hcd.c

linux-2.6.15.6

		// always USB_DIR_IN, toward host
		memcpy (ubuf, bufp, len);

		/* report whether RH hardware supports remote wakeup */
		if (patch_wakeup &&
				len > offsetof (struct usb_config_descriptor,
						bmAttributes))
			((struct usb_config_descriptor *)ubuf)->bmAttributes
				|= USB_CONFIG_ATT_WAKEUP;
	}

	/* any errors get returned through the urb completion */
	local_irq_save (flags);
	spin_lock (&urb->lock);
	if (urb->status == -EINPROGRESS)
		urb->status = status;
	spin_unlock (&urb->lock);
	usb_hcd_giveback_urb (hcd, urb, NULL);
	local_irq_restore (flags);
	return 0;
}

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

/*
 * Root Hub interrupt transfers are polled using a timer if the
 * driver requests it; otherwise the driver is responsible for
 * calling usb_hcd_poll_rh_status() when an event occurs.
 *
 * Completions are called in_interrupt(), but they may or may not
 * be in_irq().
 */
void usb_hcd_poll_rh_status(struct usb_hcd *hcd)
{
	struct urb	*urb;
	int		length;
	unsigned long	flags;
	char		buffer[4];	/* Any root hubs with > 31 ports? */

	if (!hcd->uses_new_polling && !hcd->status_urb)
		return;

	length = hcd->driver->hub_status_data(hcd, buffer);
	if (length > 0) {

		/* try to complete the status urb */
		local_irq_save (flags);
		spin_lock(&hcd_root_hub_lock);
		urb = hcd->status_urb;
		if (urb) {
			spin_lock(&urb->lock);
			if (urb->status == -EINPROGRESS) {
				hcd->poll_pending = 0;
				hcd->status_urb = NULL;
				urb->status = 0;
				urb->hcpriv = NULL;
				urb->actual_length = length;
				memcpy(urb->transfer_buffer, buffer, length);
			} else		/* urb has been unlinked */
				length = 0;
			spin_unlock(&urb->lock);
		} else
			length = 0;
		spin_unlock(&hcd_root_hub_lock);

		/* local irqs are always blocked in completions */
		if (length > 0)
			usb_hcd_giveback_urb (hcd, urb, NULL);
		else
			hcd->poll_pending = 1;
		local_irq_restore (flags);
	}

	/* The USB 2.0 spec says 256 ms.  This is close enough and won't
	 * exceed that limit if HZ is 100. */
	if (hcd->uses_new_polling ? hcd->poll_rh :
			(length == 0 && hcd->status_urb != NULL))
		mod_timer (&hcd->rh_timer, jiffies + msecs_to_jiffies(250));
}
EXPORT_SYMBOL_GPL(usb_hcd_poll_rh_status);

/* timer callback */
static void rh_timer_func (unsigned long _hcd)
{
	usb_hcd_poll_rh_status((struct usb_hcd *) _hcd);
}

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

static int rh_queue_status (struct usb_hcd *hcd, struct urb *urb)
{
	int		retval;
	unsigned long	flags;
	int		len = 1 + (urb->dev->maxchild / 8);

	spin_lock_irqsave (&hcd_root_hub_lock, flags);
	if (urb->status != -EINPROGRESS)	/* already unlinked */
		retval = urb->status;
	else if (hcd->status_urb || urb->transfer_buffer_length < len) {
		dev_dbg (hcd->self.controller, "not queuing rh status urb\n");
		retval = -EINVAL;
	} else {
		hcd->status_urb = urb;
		urb->hcpriv = hcd;	/* indicate it's queued */

		if (!hcd->uses_new_polling)
			mod_timer (&hcd->rh_timer, jiffies +
					msecs_to_jiffies(250));

		/* If a status change has already occurred, report it ASAP */
		else if (hcd->poll_pending)
			mod_timer (&hcd->rh_timer, jiffies);
		retval = 0;
	}
	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
	return retval;
}

static int rh_urb_enqueue (struct usb_hcd *hcd, struct urb *urb)
{
	if (usb_pipeint (urb->pipe))
		return rh_queue_status (hcd, urb);
	if (usb_pipecontrol (urb->pipe))
		return rh_call_control (hcd, urb);
	return -EINVAL;
}

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

/* Asynchronous unlinks of root-hub control URBs are legal, but they
 * don't do anything.  Status URB unlinks must be made in process context
 * with interrupts enabled.
 */
static int usb_rh_urb_dequeue (struct usb_hcd *hcd, struct urb *urb)
{
	if (usb_pipeendpoint(urb->pipe) == 0) {	/* Control URB */
		if (in_interrupt())
			return 0;		/* nothing to do */

		spin_lock_irq(&urb->lock);	/* from usb_kill_urb */
		++urb->reject;
		spin_unlock_irq(&urb->lock);

		wait_event(usb_kill_urb_queue,
				atomic_read(&urb->use_count) == 0);

		spin_lock_irq(&urb->lock);
		--urb->reject;
		spin_unlock_irq(&urb->lock);

	} else {				/* Status URB */
		if (!hcd->uses_new_polling)
			del_timer_sync (&hcd->rh_timer);
		local_irq_disable ();
		spin_lock (&hcd_root_hub_lock);
		if (urb == hcd->status_urb) {
			hcd->status_urb = NULL;
			urb->hcpriv = NULL;
		} else
			urb = NULL;		/* wasn't fully queued */
		spin_unlock (&hcd_root_hub_lock);
		if (urb)
			usb_hcd_giveback_urb (hcd, urb, NULL);
		local_irq_enable ();
	}

	return 0;
}

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

/* exported only within usbcore */
struct usb_bus *usb_bus_get(struct usb_bus *bus)
{
	if (bus)
		kref_get(&bus->kref);
	return bus;
}

static void usb_host_release(struct kref *kref)
{
	struct usb_bus *bus = container_of(kref, struct usb_bus, kref);

	if (bus->release)
		bus->release(bus);
}

/* exported only within usbcore */
void usb_bus_put(struct usb_bus *bus)
{
	if (bus)
		kref_put(&bus->kref, usb_host_release);
}

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

static struct class *usb_host_class;

int usb_host_init(void)
{
	int retval = 0;

	usb_host_class = class_create(THIS_MODULE, "usb_host");
	if (IS_ERR(usb_host_class))
		retval = PTR_ERR(usb_host_class);
	return retval;
}

void usb_host_cleanup(void)
{
	class_destroy(usb_host_class);
}

/**
 * usb_bus_init - shared initialization code
 * @bus: the bus structure being initialized
 *
 * This code is used to initialize a usb_bus structure, memory for which is
 * separately managed.
 */
static void usb_bus_init (struct usb_bus *bus)
{
	memset (&bus->devmap, 0, sizeof(struct usb_devmap));

	bus->devnum_next = 1;

	bus->root_hub = NULL;
	bus->hcpriv = NULL;
	bus->busnum = -1;
	bus->bandwidth_allocated = 0;
	bus->bandwidth_int_reqs  = 0;
	bus->bandwidth_isoc_reqs = 0;

	INIT_LIST_HEAD (&bus->bus_list);

	kref_init(&bus->kref);
}

/**
 * usb_alloc_bus - creates a new USB host controller structure
 * @op: pointer to a struct usb_operations that this bus structure should use
 * Context: !in_interrupt()
 *
 * Creates a USB host controller bus structure with the specified 
 * usb_operations and initializes all the necessary internal objects.
 *
 * If no memory is available, NULL is returned.
 *
 * The caller should call usb_put_bus() when it is finished with the structure.
 */
struct usb_bus *usb_alloc_bus (struct usb_operations *op)
{
	struct usb_bus *bus;

	bus = kzalloc (sizeof *bus, GFP_KERNEL);
	if (!bus)
		return NULL;
	usb_bus_init (bus);
	bus->op = op;
	return bus;
}

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

/**
 * usb_register_bus - registers the USB host controller with the usb core
 * @bus: pointer to the bus to register
 * Context: !in_interrupt()
 *
 * Assigns a bus number, and links the controller into usbcore data
 * structures so that it can be seen by scanning the bus list.
 */
static int usb_register_bus(struct usb_bus *bus)
{
	int busnum;

	down (&usb_bus_list_lock);
	busnum = find_next_zero_bit (busmap.busmap, USB_MAXBUS, 1);
	if (busnum < USB_MAXBUS) {
		set_bit (busnum, busmap.busmap);
		bus->busnum = busnum;
	} else {
		printk (KERN_ERR "%s: too many buses\n", usbcore_name);
		up(&usb_bus_list_lock);
		return -E2BIG;
	}

	bus->class_dev = class_device_create(usb_host_class, NULL, MKDEV(0,0),
					     bus->controller, "usb_host%d", busnum);
	if (IS_ERR(bus->class_dev)) {
		clear_bit(busnum, busmap.busmap);
		up(&usb_bus_list_lock);
		return PTR_ERR(bus->class_dev);
	}

	class_set_devdata(bus->class_dev, bus);

	/* Add it to the local list of buses */
	list_add (&bus->bus_list, &usb_bus_list);
	up (&usb_bus_list_lock);

	usb_notify_add_bus(bus);

	dev_info (bus->controller, "new USB bus registered, assigned bus number %d\n", bus->busnum);
	return 0;
}

/**
 * usb_deregister_bus - deregisters the USB host controller
 * @bus: pointer to the bus to deregister
 * Context: !in_interrupt()
 *
 * Recycles the bus number, and unlinks the controller from usbcore data
 * structures so that it won't be seen by scanning the bus list.
 */
static void usb_deregister_bus (struct usb_bus *bus)
{
	dev_info (bus->controller, "USB bus %d deregistered\n", bus->busnum);

	/*
	 * NOTE: make sure that all the devices are removed by the
	 * controller code, as well as having it call this when cleaning
	 * itself up
	 */
	down (&usb_bus_list_lock);
	list_del (&bus->bus_list);
	up (&usb_bus_list_lock);

	usb_notify_remove_bus(bus);

	clear_bit (bus->busnum, busmap.busmap);

	class_device_unregister(bus->class_dev);
}

/**
 * register_root_hub - called by usb_add_hcd() to register a root hub
 * @usb_dev: the usb root hub device to be registered.
 * @hcd: host controller for this root hub
 *
 * This function registers the root hub with the USB subsystem.  It sets up
 * the device properly in the device tree and stores the root_hub pointer
 * in the bus structure, then calls usb_new_device() to register the usb
 * device.  It also assigns the root hub's USB address (always 1).
 */
static int register_root_hub (struct usb_device *usb_dev,
		struct usb_hcd *hcd)
{
	struct device *parent_dev = hcd->self.controller;
	const int devnum = 1;
	int retval;

	usb_dev->devnum = devnum;
	usb_dev->bus->devnum_next = devnum + 1;
	memset (&usb_dev->bus->devmap.devicemap, 0,
			sizeof usb_dev->bus->devmap.devicemap);
	set_bit (devnum, usb_dev->bus->devmap.devicemap);
	usb_set_device_state(usb_dev, USB_STATE_ADDRESS);

	down (&usb_bus_list_lock);
	usb_dev->bus->root_hub = usb_dev;

	usb_dev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(64);
	retval = usb_get_device_descriptor(usb_dev, USB_DT_DEVICE_SIZE);
	if (retval != sizeof usb_dev->descriptor) {
		usb_dev->bus->root_hub = NULL;
		up (&usb_bus_list_lock);
		dev_dbg (parent_dev, "can't read %s device descriptor %d\n",
				usb_dev->dev.bus_id, retval);
		return (retval < 0) ? retval : -EMSGSIZE;
	}

	usb_lock_device (usb_dev);
	retval = usb_new_device (usb_dev);
	usb_unlock_device (usb_dev);
	if (retval) {
		usb_dev->bus->root_hub = NULL;
		dev_err (parent_dev, "can't register root hub for %s, %d\n",
				usb_dev->dev.bus_id, retval);
	}
	up (&usb_bus_list_lock);

	if (retval == 0) {
		spin_lock_irq (&hcd_root_hub_lock);
		hcd->rh_registered = 1;
		spin_unlock_irq (&hcd_root_hub_lock);

		/* Did the HC die before the root hub was registered? */
		if (hcd->state == HC_STATE_HALT)
			usb_hc_died (hcd);	/* This time clean up */
	}

	return retval;
}

void usb_enable_root_hub_irq (struct usb_bus *bus)
{
	struct usb_hcd *hcd;

	hcd = container_of (bus, struct usb_hcd, self);
	if (hcd->driver->hub_irq_enable && !hcd->poll_rh &&
			hcd->state != HC_STATE_HALT)
		hcd->driver->hub_irq_enable (hcd);
}


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

/**
 * usb_calc_bus_time - approximate periodic transaction time in nanoseconds
 * @speed: from dev->speed; USB_SPEED_{LOW,FULL,HIGH}
 * @is_input: true iff the transaction sends data to the host
 * @isoc: true for isochronous transactions, false for interrupt ones
 * @bytecount: how many bytes in the transaction.
 *
 * Returns approximate bus time in nanoseconds for a periodic transaction.
 * See USB 2.0 spec section 5.11.3; only periodic transfers need to be
 * scheduled in software, this function is only used for such scheduling.
 */
long usb_calc_bus_time (int speed, int is_input, int isoc, int bytecount)
{
	unsigned long	tmp;

	switch (speed) {
	case USB_SPEED_LOW: 	/* INTR only */
		if (is_input) {
			tmp = (67667L * (31L + 10L * BitTime (bytecount))) / 1000L;
			return (64060L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp);
		} else {
			tmp = (66700L * (31L + 10L * BitTime (bytecount))) / 1000L;
			return (64107L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp);
		}
	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);

/*
 * usb_check_bandwidth():
 *
 * old_alloc is from host_controller->bandwidth_allocated in microseconds;
 * bustime is from calc_bus_time(), but converted to microseconds.
 *
 * returns <bustime in us> if successful,
 * or -ENOSPC if bandwidth request fails.
 *
 * FIXME:
 * This initial implementation does not use Endpoint.bInterval
 * in managing bandwidth allocation.
 * It probably needs to be expanded to use Endpoint.bInterval.
 * This can be done as a later enhancement (correction).
 *
 * This will also probably require some kind of
 * frame allocation tracking...meaning, for example,
 * that if multiple drivers request interrupts every 10 USB frames,
 * they don't all have to be allocated at
 * frame numbers N, N+10, N+20, etc.  Some of them could be at
 * N+11, N+21, N+31, etc., and others at
 * N+12, N+22, N+32, etc.
 *
 * Similarly for isochronous transfers...
 *
 * Individual HCDs can schedule more directly ... this logic
 * is not correct for high speed transfers.
 */
int usb_check_bandwidth (struct usb_device *dev, struct urb *urb)
{
	unsigned int	pipe = urb->pipe;
	long		bustime;
	int		is_in = usb_pipein (pipe);