xref: /openbmc/linux/drivers/mmc/host/sdhci-msm.c (revision ff06ce41)

/*
 * 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/pm_runtime.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 FF_CLK_SW_RST_DIS	BIT(13)

#define CORE_PWRCTL_STATUS	0xdc
#define CORE_PWRCTL_MASK	0xe0
#define CORE_PWRCTL_CLEAR	0xe4
#define CORE_PWRCTL_CTL		0xe8
#define CORE_PWRCTL_BUS_OFF	BIT(0)
#define CORE_PWRCTL_BUS_ON	BIT(1)
#define CORE_PWRCTL_IO_LOW	BIT(2)
#define CORE_PWRCTL_IO_HIGH	BIT(3)
#define CORE_PWRCTL_BUS_SUCCESS BIT(0)
#define CORE_PWRCTL_IO_SUCCESS	BIT(2)
#define REQ_BUS_OFF		BIT(0)
#define REQ_BUS_ON		BIT(1)
#define REQ_IO_LOW		BIT(2)
#define REQ_IO_HIGH		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_STATUS		0x108

#define CORE_DLL_CONFIG_2	0x1b4
#define CORE_FLL_CYCLE_CNT	BIT(18)
#define CORE_DLL_CLOCK_DISABLE	BIT(21)

#define CORE_VENDOR_SPEC	0x10c
#define CORE_CLK_PWRSAVE	BIT(1)
#define CORE_HC_MCLK_SEL_DFLT	(2 << 8)
#define CORE_HC_MCLK_SEL_HS400	(3 << 8)
#define CORE_HC_MCLK_SEL_MASK	(3 << 8)
#define CORE_HC_SELECT_IN_EN	BIT(18)
#define CORE_HC_SELECT_IN_HS400	(6 << 19)
#define CORE_HC_SELECT_IN_MASK	(7 << 19)

#define CORE_VENDOR_SPEC_CAPABILITIES0	0x11c

#define SDHCI_MSM_MIN_CLOCK	400000
#define CORE_FREQ_100MHZ	(100 * 1000 * 1000)

#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)

#define MSM_MMC_AUTOSUSPEND_DELAY_MS	50
struct sdhci_msm_host {
	struct platform_device *pdev;
	void __iomem *core_mem;	/* MSM SDCC mapped address */
	int pwr_irq;		/* power irq */
	struct clk *clk;	/* main SD/MMC bus clock */
	struct clk *pclk;	/* SDHC peripheral bus clock */
	struct clk *bus_clk;	/* SDHC bus voter clock */
	struct clk *xo_clk;	/* TCXO clk needed for FLL feature of cm_dll*/
	unsigned long clk_rate;
	struct mmc_host *mmc;
	bool use_14lpp_dll_reset;
	bool tuning_done;
	bool calibration_done;
};

/* 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);

	config = readl_relaxed(host->ioaddr + CORE_DLL_CONFIG);
	config |= CORE_CK_OUT_EN;
	writel_relaxed(config, 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
 * HS400/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;
	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
	int wait_cnt = 50;
	unsigned long flags;
	u32 config;

	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.
	 */
	config = readl_relaxed(host->ioaddr + CORE_VENDOR_SPEC);
	config &= ~CORE_CLK_PWRSAVE;
	writel_relaxed(config, host->ioaddr + CORE_VENDOR_SPEC);

	if (msm_host->use_14lpp_dll_reset) {
		config = readl_relaxed(host->ioaddr + CORE_DLL_CONFIG);
		config &= ~CORE_CK_OUT_EN;
		writel_relaxed(config, host->ioaddr + CORE_DLL_CONFIG);

		config = readl_relaxed(host->ioaddr + CORE_DLL_CONFIG_2);
		config |= CORE_DLL_CLOCK_DISABLE;
		writel_relaxed(config, host->ioaddr + CORE_DLL_CONFIG_2);
	}

	config = readl_relaxed(host->ioaddr + CORE_DLL_CONFIG);
	config |= CORE_DLL_RST;
	writel_relaxed(config, host->ioaddr + CORE_DLL_CONFIG);

	config = readl_relaxed(host->ioaddr + CORE_DLL_CONFIG);
	config |= CORE_DLL_PDN;
	writel_relaxed(config, host->ioaddr + CORE_DLL_CONFIG);
	msm_cm_dll_set_freq(host);

	if (msm_host->use_14lpp_dll_reset &&
	    !IS_ERR_OR_NULL(msm_host->xo_clk)) {
		u32 mclk_freq = 0;

		config = readl_relaxed(host->ioaddr + CORE_DLL_CONFIG_2);
		config &= CORE_FLL_CYCLE_CNT;
		if (config)
			mclk_freq = DIV_ROUND_CLOSEST_ULL((host->clock * 8),
					clk_get_rate(msm_host->xo_clk));
		else
			mclk_freq = DIV_ROUND_CLOSEST_ULL((host->clock * 4),
					clk_get_rate(msm_host->xo_clk));

		config = readl_relaxed(host->ioaddr + CORE_DLL_CONFIG_2);
		config &= ~(0xFF << 10);
		config |= mclk_freq << 10;

		writel_relaxed(config, host->ioaddr + CORE_DLL_CONFIG_2);
		/* wait for 5us before enabling DLL clock */
		udelay(5);
	}

	config = readl_relaxed(host->ioaddr + CORE_DLL_CONFIG);
	config &= ~CORE_DLL_RST;
	writel_relaxed(config, host->ioaddr + CORE_DLL_CONFIG);

	config = readl_relaxed(host->ioaddr + CORE_DLL_CONFIG);
	config &= ~CORE_DLL_PDN;
	writel_relaxed(config, host->ioaddr + CORE_DLL_CONFIG);

	if (msm_host->use_14lpp_dll_reset) {
		msm_cm_dll_set_freq(host);
		config = readl_relaxed(host->ioaddr + CORE_DLL_CONFIG_2);
		config &= ~CORE_DLL_CLOCK_DISABLE;
		writel_relaxed(config, host->ioaddr + CORE_DLL_CONFIG_2);
	}

	config = readl_relaxed(host->ioaddr + CORE_DLL_CONFIG);
	config |= CORE_DLL_EN;
	writel_relaxed(config, host->ioaddr + CORE_DLL_CONFIG);

	config = readl_relaxed(host->ioaddr + CORE_DLL_CONFIG);
	config |= CORE_CK_OUT_EN;
	writel_relaxed(config, 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 <= CORE_FREQ_100MHZ ||
	    !(ios.timing == MMC_TIMING_MMC_HS400 ||
	    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, opcode, NULL);
		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;
	}

	if (!rc)
		msm_host->tuning_done = true;
	return rc;
}

static void sdhci_msm_set_uhs_signaling(struct sdhci_host *host,
					unsigned int uhs)
{
	struct mmc_host *mmc = host->mmc;
	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
	u16 ctrl_2;
	u32 config;

	ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
	/* Select Bus Speed Mode for host */
	ctrl_2 &= ~SDHCI_CTRL_UHS_MASK;
	switch (uhs) {
	case MMC_TIMING_UHS_SDR12:
		ctrl_2 |= SDHCI_CTRL_UHS_SDR12;
		break;
	case MMC_TIMING_UHS_SDR25:
		ctrl_2 |= SDHCI_CTRL_UHS_SDR25;
		break;
	case MMC_TIMING_UHS_SDR50:
		ctrl_2 |= SDHCI_CTRL_UHS_SDR50;
		break;
	case MMC_TIMING_MMC_HS400:
	case MMC_TIMING_MMC_HS200:
	case MMC_TIMING_UHS_SDR104:
		ctrl_2 |= SDHCI_CTRL_UHS_SDR104;
		break;
	case MMC_TIMING_UHS_DDR50:
	case MMC_TIMING_MMC_DDR52:
		ctrl_2 |= SDHCI_CTRL_UHS_DDR50;
		break;
	}

	/*
	 * When clock frequency is less than 100MHz, the feedback clock must be
	 * provided and DLL must not be used so that tuning can be skipped. To
	 * provide feedback clock, the mode selection can be any value less
	 * than 3'b011 in bits [2:0] of HOST CONTROL2 register.
	 */
	if (host->clock <= CORE_FREQ_100MHZ) {
		if (uhs == MMC_TIMING_MMC_HS400 ||
		    uhs == MMC_TIMING_MMC_HS200 ||
		    uhs == MMC_TIMING_UHS_SDR104)
			ctrl_2 &= ~SDHCI_CTRL_UHS_MASK;
		/*
		 * DLL is not required for clock <= 100MHz
		 * Thus, make sure DLL it is disabled when not required
		 */
		config = readl_relaxed(host->ioaddr + CORE_DLL_CONFIG);
		config |= CORE_DLL_RST;
		writel_relaxed(config, host->ioaddr + CORE_DLL_CONFIG);

		config = readl_relaxed(host->ioaddr + CORE_DLL_CONFIG);
		config |= CORE_DLL_PDN;
		writel_relaxed(config, host->ioaddr + CORE_DLL_CONFIG);

		/*
		 * The DLL needs to be restored and CDCLP533 recalibrated
		 * when the clock frequency is set back to 400MHz.
		 */
		msm_host->calibration_done = false;
	}

	dev_dbg(mmc_dev(mmc), "%s: clock=%u uhs=%u ctrl_2=0x%x\n",
		mmc_hostname(host->mmc), host->clock, uhs, ctrl_2);
	sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
}

static void sdhci_msm_voltage_switch(struct sdhci_host *host)
{
	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
	u32 irq_status, irq_ack = 0;

	irq_status = readl_relaxed(msm_host->core_mem + CORE_PWRCTL_STATUS);
	irq_status &= INT_MASK;

	writel_relaxed(irq_status, msm_host->core_mem + CORE_PWRCTL_CLEAR);

	if (irq_status & (CORE_PWRCTL_BUS_ON | CORE_PWRCTL_BUS_OFF))
		irq_ack |= CORE_PWRCTL_BUS_SUCCESS;
	if (irq_status & (CORE_PWRCTL_IO_LOW | CORE_PWRCTL_IO_HIGH))
		irq_ack |= CORE_PWRCTL_IO_SUCCESS;

	/*
	 * The driver has to acknowledge the interrupt, switch voltages and
	 * report back if it succeded or not to this register. The voltage
	 * switches are handled by the sdhci core, so just report success.
	 */
	writel_relaxed(irq_ack, msm_host->core_mem + CORE_PWRCTL_CTL);
}

static irqreturn_t sdhci_msm_pwr_irq(int irq, void *data)
{
	struct sdhci_host *host = (struct sdhci_host *)data;

	sdhci_msm_voltage_switch(host);

	return IRQ_HANDLED;
}

static unsigned int sdhci_msm_get_max_clock(struct sdhci_host *host)
{
	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);

	return clk_round_rate(msm_host->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.
 *
 * Description:
 * MSM controller does not use internal divider and
 * instead directly control the GCC clock as per
 * HW recommendation.
 **/
void __sdhci_msm_set_clock(struct sdhci_host *host, unsigned int clock)
{
	u16 clk;
	/*
	 * Keep actual_clock as zero -
	 * - since there is no divider used so no need of having actual_clock.
	 * - MSM controller uses SDCLK for data timeout calculation. If
	 *   actual_clock is zero, host->clock is taken for calculation.
	 */
	host->mmc->actual_clock = 0;

	sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);

	if (clock == 0)
		return;

	/*
	 * MSM controller do not use clock divider.
	 * Thus read SDHCI_CLOCK_CONTROL and only enable
	 * clock with no divider value programmed.
	 */
	clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
	sdhci_enable_clk(host, clk);
}

/* sdhci_msm_set_clock - Called with (host->lock) spinlock held. */
static void sdhci_msm_set_clock(struct sdhci_host *host, unsigned int clock)
{
	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
	struct mmc_ios curr_ios = host->mmc->ios;
	u32 config;
	int rc;

	if (!clock) {
		msm_host->clk_rate = clock;
		goto out;
	}

	spin_unlock_irq(&host->lock);
	/*
	 * The SDHC requires internal clock frequency to be double the
	 * actual clock that will be set for DDR mode. The controller
	 * uses the faster clock(100/400MHz) for some of its parts and
	 * send the actual required clock (50/200MHz) to the card.
	 */
	if (curr_ios.timing == MMC_TIMING_UHS_DDR50 ||
	    curr_ios.timing == MMC_TIMING_MMC_DDR52 ||
	    curr_ios.timing == MMC_TIMING_MMC_HS400)
		clock *= 2;
	/*
	 * In general all timing modes are controlled via UHS mode select in
	 * Host Control2 register. eMMC specific HS200/HS400 doesn't have
	 * their respective modes defined here, hence we use these values.
	 *
	 * HS200 - SDR104 (Since they both are equivalent in functionality)
	 * HS400 - This involves multiple configurations
	 *		Initially SDR104 - when tuning is required as HS200
	 *		Then when switching to DDR @ 400MHz (HS400) we use
	 *		the vendor specific HC_SELECT_IN to control the mode.
	 *
	 * In addition to controlling the modes we also need to select the
	 * correct input clock for DLL depending on the mode.
	 *
	 * HS400 - divided clock (free running MCLK/2)
	 * All other modes - default (free running MCLK)
	 */
	if (curr_ios.timing == MMC_TIMING_MMC_HS400) {
		/* Select the divided clock (free running MCLK/2) */
		config = readl_relaxed(host->ioaddr + CORE_VENDOR_SPEC);
		config &= ~CORE_HC_MCLK_SEL_MASK;
		config |= CORE_HC_MCLK_SEL_HS400;

		writel_relaxed(config, host->ioaddr + CORE_VENDOR_SPEC);
		/*
		 * Select HS400 mode using the HC_SELECT_IN from VENDOR SPEC
		 * register
		 */
		if (msm_host->tuning_done && !msm_host->calibration_done) {
			/*
			 * Write 0x6 to HC_SELECT_IN and 1 to HC_SELECT_IN_EN
			 * field in VENDOR_SPEC_FUNC
			 */
			config = readl_relaxed(host->ioaddr + CORE_VENDOR_SPEC);
			config |= CORE_HC_SELECT_IN_HS400;
			config |= CORE_HC_SELECT_IN_EN;
			writel_relaxed(config, host->ioaddr + CORE_VENDOR_SPEC);
		}
	} else {
		config = readl_relaxed(host->ioaddr + CORE_VENDOR_SPEC);
		config &= ~CORE_HC_MCLK_SEL_MASK;
		config |= CORE_HC_MCLK_SEL_DFLT;
		writel_relaxed(config, host->ioaddr + CORE_VENDOR_SPEC);

		/*
		 * Disable HC_SELECT_IN to be able to use the UHS mode select
		 * configuration from Host Control2 register for all other
		 * modes.
		 * Write 0 to HC_SELECT_IN and HC_SELECT_IN_EN field
		 * in VENDOR_SPEC_FUNC
		 */
		config = readl_relaxed(host->ioaddr + CORE_VENDOR_SPEC);
		config &= ~CORE_HC_SELECT_IN_EN;
		config &= ~CORE_HC_SELECT_IN_MASK;
		writel_relaxed(config, host->ioaddr + CORE_VENDOR_SPEC);
	}

	/*
	 * Make sure above writes impacting free running MCLK are completed
	 * before changing the clk_rate at GCC.
	 */
	wmb();

	rc = clk_set_rate(msm_host->clk, clock);
	if (rc) {
		pr_err("%s: Failed to set clock at rate %u at timing %d\n",
		       mmc_hostname(host->mmc), clock,
		       curr_ios.timing);
		goto out_lock;
	}
	msm_host->clk_rate = clock;
	pr_debug("%s: Setting clock at rate %lu at timing %d\n",
		 mmc_hostname(host->mmc), clk_get_rate(msm_host->clk),
		 curr_ios.timing);

out_lock:
	spin_lock_irq(&host->lock);
out:
	__sdhci_msm_set_clock(host, clock);
}

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

MODULE_DEVICE_TABLE(of, sdhci_msm_dt_match);

static const struct sdhci_ops sdhci_msm_ops = {
	.platform_execute_tuning = sdhci_msm_execute_tuning,
	.reset = sdhci_reset,
	.set_clock = sdhci_msm_set_clock,
	.get_min_clock = sdhci_msm_get_min_clock,
	.get_max_clock = sdhci_msm_get_max_clock,
	.set_bus_width = sdhci_set_bus_width,
	.set_uhs_signaling = sdhci_msm_set_uhs_signaling,
	.voltage_switch = sdhci_msm_voltage_switch,
};

static const struct sdhci_pltfm_data sdhci_msm_pdata = {
	.quirks = SDHCI_QUIRK_BROKEN_CARD_DETECTION |
		  SDHCI_QUIRK_NO_CARD_NO_RESET |
		  SDHCI_QUIRK_SINGLE_POWER_WRITE |
		  SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
	.ops = &sdhci_msm_ops,
};

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, config;
	u8 core_major;

	host = sdhci_pltfm_init(pdev, &sdhci_msm_pdata, sizeof(*msm_host));
	if (IS_ERR(host))
		return PTR_ERR(host);

	pltfm_host = sdhci_priv(host);
	msm_host = sdhci_pltfm_priv(pltfm_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, "Peripheral 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;
	}

	/*
	 * xo clock is needed for FLL feature of cm_dll.
	 * In case if xo clock is not mentioned in DT, warn and proceed.
	 */
	msm_host->xo_clk = devm_clk_get(&pdev->dev, "xo");
	if (IS_ERR(msm_host->xo_clk)) {
		ret = PTR_ERR(msm_host->xo_clk);
		dev_warn(&pdev->dev, "TCXO clk not present (%d)\n", ret);
	}

	/* Vote for maximum clock rate for maximum performance */
	ret = clk_set_rate(msm_host->clk, INT_MAX);
	if (ret)
		dev_warn(&pdev->dev, "core clock boost failed\n");

	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;
	}

	config = readl_relaxed(msm_host->core_mem + CORE_POWER);
	config |= CORE_SW_RST;
	writel_relaxed(config, 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));

	config = readl_relaxed(msm_host->core_mem + CORE_HC_MODE);
	config |= FF_CLK_SW_RST_DIS;
	writel_relaxed(config, msm_host->core_mem + CORE_HC_MODE);

	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);

	if (core_major == 1 && core_minor >= 0x42)
		msm_host->use_14lpp_dll_reset = true;

	/*
	 * 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) {
		config = readl_relaxed(host->ioaddr + SDHCI_CAPABILITIES);
		config |= SDHCI_CAN_VDD_300 | SDHCI_CAN_DO_8BIT;
		writel_relaxed(config, host->ioaddr +
			       CORE_VENDOR_SPEC_CAPABILITIES0);
	}

	/* Setup IRQ for handling power/voltage tasks with PMIC */
	msm_host->pwr_irq = platform_get_irq_byname(pdev, "pwr_irq");
	if (msm_host->pwr_irq < 0) {
		dev_err(&pdev->dev, "Get pwr_irq failed (%d)\n",
			msm_host->pwr_irq);
		ret = msm_host->pwr_irq;
		goto clk_disable;
	}

	ret = devm_request_threaded_irq(&pdev->dev, msm_host->pwr_irq, NULL,
					sdhci_msm_pwr_irq, IRQF_ONESHOT,
					dev_name(&pdev->dev), host);
	if (ret) {
		dev_err(&pdev->dev, "Request IRQ failed (%d)\n", ret);
		goto clk_disable;
	}

	pm_runtime_get_noresume(&pdev->dev);
	pm_runtime_set_active(&pdev->dev);
	pm_runtime_enable(&pdev->dev);
	pm_runtime_set_autosuspend_delay(&pdev->dev,
					 MSM_MMC_AUTOSUSPEND_DELAY_MS);
	pm_runtime_use_autosuspend(&pdev->dev);

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

	pm_runtime_mark_last_busy(&pdev->dev);
	pm_runtime_put_autosuspend(&pdev->dev);

	return 0;

pm_runtime_disable:
	pm_runtime_disable(&pdev->dev);
	pm_runtime_set_suspended(&pdev->dev);
	pm_runtime_put_noidle(&pdev->dev);
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 = sdhci_pltfm_priv(pltfm_host);
	int dead = (readl_relaxed(host->ioaddr + SDHCI_INT_STATUS) ==
		    0xffffffff);

	sdhci_remove_host(host, dead);

	pm_runtime_get_sync(&pdev->dev);
	pm_runtime_disable(&pdev->dev);
	pm_runtime_put_noidle(&pdev->dev);

	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);
	sdhci_pltfm_free(pdev);
	return 0;
}

#ifdef CONFIG_PM
static int sdhci_msm_runtime_suspend(struct device *dev)
{
	struct sdhci_host *host = dev_get_drvdata(dev);
	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);

	clk_disable_unprepare(msm_host->clk);
	clk_disable_unprepare(msm_host->pclk);

	return 0;
}

static int sdhci_msm_runtime_resume(struct device *dev)
{
	struct sdhci_host *host = dev_get_drvdata(dev);
	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
	int ret;

	ret = clk_prepare_enable(msm_host->clk);
	if (ret) {
		dev_err(dev, "clk_enable failed for core_clk: %d\n", ret);
		return ret;
	}
	ret = clk_prepare_enable(msm_host->pclk);
	if (ret) {
		dev_err(dev, "clk_enable failed for iface_clk: %d\n", ret);
		clk_disable_unprepare(msm_host->clk);
		return ret;
	}

	return 0;
}
#endif

static const struct dev_pm_ops sdhci_msm_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
				pm_runtime_force_resume)
	SET_RUNTIME_PM_OPS(sdhci_msm_runtime_suspend,
			   sdhci_msm_runtime_resume,
			   NULL)
};

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,
		   .pm = &sdhci_msm_pm_ops,
	},
};

module_platform_driver(sdhci_msm_driver);

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