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Commit 5f8b1f877e0212bfde8cb950725391f4a50c9396

Authored by Guenter Roeck
Committed by Jean Delvare
1 parent 1c720093f6
Exists in master and in 6 other branches imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

hwmon: (sysfs-interface) Update tempX_type attribute to be more generic 

The temp[1-*]_type attribute reports the temperature sensor type. Sensor type 1
is described as "PII/Celeron Diode", which is quite restrictive; other CPUs
may also have an embedded temperature sensor diode with similar characteristics.
Change description to "CPU embedded diode" to be more generic.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

Showing 1 changed file with 1 additions and 1 deletions Inline Diff

Documentation/hwmon/sysfs-interface
Diff comments   View file @ 5f8b1f8
1 Naming and data format standards for sysfs files 1 Naming and data format standards for sysfs files
2 ------------------------------------------------ 2 ------------------------------------------------
3 3
4 The libsensors library offers an interface to the raw sensors data 4 The libsensors library offers an interface to the raw sensors data
5 through the sysfs interface. Since lm-sensors 3.0.0, libsensors is 5 through the sysfs interface. Since lm-sensors 3.0.0, libsensors is
6 completely chip-independent. It assumes that all the kernel drivers 6 completely chip-independent. It assumes that all the kernel drivers
7 implement the standard sysfs interface described in this document. 7 implement the standard sysfs interface described in this document.
8 This makes adding or updating support for any given chip very easy, as 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. 9 libsensors, and applications using it, do not need to be modified.
10 This is a major improvement compared to lm-sensors 2. 10 This is a major improvement compared to lm-sensors 2.
11 11
12 Note that motherboards vary widely in the connections to sensor chips. 12 Note that motherboards vary widely in the connections to sensor chips.
13 There is no standard that ensures, for example, that the second 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 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 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 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 17 voltages between 0 and +4V. Other voltages are scaled back into that
18 range using external resistors. Since the values of these resistors 18 range using external resistors. Since the values of these resistors
19 can change from motherboard to motherboard, the conversions cannot be 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. 20 hard coded into the driver and have to be done in user space.
21 21
22 For this reason, even if we aim at a chip-independent libsensors, it will 22 For this reason, even if we aim at a chip-independent libsensors, it will
23 still require a configuration file (e.g. /etc/sensors.conf) for proper 23 still require a configuration file (e.g. /etc/sensors.conf) for proper
24 values conversion, labeling of inputs and hiding of unused inputs. 24 values conversion, labeling of inputs and hiding of unused inputs.
25 25
26 An alternative method that some programs use is to access the sysfs 26 An alternative method that some programs use is to access the sysfs
27 files directly. This document briefly describes the standards that the 27 files directly. This document briefly describes the standards that the
28 drivers follow, so that an application program can scan for entries and 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 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 30 will have to implement conversion, labeling and hiding of inputs. For
31 this reason, it is still not recommended to bypass the library. 31 this reason, it is still not recommended to bypass the library.
32 32
33 Each chip gets its own directory in the sysfs /sys/devices tree. To 33 Each chip gets its own directory in the sysfs /sys/devices tree. To
34 find all sensor chips, it is easier to follow the device symlinks from 34 find all sensor chips, it is easier to follow the device symlinks from
35 /sys/class/hwmon/hwmon*. 35 /sys/class/hwmon/hwmon*.
36 36
37 Up to lm-sensors 3.0.0, libsensors looks for hardware monitoring attributes 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 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 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 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 41 avoid namespace pollution. The only drawback will be that older versions of
42 libsensors won't support the driver in question. 42 libsensors won't support the driver in question.
43 43
44 All sysfs values are fixed point numbers. 44 All sysfs values are fixed point numbers.
45 45
46 There is only one value per file, unlike the older /proc specification. 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 47 The common scheme for files naming is: <type><number>_<item>. Usual
48 types for sensor chips are "in" (voltage), "temp" (temperature) and 48 types for sensor chips are "in" (voltage), "temp" (temperature) and
49 "fan" (fan). Usual items are "input" (measured value), "max" (high 49 "fan" (fan). Usual items are "input" (measured value), "max" (high
50 threshold, "min" (low threshold). Numbering usually starts from 1, 50 threshold, "min" (low threshold). Numbering usually starts from 1,
51 except for voltages which start from 0 (because most data sheets use 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 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 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 54 specific chip. Other files do not refer to a specific element, so
55 they have a simple name, and no number. 55 they have a simple name, and no number.
56 56
57 Alarms are direct indications read from the chips. The drivers do NOT 57 Alarms are direct indications read from the chips. The drivers do NOT
58 make comparisons of readings to thresholds. This allows violations 58 make comparisons of readings to thresholds. This allows violations
59 between readings to be caught and alarmed. The exact definition of an 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 60 alarm (for example, whether a threshold must be met or must be exceeded
61 to cause an alarm) is chip-dependent. 61 to cause an alarm) is chip-dependent.
62 62
63 When setting values of hwmon sysfs attributes, the string representation of 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 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 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. 66 "sysfs attribute writes interpretation" section at the end of this file.
67 67
68 ------------------------------------------------------------------------- 68 -------------------------------------------------------------------------
69 69
70 [0-*] denotes any positive number starting from 0 70 [0-*] denotes any positive number starting from 0
71 [1-*] denotes any positive number starting from 1 71 [1-*] denotes any positive number starting from 1
72 RO read only value 72 RO read only value
73 WO write only value 73 WO write only value
74 RW read/write value 74 RW read/write value
75 75
76 Read/write values may be read-only for some chips, depending on the 76 Read/write values may be read-only for some chips, depending on the
77 hardware implementation. 77 hardware implementation.
78 78
79 All entries (except name) are optional, and should only be created in a 79 All entries (except name) are optional, and should only be created in a
80 given driver if the chip has the feature. 80 given driver if the chip has the feature.
81 81
82 82
83 ********************* 83 *********************
84 * Global attributes * 84 * Global attributes *
85 ********************* 85 *********************
86 86
87 name The chip name. 87 name The chip name.
88 This should be a short, lowercase string, not containing 88 This should be a short, lowercase string, not containing
89 spaces nor dashes, representing the chip name. This is 89 spaces nor dashes, representing the chip name. This is
90 the only mandatory attribute. 90 the only mandatory attribute.
91 I2C devices get this attribute created automatically. 91 I2C devices get this attribute created automatically.
92 RO 92 RO
93 93
94 update_interval The interval at which the chip will update readings. 94 update_interval The interval at which the chip will update readings.
95 Unit: millisecond 95 Unit: millisecond
96 RW 96 RW
97 Some devices have a variable update rate or interval. 97 Some devices have a variable update rate or interval.
98 This attribute can be used to change it to the desired value. 98 This attribute can be used to change it to the desired value.
99 99
100 100
101 ************ 101 ************
102 * Voltages * 102 * Voltages *
103 ************ 103 ************
104 104
105 in[0-*]_min Voltage min value. 105 in[0-*]_min Voltage min value.
106 Unit: millivolt 106 Unit: millivolt
107 RW 107 RW
108 108
109 in[0-*]_lcrit Voltage critical min value. 109 in[0-*]_lcrit Voltage critical min value.
110 Unit: millivolt 110 Unit: millivolt
111 RW 111 RW
112 If voltage drops to or below this limit, the system may 112 If voltage drops to or below this limit, the system may
113 take drastic action such as power down or reset. At the very 113 take drastic action such as power down or reset. At the very
114 least, it should report a fault. 114 least, it should report a fault.
115 115
116 in[0-*]_max Voltage max value. 116 in[0-*]_max Voltage max value.
117 Unit: millivolt 117 Unit: millivolt
118 RW 118 RW
119 119
120 in[0-*]_crit Voltage critical max value. 120 in[0-*]_crit Voltage critical max value.
121 Unit: millivolt 121 Unit: millivolt
122 RW 122 RW
123 If voltage reaches or exceeds this limit, the system may 123 If voltage reaches or exceeds this limit, the system may
124 take drastic action such as power down or reset. At the very 124 take drastic action such as power down or reset. At the very
125 least, it should report a fault. 125 least, it should report a fault.
126 126
127 in[0-*]_input Voltage input value. 127 in[0-*]_input Voltage input value.
128 Unit: millivolt 128 Unit: millivolt
129 RO 129 RO
130 Voltage measured on the chip pin. 130 Voltage measured on the chip pin.
131 Actual voltage depends on the scaling resistors on the 131 Actual voltage depends on the scaling resistors on the
132 motherboard, as recommended in the chip datasheet. 132 motherboard, as recommended in the chip datasheet.
133 This varies by chip and by motherboard. 133 This varies by chip and by motherboard.
134 Because of this variation, values are generally NOT scaled 134 Because of this variation, values are generally NOT scaled
135 by the chip driver, and must be done by the application. 135 by the chip driver, and must be done by the application.
136 However, some drivers (notably lm87 and via686a) 136 However, some drivers (notably lm87 and via686a)
137 do scale, because of internal resistors built into a chip. 137 do scale, because of internal resistors built into a chip.
138 These drivers will output the actual voltage. Rule of 138 These drivers will output the actual voltage. Rule of
139 thumb: drivers should report the voltage values at the 139 thumb: drivers should report the voltage values at the
140 "pins" of the chip. 140 "pins" of the chip.
141 141
142 in[0-*]_average 142 in[0-*]_average
143 Average voltage 143 Average voltage
144 Unit: millivolt 144 Unit: millivolt
145 RO 145 RO
146 146
147 in[0-*]_lowest 147 in[0-*]_lowest
148 Historical minimum voltage 148 Historical minimum voltage
149 Unit: millivolt 149 Unit: millivolt
150 RO 150 RO
151 151
152 in[0-*]_highest 152 in[0-*]_highest
153 Historical maximum voltage 153 Historical maximum voltage
154 Unit: millivolt 154 Unit: millivolt
155 RO 155 RO
156 156
157 in[0-*]_reset_history 157 in[0-*]_reset_history
158 Reset inX_lowest and inX_highest 158 Reset inX_lowest and inX_highest
159 WO 159 WO
160 160
161 in_reset_history 161 in_reset_history
162 Reset inX_lowest and inX_highest for all sensors 162 Reset inX_lowest and inX_highest for all sensors
163 WO 163 WO
164 164
165 in[0-*]_label Suggested voltage channel label. 165 in[0-*]_label Suggested voltage channel label.
166 Text string 166 Text string
167 Should only be created if the driver has hints about what 167 Should only be created if the driver has hints about what
168 this voltage channel is being used for, and user-space 168 this voltage channel is being used for, and user-space
169 doesn't. In all other cases, the label is provided by 169 doesn't. In all other cases, the label is provided by
170 user-space. 170 user-space.
171 RO 171 RO
172 172
173 cpu[0-*]_vid CPU core reference voltage. 173 cpu[0-*]_vid CPU core reference voltage.
174 Unit: millivolt 174 Unit: millivolt
175 RO 175 RO
176 Not always correct. 176 Not always correct.
177 177
178 vrm Voltage Regulator Module version number. 178 vrm Voltage Regulator Module version number.
179 RW (but changing it should no more be necessary) 179 RW (but changing it should no more be necessary)
180 Originally the VRM standard version multiplied by 10, but now 180 Originally the VRM standard version multiplied by 10, but now
181 an arbitrary number, as not all standards have a version 181 an arbitrary number, as not all standards have a version
182 number. 182 number.
183 Affects the way the driver calculates the CPU core reference 183 Affects the way the driver calculates the CPU core reference
184 voltage from the vid pins. 184 voltage from the vid pins.
185 185
186 Also see the Alarms section for status flags associated with voltages. 186 Also see the Alarms section for status flags associated with voltages.
187 187
188 188
189 ******** 189 ********
190 * Fans * 190 * Fans *
191 ******** 191 ********
192 192
193 fan[1-*]_min Fan minimum value 193 fan[1-*]_min Fan minimum value
194 Unit: revolution/min (RPM) 194 Unit: revolution/min (RPM)
195 RW 195 RW
196 196
197 fan[1-*]_max Fan maximum value 197 fan[1-*]_max Fan maximum value
198 Unit: revolution/min (RPM) 198 Unit: revolution/min (RPM)
199 Only rarely supported by the hardware. 199 Only rarely supported by the hardware.
200 RW 200 RW
201 201
202 fan[1-*]_input Fan input value. 202 fan[1-*]_input Fan input value.
203 Unit: revolution/min (RPM) 203 Unit: revolution/min (RPM)
204 RO 204 RO
205 205
206 fan[1-*]_div Fan divisor. 206 fan[1-*]_div Fan divisor.
207 Integer value in powers of two (1, 2, 4, 8, 16, 32, 64, 128). 207 Integer value in powers of two (1, 2, 4, 8, 16, 32, 64, 128).
208 RW 208 RW
209 Some chips only support values 1, 2, 4 and 8. 209 Some chips only support values 1, 2, 4 and 8.
210 Note that this is actually an internal clock divisor, which 210 Note that this is actually an internal clock divisor, which
211 affects the measurable speed range, not the read value. 211 affects the measurable speed range, not the read value.
212 212
213 fan[1-*]_pulses Number of tachometer pulses per fan revolution. 213 fan[1-*]_pulses Number of tachometer pulses per fan revolution.
214 Integer value, typically between 1 and 4. 214 Integer value, typically between 1 and 4.
215 RW 215 RW
216 This value is a characteristic of the fan connected to the 216 This value is a characteristic of the fan connected to the
217 device's input, so it has to be set in accordance with the fan 217 device's input, so it has to be set in accordance with the fan
218 model. 218 model.
219 Should only be created if the chip has a register to configure 219 Should only be created if the chip has a register to configure
220 the number of pulses. In the absence of such a register (and 220 the number of pulses. In the absence of such a register (and
221 thus attribute) the value assumed by all devices is 2 pulses 221 thus attribute) the value assumed by all devices is 2 pulses
222 per fan revolution. 222 per fan revolution.
223 223
224 fan[1-*]_target 224 fan[1-*]_target
225 Desired fan speed 225 Desired fan speed
226 Unit: revolution/min (RPM) 226 Unit: revolution/min (RPM)
227 RW 227 RW
228 Only makes sense if the chip supports closed-loop fan speed 228 Only makes sense if the chip supports closed-loop fan speed
229 control based on the measured fan speed. 229 control based on the measured fan speed.
230 230
231 fan[1-*]_label Suggested fan channel label. 231 fan[1-*]_label Suggested fan channel label.
232 Text string 232 Text string
233 Should only be created if the driver has hints about what 233 Should only be created if the driver has hints about what
234 this fan channel is being used for, and user-space doesn't. 234 this fan channel is being used for, and user-space doesn't.
235 In all other cases, the label is provided by user-space. 235 In all other cases, the label is provided by user-space.
236 RO 236 RO
237 237
238 Also see the Alarms section for status flags associated with fans. 238 Also see the Alarms section for status flags associated with fans.
239 239
240 240
241 ******* 241 *******
242 * PWM * 242 * PWM *
243 ******* 243 *******
244 244
245 pwm[1-*] Pulse width modulation fan control. 245 pwm[1-*] Pulse width modulation fan control.
246 Integer value in the range 0 to 255 246 Integer value in the range 0 to 255
247 RW 247 RW
248 255 is max or 100%. 248 255 is max or 100%.
249 249
250 pwm[1-*]_enable 250 pwm[1-*]_enable
251 Fan speed control method: 251 Fan speed control method:
252 0: no fan speed control (i.e. fan at full speed) 252 0: no fan speed control (i.e. fan at full speed)
253 1: manual fan speed control enabled (using pwm[1-*]) 253 1: manual fan speed control enabled (using pwm[1-*])
254 2+: automatic fan speed control enabled 254 2+: automatic fan speed control enabled
255 Check individual chip documentation files for automatic mode 255 Check individual chip documentation files for automatic mode
256 details. 256 details.
257 RW 257 RW
258 258
259 pwm[1-*]_mode 0: DC mode (direct current) 259 pwm[1-*]_mode 0: DC mode (direct current)
260 1: PWM mode (pulse-width modulation) 260 1: PWM mode (pulse-width modulation)
261 RW 261 RW
262 262
263 pwm[1-*]_freq Base PWM frequency in Hz. 263 pwm[1-*]_freq Base PWM frequency in Hz.
264 Only possibly available when pwmN_mode is PWM, but not always 264 Only possibly available when pwmN_mode is PWM, but not always
265 present even then. 265 present even then.
266 RW 266 RW
267 267
268 pwm[1-*]_auto_channels_temp 268 pwm[1-*]_auto_channels_temp
269 Select which temperature channels affect this PWM output in 269 Select which temperature channels affect this PWM output in
270 auto mode. Bitfield, 1 is temp1, 2 is temp2, 4 is temp3 etc... 270 auto mode. Bitfield, 1 is temp1, 2 is temp2, 4 is temp3 etc...
271 Which values are possible depend on the chip used. 271 Which values are possible depend on the chip used.
272 RW 272 RW
273 273
274 pwm[1-*]_auto_point[1-*]_pwm 274 pwm[1-*]_auto_point[1-*]_pwm
275 pwm[1-*]_auto_point[1-*]_temp 275 pwm[1-*]_auto_point[1-*]_temp
276 pwm[1-*]_auto_point[1-*]_temp_hyst 276 pwm[1-*]_auto_point[1-*]_temp_hyst
277 Define the PWM vs temperature curve. Number of trip points is 277 Define the PWM vs temperature curve. Number of trip points is
278 chip-dependent. Use this for chips which associate trip points 278 chip-dependent. Use this for chips which associate trip points
279 to PWM output channels. 279 to PWM output channels.
280 RW 280 RW
281 281
282 temp[1-*]_auto_point[1-*]_pwm 282 temp[1-*]_auto_point[1-*]_pwm
283 temp[1-*]_auto_point[1-*]_temp 283 temp[1-*]_auto_point[1-*]_temp
284 temp[1-*]_auto_point[1-*]_temp_hyst 284 temp[1-*]_auto_point[1-*]_temp_hyst
285 Define the PWM vs temperature curve. Number of trip points is 285 Define the PWM vs temperature curve. Number of trip points is
286 chip-dependent. Use this for chips which associate trip points 286 chip-dependent. Use this for chips which associate trip points
287 to temperature channels. 287 to temperature channels.
288 RW 288 RW
289 289
290 There is a third case where trip points are associated to both PWM output 290 There is a third case where trip points are associated to both PWM output
291 channels and temperature channels: the PWM values are associated to PWM 291 channels and temperature channels: the PWM values are associated to PWM
292 output channels while the temperature values are associated to temperature 292 output channels while the temperature values are associated to temperature
293 channels. In that case, the result is determined by the mapping between 293 channels. In that case, the result is determined by the mapping between
294 temperature inputs and PWM outputs. When several temperature inputs are 294 temperature inputs and PWM outputs. When several temperature inputs are
295 mapped to a given PWM output, this leads to several candidate PWM values. 295 mapped to a given PWM output, this leads to several candidate PWM values.
296 The actual result is up to the chip, but in general the highest candidate 296 The actual result is up to the chip, but in general the highest candidate
297 value (fastest fan speed) wins. 297 value (fastest fan speed) wins.
298 298
299 299
300 **************** 300 ****************
301 * Temperatures * 301 * Temperatures *
302 **************** 302 ****************
303 303
304 temp[1-*]_type Sensor type selection. 304 temp[1-*]_type Sensor type selection.
305 Integers 1 to 6 305 Integers 1 to 6
306 RW 306 RW
307 1: PII/Celeron Diode 307 1: CPU embedded diode
308 2: 3904 transistor 308 2: 3904 transistor
309 3: thermal diode 309 3: thermal diode
310 4: thermistor 310 4: thermistor
311 5: AMD AMDSI 311 5: AMD AMDSI
312 6: Intel PECI 312 6: Intel PECI
313 Not all types are supported by all chips 313 Not all types are supported by all chips
314 314
315 temp[1-*]_max Temperature max value. 315 temp[1-*]_max Temperature max value.
316 Unit: millidegree Celsius (or millivolt, see below) 316 Unit: millidegree Celsius (or millivolt, see below)
317 RW 317 RW
318 318
319 temp[1-*]_min Temperature min value. 319 temp[1-*]_min Temperature min value.
320 Unit: millidegree Celsius 320 Unit: millidegree Celsius
321 RW 321 RW
322 322
323 temp[1-*]_max_hyst 323 temp[1-*]_max_hyst
324 Temperature hysteresis value for max limit. 324 Temperature hysteresis value for max limit.
325 Unit: millidegree Celsius 325 Unit: millidegree Celsius
326 Must be reported as an absolute temperature, NOT a delta 326 Must be reported as an absolute temperature, NOT a delta
327 from the max value. 327 from the max value.
328 RW 328 RW
329 329
330 temp[1-*]_input Temperature input value. 330 temp[1-*]_input Temperature input value.
331 Unit: millidegree Celsius 331 Unit: millidegree Celsius
332 RO 332 RO
333 333
334 temp[1-*]_crit Temperature critical max value, typically greater than 334 temp[1-*]_crit Temperature critical max value, typically greater than
335 corresponding temp_max values. 335 corresponding temp_max values.
336 Unit: millidegree Celsius 336 Unit: millidegree Celsius
337 RW 337 RW
338 338
339 temp[1-*]_crit_hyst 339 temp[1-*]_crit_hyst
340 Temperature hysteresis value for critical limit. 340 Temperature hysteresis value for critical limit.
341 Unit: millidegree Celsius 341 Unit: millidegree Celsius
342 Must be reported as an absolute temperature, NOT a delta 342 Must be reported as an absolute temperature, NOT a delta
343 from the critical value. 343 from the critical value.
344 RW 344 RW
345 345
346 temp[1-*]_emergency 346 temp[1-*]_emergency
347 Temperature emergency max value, for chips supporting more than 347 Temperature emergency max value, for chips supporting more than
348 two upper temperature limits. Must be equal or greater than 348 two upper temperature limits. Must be equal or greater than
349 corresponding temp_crit values. 349 corresponding temp_crit values.
350 Unit: millidegree Celsius 350 Unit: millidegree Celsius
351 RW 351 RW
352 352
353 temp[1-*]_emergency_hyst 353 temp[1-*]_emergency_hyst
354 Temperature hysteresis value for emergency limit. 354 Temperature hysteresis value for emergency limit.
355 Unit: millidegree Celsius 355 Unit: millidegree Celsius
356 Must be reported as an absolute temperature, NOT a delta 356 Must be reported as an absolute temperature, NOT a delta
357 from the emergency value. 357 from the emergency value.
358 RW 358 RW
359 359
360 temp[1-*]_lcrit Temperature critical min value, typically lower than 360 temp[1-*]_lcrit Temperature critical min value, typically lower than
361 corresponding temp_min values. 361 corresponding temp_min values.
362 Unit: millidegree Celsius 362 Unit: millidegree Celsius
363 RW 363 RW
364 364
365 temp[1-*]_offset 365 temp[1-*]_offset
366 Temperature offset which is added to the temperature reading 366 Temperature offset which is added to the temperature reading
367 by the chip. 367 by the chip.
368 Unit: millidegree Celsius 368 Unit: millidegree Celsius
369 Read/Write value. 369 Read/Write value.
370 370
371 temp[1-*]_label Suggested temperature channel label. 371 temp[1-*]_label Suggested temperature channel label.
372 Text string 372 Text string
373 Should only be created if the driver has hints about what 373 Should only be created if the driver has hints about what
374 this temperature channel is being used for, and user-space 374 this temperature channel is being used for, and user-space
375 doesn't. In all other cases, the label is provided by 375 doesn't. In all other cases, the label is provided by
376 user-space. 376 user-space.
377 RO 377 RO
378 378
379 temp[1-*]_lowest 379 temp[1-*]_lowest
380 Historical minimum temperature 380 Historical minimum temperature
381 Unit: millidegree Celsius 381 Unit: millidegree Celsius
382 RO 382 RO
383 383
384 temp[1-*]_highest 384 temp[1-*]_highest
385 Historical maximum temperature 385 Historical maximum temperature
386 Unit: millidegree Celsius 386 Unit: millidegree Celsius
387 RO 387 RO
388 388
389 temp[1-*]_reset_history 389 temp[1-*]_reset_history
390 Reset temp_lowest and temp_highest 390 Reset temp_lowest and temp_highest
391 WO 391 WO
392 392
393 temp_reset_history 393 temp_reset_history
394 Reset temp_lowest and temp_highest for all sensors 394 Reset temp_lowest and temp_highest for all sensors
395 WO 395 WO
396 396
397 Some chips measure temperature using external thermistors and an ADC, and 397 Some chips measure temperature using external thermistors and an ADC, and
398 report the temperature measurement as a voltage. Converting this voltage 398 report the temperature measurement as a voltage. Converting this voltage
399 back to a temperature (or the other way around for limits) requires 399 back to a temperature (or the other way around for limits) requires
400 mathematical functions not available in the kernel, so the conversion 400 mathematical functions not available in the kernel, so the conversion
401 must occur in user space. For these chips, all temp* files described 401 must occur in user space. For these chips, all temp* files described
402 above should contain values expressed in millivolt instead of millidegree 402 above should contain values expressed in millivolt instead of millidegree
403 Celsius. In other words, such temperature channels are handled as voltage 403 Celsius. In other words, such temperature channels are handled as voltage
404 channels by the driver. 404 channels by the driver.
405 405
406 Also see the Alarms section for status flags associated with temperatures. 406 Also see the Alarms section for status flags associated with temperatures.
407 407
408 408
409 ************ 409 ************
410 * Currents * 410 * Currents *
411 ************ 411 ************
412 412
413 curr[1-*]_max Current max value 413 curr[1-*]_max Current max value
414 Unit: milliampere 414 Unit: milliampere
415 RW 415 RW
416 416
417 curr[1-*]_min Current min value. 417 curr[1-*]_min Current min value.
418 Unit: milliampere 418 Unit: milliampere
419 RW 419 RW
420 420
421 curr[1-*]_lcrit Current critical low value 421 curr[1-*]_lcrit Current critical low value
422 Unit: milliampere 422 Unit: milliampere
423 RW 423 RW
424 424
425 curr[1-*]_crit Current critical high value. 425 curr[1-*]_crit Current critical high value.
426 Unit: milliampere 426 Unit: milliampere
427 RW 427 RW
428 428
429 curr[1-*]_input Current input value 429 curr[1-*]_input Current input value
430 Unit: milliampere 430 Unit: milliampere
431 RO 431 RO
432 432
433 curr[1-*]_average 433 curr[1-*]_average
434 Average current use 434 Average current use
435 Unit: milliampere 435 Unit: milliampere
436 RO 436 RO
437 437
438 curr[1-*]_lowest 438 curr[1-*]_lowest
439 Historical minimum current 439 Historical minimum current
440 Unit: milliampere 440 Unit: milliampere
441 RO 441 RO
442 442
443 curr[1-*]_highest 443 curr[1-*]_highest
444 Historical maximum current 444 Historical maximum current
445 Unit: milliampere 445 Unit: milliampere
446 RO 446 RO
447 447
448 curr[1-*]_reset_history 448 curr[1-*]_reset_history
449 Reset currX_lowest and currX_highest 449 Reset currX_lowest and currX_highest
450 WO 450 WO
451 451
452 curr_reset_history 452 curr_reset_history
453 Reset currX_lowest and currX_highest for all sensors 453 Reset currX_lowest and currX_highest for all sensors
454 WO 454 WO
455 455
456 Also see the Alarms section for status flags associated with currents. 456 Also see the Alarms section for status flags associated with currents.
457 457
458 ********* 458 *********
459 * Power * 459 * Power *
460 ********* 460 *********
461 461
462 power[1-*]_average Average power use 462 power[1-*]_average Average power use
463 Unit: microWatt 463 Unit: microWatt
464 RO 464 RO
465 465
466 power[1-*]_average_interval Power use averaging interval. A poll 466 power[1-*]_average_interval Power use averaging interval. A poll
467 notification is sent to this file if the 467 notification is sent to this file if the
468 hardware changes the averaging interval. 468 hardware changes the averaging interval.
469 Unit: milliseconds 469 Unit: milliseconds
470 RW 470 RW
471 471
472 power[1-*]_average_interval_max Maximum power use averaging interval 472 power[1-*]_average_interval_max Maximum power use averaging interval
473 Unit: milliseconds 473 Unit: milliseconds
474 RO 474 RO
475 475
476 power[1-*]_average_interval_min Minimum power use averaging interval 476 power[1-*]_average_interval_min Minimum power use averaging interval
477 Unit: milliseconds 477 Unit: milliseconds
478 RO 478 RO
479 479
480 power[1-*]_average_highest Historical average maximum power use 480 power[1-*]_average_highest Historical average maximum power use
481 Unit: microWatt 481 Unit: microWatt
482 RO 482 RO
483 483
484 power[1-*]_average_lowest Historical average minimum power use 484 power[1-*]_average_lowest Historical average minimum power use
485 Unit: microWatt 485 Unit: microWatt
486 RO 486 RO
487 487
488 power[1-*]_average_max A poll notification is sent to 488 power[1-*]_average_max A poll notification is sent to
489 power[1-*]_average when power use 489 power[1-*]_average when power use
490 rises above this value. 490 rises above this value.
491 Unit: microWatt 491 Unit: microWatt
492 RW 492 RW
493 493
494 power[1-*]_average_min A poll notification is sent to 494 power[1-*]_average_min A poll notification is sent to
495 power[1-*]_average when power use 495 power[1-*]_average when power use
496 sinks below this value. 496 sinks below this value.
497 Unit: microWatt 497 Unit: microWatt
498 RW 498 RW
499 499
500 power[1-*]_input Instantaneous power use 500 power[1-*]_input Instantaneous power use
501 Unit: microWatt 501 Unit: microWatt
502 RO 502 RO
503 503
504 power[1-*]_input_highest Historical maximum power use 504 power[1-*]_input_highest Historical maximum power use
505 Unit: microWatt 505 Unit: microWatt
506 RO 506 RO
507 507
508 power[1-*]_input_lowest Historical minimum power use 508 power[1-*]_input_lowest Historical minimum power use
509 Unit: microWatt 509 Unit: microWatt
510 RO 510 RO
511 511
512 power[1-*]_reset_history Reset input_highest, input_lowest, 512 power[1-*]_reset_history Reset input_highest, input_lowest,
513 average_highest and average_lowest. 513 average_highest and average_lowest.
514 WO 514 WO
515 515
516 power[1-*]_accuracy Accuracy of the power meter. 516 power[1-*]_accuracy Accuracy of the power meter.
517 Unit: Percent 517 Unit: Percent
518 RO 518 RO
519 519
520 power[1-*]_cap If power use rises above this limit, the 520 power[1-*]_cap If power use rises above this limit, the
521 system should take action to reduce power use. 521 system should take action to reduce power use.
522 A poll notification is sent to this file if the 522 A poll notification is sent to this file if the
523 cap is changed by the hardware. The *_cap 523 cap is changed by the hardware. The *_cap
524 files only appear if the cap is known to be 524 files only appear if the cap is known to be
525 enforced by hardware. 525 enforced by hardware.
526 Unit: microWatt 526 Unit: microWatt
527 RW 527 RW
528 528
529 power[1-*]_cap_hyst Margin of hysteresis built around capping and 529 power[1-*]_cap_hyst Margin of hysteresis built around capping and
530 notification. 530 notification.
531 Unit: microWatt 531 Unit: microWatt
532 RW 532 RW
533 533
534 power[1-*]_cap_max Maximum cap that can be set. 534 power[1-*]_cap_max Maximum cap that can be set.
535 Unit: microWatt 535 Unit: microWatt
536 RO 536 RO
537 537
538 power[1-*]_cap_min Minimum cap that can be set. 538 power[1-*]_cap_min Minimum cap that can be set.
539 Unit: microWatt 539 Unit: microWatt
540 RO 540 RO
541 541
542 power[1-*]_max Maximum power. 542 power[1-*]_max Maximum power.
543 Unit: microWatt 543 Unit: microWatt
544 RW 544 RW
545 545
546 power[1-*]_crit Critical maximum power. 546 power[1-*]_crit Critical maximum power.
547 If power rises to or above this limit, the 547 If power rises to or above this limit, the
548 system is expected take drastic action to reduce 548 system is expected take drastic action to reduce
549 power consumption, such as a system shutdown or 549 power consumption, such as a system shutdown or
550 a forced powerdown of some devices. 550 a forced powerdown of some devices.
551 Unit: microWatt 551 Unit: microWatt
552 RW 552 RW
553 553
554 Also see the Alarms section for status flags associated with power readings. 554 Also see the Alarms section for status flags associated with power readings.
555 555
556 ********** 556 **********
557 * Energy * 557 * Energy *
558 ********** 558 **********
559 559
560 energy[1-*]_input Cumulative energy use 560 energy[1-*]_input Cumulative energy use
561 Unit: microJoule 561 Unit: microJoule
562 RO 562 RO
563 563
564 564
565 ************ 565 ************
566 * Humidity * 566 * Humidity *
567 ************ 567 ************
568 568
569 humidity[1-*]_input Humidity 569 humidity[1-*]_input Humidity
570 Unit: milli-percent (per cent mille, pcm) 570 Unit: milli-percent (per cent mille, pcm)
571 RO 571 RO
572 572
573 573
574 ********** 574 **********
575 * Alarms * 575 * Alarms *
576 ********** 576 **********
577 577
578 Each channel or limit may have an associated alarm file, containing a 578 Each channel or limit may have an associated alarm file, containing a
579 boolean value. 1 means than an alarm condition exists, 0 means no alarm. 579 boolean value. 1 means than an alarm condition exists, 0 means no alarm.
580 580
581 Usually a given chip will either use channel-related alarms, or 581 Usually a given chip will either use channel-related alarms, or
582 limit-related alarms, not both. The driver should just reflect the hardware 582 limit-related alarms, not both. The driver should just reflect the hardware
583 implementation. 583 implementation.
584 584
585 in[0-*]_alarm 585 in[0-*]_alarm
586 curr[1-*]_alarm 586 curr[1-*]_alarm
587 power[1-*]_alarm 587 power[1-*]_alarm
588 fan[1-*]_alarm 588 fan[1-*]_alarm
589 temp[1-*]_alarm 589 temp[1-*]_alarm
590 Channel alarm 590 Channel alarm
591 0: no alarm 591 0: no alarm
592 1: alarm 592 1: alarm
593 RO 593 RO
594 594
595 OR 595 OR
596 596
597 in[0-*]_min_alarm 597 in[0-*]_min_alarm
598 in[0-*]_max_alarm 598 in[0-*]_max_alarm
599 in[0-*]_lcrit_alarm 599 in[0-*]_lcrit_alarm
600 in[0-*]_crit_alarm 600 in[0-*]_crit_alarm
601 curr[1-*]_min_alarm 601 curr[1-*]_min_alarm
602 curr[1-*]_max_alarm 602 curr[1-*]_max_alarm
603 curr[1-*]_lcrit_alarm 603 curr[1-*]_lcrit_alarm
604 curr[1-*]_crit_alarm 604 curr[1-*]_crit_alarm
605 power[1-*]_cap_alarm 605 power[1-*]_cap_alarm
606 power[1-*]_max_alarm 606 power[1-*]_max_alarm
607 power[1-*]_crit_alarm 607 power[1-*]_crit_alarm
608 fan[1-*]_min_alarm 608 fan[1-*]_min_alarm
609 fan[1-*]_max_alarm 609 fan[1-*]_max_alarm
610 temp[1-*]_min_alarm 610 temp[1-*]_min_alarm
611 temp[1-*]_max_alarm 611 temp[1-*]_max_alarm
612 temp[1-*]_lcrit_alarm 612 temp[1-*]_lcrit_alarm
613 temp[1-*]_crit_alarm 613 temp[1-*]_crit_alarm
614 temp[1-*]_emergency_alarm 614 temp[1-*]_emergency_alarm
615 Limit alarm 615 Limit alarm
616 0: no alarm 616 0: no alarm
617 1: alarm 617 1: alarm
618 RO 618 RO
619 619
620 Each input channel may have an associated fault file. This can be used 620 Each input channel may have an associated fault file. This can be used
621 to notify open diodes, unconnected fans etc. where the hardware 621 to notify open diodes, unconnected fans etc. where the hardware
622 supports it. When this boolean has value 1, the measurement for that 622 supports it. When this boolean has value 1, the measurement for that
623 channel should not be trusted. 623 channel should not be trusted.
624 624
625 fan[1-*]_fault 625 fan[1-*]_fault
626 temp[1-*]_fault 626 temp[1-*]_fault
627 Input fault condition 627 Input fault condition
628 0: no fault occurred 628 0: no fault occurred
629 1: fault condition 629 1: fault condition
630 RO 630 RO
631 631
632 Some chips also offer the possibility to get beeped when an alarm occurs: 632 Some chips also offer the possibility to get beeped when an alarm occurs:
633 633
634 beep_enable Master beep enable 634 beep_enable Master beep enable
635 0: no beeps 635 0: no beeps
636 1: beeps 636 1: beeps
637 RW 637 RW
638 638
639 in[0-*]_beep 639 in[0-*]_beep
640 curr[1-*]_beep 640 curr[1-*]_beep
641 fan[1-*]_beep 641 fan[1-*]_beep
642 temp[1-*]_beep 642 temp[1-*]_beep
643 Channel beep 643 Channel beep
644 0: disable 644 0: disable
645 1: enable 645 1: enable
646 RW 646 RW
647 647
648 In theory, a chip could provide per-limit beep masking, but no such chip 648 In theory, a chip could provide per-limit beep masking, but no such chip
649 was seen so far. 649 was seen so far.
650 650
651 Old drivers provided a different, non-standard interface to alarms and 651 Old drivers provided a different, non-standard interface to alarms and
652 beeps. These interface files are deprecated, but will be kept around 652 beeps. These interface files are deprecated, but will be kept around
653 for compatibility reasons: 653 for compatibility reasons:
654 654
655 alarms Alarm bitmask. 655 alarms Alarm bitmask.
656 RO 656 RO
657 Integer representation of one to four bytes. 657 Integer representation of one to four bytes.
658 A '1' bit means an alarm. 658 A '1' bit means an alarm.
659 Chips should be programmed for 'comparator' mode so that 659 Chips should be programmed for 'comparator' mode so that
660 the alarm will 'come back' after you read the register 660 the alarm will 'come back' after you read the register
661 if it is still valid. 661 if it is still valid.
662 Generally a direct representation of a chip's internal 662 Generally a direct representation of a chip's internal
663 alarm registers; there is no standard for the position 663 alarm registers; there is no standard for the position
664 of individual bits. For this reason, the use of this 664 of individual bits. For this reason, the use of this
665 interface file for new drivers is discouraged. Use 665 interface file for new drivers is discouraged. Use
666 individual *_alarm and *_fault files instead. 666 individual *_alarm and *_fault files instead.
667 Bits are defined in kernel/include/sensors.h. 667 Bits are defined in kernel/include/sensors.h.
668 668
669 beep_mask Bitmask for beep. 669 beep_mask Bitmask for beep.
670 Same format as 'alarms' with the same bit locations, 670 Same format as 'alarms' with the same bit locations,
671 use discouraged for the same reason. Use individual 671 use discouraged for the same reason. Use individual
672 *_beep files instead. 672 *_beep files instead.
673 RW 673 RW
674 674
675 675
676 *********************** 676 ***********************
677 * Intrusion detection * 677 * Intrusion detection *
678 *********************** 678 ***********************
679 679
680 intrusion[0-*]_alarm 680 intrusion[0-*]_alarm
681 Chassis intrusion detection 681 Chassis intrusion detection
682 0: OK 682 0: OK
683 1: intrusion detected 683 1: intrusion detected
684 RW 684 RW
685 Contrary to regular alarm flags which clear themselves 685 Contrary to regular alarm flags which clear themselves
686 automatically when read, this one sticks until cleared by 686 automatically when read, this one sticks until cleared by
687 the user. This is done by writing 0 to the file. Writing 687 the user. This is done by writing 0 to the file. Writing
688 other values is unsupported. 688 other values is unsupported.
689 689
690 intrusion[0-*]_beep 690 intrusion[0-*]_beep
691 Chassis intrusion beep 691 Chassis intrusion beep
692 0: disable 692 0: disable
693 1: enable 693 1: enable
694 RW 694 RW
695 695
696 696
697 sysfs attribute writes interpretation 697 sysfs attribute writes interpretation
698 ------------------------------------- 698 -------------------------------------
699 699
700 hwmon sysfs attributes always contain numbers, so the first thing to do is to 700 hwmon sysfs attributes always contain numbers, so the first thing to do is to
701 convert the input to a number, there are 2 ways todo this depending whether 701 convert the input to a number, there are 2 ways todo this depending whether
702 the number can be negative or not: 702 the number can be negative or not:
703 unsigned long u = simple_strtoul(buf, NULL, 10); 703 unsigned long u = simple_strtoul(buf, NULL, 10);
704 long s = simple_strtol(buf, NULL, 10); 704 long s = simple_strtol(buf, NULL, 10);
705 705
706 With buf being the buffer with the user input being passed by the kernel. 706 With buf being the buffer with the user input being passed by the kernel.
707 Notice that we do not use the second argument of strto[u]l, and thus cannot 707 Notice that we do not use the second argument of strto[u]l, and thus cannot
708 tell when 0 is returned, if this was really 0 or is caused by invalid input. 708 tell when 0 is returned, if this was really 0 or is caused by invalid input.
709 This is done deliberately as checking this everywhere would add a lot of 709 This is done deliberately as checking this everywhere would add a lot of
710 code to the kernel. 710 code to the kernel.
711 711
712 Notice that it is important to always store the converted value in an 712 Notice that it is important to always store the converted value in an
713 unsigned long or long, so that no wrap around can happen before any further 713 unsigned long or long, so that no wrap around can happen before any further
714 checking. 714 checking.
715 715
716 After the input string is converted to an (unsigned) long, the value should be 716 After the input string is converted to an (unsigned) long, the value should be
717 checked if its acceptable. Be careful with further conversions on the value 717 checked if its acceptable. Be careful with further conversions on the value
718 before checking it for validity, as these conversions could still cause a wrap 718 before checking it for validity, as these conversions could still cause a wrap
719 around before the check. For example do not multiply the result, and only 719 around before the check. For example do not multiply the result, and only
720 add/subtract if it has been divided before the add/subtract. 720 add/subtract if it has been divided before the add/subtract.
721 721
722 What to do if a value is found to be invalid, depends on the type of the 722 What to do if a value is found to be invalid, depends on the type of the
723 sysfs attribute that is being set. If it is a continuous setting like a 723 sysfs attribute that is being set. If it is a continuous setting like a
724 tempX_max or inX_max attribute, then the value should be clamped to its 724 tempX_max or inX_max attribute, then the value should be clamped to its
725 limits using SENSORS_LIMIT(value, min_limit, max_limit). If it is not 725 limits using SENSORS_LIMIT(value, min_limit, max_limit). If it is not
726 continuous like for example a tempX_type, then when an invalid value is 726 continuous like for example a tempX_type, then when an invalid value is
727 written, -EINVAL should be returned. 727 written, -EINVAL should be returned.
728 728
729 Example1, temp1_max, register is a signed 8 bit value (-128 - 127 degrees): 729 Example1, temp1_max, register is a signed 8 bit value (-128 - 127 degrees):
730 730
731 long v = simple_strtol(buf, NULL, 10) / 1000; 731 long v = simple_strtol(buf, NULL, 10) / 1000;
732 v = SENSORS_LIMIT(v, -128, 127); 732 v = SENSORS_LIMIT(v, -128, 127);
733 /* write v to register */ 733 /* write v to register */
734 734
735 Example2, fan divider setting, valid values 2, 4 and 8: 735 Example2, fan divider setting, valid values 2, 4 and 8:
736 736
737 unsigned long v = simple_strtoul(buf, NULL, 10); 737 unsigned long v = simple_strtoul(buf, NULL, 10);
738 738
739 switch (v) { 739 switch (v) {
740 case 2: v = 1; break; 740 case 2: v = 1; break;
741 case 4: v = 2; break; 741 case 4: v = 2; break;
742 case 8: v = 3; break; 742 case 8: v = 3; break;
743 default: 743 default:
744 return -EINVAL; 744 return -EINVAL;
745 } 745 }
746 /* write v to register */ 746 /* write v to register */
747 747