brightness.lcd_backlight
========================
**Source code:** `brightness/lcd_backlight.py <https://chromium.googlesource.com/chromiumos/platform/factory/+/refs/heads/main/py/test/pytests/brightness/lcd_backlight.py>`_

This is a factory test to check the functionality of LCD backlight module.

Description
-----------

This is another version of :doc:`backlight <backlight>`.

The goal is to share code between led, lcd_backlight, keyboard_backlight, and so
on. However, users still use the backlight test.

Test Procedure
--------------

1. Enumerate levels and set brightness to each level.
2. Operators decide pass or fail.

Dependency
----------
- Device API ``cros.factory.device.display.SetBacklightBrightness``.

Examples
--------
An example:

.. test_list::

  generic_display_panel_examples:DisplayPanelTests.BrightnessLCDBacklight



Test Arguments
--------------
.. list-table::
   :widths: 20 10 60
   :header-rows: 1
   :align: left

   * - Name
     - Type
     - Description

   * - msg
     - str, dict
     - (optional; default: ``{'en-US': 'Please check if backlight brightness is changing from dark to bright.'}``) Message HTML

   * - timeout_secs
     - int
     - (optional; default: ``10``) Timeout value for the test in seconds.

   * - levels
     - list, None
     - (optional; default: ``None``) A sequence of brightness levels.

   * - interval_secs
     - int, float
     - (optional; default: ``0.5``) Time for each brightness level in seconds.