How to use SDMA in i.MX7D ?

[ko-hey]

Hi all

I plan to use i.MX7D and have questions about SDMA.

Could someone teach me the following questions ?

Q1.

I think the DMA works by loading the binary file and execute the program.

Is my understanding correct ?

Q2

If Q1 is yes, the binary is sdma-imx7d.bin which can found in following link.

http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git/tree/firmware/imx/sdma?h=imx_4.1.15_1.0....

Am I correct ?

Q3

If Q2 is yes, please tell me the licence type.

According to the README.txt which is in linux-2.6-imx.git - Freescale i.MX Linux Tree , the firmware directory doesn't contain the GPL'ed work files.

This means that the conditions listed under GPL do not apply to firmware's directory.

Am I correct ?

Q4

If Q3 is yes, could you tell me the licence type ?

Ko-hey

[ko-hey]

Hi Bio_TICFSL 

I have a additional question.

According to the linux code, the license is as it can be interpreted as either GPLv2 or later version.

Is sdma-imx7.bin being provided aware of the license as GPLv2 or later verison license?
If not, please tell me the exact version of the GPL.

Ko-hey

[Bio_TICFSL]

Hi ko-hey,

Yes, it is provided as GPLv2

Regards

[ko-hey]

Hi Bio_TICFSL‌

Could you follow and answer the question ?

Ko-hey

[Bio_TICFSL · Accepted solution]

Hi ko-hey

A1: The driver provides an API for other drivers to control SDMA channels. SDMA channels run dedicated scripts according to peripheral and transfer types. The SDMA API driver is responsible for loading the scripts into SDMA memory, initializing the channel descriptors, and controlling the buffer descriptors and SDMA registers. the source files available in the directory / <Yocto_BuildDir>/linux/drivers/dma

dmaengine.c - SDMA management routine
imx-sdma.c   -  SDMA implement driver

the image files available in the directory / <Yocto_BuildDir>/linux/firmware/imx/sdma

sdma-mx7d.bin.ihex - SDMA RAM scripts

A2: Correct!

A3:  Unfortunately GPL can not be avoided, all sdma script from NXP has GPL on it. there is no any SDMA or API library without GPL license

Regards