text: // SPDX-License-Identifier: GPL-2.0
  /*
  * Driver for EHCI HCD on SPEAr SOC
  *
  * Copyright (C) 2010 ST Micro Electronics,
  * Deepak Sikri <deepak.sikri@st.com>
  *
  * Based on various ehci-*.c drivers
  */
  
  #include <linux/clk.h>
  #include <linux/dma-mapping.h>
  #include <linux/io.h>
  #include <linux/jiffies.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/of.h>
  #include <linux/platform_device.h>
  #include <linux/pm.h>
  #include <linux/usb.h>
  #include <linux/usb/hcd.h>
  
  #include "ehci.h"
  
  #define DRIVER_DESC "EHCI SPEAr driver"
  
  static const char hcd_name[] = "SPEAr-ehci";
  
  struct spear_ehci {
  	struct clk *clk;
  };
  
  #define to_spear_ehci(hcd)	(struct spear_ehci *)(hcd_to_ehci(hcd)->priv)
  
  static struct hc_driver __read_mostly ehci_spear_hc_driver;
  
  #ifdef CONFIG_PM_SLEEP
  static int ehci_spear_drv_suspend(struct device *dev)
  {
  	struct usb_hcd *hcd = dev_get_drvdata(dev);
  	bool do_wakeup = device_may_wakeup(dev);
  
  	return ehci_suspend(hcd, do_wakeup);
  }
  
  static int ehci_spear_drv_resume(struct device *dev)
  {
  	struct usb_hcd *hcd = dev_get_drvdata(dev);
  
  	ehci_resume(hcd, false);
  	return 0;
  }
  #endif /* CONFIG_PM_SLEEP */
  
  static SIMPLE_DEV_PM_OPS(ehci_spear_pm_ops, ehci_spear_drv_suspend,
  		ehci_spear_drv_resume);
  
  static int spear_ehci_hcd_drv_probe(struct platform_device *pdev)
  {
  	struct usb_hcd *hcd ;
  	struct spear_ehci *sehci;
  	struct resource *res;
  	struct clk *usbh_clk;
  	const struct hc_driver *driver = &ehci_spear_hc_driver;
  	int irq, retval;
  
  	if (usb_disabled())
  		return -ENODEV;
  
  	irq = platform_get_irq(pdev, 0);
  	if (irq < 0) {
  		retval = irq;
  		goto fail;
  	}
  
  	/*
  	 * 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.
  	 */
  	retval = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
  	if (retval)
  		goto fail;
  
  	usbh_clk = devm_clk_get(&pdev->dev, NULL);
  	if (IS_ERR(usbh_clk)) {
  		dev_err(&pdev->dev, "Error getting interface clock\n");
  		retval = PTR_ERR(usbh_clk);
  		goto fail;
  	}
  
  	hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
  	if (!hcd) {
  		retval = -ENOMEM;
  		goto fail;
  	}
  
  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	hcd->regs = devm_ioremap_resource(&pdev->dev, res);
  	if (IS_ERR(hcd->regs)) {
  		retval = PTR_ERR(hcd->regs);
  		goto err_put_hcd;
  	}
  	hcd->rsrc_start = res->start;
  	hcd->rsrc_len = resource_size(res);
  
  	sehci = to_spear_ehci(hcd);
  	sehci->clk = usbh_clk;
  
  	/* registers start at offset 0x0 */
  	hcd_to_ehci(hcd)->caps = hcd->regs;
  
  	clk_prepare_enable(sehci->clk);
  	retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
  	if (retval)
  		goto err_stop_ehci;
  
  	device_wakeup_enable(hcd->self.controller);
  	return retval;
  
  err_stop_ehci:
  	clk_disable_unprepare(sehci->clk);
  err_put_hcd:
  	usb_put_hcd(hcd);
  fail:
  	dev_err(&pdev->dev, "init fail, %d\n", retval);
  
  	return retval ;
  }
  
  static int spear_ehci_hcd_drv_remove(struct platform_device *pdev)
  {
  	struct usb_hcd *hcd = platform_get_drvdata(pdev);
  	struct spear_ehci *sehci = to_spear_ehci(hcd);
  
  	usb_remove_hcd(hcd);
  
  	if (sehci->clk)
  		clk_disable_unprepare(sehci->clk);
  	usb_put_hcd(hcd);
  
  	return 0;
  }
  
  static const struct of_device_id spear_ehci_id_table[] = {
  	{ .compatible = "st,spear600-ehci", },
  	{ },
  };
  MODULE_DEVICE_TABLE(of, spear_ehci_id_table);
  
  static struct platform_driver spear_ehci_hcd_driver = {
  	.probe		= spear_ehci_hcd_drv_probe,
  	.remove		= spear_ehci_hcd_drv_remove,
  	.shutdown	= usb_hcd_platform_shutdown,
  	.driver		= {
  		.name = "spear-ehci",
  		.bus = &platform_bus_type,
  		.pm = &ehci_spear_pm_ops,
  		.of_match_table = spear_ehci_id_table,
  	}
  };
  
  static const struct ehci_driver_overrides spear_overrides __initconst = {
  	.extra_priv_size = sizeof(struct spear_ehci),
  };
  
  static int __init ehci_spear_init(void)
  {
  	if (usb_disabled())
  		return -ENODEV;
  
  	pr_info("%s: " DRIVER_DESC "\n", hcd_name);
  
  	ehci_init_driver(&ehci_spear_hc_driver, &spear_overrides);
  	return platform_driver_register(&spear_ehci_hcd_driver);
  }
  module_init(ehci_spear_init);
  
  static void __exit ehci_spear_cleanup(void)
  {
  	platform_driver_unregister(&spear_ehci_hcd_driver);
  }
  module_exit(ehci_spear_cleanup);
  
  MODULE_DESCRIPTION(DRIVER_DESC);
  MODULE_ALIAS("platform:spear-ehci");
  MODULE_AUTHOR("Deepak Sikri");
  MODULE_LICENSE("GPL");
  