Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | Naming and data format standards for sysfs files |
2 | ------------------------------------------------ | |
3 | ||
4 | The libsensors library offers an interface to the raw sensors data | |
125ff808 JD |
5 | through the sysfs interface. Since lm-sensors 3.0.0, libsensors is |
6 | completely chip-independent. It assumes that all the kernel drivers | |
7 | implement the standard sysfs interface described in this document. | |
8 | This makes adding or updating support for any given chip very easy, as | |
9 | libsensors, and applications using it, do not need to be modified. | |
10 | This is a major improvement compared to lm-sensors 2. | |
1da177e4 LT |
11 | |
12 | Note that motherboards vary widely in the connections to sensor chips. | |
13 | There is no standard that ensures, for example, that the second | |
14 | temperature sensor is connected to the CPU, or that the second fan is on | |
15 | the CPU. Also, some values reported by the chips need some computation | |
16 | before they make full sense. For example, most chips can only measure | |
17 | voltages between 0 and +4V. Other voltages are scaled back into that | |
18 | range using external resistors. Since the values of these resistors | |
19 | can change from motherboard to motherboard, the conversions cannot be | |
20 | hard coded into the driver and have to be done in user space. | |
21 | ||
740e06a8 | 22 | For this reason, even if we aim at a chip-independent libsensors, it will |
1da177e4 LT |
23 | still require a configuration file (e.g. /etc/sensors.conf) for proper |
24 | values conversion, labeling of inputs and hiding of unused inputs. | |
25 | ||
26 | An alternative method that some programs use is to access the sysfs | |
27 | files directly. This document briefly describes the standards that the | |
28 | drivers follow, so that an application program can scan for entries and | |
29 | access this data in a simple and consistent way. That said, such programs | |
30 | will have to implement conversion, labeling and hiding of inputs. For | |
31 | this reason, it is still not recommended to bypass the library. | |
32 | ||
1da177e4 | 33 | Each chip gets its own directory in the sysfs /sys/devices tree. To |
740e06a8 JD |
34 | find all sensor chips, it is easier to follow the device symlinks from |
35 | /sys/class/hwmon/hwmon*. | |
1da177e4 | 36 | |
125ff808 JD |
37 | Up to lm-sensors 3.0.0, libsensors looks for hardware monitoring attributes |
38 | in the "physical" device directory. Since lm-sensors 3.0.1, attributes found | |
39 | in the hwmon "class" device directory are also supported. Complex drivers | |
40 | (e.g. drivers for multifunction chips) may want to use this possibility to | |
41 | avoid namespace pollution. The only drawback will be that older versions of | |
42 | libsensors won't support the driver in question. | |
43 | ||
740e06a8 | 44 | All sysfs values are fixed point numbers. |
1da177e4 LT |
45 | |
46 | There is only one value per file, unlike the older /proc specification. | |
47 | The common scheme for files naming is: <type><number>_<item>. Usual | |
48 | types for sensor chips are "in" (voltage), "temp" (temperature) and | |
49 | "fan" (fan). Usual items are "input" (measured value), "max" (high | |
50 | threshold, "min" (low threshold). Numbering usually starts from 1, | |
51 | except for voltages which start from 0 (because most data sheets use | |
52 | this). A number is always used for elements that can be present more | |
53 | than once, even if there is a single element of the given type on the | |
54 | specific chip. Other files do not refer to a specific element, so | |
55 | they have a simple name, and no number. | |
56 | ||
57 | Alarms are direct indications read from the chips. The drivers do NOT | |
58 | make comparisons of readings to thresholds. This allows violations | |
59 | between readings to be caught and alarmed. The exact definition of an | |
60 | alarm (for example, whether a threshold must be met or must be exceeded | |
61 | to cause an alarm) is chip-dependent. | |
62 | ||
2ed42633 HG |
63 | When setting values of hwmon sysfs attributes, the string representation of |
64 | the desired value must be written, note that strings which are not a number | |
65 | are interpreted as 0! For more on how written strings are interpreted see the | |
66 | "sysfs attribute writes interpretation" section at the end of this file. | |
1da177e4 LT |
67 | |
68 | ------------------------------------------------------------------------- | |
69 | ||
057bc350 RM |
70 | [0-*] denotes any positive number starting from 0 |
71 | [1-*] denotes any positive number starting from 1 | |
72 | RO read only value | |
cd4e96c5 | 73 | WO write only value |
057bc350 RM |
74 | RW read/write value |
75 | ||
76 | Read/write values may be read-only for some chips, depending on the | |
77 | hardware implementation. | |
78 | ||
176544dc JD |
79 | All entries (except name) are optional, and should only be created in a |
80 | given driver if the chip has the feature. | |
81 | ||
82 | ||
d2b847d4 IS |
83 | ********************* |
84 | * Global attributes * | |
85 | ********************* | |
176544dc JD |
86 | |
87 | name The chip name. | |
88 | This should be a short, lowercase string, not containing | |
f1728415 GR |
89 | whitespace, dashes, or the wildcard character '*'. |
90 | This attribute represents the chip name. It is the only | |
91 | mandatory attribute. | |
176544dc JD |
92 | I2C devices get this attribute created automatically. |
93 | RO | |
94 | ||
a51b9944 | 95 | update_interval The interval at which the chip will update readings. |
d2b847d4 IS |
96 | Unit: millisecond |
97 | RW | |
a51b9944 GR |
98 | Some devices have a variable update rate or interval. |
99 | This attribute can be used to change it to the desired value. | |
d2b847d4 | 100 | |
740e06a8 | 101 | |
1da177e4 LT |
102 | ************ |
103 | * Voltages * | |
104 | ************ | |
105 | ||
057bc350 | 106 | in[0-*]_min Voltage min value. |
1da177e4 | 107 | Unit: millivolt |
057bc350 | 108 | RW |
1da177e4 | 109 | |
f46fc8cd GR |
110 | in[0-*]_lcrit Voltage critical min value. |
111 | Unit: millivolt | |
112 | RW | |
113 | If voltage drops to or below this limit, the system may | |
114 | take drastic action such as power down or reset. At the very | |
115 | least, it should report a fault. | |
116 | ||
057bc350 | 117 | in[0-*]_max Voltage max value. |
1da177e4 | 118 | Unit: millivolt |
057bc350 | 119 | RW |
1da177e4 | 120 | |
f46fc8cd GR |
121 | in[0-*]_crit Voltage critical max value. |
122 | Unit: millivolt | |
123 | RW | |
124 | If voltage reaches or exceeds this limit, the system may | |
125 | take drastic action such as power down or reset. At the very | |
126 | least, it should report a fault. | |
127 | ||
057bc350 | 128 | in[0-*]_input Voltage input value. |
1da177e4 | 129 | Unit: millivolt |
057bc350 RM |
130 | RO |
131 | Voltage measured on the chip pin. | |
1da177e4 LT |
132 | Actual voltage depends on the scaling resistors on the |
133 | motherboard, as recommended in the chip datasheet. | |
134 | This varies by chip and by motherboard. | |
135 | Because of this variation, values are generally NOT scaled | |
136 | by the chip driver, and must be done by the application. | |
137 | However, some drivers (notably lm87 and via686a) | |
057bc350 | 138 | do scale, because of internal resistors built into a chip. |
176544dc JD |
139 | These drivers will output the actual voltage. Rule of |
140 | thumb: drivers should report the voltage values at the | |
141 | "pins" of the chip. | |
142 | ||
0084e9fa GR |
143 | in[0-*]_average |
144 | Average voltage | |
145 | Unit: millivolt | |
146 | RO | |
147 | ||
148 | in[0-*]_lowest | |
149 | Historical minimum voltage | |
150 | Unit: millivolt | |
151 | RO | |
152 | ||
153 | in[0-*]_highest | |
154 | Historical maximum voltage | |
155 | Unit: millivolt | |
156 | RO | |
157 | ||
158 | in[0-*]_reset_history | |
159 | Reset inX_lowest and inX_highest | |
160 | WO | |
161 | ||
162 | in_reset_history | |
163 | Reset inX_lowest and inX_highest for all sensors | |
164 | WO | |
165 | ||
176544dc JD |
166 | in[0-*]_label Suggested voltage channel label. |
167 | Text string | |
168 | Should only be created if the driver has hints about what | |
169 | this voltage channel is being used for, and user-space | |
170 | doesn't. In all other cases, the label is provided by | |
171 | user-space. | |
172 | RO | |
1da177e4 | 173 | |
057bc350 | 174 | cpu[0-*]_vid CPU core reference voltage. |
1da177e4 | 175 | Unit: millivolt |
057bc350 | 176 | RO |
1da177e4 LT |
177 | Not always correct. |
178 | ||
179 | vrm Voltage Regulator Module version number. | |
057bc350 RM |
180 | RW (but changing it should no more be necessary) |
181 | Originally the VRM standard version multiplied by 10, but now | |
182 | an arbitrary number, as not all standards have a version | |
183 | number. | |
1da177e4 LT |
184 | Affects the way the driver calculates the CPU core reference |
185 | voltage from the vid pins. | |
186 | ||
057bc350 RM |
187 | Also see the Alarms section for status flags associated with voltages. |
188 | ||
1da177e4 LT |
189 | |
190 | ******** | |
191 | * Fans * | |
192 | ******** | |
193 | ||
057bc350 | 194 | fan[1-*]_min Fan minimum value |
1da177e4 | 195 | Unit: revolution/min (RPM) |
057bc350 | 196 | RW |
1da177e4 | 197 | |
d54d4624 CE |
198 | fan[1-*]_max Fan maximum value |
199 | Unit: revolution/min (RPM) | |
200 | Only rarely supported by the hardware. | |
201 | RW | |
202 | ||
057bc350 | 203 | fan[1-*]_input Fan input value. |
1da177e4 | 204 | Unit: revolution/min (RPM) |
057bc350 | 205 | RO |
1da177e4 | 206 | |
057bc350 | 207 | fan[1-*]_div Fan divisor. |
1da177e4 | 208 | Integer value in powers of two (1, 2, 4, 8, 16, 32, 64, 128). |
057bc350 | 209 | RW |
1da177e4 LT |
210 | Some chips only support values 1, 2, 4 and 8. |
211 | Note that this is actually an internal clock divisor, which | |
212 | affects the measurable speed range, not the read value. | |
213 | ||
2d2e148a GR |
214 | fan[1-*]_pulses Number of tachometer pulses per fan revolution. |
215 | Integer value, typically between 1 and 4. | |
216 | RW | |
217 | This value is a characteristic of the fan connected to the | |
218 | device's input, so it has to be set in accordance with the fan | |
219 | model. | |
220 | Should only be created if the chip has a register to configure | |
221 | the number of pulses. In the absence of such a register (and | |
222 | thus attribute) the value assumed by all devices is 2 pulses | |
223 | per fan revolution. | |
224 | ||
2dbc514a JD |
225 | fan[1-*]_target |
226 | Desired fan speed | |
227 | Unit: revolution/min (RPM) | |
228 | RW | |
229 | Only makes sense if the chip supports closed-loop fan speed | |
230 | control based on the measured fan speed. | |
231 | ||
176544dc JD |
232 | fan[1-*]_label Suggested fan channel label. |
233 | Text string | |
234 | Should only be created if the driver has hints about what | |
235 | this fan channel is being used for, and user-space doesn't. | |
236 | In all other cases, the label is provided by user-space. | |
237 | RO | |
238 | ||
057bc350 RM |
239 | Also see the Alarms section for status flags associated with fans. |
240 | ||
241 | ||
1da177e4 LT |
242 | ******* |
243 | * PWM * | |
244 | ******* | |
245 | ||
057bc350 | 246 | pwm[1-*] Pulse width modulation fan control. |
1da177e4 | 247 | Integer value in the range 0 to 255 |
057bc350 | 248 | RW |
1da177e4 LT |
249 | 255 is max or 100%. |
250 | ||
057bc350 | 251 | pwm[1-*]_enable |
875f25d5 JD |
252 | Fan speed control method: |
253 | 0: no fan speed control (i.e. fan at full speed) | |
254 | 1: manual fan speed control enabled (using pwm[1-*]) | |
255 | 2+: automatic fan speed control enabled | |
f8d0c19a JD |
256 | Check individual chip documentation files for automatic mode |
257 | details. | |
057bc350 RM |
258 | RW |
259 | ||
f8d0c19a JD |
260 | pwm[1-*]_mode 0: DC mode (direct current) |
261 | 1: PWM mode (pulse-width modulation) | |
262 | RW | |
263 | ||
264 | pwm[1-*]_freq Base PWM frequency in Hz. | |
265 | Only possibly available when pwmN_mode is PWM, but not always | |
266 | present even then. | |
057bc350 | 267 | RW |
1da177e4 LT |
268 | |
269 | pwm[1-*]_auto_channels_temp | |
270 | Select which temperature channels affect this PWM output in | |
271 | auto mode. Bitfield, 1 is temp1, 2 is temp2, 4 is temp3 etc... | |
272 | Which values are possible depend on the chip used. | |
057bc350 | 273 | RW |
1da177e4 LT |
274 | |
275 | pwm[1-*]_auto_point[1-*]_pwm | |
276 | pwm[1-*]_auto_point[1-*]_temp | |
277 | pwm[1-*]_auto_point[1-*]_temp_hyst | |
278 | Define the PWM vs temperature curve. Number of trip points is | |
279 | chip-dependent. Use this for chips which associate trip points | |
280 | to PWM output channels. | |
057bc350 | 281 | RW |
1da177e4 | 282 | |
1da177e4 LT |
283 | temp[1-*]_auto_point[1-*]_pwm |
284 | temp[1-*]_auto_point[1-*]_temp | |
285 | temp[1-*]_auto_point[1-*]_temp_hyst | |
286 | Define the PWM vs temperature curve. Number of trip points is | |
287 | chip-dependent. Use this for chips which associate trip points | |
288 | to temperature channels. | |
057bc350 | 289 | RW |
1da177e4 | 290 | |
f7290e24 JD |
291 | There is a third case where trip points are associated to both PWM output |
292 | channels and temperature channels: the PWM values are associated to PWM | |
293 | output channels while the temperature values are associated to temperature | |
294 | channels. In that case, the result is determined by the mapping between | |
295 | temperature inputs and PWM outputs. When several temperature inputs are | |
296 | mapped to a given PWM output, this leads to several candidate PWM values. | |
297 | The actual result is up to the chip, but in general the highest candidate | |
298 | value (fastest fan speed) wins. | |
299 | ||
1da177e4 LT |
300 | |
301 | **************** | |
302 | * Temperatures * | |
303 | **************** | |
304 | ||
057bc350 | 305 | temp[1-*]_type Sensor type selection. |
b26f9330 | 306 | Integers 1 to 6 |
057bc350 | 307 | RW |
5f8b1f87 | 308 | 1: CPU embedded diode |
1da177e4 LT |
309 | 2: 3904 transistor |
310 | 3: thermal diode | |
b26f9330 | 311 | 4: thermistor |
61db011d RM |
312 | 5: AMD AMDSI |
313 | 6: Intel PECI | |
1da177e4 LT |
314 | Not all types are supported by all chips |
315 | ||
057bc350 | 316 | temp[1-*]_max Temperature max value. |
740e06a8 | 317 | Unit: millidegree Celsius (or millivolt, see below) |
057bc350 | 318 | RW |
1da177e4 | 319 | |
057bc350 | 320 | temp[1-*]_min Temperature min value. |
740e06a8 | 321 | Unit: millidegree Celsius |
057bc350 | 322 | RW |
1da177e4 | 323 | |
057bc350 | 324 | temp[1-*]_max_hyst |
1da177e4 | 325 | Temperature hysteresis value for max limit. |
740e06a8 | 326 | Unit: millidegree Celsius |
1da177e4 LT |
327 | Must be reported as an absolute temperature, NOT a delta |
328 | from the max value. | |
057bc350 | 329 | RW |
1da177e4 | 330 | |
01325145 JD |
331 | temp[1-*]_min_hyst |
332 | Temperature hysteresis value for min limit. | |
333 | Unit: millidegree Celsius | |
334 | Must be reported as an absolute temperature, NOT a delta | |
335 | from the min value. | |
336 | RW | |
337 | ||
057bc350 | 338 | temp[1-*]_input Temperature input value. |
740e06a8 | 339 | Unit: millidegree Celsius |
057bc350 | 340 | RO |
1da177e4 | 341 | |
f46fc8cd | 342 | temp[1-*]_crit Temperature critical max value, typically greater than |
1da177e4 | 343 | corresponding temp_max values. |
740e06a8 | 344 | Unit: millidegree Celsius |
057bc350 | 345 | RW |
1da177e4 | 346 | |
057bc350 | 347 | temp[1-*]_crit_hyst |
1da177e4 | 348 | Temperature hysteresis value for critical limit. |
740e06a8 | 349 | Unit: millidegree Celsius |
1da177e4 LT |
350 | Must be reported as an absolute temperature, NOT a delta |
351 | from the critical value. | |
057bc350 | 352 | RW |
1da177e4 | 353 | |
28e7438f GR |
354 | temp[1-*]_emergency |
355 | Temperature emergency max value, for chips supporting more than | |
356 | two upper temperature limits. Must be equal or greater than | |
357 | corresponding temp_crit values. | |
358 | Unit: millidegree Celsius | |
359 | RW | |
360 | ||
361 | temp[1-*]_emergency_hyst | |
362 | Temperature hysteresis value for emergency limit. | |
363 | Unit: millidegree Celsius | |
364 | Must be reported as an absolute temperature, NOT a delta | |
365 | from the emergency value. | |
366 | RW | |
367 | ||
f46fc8cd GR |
368 | temp[1-*]_lcrit Temperature critical min value, typically lower than |
369 | corresponding temp_min values. | |
370 | Unit: millidegree Celsius | |
371 | RW | |
372 | ||
01325145 JD |
373 | temp[1-*]_lcrit_hyst |
374 | Temperature hysteresis value for critical min limit. | |
375 | Unit: millidegree Celsius | |
376 | Must be reported as an absolute temperature, NOT a delta | |
377 | from the critical min value. | |
378 | RW | |
379 | ||
176544dc | 380 | temp[1-*]_offset |
59ac8367 HR |
381 | Temperature offset which is added to the temperature reading |
382 | by the chip. | |
383 | Unit: millidegree Celsius | |
384 | Read/Write value. | |
385 | ||
176544dc JD |
386 | temp[1-*]_label Suggested temperature channel label. |
387 | Text string | |
388 | Should only be created if the driver has hints about what | |
389 | this temperature channel is being used for, and user-space | |
390 | doesn't. In all other cases, the label is provided by | |
391 | user-space. | |
392 | RO | |
1da177e4 | 393 | |
cd4e96c5 AP |
394 | temp[1-*]_lowest |
395 | Historical minimum temperature | |
396 | Unit: millidegree Celsius | |
397 | RO | |
398 | ||
399 | temp[1-*]_highest | |
400 | Historical maximum temperature | |
401 | Unit: millidegree Celsius | |
402 | RO | |
403 | ||
404 | temp[1-*]_reset_history | |
405 | Reset temp_lowest and temp_highest | |
406 | WO | |
407 | ||
408 | temp_reset_history | |
409 | Reset temp_lowest and temp_highest for all sensors | |
410 | WO | |
411 | ||
740e06a8 JD |
412 | Some chips measure temperature using external thermistors and an ADC, and |
413 | report the temperature measurement as a voltage. Converting this voltage | |
414 | back to a temperature (or the other way around for limits) requires | |
415 | mathematical functions not available in the kernel, so the conversion | |
416 | must occur in user space. For these chips, all temp* files described | |
417 | above should contain values expressed in millivolt instead of millidegree | |
418 | Celsius. In other words, such temperature channels are handled as voltage | |
419 | channels by the driver. | |
420 | ||
057bc350 RM |
421 | Also see the Alarms section for status flags associated with temperatures. |
422 | ||
1da177e4 LT |
423 | |
424 | ************ | |
425 | * Currents * | |
426 | ************ | |
427 | ||
057bc350 | 428 | curr[1-*]_max Current max value |
1da177e4 | 429 | Unit: milliampere |
057bc350 | 430 | RW |
1da177e4 | 431 | |
057bc350 | 432 | curr[1-*]_min Current min value. |
1da177e4 | 433 | Unit: milliampere |
057bc350 | 434 | RW |
1da177e4 | 435 | |
581693b5 GR |
436 | curr[1-*]_lcrit Current critical low value |
437 | Unit: milliampere | |
438 | RW | |
439 | ||
440 | curr[1-*]_crit Current critical high value. | |
441 | Unit: milliampere | |
442 | RW | |
443 | ||
057bc350 | 444 | curr[1-*]_input Current input value |
1da177e4 | 445 | Unit: milliampere |
057bc350 | 446 | RO |
1da177e4 | 447 | |
0084e9fa GR |
448 | curr[1-*]_average |
449 | Average current use | |
450 | Unit: milliampere | |
451 | RO | |
452 | ||
453 | curr[1-*]_lowest | |
454 | Historical minimum current | |
455 | Unit: milliampere | |
456 | RO | |
457 | ||
458 | curr[1-*]_highest | |
459 | Historical maximum current | |
460 | Unit: milliampere | |
461 | RO | |
462 | ||
463 | curr[1-*]_reset_history | |
464 | Reset currX_lowest and currX_highest | |
465 | WO | |
466 | ||
467 | curr_reset_history | |
468 | Reset currX_lowest and currX_highest for all sensors | |
469 | WO | |
470 | ||
581693b5 GR |
471 | Also see the Alarms section for status flags associated with currents. |
472 | ||
38fb56a2 DW |
473 | ********* |
474 | * Power * | |
475 | ********* | |
476 | ||
477 | power[1-*]_average Average power use | |
478 | Unit: microWatt | |
479 | RO | |
480 | ||
115a57c5 DW |
481 | power[1-*]_average_interval Power use averaging interval. A poll |
482 | notification is sent to this file if the | |
483 | hardware changes the averaging interval. | |
ddedc658 DW |
484 | Unit: milliseconds |
485 | RW | |
486 | ||
115a57c5 DW |
487 | power[1-*]_average_interval_max Maximum power use averaging interval |
488 | Unit: milliseconds | |
489 | RO | |
490 | ||
491 | power[1-*]_average_interval_min Minimum power use averaging interval | |
492 | Unit: milliseconds | |
493 | RO | |
494 | ||
38fb56a2 DW |
495 | power[1-*]_average_highest Historical average maximum power use |
496 | Unit: microWatt | |
497 | RO | |
498 | ||
499 | power[1-*]_average_lowest Historical average minimum power use | |
500 | Unit: microWatt | |
501 | RO | |
502 | ||
115a57c5 DW |
503 | power[1-*]_average_max A poll notification is sent to |
504 | power[1-*]_average when power use | |
505 | rises above this value. | |
506 | Unit: microWatt | |
507 | RW | |
508 | ||
509 | power[1-*]_average_min A poll notification is sent to | |
510 | power[1-*]_average when power use | |
511 | sinks below this value. | |
512 | Unit: microWatt | |
513 | RW | |
514 | ||
38fb56a2 DW |
515 | power[1-*]_input Instantaneous power use |
516 | Unit: microWatt | |
517 | RO | |
518 | ||
519 | power[1-*]_input_highest Historical maximum power use | |
520 | Unit: microWatt | |
521 | RO | |
522 | ||
523 | power[1-*]_input_lowest Historical minimum power use | |
524 | Unit: microWatt | |
525 | RO | |
526 | ||
527 | power[1-*]_reset_history Reset input_highest, input_lowest, | |
528 | average_highest and average_lowest. | |
529 | WO | |
1da177e4 | 530 | |
115a57c5 DW |
531 | power[1-*]_accuracy Accuracy of the power meter. |
532 | Unit: Percent | |
533 | RO | |
534 | ||
115a57c5 DW |
535 | power[1-*]_cap If power use rises above this limit, the |
536 | system should take action to reduce power use. | |
537 | A poll notification is sent to this file if the | |
538 | cap is changed by the hardware. The *_cap | |
539 | files only appear if the cap is known to be | |
540 | enforced by hardware. | |
541 | Unit: microWatt | |
542 | RW | |
543 | ||
544 | power[1-*]_cap_hyst Margin of hysteresis built around capping and | |
545 | notification. | |
546 | Unit: microWatt | |
547 | RW | |
548 | ||
549 | power[1-*]_cap_max Maximum cap that can be set. | |
550 | Unit: microWatt | |
551 | RO | |
552 | ||
553 | power[1-*]_cap_min Minimum cap that can be set. | |
554 | Unit: microWatt | |
555 | RO | |
556 | ||
581693b5 GR |
557 | power[1-*]_max Maximum power. |
558 | Unit: microWatt | |
559 | RW | |
560 | ||
561 | power[1-*]_crit Critical maximum power. | |
562 | If power rises to or above this limit, the | |
563 | system is expected take drastic action to reduce | |
564 | power consumption, such as a system shutdown or | |
565 | a forced powerdown of some devices. | |
566 | Unit: microWatt | |
567 | RW | |
568 | ||
569 | Also see the Alarms section for status flags associated with power readings. | |
570 | ||
ddedc658 DW |
571 | ********** |
572 | * Energy * | |
573 | ********** | |
574 | ||
575 | energy[1-*]_input Cumulative energy use | |
576 | Unit: microJoule | |
577 | RO | |
578 | ||
ec199209 | 579 | |
c6c2c163 GR |
580 | ************ |
581 | * Humidity * | |
582 | ************ | |
583 | ||
584 | humidity[1-*]_input Humidity | |
585 | Unit: milli-percent (per cent mille, pcm) | |
586 | RO | |
587 | ||
588 | ||
400b48ec JD |
589 | ********** |
590 | * Alarms * | |
591 | ********** | |
592 | ||
593 | Each channel or limit may have an associated alarm file, containing a | |
594 | boolean value. 1 means than an alarm condition exists, 0 means no alarm. | |
595 | ||
596 | Usually a given chip will either use channel-related alarms, or | |
597 | limit-related alarms, not both. The driver should just reflect the hardware | |
598 | implementation. | |
599 | ||
057bc350 | 600 | in[0-*]_alarm |
e04a715e | 601 | curr[1-*]_alarm |
581693b5 | 602 | power[1-*]_alarm |
057bc350 RM |
603 | fan[1-*]_alarm |
604 | temp[1-*]_alarm | |
400b48ec | 605 | Channel alarm |
057bc350 RM |
606 | 0: no alarm |
607 | 1: alarm | |
608 | RO | |
400b48ec JD |
609 | |
610 | OR | |
611 | ||
057bc350 RM |
612 | in[0-*]_min_alarm |
613 | in[0-*]_max_alarm | |
581693b5 GR |
614 | in[0-*]_lcrit_alarm |
615 | in[0-*]_crit_alarm | |
e04a715e GR |
616 | curr[1-*]_min_alarm |
617 | curr[1-*]_max_alarm | |
581693b5 GR |
618 | curr[1-*]_lcrit_alarm |
619 | curr[1-*]_crit_alarm | |
620 | power[1-*]_cap_alarm | |
621 | power[1-*]_max_alarm | |
622 | power[1-*]_crit_alarm | |
057bc350 | 623 | fan[1-*]_min_alarm |
d54d4624 | 624 | fan[1-*]_max_alarm |
057bc350 RM |
625 | temp[1-*]_min_alarm |
626 | temp[1-*]_max_alarm | |
581693b5 | 627 | temp[1-*]_lcrit_alarm |
057bc350 | 628 | temp[1-*]_crit_alarm |
28e7438f | 629 | temp[1-*]_emergency_alarm |
400b48ec | 630 | Limit alarm |
057bc350 RM |
631 | 0: no alarm |
632 | 1: alarm | |
633 | RO | |
400b48ec JD |
634 | |
635 | Each input channel may have an associated fault file. This can be used | |
636 | to notify open diodes, unconnected fans etc. where the hardware | |
637 | supports it. When this boolean has value 1, the measurement for that | |
638 | channel should not be trusted. | |
639 | ||
7817a39e JD |
640 | fan[1-*]_fault |
641 | temp[1-*]_fault | |
400b48ec | 642 | Input fault condition |
25985edc | 643 | 0: no fault occurred |
057bc350 RM |
644 | 1: fault condition |
645 | RO | |
400b48ec JD |
646 | |
647 | Some chips also offer the possibility to get beeped when an alarm occurs: | |
648 | ||
649 | beep_enable Master beep enable | |
057bc350 RM |
650 | 0: no beeps |
651 | 1: beeps | |
652 | RW | |
400b48ec | 653 | |
057bc350 | 654 | in[0-*]_beep |
e04a715e | 655 | curr[1-*]_beep |
057bc350 RM |
656 | fan[1-*]_beep |
657 | temp[1-*]_beep | |
400b48ec | 658 | Channel beep |
057bc350 RM |
659 | 0: disable |
660 | 1: enable | |
661 | RW | |
400b48ec JD |
662 | |
663 | In theory, a chip could provide per-limit beep masking, but no such chip | |
664 | was seen so far. | |
665 | ||
666 | Old drivers provided a different, non-standard interface to alarms and | |
667 | beeps. These interface files are deprecated, but will be kept around | |
668 | for compatibility reasons: | |
1da177e4 LT |
669 | |
670 | alarms Alarm bitmask. | |
057bc350 | 671 | RO |
1da177e4 LT |
672 | Integer representation of one to four bytes. |
673 | A '1' bit means an alarm. | |
674 | Chips should be programmed for 'comparator' mode so that | |
675 | the alarm will 'come back' after you read the register | |
676 | if it is still valid. | |
677 | Generally a direct representation of a chip's internal | |
678 | alarm registers; there is no standard for the position | |
400b48ec JD |
679 | of individual bits. For this reason, the use of this |
680 | interface file for new drivers is discouraged. Use | |
681 | individual *_alarm and *_fault files instead. | |
1da177e4 LT |
682 | Bits are defined in kernel/include/sensors.h. |
683 | ||
1da177e4 | 684 | beep_mask Bitmask for beep. |
400b48ec JD |
685 | Same format as 'alarms' with the same bit locations, |
686 | use discouraged for the same reason. Use individual | |
687 | *_beep files instead. | |
057bc350 | 688 | RW |
2ed42633 HG |
689 | |
690 | ||
ec199209 JD |
691 | *********************** |
692 | * Intrusion detection * | |
693 | *********************** | |
694 | ||
695 | intrusion[0-*]_alarm | |
696 | Chassis intrusion detection | |
697 | 0: OK | |
698 | 1: intrusion detected | |
699 | RW | |
700 | Contrary to regular alarm flags which clear themselves | |
701 | automatically when read, this one sticks until cleared by | |
702 | the user. This is done by writing 0 to the file. Writing | |
703 | other values is unsupported. | |
704 | ||
705 | intrusion[0-*]_beep | |
706 | Chassis intrusion beep | |
707 | 0: disable | |
708 | 1: enable | |
709 | RW | |
710 | ||
711 | ||
2ed42633 HG |
712 | sysfs attribute writes interpretation |
713 | ------------------------------------- | |
714 | ||
715 | hwmon sysfs attributes always contain numbers, so the first thing to do is to | |
716 | convert the input to a number, there are 2 ways todo this depending whether | |
717 | the number can be negative or not: | |
718 | unsigned long u = simple_strtoul(buf, NULL, 10); | |
719 | long s = simple_strtol(buf, NULL, 10); | |
720 | ||
721 | With buf being the buffer with the user input being passed by the kernel. | |
722 | Notice that we do not use the second argument of strto[u]l, and thus cannot | |
723 | tell when 0 is returned, if this was really 0 or is caused by invalid input. | |
724 | This is done deliberately as checking this everywhere would add a lot of | |
725 | code to the kernel. | |
726 | ||
727 | Notice that it is important to always store the converted value in an | |
728 | unsigned long or long, so that no wrap around can happen before any further | |
729 | checking. | |
730 | ||
731 | After the input string is converted to an (unsigned) long, the value should be | |
732 | checked if its acceptable. Be careful with further conversions on the value | |
733 | before checking it for validity, as these conversions could still cause a wrap | |
734 | around before the check. For example do not multiply the result, and only | |
735 | add/subtract if it has been divided before the add/subtract. | |
736 | ||
737 | What to do if a value is found to be invalid, depends on the type of the | |
738 | sysfs attribute that is being set. If it is a continuous setting like a | |
739 | tempX_max or inX_max attribute, then the value should be clamped to its | |
c25fb816 GR |
740 | limits using clamp_val(value, min_limit, max_limit). If it is not continuous |
741 | like for example a tempX_type, then when an invalid value is written, | |
742 | -EINVAL should be returned. | |
2ed42633 HG |
743 | |
744 | Example1, temp1_max, register is a signed 8 bit value (-128 - 127 degrees): | |
5fbea518 JD |
745 | |
746 | long v = simple_strtol(buf, NULL, 10) / 1000; | |
c25fb816 | 747 | v = clamp_val(v, -128, 127); |
5fbea518 | 748 | /* write v to register */ |
2ed42633 HG |
749 | |
750 | Example2, fan divider setting, valid values 2, 4 and 8: | |
5fbea518 JD |
751 | |
752 | unsigned long v = simple_strtoul(buf, NULL, 10); | |
753 | ||
754 | switch (v) { | |
755 | case 2: v = 1; break; | |
756 | case 4: v = 2; break; | |
757 | case 8: v = 3; break; | |
758 | default: | |
759 | return -EINVAL; | |
760 | } | |
761 | /* write v to register */ |