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Diffstat (limited to 'drivers/staging/iio/Documentation/overview.txt')
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diff --git a/drivers/staging/iio/Documentation/overview.txt b/drivers/staging/iio/Documentation/overview.txt deleted file mode 100644 index ebdc64f451d7..000000000000 --- a/drivers/staging/iio/Documentation/overview.txt +++ /dev/null @@ -1,57 +0,0 @@ -Overview of IIO - -The Industrial I/O subsystem is intended to provide support for devices -that in some sense are analog to digital converters (ADCs). As many -actual devices combine some ADCs with digital to analog converters -(DACs) that functionality is also supported. - -The aim is to fill the gap between the somewhat similar hwmon and -input subsystems. Hwmon is very much directed at low sample rate -sensors used in applications such as fan speed control and temperature -measurement. Input is, as its name suggests focused on input -devices. In some cases there is considerable overlap between these and -IIO. - -A typical device falling into this category would be connected via SPI -or I2C. - -Functionality of IIO - -* Basic device registration and handling. This is very similar to -hwmon with simple polled access to device channels via sysfs. - -* Event chrdevs. These are similar to input in that they provide a -route to user space for hardware triggered events. Such events include -threshold detectors, free-fall detectors and more complex action -detection. The events themselves are currently very simple with -merely an event code and a timestamp. Any data associated with the -event must be accessed via polling. - -Note: A given device may have one or more event channel. These events are -turned on or off (if possible) via sysfs interfaces. - -* Hardware buffer support. Some recent sensors have included -fifo / ring buffers on the sensor chip. These greatly reduce the load -on the host CPU by buffering relatively large numbers of data samples -based on an internal sampling clock. Examples include VTI SCA3000 -series and Analog Devices ADXL345 accelerometers. Each buffer supports -polling to establish when data is available. - -* Trigger and software buffer support. In many data analysis -applications it it useful to be able to capture data based on some -external signal (trigger). These triggers might be a data ready -signal, a gpio line connected to some external system or an on -processor periodic interrupt. A single trigger may initialize data -capture or reading from a number of sensors. These triggers are -used in IIO to fill software buffers acting in a very similar -fashion to the hardware buffers described above. - -Other documentation: - -device.txt - elements of a typical device driver. - -trigger.txt - elements of a typical trigger driver. - -ring.txt - additional elements required for buffer support. - -sysfs-bus-iio - abi documentation file. |