RTOS/AM5728: EDMA read from PCIe

Manjula KS

Part Number: AM5728

Tool/software: TI-RTOS

Hi,

My setup is something like this. My TI board is Root Complex and FPGA acts as End Point. Some MAC client is sitting on TI board as End Point. Now I receive a buffer from FPGA. Should I do EDMA read saying pcie address as source and my dma memory as destination?

I need to send the same data to the MAC client.

over 7 years ago

0 Biser Gatchev-XID over 7 years ago

TI__Guru**** 393215 points

The RTOS team have been notified. They will respond here.

0 lding over 7 years ago in reply to Biser Gatchev-XID

TI__Guru* 95265 points

Hi,

Can you explain your topology? AM572x is the PCIE RC, and there are several EP in the system? One is FPGA and the other are MAC clients? And you want to read data from FPGA and write into a MAC client using EMDA on the RC?

Regards, Eric

0 Manjula KS over 7 years ago in reply to lding

Intellectual 430 points

Yes. The topology is correct. Now please tell me how do I do edma receive from FPGA to RC.

I have one more requirement. I need to handle GPIO interrupt from FPGA to RC. How can I do it. Please let me know complete steps.

Thank you

0 lding over 7 years ago in reply to Manjula KS

TI__Guru* 95265 points

Hi,

Please check the PCIE driver example processors.wiki.ti.com/.../Processor_SDK_RTOS_PCIe how to use the EDMA. The SRC address would be something like 0x2xxx_xxxx, destination would be something like DDR or OCMC for the EDMA read.

For GPIO, please check GPIO driver: processors.wiki.ti.com/.../Processor_SDK_RTOS_GPIO

Regards, Eric

0 Manjula KS over 7 years ago in reply to lding

Intellectual 430 points

Hi Eric

I have gone through the example code of pcie. In that using EDMA they to transfer data from RC L2SRAM to 0x2xxx xxxx to EP. Since INBOUND REGION is configured, whenever the EP loopsback same data back to RC, it is available in L2SRAM. Where I am performing EDMA receive from 0x2xxx xxxx to L2SRAM/DDR

It looks to me I am using EDMA to transfer data from L2SRAM/DDR to 0x2xxx xxxx. My scenario is I have to receive data from EP to RC DDR.

I understand that my src can be given 0x2xxx xxxx and destination can be RC DDR, I want to understand is INBOUND REGION configuration still required in EDMA receive.

Thanks

0 lding over 7 years ago in reply to Manjula KS

TI__Guru* 95265 points

Hi,

In your case, the RC EDMA generates read request with source 0x2xxx_xxxx and destination 0x8xxx_xxxx. You don't need inbound translation in RC side. But for EP side, you need inbound translation, that is, translating the incoming 0x2xxxx_xxxx address into certain memory address inside the EP (e.g, could be OCMC, DDR, or peripheral etc).

Regards, Eric

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RTOS/AM5728: EDMA read from PCIe