[v5, 0/5] Add SD UHS-I and eMMC HS200 support for eSDHC

[v5, 0/5] Add SD UHS-I and eMMC HS200 support for eSDHC

[Yangbo Lu]

It's complicated to support SD UHS-I and eMMC HS200 for eSDHC because
there're many differences between eSDHC and SD/eMMC spec. Several
differences as below must be considered:
1. Peripheral clock must be used instead of platform clock.
    - eSDHC could select peripheral clock or platform clock as its clock
      source. According to RM, UHS-I/HS200 must use peripheral clock since
      it supports higher frequency than platform clock.
    - Patch 1 is to support this.
2. Signal voltage switching requires a control circuit out of eSDHC.
    - 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.
    - Patch 2 is to support this.
3. eSDHC uses tuning block for tuning procedure.
    - Tuning clock control register must be configured before tuning.
    - Patch 3 is to support this.
4. Delay is needed between tuning cycles for HS200 tuning.
    - Once a patch removed mdelay between tuning cycles.
      But eSDHC needs it.
    - Patch 4 and patch 5 is to support this.

Adrian Hunter (1):
  mmc: sdhci: Control the delay between tuning commands

Yangbo Lu (4):
  mmc: sdhci-of-esdhc: add peripheral clock support
  mmc: sdhci-of-esdhc: add support for signal voltage switch
  mmc: sdhci-of-esdhc: add tuning support
  mmc: sdhci-of-esdhc: add delay between tuning cycles

 drivers/mmc/host/sdhci-esdhc.h    |   7 ++
 drivers/mmc/host/sdhci-of-esdhc.c | 168 +++++++++++++++++++++++++++++++++++++-
 drivers/mmc/host/sdhci.c          |  11 ++-
 drivers/mmc/host/sdhci.h          |   2 +
 4 files changed, 183 insertions(+), 5 deletions(-)

-- 
2.1.0.27.g96db324

[v5, 1/5] mmc: sdhci-of-esdhc: add peripheral clock support

[Yangbo Lu]

eSDHC could select peripheral clock or platform clock as clock source by
the PCS bit of eSDHC Control Register, and this bit couldn't be reset by
software reset for all. In default, the platform clock is used. But we have
to use peripheral clock since it has a higher frequency to support eMMC
HS200 mode and SD UHS-I mode. This patch is to add peripheral clock support
and use it instead of platform clock if it's declared in eSDHC dts node.

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
---
Changes for v2:
	- None
Changes for v3:
	- None
Changes for v4:
	- Added clk_put()
	- Used udelay() to poll ESDHC_CLOCK_STABLE
Changes for v5:
	- Included ktime.h
	- Added Adrian's ACK
---
 drivers/mmc/host/sdhci-esdhc.h    |  1 +
 drivers/mmc/host/sdhci-of-esdhc.c | 73 +++++++++++++++++++++++++++++++++++++--
 2 files changed, 72 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/sdhci-esdhc.h b/drivers/mmc/host/sdhci-esdhc.h
index ece8b37..5343fc0 100644
--- a/drivers/mmc/host/sdhci-esdhc.h
+++ b/drivers/mmc/host/sdhci-esdhc.h
@@ -54,6 +54,7 @@
 
 /* Control Register for DMA transfer */
 #define ESDHC_DMA_SYSCTL		0x40c
+#define ESDHC_PERIPHERAL_CLK_SEL	0x00080000
 #define ESDHC_DMA_SNOOP			0x00000040
 
 #endif /* _DRIVERS_MMC_SDHCI_ESDHC_H */
diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
index ff37e74..0b3f05a 100644
--- a/drivers/mmc/host/sdhci-of-esdhc.c
+++ b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -19,6 +19,8 @@
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/sys_soc.h>
+#include <linux/clk.h>
+#include <linux/ktime.h>
 #include <linux/mmc/host.h>
 #include "sdhci-pltfm.h"
 #include "sdhci-esdhc.h"
@@ -30,6 +32,7 @@ struct sdhci_esdhc {
 	u8 vendor_ver;
 	u8 spec_ver;
 	bool quirk_incorrect_hostver;
+	unsigned int peripheral_clock;
 };
 
 /**
@@ -414,15 +417,25 @@ static int esdhc_of_enable_dma(struct sdhci_host *host)
 static unsigned int esdhc_of_get_max_clock(struct sdhci_host *host)
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_esdhc *esdhc = sdhci_pltfm_priv(pltfm_host);
 
-	return pltfm_host->clock;
+	if (esdhc->peripheral_clock)
+		return esdhc->peripheral_clock;
+	else
+		return pltfm_host->clock;
 }
 
 static unsigned int esdhc_of_get_min_clock(struct sdhci_host *host)
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_esdhc *esdhc = sdhci_pltfm_priv(pltfm_host);
+	unsigned int clock;
 
-	return pltfm_host->clock / 256 / 16;
+	if (esdhc->peripheral_clock)
+		clock = esdhc->peripheral_clock;
+	else
+		clock = pltfm_host->clock;
+	return clock / 256 / 16;
 }
 
 static void esdhc_of_set_clock(struct sdhci_host *host, unsigned int clock)
@@ -512,6 +525,33 @@ static void esdhc_pltfm_set_bus_width(struct sdhci_host *host, int width)
 	sdhci_writel(host, ctrl, ESDHC_PROCTL);
 }
 
+static void esdhc_clock_enable(struct sdhci_host *host, bool enable)
+{
+	u32 val;
+	ktime_t timeout;
+
+	val = sdhci_readl(host, ESDHC_SYSTEM_CONTROL);
+
+	if (enable)
+		val |= ESDHC_CLOCK_SDCLKEN;
+	else
+		val &= ~ESDHC_CLOCK_SDCLKEN;
+
+	sdhci_writel(host, val, ESDHC_SYSTEM_CONTROL);
+
+	/* Wait max 20 ms */
+	timeout = ktime_add_ms(ktime_get(), 20);
+	val = ESDHC_CLOCK_STABLE;
+	while (!(sdhci_readl(host, ESDHC_PRSSTAT) & val)) {
+		if (ktime_after(ktime_get(), timeout)) {
+			pr_err("%s: Internal clock never stabilised.\n",
+				mmc_hostname(host->mmc));
+			break;
+		}
+		udelay(10);
+	}
+}
+
 static void esdhc_reset(struct sdhci_host *host, u8 mask)
 {
 	sdhci_reset(host, mask);
@@ -613,6 +653,9 @@ static void esdhc_init(struct platform_device *pdev, struct sdhci_host *host)
 {
 	struct sdhci_pltfm_host *pltfm_host;
 	struct sdhci_esdhc *esdhc;
+	struct device_node *np;
+	struct clk *clk;
+	u32 val;
 	u16 host_ver;
 
 	pltfm_host = sdhci_priv(host);
@@ -626,6 +669,32 @@ static void esdhc_init(struct platform_device *pdev, struct sdhci_host *host)
 		esdhc->quirk_incorrect_hostver = true;
 	else
 		esdhc->quirk_incorrect_hostver = false;
+
+	np = pdev->dev.of_node;
+	clk = of_clk_get(np, 0);
+	if (!IS_ERR(clk)) {
+		/*
+		 * esdhc->peripheral_clock would be assigned with a value
+		 * which is eSDHC base clock when use periperal clock.
+		 * For ls1046a, the clock value got by common clk API is
+		 * peripheral clock while the eSDHC base clock is 1/2
+		 * peripheral clock.
+		 */
+		if (of_device_is_compatible(np, "fsl,ls1046a-esdhc"))
+			esdhc->peripheral_clock = clk_get_rate(clk) / 2;
+		else
+			esdhc->peripheral_clock = clk_get_rate(clk);
+
+		clk_put(clk);
+	}
+
+	if (esdhc->peripheral_clock) {
+		esdhc_clock_enable(host, false);
+		val = sdhci_readl(host, ESDHC_DMA_SYSCTL);
+		val |= ESDHC_PERIPHERAL_CLK_SEL;
+		sdhci_writel(host, val, ESDHC_DMA_SYSCTL);
+		esdhc_clock_enable(host, true);
+	}
 }
 
 static int sdhci_esdhc_probe(struct platform_device *pdev)
-- 
2.1.0.27.g96db324

[v5, 2/5] mmc: sdhci-of-esdhc: add support for signal voltage switch

[Yangbo Lu]

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>
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.
Changes for v4:
	- None
Changes for v5:
	- Added Adrian's ACK
---
 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 0b3f05a..f2d7002 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>
@@ -560,6 +561,76 @@ 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)
@@ -717,6 +788,9 @@ 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);
-- 
2.1.0.27.g96db324

Re: [v5, 2/5] mmc: sdhci-of-esdhc: add support for signal voltage switch

[Ulf Hansson]

[...]

> +       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);

Why don't you do this at probe time instead of every time you do the
voltage switch?

Never mind at this point, I have queued this up for 4.12, however feel
free to send a new patch on top.

> +               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;
> +       }
> +}

[...]

Kind regards
Uffe

RE: [v5, 2/5] mmc: sdhci-of-esdhc: add support for signal voltage switch

[Y.B. Lu]

Hi Uffe,


> -----Original Message-----
> From: Ulf Hansson [mailto:ulf.hansson@linaro.org]
> Sent: Thursday, April 20, 2017 10:06 PM
> To: Y.B. Lu
> Cc: linux-mmc@vger.kernel.org; Adrian Hunter; Xiaobo Xie
> Subject: Re: [v5, 2/5] mmc: sdhci-of-esdhc: add support for signal
> voltage switch
> 
> [...]
> 
> > +       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);
> 
> Why don't you do this at probe time instead of every time you do the
> voltage switch?
> 
> Never mind at this point, I have queued this up for 4.12, however feel
> free to send a new patch on top.

[Lu Yangbo-B47093] Thank you very much for point out this.
I will work on another patch to fix this :)

- Yangbo Lu

> 
> > +               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;
> > +       }
> > +}
> 
> [...]
> 
> Kind regards
> Uffe

[v5, 3/5] mmc: sdhci-of-esdhc: add tuning support

[Yangbo Lu]

eSDHC uses tuning block for tuning procedure. So the tuning
block control register must be configured properly before tuning.

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
---
Changes for v2:
	- Replaced old function for mmc_host_ops.execute_tuning with
	  esdhc_execute_tuning to support eSDHC tuning.
Changes for v3:
	- Put .execute_tuning assigning after after IS_ERR(host) check.
Changes for v4:
	- None
Changes for v5:
	- Added Adrian's ACK
---
 drivers/mmc/host/sdhci-esdhc.h    |  5 +++++
 drivers/mmc/host/sdhci-of-esdhc.c | 20 ++++++++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/drivers/mmc/host/sdhci-esdhc.h b/drivers/mmc/host/sdhci-esdhc.h
index 6869567..c4bbd74 100644
--- a/drivers/mmc/host/sdhci-esdhc.h
+++ b/drivers/mmc/host/sdhci-esdhc.h
@@ -53,9 +53,14 @@
 #define ESDHC_CLOCK_HCKEN		0x00000002
 #define ESDHC_CLOCK_IPGEN		0x00000001
 
+/* Tuning Block Control Register */
+#define ESDHC_TBCTL			0x120
+#define ESDHC_TB_EN			0x00000004
+
 /* Control Register for DMA transfer */
 #define ESDHC_DMA_SYSCTL		0x40c
 #define ESDHC_PERIPHERAL_CLK_SEL	0x00080000
+#define ESDHC_FLUSH_ASYNC_FIFO		0x00040000
 #define ESDHC_DMA_SNOOP			0x00000040
 
 #endif /* _DRIVERS_MMC_SDHCI_ESDHC_H */
diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
index f2d7002..607e512 100644
--- a/drivers/mmc/host/sdhci-of-esdhc.c
+++ b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -631,6 +631,25 @@ static int esdhc_signal_voltage_switch(struct mmc_host *mmc,
 	}
 }
 
+static int esdhc_execute_tuning(struct mmc_host *mmc, u32 opcode)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	u32 val;
+
+	/* Use tuning block for tuning procedure */
+	esdhc_clock_enable(host, false);
+	val = sdhci_readl(host, ESDHC_DMA_SYSCTL);
+	val |= ESDHC_FLUSH_ASYNC_FIFO;
+	sdhci_writel(host, val, ESDHC_DMA_SYSCTL);
+
+	val = sdhci_readl(host, ESDHC_TBCTL);
+	val |= ESDHC_TB_EN;
+	sdhci_writel(host, val, ESDHC_TBCTL);
+	esdhc_clock_enable(host, true);
+
+	return sdhci_execute_tuning(mmc, opcode);
+}
+
 #ifdef CONFIG_PM_SLEEP
 static u32 esdhc_proctl;
 static int esdhc_of_suspend(struct device *dev)
@@ -790,6 +809,7 @@ static int sdhci_esdhc_probe(struct platform_device *pdev)
 
 	host->mmc_host_ops.start_signal_voltage_switch =
 		esdhc_signal_voltage_switch;
+	host->mmc_host_ops.execute_tuning = esdhc_execute_tuning;
 
 	esdhc_init(pdev, host);
 
-- 
2.1.0.27.g96db324

[v5, 4/5] mmc: sdhci: Control the delay between tuning commands

[Yangbo Lu]

From: Adrian Hunter <adrian.hunter@intel.com>

The delay between tuning commands for SD cards is not part of the
specification. A driver that needs it probably needs it for eMMC
too, whereas most drivers would probably like to set it to 0. Make
it a host member (host->tuning_delay) that defaults to the existing
behaviour. Drivers can set it to zero to eliminate the delay, or
set it to a positive value to always have a delay.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
---
Changes for v2:
	- None
Changes for v3:
	- Used a host member for tuning delay instead of a quirk.(Adrian's patch)
	- Addressed warning in checkpatch.
Changes for v4:
	- None
Changes for v5:
	- None
---
 drivers/mmc/host/sdhci.c | 11 ++++++++---
 drivers/mmc/host/sdhci.h |  2 ++
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 4bdad89..ecd0d43 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2108,9 +2108,9 @@ static void __sdhci_execute_tuning(struct sdhci_host *host, u32 opcode)
 			break;
 		}
 
-		/* eMMC spec does not require a delay between tuning cycles */
-		if (opcode == MMC_SEND_TUNING_BLOCK)
-			mdelay(1);
+		/* Spec does not require a delay between tuning cycles */
+		if (host->tuning_delay > 0)
+			mdelay(host->tuning_delay);
 	}
 
 	pr_info("%s: Tuning failed, falling back to fixed sampling clock\n",
@@ -2172,6 +2172,9 @@ int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
 
 	host->mmc->retune_period = tuning_count;
 
+	if (host->tuning_delay < 0)
+		host->tuning_delay = opcode == MMC_SEND_TUNING_BLOCK;
+
 	sdhci_start_tuning(host);
 
 	__sdhci_execute_tuning(host, opcode);
@@ -3114,6 +3117,8 @@ struct sdhci_host *sdhci_alloc_host(struct device *dev,
 	host->cqe_ier     = SDHCI_CQE_INT_MASK;
 	host->cqe_err_ier = SDHCI_CQE_INT_ERR_MASK;
 
+	host->tuning_delay = -1;
+
 	return host;
 }
 
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 78437f8..0469fa1 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -538,6 +538,8 @@ struct sdhci_host {
 #define SDHCI_TUNING_MODE_1	0
 #define SDHCI_TUNING_MODE_2	1
 #define SDHCI_TUNING_MODE_3	2
+	/* Delay (ms) between tuning commands */
+	int			tuning_delay;
 
 	unsigned long private[0] ____cacheline_aligned;
 };
-- 
2.1.0.27.g96db324

[v5, 5/5] mmc: sdhci-of-esdhc: add delay between tuning cycles

[Yangbo Lu]

It's observed that eSDHC needed delay between tuning cycles for
HS200 successful tuning. This patch is to set 1ms delay for that.

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
---
Changes for v2:
	- None
Changes for v3:
	- Used a host member for tuning delay instead of a quirk.
Changes for v4:
	- None
Changes for v5:
	- Added Adrian's ACK
---
 drivers/mmc/host/sdhci-of-esdhc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
index 607e512..7518360 100644
--- a/drivers/mmc/host/sdhci-of-esdhc.c
+++ b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -810,6 +810,7 @@ static int sdhci_esdhc_probe(struct platform_device *pdev)
 	host->mmc_host_ops.start_signal_voltage_switch =
 		esdhc_signal_voltage_switch;
 	host->mmc_host_ops.execute_tuning = esdhc_execute_tuning;
+	host->tuning_delay = 1;
 
 	esdhc_init(pdev, host);
 
-- 
2.1.0.27.g96db324

Re: [v5, 0/5] Add SD UHS-I and eMMC HS200 support for eSDHC

[Ulf Hansson]

On 20 April 2017 at 10:14, Yangbo Lu <yangbo.lu@nxp.com> wrote:
> It's complicated to support SD UHS-I and eMMC HS200 for eSDHC because
> there're many differences between eSDHC and SD/eMMC spec. Several
> differences as below must be considered:
> 1. Peripheral clock must be used instead of platform clock.
>     - eSDHC could select peripheral clock or platform clock as its clock
>       source. According to RM, UHS-I/HS200 must use peripheral clock since
>       it supports higher frequency than platform clock.
>     - Patch 1 is to support this.
> 2. Signal voltage switching requires a control circuit out of eSDHC.
>     - 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.
>     - Patch 2 is to support this.
> 3. eSDHC uses tuning block for tuning procedure.
>     - Tuning clock control register must be configured before tuning.
>     - Patch 3 is to support this.
> 4. Delay is needed between tuning cycles for HS200 tuning.
>     - Once a patch removed mdelay between tuning cycles.
>       But eSDHC needs it.
>     - Patch 4 and patch 5 is to support this.
>
> Adrian Hunter (1):
>   mmc: sdhci: Control the delay between tuning commands
>
> Yangbo Lu (4):
>   mmc: sdhci-of-esdhc: add peripheral clock support
>   mmc: sdhci-of-esdhc: add support for signal voltage switch
>   mmc: sdhci-of-esdhc: add tuning support
>   mmc: sdhci-of-esdhc: add delay between tuning cycles
>
>  drivers/mmc/host/sdhci-esdhc.h    |   7 ++
>  drivers/mmc/host/sdhci-of-esdhc.c | 168 +++++++++++++++++++++++++++++++++++++-
>  drivers/mmc/host/sdhci.c          |  11 ++-
>  drivers/mmc/host/sdhci.h          |   2 +
>  4 files changed, 183 insertions(+), 5 deletions(-)
>
> --
> 2.1.0.27.g96db324
>

Thanks, applied for next!

Kind regards
Uffe