> -----Original Message-----
> From: linux-mmc-ow...@vger.kernel.org [mailto:linux-mmc-
> ow...@vger.kernel.org] On Behalf Of Nath, Arindam
> Sent: Thursday, March 10, 2011 7:20 PM
> To: subha...@codeaurora.org; c...@laptop.org
> Cc: zhangfei....@gmail.com; prak...@marvell.com; linux-
> m...@vger.kernel.org; Su, Henry; Lu, Aaron; anath....@gmail.com
> Subject: RE: [PATCH v2 10/12] mmc: sdhci: enable preset value after uhs
> initialization
>
> > -----Original Message-----
> > From: subha...@codeaurora.org [mailto:subha...@codeaurora.org]
> > Sent: Thursday, March 10, 2011 7:15 PM
> > To: Nath, Arindam; c...@laptop.org
> > Cc: zhangfei....@gmail.com; prak...@marvell.com; linux-
> > m...@vger.kernel.org; Su, Henry; Lu, Aaron; anath....@gmail.com
> > Subject: RE: [PATCH v2 10/12] mmc: sdhci: enable preset value after
> uhs
> > initialization
> >
> >
> >
> > > -----Original Message-----
> > > From: linux-mmc-ow...@vger.kernel.org [mailto:linux-mmc-
> > > ow...@vger.kernel.org] On Behalf Of Nath, Arindam
> > > Sent: Thursday, March 10, 2011 7:01 PM
> > > To: subha...@codeaurora.org; c...@laptop.org
> > > Cc: zhangfei....@gmail.com; prak...@marvell.com; linux-
> > > m...@vger.kernel.org; Su, Henry; Lu, Aaron; anath....@gmail.com
> > > Subject: RE: [PATCH v2 10/12] mmc: sdhci: enable preset value after
> > uhs
> > > initialization
> > >
> > > Hi Subhash,
> > >
> > >
> > > > -----Original Message-----
> > > > From: subha...@codeaurora.org [mailto:subha...@codeaurora.org]
> > > > Sent: Thursday, March 10, 2011 6:54 PM
> > > > To: Nath, Arindam; c...@laptop.org
> > > > Cc: zhangfei....@gmail.com; prak...@marvell.com; linux-
> > > > m...@vger.kernel.org; Su, Henry; Lu, Aaron; anath....@gmail.com
> > > > Subject: RE: [PATCH v2 10/12] mmc: sdhci: enable preset value
> after
> > > uhs
> > > > initialization
> > > >
> > > >
> > > >
> > > > > -----Original Message-----
> > > > > From: linux-mmc-ow...@vger.kernel.org [mailto:linux-mmc-
> > > > > ow...@vger.kernel.org] On Behalf Of Arindam Nath
> > > > > Sent: Friday, March 04, 2011 5:03 PM
> > > > > To: c...@laptop.org
> > > > > Cc: zhangfei....@gmail.com; prak...@marvell.com;
> > > > > subha...@codeaurora.org; linux-mmc@vger.kernel.org;
> > > henry...@amd.com;
> > > > > aaron...@amd.com; anath....@gmail.com; Arindam Nath
> > > > > Subject: [PATCH v2 10/12] mmc: sdhci: enable preset value after
> > uhs
> > > > > initialization
> > > > >
> > > > > According to the Host Controller spec v3.00, setting Preset
> Value
> > > > > Enable
> > > > > in the Host Control2 register lets SDCLK Frequency Select,
> Clock
> > > > > Generator
> > > > > Select and Driver Strength Select to be set automatically by
> the
> > > Host
> > > > > Controller based on the UHS-I mode set. This patch enables this
> > > > > feature.
> > > > > We also reset Preset Value Enable when the card is removed from
> > the
> > > > > slot.
> > > >
> > > > What does this preset_value means? Is this defined in SD3.01
> spec?
> > I
> > > > think
> > > > it looks like specific to your controller (sdhci). If it's
> specific
> > > to
> > > > your
> > > > controller then this new mmc_ops should not be added.
> > >
> > > Preset Value Enable is very much part of the standard SD Host
> > > Controller spec v3.00. Please refer to Host Control 2 register.
> >
> > I don't think all controllers should be compliant to SD host
> controller
> > spec. I don't think controller on our chips has something like this.
>
> But from the spec it looks as if controllers conforming to v3.00 should
> provide this feature. There is no other bit anywhere else in the spec
> which can indicate support for Preset Value Enable except for the
> controller version number.
Actually, I am not aware about this controller spec v3.00. can you please
point me to the link for this spec (if it's available)?
>
> Thanks,
> Arindam
>
> >
> > >
> > > Thanks,
> > > Arindam
> > >
> > > >
> > > >
> > > > >
> > > > > Signed-off-by: Arindam Nath <arindam.n...@amd.com>
> > > > > ---
> > > > > drivers/mmc/core/sd.c | 7 +++++++
> > > > > drivers/mmc/host/sdhci.c | 36
> > > ++++++++++++++++++++++++++++++++++++
> > > > > include/linux/mmc/host.h | 1 +
> > > > > 3 files changed, 44 insertions(+), 0 deletions(-)
> > > > >
> > > > > diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
> > > > > index 1e2d157..ae7a771 100644
> > > > > --- a/drivers/mmc/core/sd.c
> > > > > +++ b/drivers/mmc/core/sd.c
> > > > > @@ -962,6 +962,13 @@ static int mmc_sd_init_card(struct
> mmc_host
> > > > *host,
> > > > > u32 ocr,
> > > > > }
> > > > > }
> > > > >
> > > > > + /*
> > > > > + * Since initialization is now complete, enable preset
> > > > > + * value registers.
> > > > > + */
> > > > > + if (host->ops->enable_preset_value)
> > > > > + host->ops->enable_preset_value(host);
> > > > > +
> > > > > host->card = card;
> > > > > return 0;
> > > > >
> > > > > diff --git a/drivers/mmc/host/sdhci.c
> b/drivers/mmc/host/sdhci.c
> > > > > index 8f4f102..1f6e4ad 100644
> > > > > --- a/drivers/mmc/host/sdhci.c
> > > > > +++ b/drivers/mmc/host/sdhci.c
> > > > > @@ -1602,6 +1602,40 @@ out:
> > > > > spin_unlock_irqrestore(&host->lock, flags);
> > > > > }
> > > > >
> > > > > +static void sdhci_enable_preset_value(struct mmc_host *mmc)
> > > > > +{
> > > > > + struct sdhci_host *host;
> > > > > + u16 ctrl;
> > > > > + unsigned long flags;
> > > > > +
> > > > > + host = mmc_priv(mmc);
> > > > > +
> > > > > + /* Host Controller v3.00 defines preset value registers */
> > > > > + if (host->version < SDHCI_SPEC_300)
> > > > > + return;
> > > > > +
> > > > > + spin_lock_irqsave(&host->lock, flags);
> > > > > +
> > > > > + ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> > > > > + ctrl |= SDHCI_CTRL_PRESET_VAL_ENABLE;
> > > > > + sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
> > > > > +
> > > > > + spin_unlock_irqrestore(&host->lock, flags);
> > > > > +}
> > > > > +
> > > > > +static void sdhci_disable_preset_value(struct sdhci_host
> *host)
> > > > > +{
> > > > > + u16 ctrl;
> > > > > +
> > > > > + /* Only for Host Controller version >= v3.00 */
> > > > > + if (host->version < SDHCI_SPEC_300)
> > > > > + return;
> > > > > +
> > > > > + ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> > > > > + ctrl &= ~SDHCI_CTRL_PRESET_VAL_ENABLE;
> > > > > + sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
> > > > > +}
> > > > > +
> > > > > static const struct mmc_host_ops sdhci_ops = {
> > > > > .request = sdhci_request,
> > > > > .set_ios = sdhci_set_ios,
> > > > > @@ -1610,6 +1644,7 @@ static const struct mmc_host_ops
> sdhci_ops
> > =
> > > {
> > > > > .start_signal_voltage_switch =
> > > > > sdhci_start_signal_voltage_switch,
> > > > > .get_max_current_180 = sdhci_get_max_current_180,
> > > > > .execute_tuning = sdhci_execute_tuning,
> > > > > + .enable_preset_value = sdhci_enable_preset_value,
> > > > > };
> > > > >
> > > > >
> > > > >
> > > >
> > >
> >
> /**********************************************************************
> > > > > *******\
> > > > > @@ -1920,6 +1955,7 @@ static irqreturn_t sdhci_irq(int irq,
> void
> > > > > *dev_id)
> > > > > sdhci_writel(host, intmask & (SDHCI_INT_CARD_INSERT
|
> > > > > SDHCI_INT_CARD_REMOVE), SDHCI_INT_STATUS);
> > > > > tasklet_schedule(&host->card_tasklet);
> > > > > + sdhci_disable_preset_value(host);
> > > > > }
> > > > >
> > > > > intmask &= ~(SDHCI_INT_CARD_INSERT |
> > SDHCI_INT_CARD_REMOVE);
> > > > > diff --git a/include/linux/mmc/host.h
> b/include/linux/mmc/host.h
> > > > > index 651e40b..e63e063 100644
> > > > > --- a/include/linux/mmc/host.h
> > > > > +++ b/include/linux/mmc/host.h
> > > > > @@ -130,6 +130,7 @@ struct mmc_host_ops {
> > > > > int (*start_signal_voltage_switch)(struct mmc_host
> > *host);
> > > > > int (*get_max_current_180)(struct mmc_host *mmc);
> > > > > void (*execute_tuning)(struct mmc_host *host);
> > > > > + void (*enable_preset_value)(struct mmc_host *host);
> > > > > };
> > > > >
> > > > > struct mmc_card;
> > > > > --
> > > > > 1.7.1
> > > > >
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