dummy_hcd.c

h内核

static int dummy_set_selfpowered (struct usb_gadget *_gadget, int value)
{
	struct dummy	*dum;

	dum = gadget_to_dummy (_gadget);
	if (value)
		dum->devstatus |= (1 << USB_DEVICE_SELF_POWERED);
	else
		dum->devstatus &= ~(1 << USB_DEVICE_SELF_POWERED);
	return 0;
}

static const struct usb_gadget_ops dummy_ops = {
	.get_frame	= dummy_g_get_frame,
	.wakeup		= dummy_wakeup,
	.set_selfpowered = dummy_set_selfpowered,
};

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

/* "function" sysfs attribute */
static ssize_t
show_function (struct device *dev, char *buf)
{
	struct dummy	*dum = gadget_dev_to_dummy (dev);

	if (!dum->driver || !dum->driver->function)
		return 0;
	return scnprintf (buf, PAGE_SIZE, "%s\n", dum->driver->function);
}
DEVICE_ATTR (function, S_IRUGO, show_function, NULL);

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

/*
 * Driver registration/unregistration.
 *
 * This is basically hardware-specific; there's usually only one real USB
 * device (not host) controller since that's how USB devices are intended
 * to work.  So most implementations of these api calls will rely on the
 * fact that only one driver will ever bind to the hardware.  But curious
 * hardware can be built with discrete components, so the gadget API doesn't
 * require that assumption.
 *
 * For this emulator, it might be convenient to create a usb slave device
 * for each driver that registers:  just add to a big root hub.
 */

static void
dummy_udc_release (struct device *dev)
{
}

static void
dummy_pdev_release (struct device *dev)
{
}

static int
dummy_register_udc (struct dummy *dum)
{
	int		rc;

	strcpy (dum->gadget.dev.bus_id, "udc");
	dum->gadget.dev.parent = dummy_dev(dum);
	dum->gadget.dev.release = dummy_udc_release;

	rc = device_register (&dum->gadget.dev);
	if (rc == 0)
		device_create_file (&dum->gadget.dev, &dev_attr_function);
	return rc;
}

static void
dummy_unregister_udc (struct dummy *dum)
{
	device_remove_file (&dum->gadget.dev, &dev_attr_function);
	device_unregister (&dum->gadget.dev);
}

int
usb_gadget_register_driver (struct usb_gadget_driver *driver)
{
	struct dummy	*dum = the_controller;
	int		retval, i;

	if (!dum)
		return -EINVAL;
	if (dum->driver)
		return -EBUSY;
	if (!driver->bind || !driver->unbind || !driver->setup
			|| driver->speed == USB_SPEED_UNKNOWN)
		return -EINVAL;

	/*
	 * SLAVE side init ... the layer above hardware, which
	 * can't enumerate without help from the driver we're binding.
	 */
	dum->gadget.name = gadget_name;
	dum->gadget.ops = &dummy_ops;
	dum->gadget.is_dualspeed = 1;

	dum->devstatus = 0;
	dum->resuming = 0;

	INIT_LIST_HEAD (&dum->gadget.ep_list);
	for (i = 0; i < DUMMY_ENDPOINTS; i++) {
		struct dummy_ep	*ep = &dum->ep [i];

		if (!ep_name [i])
			break;
		ep->ep.name = ep_name [i];
		ep->ep.ops = &dummy_ep_ops;
		list_add_tail (&ep->ep.ep_list, &dum->gadget.ep_list);
		ep->halted = ep->already_seen = ep->setup_stage = 0;
		ep->ep.maxpacket = ~0;
		ep->last_io = jiffies;
		ep->gadget = &dum->gadget;
		ep->desc = NULL;
		INIT_LIST_HEAD (&ep->queue);
	}

	dum->gadget.ep0 = &dum->ep [0].ep;
	dum->ep [0].ep.maxpacket = 64;
	list_del_init (&dum->ep [0].ep.ep_list);
	INIT_LIST_HEAD(&dum->fifo_req.queue);

	dum->driver = driver;
	dum->gadget.dev.driver = &driver->driver;
	dev_dbg (dummy_dev(dum), "binding gadget driver '%s'\n",
			driver->driver.name);
	if ((retval = driver->bind (&dum->gadget)) != 0) {
		dum->driver = NULL;
		dum->gadget.dev.driver = NULL;
		return retval;
	}

	// FIXME: Check these calls for errors and re-order
	driver->driver.bus = dum->gadget.dev.parent->bus;
	driver_register (&driver->driver);

	device_bind_driver (&dum->gadget.dev);

	/* khubd will enumerate this in a while */
	dum->port_status |= USB_PORT_STAT_CONNECTION
		| (1 << USB_PORT_FEAT_C_CONNECTION);
	return 0;
}
EXPORT_SYMBOL (usb_gadget_register_driver);

/* caller must hold lock */
static void
stop_activity (struct dummy *dum, struct usb_gadget_driver *driver)
{
	struct dummy_ep	*ep;

	/* prevent any more requests */
	dum->address = 0;

	/* The timer is left running so that outstanding URBs can fail */

	/* nuke any pending requests first, so driver i/o is quiesced */
	list_for_each_entry (ep, &dum->gadget.ep_list, ep.ep_list)
		nuke (dum, ep);

	/* driver now does any non-usb quiescing necessary */
	if (driver) {
		spin_unlock (&dum->lock);
		driver->disconnect (&dum->gadget);
		spin_lock (&dum->lock);
	}
}

int
usb_gadget_unregister_driver (struct usb_gadget_driver *driver)
{
	struct dummy	*dum = the_controller;
	unsigned long	flags;

	if (!dum)
		return -ENODEV;
	if (!driver || driver != dum->driver)
		return -EINVAL;

	dev_dbg (dummy_dev(dum), "unregister gadget driver '%s'\n",
			driver->driver.name);

	spin_lock_irqsave (&dum->lock, flags);
	stop_activity (dum, driver);
	dum->port_status &= ~(USB_PORT_STAT_CONNECTION | USB_PORT_STAT_ENABLE |
			USB_PORT_STAT_LOW_SPEED | USB_PORT_STAT_HIGH_SPEED);
	dum->port_status |= (1 << USB_PORT_FEAT_C_CONNECTION);
	spin_unlock_irqrestore (&dum->lock, flags);

	driver->unbind (&dum->gadget);
	dum->driver = NULL;

	device_release_driver (&dum->gadget.dev);

	driver_unregister (&driver->driver);

	return 0;
}
EXPORT_SYMBOL (usb_gadget_unregister_driver);

#undef is_enabled

int net2280_set_fifo_mode (struct usb_gadget *gadget, int mode)
{
	return -ENOSYS;
}
EXPORT_SYMBOL (net2280_set_fifo_mode);

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

/* MASTER/HOST SIDE DRIVER
 *
 * this uses the hcd framework to hook up to host side drivers.
 * its root hub will only have one device, otherwise it acts like
 * a normal host controller.
 *
 * when urbs are queued, they're just stuck on a list that we
 * scan in a timer callback.  that callback connects writes from
 * the host with reads from the device, and so on, based on the
 * usb 2.0 rules.
 */

static int dummy_urb_enqueue (
	struct usb_hcd			*hcd,
	struct usb_host_endpoint	*ep,
	struct urb			*urb,
	int				mem_flags
) {
	struct dummy	*dum;
	struct urbp	*urbp;
	unsigned long	flags;

	if (!urb->transfer_buffer && urb->transfer_buffer_length)
		return -EINVAL;

	urbp = kmalloc (sizeof *urbp, mem_flags);
	if (!urbp)
		return -ENOMEM;
	urbp->urb = urb;

	dum = hcd_to_dummy (hcd);
	spin_lock_irqsave (&dum->lock, flags);

	if (!dum->udev) {
		dum->udev = urb->dev;
		usb_get_dev (dum->udev);
	} else if (unlikely (dum->udev != urb->dev))
		dev_err (dummy_dev(dum), "usb_device address has changed!\n");

	list_add_tail (&urbp->urbp_list, &dum->urbp_list);
	urb->hcpriv = urbp;
	if (usb_pipetype (urb->pipe) == PIPE_CONTROL)
		urb->error_count = 1;		/* mark as a new urb */

	/* kick the scheduler, it'll do the rest */
	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)
{
	/* giveback happens automatically in timer callback */
	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 = le16_to_cpu (tmp);
		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;
		}
		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;

			setup = *(struct usb_ctrlrequest*) urb->setup_packet;
			le16_to_cpus (&setup.wIndex);
			le16_to_cpus (&setup.wValue);
			le16_to_cpus (&setup.wLength);
			if (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 (dummy_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 = setup.wValue;
				maybe_set_status (urb, 0);
				dev_dbg (dummy_dev(dum), "set_address = %d\n",
						setup.wValue);
				value = 0;
				break;
			case USB_REQ_SET_FEATURE:
				if (setup.bRequestType == Dev_Request) {
					value = 0;
					switch (setup.wValue) {
					case USB_DEVICE_REMOTE_WAKEUP:
						break;
					default:
						value = -EOPNOTSUPP;
					}
					if (value == 0) {
						dum->devstatus |=
							(1 << setup.wValue);
						maybe_set_status (urb, 0);
					}