[U-Boot] fsl_esdhc.c: eMMC 4.4 support?

[stefano babic <sbabic@denx.de>]

Am 24/02/2012 08:20, schrieb Dirk Behme:
> On 23.02.2012 22:45, Andy Fleming wrote:
>> Yes, that's very annoying. Of course, Freescale *does* use fsl_esdhc,
>> but for Power Architecture. I know that changes were submitted to
>> support i.MX on fsl_esdhc, too, so I don't know why they've opted to
>> use their own file in that tree. Hopefully they can be convinced to
>> add support to mainline.
> 
> I'm not sure if they can be convinced :(
> 
> Anyway, what would be the preferred way to improve the xxx_esdhc in
> mainline U-Boot?

Sorry, but support for SDHC *is* already in u-boot. The fsl_esdhc.c
supports *both* architectures.

> 
> Both, the Freescale U-Boot [1] and Barebox [2] have a imx-esdhc.c. With
> this, the options I see for mainline U-Boot are

There are a lot of other drivers that are duplicated in the sources
delivered by Freescale [1]. This is not a good reason to do the same in
mainline. And Freescale's sources do not use the MMC framework we
currently use, as fas as I remember.

> 
> a) to port the Freescale/Barebox imx-esdhc.c changes/improvements into
> U-Boot's fsl_esdhc.c

Yes. We have already profit in the past from changes done for PowerPC,
that fixed the same issues for i.MX. Are you really sure that the
missing feature (8 bit support) cannot be used on PowerPc, too ?

I am for maintaining one single driver and avoid as much as possible to
duplicate code when it is not strictly needed.

> 
> or
> 
> b) create a new imx-esdhc.c in U-Boot, too.

No, don't do it. fsl_esdhc.c driver was modified in the past to add
support for i.MX *after* Freescale published imx-esdh.c. And also at
that time, the decision was to modify the driver for i.MX instead of
adding a new one.

Best regards,
Stefano Babic

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