ehci-hcd.c

linux客户机函数定义的实际例子

		if ((temp & PORT_PE) == 0
				|| (temp & PORT_OWNER) != 0)
			continue;
dbg ("%s: suspend port %d", hcd->self.bus_name, i);
		temp |= PORT_SUSPEND;
		writel (temp, &ehci->regs->port_status [i]);
	}

	if (hcd->state == USB_STATE_RUNNING)
		ehci_ready (ehci);
	while (readl (&ehci->regs->status) & (STS_ASS | STS_PSS))
		udelay (100);
	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;

	dbg ("%s: resume", hcd->self.bus_name);

	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;
dbg ("%s: resume port %d", hcd->self.bus_name, 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

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

/*
 * tasklet scheduled by some interrupts and other events
 * calls driver completion functions ... but not in_irq()
 */
static void ehci_tasklet (unsigned long param)
{
	struct ehci_hcd		*ehci = (struct ehci_hcd *) param;

	if (ehci->reclaim_ready)
		end_unlink_async (ehci);
	scan_async (ehci);
	if (ehci->next_uframe != -1)
		scan_periodic (ehci);
}

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

static void ehci_irq (struct usb_hcd *hcd)
{
	struct ehci_hcd		*ehci = hcd_to_ehci (hcd);
	u32			status = readl (&ehci->regs->status);
	int			bh;

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

	/* 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))
		bh = 1;

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

	/* PCI errors [4.15.2.4] */
	if (unlikely ((status & STS_FATAL) != 0)) {
		err ("%s: fatal error, state %x", hcd->self.bus_name, hcd->state);
		ehci_reset (ehci);
		// generic layer kills/unlinks all urbs
		// then tasklet cleans up the rest
		bh = 1;
	}

	/* most work doesn't need to be in_irq() */
	if (likely (bh == 1))
		tasklet_schedule (&ehci->tasklet);
}

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

/*
 * 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:  EHCI queues control and bulk requests transparently, like OHCI.
 */
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:
		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 */

	default:	/* can't happen */
		return -ENOSYS;
	}
}

/* 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 = (struct ehci_qh *) urb->hcpriv;
	unsigned long		flags;

	dbg ("%s urb_dequeue %p qh state %d",
		hcd->self.bus_name, urb, qh->qh_state);

	switch (usb_pipetype (urb->pipe)) {
	case PIPE_CONTROL:
	case PIPE_BULK:
		spin_lock_irqsave (&ehci->lock, flags);
		if (ehci->reclaim) {
dbg ("dq: reclaim busy, %s", RUN_CONTEXT);
			if (in_interrupt ()) {
				spin_unlock_irqrestore (&ehci->lock, flags);
				return -EAGAIN;
			}
			while (qh->qh_state == QH_STATE_LINKED
					&& ehci->reclaim
					&& ehci->hcd.state != USB_STATE_HALT
					) {
				spin_unlock_irqrestore (&ehci->lock, flags);
// yeech ... this could spin for up to two frames!
dbg ("wait for dequeue: state %d, reclaim %p, hcd state %d",
    qh->qh_state, ehci->reclaim, ehci->hcd.state
);
				udelay (100);
				spin_lock_irqsave (&ehci->lock, flags);
			}
		}
		if (qh->qh_state == QH_STATE_LINKED)
			start_unlink_async (ehci, qh);
		spin_unlock_irqrestore (&ehci->lock, flags);
		return 0;

	case PIPE_INTERRUPT:
		intr_deschedule (ehci, urb->start_frame, qh,
			(urb->dev->speed == USB_SPEED_HIGH)
			    ? urb->interval
			    : (urb->interval << 3));
		if (ehci->hcd.state == USB_STATE_HALT)
			urb->status = -ESHUTDOWN;
		qh_completions (ehci, qh, 1);
		return 0;

	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;
		return 0;
	}
	return -EINVAL;
}

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

// 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:  nobody can be submitting urbs for this any more */

	dbg ("%s: free_config devnum %d", hcd->self.bus_name, udev->devnum);

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

			/* dev->ep never has ITDs or SITDs */
			qh = (struct ehci_qh *) dev->ep [i];
			vdbg ("free_config, ep 0x%02x qh %p", i, qh);
			if (!list_empty (&qh->qtd_list)) {
				dbg ("ep 0x%02x qh %p not empty!", i, qh);
				BUG ();
			}
			dev->ep [i] = 0;

			/* wait_ms() won't spin here -- we're a thread */
			while (qh->qh_state == QH_STATE_LINKED
					&& ehci->reclaim
					&& ehci->hcd.state != USB_STATE_HALT
					) {
				spin_unlock_irqrestore (&ehci->lock, flags);
				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) {
					spin_unlock_irqrestore (&ehci->lock,
						flags);
					wait_ms (1);
					spin_lock_irqsave (&ehci->lock, flags);
				}
			}
			qh_put (ehci, qh);
		}
	}

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

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

static const char	hcd_name [] = "ehci-hcd";

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);