[U-Boot] [PATCH] powerpc/esdhc: force the bus width to 4bit
Marek Vasut
marex at denx.de
Tue Oct 23 09:24:27 CEST 2012
Dear Chang-Ming.Huang at freescale.com,
> From: Jerry Huang <Chang-Ming.Huang at freescale.com>
>
> For the current u-boot codes, only 4bit/1bit SD/SDHC bus width is support.
> So for MMC card, we also support 4bit bus width,
> otherwiase, we will get the 12bit bus width, which is not correct:
Andy ... can you please explain? I don't quite understand the problem, I thought
we had no problem supporting 8bit mmc (esp. if the controller handles that for
us mostly).
> => mmcinfo
> Device: FSL_SDHC
> Manufacturer ID: 1e
> OEM: ffff
> Name: MMC
> Tran Speed: 52000000
> Rd Block Len: 512
> MMC version 4.0
> High Capacity: No
> Capacity: 1.9 GiB
> Bus Width: 12-bit
>
> Signed-off-by: Jerry Huang <Chang-Ming.Huang at freescalecom>
> CC: Andy Fleming <afleming at gmail.com>
> CC: Marek Vasut <marex at denx.de>
> ---
> drivers/mmc/fsl_esdhc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c
> index 3f8d30d..7b83dd2 100644
> --- a/drivers/mmc/fsl_esdhc.c
> +++ b/drivers/mmc/fsl_esdhc.c
> @@ -577,7 +577,7 @@ int fsl_esdhc_initialize(bd_t *bis, struct
> fsl_esdhc_cfg *cfg) return -1;
> }
>
> - mmc->host_caps = MMC_MODE_4BIT | MMC_MODE_8BIT;
> + mmc->host_caps = MMC_MODE_4BIT;
>
> if (caps & ESDHC_HOSTCAPBLT_HSS)
> mmc->host_caps |= MMC_MODE_HS_52MHz | MMC_MODE_HS;
Best regards,
Marek Vasut
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