
| 62 | |
| 63 | bit - alarm on: |
| 64 | 0 - in0 |
| 65 | 1 - in1 |
| 66 | 2 - temp1 |
| 67 | 3 - temp2 |
| 68 | 4 - temp3 |
| 69 | 5 - fan1 |
| 70 | 6 - fan2 |
| 71 | 7 - fan3 |
| 72 | 8 - in2 |
| 73 | 9 - in3 |
| 74 | 10 - in4 |
| 75 | 11 - in5 |
| 76 | 12 - in6 |
| 77 | 13 - VID change |
| 78 | 14 - chassis |
| 79 | 15 - fan7 |
| 80 | 16 - tart1 |
| 81 | 17 - tart2 |
| 82 | 18 - tart3 |
| 83 | 19 - in7 |
| 84 | 20 - in8 |
| 85 | 21 - fan4 |
| 86 | 22 - fan5 |
| 87 | 23 - fan6 |
| 88 | |
| 89 | Tart will be asserted while target temperature cannot be achieved after 3 minutes |
| 90 | of full speed rotation of corresponding fan. |
| 91 | |
| 92 | In addition to the alarms described above, there is a CHAS alarm on the chips |
| 93 | which triggers if your computer case is open (This one is latched, contrary |
| 94 | to realtime alarms). |
| 95 | |
| 96 | The chips only update values each 3 seconds; reading them more often will |
| 97 | do no harm, but will return 'old' values. |
| 98 | |
| 99 | |
| 100 | W83792D PROBLEMS |
| 101 | ---------------- |
| 102 | Known problems: |
| 103 | - This driver is only for Winbond W83792D C version device, there |
| 104 | are also some motherboards with B version W83792D device. The |
| 105 | calculation method to in6-in7(measured value, limits) is a little |
| 106 | different between C and B version. C or B version can be identified |
| 107 | by CR[0x49h]. |
| 108 | - The function of vid and vrm has not been finished, because I'm NOT |
| 109 | very familiar with them. Adding support is welcome. |
| 110 | - The function of chassis open detection needs more tests. |
| 111 | - If you have ASUS server board and chip was not found: Then you will |
| 112 | need to upgrade to latest (or beta) BIOS. If it does not help please |
| 113 | contact us. |
| 114 | |
| 115 | Fan control |
| 116 | ----------- |
| 117 | |
| 118 | Manual mode |
| 119 | ----------- |
| 120 | |
| 121 | Works as expected. You just need to specify desired PWM/DC value (fan speed) |
| 122 | in appropriate pwm# file. |
| 123 | |
| 124 | Thermal cruise |
| 125 | -------------- |
| 126 | |
| 127 | In this mode, W83792D provides the Smart Fan system to automatically control |
| 128 | fan speed to keep the temperatures of CPU and the system within specific |
| 129 | range. At first a wanted temperature and interval must be set. This is done |
| 130 | via thermal_cruise# file. The tolerance# file serves to create T +- tolerance |
| 131 | interval. The fan speed will be lowered as long as the current temperature |
| 132 | remains below the thermal_cruise# +- tolerance# value. Once the temperature |
| 133 | exceeds the high limit (T+tolerance), the fan will be turned on with a |
| 134 | specific speed set by pwm# and automatically controlled its PWM duty cycle |
| 135 | with the temperature varying. Three conditions may occur: |
| 136 | |
| 137 | (1) If the temperature still exceeds the high limit, PWM duty |
| 138 | cycle will increase slowly. |
| 139 | |
| 140 | (2) If the temperature goes below the high limit, but still above the low |
| 141 | limit (T-tolerance), the fan speed will be fixed at the current speed because |
| 142 | the temperature is in the target range. |
| 143 | |
| 144 | (3) If the temperature goes below the low limit, PWM duty cycle will decrease |
| 145 | slowly to 0 or a preset stop value until the temperature exceeds the low |
| 146 | limit. (The preset stop value handling is not yet implemented in driver) |
| 147 | |
| 148 | Smart Fan II |
| 149 | ------------ |
| 150 | |
| 151 | W83792D also provides a special mode for fan. Four temperature points are |
| 152 | available. When related temperature sensors detects the temperature in preset |
| 153 | temperature region (sf2_point@_fan# +- tolerance#) it will cause fans to run |
| 154 | on programmed value from sf2_level@_fan#. You need to set four temperatures |
| 155 | for each fan. |
| 156 | |
| 157 | |
| 158 | /sys files |
| 159 | ---------- |
| 160 | |
| 161 | pwm[1-3] - this file stores PWM duty cycle or DC value (fan speed) in range: |
| 162 | 0 (stop) to 255 (full) |
| 163 | pwm[1-3]_enable - this file controls mode of fan/temperature control: |
| 164 | * 0 Disabled |
| 165 | * 1 Manual mode |
| 166 | * 2 Smart Fan II |
| 167 | * 3 Thermal Cruise |
| 168 | pwm[1-3]_mode - Select PWM of DC mode |
| 169 | * 0 DC |
| 170 | * 1 PWM |
| 171 | thermal_cruise[1-3] - Selects the desired temperature for cruise (degC) |
| 172 | tolerance[1-3] - Value in degrees of Celsius (degC) for +- T |
| 173 | sf2_point[1-4]_fan[1-3] - four temperature points for each fan for Smart Fan II |
| 174 | sf2_level[1-3]_fan[1-3] - three PWM/DC levels for each fan for Smart Fan II |