stm32: sai: evolution roadmap

[mariopaja]

Summary

STM32 SAI driver is at the moment implemented specifically and only tested with STM32U5xx series

Describe the solution you'd like

Enhancement:

• add mclk-divider property drivers: i2s: stm32 sai add mclk-divider property #91404
• fix drain and stop of tx stream drivers: i2s: stm32_sai fix drain and stop of tx stream #94696
• fix tx callback mem_buff release drivers: i2s: stm32 sai fix tx callback mem_buff release #95197
• use DMA defines to describe SAI DMA configuration on U5xx & H5xx dts: st: use dma defines to describe sai dma configs #94723
• allow SAI DMA priority configuration
• fix H7 DMA configuration drivers: i2s: stm32 sai fix H7xx dma configuration #95199
• stop sai after stoping
• reorganize DMA configs based on the DMA rather on board series
• Fix H7 stream ID dts: st: h7: fix dma stream #95803

• Looking into dmic_stm32_pdm implementation, but no commitment yet

I intend to implement & test

• STM32U3xx dts: st: u3: enable sai node for stm32u3xx #92575
  • Related PR:
    • dts: st: u3: stm32u385rgtxq: add missing sa1_fs_a pins hal_stm32#301
    • stm32: samples: drivers: i2s: output: board: update nucleo_u385rg_q sa1 pins node #94082
• STM32U5xx drivers: i2s: add sai support for stm32u5xx #82945
• STM32G4xx drivers: i2s: stm32_sai: add sai support for stm32g4xx #93480
• STM32L4xx drivers: i2s: stm32_sai add support for stm32l4xx series #95021
• STM32L5xx drivers: i2s: stm32 sai enable stm32l5xx series #96009
• STM32H5xx drivers: i2s: add sai support for stm32h5xx #91555
• STM32H7xx drivers: i2s: add sai support for stm32h7xx #92887
• STM32H7RS drivers: i2s: add sai support for stm32h7rs #93317
• STM32F4xx
• STM32F7xx (ongoing)
• STM32N6xx drivers: i2s: add sai support for stm32n6xx #94631
• STM32WBA55 (blocked due to issues with fs...) drivers: i2s: add sai support for stm32wba55 #94960

PS: These are the only platforms which I have HW. Since this is a side project might take a while to implement and test all the platforms. Support is always welcomed :)

[mariopaja]

Special thanks to @erwango and ST for their support with WBA5, F7, H7RS & N6 series :D

[evgeniy-paltsev]

@mariopaja I can test (and review) part of the changes related to STM32L4 - so feel free to ping me when it's ready :)

[mariopaja]

hi @evgeniy-paltsev

I can test (and review) part of the changes related to STM32L4 - so feel free to ping me when it's ready :)

To which STM32L4xx do you have access to? Do you have any L4+ boards?

[evgeniy-paltsev]

@mariopaja

To which STM32L4xx do you have access to?

Right now STM32L431RCT6, soon also to STM32L471RGT6. (They are both quite similar in case of sai - 471 just has two sai peripherals (sai1 & sai2) and 2 sai PLLs).

Do you have any L4+ boards?

Nope, haven't tried these ones.

[mariopaja]

@evgeniy-paltsev i already pushed an initial draft for L4xx series. At the moment I am facing issues with DMA transfers. Do you have previous experience with the DMA on L4 series?

[evgeniy-paltsev]

At the moment I am facing issues with DMA transfers. Do you have previous experience with the DMA on L4 series?

I do (but not with the SAI itself). I'll check if there is some obvious issue.

Do you have issues with G4 as well? (as I remember G4 and L4 have identical DMA and SAI IP).

[mariopaja]

@evgeniy-paltsev I stopped G4 because I saw similarities to H7 and I wanted to implement initially H7. I will soon have a look into G4 and see how it goes.

DMA of G4 should be similar to H7. It also implements DMAMUX AN5224