usb.c

有关于USB的一些主机端驱动

				/* 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;
	}
	
//	printf("The device number is:%d\n",devnum);//added by Changming HUANG
}

/*
 * These are the actual routines to send
 * and receive control messages.
 */

#define GET_TIMEOUT 3
#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 {
				if (ep[e].wMaxPacketSize > dev->epmaxpacketin [b])
					dev->epmaxpacketin [b] = ep[e].wMaxPacketSize;
			}
		}
	}
}

/*
 * endp: endpoint number in bits 0-3;
 *	direction flag in bit 7 (1 = IN, 0 = OUT)
 */
int usb_clear_halt(struct usb_device *dev, int pipe)
{
	int result;
	__u16 status;
	unsigned char *buffer;
	int endp=usb_pipeendpoint(pipe)|(usb_pipein(pipe)<<7);

/*
	if (!usb_endpoint_halted(dev, endp & 0x0f, usb_endpoint_out(endp)))
		return 0;
*/

	result = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
		USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT, 0, endp, NULL, 0, HZ * SET_TIMEOUT);

	/* don't clear if failed */
	if (result < 0)
		return result;

	buffer = (unsigned char *)malloc(sizeof(status));
	if (!buffer) {
		err("unable to allocate memory for configuration descriptors");
		return -ENOMEM;
	}

	result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
		USB_REQ_GET_STATUS, USB_DIR_IN | USB_RECIP_ENDPOINT, 0, endp,
		buffer, sizeof(status), HZ * SET_TIMEOUT);

	memcpy(&status, buffer, sizeof(status));
	free(buffer);

	if (result < 0)
		return result;

	if (le16_to_cpu(status) & 1)
		return -EPIPE;		/* still halted */

	usb_endpoint_running(dev, usb_pipeendpoint(pipe), usb_pipeout(pipe));

	/* toggle is reset on clear */

	usb_settoggle(dev, usb_pipeendpoint(pipe), usb_pipeout(pipe), 0);

	return 0;
}

int usb_set_interface(struct usb_device *dev, int interface, int alternate)
{
	struct usb_interface *iface;
	int ret;

	iface = usb_ifnum_to_if(dev, interface);
	if (!iface) {
		warn("selecting invalid interface %d", interface);
		return -EINVAL;
	}

	if ((ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
	    USB_REQ_SET_INTERFACE, USB_RECIP_INTERFACE, alternate,
	    interface, NULL, 0, HZ * 5)) < 0)
		return ret;

	iface->act_altsetting = alternate;
	dev->toggle[0] = 0;	/* 9.1.1.5 says to do this */
	dev->toggle[1] = 0;
	usb_set_maxpacket(dev);
	return 0;
}

int usb_set_configuration(struct usb_device *dev, int configuration)
{
	int i, ret;
	struct usb_config_descriptor *cp = NULL;
	
	for (i=0; i<dev->descriptor.bNumConfigurations; i++) {
		if (dev->config[i].bConfigurationValue == configuration) {
			cp = &dev->config[i];
			break;
		}
	}
	if (!cp) {
		warn("selecting invalid configuration %d", configuration);
		return -EINVAL;
	}

	if ((ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
	    USB_REQ_SET_CONFIGURATION, 0, configuration, 0, NULL, 0, HZ * SET_TIMEOUT)) < 0)
		return ret;

	dev->actconfig = cp;
	dev->toggle[0] = 0;
	dev->toggle[1] = 0;
	usb_set_maxpacket(dev);

	return 0;
}

int usb_get_report(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_REPORT, USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
		(type << 8) + id, ifnum, buf, size, HZ * GET_TIMEOUT);
}

int usb_set_report(struct usb_device *dev, int ifnum, unsigned char type, unsigned char id, void *buf, int size)
{
	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
		USB_REQ_SET_REPORT, USB_TYPE_CLASS | USB_RECIP_INTERFACE,
		(type << 8) + id, ifnum, buf, size, HZ);
}

int usb_get_configuration(struct usb_device *dev)
{
	int result;
	unsigned int cfgno, length;
	unsigned char *buffer;
	unsigned char *bigbuffer;
 	struct usb_config_descriptor *desc;

	if (dev->descriptor.bNumConfigurations > USB_MAXCONFIG) {
		warn("too many configurations");
		return -EINVAL;
	}

	if (dev->descriptor.bNumConfigurations < 1) {
		warn("not enough configurations");
		return -EINVAL;
	}

	dev->config = (struct usb_config_descriptor *)
		malloc(dev->descriptor.bNumConfigurations *
		sizeof(struct usb_config_descriptor));
	if (!dev->config) {
		err("out of memory");
		return -ENOMEM;	
	}
	memset(dev->config, 0, dev->descriptor.bNumConfigurations *
		sizeof(struct usb_config_descriptor));

	dev->rawdescriptors = (char **)malloc(sizeof(char *) *
		dev->descriptor.bNumConfigurations);
	if (!dev->rawdescriptors) {
		err("out of memory");
		return -ENOMEM;
	}

	buffer = (unsigned char *)malloc(8);
	if (!buffer) {
		err("unable to allocate memory for configuration descriptors");
		return -ENOMEM;
	}
	desc = (struct usb_config_descriptor *)buffer;

	for (cfgno = 0; cfgno < dev->descriptor.bNumConfigurations; cfgno++) {
		/* We grab the first 8 bytes so we know how long the whole */
		/*  configuration is */
		result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno, buffer, 8);
		if (result < 8) {
			if (result < 0)
				err("unable to get descriptor");
			else {
				err("config descriptor too short (expected %i, got %i)", 8, result);
				result = -EINVAL;
			}
			goto err;
		}

  	  	/* Get the full buffer */
		length = le16_to_cpu(desc->wTotalLength);

		bigbuffer = (unsigned char *)malloc(length);
		if (!bigbuffer) {
			err("unable to allocate memory for configuration descriptors");
			result = -ENOMEM;
			goto err;
		}

		/* Now that we know the length, get the whole thing */
		result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno, bigbuffer, length);
		if (result < 0) {
			err("couldn't get all of config descriptors");
			free(bigbuffer);
			goto err;
		}	
	
		if (result < length) {
			err("config descriptor too short (expected %i, got %i)", length, result);
			result = -EINVAL;
			free(bigbuffer);
			goto err;
		}

		dev->rawdescriptors[cfgno] = bigbuffer;

		result = usb_parse_configuration(&dev->config[cfgno], bigbuffer);
		if (result > 0)
			printf("descriptor data left");
		else if (result < 0) {
			result = -EINVAL;
			goto err;
		}
	}

	free(buffer);
	return 0;
err:
	free(buffer);
	dev->descriptor.bNumConfigurations = cfgno;
	return result;
}

/*
 * usb_string:
 *	returns string length (> 0) or error (< 0)
 */
int usb_string(struct usb_device *dev, int index, char *buf, size_t size)
{
	unsigned char *tbuf;
	int err;
	unsigned int u, idx;

	if (size <= 0 || !buf || !index)
		return -EINVAL;
	buf[0] = 0;
	tbuf = (unsigned char *)malloc(256);
	if (!tbuf)
		return -ENOMEM;

	/* get langid for strings if it's not yet known */
	if (!dev->have_langid) {
		err = usb_get_string(dev, 0, 0, tbuf, 4);
		if (err < 0) {
//			err("error getting string descriptor 0 (error=%d)", err);
			goto errout;
		} else if (tbuf[0] < 4) {
//			err("string descriptor 0 too short");
			err = -EINVAL;
			goto errout;
		} else {
			dev->have_langid = -1;
			dev->string_langid = tbuf[2] | (tbuf[3]<< 8);
				/* always use the first langid listed */
//			printf("USB device number %d default language ID %d",
//				dev->devnum, dev->string_langid);
		}
	}

	/*
	 * Just ask for a maximum length string and then take the length
	 * that was returned.
	 */
	err = usb_get_string(dev, dev->string_langid, index, tbuf, 255);
	if (err < 0)
		goto errout;

	size--;		/* leave room for trailing NULL char in output buffer */
	for (idx = 0, u = 2; u < err; u += 2) {
		if (idx >= size)
			break;
		if (tbuf[u+1])			/* high byte */
			buf[idx++] = '?';  /* non-ASCII character */
		else
			buf[idx++] = tbuf[u];
	}
	buf[idx] = 0;
	err = idx;

 errout:
	free(tbuf);
	return err;
}

/*
 * By the time we get here, the device has gotten a new device ID
 * and is in the default state. We need to identify the thing and
 * get the ball rolling..
 *