/*
   * OHCI HCD (Host Controller Driver) for USB.
   *
   *  Copyright (C) 2004 SAN People (Pty) Ltd.
   *  Copyright (C) 2005 Thibaut VARENE <varenet@parisc-linux.org>
   *
   * AT91 Bus Glue
   *
   * Based on fragments of 2.4 driver by Rick Bronson.
   * Based on ohci-omap.c
   *
   * This file is licenced under the GPL.
   */
  
  #include <linux/clk.h>
  #include <linux/dma-mapping.h>
  #include <linux/of_platform.h>
  #include <linux/of_gpio.h>
  #include <linux/platform_device.h>
  #include <linux/platform_data/atmel.h>
  #include <linux/io.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/usb.h>
  #include <linux/usb/hcd.h>
  
  #include <mach/hardware.h>
  #include <asm/gpio.h>
  
  #include <mach/cpu.h>
  
  
  #include "ohci.h"
  
  #define valid_port(index)	((index) >= 0 && (index) < AT91_MAX_USBH_PORTS)
  #define at91_for_each_port(index)	\
  		for ((index) = 0; (index) < AT91_MAX_USBH_PORTS; (index)++)
  
  /* interface, function and usb clocks; sometimes also an AHB clock */
  static struct clk *iclk, *fclk, *uclk, *hclk;
  /* interface and function clocks; sometimes also an AHB clock */
  
  #define DRIVER_DESC "OHCI Atmel driver"
  
  static const char hcd_name[] = "ohci-atmel";
  
  static struct hc_driver __read_mostly ohci_at91_hc_driver;
  static int clocked;
  static int (*orig_ohci_hub_control)(struct usb_hcd  *hcd, u16 typeReq,
  			u16 wValue, u16 wIndex, char *buf, u16 wLength);
  static int (*orig_ohci_hub_status_data)(struct usb_hcd *hcd, char *buf);
  
  extern int usb_disabled(void);
  
  /*-------------------------------------------------------------------------*/
  
  static void at91_start_clock(void)
  {
  	if (IS_ENABLED(CONFIG_COMMON_CLK)) {
  		clk_set_rate(uclk, 48000000);
  		clk_prepare_enable(uclk);
  	}
  	clk_prepare_enable(hclk);
  	clk_prepare_enable(iclk);
  	clk_prepare_enable(fclk);
  	clocked = 1;
  }
  
  static void at91_stop_clock(void)
  {
  	clk_disable_unprepare(fclk);
  	clk_disable_unprepare(iclk);
  	clk_disable_unprepare(hclk);
  	if (IS_ENABLED(CONFIG_COMMON_CLK))
  		clk_disable_unprepare(uclk);
  	clocked = 0;
  }
  
  static void at91_start_hc(struct platform_device *pdev)
  {
  	struct usb_hcd *hcd = platform_get_drvdata(pdev);
  	struct ohci_regs __iomem *regs = hcd->regs;
  
  	dev_dbg(&pdev->dev, "start
  ");
  
  	/*
  	 * Start the USB clocks.
  	 */
  	at91_start_clock();
  
  	/*
  	 * The USB host controller must remain in reset.
  	 */
  	writel(0, &regs->control);
  }
  
  static void at91_stop_hc(struct platform_device *pdev)
  {
  	struct usb_hcd *hcd = platform_get_drvdata(pdev);
  	struct ohci_regs __iomem *regs = hcd->regs;
  
  	dev_dbg(&pdev->dev, "stop
  ");
  
  	/*
  	 * Put the USB host controller into reset.
  	 */
  	writel(0, &regs->control);
  
  	/*
  	 * Stop the USB clocks.
  	 */
  	at91_stop_clock();
  }
  
  
  /*-------------------------------------------------------------------------*/
  
  static void usb_hcd_at91_remove (struct usb_hcd *, struct platform_device *);
  
  /* configure so an HC device and id are always provided */
  /* always called with process context; sleeping is OK */
  
  
  /**
   * usb_hcd_at91_probe - initialize AT91-based HCDs
   * Context: !in_interrupt()
   *
   * Allocates basic resources for this USB host controller, and
   * then invokes the start() method for the HCD associated with it
   * through the hotplug entry's driver_data.
   */
  static int usb_hcd_at91_probe(const struct hc_driver *driver,
  			struct platform_device *pdev)
  {
  	struct at91_usbh_data *board;
  	struct ohci_hcd *ohci;
  	int retval;
  	struct usb_hcd *hcd = NULL;
  	struct device *dev = &pdev->dev;
  	struct resource *res;
  	int irq;
  
  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	if (!res) {
  		dev_dbg(dev, "hcd probe: missing memory resource
  ");
  		return -ENXIO;
  	}
  
  	irq = platform_get_irq(pdev, 0);
  	if (irq < 0) {
  		dev_dbg(dev, "hcd probe: missing irq resource
  ");
  		return irq;
  	}
  
  	hcd = usb_create_hcd(driver, dev, "at91");
  	if (!hcd)
  		return -ENOMEM;
  	hcd->rsrc_start = res->start;
  	hcd->rsrc_len = resource_size(res);
  
  	hcd->regs = devm_ioremap_resource(dev, res);
  	if (IS_ERR(hcd->regs)) {
  		retval = PTR_ERR(hcd->regs);
  		goto err;
  	}
  
  	iclk = devm_clk_get(dev, "ohci_clk");
  	if (IS_ERR(iclk)) {
  		dev_err(dev, "failed to get ohci_clk
  ");
  		retval = PTR_ERR(iclk);
  		goto err;
  	}
  	fclk = devm_clk_get(dev, "uhpck");
  	if (IS_ERR(fclk)) {
  		dev_err(dev, "failed to get uhpck
  ");
  		retval = PTR_ERR(fclk);
  		goto err;
  	}
  	hclk = devm_clk_get(dev, "hclk");
  	if (IS_ERR(hclk)) {
  		dev_err(dev, "failed to get hclk
  ");
  		retval = PTR_ERR(hclk);
  		goto err;
  	}
  	if (IS_ENABLED(CONFIG_COMMON_CLK)) {
  		uclk = devm_clk_get(dev, "usb_clk");
  		if (IS_ERR(uclk)) {
  			dev_err(dev, "failed to get uclk
  ");
  			retval = PTR_ERR(uclk);
  			goto err;
  		}
  	}
  
  	board = hcd->self.controller->platform_data;
  	ohci = hcd_to_ohci(hcd);
  	ohci->num_ports = board->ports;
  	at91_start_hc(pdev);
  
  	retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
  	if (retval == 0) {
  		device_wakeup_enable(hcd->self.controller);
  		return retval;
  	}
  
  	/* Error handling */
  	at91_stop_hc(pdev);
  
   err:
  	usb_put_hcd(hcd);
  	return retval;
  }
  
  
  /* may be called with controller, bus, and devices active */
  
  /**
   * usb_hcd_at91_remove - shutdown processing for AT91-based HCDs
   * @dev: USB Host Controller being removed
   * Context: !in_interrupt()
   *
   * Reverses the effect of usb_hcd_at91_probe(), first invoking
   * the HCD's stop() method.  It is always called from a thread
   * context, "rmmod" or something similar.
   *
   */
  static void usb_hcd_at91_remove(struct usb_hcd *hcd,
  				struct platform_device *pdev)
  {
  	usb_remove_hcd(hcd);
  	at91_stop_hc(pdev);
  	usb_put_hcd(hcd);
  }
  
  /*-------------------------------------------------------------------------*/
  static void ohci_at91_usb_set_power(struct at91_usbh_data *pdata, int port, int enable)
  {
  	if (!valid_port(port))
  		return;
  
  	if (!gpio_is_valid(pdata->vbus_pin[port]))
  		return;
  
  	gpio_set_value(pdata->vbus_pin[port],
  		       pdata->vbus_pin_active_low[port] ^ enable);
  }
  
  static int ohci_at91_usb_get_power(struct at91_usbh_data *pdata, int port)
  {
  	if (!valid_port(port))
  		return -EINVAL;
  
  	if (!gpio_is_valid(pdata->vbus_pin[port]))
  		return -EINVAL;
  
  	return gpio_get_value(pdata->vbus_pin[port]) ^
  		pdata->vbus_pin_active_low[port];
  }
  
  /*
   * Update the status data from the hub with the over-current indicator change.
   */
  static int ohci_at91_hub_status_data(struct usb_hcd *hcd, char *buf)
  {
  	struct at91_usbh_data *pdata = hcd->self.controller->platform_data;
  	int length = orig_ohci_hub_status_data(hcd, buf);
  	int port;
  
  	at91_for_each_port(port) {
  		if (pdata->overcurrent_changed[port]) {
  			if (!length)
  				length = 1;
  			buf[0] |= 1 << (port + 1);
  		}
  	}
  
  	return length;
  }
  
  /*
   * Look at the control requests to the root hub and see if we need to override.
   */
  static int ohci_at91_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
  				 u16 wIndex, char *buf, u16 wLength)
  {
  	struct at91_usbh_data *pdata = dev_get_platdata(hcd->self.controller);
  	struct usb_hub_descriptor *desc;
  	int ret = -EINVAL;
  	u32 *data = (u32 *)buf;
  
  	dev_dbg(hcd->self.controller,
  		"ohci_at91_hub_control(%p,0x%04x,0x%04x,0x%04x,%p,%04x)
  ",
  		hcd, typeReq, wValue, wIndex, buf, wLength);
  
  	wIndex--;
  
  	switch (typeReq) {
  	case SetPortFeature:
  		if (wValue == USB_PORT_FEAT_POWER) {
  			dev_dbg(hcd->self.controller, "SetPortFeat: POWER
  ");
  			if (valid_port(wIndex)) {
  				ohci_at91_usb_set_power(pdata, wIndex, 1);
  				ret = 0;
  			}
  
  			goto out;
  		}
  		break;
  
  	case ClearPortFeature:
  		switch (wValue) {
  		case USB_PORT_FEAT_C_OVER_CURRENT:
  			dev_dbg(hcd->self.controller,
  				"ClearPortFeature: C_OVER_CURRENT
  ");
  
  			if (valid_port(wIndex)) {
  				pdata->overcurrent_changed[wIndex] = 0;
  				pdata->overcurrent_status[wIndex] = 0;
  			}
  
  			goto out;
  
  		case USB_PORT_FEAT_OVER_CURRENT:
  			dev_dbg(hcd->self.controller,
  				"ClearPortFeature: OVER_CURRENT
  ");
  
  			if (valid_port(wIndex))
  				pdata->overcurrent_status[wIndex] = 0;
  
  			goto out;
  
  		case USB_PORT_FEAT_POWER:
  			dev_dbg(hcd->self.controller,
  				"ClearPortFeature: POWER
  ");
  
  			if (valid_port(wIndex)) {
  				ohci_at91_usb_set_power(pdata, wIndex, 0);
  				return 0;
  			}
  		}
  		break;
  	}
  
  	ret = orig_ohci_hub_control(hcd, typeReq, wValue, wIndex + 1,
  				buf, wLength);
  	if (ret)
  		goto out;
  
  	switch (typeReq) {
  	case GetHubDescriptor:
  
  		/* update the hub's descriptor */
  
  		desc = (struct usb_hub_descriptor *)buf;
  
  		dev_dbg(hcd->self.controller, "wHubCharacteristics 0x%04x
  ",
  			desc->wHubCharacteristics);
  
  		/* remove the old configurations for power-switching, and
  		 * over-current protection, and insert our new configuration
  		 */
  
  		desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_LPSM);
  		desc->wHubCharacteristics |= cpu_to_le16(0x0001);
  
  		if (pdata->overcurrent_supported) {
  			desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_OCPM);
  			desc->wHubCharacteristics |=  cpu_to_le16(0x0008|0x0001);
  		}
  
  		dev_dbg(hcd->self.controller, "wHubCharacteristics after 0x%04x
  ",
  			desc->wHubCharacteristics);
  
  		return ret;
  
  	case GetPortStatus:
  		/* check port status */
  
  		dev_dbg(hcd->self.controller, "GetPortStatus(%d)
  ", wIndex);
  
  		if (valid_port(wIndex)) {
  			if (!ohci_at91_usb_get_power(pdata, wIndex))
  				*data &= ~cpu_to_le32(RH_PS_PPS);
  
  			if (pdata->overcurrent_changed[wIndex])
  				*data |= cpu_to_le32(RH_PS_OCIC);
  
  			if (pdata->overcurrent_status[wIndex])
  				*data |= cpu_to_le32(RH_PS_POCI);
  		}
  	}
  
   out:
  	return ret;
  }
  
  /*-------------------------------------------------------------------------*/
  
  static irqreturn_t ohci_hcd_at91_overcurrent_irq(int irq, void *data)
  {
  	struct platform_device *pdev = data;
  	struct at91_usbh_data *pdata = dev_get_platdata(&pdev->dev);
  	int val, gpio, port;
  
  	/* From the GPIO notifying the over-current situation, find
  	 * out the corresponding port */
  	at91_for_each_port(port) {
  		if (gpio_is_valid(pdata->overcurrent_pin[port]) &&
  				gpio_to_irq(pdata->overcurrent_pin[port]) == irq) {
  			gpio = pdata->overcurrent_pin[port];
  			break;
  		}
  	}
  
  	if (port == AT91_MAX_USBH_PORTS) {
  		dev_err(& pdev->dev, "overcurrent interrupt from unknown GPIO
  ");
  		return IRQ_HANDLED;
  	}
  
  	val = gpio_get_value(gpio);
  
  	/* When notified of an over-current situation, disable power
  	   on the corresponding port, and mark this port in
  	   over-current. */
  	if (!val) {
  		ohci_at91_usb_set_power(pdata, port, 0);
  		pdata->overcurrent_status[port]  = 1;
  		pdata->overcurrent_changed[port] = 1;
  	}
  
  	dev_dbg(& pdev->dev, "overcurrent situation %s
  ",
  		val ? "exited" : "notified");
  
  	return IRQ_HANDLED;
  }
  
  #ifdef CONFIG_OF
  static const struct of_device_id at91_ohci_dt_ids[] = {
  	{ .compatible = "atmel,at91rm9200-ohci" },
  	{ /* sentinel */ }
  };
  
  MODULE_DEVICE_TABLE(of, at91_ohci_dt_ids);
  
  static int ohci_at91_of_init(struct platform_device *pdev)
  {
  	struct device_node *np = pdev->dev.of_node;
  	int i, gpio, ret;
  	enum of_gpio_flags flags;
  	struct at91_usbh_data	*pdata;
  	u32 ports;
  
  	if (!np)
  		return 0;
  
  	/* 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 have dma capability bindings this can go away.
  	 */
  	ret = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
  	if (ret)
  		return ret;
  
  	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
  	if (!pdata)
  		return -ENOMEM;
  
  	if (!of_property_read_u32(np, "num-ports", &ports))
  		pdata->ports = ports;
  
  	at91_for_each_port(i) {
  		gpio = of_get_named_gpio_flags(np, "atmel,vbus-gpio", i, &flags);
  		pdata->vbus_pin[i] = gpio;
  		if (!gpio_is_valid(gpio))
  			continue;
  		pdata->vbus_pin_active_low[i] = flags & OF_GPIO_ACTIVE_LOW;
  	}
  
  	at91_for_each_port(i)
  		pdata->overcurrent_pin[i] =
  			of_get_named_gpio_flags(np, "atmel,oc-gpio", i, &flags);
  
  	pdev->dev.platform_data = pdata;
  
  	return 0;
  }
  #else
  static int ohci_at91_of_init(struct platform_device *pdev)
  {
  	return 0;
  }
  #endif
  
  /*-------------------------------------------------------------------------*/
  
  static int ohci_hcd_at91_drv_probe(struct platform_device *pdev)
  {
  	struct at91_usbh_data	*pdata;
  	int			i;
  	int			gpio;
  	int			ret;
  
  	ret = ohci_at91_of_init(pdev);
  	if (ret)
  		return ret;
  
  	pdata = dev_get_platdata(&pdev->dev);
  
  	if (pdata) {
  		at91_for_each_port(i) {
  			/*
  			 * do not configure PIO if not in relation with
  			 * real USB port on board
  			 */
  			if (i >= pdata->ports) {
  				pdata->vbus_pin[i] = -EINVAL;
  				pdata->overcurrent_pin[i] = -EINVAL;
  				break;
  			}
  
  			if (!gpio_is_valid(pdata->vbus_pin[i]))
  				continue;
  			gpio = pdata->vbus_pin[i];
  
  			ret = gpio_request(gpio, "ohci_vbus");
  			if (ret) {
  				dev_err(&pdev->dev,
  					"can't request vbus gpio %d
  ", gpio);
  				continue;
  			}
  			ret = gpio_direction_output(gpio,
  						!pdata->vbus_pin_active_low[i]);
  			if (ret) {
  				dev_err(&pdev->dev,
  					"can't put vbus gpio %d as output %d
  ",
  					gpio, !pdata->vbus_pin_active_low[i]);
  				gpio_free(gpio);
  				continue;
  			}
  
  			ohci_at91_usb_set_power(pdata, i, 1);
  		}
  
  		at91_for_each_port(i) {
  			if (!gpio_is_valid(pdata->overcurrent_pin[i]))
  				continue;
  			gpio = pdata->overcurrent_pin[i];
  
  			ret = gpio_request(gpio, "ohci_overcurrent");
  			if (ret) {
  				dev_err(&pdev->dev,
  					"can't request overcurrent gpio %d
  ",
  					gpio);
  				continue;
  			}
  
  			ret = gpio_direction_input(gpio);
  			if (ret) {
  				dev_err(&pdev->dev,
  					"can't configure overcurrent gpio %d as input
  ",
  					gpio);
  				gpio_free(gpio);
  				continue;
  			}
  
  			ret = request_irq(gpio_to_irq(gpio),
  					  ohci_hcd_at91_overcurrent_irq,
  					  IRQF_SHARED, "ohci_overcurrent", pdev);
  			if (ret) {
  				gpio_free(gpio);
  				dev_err(&pdev->dev,
  					"can't get gpio IRQ for overcurrent
  ");
  			}
  		}
  	}
  
  	device_init_wakeup(&pdev->dev, 1);
  	return usb_hcd_at91_probe(&ohci_at91_hc_driver, pdev);
  }
  
  static int ohci_hcd_at91_drv_remove(struct platform_device *pdev)
  {
  	struct at91_usbh_data	*pdata = dev_get_platdata(&pdev->dev);
  	int			i;
  
  	if (pdata) {
  		at91_for_each_port(i) {
  			if (!gpio_is_valid(pdata->vbus_pin[i]))
  				continue;
  			ohci_at91_usb_set_power(pdata, i, 0);
  			gpio_free(pdata->vbus_pin[i]);
  		}
  
  		at91_for_each_port(i) {
  			if (!gpio_is_valid(pdata->overcurrent_pin[i]))
  				continue;
  			free_irq(gpio_to_irq(pdata->overcurrent_pin[i]), pdev);
  			gpio_free(pdata->overcurrent_pin[i]);
  		}
  	}
  
  	device_init_wakeup(&pdev->dev, 0);
  	usb_hcd_at91_remove(platform_get_drvdata(pdev), pdev);
  	return 0;
  }
  
  #ifdef CONFIG_PM
  
  static int
  ohci_hcd_at91_drv_suspend(struct platform_device *pdev, pm_message_t mesg)
  {
  	struct usb_hcd	*hcd = platform_get_drvdata(pdev);
  	struct ohci_hcd	*ohci = hcd_to_ohci(hcd);
  	bool		do_wakeup = device_may_wakeup(&pdev->dev);
  	int		ret;
  
  	if (do_wakeup)
  		enable_irq_wake(hcd->irq);
  
  	ret = ohci_suspend(hcd, do_wakeup);
  	if (ret) {
  		disable_irq_wake(hcd->irq);
  		return ret;
  	}
  	/*
  	 * The integrated transceivers seem unable to notice disconnect,
  	 * reconnect, or wakeup without the 48 MHz clock active.  so for
  	 * correctness, always discard connection state (using reset).
  	 *
  	 * REVISIT: some boards will be able to turn VBUS off...
  	 */
  	if (at91_suspend_entering_slow_clock()) {
  		ohci->hc_control = ohci_readl(ohci, &ohci->regs->control);
  		ohci->hc_control &= OHCI_CTRL_RWC;
  		ohci_writel(ohci, ohci->hc_control, &ohci->regs->control);
  		ohci->rh_state = OHCI_RH_HALTED;
  
  		/* flush the writes */
  		(void) ohci_readl (ohci, &ohci->regs->control);
  		at91_stop_clock();
  	}
  
  	return ret;
  }
  
  static int ohci_hcd_at91_drv_resume(struct platform_device *pdev)
  {
  	struct usb_hcd	*hcd = platform_get_drvdata(pdev);
  
  	if (device_may_wakeup(&pdev->dev))
  		disable_irq_wake(hcd->irq);
  
  	if (!clocked)
  		at91_start_clock();
  
  	ohci_resume(hcd, false);
  	return 0;
  }
  #else
  #define ohci_hcd_at91_drv_suspend NULL
  #define ohci_hcd_at91_drv_resume  NULL
  #endif
  
  static struct platform_driver ohci_hcd_at91_driver = {
  	.probe		= ohci_hcd_at91_drv_probe,
  	.remove		= ohci_hcd_at91_drv_remove,
  	.shutdown	= usb_hcd_platform_shutdown,
  	.suspend	= ohci_hcd_at91_drv_suspend,
  	.resume		= ohci_hcd_at91_drv_resume,
  	.driver		= {
  		.name	= "at91_ohci",
  		.owner	= THIS_MODULE,
  		.of_match_table	= of_match_ptr(at91_ohci_dt_ids),
  	},
  };
  
  static int __init ohci_at91_init(void)
  {
  	if (usb_disabled())
  		return -ENODEV;
  
  	pr_info("%s: " DRIVER_DESC "
  ", hcd_name);
  	ohci_init_driver(&ohci_at91_hc_driver, NULL);
  
  	/*
  	 * The Atmel HW has some unusual quirks, which require Atmel-specific
  	 * workarounds. We override certain hc_driver functions here to
  	 * achieve that. We explicitly do not enhance ohci_driver_overrides to
  	 * allow this more easily, since this is an unusual case, and we don't
  	 * want to encourage others to override these functions by making it
  	 * too easy.
  	 */
  
  	orig_ohci_hub_control = ohci_at91_hc_driver.hub_control;
  	orig_ohci_hub_status_data = ohci_at91_hc_driver.hub_status_data;
  
  	ohci_at91_hc_driver.hub_status_data	= ohci_at91_hub_status_data;
  	ohci_at91_hc_driver.hub_control		= ohci_at91_hub_control;
  
  	return platform_driver_register(&ohci_hcd_at91_driver);
  }
  module_init(ohci_at91_init);
  
  static void __exit ohci_at91_cleanup(void)
  {
  	platform_driver_unregister(&ohci_hcd_at91_driver);
  }
  module_exit(ohci_at91_cleanup);
  
  MODULE_DESCRIPTION(DRIVER_DESC);
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:at91_ohci");