text: // SPDX-License-Identifier: GPL-2.0+
  /*
   * (C) Copyright David Brownell 2000-2002
   */
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/pci.h>
  #include <linux/usb.h>
  #include <linux/usb/hcd.h>
  
  #include <asm/io.h>
  #include <asm/irq.h>
  
  #ifdef CONFIG_PPC_PMAC
  #include <asm/machdep.h>
  #include <asm/pmac_feature.h>
  #include <asm/prom.h>
  #endif
  
  #include "usb.h"
  
  
  /* PCI-based HCs are common, but plenty of non-PCI HCs are used too */
  
  /*
   * Coordinate handoffs between EHCI and companion controllers
   * during EHCI probing and system resume.
   */
  
  static DECLARE_RWSEM(companions_rwsem);
  
  #define CL_UHCI		PCI_CLASS_SERIAL_USB_UHCI
  #define CL_OHCI		PCI_CLASS_SERIAL_USB_OHCI
  #define CL_EHCI		PCI_CLASS_SERIAL_USB_EHCI
  
  static inline int is_ohci_or_uhci(struct pci_dev *pdev)
  {
  	return pdev->class == CL_OHCI || pdev->class == CL_UHCI;
  }
  
  typedef void (*companion_fn)(struct pci_dev *pdev, struct usb_hcd *hcd,
  		struct pci_dev *companion, struct usb_hcd *companion_hcd);
  
  /* Iterate over PCI devices in the same slot as pdev and call fn for each */
  static void for_each_companion(struct pci_dev *pdev, struct usb_hcd *hcd,
  		companion_fn fn)
  {
  	struct pci_dev		*companion;
  	struct usb_hcd		*companion_hcd;
  	unsigned int		slot = PCI_SLOT(pdev->devfn);
  
  	/*
  	 * Iterate through other PCI functions in the same slot.
  	 * If the function's drvdata isn't set then it isn't bound to
  	 * a USB host controller driver, so skip it.
  	 */
  	companion = NULL;
  	for_each_pci_dev(companion) {
  		if (companion->bus != pdev->bus ||
  				PCI_SLOT(companion->devfn) != slot)
  			continue;
  
  		/*
  		 * Companion device should be either UHCI,OHCI or EHCI host
  		 * controller, otherwise skip.
  		 */
  		if (companion->class != CL_UHCI && companion->class != CL_OHCI &&
  				companion->class != CL_EHCI)
  			continue;
  
  		companion_hcd = pci_get_drvdata(companion);
  		if (!companion_hcd || !companion_hcd->self.root_hub)
  			continue;
  		fn(pdev, hcd, companion, companion_hcd);
  	}
  }
  
  /*
   * We're about to add an EHCI controller, which will unceremoniously grab
   * all the port connections away from its companions.  To prevent annoying
   * error messages, lock the companion's root hub and gracefully unconfigure
   * it beforehand.  Leave it locked until the EHCI controller is all set.
   */
  static void ehci_pre_add(struct pci_dev *pdev, struct usb_hcd *hcd,
  		struct pci_dev *companion, struct usb_hcd *companion_hcd)
  {
  	struct usb_device *udev;
  
  	if (is_ohci_or_uhci(companion)) {
  		udev = companion_hcd->self.root_hub;
  		usb_lock_device(udev);
  		usb_set_configuration(udev, 0);
  	}
  }
  
  /*
   * Adding the EHCI controller has either succeeded or failed.  Set the
   * companion pointer accordingly, and in either case, reconfigure and
   * unlock the root hub.
   */
  static void ehci_post_add(struct pci_dev *pdev, struct usb_hcd *hcd,
  		struct pci_dev *companion, struct usb_hcd *companion_hcd)
  {
  	struct usb_device *udev;
  
  	if (is_ohci_or_uhci(companion)) {
  		if (dev_get_drvdata(&pdev->dev)) {	/* Succeeded */
  			dev_dbg(&pdev->dev, "HS companion for %s\n",
  					dev_name(&companion->dev));
  			companion_hcd->self.hs_companion = &hcd->self;
  		}
  		udev = companion_hcd->self.root_hub;
  		usb_set_configuration(udev, 1);
  		usb_unlock_device(udev);
  	}
  }
  
  /*
   * We just added a non-EHCI controller.  Find the EHCI controller to
   * which it is a companion, and store a pointer to the bus structure.
   */
  static void non_ehci_add(struct pci_dev *pdev, struct usb_hcd *hcd,
  		struct pci_dev *companion, struct usb_hcd *companion_hcd)
  {
  	if (is_ohci_or_uhci(pdev) && companion->class == CL_EHCI) {
  		dev_dbg(&pdev->dev, "FS/LS companion for %s\n",
  				dev_name(&companion->dev));
  		hcd->self.hs_companion = &companion_hcd->self;
  	}
  }
  
  /* We are removing an EHCI controller.  Clear the companions' pointers. */
  static void ehci_remove(struct pci_dev *pdev, struct usb_hcd *hcd,
  		struct pci_dev *companion, struct usb_hcd *companion_hcd)
  {
  	if (is_ohci_or_uhci(companion))
  		companion_hcd->self.hs_companion = NULL;
  }
  
  #ifdef	CONFIG_PM
  
  /* An EHCI controller must wait for its companions before resuming. */
  static void ehci_wait_for_companions(struct pci_dev *pdev, struct usb_hcd *hcd,
  		struct pci_dev *companion, struct usb_hcd *companion_hcd)
  {
  	if (is_ohci_or_uhci(companion))
  		device_pm_wait_for_dev(&pdev->dev, &companion->dev);
  }
  
  #endif	/* CONFIG_PM */
  
  /*-------------------------------------------------------------------------*/
  
  /* configure so an HC device and id are always provided */
  /* always called with process context; sleeping is OK */
  
  /**
   * usb_hcd_pci_probe - initialize PCI-based HCDs
   * @dev: USB Host Controller being probed
   * @id: pci hotplug id connecting controller to HCD framework
   * Context: !in_interrupt()
   *
   * Allocates basic PCI 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.
   *
   * Store this function in the HCD's struct pci_driver as probe().
   *
   * Return: 0 if successful.
   */
  int usb_hcd_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
  {
  	struct hc_driver	*driver;
  	struct usb_hcd		*hcd;
  	int			retval;
  	int			hcd_irq = 0;
  
  	if (usb_disabled())
  		return -ENODEV;
  
  	if (!id)
  		return -EINVAL;
  	driver = (struct hc_driver *)id->driver_data;
  	if (!driver)
  		return -EINVAL;
  
  	if (pci_enable_device(dev) < 0)
  		return -ENODEV;
  
  	/*
  	 * The xHCI driver has its own irq management
  	 * make sure irq setup is not touched for xhci in generic hcd code
  	 */
  	if ((driver->flags & HCD_MASK) < HCD_USB3) {
  		if (!dev->irq) {
  			dev_err(&dev->dev,
  			"Found HC with no IRQ. Check BIOS/PCI %s setup!\n",
  				pci_name(dev));
  			retval = -ENODEV;
  			goto disable_pci;
  		}
  		hcd_irq = dev->irq;
  	}
  
  	hcd = usb_create_hcd(driver, &dev->dev, pci_name(dev));
  	if (!hcd) {
  		retval = -ENOMEM;
  		goto disable_pci;
  	}
  
  	hcd->amd_resume_bug = (usb_hcd_amd_remote_wakeup_quirk(dev) &&
  			driver->flags & (HCD_USB11 | HCD_USB3)) ? 1 : 0;
  
  	if (driver->flags & HCD_MEMORY) {
  		/* EHCI, OHCI */
  		hcd->rsrc_start = pci_resource_start(dev, 0);
  		hcd->rsrc_len = pci_resource_len(dev, 0);
  		if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len,
  				driver->description)) {
  			dev_dbg(&dev->dev, "controller already in use\n");
  			retval = -EBUSY;
  			goto put_hcd;
  		}
  		hcd->regs = ioremap_nocache(hcd->rsrc_start, hcd->rsrc_len);
  		if (hcd->regs == NULL) {
  			dev_dbg(&dev->dev, "error mapping memory\n");
  			retval = -EFAULT;
  			goto release_mem_region;
  		}
  
  	} else {
  		/* UHCI */
  		int	region;
  
  		for (region = 0; region < PCI_ROM_RESOURCE; region++) {
  			if (!(pci_resource_flags(dev, region) &
  					IORESOURCE_IO))
  				continue;
  
  			hcd->rsrc_start = pci_resource_start(dev, region);
  			hcd->rsrc_len = pci_resource_len(dev, region);
  			if (request_region(hcd->rsrc_start, hcd->rsrc_len,
  					driver->description))
  				break;
  		}
  		if (region == PCI_ROM_RESOURCE) {
  			dev_dbg(&dev->dev, "no i/o regions available\n");
  			retval = -EBUSY;
  			goto put_hcd;
  		}
  	}
  
  	pci_set_master(dev);
  
  	/* Note: dev_set_drvdata must be called while holding the rwsem */
  	if (dev->class == CL_EHCI) {
  		down_write(&companions_rwsem);
  		dev_set_drvdata(&dev->dev, hcd);
  		for_each_companion(dev, hcd, ehci_pre_add);
  		retval = usb_add_hcd(hcd, hcd_irq, IRQF_SHARED);
  		if (retval != 0)
  			dev_set_drvdata(&dev->dev, NULL);
  		for_each_companion(dev, hcd, ehci_post_add);
  		up_write(&companions_rwsem);
  	} else {
  		down_read(&companions_rwsem);
  		dev_set_drvdata(&dev->dev, hcd);
  		retval = usb_add_hcd(hcd, hcd_irq, IRQF_SHARED);
  		if (retval != 0)
  			dev_set_drvdata(&dev->dev, NULL);
  		else
  			for_each_companion(dev, hcd, non_ehci_add);
  		up_read(&companions_rwsem);
  	}
  
  	if (retval != 0)
  		goto unmap_registers;
  	device_wakeup_enable(hcd->self.controller);
  
  	if (pci_dev_run_wake(dev))
  		pm_runtime_put_noidle(&dev->dev);
  	return retval;
  
  unmap_registers:
  	if (driver->flags & HCD_MEMORY) {
  		iounmap(hcd->regs);
  release_mem_region:
  		release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
  	} else
  		release_region(hcd->rsrc_start, hcd->rsrc_len);
  put_hcd:
  	usb_put_hcd(hcd);
  disable_pci:
  	pci_disable_device(dev);
  	dev_err(&dev->dev, "init %s fail, %d\n", pci_name(dev), retval);
  	return retval;
  }
  EXPORT_SYMBOL_GPL(usb_hcd_pci_probe);
  
  
  /* may be called without controller electrically present */
  /* may be called with controller, bus, and devices active */
  
  /**
   * usb_hcd_pci_remove - shutdown processing for PCI-based HCDs
   * @dev: USB Host Controller being removed
   * Context: !in_interrupt()
   *
   * Reverses the effect of usb_hcd_pci_probe(), first invoking
   * the HCD's stop() method.  It is always called from a thread
   * context, normally "rmmod", "apmd", or something similar.
   *
   * Store this function in the HCD's struct pci_driver as remove().
   */
  void usb_hcd_pci_remove(struct pci_dev *dev)
  {
  	struct usb_hcd		*hcd;
  
  	hcd = pci_get_drvdata(dev);
  	if (!hcd)
  		return;
  
  	if (pci_dev_run_wake(dev))
  		pm_runtime_get_noresume(&dev->dev);
  
  	/* Fake an interrupt request in order to give the driver a chance
  	 * to test whether the controller hardware has been removed (e.g.,
  	 * cardbus physical eject).
  	 */
  	local_irq_disable();
  	usb_hcd_irq(0, hcd);
  	local_irq_enable();
  
  	/* Note: dev_set_drvdata must be called while holding the rwsem */
  	if (dev->class == CL_EHCI) {
  		down_write(&companions_rwsem);
  		for_each_companion(dev, hcd, ehci_remove);
  		usb_remove_hcd(hcd);
  		dev_set_drvdata(&dev->dev, NULL);
  		up_write(&companions_rwsem);
  	} else {
  		/* Not EHCI; just clear the companion pointer */
  		down_read(&companions_rwsem);
  		hcd->self.hs_companion = NULL;
  		usb_remove_hcd(hcd);
  		dev_set_drvdata(&dev->dev, NULL);
  		up_read(&companions_rwsem);
  	}
  
  	if (hcd->driver->flags & HCD_MEMORY) {
  		iounmap(hcd->regs);
  		release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
  	} else {
  		release_region(hcd->rsrc_start, hcd->rsrc_len);
  	}
  
  	usb_put_hcd(hcd);
  	pci_disable_device(dev);
  }
  EXPORT_SYMBOL_GPL(usb_hcd_pci_remove);
  
  /**
   * usb_hcd_pci_shutdown - shutdown host controller
   * @dev: USB Host Controller being shutdown
   */
  void usb_hcd_pci_shutdown(struct pci_dev *dev)
  {
  	struct usb_hcd		*hcd;
  
  	hcd = pci_get_drvdata(dev);
  	if (!hcd)
  		return;
  
  	if (test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags) &&
  			hcd->driver->shutdown) {
  		hcd->driver->shutdown(hcd);
  		if (usb_hcd_is_primary_hcd(hcd) && hcd->irq > 0)
  			free_irq(hcd->irq, hcd);
  		pci_disable_device(dev);
  	}
  }
  EXPORT_SYMBOL_GPL(usb_hcd_pci_shutdown);
  
  #ifdef	CONFIG_PM
  
  #ifdef	CONFIG_PPC_PMAC
  static void powermac_set_asic(struct pci_dev *pci_dev, int enable)
  {
  	/* Enanble or disable ASIC clocks for USB */
  	if (machine_is(powermac)) {
  		struct device_node	*of_node;
  
  		of_node = pci_device_to_OF_node(pci_dev);
  		if (of_node)
  			pmac_call_feature(PMAC_FTR_USB_ENABLE,
  					of_node, 0, enable);
  	}
  }
  
  #else
  
  static inline void powermac_set_asic(struct pci_dev *pci_dev, int enable)
  {}
  
  #endif	/* CONFIG_PPC_PMAC */
  
  static int check_root_hub_suspended(struct device *dev)
  {
  	struct pci_dev		*pci_dev = to_pci_dev(dev);
  	struct usb_hcd		*hcd = pci_get_drvdata(pci_dev);
  
  	if (HCD_RH_RUNNING(hcd)) {
  		dev_warn(dev, "Root hub is not suspended\n");
  		return -EBUSY;
  	}
  	if (hcd->shared_hcd) {
  		hcd = hcd->shared_hcd;
  		if (HCD_RH_RUNNING(hcd)) {
  			dev_warn(dev, "Secondary root hub is not suspended\n");
  			return -EBUSY;
  		}
  	}
  	return 0;
  }
  
  static int suspend_common(struct device *dev, bool do_wakeup)
  {
  	struct pci_dev		*pci_dev = to_pci_dev(dev);
  	struct usb_hcd		*hcd = pci_get_drvdata(pci_dev);
  	int			retval;
  
  	/* Root hub suspend should have stopped all downstream traffic,
  	 * and all bus master traffic.  And done so for both the interface
  	 * and the stub usb_device (which we check here).  But maybe it
  	 * didn't; writing sysfs power/state files ignores such rules...
  	 */
  	retval = check_root_hub_suspended(dev);
  	if (retval)
  		return retval;
  
  	if (hcd->driver->pci_suspend && !HCD_DEAD(hcd)) {
  		/* Optimization: Don't suspend if a root-hub wakeup is
  		 * pending and it would cause the HCD to wake up anyway.
  		 */
  		if (do_wakeup && HCD_WAKEUP_PENDING(hcd))
  			return -EBUSY;
  		if (do_wakeup && hcd->shared_hcd &&
  				HCD_WAKEUP_PENDING(hcd->shared_hcd))
  			return -EBUSY;
  		retval = hcd->driver->pci_suspend(hcd, do_wakeup);
  		suspend_report_result(hcd->driver->pci_suspend, retval);
  
  		/* Check again in case wakeup raced with pci_suspend */
  		if ((retval == 0 && do_wakeup && HCD_WAKEUP_PENDING(hcd)) ||
  				(retval == 0 && do_wakeup && hcd->shared_hcd &&
  				 HCD_WAKEUP_PENDING(hcd->shared_hcd))) {
  			if (hcd->driver->pci_resume)
  				hcd->driver->pci_resume(hcd, false);
  			retval = -EBUSY;
  		}
  		if (retval)
  			return retval;
  	}
  
  	/* If MSI-X is enabled, the driver will have synchronized all vectors
  	 * in pci_suspend(). If MSI or legacy PCI is enabled, that will be
  	 * synchronized here.
  	 */
  	if (!hcd->msix_enabled)
  		synchronize_irq(pci_dev->irq);
  
  	/* Downstream ports from this root hub should already be quiesced, so
  	 * there will be no DMA activity.  Now we can shut down the upstream
  	 * link (except maybe for PME# resume signaling).  We'll enter a
  	 * low power state during suspend_noirq, if the hardware allows.
  	 */
  	pci_disable_device(pci_dev);
  	return retval;
  }
  
  static int resume_common(struct device *dev, int event)
  {
  	struct pci_dev		*pci_dev = to_pci_dev(dev);
  	struct usb_hcd		*hcd = pci_get_drvdata(pci_dev);
  	int			retval;
  
  	if (HCD_RH_RUNNING(hcd) ||
  			(hcd->shared_hcd &&
  			 HCD_RH_RUNNING(hcd->shared_hcd))) {
  		dev_dbg(dev, "can't resume, not suspended!\n");
  		return 0;
  	}
  
  	retval = pci_enable_device(pci_dev);
  	if (retval < 0) {
  		dev_err(dev, "can't re-enable after resume, %d!\n", retval);
  		return retval;
  	}
  
  	pci_set_master(pci_dev);
  
  	if (hcd->driver->pci_resume && !HCD_DEAD(hcd)) {
  
  		/*
  		 * Only EHCI controllers have to wait for their companions.
  		 * No locking is needed because PCI controller drivers do not
  		 * get unbound during system resume.
  		 */
  		if (pci_dev->class == CL_EHCI && event != PM_EVENT_AUTO_RESUME)
  			for_each_companion(pci_dev, hcd,
  					ehci_wait_for_companions);
  
  		retval = hcd->driver->pci_resume(hcd,
  				event == PM_EVENT_RESTORE);
  		if (retval) {
  			dev_err(dev, "PCI post-resume error %d!\n", retval);
  			if (hcd->shared_hcd)
  				usb_hc_died(hcd->shared_hcd);
  			usb_hc_died(hcd);
  		}
  	}
  	return retval;
  }
  
  #ifdef	CONFIG_PM_SLEEP
  
  static int hcd_pci_suspend(struct device *dev)
  {
  	return suspend_common(dev, device_may_wakeup(dev));
  }
  
  static int hcd_pci_suspend_noirq(struct device *dev)
  {
  	struct pci_dev		*pci_dev = to_pci_dev(dev);
  	struct usb_hcd		*hcd = pci_get_drvdata(pci_dev);
  	int			retval;
  
  	retval = check_root_hub_suspended(dev);
  	if (retval)
  		return retval;
  
  	pci_save_state(pci_dev);
  
  	/* If the root hub is dead rather than suspended, disallow remote
  	 * wakeup.  usb_hc_died() should ensure that both hosts are marked as
  	 * dying, so we only need to check the primary roothub.
  	 */
  	if (HCD_DEAD(hcd))
  		device_set_wakeup_enable(dev, 0);
  	dev_dbg(dev, "wakeup: %d\n", device_may_wakeup(dev));
  
  	/* Possibly enable remote wakeup,
  	 * choose the appropriate low-power state, and go to that state.
  	 */
  	retval = pci_prepare_to_sleep(pci_dev);
  	if (retval == -EIO) {		/* Low-power not supported */
  		dev_dbg(dev, "--> PCI D0 legacy\n");
  		retval = 0;
  	} else if (retval == 0) {
  		dev_dbg(dev, "--> PCI %s\n",
  				pci_power_name(pci_dev->current_state));
  	} else {
  		suspend_report_result(pci_prepare_to_sleep, retval);
  		return retval;
  	}
  
  	powermac_set_asic(pci_dev, 0);
  	return retval;
  }
  
  static int hcd_pci_resume_noirq(struct device *dev)
  {
  	powermac_set_asic(to_pci_dev(dev), 1);
  	return 0;
  }
  
  static int hcd_pci_resume(struct device *dev)
  {
  	return resume_common(dev, PM_EVENT_RESUME);
  }
  
  static int hcd_pci_restore(struct device *dev)
  {
  	return resume_common(dev, PM_EVENT_RESTORE);
  }
  
  #else
  
  #define hcd_pci_suspend		NULL
  #define hcd_pci_suspend_noirq	NULL
  #define hcd_pci_resume_noirq	NULL
  #define hcd_pci_resume		NULL
  #define hcd_pci_restore		NULL
  
  #endif	/* CONFIG_PM_SLEEP */
  
  static int hcd_pci_runtime_suspend(struct device *dev)
  {
  	int	retval;
  
  	retval = suspend_common(dev, true);
  	if (retval == 0)
  		powermac_set_asic(to_pci_dev(dev), 0);
  	dev_dbg(dev, "hcd_pci_runtime_suspend: %d\n", retval);
  	return retval;
  }
  
  static int hcd_pci_runtime_resume(struct device *dev)
  {
  	int	retval;
  
  	powermac_set_asic(to_pci_dev(dev), 1);
  	retval = resume_common(dev, PM_EVENT_AUTO_RESUME);
  	dev_dbg(dev, "hcd_pci_runtime_resume: %d\n", retval);
  	return retval;
  }
  
  const struct dev_pm_ops usb_hcd_pci_pm_ops = {
  	.suspend	= hcd_pci_suspend,
  	.suspend_noirq	= hcd_pci_suspend_noirq,
  	.resume_noirq	= hcd_pci_resume_noirq,
  	.resume		= hcd_pci_resume,
  	.freeze		= check_root_hub_suspended,
  	.freeze_noirq	= check_root_hub_suspended,
  	.thaw_noirq	= NULL,
  	.thaw		= NULL,
  	.poweroff	= hcd_pci_suspend,
  	.poweroff_noirq	= hcd_pci_suspend_noirq,
  	.restore_noirq	= hcd_pci_resume_noirq,
  	.restore	= hcd_pci_restore,
  	.runtime_suspend = hcd_pci_runtime_suspend,
  	.runtime_resume	= hcd_pci_runtime_resume,
  };
  EXPORT_SYMBOL_GPL(usb_hcd_pci_pm_ops);
  
  #endif	/* CONFIG_PM */
  