SPI slave

[Dave-Poissant]

Hi, I'm trying to make an SPI slave out of my stm32f411ce and I seem to be having a bit of trouble with the configurations (I think).

Context:
My program right now is only 2 threads running simultaneously. One is the main blinking a user LED at every XX delay. The other one is an spi handler thread which waits for a semaphore to be given in order to initiate any spi communication.
I have an arduino who pulls down the cs pin of my stm32f411ce which activates an interrupt which gives the said semaphore. This gives the chance to the spi handler thread to send or receive anything with adequatly set buffers and the spi device needed.

Now, if I put my device in master mode, everything is fine. Whenever i try to put it in slave mode, by adding in prj,conf CONFIG_SPI_SLAVE=y and changing SPI_OP_MODE_MASTER for SPI_OP_MODE_SLAVE in my spi_config struct, function spi_transceive(...) returns -22 (wrong arguments).

Am I missing something in configs or am I suppose to be handling a slave differently?

blackpill_spi_test_zip.zip

[Dave-Poissant]

Also good to know, I have hooked up my MISO and MOSI lines together in order to simplify debugging it all.

[Dave-Poissant]

I've tryed hooking the stm32f411ce to an arduino mega 2560 as the master, but i get the same result (same error errno =-22).