[PATCH v5 4/4] mmc: sdhci-msm: Rectify DLL programming sequence for SDCC

Ram Prakash Gupta posted 4 patches 2 months ago
[PATCH v5 4/4] mmc: sdhci-msm: Rectify DLL programming sequence for SDCC
Posted by Ram Prakash Gupta 2 months ago
From: Sachin Gupta <quic_sachgupt@quicinc.com>

With the current DLL sequence stability issues for data
transfer seen in HS400 and HS200 modes.

"mmc0: cqhci: error IRQ status: 0x00000000 cmd error -84
data error 0"

Rectify the DLL programming sequence as per latest hardware
programming guide

Signed-off-by: Sachin Gupta <quic_sachgupt@quicinc.com>
Signed-off-by: Ram Prakash Gupta <quic_rampraka@quicinc.com>
---
 drivers/mmc/host/sdhci-msm.c | 272 ++++++++++++++++++++++++++++++++---
 1 file changed, 253 insertions(+), 19 deletions(-)

diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index 8038b8def355..a875e92f8663 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -28,6 +28,7 @@
 #define CORE_VERSION_MAJOR_SHIFT	28
 #define CORE_VERSION_MAJOR_MASK		(0xf << CORE_VERSION_MAJOR_SHIFT)
 #define CORE_VERSION_MINOR_MASK		0xff
+#define SDHCI_MSM_MIN_V_7FF		0x6e
 
 #define CORE_MCI_GENERICS		0x70
 #define SWITCHABLE_SIGNALING_VOLTAGE	BIT(29)
@@ -119,7 +120,8 @@
 #define CORE_PWRSAVE_DLL	BIT(3)
 
 #define DDR_CONFIG_POR_VAL	0x80040873
-
+#define DLL_CONFIG_3_POR_VAL	0x10
+#define TCXO_FREQ               19200000
 
 #define INVALID_TUNING_PHASE	-1
 #define SDHCI_MSM_MIN_CLOCK	400000
@@ -319,6 +321,16 @@ struct sdhci_msm_host {
 	bool artanis_dll;
 };
 
+enum dll_init_context {
+	DLL_INIT_NORMAL,
+	DLL_INIT_FROM_CX_COLLAPSE_EXIT,
+};
+
+enum mode {
+	HS400, // equivalent to SDR104 mode for DLL.
+	HS200, // equivalent to SDR50 mode for DLL.
+};
+
 static const struct sdhci_msm_offset *sdhci_priv_msm_offset(struct sdhci_host *host)
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -803,6 +815,209 @@ static int msm_init_cm_dll(struct sdhci_host *host)
 	return 0;
 }
 
+static unsigned int sdhci_msm_get_min_clock(struct sdhci_host *host)
+{
+	return SDHCI_MSM_MIN_CLOCK;
+}
+
+static unsigned int sdhci_msm_get_clk_rate(struct sdhci_host *host, u32 req_clk)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
+	struct clk *core_clk = msm_host->bulk_clks[0].clk;
+	struct mmc_ios ios = host->mmc->ios;
+	unsigned int sup_clk;
+
+	if (req_clk < sdhci_msm_get_min_clock(host))
+		return sdhci_msm_get_min_clock(host);
+
+	sup_clk = clk_get_rate(core_clk);
+
+	if (ios.timing == MMC_TIMING_MMC_HS400 ||
+	    host->flags & SDHCI_HS400_TUNING)
+		sup_clk = sup_clk / 2;
+
+	return sup_clk;
+}
+
+/* Initialize the DLL (Programmable Delay Line) */
+static int sdhci_msm_configure_dll(struct sdhci_host *host, enum dll_init_context
+				 init_context, enum mode index)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
+	const struct sdhci_msm_offset *msm_offset = msm_host->offset;
+	struct mmc_host *mmc = host->mmc;
+	u32 ddr_cfg_offset, core_vendor_spec, config;
+	void __iomem *ioaddr = host->ioaddr;
+	unsigned long flags, dll_clock;
+	int rc = 0, wait_cnt = 50;
+
+	dll_clock = sdhci_msm_get_clk_rate(host, host->clock);
+	spin_lock_irqsave(&host->lock, flags);
+
+	core_vendor_spec = readl_relaxed(ioaddr + msm_offset->core_vendor_spec);
+
+	/*
+	 * Always disable PWRSAVE during the DLL power
+	 * up regardless of its current setting.
+	 */
+	core_vendor_spec &= ~CORE_CLK_PWRSAVE;
+	writel_relaxed(core_vendor_spec, ioaddr + msm_offset->core_vendor_spec);
+
+	if (msm_host->use_14lpp_dll_reset) {
+		/* Disable CK_OUT */
+		config = readl_relaxed(ioaddr + msm_offset->core_dll_config);
+		config &= ~CORE_CK_OUT_EN;
+		writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
+
+		/* Disable the DLL clock */
+		config = readl_relaxed(ioaddr + msm_offset->core_dll_config_2);
+		config |= CORE_DLL_CLOCK_DISABLE;
+		writel_relaxed(config, ioaddr + msm_offset->core_dll_config_2);
+	}
+
+	/*
+	 * Write 1 to DLL_RST bit of DLL_CONFIG register
+	 * and Write 1 to DLL_PDN bit of DLL_CONFIG register.
+	 */
+	config = readl_relaxed(ioaddr + msm_offset->core_dll_config);
+	config |= (CORE_DLL_RST | CORE_DLL_PDN);
+	writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
+
+	/*
+	 * Configure DLL_CONFIG_3 and USER_CTRL
+	 * (Only applicable for 7FF projects).
+	 */
+	if (msm_host->core_minor >= SDHCI_MSM_MIN_V_7FF) {
+		writel_relaxed(msm_host->dll[index].dll_config_3,
+			       ioaddr + msm_offset->core_dll_config_3);
+		writel_relaxed(msm_host->dll[index].dll_usr_ctl,
+			       ioaddr + msm_offset->core_dll_usr_ctl);
+	}
+
+	/*
+	 * Set DDR_CONFIG since step 7 is setting TEST_CTRL that can be skipped.
+	 */
+	ddr_cfg_offset = msm_host->updated_ddr_cfg ? msm_offset->core_ddr_config
+					: msm_offset->core_ddr_config_old;
+
+	config = msm_host->dll[index].ddr_config;
+	writel_relaxed(config, ioaddr + ddr_cfg_offset);
+
+	/* Set DLL_CONFIG_2 */
+	if (msm_host->use_14lpp_dll_reset) {
+		u32 mclk_freq;
+		int cycle_cnt;
+
+		/*
+		 * Only configure the mclk_freq in normal DLL init
+		 * context. If the DLL init is coming from
+		 * CX Collapse Exit context, the host->clock may be zero.
+		 * The DLL_CONFIG_2 register has already been restored to
+		 * proper value prior to getting here.
+		 */
+		if (init_context == DLL_INIT_NORMAL) {
+			cycle_cnt = readl_relaxed(ioaddr +
+					msm_offset->core_dll_config_2)
+					& CORE_FLL_CYCLE_CNT ? 8 : 4;
+
+			mclk_freq = DIV_ROUND_CLOSEST_ULL(dll_clock * cycle_cnt, TCXO_FREQ);
+
+			if (dll_clock < 100000000) {
+				pr_err("%s: %s: Non standard clk freq =%u\n",
+				       mmc_hostname(mmc), __func__, dll_clock);
+				rc = -EINVAL;
+				goto out;
+			}
+
+			config = readl_relaxed(ioaddr + msm_offset->core_dll_config_2);
+			config = (config & ~GENMASK(17, 10)) |
+					FIELD_PREP(GENMASK(17, 10), mclk_freq);
+			writel_relaxed(config, ioaddr + msm_offset->core_dll_config_2);
+		}
+		/* wait for 5us before enabling DLL clock */
+		udelay(5);
+	}
+
+	config = msm_host->dll[index].dll_config;
+	writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
+
+	/* Wait for 52us */
+	spin_unlock_irqrestore(&host->lock, flags);
+	usleep_range(60, 70);
+	spin_lock_irqsave(&host->lock, flags);
+
+	/*
+	 * Write 0 to DLL_RST bit of DLL_CONFIG register
+	 * and Write 0 to DLL_PDN bit of DLL_CONFIG register.
+	 */
+	config &= ~CORE_DLL_RST;
+	writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
+
+	config &= ~CORE_DLL_PDN;
+	writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
+	/* Write 1 to DLL_RST bit of DLL_CONFIG register */
+	config |= CORE_DLL_RST;
+	writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
+
+	/* Write 0 to DLL_RST bit of DLL_CONFIG register */
+	config &= ~CORE_DLL_RST;
+	writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
+
+	/* Set CORE_DLL_CLOCK_DISABLE to 0 */
+	if (msm_host->use_14lpp_dll_reset) {
+		config = readl_relaxed(ioaddr + msm_offset->core_dll_config_2);
+		config &= ~CORE_DLL_CLOCK_DISABLE;
+		writel_relaxed(config, ioaddr + msm_offset->core_dll_config_2);
+	}
+
+	/* Set DLL_EN bit to 1. */
+	config = readl_relaxed(ioaddr + msm_offset->core_dll_config);
+	config |= CORE_DLL_EN;
+	writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
+
+	/*
+	 * Wait for 8000 input clock. Here we calculate the
+	 * delay from fixed clock freq 192MHz, which turns out 42us.
+	 */
+	spin_unlock_irqrestore(&host->lock, flags);
+	usleep_range(50, 60);
+	spin_lock_irqsave(&host->lock, flags);
+
+	/* Set CK_OUT_EN bit to 1. */
+	config |= CORE_CK_OUT_EN;
+	writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
+
+	/*
+	 * Wait until DLL_LOCK bit of DLL_STATUS register
+	 * becomes '1'.
+	 */
+	while (!(readl_relaxed(ioaddr + msm_offset->core_dll_status) &
+		 CORE_DLL_LOCK)) {
+		/* max. wait for 50us sec for LOCK bit to be set */
+		if (--wait_cnt == 0) {
+			dev_err(mmc_dev(mmc), "%s: DLL failed to LOCK\n",
+				mmc_hostname(mmc));
+			rc = -ETIMEDOUT;
+			goto out;
+		}
+		/* wait for 1us before polling again */
+		udelay(1);
+	}
+
+out:
+	if (core_vendor_spec & CORE_CLK_PWRSAVE) {
+		/* Reenable PWRSAVE as needed */
+		config = readl_relaxed(ioaddr + msm_offset->core_vendor_spec);
+		config |= CORE_CLK_PWRSAVE;
+		writel_relaxed(config, ioaddr + msm_offset->core_vendor_spec);
+	}
+
+	spin_unlock_irqrestore(&host->lock, flags);
+	return rc;
+}
+
 static void msm_hc_select_default(struct sdhci_host *host)
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -925,14 +1140,31 @@ static void sdhci_msm_hc_select_mode(struct sdhci_host *host)
 		msm_hc_select_default(host);
 }
 
+static int sdhci_msm_init_dll(struct sdhci_host *host, enum dll_init_context init_context)
+{
+	if (host->mmc->ios.timing == MMC_TIMING_UHS_SDR104 ||
+	    host->mmc->ios.timing == MMC_TIMING_MMC_HS400)
+		return sdhci_msm_configure_dll(host, init_context, HS400);
+
+	return sdhci_msm_configure_dll(host, init_context, HS200);
+}
+
+static int sdhci_msm_dll_config(struct sdhci_host *host, enum dll_init_context init_context)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
+
+	return msm_host->artanis_dll ? sdhci_msm_init_dll(host, init_context) :
+		msm_init_cm_dll(host);
+}
+
 static int sdhci_msm_cdclp533_calibration(struct sdhci_host *host)
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
+	const struct sdhci_msm_offset *msm_offset = msm_host->offset;
 	u32 config, calib_done;
 	int ret;
-	const struct sdhci_msm_offset *msm_offset =
-					msm_host->offset;
 
 	pr_debug("%s: %s: Enter\n", mmc_hostname(host->mmc), __func__);
 
@@ -940,7 +1172,7 @@ static int sdhci_msm_cdclp533_calibration(struct sdhci_host *host)
 	 * Retuning in HS400 (DDR mode) will fail, just reset the
 	 * tuning block and restore the saved tuning phase.
 	 */
-	ret = msm_init_cm_dll(host);
+	ret = sdhci_msm_dll_config(host, DLL_INIT_NORMAL);
 	if (ret)
 		goto out;
 
@@ -1028,7 +1260,7 @@ static int sdhci_msm_cdclp533_calibration(struct sdhci_host *host)
 	return ret;
 }
 
-static int sdhci_msm_cm_dll_sdc4_calibration(struct sdhci_host *host)
+static int sdhci_msm_cm_dll_sdc4_calibration(struct sdhci_host *host, enum mode index)
 {
 	struct mmc_host *mmc = host->mmc;
 	u32 dll_status, config, ddr_cfg_offset;
@@ -1051,7 +1283,11 @@ static int sdhci_msm_cm_dll_sdc4_calibration(struct sdhci_host *host)
 		ddr_cfg_offset = msm_offset->core_ddr_config;
 	else
 		ddr_cfg_offset = msm_offset->core_ddr_config_old;
-	writel_relaxed(msm_host->ddr_config, host->ioaddr + ddr_cfg_offset);
+
+	if (msm_host->artanis_dll)
+		writel_relaxed(msm_host->dll[index].ddr_config, host->ioaddr + ddr_cfg_offset);
+	else
+		writel_relaxed(msm_host->ddr_config, host->ioaddr + ddr_cfg_offset);
 
 	if (mmc->ios.enhanced_strobe) {
 		config = readl_relaxed(host->ioaddr +
@@ -1108,11 +1344,10 @@ static int sdhci_msm_hs400_dll_calibration(struct sdhci_host *host)
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
+	const struct sdhci_msm_offset *msm_offset = msm_host->offset;
 	struct mmc_host *mmc = host->mmc;
-	int ret;
 	u32 config;
-	const struct sdhci_msm_offset *msm_offset =
-					msm_host->offset;
+	int ret;
 
 	pr_debug("%s: %s: Enter\n", mmc_hostname(host->mmc), __func__);
 
@@ -1120,7 +1355,8 @@ static int sdhci_msm_hs400_dll_calibration(struct sdhci_host *host)
 	 * Retuning in HS400 (DDR mode) will fail, just reset the
 	 * tuning block and restore the saved tuning phase.
 	 */
-	ret = msm_init_cm_dll(host);
+	ret = sdhci_msm_dll_config(host, DLL_INIT_NORMAL);
+
 	if (ret)
 		goto out;
 
@@ -1140,7 +1376,7 @@ static int sdhci_msm_hs400_dll_calibration(struct sdhci_host *host)
 	if (msm_host->use_cdclp533)
 		ret = sdhci_msm_cdclp533_calibration(host);
 	else
-		ret = sdhci_msm_cm_dll_sdc4_calibration(host);
+		ret = sdhci_msm_cm_dll_sdc4_calibration(host, HS400);
 out:
 	pr_debug("%s: %s: Exit, ret %d\n", mmc_hostname(host->mmc),
 		 __func__, ret);
@@ -1183,7 +1419,8 @@ static int sdhci_msm_restore_sdr_dll_config(struct sdhci_host *host)
 		return 0;
 
 	/* Reset the tuning block */
-	ret = msm_init_cm_dll(host);
+	ret = sdhci_msm_dll_config(host, DLL_INIT_NORMAL);
+
 	if (ret)
 		return ret;
 
@@ -1257,12 +1494,11 @@ static int sdhci_msm_execute_tuning(struct mmc_host *mmc, u32 opcode)
 	if (host->flags & SDHCI_HS400_TUNING) {
 		sdhci_msm_hc_select_mode(host);
 		msm_set_clock_rate_for_bus_mode(host, ios.clock);
-		host->flags &= ~SDHCI_HS400_TUNING;
 	}
 
 retry:
 	/* First of all reset the tuning block */
-	rc = msm_init_cm_dll(host);
+	rc = sdhci_msm_dll_config(host, DLL_INIT_NORMAL);
 	if (rc)
 		return rc;
 
@@ -1325,6 +1561,9 @@ static int sdhci_msm_execute_tuning(struct mmc_host *mmc, u32 opcode)
 		rc = -EIO;
 	}
 
+	if (host->flags & SDHCI_HS400_TUNING)
+		host->flags &= ~SDHCI_HS400_TUNING;
+
 	if (!rc)
 		msm_host->tuning_done = true;
 	return rc;
@@ -1845,11 +2084,6 @@ static unsigned int sdhci_msm_get_max_clock(struct sdhci_host *host)
 	return clk_round_rate(core_clk, ULONG_MAX);
 }
 
-static unsigned int sdhci_msm_get_min_clock(struct sdhci_host *host)
-{
-	return SDHCI_MSM_MIN_CLOCK;
-}
-
 /*
  * __sdhci_msm_set_clock - sdhci_msm clock control.
  *
-- 
2.34.1
Re: [PATCH v5 4/4] mmc: sdhci-msm: Rectify DLL programming sequence for SDCC
Posted by Adrian Hunter 2 months ago
On 13/10/2025 17:53, Ram Prakash Gupta wrote:
> From: Sachin Gupta <quic_sachgupt@quicinc.com>
> 
> With the current DLL sequence stability issues for data
> transfer seen in HS400 and HS200 modes.
> 
> "mmc0: cqhci: error IRQ status: 0x00000000 cmd error -84
> data error 0"
> 
> Rectify the DLL programming sequence as per latest hardware
> programming guide
> 
> Signed-off-by: Sachin Gupta <quic_sachgupt@quicinc.com>
> Signed-off-by: Ram Prakash Gupta <quic_rampraka@quicinc.com>
> ---
>  drivers/mmc/host/sdhci-msm.c | 272 ++++++++++++++++++++++++++++++++---
>  1 file changed, 253 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index 8038b8def355..a875e92f8663 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -28,6 +28,7 @@
>  #define CORE_VERSION_MAJOR_SHIFT	28
>  #define CORE_VERSION_MAJOR_MASK		(0xf << CORE_VERSION_MAJOR_SHIFT)
>  #define CORE_VERSION_MINOR_MASK		0xff
> +#define SDHCI_MSM_MIN_V_7FF		0x6e
>  
>  #define CORE_MCI_GENERICS		0x70
>  #define SWITCHABLE_SIGNALING_VOLTAGE	BIT(29)
> @@ -119,7 +120,8 @@
>  #define CORE_PWRSAVE_DLL	BIT(3)
>  
>  #define DDR_CONFIG_POR_VAL	0x80040873
> -
> +#define DLL_CONFIG_3_POR_VAL	0x10
> +#define TCXO_FREQ               19200000
>  
>  #define INVALID_TUNING_PHASE	-1
>  #define SDHCI_MSM_MIN_CLOCK	400000
> @@ -319,6 +321,16 @@ struct sdhci_msm_host {
>  	bool artanis_dll;
>  };
>  
> +enum dll_init_context {
> +	DLL_INIT_NORMAL,
> +	DLL_INIT_FROM_CX_COLLAPSE_EXIT,

DLL_INIT_FROM_CX_COLLAPSE_EXIT is never used?

> +};
> +
> +enum mode {
> +	HS400, // equivalent to SDR104 mode for DLL.
> +	HS200, // equivalent to SDR50 mode for DLL.
> +};
> +
>  static const struct sdhci_msm_offset *sdhci_priv_msm_offset(struct sdhci_host *host)
>  {
>  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> @@ -803,6 +815,209 @@ static int msm_init_cm_dll(struct sdhci_host *host)
>  	return 0;
>  }
>  
> +static unsigned int sdhci_msm_get_min_clock(struct sdhci_host *host)
> +{
> +	return SDHCI_MSM_MIN_CLOCK;
> +}
> +
> +static unsigned int sdhci_msm_get_clk_rate(struct sdhci_host *host, u32 req_clk)
> +{
> +	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> +	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
> +	struct clk *core_clk = msm_host->bulk_clks[0].clk;
> +	struct mmc_ios ios = host->mmc->ios;
> +	unsigned int sup_clk;
> +
> +	if (req_clk < sdhci_msm_get_min_clock(host))
> +		return sdhci_msm_get_min_clock(host);
> +
> +	sup_clk = clk_get_rate(core_clk);
> +
> +	if (ios.timing == MMC_TIMING_MMC_HS400 ||
> +	    host->flags & SDHCI_HS400_TUNING)
> +		sup_clk = sup_clk / 2;
> +
> +	return sup_clk;
> +}
> +
> +/* Initialize the DLL (Programmable Delay Line) */
> +static int sdhci_msm_configure_dll(struct sdhci_host *host, enum dll_init_context
> +				 init_context, enum mode index)
> +{
> +	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> +	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
> +	const struct sdhci_msm_offset *msm_offset = msm_host->offset;
> +	struct mmc_host *mmc = host->mmc;
> +	u32 ddr_cfg_offset, core_vendor_spec, config;
> +	void __iomem *ioaddr = host->ioaddr;
> +	unsigned long flags, dll_clock;
> +	int rc = 0, wait_cnt = 50;
> +
> +	dll_clock = sdhci_msm_get_clk_rate(host, host->clock);
> +	spin_lock_irqsave(&host->lock, flags);
> +
> +	core_vendor_spec = readl_relaxed(ioaddr + msm_offset->core_vendor_spec);
> +
> +	/*
> +	 * Always disable PWRSAVE during the DLL power
> +	 * up regardless of its current setting.
> +	 */
> +	core_vendor_spec &= ~CORE_CLK_PWRSAVE;
> +	writel_relaxed(core_vendor_spec, ioaddr + msm_offset->core_vendor_spec);
> +
> +	if (msm_host->use_14lpp_dll_reset) {
> +		/* Disable CK_OUT */
> +		config = readl_relaxed(ioaddr + msm_offset->core_dll_config);
> +		config &= ~CORE_CK_OUT_EN;
> +		writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
> +
> +		/* Disable the DLL clock */
> +		config = readl_relaxed(ioaddr + msm_offset->core_dll_config_2);
> +		config |= CORE_DLL_CLOCK_DISABLE;
> +		writel_relaxed(config, ioaddr + msm_offset->core_dll_config_2);
> +	}
> +
> +	/*
> +	 * Write 1 to DLL_RST bit of DLL_CONFIG register
> +	 * and Write 1 to DLL_PDN bit of DLL_CONFIG register.
> +	 */
> +	config = readl_relaxed(ioaddr + msm_offset->core_dll_config);
> +	config |= (CORE_DLL_RST | CORE_DLL_PDN);
> +	writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
> +
> +	/*
> +	 * Configure DLL_CONFIG_3 and USER_CTRL
> +	 * (Only applicable for 7FF projects).
> +	 */
> +	if (msm_host->core_minor >= SDHCI_MSM_MIN_V_7FF) {
> +		writel_relaxed(msm_host->dll[index].dll_config_3,
> +			       ioaddr + msm_offset->core_dll_config_3);
> +		writel_relaxed(msm_host->dll[index].dll_usr_ctl,
> +			       ioaddr + msm_offset->core_dll_usr_ctl);
> +	}
> +
> +	/*
> +	 * Set DDR_CONFIG since step 7 is setting TEST_CTRL that can be skipped.
> +	 */
> +	ddr_cfg_offset = msm_host->updated_ddr_cfg ? msm_offset->core_ddr_config
> +					: msm_offset->core_ddr_config_old;
> +
> +	config = msm_host->dll[index].ddr_config;
> +	writel_relaxed(config, ioaddr + ddr_cfg_offset);
> +
> +	/* Set DLL_CONFIG_2 */
> +	if (msm_host->use_14lpp_dll_reset) {
> +		u32 mclk_freq;
> +		int cycle_cnt;
> +
> +		/*
> +		 * Only configure the mclk_freq in normal DLL init
> +		 * context. If the DLL init is coming from
> +		 * CX Collapse Exit context, the host->clock may be zero.
> +		 * The DLL_CONFIG_2 register has already been restored to
> +		 * proper value prior to getting here.
> +		 */
> +		if (init_context == DLL_INIT_NORMAL) {
> +			cycle_cnt = readl_relaxed(ioaddr +
> +					msm_offset->core_dll_config_2)
> +					& CORE_FLL_CYCLE_CNT ? 8 : 4;
> +
> +			mclk_freq = DIV_ROUND_CLOSEST_ULL(dll_clock * cycle_cnt, TCXO_FREQ);
> +
> +			if (dll_clock < 100000000) {
> +				pr_err("%s: %s: Non standard clk freq =%u\n",
> +				       mmc_hostname(mmc), __func__, dll_clock);
> +				rc = -EINVAL;
> +				goto out;
> +			}
> +
> +			config = readl_relaxed(ioaddr + msm_offset->core_dll_config_2);
> +			config = (config & ~GENMASK(17, 10)) |
> +					FIELD_PREP(GENMASK(17, 10), mclk_freq);
> +			writel_relaxed(config, ioaddr + msm_offset->core_dll_config_2);
> +		}
> +		/* wait for 5us before enabling DLL clock */
> +		udelay(5);
> +	}
> +
> +	config = msm_host->dll[index].dll_config;
> +	writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
> +
> +	/* Wait for 52us */
> +	spin_unlock_irqrestore(&host->lock, flags);
> +	usleep_range(60, 70);
> +	spin_lock_irqsave(&host->lock, flags);
> +
> +	/*
> +	 * Write 0 to DLL_RST bit of DLL_CONFIG register
> +	 * and Write 0 to DLL_PDN bit of DLL_CONFIG register.
> +	 */
> +	config &= ~CORE_DLL_RST;
> +	writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
> +
> +	config &= ~CORE_DLL_PDN;
> +	writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
> +	/* Write 1 to DLL_RST bit of DLL_CONFIG register */
> +	config |= CORE_DLL_RST;
> +	writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
> +
> +	/* Write 0 to DLL_RST bit of DLL_CONFIG register */
> +	config &= ~CORE_DLL_RST;
> +	writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
> +
> +	/* Set CORE_DLL_CLOCK_DISABLE to 0 */
> +	if (msm_host->use_14lpp_dll_reset) {
> +		config = readl_relaxed(ioaddr + msm_offset->core_dll_config_2);
> +		config &= ~CORE_DLL_CLOCK_DISABLE;
> +		writel_relaxed(config, ioaddr + msm_offset->core_dll_config_2);
> +	}
> +
> +	/* Set DLL_EN bit to 1. */
> +	config = readl_relaxed(ioaddr + msm_offset->core_dll_config);
> +	config |= CORE_DLL_EN;
> +	writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
> +
> +	/*
> +	 * Wait for 8000 input clock. Here we calculate the
> +	 * delay from fixed clock freq 192MHz, which turns out 42us.
> +	 */
> +	spin_unlock_irqrestore(&host->lock, flags);
> +	usleep_range(50, 60);
> +	spin_lock_irqsave(&host->lock, flags);
> +
> +	/* Set CK_OUT_EN bit to 1. */
> +	config |= CORE_CK_OUT_EN;
> +	writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
> +
> +	/*
> +	 * Wait until DLL_LOCK bit of DLL_STATUS register
> +	 * becomes '1'.
> +	 */
> +	while (!(readl_relaxed(ioaddr + msm_offset->core_dll_status) &
> +		 CORE_DLL_LOCK)) {
> +		/* max. wait for 50us sec for LOCK bit to be set */
> +		if (--wait_cnt == 0) {
> +			dev_err(mmc_dev(mmc), "%s: DLL failed to LOCK\n",
> +				mmc_hostname(mmc));
> +			rc = -ETIMEDOUT;
> +			goto out;
> +		}
> +		/* wait for 1us before polling again */
> +		udelay(1);
> +	}

Please use an iopoll macro like readl_relaxed_poll_timeout_atomic().

> +
> +out:
> +	if (core_vendor_spec & CORE_CLK_PWRSAVE) {
> +		/* Reenable PWRSAVE as needed */
> +		config = readl_relaxed(ioaddr + msm_offset->core_vendor_spec);
> +		config |= CORE_CLK_PWRSAVE;
> +		writel_relaxed(config, ioaddr + msm_offset->core_vendor_spec);
> +	}
> +
> +	spin_unlock_irqrestore(&host->lock, flags);
> +	return rc;
> +}
> +
>  static void msm_hc_select_default(struct sdhci_host *host)
>  {
>  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> @@ -925,14 +1140,31 @@ static void sdhci_msm_hc_select_mode(struct sdhci_host *host)
>  		msm_hc_select_default(host);
>  }
>  
> +static int sdhci_msm_init_dll(struct sdhci_host *host, enum dll_init_context init_context)
> +{
> +	if (host->mmc->ios.timing == MMC_TIMING_UHS_SDR104 ||
> +	    host->mmc->ios.timing == MMC_TIMING_MMC_HS400)
> +		return sdhci_msm_configure_dll(host, init_context, HS400);
> +
> +	return sdhci_msm_configure_dll(host, init_context, HS200);
> +}
> +
> +static int sdhci_msm_dll_config(struct sdhci_host *host, enum dll_init_context init_context)
> +{
> +	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> +	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
> +
> +	return msm_host->artanis_dll ? sdhci_msm_init_dll(host, init_context) :
> +		msm_init_cm_dll(host);
> +}
> +
>  static int sdhci_msm_cdclp533_calibration(struct sdhci_host *host)
>  {
>  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>  	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
> +	const struct sdhci_msm_offset *msm_offset = msm_host->offset;
>  	u32 config, calib_done;
>  	int ret;
> -	const struct sdhci_msm_offset *msm_offset =
> -					msm_host->offset;
>  
>  	pr_debug("%s: %s: Enter\n", mmc_hostname(host->mmc), __func__);
>  
> @@ -940,7 +1172,7 @@ static int sdhci_msm_cdclp533_calibration(struct sdhci_host *host)
>  	 * Retuning in HS400 (DDR mode) will fail, just reset the
>  	 * tuning block and restore the saved tuning phase.
>  	 */
> -	ret = msm_init_cm_dll(host);
> +	ret = sdhci_msm_dll_config(host, DLL_INIT_NORMAL);
>  	if (ret)
>  		goto out;
>  
> @@ -1028,7 +1260,7 @@ static int sdhci_msm_cdclp533_calibration(struct sdhci_host *host)
>  	return ret;
>  }
>  
> -static int sdhci_msm_cm_dll_sdc4_calibration(struct sdhci_host *host)
> +static int sdhci_msm_cm_dll_sdc4_calibration(struct sdhci_host *host, enum mode index)
>  {
>  	struct mmc_host *mmc = host->mmc;
>  	u32 dll_status, config, ddr_cfg_offset;
> @@ -1051,7 +1283,11 @@ static int sdhci_msm_cm_dll_sdc4_calibration(struct sdhci_host *host)
>  		ddr_cfg_offset = msm_offset->core_ddr_config;
>  	else
>  		ddr_cfg_offset = msm_offset->core_ddr_config_old;
> -	writel_relaxed(msm_host->ddr_config, host->ioaddr + ddr_cfg_offset);
> +
> +	if (msm_host->artanis_dll)
> +		writel_relaxed(msm_host->dll[index].ddr_config, host->ioaddr + ddr_cfg_offset);
> +	else
> +		writel_relaxed(msm_host->ddr_config, host->ioaddr + ddr_cfg_offset);
>  
>  	if (mmc->ios.enhanced_strobe) {
>  		config = readl_relaxed(host->ioaddr +
> @@ -1108,11 +1344,10 @@ static int sdhci_msm_hs400_dll_calibration(struct sdhci_host *host)
>  {
>  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>  	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
> +	const struct sdhci_msm_offset *msm_offset = msm_host->offset;
>  	struct mmc_host *mmc = host->mmc;
> -	int ret;
>  	u32 config;
> -	const struct sdhci_msm_offset *msm_offset =
> -					msm_host->offset;
> +	int ret;

Here and elsewhere, this re-ordering of local definitions is a nice
improvement but it would be better as a separate patch

>  
>  	pr_debug("%s: %s: Enter\n", mmc_hostname(host->mmc), __func__);
>  
> @@ -1120,7 +1355,8 @@ static int sdhci_msm_hs400_dll_calibration(struct sdhci_host *host)
>  	 * Retuning in HS400 (DDR mode) will fail, just reset the
>  	 * tuning block and restore the saved tuning phase.
>  	 */
> -	ret = msm_init_cm_dll(host);
> +	ret = sdhci_msm_dll_config(host, DLL_INIT_NORMAL);
> +
>  	if (ret)
>  		goto out;
>  
> @@ -1140,7 +1376,7 @@ static int sdhci_msm_hs400_dll_calibration(struct sdhci_host *host)
>  	if (msm_host->use_cdclp533)
>  		ret = sdhci_msm_cdclp533_calibration(host);
>  	else
> -		ret = sdhci_msm_cm_dll_sdc4_calibration(host);
> +		ret = sdhci_msm_cm_dll_sdc4_calibration(host, HS400);
>  out:
>  	pr_debug("%s: %s: Exit, ret %d\n", mmc_hostname(host->mmc),
>  		 __func__, ret);
> @@ -1183,7 +1419,8 @@ static int sdhci_msm_restore_sdr_dll_config(struct sdhci_host *host)
>  		return 0;
>  
>  	/* Reset the tuning block */
> -	ret = msm_init_cm_dll(host);
> +	ret = sdhci_msm_dll_config(host, DLL_INIT_NORMAL);
> +
>  	if (ret)
>  		return ret;
>  
> @@ -1257,12 +1494,11 @@ static int sdhci_msm_execute_tuning(struct mmc_host *mmc, u32 opcode)
>  	if (host->flags & SDHCI_HS400_TUNING) {
>  		sdhci_msm_hc_select_mode(host);
>  		msm_set_clock_rate_for_bus_mode(host, ios.clock);
> -		host->flags &= ~SDHCI_HS400_TUNING;
>  	}
>  
>  retry:
>  	/* First of all reset the tuning block */
> -	rc = msm_init_cm_dll(host);
> +	rc = sdhci_msm_dll_config(host, DLL_INIT_NORMAL);
>  	if (rc)
>  		return rc;
>  
> @@ -1325,6 +1561,9 @@ static int sdhci_msm_execute_tuning(struct mmc_host *mmc, u32 opcode)
>  		rc = -EIO;
>  	}
>  
> +	if (host->flags & SDHCI_HS400_TUNING)
> +		host->flags &= ~SDHCI_HS400_TUNING;

Really the flag should be cleared on all return paths

> +
>  	if (!rc)
>  		msm_host->tuning_done = true;
>  	return rc;
> @@ -1845,11 +2084,6 @@ static unsigned int sdhci_msm_get_max_clock(struct sdhci_host *host)
>  	return clk_round_rate(core_clk, ULONG_MAX);
>  }
>  
> -static unsigned int sdhci_msm_get_min_clock(struct sdhci_host *host)
> -{
> -	return SDHCI_MSM_MIN_CLOCK;
> -}
> -
>  /*
>   * __sdhci_msm_set_clock - sdhci_msm clock control.
>   *
Re: [PATCH v5 4/4] mmc: sdhci-msm: Rectify DLL programming sequence for SDCC
Posted by Ram Prakash Gupta 1 month, 3 weeks ago
On 10/16/2025 11:54 AM, Adrian Hunter wrote:
> On 13/10/2025 17:53, Ram Prakash Gupta wrote:
>> From: Sachin Gupta <quic_sachgupt@quicinc.com>
>>
>> With the current DLL sequence stability issues for data
>> transfer seen in HS400 and HS200 modes.
>>
>> "mmc0: cqhci: error IRQ status: 0x00000000 cmd error -84
>> data error 0"
>>
>> Rectify the DLL programming sequence as per latest hardware
>> programming guide
>>
>> Signed-off-by: Sachin Gupta <quic_sachgupt@quicinc.com>
>> Signed-off-by: Ram Prakash Gupta <quic_rampraka@quicinc.com>
>> ---
>>  drivers/mmc/host/sdhci-msm.c | 272 ++++++++++++++++++++++++++++++++---
>>  1 file changed, 253 insertions(+), 19 deletions(-)
>>
>> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
>> index 8038b8def355..a875e92f8663 100644
>> --- a/drivers/mmc/host/sdhci-msm.c
>> +++ b/drivers/mmc/host/sdhci-msm.c
>> @@ -28,6 +28,7 @@
>>  #define CORE_VERSION_MAJOR_SHIFT	28
>>  #define CORE_VERSION_MAJOR_MASK		(0xf << CORE_VERSION_MAJOR_SHIFT)
>>  #define CORE_VERSION_MINOR_MASK		0xff
>> +#define SDHCI_MSM_MIN_V_7FF		0x6e
>>  
>>  #define CORE_MCI_GENERICS		0x70
>>  #define SWITCHABLE_SIGNALING_VOLTAGE	BIT(29)
>> @@ -119,7 +120,8 @@
>>  #define CORE_PWRSAVE_DLL	BIT(3)
>>  
>>  #define DDR_CONFIG_POR_VAL	0x80040873
>> -
>> +#define DLL_CONFIG_3_POR_VAL	0x10
>> +#define TCXO_FREQ               19200000
>>  
>>  #define INVALID_TUNING_PHASE	-1
>>  #define SDHCI_MSM_MIN_CLOCK	400000
>> @@ -319,6 +321,16 @@ struct sdhci_msm_host {
>>  	bool artanis_dll;
>>  };
>>  
>> +enum dll_init_context {
>> +	DLL_INIT_NORMAL,
>> +	DLL_INIT_FROM_CX_COLLAPSE_EXIT,
> DLL_INIT_FROM_CX_COLLAPSE_EXIT is never used?

This is ball parked for a collapse scenario, but that is yet to be
added, will remove this for time being in next patchset.

>
>> +};
>> +
>> +enum mode {
>> +	HS400, // equivalent to SDR104 mode for DLL.
>> +	HS200, // equivalent to SDR50 mode for DLL.
>> +};
>> +
>>  static const struct sdhci_msm_offset *sdhci_priv_msm_offset(struct sdhci_host *host)
>>  {
>>  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>> @@ -803,6 +815,209 @@ static int msm_init_cm_dll(struct sdhci_host *host)
>>  	return 0;
>>  }
>>  
>> +static unsigned int sdhci_msm_get_min_clock(struct sdhci_host *host)
>> +{
>> +	return SDHCI_MSM_MIN_CLOCK;
>> +}
>> +
>> +static unsigned int sdhci_msm_get_clk_rate(struct sdhci_host *host, u32 req_clk)
>> +{
>> +	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>> +	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
>> +	struct clk *core_clk = msm_host->bulk_clks[0].clk;
>> +	struct mmc_ios ios = host->mmc->ios;
>> +	unsigned int sup_clk;
>> +
>> +	if (req_clk < sdhci_msm_get_min_clock(host))
>> +		return sdhci_msm_get_min_clock(host);
>> +
>> +	sup_clk = clk_get_rate(core_clk);
>> +
>> +	if (ios.timing == MMC_TIMING_MMC_HS400 ||
>> +	    host->flags & SDHCI_HS400_TUNING)
>> +		sup_clk = sup_clk / 2;
>> +
>> +	return sup_clk;
>> +}
>> +
>> +/* Initialize the DLL (Programmable Delay Line) */
>> +static int sdhci_msm_configure_dll(struct sdhci_host *host, enum dll_init_context
>> +				 init_context, enum mode index)
>> +{
>> +	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>> +	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
>> +	const struct sdhci_msm_offset *msm_offset = msm_host->offset;
>> +	struct mmc_host *mmc = host->mmc;
>> +	u32 ddr_cfg_offset, core_vendor_spec, config;
>> +	void __iomem *ioaddr = host->ioaddr;
>> +	unsigned long flags, dll_clock;
>> +	int rc = 0, wait_cnt = 50;
>> +
>> +	dll_clock = sdhci_msm_get_clk_rate(host, host->clock);
>> +	spin_lock_irqsave(&host->lock, flags);
>> +
>> +	core_vendor_spec = readl_relaxed(ioaddr + msm_offset->core_vendor_spec);
>> +
>> +	/*
>> +	 * Always disable PWRSAVE during the DLL power
>> +	 * up regardless of its current setting.
>> +	 */
>> +	core_vendor_spec &= ~CORE_CLK_PWRSAVE;
>> +	writel_relaxed(core_vendor_spec, ioaddr + msm_offset->core_vendor_spec);
>> +
>> +	if (msm_host->use_14lpp_dll_reset) {
>> +		/* Disable CK_OUT */
>> +		config = readl_relaxed(ioaddr + msm_offset->core_dll_config);
>> +		config &= ~CORE_CK_OUT_EN;
>> +		writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
>> +
>> +		/* Disable the DLL clock */
>> +		config = readl_relaxed(ioaddr + msm_offset->core_dll_config_2);
>> +		config |= CORE_DLL_CLOCK_DISABLE;
>> +		writel_relaxed(config, ioaddr + msm_offset->core_dll_config_2);
>> +	}
>> +
>> +	/*
>> +	 * Write 1 to DLL_RST bit of DLL_CONFIG register
>> +	 * and Write 1 to DLL_PDN bit of DLL_CONFIG register.
>> +	 */
>> +	config = readl_relaxed(ioaddr + msm_offset->core_dll_config);
>> +	config |= (CORE_DLL_RST | CORE_DLL_PDN);
>> +	writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
>> +
>> +	/*
>> +	 * Configure DLL_CONFIG_3 and USER_CTRL
>> +	 * (Only applicable for 7FF projects).
>> +	 */
>> +	if (msm_host->core_minor >= SDHCI_MSM_MIN_V_7FF) {
>> +		writel_relaxed(msm_host->dll[index].dll_config_3,
>> +			       ioaddr + msm_offset->core_dll_config_3);
>> +		writel_relaxed(msm_host->dll[index].dll_usr_ctl,
>> +			       ioaddr + msm_offset->core_dll_usr_ctl);
>> +	}
>> +
>> +	/*
>> +	 * Set DDR_CONFIG since step 7 is setting TEST_CTRL that can be skipped.
>> +	 */
>> +	ddr_cfg_offset = msm_host->updated_ddr_cfg ? msm_offset->core_ddr_config
>> +					: msm_offset->core_ddr_config_old;
>> +
>> +	config = msm_host->dll[index].ddr_config;
>> +	writel_relaxed(config, ioaddr + ddr_cfg_offset);
>> +
>> +	/* Set DLL_CONFIG_2 */
>> +	if (msm_host->use_14lpp_dll_reset) {
>> +		u32 mclk_freq;
>> +		int cycle_cnt;
>> +
>> +		/*
>> +		 * Only configure the mclk_freq in normal DLL init
>> +		 * context. If the DLL init is coming from
>> +		 * CX Collapse Exit context, the host->clock may be zero.
>> +		 * The DLL_CONFIG_2 register has already been restored to
>> +		 * proper value prior to getting here.
>> +		 */
>> +		if (init_context == DLL_INIT_NORMAL) {
>> +			cycle_cnt = readl_relaxed(ioaddr +
>> +					msm_offset->core_dll_config_2)
>> +					& CORE_FLL_CYCLE_CNT ? 8 : 4;
>> +
>> +			mclk_freq = DIV_ROUND_CLOSEST_ULL(dll_clock * cycle_cnt, TCXO_FREQ);
>> +
>> +			if (dll_clock < 100000000) {
>> +				pr_err("%s: %s: Non standard clk freq =%u\n",
>> +				       mmc_hostname(mmc), __func__, dll_clock);
>> +				rc = -EINVAL;
>> +				goto out;
>> +			}
>> +
>> +			config = readl_relaxed(ioaddr + msm_offset->core_dll_config_2);
>> +			config = (config & ~GENMASK(17, 10)) |
>> +					FIELD_PREP(GENMASK(17, 10), mclk_freq);
>> +			writel_relaxed(config, ioaddr + msm_offset->core_dll_config_2);
>> +		}
>> +		/* wait for 5us before enabling DLL clock */
>> +		udelay(5);
>> +	}
>> +
>> +	config = msm_host->dll[index].dll_config;
>> +	writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
>> +
>> +	/* Wait for 52us */
>> +	spin_unlock_irqrestore(&host->lock, flags);
>> +	usleep_range(60, 70);
>> +	spin_lock_irqsave(&host->lock, flags);
>> +
>> +	/*
>> +	 * Write 0 to DLL_RST bit of DLL_CONFIG register
>> +	 * and Write 0 to DLL_PDN bit of DLL_CONFIG register.
>> +	 */
>> +	config &= ~CORE_DLL_RST;
>> +	writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
>> +
>> +	config &= ~CORE_DLL_PDN;
>> +	writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
>> +	/* Write 1 to DLL_RST bit of DLL_CONFIG register */
>> +	config |= CORE_DLL_RST;
>> +	writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
>> +
>> +	/* Write 0 to DLL_RST bit of DLL_CONFIG register */
>> +	config &= ~CORE_DLL_RST;
>> +	writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
>> +
>> +	/* Set CORE_DLL_CLOCK_DISABLE to 0 */
>> +	if (msm_host->use_14lpp_dll_reset) {
>> +		config = readl_relaxed(ioaddr + msm_offset->core_dll_config_2);
>> +		config &= ~CORE_DLL_CLOCK_DISABLE;
>> +		writel_relaxed(config, ioaddr + msm_offset->core_dll_config_2);
>> +	}
>> +
>> +	/* Set DLL_EN bit to 1. */
>> +	config = readl_relaxed(ioaddr + msm_offset->core_dll_config);
>> +	config |= CORE_DLL_EN;
>> +	writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
>> +
>> +	/*
>> +	 * Wait for 8000 input clock. Here we calculate the
>> +	 * delay from fixed clock freq 192MHz, which turns out 42us.
>> +	 */
>> +	spin_unlock_irqrestore(&host->lock, flags);
>> +	usleep_range(50, 60);
>> +	spin_lock_irqsave(&host->lock, flags);
>> +
>> +	/* Set CK_OUT_EN bit to 1. */
>> +	config |= CORE_CK_OUT_EN;
>> +	writel_relaxed(config, ioaddr + msm_offset->core_dll_config);
>> +
>> +	/*
>> +	 * Wait until DLL_LOCK bit of DLL_STATUS register
>> +	 * becomes '1'.
>> +	 */
>> +	while (!(readl_relaxed(ioaddr + msm_offset->core_dll_status) &
>> +		 CORE_DLL_LOCK)) {
>> +		/* max. wait for 50us sec for LOCK bit to be set */
>> +		if (--wait_cnt == 0) {
>> +			dev_err(mmc_dev(mmc), "%s: DLL failed to LOCK\n",
>> +				mmc_hostname(mmc));
>> +			rc = -ETIMEDOUT;
>> +			goto out;
>> +		}
>> +		/* wait for 1us before polling again */
>> +		udelay(1);
>> +	}
> Please use an iopoll macro like readl_relaxed_poll_timeout_atomic().

sure, thanks, will explore and update accordingly.

>
>> +
>> +out:
>> +	if (core_vendor_spec & CORE_CLK_PWRSAVE) {
>> +		/* Reenable PWRSAVE as needed */
>> +		config = readl_relaxed(ioaddr + msm_offset->core_vendor_spec);
>> +		config |= CORE_CLK_PWRSAVE;
>> +		writel_relaxed(config, ioaddr + msm_offset->core_vendor_spec);
>> +	}
>> +
>> +	spin_unlock_irqrestore(&host->lock, flags);
>> +	return rc;
>> +}
>> +
>>  static void msm_hc_select_default(struct sdhci_host *host)
>>  {
>>  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>> @@ -925,14 +1140,31 @@ static void sdhci_msm_hc_select_mode(struct sdhci_host *host)
>>  		msm_hc_select_default(host);
>>  }
>>  
>> +static int sdhci_msm_init_dll(struct sdhci_host *host, enum dll_init_context init_context)
>> +{
>> +	if (host->mmc->ios.timing == MMC_TIMING_UHS_SDR104 ||
>> +	    host->mmc->ios.timing == MMC_TIMING_MMC_HS400)
>> +		return sdhci_msm_configure_dll(host, init_context, HS400);
>> +
>> +	return sdhci_msm_configure_dll(host, init_context, HS200);
>> +}
>> +
>> +static int sdhci_msm_dll_config(struct sdhci_host *host, enum dll_init_context init_context)
>> +{
>> +	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>> +	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
>> +
>> +	return msm_host->artanis_dll ? sdhci_msm_init_dll(host, init_context) :
>> +		msm_init_cm_dll(host);
>> +}
>> +
>>  static int sdhci_msm_cdclp533_calibration(struct sdhci_host *host)
>>  {
>>  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>>  	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
>> +	const struct sdhci_msm_offset *msm_offset = msm_host->offset;
>>  	u32 config, calib_done;
>>  	int ret;
>> -	const struct sdhci_msm_offset *msm_offset =
>> -					msm_host->offset;
>>  
>>  	pr_debug("%s: %s: Enter\n", mmc_hostname(host->mmc), __func__);
>>  
>> @@ -940,7 +1172,7 @@ static int sdhci_msm_cdclp533_calibration(struct sdhci_host *host)
>>  	 * Retuning in HS400 (DDR mode) will fail, just reset the
>>  	 * tuning block and restore the saved tuning phase.
>>  	 */
>> -	ret = msm_init_cm_dll(host);
>> +	ret = sdhci_msm_dll_config(host, DLL_INIT_NORMAL);
>>  	if (ret)
>>  		goto out;
>>  
>> @@ -1028,7 +1260,7 @@ static int sdhci_msm_cdclp533_calibration(struct sdhci_host *host)
>>  	return ret;
>>  }
>>  
>> -static int sdhci_msm_cm_dll_sdc4_calibration(struct sdhci_host *host)
>> +static int sdhci_msm_cm_dll_sdc4_calibration(struct sdhci_host *host, enum mode index)
>>  {
>>  	struct mmc_host *mmc = host->mmc;
>>  	u32 dll_status, config, ddr_cfg_offset;
>> @@ -1051,7 +1283,11 @@ static int sdhci_msm_cm_dll_sdc4_calibration(struct sdhci_host *host)
>>  		ddr_cfg_offset = msm_offset->core_ddr_config;
>>  	else
>>  		ddr_cfg_offset = msm_offset->core_ddr_config_old;
>> -	writel_relaxed(msm_host->ddr_config, host->ioaddr + ddr_cfg_offset);
>> +
>> +	if (msm_host->artanis_dll)
>> +		writel_relaxed(msm_host->dll[index].ddr_config, host->ioaddr + ddr_cfg_offset);
>> +	else
>> +		writel_relaxed(msm_host->ddr_config, host->ioaddr + ddr_cfg_offset);
>>  
>>  	if (mmc->ios.enhanced_strobe) {
>>  		config = readl_relaxed(host->ioaddr +
>> @@ -1108,11 +1344,10 @@ static int sdhci_msm_hs400_dll_calibration(struct sdhci_host *host)
>>  {
>>  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>>  	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
>> +	const struct sdhci_msm_offset *msm_offset = msm_host->offset;
>>  	struct mmc_host *mmc = host->mmc;
>> -	int ret;
>>  	u32 config;
>> -	const struct sdhci_msm_offset *msm_offset =
>> -					msm_host->offset;
>> +	int ret;
> Here and elsewhere, this re-ordering of local definitions is a nice
> improvement but it would be better as a separate patch

sure will update separately, will remove this change in next patchset.

>
>>  
>>  	pr_debug("%s: %s: Enter\n", mmc_hostname(host->mmc), __func__);
>>  
>> @@ -1120,7 +1355,8 @@ static int sdhci_msm_hs400_dll_calibration(struct sdhci_host *host)
>>  	 * Retuning in HS400 (DDR mode) will fail, just reset the
>>  	 * tuning block and restore the saved tuning phase.
>>  	 */
>> -	ret = msm_init_cm_dll(host);
>> +	ret = sdhci_msm_dll_config(host, DLL_INIT_NORMAL);
>> +
>>  	if (ret)
>>  		goto out;
>>  
>> @@ -1140,7 +1376,7 @@ static int sdhci_msm_hs400_dll_calibration(struct sdhci_host *host)
>>  	if (msm_host->use_cdclp533)
>>  		ret = sdhci_msm_cdclp533_calibration(host);
>>  	else
>> -		ret = sdhci_msm_cm_dll_sdc4_calibration(host);
>> +		ret = sdhci_msm_cm_dll_sdc4_calibration(host, HS400);
>>  out:
>>  	pr_debug("%s: %s: Exit, ret %d\n", mmc_hostname(host->mmc),
>>  		 __func__, ret);
>> @@ -1183,7 +1419,8 @@ static int sdhci_msm_restore_sdr_dll_config(struct sdhci_host *host)
>>  		return 0;
>>  
>>  	/* Reset the tuning block */
>> -	ret = msm_init_cm_dll(host);
>> +	ret = sdhci_msm_dll_config(host, DLL_INIT_NORMAL);
>> +
>>  	if (ret)
>>  		return ret;
>>  
>> @@ -1257,12 +1494,11 @@ static int sdhci_msm_execute_tuning(struct mmc_host *mmc, u32 opcode)
>>  	if (host->flags & SDHCI_HS400_TUNING) {
>>  		sdhci_msm_hc_select_mode(host);
>>  		msm_set_clock_rate_for_bus_mode(host, ios.clock);
>> -		host->flags &= ~SDHCI_HS400_TUNING;
>>  	}
>>  
>>  retry:
>>  	/* First of all reset the tuning block */
>> -	rc = msm_init_cm_dll(host);
>> +	rc = sdhci_msm_dll_config(host, DLL_INIT_NORMAL);
>>  	if (rc)
>>  		return rc;
>>  
>> @@ -1325,6 +1561,9 @@ static int sdhci_msm_execute_tuning(struct mmc_host *mmc, u32 opcode)
>>  		rc = -EIO;
>>  	}
>>  
>> +	if (host->flags & SDHCI_HS400_TUNING)
>> +		host->flags &= ~SDHCI_HS400_TUNING;
> Really the flag should be cleared on all return paths

Primary reason for moving this here is to have the flag set during 
sdhci_msm_dll_config(), for right clk division as per requirement,
so to keep it clear, I ll move just after sdhci_msm_dll_config()
then no other path would come into picture.

>
>> +
>>  	if (!rc)
>>  		msm_host->tuning_done = true;
>>  	return rc;
>> @@ -1845,11 +2084,6 @@ static unsigned int sdhci_msm_get_max_clock(struct sdhci_host *host)
>>  	return clk_round_rate(core_clk, ULONG_MAX);
>>  }
>>  
>> -static unsigned int sdhci_msm_get_min_clock(struct sdhci_host *host)
>> -{
>> -	return SDHCI_MSM_MIN_CLOCK;
>> -}
>> -
>>  /*
>>   * __sdhci_msm_set_clock - sdhci_msm clock control.
>>   *