[U-Boot] [PATCH 3/4] mmc: fsl_esdhc: Implement card-detect hook.

Thierry Reding
2011-12-05T12:49:52Z

* Stefano Babic wrote:
> On 05/12/2011 09:23, Thierry Reding wrote:
> > This card-detect hook probably doesn't work. Perhaps somebody with more
> > knowledge about the hardware can comment on this. I think that perhaps
> > even the complete code from esdhc_init() could go into the getcd()
>
> The reason was only that the SDHC controller returns (up now) if the car
> is inserted or not. However, there is no hardware related reason to make
> this function called by the esdhc_init().

Does that mean that the prsstat register work even if the controller hasn't
been initialized? If so, then the hook should work as is.

> > function instead or mmc_getcd() needs to be called at some later time
> > after mmc_init(), which, however, would require many other drivers to
> > change.
> >
> > Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
> > ---
> > drivers/mmc/fsl_esdhc.c | 29 ++++++++++++-----------------
> > 1 files changed, 12 insertions(+), 17 deletions(-)
> >
> > diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c
> > index f719afd..b46bf9f 100644
> > --- a/drivers/mmc/fsl_esdhc.c
> > +++ b/drivers/mmc/fsl_esdhc.c
> > @@ -412,7 +412,6 @@ static int esdhc_init(struct mmc *mmc)
> > struct fsl_esdhc_cfg *cfg = (struct fsl_esdhc_cfg *)mmc->priv;
> > struct fsl_esdhc *regs = (struct fsl_esdhc *)cfg->esdhc_base;
> > int timeout = 1000;
> > - int ret = 0;
> >
> > /* Reset the entire host controller */
> > esdhc_write32(&regs->sysctl, SYSCTL_RSTA);
> > @@ -439,24 +438,19 @@ static int esdhc_init(struct mmc *mmc)
> > /* Set timout to the maximum value */
> > esdhc_clrsetbits32(&regs->sysctl, SYSCTL_TIMEOUT_MASK, 14 << 16);
> >
> > - /* Check if there is a callback for detecting the card */
> > - ret = board_mmc_getcd(mmc);
> > - if (ret < 0) {
> > - timeout = 1000;
> > - while (!(esdhc_read32(&regs->prsstat) & PRSSTAT_CINS) &&
> > - --timeout)
> > - udelay(1000);
> > + return 0;
> > +}
>
> This is wrong, we have on fsl_esdhc.c at least two cases:
> - the Card Detect is executed directly by the controller reading the
> prsstat register - this happens for most (or all) PowerPC SOC haveing a
> ESDHC controller.
>
> - The Card Detect is done via GPIOs, as most of MX5 boards are doing
> now, and as you implemented for Tegra (next patch).
>
> You drop the way via GPIOs, breaking several boards.

No, patch 2 already moved board_mmc_getcd() to mmc_getcd() and calls
mmc_getcd() before mmc_init() is even called. So all boards should work as
before. This really only removes the duplicate check. Perhaps I should
mention that in the commit message.

Thierry
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