/*

   * Copyright 2012-2014 Freescale Semiconductor, Inc.

   * Copyright (C) 2012 Marek Vasut <marex@denx.de>
   * on behalf of DENX Software Engineering GmbH
   *
   * The code contained herein is licensed under the GNU General Public
   * License. You may obtain a copy of the GNU General Public License
   * Version 2 or later at the following locations:
   *
   * http://www.opensource.org/licenses/gpl-license.html
   * http://www.gnu.org/copyleft/gpl.html
   */
  
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/platform_device.h>
  #include <linux/clk.h>
  #include <linux/usb/otg.h>
  #include <linux/stmp_device.h>
  #include <linux/delay.h>
  #include <linux/err.h>
  #include <linux/io.h>

  #include <linux/of_device.h>

  #include <linux/regmap.h>
  #include <linux/mfd/syscon.h>

  
  #define DRIVER_NAME "mxs_phy"
  
  #define HW_USBPHY_PWD				0x00
  #define HW_USBPHY_CTRL				0x30
  #define HW_USBPHY_CTRL_SET			0x34
  #define HW_USBPHY_CTRL_CLR			0x38

  #define HW_USBPHY_DEBUG_SET			0x54
  #define HW_USBPHY_DEBUG_CLR			0x58

  #define HW_USBPHY_IP				0x90
  #define HW_USBPHY_IP_SET			0x94
  #define HW_USBPHY_IP_CLR			0x98

  #define BM_USBPHY_CTRL_SFTRST			BIT(31)
  #define BM_USBPHY_CTRL_CLKGATE			BIT(30)

  #define BM_USBPHY_CTRL_ENAUTOSET_USBCLKS	BIT(26)
  #define BM_USBPHY_CTRL_ENAUTOCLR_USBCLKGATE	BIT(25)

  #define BM_USBPHY_CTRL_ENVBUSCHG_WKUP		BIT(23)
  #define BM_USBPHY_CTRL_ENIDCHG_WKUP		BIT(22)
  #define BM_USBPHY_CTRL_ENDPDMCHG_WKUP		BIT(21)

  #define BM_USBPHY_CTRL_ENAUTOCLR_PHY_PWD	BIT(20)
  #define BM_USBPHY_CTRL_ENAUTOCLR_CLKGATE	BIT(19)
  #define BM_USBPHY_CTRL_ENAUTO_PWRON_PLL		BIT(18)

  #define BM_USBPHY_CTRL_ENUTMILEVEL3		BIT(15)
  #define BM_USBPHY_CTRL_ENUTMILEVEL2		BIT(14)
  #define BM_USBPHY_CTRL_ENHOSTDISCONDETECT	BIT(1)

  #define BM_USBPHY_IP_FIX                       (BIT(17) | BIT(18))

  #define BM_USBPHY_DEBUG_CLKGATE			BIT(30)
  
  /* Anatop Registers */

  #define ANADIG_ANA_MISC0			0x150
  #define ANADIG_ANA_MISC0_SET			0x154
  #define ANADIG_ANA_MISC0_CLR			0x158

  #define ANADIG_USB1_VBUS_DET_STAT		0x1c0
  #define ANADIG_USB2_VBUS_DET_STAT		0x220
  
  #define ANADIG_USB1_LOOPBACK_SET		0x1e4
  #define ANADIG_USB1_LOOPBACK_CLR		0x1e8
  #define ANADIG_USB2_LOOPBACK_SET		0x244
  #define ANADIG_USB2_LOOPBACK_CLR		0x248

  #define BM_ANADIG_ANA_MISC0_STOP_MODE_CONFIG	BIT(12)
  #define BM_ANADIG_ANA_MISC0_STOP_MODE_CONFIG_SL BIT(11)

  #define BM_ANADIG_USB1_VBUS_DET_STAT_VBUS_VALID	BIT(3)
  #define BM_ANADIG_USB2_VBUS_DET_STAT_VBUS_VALID	BIT(3)
  
  #define BM_ANADIG_USB1_LOOPBACK_UTMI_DIG_TST1	BIT(2)
  #define BM_ANADIG_USB1_LOOPBACK_TSTI_TX_EN	BIT(5)
  #define BM_ANADIG_USB2_LOOPBACK_UTMI_DIG_TST1	BIT(2)
  #define BM_ANADIG_USB2_LOOPBACK_TSTI_TX_EN	BIT(5)

  #define to_mxs_phy(p) container_of((p), struct mxs_phy, phy)
  
  /* Do disconnection between PHY and controller without vbus */
  #define MXS_PHY_DISCONNECT_LINE_WITHOUT_VBUS	BIT(0)
  
  /*
   * The PHY will be in messy if there is a wakeup after putting
   * bus to suspend (set portsc.suspendM) but before setting PHY to low
   * power mode (set portsc.phcd).
   */
  #define MXS_PHY_ABNORMAL_IN_SUSPEND		BIT(1)
  
  /*
   * The SOF sends too fast after resuming, it will cause disconnection
   * between host and high speed device.
   */
  #define MXS_PHY_SENDING_SOF_TOO_FAST		BIT(2)

  /*
   * IC has bug fixes logic, they include
   * MXS_PHY_ABNORMAL_IN_SUSPEND and MXS_PHY_SENDING_SOF_TOO_FAST
   * which are described at above flags, the RTL will handle it
   * according to different versions.
   */
  #define MXS_PHY_NEED_IP_FIX			BIT(3)

  struct mxs_phy_data {
  	unsigned int flags;
  };
  
  static const struct mxs_phy_data imx23_phy_data = {
  	.flags = MXS_PHY_ABNORMAL_IN_SUSPEND | MXS_PHY_SENDING_SOF_TOO_FAST,
  };
  
  static const struct mxs_phy_data imx6q_phy_data = {
  	.flags = MXS_PHY_SENDING_SOF_TOO_FAST |

  		MXS_PHY_DISCONNECT_LINE_WITHOUT_VBUS |
  		MXS_PHY_NEED_IP_FIX,

  };
  
  static const struct mxs_phy_data imx6sl_phy_data = {

  	.flags = MXS_PHY_DISCONNECT_LINE_WITHOUT_VBUS |
  		MXS_PHY_NEED_IP_FIX,

  };

  static const struct mxs_phy_data vf610_phy_data = {
  	.flags = MXS_PHY_DISCONNECT_LINE_WITHOUT_VBUS |
  		MXS_PHY_NEED_IP_FIX,
  };

  static const struct mxs_phy_data imx6sx_phy_data = {
  	.flags = MXS_PHY_DISCONNECT_LINE_WITHOUT_VBUS |
  		MXS_PHY_NEED_IP_FIX,
  };

  static const struct of_device_id mxs_phy_dt_ids[] = {

  	{ .compatible = "fsl,imx6sx-usbphy", .data = &imx6sx_phy_data, },

  	{ .compatible = "fsl,imx6sl-usbphy", .data = &imx6sl_phy_data, },
  	{ .compatible = "fsl,imx6q-usbphy", .data = &imx6q_phy_data, },
  	{ .compatible = "fsl,imx23-usbphy", .data = &imx23_phy_data, },

  	{ .compatible = "fsl,vf610-usbphy", .data = &vf610_phy_data, },

  	{ /* sentinel */ }
  };
  MODULE_DEVICE_TABLE(of, mxs_phy_dt_ids);

  struct mxs_phy {
  	struct usb_phy phy;
  	struct clk *clk;

  	const struct mxs_phy_data *data;

  	struct regmap *regmap_anatop;

  	int port_id;

  };

  static inline bool is_imx6q_phy(struct mxs_phy *mxs_phy)
  {
  	return mxs_phy->data == &imx6q_phy_data;
  }
  
  static inline bool is_imx6sl_phy(struct mxs_phy *mxs_phy)
  {
  	return mxs_phy->data == &imx6sl_phy_data;
  }

  /*
   * PHY needs some 32K cycles to switch from 32K clock to
   * bus (such as AHB/AXI, etc) clock.
   */
  static void mxs_phy_clock_switch_delay(void)
  {
  	usleep_range(300, 400);
  }

  static int mxs_phy_hw_init(struct mxs_phy *mxs_phy)

  {

  	int ret;

  	void __iomem *base = mxs_phy->phy.io_priv;

  	ret = stmp_reset_block(base + HW_USBPHY_CTRL);
  	if (ret)
  		return ret;

  
  	/* Power up the PHY */

  	writel(0, base + HW_USBPHY_PWD);

  	/*
  	 * USB PHY Ctrl Setting
  	 * - Auto clock/power on
  	 * - Enable full/low speed support
  	 */
  	writel(BM_USBPHY_CTRL_ENAUTOSET_USBCLKS |
  		BM_USBPHY_CTRL_ENAUTOCLR_USBCLKGATE |
  		BM_USBPHY_CTRL_ENAUTOCLR_PHY_PWD |
  		BM_USBPHY_CTRL_ENAUTOCLR_CLKGATE |
  		BM_USBPHY_CTRL_ENAUTO_PWRON_PLL |
  		BM_USBPHY_CTRL_ENUTMILEVEL2 |
  		BM_USBPHY_CTRL_ENUTMILEVEL3,

  	       base + HW_USBPHY_CTRL_SET);

  	if (mxs_phy->data->flags & MXS_PHY_NEED_IP_FIX)
  		writel(BM_USBPHY_IP_FIX, base + HW_USBPHY_IP_SET);

  	return 0;

  }

  /* Return true if the vbus is there */
  static bool mxs_phy_get_vbus_status(struct mxs_phy *mxs_phy)
  {
  	unsigned int vbus_value;
  
  	if (mxs_phy->port_id == 0)
  		regmap_read(mxs_phy->regmap_anatop,
  			ANADIG_USB1_VBUS_DET_STAT,
  			&vbus_value);
  	else if (mxs_phy->port_id == 1)
  		regmap_read(mxs_phy->regmap_anatop,
  			ANADIG_USB2_VBUS_DET_STAT,
  			&vbus_value);
  
  	if (vbus_value & BM_ANADIG_USB1_VBUS_DET_STAT_VBUS_VALID)
  		return true;
  	else
  		return false;
  }
  
  static void __mxs_phy_disconnect_line(struct mxs_phy *mxs_phy, bool disconnect)
  {
  	void __iomem *base = mxs_phy->phy.io_priv;
  	u32 reg;
  
  	if (disconnect)
  		writel_relaxed(BM_USBPHY_DEBUG_CLKGATE,
  			base + HW_USBPHY_DEBUG_CLR);
  
  	if (mxs_phy->port_id == 0) {
  		reg = disconnect ? ANADIG_USB1_LOOPBACK_SET
  			: ANADIG_USB1_LOOPBACK_CLR;
  		regmap_write(mxs_phy->regmap_anatop, reg,
  			BM_ANADIG_USB1_LOOPBACK_UTMI_DIG_TST1 |
  			BM_ANADIG_USB1_LOOPBACK_TSTI_TX_EN);
  	} else if (mxs_phy->port_id == 1) {
  		reg = disconnect ? ANADIG_USB2_LOOPBACK_SET
  			: ANADIG_USB2_LOOPBACK_CLR;
  		regmap_write(mxs_phy->regmap_anatop, reg,
  			BM_ANADIG_USB2_LOOPBACK_UTMI_DIG_TST1 |
  			BM_ANADIG_USB2_LOOPBACK_TSTI_TX_EN);
  	}
  
  	if (!disconnect)
  		writel_relaxed(BM_USBPHY_DEBUG_CLKGATE,
  			base + HW_USBPHY_DEBUG_SET);
  
  	/* Delay some time, and let Linestate be SE0 for controller */
  	if (disconnect)
  		usleep_range(500, 1000);
  }
  
  static void mxs_phy_disconnect_line(struct mxs_phy *mxs_phy, bool on)
  {
  	bool vbus_is_on = false;
  
  	/* If the SoCs don't need to disconnect line without vbus, quit */
  	if (!(mxs_phy->data->flags & MXS_PHY_DISCONNECT_LINE_WITHOUT_VBUS))
  		return;
  
  	/* If the SoCs don't have anatop, quit */
  	if (!mxs_phy->regmap_anatop)
  		return;
  
  	vbus_is_on = mxs_phy_get_vbus_status(mxs_phy);
  
  	if (on && !vbus_is_on)
  		__mxs_phy_disconnect_line(mxs_phy, true);
  	else
  		__mxs_phy_disconnect_line(mxs_phy, false);
  
  }

  static int mxs_phy_init(struct usb_phy *phy)
  {

  	int ret;

  	struct mxs_phy *mxs_phy = to_mxs_phy(phy);

  	mxs_phy_clock_switch_delay();

  	ret = clk_prepare_enable(mxs_phy->clk);
  	if (ret)
  		return ret;

  	return mxs_phy_hw_init(mxs_phy);

  }
  
  static void mxs_phy_shutdown(struct usb_phy *phy)
  {
  	struct mxs_phy *mxs_phy = to_mxs_phy(phy);

  	writel(BM_USBPHY_CTRL_CLKGATE,
  	       phy->io_priv + HW_USBPHY_CTRL_SET);

  
  	clk_disable_unprepare(mxs_phy->clk);
  }

  static int mxs_phy_suspend(struct usb_phy *x, int suspend)
  {

  	int ret;

  	struct mxs_phy *mxs_phy = to_mxs_phy(x);
  
  	if (suspend) {

  		writel(0xffffffff, x->io_priv + HW_USBPHY_PWD);
  		writel(BM_USBPHY_CTRL_CLKGATE,
  		       x->io_priv + HW_USBPHY_CTRL_SET);

  		clk_disable_unprepare(mxs_phy->clk);
  	} else {

  		mxs_phy_clock_switch_delay();

  		ret = clk_prepare_enable(mxs_phy->clk);
  		if (ret)
  			return ret;

  		writel(BM_USBPHY_CTRL_CLKGATE,
  		       x->io_priv + HW_USBPHY_CTRL_CLR);
  		writel(0, x->io_priv + HW_USBPHY_PWD);

  	}
  
  	return 0;
  }

  static int mxs_phy_set_wakeup(struct usb_phy *x, bool enabled)
  {
  	struct mxs_phy *mxs_phy = to_mxs_phy(x);
  	u32 value = BM_USBPHY_CTRL_ENVBUSCHG_WKUP |
  			BM_USBPHY_CTRL_ENDPDMCHG_WKUP |
  				BM_USBPHY_CTRL_ENIDCHG_WKUP;
  	if (enabled) {
  		mxs_phy_disconnect_line(mxs_phy, true);
  		writel_relaxed(value, x->io_priv + HW_USBPHY_CTRL_SET);
  	} else {
  		writel_relaxed(value, x->io_priv + HW_USBPHY_CTRL_CLR);
  		mxs_phy_disconnect_line(mxs_phy, false);
  	}
  
  	return 0;
  }

  static int mxs_phy_on_connect(struct usb_phy *phy,
  		enum usb_device_speed speed)

  {

  	dev_dbg(phy->dev, "%s device has connected
  ",
  		(speed == USB_SPEED_HIGH) ? "HS" : "FS/LS");

  	if (speed == USB_SPEED_HIGH)

  		writel(BM_USBPHY_CTRL_ENHOSTDISCONDETECT,
  		       phy->io_priv + HW_USBPHY_CTRL_SET);

  
  	return 0;
  }

  static int mxs_phy_on_disconnect(struct usb_phy *phy,
  		enum usb_device_speed speed)

  {

  	dev_dbg(phy->dev, "%s device has disconnected
  ",
  		(speed == USB_SPEED_HIGH) ? "HS" : "FS/LS");

  	if (speed == USB_SPEED_HIGH)

  		writel(BM_USBPHY_CTRL_ENHOSTDISCONDETECT,
  		       phy->io_priv + HW_USBPHY_CTRL_CLR);

  
  	return 0;
  }
  
  static int mxs_phy_probe(struct platform_device *pdev)
  {
  	struct resource *res;
  	void __iomem *base;
  	struct clk *clk;
  	struct mxs_phy *mxs_phy;

  	int ret;

  	const struct of_device_id *of_id =
  			of_match_device(mxs_phy_dt_ids, &pdev->dev);

  	struct device_node *np = pdev->dev.of_node;

  
  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

  	base = devm_ioremap_resource(&pdev->dev, res);
  	if (IS_ERR(base))
  		return PTR_ERR(base);

  
  	clk = devm_clk_get(&pdev->dev, NULL);
  	if (IS_ERR(clk)) {
  		dev_err(&pdev->dev,
  			"can't get the clock, err=%ld", PTR_ERR(clk));
  		return PTR_ERR(clk);
  	}
  
  	mxs_phy = devm_kzalloc(&pdev->dev, sizeof(*mxs_phy), GFP_KERNEL);
  	if (!mxs_phy) {
  		dev_err(&pdev->dev, "Failed to allocate USB PHY structure!
  ");
  		return -ENOMEM;
  	}

  	/* Some SoCs don't have anatop registers */
  	if (of_get_property(np, "fsl,anatop", NULL)) {
  		mxs_phy->regmap_anatop = syscon_regmap_lookup_by_phandle
  			(np, "fsl,anatop");
  		if (IS_ERR(mxs_phy->regmap_anatop)) {
  			dev_dbg(&pdev->dev,
  				"failed to find regmap for anatop
  ");
  			return PTR_ERR(mxs_phy->regmap_anatop);
  		}
  	}

  	ret = of_alias_get_id(np, "usbphy");
  	if (ret < 0)
  		dev_dbg(&pdev->dev, "failed to get alias id, errno %d
  ", ret);
  	mxs_phy->port_id = ret;

  	mxs_phy->phy.io_priv		= base;
  	mxs_phy->phy.dev		= &pdev->dev;
  	mxs_phy->phy.label		= DRIVER_NAME;
  	mxs_phy->phy.init		= mxs_phy_init;
  	mxs_phy->phy.shutdown		= mxs_phy_shutdown;

  	mxs_phy->phy.set_suspend	= mxs_phy_suspend;

  	mxs_phy->phy.notify_connect	= mxs_phy_on_connect;
  	mxs_phy->phy.notify_disconnect	= mxs_phy_on_disconnect;

  	mxs_phy->phy.type		= USB_PHY_TYPE_USB2;

  	mxs_phy->phy.set_wakeup		= mxs_phy_set_wakeup;

  	mxs_phy->clk = clk;

  	mxs_phy->data = of_id->data;

  	platform_set_drvdata(pdev, mxs_phy);

  	device_set_wakeup_capable(&pdev->dev, true);

  	ret = usb_add_phy_dev(&mxs_phy->phy);
  	if (ret)
  		return ret;

  	return 0;
  }

  static int mxs_phy_remove(struct platform_device *pdev)

  {

  	struct mxs_phy *mxs_phy = platform_get_drvdata(pdev);
  
  	usb_remove_phy(&mxs_phy->phy);

  	return 0;
  }

  #ifdef CONFIG_PM_SLEEP
  static void mxs_phy_enable_ldo_in_suspend(struct mxs_phy *mxs_phy, bool on)
  {
  	unsigned int reg = on ? ANADIG_ANA_MISC0_SET : ANADIG_ANA_MISC0_CLR;
  
  	/* If the SoCs don't have anatop, quit */
  	if (!mxs_phy->regmap_anatop)
  		return;
  
  	if (is_imx6q_phy(mxs_phy))
  		regmap_write(mxs_phy->regmap_anatop, reg,
  			BM_ANADIG_ANA_MISC0_STOP_MODE_CONFIG);
  	else if (is_imx6sl_phy(mxs_phy))
  		regmap_write(mxs_phy->regmap_anatop,
  			reg, BM_ANADIG_ANA_MISC0_STOP_MODE_CONFIG_SL);
  }
  
  static int mxs_phy_system_suspend(struct device *dev)
  {
  	struct mxs_phy *mxs_phy = dev_get_drvdata(dev);
  
  	if (device_may_wakeup(dev))
  		mxs_phy_enable_ldo_in_suspend(mxs_phy, true);
  
  	return 0;
  }
  
  static int mxs_phy_system_resume(struct device *dev)
  {
  	struct mxs_phy *mxs_phy = dev_get_drvdata(dev);
  
  	if (device_may_wakeup(dev))
  		mxs_phy_enable_ldo_in_suspend(mxs_phy, false);
  
  	return 0;
  }
  #endif /* CONFIG_PM_SLEEP */
  
  static SIMPLE_DEV_PM_OPS(mxs_phy_pm, mxs_phy_system_suspend,
  		mxs_phy_system_resume);

  static struct platform_driver mxs_phy_driver = {
  	.probe = mxs_phy_probe,

  	.remove = mxs_phy_remove,

  	.driver = {
  		.name = DRIVER_NAME,
  		.owner	= THIS_MODULE,
  		.of_match_table = mxs_phy_dt_ids,

  		.pm = &mxs_phy_pm,

  	 },
  };
  
  static int __init mxs_phy_module_init(void)
  {
  	return platform_driver_register(&mxs_phy_driver);
  }
  postcore_initcall(mxs_phy_module_init);
  
  static void __exit mxs_phy_module_exit(void)
  {
  	platform_driver_unregister(&mxs_phy_driver);
  }
  module_exit(mxs_phy_module_exit);
  
  MODULE_ALIAS("platform:mxs-usb-phy");
  MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
  MODULE_AUTHOR("Richard Zhao <richard.zhao@freescale.com>");
  MODULE_DESCRIPTION("Freescale MXS USB PHY driver");
  MODULE_LICENSE("GPL");