[U-Boot] [PATCH 2/2 v3] FSL/eSDHC: enable the clock to detect the SD card

Marek Vasut marex at denx.de
Fri May 18 18:03:15 CEST 2012


Dear Chang-Ming.Huang at freescale.com,

> From: Jerry Huang <Chang-Ming.Huang at freescale.com>
> 
> For FSL low-end processors (VVN2.2)

What's VVN2.2 ?

> , in order to detect the SD card,
> we should enable PEREN, HCKEN and IPGEN to enable the clock.
> Otherwise, after booting the u-boot, and then inserting the SD card,
> the SD card can't be detected.
> For SDHC VVN2.3 IP

VVN2.3 ?

> , these bits are reserved, and SDCLKEN is used.
> And when accessing to these reserved bit, no any impact happened.
> 
> Signed-off-by: Jerry Huang <Chang-Ming.Huang at freescale.com>
> CC: Andy Fleming <afleming at gmail.com>
> CC: Marek Vasut <marex at denx.de>
> ---
> changes for v2:
> 	- correct the typo
> changes for v3:
> 	- enable all clock bits for VVN2.3 and VVN2.2
> 	- use funciton esdhc_setbits32
> 	- tested on p1022ds, p1025rdb, p1020mbg-pc, mpc8536ds, p3041ds
> 
>  drivers/mmc/fsl_esdhc.c |    3 +++
>  1 files changed, 3 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c
> index a2f35e3..930a5c5 100644
> --- a/drivers/mmc/fsl_esdhc.c
> +++ b/drivers/mmc/fsl_esdhc.c
> @@ -491,6 +491,9 @@ int fsl_esdhc_initialize(bd_t *bis, struct
> fsl_esdhc_cfg *cfg) /* First reset the eSDHC controller */
>  	esdhc_reset(regs);
> 
> +	esdhc_setbits32(&regs->sysctl, SYSCTL_PEREN | SYSCTL_HCKEN
> +				| SYSCTL_IPGEN | SYSCTL_CKEN);
> +
>  	mmc->priv = cfg;
>  	mmc->send_cmd = esdhc_send_cmd;
>  	mmc->set_ios = esdhc_set_ios;

Best regards,
Marek Vasut


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