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chromium / chromiumos / platform2 / libmems / 0dd994dc32d0c36c352f79539375d37e04a6b82b
commit0dd994dc32d0c36c352f79539375d37e04a6b82b[log] [tgz]
authorHarvey Yang <chenghaoyang@chromium.org>Sat Jan 16 15:43:45 2021
committerCopybara-Service <copybara-worker@google.com>Fri Jan 22 10:15:00 2021
tree52fcc3c23ad7e3d9628eea3b267edc585ca07eb7
parent0e2a2d4994192b83f16810b32750feecb564b4fc [diff]
libmems: Add CreateBuffer and FreeBuffer in IioDevice

To flush old samples in IIO buffer, we should add CreateBuffer and
FreeBuffer in IioDevice to allow users to control the lifetime of the
buffer directly.

BUG=b:177707650
TEST=unit tests

Cq-Depend: chromium:2631711
Change-Id: Ic113f5a8c69aa60b410c822bc5f45f8210e60c15
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform2/+/2631710
Tested-by: Gwendal Grignou <gwendal@chromium.org>
Commit-Queue: Cheng-Hao Yang <chenghaoyang@chromium.org>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
GitOrigin-RevId: df365181399a901c864dc038cc395ea3caf64073
6 files changed
tree: 52fcc3c23ad7e3d9628eea3b267edc585ca07eb7
  1. BUILD.gn
  2. common_types.h
  3. export.h
  4. iio_channel.h
  5. iio_channel_impl.cc
  6. iio_channel_impl.h
  7. iio_context.h
  8. iio_context_impl.cc
  9. iio_context_impl.h
  10. iio_device.cc
  11. iio_device.h
  12. iio_device_impl.cc
  13. iio_device_impl.h
  14. iio_device_test.cc
  15. iio_device_trigger_impl.cc
  16. iio_device_trigger_impl.h
  17. libmems.pc
  18. libmems_test_support.pc
  19. OWNERS
  20. README.md
  21. test_fakes.cc
  22. test_fakes.h
README.md

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.