hub.c

基于S3CEB2410平台LINUX操作系统下 USB驱动源代码

				struct usb_device *dev, unsigned int delay)
{
	int delay_time, ret;
	struct usb_port_status portsts;
	unsigned short portchange, portstatus;

	for (delay_time = 0; delay_time < HUB_RESET_TIMEOUT; delay_time += delay) {
		/* wait to give the device a chance to reset */
		wait_ms(delay);

		/* read and decode port status */
		ret = usb_get_port_status(hub, port + 1, &portsts);
		if (ret < 0) {
			err("get_port_status(%d) failed (err = %d)", port + 1, ret);
			return -1;
		}

		portstatus = le16_to_cpu(portsts.wPortStatus);
		portchange = le16_to_cpu(portsts.wPortChange);
		dbg("port %d, portstatus %x, change %x, %s", port + 1,
			portstatus, portchange, portspeed (portstatus));

		/* bomb out completely if something weird happened */
		if ((portchange & USB_PORT_STAT_C_CONNECTION))
			return -1;

		/* if we`ve finished resetting, then break out of the loop */
		if (!(portstatus & USB_PORT_STAT_RESET) &&
		    (portstatus & USB_PORT_STAT_ENABLE)) {
			if (portstatus & USB_PORT_STAT_HIGH_SPEED)
				dev->speed = USB_SPEED_HIGH;
			else if (portstatus & USB_PORT_STAT_LOW_SPEED)
				dev->speed = USB_SPEED_LOW;
			else
				dev->speed = USB_SPEED_FULL;
			return 0;
		}

		/* switch to the long delay after two short delay failures */
		if (delay_time >= 2 * HUB_SHORT_RESET_TIME)
			delay = HUB_LONG_RESET_TIME;

		dbg("port %d of hub %d not reset yet, waiting %dms", port + 1,
			hub->devnum, delay);
	}

	return -1;
}

/* return: -1 on error, 0 on success, 1 on disconnect.  */
static int usb_hub_port_reset(struct usb_device *hub, int port,
				struct usb_device *dev, unsigned int delay)
{
	int i, status;

	/* Reset the port */
	for (i = 0; i < HUB_RESET_TRIES; i++) {
		usb_set_port_feature(hub, port + 1, USB_PORT_FEAT_RESET);

		/* return on disconnect or reset */
		status = usb_hub_port_wait_reset(hub, port, dev, delay);
		if (status != -1) {
			usb_clear_port_feature(hub, port + 1, USB_PORT_FEAT_C_RESET);
			return status;
		}

		dbg("port %d of hub %d not enabled, trying reset again...",
			port + 1, hub->devnum);
		delay = HUB_LONG_RESET_TIME;
	}

	err("Cannot enable port %i of hub %d, disabling port.",
		port + 1, hub->devnum);
	err("Maybe the USB cable is bad?");

	return -1;
}

void usb_hub_port_disable(struct usb_device *hub, int port)
{
	int ret;

	ret = usb_clear_port_feature(hub, port + 1, USB_PORT_FEAT_ENABLE);
	if (ret)
		err("cannot disable port %d of hub %d (err = %d)",
			port + 1, hub->devnum, ret);
}

static void usb_hub_port_connect_change(struct usb_device *hub, int port,
					struct usb_port_status *portsts)
{
	struct usb_device *dev;
	unsigned short portstatus, portchange;
	unsigned int delay = HUB_SHORT_RESET_TIME;
	int i;
	char *portstr, *tempstr;

	portstatus = le16_to_cpu(portsts->wPortStatus);
	portchange = le16_to_cpu(portsts->wPortChange);
	dbg("port %d, portstatus %x, change %x, %s",
		port + 1, portstatus, portchange, portspeed (portstatus));

	/* Clear the connection change status */
	usb_clear_port_feature(hub, port + 1, USB_PORT_FEAT_C_CONNECTION);

	/* Disconnect any existing devices under this port */
	if (hub->children[port])
		usb_disconnect(&hub->children[port]);

	/* Return now if nothing is connected */
	if (!(portstatus & USB_PORT_STAT_CONNECTION)) {
		if (portstatus & USB_PORT_STAT_ENABLE)
			usb_hub_port_disable(hub, port);

		return;
	}

	/* Some low speed devices have problems with the quick delay, so */
	/*  be a bit pessimistic with those devices. RHbug #23670 */
	if (portstatus & USB_PORT_STAT_LOW_SPEED) {
		wait_ms(400);
		delay = HUB_LONG_RESET_TIME;
	}

	down(&usb_address0_sem);

	tempstr = kmalloc(1024, GFP_KERNEL);
	portstr = kmalloc(1024, GFP_KERNEL);

	for (i = 0; i < HUB_PROBE_TRIES; i++) {
		struct usb_device *pdev, *cdev;

		/* Allocate a new device struct */
		dev = usb_alloc_dev(hub, hub->bus);
		if (!dev) {
			err("couldn't allocate usb_device");
			break;
		}

		hub->children[port] = dev;

		/* Reset the device */
		if (usb_hub_port_reset(hub, port, dev, delay)) {
			usb_free_dev(dev);
			break;
		}

		/* Find a new device ID for it */
		usb_connect(dev);

		/* Create a readable topology string */
		cdev = dev;
		pdev = dev->parent;
		if (portstr && tempstr) {
			portstr[0] = 0;
			while (pdev) {
				int port;

				for (port = 0; port < pdev->maxchild; port++)
					if (pdev->children[port] == cdev)
						break;

				strcpy(tempstr, portstr);
				if (!strlen(tempstr))
					sprintf(portstr, "%d", port + 1);
				else
					sprintf(portstr, "%d/%s", port + 1, tempstr);

				cdev = pdev;
				pdev = pdev->parent;
			}
			info("USB new device connect on bus%d/%s, assigned device number %d",
				dev->bus->busnum, portstr, dev->devnum);
		} else
			info("USB new device connect on bus%d, assigned device number %d",
				dev->bus->busnum, dev->devnum);

		/* Run it through the hoops (find a driver, etc) */
		if (!usb_new_device(dev))
			goto done;

		/* Free the configuration if there was an error */
		usb_free_dev(dev);

		/* Switch to a long reset time */
		delay = HUB_LONG_RESET_TIME;
	}

	hub->children[port] = NULL;
	usb_hub_port_disable(hub, port);
done:
	up(&usb_address0_sem);
	if (portstr)
		kfree(portstr);
	if (tempstr)
		kfree(tempstr);
}

static void usb_hub_events(void)
{
	unsigned long flags;
	struct list_head *tmp;
	struct usb_device *dev;
	struct usb_hub *hub;
	struct usb_hub_status hubsts;
	unsigned short hubstatus, hubchange;
	int i, ret;

	/*
	 *  We restart the list everytime to avoid a deadlock with
	 * deleting hubs downstream from this one. This should be
	 * safe since we delete the hub from the event list.
	 * Not the most efficient, but avoids deadlocks.
	 */
	while (1) {
		spin_lock_irqsave(&hub_event_lock, flags);

		if (list_empty(&hub_event_list))
			break;

		/* Grab the next entry from the beginning of the list */
		tmp = hub_event_list.next;

		hub = list_entry(tmp, struct usb_hub, event_list);
		dev = hub->dev;

		list_del(tmp);
		INIT_LIST_HEAD(tmp);

		down(&hub->khubd_sem); /* never blocks, we were on list */
		spin_unlock_irqrestore(&hub_event_lock, flags);

		if (hub->error) {
			dbg("resetting hub %d for error %d", dev->devnum, hub->error);

			if (usb_hub_reset(hub)) {
				err("error resetting hub %d - disconnecting", dev->devnum);
				up(&hub->khubd_sem);
				usb_hub_disconnect(dev);
				continue;
			}

			hub->nerrors = 0;
			hub->error = 0;
		}

		for (i = 0; i < hub->descriptor->bNbrPorts; i++) {
			struct usb_port_status portsts;
			unsigned short portstatus, portchange;

			ret = usb_get_port_status(dev, i + 1, &portsts);
			if (ret < 0) {
				err("get_port_status failed (err = %d)", ret);
				continue;
			}

			portstatus = le16_to_cpu(portsts.wPortStatus);
			portchange = le16_to_cpu(portsts.wPortChange);

			if (portchange & USB_PORT_STAT_C_CONNECTION) {
				dbg("port %d connection change", i + 1);

				usb_hub_port_connect_change(dev, i, &portsts);
			} else if (portchange & USB_PORT_STAT_C_ENABLE) {
				dbg("port %d enable change, status %x", i + 1, portstatus);
				usb_clear_port_feature(dev, i + 1, USB_PORT_FEAT_C_ENABLE);

				/*
				 * EM interference sometimes causes bad shielded USB devices to 
				 * be shutdown by the hub, this hack enables them again.
				 * Works at least with mouse driver. 
				 */
				if (!(portstatus & USB_PORT_STAT_ENABLE) && 
				    (portstatus & USB_PORT_STAT_CONNECTION) && (dev->children[i])) {
					err("already running port %i disabled by hub (EMI?), re-enabling...",
						i + 1);
					usb_hub_port_connect_change(dev, i, &portsts);
				}
			}

			if (portchange & USB_PORT_STAT_C_SUSPEND) {
				dbg("port %d suspend change", i + 1);
				usb_clear_port_feature(dev, i + 1,  USB_PORT_FEAT_C_SUSPEND);
			}
			
			if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
				err("port %d over-current change", i + 1);
				usb_clear_port_feature(dev, i + 1, USB_PORT_FEAT_C_OVER_CURRENT);
				usb_hub_power_on(hub);
			}

			if (portchange & USB_PORT_STAT_C_RESET) {
				dbg("port %d reset change", i + 1);
				usb_clear_port_feature(dev, i + 1, USB_PORT_FEAT_C_RESET);
			}
		} /* end for i */

		/* deal with hub status changes */
		if (usb_get_hub_status(dev, &hubsts) < 0)
			err("get_hub_status failed");
		else {
			hubstatus = le16_to_cpup(&hubsts.wHubStatus);
			hubchange = le16_to_cpup(&hubsts.wHubChange);
			if (hubchange & HUB_CHANGE_LOCAL_POWER) {
				dbg("hub power change");
				usb_clear_hub_feature(dev, C_HUB_LOCAL_POWER);
			}
			if (hubchange & HUB_CHANGE_OVERCURRENT) {
				dbg("hub overcurrent change");
				wait_ms(500);	/* Cool down */
				usb_clear_hub_feature(dev, C_HUB_OVER_CURRENT);
                        	usb_hub_power_on(hub);
			}
		}
		up(&hub->khubd_sem);
        } /* end while (1) */

	spin_unlock_irqrestore(&hub_event_lock, flags);
}

static int usb_hub_thread(void *__hub)
{
	lock_kernel();

	/*
	 * This thread doesn't need any user-level access,
	 * so get rid of all our resources
	 */

	daemonize();

	/* Setup a nice name */
	strcpy(current->comm, "khubd");

	/* Send me a signal to get me die (for debugging) */
	do {
		usb_hub_events();
		interruptible_sleep_on(&khubd_wait);
	} while (!signal_pending(current));

	dbg("usb_hub_thread exiting");

	unlock_kernel();
	complete_and_exit(&khubd_exited, 0);
}

static struct usb_device_id hub_id_table [] = {
    { match_flags: USB_DEVICE_ID_MATCH_INT_CLASS,
      bInterfaceClass: USB_CLASS_HUB},
    { }						/* Terminating entry */
};

MODULE_DEVICE_TABLE (usb, hub_id_table);

static struct usb_driver hub_driver = {
	name:		"hub",
	probe:		hub_probe,
	ioctl:		hub_ioctl,
	disconnect:	hub_disconnect,
	id_table:	hub_id_table,
};

/*
 * This should be a separate module.
 */
int usb_hub_init(void)
{
	int pid;

	if (usb_register(&hub_driver) < 0) {
		err("Unable to register USB hub driver");
		return -1;
	}

	pid = kernel_thread(usb_hub_thread, NULL,
		CLONE_FS | CLONE_FILES | CLONE_SIGHAND);
	if (pid >= 0) {
		khubd_pid = pid;

		return 0;
	}

	/* Fall through if kernel_thread failed */
	usb_deregister(&hub_driver);
	err("failed to start usb_hub_thread");

	return -1;
}

void usb_hub_cleanup(void)
{
	int ret;

	/* Kill the thread */
	ret = kill_proc(khubd_pid, SIGTERM, 1);

	wait_for_completion(&khubd_exited);

	/*
	 * Hub resources are freed for us by usb_deregister. It calls
	 * usb_driver_purge on every device which in turn calls that
	 * devices disconnect function if it is using this driver.
	 * The hub_disconnect function takes care of releasing the
	 * individual hub resources. -greg
	 */
	usb_deregister(&hub_driver);
} /* usb_hub_cleanup() */

/*
 * WARNING - If a driver calls usb_reset_device, you should simulate a
 * disconnect() and probe() for other interfaces you doesn't claim. This
 * is left up to the driver writer right now. This insures other drivers
 * have a chance to re-setup their interface.
 *
 * Take a look at proc_resetdevice in devio.c for some sample code to
 * do this.
 */
int usb_reset_device(struct usb_device *dev)
{
	struct usb_device *parent = dev->parent;
	struct usb_device_descriptor descriptor;
	int i, ret, port = -1;

	if (!parent) {
		err("attempting to reset root hub!");
		return -EINVAL;
	}

	for (i = 0; i < parent->maxchild; i++)
		if (parent->children[i] == dev) {
			port = i;
			break;
		}

	if (port < 0)
		return -ENOENT;

	down(&usb_address0_sem);

	/* Send a reset to the device */
	if (usb_hub_port_reset(parent, port, dev, HUB_SHORT_RESET_TIME)) {
		usb_hub_port_disable(parent, port);
		up(&usb_address0_sem);
		return(-ENODEV);
	}

	/* Reprogram the Address */
	ret = usb_set_address(dev);
	if (ret < 0) {
		err("USB device not accepting new address (error=%d)", ret);
		usb_hub_port_disable(parent, port);
		up(&usb_address0_sem);
		return ret;
	}

	/* Let the SET_ADDRESS settle */
	wait_ms(10);

	up(&usb_address0_sem);

	/*
	 * Now we fetch the configuration descriptors for the device and
	 * see if anything has changed. If it has, we dump the current
	 * parsed descriptors and reparse from scratch. Then we leave
	 * the device alone for the caller to finish setting up.
	 *
	 * If nothing changed, we reprogram the configuration and then
	 * the alternate settings.
	 */
	ret = usb_get_descriptor(dev, USB_DT_DEVICE, 0, &descriptor,
			sizeof(descriptor));
	if (ret < 0)
		return ret;

	le16_to_cpus(&descriptor.bcdUSB);
	le16_to_cpus(&descriptor.idVendor);
	le16_to_cpus(&descriptor.idProduct);
	le16_to_cpus(&descriptor.bcdDevice);

	if (memcmp(&dev->descriptor, &descriptor, sizeof(descriptor))) {
		usb_destroy_configuration(dev);

		ret = usb_get_device_descriptor(dev);
		if (ret < sizeof(dev->descriptor)) {
			if (ret < 0)
				err("unable to get device descriptor (error=%d)", ret);
			else
				err("USB device descriptor short read (expected %Zi, got %i)", sizeof(dev->descriptor), ret);
        
			clear_bit(dev->devnum, &dev->bus->devmap.devicemap);
			dev->devnum = -1;
			return -EIO;
		}

		ret = usb_get_configuration(dev);
		if (ret < 0) {
			err("unable to get configuration (error=%d)", ret);
			usb_destroy_configuration(dev);
			clear_bit(dev->devnum, &dev->bus->devmap.devicemap);
			dev->devnum = -1;
			return 1;
		}

		dev->actconfig = dev->config;
		usb_set_maxpacket(dev);

		return 1;
	}

	ret = usb_set_configuration(dev, dev->actconfig->bConfigurationValue);
	if (ret < 0) {
		err("failed to set active configuration (error=%d)", ret);
		return ret;
	}

	for (i = 0; i < dev->actconfig->bNumInterfaces; i++) {
		struct usb_interface *intf = &dev->actconfig->interface[i];
		struct usb_interface_descriptor *as = &intf->altsetting[intf->act_altsetting];

		ret = usb_set_interface(dev, as->bInterfaceNumber, as->bAlternateSetting);
		if (ret < 0) {
			err("failed to set active alternate setting for interface %d (error=%d)", i, ret);
			return ret;
		}
	}

	return 0;
}