i2c: stm32: dma enhancement

[sgilbert182]

Add DMA enhancement for stm32 i2c_v2 driver

Fix #34354

[github-actions]

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[erwango]

@sgilbert182 Thanks for this contribution. We'll try to review in best delays. Meanwhile,please have a look at feedback reported by compliance scripts
Also, would you mind providing some details on testing (which platforms, which tests, ..) ?

[sgilbert182]

Hi, no worries. I tested this on a g4

[erwango]

@sgilbert182 Quick hint: Clang format is not mandatory (and I agree this isn't clear at all, these warning are recent and should be deactivated IMO), if you want to make your life easier, you can drop format related changes.

[erwango]

To be clear on formatting changes (and hopefully we can focus on the content afterwards):

You should fix those (not fixing will block CI)

You are not requested to fix those (and even sometimes, it is better not to apply):

[sgilbert182]

To be clear on formatting changes (and hopefully we can focus on the content afterwards):

You should fix those (not fixing will block CI)

You are not requested to fix those (and even sometimes, it is better not to apply):

I seem to have some issues with Clang Format, I run it locally and it produces results that fail CI. Looks like I need to make the changes manually

[erwango]

Initial review attempt:

Mains request before going further:
Did you consider implementing I2C_CALLBACK which is supposed to be the async version of I2C API while you're at?
If adding DMA support it would be more logical to make use of this API which allows truly async transfers rather than adding DMA support on a blocking API.
Reason I ask is to avoid current state of STM32 SPI driver which is in a similar state today with a sync API allowing use of DMA and ASYNC API effectively blocking.

(Note also that driver is supposed to get further changes to support RTIO API, so let's limit the changes to where it makes real sense)

Then let's club all DMA related additions to the driver in a single commit to make it easier to review.

Finally, if possible, let's rebase on top of #82015 (once merged) in order to get rid of clang-format suggestions.

[sgilbert182]

Mains request before going further: Did you consider implementing I2C_CALLBACK which is supposed to be the async version of I2C API while you're at? If adding DMA support it would be more logical to make use of this API which allows truly async transfers rather than adding DMA support on a blocking API. Reason I ask is to avoid current state of STM32 SPI driver which is in a similar state today with a sync API allowing use of DMA and ASYNC API effectively blocking.

I did not, I was porting over changes I was using for a project but I can take a look at this when I have time.

(Note also that driver is supposed to get further changes to support RTIO API, so let's limit the changes to where it makes real sense)

I will revert this

Then let's club all DMA related additions to the driver in a single commit to make it easier to review.

Finally, if possible, let's rebase on top of #82015 (once merged) in order to get rid of clang-format suggestions.

should I close this MR until this can be rebased and I've had a chance to look at the callback mechanism?

[erwango]

I did not, I was porting over changes I was using for a project but I can take a look at this when I have time.

Would be great. Thanks

should I close this MR until this can be rebased and I've had a chance to look at the callback mechanism?

Not required. But for clarity, you can move it to draft.

[erwango]

@JarmouniA PTAL

[erwango]

@JarmouniA Do you think you'll be able to have a new look soon ? Your comments have been addressed as far as I can tell.

Comments addressed.

[github-actions]

Hi @sgilbert182!
Congratulations on getting your very first Zephyr pull request merged 🎉🥳. This is a fantastic achievement, and we're thrilled to have you as part of our community!

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Thank you for your valuable input, and we look forward to seeing more of your contributions in the future! 🪁

[JarmouniA]

@JarmouniA Do you think you'll be able to have a new look soon ? Your comments have been addressed as far as I can tell.

Sorry I missed the notif, yes they have been addressed.