1 Kernel driver lm85 1 Kernel driver lm85
2 ================== 2 ==================
3 3
4 Supported chips: 4 Supported chips:
5 5
6 * National Semiconductor LM85 (B and C versi 6 * National Semiconductor LM85 (B and C versions)
7 7
8 Prefix: 'lm85b' or 'lm85c' 8 Prefix: 'lm85b' or 'lm85c'
9 9
10 Addresses scanned: I2C 0x2c, 0x2d, 0x2e 10 Addresses scanned: I2C 0x2c, 0x2d, 0x2e
11 11
12 Datasheet: http://www.national.com/pf/LM/L 12 Datasheet: http://www.national.com/pf/LM/LM85.html
13 13
14 * Texas Instruments LM96000 14 * Texas Instruments LM96000
15 15
16 Prefix: 'lm9600' 16 Prefix: 'lm9600'
17 17
18 Addresses scanned: I2C 0x2c, 0x2d, 0x2e 18 Addresses scanned: I2C 0x2c, 0x2d, 0x2e
19 19
20 Datasheet: https://www.ti.com/lit/ds/symli 20 Datasheet: https://www.ti.com/lit/ds/symlink/lm96000.pdf
21 21
22 * Analog Devices ADM1027 22 * Analog Devices ADM1027
23 23
24 Prefix: 'adm1027' 24 Prefix: 'adm1027'
25 25
26 Addresses scanned: I2C 0x2c, 0x2d, 0x2e 26 Addresses scanned: I2C 0x2c, 0x2d, 0x2e
27 27
28 Datasheet: https://www.onsemi.com/PowerSol 28 Datasheet: https://www.onsemi.com/PowerSolutions/product.do?id=ADM1027
29 29
30 * Analog Devices ADT7463 30 * Analog Devices ADT7463
31 31
32 Prefix: 'adt7463' 32 Prefix: 'adt7463'
33 33
34 Addresses scanned: I2C 0x2c, 0x2d, 0x2e 34 Addresses scanned: I2C 0x2c, 0x2d, 0x2e
35 35
36 Datasheet: https://www.onsemi.com/PowerSol 36 Datasheet: https://www.onsemi.com/PowerSolutions/product.do?id=ADT7463
37 37
38 * Analog Devices ADT7468 38 * Analog Devices ADT7468
39 39
40 Prefix: 'adt7468' 40 Prefix: 'adt7468'
41 41
42 Addresses scanned: I2C 0x2c, 0x2d, 0x2e 42 Addresses scanned: I2C 0x2c, 0x2d, 0x2e
43 43
44 Datasheet: https://www.onsemi.com/PowerSol 44 Datasheet: https://www.onsemi.com/PowerSolutions/product.do?id=ADT7468
45 45
46 * SMSC EMC6D100, SMSC EMC6D101 46 * SMSC EMC6D100, SMSC EMC6D101
47 47
48 Prefix: 'emc6d100' 48 Prefix: 'emc6d100'
49 49
50 Addresses scanned: I2C 0x2c, 0x2d, 0x2e 50 Addresses scanned: I2C 0x2c, 0x2d, 0x2e
51 51
52 Datasheet: http://www.smsc.com/media/Downl 52 Datasheet: http://www.smsc.com/media/Downloads_Public/discontinued/6d100.pdf
53 53
54 * SMSC EMC6D102 54 * SMSC EMC6D102
55 55
56 Prefix: 'emc6d102' 56 Prefix: 'emc6d102'
57 57
58 Addresses scanned: I2C 0x2c, 0x2d, 0x2e 58 Addresses scanned: I2C 0x2c, 0x2d, 0x2e
59 59
60 Datasheet: http://www.smsc.com/main/catalo 60 Datasheet: http://www.smsc.com/main/catalog/emc6d102.html
61 61
62 * SMSC EMC6D103 62 * SMSC EMC6D103
63 63
64 Prefix: 'emc6d103' 64 Prefix: 'emc6d103'
65 65
66 Addresses scanned: I2C 0x2c, 0x2d, 0x2e 66 Addresses scanned: I2C 0x2c, 0x2d, 0x2e
67 67
68 Datasheet: http://www.smsc.com/main/catalo 68 Datasheet: http://www.smsc.com/main/catalog/emc6d103.html
69 69
70 * SMSC EMC6D103S 70 * SMSC EMC6D103S
71 71
72 Prefix: 'emc6d103s' 72 Prefix: 'emc6d103s'
73 73
74 Addresses scanned: I2C 0x2c, 0x2d, 0x2e 74 Addresses scanned: I2C 0x2c, 0x2d, 0x2e
75 75
76 Datasheet: http://www.smsc.com/main/catalo 76 Datasheet: http://www.smsc.com/main/catalog/emc6d103s.html
77 77
78 Authors: 78 Authors:
79 - Philip Pokorny <ppokorny@penguincomput 79 - Philip Pokorny <ppokorny@penguincomputing.com>,
80 - Frodo Looijaard <frodol@dds.nl>, 80 - Frodo Looijaard <frodol@dds.nl>,
81 - Richard Barrington <rich_b_nz@clear.ne 81 - Richard Barrington <rich_b_nz@clear.net.nz>,
82 - Margit Schubert-While <margitsw@t-onli 82 - Margit Schubert-While <margitsw@t-online.de>,
83 - Justin Thiessen <jthiessen@penguincomp 83 - Justin Thiessen <jthiessen@penguincomputing.com>
84 84
85 Description 85 Description
86 ----------- 86 -----------
87 87
88 This driver implements support for the Nationa 88 This driver implements support for the National Semiconductor LM85 and
89 compatible chips including the Analog Devices 89 compatible chips including the Analog Devices ADM1027, ADT7463, ADT7468 and
90 SMSC EMC6D10x chips family. 90 SMSC EMC6D10x chips family.
91 91
92 The LM85 uses the 2-wire interface compatible 92 The LM85 uses the 2-wire interface compatible with the SMBUS 2.0
93 specification. Using an analog to digital conv 93 specification. Using an analog to digital converter it measures three (3)
94 temperatures and five (5) voltages. It has fou 94 temperatures and five (5) voltages. It has four (4) 16-bit counters for
95 measuring fan speed. Five (5) digital inputs a 95 measuring fan speed. Five (5) digital inputs are provided for sampling the
96 VID signals from the processor to the VRM. Las 96 VID signals from the processor to the VRM. Lastly, there are three (3) PWM
97 outputs that can be used to control fan speed. 97 outputs that can be used to control fan speed.
98 98
99 The voltage inputs have internal scaling resis 99 The voltage inputs have internal scaling resistors so that the following
100 voltage can be measured without external resis 100 voltage can be measured without external resistors:
101 101
102 2.5V, 3.3V, 5V, 12V, and CPU core voltage (2 102 2.5V, 3.3V, 5V, 12V, and CPU core voltage (2.25V)
103 103
104 The temperatures measured are one internal dio 104 The temperatures measured are one internal diode, and two remote diodes.
105 Remote 1 is generally the CPU temperature. The 105 Remote 1 is generally the CPU temperature. These inputs are designed to
106 measure a thermal diode like the one in a Pent 106 measure a thermal diode like the one in a Pentium 4 processor in a socket
107 423 or socket 478 package. They can also measu 107 423 or socket 478 package. They can also measure temperature using a
108 transistor like the 2N3904. 108 transistor like the 2N3904.
109 109
110 A sophisticated control system for the PWM out 110 A sophisticated control system for the PWM outputs is designed into the
111 LM85 that allows fan speed to be adjusted auto 111 LM85 that allows fan speed to be adjusted automatically based on any of the
112 three temperature sensors. Each PWM output is 112 three temperature sensors. Each PWM output is individually adjustable and
113 programmable. Once configured, the LM85 will a 113 programmable. Once configured, the LM85 will adjust the PWM outputs in
114 response to the measured temperatures without 114 response to the measured temperatures without further host intervention.
115 This feature can also be disabled for manual c 115 This feature can also be disabled for manual control of the PWM's.
116 116
117 Each of the measured inputs (voltage, temperat 117 Each of the measured inputs (voltage, temperature, fan speed) has
118 corresponding high/low limit values. The LM85 118 corresponding high/low limit values. The LM85 will signal an ALARM if any
119 measured value exceeds either limit. 119 measured value exceeds either limit.
120 120
121 The LM85 samples all inputs continuously. The 121 The LM85 samples all inputs continuously. The lm85 driver will not read
122 the registers more often than once a second. F 122 the registers more often than once a second. Further, configuration data is
123 only read once each 5 minutes. There is twice 123 only read once each 5 minutes. There is twice as much config data as
124 measurements, so this would seem to be a worth 124 measurements, so this would seem to be a worthwhile optimization.
125 125
126 Special Features 126 Special Features
127 ---------------- 127 ----------------
128 128
129 The LM85 has four fan speed monitoring modes. 129 The LM85 has four fan speed monitoring modes. The ADM1027 has only two.
130 Both have special circuitry to compensate for 130 Both have special circuitry to compensate for PWM interactions with the
131 TACH signal from the fans. The ADM1027 can be 131 TACH signal from the fans. The ADM1027 can be configured to measure the
132 speed of a two wire fan, but the input conditi 132 speed of a two wire fan, but the input conditioning circuitry is different
133 for 3-wire and 2-wire mode. For this reason, t 133 for 3-wire and 2-wire mode. For this reason, the 2-wire fan modes are not
134 exposed to user control. The BIOS should initi 134 exposed to user control. The BIOS should initialize them to the correct
135 mode. If you've designed your own ADM1027, you 135 mode. If you've designed your own ADM1027, you'll have to modify the
136 init_client function and add an insmod paramet 136 init_client function and add an insmod parameter to set this up.
137 137
138 To smooth the response of fans to changes in t 138 To smooth the response of fans to changes in temperature, the LM85 has an
139 optional filter for smoothing temperatures. Th 139 optional filter for smoothing temperatures. The ADM1027 has the same
140 config option but uses it to rate limit the ch 140 config option but uses it to rate limit the changes to fan speed instead.
141 141
142 The ADM1027, ADT7463 and ADT7468 have a 10-bit 142 The ADM1027, ADT7463 and ADT7468 have a 10-bit ADC and can therefore
143 measure temperatures with 0.25 degC resolution 143 measure temperatures with 0.25 degC resolution. They also provide an offset
144 to the temperature readings that is automatica 144 to the temperature readings that is automatically applied during
145 measurement. This offset can be used to zero o 145 measurement. This offset can be used to zero out any errors due to traces
146 and placement. The documentation says that the 146 and placement. The documentation says that the offset is in 0.25 degC
147 steps, but in initial testing of the ADM1027 i 147 steps, but in initial testing of the ADM1027 it was 1.00 degC steps. Analog
148 Devices has confirmed this "bug". The ADT7463 148 Devices has confirmed this "bug". The ADT7463 is reported to work as
149 described in the documentation. The current lm 149 described in the documentation. The current lm85 driver does not show the
150 offset register. 150 offset register.
151 151
152 The ADT7468 has a high-frequency PWM mode, whe 152 The ADT7468 has a high-frequency PWM mode, where all PWM outputs are
153 driven by a 22.5 kHz clock. This is a global m 153 driven by a 22.5 kHz clock. This is a global mode, not per-PWM output,
154 which means that setting any PWM frequency abo 154 which means that setting any PWM frequency above 11.3 kHz will switch
155 all 3 PWM outputs to a 22.5 kHz frequency. Con 155 all 3 PWM outputs to a 22.5 kHz frequency. Conversely, setting any PWM
156 frequency below 11.3 kHz will switch all 3 PWM 156 frequency below 11.3 kHz will switch all 3 PWM outputs to a frequency
157 between 10 and 100 Hz, which can then be tuned 157 between 10 and 100 Hz, which can then be tuned separately.
158 158
159 See the vendor datasheets for more information 159 See the vendor datasheets for more information. There is application note
160 from National (AN-1260) with some additional i 160 from National (AN-1260) with some additional information about the LM85.
161 The Analog Devices datasheet is very detailed 161 The Analog Devices datasheet is very detailed and describes a procedure for
162 determining an optimal configuration for the a 162 determining an optimal configuration for the automatic PWM control.
163 163
164 The SMSC EMC6D100 & EMC6D101 monitor external 164 The SMSC EMC6D100 & EMC6D101 monitor external voltages, temperatures, and
165 fan speeds. They use this monitoring capabilit 165 fan speeds. They use this monitoring capability to alert the system to out
166 of limit conditions and can automatically cont 166 of limit conditions and can automatically control the speeds of multiple
167 fans in a PC or embedded system. The EMC6D101, 167 fans in a PC or embedded system. The EMC6D101, available in a 24-pin SSOP
168 package, and the EMC6D100, available in a 28-p 168 package, and the EMC6D100, available in a 28-pin SSOP package, are designed
169 to be register compatible. The EMC6D100 offers 169 to be register compatible. The EMC6D100 offers all the features of the
170 EMC6D101 plus additional voltage monitoring an 170 EMC6D101 plus additional voltage monitoring and system control features.
171 Unfortunately it is not possible to distinguis 171 Unfortunately it is not possible to distinguish between the package
172 versions on register level so these additional 172 versions on register level so these additional voltage inputs may read
173 zero. EMC6D102 and EMC6D103 feature additional 173 zero. EMC6D102 and EMC6D103 feature additional ADC bits thus extending precision
174 of voltage and temperature channels. 174 of voltage and temperature channels.
175 175
176 SMSC EMC6D103S is similar to EMC6D103, but doe 176 SMSC EMC6D103S is similar to EMC6D103, but does not support pwm#_auto_pwm_minctl
177 and temp#_auto_temp_off. 177 and temp#_auto_temp_off.
178 178
179 The LM96000 supports additional high frequency 179 The LM96000 supports additional high frequency PWM modes (22.5 kHz, 24 kHz,
180 25.7 kHz, 27.7 kHz and 30 kHz), which can be c 180 25.7 kHz, 27.7 kHz and 30 kHz), which can be configured on a per-PWM basis.
181 181
182 Hardware Configurations 182 Hardware Configurations
183 ----------------------- 183 -----------------------
184 184
185 The LM85 can be jumpered for 3 different SMBus 185 The LM85 can be jumpered for 3 different SMBus addresses. There are
186 no other hardware configuration options for th 186 no other hardware configuration options for the LM85.
187 187
188 The lm85 driver detects both LM85B and LM85C r 188 The lm85 driver detects both LM85B and LM85C revisions of the chip. See the
189 datasheet for a complete description of the di 189 datasheet for a complete description of the differences. Other than
190 identifying the chip, the driver behaves no di 190 identifying the chip, the driver behaves no differently with regard to
191 these two chips. The LM85B is recommended for 191 these two chips. The LM85B is recommended for new designs.
192 192
193 The ADM1027, ADT7463 and ADT7468 chips have an 193 The ADM1027, ADT7463 and ADT7468 chips have an optional SMBALERT output
194 that can be used to signal the chipset in case 194 that can be used to signal the chipset in case a limit is exceeded or the
195 temperature sensors fail. Individual sensor in 195 temperature sensors fail. Individual sensor interrupts can be masked so
196 they won't trigger SMBALERT. The SMBALERT outp 196 they won't trigger SMBALERT. The SMBALERT output if configured replaces one
197 of the other functions (PWM2 or IN0). This fun 197 of the other functions (PWM2 or IN0). This functionality is not implemented
198 in current driver. 198 in current driver.
199 199
200 The ADT7463 and ADT7468 also have an optional 200 The ADT7463 and ADT7468 also have an optional THERM output/input which can
201 be connected to the processor PROC_HOT output. 201 be connected to the processor PROC_HOT output. If available, the autofan
202 control dynamic Tmin feature can be enabled to 202 control dynamic Tmin feature can be enabled to keep the system temperature
203 within spec (just?!) with the least possible f 203 within spec (just?!) with the least possible fan noise.
204 204
205 Configuration Notes 205 Configuration Notes
206 ------------------- 206 -------------------
207 207
208 Besides standard interfaces driver adds follow 208 Besides standard interfaces driver adds following:
209 209
210 * Temperatures and Zones 210 * Temperatures and Zones
211 211
212 Each temperature sensor is associated with a Z 212 Each temperature sensor is associated with a Zone. There are three
213 sensors and therefore three zones (# 1, 2 and 213 sensors and therefore three zones (# 1, 2 and 3). Each zone has the following
214 temperature configuration points: 214 temperature configuration points:
215 215
216 * temp#_auto_temp_off 216 * temp#_auto_temp_off
217 - temperature below which fans should 217 - temperature below which fans should be off or spinning very low.
218 * temp#_auto_temp_min 218 * temp#_auto_temp_min
219 - temperature over which fans start to 219 - temperature over which fans start to spin.
220 * temp#_auto_temp_max 220 * temp#_auto_temp_max
221 - temperature when fans spin at full s 221 - temperature when fans spin at full speed.
222 * temp#_auto_temp_crit 222 * temp#_auto_temp_crit
223 - temperature when all fans will run f 223 - temperature when all fans will run full speed.
224 224
225 PWM Control 225 PWM Control
226 ^^^^^^^^^^^ 226 ^^^^^^^^^^^
227 227
228 There are three PWM outputs. The LM85 datashee 228 There are three PWM outputs. The LM85 datasheet suggests that the
229 pwm3 output control both fan3 and fan4. Each P 229 pwm3 output control both fan3 and fan4. Each PWM can be individually
230 configured and assigned to a zone for its cont 230 configured and assigned to a zone for its control value. Each PWM can be
231 configured individually according to the follo 231 configured individually according to the following options.
232 232
233 * pwm#_auto_pwm_min 233 * pwm#_auto_pwm_min
234 - this specifies the PWM value for tem 234 - this specifies the PWM value for temp#_auto_temp_off
235 temperature. (PWM value from 0 to 25 235 temperature. (PWM value from 0 to 255)
236 236
237 * pwm#_auto_pwm_minctl 237 * pwm#_auto_pwm_minctl
238 - this flags selects for temp#_auto_te 238 - this flags selects for temp#_auto_temp_off temperature
239 the behaviour of fans. Write 1 to le 239 the behaviour of fans. Write 1 to let fans spinning at
240 pwm#_auto_pwm_min or write 0 to let 240 pwm#_auto_pwm_min or write 0 to let them off.
241 241
242 .. note:: 242 .. note::
243 243
244 It has been reported that there is a b 244 It has been reported that there is a bug in the LM85 that causes
245 the flag to be associated with the zon 245 the flag to be associated with the zones not the PWMs. This
246 contradicts all the published document 246 contradicts all the published documentation. Setting pwm#_min_ctl
247 in this case actually affects all PWMs 247 in this case actually affects all PWMs controlled by zone '#'.
248 248
249 PWM Controlling Zone selection 249 PWM Controlling Zone selection
250 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 250 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
251 251
252 * pwm#_auto_channels 252 * pwm#_auto_channels
253 - controls zone that is associated wit 253 - controls zone that is associated with PWM
254 254
255 Configuration choices: 255 Configuration choices:
256 256
257 ========== =================================== 257 ========== =============================================
258 Value Meaning 258 Value Meaning
259 ========== =================================== 259 ========== =============================================
260 1 Controlled by Zone 1 260 1 Controlled by Zone 1
261 2 Controlled by Zone 2 261 2 Controlled by Zone 2
262 3 Controlled by Zone 3 262 3 Controlled by Zone 3
263 23 Controlled by higher temp of Zone 2 263 23 Controlled by higher temp of Zone 2 or 3
264 123 Controlled by highest temp of Zone 264 123 Controlled by highest temp of Zone 1, 2 or 3
265 0 PWM always 0% (off) 265 0 PWM always 0% (off)
266 -1 PWM always 100% (full on) 266 -1 PWM always 100% (full on)
267 -2 Manual control (write to 'pwm#' to 267 -2 Manual control (write to 'pwm#' to set)
268 ========== =================================== 268 ========== =============================================
269 269
270 The National LM85's have two vendor specific c 270 The National LM85's have two vendor specific configuration
271 features. Tach. mode and Spinup Control. For m 271 features. Tach. mode and Spinup Control. For more details on these,
272 see the LM85 datasheet or Application Note AN- 272 see the LM85 datasheet or Application Note AN-1260. These features
273 are not currently supported by the lm85 driver 273 are not currently supported by the lm85 driver.
274 274
275 The Analog Devices ADM1027 has several vendor 275 The Analog Devices ADM1027 has several vendor specific enhancements.
276 The number of pulses-per-rev of the fans can b 276 The number of pulses-per-rev of the fans can be set, Tach monitoring
277 can be optimized for PWM operation, and an off 277 can be optimized for PWM operation, and an offset can be applied to
278 the temperatures to compensate for systemic er 278 the temperatures to compensate for systemic errors in the
279 measurements. These features are not currently 279 measurements. These features are not currently supported by the lm85
280 driver. 280 driver.
281 281
282 In addition to the ADM1027 features, the ADT74 282 In addition to the ADM1027 features, the ADT7463 and ADT7468 also have
283 Tmin control and THERM asserted counts. Automa 283 Tmin control and THERM asserted counts. Automatic Tmin control acts to
284 adjust the Tmin value to maintain the measured 284 adjust the Tmin value to maintain the measured temperature sensor at a
285 specified temperature. There isn't much docume 285 specified temperature. There isn't much documentation on this feature in
286 the ADT7463 data sheet. This is not supported 286 the ADT7463 data sheet. This is not supported by current driver.
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