/**
   * omap-usb-tll.c - The USB TLL driver for OMAP EHCI & OHCI
   *

   * Copyright (C) 2012-2013 Texas Instruments Incorporated - http://www.ti.com

   * Author: Keshava Munegowda <keshava_mgowda@ti.com>

   * Author: Roger Quadros <rogerq@ti.com>

   *
   * This program is free software: you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2  of
   * the License 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.
   *
   * 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/types.h>
  #include <linux/slab.h>
  #include <linux/spinlock.h>
  #include <linux/platform_device.h>
  #include <linux/clk.h>
  #include <linux/io.h>
  #include <linux/err.h>

  #include <linux/pm_runtime.h>

  #include <linux/platform_data/usb-omap.h>

  #include <linux/of.h>

  #include "omap-usb.h"

  #define USBTLL_DRIVER_NAME	"usbhs_tll"
  
  /* TLL Register Set */
  #define	OMAP_USBTLL_REVISION				(0x00)
  #define	OMAP_USBTLL_SYSCONFIG				(0x10)
  #define	OMAP_USBTLL_SYSCONFIG_CACTIVITY			(1 << 8)
  #define	OMAP_USBTLL_SYSCONFIG_SIDLEMODE			(1 << 3)
  #define	OMAP_USBTLL_SYSCONFIG_ENAWAKEUP			(1 << 2)
  #define	OMAP_USBTLL_SYSCONFIG_SOFTRESET			(1 << 1)
  #define	OMAP_USBTLL_SYSCONFIG_AUTOIDLE			(1 << 0)
  
  #define	OMAP_USBTLL_SYSSTATUS				(0x14)
  #define	OMAP_USBTLL_SYSSTATUS_RESETDONE			(1 << 0)
  
  #define	OMAP_USBTLL_IRQSTATUS				(0x18)
  #define	OMAP_USBTLL_IRQENABLE				(0x1C)
  
  #define	OMAP_TLL_SHARED_CONF				(0x30)
  #define	OMAP_TLL_SHARED_CONF_USB_90D_DDR_EN		(1 << 6)
  #define	OMAP_TLL_SHARED_CONF_USB_180D_SDR_EN		(1 << 5)
  #define	OMAP_TLL_SHARED_CONF_USB_DIVRATION		(1 << 2)
  #define	OMAP_TLL_SHARED_CONF_FCLK_REQ			(1 << 1)
  #define	OMAP_TLL_SHARED_CONF_FCLK_IS_ON			(1 << 0)
  
  #define	OMAP_TLL_CHANNEL_CONF(num)			(0x040 + 0x004 * num)
  #define OMAP_TLL_CHANNEL_CONF_FSLSMODE_SHIFT		24

  #define OMAP_TLL_CHANNEL_CONF_DRVVBUS			(1 << 16)
  #define OMAP_TLL_CHANNEL_CONF_CHRGVBUS			(1 << 15)

  #define	OMAP_TLL_CHANNEL_CONF_ULPINOBITSTUFF		(1 << 11)
  #define	OMAP_TLL_CHANNEL_CONF_ULPI_ULPIAUTOIDLE		(1 << 10)
  #define	OMAP_TLL_CHANNEL_CONF_UTMIAUTOIDLE		(1 << 9)
  #define	OMAP_TLL_CHANNEL_CONF_ULPIDDRMODE		(1 << 8)

  #define OMAP_TLL_CHANNEL_CONF_MODE_TRANSPARENT_UTMI	(2 << 1)

  #define OMAP_TLL_CHANNEL_CONF_CHANMODE_FSLS		(1 << 1)
  #define	OMAP_TLL_CHANNEL_CONF_CHANEN			(1 << 0)
  
  #define OMAP_TLL_FSLSMODE_6PIN_PHY_DAT_SE0		0x0
  #define OMAP_TLL_FSLSMODE_6PIN_PHY_DP_DM		0x1
  #define OMAP_TLL_FSLSMODE_3PIN_PHY			0x2
  #define OMAP_TLL_FSLSMODE_4PIN_PHY			0x3
  #define OMAP_TLL_FSLSMODE_6PIN_TLL_DAT_SE0		0x4
  #define OMAP_TLL_FSLSMODE_6PIN_TLL_DP_DM		0x5
  #define OMAP_TLL_FSLSMODE_3PIN_TLL			0x6
  #define OMAP_TLL_FSLSMODE_4PIN_TLL			0x7
  #define OMAP_TLL_FSLSMODE_2PIN_TLL_DAT_SE0		0xA
  #define OMAP_TLL_FSLSMODE_2PIN_DAT_DP_DM		0xB
  
  #define	OMAP_TLL_ULPI_FUNCTION_CTRL(num)		(0x804 + 0x100 * num)
  #define	OMAP_TLL_ULPI_INTERFACE_CTRL(num)		(0x807 + 0x100 * num)
  #define	OMAP_TLL_ULPI_OTG_CTRL(num)			(0x80A + 0x100 * num)
  #define	OMAP_TLL_ULPI_INT_EN_RISE(num)			(0x80D + 0x100 * num)
  #define	OMAP_TLL_ULPI_INT_EN_FALL(num)			(0x810 + 0x100 * num)
  #define	OMAP_TLL_ULPI_INT_STATUS(num)			(0x813 + 0x100 * num)
  #define	OMAP_TLL_ULPI_INT_LATCH(num)			(0x814 + 0x100 * num)
  #define	OMAP_TLL_ULPI_DEBUG(num)			(0x815 + 0x100 * num)
  #define	OMAP_TLL_ULPI_SCRATCH_REGISTER(num)		(0x816 + 0x100 * num)
  
  #define OMAP_REV2_TLL_CHANNEL_COUNT			2
  #define OMAP_TLL_CHANNEL_COUNT				3
  #define OMAP_TLL_CHANNEL_1_EN_MASK			(1 << 0)
  #define OMAP_TLL_CHANNEL_2_EN_MASK			(1 << 1)
  #define OMAP_TLL_CHANNEL_3_EN_MASK			(1 << 2)
  
  /* Values of USBTLL_REVISION - Note: these are not given in the TRM */
  #define OMAP_USBTLL_REV1		0x00000015	/* OMAP3 */
  #define OMAP_USBTLL_REV2		0x00000018	/* OMAP 3630 */
  #define OMAP_USBTLL_REV3		0x00000004	/* OMAP4 */

  #define OMAP_USBTLL_REV4		0x00000006	/* OMAP5 */

  
  #define is_ehci_tll_mode(x)	(x == OMAP_EHCI_PORT_MODE_TLL)

  /* only PHY and UNUSED modes don't need TLL */
  #define omap_usb_mode_needs_tll(x)	((x) != OMAP_USBHS_PORT_MODE_UNUSED &&\
  					 (x) != OMAP_EHCI_PORT_MODE_PHY)

  struct usbtll_omap {

  	int					nch;	/* num. of channels */

  	struct clk				**ch_clk;

  	void __iomem				*base;

  };
  
  /*-------------------------------------------------------------------------*/

  static const char usbtll_driver_name[] = USBTLL_DRIVER_NAME;
  static struct device	*tll_dev;

  static DEFINE_SPINLOCK(tll_lock);	/* serialize access to tll_dev */

  
  /*-------------------------------------------------------------------------*/
  
  static inline void usbtll_write(void __iomem *base, u32 reg, u32 val)
  {

  	writel_relaxed(val, base + reg);

  }
  
  static inline u32 usbtll_read(void __iomem *base, u32 reg)
  {

  	return readl_relaxed(base + reg);

  }
  
  static inline void usbtll_writeb(void __iomem *base, u8 reg, u8 val)
  {

  	writeb_relaxed(val, base + reg);

  }
  
  static inline u8 usbtll_readb(void __iomem *base, u8 reg)
  {

  	return readb_relaxed(base + reg);

  }
  
  /*-------------------------------------------------------------------------*/
  
  static bool is_ohci_port(enum usbhs_omap_port_mode pmode)
  {
  	switch (pmode) {
  	case OMAP_OHCI_PORT_MODE_PHY_6PIN_DATSE0:
  	case OMAP_OHCI_PORT_MODE_PHY_6PIN_DPDM:
  	case OMAP_OHCI_PORT_MODE_PHY_3PIN_DATSE0:
  	case OMAP_OHCI_PORT_MODE_PHY_4PIN_DPDM:
  	case OMAP_OHCI_PORT_MODE_TLL_6PIN_DATSE0:
  	case OMAP_OHCI_PORT_MODE_TLL_6PIN_DPDM:
  	case OMAP_OHCI_PORT_MODE_TLL_3PIN_DATSE0:
  	case OMAP_OHCI_PORT_MODE_TLL_4PIN_DPDM:
  	case OMAP_OHCI_PORT_MODE_TLL_2PIN_DATSE0:
  	case OMAP_OHCI_PORT_MODE_TLL_2PIN_DPDM:
  		return true;
  
  	default:
  		return false;
  	}
  }
  
  /*
   * convert the port-mode enum to a value we can use in the FSLSMODE
   * field of USBTLL_CHANNEL_CONF
   */
  static unsigned ohci_omap3_fslsmode(enum usbhs_omap_port_mode mode)
  {
  	switch (mode) {
  	case OMAP_USBHS_PORT_MODE_UNUSED:
  	case OMAP_OHCI_PORT_MODE_PHY_6PIN_DATSE0:
  		return OMAP_TLL_FSLSMODE_6PIN_PHY_DAT_SE0;
  
  	case OMAP_OHCI_PORT_MODE_PHY_6PIN_DPDM:
  		return OMAP_TLL_FSLSMODE_6PIN_PHY_DP_DM;
  
  	case OMAP_OHCI_PORT_MODE_PHY_3PIN_DATSE0:
  		return OMAP_TLL_FSLSMODE_3PIN_PHY;
  
  	case OMAP_OHCI_PORT_MODE_PHY_4PIN_DPDM:
  		return OMAP_TLL_FSLSMODE_4PIN_PHY;
  
  	case OMAP_OHCI_PORT_MODE_TLL_6PIN_DATSE0:
  		return OMAP_TLL_FSLSMODE_6PIN_TLL_DAT_SE0;
  
  	case OMAP_OHCI_PORT_MODE_TLL_6PIN_DPDM:
  		return OMAP_TLL_FSLSMODE_6PIN_TLL_DP_DM;
  
  	case OMAP_OHCI_PORT_MODE_TLL_3PIN_DATSE0:
  		return OMAP_TLL_FSLSMODE_3PIN_TLL;
  
  	case OMAP_OHCI_PORT_MODE_TLL_4PIN_DPDM:
  		return OMAP_TLL_FSLSMODE_4PIN_TLL;
  
  	case OMAP_OHCI_PORT_MODE_TLL_2PIN_DATSE0:
  		return OMAP_TLL_FSLSMODE_2PIN_TLL_DAT_SE0;
  
  	case OMAP_OHCI_PORT_MODE_TLL_2PIN_DPDM:
  		return OMAP_TLL_FSLSMODE_2PIN_DAT_DP_DM;
  	default:
  		pr_warn("Invalid port mode, using default
  ");
  		return OMAP_TLL_FSLSMODE_6PIN_PHY_DAT_SE0;
  	}
  }
  
  /**
   * usbtll_omap_probe - initialize TI-based HCDs
   *
   * Allocates basic resources for this USB host controller.
   */

  static int usbtll_omap_probe(struct platform_device *pdev)

  {
  	struct device				*dev =  &pdev->dev;

  	struct resource				*res;
  	struct usbtll_omap			*tll;

  	int					ret = 0;

  	int					i, ver;

  
  	dev_dbg(dev, "starting TI HSUSB TLL Controller
  ");

  	tll = devm_kzalloc(dev, sizeof(struct usbtll_omap), GFP_KERNEL);

  	if (!tll) {
  		dev_err(dev, "Memory allocation failed
  ");

  		return -ENOMEM;

  	}

  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

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

  
  	platform_set_drvdata(pdev, tll);
  	pm_runtime_enable(dev);
  	pm_runtime_get_sync(dev);

  	ver =  usbtll_read(tll->base, OMAP_USBTLL_REVISION);

  	switch (ver) {
  	case OMAP_USBTLL_REV1:

  	case OMAP_USBTLL_REV4:

  		tll->nch = OMAP_TLL_CHANNEL_COUNT;

  		break;

  	case OMAP_USBTLL_REV2:

  	case OMAP_USBTLL_REV3:

  		tll->nch = OMAP_REV2_TLL_CHANNEL_COUNT;

  		break;
  	default:

  		tll->nch = OMAP_TLL_CHANNEL_COUNT;
  		dev_dbg(dev,
  		 "USB TLL Rev : 0x%x not recognized, assuming %d channels
  ",
  			ver, tll->nch);
  		break;

  	}

  	tll->ch_clk = devm_kzalloc(dev, sizeof(struct clk *) * tll->nch,

  						GFP_KERNEL);
  	if (!tll->ch_clk) {
  		ret = -ENOMEM;
  		dev_err(dev, "Couldn't allocate memory for channel clocks
  ");
  		goto err_clk_alloc;
  	}
  
  	for (i = 0; i < tll->nch; i++) {
  		char clkname[] = "usb_tll_hs_usb_chx_clk";
  
  		snprintf(clkname, sizeof(clkname),
  					"usb_tll_hs_usb_ch%d_clk", i);
  		tll->ch_clk[i] = clk_get(dev, clkname);
  
  		if (IS_ERR(tll->ch_clk[i]))
  			dev_dbg(dev, "can't get clock : %s
  ", clkname);

  		else
  			clk_prepare(tll->ch_clk[i]);

  	}

  	pm_runtime_put_sync(dev);
  	/* only after this can omap_tll_enable/disable work */
  	spin_lock(&tll_lock);
  	tll_dev = dev;
  	spin_unlock(&tll_lock);
  
  	return 0;
  
  err_clk_alloc:
  	pm_runtime_put_sync(dev);
  	pm_runtime_disable(dev);
  
  	return ret;
  }
  
  /**
   * usbtll_omap_remove - shutdown processing for UHH & TLL HCDs
   * @pdev: USB Host Controller being removed
   *
   * Reverses the effect of usbtll_omap_probe().
   */
  static int usbtll_omap_remove(struct platform_device *pdev)
  {
  	struct usbtll_omap *tll = platform_get_drvdata(pdev);
  	int i;
  
  	spin_lock(&tll_lock);
  	tll_dev = NULL;
  	spin_unlock(&tll_lock);

  	for (i = 0; i < tll->nch; i++) {
  		if (!IS_ERR(tll->ch_clk[i])) {
  			clk_unprepare(tll->ch_clk[i]);

  			clk_put(tll->ch_clk[i]);

  		}
  	}

  
  	pm_runtime_disable(&pdev->dev);
  	return 0;
  }

  static const struct of_device_id usbtll_omap_dt_ids[] = {
  	{ .compatible = "ti,usbhs-tll" },
  	{ }
  };
  
  MODULE_DEVICE_TABLE(of, usbtll_omap_dt_ids);

  static struct platform_driver usbtll_omap_driver = {
  	.driver = {
  		.name		= (char *)usbtll_driver_name,

  		.of_match_table = usbtll_omap_dt_ids,

  	},
  	.probe		= usbtll_omap_probe,
  	.remove		= usbtll_omap_remove,
  };
  
  int omap_tll_init(struct usbhs_omap_platform_data *pdata)
  {
  	int i;
  	bool needs_tll;
  	unsigned reg;
  	struct usbtll_omap *tll;

  	if (!tll_dev)

  		return -ENODEV;

  	pm_runtime_get_sync(tll_dev);

  	spin_lock(&tll_lock);
  	tll = dev_get_drvdata(tll_dev);

  	needs_tll = false;
  	for (i = 0; i < tll->nch; i++)
  		needs_tll |= omap_usb_mode_needs_tll(pdata->port_mode[i]);
  
  	if (needs_tll) {

  		void __iomem *base = tll->base;

  
  		/* Program Common TLL register */
  		reg = usbtll_read(base, OMAP_TLL_SHARED_CONF);
  		reg |= (OMAP_TLL_SHARED_CONF_FCLK_IS_ON
  			| OMAP_TLL_SHARED_CONF_USB_DIVRATION);
  		reg &= ~OMAP_TLL_SHARED_CONF_USB_90D_DDR_EN;
  		reg &= ~OMAP_TLL_SHARED_CONF_USB_180D_SDR_EN;
  
  		usbtll_write(base, OMAP_TLL_SHARED_CONF, reg);
  
  		/* Enable channels now */

  		for (i = 0; i < tll->nch; i++) {

  			reg = usbtll_read(base,	OMAP_TLL_CHANNEL_CONF(i));
  
  			if (is_ohci_port(pdata->port_mode[i])) {
  				reg |= ohci_omap3_fslsmode(pdata->port_mode[i])
  				<< OMAP_TLL_CHANNEL_CONF_FSLSMODE_SHIFT;
  				reg |= OMAP_TLL_CHANNEL_CONF_CHANMODE_FSLS;
  			} else if (pdata->port_mode[i] ==
  					OMAP_EHCI_PORT_MODE_TLL) {
  				/*
  				 * Disable AutoIdle, BitStuffing
  				 * and use SDR Mode
  				 */
  				reg &= ~(OMAP_TLL_CHANNEL_CONF_UTMIAUTOIDLE
  					| OMAP_TLL_CHANNEL_CONF_ULPINOBITSTUFF
  					| OMAP_TLL_CHANNEL_CONF_ULPIDDRMODE);

  			} else if (pdata->port_mode[i] ==
  					OMAP_EHCI_PORT_MODE_HSIC) {
  				/*
  				 * HSIC Mode requires UTMI port configurations
  				 */
  				reg |= OMAP_TLL_CHANNEL_CONF_DRVVBUS
  				 | OMAP_TLL_CHANNEL_CONF_CHRGVBUS
  				 | OMAP_TLL_CHANNEL_CONF_MODE_TRANSPARENT_UTMI
  				 | OMAP_TLL_CHANNEL_CONF_ULPINOBITSTUFF;

  			} else {
  				continue;
  			}
  			reg |= OMAP_TLL_CHANNEL_CONF_CHANEN;
  			usbtll_write(base, OMAP_TLL_CHANNEL_CONF(i), reg);
  
  			usbtll_writeb(base,
  				      OMAP_TLL_ULPI_SCRATCH_REGISTER(i),
  				      0xbe);
  		}
  	}

  	spin_unlock(&tll_lock);

  	pm_runtime_put_sync(tll_dev);

  	return 0;

  }

  EXPORT_SYMBOL_GPL(omap_tll_init);

  int omap_tll_enable(struct usbhs_omap_platform_data *pdata)

  {

  	int i;

  	struct usbtll_omap *tll;

  	if (!tll_dev)

  		return -ENODEV;

  	pm_runtime_get_sync(tll_dev);

  	spin_lock(&tll_lock);
  	tll = dev_get_drvdata(tll_dev);

  	for (i = 0; i < tll->nch; i++) {

  		if (omap_usb_mode_needs_tll(pdata->port_mode[i])) {

  			int r;

  			if (IS_ERR(tll->ch_clk[i]))
  				continue;

  			r = clk_enable(tll->ch_clk[i]);

  			if (r) {

  				dev_err(tll_dev,

  				 "Error enabling ch %d clock: %d
  ", i, r);
  			}
  		}
  	}

  	spin_unlock(&tll_lock);

  	return 0;
  }

  EXPORT_SYMBOL_GPL(omap_tll_enable);

  int omap_tll_disable(struct usbhs_omap_platform_data *pdata)

  {

  	int i;

  	struct usbtll_omap *tll;

  	if (!tll_dev)

  		return -ENODEV;

  	spin_lock(&tll_lock);

  	tll = dev_get_drvdata(tll_dev);

  	for (i = 0; i < tll->nch; i++) {

  		if (omap_usb_mode_needs_tll(pdata->port_mode[i])) {

  			if (!IS_ERR(tll->ch_clk[i]))

  				clk_disable(tll->ch_clk[i]);

  		}
  	}

  	spin_unlock(&tll_lock);

  	pm_runtime_put_sync(tll_dev);

  	return 0;

  }
  EXPORT_SYMBOL_GPL(omap_tll_disable);
  
  MODULE_AUTHOR("Keshava Munegowda <keshava_mgowda@ti.com>");

  MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>");

  MODULE_ALIAS("platform:" USBHS_DRIVER_NAME);
  MODULE_LICENSE("GPL v2");
  MODULE_DESCRIPTION("usb tll driver for TI OMAP EHCI and OHCI controllers");
  
  static int __init omap_usbtll_drvinit(void)
  {
  	return platform_driver_register(&usbtll_omap_driver);
  }
  
  /*
   * init before usbhs core driver;
   * The usbtll driver should be initialized before
   * the usbhs core driver probe function is called.
   */
  fs_initcall(omap_usbtll_drvinit);
  
  static void __exit omap_usbtll_drvexit(void)
  {
  	platform_driver_unregister(&usbtll_omap_driver);
  }
  module_exit(omap_usbtll_drvexit);