usb.c

基于S3CEB2410平台LINUX操作系统下 USB驱动源代码

	INIT_LIST_HEAD(&dev->inodes);
	INIT_LIST_HEAD(&dev->filelist);

	init_MUTEX(&dev->serialize);

	dev->bus->op->allocate(dev);

	return dev;
}

void usb_free_dev(struct usb_device *dev)
{
	if (atomic_dec_and_test(&dev->refcnt)) {
		dev->bus->op->deallocate(dev);
		usb_destroy_configuration(dev);

		usb_bus_put(dev->bus);

		kfree(dev);
	}
}

void usb_inc_dev_use(struct usb_device *dev)
{
	atomic_inc(&dev->refcnt);
}

/* ------------------------------------------------------------------------------------- 
 * New USB Core Functions
 * -------------------------------------------------------------------------------------*/

/**
 *	usb_alloc_urb - creates a new urb for a USB driver to use
 *	@iso_packets: number of iso packets for this urb
 *
 *	Creates an urb for the USB driver to use and returns a pointer to it.
 *	If no memory is available, NULL is returned.
 *
 *	If the driver want to use this urb for interrupt, control, or bulk
 *	endpoints, pass '0' as the number of iso packets.
 *
 *	The driver should call usb_free_urb() when it is finished with the urb.
 */
urb_t *usb_alloc_urb(int iso_packets)
{
	urb_t *urb;

	urb = (urb_t *)kmalloc(sizeof(urb_t) + iso_packets * sizeof(iso_packet_descriptor_t),
	      in_interrupt() ? GFP_ATOMIC : GFP_KERNEL);
	if (!urb) {
		err("alloc_urb: kmalloc failed");
		return NULL;
	}

	memset(urb, 0, sizeof(*urb));

	spin_lock_init(&urb->lock);

	return urb;
}

/**
 *	usb_free_urb - frees the memory used by a urb
 *	@urb: pointer to the urb to free
 *
 *	If an urb is created with a call to usb_create_urb() it should be
 *	cleaned up with a call to usb_free_urb() when the driver is finished
 *	with it.
 */
void usb_free_urb(urb_t* urb)
{
	if (urb)
		kfree(urb);
}
/*-------------------------------------------------------------------*/
int usb_submit_urb(urb_t *urb)
{
	if (urb && urb->dev && urb->dev->bus && urb->dev->bus->op)
		return urb->dev->bus->op->submit_urb(urb);
	else
		return -ENODEV;
}

/*-------------------------------------------------------------------*/
int usb_unlink_urb(urb_t *urb)
{
	if (urb && urb->dev && urb->dev->bus && urb->dev->bus->op)
		return urb->dev->bus->op->unlink_urb(urb);
	else
		return -ENODEV;
}
/*-------------------------------------------------------------------*
 *                     COMPLETION HANDLERS                           *
 *-------------------------------------------------------------------*/

/*-------------------------------------------------------------------*
 * completion handler for compatibility wrappers (sync control/bulk) *
 *-------------------------------------------------------------------*/
static void usb_api_blocking_completion(urb_t *urb)
{
	struct usb_api_data *awd = (struct usb_api_data *)urb->context;

	awd->done = 1;
	wmb();
	wake_up(&awd->wqh);
}

/*-------------------------------------------------------------------*
 *                         COMPATIBILITY STUFF                       *
 *-------------------------------------------------------------------*/

// Starts urb and waits for completion or timeout
static int usb_start_wait_urb(urb_t *urb, int timeout, int* actual_length)
{ 
	DECLARE_WAITQUEUE(wait, current);
	struct usb_api_data awd;
	int status;

	init_waitqueue_head(&awd.wqh); 	
	awd.done = 0;

	set_current_state(TASK_UNINTERRUPTIBLE);
	add_wait_queue(&awd.wqh, &wait);

	urb->context = &awd;
	status = usb_submit_urb(urb);
	if (status) {
		// something went wrong
		usb_free_urb(urb);
		set_current_state(TASK_RUNNING);
		remove_wait_queue(&awd.wqh, &wait);
		return status;
	}

	while (timeout && !awd.done)
	{
		timeout = schedule_timeout(timeout);
		set_current_state(TASK_UNINTERRUPTIBLE);
		rmb();
	}

	set_current_state(TASK_RUNNING);
	remove_wait_queue(&awd.wqh, &wait);

	if (!timeout && !awd.done) {
		if (urb->status != -EINPROGRESS) {	/* No callback?!! */
			printk("usb: raced timeout, "
			    "pipe 0x%x status %d time left %d\n",
			    urb->pipe, urb->status, timeout);
			status = urb->status;
		} else {
			printk("usb_control/bulk_msg: timeout\n");
			usb_unlink_urb(urb);  // remove urb safely
			status = -ETIMEDOUT;
		}
	} else {
		status = urb->status;
	}

	if (actual_length)
		*actual_length = urb->actual_length;

	usb_free_urb(urb);
  	return status;
}

/*-------------------------------------------------------------------*/
// returns status (negative) or length (positive)
int usb_internal_control_msg(struct usb_device *usb_dev, unsigned int pipe, 
			    devrequest *cmd,  void *data, int len, int timeout)
{
	urb_t *urb;
	int retv;
	int length;

	urb = usb_alloc_urb(0);
	if (!urb)
		return -ENOMEM;
  
	FILL_CONTROL_URB(urb, usb_dev, pipe, (unsigned char*)cmd, data, len,
		   usb_api_blocking_completion, 0);

	retv = usb_start_wait_urb(urb, timeout, &length);
	if (retv < 0) {
		return retv;
	} else {
		return length;
	}
}

/**
 *	usb_control_msg - Builds a control urb, sends it off and waits for completion
 *	@dev: pointer to the usb device to send the message to
 *	@pipe: endpoint "pipe" to send the message to
 *	@request: USB message request value
 *	@requesttype: USB message request type value
 *	@value: USB message value
 *	@index: USB message index value
 *	@data: pointer to the data to send
 *	@size: length in bytes of the data to send
 *	@timeout: time to wait for the message to complete before timing out (if 0 the wait is forever)
 *
 *	This function sends a simple control message to a specified endpoint
 *	and waits for the message to complete, or timeout.
 *	
 *	If successful, it returns 0, othwise a negative error number.
 *
 *	Don't use this function from within an interrupt context, like a
 *	bottom half handler.  If you need a asyncronous message, or need to send
 *	a message from within interrupt context, use usb_submit_urb()
 */
int usb_control_msg(struct usb_device *dev, unsigned int pipe, __u8 request, __u8 requesttype,
			 __u16 value, __u16 index, void *data, __u16 size, int timeout)
{
	devrequest *dr = kmalloc(sizeof(devrequest), GFP_KERNEL);
	int ret;

	
	if (!dr)
		return -ENOMEM;

	dr->requesttype = requesttype;
	dr->request = request;
	dr->value = cpu_to_le16p(&value);
	dr->index = cpu_to_le16p(&index);
	dr->length = cpu_to_le16p(&size);

	//dbg("usb_control_msg");	

	ret = usb_internal_control_msg(dev, pipe, dr, data, size, timeout);

	kfree(dr);

	return ret;
}


/**
 *	usb_bulk_msg - Builds a bulk urb, sends it off and waits for completion
 *	@usb_dev: pointer to the usb device to send the message to
 *	@pipe: endpoint "pipe" to send the message to
 *	@data: pointer to the data to send
 *	@len: length in bytes of the data to send
 *	@actual_length: pointer to a location to put the actual length transferred in bytes
 *	@timeout: time to wait for the message to complete before timing out (if 0 the wait is forever)
 *
 *	This function sends a simple bulk message to a specified endpoint
 *	and waits for the message to complete, or timeout.
 *	
 *	If successful, it returns 0, othwise a negative error number.
 *	The number of actual bytes transferred will be plaed in the 
 *	actual_timeout paramater.
 *
 *	Don't use this function from within an interrupt context, like a
 *	bottom half handler.  If you need a asyncronous message, or need to
 *	send a message from within interrupt context, use usb_submit_urb()
 */
int usb_bulk_msg(struct usb_device *usb_dev, unsigned int pipe, 
			void *data, int len, int *actual_length, int timeout)
{
	urb_t *urb;

	if (len < 0)
		return -EINVAL;

	urb=usb_alloc_urb(0);
	if (!urb)
		return -ENOMEM;

	FILL_BULK_URB(urb, usb_dev, pipe, data, len,
		    usb_api_blocking_completion, 0);

	return usb_start_wait_urb(urb,timeout,actual_length);
}

/*
 * usb_get_current_frame_number()
 *
 * returns the current frame number for the parent USB bus/controller
 * of the given USB device.
 */
int usb_get_current_frame_number(struct usb_device *usb_dev)
{
	return usb_dev->bus->op->get_frame_number (usb_dev);
}
/*-------------------------------------------------------------------*/

static int usb_parse_endpoint(struct usb_endpoint_descriptor *endpoint, unsigned char *buffer, int size)
{
	struct usb_descriptor_header *header;
	unsigned char *begin;
	int parsed = 0, len, numskipped;

	header = (struct usb_descriptor_header *)buffer;

	/* Everything should be fine being passed into here, but we sanity */
	/*  check JIC */
	if (header->bLength > size) {
		err("ran out of descriptors parsing");
		return -1;
	}
		
	if (header->bDescriptorType != USB_DT_ENDPOINT) {
		warn("unexpected descriptor 0x%X, expecting endpoint descriptor, type 0x%X",
			endpoint->bDescriptorType, USB_DT_ENDPOINT);
		return parsed;
	}

	if (header->bLength == USB_DT_ENDPOINT_AUDIO_SIZE)
		memcpy(endpoint, buffer, USB_DT_ENDPOINT_AUDIO_SIZE);
	else
		memcpy(endpoint, buffer, USB_DT_ENDPOINT_SIZE);
	
	le16_to_cpus(&endpoint->wMaxPacketSize);

	buffer += header->bLength;
	size -= header->bLength;
	parsed += header->bLength;

	/* Skip over the rest of the Class Specific or Vendor Specific */
	/*  descriptors */
	begin = buffer;
	numskipped = 0;
	while (size >= sizeof(struct usb_descriptor_header)) {
		header = (struct usb_descriptor_header *)buffer;

		if (header->bLength < 2) {
			err("invalid descriptor length of %d", header->bLength);
			return -1;
		}

		/* If we find another "proper" descriptor then we're done  */
		if ((header->bDescriptorType == USB_DT_ENDPOINT) ||
		    (header->bDescriptorType == USB_DT_INTERFACE) ||
		    (header->bDescriptorType == USB_DT_CONFIG) ||
		    (header->bDescriptorType == USB_DT_DEVICE))
			break;

		dbg("skipping descriptor 0x%X",
			header->bDescriptorType);
		numskipped++;

		buffer += header->bLength;
		size -= header->bLength;
		parsed += header->bLength;
	}
	if (numskipped)
		dbg("skipped %d class/vendor specific endpoint descriptors", numskipped);

	/* Copy any unknown descriptors into a storage area for drivers */
	/*  to later parse */
	len = (int)(buffer - begin);
	if (!len) {
		endpoint->extra = NULL;
		endpoint->extralen = 0;
		return parsed;
	}

	endpoint->extra = kmalloc(len, GFP_KERNEL);

	if (!endpoint->extra) {
		err("couldn't allocate memory for endpoint extra descriptors");
		endpoint->extralen = 0;
		return parsed;
	}

	memcpy(endpoint->extra, begin, len);
	endpoint->extralen = len;

	return parsed;
}

static int usb_parse_interface(struct usb_interface *interface, unsigned char *buffer, int size)
{
	int i, len, numskipped, retval, parsed = 0;
	struct usb_descriptor_header *header;
	struct usb_interface_descriptor *ifp;
	unsigned char *begin;

	interface->act_altsetting = 0;
	interface->num_altsetting = 0;
	interface->max_altsetting = USB_ALTSETTINGALLOC;

	interface->altsetting = kmalloc(sizeof(struct usb_interface_descriptor) * interface->max_altsetting, GFP_KERNEL);
	
	if (!interface->altsetting) {
		err("couldn't kmalloc interface->altsetting");
		return -1;
	}

	while (size > 0) {
		if (interface->num_altsetting >= interface->max_altsetting) {
			void *ptr;
			int oldmas;

			oldmas = interface->max_altsetting;
			interface->max_altsetting += USB_ALTSETTINGALLOC;
			if (interface->max_altsetting > USB_MAXALTSETTING) {
				warn("too many alternate settings (max %d)",
					USB_MAXALTSETTING);
				return -1;
			}

			ptr = interface->altsetting;
			interface->altsetting = kmalloc(sizeof(struct usb_interface_descriptor) * interface->max_altsetting, GFP_KERNEL);
			if (!interface->altsetting) {
				err("couldn't kmalloc interface->altsetting");
				interface->altsetting = ptr;
				return -1;
			}
			memcpy(interface->altsetting, ptr, sizeof(struct usb_interface_descriptor) * oldmas);

			kfree(ptr);
		}

		ifp = interface->altsetting + interface->num_altsetting;
		interface->num_altsetting++;

		memcpy(ifp, buffer, USB_DT_INTERFACE_SIZE);

		/* Skip over the interface */
		buffer += ifp->bLength;
		parsed += ifp->bLength;
		size -= ifp->bLength;

		begin = buffer;
		numskipped = 0;

		/* Skip over any interface, class or vendor descriptors */
		while (size >= sizeof(struct usb_descriptor_header)) {
			header = (struct usb_descriptor_header *)buffer;

			if (header->bLength < 2) {
				err("invalid descriptor length of %d", header->bLength);
				return -1;
			}

			/* If we find another "proper" descriptor then we're done  */
			if ((header->bDescriptorType == USB_DT_INTERFACE) ||
			    (header->bDescriptorType == USB_DT_ENDPOINT) ||
			    (header->bDescriptorType == USB_DT_CONFIG) ||
			    (header->bDescriptorType == USB_DT_DEVICE))
				break;

			numskipped++;

			buffer += header->bLength;
			parsed += header->bLength;
			size -= header->bLength;
		}

		if (numskipped)
			dbg("skipped %d class/vendor specific interface descriptors", numskipped);

		/* Copy any unknown descriptors into a storage area for */
		/*  drivers to later parse */
		len = (int)(buffer - begin);
		if (!len) {
			ifp->extra = NULL;
			ifp->extralen = 0;
		} else {
			ifp->extra = kmalloc(len, GFP_KERNEL);

			if (!ifp->extra) {
				err("couldn't allocate memory for interface extra descriptors");
				ifp->extralen = 0;
				return -1;
			}
			memcpy(ifp->extra, begin, len);
			ifp->extralen = len;
		}