SPI with GPDMA

[Rickou73]

Hi!

I would like to know if there is a way to handle "automaticaly" a transmit then receive transfert using SPI and DMA ?

I think using linked list should be possible, but i don't know how to configure that.. 

-Create a single linked list (only 1 GPDMA channel)

-Configure a 1st node with request from SPI1_TX, the tx buffer and len and add it to the linked list

-Configure a 2nd node with request from SPI1_RX, the rx buffer and len and add it to the linked list

-Call HAL_SPI_TransmitReceive_DMA

do you think it should works ?

The goal is multiple.. only 1 GPDMA channel used, manage automatically Transmit then Receive for 1 transfert..

I have same needs for 2 QuadSPI drivers.

thank for help.

[KDJEM.1]

Hello @Rickou73 ,

To configure SPI with GPDMA, I recommend you to start with available SPIs examples like these:

- SPI_FullDuplex_ComDMA_Slave

- SPI_FullDuplex_ComDMA_Master

Also, I advise you to take a look at this FAQ may help you "How to configure the GPDMA - STMicroelectronics Community"

I hope this help you.

Kaouthar

[Rickou73]

hi @KDJEM.1 

thank you but I already know these examples..

In my case, I'm targeting a device that is not full duplex.

In this specific setup, i need in a same chip select transfer to 1st transmit some bytes, then receive some bytes.

So, I asks if it's possible to:

Using a Single (or 2) DMA channel with linked list and HAL to do both "half transfert" in a single transaction without code interaction ?

actual pseudo-code:

txbuffer[4]={......};

rxbuffer[128];

ChipSelect_Enable();

HAL_SPI_Transmit_DMA(dmaCh1, txbuffer,4);

WaitForDMAComplete(dmaCh1);

HAL_SPI_Receive_DMA(dmaCh2,rxbuffer,128);

WaitForDMAComplete(dmaCh2);

ChipSelect_Disable();

Thinking pseudo-code:

txbuffer[4]={......};

rxbuffer[128];

ChipSelect_Enable();

HAL_SPI_Transmit_Receive_DMA(dmaCh1,txbuffer,4,rxbuffer,128); // In half duplex !

WaitForDMAComplete(dmaCh1);

ChipSelect_Disable();