> -----Original Message----- > From: subhashj@xxxxxxxxxxxxxx [mailto:subhashj@xxxxxxxxxxxxxx] > Sent: Thursday, March 10, 2011 7:15 PM > To: Nath, Arindam; cjb@xxxxxxxxxx > Cc: zhangfei.gao@xxxxxxxxx; prakity@xxxxxxxxxxx; linux- > mmc@xxxxxxxxxxxxxxx; Su, Henry; Lu, Aaron; anath.amd@xxxxxxxxx > Subject: RE: [PATCH v2 10/12] mmc: sdhci: enable preset value after uhs > initialization > > > > > -----Original Message----- > > From: linux-mmc-owner@xxxxxxxxxxxxxxx [mailto:linux-mmc- > > owner@xxxxxxxxxxxxxxx] On Behalf Of Nath, Arindam > > Sent: Thursday, March 10, 2011 7:01 PM > > To: subhashj@xxxxxxxxxxxxxx; cjb@xxxxxxxxxx > > Cc: zhangfei.gao@xxxxxxxxx; prakity@xxxxxxxxxxx; linux- > > mmc@xxxxxxxxxxxxxxx; Su, Henry; Lu, Aaron; anath.amd@xxxxxxxxx > > Subject: RE: [PATCH v2 10/12] mmc: sdhci: enable preset value after > uhs > > initialization > > > > Hi Subhash, > > > > > > > -----Original Message----- > > > From: subhashj@xxxxxxxxxxxxxx [mailto:subhashj@xxxxxxxxxxxxxx] > > > Sent: Thursday, March 10, 2011 6:54 PM > > > To: Nath, Arindam; cjb@xxxxxxxxxx > > > Cc: zhangfei.gao@xxxxxxxxx; prakity@xxxxxxxxxxx; linux- > > > mmc@xxxxxxxxxxxxxxx; Su, Henry; Lu, Aaron; anath.amd@xxxxxxxxx > > > Subject: RE: [PATCH v2 10/12] mmc: sdhci: enable preset value after > > uhs > > > initialization > > > > > > > > > > > > > -----Original Message----- > > > > From: linux-mmc-owner@xxxxxxxxxxxxxxx [mailto:linux-mmc- > > > > owner@xxxxxxxxxxxxxxx] On Behalf Of Arindam Nath > > > > Sent: Friday, March 04, 2011 5:03 PM > > > > To: cjb@xxxxxxxxxx > > > > Cc: zhangfei.gao@xxxxxxxxx; prakity@xxxxxxxxxxx; > > > > subhashj@xxxxxxxxxxxxxx; linux-mmc@xxxxxxxxxxxxxxx; > > henry.su@xxxxxxx; > > > > aaron.lu@xxxxxxx; anath.amd@xxxxxxxxx; 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. Thanks, Arindam > > > > > Thanks, > > Arindam > > > > > > > > > > > > > > > > Signed-off-by: Arindam Nath <arindam.nath@xxxxxxx> > > > > --- > > > > 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 majordomo@xxxxxxxxxxxxxxx > > > > 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 majordomo@xxxxxxxxxxxxxxx > > 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 majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
