dummy_hcd.c

ARM S3C2410 USB SLAVE LINUX驱动

	if (!timer_pending (&dum->timer))
		mod_timer (&dum->timer, jiffies + 1);

	spin_unlock_irqrestore (&dum->lock, flags);
	return 0;
}

static int dummy_urb_dequeue (struct usb_hcd *hcd, struct urb *urb)
{
	struct dummy	*dum;
	unsigned long	flags;

	/* giveback happens automatically in timer callback,
	 * so make sure the callback happens */
	dum = hcd_to_dummy (hcd);
	spin_lock_irqsave (&dum->lock, flags);
	if (dum->rh_state != DUMMY_RH_RUNNING && !list_empty(&dum->urbp_list))
		mod_timer (&dum->timer, jiffies);
	spin_unlock_irqrestore (&dum->lock, flags);
	return 0;
}

static void maybe_set_status (struct urb *urb, int status)
{
	spin_lock (&urb->lock);
	if (urb->status == -EINPROGRESS)
		urb->status = status;
	spin_unlock (&urb->lock);
}

/* transfer up to a frame's worth; caller must own lock */
static int
transfer (struct dummy *dum, struct urb *urb, struct dummy_ep *ep, int limit)
{
	struct dummy_request	*req;

top:
	/* if there's no request queued, the device is NAKing; return */
	list_for_each_entry (req, &ep->queue, queue) {
		unsigned	host_len, dev_len, len;
		int		is_short, to_host;
		int		rescan = 0;

		/* 1..N packets of ep->ep.maxpacket each ... the last one
		 * may be short (including zero length).
		 *
		 * writer can send a zlp explicitly (length 0) or implicitly
		 * (length mod maxpacket zero, and 'zero' flag); they always
		 * terminate reads.
		 */
		host_len = urb->transfer_buffer_length - urb->actual_length;
		dev_len = req->req.length - req->req.actual;
		len = min (host_len, dev_len);

		/* FIXME update emulated data toggle too */

		to_host = usb_pipein (urb->pipe);
		if (unlikely (len == 0))
			is_short = 1;
		else {
			char		*ubuf, *rbuf;

			/* not enough bandwidth left? */
			if (limit < ep->ep.maxpacket && limit < len)
				break;
			len = min (len, (unsigned) limit);
			if (len == 0)
				break;

			/* use an extra pass for the final short packet */
			if (len > ep->ep.maxpacket) {
				rescan = 1;
				len -= (len % ep->ep.maxpacket);
			}
			is_short = (len % ep->ep.maxpacket) != 0;

			/* else transfer packet(s) */
			ubuf = urb->transfer_buffer + urb->actual_length;
			rbuf = req->req.buf + req->req.actual;
			if (to_host)
				memcpy (ubuf, rbuf, len);
			else
				memcpy (rbuf, ubuf, len);
			ep->last_io = jiffies;

			limit -= len;
			urb->actual_length += len;
			req->req.actual += len;
		}

		/* short packets terminate, maybe with overflow/underflow.
		 * it's only really an error to write too much.
		 *
		 * partially filling a buffer optionally blocks queue advances
		 * (so completion handlers can clean up the queue) but we don't
		 * need to emulate such data-in-flight.  so we only show part
		 * of the URB_SHORT_NOT_OK effect: completion status.
		 */
		if (is_short) {
			if (host_len == dev_len) {
				req->req.status = 0;
				maybe_set_status (urb, 0);
			} else if (to_host) {
				req->req.status = 0;
				if (dev_len > host_len)
					maybe_set_status (urb, -EOVERFLOW);
				else
					maybe_set_status (urb,
						(urb->transfer_flags
							& URB_SHORT_NOT_OK)
						? -EREMOTEIO : 0);
			} else if (!to_host) {
				maybe_set_status (urb, 0);
				if (host_len > dev_len)
					req->req.status = -EOVERFLOW;
				else
					req->req.status = 0;
			}

		/* many requests terminate without a short packet */
		} else {
			if (req->req.length == req->req.actual
					&& !req->req.zero)
				req->req.status = 0;
			if (urb->transfer_buffer_length == urb->actual_length
					&& !(urb->transfer_flags
						& URB_ZERO_PACKET)) {
				maybe_set_status (urb, 0);
			}
		}

		/* device side completion --> continuable */
		if (req->req.status != -EINPROGRESS) {
			list_del_init (&req->queue);

			spin_unlock (&dum->lock);
			req->req.complete (&ep->ep, &req->req);
			spin_lock (&dum->lock);

			/* requests might have been unlinked... */
			rescan = 1;
		}

		/* host side completion --> terminate */
		if (urb->status != -EINPROGRESS)
			break;

		/* rescan to continue with any other queued i/o */
		if (rescan)
			goto top;
	}
	return limit;
}

static int periodic_bytes (struct dummy *dum, struct dummy_ep *ep)
{
	int	limit = ep->ep.maxpacket;

	if (dum->gadget.speed == USB_SPEED_HIGH) {
		int	tmp;

		/* high bandwidth mode */
		tmp = le16_to_cpu(ep->desc->wMaxPacketSize);
		tmp = (tmp >> 11) & 0x03;
		tmp *= 8 /* applies to entire frame */;
		limit += limit * tmp;
	}
	return limit;
}

#define is_active(dum)	((dum->port_status & \
		(USB_PORT_STAT_CONNECTION | USB_PORT_STAT_ENABLE | \
			USB_PORT_STAT_SUSPEND)) \
		== (USB_PORT_STAT_CONNECTION | USB_PORT_STAT_ENABLE))

static struct dummy_ep *find_endpoint (struct dummy *dum, u8 address)
{
	int		i;

	if (!is_active (dum))
		return NULL;
	if ((address & ~USB_DIR_IN) == 0)
		return &dum->ep [0];
	for (i = 1; i < DUMMY_ENDPOINTS; i++) {
		struct dummy_ep	*ep = &dum->ep [i];

		if (!ep->desc)
			continue;
		if (ep->desc->bEndpointAddress == address)
			return ep;
	}
	return NULL;
}

#undef is_active

#define Dev_Request	(USB_TYPE_STANDARD | USB_RECIP_DEVICE)
#define Dev_InRequest	(Dev_Request | USB_DIR_IN)
#define Intf_Request	(USB_TYPE_STANDARD | USB_RECIP_INTERFACE)
#define Intf_InRequest	(Intf_Request | USB_DIR_IN)
#define Ep_Request	(USB_TYPE_STANDARD | USB_RECIP_ENDPOINT)
#define Ep_InRequest	(Ep_Request | USB_DIR_IN)

/* drive both sides of the transfers; looks like irq handlers to
 * both drivers except the callbacks aren't in_irq().
 */
static void dummy_timer (unsigned long _dum)
{
	struct dummy		*dum = (struct dummy *) _dum;
	struct urbp		*urbp, *tmp;
	unsigned long		flags;
	int			limit, total;
	int			i;

	/* simplistic model for one frame's bandwidth */
	switch (dum->gadget.speed) {
	case USB_SPEED_LOW:
		total = 8/*bytes*/ * 12/*packets*/;
		break;
	case USB_SPEED_FULL:
		total = 64/*bytes*/ * 19/*packets*/;
		break;
	case USB_SPEED_HIGH:
		total = 512/*bytes*/ * 13/*packets*/ * 8/*uframes*/;
		break;
	default:
		dev_err (dummy_dev(dum), "bogus device speed\n");
		return;
	}

	/* FIXME if HZ != 1000 this will probably misbehave ... */

	/* look at each urb queued by the host side driver */
	spin_lock_irqsave (&dum->lock, flags);

	if (!dum->udev) {
		dev_err (dummy_dev(dum),
				"timer fired with no URBs pending?\n");
		spin_unlock_irqrestore (&dum->lock, flags);
		return;
	}

	for (i = 0; i < DUMMY_ENDPOINTS; i++) {
		if (!ep_name [i])
			break;
		dum->ep [i].already_seen = 0;
	}

restart:
	list_for_each_entry_safe (urbp, tmp, &dum->urbp_list, urbp_list) {
		struct urb		*urb;
		struct dummy_request	*req;
		u8			address;
		struct dummy_ep		*ep = NULL;
		int			type;

		urb = urbp->urb;
		if (urb->status != -EINPROGRESS) {
			/* likely it was just unlinked */
			goto return_urb;
		} else if (dum->rh_state != DUMMY_RH_RUNNING)
			continue;
		type = usb_pipetype (urb->pipe);

		/* used up this frame's non-periodic bandwidth?
		 * FIXME there's infinite bandwidth for control and
		 * periodic transfers ... unrealistic.
		 */
		if (total <= 0 && type == PIPE_BULK)
			continue;

		/* find the gadget's ep for this request (if configured) */
		address = usb_pipeendpoint (urb->pipe);
		if (usb_pipein (urb->pipe))
			address |= USB_DIR_IN;
		ep = find_endpoint(dum, address);
		if (!ep) {
			/* set_configuration() disagreement */
			dev_dbg (dummy_dev(dum),
				"no ep configured for urb %p\n",
				urb);
			maybe_set_status (urb, -EPROTO);
			goto return_urb;
		}

		if (ep->already_seen)
			continue;
		ep->already_seen = 1;
		if (ep == &dum->ep [0] && urb->error_count) {
			ep->setup_stage = 1;	/* a new urb */
			urb->error_count = 0;
		}
		if (ep->halted && !ep->setup_stage) {
			/* NOTE: must not be iso! */
			dev_dbg (dummy_dev(dum), "ep %s halted, urb %p\n",
					ep->ep.name, urb);
			maybe_set_status (urb, -EPIPE);
			goto return_urb;
		}
		/* FIXME make sure both ends agree on maxpacket */

		/* handle control requests */
		if (ep == &dum->ep [0] && ep->setup_stage) {
			struct usb_ctrlrequest		setup;
			int				value = 1;
			struct dummy_ep			*ep2;
			unsigned			w_index;
			unsigned			w_value;

			setup = *(struct usb_ctrlrequest*) urb->setup_packet;
			w_index = le16_to_cpu(setup.wIndex);
			w_value = le16_to_cpu(setup.wValue);
			if (le16_to_cpu(setup.wLength) !=
					urb->transfer_buffer_length) {
				maybe_set_status (urb, -EOVERFLOW);
				goto return_urb;
			}

			/* paranoia, in case of stale queued data */
			list_for_each_entry (req, &ep->queue, queue) {
				list_del_init (&req->queue);
				req->req.status = -EOVERFLOW;
				dev_dbg (udc_dev(dum), "stale req = %p\n",
						req);

				spin_unlock (&dum->lock);
				req->req.complete (&ep->ep, &req->req);
				spin_lock (&dum->lock);
				ep->already_seen = 0;
				goto restart;
			}

			/* gadget driver never sees set_address or operations
			 * on standard feature flags.  some hardware doesn't
			 * even expose them.
			 */
			ep->last_io = jiffies;
			ep->setup_stage = 0;
			ep->halted = 0;
			switch (setup.bRequest) {
			case USB_REQ_SET_ADDRESS:
				if (setup.bRequestType != Dev_Request)
					break;
				dum->address = w_value;
				maybe_set_status (urb, 0);
				dev_dbg (udc_dev(dum), "set_address = %d\n",
						w_value);
				value = 0;
				break;
			case USB_REQ_SET_FEATURE:
				if (setup.bRequestType == Dev_Request) {
					value = 0;
					switch (w_value) {
					case USB_DEVICE_REMOTE_WAKEUP:
						break;
					case USB_DEVICE_B_HNP_ENABLE:
						dum->gadget.b_hnp_enable = 1;
						break;
					case USB_DEVICE_A_HNP_SUPPORT:
						dum->gadget.a_hnp_support = 1;
						break;
					case USB_DEVICE_A_ALT_HNP_SUPPORT:
						dum->gadget.a_alt_hnp_support
							= 1;
						break;
					default:
						value = -EOPNOTSUPP;
					}
					if (value == 0) {
						dum->devstatus |=
							(1 << w_value);
						maybe_set_status (urb, 0);
					}

				} else if (setup.bRequestType == Ep_Request) {
					// endpoint halt
					ep2 = find_endpoint (dum, w_index);
					if (!ep2) {
						value = -EOPNOTSUPP;
						break;
					}
					ep2->halted = 1;
					value = 0;
					maybe_set_status (urb, 0);
				}
				break;
			case USB_REQ_CLEAR_FEATURE:
				if (setup.bRequestType == Dev_Request) {
					switch (w_value) {
					case USB_DEVICE_REMOTE_WAKEUP:
						dum->devstatus &= ~(1 <<
							USB_DEVICE_REMOTE_WAKEUP);
						value = 0;
						maybe_set_status (urb, 0);
						break;
					default:
						value = -EOPNOTSUPP;
						break;
					}
				} else if (setup.bRequestType == Ep_Request) {
					// endpoint halt
					ep2 = find_endpoint (dum, w_index);
					if (!ep2) {
						value = -EOPNOTSUPP;
						break;
					}
					ep2->halted = 0;
					value = 0;
					maybe_set_status (urb, 0);
				}
				break;
			case USB_REQ_GET_STATUS:
				if (setup.bRequestType == Dev_InRequest
						|| setup.bRequestType
							== Intf_InRequest
						|| setup.bRequestType
							== Ep_InRequest
						) {
					char *buf;

					// device: remote wakeup, selfpowered
					// interface: nothing
					// endpoint: halt
					buf = (char *)urb->transfer_buffer;
					if (urb->transfer_buffer_length > 0) {
						if (setup.bRequestType ==
								Ep_InRequest) {
	ep2 = find_endpoint (dum, w_index);
	if (!ep2) {
		value = -EOPNOTSUPP;
		break;
	}
	buf [0] = ep2->halted;
						} else if (setup.bRequestType ==
								Dev_InRequest) {
							buf [0] = (u8)
								dum->devstatus;
						} else
							buf [0] = 0;
					}
					if (urb->transfer_buffer_length > 1)
						buf [1] = 0;
					urb->actual_length = min (2,
						urb->transfer_buffer_length);
					value = 0;
					maybe_set_status (urb, 0);
				}
				break;
			}

			/* gadget driver handles all other requests.  block
			 * until setup() returns; no reentrancy issues etc.
			 */
			if (value > 0) {
				spin_unlock (&dum->lock);
				value = dum->driver->setup (&dum->gadget,
						&setup);
				spin_lock (&dum->lock);

				if (value >= 0) {
					/* no delays (max 64KB data stage) */
					limit = 64*1024;
					goto treat_control_like_bulk;
				}
				/* error, see below */
			}

			if (value < 0) {
				if (value != -EOPNOTSUPP)
					dev_dbg (udc_dev(dum),
						"setup --> %d\n",
						value);
				maybe_set_status (urb, -EPIPE);
				urb->actual_length = 0;
			}

			goto return_urb;
		}

		/* non-control requests */
		limit = total;
		switch (usb_pipetype (urb->pipe)) {
		case PIPE_ISOCHRONOUS:
			/* FIXME is it urb->interval since the last xfer?
			 * use urb->iso_frame_desc[i].
			 * complete whether or not ep has requests queued.
			 * report random errors, to debug drivers.
			 */
			limit = max (limit, periodic_bytes (dum, ep));
			maybe_set_status (urb, -ENOSYS);
			break;

		case PIPE_INTERRUPT:
			/* FIXME is it urb->interval since the last xfer?
			 * this almost certainly polls too fast.
			 */
			limit = max (limit, periodic_bytes (dum, ep));
			/* FALLTHROUGH */

		// case PIPE_BULK:  case PIPE_CONTROL:
		default:
		treat_control_like_bulk:
			ep->last_io = jiffies;
			total = transfer (dum, urb, ep, limit);
			break;
		}

		/* incomplete transfer? */
		if (urb->status == -EINPROGRESS)
			continue;

return_urb:
		urb->hcpriv = NULL;
		list_del (&urbp->urbp_list);
		kfree (urbp);