Based on kernel version 2.6.26. Page generated on 2008-07-16 21:12 EST.
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/E-WINBONDHTM/partner/PDFresult.asp?Pname=1035 9 10 Author: Chunhao Huang 11 Contact: DZShen <DZShen[AT]Winbond.com[DOT]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 Â - 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[AT]_fan#[DOT] 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