[U-Boot] Help : Marvell SDIO/MMC driver for Sheevaplug

From: Rommel G Custodio <sessyargc@gmail.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] Help : Marvell SDIO/MMC driver for Sheevaplug
Date: Wed, 30 Jan 2013 22:06:32 +0900	[thread overview]
Message-ID: <20130130130632.GC76203@crg> (raw)
In-Reply-To: <51080F78.9000407@doukki.net>

On 2013.01/29, DrEagle wrote:
> Hi all,
> 
> > > -----Original Message-----
> > > From: u-boot-bounces at lists.denx.de [mailto:u-boot-
> > > bounces at lists.denx.de] On Behalf Of DrEagle
> > > Sent: 22 September 2012 12:45
> > > To: DrEagle
> > > Cc: Lior Amsalem; u-boot at lists.denx.de; uboot at doukki.net
> > > Subject: [U-Boot] [PATCH v2 0/5] Marvell SDIO/MMC driver for
> > > Sheevaplug
> > > 
> > > 
> > > This serie of patch add SDIO/MMC support to Sheevaplug board
> > > 
> > > Change from v1:
> > > - Fix an issue with most SDHC cards because of timeout delay
> > > 
> > > drEagle (5):
> > >   Add Marvell SDIO/MMC driver for Kirkwood SoC
> > >   Add SDIO/MMC support for kirkwood SoC
> > >   Add SDIO/MMC support for Sheevaplug board
> > >   Fix env address for Sheevaplug board
> > >   Fix timeout in Marvell SDIO MMC driver
> >
> > Hi DrEagle
> > I still request you to study mvsdhci.c which is similar framework used for Pantheon family of SoCs, 
> > try to use this infrastructure is possible for Kirkwood support.
> >
> > Regards...
> > Prafulla . . .
> 
> I have started looking at sdhci component but I find only theses small details :
> 
> ...
>   9) mv_sdhci.c
>   -------------
>   This is a component of the SDHCI support, allowing it to run on Marvell
>   Kirkwood chip. It is probable the SDHCI support will have to be modified to
>   allow calling functions from this file based on information passed via
>   platform_data.

Slow down ...
AFAIK u-boot does not have a platform_data.
You might be confusing the Linux kernel with u-boot code.

> ...
>   16) sdhci.c
>   -----------
>   Follows the new API and also has a good encapsulation of the whole driver. The
>   conversion here will be simple, though it'd be necessary to modify this driver
>   to also support the Kirkwood series and probably also Tegra series of CPUs.
>   See the respective parts of this section for details.
> ...
> 
> Can anybody give me more advice on how to port efficiently a patch for SDIO/MMC for SheevaPlug/Kirkwood SoC while using, as Prafulla asked, the *sdhci* framework.
> 

The u-boot SDHCI framework is simple.
mmc.c and sdhci.c implements the basic core functionality for SD/MMC
access.

The developer has to define the controller as Jagan mentioned in another
e-mail. In defining the controller you can provide your register access
functions (XXX_ACCESSORS) for those host controllers that don't follow
the SD Host contoller register layout or for quirks in accessing the
registers.

All the best,
Rommel

> What are the best practices and the technical details which can help me into this ?
> 
> Regards,
> drEagle
> 

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