hcd.c

来自「omap3 linux 2.6 用nocc去除了冗余代码」· C语言 代码 · 共 1,743 行 · 第 1/4 页

	case USB_SPEED_FULL:	/* ISOC or INTR */
		if (isoc) {
			tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
			return (((is_input) ? 7268L : 6265L) + BW_HOST_DELAY + tmp);
		} else {
			tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
			return (9107L + BW_HOST_DELAY + tmp);
		}
	case USB_SPEED_HIGH:	/* ISOC or INTR */
		// FIXME adjust for input vs output
		if (isoc)
			tmp = HS_NSECS_ISO (bytecount);
		else
			tmp = HS_NSECS (bytecount);
		return tmp;
	default:
		pr_debug ("%s: bogus device speed!\n", usbcore_name);
		return -1;
	}
}
EXPORT_SYMBOL (usb_calc_bus_time);


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

/*
 * Generic HC operations.
 */

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

static void urb_unlink (struct urb *urb)
{
	unsigned long		flags;

	/* clear all state linking urb to this dev (and hcd) */

	spin_lock_irqsave (&hcd_data_lock, flags);
	list_del_init (&urb->urb_list);
	spin_unlock_irqrestore (&hcd_data_lock, flags);
}


/* may be called in any context with a valid urb->dev usecount
 * caller surrenders "ownership" of urb
 * expects usb_submit_urb() to have sanity checked and conditioned all
 * inputs in the urb
 */
int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags)
{
	int			status;
	struct usb_hcd		*hcd = bus_to_hcd(urb->dev->bus);
	struct usb_host_endpoint *ep;
	unsigned long		flags;

	if (!hcd)
		return -ENODEV;

	usbmon_urb_submit(&hcd->self, urb);

	/*
	 * Atomically queue the urb,  first to our records, then to the HCD.
	 * Access to urb->status is controlled by urb->lock ... changes on
	 * i/o completion (normal or fault) or unlinking.
	 */

	// FIXME:  verify that quiescing hc works right (RH cleans up)

	spin_lock_irqsave (&hcd_data_lock, flags);
	ep = (usb_pipein(urb->pipe) ? urb->dev->ep_in : urb->dev->ep_out)
			[usb_pipeendpoint(urb->pipe)];
	if (unlikely (!ep))
		status = -ENOENT;
	else if (unlikely (urb->reject))
		status = -EPERM;
	else switch (hcd->state) {
	case HC_STATE_RUNNING:
	case HC_STATE_RESUMING:
doit:
		list_add_tail (&urb->urb_list, &ep->urb_list);
		status = 0;
		break;
	case HC_STATE_SUSPENDED:
		/* HC upstream links (register access, wakeup signaling) can work
		 * even when the downstream links (and DMA etc) are quiesced; let
		 * usbcore talk to the root hub.
		 */
		if (hcd->self.controller->power.power_state.event == PM_EVENT_ON
				&& urb->dev->parent == NULL)
			goto doit;
		/* FALL THROUGH */
	default:
		status = -ESHUTDOWN;
		break;
	}
	spin_unlock_irqrestore (&hcd_data_lock, flags);
	if (status) {
		INIT_LIST_HEAD (&urb->urb_list);
		usbmon_urb_submit_error(&hcd->self, urb, status);
		return status;
	}

	/* increment urb's reference count as part of giving it to the HCD
	 * (which now controls it).  HCD guarantees that it either returns
	 * an error or calls giveback(), but not both.
	 */
	urb = usb_get_urb (urb);
	atomic_inc (&urb->use_count);

	if (urb->dev == hcd->self.root_hub) {
		/* NOTE:  requirement on hub callers (usbfs and the hub
		 * driver, for now) that URBs' urb->transfer_buffer be
		 * valid and usb_buffer_{sync,unmap}() not be needed, since
		 * they could clobber root hub response data.
		 */
		status = rh_urb_enqueue (hcd, urb);
		goto done;
	}

	/* lower level hcd code should use *_dma exclusively,
	 * unless it uses pio or talks to another transport.
	 */
	if (hcd->self.uses_dma) {
		if (usb_pipecontrol (urb->pipe)
			&& !(urb->transfer_flags & URB_NO_SETUP_DMA_MAP))
			urb->setup_dma = dma_map_single (
					hcd->self.controller,
					urb->setup_packet,
					sizeof (struct usb_ctrlrequest),
					DMA_TO_DEVICE);
		if (urb->transfer_buffer_length != 0
			&& !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP))
			urb->transfer_dma = dma_map_single (
					hcd->self.controller,
					urb->transfer_buffer,
					urb->transfer_buffer_length,
					usb_pipein (urb->pipe)
					    ? DMA_FROM_DEVICE
					    : DMA_TO_DEVICE);
	}

	status = hcd->driver->urb_enqueue (hcd, ep, urb, mem_flags);
done:
	if (unlikely (status)) {
		urb_unlink (urb);
		atomic_dec (&urb->use_count);
		if (urb->reject)
			wake_up (&usb_kill_urb_queue);
		usbmon_urb_submit_error(&hcd->self, urb, status);
		usb_put_urb (urb);
	}
	return status;
}

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

/* called in any context */
int usb_hcd_get_frame_number (struct usb_device *udev)
{
	struct usb_hcd	*hcd = bus_to_hcd(udev->bus);

	if (!HC_IS_RUNNING (hcd->state))
		return -ESHUTDOWN;
	return hcd->driver->get_frame_number (hcd);
}

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

/* this makes the hcd giveback() the urb more quickly, by kicking it
 * off hardware queues (which may take a while) and returning it as
 * soon as practical.  we've already set up the urb's return status,
 * but we can't know if the callback completed already.
 */
static int
unlink1 (struct usb_hcd *hcd, struct urb *urb)
{
	int		value;

	if (urb->dev == hcd->self.root_hub)
		value = usb_rh_urb_dequeue (hcd, urb);
	else {

		/* The only reason an HCD might fail this call is if
		 * it has not yet fully queued the urb to begin with.
		 * Such failures should be harmless. */
		value = hcd->driver->urb_dequeue (hcd, urb);
	}

	if (value != 0)
		dev_dbg (hcd->self.controller, "dequeue %p --> %d\n",
				urb, value);
	return value;
}

/*
 * called in any context
 *
 * caller guarantees urb won't be recycled till both unlink()
 * and the urb's completion function return
 */
int usb_hcd_unlink_urb (struct urb *urb, int status)
{
	struct usb_host_endpoint	*ep;
	struct usb_hcd			*hcd = NULL;
	struct device			*sys = NULL;
	unsigned long			flags;
	struct list_head		*tmp;
	int				retval;

	if (!urb)
		return -EINVAL;
	if (!urb->dev || !urb->dev->bus)
		return -ENODEV;
	ep = (usb_pipein(urb->pipe) ? urb->dev->ep_in : urb->dev->ep_out)
			[usb_pipeendpoint(urb->pipe)];
	if (!ep)
		return -ENODEV;

	/*
	 * we contend for urb->status with the hcd core,
	 * which changes it while returning the urb.
	 *
	 * Caller guaranteed that the urb pointer hasn't been freed, and
	 * that it was submitted.  But as a rule it can't know whether or
	 * not it's already been unlinked ... so we respect the reversed
	 * lock sequence needed for the usb_hcd_giveback_urb() code paths
	 * (urb lock, then hcd_data_lock) in case some other CPU is now
	 * unlinking it.
	 */
	spin_lock_irqsave (&urb->lock, flags);
	spin_lock (&hcd_data_lock);

	sys = &urb->dev->dev;
	hcd = bus_to_hcd(urb->dev->bus);
	if (hcd == NULL) {
		retval = -ENODEV;
		goto done;
	}

	/* insist the urb is still queued */
	list_for_each(tmp, &ep->urb_list) {
		if (tmp == &urb->urb_list)
			break;
	}
	if (tmp != &urb->urb_list) {
		retval = -EIDRM;
		goto done;
	}

	/* Any status except -EINPROGRESS means something already started to
	 * unlink this URB from the hardware.  So there's no more work to do.
	 */
	if (urb->status != -EINPROGRESS) {
		retval = -EBUSY;
		goto done;
	}

	/* IRQ setup can easily be broken so that USB controllers
	 * never get completion IRQs ... maybe even the ones we need to
	 * finish unlinking the initial failed usb_set_address()
	 * or device descriptor fetch.
	 */
	if (!test_bit(HCD_FLAG_SAW_IRQ, &hcd->flags)
	    && hcd->self.root_hub != urb->dev) {
		dev_warn (hcd->self.controller, "Unlink after no-IRQ?  "
			"Controller is probably using the wrong IRQ."
			"\n");
		set_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
	}

	urb->status = status;

	spin_unlock (&hcd_data_lock);
	spin_unlock_irqrestore (&urb->lock, flags);

	retval = unlink1 (hcd, urb);
	if (retval == 0)
		retval = -EINPROGRESS;
	return retval;

done:
	spin_unlock (&hcd_data_lock);
	spin_unlock_irqrestore (&urb->lock, flags);
	if (retval != -EIDRM && sys && sys->driver)
		dev_dbg (sys, "hcd_unlink_urb %p fail %d\n", urb, retval);
	return retval;
}

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

/* disables the endpoint: cancels any pending urbs, then synchronizes with
 * the hcd to make sure all endpoint state is gone from hardware, and then
 * waits until the endpoint's queue is completely drained. use for
 * set_configuration, set_interface, driver removal, physical disconnect.
 *
 * example:  a qh stored in ep->hcpriv, holding state related to endpoint
 * type, maxpacket size, toggle, halt status, and scheduling.
 */
void usb_hcd_endpoint_disable (struct usb_device *udev,
		struct usb_host_endpoint *ep)
{
	struct usb_hcd		*hcd;
	struct urb		*urb;

	hcd = bus_to_hcd(udev->bus);
	local_irq_disable ();

	/* ep is already gone from udev->ep_{in,out}[]; no more submits */
rescan:
	spin_lock (&hcd_data_lock);
	list_for_each_entry (urb, &ep->urb_list, urb_list) {
		int	tmp;

		/* the urb may already have been unlinked */
		if (urb->status != -EINPROGRESS)
			continue;
		usb_get_urb (urb);
		spin_unlock (&hcd_data_lock);

		spin_lock (&urb->lock);
		tmp = urb->status;
		if (tmp == -EINPROGRESS)
			urb->status = -ESHUTDOWN;
		spin_unlock (&urb->lock);

		/* kick hcd unless it's already returning this */
		if (tmp == -EINPROGRESS) {
			tmp = urb->pipe;
			unlink1 (hcd, urb);
			dev_dbg (hcd->self.controller,
				"shutdown urb %p pipe %08x ep%d%s%s\n",
				urb, tmp, usb_pipeendpoint (tmp),
				(tmp & USB_DIR_IN) ? "in" : "out",
				({ char *s; \
				 switch (usb_pipetype (tmp)) { \
				 case PIPE_CONTROL:	s = ""; break; \
				 case PIPE_BULK:	s = "-bulk"; break; \
				 case PIPE_INTERRUPT:	s = "-intr"; break; \
				 default: 		s = "-iso"; break; \
				}; s;}));
		}
		usb_put_urb (urb);

		/* list contents may have changed */
		goto rescan;
	}
	spin_unlock (&hcd_data_lock);
	local_irq_enable ();

	/* synchronize with the hardware, so old configuration state
	 * clears out immediately (and will be freed).
	 */
	might_sleep ();
	if (hcd->driver->endpoint_disable)
		hcd->driver->endpoint_disable (hcd, ep);

	/* Wait until the endpoint queue is completely empty.  Most HCDs
	 * will have done this already in their endpoint_disable method,
	 * but some might not.  And there could be root-hub control URBs
	 * still pending since they aren't affected by the HCDs'
	 * endpoint_disable methods.
	 */
	while (!list_empty (&ep->urb_list)) {
		spin_lock_irq (&hcd_data_lock);

		/* The list may have changed while we acquired the spinlock */
		urb = NULL;
		if (!list_empty (&ep->urb_list)) {
			urb = list_entry (ep->urb_list.prev, struct urb,
					urb_list);
			usb_get_urb (urb);
		}
		spin_unlock_irq (&hcd_data_lock);

		if (urb) {
			usb_kill_urb (urb);
			usb_put_urb (urb);
		}
	}
}

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


int hcd_bus_suspend (struct usb_bus *bus)
{
	struct usb_hcd		*hcd;
	int			status;

	hcd = container_of (bus, struct usb_hcd, self);
	if (!hcd->driver->bus_suspend)
		return -ENOENT;
	hcd->state = HC_STATE_QUIESCING;
	status = hcd->driver->bus_suspend (hcd);
	if (status == 0)
		hcd->state = HC_STATE_SUSPENDED;
	else
		dev_dbg(&bus->root_hub->dev, "%s fail, err %d\n",
				"suspend", status);
	return status;
}

int hcd_bus_resume (struct usb_bus *bus)
{
	struct usb_hcd		*hcd;
	int			status;

	hcd = container_of (bus, struct usb_hcd, self);
	if (!hcd->driver->bus_resume)
		return -ENOENT;
	if (hcd->state == HC_STATE_RUNNING)
		return 0;
	hcd->state = HC_STATE_RESUMING;
	status = hcd->driver->bus_resume (hcd);
	if (status == 0)
		hcd->state = HC_STATE_RUNNING;
	else {
		dev_dbg(&bus->root_hub->dev, "%s fail, err %d\n",
				"resume", status);
		usb_hc_died(hcd);
	}
	return status;
}

/* Workqueue routine for root-hub remote wakeup */
static void hcd_resume_work(struct work_struct *work)
{
	struct usb_hcd *hcd = container_of(work, struct usb_hcd, wakeup_work);
	struct usb_device *udev = hcd->self.root_hub;

	usb_lock_device(udev);
	usb_mark_last_busy(udev);
	usb_external_resume_device(udev);
	usb_unlock_device(udev);
}