POC for a new harness designed for power measurement purposes.

[gbarkadiusz]

POC of Power twister harness.

This pr adds support for power measurements for twister and three example tests.
pm.states: Verifies the transition to all available power states on stm32l562e_dk.

During the test, pytest detects each step and calculates the RMS (Root Mean Square) current for every detected state. The test then compares the calculated RMS values against the expected values, which have been determined manually through experimental observation

pm.residency_time: Tests the residency time of each power state.
This test evaluates the residency time of different power states on the stm32l562e_dk board.

pm.wakeup_timer: Tests the RTC alarm’s ability to wake the CPU from the lowest power state.

Each test calculates RMS current values for each detected state and compares them to expected values, which were manually set based on experimental data.

Setup

To reproduce.:

• Configure the stm32l562e_dk board according to the instructions provided above.
• Connect both USB ports of the board to your host system. The board will appear as two separate targets:
  Power Monitor: e.g., /dev/ttyACM0 or /dev/serial/by-id/usb-STMicroelectronics_PowerShield__Virtual_ComPort_in_FS_Mode__FFFFFFFEFFFF-if00
  Target: e.g., /dev/ttyACM1 or /dev/serial/by-id/usb-STMicroelectronics_STLINK-V3_004##############39-if02
• Run twister commend:

twister --device-testing --device-serial /dev/ttyACM1 -p stm32l562e_dk -T tests/subsys/pm/power_residency_time/ --west-flash="--dev-id=004800483137510D33333639" --west-runner=pyocd -vv  -ll DEBUG -xCONFIG_BOOT_DELAY=500 --pm-probe=stm_powershield --pm-probe-port=/dev/serial/by-id/usb-S
TMicroelectronics_PowerShield__Virtual_ComPort_in_FS_Mode__FFFFFFFEFFFF-if00

[bjarki-andreasen]

These two args (--probe and --probe-port ) should be provided via the command line, as they vary, as opposed to the pytest_dut_scope: session and the properties in test_expected_values.yaml file which are "portable"/"fixed" regardless of the probe and port used :)

[bjarki-andreasen]

Would it be possible to move

-  name: "wakeup_timer"
     measurement_time: 2
     num_of_transitions: 1
     rms: [0.26, 140]

to

harness_config:
  measurements:
    - name: "wakeup_timer"
      measurement_time: 2
      num_of_transitions: 1
      rms: [0.26, 140]

instead of the separate file? not sure what having the commands in a separate file acheives :)

[gbarkadiusz]

@bjarki-andreasen Please take another look. I'm not sure that moving --probe and --probe-port to the Twister parameter is a good approach. They're more closely related to the harness's parameters rather than Twister's, so I suggest leaving them in the harness_config section.

[bjarki-andreasen]

@bjarki-andreasen Please take another look. I'm not sure that moving --probe and --probe-port to the Twister parameter is a good approach. They're more closely related to the harness's parameters rather than Twister's, so I suggest leaving them in the harness_config section.

Would you argue the same for the --serial option and its parameters? The probe and probe-port are instances of actual hardware right? If i ran the same test locally, would I not need to change the port to match my setup?

[gbarkadiusz]

@bjarki-andreasen Please take another look. I'm not sure that moving --probe and --probe-port to the Twister parameter is a good approach. They're more closely related to the harness's parameters rather than Twister's, so I suggest leaving them in the harness_config section.

Would you argue the same for the --serial option and its parameters? The probe and probe-port are instances of actual hardware right? If i ran the same test locally, would I not need to change the port to match my setup?

Yes, you need to change the port to match your setup.
Regarding the twister parameters. You right, so I've applied your suggestions, There's the example twister's command with these two parameters --pm-probe and --pm-probe-port.

twister --device-testing --device-serial /dev/ttyACM1 -p stm32l562e_dk -T tests/subsys/pm/power_residency_time/ --west-flash="--dev-id=004800483137510D33333639" --west-runner=pyocd -vv  -ll DEBUG -xCONFIG_BOOT_DELAY=500 --pm-probe=stm_powershield --pm-probe-port=/dev/serial/by-id/usb-S
TMicroelectronics_PowerShield__Virtual_ComPort_in_FS_Mode__FFFFFFFEFFFF-if00

@bjarki-andreasen , @nashif Please take a look.

[gbarkadiusz]

@PerMac I've changed the code according to your suggestions, please take a look again.
Now, the proper command to run the test is:

twister --device-testing --device-serial /dev/ttyACM1 -p stm32l562e_dk -T tests/subsys/pm/power_states/ --west-flash="--dev-id=004800483137510D33333639" --west-runner=pyocd -vv  -X pm_probe:/dev/serial/by-id/usb-STMicroelectronics_PowerShield__Virtual_ComPort_in_FS_Mode__FFFFFFFEFFFF-if00

[PerMac]

In pytest, using yield in a fixture is generally preferred when you need to perform setup and teardown actions. The yield statement allows you to define a teardown step that will be executed after the test completes, ensuring proper cleanup.

Here's why using yield is beneficial in your case:

Explicit Teardown: By using yield, you can explicitly define the teardown process within the fixture, making it clear and maintainable.
Resource Management: It ensures that resources like serial connections are properly closed, avoiding potential issues with resource leaks.
Using del for cleanup is not recommended because:

Unpredictable Timing: The del method is called when an object is garbage collected, which can be unpredictable and may not happen immediately after the test.
Resource Leaks: If the garbage collector does not run promptly, resources may remain open longer than necessary.

[gbarkadiusz]

@PerMac Thank you for your feedback, I've applied your suggestions, please take a look.
@nashif @bjarki-andreasen @nordic-piks FYI.

[PerMac]

All my comments were addressed

[gbarkadiusz]

All my comments were addressed

If so, please resolve all your conversations, Thank you.

[nashif]

Hey, the second commit:

CI: Add power_states, power_wakeup_timer and power_residency_time tests

This is not related to CI, please split this into 3 commits with more details in the commit body explaining what is being tested, for example:

tests: power_states: tests blah blah

This test verified foo bar using the power harness using the STM32XYZ board.....

Do the same for the other tests.