i.MX Processors中的主题 Re: spi-imx dma support and transfer data issue

spi-imx dma support and transfer data issue

surendradhobale — Thu, 11 Jan 2018 06:12:02 GMT

Hello,

I am trying to use the dma support for the ecspi in imx6ul. I read multiple discussion on community,saying no support for the dma. (https://community.nxp.com/thread/452083)

But when i saw the driver code in spi-imx.c, dma support related functions already exist, also in the imx6ul.dtsi file for the ecspi nodes dmas and dma-names property has set. For me it looks dma support is enable for the spi-imx.

Is it really functional ?

I am trying to use that. In the spi-imx.c ( nxp kernel 4.9.11)

when spi_imx_setupxfer() called its checking for dma ( spi_imx_can_dma()). Bydefault rxwml level is 32. I am transfering 1 or 2 bytes i.e transfter-> len = 2. and functions returns false and every time used pio mode i.e without dma.

and not transfer data to dma descriptors.

What could be the issue ? What action need to take?

Re: spi-imx dma support and transfer data issue

jimmychan — Tue, 16 Jan 2018 04:59:33 GMT

Have you add the 'dmas' and 'dma-name' in your devicetree file?

like this : linux-imx.git - i.MX Linux Kernel

Re: spi-imx dma support and transfer data issue

surendradhobale — Wed, 24 Jan 2018 05:05:35 GMT

Yes, I have added the dmas and dma-name in our device tree.

Re: spi-imx dma support and transfer data issue

GregT — Mon, 11 Mar 2019 14:31:53 GMT

Hi Surendra,

Did you get dma and spi working?

Thanks,

Greg