[U-Boot] [PATCH 5/6] i.mx: fsl_esdhc: add the i.mx6q support

[Jason Hui]

On Mon, Nov 14, 2011 at 6:42 PM, Marek Vasut <marek.vasut at gmail.com> wrote:
>> On Sun, Nov 13, 2011 at 12:35 AM, Marek Vasut <marek.vasut at gmail.com> wrote:
>> >> The mmc host controller on the i.mx6q is called usdhc which
>> >> is redesigned based on the freescale esdhc controller.
>> >>
>> >> The usdhc controller is almost compatible with esdhc except
>> >> it adds one misc control register from user using experience.
>> >>
>> >> Signed-off-by: Jason Liu <jason.hui at linaro.org>
>> >> ---
>> >>  drivers/mmc/fsl_esdhc.c |   14 +++++++++++++-
>> >>  1 files changed, 13 insertions(+), 1 deletions(-)
>> >>
>> >> diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c
>> >> index ec953f0..cd17ef2 100644
>> >> --- a/drivers/mmc/fsl_esdhc.c
>> >> +++ b/drivers/mmc/fsl_esdhc.c
>> >> @@ -58,7 +58,12 @@ struct fsl_esdhc {
>> >>       uint    autoc12err;
>> >>       uint    hostcapblt;
>> >>       uint    wml;
>> >> -     char    reserved1[8];
>> >> +#if defined(CONFIG_FSL_USDHC)
>> >> +     uint    mixctrl;
>> >> +     char    reserved1[4];
>> >> +#else
>> >> +     char    reserved1[8];
>> >> +#endif
>> >
>> > Hi Jason,
>> >
>> > can't we just drop this ifdef ?
>>
>> Yes, I think we can. I will drop it later.
>
> Please drop now so it's not forgotten ;-)
>
>>
>> >>       uint    fevt;
>> >>       char    reserved2[168];
>> >>       uint    hostver;
>> >> @@ -298,6 +303,9 @@ esdhc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
>> >> struct mmc_data *data)
>> >>
>> >>       /* Send the command */
>> >>       esdhc_write32(&regs->cmdarg, cmd->cmdarg);
>> >> +#if defined(CONFIG_FSL_USDHC)
>> >> +     esdhc_write32(&regs->mixctrl, xfertyp & 0xFFFF);
>> >> +#endif
>> >>       esdhc_write32(&regs->xfertyp, xfertyp);
>> >
>> > Why is this duplicated? This seems like a huge user-experience nonsense
>> > to me :)
>> >
>> > If you write to xfertyp register, you still have to write the same thing
>> > to mixctrl? Or if you do it vice versa, won't it work ? Why did you add
>> > the register?
>>
>> This is due to that on i.mx6q usdhc, it adds one extra mixctrl(offset
>> 0x48) register to accommodate the
>> low 16-bits of tranfertype and the high 16-bits of tranfertype will
>> still go via the xfertyp register.
>> On the i.mx6q usdhc, the xfertyp(offset 0xc) register, the low 16-bits
>> is not used and only
>> high 16-bits have been used. I can make the above code clear as the
>> followings,
>>
>> #if defined(CONFIG_FSL_USDHC)
>> esdhc_write32(&regs->mixctrl, xfertyp & 0x0000FFFF);
>> esdhc_write32(&regs->xfertyp, xfertyp & 0xFFFF0000);
>> #else
>> esdhc_write32(&regs->xfertyp, xfertyp);
>> #endif
>
> Well this is insane, is the datasheet for mx6q available already so I can check
> for myself?

This is mx6q usdhc design and datasheet is not public now.
Without this, the mmc driver does not work.

Jason Liu

>
>>
>> >>       /* Wait for the command to complete */
>> >> @@ -482,7 +490,11 @@ int fsl_esdhc_initialize(bd_t *bis, struct
>> >> fsl_esdhc_cfg *cfg)
>> >>
>> >>       mmc = malloc(sizeof(struct mmc));
>> >>
>> >> +#if defined(CONFIG_FSL_USDHC)
>> >> +     sprintf(mmc->name, "FSL_USDHC");
>> >> +#else
>> >>       sprintf(mmc->name, "FSL_ESDHC");
>> >> +#endif
>> >
>> > Why not just rename it to FSL_SDHC and be done with it ?
>>
>> OK, I will do it.
>>
>> >>       regs = (struct fsl_esdhc *)cfg->esdhc_base;
>> >>
>> >>       /* First reset the eSDHC controller */
>>
>> Jason Liu
>