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Regarding nordic SPI driver implicitly using DMA

Hi,

Request confirmation that nCS nordic SPIM & SPIS drivers implicitly use DMA,
I found the response as in: https://devzone.nordicsemi.com/f/nordic-q-a/83593/zephyr-rtos-spi-dma-sample-code

Hence the query, request you to also point to me towards DMA usage code snippets in driver files "spi_nrfx_spim" & "spi_nrfx_spis", or in nordic legacy SPI drivers, so that I can justify my development.

Thanks,

Ubaid

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0 user87869 over 4 years ago

Hello Ubaid,

The SPIM and SPIS peripherals use easyDMA explicitly - there is no other option. The drivers for these specific peripherals thus has no influence on the usage of easyDMA.
I do not know which device you are working with, but you could read more about this in the respective device's Product Specification under Peripherals -> SPIM -> EasyDMA.

Best regards,
Karl
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0 user108934 over 4 years ago in reply to user87869

Hi Karl,

Thanks for the confirmation, so I am to understand that in the compatible property, if I am using:

compatible = "nordic,nrf-spis"

or

compatible = "nordic,nrf-spim"

Than it implies I am also using EasyDMA.

I am using nrf52833_dk device.

Thanks,

Ubaid
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0 user108934 over 4 years ago in reply to user87869

Hi Karl,

Thanks for the confirmation, so I am to understand that in the compatible property, if I am using:

compatible = "nordic,nrf-spis"

or

compatible = "nordic,nrf-spim"

Than it implies I am also using EasyDMA.

I am using nrf52833_dk device.

Thanks,

Ubaid
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0 user87869 over 4 years ago in reply to user108934

Ubaid_M said:
Thanks for the confirmation

No problem at all, I am happy to help!

Ubaid_M said:
compatible = "nordic,nrf-spis"

or

compatible = "nordic,nrf-spim"

Than it implies I am also using EasyDMA.

Yes, when using the SPIM or SPIS peripheral they will always use easyDMA.
Is your intention to avoid using EasyDMA in your application? If so, could you elaborate on this requirement / constraint?

Best regards,
Karl
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0 user108934 over 4 years ago in reply to user87869

Hello Karl,

user87869 said:
Is your intention to avoid using EasyDMA in your application?

Just for the sake of understanding, How can I disable EasyDMA, from SPIM.?

Thanks,

Ubaid
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0 user87869 over 4 years ago in reply to user108934

Ubaid_M said:
Just for the sake of understanding, How can I disable EasyDMA, from SPIM.?

Thank you for clarifying. As mentioned, there is no way to disable EasyDMA for the SPIM peripheral, so if you intend to not use EasyDMA you will have to use the legacy SPI peripheral instead, if available.

Best regards,
Karl
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0 user108934 over 4 years ago in reply to user87869

user87869 said:
there is no way to disable EasyDMA for the SPIM peripheral

Thanks Karl,
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+1 user87869 over 4 years ago in reply to user108934

No problem at all - I am happy to help, Ubaid!

Please do not hesitate to open another ticket if you should encounter any issues or questions in the future.

Good luck with your development!

Best regards,
Karl
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