[U-Boot] [PATCH 4/6] mmc: fsl_esdhc: Add support to force VSELECT set

[Stefano Babic]

Hi Otavio,

On 16/06/2014 02:46, Otavio Salvador wrote:
> There are board were we cannot do voltage negotiation but want to set
> the VSELECT bit forcely to ensure it to work at 1.8V.
> 
> This commit adds CONFIG_SYS_FSL_ESDHC_FORCE_VSELECT flag for this use.
> 
> Signed-off-by: Otavio Salvador <otavio at ossystems.com.br>
> ---
> 
>  drivers/mmc/fsl_esdhc.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c
> index c75b38f..b3870e2 100644
> --- a/drivers/mmc/fsl_esdhc.c
> +++ b/drivers/mmc/fsl_esdhc.c
> @@ -517,6 +517,10 @@ static int esdhc_init(struct mmc *mmc)
>  	/* Set timout to the maximum value */
>  	esdhc_clrsetbits32(&regs->sysctl, SYSCTL_TIMEOUT_MASK, 14 << 16);
>  
> +#ifdef CONFIG_SYS_FSL_ESDHC_FORCE_VSELECT
> +	esdhc_setbits32(&regs->vendorspec, ESDHC_VENDORSPEC_VSELECT);
> +#endif

Instead of adding a new compiler switch that should be documented (I
have already read Marek's comments), what do you think to extend struct
fsl_esdhc_cfg, putting for exmaple an "options" field with this kind of
specialization ?

I see also a CONFIG_SYS_FSL_ESDHC_USE_PIO that slipped into mainline
(you are both right : Otavio is not the first to add such kind of
configuration switches that are still undocumented, but according to
rules should be documented as Marek said).

I would suggest to get rid as much as possible with these CONFIG_
switches. If we have some specialization for this driver before calling
esdhc_init (better: fsl_esdhc_initialize), they are self explaining and
we do not need further documentation. What do you think ?

Best regards,
Stefano


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