usb.c

基于S3CEB2410平台LINUX操作系统下 USB驱动源代码

		/* Did we hit an unexpected descriptor? */
		header = (struct usb_descriptor_header *)buffer;
		if ((size >= sizeof(struct usb_descriptor_header)) &&
		    ((header->bDescriptorType == USB_DT_CONFIG) ||
		     (header->bDescriptorType == USB_DT_DEVICE)))
			return parsed;

		if (ifp->bNumEndpoints > USB_MAXENDPOINTS) {
			warn("too many endpoints");
			return -1;
		}

		ifp->endpoint = (struct usb_endpoint_descriptor *)
			kmalloc(ifp->bNumEndpoints *
			sizeof(struct usb_endpoint_descriptor), GFP_KERNEL);
		if (!ifp->endpoint) {
			err("out of memory");
			return -1;	
		}

		memset(ifp->endpoint, 0, ifp->bNumEndpoints *
			sizeof(struct usb_endpoint_descriptor));
	
		for (i = 0; i < ifp->bNumEndpoints; i++) {
			header = (struct usb_descriptor_header *)buffer;

			if (header->bLength > size) {
				err("ran out of descriptors parsing");
				return -1;
			}
		
			retval = usb_parse_endpoint(ifp->endpoint + i, buffer, size);
			if (retval < 0)
				return retval;

			buffer += retval;
			parsed += retval;
			size -= retval;
		}

		/* We check to see if it's an alternate to this one */
		ifp = (struct usb_interface_descriptor *)buffer;
		if (size < USB_DT_INTERFACE_SIZE ||
		    ifp->bDescriptorType != USB_DT_INTERFACE ||
		    !ifp->bAlternateSetting)
			return parsed;
	}

	return parsed;
}

int usb_parse_configuration(struct usb_config_descriptor *config, char *buffer)
{
	int i, retval, size;
	struct usb_descriptor_header *header;

	memcpy(config, buffer, USB_DT_CONFIG_SIZE);
	le16_to_cpus(&config->wTotalLength);
	size = config->wTotalLength;

	if (config->bNumInterfaces > USB_MAXINTERFACES) {
		warn("too many interfaces");
		return -1;
	}

	config->interface = (struct usb_interface *)
		kmalloc(config->bNumInterfaces *
		sizeof(struct usb_interface), GFP_KERNEL);
	dbg("kmalloc IF %p, numif %i", config->interface, config->bNumInterfaces);
	if (!config->interface) {
		err("out of memory");
		return -1;	
	}

	memset(config->interface, 0,
	       config->bNumInterfaces * sizeof(struct usb_interface));

	buffer += config->bLength;
	size -= config->bLength;
	
	config->extra = NULL;
	config->extralen = 0;

	for (i = 0; i < config->bNumInterfaces; i++) {
		int numskipped, len;
		char *begin;

		/* 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 > size) || (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;
		}
		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) {
			if (config->extralen) {
				warn("extra config descriptor");
			} else {
				config->extra = kmalloc(len, GFP_KERNEL);
				if (!config->extra) {
					err("couldn't allocate memory for config extra descriptors");
					config->extralen = 0;
					return -1;
				}

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

		retval = usb_parse_interface(config->interface + i, buffer, size);
		if (retval < 0)
			return retval;

		buffer += retval;
		size -= retval;
	}

	return size;
}

void usb_destroy_configuration(struct usb_device *dev)
{
	int c, i, j, k;
	
	if (!dev->config)
		return;

	if (dev->rawdescriptors) {
		for (i = 0; i < dev->descriptor.bNumConfigurations; i++)
			kfree(dev->rawdescriptors[i]);

		kfree(dev->rawdescriptors);
	}

	for (c = 0; c < dev->descriptor.bNumConfigurations; c++) {
		struct usb_config_descriptor *cf = &dev->config[c];

		if (!cf->interface)
			break;

		for (i = 0; i < cf->bNumInterfaces; i++) {
			struct usb_interface *ifp =
				&cf->interface[i];
				
			if (!ifp->altsetting)
				break;

			for (j = 0; j < ifp->num_altsetting; j++) {
				struct usb_interface_descriptor *as =
					&ifp->altsetting[j];
					
				if(as->extra) {
					kfree(as->extra);
				}

				if (!as->endpoint)
					break;
					
				for(k = 0; k < as->bNumEndpoints; k++) {
					if(as->endpoint[k].extra) {
						kfree(as->endpoint[k].extra);
					}
				}	
				kfree(as->endpoint);
			}

			kfree(ifp->altsetting);
		}
		kfree(cf->interface);
	}
	kfree(dev->config);
}

/* for returning string descriptors in UTF-16LE */
static int ascii2utf (char *ascii, __u8 *utf, int utfmax)
{
	int retval;

	for (retval = 0; *ascii && utfmax > 1; utfmax -= 2, retval += 2) {
		*utf++ = *ascii++ & 0x7f;
		*utf++ = 0;
	}
	return retval;
}

/*
 * root_hub_string is used by each host controller's root hub code,
 * so that they're identified consistently throughout the system.
 */
int usb_root_hub_string (int id, int serial, char *type, __u8 *data, int len)
{
	char buf [30];

	// assert (len > (2 * (sizeof (buf) + 1)));
	// assert (strlen (type) <= 8);

	// language ids
	if (id == 0) {
		*data++ = 4; *data++ = 3;	/* 4 bytes data */
		*data++ = 0; *data++ = 0;	/* some language id */
		return 4;

	// serial number
	} else if (id == 1) {
		sprintf (buf, "%x", serial);

	// product description
	} else if (id == 2) {
		sprintf (buf, "USB %s Root Hub", type);

	// id 3 == vendor description

	// unsupported IDs --> "stall"
	} else
	    return 0;

	data [0] = 2 + ascii2utf (buf, data + 2, len - 2);
	data [1] = 3;
	return data [0];
}

/*
 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
 * extra field of the interface and endpoint descriptor structs.
 */

int __usb_get_extra_descriptor(char *buffer, unsigned size, unsigned char type, void **ptr)
{
	struct usb_descriptor_header *header;

	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 (header->bDescriptorType == type) {
			*ptr = header;
			return 0;
		}

		buffer += header->bLength;
		size -= header->bLength;
	}
	return -1;
}

/*
 * Something got disconnected. Get rid of it, and all of its children.
 */
void usb_disconnect(struct usb_device **pdev)
{
	struct usb_device * dev = *pdev;
	int i;

	if (!dev)
		return;

	*pdev = NULL;

	info("USB disconnect on device %d", dev->devnum);

	if (dev->actconfig) {
		for (i = 0; i < dev->actconfig->bNumInterfaces; i++) {
			struct usb_interface *interface = &dev->actconfig->interface[i];
			struct usb_driver *driver = interface->driver;
			if (driver) {
				down(&driver->serialize);
				driver->disconnect(dev, interface->private_data);
				up(&driver->serialize);
				/* if driver->disconnect didn't release the interface */
				if (interface->driver)
					usb_driver_release_interface(driver, interface);
			}
		}
	}

	/* Free up all the children.. */
	for (i = 0; i < USB_MAXCHILDREN; i++) {
		struct usb_device **child = dev->children + i;
		if (*child)
			usb_disconnect(child);
	}

	/* Let policy agent unload modules etc */
	call_policy ("remove", dev);

	/* Free the device number and remove the /proc/bus/usb entry */
	if (dev->devnum > 0) {
		clear_bit(dev->devnum, &dev->bus->devmap.devicemap);
		usbdevfs_remove_device(dev);
	}

	/* Free up the device itself */
	usb_free_dev(dev);
}

/*
 * Connect a new USB device. This basically just initializes
 * the USB device information and sets up the topology - it's
 * up to the low-level driver to reset the port and actually
 * do the setup (the upper levels don't know how to do that).
 */
void usb_connect(struct usb_device *dev)
{
	int devnum;
	// FIXME needs locking for SMP!!
	/* why? this is called only from the hub thread, 
	 * which hopefully doesn't run on multiple CPU's simultaneously 8-)
	 */
	dev->descriptor.bMaxPacketSize0 = 8;  /* Start off at 8 bytes  */
#ifndef DEVNUM_ROUND_ROBIN
	devnum = find_next_zero_bit(dev->bus->devmap.devicemap, 128, 1);
#else	/* round_robin alloc of devnums */
	/* Try to allocate the next devnum beginning at bus->devnum_next. */
	devnum = find_next_zero_bit(dev->bus->devmap.devicemap, 128, dev->bus->devnum_next);
	if (devnum >= 128)
		devnum = find_next_zero_bit(dev->bus->devmap.devicemap, 128, 1);

	dev->bus->devnum_next = ( devnum >= 127 ? 1 : devnum + 1);
#endif	/* round_robin alloc of devnums */

	if (devnum < 128) {
		set_bit(devnum, dev->bus->devmap.devicemap);
		dev->devnum = devnum;
	}
}

/*
 * These are the actual routines to send
 * and receive control messages.
 */
#ifdef CONFIG_USB_LONG_TIMEOUT
#define GET_TIMEOUT 10 
#else
#define GET_TIMEOUT 3
#endif
#define SET_TIMEOUT 3

int usb_set_address(struct usb_device *dev)
{
	return usb_control_msg(dev, usb_snddefctrl(dev), USB_REQ_SET_ADDRESS,
		0, dev->devnum, 0, NULL, 0, HZ * GET_TIMEOUT);
}

int usb_get_descriptor(struct usb_device *dev, unsigned char type, unsigned char index, void *buf, int size)
{
	int i = 5;
	int result;
	
	memset(buf,0,size);	// Make sure we parse really received data

	while (i--) {
		if ((result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
			USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
			(type << 8) + index, 0, buf, size, HZ * GET_TIMEOUT)) > 0 ||
		     result == -EPIPE)
			break;	/* retry if the returned length was 0; flaky device */
	}
	return result;
}

int usb_get_class_descriptor(struct usb_device *dev, int ifnum,
		unsigned char type, unsigned char id, void *buf, int size)
{
	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
		USB_REQ_GET_DESCRIPTOR, USB_RECIP_INTERFACE | USB_DIR_IN,
		(type << 8) + id, ifnum, buf, size, HZ * GET_TIMEOUT);
}

int usb_get_string(struct usb_device *dev, unsigned short langid, unsigned char index, void *buf, int size)
{
	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
		USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
		(USB_DT_STRING << 8) + index, langid, buf, size, HZ * GET_TIMEOUT);
}

int usb_get_device_descriptor(struct usb_device *dev)
{
	int ret = usb_get_descriptor(dev, USB_DT_DEVICE, 0, &dev->descriptor,
				     sizeof(dev->descriptor));
	if (ret >= 0) {
		le16_to_cpus(&dev->descriptor.bcdUSB);
		le16_to_cpus(&dev->descriptor.idVendor);
		le16_to_cpus(&dev->descriptor.idProduct);
		le16_to_cpus(&dev->descriptor.bcdDevice);
	}
	return ret;
}

int usb_get_status(struct usb_device *dev, int type, int target, void *data)
{
	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
		USB_REQ_GET_STATUS, USB_DIR_IN | type, 0, target, data, 2, HZ * GET_TIMEOUT);
}

int usb_get_protocol(struct usb_device *dev, int ifnum)
{
	unsigned char type;
	int ret;

	if ((ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
	    USB_REQ_GET_PROTOCOL, USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
	    0, ifnum, &type, 1, HZ * GET_TIMEOUT)) < 0)
		return ret;

	return type;
}

int usb_set_protocol(struct usb_device *dev, int ifnum, int protocol)
{
	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
		USB_REQ_SET_PROTOCOL, USB_TYPE_CLASS | USB_RECIP_INTERFACE,
		protocol, ifnum, NULL, 0, HZ * SET_TIMEOUT);
}

int usb_set_idle(struct usb_device *dev, int ifnum, int duration, int report_id)
{
	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
		USB_REQ_SET_IDLE, USB_TYPE_CLASS | USB_RECIP_INTERFACE,
		(duration << 8) | report_id, ifnum, NULL, 0, HZ * SET_TIMEOUT);
}

void usb_set_maxpacket(struct usb_device *dev)
{
	int i, b;

	for (i=0; i<dev->actconfig->bNumInterfaces; i++) {
		struct usb_interface *ifp = dev->actconfig->interface + i;
		struct usb_interface_descriptor *as = ifp->altsetting + ifp->act_altsetting;
		struct usb_endpoint_descriptor *ep = as->endpoint;
		int e;

		for (e=0; e<as->bNumEndpoints; e++) {
			b = ep[e].bEndpointAddress & USB_ENDPOINT_NUMBER_MASK;
			if ((ep[e].bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
				USB_ENDPOINT_XFER_CONTROL) {	/* Control => bidirectional */
				dev->epmaxpacketout[b] = ep[e].wMaxPacketSize;
				dev->epmaxpacketin [b] = ep[e].wMaxPacketSize;
				}
			else if (usb_endpoint_out(ep[e].bEndpointAddress)) {
				if (ep[e].wMaxPacketSize > dev->epmaxpacketout[b])
					dev->epmaxpacketout[b] = ep[e].wMaxPacketSize;
			}
			else {