/*
 * copyright (c) 2013 Freescale Semiconductor, Inc.
 * Freescale IMX AHCI SATA platform driver
 *
 * based on the AHCI SATA platform driver by Jeff Garzik and Anton Vorontsov
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program. If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/ahci_platform.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>
#include <linux/of_device.h>
#include <linux/mfd/syscon.h>
#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
#include <linux/libata.h>
#include "ahci.h"

#define DRV_NAME "ahci-imx"

enum {
	/* Timer 1-ms Register */
	IMX_TIMER1MS				= 0x00e0,
	/* Port0 PHY Control Register */
	IMX_P0PHYCR				= 0x0178,
	IMX_P0PHYCR_TEST_PDDQ			= 1 << 20,
	IMX_P0PHYCR_CR_READ			= 1 << 19,
	IMX_P0PHYCR_CR_WRITE			= 1 << 18,
	IMX_P0PHYCR_CR_CAP_DATA			= 1 << 17,
	IMX_P0PHYCR_CR_CAP_ADDR			= 1 << 16,
	/* Port0 PHY Status Register */
	IMX_P0PHYSR				= 0x017c,
	IMX_P0PHYSR_CR_ACK			= 1 << 18,
	IMX_P0PHYSR_CR_DATA_OUT			= 0xffff << 0,
	/* Lane0 Output Status Register */
	IMX_LANE0_OUT_STAT			= 0x2003,
	IMX_LANE0_OUT_STAT_RX_PLL_STATE		= 1 << 1,
	/* Clock Reset Register */
	IMX_CLOCK_RESET				= 0x7f3f,
	IMX_CLOCK_RESET_RESET			= 1 << 0,
	/* IMX8QM HSIO AHCI definitions */
	IMX8QM_SATA_PHY_RX_IMPED_RATIO_OFFSET	= 0x03,
	IMX8QM_SATA_PHY_TX_IMPED_RATIO_OFFSET	= 0x09,
	IMX8QM_SATA_PHY_IMPED_RATIO_85OHM	= 0x6c,
	IMX8QM_LPCG_PHYX2_OFFSET		= 0x00000,
	IMX8QM_CSR_PHYX2_OFFSET			= 0x90000,
	IMX8QM_CSR_PHYX1_OFFSET			= 0xa0000,
	IMX8QM_CSR_PHYX_STTS0_OFFSET		= 0x4,
	IMX8QM_CSR_PCIEA_OFFSET			= 0xb0000,
	IMX8QM_CSR_PCIEB_OFFSET			= 0xc0000,
	IMX8QM_CSR_SATA_OFFSET			= 0xd0000,
	IMX8QM_CSR_PCIE_CTRL2_OFFSET		= 0x8,
	IMX8QM_CSR_MISC_OFFSET			= 0xe0000,

	IMX8QM_LPCG_PHYX2_PCLK0_MASK		= (0x3 << 16),
	IMX8QM_LPCG_PHYX2_PCLK1_MASK		= (0x3 << 20),
	IMX8QM_PHY_APB_RSTN_0			= BIT(0),
	IMX8QM_PHY_MODE_SATA			= BIT(19),
	IMX8QM_PHY_MODE_MASK			= (0xf << 17),
	IMX8QM_PHY_PIPE_RSTN_0			= BIT(24),
	IMX8QM_PHY_PIPE_RSTN_OVERRIDE_0		= BIT(25),
	IMX8QM_PHY_PIPE_RSTN_1			= BIT(26),
	IMX8QM_PHY_PIPE_RSTN_OVERRIDE_1		= BIT(27),
	IMX8QM_STTS0_LANE0_TX_PLL_LOCK		= BIT(4),
	IMX8QM_MISC_IOB_RXENA			= BIT(0),
	IMX8QM_MISC_IOB_TXENA			= BIT(1),
	IMX8QM_MISC_PHYX1_EPCS_SEL		= BIT(12),
	IMX8QM_MISC_CLKREQN_OUT_OVERRIDE_1	= BIT(24),
	IMX8QM_MISC_CLKREQN_OUT_OVERRIDE_0	= BIT(25),
	IMX8QM_MISC_CLKREQN_IN_OVERRIDE_1	= BIT(28),
	IMX8QM_MISC_CLKREQN_IN_OVERRIDE_0	= BIT(29),
	IMX8QM_SATA_CTRL_RESET_N		= BIT(12),
	IMX8QM_SATA_CTRL_EPCS_PHYRESET_N	= BIT(7),
	IMX8QM_CTRL_BUTTON_RST_N		= BIT(21),
	IMX8QM_CTRL_POWER_UP_RST_N		= BIT(23),
	IMX8QM_CTRL_LTSSM_ENABLE		= BIT(4),
};

enum ahci_imx_type {
	AHCI_IMX53,
	AHCI_IMX6Q,
	AHCI_IMX6QP,
	AHCI_IMX8QM,
};

struct imx_ahci_priv {
	struct platform_device *ahci_pdev;
	enum ahci_imx_type type;
	struct clk *sata_clk;
	struct clk *sata_ref_clk;
	struct clk *ahb_clk;
	struct clk *epcs_tx_clk;
	struct clk *epcs_rx_clk;
	struct clk *phy_apbclk;
	struct clk *phy_pclk0;
	struct clk *phy_pclk1;
	void __iomem *phy_base;
	int clkreq_gpio;
	struct regmap *gpr;
	bool no_device;
	bool first_time;
	u32 phy_params;
	u32 imped_ratio;
};

void *sg_io_buffer_hack;

static int ahci_imx_hotplug;
module_param_named(hotplug, ahci_imx_hotplug, int, 0644);
MODULE_PARM_DESC(hotplug, "AHCI IMX hot-plug support (0=Don't support, 1=support)");

static void ahci_imx_host_stop(struct ata_host *host);

static int imx_phy_crbit_assert(void __iomem *mmio, u32 bit, bool assert)
{
	int timeout = 10;
	u32 crval;
	u32 srval;

	/* Assert or deassert the bit */
	crval = readl(mmio + IMX_P0PHYCR);
	if (assert)
		crval |= bit;
	else
		crval &= ~bit;
	writel(crval, mmio + IMX_P0PHYCR);

	/* Wait for the cr_ack signal */
	do {
		srval = readl(mmio + IMX_P0PHYSR);
		if ((assert ? srval : ~srval) & IMX_P0PHYSR_CR_ACK)
			break;
		usleep_range(100, 200);
	} while (--timeout);

	return timeout ? 0 : -ETIMEDOUT;
}

static int imx_phy_reg_addressing(u16 addr, void __iomem *mmio)
{
	u32 crval = addr;
	int ret;

	/* Supply the address on cr_data_in */
	writel(crval, mmio + IMX_P0PHYCR);

	/* Assert the cr_cap_addr signal */
	ret = imx_phy_crbit_assert(mmio, IMX_P0PHYCR_CR_CAP_ADDR, true);
	if (ret)
		return ret;

	/* Deassert cr_cap_addr */
	ret = imx_phy_crbit_assert(mmio, IMX_P0PHYCR_CR_CAP_ADDR, false);
	if (ret)
		return ret;

	return 0;
}

static int imx_phy_reg_write(u16 val, void __iomem *mmio)
{
	u32 crval = val;
	int ret;

	/* Supply the data on cr_data_in */
	writel(crval, mmio + IMX_P0PHYCR);

	/* Assert the cr_cap_data signal */
	ret = imx_phy_crbit_assert(mmio, IMX_P0PHYCR_CR_CAP_DATA, true);
	if (ret)
		return ret;

	/* Deassert cr_cap_data */
	ret = imx_phy_crbit_assert(mmio, IMX_P0PHYCR_CR_CAP_DATA, false);
	if (ret)
		return ret;

	if (val & IMX_CLOCK_RESET_RESET) {
		/*
		 * In case we're resetting the phy, it's unable to acknowledge,
		 * so we return immediately here.
		 */
		crval |= IMX_P0PHYCR_CR_WRITE;
		writel(crval, mmio + IMX_P0PHYCR);
		goto out;
	}

	/* Assert the cr_write signal */
	ret = imx_phy_crbit_assert(mmio, IMX_P0PHYCR_CR_WRITE, true);
	if (ret)
		return ret;

	/* Deassert cr_write */
	ret = imx_phy_crbit_assert(mmio, IMX_P0PHYCR_CR_WRITE, false);
	if (ret)
		return ret;

out:
	return 0;
}

static int imx_phy_reg_read(u16 *val, void __iomem *mmio)
{
	int ret;

	/* Assert the cr_read signal */
	ret = imx_phy_crbit_assert(mmio, IMX_P0PHYCR_CR_READ, true);
	if (ret)
		return ret;

	/* Capture the data from cr_data_out[] */
	*val = readl(mmio + IMX_P0PHYSR) & IMX_P0PHYSR_CR_DATA_OUT;

	/* Deassert cr_read */
	ret = imx_phy_crbit_assert(mmio, IMX_P0PHYCR_CR_READ, false);
	if (ret)
		return ret;

	return 0;
}

static int imx_sata_phy_reset(struct ahci_host_priv *hpriv)
{
	void __iomem *mmio = hpriv->mmio;
	int timeout = 10;
	u16 val;
	int ret;

	/* Reset SATA PHY by setting RESET bit of PHY register CLOCK_RESET */
	ret = imx_phy_reg_addressing(IMX_CLOCK_RESET, mmio);
	if (ret)
		return ret;
	ret = imx_phy_reg_write(IMX_CLOCK_RESET_RESET, mmio);
	if (ret)
		return ret;

	/* Wait for PHY RX_PLL to be stable */
	do {
		usleep_range(100, 200);
		ret = imx_phy_reg_addressing(IMX_LANE0_OUT_STAT, mmio);
		if (ret)
			return ret;
		ret = imx_phy_reg_read(&val, mmio);
		if (ret)
			return ret;
		if (val & IMX_LANE0_OUT_STAT_RX_PLL_STATE)
			break;
	} while (--timeout);

	return timeout ? 0 : -ETIMEDOUT;
}

static int imx8_sata_enable(struct ahci_host_priv *hpriv)
{
	u32 val, reg;
	int i, ret;
	struct imx_ahci_priv *imxpriv = hpriv->plat_data;
	struct device *dev = &imxpriv->ahci_pdev->dev;

	/* configure the hsio for sata */
	ret = clk_prepare_enable(imxpriv->phy_pclk0);
	if (ret < 0) {
		dev_err(dev, "can't enable phy pclk0.\n");
		return ret;
	}
	ret = clk_prepare_enable(imxpriv->phy_pclk1);
	if (ret < 0) {
		dev_err(dev, "can't enable phy pclk1.\n");
		goto disable_phy_pclk0;
	}
	ret = clk_prepare_enable(imxpriv->epcs_tx_clk);
	if (ret < 0) {
		dev_err(dev, "can't enable epcs tx clk.\n");
		goto disable_phy_pclk1;
	}
	ret = clk_prepare_enable(imxpriv->epcs_rx_clk);
	if (ret < 0) {
		dev_err(dev, "can't enable epcs rx clk.\n");
		goto disable_epcs_tx_clk;
	}
	ret = clk_prepare_enable(imxpriv->phy_apbclk);
	if (ret < 0) {
		dev_err(dev, "can't enable phy pclk1.\n");
		goto disable_epcs_rx_clk;
	}
	/* Configure PHYx2 PIPE_RSTN */
	regmap_read(imxpriv->gpr, IMX8QM_CSR_PCIEA_OFFSET
			+ IMX8QM_CSR_PCIE_CTRL2_OFFSET, &val);
	if ((val & IMX8QM_CTRL_LTSSM_ENABLE) == 0) {
		 /* PCIEA of HSIO is down too */
		regmap_update_bits(imxpriv->gpr,
				IMX8QM_CSR_PHYX2_OFFSET,
				IMX8QM_PHY_PIPE_RSTN_0
				| IMX8QM_PHY_PIPE_RSTN_OVERRIDE_0,
				IMX8QM_PHY_PIPE_RSTN_0
				| IMX8QM_PHY_PIPE_RSTN_OVERRIDE_0);
	}
	regmap_read(imxpriv->gpr, IMX8QM_CSR_PCIEB_OFFSET
			+ IMX8QM_CSR_PCIE_CTRL2_OFFSET, &reg);
	if ((reg & IMX8QM_CTRL_LTSSM_ENABLE) == 0) {
		 /* PCIEB of HSIO is down */
		regmap_update_bits(imxpriv->gpr,
				IMX8QM_CSR_PHYX2_OFFSET,
				IMX8QM_PHY_PIPE_RSTN_1
				| IMX8QM_PHY_PIPE_RSTN_OVERRIDE_1,
				IMX8QM_PHY_PIPE_RSTN_1
				| IMX8QM_PHY_PIPE_RSTN_OVERRIDE_1);
	}
	if (((reg | val) & IMX8QM_CTRL_LTSSM_ENABLE) == 0) {
		 /* Both PCIA and PCIEB of HSIO is down */
		regmap_update_bits(imxpriv->gpr,
				IMX8QM_LPCG_PHYX2_OFFSET,
				IMX8QM_LPCG_PHYX2_PCLK0_MASK
				| IMX8QM_LPCG_PHYX2_PCLK1_MASK,
				0);
	}

	/* set PWR_RST and BT_RST of csr_pciea */
	val = IMX8QM_CSR_PCIEA_OFFSET + IMX8QM_CSR_PCIE_CTRL2_OFFSET;
	regmap_update_bits(imxpriv->gpr,
			val,
			IMX8QM_CTRL_BUTTON_RST_N,
			IMX8QM_CTRL_BUTTON_RST_N);
	regmap_update_bits(imxpriv->gpr,
			val,
			IMX8QM_CTRL_POWER_UP_RST_N,
			IMX8QM_CTRL_POWER_UP_RST_N);

	/* PHYX1_MODE to SATA */
	regmap_update_bits(imxpriv->gpr,
			IMX8QM_CSR_PHYX1_OFFSET,
			IMX8QM_PHY_MODE_MASK,
			IMX8QM_PHY_MODE_SATA);

	/*
	 * bit0 rx ena 1, bit1 tx ena 0
	 * bit12 PHY_X1_EPCS_SEL 1.
	 */
	regmap_update_bits(imxpriv->gpr,
			IMX8QM_CSR_MISC_OFFSET,
			IMX8QM_MISC_IOB_RXENA,
			IMX8QM_MISC_IOB_RXENA);
	regmap_update_bits(imxpriv->gpr,
			IMX8QM_CSR_MISC_OFFSET,
			IMX8QM_MISC_IOB_TXENA,
			0);
	regmap_update_bits(imxpriv->gpr,
			IMX8QM_CSR_MISC_OFFSET,
			IMX8QM_MISC_PHYX1_EPCS_SEL,
			IMX8QM_MISC_PHYX1_EPCS_SEL);
	/*
	 * It is possible, for PCIe and SATA are sharing
	 * the same clock source, HPLL or external oscillator.
	 * When PCIe is in low power modes (L1.X or L2 etc),
	 * the clock source can be turned off. In this case,
	 * if this clock source is required to be toggling by
	 * SATA, then SATA functions will be abnormal.
	 */
	regmap_update_bits(imxpriv->gpr,
			IMX8QM_CSR_MISC_OFFSET,
			IMX8QM_MISC_CLKREQN_OUT_OVERRIDE_1
			| IMX8QM_MISC_CLKREQN_OUT_OVERRIDE_0
			| IMX8QM_MISC_CLKREQN_IN_OVERRIDE_1
			| IMX8QM_MISC_CLKREQN_IN_OVERRIDE_0,
			IMX8QM_MISC_CLKREQN_OUT_OVERRIDE_1
			| IMX8QM_MISC_CLKREQN_OUT_OVERRIDE_0
			| IMX8QM_MISC_CLKREQN_IN_OVERRIDE_1
			| IMX8QM_MISC_CLKREQN_IN_OVERRIDE_0);

	/* clear PHY RST, then set it */
	regmap_update_bits(imxpriv->gpr,
			IMX8QM_CSR_SATA_OFFSET,
			IMX8QM_SATA_CTRL_EPCS_PHYRESET_N,
			0);

	regmap_update_bits(imxpriv->gpr,
			IMX8QM_CSR_SATA_OFFSET,
			IMX8QM_SATA_CTRL_EPCS_PHYRESET_N,
			IMX8QM_SATA_CTRL_EPCS_PHYRESET_N);

	/* CTRL RST: SET -> delay 1 us -> CLEAR -> SET */
	regmap_update_bits(imxpriv->gpr,
			IMX8QM_CSR_SATA_OFFSET,
			IMX8QM_SATA_CTRL_RESET_N,
			IMX8QM_SATA_CTRL_RESET_N);
	udelay(1);
	regmap_update_bits(imxpriv->gpr,
			IMX8QM_CSR_SATA_OFFSET,
			IMX8QM_SATA_CTRL_RESET_N,
			0);
	regmap_update_bits(imxpriv->gpr,
			IMX8QM_CSR_SATA_OFFSET,
			IMX8QM_SATA_CTRL_RESET_N,
			IMX8QM_SATA_CTRL_RESET_N);

	/* APB reset */
	regmap_update_bits(imxpriv->gpr,
			IMX8QM_CSR_PHYX1_OFFSET,
			IMX8QM_PHY_APB_RSTN_0,
			IMX8QM_PHY_APB_RSTN_0);

	for (i = 0; i < 100; i++) {
		reg = IMX8QM_CSR_PHYX1_OFFSET
			+ IMX8QM_CSR_PHYX_STTS0_OFFSET;
		regmap_read(imxpriv->gpr, reg, &val);
		val &= IMX8QM_STTS0_LANE0_TX_PLL_LOCK;
		if (val == IMX8QM_STTS0_LANE0_TX_PLL_LOCK)
			break;
		udelay(1);
	}

	if (val != IMX8QM_STTS0_LANE0_TX_PLL_LOCK) {
		dev_err(dev, "TX PLL of the PHY is not locked\n");
		ret = -ENODEV;
	} else {
		writeb(imxpriv->imped_ratio, imxpriv->phy_base
				+ IMX8QM_SATA_PHY_RX_IMPED_RATIO_OFFSET);
		writeb(imxpriv->imped_ratio, imxpriv->phy_base
				+ IMX8QM_SATA_PHY_TX_IMPED_RATIO_OFFSET);
		reg = readb(imxpriv->phy_base
				+ IMX8QM_SATA_PHY_RX_IMPED_RATIO_OFFSET);
		if (unlikely(reg != imxpriv->imped_ratio))
			dev_info(dev, "Can't set PHY RX impedance ratio.\n");
		reg = readb(imxpriv->phy_base
				+ IMX8QM_SATA_PHY_TX_IMPED_RATIO_OFFSET);
		if (unlikely(reg != imxpriv->imped_ratio))
			dev_info(dev, "Can't set PHY TX impedance ratio.\n");
		usleep_range(50, 100);

		/*
		 * To reduce the power consumption, gate off
		 * the PHY clks
		 */
		clk_disable_unprepare(imxpriv->phy_apbclk);
		clk_disable_unprepare(imxpriv->phy_pclk1);
		clk_disable_unprepare(imxpriv->phy_pclk0);
		return ret;
	}

	clk_disable_unprepare(imxpriv->phy_apbclk);
disable_epcs_rx_clk:
	clk_disable_unprepare(imxpriv->epcs_rx_clk);
disable_epcs_tx_clk:
	clk_disable_unprepare(imxpriv->epcs_tx_clk);
disable_phy_pclk1:
	clk_disable_unprepare(imxpriv->phy_pclk1);
disable_phy_pclk0:
	clk_disable_unprepare(imxpriv->phy_pclk0);

	return ret;
}

static int imx_sata_enable(struct ahci_host_priv *hpriv)
{
	struct imx_ahci_priv *imxpriv = hpriv->plat_data;
	struct device *dev = &imxpriv->ahci_pdev->dev;
	int ret;

	if (imxpriv->no_device)
		return 0;

	ret = ahci_platform_enable_regulators(hpriv);
	if (ret)
		return ret;

	ret = clk_prepare_enable(imxpriv->sata_ref_clk);
	if (ret < 0)
		goto disable_regulator;

	if (imxpriv->type == AHCI_IMX6Q || imxpriv->type == AHCI_IMX6QP) {
		/*
		 * set PHY Paremeters, two steps to configure the GPR13,
		 * one write for rest of parameters, mask of first write
		 * is 0x07ffffff, and the other one write for setting
		 * the mpll_clk_en.
		 */
		regmap_update_bits(imxpriv->gpr, IOMUXC_GPR13,
				   IMX6Q_GPR13_SATA_RX_EQ_VAL_MASK |
				   IMX6Q_GPR13_SATA_RX_LOS_LVL_MASK |
				   IMX6Q_GPR13_SATA_RX_DPLL_MODE_MASK |
				   IMX6Q_GPR13_SATA_SPD_MODE_MASK |
				   IMX6Q_GPR13_SATA_MPLL_SS_EN |
				   IMX6Q_GPR13_SATA_TX_ATTEN_MASK |
				   IMX6Q_GPR13_SATA_TX_BOOST_MASK |
				   IMX6Q_GPR13_SATA_TX_LVL_MASK |
				   IMX6Q_GPR13_SATA_MPLL_CLK_EN |
				   IMX6Q_GPR13_SATA_TX_EDGE_RATE,
				   imxpriv->phy_params);
		regmap_update_bits(imxpriv->gpr, IOMUXC_GPR13,
				   IMX6Q_GPR13_SATA_MPLL_CLK_EN,
				   IMX6Q_GPR13_SATA_MPLL_CLK_EN);

		usleep_range(100, 200);
	}


	if (imxpriv->type == AHCI_IMX6Q) {
		ret = imx_sata_phy_reset(hpriv);
	} else if (imxpriv->type == AHCI_IMX6QP) {
		/* 6qp adds the sata reset mechanism, use it for 6qp sata */
		regmap_update_bits(imxpriv->gpr, IOMUXC_GPR5,
				   BIT(10), 0);

		regmap_update_bits(imxpriv->gpr, IOMUXC_GPR5,
				   BIT(11), 0);
		udelay(50);
		regmap_update_bits(imxpriv->gpr, IOMUXC_GPR5,
				   BIT(11), BIT(11));
	} else if (imxpriv->type == AHCI_IMX8QM) {
		ret = imx8_sata_enable(hpriv);
	}

	if (ret) {
		dev_err(dev, "failed to reset phy: %d\n", ret);
		goto disable_clk;
	}

	usleep_range(1000, 2000);

	return 0;

disable_clk:
	clk_disable_unprepare(imxpriv->sata_ref_clk);
disable_regulator:
	ahci_platform_disable_regulators(hpriv);

	return ret;
}

static void imx_sata_disable(struct ahci_host_priv *hpriv)
{
	struct imx_ahci_priv *imxpriv = hpriv->plat_data;

	if (imxpriv->no_device)
		return;

	if (imxpriv->type == AHCI_IMX6QP)
		regmap_update_bits(imxpriv->gpr, IOMUXC_GPR5,
				   BIT(10), BIT(10));

	if (imxpriv->type == AHCI_IMX6Q || imxpriv->type == AHCI_IMX6QP) {
		regmap_update_bits(imxpriv->gpr, IOMUXC_GPR13,
				   IMX6Q_GPR13_SATA_MPLL_CLK_EN,
				   !IMX6Q_GPR13_SATA_MPLL_CLK_EN);
	}

	if (imxpriv->type == AHCI_IMX8QM) {
		clk_disable_unprepare(imxpriv->epcs_rx_clk);
		clk_disable_unprepare(imxpriv->epcs_tx_clk);
	}
	clk_disable_unprepare(imxpriv->sata_ref_clk);

	ahci_platform_disable_regulators(hpriv);
}

static void ahci_imx_error_handler(struct ata_port *ap)
{
	u32 reg_val;
	struct ata_device *dev;
	struct ata_host *host = dev_get_drvdata(ap->dev);
	struct ahci_host_priv *hpriv = host->private_data;
	void __iomem *mmio = hpriv->mmio;
	struct imx_ahci_priv *imxpriv = hpriv->plat_data;

	ahci_error_handler(ap);

	if (!(imxpriv->first_time) || ahci_imx_hotplug
			|| (imxpriv->type == AHCI_IMX8QM))
		return;

	imxpriv->first_time = false;

	ata_for_each_dev(dev, &ap->link, ENABLED)
		return;
	/*
	 * Disable link to save power.  An imx ahci port can't be recovered
	 * without full reset once the pddq mode is enabled making it
	 * impossible to use as part of libata LPM.
	 */
	reg_val = readl(mmio + IMX_P0PHYCR);
	writel(reg_val | IMX_P0PHYCR_TEST_PDDQ, mmio + IMX_P0PHYCR);
	imx_sata_disable(hpriv);
	imxpriv->no_device = true;

	dev_info(ap->dev, "no device found, disabling link.\n");
	dev_info(ap->dev, "pass " MODULE_PARAM_PREFIX ".hotplug=1 to enable hotplug\n");
}

static int ahci_imx_softreset(struct ata_link *link, unsigned int *class,
		       unsigned long deadline)
{
	struct ata_port *ap = link->ap;
	struct ata_host *host = dev_get_drvdata(ap->dev);
	struct ahci_host_priv *hpriv = host->private_data;
	struct imx_ahci_priv *imxpriv = hpriv->plat_data;
	int ret = -EIO;

	if (imxpriv->type == AHCI_IMX53)
		ret = ahci_pmp_retry_srst_ops.softreset(link, class, deadline);
	else
		ret = ahci_ops.softreset(link, class, deadline);

	return ret;
}

static struct ata_port_operations ahci_imx_ops = {
	.inherits	= &ahci_ops,
	.host_stop	= ahci_imx_host_stop,
	.error_handler	= ahci_imx_error_handler,
	.softreset	= ahci_imx_softreset,
};

static const struct ata_port_info ahci_imx_port_info = {
	.flags		= AHCI_FLAG_COMMON,
	.pio_mask	= ATA_PIO4,
	.udma_mask	= ATA_UDMA6,
	.port_ops	= &ahci_imx_ops,
};

static const struct of_device_id imx_ahci_of_match[] = {
	{ .compatible = "fsl,imx53-ahci", .data = (void *)AHCI_IMX53 },
	{ .compatible = "fsl,imx6q-ahci", .data = (void *)AHCI_IMX6Q },
	{ .compatible = "fsl,imx6qp-ahci", .data = (void *)AHCI_IMX6QP },
	{ .compatible = "fsl,imx8qm-ahci", .data = (void *)AHCI_IMX8QM },
	{},
};
MODULE_DEVICE_TABLE(of, imx_ahci_of_match);

struct reg_value {
	u32 of_value;
	u32 reg_value;
};

struct reg_property {
	const char *name;
	const struct reg_value *values;
	size_t num_values;
	u32 def_value;
	u32 set_value;
};

static const struct reg_value gpr13_tx_level[] = {
	{  937, IMX6Q_GPR13_SATA_TX_LVL_0_937_V },
	{  947, IMX6Q_GPR13_SATA_TX_LVL_0_947_V },
	{  957, IMX6Q_GPR13_SATA_TX_LVL_0_957_V },
	{  966, IMX6Q_GPR13_SATA_TX_LVL_0_966_V },
	{  976, IMX6Q_GPR13_SATA_TX_LVL_0_976_V },
	{  986, IMX6Q_GPR13_SATA_TX_LVL_0_986_V },
	{  996, IMX6Q_GPR13_SATA_TX_LVL_0_996_V },
	{ 1005, IMX6Q_GPR13_SATA_TX_LVL_1_005_V },
	{ 1015, IMX6Q_GPR13_SATA_TX_LVL_1_015_V },
	{ 1025, IMX6Q_GPR13_SATA_TX_LVL_1_025_V },
	{ 1035, IMX6Q_GPR13_SATA_TX_LVL_1_035_V },
	{ 1045, IMX6Q_GPR13_SATA_TX_LVL_1_045_V },
	{ 1054, IMX6Q_GPR13_SATA_TX_LVL_1_054_V },
	{ 1064, IMX6Q_GPR13_SATA_TX_LVL_1_064_V },
	{ 1074, IMX6Q_GPR13_SATA_TX_LVL_1_074_V },
	{ 1084, IMX6Q_GPR13_SATA_TX_LVL_1_084_V },
	{ 1094, IMX6Q_GPR13_SATA_TX_LVL_1_094_V },
	{ 1104, IMX6Q_GPR13_SATA_TX_LVL_1_104_V },
	{ 1113, IMX6Q_GPR13_SATA_TX_LVL_1_113_V },
	{ 1123, IMX6Q_GPR13_SATA_TX_LVL_1_123_V },
	{ 1133, IMX6Q_GPR13_SATA_TX_LVL_1_133_V },
	{ 1143, IMX6Q_GPR13_SATA_TX_LVL_1_143_V },
	{ 1152, IMX6Q_GPR13_SATA_TX_LVL_1_152_V },
	{ 1162, IMX6Q_GPR13_SATA_TX_LVL_1_162_V },
	{ 1172, IMX6Q_GPR13_SATA_TX_LVL_1_172_V },
	{ 1182, IMX6Q_GPR13_SATA_TX_LVL_1_182_V },
	{ 1191, IMX6Q_GPR13_SATA_TX_LVL_1_191_V },
	{ 1201, IMX6Q_GPR13_SATA_TX_LVL_1_201_V },
	{ 1211, IMX6Q_GPR13_SATA_TX_LVL_1_211_V },
	{ 1221, IMX6Q_GPR13_SATA_TX_LVL_1_221_V },
	{ 1230, IMX6Q_GPR13_SATA_TX_LVL_1_230_V },
	{ 1240, IMX6Q_GPR13_SATA_TX_LVL_1_240_V }
};

static const struct reg_value gpr13_tx_boost[] = {
	{    0, IMX6Q_GPR13_SATA_TX_BOOST_0_00_DB },
	{  370, IMX6Q_GPR13_SATA_TX_BOOST_0_37_DB },
	{  740, IMX6Q_GPR13_SATA_TX_BOOST_0_74_DB },
	{ 1110, IMX6Q_GPR13_SATA_TX_BOOST_1_11_DB },
	{ 1480, IMX6Q_GPR13_SATA_TX_BOOST_1_48_DB },
	{ 1850, IMX6Q_GPR13_SATA_TX_BOOST_1_85_DB },
	{ 2220, IMX6Q_GPR13_SATA_TX_BOOST_2_22_DB },
	{ 2590, IMX6Q_GPR13_SATA_TX_BOOST_2_59_DB },
	{ 2960, IMX6Q_GPR13_SATA_TX_BOOST_2_96_DB },
	{ 3330, IMX6Q_GPR13_SATA_TX_BOOST_3_33_DB },
	{ 3700, IMX6Q_GPR13_SATA_TX_BOOST_3_70_DB },
	{ 4070, IMX6Q_GPR13_SATA_TX_BOOST_4_07_DB },
	{ 4440, IMX6Q_GPR13_SATA_TX_BOOST_4_44_DB },
	{ 4810, IMX6Q_GPR13_SATA_TX_BOOST_4_81_DB },
	{ 5280, IMX6Q_GPR13_SATA_TX_BOOST_5_28_DB },
	{ 5750, IMX6Q_GPR13_SATA_TX_BOOST_5_75_DB }
};

static const struct reg_value gpr13_tx_atten[] = {
	{  8, IMX6Q_GPR13_SATA_TX_ATTEN_8_16 },
	{  9, IMX6Q_GPR13_SATA_TX_ATTEN_9_16 },
	{ 10, IMX6Q_GPR13_SATA_TX_ATTEN_10_16 },
	{ 12, IMX6Q_GPR13_SATA_TX_ATTEN_12_16 },
	{ 14, IMX6Q_GPR13_SATA_TX_ATTEN_14_16 },
	{ 16, IMX6Q_GPR13_SATA_TX_ATTEN_16_16 },
};

static const struct reg_value gpr13_rx_eq[] = {
	{  500, IMX6Q_GPR13_SATA_RX_EQ_VAL_0_5_DB },
	{ 1000, IMX6Q_GPR13_SATA_RX_EQ_VAL_1_0_DB },
	{ 1500, IMX6Q_GPR13_SATA_RX_EQ_VAL_1_5_DB },
	{ 2000, IMX6Q_GPR13_SATA_RX_EQ_VAL_2_0_DB },
	{ 2500, IMX6Q_GPR13_SATA_RX_EQ_VAL_2_5_DB },
	{ 3000, IMX6Q_GPR13_SATA_RX_EQ_VAL_3_0_DB },
	{ 3500, IMX6Q_GPR13_SATA_RX_EQ_VAL_3_5_DB },
	{ 4000, IMX6Q_GPR13_SATA_RX_EQ_VAL_4_0_DB },
};

static const struct reg_property gpr13_props[] = {
	{
		.name = "fsl,transmit-level-mV",
		.values = gpr13_tx_level,
		.num_values = ARRAY_SIZE(gpr13_tx_level),
		.def_value = IMX6Q_GPR13_SATA_TX_LVL_1_025_V,
	}, {
		.name = "fsl,transmit-boost-mdB",
		.values = gpr13_tx_boost,
		.num_values = ARRAY_SIZE(gpr13_tx_boost),
		.def_value = IMX6Q_GPR13_SATA_TX_BOOST_3_33_DB,
	}, {
		.name = "fsl,transmit-atten-16ths",
		.values = gpr13_tx_atten,
		.num_values = ARRAY_SIZE(gpr13_tx_atten),
		.def_value = IMX6Q_GPR13_SATA_TX_ATTEN_9_16,
	}, {
		.name = "fsl,receive-eq-mdB",
		.values = gpr13_rx_eq,
		.num_values = ARRAY_SIZE(gpr13_rx_eq),
		.def_value = IMX6Q_GPR13_SATA_RX_EQ_VAL_3_0_DB,
	}, {
		.name = "fsl,no-spread-spectrum",
		.def_value = IMX6Q_GPR13_SATA_MPLL_SS_EN,
		.set_value = 0,
	},
};

static u32 imx_ahci_parse_props(struct device *dev,
				const struct reg_property *prop, size_t num)
{
	struct device_node *np = dev->of_node;
	u32 reg_value = 0;
	int i, j;

	for (i = 0; i < num; i++, prop++) {
		u32 of_val;

		if (prop->num_values == 0) {
			if (of_property_read_bool(np, prop->name))
				reg_value |= prop->set_value;
			else
				reg_value |= prop->def_value;
			continue;
		}

		if (of_property_read_u32(np, prop->name, &of_val)) {
			dev_info(dev, "%s not specified, using %08x\n",
				prop->name, prop->def_value);
			reg_value |= prop->def_value;
			continue;
		}

		for (j = 0; j < prop->num_values; j++) {
			if (prop->values[j].of_value == of_val) {
				dev_info(dev, "%s value %u, using %08x\n",
					prop->name, of_val, prop->values[j].reg_value);
				reg_value |= prop->values[j].reg_value;
				break;
			}
		}

		if (j == prop->num_values) {
			dev_err(dev, "DT property %s is not a valid value\n",
				prop->name);
			reg_value |= prop->def_value;
		}
	}

	return reg_value;
}

static struct scsi_host_template ahci_platform_sht = {
	AHCI_SHT(DRV_NAME),
};

static int imx8_sata_probe(struct device *dev, struct imx_ahci_priv *imxpriv)
{
	int ret;
	struct resource *phy_res;
	struct platform_device *pdev = imxpriv->ahci_pdev;
	struct device_node *np = dev->of_node;

	if (of_property_read_u32(np, "fsl,phy-imp", &imxpriv->imped_ratio)) {
		/*
		 * Regarding to the differnet Hw designs,
		 * Set the impedance ratio to 0x6c when 85OHM is used.
		 * Keep it to default value 0x80, when 100OHM is used.
		 */
		dev_info(dev, "phy impedance ratio is not specified.\n");
		imxpriv->imped_ratio = IMX8QM_SATA_PHY_IMPED_RATIO_85OHM;
	}
	phy_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "phy");
	if (phy_res) {
		imxpriv->phy_base = devm_ioremap(dev, phy_res->start,
					resource_size(phy_res));
		if (!imxpriv->phy_base) {
			dev_err(dev, "error with ioremap\n");
			return -ENOMEM;
		}
	} else {
		dev_err(dev, "missing *phy* reg region.\n");
		return -ENOMEM;
	}
	imxpriv->gpr =
		 syscon_regmap_lookup_by_phandle(np, "hsio");
	if (IS_ERR(imxpriv->gpr)) {
		dev_err(dev, "unable to find gpr registers\n");
		return PTR_ERR(imxpriv->gpr);
	}
	imxpriv->epcs_tx_clk = devm_clk_get(dev, "epcs_tx");
	if (IS_ERR(imxpriv->epcs_tx_clk)) {
		dev_err(dev, "can't get sata_epcs tx clock.\n");
		return PTR_ERR(imxpriv->epcs_tx_clk);
	}

	imxpriv->epcs_rx_clk = devm_clk_get(dev, "epcs_rx");
	if (IS_ERR(imxpriv->epcs_rx_clk)) {
		dev_err(dev, "can't get sata_epcs rx clock.\n");
		return PTR_ERR(imxpriv->epcs_rx_clk);
	}

	imxpriv->phy_pclk0 = devm_clk_get(dev, "phy_pclk0");
	if (IS_ERR(imxpriv->phy_pclk0)) {
		dev_err(dev, "can't get sata_phy_pclk0 clock.\n");
		return PTR_ERR(imxpriv->phy_pclk0);
	}

	imxpriv->phy_pclk1 = devm_clk_get(dev, "phy_pclk1");
	if (IS_ERR(imxpriv->phy_pclk1)) {
		dev_err(dev, "can't get sata_phy_pclk1 clock.\n");
		return PTR_ERR(imxpriv->phy_pclk1);
	}

	imxpriv->phy_apbclk = devm_clk_get(dev, "phy_apbclk");
	if (IS_ERR(imxpriv->phy_apbclk)) {
		dev_err(dev, "can't get sata_phy_apbclk clock.\n");
		return PTR_ERR(imxpriv->phy_apbclk);
	}

	/* Fetch GPIO, then enable the external OSC */
	imxpriv->clkreq_gpio = of_get_named_gpio(np, "clkreq-gpio", 0);
	if (gpio_is_valid(imxpriv->clkreq_gpio)) {
		ret = devm_gpio_request_one(dev, imxpriv->clkreq_gpio,
					    GPIOF_OUT_INIT_LOW,
					    "SATA CLKREQ");
		if (ret == -EBUSY) {
			dev_info(dev, "clkreq had been initialized.\n");
		} else if (ret) {
			dev_err(dev, "%d unable to get clkreq.\n", ret);
			return ret;
		}
	} else if (imxpriv->clkreq_gpio == -EPROBE_DEFER) {
		return imxpriv->clkreq_gpio;
	}

	return 0;
}

static int imx_ahci_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	const struct of_device_id *of_id;
	struct ahci_host_priv *hpriv;
	struct imx_ahci_priv *imxpriv;
	unsigned int reg_val;
	int ret;

	of_id = of_match_device(imx_ahci_of_match, dev);
	if (!of_id)
		return -EINVAL;

	imxpriv = devm_kzalloc(dev, sizeof(*imxpriv), GFP_KERNEL);
	if (!imxpriv)
		return -ENOMEM;

	imxpriv->ahci_pdev = pdev;
	imxpriv->no_device = false;
	imxpriv->first_time = true;
	imxpriv->type = (enum ahci_imx_type)of_id->data;

	imxpriv->sata_clk = devm_clk_get(dev, "sata");
	if (IS_ERR(imxpriv->sata_clk)) {
		dev_err(dev, "can't get sata clock.\n");
		return PTR_ERR(imxpriv->sata_clk);
	}

	imxpriv->sata_ref_clk = devm_clk_get(dev, "sata_ref");
	if (IS_ERR(imxpriv->sata_ref_clk)) {
		dev_err(dev, "can't get sata_ref clock.\n");
		return PTR_ERR(imxpriv->sata_ref_clk);
	}

	if (imxpriv->type == AHCI_IMX6Q || imxpriv->type == AHCI_IMX6QP) {
		u32 reg_value;

		imxpriv->gpr = syscon_regmap_lookup_by_compatible(
							"fsl,imx6q-iomuxc-gpr");
		if (IS_ERR(imxpriv->gpr)) {
			dev_err(dev,
				"failed to find fsl,imx6q-iomux-gpr regmap\n");
			return PTR_ERR(imxpriv->gpr);
		}

		reg_value = imx_ahci_parse_props(dev, gpr13_props,
						 ARRAY_SIZE(gpr13_props));

		imxpriv->phy_params =
				   IMX6Q_GPR13_SATA_RX_LOS_LVL_SATA2M |
				   IMX6Q_GPR13_SATA_RX_DPLL_MODE_2P_4F |
				   IMX6Q_GPR13_SATA_SPD_MODE_3P0G |
				   reg_value;
	} else if (imxpriv->type == AHCI_IMX8QM) {
		ret =  imx8_sata_probe(dev, imxpriv);
		if (ret)
			return ret;
	}

	hpriv = ahci_platform_get_resources(pdev);
	if (IS_ERR(hpriv))
		return PTR_ERR(hpriv);

	hpriv->plat_data = imxpriv;

	ret = clk_prepare_enable(imxpriv->sata_clk);
	if (ret)
		return ret;

	ret = imx_sata_enable(hpriv);
	if (ret)
		goto disable_clk;

	/*
	 * Configure the HWINIT bits of the HOST_CAP and HOST_PORTS_IMPL,
	 * and IP vendor specific register IMX_TIMER1MS.
	 * Configure CAP_SSS (support stagered spin up).
	 * Implement the port0.
	 * Get the ahb clock rate, and configure the TIMER1MS register.
	 */
	reg_val = readl(hpriv->mmio + HOST_CAP);
	if (!(reg_val & HOST_CAP_SSS)) {
		reg_val |= HOST_CAP_SSS;
		writel(reg_val, hpriv->mmio + HOST_CAP);
	}
	reg_val = readl(hpriv->mmio + HOST_PORTS_IMPL);
	if (!(reg_val & 0x1)) {
		reg_val |= 0x1;
		writel(reg_val, hpriv->mmio + HOST_PORTS_IMPL);
	}

	imxpriv->ahb_clk = devm_clk_get(dev, "ahb");
	if (IS_ERR(imxpriv->ahb_clk)) {
		dev_info(dev, "no ahb clock.\n");
	} else {
		/*
		 * AHB clock is only used to configure the vendor specified
		 * TIMER1MS register. Set it if the AHB clock is defined.
		 */
		reg_val = clk_get_rate(imxpriv->ahb_clk) / 1000;
		writel(reg_val, hpriv->mmio + IMX_TIMER1MS);
	}

	/*
	* Due to IP bug on the Synopsis 3.00 SATA version,
	* which is present on mx6q, and not on mx53,
	* we should use sg_tablesize = 1 for reliable operation
	*/
	if (imxpriv->type == AHCI_IMX6Q || imxpriv->type == AHCI_IMX6QP) {
		dma_addr_t dma;

		ahci_platform_sht.sg_tablesize = 1;

		sg_io_buffer_hack = dma_alloc_coherent(NULL, 0x10000,
				&dma, GFP_KERNEL);
		if (!sg_io_buffer_hack) {
			ret = -ENOMEM;
			goto disable_sata;
		}
	}

	ret = ahci_platform_init_host(pdev, hpriv, &ahci_imx_port_info,
				      &ahci_platform_sht);
	if (ret)
		goto disable_sata;

	return 0;

disable_sata:
	imx_sata_disable(hpriv);
disable_clk:
	clk_disable_unprepare(imxpriv->sata_clk);
	return ret;
}

static void ahci_imx_host_stop(struct ata_host *host)
{
	struct ahci_host_priv *hpriv = host->private_data;
	struct imx_ahci_priv *imxpriv = hpriv->plat_data;

	imx_sata_disable(hpriv);
	clk_disable_unprepare(imxpriv->sata_clk);
}

#ifdef CONFIG_PM_SLEEP
static int imx_ahci_suspend(struct device *dev)
{
	struct ata_host *host = dev_get_drvdata(dev);
	struct ahci_host_priv *hpriv = host->private_data;
	int ret;

	ret = ahci_platform_suspend_host(dev);
	if (ret)
		return ret;

	imx_sata_disable(hpriv);

	return 0;
}

static int imx_ahci_resume(struct device *dev)
{
	struct ata_host *host = dev_get_drvdata(dev);
	struct ahci_host_priv *hpriv = host->private_data;
	int ret;

	ret = imx_sata_enable(hpriv);
	if (ret)
		return ret;

	return ahci_platform_resume_host(dev);
}
#endif

static SIMPLE_DEV_PM_OPS(ahci_imx_pm_ops, imx_ahci_suspend, imx_ahci_resume);

static struct platform_driver imx_ahci_driver = {
	.probe = imx_ahci_probe,
	.remove = ata_platform_remove_one,
	.driver = {
		.name = DRV_NAME,
		.of_match_table = imx_ahci_of_match,
		.pm = &ahci_imx_pm_ops,
	},
};
module_platform_driver(imx_ahci_driver);

MODULE_DESCRIPTION("Freescale i.MX AHCI SATA platform driver");
MODULE_AUTHOR("Richard Zhu <Hong-Xing.Zhu@freescale.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ahci:imx");