| Fixed Regulator |
| ############### |
| |
| This application tests the fixed regulator driver in multiple |
| configurations. Like the GPIO driver test it requires that two GPIO |
| pins be shorted so that changes made to the state of one can be verified |
| by inspecting the other. |
| |
| Unlike the GPIO driver test the behavior of a fixed regulator depends |
| heavily on the properties specified in its devicetree node. The |
| ``compatible`` property causes the underlying driver implementation to |
| select between one that supports asynchronous transitions and an |
| optimized one synchronous transitions. The initial state of the |
| regulator, whether it can be changed, and enforced transition delays are |
| all controlled by devicetree properties. |
| |
| Because the regulator can only be configured at system startup it is |
| necessary to test varying configurations in separate test sessions. The |
| ``testcase.yaml`` file provides a variety of flags intended to cover the |
| various behaviors. |
| |
| Only boards for which an overlay is present can pass this test. Boards |
| without an overlay, or for which the required wiring is not provided, |
| will fail with an error like this: |
| |
| Assertion failed at ../src/main.c:182: test_preconditions: (precheck not equal to PC_OK) |
| precheck failed: active check failed |
| |
| No special build options are required to make use of the overlay. |
