ehci-hcd.c

一个2.4.21版本的嵌入式linux内核

	/* no more interrupts ... */
	if (hcd->state == USB_STATE_RUNNING)
		ehci_ready (ehci);
	if (in_interrupt ()) {		/* must not happen!! */
		ehci_err (ehci, "stopped in_interrupt!\n");
		return;
	}
	del_timer_sync (&ehci->watchdog);
	ehci_reset (ehci);

	/* let companion controllers work when we aren't */
	writel (0, &ehci->regs->configured_flag);
	unregister_reboot_notifier (&ehci->reboot_notifier);

	remove_debug_files (ehci);

	/* root hub is shut down separately (first, when possible) */
	spin_lock_irq (&ehci->lock);
	ehci_work (ehci, NULL);
	spin_unlock_irq (&ehci->lock);
	ehci_mem_cleanup (ehci);

#ifdef	EHCI_STATS
	ehci_dbg (ehci, "irq normal %ld err %ld reclaim %ld (lost %ld)\n",
		ehci->stats.normal, ehci->stats.error, ehci->stats.reclaim,
		ehci->stats.lost_iaa);
	ehci_dbg (ehci, "complete %ld unlink %ld\n",
		ehci->stats.complete, ehci->stats.unlink);
#endif

	dbg_status (ehci, "ehci_stop completed", readl (&ehci->regs->status));
}

static int ehci_get_frame (struct usb_hcd *hcd)
{
	struct ehci_hcd		*ehci = hcd_to_ehci (hcd);
	return (readl (&ehci->regs->frame_index) >> 3) % ehci->periodic_size;
}

/*-------------------------------------------------------------------------*/

#ifdef	CONFIG_PM

/* suspend/resume, section 4.3 */

static int ehci_suspend (struct usb_hcd *hcd, u32 state)
{
	struct ehci_hcd		*ehci = hcd_to_ehci (hcd);
	int			ports;
	int			i;

	ehci_dbg (ehci, "suspend to %d\n", state);

	ports = HCS_N_PORTS (ehci->hcs_params);

	// FIXME:  This assumes what's probably a D3 level suspend...

	// FIXME:  usb wakeup events on this bus should resume the machine.
	// pci config register PORTWAKECAP controls which ports can do it;
	// bios may have initted the register...

	/* suspend each port, then stop the hc */
	for (i = 0; i < ports; i++) {
		int	temp = readl (&ehci->regs->port_status [i]);

		if ((temp & PORT_PE) == 0
				|| (temp & PORT_OWNER) != 0)
			continue;
		ehci_dbg (ehci, "suspend port %d", i);
		temp |= PORT_SUSPEND;
		writel (temp, &ehci->regs->port_status [i]);
	}

	if (hcd->state == USB_STATE_RUNNING)
		ehci_ready (ehci);
	writel (readl (&ehci->regs->command) & ~CMD_RUN, &ehci->regs->command);

// save pci FLADJ value

	/* who tells PCI to reduce power consumption? */

	return 0;
}

static int ehci_resume (struct usb_hcd *hcd)
{
	struct ehci_hcd		*ehci = hcd_to_ehci (hcd);
	int			ports;
	int			i;

	ehci_dbg (ehci, "resume\n");

	ports = HCS_N_PORTS (ehci->hcs_params);

	// FIXME:  if controller didn't retain state,
	// return and let generic code clean it up
	// test configured_flag ?

	/* resume HC and each port */
// restore pci FLADJ value
	// khubd and drivers will set HC running, if needed;
	hcd->state = USB_STATE_READY;
	// FIXME Philips/Intel/... etc don't really have a "READY"
	// state ... turn on CMD_RUN too
	for (i = 0; i < ports; i++) {
		int	temp = readl (&ehci->regs->port_status [i]);

		if ((temp & PORT_PE) == 0
				|| (temp & PORT_SUSPEND) != 0)
			continue;
		ehci_dbg (ehci, "resume port %d", i);
		temp |= PORT_RESUME;
		writel (temp, &ehci->regs->port_status [i]);
		readl (&ehci->regs->command);	/* unblock posted writes */

		wait_ms (20);
		temp &= ~PORT_RESUME;
		writel (temp, &ehci->regs->port_status [i]);
	}
	readl (&ehci->regs->command);	/* unblock posted writes */
	return 0;
}

#endif

/*-------------------------------------------------------------------------*/

/*
 * ehci_work is called from some interrupts, timers, and so on.
 * it calls driver completion functions, after dropping ehci->lock.
 */
static void ehci_work (struct ehci_hcd *ehci, struct pt_regs *regs)
{
	if (ehci->reclaim_ready)
		end_unlink_async (ehci, regs);
	scan_async (ehci, regs);
	if (ehci->next_uframe != -1)
		scan_periodic (ehci, regs);
}

/*-------------------------------------------------------------------------*/

static void ehci_irq (struct usb_hcd *hcd, struct pt_regs *regs)
{
	struct ehci_hcd		*ehci = hcd_to_ehci (hcd);
	u32			status;
	int			bh;

	spin_lock (&ehci->lock);

	status = readl (&ehci->regs->status);

	/* e.g. cardbus physical eject */
	if (status == ~(u32) 0) {
		ehci_dbg (ehci, "device removed\n");
		goto dead;
	}

	status &= INTR_MASK;
	if (!status)			/* irq sharing? */
		goto done;

	/* clear (just) interrupts */
	writel (status, &ehci->regs->status);
	readl (&ehci->regs->command);	/* unblock posted write */
	bh = 0;

#ifdef	EHCI_VERBOSE_DEBUG
	/* unrequested/ignored: Port Change Detect, Frame List Rollover */
	dbg_status (ehci, "irq", status);
#endif

	/* INT, ERR, and IAA interrupt rates can be throttled */

	/* normal [4.15.1.2] or error [4.15.1.1] completion */
	if (likely ((status & (STS_INT|STS_ERR)) != 0)) {
		if (likely ((status & STS_ERR) == 0))
			COUNT (ehci->stats.normal);
		else
			COUNT (ehci->stats.error);
		bh = 1;
	}

	/* complete the unlinking of some qh [4.15.2.3] */
	if (status & STS_IAA) {
		COUNT (ehci->stats.reclaim);
		ehci->reclaim_ready = 1;
		bh = 1;
	}

	/* PCI errors [4.15.2.4] */
	if (unlikely ((status & STS_FATAL) != 0)) {
		ehci_err (ehci, "fatal error\n");
dead:
		ehci_reset (ehci);
		/* generic layer kills/unlinks all urbs, then
		 * uses ehci_stop to clean up the rest
		 */
		bh = 1;
	}

	if (bh)
		ehci_work (ehci, regs);
done:
	spin_unlock (&ehci->lock);
}

/*-------------------------------------------------------------------------*/

/*
 * non-error returns are a promise to giveback() the urb later
 * we drop ownership so next owner (or urb unlink) can get it
 *
 * urb + dev is in hcd_dev.urb_list
 * we're queueing TDs onto software and hardware lists
 *
 * hcd-specific init for hcpriv hasn't been done yet
 *
 * NOTE:  control, bulk, and interrupt share the same code to append TDs
 * to a (possibly active) QH, and the same QH scanning code.
 */
static int ehci_urb_enqueue (
	struct usb_hcd	*hcd,
	struct urb	*urb,
	int		mem_flags
) {
	struct ehci_hcd		*ehci = hcd_to_ehci (hcd);
	struct list_head	qtd_list;

	urb->transfer_flags &= ~EHCI_STATE_UNLINK;
	INIT_LIST_HEAD (&qtd_list);

	switch (usb_pipetype (urb->pipe)) {
	// case PIPE_CONTROL:
	// case PIPE_BULK:
	default:
		if (!qh_urb_transaction (ehci, urb, &qtd_list, mem_flags))
			return -ENOMEM;
		return submit_async (ehci, urb, &qtd_list, mem_flags);

	case PIPE_INTERRUPT:
		if (!qh_urb_transaction (ehci, urb, &qtd_list, mem_flags))
			return -ENOMEM;
		return intr_submit (ehci, urb, &qtd_list, mem_flags);

	case PIPE_ISOCHRONOUS:
		if (urb->dev->speed == USB_SPEED_HIGH)
			return itd_submit (ehci, urb, mem_flags);
#ifdef have_split_iso
		else
			return sitd_submit (ehci, urb, mem_flags);
#else
		dbg ("no split iso support yet");
		return -ENOSYS;
#endif /* have_split_iso */
	}
}

/* remove from hardware lists
 * completions normally happen asynchronously
 */

static int ehci_urb_dequeue (struct usb_hcd *hcd, struct urb *urb)
{
	struct ehci_hcd		*ehci = hcd_to_ehci (hcd);
	struct ehci_qh		*qh;
	unsigned long		flags;

	spin_lock_irqsave (&ehci->lock, flags);
	switch (usb_pipetype (urb->pipe)) {
	// case PIPE_CONTROL:
	// case PIPE_BULK:
	default:
		qh = (struct ehci_qh *) urb->hcpriv;
		if (!qh)
			break;

		/* if we need to use IAA and it's busy, defer */
		if (qh->qh_state == QH_STATE_LINKED
				&& ehci->reclaim
				&& HCD_IS_RUNNING (ehci->hcd.state)
				) {
			struct ehci_qh		*last;

			for (last = ehci->reclaim;
					last->reclaim;
					last = last->reclaim)
				continue;
			qh->qh_state = QH_STATE_UNLINK_WAIT;
			last->reclaim = qh;

		/* bypass IAA if the hc can't care */
		} else if (!HCD_IS_RUNNING (ehci->hcd.state) && ehci->reclaim)
			end_unlink_async (ehci, NULL);

		/* something else might have unlinked the qh by now */
		if (qh->qh_state == QH_STATE_LINKED)
			start_unlink_async (ehci, qh);
		break;

	case PIPE_INTERRUPT:
		qh = (struct ehci_qh *) urb->hcpriv;
		if (!qh)
			break;
		if (qh->qh_state == QH_STATE_LINKED) {
			/* messy, can spin or block a microframe ... */
			intr_deschedule (ehci, qh, 1);
			/* qh_state == IDLE */
		}
		qh_completions (ehci, qh, NULL);

		/* reschedule QH iff another request is queued */
		if (!list_empty (&qh->qtd_list)
				&& HCD_IS_RUNNING (ehci->hcd.state)) {
			int status;

			status = qh_schedule (ehci, qh);
			spin_unlock_irqrestore (&ehci->lock, flags);

			if (status != 0) {
				// shouldn't happen often, but ...
				// FIXME kill those tds' urbs
				err ("can't reschedule qh %p, err %d",
					qh, status);
			}
			return status;
		}
		break;

	case PIPE_ISOCHRONOUS:
		// itd or sitd ...

		// wait till next completion, do it then.
		// completion irqs can wait up to 1024 msec,
		urb->transfer_flags |= EHCI_STATE_UNLINK;
		break;
	}
	spin_unlock_irqrestore (&ehci->lock, flags);
	return 0;
}

/*-------------------------------------------------------------------------*/

// bulk qh holds the data toggle

static void ehci_free_config (struct usb_hcd *hcd, struct usb_device *udev)
{
	struct hcd_dev		*dev = (struct hcd_dev *)udev->hcpriv;
	struct ehci_hcd		*ehci = hcd_to_ehci (hcd);
	int			i;
	unsigned long		flags;

	/* ASSERT:  no requests/urbs are still linked (so no TDs) */
	/* ASSERT:  nobody can be submitting urbs for this any more */

	ehci_dbg (ehci, "free_config %s devnum %d\n",
			udev->devpath, udev->devnum);

	spin_lock_irqsave (&ehci->lock, flags);
	for (i = 0; i < 32; i++) {
		if (dev->ep [i]) {
			struct ehci_qh		*qh;
			char			*why;

			/* dev->ep never has ITDs or SITDs */
			qh = (struct ehci_qh *) dev->ep [i];

			/* detect/report non-recoverable errors */
			if (in_interrupt ()) 
				why = "disconnect() didn't";
			else if ((qh->hw_info2 & cpu_to_le32 (0xffff)) != 0
					&& qh->qh_state != QH_STATE_IDLE)
				why = "(active periodic)";
			else
				why = 0;
			if (why) {
				err ("dev %s-%s ep %d-%s error: %s",
					hcd_to_bus (hcd)->bus_name,
					udev->devpath,
					i & 0xf, (i & 0x10) ? "IN" : "OUT",
					why);
				BUG ();
			}

			dev->ep [i] = 0;
			if (qh->qh_state == QH_STATE_IDLE)
				goto idle;
			ehci_dbg (ehci, "free_config, async ep 0x%02x qh %p",
					i, qh);

			/* scan_async() empties the ring as it does its work,
			 * using IAA, but doesn't (yet?) turn it off.  if it
			 * doesn't empty this qh, likely it's the last entry.
			 */
			while (qh->qh_state == QH_STATE_LINKED
					&& ehci->reclaim
					&& HCD_IS_RUNNING (ehci->hcd.state)
					) {
				spin_unlock_irqrestore (&ehci->lock, flags);
				/* wait_ms() won't spin, we're a thread;
				 * and we know IRQ/timer/... can progress
				 */
				wait_ms (1);
				spin_lock_irqsave (&ehci->lock, flags);
			}
			if (qh->qh_state == QH_STATE_LINKED)
				start_unlink_async (ehci, qh);
			while (qh->qh_state != QH_STATE_IDLE
					&& ehci->hcd.state != USB_STATE_HALT) {
				spin_unlock_irqrestore (&ehci->lock, flags);
				wait_ms (1);
				spin_lock_irqsave (&ehci->lock, flags);
			}
idle:
			qh_put (ehci, qh);
		}
	}

	spin_unlock_irqrestore (&ehci->lock, flags);
}

/*-------------------------------------------------------------------------*/

static const struct hc_driver ehci_driver = {
	.description =		hcd_name,

	/*
	 * generic hardware linkage
	 */
	.irq =			ehci_irq,
	.flags =		HCD_MEMORY | HCD_USB2,

	/*
	 * basic lifecycle operations
	 */
	.start =		ehci_start,
#ifdef	CONFIG_PM
	.suspend =		ehci_suspend,
	.resume =		ehci_resume,
#endif
	.stop =			ehci_stop,

	/*
	 * memory lifecycle (except per-request)
	 */
	.hcd_alloc =		ehci_hcd_alloc,
	.hcd_free =		ehci_hcd_free,

	/*
	 * managing i/o requests and associated device resources
	 */
	.urb_enqueue =		ehci_urb_enqueue,
	.urb_dequeue =		ehci_urb_dequeue,
	.free_config =		ehci_free_config,

	/*
	 * scheduling support
	 */
	.get_frame_number =	ehci_get_frame,

	/*
	 * root hub support
	 */
	.hub_status_data =	ehci_hub_status_data,
	.hub_control =		ehci_hub_control,
};

/*-------------------------------------------------------------------------*/

/* EHCI spec says PCI is required. */

/* PCI driver selection metadata; PCI hotplugging uses this */
static const struct pci_device_id __devinitdata pci_ids [] = { {

	/* handle any USB 2.0 EHCI controller */

	.class = 		((PCI_CLASS_SERIAL_USB << 8) | 0x20),
	.class_mask = 	~0,
	.driver_data =	(unsigned long) &ehci_driver,

	/* no matter who makes it */
	.vendor =	PCI_ANY_ID,
	.device =	PCI_ANY_ID,
	.subvendor =	PCI_ANY_ID,
	.subdevice =	PCI_ANY_ID,

}, { /* end: all zeroes */ }
};
MODULE_DEVICE_TABLE (pci, pci_ids);

/* pci driver glue; this is a "new style" PCI driver module */
static struct pci_driver ehci_pci_driver = {
	.name =		(char *) hcd_name,
	.id_table =	pci_ids,

	.probe =	usb_hcd_pci_probe,
	.remove =	usb_hcd_pci_remove,

#ifdef	CONFIG_PM
	.suspend =	usb_hcd_pci_suspend,
	.resume =	usb_hcd_pci_resume,
#endif
};

#define DRIVER_INFO DRIVER_VERSION " " DRIVER_DESC

MODULE_DESCRIPTION (DRIVER_INFO);
MODULE_AUTHOR (DRIVER_AUTHOR);
MODULE_LICENSE ("GPL");

static int __init init (void) 
{
	dbg (DRIVER_INFO);
	dbg ("block sizes: qh %Zd qtd %Zd itd %Zd sitd %Zd",
		sizeof (struct ehci_qh), sizeof (struct ehci_qtd),
		sizeof (struct ehci_itd), sizeof (struct ehci_sitd));

	return pci_module_init (&ehci_pci_driver);
}
module_init (init);

static void __exit cleanup (void) 
{	
	pci_unregister_driver (&ehci_pci_driver);
}
module_exit (cleanup);