diff mbox

[v3,2/7] mmc: sdhci-of-esdhc: add support for signal voltage switch

Message ID 1490600982-5410-3-git-send-email-yangbo.lu@nxp.com (mailing list archive)
State New, archived
Headers show

Commit Message

Yangbo Lu March 27, 2017, 7:49 a.m. UTC
eSDHC supports signal voltage switch from 3.3v to 1.8v by
eSDHC_PROCTL[VOLT_SEL] bit. This bit changes the value of output
signal SDHC_VS, and there must be a control circuit out of eSDHC
to change the signal voltage according to SDHC_VS output signal.

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
---
Changes for v2:
	- Used Adrain's method to support voltage switching:
          host->mmc_host_ops.start_signal_voltage_switch =
                     esdhc_signal_voltage_switch;
Changes for v3:
	- Put .start_signal_voltage_switch assigning after IS_ERR(host) check.
---
 drivers/mmc/host/sdhci-esdhc.h    |  1 +
 drivers/mmc/host/sdhci-of-esdhc.c | 74 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 75 insertions(+)

Comments

Adrian Hunter April 10, 2017, 12:37 p.m. UTC | #1
On 27/03/17 10:49, Yangbo Lu wrote:
> eSDHC supports signal voltage switch from 3.3v to 1.8v by
> eSDHC_PROCTL[VOLT_SEL] bit. This bit changes the value of output
> signal SDHC_VS, and there must be a control circuit out of eSDHC
> to change the signal voltage according to SDHC_VS output signal.
> 
> Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>

Apart from minor comment below:

Acked-by: Adrian Hunter <adrian.hunter@intel.com>

> ---
> Changes for v2:
> 	- Used Adrain's method to support voltage switching:
>           host->mmc_host_ops.start_signal_voltage_switch =
>                      esdhc_signal_voltage_switch;
> Changes for v3:
> 	- Put .start_signal_voltage_switch assigning after IS_ERR(host) check.
> ---
>  drivers/mmc/host/sdhci-esdhc.h    |  1 +
>  drivers/mmc/host/sdhci-of-esdhc.c | 74 +++++++++++++++++++++++++++++++++++++++
>  2 files changed, 75 insertions(+)
> 
> diff --git a/drivers/mmc/host/sdhci-esdhc.h b/drivers/mmc/host/sdhci-esdhc.h
> index 5343fc0..6869567 100644
> --- a/drivers/mmc/host/sdhci-esdhc.h
> +++ b/drivers/mmc/host/sdhci-esdhc.h
> @@ -37,6 +37,7 @@
>  
>  /* Protocol Control Register */
>  #define ESDHC_PROCTL			0x28
> +#define ESDHC_VOLT_SEL			0x00000400
>  #define ESDHC_CTRL_4BITBUS		(0x1 << 1)
>  #define ESDHC_CTRL_8BITBUS		(0x2 << 1)
>  #define ESDHC_CTRL_BUSWIDTH_MASK	(0x3 << 1)
> diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
> index 7ce1caf..a70499a 100644
> --- a/drivers/mmc/host/sdhci-of-esdhc.c
> +++ b/drivers/mmc/host/sdhci-of-esdhc.c
> @@ -16,6 +16,7 @@
>  #include <linux/err.h>
>  #include <linux/io.h>
>  #include <linux/of.h>
> +#include <linux/of_address.h>
>  #include <linux/delay.h>
>  #include <linux/module.h>
>  #include <linux/sys_soc.h>
> @@ -559,6 +560,76 @@ static void esdhc_reset(struct sdhci_host *host, u8 mask)
>  	sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
>  }
>  
> +/* The SCFG, Supplemental Configuration Unit, provides SoC specific
> + * configuration and status registers for the device. There is a
> + * SDHC IO VSEL control register on SCFG for some platforms. It's
> + * used to support SDHC IO voltage switching.
> + */
> +static const struct of_device_id scfg_device_ids[] = {
> +	{ .compatible = "fsl,t1040-scfg", },
> +	{ .compatible = "fsl,ls1012a-scfg", },
> +	{ .compatible = "fsl,ls1046a-scfg", },
> +	{}
> +};
> +
> +/* SDHC IO VSEL control register definition */
> +#define SCFG_SDHCIOVSELCR	0x408
> +#define SDHCIOVSELCR_TGLEN	0x80000000
> +#define SDHCIOVSELCR_VSELVAL	0x60000000
> +#define SDHCIOVSELCR_SDHC_VS	0x00000001
> +
> +static int esdhc_signal_voltage_switch(struct mmc_host *mmc,
> +				       struct mmc_ios *ios)
> +{
> +	struct sdhci_host *host = mmc_priv(mmc);
> +	struct device_node *scfg_node;
> +	void __iomem *scfg_base = NULL;
> +	u32 sdhciovselcr;
> +	u32 val;
> +
> +	/*
> +	 * Signal Voltage Switching is only applicable for Host Controllers
> +	 * v3.00 and above.
> +	 */
> +	if (host->version < SDHCI_SPEC_300)
> +		return 0;
> +
> +	val = sdhci_readl(host, ESDHC_PROCTL);
> +
> +	switch (ios->signal_voltage) {
> +	case MMC_SIGNAL_VOLTAGE_330:
> +		val &= ~ESDHC_VOLT_SEL;
> +		sdhci_writel(host, val, ESDHC_PROCTL);
> +		return 0;
> +	case MMC_SIGNAL_VOLTAGE_180:
> +		scfg_node = of_find_matching_node(NULL, scfg_device_ids);
> +		if (scfg_node)
> +			scfg_base = of_iomap(scfg_node, 0);
> +		if (scfg_base) {
> +			sdhciovselcr = SDHCIOVSELCR_TGLEN |
> +				       SDHCIOVSELCR_VSELVAL;
> +			iowrite32be(sdhciovselcr,
> +				scfg_base + SCFG_SDHCIOVSELCR);

In other places there is support for little endian also, so why not here?

> +
> +			val |= ESDHC_VOLT_SEL;
> +			sdhci_writel(host, val, ESDHC_PROCTL);
> +			mdelay(5);
> +
> +			sdhciovselcr = SDHCIOVSELCR_TGLEN |
> +				       SDHCIOVSELCR_SDHC_VS;
> +			iowrite32be(sdhciovselcr,
> +				scfg_base + SCFG_SDHCIOVSELCR);
> +			iounmap(scfg_base);
> +		} else {
> +			val |= ESDHC_VOLT_SEL;
> +			sdhci_writel(host, val, ESDHC_PROCTL);
> +		}
> +		return 0;
> +	default:
> +		return 0;
> +	}
> +}
> +
>  #ifdef CONFIG_PM_SLEEP
>  static u32 esdhc_proctl;
>  static int esdhc_of_suspend(struct device *dev)
> @@ -714,6 +785,9 @@ static int sdhci_esdhc_probe(struct platform_device *pdev)
>  	if (IS_ERR(host))
>  		return PTR_ERR(host);
>  
> +	host->mmc_host_ops.start_signal_voltage_switch =
> +		esdhc_signal_voltage_switch;
> +
>  	esdhc_init(pdev, host);
>  
>  	sdhci_get_of_property(pdev);
>
Yangbo Lu April 11, 2017, 5:20 a.m. UTC | #2
Hi Adrian,


> -----Original Message-----
> From: linux-mmc-owner@vger.kernel.org [mailto:linux-mmc-
> owner@vger.kernel.org] On Behalf Of Adrian Hunter
> Sent: Monday, April 10, 2017 8:38 PM
> To: Y.B. Lu; linux-mmc@vger.kernel.org; devicetree@vger.kernel.org;
> linux-arm-kernel@lists.infradead.org; ulf.hansson@linaro.org; Rob Herring;
> Mark Rutland; Catalin Marinas; Will Deacon
> Cc: Xiaobo Xie
> Subject: Re: [v3, 2/7] mmc: sdhci-of-esdhc: add support for signal
> voltage switch
> 
> On 27/03/17 10:49, Yangbo Lu wrote:
> > eSDHC supports signal voltage switch from 3.3v to 1.8v by
> > eSDHC_PROCTL[VOLT_SEL] bit. This bit changes the value of output
> > signal SDHC_VS, and there must be a control circuit out of eSDHC to
> > change the signal voltage according to SDHC_VS output signal.
> >
> > Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
> 
> Apart from minor comment below:
> 
> Acked-by: Adrian Hunter <adrian.hunter@intel.com>
> 
> > ---
> > Changes for v2:
> > 	- Used Adrain's method to support voltage switching:
> >           host->mmc_host_ops.start_signal_voltage_switch =
> >                      esdhc_signal_voltage_switch; Changes for v3:
> > 	- Put .start_signal_voltage_switch assigning after IS_ERR(host)
> check.
> > ---
> >  drivers/mmc/host/sdhci-esdhc.h    |  1 +
> >  drivers/mmc/host/sdhci-of-esdhc.c | 74
> > +++++++++++++++++++++++++++++++++++++++
> >  2 files changed, 75 insertions(+)
> >
> > diff --git a/drivers/mmc/host/sdhci-esdhc.h
> > b/drivers/mmc/host/sdhci-esdhc.h index 5343fc0..6869567 100644
> > --- a/drivers/mmc/host/sdhci-esdhc.h
> > +++ b/drivers/mmc/host/sdhci-esdhc.h
> > @@ -37,6 +37,7 @@
> >
> >  /* Protocol Control Register */
> >  #define ESDHC_PROCTL			0x28
> > +#define ESDHC_VOLT_SEL			0x00000400
> >  #define ESDHC_CTRL_4BITBUS		(0x1 << 1)
> >  #define ESDHC_CTRL_8BITBUS		(0x2 << 1)
> >  #define ESDHC_CTRL_BUSWIDTH_MASK	(0x3 << 1)
> > diff --git a/drivers/mmc/host/sdhci-of-esdhc.c
> > b/drivers/mmc/host/sdhci-of-esdhc.c
> > index 7ce1caf..a70499a 100644
> > --- a/drivers/mmc/host/sdhci-of-esdhc.c
> > +++ b/drivers/mmc/host/sdhci-of-esdhc.c
> > @@ -16,6 +16,7 @@
> >  #include <linux/err.h>
> >  #include <linux/io.h>
> >  #include <linux/of.h>
> > +#include <linux/of_address.h>
> >  #include <linux/delay.h>
> >  #include <linux/module.h>
> >  #include <linux/sys_soc.h>
> > @@ -559,6 +560,76 @@ static void esdhc_reset(struct sdhci_host *host,
> u8 mask)
> >  	sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);  }
> >
> > +/* The SCFG, Supplemental Configuration Unit, provides SoC specific
> > + * configuration and status registers for the device. There is a
> > + * SDHC IO VSEL control register on SCFG for some platforms. It's
> > + * used to support SDHC IO voltage switching.
> > + */
> > +static const struct of_device_id scfg_device_ids[] = {
> > +	{ .compatible = "fsl,t1040-scfg", },
> > +	{ .compatible = "fsl,ls1012a-scfg", },
> > +	{ .compatible = "fsl,ls1046a-scfg", },
> > +	{}
> > +};
> > +
> > +/* SDHC IO VSEL control register definition */
> > +#define SCFG_SDHCIOVSELCR	0x408
> > +#define SDHCIOVSELCR_TGLEN	0x80000000
> > +#define SDHCIOVSELCR_VSELVAL	0x60000000
> > +#define SDHCIOVSELCR_SDHC_VS	0x00000001
> > +
> > +static int esdhc_signal_voltage_switch(struct mmc_host *mmc,
> > +				       struct mmc_ios *ios)
> > +{
> > +	struct sdhci_host *host = mmc_priv(mmc);
> > +	struct device_node *scfg_node;
> > +	void __iomem *scfg_base = NULL;
> > +	u32 sdhciovselcr;
> > +	u32 val;
> > +
> > +	/*
> > +	 * Signal Voltage Switching is only applicable for Host Controllers
> > +	 * v3.00 and above.
> > +	 */
> > +	if (host->version < SDHCI_SPEC_300)
> > +		return 0;
> > +
> > +	val = sdhci_readl(host, ESDHC_PROCTL);
> > +
> > +	switch (ios->signal_voltage) {
> > +	case MMC_SIGNAL_VOLTAGE_330:
> > +		val &= ~ESDHC_VOLT_SEL;
> > +		sdhci_writel(host, val, ESDHC_PROCTL);
> > +		return 0;
> > +	case MMC_SIGNAL_VOLTAGE_180:
> > +		scfg_node = of_find_matching_node(NULL, scfg_device_ids);
> > +		if (scfg_node)
> > +			scfg_base = of_iomap(scfg_node, 0);
> > +		if (scfg_base) {
> > +			sdhciovselcr = SDHCIOVSELCR_TGLEN |
> > +				       SDHCIOVSELCR_VSELVAL;
> > +			iowrite32be(sdhciovselcr,
> > +				scfg_base + SCFG_SDHCIOVSELCR);
> 
> In other places there is support for little endian also, so why not here?

[Lu Yangbo-B47093] The SCFG unit is always a big-endian module on both ARM and PPC QorIQ platforms.
There is little possibility to have little-endian in future.

> 
> > +
> > +			val |= ESDHC_VOLT_SEL;
> > +			sdhci_writel(host, val, ESDHC_PROCTL);
> > +			mdelay(5);
> > +
> > +			sdhciovselcr = SDHCIOVSELCR_TGLEN |
> > +				       SDHCIOVSELCR_SDHC_VS;
> > +			iowrite32be(sdhciovselcr,
> > +				scfg_base + SCFG_SDHCIOVSELCR);
> > +			iounmap(scfg_base);
> > +		} else {
> > +			val |= ESDHC_VOLT_SEL;
> > +			sdhci_writel(host, val, ESDHC_PROCTL);
> > +		}
> > +		return 0;
> > +	default:
> > +		return 0;
> > +	}
> > +}
> > +
> >  #ifdef CONFIG_PM_SLEEP
> >  static u32 esdhc_proctl;
> >  static int esdhc_of_suspend(struct device *dev) @@ -714,6 +785,9 @@
> > static int sdhci_esdhc_probe(struct platform_device *pdev)
> >  	if (IS_ERR(host))
> >  		return PTR_ERR(host);
> >
> > +	host->mmc_host_ops.start_signal_voltage_switch =
> > +		esdhc_signal_voltage_switch;
> > +
> >  	esdhc_init(pdev, host);
> >
> >  	sdhci_get_of_property(pdev);
> >
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> the body of a message to majordomo@vger.kernel.org More majordomo info at
> http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/drivers/mmc/host/sdhci-esdhc.h b/drivers/mmc/host/sdhci-esdhc.h
index 5343fc0..6869567 100644
--- a/drivers/mmc/host/sdhci-esdhc.h
+++ b/drivers/mmc/host/sdhci-esdhc.h
@@ -37,6 +37,7 @@ 
 
 /* Protocol Control Register */
 #define ESDHC_PROCTL			0x28
+#define ESDHC_VOLT_SEL			0x00000400
 #define ESDHC_CTRL_4BITBUS		(0x1 << 1)
 #define ESDHC_CTRL_8BITBUS		(0x2 << 1)
 #define ESDHC_CTRL_BUSWIDTH_MASK	(0x3 << 1)
diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
index 7ce1caf..a70499a 100644
--- a/drivers/mmc/host/sdhci-of-esdhc.c
+++ b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -16,6 +16,7 @@ 
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/of.h>
+#include <linux/of_address.h>
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/sys_soc.h>
@@ -559,6 +560,76 @@  static void esdhc_reset(struct sdhci_host *host, u8 mask)
 	sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
 }
 
+/* The SCFG, Supplemental Configuration Unit, provides SoC specific
+ * configuration and status registers for the device. There is a
+ * SDHC IO VSEL control register on SCFG for some platforms. It's
+ * used to support SDHC IO voltage switching.
+ */
+static const struct of_device_id scfg_device_ids[] = {
+	{ .compatible = "fsl,t1040-scfg", },
+	{ .compatible = "fsl,ls1012a-scfg", },
+	{ .compatible = "fsl,ls1046a-scfg", },
+	{}
+};
+
+/* SDHC IO VSEL control register definition */
+#define SCFG_SDHCIOVSELCR	0x408
+#define SDHCIOVSELCR_TGLEN	0x80000000
+#define SDHCIOVSELCR_VSELVAL	0x60000000
+#define SDHCIOVSELCR_SDHC_VS	0x00000001
+
+static int esdhc_signal_voltage_switch(struct mmc_host *mmc,
+				       struct mmc_ios *ios)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	struct device_node *scfg_node;
+	void __iomem *scfg_base = NULL;
+	u32 sdhciovselcr;
+	u32 val;
+
+	/*
+	 * Signal Voltage Switching is only applicable for Host Controllers
+	 * v3.00 and above.
+	 */
+	if (host->version < SDHCI_SPEC_300)
+		return 0;
+
+	val = sdhci_readl(host, ESDHC_PROCTL);
+
+	switch (ios->signal_voltage) {
+	case MMC_SIGNAL_VOLTAGE_330:
+		val &= ~ESDHC_VOLT_SEL;
+		sdhci_writel(host, val, ESDHC_PROCTL);
+		return 0;
+	case MMC_SIGNAL_VOLTAGE_180:
+		scfg_node = of_find_matching_node(NULL, scfg_device_ids);
+		if (scfg_node)
+			scfg_base = of_iomap(scfg_node, 0);
+		if (scfg_base) {
+			sdhciovselcr = SDHCIOVSELCR_TGLEN |
+				       SDHCIOVSELCR_VSELVAL;
+			iowrite32be(sdhciovselcr,
+				scfg_base + SCFG_SDHCIOVSELCR);
+
+			val |= ESDHC_VOLT_SEL;
+			sdhci_writel(host, val, ESDHC_PROCTL);
+			mdelay(5);
+
+			sdhciovselcr = SDHCIOVSELCR_TGLEN |
+				       SDHCIOVSELCR_SDHC_VS;
+			iowrite32be(sdhciovselcr,
+				scfg_base + SCFG_SDHCIOVSELCR);
+			iounmap(scfg_base);
+		} else {
+			val |= ESDHC_VOLT_SEL;
+			sdhci_writel(host, val, ESDHC_PROCTL);
+		}
+		return 0;
+	default:
+		return 0;
+	}
+}
+
 #ifdef CONFIG_PM_SLEEP
 static u32 esdhc_proctl;
 static int esdhc_of_suspend(struct device *dev)
@@ -714,6 +785,9 @@  static int sdhci_esdhc_probe(struct platform_device *pdev)
 	if (IS_ERR(host))
 		return PTR_ERR(host);
 
+	host->mmc_host_ops.start_signal_voltage_switch =
+		esdhc_signal_voltage_switch;
+
 	esdhc_init(pdev, host);
 
 	sdhci_get_of_property(pdev);