/*
   * Copyright 2012 Tilera Corporation. All Rights Reserved.
   *
   *   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, version 2.
   *
   *   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, GOOD TITLE or
   *   NON INFRINGEMENT.  See the GNU General Public License for
   *   more details.
   */
  
  /*
   * Tilera TILE-Gx USB EHCI host controller driver.
   */
  
  #include <linux/irq.h>
  #include <linux/platform_device.h>
  #include <linux/usb/tilegx.h>
  #include <linux/usb.h>
  
  #include <asm/homecache.h>
  
  #include <gxio/iorpc_usb_host.h>
  #include <gxio/usb_host.h>
  
  static void tilegx_start_ehc(void)
  {
  }
  
  static void tilegx_stop_ehc(void)
  {
  }
  
  static int tilegx_ehci_setup(struct usb_hcd *hcd)
  {
  	int ret = ehci_init(hcd);
  
  	/*
  	 * Some drivers do:
  	 *
  	 *   struct ehci_hcd *ehci = hcd_to_ehci(hcd);
  	 *   ehci->need_io_watchdog = 0;
  	 *
  	 * here, but since this is a new driver we're going to leave the
  	 * watchdog enabled.  Later we may try to turn it off and see
  	 * whether we run into any problems.
  	 */
  
  	return ret;
  }
  
  static const struct hc_driver ehci_tilegx_hc_driver = {
  	.description		= hcd_name,
  	.product_desc		= "Tile-Gx EHCI",
  	.hcd_priv_size		= sizeof(struct ehci_hcd),
  
  	/*
  	 * Generic hardware linkage.
  	 */
  	.irq			= ehci_irq,
  	.flags			= HCD_MEMORY | HCD_USB2 | HCD_BH,
  
  	/*
  	 * Basic lifecycle operations.
  	 */
  	.reset			= tilegx_ehci_setup,
  	.start			= ehci_run,
  	.stop			= ehci_stop,
  	.shutdown		= ehci_shutdown,
  
  	/*
  	 * Managing I/O requests and associated device resources.
  	 */
  	.urb_enqueue		= ehci_urb_enqueue,
  	.urb_dequeue		= ehci_urb_dequeue,
  	.endpoint_disable	= ehci_endpoint_disable,
  	.endpoint_reset		= ehci_endpoint_reset,
  
  	/*
  	 * Scheduling support.
  	 */
  	.get_frame_number	= ehci_get_frame,
  
  	/*
  	 * Root hub support.
  	 */
  	.hub_status_data	= ehci_hub_status_data,
  	.hub_control		= ehci_hub_control,
  	.bus_suspend		= ehci_bus_suspend,
  	.bus_resume		= ehci_bus_resume,
  	.relinquish_port	= ehci_relinquish_port,
  	.port_handed_over	= ehci_port_handed_over,
  
  	.clear_tt_buffer_complete	= ehci_clear_tt_buffer_complete,
  };
  
  static int ehci_hcd_tilegx_drv_probe(struct platform_device *pdev)
  {
  	struct usb_hcd *hcd;
  	struct ehci_hcd *ehci;
  	struct tilegx_usb_platform_data *pdata = dev_get_platdata(&pdev->dev);
  	pte_t pte = { 0 };
  	int my_cpu = smp_processor_id();
  	int ret;
  
  	if (usb_disabled())
  		return -ENODEV;
  
  	/*
  	 * Try to initialize our GXIO context; if we can't, the device
  	 * doesn't exist.
  	 */
  	if (gxio_usb_host_init(&pdata->usb_ctx, pdata->dev_index, 1) != 0)
  		return -ENXIO;
  
  	hcd = usb_create_hcd(&ehci_tilegx_hc_driver, &pdev->dev,
  			     dev_name(&pdev->dev));
  	if (!hcd) {
            ret = -ENOMEM;
            goto err_hcd;
          }
  
  	/*
  	 * We don't use rsrc_start to map in our registers, but seems like
  	 * we ought to set it to something, so we use the register VA.
  	 */
  	hcd->rsrc_start =
  		(ulong) gxio_usb_host_get_reg_start(&pdata->usb_ctx);
  	hcd->rsrc_len = gxio_usb_host_get_reg_len(&pdata->usb_ctx);
  	hcd->regs = gxio_usb_host_get_reg_start(&pdata->usb_ctx);
  
  	tilegx_start_ehc();
  
  	ehci = hcd_to_ehci(hcd);
  	ehci->caps = hcd->regs;
  	ehci->regs =
  		hcd->regs + HC_LENGTH(ehci, readl(&ehci->caps->hc_capbase));
  	/* cache this readonly data; minimize chip reads */
  	ehci->hcs_params = readl(&ehci->caps->hcs_params);
  
  	/* Create our IRQs and register them. */
  	pdata->irq = create_irq();
  	if (pdata->irq < 0) {
  		ret = -ENXIO;
  		goto err_no_irq;
  	}
  
  	tile_irq_activate(pdata->irq, TILE_IRQ_PERCPU);
  
  	/* Configure interrupts. */
  	ret = gxio_usb_host_cfg_interrupt(&pdata->usb_ctx,
  					  cpu_x(my_cpu), cpu_y(my_cpu),
  					  KERNEL_PL, pdata->irq);
  	if (ret) {
  		ret = -ENXIO;
  		goto err_have_irq;
  	}
  
  	/* Register all of our memory. */
  	pte = pte_set_home(pte, PAGE_HOME_HASH);
  	ret = gxio_usb_host_register_client_memory(&pdata->usb_ctx, pte, 0);
  	if (ret) {
  		ret = -ENXIO;
  		goto err_have_irq;
  	}
  
  	ret = usb_add_hcd(hcd, pdata->irq, IRQF_SHARED);
  	if (ret == 0) {
  		platform_set_drvdata(pdev, hcd);
  		device_wakeup_enable(hcd->self.controller);
  		return ret;
  	}
  
  err_have_irq:
  	destroy_irq(pdata->irq);
  err_no_irq:
  	tilegx_stop_ehc();
  	usb_put_hcd(hcd);
  err_hcd:
  	gxio_usb_host_destroy(&pdata->usb_ctx);
  	return ret;
  }
  
  static int ehci_hcd_tilegx_drv_remove(struct platform_device *pdev)
  {
  	struct usb_hcd *hcd = platform_get_drvdata(pdev);
  	struct tilegx_usb_platform_data *pdata = dev_get_platdata(&pdev->dev);
  
  	usb_remove_hcd(hcd);
  	usb_put_hcd(hcd);
  	tilegx_stop_ehc();
  	gxio_usb_host_destroy(&pdata->usb_ctx);
  	destroy_irq(pdata->irq);
  
  	return 0;
  }
  
  static void ehci_hcd_tilegx_drv_shutdown(struct platform_device *pdev)
  {
  	usb_hcd_platform_shutdown(pdev);
  	ehci_hcd_tilegx_drv_remove(pdev);
  }
  
  static struct platform_driver ehci_hcd_tilegx_driver = {
  	.probe		= ehci_hcd_tilegx_drv_probe,
  	.remove		= ehci_hcd_tilegx_drv_remove,
  	.shutdown	= ehci_hcd_tilegx_drv_shutdown,
  	.driver = {
  		.name	= "tilegx-ehci",
  		.owner	= THIS_MODULE,
  	}
  };
  
  MODULE_ALIAS("platform:tilegx-ehci");