| What: /sys/bus/iio/devices/device[n] |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Hardware chip or device accessed by on communication port. |
| Corresponds to a grouping of sensor channels. |
| |
| What: /sys/bus/iio/devices/trigger[n] |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| An event driven driver of data capture to an in kernel buffer. |
| May be provided by a device driver that also has an IIO device |
| based on hardware generated events (e.g. data ready) or |
| provided by a separate driver for other hardware (e.g. |
| periodic timer, gpio or high resolution timer). |
| Contains trigger type specific elements. These do not |
| generalize well and hence are not documented in this file. |
| |
| What: /sys/bus/iio/devices/device[n]:buffer |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Link to /sys/class/iio/device[n]/device[n]:buffer. n indicates |
| the device with which this buffer buffer is associated. |
| |
| What: /sys/.../device[n]/name |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Description of the physical chip / device. Typically a part |
| number. |
| |
| What: /sys/.../device[n]/sampling_frequency |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Some devices have internal clocks. This parameter sets the |
| resulting sampling frequency. In many devices this |
| parameter has an effect on input filters etc rather than |
| simply controlling when the input is sampled. As this |
| effects datardy triggers, hardware buffers and the sysfs |
| direct access interfaces, it may be found in any of the |
| relevant directories. If it effects all of the above |
| then it is to be found in the base device directory as here. |
| |
| What: /sys/.../device[n]/sampling_frequency_available |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| When the internal sampling clock can only take a small |
| discrete set of values, this file lists those availale. |
| |
| What: /sys/.../device[n]/in[m][_name]_raw |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Raw (unscaled no bias removal etc) voltage measurement from |
| channel m. name is used in special cases where this does |
| not correspond to externally available input (e.g. supply |
| voltage monitoring in which case the file is in_supply_raw). |
| If the device supports events on this channel then m must be |
| specified (even on named channels) so as to allow the source |
| of event codes to be identified. |
| |
| What: /sys/.../device[n]/in[m][_name]_offset |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| If known for a device, offset to be added to in[m]_raw prior |
| to scaling by in[_name][m]_scale in order to obtain voltage in |
| millivolts. Not present if the offset is always 0 or unknown. |
| If m is not present, then voltage offset applies to all in |
| channels. May be writable if a variable offset is controlled |
| by the device. Note that this is different to calibbias which |
| is for devices that apply offsets to compensate for variation |
| between different instances of the part, typically adjusted by |
| using some hardware supported calibration procedure. |
| |
| What: /sys/.../device[n]/in[m][_name]_offset_available |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| If a small number of discrete offset values are available, this |
| will be a space separated list. If these are independant (but |
| options the same) for individual offsets then m should not be |
| present. |
| |
| What: /sys/.../device[n]/in[m][_name]_offset_[min|max] |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| If a more or less continuous range of voltage offsets are |
| supported then these specify the minimum and maximum. If shared |
| by all in channels then m is not present. |
| |
| What: /sys/.../device[n]/in[m][_name]_calibbias |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Hardware applied calibration offset. (assumed to fix production |
| inaccuracies) |
| |
| What /sys/.../device[n]/in[m][_name]_calibscale |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Hardware applied calibration scale factor. (assumed to fix |
| production inaccuracies) |
| |
| What: /sys/.../device[n]/in[m][_name]_scale |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| If known for a device, scale to be applied to volt[m]_raw post |
| addition of in[_name][m]_offset in order to obtain the measured |
| voltage in millivolts. If shared across all in channels then |
| m is not present. |
| |
| What: /sys/.../device[n]/in[m]-in[o]_raw |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Raw (unscaled) differential voltage measurement equivalent to |
| channel m - channel o where these channel numbers apply to the |
| physically equivalent inputs when non differential readings are |
| separately available. In differential only parts, then all that |
| is required is a consistent labelling. |
| |
| What: /sys/.../device[n]/accel[_x|_y|_z][m]_raw |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Acceleration in direction x, y or z (may be arbitrarily assigned |
| but should match other such assignments on device) |
| channel m (not present if only one accelerometer channel at |
| this orientation). Has all of the equivalent parameters as per |
| in[m]. Units after application of scale and offset are m/s^2. |
| |
| What: /sys/.../device[n]/gyro[_x|_y|_z][m]_raw |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Angular velocity about axis x, y or z (may be arbitrarily |
| assigned) channel m (not present if only one gyroscope at |
| this orientation). |
| Data converted by application of offset then scale to |
| radians per second. Has all the equivalent parameters as |
| per in[m]. |
| |
| What: /sys/.../device[n]/incli[_x|_y|_z][m]_raw |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Inclination raw reading about axis x, y or z (may be arbitarily |
| assigned) channel m (not present if only one inclinometer at |
| this orientation). Data converted by application of offset |
| and scale to Degrees. |
| |
| What: /sys/.../device[n]/magn[_x|_y|_z][m]_raw |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Magnetic field along axis x, y or z (may be arbitrarily |
| assigned) channel m (not present if only one magnetometer |
| at this orientation). Data converted by application of |
| offset then scale to Gauss. Has all the equivalent modifiers |
| as per in[m]. |
| |
| What: /sys/.../device[n]/device[n]:event[m] |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Configuration of which hardware generated events are passed up to |
| userspace. Some of these are a bit complex to generalize so this |
| section is a work in progress. |
| |
| What: /sys/.../device[n]:event[m]/dev |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| major:minor character device numbers for the event line. |
| |
| Taking accel_x0 as an example |
| |
| What: /sys/.../device[n]:event[m]/accel_x0_thresh[_rising|_falling]_en |
| KernelVersion: 2.6.37 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Event generated when accel_x0 passes a threshold in the specfied |
| (_rising|_falling) direction. If the direction is not specified, |
| then either the device will report an event which ever direction |
| a single threshold value is called in (e.g. |
| accel_x0_<raw|input>_thresh_value) or |
| accel_x0_<raw|input>_thresh_rising_value and |
| accel_x0_<raw|input>_thresh_falling_value may take different |
| values, but the device can only enable both thresholds or |
| neither. |
| Note the driver will assume the last p events requested are |
| to be enabled where p is however many it supports (which may |
| vary depending on the exact set requested. So if you want to be |
| sure you have set what you think you have, check the contents of |
| these attributes after everything is configured. Drivers may |
| have to buffer any parameters so that they are consistent when |
| a given event type is enabled a future point (and not those for |
| whatever event was previously enabled). |
| |
| What: /sys/.../accel_x0_<raw|input>_thresh[_rising|_falling]_value |
| KernelVersion: 2.6.37 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Specifies the value of threshold that the device is comparing |
| against for the events enabled by |
| accel_x0_<raw|input>_thresh[_rising|falling]_en. |
| If seperate exist for the two directions, but direction is |
| not specified for this attribute, then a single threshold value |
| applies to both directions. |
| The raw or input element of the name indicates whether the |
| value is in raw device units or in processed units (as _raw |
| and _input do on sysfs direct channel read attributes). |
| |
| What: /sys/.../accel_x0_thresh[_rising|_falling]_meanperiod |
| KernelVersion: 2.6.37 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Period of time (in seconds) over which the raw channel value |
| is averaged before being compared with the threshold set in |
| accel_x0_thresh[_rising|_falling]_meanperiod. If direction is |
| not specified then this mean period applies to both directions. |
| |
| What: /sys/.../accel_x0_thresh[_rising|_falling]_period |
| KernelVersion: 2.6.37 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Period of time (in seconds) for which the threshold must be |
| passed before an event is generated. If direction is not |
| specified then this period applies to both directions. |
| |
| What: /sys/.../device[n]:event[m]/accel_x0_mag[_rising|_falling]_en |
| KernelVersion: 2.6.37 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Similar to accel_x0_thresh[_rising|_falling]_en, but here the |
| magnitude of the channel is compared to the threshold, not its |
| signed value. |
| |
| What: /sys/.../accel_x0_<raw|input>_mag[_rising|_falling]_value |
| KernelVersion: 2.6.37 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| The value to which the magnitude of the channel is compared. |
| |
| What: /sys/.../accel_x0_mag[_rising|_falling]_meanperiod |
| KernelVersion: 2.6.37 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Period of time (in seconds) over which the value of the channel |
| is averaged before being compared to the threshold |
| |
| What: /sys/.../accel_x0_mag[_rising|_falling]_period |
| KernelVersion: 2.6.37 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Period of time (in seconds) for which the condition must be true |
| before an event occurs. |
| |
| What: /sys/.../device[n]:event[m]/accel_x0_roc[_rising|_falling]_en |
| KernelVersion: 2.6.37 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Similar to accel_x0_thresh[_rising|_falling]_en, but here the |
| first differential is compared with the threshold. |
| |
| What: /sys/.../accel_x0_<raw|input>_roc[_rising|_falling]_value |
| KernelVersion: 2.6.37 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| The value to which the first differential of the channel is |
| compared. |
| |
| What: /sys/.../accel_x0_roc[_rising|_falling]_meanperiod |
| KernelVersion: 2.6.37 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Period of time (in seconds) over which the value of the channel |
| is averaged before being compared to the threshold |
| |
| What: /sys/.../accel_x0_roc[_rising|_falling]_period |
| KernelVersion: 2.6.37 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Period of time (in seconds) for which the condition must be true |
| before an event occurs. |
| |
| What: /sys/.../device[n]/device[n]:buffer:event/dev |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Buffer for device n event character device major:minor numbers. |
| |
| What: /sys/.../device[n]/device[n]:buffer:access/dev |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Buffer for device n access character device o major:minor numbers. |
| |
| What: /sys/.../device[n]:buffer/trigger |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| The name of the trigger source being used, as per string given |
| in /sys/class/iio/trigger[n]/name. |
| |
| What: /sys/.../device[n]:buffer/length |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Number of scans contained by the buffer. |
| |
| What: /sys/.../device[n]:buffer/bytes_per_datum |
| KernelVersion: 2.6.37 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Bytes per scan. Due to alignment fun, the scan may be larger |
| than implied directly by the scan_element parameters. |
| |
| What: /sys/.../device[n]:buffer/enable |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Actually start the buffer capture up. Will start trigger |
| if first device and appropriate. |
| |
| What: /sys/.../device[n]:buffer/alignment |
| KernelVersion: 2.6.35 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Minimum data alignment. Scan elements larger than this are |
| aligned to the nearest power of 2 times this. (may not be |
| true in weird hardware buffers that pack data well) |
| |
| What: /sys/.../device[n]/buffer/scan_elements |
| KernelVersion: 2.6.37 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Directory containing interfaces for elements that will be |
| captured for a single triggered sample set in the buffer. |
| |
| What: /sys/.../device[n]/buffer/scan_elements/accel_x0_en |
| KernelVersion: 2.6.37 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Scan element control for triggered data capture. |
| |
| What: /sys/.../device[n]/buffer/scan_elements/accel[_x0]_type |
| KernelVersion: 2.6.37 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| Description of the scan element data storage within the buffer |
| and hence the form in which it is read from userspace. |
| Form is [s|u]bits/storagebits. s or u specifies if signed |
| (2's complement) or unsigned. bits is the number of bits of |
| data and storagebits is the space (after padding) that it |
| occupies in the buffer. Note that some devices will have |
| additional information in the unused bits so to get a clean |
| value, the bits value must be used to mask the buffer output |
| value appropriately. The storagebits value also specifies the |
| data alignment. So s48/64 will be a signed 48 bit integer |
| stored in a 64 bit location aligned to a a64 bit boundary. |
| For other storage combinations this attribute will be extended |
| appropriately. |
| |
| What: /sys/.../device[n]/buffer/scan_elements/accel[_x0]_index |
| KernelVersion: 2.6.37 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| A single positive integer specifying the position of this |
| scan element in the buffer. Note these are not dependant on |
| what is enabled and may not be contiguous. Thus for userspace |
| to establish the full layout these must be used in conjunction |
| with all _en attributes to establish which channels are present, |
| and the relevant _type attributes to establish the data storage |
| format. |
| |
| What: /sys/.../device[n]/buffer/scan_elements/accel[_x0]_shift |
| KernelVersion: 2.6.37 |
| Contact: linux-iio@vger.kernel.org |
| Description: |
| A bit shift (to right) that must be applied prior to |
| extracting the bits specified by accel[_x0]_precision. |
