1 Kernel driver vt1211 1 Kernel driver vt1211
2 ==================== 2 ====================
3 3
4 Supported chips: 4 Supported chips:
5 5
6 * VIA VT1211 6 * VIA VT1211
7 7
8 Prefix: 'vt1211' 8 Prefix: 'vt1211'
9 9
10 Addresses scanned: none, address read from 10 Addresses scanned: none, address read from Super-I/O config space
11 11
12 Datasheet: Provided by VIA upon request an 12 Datasheet: Provided by VIA upon request and under NDA
13 13
14 Authors: Juerg Haefliger <juergh@gmail.com> 14 Authors: Juerg Haefliger <juergh@gmail.com>
15 15
16 This driver is based on the driver for kernel 16 This driver is based on the driver for kernel 2.4 by Mark D. Studebaker and
17 its port to kernel 2.6 by Lars Ekman. 17 its port to kernel 2.6 by Lars Ekman.
18 18
19 Thanks to Joseph Chan and Fiona Gatt from VIA 19 Thanks to Joseph Chan and Fiona Gatt from VIA for providing documentation and
20 technical support. 20 technical support.
21 21
22 22
23 Module Parameters 23 Module Parameters
24 ----------------- 24 -----------------
25 25
26 26
27 * uch_config: int 27 * uch_config: int
28 Override the BIOS defa 28 Override the BIOS default universal channel (UCH)
29 configuration for chan 29 configuration for channels 1-5.
30 Legal values are in th 30 Legal values are in the range of 0-31. Bit 0 maps to
31 UCH1, bit 1 maps to UC 31 UCH1, bit 1 maps to UCH2 and so on. Setting a bit to 1
32 enables the thermal in 32 enables the thermal input of that particular UCH and
33 setting a bit to 0 ena 33 setting a bit to 0 enables the voltage input.
34 34
35 * int_mode: int 35 * int_mode: int
36 Override the BIOS defa 36 Override the BIOS default temperature interrupt mode.
37 The only possible valu 37 The only possible value is 0 which forces interrupt
38 mode 0. In this mode, 38 mode 0. In this mode, any pending interrupt is cleared
39 when the status regist 39 when the status register is read but is regenerated as
40 long as the temperatur 40 long as the temperature stays above the hysteresis
41 limit. 41 limit.
42 42
43 Be aware that overriding BIOS defaults might c 43 Be aware that overriding BIOS defaults might cause some unwanted side effects!
44 44
45 45
46 Description 46 Description
47 ----------- 47 -----------
48 48
49 The VIA VT1211 Super-I/O chip includes complet 49 The VIA VT1211 Super-I/O chip includes complete hardware monitoring
50 capabilities. It monitors 2 dedicated temperat 50 capabilities. It monitors 2 dedicated temperature sensor inputs (temp1 and
51 temp2), 1 dedicated voltage (in5) and 2 fans. 51 temp2), 1 dedicated voltage (in5) and 2 fans. Additionally, the chip
52 implements 5 universal input channels (UCH1-5) 52 implements 5 universal input channels (UCH1-5) that can be individually
53 programmed to either monitor a voltage or a te 53 programmed to either monitor a voltage or a temperature.
54 54
55 This chip also provides manual and automatic c 55 This chip also provides manual and automatic control of fan speeds (according
56 to the datasheet). The driver only supports au 56 to the datasheet). The driver only supports automatic control since the manual
57 mode doesn't seem to work as advertised in the 57 mode doesn't seem to work as advertised in the datasheet. In fact I couldn't
58 get manual mode to work at all! Be aware that 58 get manual mode to work at all! Be aware that automatic mode hasn't been
59 tested very well (due to the fact that my EPIA 59 tested very well (due to the fact that my EPIA M10000 doesn't have the fans
60 connected to the PWM outputs of the VT1211 :-( 60 connected to the PWM outputs of the VT1211 :-().
61 61
62 The following table shows the relationship bet 62 The following table shows the relationship between the vt1211 inputs and the
63 sysfs nodes. 63 sysfs nodes.
64 64
65 =============== ============== =========== === 65 =============== ============== =========== ================================
66 Sensor Voltage Mode Temp Mode Def 66 Sensor Voltage Mode Temp Mode Default Use (from the datasheet)
67 =============== ============== =========== === 67 =============== ============== =========== ================================
68 Reading 1 temp1 Int 68 Reading 1 temp1 Intel thermal diode
69 Reading 3 temp2 Int 69 Reading 3 temp2 Internal thermal diode
70 UCH1/Reading2 in0 temp3 NTC 70 UCH1/Reading2 in0 temp3 NTC type thermistor
71 UCH2 in1 temp4 +2. 71 UCH2 in1 temp4 +2.5V
72 UCH3 in2 temp5 Vcc 72 UCH3 in2 temp5 VccP (processor core)
73 UCH4 in3 temp6 +5V 73 UCH4 in3 temp6 +5V
74 UCH5 in4 temp7 +12 74 UCH5 in4 temp7 +12V
75 +3.3V in5 Int 75 +3.3V in5 Internal VCC (+3.3V)
76 =============== ============== =========== === 76 =============== ============== =========== ================================
77 77
78 78
79 Voltage Monitoring 79 Voltage Monitoring
80 ------------------ 80 ------------------
81 81
82 Voltages are sampled by an 8-bit ADC with a LS 82 Voltages are sampled by an 8-bit ADC with a LSB of ~10mV. The supported input
83 range is thus from 0 to 2.60V. Voltage values 83 range is thus from 0 to 2.60V. Voltage values outside of this range need
84 external scaling resistors. This external scal 84 external scaling resistors. This external scaling needs to be compensated for
85 via compute lines in sensors.conf, like: 85 via compute lines in sensors.conf, like:
86 86
87 compute inx @*(1+R1/R2), @/(1+R1/R2) 87 compute inx @*(1+R1/R2), @/(1+R1/R2)
88 88
89 The board level scaling resistors according to 89 The board level scaling resistors according to VIA's recommendation are as
90 follows. And this is of course totally depende 90 follows. And this is of course totally dependent on the actual board
91 implementation :-) You will have to find docum 91 implementation :-) You will have to find documentation for your own
92 motherboard and edit sensors.conf accordingly. 92 motherboard and edit sensors.conf accordingly.
93 93
94 ============= ====== ====== ========= ======== 94 ============= ====== ====== ========= ============
95 Expected 95 Expected
96 Voltage R1 R2 Divider Raw Valu 96 Voltage R1 R2 Divider Raw Value
97 ============= ====== ====== ========= ======== 97 ============= ====== ====== ========= ============
98 +2.5V 2K 10K 1.2 2083 mV 98 +2.5V 2K 10K 1.2 2083 mV
99 VccP --- --- 1.0 1400 mV 99 VccP --- --- 1.0 1400 mV [1]_
100 +5V 14K 10K 2.4 2083 mV 100 +5V 14K 10K 2.4 2083 mV
101 +12V 47K 10K 5.7 2105 mV 101 +12V 47K 10K 5.7 2105 mV
102 +3.3V (int) 2K 3.4K 1.588 3300 mV 102 +3.3V (int) 2K 3.4K 1.588 3300 mV [2]_
103 +3.3V (ext) 6.8K 10K 1.68 1964 mV 103 +3.3V (ext) 6.8K 10K 1.68 1964 mV
104 ============= ====== ====== ========= ======== 104 ============= ====== ====== ========= ============
105 105
106 .. [1] Depending on the CPU (1.4V is for a VIA 106 .. [1] Depending on the CPU (1.4V is for a VIA C3 Nehemiah).
107 107
108 .. [2] R1 and R2 for 3.3V (int) are internal t 108 .. [2] R1 and R2 for 3.3V (int) are internal to the VT1211 chip and the driver
109 performs the scaling and returns the pr 109 performs the scaling and returns the properly scaled voltage value.
110 110
111 Each measured voltage has an associated low an 111 Each measured voltage has an associated low and high limit which triggers an
112 alarm when crossed. 112 alarm when crossed.
113 113
114 114
115 Temperature Monitoring 115 Temperature Monitoring
116 ---------------------- 116 ----------------------
117 117
118 Temperatures are reported in millidegree Celsi 118 Temperatures are reported in millidegree Celsius. Each measured temperature
119 has a high limit which triggers an alarm if cr 119 has a high limit which triggers an alarm if crossed. There is an associated
120 hysteresis value with each temperature below w 120 hysteresis value with each temperature below which the temperature has to drop
121 before the alarm is cleared (this is only true 121 before the alarm is cleared (this is only true for interrupt mode 0). The
122 interrupt mode can be forced to 0 in case the 122 interrupt mode can be forced to 0 in case the BIOS doesn't do it
123 automatically. See the 'Module Parameters' sec 123 automatically. See the 'Module Parameters' section for details.
124 124
125 All temperature channels except temp2 are exte 125 All temperature channels except temp2 are external. Temp2 is the VT1211
126 internal thermal diode and the driver does all 126 internal thermal diode and the driver does all the scaling for temp2 and
127 returns the temperature in millidegree Celsius 127 returns the temperature in millidegree Celsius. For the external channels
128 temp1 and temp3-temp7, scaling depends on the 128 temp1 and temp3-temp7, scaling depends on the board implementation and needs
129 to be performed in userspace via sensors.conf. 129 to be performed in userspace via sensors.conf.
130 130
131 Temp1 is an Intel-type thermal diode which req 131 Temp1 is an Intel-type thermal diode which requires the following formula to
132 convert between sysfs readings and real temper 132 convert between sysfs readings and real temperatures:
133 133
134 compute temp1 (@-Offset)/Gain, (@*Gain)+Offset 134 compute temp1 (@-Offset)/Gain, (@*Gain)+Offset
135 135
136 According to the VIA VT1211 BIOS porting guide 136 According to the VIA VT1211 BIOS porting guide, the following gain and offset
137 values should be used: 137 values should be used:
138 138
139 =============== ======== =========== 139 =============== ======== ===========
140 Diode Type Offset Gain 140 Diode Type Offset Gain
141 =============== ======== =========== 141 =============== ======== ===========
142 Intel CPU 88.638 0.9528 142 Intel CPU 88.638 0.9528
143 65.000 0.9686 [3]_ 143 65.000 0.9686 [3]_
144 VIA C3 Ezra 83.869 0.9528 144 VIA C3 Ezra 83.869 0.9528
145 VIA C3 Ezra-T 73.869 0.9528 145 VIA C3 Ezra-T 73.869 0.9528
146 =============== ======== =========== 146 =============== ======== ===========
147 147
148 .. [3] This is the formula from the lm_sensors 148 .. [3] This is the formula from the lm_sensors 2.10.0 sensors.conf file. I don't
149 know where it comes from or how it was 149 know where it comes from or how it was derived, it's just listed here for
150 completeness. 150 completeness.
151 151
152 Temp3-temp7 support NTC thermistors. For these 152 Temp3-temp7 support NTC thermistors. For these channels, the driver returns
153 the voltages as seen at the individual pins of 153 the voltages as seen at the individual pins of UCH1-UCH5. The voltage at the
154 pin (Vpin) is formed by a voltage divider made 154 pin (Vpin) is formed by a voltage divider made of the thermistor (Rth) and a
155 scaling resistor (Rs):: 155 scaling resistor (Rs)::
156 156
157 Vpin = 2200 * Rth / (Rs + Rth) (2200 is th 157 Vpin = 2200 * Rth / (Rs + Rth) (2200 is the ADC max limit of 2200 mV)
158 158
159 The equation for the thermistor is as follows 159 The equation for the thermistor is as follows (google it if you want to know
160 more about it):: 160 more about it)::
161 161
162 Rth = Ro * exp(B * (1 / T - 1 / To)) (To i 162 Rth = Ro * exp(B * (1 / T - 1 / To)) (To is 298.15K (25C) and Ro is the
163 nomi 163 nominal resistance at 25C)
164 164
165 Mingling the above two equations and assuming 165 Mingling the above two equations and assuming Rs = Ro and B = 3435 yields the
166 following formula for sensors.conf:: 166 following formula for sensors.conf::
167 167
168 compute tempx 1 / (1 / 298.15 - (` (2200 / @ 168 compute tempx 1 / (1 / 298.15 - (` (2200 / @ - 1)) / 3435) - 273.15,
169 2200 / (1 + (^ (3435 / 298.15 169 2200 / (1 + (^ (3435 / 298.15 - 3435 / (273.15 + @))))
170 170
171 171
172 Fan Speed Control 172 Fan Speed Control
173 ----------------- 173 -----------------
174 174
175 The VT1211 provides 2 programmable PWM outputs 175 The VT1211 provides 2 programmable PWM outputs to control the speeds of 2
176 fans. Writing a 2 to any of the two pwm[1-2]_e 176 fans. Writing a 2 to any of the two pwm[1-2]_enable sysfs nodes will put the
177 PWM controller in automatic mode. There is onl 177 PWM controller in automatic mode. There is only a single controller that
178 controls both PWM outputs but each PWM output 178 controls both PWM outputs but each PWM output can be individually enabled and
179 disabled. 179 disabled.
180 180
181 Each PWM has 4 associated distinct output duty 181 Each PWM has 4 associated distinct output duty-cycles: full, high, low and
182 off. Full and off are internally hard-wired to 182 off. Full and off are internally hard-wired to 255 (100%) and 0 (0%),
183 respectively. High and low can be programmed v 183 respectively. High and low can be programmed via
184 pwm[1-2]_auto_point[2-3]_pwm. Each PWM output 184 pwm[1-2]_auto_point[2-3]_pwm. Each PWM output can be associated with a
185 different thermal input but - and here's the w 185 different thermal input but - and here's the weird part - only one set of
186 thermal thresholds exist that controls both PW 186 thermal thresholds exist that controls both PWMs output duty-cycles. The
187 thermal thresholds are accessible via pwm[1-2] 187 thermal thresholds are accessible via pwm[1-2]_auto_point[1-4]_temp. Note
188 that even though there are 2 sets of 4 auto po 188 that even though there are 2 sets of 4 auto points each, they map to the same
189 registers in the VT1211 and programming one se 189 registers in the VT1211 and programming one set is sufficient (actually only
190 the first set pwm1_auto_point[1-4]_temp is wri 190 the first set pwm1_auto_point[1-4]_temp is writable, the second set is
191 read-only). 191 read-only).
192 192
193 ========================== =================== 193 ========================== =========================================
194 PWM Auto Point PWM Output Duty-Cyc 194 PWM Auto Point PWM Output Duty-Cycle
195 ========================== =================== 195 ========================== =========================================
196 pwm[1-2]_auto_point4_pwm full speed duty-cyc 196 pwm[1-2]_auto_point4_pwm full speed duty-cycle (hard-wired to 255)
197 pwm[1-2]_auto_point3_pwm high speed duty-cyc 197 pwm[1-2]_auto_point3_pwm high speed duty-cycle
198 pwm[1-2]_auto_point2_pwm low speed duty-cycl 198 pwm[1-2]_auto_point2_pwm low speed duty-cycle
199 pwm[1-2]_auto_point1_pwm off duty-cycle (har 199 pwm[1-2]_auto_point1_pwm off duty-cycle (hard-wired to 0)
200 ========================== =================== 200 ========================== =========================================
201 201
202 ========================== ================= 202 ========================== =================
203 Temp Auto Point Thermal Threshold 203 Temp Auto Point Thermal Threshold
204 ========================== ================= 204 ========================== =================
205 pwm[1-2]_auto_point4_temp full speed temp 205 pwm[1-2]_auto_point4_temp full speed temp
206 pwm[1-2]_auto_point3_temp high speed temp 206 pwm[1-2]_auto_point3_temp high speed temp
207 pwm[1-2]_auto_point2_temp low speed temp 207 pwm[1-2]_auto_point2_temp low speed temp
208 pwm[1-2]_auto_point1_temp off temp 208 pwm[1-2]_auto_point1_temp off temp
209 ========================== ================= 209 ========================== =================
210 210
211 Long story short, the controller implements th 211 Long story short, the controller implements the following algorithm to set the
212 PWM output duty-cycle based on the input tempe 212 PWM output duty-cycle based on the input temperature:
213 213
214 =================== ======================= == 214 =================== ======================= ========================
215 Thermal Threshold Output Duty-Cycle Ou 215 Thermal Threshold Output Duty-Cycle Output Duty-Cycle
216 (Rising Temp) (F 216 (Rising Temp) (Falling Temp)
217 =================== ======================= == 217 =================== ======================= ========================
218 - full speed duty-cycle fu 218 - full speed duty-cycle full speed duty-cycle
219 full speed temp 219 full speed temp
220 - high speed duty-cycle fu 220 - high speed duty-cycle full speed duty-cycle
221 high speed temp 221 high speed temp
222 - low speed duty-cycle hi 222 - low speed duty-cycle high speed duty-cycle
223 low speed temp 223 low speed temp
224 - off duty-cycle lo 224 - off duty-cycle low speed duty-cycle
225 off temp 225 off temp
226 =================== ======================= == 226 =================== ======================= ========================
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