[U-Boot] [PATCH] mmc:fix: Set mmc width according to MMC host capabilities

[Lukasz Majewski]

Hi Andy,

> Hi Andy,
> 
> > This patch sets the MMC width according to the MMC host
> > capabilities. It turned out, that there are some targets (e.g.
> > GONI), which are able to read data from SPI only at 4 bit mode.
> > This patch restricts the width number according to the MMC host.
> > 
> > Signed-off-by: Lukasz Majewski <l.majewski at samsung.com>
> > Signed-off-by: Kyungmin Park <kyungmin.park at samsung.com>
> > Cc: Andy Fleming <afleming at gmail.com>
> > ---
> >  drivers/mmc/mmc.c |    4 +++-
> >  include/mmc.h     |    3 +++
> >  2 files changed, 6 insertions(+), 1 deletions(-)
> > 
> > diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
> > index 49c3349..51c0106 100644
> > --- a/drivers/mmc/mmc.c
> > +++ b/drivers/mmc/mmc.c
> > @@ -1103,7 +1103,9 @@ int mmc_startup(struct mmc *mmc)
> >  		else
> >  			mmc_set_clock(mmc, 25000000);
> >  	} else {
> > -		for (width = EXT_CSD_BUS_WIDTH_8; width >= 0;
> > width--) {
> > +		width = ((mmc->host_caps &
> > MMC_MODE_MASK_WIDTH_BITS)
> > >>
> > +			 MMC_MODE_WIDTH_BITS_SHIFT);
> > +		for (; width >= 0; width--) {
> >  			/* Set the card to use 4 bit*/
> >  			err = mmc_switch(mmc,
> > EXT_CSD_CMD_SET_NORMAL, EXT_CSD_BUS_WIDTH, width);
> > diff --git a/include/mmc.h b/include/mmc.h
> > index 30c2375..ff2f28e 100644
> > --- a/include/mmc.h
> > +++ b/include/mmc.h
> > @@ -47,6 +47,9 @@
> >  #define MMC_MODE_SPI		0x400
> >  #define MMC_MODE_HC		0x800
> >  
> > +#define MMC_MODE_MASK_WIDTH_BITS (MMC_MODE_4BIT | MMC_MODE_8BIT)
> > +#define MMC_MODE_WIDTH_BITS_SHIFT 8
> > +
> >  #define SD_DATA_4BIT	0x00040000
> >  
> >  #define IS_SD(x) (x->version & SD_VERSION_SD)
> 
> Do you have any opinions/comments about this patch?
> It has already spent some time on the mainling list and nobody
> complaint :-)
> 

Do you have any questions about this patch?


-- 
Best regards,

Lukasz Majewski

Samsung Poland R&D Center
Platform Group