nRF54L15DK, cannot port HAL SPI code that was working in nRF53

[esmart-engineering]

I had previously gotten working code to communicate with my SPI device on the nRF5340DK w/ NCS v2.5.0 that uses the HAL SPI library inside TF-M. I used NCS v2.5.0 (nrf\samples\tfm\tfm_secure_peripheral) as the baseline.

I now need to port that code to nRF54L15DK w/ NCS v2.9.0, but am having issues where I see the SPI transactions (w/ logic analyzer) but the data being read in is wrong (and/or it's an issue with the writes I'm using when I configure my SPI device).

I tried looking through the NCS examples, but could find no examples of HAL SPI, or "HAL-SPI + TFM-secure-partition" that use the nRF54. With that, I have several questions:

1. Can you provide code for a simple working "HAL-SPI + TFM-secure-partition" example that works on nRF54L15DK and NCS v2.9.0?
2. Can you provide code for a simple working "HAL-SPI only" example that works on nRF54L15DK and NCS v2.9.0?
   1. We would like to see if the issue is related to TF-M or not.
3. Are you aware of any other issues in the DK or NCS v2.9.0 that can cause issues with SPI?
   1. This could be related to overlays, KConfig, or anything.

For context, my setup is using a Windows 10 machine, VS Code (with nRF Connect extensions).

[esmart-engineering]

Thank you for everyone's help; I appreciate all your input. I was able to resolve the issue with my project, by fixing the following:

• Increasing voltage on the I/O pins. It seems the default on nRF54 was too low for my SPI slave device.
• Ensuring enough time between register writes to configure SPI slave device