diff mbox

[v3,09/11] mmc: sdhci: enable preset value after uhs initialization

Message ID 1303291861-1788-10-git-send-email-arindam.nath@amd.com (mailing list archive)
State New, archived
Headers show

Commit Message

Arindam Nath April 20, 2011, 9:30 a.m. UTC
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 next time before initialization.

Signed-off-by: Arindam Nath <arindam.nath@amd.com>
---
 drivers/mmc/core/sd.c    |   11 +++++++++++
 drivers/mmc/host/sdhci.c |   32 ++++++++++++++++++++++++++++++++
 include/linux/mmc/host.h |    1 +
 3 files changed, 44 insertions(+), 0 deletions(-)

Comments

Zhangfei Gao April 28, 2011, 5:16 a.m. UTC | #1
On Wed, Apr 20, 2011 at 5:30 AM, Arindam Nath <arindam.nath@amd.com> wrote:
> 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 next time before initialization.
>
> Signed-off-by: Arindam Nath <arindam.nath@amd.com>

Hi, Arindam

This patch cause abnormal behavior of general hs card, since
enable_preset_value(host, 1) is set to both uhs card and general card
here.
Your patch serious basically works with the fix, thanks a lot.
Additional call back to enable external regulator output voltage is
needed on our platform for testing.

Thanks

> ---
>  drivers/mmc/core/sd.c    |   11 +++++++++++
>  drivers/mmc/host/sdhci.c |   32 ++++++++++++++++++++++++++++++++
>  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 f3ecdef..08305ab 100644
> --- a/drivers/mmc/core/sd.c
> +++ b/drivers/mmc/core/sd.c
> @@ -959,6 +959,13 @@ 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, 1);
> +

Could you move this after mmc_sd_card_set_uhs, and only for uhs card.
General hs card may not properly if enable this feature.

>        host->card = card;
>        return 0;
>
> @@ -1109,6 +1116,10 @@ int mmc_attach_sd(struct mmc_host *host)
>        if (err)
>                return err;
>
> +       /* Disable preset value enable if already set from last time */
> +       if (host->ops->enable_preset_value)
> +               host->ops->enable_preset_value(host, 0);
> +
>        /*
>         * We need to get OCR a different way for SPI.
>         */
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 9065157..c25ab83 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1614,6 +1614,37 @@ out:
>        return err;
>  }
>
> +static void sdhci_enable_preset_value(struct mmc_host *mmc, int enable)
> +{
> +       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);
> +
> +       /*
> +        * We only enable or disable Preset Value if they are not already
> +        * enabled or disabled respectively. Otherwise, we bail out.
> +        */
> +       if (enable && !(ctrl & SDHCI_CTRL_PRESET_VAL_ENABLE)) {
> +               ctrl |= SDHCI_CTRL_PRESET_VAL_ENABLE;
> +               sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
> +       } else if (!enable && (ctrl & SDHCI_CTRL_PRESET_VAL_ENABLE)) {
> +               ctrl &= ~SDHCI_CTRL_PRESET_VAL_ENABLE;
> +               sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
> +       }
> +
> +       spin_unlock_irqrestore(&host->lock, flags);
> +}
> +
>  static const struct mmc_host_ops sdhci_ops = {
>        .request        = sdhci_request,
>        .set_ios        = sdhci_set_ios,
> @@ -1621,6 +1652,7 @@ static const struct mmc_host_ops sdhci_ops = {
>        .enable_sdio_irq = sdhci_enable_sdio_irq,
>        .start_signal_voltage_switch    = sdhci_start_signal_voltage_switch,
>        .execute_tuning                 = sdhci_execute_tuning,
> +       .enable_preset_value            = sdhci_enable_preset_value,
>  };
>
>  /*****************************************************************************\
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index ca7007f..2209e01 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -137,6 +137,7 @@ struct mmc_host_ops {
>
>        int     (*start_signal_voltage_switch)(struct mmc_host *host, struct mmc_ios *ios);
>        int     (*execute_tuning)(struct mmc_host *host);
> +       void    (*enable_preset_value)(struct mmc_host *host, int enable);
>  };
>
>  struct mmc_card;
> --
> 1.7.1
>
>
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Arindam Nath April 28, 2011, 5:50 a.m. UTC | #2
Hi Zhangfei,


> -----Original Message-----
> From: zhangfei gao [mailto:zhangfei.gao@gmail.com]
> Sent: Thursday, April 28, 2011 10:47 AM
> To: Nath, Arindam
> Cc: cjb@laptop.org; linux-mmc@vger.kernel.org; prakity@marvell.com;
> subhashj@codeaurora.org; Su, Henry; Lu, Aaron; anath.amd@gmail.com
> Subject: Re: [PATCH v3 09/11] mmc: sdhci: enable preset value after uhs
> initialization
> 
> On Wed, Apr 20, 2011 at 5:30 AM, Arindam Nath <arindam.nath@amd.com>
> wrote:
> > 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 next time before initialization.
> >
> > Signed-off-by: Arindam Nath <arindam.nath@amd.com>
> 
> Hi, Arindam
> 
> This patch cause abnormal behavior of general hs card, since
> enable_preset_value(host, 1) is set to both uhs card and general card
> here.
> Your patch serious basically works with the fix, thanks a lot.
> Additional call back to enable external regulator output voltage is
> needed on our platform for testing.
> 
> Thanks
> 
> > ---
> >  drivers/mmc/core/sd.c    |   11 +++++++++++
> >  drivers/mmc/host/sdhci.c |   32 ++++++++++++++++++++++++++++++++
> >  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 f3ecdef..08305ab 100644
> > --- a/drivers/mmc/core/sd.c
> > +++ b/drivers/mmc/core/sd.c
> > @@ -959,6 +959,13 @@ 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, 1);
> > +
> 
> Could you move this after mmc_sd_card_set_uhs, and only for uhs card.
> General hs card may not properly if enable this feature.

Yes, that would make sense. Will fix it.

Thanks,
Arindam


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diff mbox

Patch

diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index f3ecdef..08305ab 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -959,6 +959,13 @@  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, 1);
+
 	host->card = card;
 	return 0;
 
@@ -1109,6 +1116,10 @@  int mmc_attach_sd(struct mmc_host *host)
 	if (err)
 		return err;
 
+	/* Disable preset value enable if already set from last time */
+	if (host->ops->enable_preset_value)
+		host->ops->enable_preset_value(host, 0);
+
 	/*
 	 * We need to get OCR a different way for SPI.
 	 */
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 9065157..c25ab83 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1614,6 +1614,37 @@  out:
 	return err;
 }
 
+static void sdhci_enable_preset_value(struct mmc_host *mmc, int enable)
+{
+	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);
+
+	/*
+	 * We only enable or disable Preset Value if they are not already
+	 * enabled or disabled respectively. Otherwise, we bail out.
+	 */
+	if (enable && !(ctrl & SDHCI_CTRL_PRESET_VAL_ENABLE)) {
+		ctrl |= SDHCI_CTRL_PRESET_VAL_ENABLE;
+		sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
+	} else if (!enable && (ctrl & SDHCI_CTRL_PRESET_VAL_ENABLE)) {
+		ctrl &= ~SDHCI_CTRL_PRESET_VAL_ENABLE;
+		sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
+	}
+
+	spin_unlock_irqrestore(&host->lock, flags);
+}
+
 static const struct mmc_host_ops sdhci_ops = {
 	.request	= sdhci_request,
 	.set_ios	= sdhci_set_ios,
@@ -1621,6 +1652,7 @@  static const struct mmc_host_ops sdhci_ops = {
 	.enable_sdio_irq = sdhci_enable_sdio_irq,
 	.start_signal_voltage_switch	= sdhci_start_signal_voltage_switch,
 	.execute_tuning			= sdhci_execute_tuning,
+	.enable_preset_value		= sdhci_enable_preset_value,
 };
 
 /*****************************************************************************\
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index ca7007f..2209e01 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -137,6 +137,7 @@  struct mmc_host_ops {
 
 	int	(*start_signal_voltage_switch)(struct mmc_host *host, struct mmc_ios *ios);
 	int	(*execute_tuning)(struct mmc_host *host);
+	void	(*enable_preset_value)(struct mmc_host *host, int enable);
 };
 
 struct mmc_card;