hcd.c

h内核

				ubuf, wLength);
			break;
		default:
			goto error;
		}
		break;
	case DeviceRequest | USB_REQ_GET_INTERFACE:
		ubuf [0] = 0;
			/* FALLTHROUGH */
	case DeviceOutRequest | USB_REQ_SET_INTERFACE:
		break;
	case DeviceOutRequest | USB_REQ_SET_ADDRESS:
		// wValue == urb->dev->devaddr
		dev_dbg (hcd->self.controller, "root hub device address %d\n",
			wValue);
		break;

	/* INTERFACE REQUESTS (no defined feature/status flags) */

	/* ENDPOINT REQUESTS */

	case EndpointRequest | USB_REQ_GET_STATUS:
		// ENDPOINT_HALT flag
		ubuf [0] = 0;
		ubuf [1] = 0;
			/* FALLTHROUGH */
	case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
	case EndpointOutRequest | USB_REQ_SET_FEATURE:
		dev_dbg (hcd->self.controller, "no endpoint features yet\n");
		break;

	/* CLASS REQUESTS (and errors) */

	default:
		/* non-generic request */
		if (HCD_IS_SUSPENDED (hcd->state))
			urb->status = -EAGAIN;
		else
			urb->status = hcd->driver->hub_control (hcd,
				typeReq, wValue, wIndex,
				ubuf, wLength);
		break;
error:
		/* "protocol stall" on error */
		urb->status = -EPIPE;
	}
	if (urb->status) {
		urb->actual_length = 0;
		if (urb->status != -EPIPE) {
			dev_dbg (hcd->self.controller,
				"CTRL: TypeReq=0x%x val=0x%x "
				"idx=0x%x len=%d ==> %d\n",
				typeReq, wValue, wIndex,
				wLength, urb->status);
		}
	}
	if (bufp) {
		if (urb->transfer_buffer_length < len)
			len = urb->transfer_buffer_length;
		urb->actual_length = len;
		// always USB_DIR_IN, toward host
		memcpy (ubuf, bufp, len);

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

	/* any errors get returned through the urb completion */
	local_irq_save (flags);
	usb_hcd_giveback_urb (hcd, urb, NULL);
	local_irq_restore (flags);
	return 0;
}

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

/*
 * Root Hub interrupt transfers are synthesized with a timer.
 * Completions are called in_interrupt() but not in_irq().
 *
 * Note: some root hubs (including common UHCI based designs) can't
 * correctly issue port change IRQs.  They're the ones that _need_ a
 * timer; most other root hubs don't.  Some systems could save a
 * lot of battery power by eliminating these root hub timer IRQs.
 */

static void rh_report_status (unsigned long ptr);

static int rh_status_urb (struct usb_hcd *hcd, struct urb *urb) 
{
	int	len = 1 + (urb->dev->maxchild / 8);

	/* rh_timer protected by hcd_data_lock */
	if (hcd->rh_timer.data || urb->transfer_buffer_length < len) {
		dev_dbg (hcd->self.controller,
				"not queuing rh status urb, stat %d\n",
				urb->status);
		return -EINVAL;
	}

	init_timer (&hcd->rh_timer);
	hcd->rh_timer.function = rh_report_status;
	hcd->rh_timer.data = (unsigned long) urb;
	/* USB 2.0 spec says 256msec; this is close enough */
	hcd->rh_timer.expires = jiffies + HZ/4;
	add_timer (&hcd->rh_timer);
	urb->hcpriv = hcd;	/* nonzero to indicate it's queued */
	return 0;
}

/* timer callback */

static void rh_report_status (unsigned long ptr)
{
	struct urb	*urb;
	struct usb_hcd	*hcd;
	int		length = 0;
	unsigned long	flags;

	urb = (struct urb *) ptr;
	local_irq_save (flags);
	spin_lock (&urb->lock);

	/* do nothing if the urb's been unlinked */
	if (!urb->dev
			|| urb->status != -EINPROGRESS
			|| (hcd = urb->dev->bus->hcpriv) == NULL) {
		spin_unlock (&urb->lock);
		local_irq_restore (flags);
		return;
	}

	/* complete the status urb, or retrigger the timer */
	spin_lock (&hcd_data_lock);
	if (urb->dev->state == USB_STATE_CONFIGURED) {
		length = hcd->driver->hub_status_data (
					hcd, urb->transfer_buffer);
		if (length > 0) {
			hcd->rh_timer.data = 0;
			urb->actual_length = length;
			urb->status = 0;
			urb->hcpriv = NULL;
		} else
			mod_timer (&hcd->rh_timer, jiffies + HZ/4);
	}
	spin_unlock (&hcd_data_lock);
	spin_unlock (&urb->lock);

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

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

static int rh_urb_enqueue (struct usb_hcd *hcd, struct urb *urb)
{
	if (usb_pipeint (urb->pipe)) {
		int		retval;
		unsigned long	flags;

		spin_lock_irqsave (&hcd_data_lock, flags);
		retval = rh_status_urb (hcd, urb);
		spin_unlock_irqrestore (&hcd_data_lock, flags);
		return retval;
	}
	if (usb_pipecontrol (urb->pipe))
		return rh_call_control (hcd, urb);
	else
		return -EINVAL;
}

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

static int usb_rh_urb_dequeue (struct usb_hcd *hcd, struct urb *urb)
{
	unsigned long	flags;

	/* note:  always a synchronous unlink */
	if ((unsigned long) urb == hcd->rh_timer.data) {
		del_timer_sync (&hcd->rh_timer);
		hcd->rh_timer.data = 0;

		local_irq_save (flags);
		urb->hcpriv = NULL;
		usb_hcd_giveback_urb (hcd, urb, NULL);
		local_irq_restore (flags);

	} else if (usb_pipeendpoint(urb->pipe) == 0) {
		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
		return -EINVAL;

	return 0;
}

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

/* exported only within usbcore */
struct usb_bus *usb_bus_get (struct usb_bus *bus)
{
	struct class_device *tmp;

	if (!bus)
		return NULL;

	tmp = class_device_get(&bus->class_dev);
	if (tmp)        
		return to_usb_bus(tmp);
	else
		return NULL;
}

/* exported only within usbcore */
void usb_bus_put (struct usb_bus *bus)
{
	if (bus)
		class_device_put(&bus->class_dev);
}

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

static void usb_host_release(struct class_device *class_dev)
{
	struct usb_bus *bus = to_usb_bus(class_dev);

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

static struct class usb_host_class = {
	.name		= "usb_host",
	.release	= &usb_host_release,
};

int usb_host_init(void)
{
	return class_register(&usb_host_class);
}

void usb_host_cleanup(void)
{
	class_unregister(&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.
 */
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);

	class_device_initialize(&bus->class_dev);
	bus->class_dev.class = &usb_host_class;
}
EXPORT_SYMBOL (usb_bus_init);

/**
 * 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 = kmalloc (sizeof *bus, GFP_KERNEL);
	if (!bus)
		return NULL;
	memset(bus, 0, sizeof(struct usb_bus));
	usb_bus_init (bus);
	bus->op = op;
	return bus;
}
EXPORT_SYMBOL (usb_alloc_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.
 */
int usb_register_bus(struct usb_bus *bus)
{
	int busnum;
	int retval;

	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;
	}

	snprintf(bus->class_dev.class_id, BUS_ID_SIZE, "usb%d", busnum);
	bus->class_dev.dev = bus->controller;
	retval = class_device_add(&bus->class_dev);
	if (retval) {
		clear_bit(busnum, busmap.busmap);
		up(&usb_bus_list_lock);
		return retval;
	}

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

	usbfs_add_bus (bus);

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

/**
 * 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.
 */
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);

	usbfs_remove_bus (bus);

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

	class_device_unregister(&bus->class_dev);
}
EXPORT_SYMBOL (usb_deregister_bus);

/**
 * usb_register_root_hub - called by HCD to register its root hub 
 * @usb_dev: the usb root hub device to be registered.
 * @parent_dev: the parent device of this root hub.
 *
 * The USB host controller calls this function to register the root hub
 * properly 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).
 */
int usb_register_root_hub (struct usb_device *usb_dev, struct device *parent_dev)
{
	const int devnum = 1;