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Diffstat (limited to 'Documentation/hwmon/sysfs-interface')
| -rw-r--r-- | Documentation/hwmon/sysfs-interface | 731 |
1 files changed, 495 insertions, 236 deletions
diff --git a/Documentation/hwmon/sysfs-interface b/Documentation/hwmon/sysfs-interface index 7b91706d01c8..fd590633bb14 100644 --- a/Documentation/hwmon/sysfs-interface +++ b/Documentation/hwmon/sysfs-interface @@ -1,5 +1,5 @@ Naming and data format standards for sysfs files ------------------------------------------------- +================================================ The libsensors library offers an interface to the raw sensors data through the sysfs interface. Since lm-sensors 3.0.0, libsensors is @@ -32,7 +32,7 @@ this reason, it is still not recommended to bypass the library. Each chip gets its own directory in the sysfs /sys/devices tree. To find all sensor chips, it is easier to follow the device symlinks from -/sys/class/hwmon/hwmon*. +`/sys/class/hwmon/hwmon*`. Up to lm-sensors 3.0.0, libsensors looks for hardware monitoring attributes in the "physical" device directory. Since lm-sensors 3.0.1, attributes found @@ -67,11 +67,13 @@ are interpreted as 0! For more on how written strings are interpreted see the ------------------------------------------------------------------------- -[0-*] denotes any positive number starting from 0 -[1-*] denotes any positive number starting from 1 +======= =========================================== +`[0-*]` denotes any positive number starting from 0 +`[1-*]` denotes any positive number starting from 1 RO read only value WO write only value RW read/write value +======= =========================================== Read/write values may be read-only for some chips, depending on the hardware implementation. @@ -80,57 +82,82 @@ All entries (except name) are optional, and should only be created in a given driver if the chip has the feature. -********************* -* Global attributes * -********************* +***************** +Global attributes +***************** -name The chip name. +`name` + The chip name. This should be a short, lowercase string, not containing whitespace, dashes, or the wildcard character '*'. This attribute represents the chip name. It is the only mandatory attribute. I2C devices get this attribute created automatically. + RO -update_interval The interval at which the chip will update readings. +`update_interval` + The interval at which the chip will update readings. Unit: millisecond + RW + Some devices have a variable update rate or interval. This attribute can be used to change it to the desired value. -************ -* Voltages * -************ +******** +Voltages +******** + +`in[0-*]_min` + Voltage min value. -in[0-*]_min Voltage min value. Unit: millivolt + RW - -in[0-*]_lcrit Voltage critical min value. + +`in[0-*]_lcrit` + Voltage critical min value. + Unit: millivolt + RW + If voltage drops to or below this limit, the system may take drastic action such as power down or reset. At the very least, it should report a fault. -in[0-*]_max Voltage max value. +`in[0-*]_max` + Voltage max value. + Unit: millivolt + RW - -in[0-*]_crit Voltage critical max value. + +`in[0-*]_crit` + Voltage critical max value. + Unit: millivolt + RW + If voltage reaches or exceeds this limit, the system may take drastic action such as power down or reset. At the very least, it should report a fault. -in[0-*]_input Voltage input value. +`in[0-*]_input` + Voltage input value. + Unit: millivolt + RO + Voltage measured on the chip pin. + Actual voltage depends on the scaling resistors on the motherboard, as recommended in the chip datasheet. + This varies by chip and by motherboard. Because of this variation, values are generally NOT scaled by the chip driver, and must be done by the application. @@ -140,166 +167,232 @@ in[0-*]_input Voltage input value. thumb: drivers should report the voltage values at the "pins" of the chip. -in[0-*]_average +`in[0-*]_average` Average voltage + Unit: millivolt + RO -in[0-*]_lowest +`in[0-*]_lowest` Historical minimum voltage + Unit: millivolt + RO -in[0-*]_highest +`in[0-*]_highest` Historical maximum voltage + Unit: millivolt + RO -in[0-*]_reset_history +`in[0-*]_reset_history` Reset inX_lowest and inX_highest + WO -in_reset_history +`in_reset_history` Reset inX_lowest and inX_highest for all sensors + WO -in[0-*]_label Suggested voltage channel label. +`in[0-*]_label` + Suggested voltage channel label. + Text string + Should only be created if the driver has hints about what this voltage channel is being used for, and user-space doesn't. In all other cases, the label is provided by user-space. + RO -in[0-*]_enable +`in[0-*]_enable` Enable or disable the sensors. + When disabled the sensor read will return -ENODATA. - 1: Enable - 0: Disable + + - 1: Enable + - 0: Disable + RW -cpu[0-*]_vid CPU core reference voltage. +`cpu[0-*]_vid` + CPU core reference voltage. + Unit: millivolt + RO + Not always correct. -vrm Voltage Regulator Module version number. +`vrm` + Voltage Regulator Module version number. + RW (but changing it should no more be necessary) + Originally the VRM standard version multiplied by 10, but now an arbitrary number, as not all standards have a version number. + Affects the way the driver calculates the CPU core reference voltage from the vid pins. Also see the Alarms section for status flags associated with voltages. -******** -* Fans * -******** +**** +Fans +**** + +`fan[1-*]_min` + Fan minimum value -fan[1-*]_min Fan minimum value Unit: revolution/min (RPM) + RW -fan[1-*]_max Fan maximum value +`fan[1-*]_max` + Fan maximum value + Unit: revolution/min (RPM) + Only rarely supported by the hardware. RW -fan[1-*]_input Fan input value. +`fan[1-*]_input` + Fan input value. + Unit: revolution/min (RPM) + RO -fan[1-*]_div Fan divisor. +`fan[1-*]_div` + Fan divisor. + Integer value in powers of two (1, 2, 4, 8, 16, 32, 64, 128). + RW + Some chips only support values 1, 2, 4 and 8. Note that this is actually an internal clock divisor, which affects the measurable speed range, not the read value. -fan[1-*]_pulses Number of tachometer pulses per fan revolution. +`fan[1-*]_pulses` + Number of tachometer pulses per fan revolution. + Integer value, typically between 1 and 4. + RW + This value is a characteristic of the fan connected to the device's input, so it has to be set in accordance with the fan model. + Should only be created if the chip has a register to configure the number of pulses. In the absence of such a register (and thus attribute) the value assumed by all devices is 2 pulses per fan revolution. -fan[1-*]_target +`fan[1-*]_target` Desired fan speed + Unit: revolution/min (RPM) + RW + Only makes sense if the chip supports closed-loop fan speed control based on the measured fan speed. -fan[1-*]_label Suggested fan channel label. +`fan[1-*]_label` + Suggested fan channel label. + Text string + Should only be created if the driver has hints about what this fan channel is being used for, and user-space doesn't. In all other cases, the label is provided by user-space. + RO -fan[1-*]_enable +`fan[1-*]_enable` Enable or disable the sensors. + When disabled the sensor read will return -ENODATA. - 1: Enable - 0: Disable + + - 1: Enable + - 0: Disable + RW Also see the Alarms section for status flags associated with fans. -******* -* PWM * -******* +*** +PWM +*** + +`pwm[1-*]` + Pulse width modulation fan control. -pwm[1-*] Pulse width modulation fan control. Integer value in the range 0 to 255 + RW + 255 is max or 100%. -pwm[1-*]_enable +`pwm[1-*]_enable` Fan speed control method: - 0: no fan speed control (i.e. fan at full speed) - 1: manual fan speed control enabled (using pwm[1-*]) - 2+: automatic fan speed control enabled + + - 0: no fan speed control (i.e. fan at full speed) + - 1: manual fan speed control enabled (using `pwm[1-*]`) + - 2+: automatic fan speed control enabled + Check individual chip documentation files for automatic mode details. + RW -pwm[1-*]_mode 0: DC mode (direct current) - 1: PWM mode (pulse-width modulation) +`pwm[1-*]_mode` + - 0: DC mode (direct current) + - 1: PWM mode (pulse-width modulation) + RW -pwm[1-*]_freq Base PWM frequency in Hz. +`pwm[1-*]_freq` + Base PWM frequency in Hz. + Only possibly available when pwmN_mode is PWM, but not always present even then. + RW -pwm[1-*]_auto_channels_temp +`pwm[1-*]_auto_channels_temp` Select which temperature channels affect this PWM output in - auto mode. Bitfield, 1 is temp1, 2 is temp2, 4 is temp3 etc... + auto mode. + + Bitfield, 1 is temp1, 2 is temp2, 4 is temp3 etc... Which values are possible depend on the chip used. + RW -pwm[1-*]_auto_point[1-*]_pwm -pwm[1-*]_auto_point[1-*]_temp -pwm[1-*]_auto_point[1-*]_temp_hyst - Define the PWM vs temperature curve. Number of trip points is - chip-dependent. Use this for chips which associate trip points - to PWM output channels. +`pwm[1-*]_auto_point[1-*]_pwm` / `pwm[1-*]_auto_point[1-*]_temp` / `pwm[1-*]_auto_point[1-*]_temp_hyst` + Define the PWM vs temperature curve. + + Number of trip points is chip-dependent. Use this for chips + which associate trip points to PWM output channels. + RW -temp[1-*]_auto_point[1-*]_pwm -temp[1-*]_auto_point[1-*]_temp -temp[1-*]_auto_point[1-*]_temp_hyst - Define the PWM vs temperature curve. Number of trip points is - chip-dependent. Use this for chips which associate trip points - to temperature channels. +`temp[1-*]_auto_point[1-*]_pwm` / `temp[1-*]_auto_point[1-*]_temp` / `temp[1-*]_auto_point[1-*]_temp_hyst` + Define the PWM vs temperature curve. + + Number of trip points is chip-dependent. Use this for chips + which associate trip points to temperature channels. + RW There is a third case where trip points are associated to both PWM output @@ -312,122 +405,173 @@ The actual result is up to the chip, but in general the highest candidate value (fastest fan speed) wins. -**************** -* Temperatures * -**************** +************ +Temperatures +************ + +`temp[1-*]_type` + Sensor type selection. -temp[1-*]_type Sensor type selection. Integers 1 to 6 + RW - 1: CPU embedded diode - 2: 3904 transistor - 3: thermal diode - 4: thermistor - 5: AMD AMDSI - 6: Intel PECI + + - 1: CPU embedded diode + - 2: 3904 transistor + - 3: thermal diode + - 4: thermistor + - 5: AMD AMDSI + - 6: Intel PECI + Not all types are supported by all chips -temp[1-*]_max Temperature max value. +`temp[1-*]_max` + Temperature max value. + Unit: millidegree Celsius (or millivolt, see below) + RW -temp[1-*]_min Temperature min value. +`temp[1-*]_min` + Temperature min value. + Unit: millidegree Celsius + RW -temp[1-*]_max_hyst +`temp[1-*]_max_hyst` Temperature hysteresis value for max limit. + Unit: millidegree Celsius + Must be reported as an absolute temperature, NOT a delta from the max value. + RW -temp[1-*]_min_hyst +`temp[1-*]_min_hyst` Temperature hysteresis value for min limit. Unit: millidegree Celsius + Must be reported as an absolute temperature, NOT a delta from the min value. + RW -temp[1-*]_input Temperature input value. +`temp[1-*]_input` + Temperature input value. + Unit: millidegree Celsius + RO -temp[1-*]_crit Temperature critical max value, typically greater than +`temp[1-*]_crit` + Temperature critical max value, typically greater than corresponding temp_max values. + Unit: millidegree Celsius + RW -temp[1-*]_crit_hyst +`temp[1-*]_crit_hyst` Temperature hysteresis value for critical limit. + Unit: millidegree Celsius + Must be reported as an absolute temperature, NOT a delta from the critical value. + RW -temp[1-*]_emergency +`temp[1-*]_emergency` Temperature emergency max value, for chips supporting more than two upper temperature limits. Must be equal or greater than corresponding temp_crit values. + Unit: millidegree Celsius + RW -temp[1-*]_emergency_hyst +`temp[1-*]_emergency_hyst` Temperature hysteresis value for emergency limit. + Unit: millidegree Celsius + Must be reported as an absolute temperature, NOT a delta from the emergency value. + RW -temp[1-*]_lcrit Temperature critical min value, typically lower than +`temp[1-*]_lcrit` + Temperature critical min value, typically lower than corresponding temp_min values. + Unit: millidegree Celsius + RW -temp[1-*]_lcrit_hyst +`temp[1-*]_lcrit_hyst` Temperature hysteresis value for critical min limit. + Unit: millidegree Celsius + Must be reported as an absolute temperature, NOT a delta from the critical min value. + RW -temp[1-*]_offset +`temp[1-*]_offset` Temperature offset which is added to the temperature reading by the chip. + Unit: millidegree Celsius + Read/Write value. -temp[1-*]_label Suggested temperature channel label. +`temp[1-*]_label` + Suggested temperature channel label. + Text string + Should only be created if the driver has hints about what this temperature channel is being used for, and user-space doesn't. In all other cases, the label is provided by user-space. + RO -temp[1-*]_lowest +`temp[1-*]_lowest` Historical minimum temperature + Unit: millidegree Celsius + RO -temp[1-*]_highest +`temp[1-*]_highest` Historical maximum temperature + Unit: millidegree Celsius + RO -temp[1-*]_reset_history +`temp[1-*]_reset_history` Reset temp_lowest and temp_highest + WO -temp_reset_history +`temp_reset_history` Reset temp_lowest and temp_highest for all sensors + WO -temp[1-*]_enable +`temp[1-*]_enable` Enable or disable the sensors. + When disabled the sensor read will return -ENODATA. - 1: Enable - 0: Disable + + - 1: Enable + - 0: Disable + RW Some chips measure temperature using external thermistors and an ADC, and @@ -442,201 +586,300 @@ channels by the driver. Also see the Alarms section for status flags associated with temperatures. -************ -* Currents * -************ +******** +Currents +******** + +`curr[1-*]_max` + Current max value -curr[1-*]_max Current max value Unit: milliampere + RW -curr[1-*]_min Current min value. +`curr[1-*]_min` + Current min value. + Unit: milliampere + RW -curr[1-*]_lcrit Current critical low value +`curr[1-*]_lcrit` + Current critical low value + Unit: milliampere + RW -curr[1-*]_crit Current critical high value. +`curr[1-*]_crit` + Current critical high value. + Unit: milliampere + RW -curr[1-*]_input Current input value +`curr[1-*]_input` + Current input value + Unit: milliampere + RO -curr[1-*]_average +`curr[1-*]_average` Average current use + Unit: milliampere + RO -curr[1-*]_lowest +`curr[1-*]_lowest` Historical minimum current + Unit: milliampere + RO -curr[1-*]_highest +`curr[1-*]_highest` Historical maximum current Unit: milliampere RO -curr[1-*]_reset_history +`curr[1-*]_reset_history` Reset currX_lowest and currX_highest + WO -curr_reset_history +`curr_reset_history` Reset currX_lowest and currX_highest for all sensors + WO -curr[1-*]_enable +`curr[1-*]_enable` Enable or disable the sensors. + When disabled the sensor read will return -ENODATA. - 1: Enable - 0: Disable + + - 1: Enable + - 0: Disable + RW Also see the Alarms section for status flags associated with currents. -********* -* Power * -********* +***** +Power +***** + +`power[1-*]_average` + Average power use -power[1-*]_average Average power use Unit: microWatt + RO -power[1-*]_average_interval Power use averaging interval. A poll +`power[1-*]_average_interval` + Power use averaging interval. A poll notification is sent to this file if the hardware changes the averaging interval. + Unit: milliseconds + RW -power[1-*]_average_interval_max Maximum power use averaging interval +`power[1-*]_average_interval_max` + Maximum power use averaging interval + Unit: milliseconds + RO -power[1-*]_average_interval_min Minimum power use averaging interval +`power[1-*]_average_interval_min` + Minimum power use averaging interval + Unit: milliseconds + RO -power[1-*]_average_highest Historical average maximum power use +`power[1-*]_average_highest` + Historical average maximum power use + Unit: microWatt + RO -power[1-*]_average_lowest Historical average minimum power use +`power[1-*]_average_lowest` + Historical average minimum power use + Unit: microWatt + RO -power[1-*]_average_max A poll notification is sent to - power[1-*]_average when power use +`power[1-*]_average_max` + A poll notification is sent to + `power[1-*]_average` when power use rises above this value. + Unit: microWatt + RW -power[1-*]_average_min A poll notification is sent to - power[1-*]_average when power use +`power[1-*]_average_min` + A poll notification is sent to + `power[1-*]_average` when power use sinks below this value. + Unit: microWatt + RW -power[1-*]_input Instantaneous power use +`power[1-*]_input` + Instantaneous power use + Unit: microWatt + RO -power[1-*]_input_highest Historical maximum power use +`power[1-*]_input_highest` + Historical maximum power use + Unit: microWatt + RO -power[1-*]_input_lowest Historical minimum power use +`power[1-*]_input_lowest` + Historical minimum power use + Unit: microWatt + RO -power[1-*]_reset_history Reset input_highest, input_lowest, +`power[1-*]_reset_history` + Reset input_highest, input_lowest, average_highest and average_lowest. + WO -power[1-*]_accuracy Accuracy of the power meter. +`power[1-*]_accuracy` + Accuracy of the power meter. + Unit: Percent + RO -power[1-*]_cap If power use rises above this limit, the +`power[1-*]_cap` + If power use rises above this limit, the system should take action to reduce power use. A poll notification is sent to this file if the - cap is changed by the hardware. The *_cap + cap is changed by the hardware. The `*_cap` files only appear if the cap is known to be enforced by hardware. + Unit: microWatt + RW -power[1-*]_cap_hyst Margin of hysteresis built around capping and +`power[1-*]_cap_hyst` + Margin of hysteresis built around capping and notification. + Unit: microWatt + RW -power[1-*]_cap_max Maximum cap that can be set. +`power[1-*]_cap_max` + Maximum cap that can be set. + Unit: microWatt + RO -power[1-*]_cap_min Minimum cap that can be set. +`power[1-*]_cap_min` + Minimum cap that can be set. + Unit: microWatt + RO -power[1-*]_max Maximum power. +`power[1-*]_max` + Maximum power. + Unit: microWatt + RW -power[1-*]_crit Critical maximum power. +`power[1-*]_crit` + Critical maximum power. + If power rises to or above this limit, the system is expected take drastic action to reduce power consumption, such as a system shutdown or a forced powerdown of some devices. + Unit: microWatt + RW -power[1-*]_enable Enable or disable the sensors. +`power[1-*]_enable` + Enable or disable the sensors. + When disabled the sensor read will return -ENODATA. - 1: Enable - 0: Disable + + - 1: Enable + - 0: Disable + RW Also see the Alarms section for status flags associated with power readings. -********** -* Energy * -********** +****** +Energy +****** + +`energy[1-*]_input` + Cumulative energy use -energy[1-*]_input Cumulative energy use Unit: microJoule + RO -energy[1-*]_enable Enable or disable the sensors. +`energy[1-*]_enable` + Enable or disable the sensors. + When disabled the sensor read will return -ENODATA. - 1: Enable - 0: Disable + + - 1: Enable + - 0: Disable + RW -************ -* Humidity * -************ +******** +Humidity +******** + +`humidity[1-*]_input` + Humidity -humidity[1-*]_input Humidity Unit: milli-percent (per cent mille, pcm) + RO -humidity[1-*]_enable Enable or disable the sensors +`humidity[1-*]_enable` + Enable or disable the sensors + When disabled the sensor read will return -ENODATA. - 1: Enable - 0: Disable + + - 1: Enable + - 0: Disable + RW -********** -* Alarms * -********** +****** +Alarms +****** Each channel or limit may have an associated alarm file, containing a boolean value. 1 means than an alarm condition exists, 0 means no alarm. @@ -645,67 +888,67 @@ Usually a given chip will either use channel-related alarms, or limit-related alarms, not both. The driver should just reflect the hardware implementation. -in[0-*]_alarm -curr[1-*]_alarm -power[1-*]_alarm -fan[1-*]_alarm -temp[1-*]_alarm - Channel alarm - 0: no alarm - 1: alarm - RO - -OR - -in[0-*]_min_alarm -in[0-*]_max_alarm -in[0-*]_lcrit_alarm -in[0-*]_crit_alarm -curr[1-*]_min_alarm -curr[1-*]_max_alarm -curr[1-*]_lcrit_alarm -curr[1-*]_crit_alarm -power[1-*]_cap_alarm -power[1-*]_max_alarm -power[1-*]_crit_alarm -fan[1-*]_min_alarm -fan[1-*]_max_alarm -temp[1-*]_min_alarm -temp[1-*]_max_alarm -temp[1-*]_lcrit_alarm -temp[1-*]_crit_alarm -temp[1-*]_emergency_alarm - Limit alarm - 0: no alarm - 1: alarm - RO ++-------------------------------+-----------------------+ +| **`in[0-*]_alarm`, | Channel alarm | +| `curr[1-*]_alarm`, | | +| `power[1-*]_alarm`, | - 0: no alarm | +| `fan[1-*]_alarm`, | - 1: alarm | +| `temp[1-*]_alarm`** | | +| | RO | ++-------------------------------+-----------------------+ + +**OR** + ++-------------------------------+-----------------------+ +| **`in[0-*]_min_alarm`, | Limit alarm | +| `in[0-*]_max_alarm`, | | +| `in[0-*]_lcrit_alarm`, | - 0: no alarm | +| `in[0-*]_crit_alarm`, | - 1: alarm | +| `curr[1-*]_min_alarm`, | | +| `curr[1-*]_max_alarm`, | RO | +| `curr[1-*]_lcrit_alarm`, | | +| `curr[1-*]_crit_alarm`, | | +| `power[1-*]_cap_alarm`, | | +| `power[1-*]_max_alarm`, | | +| `power[1-*]_crit_alarm`, | | +| `fan[1-*]_min_alarm`, | | +| `fan[1-*]_max_alarm`, | | +| `temp[1-*]_min_alarm`, | | +| `temp[1-*]_max_alarm`, | | +| `temp[1-*]_lcrit_alarm`, | | +| `temp[1-*]_crit_alarm`, | | +| `temp[1-*]_emergency_alarm`** | | ++-------------------------------+-----------------------+ Each input channel may have an associated fault file. This can be used to notify open diodes, unconnected fans etc. where the hardware supports it. When this boolean has value 1, the measurement for that channel should not be trusted. -fan[1-*]_fault -temp[1-*]_fault +`fan[1-*]_fault` / `temp[1-*]_fault` Input fault condition - 0: no fault occurred - 1: fault condition + + - 0: no fault occurred + - 1: fault condition + RO Some chips also offer the possibility to get beeped when an alarm occurs: -beep_enable Master beep enable - 0: no beeps - 1: beeps +`beep_enable` + Master beep enable + + - 0: no beeps + - 1: beeps + RW -in[0-*]_beep -curr[1-*]_beep -fan[1-*]_beep -temp[1-*]_beep +`in[0-*]_beep`, `curr[1-*]_beep`, `fan[1-*]_beep`, `temp[1-*]_beep`, Channel beep - 0: disable - 1: enable + + - 0: disable + - 1: enable + RW In theory, a chip could provide per-limit beep masking, but no such chip @@ -715,74 +958,90 @@ Old drivers provided a different, non-standard interface to alarms and beeps. These interface files are deprecated, but will be kept around for compatibility reasons: -alarms Alarm bitmask. +`alarms` + Alarm bitmask. + RO + Integer representation of one to four bytes. + A '1' bit means an alarm. + Chips should be programmed for 'comparator' mode so that the alarm will 'come back' after you read the register if it is still valid. + Generally a direct representation of a chip's internal alarm registers; there is no standard for the position of individual bits. For this reason, the use of this interface file for new drivers is discouraged. Use - individual *_alarm and *_fault files instead. + `individual *_alarm` and `*_fault` files instead. Bits are defined in kernel/include/sensors.h. -beep_mask Bitmask for beep. +`beep_mask` + Bitmask for beep. Same format as 'alarms' with the same bit locations, use discouraged for the same reason. Use individual - *_beep files instead. + `*_beep` files instead. RW -*********************** -* Intrusion detection * -*********************** +******************* +Intrusion detection +******************* -intrusion[0-*]_alarm +`intrusion[0-*]_alarm` Chassis intrusion detection - 0: OK - 1: intrusion detected + + - 0: OK + - 1: intrusion detected + RW + Contrary to regular alarm flags which clear themselves automatically when read, this one sticks until cleared by the user. This is done by writing 0 to the file. Writing other values is unsupported. -intrusion[0-*]_beep +`intrusion[0-*]_beep` Chassis intrusion beep + 0: disable 1: enable + RW -******************************** -* Average sample configuration * -******************************** +**************************** +Average sample configuration +**************************** Devices allowing for reading {in,power,curr,temp}_average values may export attributes for controlling number of samples used to compute average. -samples Sets number of average samples for all types of measurements. - RW - -in_samples -power_samples -curr_samples -temp_samples Sets number of average samples for specific type of measurements. - Note that on some devices it won't be possible to set all of them - to different values so changing one might also change some others. - RW - ++--------------+---------------------------------------------------------------+ +| samples | Sets number of average samples for all types of measurements. | +| | | +| | RW | ++--------------+---------------------------------------------------------------+ +| in_samples | Sets number of average samples for specific type of | +| power_samples| measurements. | +| curr_samples | | +| temp_samples | Note that on some devices it won't be possible to set all of | +| | them to different values so changing one might also change | +| | some others. | +| | | +| | RW | ++--------------+---------------------------------------------------------------+ sysfs attribute writes interpretation ------------------------------------- hwmon sysfs attributes always contain numbers, so the first thing to do is to convert the input to a number, there are 2 ways todo this depending whether -the number can be negative or not: -unsigned long u = simple_strtoul(buf, NULL, 10); -long s = simple_strtol(buf, NULL, 10); +the number can be negative or not:: + + unsigned long u = simple_strtoul(buf, NULL, 10); + long s = simple_strtol(buf, NULL, 10); With buf being the buffer with the user input being passed by the kernel. Notice that we do not use the second argument of strto[u]l, and thus cannot @@ -807,13 +1066,13 @@ limits using clamp_val(value, min_limit, max_limit). If it is not continuous like for example a tempX_type, then when an invalid value is written, -EINVAL should be returned. -Example1, temp1_max, register is a signed 8 bit value (-128 - 127 degrees): +Example1, temp1_max, register is a signed 8 bit value (-128 - 127 degrees):: long v = simple_strtol(buf, NULL, 10) / 1000; v = clamp_val(v, -128, 127); /* write v to register */ -Example2, fan divider setting, valid values 2, 4 and 8: +Example2, fan divider setting, valid values 2, 4 and 8:: unsigned long v = simple_strtoul(buf, NULL, 10); |