Linux/TMS320DM8148: Way to access EDMA From user Space in DM814x using latest EZSDK ?

Ammar

Part Number: TMS320DM8148

Tool/software: Linux

I Have seen the sample application for edma ,which can only be accessed from kernel space , How Can i use EDMA in my application . And How can we change the maximum size for Transfer.?

over 8 years ago

0 Pavel Botev over 8 years ago

TI__Guru**** 170625 points

Hi Ammar,

In DM814x EZSDK, EDMA is accessed only within the kernel level, from within other drivers (McASP, MMC). For example, ALSA user space application is accessing McASP audio kernel driver, which access EDMA kernel driver.

Regarding accessing EDMA directly from user space, see if the below e2e threads will be in help:

e2e.ti.com/.../247547
e2e.ti.com/.../670151

e2e.ti.com/.../451332

e2e.ti.com/.../535345

Regards,
Pavel

0 Pavel Botev over 8 years ago

TI__Guru**** 170625 points

Ammar said:
And How can we change the maximum size for Transfer.?

The EDMA transfer size is configured through ACNT, BCNT and CCNT params. Refer to DM814x TRM for more details.

There is also DBS (Default Burst Size) which is also configurable, see below e2e thread:

e2e.ti.com/.../245932

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Linux/TMS320DM8148: Way to access EDMA From user Space in DM814x using latest EZSDK ?