Re: [PATCH 3/4 v5] SDHCI: add sdhci_get_cd callback to detect the card

[Aaron Lu <aaron.lu@amd.com>]

Hi,

On Fri, Jan 13, 2012 at 02:25:18AM +0000, Huang Changming-R66093 wrote:
> Hi, Chris,
> Could you have any comment about this patch?
> Can it go into 3.3 or 3.4?
> 
> Thanks
> Jerry Huang
> 
> > -----Original Message-----
> > From: Huang Changming-R66093
> > Sent: Wednesday, December 14, 2011 10:18 AM
> > To: linux-mmc@vger.kernel.org
> > Cc: Huang Changming-R66093; Chris Ball
> > Subject: [PATCH 3/4 v5] SDHCI: add sdhci_get_cd callback to detect the
> > card
> > 
> > From: Jerry Huang <Chang-Ming.Huang@freescale.com>
> > 
> > Add callback function sdhci_get_cd to detect the card.
> > And one new callback added to implement the card detect in sdhci
> > struncture.
> > If special platform has the card detect callback, it will return the card
> > state, the value zero is for absent cardi and one is for present card.
> > If the controller don't support card detect, sdhci_get_cd will return -
> > ENOSYS.
> > 
> > Signed-off-by: Jerry Huang <Chang-Ming.Huang@freescale.com>
> > CC: Chris Ball <cjb@laptop.org>
> > ---
> > changes for v2:
> > 	- when controller don't support get_cd, return -ENOSYS
> > 	- add new callback for sdhci to detect the card
> > 	- add the CC
> > changes for v3:
> > 	- use pin_lock only when get_cd defined
> > changes for v4:
> > 	- enalbe the controller clock in platform, instead of core
> > changes for v5:
> > 	- remove the copyright
> > 
> >  drivers/mmc/host/sdhci.c |   21 ++++++++++++++++++++++
> >  drivers/mmc/host/sdhci.h |    2 ++
> >  2 files changed, 23 insertions(+), 0 deletions(-)
> > 
> > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> > index 6d8eea3..fbe2f46 100644
> > --- a/drivers/mmc/host/sdhci.c
> > +++ b/drivers/mmc/host/sdhci.c
> > @@ -1518,6 +1519,26 @@ static int sdhci_get_ro(struct mmc_host *mmc)
> >  	return ret;
> >  }

snip
> > 
> > +/* Return values for the sdjco_get_cd callback:
> > + *   0 for a absent card
> > + *   1 for a present card
> > + *   -ENOSYS when not supported (equal to NULL callback)
> > + */
> > +static int sdhci_get_cd(struct mmc_host *mmc)
> > +{
> > +	struct sdhci_host *host = mmc_priv(mmc);
> > +	unsigned long flags;
> > +	int present = -ENOSYS;
> > +
> > +	if (host->ops->get_cd) {
> > +		spin_lock_irqsave(&host->lock, flags);
> > +		present = host->ops->get_cd(host);
> > +		spin_unlock_irqrestore(&host->lock, flags);
> > +	}
> > +
> > +	return present;
> > +}
> > +

I think this function has to take care of standard sd host behaviour: if
a specific host has implemented the get_cd callback, then use it; if
not, then see the BROKEN_DETECT quirk; finally, use the present register
to get the value like the sdhci_request function does.

-Aaron

> >  static void sdhci_enable_sdio_irq_nolock(struct sdhci_host *host, int
> > enable)
> >  {
> >  	if (host->flags & SDHCI_DEVICE_DEAD)
> > @@ -1884,6 +1905,7 @@ static const struct mmc_host_ops sdhci_ops = {
> >  	.request	= sdhci_request,
> >  	.set_ios	= sdhci_set_ios,
> >  	.get_ro		= sdhci_get_ro,
> > +	.get_cd		= sdhci_get_cd,
> >  	.hw_reset	= sdhci_hw_reset,
> >  	.enable_sdio_irq = sdhci_enable_sdio_irq,
> >  	.start_signal_voltage_switch	= sdhci_start_signal_voltage_switch,
> > diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> > index 0a5b654..82f4d27 100644
> > --- a/drivers/mmc/host/sdhci.h
> > +++ b/drivers/mmc/host/sdhci.h
> > @@ -69,6 +69,7 @@
> >  #define  SDHCI_SPACE_AVAILABLE	0x00000400
> >  #define  SDHCI_DATA_AVAILABLE	0x00000800
> >  #define  SDHCI_CARD_PRESENT	0x00010000
> > +#define  SDHCI_CARD_CDPL	0x00040000
> >  #define  SDHCI_WRITE_PROTECT	0x00080000
> >  #define  SDHCI_DATA_LVL_MASK	0x00F00000
> >  #define   SDHCI_DATA_LVL_SHIFT	20
> > @@ -261,6 +262,7 @@ struct sdhci_ops {
> > 
> >  	void	(*set_clock)(struct sdhci_host *host, unsigned int clock);
> > 
> > +	int		(*get_cd)(struct sdhci_host *host);
> >  	int		(*enable_dma)(struct sdhci_host *host);
> >  	unsigned int	(*get_max_clock)(struct sdhci_host *host);
> >  	unsigned int	(*get_min_clock)(struct sdhci_host *host);
> > --
> > 1.7.5.4
> 
> 
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