Mcuxa lpdac test harness enhancement for second serial console checking with latest multi-dut support in twister-pytest

[hakehuang]

for mcux lpdac tests, the seconday uart is used, with dut pytest,
we can unify the test with two instance.

example usage:

    - baud: 115200
      connected: true
      id: "OY2JXE5XLYFEE"
      platform: frdm_mcxa346/mcxa346
      product: NXP
      runner: linkserver
      pre_script: /home/ubuntu/nxp/frdm_mcxa346/erase2.sh
      serial: COM0
      fixtures:
        - dac_fixture
    - connected: true
      id: "OY2JXE5XLYFEE"
      platform: unknown
      product: unknown
      runner: unknown
      serial: /dev/serial/by-id/usb-1a86_USB_Serial-if00-port0
      serial_baud: 115200
      notes: "Auxiliary serial port, not flashed"

this depends on #91338

[Copilot]

Pull request overview

This PR adds DAC (nxp,lpdac) support to the FRDM-MCXA266/346/366 boards. It defines the dac0 node in the shared SoC dtsi, enables/clocks it on the boards, adds DAC0 pinmux, updates board capability lists, and wires up the DAC sample plus a new pytest-based DAC API test that reads ztest results from the auxiliary UART (the DAC output pin conflicts with the default console LPUART2, so overlays move the console to LPUART3). It depends on PR #91338.

Changes:

• Adds dac0 to the SoC dtsi and enables it on the three boards (board_common.dtsi, board.c clocks, pinctrl, board YAMLs).
• Adds sample/test overlays moving console to LPUART3 plus README documentation.
• Adds a pytest harness test reading DAC ztest output over a secondary UART.

Reviewed changes

Copilot reviewed 18 out of 18 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
dts/arm/nxp/mcx/nxp_mcxaxx6_common.dtsi	Adds disabled dac0 node for the SoC
boards/nxp/frdm_mcxaxx6/board_common.dtsi	Enables dac0 with DAC0 pinmux by default
boards/nxp/frdm_mcxaxx6/board.c	Adds SPC/clock init for DAC0
boards/nxp/frdm_mcxaxx6/frdm_mcxa{266,346,366}-pinctrl.dtsi	Adds pinmux_dac0 on P2_2
boards/nxp/frdm_mcxaxx6/frdm_mcxa{266,346,366}.yaml	Lists dac as supported
samples/drivers/dac/boards/frdm_mcxa{266,346,366}.overlay	DAC sample overlays, console to LPUART3
samples/drivers/dac/README.rst	Documents building/running on the three boards
tests/drivers/dac/dac_api/boards/frdm_mcxa{266,346,366}.overlay	Test console overlays
tests/drivers/dac/dac_api/testcase.yaml	Adds pytest DAC test entry
tests/drivers/dac/dac_api/pytest/test_dac.py	Verifies DAC ztest output on aux UART

[martinjaeger]

I don't fully understand why this is needed. Also the changes don't have anything to do with Mcux lpdac so far, so the title is misleading. Can you please clarify?

[hakehuang]

I don't fully understand why this is needed. Also the changes don't have anything to do with Mcux lpdac so far, so the title is misleading. Can you please clarify?

@martinjaeger, this is because we are using a different UART for this particular case for those platforms, but still use default uart for other application, to make the CI can support such variation, this is necessary. otherwise, this board can only run pass with this case, all others fails. and this is only for drivers.dac.api.dac0_channel0_mcxaxx6 which is used by mcxa_lpadc

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

[hakehuang]

@martinjaeger I update the title, this pr is about testing harness setting. Thanks

[Copilot]

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[Copilot]

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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