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  1. ce0f071 libbrillo: remove version suffix in build rules by hscham · 4 weeks ago master
  2. 55ffd72 libmems: Fix test logic when adding a new trigger by Gwendal Grignou · 8 weeks ago
  3. e6a14d1 libmems: Update APIs in IioContext to access IioDevices by Harvey Yang · 9 weeks ago
  4. 0c9a49c libmems: Add IioContext::SetTimeout by Harvey Yang · 2 months ago
  5. 5f9d67a libmems: Reset trigger before applying a new one by Gwendal Grignou · 3 months ago

Chrome OS IIO Sensor Utility Library

Project goal and motivation

This library provides a set of wrapper and test helpers around libiio.

It is meant to provide a common foundation for Chrome OS to access and interface IIO sensors, with:

  • a strong emphasis on testability;
  • readable code, with the ergonomics typical of platform2;
  • high performance.

Class hierarchy

At the root of the hierarchy, there exists the IioContext, which represents the IIO devices currently available on the system. These can be retrieved by name and inspected, via instances of IioDevice.

An IioDevice allows reading and writing attributes of an IIO device via type-safe helper APIs. It also offers support for configuring the buffer and trigger of an IIO device, which we use in order to allow the Chrome UI to read accelerometer data and support screen rotation.

An IioDevice also exposes a list of IioChannels, which can individually be enabled and disabled.

Test mocks

Useful mocks for the core classes are provided, such that a test author can focus on the logic of the unit tests and share a common testing language with other engineers working in this space. Sharing the foundation of testing IIO sensor access helps ensure that any improvement in this area can benefit all clients.