[En-Nut-Discussion] STM32 SDIO support

[Ole Reinhardt]

Hi Uwe,

Am 07.10.2015 11:07, schrieb Uwe Bonnes:
>>>>>> "Ole" == Ole Reinhardt <ole.reinhardt at embedded-it.de> writes:
> No, I did not start. Things that kept me from starting:
> - other work :-)
> - I think we don't have a clean SDIO interface, if we have a defined SDIO
>   interface at all.

That's true. Wo do not yet have any API that does an SDIO interface
abstraction. But on the LPCs I just use SDIO to communicate with SD-Cards.

I first would try to write a SDIO interface driver for STM32 as well and
then try to create a new generic API, so that we write generic SDIO
client drivers, e.g. for SD Cards etc.

> - there is no app/sdio challenging and demonstrating basic functionality of
>   a SDIO driver to allow driver development and verification.

The SD Card driver for the LPC is splittet in two parts. One for the
SDIO interface (lpc177x_8x_mci.c) and one for the SD Card block device
implementation (lpc177x_8x_mmcard_sdio.c).

Currently this is still very much lpc specific (taken from the LPC
sources). But should be a good starting point for a general implementation.

> So please, go on. If you need help with the basic STM32 infracturture, like
> pin multiplexing or DMA, please let me know. SDIO is special w.r.t. DMA, as
> SDIO determines the number of transfers while in all other cases the number
> is set by the program. The STM32 DMA interface may not cope with that
> feature.

I will keep you up to date.

Best regards,

Ole


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