> -----Original Message----- > From: [email protected] [mailto:linux-mmc- > [email protected]] On Behalf Of Nath, Arindam > Sent: Thursday, March 10, 2011 7:01 PM > To: [email protected]; [email protected] > Cc: [email protected]; [email protected]; linux- > [email protected]; Su, Henry; Lu, Aaron; [email protected] > Subject: RE: [PATCH v2 10/12] mmc: sdhci: enable preset value after uhs > initialization > > Hi Subhash, > > > > -----Original Message----- > > From: [email protected] [mailto:[email protected]] > > Sent: Thursday, March 10, 2011 6:54 PM > > To: Nath, Arindam; [email protected] > > Cc: [email protected]; [email protected]; linux- > > [email protected]; Su, Henry; Lu, Aaron; [email protected] > > Subject: RE: [PATCH v2 10/12] mmc: sdhci: enable preset value after > uhs > > initialization > > > > > > > > > -----Original Message----- > > > From: [email protected] [mailto:linux-mmc- > > > [email protected]] On Behalf Of Arindam Nath > > > Sent: Friday, March 04, 2011 5:03 PM > > > To: [email protected] > > > Cc: [email protected]; [email protected]; > > > [email protected]; [email protected]; > [email protected]; > > > [email protected]; [email protected]; 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. > > Thanks, > Arindam > > > > > > > > > > > Signed-off-by: Arindam Nath <[email protected]> > > > --- > > > 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 > > > > > > -- > > > To unsubscribe from this list: send the line "unsubscribe linux- > mmc" > > in > > > the body of a message to [email protected] > > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
