Linux/TDA2: Recommended way to use EDMA in HLOS usecase

Nick Cage

Part Number: TDA2

Tool/software: Linux

Hello, I'm using Processor SDK 3.03 on Linux with kernel 4.16.7, building for custom board with TDA2 chip.

I was wondering what is the recommended way to use EDMA in a HLOS usecase. While working with RTOS I used utils_dma.c but I can't seem to find anything like that in HLOS.

Thank you in advance.

Regards,

Nick

over 7 years ago

0 Srirama Govindarajan over 7 years ago

TI__Expert 8250 points

Nick,
Can you please confirm on the Linux kernel version - have you been referring to the Processor SDK Linux Automotive releases - these are based on kernel version 4.4
Typically for HLOS use case, the DMA is programmable from within the kernel as you would be programming the Physical address es for DMA parameters and you would want this to be validated and programmed from the kernel. On linux we have dmaengine I/F www.kernel.org/.../index.html and implementation for EDMA that subscribes to this interface on TI platforms. Various device drivers inside the kernel use dmaengine I/F. There are no direct API for using DMA from userspace applications on Linux

0 Nick Cage over 7 years ago in reply to Srirama Govindarajan

Intellectual 730 points

Hi Sriram,

The kernel 4.16.7 is on my build machine and the one that is built and ran on the board is the one present in PSDK 3.03 (4.4.84).
Is there any good example among the device drivers where I can see how dmaengine is used? Also, the link you provided is dead.

Thank you in advance.
Nick

0 Srirama Govindarajan over 7 years ago in reply to Nick Cage

TI__Expert 8250 points

NIck
For the link itself, there is an appended ")" at the end of the URL which needs to be removed. I tried fixing it on the previous post, but somehow it is not taking effect.

More details on the implementation, device driver usage and testing is described under
www.kernel.org/.../provider.html
www.kernel.org/.../client.html
www.kernel.org/.../dmatest.html

Processors

Processors forum

Linux/TDA2: Recommended way to use EDMA in HLOS usecase