drivers/mmc/host/sdhci-msm.c - kernel/lockdown - Git at Google

 /*
  * drivers/mmc/host/sdhci-msm.c - Qualcomm SDHCI Platform driver
  *
  * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
  * only version 2 as published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  */

 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/delay.h>
 #include <linux/mmc/mmc.h>
 #include <linux/slab.h>

 #include "sdhci-pltfm.h"

 #define CORE_MCI_VERSION		0x50
 #define CORE_VERSION_MAJOR_SHIFT	28
 #define CORE_VERSION_MAJOR_MASK		(0xf << CORE_VERSION_MAJOR_SHIFT)
 #define CORE_VERSION_MINOR_MASK		0xff

 #define CORE_HC_MODE		0x78
 #define HC_MODE_EN		0x1
 #define CORE_POWER		0x0
 #define CORE_SW_RST		BIT(7)

 #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_STATUS		0x108

 #define CORE_VENDOR_SPEC	0x10c
 #define CORE_CLK_PWRSAVE	BIT(1)

 #define CORE_VENDOR_SPEC_CAPABILITIES0	0x11c

 #define CDR_SELEXT_SHIFT	20
 #define CDR_SELEXT_MASK		(0xf << CDR_SELEXT_SHIFT)
 #define CMUX_SHIFT_PHASE_SHIFT	24
 #define CMUX_SHIFT_PHASE_MASK	(7 << CMUX_SHIFT_PHASE_SHIFT)

 struct sdhci_msm_host {
 	struct platform_device *pdev;
 	void __iomem *core_mem;	/* MSM SDCC mapped address */
 	struct clk *clk;	/* main SD/MMC bus clock */
 	struct clk *pclk;	/* SDHC peripheral bus clock */
 	struct clk *bus_clk;	/* SDHC bus voter clock */
 	struct mmc_host *mmc;
 	struct sdhci_pltfm_data sdhci_msm_pdata;
 };

 /* Platform specific tuning */
 static inline int msm_dll_poll_ck_out_en(struct sdhci_host *host, u8 poll)
 {
 	u32 wait_cnt = 50;
 	u8 ck_out_en;
 	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;
 	static const 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.
 	 */
 	config = readl_relaxed(host->ioaddr + CORE_DLL_CONFIG);
 	config &= ~CDR_SELEXT_MASK;
 	config |= grey_coded_phase_table[phase] << CDR_SELEXT_SHIFT;
 	writel_relaxed(config, 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 = 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, config;

 	/* 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;

 	config = readl_relaxed(host->ioaddr + CORE_DLL_CONFIG);
 	config &= ~CMUX_SHIFT_PHASE_MASK;
 	config |= mclk_freq << CMUX_SHIFT_PHASE_SHIFT;
 	writel_relaxed(config, 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);

 	/*
 	 * 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;
 		}
 		udelay(1);
 	}

 	spin_unlock_irqrestore(&host->lock, flags);
 	return 0;
 }

 static int sdhci_msm_execute_tuning(struct sdhci_host *host, u32 opcode)
 {
 	int tuning_seq_cnt = 3;
 	u8 phase, tuned_phases[16], tuned_phase_cnt = 0;
 	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;

 retry:
 	/* First of all reset the tuning block */
 	rc = msm_init_cm_dll(host);
 	if (rc)
 		return rc;

 	phase = 0;
 	do {
 		/* Set the phase in delay line hw block */
 		rc = msm_config_cm_dll_phase(host, phase);
 		if (rc)
 			return rc;

 		rc = mmc_send_tuning(mmc);
 		if (!rc) {
 			/* 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 < ARRAY_SIZE(tuned_phases));

 	if (tuned_phase_cnt) {
 		rc = msm_find_most_appropriate_phase(host, tuned_phases,
 						     tuned_phase_cnt);
 		if (rc < 0)
 			return rc;
 		else
 			phase = rc;

 		/*
 		 * Finally set the selected phase in delay
 		 * line hw block.
 		 */
 		rc = msm_config_cm_dll_phase(host, phase);
 		if (rc)
 			return rc;
 		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;
 	}

 	return rc;
 }

 static const struct of_device_id sdhci_msm_dt_match[] = {
 	{ .compatible = "qcom,sdhci-msm-v4" },
 	{},
 };

 MODULE_DEVICE_TABLE(of, sdhci_msm_dt_match);

 static struct sdhci_ops sdhci_msm_ops = {
 	.platform_execute_tuning = sdhci_msm_execute_tuning,
 	.reset = sdhci_reset,
 	.set_clock = sdhci_set_clock,
 	.set_bus_width = sdhci_set_bus_width,
 	.set_uhs_signaling = sdhci_set_uhs_signaling,
 };

 static int sdhci_msm_probe(struct platform_device *pdev)
 {
 	struct sdhci_host *host;
 	struct sdhci_pltfm_host *pltfm_host;
 	struct sdhci_msm_host *msm_host;
 	struct resource *core_memres;
 	int ret;
 	u16 host_version, core_minor;
 	u32 core_version, caps;
 	u8 core_major;

 	msm_host = devm_kzalloc(&pdev->dev, sizeof(*msm_host), GFP_KERNEL);
 	if (!msm_host)
 		return -ENOMEM;

 	msm_host->sdhci_msm_pdata.ops = &sdhci_msm_ops;
 	host = sdhci_pltfm_init(pdev, &msm_host->sdhci_msm_pdata, 0);
 	if (IS_ERR(host))
 		return PTR_ERR(host);

 	pltfm_host = sdhci_priv(host);
 	pltfm_host->priv = msm_host;
 	msm_host->mmc = host->mmc;
 	msm_host->pdev = pdev;

 	ret = mmc_of_parse(host->mmc);
 	if (ret)
 		goto pltfm_free;

 	sdhci_get_of_property(pdev);

 	/* Setup SDCC bus voter clock. */
 	msm_host->bus_clk = devm_clk_get(&pdev->dev, "bus");
 	if (!IS_ERR(msm_host->bus_clk)) {
 		/* Vote for max. clk rate for max. performance */
 		ret = clk_set_rate(msm_host->bus_clk, INT_MAX);
 		if (ret)
 			goto pltfm_free;
 		ret = clk_prepare_enable(msm_host->bus_clk);
 		if (ret)
 			goto pltfm_free;
 	}

 	/* Setup main peripheral bus clock */
 	msm_host->pclk = devm_clk_get(&pdev->dev, "iface");
 	if (IS_ERR(msm_host->pclk)) {
 		ret = PTR_ERR(msm_host->pclk);
 		dev_err(&pdev->dev, "Perpheral clk setup failed (%d)\n", ret);
 		goto bus_clk_disable;
 	}

 	ret = clk_prepare_enable(msm_host->pclk);
 	if (ret)
 		goto bus_clk_disable;

 	/* Setup SDC MMC clock */
 	msm_host->clk = devm_clk_get(&pdev->dev, "core");
 	if (IS_ERR(msm_host->clk)) {
 		ret = PTR_ERR(msm_host->clk);
 		dev_err(&pdev->dev, "SDC MMC clk setup failed (%d)\n", ret);
 		goto pclk_disable;
 	}

 	ret = clk_prepare_enable(msm_host->clk);
 	if (ret)
 		goto pclk_disable;

 	core_memres = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 	msm_host->core_mem = devm_ioremap_resource(&pdev->dev, core_memres);

 	if (IS_ERR(msm_host->core_mem)) {
 		dev_err(&pdev->dev, "Failed to remap registers\n");
 		ret = PTR_ERR(msm_host->core_mem);
 		goto clk_disable;
 	}

 	/* Reset the core and Enable SDHC mode */
 	writel_relaxed(readl_relaxed(msm_host->core_mem + CORE_POWER) |
 		       CORE_SW_RST, msm_host->core_mem + CORE_POWER);

 	/* SW reset can take upto 10HCLK + 15MCLK cycles. (min 40us) */
 	usleep_range(1000, 5000);
 	if (readl(msm_host->core_mem + CORE_POWER) & CORE_SW_RST) {
 		dev_err(&pdev->dev, "Stuck in reset\n");
 		ret = -ETIMEDOUT;
 		goto clk_disable;
 	}

 	/* Set HC_MODE_EN bit in HC_MODE register */
 	writel_relaxed(HC_MODE_EN, (msm_host->core_mem + CORE_HC_MODE));

 	host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION;
 	host->quirks |= SDHCI_QUIRK_SINGLE_POWER_WRITE;

 	host_version = readw_relaxed((host->ioaddr + SDHCI_HOST_VERSION));
 	dev_dbg(&pdev->dev, "Host Version: 0x%x Vendor Version 0x%x\n",
 		host_version, ((host_version & SDHCI_VENDOR_VER_MASK) >>
 			       SDHCI_VENDOR_VER_SHIFT));

 	core_version = readl_relaxed(msm_host->core_mem + CORE_MCI_VERSION);
 	core_major = (core_version & CORE_VERSION_MAJOR_MASK) >>
 		      CORE_VERSION_MAJOR_SHIFT;
 	core_minor = core_version & CORE_VERSION_MINOR_MASK;
 	dev_dbg(&pdev->dev, "MCI Version: 0x%08x, major: 0x%04x, minor: 0x%02x\n",
 		core_version, core_major, core_minor);

 	/*
 	 * Support for some capabilities is not advertised by newer
 	 * controller versions and must be explicitly enabled.
 	 */
 	if (core_major >= 1 && core_minor != 0x11 && core_minor != 0x12) {
 		caps = readl_relaxed(host->ioaddr + SDHCI_CAPABILITIES);
 		caps |= SDHCI_CAN_VDD_300 | SDHCI_CAN_DO_8BIT;
 		writel_relaxed(caps, host->ioaddr +
 			       CORE_VENDOR_SPEC_CAPABILITIES0);
 	}

 	ret = sdhci_add_host(host);
 	if (ret)
 		goto clk_disable;

 	return 0;

 clk_disable:
 	clk_disable_unprepare(msm_host->clk);
 pclk_disable:
 	clk_disable_unprepare(msm_host->pclk);
 bus_clk_disable:
 	if (!IS_ERR(msm_host->bus_clk))
 		clk_disable_unprepare(msm_host->bus_clk);
 pltfm_free:
 	sdhci_pltfm_free(pdev);
 	return ret;
 }

 static int sdhci_msm_remove(struct platform_device *pdev)
 {
 	struct sdhci_host *host = platform_get_drvdata(pdev);
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 	struct sdhci_msm_host *msm_host = pltfm_host->priv;
 	int dead = (readl_relaxed(host->ioaddr + SDHCI_INT_STATUS) ==
 		    0xffffffff);

 	sdhci_remove_host(host, dead);
 	sdhci_pltfm_free(pdev);
 	clk_disable_unprepare(msm_host->clk);
 	clk_disable_unprepare(msm_host->pclk);
 	if (!IS_ERR(msm_host->bus_clk))
 		clk_disable_unprepare(msm_host->bus_clk);
 	return 0;
 }

 static struct platform_driver sdhci_msm_driver = {
 	.probe = sdhci_msm_probe,
 	.remove = sdhci_msm_remove,
 	.driver = {
 		   .name = "sdhci_msm",
 		   .of_match_table = sdhci_msm_dt_match,
 	},
 };

 module_platform_driver(sdhci_msm_driver);

 MODULE_DESCRIPTION("Qualcomm Secure Digital Host Controller Interface driver");
 MODULE_LICENSE("GPL v2");
	/*
	* drivers/mmc/host/sdhci-msm.c - Qualcomm SDHCI Platform driver
	*
	* Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 and
	* only version 2 as published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	*/

	#include <linux/module.h>
	#include <linux/of_device.h>
	#include <linux/delay.h>
	#include <linux/mmc/mmc.h>
	#include <linux/slab.h>

	#include "sdhci-pltfm.h"

	#define CORE_MCI_VERSION 0x50
	#define CORE_VERSION_MAJOR_SHIFT 28
	#define CORE_VERSION_MAJOR_MASK (0xf << CORE_VERSION_MAJOR_SHIFT)
	#define CORE_VERSION_MINOR_MASK 0xff

	#define CORE_HC_MODE 0x78
	#define HC_MODE_EN 0x1
	#define CORE_POWER 0x0
	#define CORE_SW_RST BIT(7)

	#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_STATUS 0x108

	#define CORE_VENDOR_SPEC 0x10c
	#define CORE_CLK_PWRSAVE BIT(1)

	#define CORE_VENDOR_SPEC_CAPABILITIES0 0x11c

	#define CDR_SELEXT_SHIFT 20
	#define CDR_SELEXT_MASK (0xf << CDR_SELEXT_SHIFT)
	#define CMUX_SHIFT_PHASE_SHIFT 24
	#define CMUX_SHIFT_PHASE_MASK (7 << CMUX_SHIFT_PHASE_SHIFT)

	struct sdhci_msm_host {
	struct platform_device *pdev;
	void __iomem core_mem; / MSM SDCC mapped address */
	struct clk clk; / main SD/MMC bus clock */
	struct clk pclk; / SDHC peripheral bus clock */
	struct clk bus_clk; / SDHC bus voter clock */
	struct mmc_host *mmc;
	struct sdhci_pltfm_data sdhci_msm_pdata;
	};

	/* Platform specific tuning */
	static inline int msm_dll_poll_ck_out_en(struct sdhci_host *host, u8 poll)
	{
	u32 wait_cnt = 50;
	u8 ck_out_en;
	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;
	static const 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.
	*/
	config = readl_relaxed(host->ioaddr + CORE_DLL_CONFIG);
	config &= ~CDR_SELEXT_MASK;
	config \|= grey_coded_phase_table[phase] << CDR_SELEXT_SHIFT;
	writel_relaxed(config, 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 = 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, config;

	/* 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;

	config = readl_relaxed(host->ioaddr + CORE_DLL_CONFIG);
	config &= ~CMUX_SHIFT_PHASE_MASK;
	config \|= mclk_freq << CMUX_SHIFT_PHASE_SHIFT;
	writel_relaxed(config, 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);

	/*
	* 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;
	}
	udelay(1);
	}

	spin_unlock_irqrestore(&host->lock, flags);
	return 0;
	}

	static int sdhci_msm_execute_tuning(struct sdhci_host *host, u32 opcode)
	{
	int tuning_seq_cnt = 3;
	u8 phase, tuned_phases[16], tuned_phase_cnt = 0;
	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;

	retry:
	/* First of all reset the tuning block */
	rc = msm_init_cm_dll(host);
	if (rc)
	return rc;

	phase = 0;
	do {
	/* Set the phase in delay line hw block */
	rc = msm_config_cm_dll_phase(host, phase);
	if (rc)
	return rc;

	rc = mmc_send_tuning(mmc);
	if (!rc) {
	/* 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 < ARRAY_SIZE(tuned_phases));

	if (tuned_phase_cnt) {
	rc = msm_find_most_appropriate_phase(host, tuned_phases,
	tuned_phase_cnt);
	if (rc < 0)
	return rc;
	else
	phase = rc;

	/*
	* Finally set the selected phase in delay
	* line hw block.
	*/
	rc = msm_config_cm_dll_phase(host, phase);
	if (rc)
	return rc;
	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;
	}

	return rc;
	}

	static const struct of_device_id sdhci_msm_dt_match[] = {
	{ .compatible = "qcom,sdhci-msm-v4" },
	{},
	};

	MODULE_DEVICE_TABLE(of, sdhci_msm_dt_match);

	static struct sdhci_ops sdhci_msm_ops = {
	.platform_execute_tuning = sdhci_msm_execute_tuning,
	.reset = sdhci_reset,
	.set_clock = sdhci_set_clock,
	.set_bus_width = sdhci_set_bus_width,
	.set_uhs_signaling = sdhci_set_uhs_signaling,
	};

	static int sdhci_msm_probe(struct platform_device *pdev)
	{
	struct sdhci_host *host;
	struct sdhci_pltfm_host *pltfm_host;
	struct sdhci_msm_host *msm_host;
	struct resource *core_memres;
	int ret;
	u16 host_version, core_minor;
	u32 core_version, caps;
	u8 core_major;

	msm_host = devm_kzalloc(&pdev->dev, sizeof(*msm_host), GFP_KERNEL);
	if (!msm_host)
	return -ENOMEM;

	msm_host->sdhci_msm_pdata.ops = &sdhci_msm_ops;
	host = sdhci_pltfm_init(pdev, &msm_host->sdhci_msm_pdata, 0);
	if (IS_ERR(host))
	return PTR_ERR(host);

	pltfm_host = sdhci_priv(host);
	pltfm_host->priv = msm_host;
	msm_host->mmc = host->mmc;
	msm_host->pdev = pdev;

	ret = mmc_of_parse(host->mmc);
	if (ret)
	goto pltfm_free;

	sdhci_get_of_property(pdev);

	/* Setup SDCC bus voter clock. */
	msm_host->bus_clk = devm_clk_get(&pdev->dev, "bus");
	if (!IS_ERR(msm_host->bus_clk)) {
	/* Vote for max. clk rate for max. performance */
	ret = clk_set_rate(msm_host->bus_clk, INT_MAX);
	if (ret)
	goto pltfm_free;
	ret = clk_prepare_enable(msm_host->bus_clk);
	if (ret)
	goto pltfm_free;
	}

	/* Setup main peripheral bus clock */
	msm_host->pclk = devm_clk_get(&pdev->dev, "iface");
	if (IS_ERR(msm_host->pclk)) {
	ret = PTR_ERR(msm_host->pclk);
	dev_err(&pdev->dev, "Perpheral clk setup failed (%d)\n", ret);
	goto bus_clk_disable;
	}

	ret = clk_prepare_enable(msm_host->pclk);
	if (ret)
	goto bus_clk_disable;

	/* Setup SDC MMC clock */
	msm_host->clk = devm_clk_get(&pdev->dev, "core");
	if (IS_ERR(msm_host->clk)) {
	ret = PTR_ERR(msm_host->clk);
	dev_err(&pdev->dev, "SDC MMC clk setup failed (%d)\n", ret);
	goto pclk_disable;
	}

	ret = clk_prepare_enable(msm_host->clk);
	if (ret)
	goto pclk_disable;

	core_memres = platform_get_resource(pdev, IORESOURCE_MEM, 1);
	msm_host->core_mem = devm_ioremap_resource(&pdev->dev, core_memres);

	if (IS_ERR(msm_host->core_mem)) {
	dev_err(&pdev->dev, "Failed to remap registers\n");
	ret = PTR_ERR(msm_host->core_mem);
	goto clk_disable;
	}

	/* Reset the core and Enable SDHC mode */
	writel_relaxed(readl_relaxed(msm_host->core_mem + CORE_POWER) \|
	CORE_SW_RST, msm_host->core_mem + CORE_POWER);

	/* SW reset can take upto 10HCLK + 15MCLK cycles. (min 40us) */
	usleep_range(1000, 5000);
	if (readl(msm_host->core_mem + CORE_POWER) & CORE_SW_RST) {
	dev_err(&pdev->dev, "Stuck in reset\n");
	ret = -ETIMEDOUT;
	goto clk_disable;
	}

	/* Set HC_MODE_EN bit in HC_MODE register */
	writel_relaxed(HC_MODE_EN, (msm_host->core_mem + CORE_HC_MODE));

	host->quirks \|= SDHCI_QUIRK_BROKEN_CARD_DETECTION;
	host->quirks \|= SDHCI_QUIRK_SINGLE_POWER_WRITE;

	host_version = readw_relaxed((host->ioaddr + SDHCI_HOST_VERSION));
	dev_dbg(&pdev->dev, "Host Version: 0x%x Vendor Version 0x%x\n",
	host_version, ((host_version & SDHCI_VENDOR_VER_MASK) >>
	SDHCI_VENDOR_VER_SHIFT));

	core_version = readl_relaxed(msm_host->core_mem + CORE_MCI_VERSION);
	core_major = (core_version & CORE_VERSION_MAJOR_MASK) >>
	CORE_VERSION_MAJOR_SHIFT;
	core_minor = core_version & CORE_VERSION_MINOR_MASK;
	dev_dbg(&pdev->dev, "MCI Version: 0x%08x, major: 0x%04x, minor: 0x%02x\n",
	core_version, core_major, core_minor);

	/*
	* Support for some capabilities is not advertised by newer
	* controller versions and must be explicitly enabled.
	*/
	if (core_major >= 1 && core_minor != 0x11 && core_minor != 0x12) {
	caps = readl_relaxed(host->ioaddr + SDHCI_CAPABILITIES);
	caps \|= SDHCI_CAN_VDD_300 \| SDHCI_CAN_DO_8BIT;
	writel_relaxed(caps, host->ioaddr +
	CORE_VENDOR_SPEC_CAPABILITIES0);
	}

	ret = sdhci_add_host(host);
	if (ret)
	goto clk_disable;

	return 0;

	clk_disable:
	clk_disable_unprepare(msm_host->clk);
	pclk_disable:
	clk_disable_unprepare(msm_host->pclk);
	bus_clk_disable:
	if (!IS_ERR(msm_host->bus_clk))
	clk_disable_unprepare(msm_host->bus_clk);
	pltfm_free:
	sdhci_pltfm_free(pdev);
	return ret;
	}

	static int sdhci_msm_remove(struct platform_device *pdev)
	{
	struct sdhci_host *host = platform_get_drvdata(pdev);
	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
	struct sdhci_msm_host *msm_host = pltfm_host->priv;
	int dead = (readl_relaxed(host->ioaddr + SDHCI_INT_STATUS) ==
	0xffffffff);

	sdhci_remove_host(host, dead);
	sdhci_pltfm_free(pdev);
	clk_disable_unprepare(msm_host->clk);
	clk_disable_unprepare(msm_host->pclk);
	if (!IS_ERR(msm_host->bus_clk))
	clk_disable_unprepare(msm_host->bus_clk);
	return 0;
	}

	static struct platform_driver sdhci_msm_driver = {
	.probe = sdhci_msm_probe,
	.remove = sdhci_msm_remove,
	.driver = {
	.name = "sdhci_msm",
	.of_match_table = sdhci_msm_dt_match,
	},
	};

	module_platform_driver(sdhci_msm_driver);

	MODULE_DESCRIPTION("Qualcomm Secure Digital Host Controller Interface driver");
	MODULE_LICENSE("GPL v2");