/*
   * SAMSUNG EXYNOS USB HOST EHCI Controller
   *
   * Copyright (C) 2011 Samsung Electronics Co.Ltd
   * Author: Jingoo Han <jg1.han@samsung.com>
   * Author: Joonyoung Shim <jy0922.shim@samsung.com>
   *
   * This program is free software; you can redistribute  it and/or modify it
   * under  the terms of  the GNU General  Public License as published by the
   * Free Software Foundation;  either version 2 of the  License, or (at your
   * option) any later version.
   *
   */
  
  #include <linux/clk.h>
  #include <linux/dma-mapping.h>
  #include <linux/io.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/of.h>
  #include <linux/of_gpio.h>
  #include <linux/platform_device.h>
  #include <linux/usb/phy.h>
  #include <linux/usb/samsung_usb_phy.h>
  #include <linux/usb.h>
  #include <linux/usb/hcd.h>
  #include <linux/usb/otg.h>
  
  #include "ehci.h"
  
  #define DRIVER_DESC "EHCI EXYNOS driver"
  
  #define EHCI_INSNREG00(base)			(base + 0x90)
  #define EHCI_INSNREG00_ENA_INCR16		(0x1 << 25)
  #define EHCI_INSNREG00_ENA_INCR8		(0x1 << 24)
  #define EHCI_INSNREG00_ENA_INCR4		(0x1 << 23)
  #define EHCI_INSNREG00_ENA_INCRX_ALIGN		(0x1 << 22)
  #define EHCI_INSNREG00_ENABLE_DMA_BURST	\
  	(EHCI_INSNREG00_ENA_INCR16 | EHCI_INSNREG00_ENA_INCR8 |	\
  	 EHCI_INSNREG00_ENA_INCR4 | EHCI_INSNREG00_ENA_INCRX_ALIGN)
  
  static const char hcd_name[] = "ehci-exynos";
  static struct hc_driver __read_mostly exynos_ehci_hc_driver;
  
  struct exynos_ehci_hcd {
  	struct clk *clk;
  	struct usb_phy *phy;
  	struct usb_otg *otg;
  };
  
  #define to_exynos_ehci(hcd) (struct exynos_ehci_hcd *)(hcd_to_ehci(hcd)->priv)
  
  static void exynos_setup_vbus_gpio(struct platform_device *pdev)
  {
  	struct device *dev = &pdev->dev;
  	int err;
  	int gpio;
  
  	if (!dev->of_node)
  		return;
  
  	gpio = of_get_named_gpio(dev->of_node, "samsung,vbus-gpio", 0);
  	if (!gpio_is_valid(gpio))
  		return;
  
  	err = devm_gpio_request_one(dev, gpio, GPIOF_OUT_INIT_HIGH,
  				    "ehci_vbus_gpio");
  	if (err)
  		dev_err(dev, "can't request ehci vbus gpio %d", gpio);
  }
  
  static int exynos_ehci_probe(struct platform_device *pdev)
  {
  	struct exynos_ehci_hcd *exynos_ehci;
  	struct usb_hcd *hcd;
  	struct ehci_hcd *ehci;
  	struct resource *res;
  	struct usb_phy *phy;
  	int irq;
  	int err;
  
  	/*
  	 * Right now device-tree probed devices don't get dma_mask set.
  	 * Since shared usb code relies on it, set it here for now.
  	 * Once we move to full device tree support this will vanish off.
  	 */
  	err = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
  	if (err)
  		return err;
  
  	exynos_setup_vbus_gpio(pdev);
  
  	hcd = usb_create_hcd(&exynos_ehci_hc_driver,
  			     &pdev->dev, dev_name(&pdev->dev));
  	if (!hcd) {
  		dev_err(&pdev->dev, "Unable to create HCD
  ");
  		return -ENOMEM;
  	}
  	exynos_ehci = to_exynos_ehci(hcd);
  
  	if (of_device_is_compatible(pdev->dev.of_node,
  					"samsung,exynos5440-ehci"))
  		goto skip_phy;
  
  	phy = devm_usb_get_phy(&pdev->dev, USB_PHY_TYPE_USB2);
  	if (IS_ERR(phy)) {
  		usb_put_hcd(hcd);
  		dev_warn(&pdev->dev, "no platform data or transceiver defined
  ");
  		return -EPROBE_DEFER;
  	} else {
  		exynos_ehci->phy = phy;
  		exynos_ehci->otg = phy->otg;
  	}
  
  skip_phy:
  
  	exynos_ehci->clk = devm_clk_get(&pdev->dev, "usbhost");
  
  	if (IS_ERR(exynos_ehci->clk)) {
  		dev_err(&pdev->dev, "Failed to get usbhost clock
  ");
  		err = PTR_ERR(exynos_ehci->clk);
  		goto fail_clk;
  	}
  
  	err = clk_prepare_enable(exynos_ehci->clk);
  	if (err)
  		goto fail_clk;
  
  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	if (!res) {
  		dev_err(&pdev->dev, "Failed to get I/O memory
  ");
  		err = -ENXIO;
  		goto fail_io;
  	}
  
  	hcd->rsrc_start = res->start;
  	hcd->rsrc_len = resource_size(res);
  	hcd->regs = devm_ioremap(&pdev->dev, res->start, hcd->rsrc_len);
  	if (!hcd->regs) {
  		dev_err(&pdev->dev, "Failed to remap I/O memory
  ");
  		err = -ENOMEM;
  		goto fail_io;
  	}
  
  	irq = platform_get_irq(pdev, 0);
  	if (!irq) {
  		dev_err(&pdev->dev, "Failed to get IRQ
  ");
  		err = -ENODEV;
  		goto fail_io;
  	}
  
  	if (exynos_ehci->otg)
  		exynos_ehci->otg->set_host(exynos_ehci->otg, &hcd->self);
  
  	if (exynos_ehci->phy)
  		usb_phy_init(exynos_ehci->phy);
  
  	ehci = hcd_to_ehci(hcd);
  	ehci->caps = hcd->regs;
  
  	/* DMA burst Enable */
  	writel(EHCI_INSNREG00_ENABLE_DMA_BURST, EHCI_INSNREG00(hcd->regs));
  
  	err = usb_add_hcd(hcd, irq, IRQF_SHARED);
  	if (err) {
  		dev_err(&pdev->dev, "Failed to add USB HCD
  ");
  		goto fail_add_hcd;
  	}
  	device_wakeup_enable(hcd->self.controller);
  
  	platform_set_drvdata(pdev, hcd);
  
  	return 0;
  
  fail_add_hcd:
  	if (exynos_ehci->phy)
  		usb_phy_shutdown(exynos_ehci->phy);
  fail_io:
  	clk_disable_unprepare(exynos_ehci->clk);
  fail_clk:
  	usb_put_hcd(hcd);
  	return err;
  }
  
  static int exynos_ehci_remove(struct platform_device *pdev)
  {
  	struct usb_hcd *hcd = platform_get_drvdata(pdev);
  	struct exynos_ehci_hcd *exynos_ehci = to_exynos_ehci(hcd);
  
  	usb_remove_hcd(hcd);
  
  	if (exynos_ehci->otg)
  		exynos_ehci->otg->set_host(exynos_ehci->otg, &hcd->self);
  
  	if (exynos_ehci->phy)
  		usb_phy_shutdown(exynos_ehci->phy);
  
  	clk_disable_unprepare(exynos_ehci->clk);
  
  	usb_put_hcd(hcd);
  
  	return 0;
  }
  
  #ifdef CONFIG_PM
  static int exynos_ehci_suspend(struct device *dev)
  {
  	struct usb_hcd *hcd = dev_get_drvdata(dev);
  	struct exynos_ehci_hcd *exynos_ehci = to_exynos_ehci(hcd);
  
  	bool do_wakeup = device_may_wakeup(dev);
  	int rc;
  
  	rc = ehci_suspend(hcd, do_wakeup);
  
  	if (exynos_ehci->otg)
  		exynos_ehci->otg->set_host(exynos_ehci->otg, &hcd->self);
  
  	if (exynos_ehci->phy)
  		usb_phy_shutdown(exynos_ehci->phy);
  
  	clk_disable_unprepare(exynos_ehci->clk);
  
  	return rc;
  }
  
  static int exynos_ehci_resume(struct device *dev)
  {
  	struct usb_hcd *hcd = dev_get_drvdata(dev);
  	struct exynos_ehci_hcd *exynos_ehci = to_exynos_ehci(hcd);
  
  	clk_prepare_enable(exynos_ehci->clk);
  
  	if (exynos_ehci->otg)
  		exynos_ehci->otg->set_host(exynos_ehci->otg, &hcd->self);
  
  	if (exynos_ehci->phy)
  		usb_phy_init(exynos_ehci->phy);
  
  	/* DMA burst Enable */
  	writel(EHCI_INSNREG00_ENABLE_DMA_BURST, EHCI_INSNREG00(hcd->regs));
  
  	ehci_resume(hcd, false);
  	return 0;
  }
  #else
  #define exynos_ehci_suspend	NULL
  #define exynos_ehci_resume	NULL
  #endif
  
  static const struct dev_pm_ops exynos_ehci_pm_ops = {
  	.suspend	= exynos_ehci_suspend,
  	.resume		= exynos_ehci_resume,
  };
  
  #ifdef CONFIG_OF
  static const struct of_device_id exynos_ehci_match[] = {
  	{ .compatible = "samsung,exynos4210-ehci" },
  	{ .compatible = "samsung,exynos5440-ehci" },
  	{},
  };
  MODULE_DEVICE_TABLE(of, exynos_ehci_match);
  #endif
  
  static struct platform_driver exynos_ehci_driver = {
  	.probe		= exynos_ehci_probe,
  	.remove		= exynos_ehci_remove,
  	.shutdown	= usb_hcd_platform_shutdown,
  	.driver = {
  		.name	= "exynos-ehci",
  		.owner	= THIS_MODULE,
  		.pm	= &exynos_ehci_pm_ops,
  		.of_match_table = of_match_ptr(exynos_ehci_match),
  	}
  };
  static const struct ehci_driver_overrides exynos_overrides __initdata = {
  	.extra_priv_size = sizeof(struct exynos_ehci_hcd),
  };
  
  static int __init ehci_exynos_init(void)
  {
  	if (usb_disabled())
  		return -ENODEV;
  
  	pr_info("%s: " DRIVER_DESC "
  ", hcd_name);
  	ehci_init_driver(&exynos_ehci_hc_driver, &exynos_overrides);
  	return platform_driver_register(&exynos_ehci_driver);
  }
  module_init(ehci_exynos_init);
  
  static void __exit ehci_exynos_cleanup(void)
  {
  	platform_driver_unregister(&exynos_ehci_driver);
  }
  module_exit(ehci_exynos_cleanup);
  
  MODULE_DESCRIPTION(DRIVER_DESC);
  MODULE_ALIAS("platform:exynos-ehci");
  MODULE_AUTHOR("Jingoo Han");
  MODULE_AUTHOR("Joonyoung Shim");
  MODULE_LICENSE("GPL v2");