diff mbox

[v8,3/3] mmc: sdhci-msm: Add platform_execute_tunning implementation

Message ID 1391107507-17321-4-git-send-email-gdjakov@mm-sol.com (mailing list archive)
State Superseded, archived
Headers show

Commit Message

Georgi Djakov Jan. 30, 2014, 6:45 p.m. UTC
This patch adds implementation for platform specific tuning in order to support
HS200 bus speed mode on Qualcomm SDHCI controller.

Signed-off-by: Georgi Djakov <gdjakov@mm-sol.com>
---
 drivers/mmc/host/sdhci-msm.c |  417 +++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 412 insertions(+), 5 deletions(-)

Comments

Stephen Boyd Feb. 8, 2014, 3:23 a.m. UTC | #1
On 01/30, Georgi Djakov wrote:
> @@ -75,17 +110,389 @@ struct sdhci_msm_host {
>  };
>  
>  /* MSM platform specific tuning */
> -int sdhci_msm_execute_tuning(struct sdhci_host *host, u32 opcode)
> +static inline int msm_dll_poll_ck_out_en(struct sdhci_host *host, u8 poll)
> +{
> +	u32 wait_cnt = 50;
> +	u8 ck_out_en = 0;

Looks like a useless assignment.

> +	struct mmc_host *mmc = host->mmc;
> +
> +	/* poll for CK_OUT_EN bit.  max. poll time = 50us */
> +	ck_out_en = !!(readl_relaxed(host->ioaddr + CORE_DLL_CONFIG) &
> +			CORE_CK_OUT_EN);
> +
> +	while (ck_out_en != poll) {
> +		if (--wait_cnt == 0) {
> +			dev_err(mmc_dev(mmc), "%s: CK_OUT_EN bit is not %d\n",
> +			       mmc_hostname(mmc), poll);
> +			return -ETIMEDOUT;
> +		}
> +		udelay(1);
> +
> +		ck_out_en = !!(readl_relaxed(host->ioaddr + CORE_DLL_CONFIG) &
> +				CORE_CK_OUT_EN);
> +	}
> +
> +	return 0;
> +}
> +
> +static int msm_config_cm_dll_phase(struct sdhci_host *host, u8 phase)
> +{
> +	int rc = 0;

Looks like a useless assignment.

> +	u8 grey_coded_phase_table[] = {
> +		0x0, 0x1, 0x3, 0x2, 0x6, 0x7, 0x5, 0x4,
> +		0xc, 0xd, 0xf, 0xe, 0xa, 0xb, 0x9, 0x8
> +	};

This could be static const?

> +	unsigned long flags;
> +	u32 config;
> +	struct mmc_host *mmc = host->mmc;
> +
> +	spin_lock_irqsave(&host->lock, flags);
> +
> +	config = readl_relaxed(host->ioaddr + CORE_DLL_CONFIG);
> +	config &= ~(CORE_CDR_EN | CORE_CK_OUT_EN);
> +	config |= (CORE_CDR_EXT_EN | CORE_DLL_EN);
> +	writel_relaxed(config, host->ioaddr + CORE_DLL_CONFIG);
> +
> +	/* Wait until CK_OUT_EN bit of DLL_CONFIG register becomes '0' */
> +	rc = msm_dll_poll_ck_out_en(host, 0);
> +	if (rc)
> +		goto err_out;
> +
> +	/*
> +	 * Write the selected DLL clock output phase (0 ... 15)
> +	 * to CDR_SELEXT bit field of DLL_CONFIG register.
> +	 */
> +	writel_relaxed(((readl_relaxed(host->ioaddr + CORE_DLL_CONFIG)
> +			 & ~(0xF << 20))
> +			| (grey_coded_phase_table[phase] << 20)),
> +		       host->ioaddr + CORE_DLL_CONFIG);

Wow this is complicated. Can we please break this up into
multiple lines? What does 0xf << 20 mean?

> +
> +	/* Set CK_OUT_EN bit of DLL_CONFIG register to 1. */
> +	writel_relaxed((readl_relaxed(host->ioaddr + CORE_DLL_CONFIG)
> +			| CORE_CK_OUT_EN), host->ioaddr + CORE_DLL_CONFIG);
> +
[...]
> +}
> +
> +static int msm_find_most_appropriate_phase(struct sdhci_host *host,
> +					   u8 *phase_table, u8 total_phases)
> +{
[...]
> +
> +	for (cnt = 0; cnt <= row_index; cnt++) {
> +		if (phases_per_row[cnt] > curr_max) {
> +			curr_max = phases_per_row[cnt];
> +			selected_row_index = cnt;
> +		}
> +	}
> +
> +	i = ((curr_max * 3) / 4);

Unnecessary extra parentheses here.

> +	if (i)
> +		i--;
> +
> +	ret = (int)ranges[selected_row_index][i];

Is this cast necessary?

> +
> +	if (ret >= MAX_PHASES) {
> +		ret = -EINVAL;
> +		dev_err(mmc_dev(mmc), "%s: invalid phase selected=%d\n",
> +		       mmc_hostname(mmc), ret);
> +	}
> +
> +	return ret;
> +}
> +
> +static inline void msm_cm_dll_set_freq(struct sdhci_host *host)
> +{
> +	u32 mclk_freq = 0;
> +
> +	/* Program the MCLK value to MCLK_FREQ bit field */
> +	if (host->clock <= 112000000)
> +		mclk_freq = 0;
> +	else if (host->clock <= 125000000)
> +		mclk_freq = 1;
> +	else if (host->clock <= 137000000)
> +		mclk_freq = 2;
> +	else if (host->clock <= 150000000)
> +		mclk_freq = 3;
> +	else if (host->clock <= 162000000)
> +		mclk_freq = 4;
> +	else if (host->clock <= 175000000)
> +		mclk_freq = 5;
> +	else if (host->clock <= 187000000)
> +		mclk_freq = 6;
> +	else if (host->clock <= 200000000)
> +		mclk_freq = 7;

This could be a case statement but I'm not sure it's any clearer.
At least the range is specified.

	switch (host->clock) {
	case 0 ... 112000000:
		mclk_freq = 0;
		break;
	case 112000001 ...  125000000:
		mclk_freq = 1;
		break;
	...

> +
> +	writel_relaxed(((readl_relaxed(host->ioaddr + CORE_DLL_CONFIG)
> +			 & ~(7 << 24)) | (mclk_freq << 24)),
> +		       host->ioaddr + CORE_DLL_CONFIG);

This is also complicated. Can you split this up into multiple lines?

> +int sdhci_msm_execute_tuning(struct sdhci_host *host, u32 opcode)
> +{
[...]
> +	do {
> +		struct mmc_command cmd = { 0 };
> +		struct mmc_data data = { 0 };
> +		struct mmc_request mrq = {
> +			.cmd = &cmd,
> +			.data = &data
> +		};
> +		struct scatterlist sg;
> +
> +		/* set the phase in delay line hw block */
> +		rc = msm_config_cm_dll_phase(host, phase);
> +		if (rc)
> +			goto out;
> +
> +		cmd.opcode = opcode;
> +		cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
> +
> +		data.blksz = size;
> +		data.blocks = 1;
> +		data.flags = MMC_DATA_READ;
> +		data.timeout_ns = 1000 * 1000 * 1000;	/* 1 sec */

NSEC_PER_SEC?

> +
> +		data.sg = &sg;
> +		data.sg_len = 1;
> +		sg_init_one(&sg, data_buf, sizeof(data_buf));
> +		memset(data_buf, 0, sizeof(data_buf));
> +		mmc_wait_for_req(mmc, &mrq);
> +
> +		if (!cmd.error && !data.error &&
> +		    !memcmp(data_buf, tuning_block_pattern, sizeof(data_buf))) {
> +			/* tuning is successful at this tuning point */
> +			tuned_phases[tuned_phase_cnt++] = phase;
> +			dev_dbg(mmc_dev(mmc), "%s: found good phase = %d\n",
> +				 mmc_hostname(mmc), phase);
> +		}
> +	} while (++phase < 16);

++phase < ARRAY_SIZE(tuned_phases) ?

> +
> +	if (tuned_phase_cnt) {
> +		rc = msm_find_most_appropriate_phase(host, tuned_phases,
> +						     tuned_phase_cnt);
> +		if (rc < 0)
> +			goto out;
> +		else
> +			phase = (u8) rc;

Unnecessary cast?

> +
> +		/*
> +		 * Finally set the selected phase in delay
> +		 * line hw block.
> +		 */
> +		rc = msm_config_cm_dll_phase(host, phase);
> +		if (rc)
> +			goto out;
> +		dev_dbg(mmc_dev(mmc), "%s: setting the tuning phase to %d\n",
> +			 mmc_hostname(mmc), phase);
> +	} else {
> +		if (--tuning_seq_cnt)
> +			goto retry;
> +		/* tuning failed */
> +		dev_dbg(mmc_dev(mmc), "%s: no tuning point found\n",
> +		       mmc_hostname(mmc));
> +		rc = -EIO;
> +	}
> +
> +out:
> +	kfree(data_buf);
> +	return rc;
> +}
> +
>  #define MAX_PROP_SIZE 32
>  static int sdhci_msm_dt_parse_vreg_info(struct device *dev,
>  			struct sdhci_msm_reg_data *vreg, const char *vreg_name)
Georgi Djakov Feb. 13, 2014, 4:42 p.m. UTC | #2
Hi Stephen,

On 02/08/2014 05:23 AM, Stephen Boyd wrote:
> On 01/30, Georgi Djakov wrote:
>> @@ -75,17 +110,389 @@ struct sdhci_msm_host {
>>   };
>>
>>   /* MSM platform specific tuning */
>> -int sdhci_msm_execute_tuning(struct sdhci_host *host, u32 opcode)
>> +static inline int msm_dll_poll_ck_out_en(struct sdhci_host *host, u8 poll)
>> +{
>> +	u32 wait_cnt = 50;
>> +	u8 ck_out_en = 0;
>
> Looks like a useless assignment.

Yes, thanks!

>
>> +	struct mmc_host *mmc = host->mmc;
>> +
>> +	/* poll for CK_OUT_EN bit.  max. poll time = 50us */
>> +	ck_out_en = !!(readl_relaxed(host->ioaddr + CORE_DLL_CONFIG) &
>> +			CORE_CK_OUT_EN);
>> +
>> +	while (ck_out_en != poll) {
>> +		if (--wait_cnt == 0) {
>> +			dev_err(mmc_dev(mmc), "%s: CK_OUT_EN bit is not %d\n",
>> +			       mmc_hostname(mmc), poll);
>> +			return -ETIMEDOUT;
>> +		}
>> +		udelay(1);
>> +
>> +		ck_out_en = !!(readl_relaxed(host->ioaddr + CORE_DLL_CONFIG) &
>> +				CORE_CK_OUT_EN);
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int msm_config_cm_dll_phase(struct sdhci_host *host, u8 phase)
>> +{
>> +	int rc = 0;
>
> Looks like a useless assignment.

Ok.

>
>> +	u8 grey_coded_phase_table[] = {
>> +		0x0, 0x1, 0x3, 0x2, 0x6, 0x7, 0x5, 0x4,
>> +		0xc, 0xd, 0xf, 0xe, 0xa, 0xb, 0x9, 0x8
>> +	};
>
> This could be static const?

Yes, indeed!

>
>> +	unsigned long flags;
>> +	u32 config;
>> +	struct mmc_host *mmc = host->mmc;
>> +
>> +	spin_lock_irqsave(&host->lock, flags);
>> +
>> +	config = readl_relaxed(host->ioaddr + CORE_DLL_CONFIG);
>> +	config &= ~(CORE_CDR_EN | CORE_CK_OUT_EN);
>> +	config |= (CORE_CDR_EXT_EN | CORE_DLL_EN);
>> +	writel_relaxed(config, host->ioaddr + CORE_DLL_CONFIG);
>> +
>> +	/* Wait until CK_OUT_EN bit of DLL_CONFIG register becomes '0' */
>> +	rc = msm_dll_poll_ck_out_en(host, 0);
>> +	if (rc)
>> +		goto err_out;
>> +
>> +	/*
>> +	 * Write the selected DLL clock output phase (0 ... 15)
>> +	 * to CDR_SELEXT bit field of DLL_CONFIG register.
>> +	 */
>> +	writel_relaxed(((readl_relaxed(host->ioaddr + CORE_DLL_CONFIG)
>> +			 & ~(0xF << 20))
>> +			| (grey_coded_phase_table[phase] << 20)),
>> +		       host->ioaddr + CORE_DLL_CONFIG);
>
> Wow this is complicated. Can we please break this up into
> multiple lines? What does 0xf << 20 mean?

Yes, sure! I will simplify it! Only bits 23:20 are used.

>
>> +
>> +	/* Set CK_OUT_EN bit of DLL_CONFIG register to 1. */
>> +	writel_relaxed((readl_relaxed(host->ioaddr + CORE_DLL_CONFIG)
>> +			| CORE_CK_OUT_EN), host->ioaddr + CORE_DLL_CONFIG);
>> +
> [...]
>> +}
>> +
>> +static int msm_find_most_appropriate_phase(struct sdhci_host *host,
>> +					   u8 *phase_table, u8 total_phases)
>> +{
> [...]
>> +
>> +	for (cnt = 0; cnt <= row_index; cnt++) {
>> +		if (phases_per_row[cnt] > curr_max) {
>> +			curr_max = phases_per_row[cnt];
>> +			selected_row_index = cnt;
>> +		}
>> +	}
>> +
>> +	i = ((curr_max * 3) / 4);
>
> Unnecessary extra parentheses here.

Thanks!

>
>> +	if (i)
>> +		i--;
>> +
>> +	ret = (int)ranges[selected_row_index][i];
>
> Is this cast necessary?

Not necessary. Will fix it!

>
>> +
>> +	if (ret >= MAX_PHASES) {
>> +		ret = -EINVAL;
>> +		dev_err(mmc_dev(mmc), "%s: invalid phase selected=%d\n",
>> +		       mmc_hostname(mmc), ret);
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static inline void msm_cm_dll_set_freq(struct sdhci_host *host)
>> +{
>> +	u32 mclk_freq = 0;
>> +
>> +	/* Program the MCLK value to MCLK_FREQ bit field */
>> +	if (host->clock <= 112000000)
>> +		mclk_freq = 0;
>> +	else if (host->clock <= 125000000)
>> +		mclk_freq = 1;
>> +	else if (host->clock <= 137000000)
>> +		mclk_freq = 2;
>> +	else if (host->clock <= 150000000)
>> +		mclk_freq = 3;
>> +	else if (host->clock <= 162000000)
>> +		mclk_freq = 4;
>> +	else if (host->clock <= 175000000)
>> +		mclk_freq = 5;
>> +	else if (host->clock <= 187000000)
>> +		mclk_freq = 6;
>> +	else if (host->clock <= 200000000)
>> +		mclk_freq = 7;
>
> This could be a case statement but I'm not sure it's any clearer.
> At least the range is specified.
>
> 	switch (host->clock) {
> 	case 0 ... 112000000:
> 		mclk_freq = 0;
> 		break;
> 	case 112000001 ...  125000000:
> 		mclk_freq = 1;
> 		break;
> 	...

It seems to be shorter with the ifs, so i prefer to keep it this way.

>
>> +
>> +	writel_relaxed(((readl_relaxed(host->ioaddr + CORE_DLL_CONFIG)
>> +			 & ~(7 << 24)) | (mclk_freq << 24)),
>> +		       host->ioaddr + CORE_DLL_CONFIG);
>
> This is also complicated. Can you split this up into multiple lines?

Yes, sure!

>
>> +int sdhci_msm_execute_tuning(struct sdhci_host *host, u32 opcode)
>> +{
> [...]
>> +	do {
>> +		struct mmc_command cmd = { 0 };
>> +		struct mmc_data data = { 0 };
>> +		struct mmc_request mrq = {
>> +			.cmd = &cmd,
>> +			.data = &data
>> +		};
>> +		struct scatterlist sg;
>> +
>> +		/* set the phase in delay line hw block */
>> +		rc = msm_config_cm_dll_phase(host, phase);
>> +		if (rc)
>> +			goto out;
>> +
>> +		cmd.opcode = opcode;
>> +		cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
>> +
>> +		data.blksz = size;
>> +		data.blocks = 1;
>> +		data.flags = MMC_DATA_READ;
>> +		data.timeout_ns = 1000 * 1000 * 1000;	/* 1 sec */
>
> NSEC_PER_SEC?

Thanks!

>
>> +
>> +		data.sg = &sg;
>> +		data.sg_len = 1;
>> +		sg_init_one(&sg, data_buf, sizeof(data_buf));
>> +		memset(data_buf, 0, sizeof(data_buf));
>> +		mmc_wait_for_req(mmc, &mrq);
>> +
>> +		if (!cmd.error && !data.error &&
>> +		    !memcmp(data_buf, tuning_block_pattern, sizeof(data_buf))) {
>> +			/* tuning is successful at this tuning point */
>> +			tuned_phases[tuned_phase_cnt++] = phase;
>> +			dev_dbg(mmc_dev(mmc), "%s: found good phase = %d\n",
>> +				 mmc_hostname(mmc), phase);
>> +		}
>> +	} while (++phase < 16);
>
> ++phase < ARRAY_SIZE(tuned_phases) ?

Thanks!

>
>> +
>> +	if (tuned_phase_cnt) {
>> +		rc = msm_find_most_appropriate_phase(host, tuned_phases,
>> +						     tuned_phase_cnt);
>> +		if (rc < 0)
>> +			goto out;
>> +		else
>> +			phase = (u8) rc;
>
> Unnecessary cast?

Yes, thank you for the review!

BR,
Georgi


--
To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" 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-msm.c b/drivers/mmc/host/sdhci-msm.c
index 900e813..5ae099f 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -19,6 +19,8 @@ 
 #include <linux/of_device.h>
 #include <linux/regulator/consumer.h>
 #include <linux/delay.h>
+#include <linux/mmc/mmc.h>
+#include <linux/slab.h>
 
 #include "sdhci-pltfm.h"
 
@@ -44,7 +46,40 @@ 
 #define CORE_PWRCTL_IO_FAIL	BIT(3)
 
 #define INT_MASK		0xf
+#define MAX_PHASES		16
+
+#define CORE_DLL_LOCK		BIT(7)
+#define CORE_DLL_EN		BIT(16)
+#define CORE_CDR_EN		BIT(17)
+#define CORE_CK_OUT_EN		BIT(18)
+#define CORE_CDR_EXT_EN		BIT(19)
+#define CORE_DLL_PDN		BIT(29)
+#define CORE_DLL_RST		BIT(30)
+#define CORE_DLL_CONFIG		0x100
+#define CORE_DLL_TEST_CTL	0x104
+#define CORE_DLL_STATUS		0x108
+
+#define CORE_VENDOR_SPEC	0x10c
+#define CORE_CLK_PWRSAVE	BIT(1)
+#define CORE_IO_PAD_PWR_SWITCH	BIT(16)
+
+static const u32 tuning_block_64[] = {
+	0x00ff0fff, 0xccc3ccff, 0xffcc3cc3, 0xeffefffe,
+	0xddffdfff, 0xfbfffbff, 0xff7fffbf, 0xefbdf777,
+	0xf0fff0ff, 0x3cccfc0f, 0xcfcc33cc, 0xeeffefff,
+	0xfdfffdff, 0xffbfffdf, 0xfff7ffbb, 0xde7b7ff7
+};
 
+static const u32 tuning_block_128[] = {
+	0xff00ffff, 0x0000ffff, 0xccccffff, 0xcccc33cc,
+	0xcc3333cc, 0xffffcccc, 0xffffeeff, 0xffeeeeff,
+	0xffddffff, 0xddddffff, 0xbbffffff, 0xbbffffff,
+	0xffffffbb, 0xffffff77, 0x77ff7777, 0xffeeddbb,
+	0x00ffffff, 0x00ffffff, 0xccffff00, 0xcc33cccc,
+	0x3333cccc, 0xffcccccc, 0xffeeffff, 0xeeeeffff,
+	0xddffffff, 0xddffffff, 0xffffffdd, 0xffffffbb,
+	0xffffbbbb, 0xffff77ff, 0xff7777ff, 0xeeddbb77
+};
 
 /* This structure keeps information per regulator */
 struct sdhci_msm_reg_data {
@@ -75,17 +110,389 @@  struct sdhci_msm_host {
 };
 
 /* MSM platform specific tuning */
-int sdhci_msm_execute_tuning(struct sdhci_host *host, u32 opcode)
+static inline int msm_dll_poll_ck_out_en(struct sdhci_host *host, u8 poll)
+{
+	u32 wait_cnt = 50;
+	u8 ck_out_en = 0;
+	struct mmc_host *mmc = host->mmc;
+
+	/* poll for CK_OUT_EN bit.  max. poll time = 50us */
+	ck_out_en = !!(readl_relaxed(host->ioaddr + CORE_DLL_CONFIG) &
+			CORE_CK_OUT_EN);
+
+	while (ck_out_en != poll) {
+		if (--wait_cnt == 0) {
+			dev_err(mmc_dev(mmc), "%s: CK_OUT_EN bit is not %d\n",
+			       mmc_hostname(mmc), poll);
+			return -ETIMEDOUT;
+		}
+		udelay(1);
+
+		ck_out_en = !!(readl_relaxed(host->ioaddr + CORE_DLL_CONFIG) &
+				CORE_CK_OUT_EN);
+	}
+
+	return 0;
+}
+
+static int msm_config_cm_dll_phase(struct sdhci_host *host, u8 phase)
+{
+	int rc = 0;
+	u8 grey_coded_phase_table[] = {
+		0x0, 0x1, 0x3, 0x2, 0x6, 0x7, 0x5, 0x4,
+		0xc, 0xd, 0xf, 0xe, 0xa, 0xb, 0x9, 0x8
+	};
+	unsigned long flags;
+	u32 config;
+	struct mmc_host *mmc = host->mmc;
+
+	spin_lock_irqsave(&host->lock, flags);
+
+	config = readl_relaxed(host->ioaddr + CORE_DLL_CONFIG);
+	config &= ~(CORE_CDR_EN | CORE_CK_OUT_EN);
+	config |= (CORE_CDR_EXT_EN | CORE_DLL_EN);
+	writel_relaxed(config, host->ioaddr + CORE_DLL_CONFIG);
+
+	/* Wait until CK_OUT_EN bit of DLL_CONFIG register becomes '0' */
+	rc = msm_dll_poll_ck_out_en(host, 0);
+	if (rc)
+		goto err_out;
+
+	/*
+	 * Write the selected DLL clock output phase (0 ... 15)
+	 * to CDR_SELEXT bit field of DLL_CONFIG register.
+	 */
+	writel_relaxed(((readl_relaxed(host->ioaddr + CORE_DLL_CONFIG)
+			 & ~(0xF << 20))
+			| (grey_coded_phase_table[phase] << 20)),
+		       host->ioaddr + CORE_DLL_CONFIG);
+
+	/* Set CK_OUT_EN bit of DLL_CONFIG register to 1. */
+	writel_relaxed((readl_relaxed(host->ioaddr + CORE_DLL_CONFIG)
+			| CORE_CK_OUT_EN), host->ioaddr + CORE_DLL_CONFIG);
+
+	/* Wait until CK_OUT_EN bit of DLL_CONFIG register becomes '1' */
+	rc = msm_dll_poll_ck_out_en(host, 1);
+	if (rc)
+		goto err_out;
+
+	config = readl_relaxed(host->ioaddr + CORE_DLL_CONFIG);
+	config |= CORE_CDR_EN;
+	config &= ~CORE_CDR_EXT_EN;
+	writel_relaxed(config, host->ioaddr + CORE_DLL_CONFIG);
+	goto out;
+
+err_out:
+	dev_err(mmc_dev(mmc), "%s: Failed to set DLL phase: %d\n",
+	       mmc_hostname(mmc), phase);
+out:
+	spin_unlock_irqrestore(&host->lock, flags);
+	return rc;
+}
+
+/*
+ * Find out the greatest range of consecuitive selected
+ * DLL clock output phases that can be used as sampling
+ * setting for SD3.0 UHS-I card read operation (in SDR104
+ * timing mode) or for eMMC4.5 card read operation (in HS200
+ * timing mode).
+ * Select the 3/4 of the range and configure the DLL with the
+ * selected DLL clock output phase.
+ */
+
+static int msm_find_most_appropriate_phase(struct sdhci_host *host,
+					   u8 *phase_table, u8 total_phases)
+{
+	int ret;
+	u8 ranges[MAX_PHASES][MAX_PHASES] = { {0}, {0} };
+	u8 phases_per_row[MAX_PHASES] = { 0 };
+	int row_index = 0, col_index = 0, selected_row_index = 0, curr_max = 0;
+	int i, cnt, phase_0_raw_index = 0, phase_15_raw_index = 0;
+	bool phase_0_found = false, phase_15_found = false;
+	struct mmc_host *mmc = host->mmc;
+
+	if (!total_phases || (total_phases > MAX_PHASES)) {
+		dev_err(mmc_dev(mmc), "%s: invalid argument: total_phases=%d\n",
+		       mmc_hostname(mmc), total_phases);
+		return -EINVAL;
+	}
+
+	for (cnt = 0; cnt < total_phases; cnt++) {
+		ranges[row_index][col_index] = phase_table[cnt];
+		phases_per_row[row_index] += 1;
+		col_index++;
+
+		if ((cnt + 1) == total_phases) {
+			continue;
+		/* check if next phase in phase_table is consecutive or not */
+		} else if ((phase_table[cnt] + 1) != phase_table[cnt + 1]) {
+			row_index++;
+			col_index = 0;
+		}
+	}
+
+	if (row_index >= MAX_PHASES)
+		return -EINVAL;
+
+	/* Check if phase-0 is present in first valid window? */
+	if (!ranges[0][0]) {
+		phase_0_found = true;
+		phase_0_raw_index = 0;
+		/* Check if cycle exist between 2 valid windows */
+		for (cnt = 1; cnt <= row_index; cnt++) {
+			if (phases_per_row[cnt]) {
+				for (i = 0; i < phases_per_row[cnt]; i++) {
+					if (ranges[cnt][i] == 15) {
+						phase_15_found = true;
+						phase_15_raw_index = cnt;
+						break;
+					}
+				}
+			}
+		}
+	}
+
+	/* If 2 valid windows form cycle then merge them as single window */
+	if (phase_0_found && phase_15_found) {
+		/* number of phases in raw where phase 0 is present */
+		u8 phases_0 = phases_per_row[phase_0_raw_index];
+		/* number of phases in raw where phase 15 is present */
+		u8 phases_15 = phases_per_row[phase_15_raw_index];
+
+		if (phases_0 + phases_15 >= MAX_PHASES)
+			/*
+			 * If there are more than 1 phase windows then total
+			 * number of phases in both the windows should not be
+			 * more than or equal to MAX_PHASES.
+			 */
+			return -EINVAL;
+
+		/* Merge 2 cyclic windows */
+		i = phases_15;
+		for (cnt = 0; cnt < phases_0; cnt++) {
+			ranges[phase_15_raw_index][i] =
+			    ranges[phase_0_raw_index][cnt];
+			if (++i >= MAX_PHASES)
+				break;
+		}
+
+		phases_per_row[phase_0_raw_index] = 0;
+		phases_per_row[phase_15_raw_index] = phases_15 + phases_0;
+	}
+
+	for (cnt = 0; cnt <= row_index; cnt++) {
+		if (phases_per_row[cnt] > curr_max) {
+			curr_max = phases_per_row[cnt];
+			selected_row_index = cnt;
+		}
+	}
+
+	i = ((curr_max * 3) / 4);
+	if (i)
+		i--;
+
+	ret = (int)ranges[selected_row_index][i];
+
+	if (ret >= MAX_PHASES) {
+		ret = -EINVAL;
+		dev_err(mmc_dev(mmc), "%s: invalid phase selected=%d\n",
+		       mmc_hostname(mmc), ret);
+	}
+
+	return ret;
+}
+
+static inline void msm_cm_dll_set_freq(struct sdhci_host *host)
+{
+	u32 mclk_freq = 0;
+
+	/* Program the MCLK value to MCLK_FREQ bit field */
+	if (host->clock <= 112000000)
+		mclk_freq = 0;
+	else if (host->clock <= 125000000)
+		mclk_freq = 1;
+	else if (host->clock <= 137000000)
+		mclk_freq = 2;
+	else if (host->clock <= 150000000)
+		mclk_freq = 3;
+	else if (host->clock <= 162000000)
+		mclk_freq = 4;
+	else if (host->clock <= 175000000)
+		mclk_freq = 5;
+	else if (host->clock <= 187000000)
+		mclk_freq = 6;
+	else if (host->clock <= 200000000)
+		mclk_freq = 7;
+
+	writel_relaxed(((readl_relaxed(host->ioaddr + CORE_DLL_CONFIG)
+			 & ~(7 << 24)) | (mclk_freq << 24)),
+		       host->ioaddr + CORE_DLL_CONFIG);
+}
+
+/* Initialize the DLL (Programmable Delay Line ) */
+static int msm_init_cm_dll(struct sdhci_host *host)
 {
+	struct mmc_host *mmc = host->mmc;
+	int wait_cnt = 50;
+	unsigned long flags;
+
+	spin_lock_irqsave(&host->lock, flags);
+
 	/*
-	 * Tuning is required for SDR104, HS200 and HS400 cards and if the clock
-	 * frequency greater than 100MHz in those modes. The standard tuning
-	 * procedure should not be executed, but a custom implementation will be
-	 * added here instead.
+	 * Make sure that clock is always enabled when DLL
+	 * tuning is in progress. Keeping PWRSAVE ON may
+	 * turn off the clock.
 	 */
+	writel_relaxed((readl_relaxed(host->ioaddr + CORE_VENDOR_SPEC)
+			& ~CORE_CLK_PWRSAVE), host->ioaddr + CORE_VENDOR_SPEC);
+
+	/* Write 1 to DLL_RST bit of DLL_CONFIG register */
+	writel_relaxed((readl_relaxed(host->ioaddr + CORE_DLL_CONFIG)
+			| CORE_DLL_RST), host->ioaddr + CORE_DLL_CONFIG);
+
+	/* Write 1 to DLL_PDN bit of DLL_CONFIG register */
+	writel_relaxed((readl_relaxed(host->ioaddr + CORE_DLL_CONFIG)
+			| CORE_DLL_PDN), host->ioaddr + CORE_DLL_CONFIG);
+	msm_cm_dll_set_freq(host);
+
+	/* Write 0 to DLL_RST bit of DLL_CONFIG register */
+	writel_relaxed((readl_relaxed(host->ioaddr + CORE_DLL_CONFIG)
+			& ~CORE_DLL_RST), host->ioaddr + CORE_DLL_CONFIG);
+
+	/* Write 0 to DLL_PDN bit of DLL_CONFIG register */
+	writel_relaxed((readl_relaxed(host->ioaddr + CORE_DLL_CONFIG)
+			& ~CORE_DLL_PDN), host->ioaddr + CORE_DLL_CONFIG);
+
+	/* Set DLL_EN bit to 1. */
+	writel_relaxed((readl_relaxed(host->ioaddr + CORE_DLL_CONFIG)
+			| CORE_DLL_EN), host->ioaddr + CORE_DLL_CONFIG);
+
+	/* Set CK_OUT_EN bit to 1. */
+	writel_relaxed((readl_relaxed(host->ioaddr + CORE_DLL_CONFIG)
+			| CORE_CK_OUT_EN), host->ioaddr + CORE_DLL_CONFIG);
+
+	/* Wait until DLL_LOCK bit of DLL_STATUS register becomes '1' */
+	while (!(readl_relaxed(host->ioaddr + 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));
+			spin_unlock_irqrestore(&host->lock, flags);
+			return -ETIMEDOUT;
+		}
+		/* wait for 1us before polling again */
+		udelay(1);
+	}
+
+	spin_unlock_irqrestore(&host->lock, flags);
 	return 0;
 }
 
+int sdhci_msm_execute_tuning(struct sdhci_host *host, u32 opcode)
+{
+	int tuning_seq_cnt = 3;
+	u8 phase, *data_buf, tuned_phases[16], tuned_phase_cnt = 0;
+	const u32 *tuning_block_pattern = tuning_block_64;
+	int size = sizeof(tuning_block_64);	/* Pattern size in bytes */
+	int rc;
+	struct mmc_host *mmc = host->mmc;
+	struct mmc_ios ios = host->mmc->ios;
+
+	/*
+	 * Tuning is required for SDR104, HS200 and HS400 cards and
+	 * if clock frequency is greater than 100MHz in these modes.
+	 */
+	if (host->clock <= 100 * 1000 * 1000 ||
+	    !((ios.timing == MMC_TIMING_MMC_HS200) ||
+	      (ios.timing == MMC_TIMING_UHS_SDR104)))
+		return 0;
+
+	if ((opcode == MMC_SEND_TUNING_BLOCK_HS200) &&
+	    (mmc->ios.bus_width == MMC_BUS_WIDTH_8)) {
+		tuning_block_pattern = tuning_block_128;
+		size = sizeof(tuning_block_128);
+	}
+
+	data_buf = kmalloc(size, GFP_KERNEL);
+	if (!data_buf)
+		return -ENOMEM;
+
+retry:
+	/* first of all reset the tuning block */
+	rc = msm_init_cm_dll(host);
+	if (rc)
+		goto out;
+
+	phase = 0;
+	do {
+		struct mmc_command cmd = { 0 };
+		struct mmc_data data = { 0 };
+		struct mmc_request mrq = {
+			.cmd = &cmd,
+			.data = &data
+		};
+		struct scatterlist sg;
+
+		/* set the phase in delay line hw block */
+		rc = msm_config_cm_dll_phase(host, phase);
+		if (rc)
+			goto out;
+
+		cmd.opcode = opcode;
+		cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
+
+		data.blksz = size;
+		data.blocks = 1;
+		data.flags = MMC_DATA_READ;
+		data.timeout_ns = 1000 * 1000 * 1000;	/* 1 sec */
+
+		data.sg = &sg;
+		data.sg_len = 1;
+		sg_init_one(&sg, data_buf, sizeof(data_buf));
+		memset(data_buf, 0, sizeof(data_buf));
+		mmc_wait_for_req(mmc, &mrq);
+
+		if (!cmd.error && !data.error &&
+		    !memcmp(data_buf, tuning_block_pattern, sizeof(data_buf))) {
+			/* tuning is successful at this tuning point */
+			tuned_phases[tuned_phase_cnt++] = phase;
+			dev_dbg(mmc_dev(mmc), "%s: found good phase = %d\n",
+				 mmc_hostname(mmc), phase);
+		}
+	} while (++phase < 16);
+
+	if (tuned_phase_cnt) {
+		rc = msm_find_most_appropriate_phase(host, tuned_phases,
+						     tuned_phase_cnt);
+		if (rc < 0)
+			goto out;
+		else
+			phase = (u8) rc;
+
+		/*
+		 * Finally set the selected phase in delay
+		 * line hw block.
+		 */
+		rc = msm_config_cm_dll_phase(host, phase);
+		if (rc)
+			goto out;
+		dev_dbg(mmc_dev(mmc), "%s: setting the tuning phase to %d\n",
+			 mmc_hostname(mmc), phase);
+	} else {
+		if (--tuning_seq_cnt)
+			goto retry;
+		/* tuning failed */
+		dev_dbg(mmc_dev(mmc), "%s: no tuning point found\n",
+		       mmc_hostname(mmc));
+		rc = -EIO;
+	}
+
+out:
+	kfree(data_buf);
+	return rc;
+}
+
 #define MAX_PROP_SIZE 32
 static int sdhci_msm_dt_parse_vreg_info(struct device *dev,
 			struct sdhci_msm_reg_data *vreg, const char *vreg_name)