Commit | Line | Data |
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7f15b664 M |
1 | Kernel driver lm85 |
2 | ================== | |
3 | ||
4 | Supported chips: | |
b04f2f7d | 5 | |
7f15b664 | 6 | * National Semiconductor LM85 (B and C versions) |
b04f2f7d | 7 | |
11650cf0 | 8 | Prefix: 'lm85b' or 'lm85c' |
b04f2f7d | 9 | |
7f15b664 | 10 | Addresses scanned: I2C 0x2c, 0x2d, 0x2e |
b04f2f7d | 11 | |
7f15b664 | 12 | Datasheet: http://www.national.com/pf/LM/LM85.html |
b04f2f7d | 13 | |
11650cf0 | 14 | * Texas Instruments LM96000 |
b04f2f7d | 15 | |
11650cf0 | 16 | Prefix: 'lm9600' |
b04f2f7d | 17 | |
11650cf0 | 18 | Addresses scanned: I2C 0x2c, 0x2d, 0x2e |
b04f2f7d | 19 | |
ad736c1a | 20 | Datasheet: https://www.ti.com/lit/ds/symlink/lm96000.pdf |
b04f2f7d | 21 | |
7f15b664 | 22 | * Analog Devices ADM1027 |
b04f2f7d | 23 | |
7f15b664 | 24 | Prefix: 'adm1027' |
b04f2f7d | 25 | |
7f15b664 | 26 | Addresses scanned: I2C 0x2c, 0x2d, 0x2e |
b04f2f7d | 27 | |
ad736c1a | 28 | Datasheet: https://www.onsemi.com/PowerSolutions/product.do?id=ADM1027 |
b04f2f7d | 29 | |
7f15b664 | 30 | * Analog Devices ADT7463 |
b04f2f7d | 31 | |
7f15b664 | 32 | Prefix: 'adt7463' |
b04f2f7d | 33 | |
7f15b664 | 34 | Addresses scanned: I2C 0x2c, 0x2d, 0x2e |
b04f2f7d | 35 | |
ad736c1a | 36 | Datasheet: https://www.onsemi.com/PowerSolutions/product.do?id=ADT7463 |
b04f2f7d | 37 | |
c36364db | 38 | * Analog Devices ADT7468 |
b04f2f7d | 39 | |
c36364db | 40 | Prefix: 'adt7468' |
b04f2f7d | 41 | |
c36364db | 42 | Addresses scanned: I2C 0x2c, 0x2d, 0x2e |
b04f2f7d | 43 | |
ad736c1a | 44 | Datasheet: https://www.onsemi.com/PowerSolutions/product.do?id=ADT7468 |
b04f2f7d | 45 | |
7f15b664 | 46 | * SMSC EMC6D100, SMSC EMC6D101 |
b04f2f7d | 47 | |
7f15b664 | 48 | Prefix: 'emc6d100' |
b04f2f7d | 49 | |
7f15b664 | 50 | Addresses scanned: I2C 0x2c, 0x2d, 0x2e |
b04f2f7d MCC |
51 | |
52 | Datasheet: http://www.smsc.com/media/Downloads_Public/discontinued/6d100.pdf | |
53 | ||
7f15b664 | 54 | * SMSC EMC6D102 |
b04f2f7d | 55 | |
7f15b664 | 56 | Prefix: 'emc6d102' |
b04f2f7d | 57 | |
7f15b664 | 58 | Addresses scanned: I2C 0x2c, 0x2d, 0x2e |
b04f2f7d | 59 | |
7f15b664 | 60 | Datasheet: http://www.smsc.com/main/catalog/emc6d102.html |
b04f2f7d | 61 | |
06923f84 | 62 | * SMSC EMC6D103 |
b04f2f7d | 63 | |
06923f84 | 64 | Prefix: 'emc6d103' |
b04f2f7d | 65 | |
06923f84 | 66 | Addresses scanned: I2C 0x2c, 0x2d, 0x2e |
b04f2f7d | 67 | |
06923f84 | 68 | Datasheet: http://www.smsc.com/main/catalog/emc6d103.html |
b04f2f7d | 69 | |
06923f84 | 70 | * SMSC EMC6D103S |
b04f2f7d | 71 | |
06923f84 | 72 | Prefix: 'emc6d103s' |
b04f2f7d | 73 | |
06923f84 | 74 | Addresses scanned: I2C 0x2c, 0x2d, 0x2e |
b04f2f7d | 75 | |
06923f84 | 76 | Datasheet: http://www.smsc.com/main/catalog/emc6d103s.html |
7f15b664 M |
77 | |
78 | Authors: | |
b04f2f7d MCC |
79 | - Philip Pokorny <ppokorny@penguincomputing.com>, |
80 | - Frodo Looijaard <frodol@dds.nl>, | |
81 | - Richard Barrington <rich_b_nz@clear.net.nz>, | |
82 | - Margit Schubert-While <margitsw@t-online.de>, | |
83 | - Justin Thiessen <jthiessen@penguincomputing.com> | |
7f15b664 M |
84 | |
85 | Description | |
86 | ----------- | |
87 | ||
88 | This driver implements support for the National Semiconductor LM85 and | |
c36364db | 89 | compatible chips including the Analog Devices ADM1027, ADT7463, ADT7468 and |
7f15b664 M |
90 | SMSC EMC6D10x chips family. |
91 | ||
92 | The LM85 uses the 2-wire interface compatible with the SMBUS 2.0 | |
93 | specification. Using an analog to digital converter it measures three (3) | |
94 | temperatures and five (5) voltages. It has four (4) 16-bit counters for | |
95 | measuring fan speed. Five (5) digital inputs are provided for sampling the | |
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. | |
98 | ||
99 | The voltage inputs have internal scaling resistors so that the following | |
100 | voltage can be measured without external resistors: | |
101 | ||
102 | 2.5V, 3.3V, 5V, 12V, and CPU core voltage (2.25V) | |
103 | ||
104 | The temperatures measured are one internal diode, and two remote diodes. | |
105 | Remote 1 is generally the CPU temperature. These inputs are designed to | |
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 measure temperature using a | |
108 | transistor like the 2N3904. | |
109 | ||
110 | A sophisticated control system for the PWM outputs is designed into the | |
111 | LM85 that allows fan speed to be adjusted automatically based on any of the | |
112 | three temperature sensors. Each PWM output is individually adjustable and | |
113 | programmable. Once configured, the LM85 will adjust the PWM outputs in | |
114 | response to the measured temperatures without further host intervention. | |
115 | This feature can also be disabled for manual control of the PWM's. | |
116 | ||
117 | Each of the measured inputs (voltage, temperature, fan speed) has | |
118 | corresponding high/low limit values. The LM85 will signal an ALARM if any | |
119 | measured value exceeds either limit. | |
120 | ||
121 | The LM85 samples all inputs continuously. The lm85 driver will not read | |
122 | the registers more often than once a second. Further, configuration data is | |
123 | only read once each 5 minutes. There is twice as much config data as | |
124 | measurements, so this would seem to be a worthwhile optimization. | |
125 | ||
126 | Special Features | |
127 | ---------------- | |
128 | ||
129 | The LM85 has four fan speed monitoring modes. The ADM1027 has only two. | |
130 | Both have special circuitry to compensate for PWM interactions with the | |
131 | TACH signal from the fans. The ADM1027 can be configured to measure the | |
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, the 2-wire fan modes are not | |
134 | exposed to user control. The BIOS should initialize them to the correct | |
135 | mode. If you've designed your own ADM1027, you'll have to modify the | |
136 | init_client function and add an insmod parameter to set this up. | |
137 | ||
138 | To smooth the response of fans to changes in temperature, the LM85 has an | |
139 | optional filter for smoothing temperatures. The ADM1027 has the same | |
140 | config option but uses it to rate limit the changes to fan speed instead. | |
141 | ||
c36364db JD |
142 | The ADM1027, ADT7463 and ADT7468 have a 10-bit ADC and can therefore |
143 | measure temperatures with 0.25 degC resolution. They also provide an offset | |
144 | to the temperature readings that is automatically applied during | |
145 | measurement. This offset can be used to zero out any errors due to traces | |
146 | and placement. The documentation says that the offset is in 0.25 degC | |
147 | steps, but in initial testing of the ADM1027 it was 1.00 degC steps. Analog | |
148 | Devices has confirmed this "bug". The ADT7463 is reported to work as | |
149 | described in the documentation. The current lm85 driver does not show the | |
150 | offset register. | |
7f15b664 | 151 | |
f6c61cff JD |
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 mode, not per-PWM output, | |
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. Conversely, setting any 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 separately. | |
158 | ||
7f15b664 M |
159 | See the vendor datasheets for more information. There is application note |
160 | from National (AN-1260) with some additional information about the LM85. | |
161 | The Analog Devices datasheet is very detailed and describes a procedure for | |
162 | determining an optimal configuration for the automatic PWM control. | |
163 | ||
164 | The SMSC EMC6D100 & EMC6D101 monitor external voltages, temperatures, and | |
165 | fan speeds. They use this monitoring capability to alert the system to out | |
166 | of limit conditions and can automatically control the speeds of multiple | |
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-pin SSOP package, are designed | |
169 | to be register compatible. The EMC6D100 offers all the features of the | |
170 | EMC6D101 plus additional voltage monitoring and system control features. | |
171 | Unfortunately it is not possible to distinguish between the package | |
172 | versions on register level so these additional voltage inputs may read | |
06923f84 | 173 | zero. EMC6D102 and EMC6D103 feature additional ADC bits thus extending precision |
7f15b664 M |
174 | of voltage and temperature channels. |
175 | ||
06923f84 GR |
176 | SMSC EMC6D103S is similar to EMC6D103, but does not support pwm#_auto_pwm_minctl |
177 | and temp#_auto_temp_off. | |
7f15b664 | 178 | |
e9b95485 JG |
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 configured on a per-PWM basis. | |
181 | ||
7f15b664 M |
182 | Hardware Configurations |
183 | ----------------------- | |
184 | ||
185 | The LM85 can be jumpered for 3 different SMBus addresses. There are | |
186 | no other hardware configuration options for the LM85. | |
187 | ||
188 | The lm85 driver detects both LM85B and LM85C revisions of the chip. See the | |
189 | datasheet for a complete description of the differences. Other than | |
190 | identifying the chip, the driver behaves no differently with regard to | |
191 | these two chips. The LM85B is recommended for new designs. | |
192 | ||
c36364db JD |
193 | The ADM1027, ADT7463 and ADT7468 chips have an optional SMBALERT output |
194 | that can be used to signal the chipset in case a limit is exceeded or the | |
195 | temperature sensors fail. Individual sensor interrupts can be masked so | |
196 | they won't trigger SMBALERT. The SMBALERT output if configured replaces one | |
197 | of the other functions (PWM2 or IN0). This functionality is not implemented | |
198 | in current driver. | |
7f15b664 | 199 | |
c36364db JD |
200 | The ADT7463 and ADT7468 also have an optional THERM output/input which can |
201 | be connected to the processor PROC_HOT output. If available, the autofan | |
202 | control dynamic Tmin feature can be enabled to keep the system temperature | |
203 | within spec (just?!) with the least possible fan noise. | |
7f15b664 M |
204 | |
205 | Configuration Notes | |
206 | ------------------- | |
207 | ||
208 | Besides standard interfaces driver adds following: | |
209 | ||
210 | * Temperatures and Zones | |
211 | ||
212 | Each temperature sensor is associated with a Zone. There are three | |
213 | sensors and therefore three zones (# 1, 2 and 3). Each zone has the following | |
214 | temperature configuration points: | |
215 | ||
b04f2f7d MCC |
216 | * temp#_auto_temp_off |
217 | - temperature below which fans should be off or spinning very low. | |
218 | * temp#_auto_temp_min | |
219 | - temperature over which fans start to spin. | |
220 | * temp#_auto_temp_max | |
221 | - temperature when fans spin at full speed. | |
222 | * temp#_auto_temp_crit | |
223 | - temperature when all fans will run full speed. | |
7f15b664 | 224 | |
b04f2f7d MCC |
225 | PWM Control |
226 | ^^^^^^^^^^^ | |
7f15b664 M |
227 | |
228 | There are three PWM outputs. The LM85 datasheet suggests that the | |
229 | pwm3 output control both fan3 and fan4. Each PWM can be individually | |
a33f3224 | 230 | configured and assigned to a zone for its control value. Each PWM can be |
7f15b664 M |
231 | configured individually according to the following options. |
232 | ||
b04f2f7d MCC |
233 | * pwm#_auto_pwm_min |
234 | - this specifies the PWM value for temp#_auto_temp_off | |
235 | temperature. (PWM value from 0 to 255) | |
236 | ||
237 | * pwm#_auto_pwm_minctl | |
238 | - this flags selects for temp#_auto_temp_off temperature | |
239 | the behaviour of fans. Write 1 to let fans spinning at | |
240 | pwm#_auto_pwm_min or write 0 to let them off. | |
7f15b664 | 241 | |
b04f2f7d | 242 | .. note:: |
7f15b664 | 243 | |
b04f2f7d MCC |
244 | It has been reported that there is a bug in the LM85 that causes |
245 | the flag to be associated with the zones not the PWMs. This | |
246 | contradicts all the published documentation. Setting pwm#_min_ctl | |
247 | in this case actually affects all PWMs controlled by zone '#'. | |
7f15b664 | 248 | |
b04f2f7d MCC |
249 | PWM Controlling Zone selection |
250 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
7f15b664 | 251 | |
b04f2f7d MCC |
252 | * pwm#_auto_channels |
253 | - controls zone that is associated with PWM | |
7f15b664 M |
254 | |
255 | Configuration choices: | |
256 | ||
b04f2f7d MCC |
257 | ========== ============================================= |
258 | Value Meaning | |
259 | ========== ============================================= | |
7f15b664 M |
260 | 1 Controlled by Zone 1 |
261 | 2 Controlled by Zone 2 | |
262 | 3 Controlled by Zone 3 | |
263 | 23 Controlled by higher temp of Zone 2 or 3 | |
264 | 123 Controlled by highest temp of Zone 1, 2 or 3 | |
265 | 0 PWM always 0% (off) | |
266 | -1 PWM always 100% (full on) | |
267 | -2 Manual control (write to 'pwm#' to set) | |
b04f2f7d | 268 | ========== ============================================= |
7f15b664 M |
269 | |
270 | The National LM85's have two vendor specific configuration | |
271 | features. Tach. mode and Spinup Control. For more details on these, | |
dd1ac538 JD |
272 | see the LM85 datasheet or Application Note AN-1260. These features |
273 | are not currently supported by the lm85 driver. | |
7f15b664 M |
274 | |
275 | The Analog Devices ADM1027 has several vendor specific enhancements. | |
276 | The number of pulses-per-rev of the fans can be set, Tach monitoring | |
277 | can be optimized for PWM operation, and an offset can be applied to | |
278 | the temperatures to compensate for systemic errors in the | |
dd1ac538 JD |
279 | measurements. These features are not currently supported by the lm85 |
280 | driver. | |
7f15b664 | 281 | |
c36364db JD |
282 | In addition to the ADM1027 features, the ADT7463 and ADT7468 also have |
283 | Tmin control and THERM asserted counts. Automatic Tmin control acts to | |
284 | adjust the Tmin value to maintain the measured temperature sensor at a | |
285 | specified temperature. There isn't much documentation on this feature in | |
286 | the ADT7463 data sheet. This is not supported by current driver. |