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* [PATCH] Add HS400 enhanced strobe support
@ 2017-02-15 13:50 ` Piotr Sroka
  0 siblings, 0 replies; 3+ messages in thread
From: Piotr Sroka @ 2017-02-15 13:50 UTC (permalink / raw)
  To: linux-mmc; +Cc: Ulf Hansson, Adrian Hunter, linux-kernel, Piotr Sroka

Add support for HS400ES mode to Cadence SDHCI driver.

Signed-off-by: Piotr Sroka <piotrs@cadence.com>
---
 drivers/mmc/host/sdhci-cadence.c | 41 +++++++++++++++++++++++++++++++++-------
 1 file changed, 34 insertions(+), 7 deletions(-)

diff --git a/drivers/mmc/host/sdhci-cadence.c b/drivers/mmc/host/sdhci-cadence.c
index 4b0ecb9..5296c7c 100644
--- a/drivers/mmc/host/sdhci-cadence.c
+++ b/drivers/mmc/host/sdhci-cadence.c
@@ -39,6 +39,7 @@
 #define   SDHCI_CDNS_HRS06_MODE_MMC_DDR		0x3
 #define   SDHCI_CDNS_HRS06_MODE_MMC_HS200	0x4
 #define   SDHCI_CDNS_HRS06_MODE_MMC_HS400	0x5
+#define   SDHCI_CDNS_HRS06_MODE_MMC_HS400ES	0x6
 
 /* SRS - Slot Register Set (SDHCI-compatible) */
 #define SDHCI_CDNS_SRS_BASE		0x200
@@ -63,6 +64,7 @@
 
 struct sdhci_cdns_priv {
 	void __iomem *hrs_addr;
+	bool enhanced_strobe;
 };
 
 static void sdhci_cdns_write_phy_reg(struct sdhci_cdns_priv *priv,
@@ -107,11 +109,22 @@ static unsigned int sdhci_cdns_get_timeout_clock(struct sdhci_host *host)
 	return host->max_clk / 1000;
 }
 
+static void sdhci_cdns_set_emmc_mode(struct sdhci_cdns_priv *priv, u32 mode)
+{
+	u32 tmp;
+
+	/* The speed mode for eMMC is selected by HRS06 register */
+	tmp = readl(priv->hrs_addr + SDHCI_CDNS_HRS06);
+	tmp &= ~SDHCI_CDNS_HRS06_MODE_MASK;
+	tmp |= mode;
+	writel(tmp, priv->hrs_addr + SDHCI_CDNS_HRS06);
+}
+
 static void sdhci_cdns_set_uhs_signaling(struct sdhci_host *host,
 					 unsigned int timing)
 {
 	struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
-	u32 mode, tmp;
+	u32 mode;
 
 	switch (timing) {
 	case MMC_TIMING_MMC_HS:
@@ -124,24 +137,35 @@ static void sdhci_cdns_set_uhs_signaling(struct sdhci_host *host,
 		mode = SDHCI_CDNS_HRS06_MODE_MMC_HS200;
 		break;
 	case MMC_TIMING_MMC_HS400:
-		mode = SDHCI_CDNS_HRS06_MODE_MMC_HS400;
+		if (priv->enhanced_strobe)
+			mode = SDHCI_CDNS_HRS06_MODE_MMC_HS400ES;
+		else
+			mode = SDHCI_CDNS_HRS06_MODE_MMC_HS400;
 		break;
 	default:
 		mode = SDHCI_CDNS_HRS06_MODE_SD;
 		break;
 	}
 
-	/* The speed mode for eMMC is selected by HRS06 register */
-	tmp = readl(priv->hrs_addr + SDHCI_CDNS_HRS06);
-	tmp &= ~SDHCI_CDNS_HRS06_MODE_MASK;
-	tmp |= mode;
-	writel(tmp, priv->hrs_addr + SDHCI_CDNS_HRS06);
+	sdhci_cdns_set_emmc_mode(priv, mode);
 
 	/* For SD, fall back to the default handler */
 	if (mode == SDHCI_CDNS_HRS06_MODE_SD)
 		sdhci_set_uhs_signaling(host, timing);
 }
 
+static void sdhci_cdns_hs400_enhanced_strobe(struct mmc_host *mmc,
+					     struct mmc_ios *ios)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
+
+	priv->enhanced_strobe = ios->enhanced_strobe;
+	if (ios->enhanced_strobe)
+		sdhci_cdns_set_emmc_mode(priv,
+					 SDHCI_CDNS_HRS06_MODE_MMC_HS400ES);
+}
+
 static const struct sdhci_ops sdhci_cdns_ops = {
 	.set_clock = sdhci_set_clock,
 	.get_timeout_clock = sdhci_cdns_get_timeout_clock,
@@ -239,8 +263,11 @@ static int sdhci_cdns_probe(struct platform_device *pdev)
 
 	priv = sdhci_cdns_priv(host);
 	priv->hrs_addr = host->ioaddr;
+	priv->enhanced_strobe = false;
 	host->ioaddr += SDHCI_CDNS_SRS_BASE;
 	host->mmc_host_ops.execute_tuning = sdhci_cdns_execute_tuning;
+	host->mmc_host_ops.hs400_enhanced_strobe =
+		sdhci_cdns_hs400_enhanced_strobe;
 
 	ret = mmc_of_parse(host->mmc);
 	if (ret)
-- 
2.2.2

^ permalink raw reply related	[flat|nested] 3+ messages in thread
* [PATCH] Add HS400 enhanced strobe support
@ 2017-02-15 13:50 ` Piotr Sroka
  0 siblings, 0 replies; 3+ messages in thread
From: Piotr Sroka @ 2017-02-15 13:50 UTC (permalink / raw)
  To: linux-mmc; +Cc: Ulf Hansson, Adrian Hunter, linux-kernel, Piotr Sroka

Add support for HS400ES mode to Cadence SDHCI driver.

Signed-off-by: Piotr Sroka <piotrs@cadence.com>
---
 drivers/mmc/host/sdhci-cadence.c | 41 +++++++++++++++++++++++++++++++++-------
 1 file changed, 34 insertions(+), 7 deletions(-)

diff --git a/drivers/mmc/host/sdhci-cadence.c b/drivers/mmc/host/sdhci-cadence.c
index 4b0ecb9..5296c7c 100644
--- a/drivers/mmc/host/sdhci-cadence.c
+++ b/drivers/mmc/host/sdhci-cadence.c
@@ -39,6 +39,7 @@
 #define   SDHCI_CDNS_HRS06_MODE_MMC_DDR		0x3
 #define   SDHCI_CDNS_HRS06_MODE_MMC_HS200	0x4
 #define   SDHCI_CDNS_HRS06_MODE_MMC_HS400	0x5
+#define   SDHCI_CDNS_HRS06_MODE_MMC_HS400ES	0x6
 
 /* SRS - Slot Register Set (SDHCI-compatible) */
 #define SDHCI_CDNS_SRS_BASE		0x200
@@ -63,6 +64,7 @@
 
 struct sdhci_cdns_priv {
 	void __iomem *hrs_addr;
+	bool enhanced_strobe;
 };
 
 static void sdhci_cdns_write_phy_reg(struct sdhci_cdns_priv *priv,
@@ -107,11 +109,22 @@ static unsigned int sdhci_cdns_get_timeout_clock(struct sdhci_host *host)
 	return host->max_clk / 1000;
 }
 
+static void sdhci_cdns_set_emmc_mode(struct sdhci_cdns_priv *priv, u32 mode)
+{
+	u32 tmp;
+
+	/* The speed mode for eMMC is selected by HRS06 register */
+	tmp = readl(priv->hrs_addr + SDHCI_CDNS_HRS06);
+	tmp &= ~SDHCI_CDNS_HRS06_MODE_MASK;
+	tmp |= mode;
+	writel(tmp, priv->hrs_addr + SDHCI_CDNS_HRS06);
+}
+
 static void sdhci_cdns_set_uhs_signaling(struct sdhci_host *host,
 					 unsigned int timing)
 {
 	struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
-	u32 mode, tmp;
+	u32 mode;
 
 	switch (timing) {
 	case MMC_TIMING_MMC_HS:
@@ -124,24 +137,35 @@ static void sdhci_cdns_set_uhs_signaling(struct sdhci_host *host,
 		mode = SDHCI_CDNS_HRS06_MODE_MMC_HS200;
 		break;
 	case MMC_TIMING_MMC_HS400:
-		mode = SDHCI_CDNS_HRS06_MODE_MMC_HS400;
+		if (priv->enhanced_strobe)
+			mode = SDHCI_CDNS_HRS06_MODE_MMC_HS400ES;
+		else
+			mode = SDHCI_CDNS_HRS06_MODE_MMC_HS400;
 		break;
 	default:
 		mode = SDHCI_CDNS_HRS06_MODE_SD;
 		break;
 	}
 
-	/* The speed mode for eMMC is selected by HRS06 register */
-	tmp = readl(priv->hrs_addr + SDHCI_CDNS_HRS06);
-	tmp &= ~SDHCI_CDNS_HRS06_MODE_MASK;
-	tmp |= mode;
-	writel(tmp, priv->hrs_addr + SDHCI_CDNS_HRS06);
+	sdhci_cdns_set_emmc_mode(priv, mode);
 
 	/* For SD, fall back to the default handler */
 	if (mode == SDHCI_CDNS_HRS06_MODE_SD)
 		sdhci_set_uhs_signaling(host, timing);
 }
 
+static void sdhci_cdns_hs400_enhanced_strobe(struct mmc_host *mmc,
+					     struct mmc_ios *ios)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
+
+	priv->enhanced_strobe = ios->enhanced_strobe;
+	if (ios->enhanced_strobe)
+		sdhci_cdns_set_emmc_mode(priv,
+					 SDHCI_CDNS_HRS06_MODE_MMC_HS400ES);
+}
+
 static const struct sdhci_ops sdhci_cdns_ops = {
 	.set_clock = sdhci_set_clock,
 	.get_timeout_clock = sdhci_cdns_get_timeout_clock,
@@ -239,8 +263,11 @@ static int sdhci_cdns_probe(struct platform_device *pdev)
 
 	priv = sdhci_cdns_priv(host);
 	priv->hrs_addr = host->ioaddr;
+	priv->enhanced_strobe = false;
 	host->ioaddr += SDHCI_CDNS_SRS_BASE;
 	host->mmc_host_ops.execute_tuning = sdhci_cdns_execute_tuning;
+	host->mmc_host_ops.hs400_enhanced_strobe =
+		sdhci_cdns_hs400_enhanced_strobe;
 
 	ret = mmc_of_parse(host->mmc);
 	if (ret)
-- 
2.2.2

^ permalink raw reply related	[flat|nested] 3+ messages in thread
* Re: [PATCH] Add HS400 enhanced strobe support
  2017-02-15 13:50 ` Piotr Sroka
  (?)
@ 2017-02-23 12:49 ` Masahiro Yamada
  -1 siblings, 0 replies; 3+ messages in thread
From: Masahiro Yamada @ 2017-02-23 12:49 UTC (permalink / raw)
  To: Piotr Sroka
  Cc: linux-mmc, Ulf Hansson, Adrian Hunter, Linux Kernel Mailing List

Hi.


2017-02-15 22:50 GMT+09:00 Piotr Sroka <piotrs@cadence.com>:
> Add support for HS400ES mode to Cadence SDHCI driver.
>
> Signed-off-by: Piotr Sroka <piotrs@cadence.com>


Next time, please add "mmc: sdhci-cadence" to the patch subject.
This will clarify which driver is being touched.



> +static void sdhci_cdns_hs400_enhanced_strobe(struct mmc_host *mmc,
> +                                            struct mmc_ios *ios)
> +{
> +       struct sdhci_host *host = mmc_priv(mmc);
> +       struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
> +
> +       priv->enhanced_strobe = ios->enhanced_strobe;
> +       if (ios->enhanced_strobe)
> +               sdhci_cdns_set_emmc_mode(priv,
> +                                        SDHCI_CDNS_HRS06_MODE_MMC_HS400ES);
> +}


This function, if ios->enhanced_strobe is true, enables it immediately,
but nothing happens if ios->enhanced_strobe is false.
(it will be disabled at the next call of sdhci_cdns_set_uhs_signaling().)

If you look at drivers/mmc/core/core.c,
mmc_set_ios() is called immediately after
host->ops->hs400_enhanced_strobe(host, &host->ios),
but I am not quite sure if we should rely on that fact.

I am just putting my untested code below.


static void sdhci_cdns_hs400_enhanced_strobe(struct mmc_host *mmc,
                                             struct mmc_ios *ios)
{
        struct sdhci_host *host = mmc_priv(mmc);
        struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
        u32 mode;

        mode = readl(priv->hrs_addr + SDHCI_CDNS_HRS06) &
               SDHCI_CDNS_HRS06_MODE_MASK;

        switch (mode) {
        case SDHCI_CDNS_HRS06_MODE_MMC_HS400:
                if (ios->enhanced_strobe)
                        mode = SDHCI_CDNS_HRS06_MODE_MMC_HS400ES;
                break;
        case SDHCI_CDNS_HRS06_MODE_MMC_HS400ES:
                if (!ios->enhanced_strobe)
                        mode = SDHCI_CDNS_HRS06_MODE_MMC_HS400;
                break;
        default:
                break;
        }

        sdhci_cdns_set_emmc_mode(priv, mode);

        priv->enhanced_strobe = ios->enhanced_strobe;
}


BTW, I prefer sdhci_cdns_hs400_enhanced_strobe()
is placed below sdhci_cdns_execute_tuning()
because these two callbacks belong to the same group.

These two are not members of sdhci_ops,
but replacements for host->mmc_host_ops.



The other parts look good to me.

-- 
Best Regards
Masahiro Yamada

^ permalink raw reply	[flat|nested] 3+ messages in thread
end of thread, other threads:[~2017-02-23 12:50 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2017-02-15 13:50 [PATCH] Add HS400 enhanced strobe support Piotr Sroka
2017-02-15 13:50 ` Piotr Sroka
2017-02-23 12:49 ` Masahiro Yamada

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