Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1558 insertions, 0 deletions

diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
new file mode 100644
index 0000000000..17b09f03ef
--- /dev/null
+++ b/drivers/usb/serial/usb-serial.c
@@ -0,0 +1,1558 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * USB Serial Converter driver
+ *
+ * Copyright (C) 2009 - 2013 Johan Hovold (jhovold@gmail.com)
+ * Copyright (C) 1999 - 2012 Greg Kroah-Hartman (greg@kroah.com)
+ * Copyright (C) 2000 Peter Berger (pberger@brimson.com)
+ * Copyright (C) 2000 Al Borchers (borchers@steinerpoint.com)
+ *
+ * This driver was originally based on the ACM driver by Armin Fuerst (which was
+ * based on a driver by Brad Keryan)
+ *
+ * See Documentation/usb/usb-serial.rst for more information on using this
+ * driver
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/seq_file.h>
+#include <linux/spinlock.h>
+#include <linux/mutex.h>
+#include <linux/list.h>
+#include <linux/uaccess.h>
+#include <linux/serial.h>
+#include <linux/usb.h>
+#include <linux/usb/serial.h>
+#include <linux/kfifo.h>
+#include <linux/idr.h>
+
+#define DRIVER_AUTHOR "Greg Kroah-Hartman <gregkh@linuxfoundation.org>"
+#define DRIVER_DESC "USB Serial Driver core"
+
+#define USB_SERIAL_TTY_MAJOR	188
+#define USB_SERIAL_TTY_MINORS	512	/* should be enough for a while */
+
+/* There is no MODULE_DEVICE_TABLE for usbserial.c.  Instead
+   the MODULE_DEVICE_TABLE declarations in each serial driver
+   cause the "hotplug" program to pull in whatever module is necessary
+   via modprobe, and modprobe will load usbserial because the serial
+   drivers depend on it.
+*/
+
+static DEFINE_IDR(serial_minors);
+static DEFINE_MUTEX(table_lock);
+static LIST_HEAD(usb_serial_driver_list);
+
+/*
+ * Look up the serial port structure.  If it is found and it hasn't been
+ * disconnected, return with the parent usb_serial structure's disc_mutex held
+ * and its refcount incremented.  Otherwise return NULL.
+ */
+struct usb_serial_port *usb_serial_port_get_by_minor(unsigned minor)
+{
+	struct usb_serial *serial;
+	struct usb_serial_port *port;
+
+	mutex_lock(&table_lock);
+	port = idr_find(&serial_minors, minor);
+	if (!port)
+		goto exit;
+
+	serial = port->serial;
+	mutex_lock(&serial->disc_mutex);
+	if (serial->disconnected) {
+		mutex_unlock(&serial->disc_mutex);
+		port = NULL;
+	} else {
+		kref_get(&serial->kref);
+	}
+exit:
+	mutex_unlock(&table_lock);
+	return port;
+}
+
+static int allocate_minors(struct usb_serial *serial, int num_ports)
+{
+	struct usb_serial_port *port;
+	unsigned int i, j;
+	int minor;
+
+	dev_dbg(&serial->interface->dev, "%s %d\n", __func__, num_ports);
+
+	mutex_lock(&table_lock);
+	for (i = 0; i < num_ports; ++i) {
+		port = serial->port[i];
+		minor = idr_alloc(&serial_minors, port, 0,
+					USB_SERIAL_TTY_MINORS, GFP_KERNEL);
+		if (minor < 0)
+			goto error;
+		port->minor = minor;
+		port->port_number = i;
+	}
+	serial->minors_reserved = 1;
+	mutex_unlock(&table_lock);
+	return 0;
+error:
+	/* unwind the already allocated minors */
+	for (j = 0; j < i; ++j)
+		idr_remove(&serial_minors, serial->port[j]->minor);
+	mutex_unlock(&table_lock);
+	return minor;
+}
+
+static void release_minors(struct usb_serial *serial)
+{
+	int i;
+
+	mutex_lock(&table_lock);
+	for (i = 0; i < serial->num_ports; ++i)
+		idr_remove(&serial_minors, serial->port[i]->minor);
+	mutex_unlock(&table_lock);
+	serial->minors_reserved = 0;
+}
+
+int usb_serial_claim_interface(struct usb_serial *serial, struct usb_interface *intf)
+{
+	struct usb_driver *driver = serial->type->usb_driver;
+	int ret;
+
+	if (serial->sibling)
+		return -EBUSY;
+
+	ret = usb_driver_claim_interface(driver, intf, serial);
+	if (ret) {
+		dev_err(&serial->interface->dev,
+				"failed to claim sibling interface: %d\n", ret);
+		return ret;
+	}
+
+	serial->sibling = intf;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(usb_serial_claim_interface);
+
+static void release_sibling(struct usb_serial *serial, struct usb_interface *intf)
+{
+	struct usb_driver *driver = serial->type->usb_driver;
+	struct usb_interface *sibling;
+
+	if (!serial->sibling)
+		return;
+
+	if (intf == serial->sibling)
+		sibling = serial->interface;
+	else
+		sibling = serial->sibling;
+
+	usb_set_intfdata(sibling, NULL);
+	usb_driver_release_interface(driver, sibling);
+}
+
+static void destroy_serial(struct kref *kref)
+{
+	struct usb_serial *serial;
+	struct usb_serial_port *port;
+	int i;
+
+	serial = to_usb_serial(kref);
+
+	/* return the minor range that this device had */
+	if (serial->minors_reserved)
+		release_minors(serial);
+
+	if (serial->attached && serial->type->release)
+		serial->type->release(serial);
+
+	/* Now that nothing is using the ports, they can be freed */
+	for (i = 0; i < serial->num_port_pointers; ++i) {
+		port = serial->port[i];
+		if (port) {
+			port->serial = NULL;
+			put_device(&port->dev);
+		}
+	}
+
+	usb_put_intf(serial->interface);
+	usb_put_dev(serial->dev);
+	kfree(serial);
+}
+
+void usb_serial_put(struct usb_serial *serial)
+{
+	kref_put(&serial->kref, destroy_serial);
+}
+
+/*****************************************************************************
+ * Driver tty interface functions
+ *****************************************************************************/
+
+/**
+ * serial_install - install tty
+ * @driver: the driver (USB in our case)
+ * @tty: the tty being created
+ *
+ * Initialise the termios structure for this tty.  We use the default
+ * USB serial settings but permit them to be overridden by
+ * serial->type->init_termios on first open.
+ *
+ * This is the first place a new tty gets used.  Hence this is where we
+ * acquire references to the usb_serial structure and the driver module,
+ * where we store a pointer to the port.  All these actions are reversed
+ * in serial_cleanup().
+ */
+static int serial_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+	int idx = tty->index;
+	struct usb_serial *serial;
+	struct usb_serial_port *port;
+	bool init_termios;
+	int retval = -ENODEV;
+
+	port = usb_serial_port_get_by_minor(idx);
+	if (!port)
+		return retval;
+
+	serial = port->serial;
+	if (!try_module_get(serial->type->driver.owner))
+		goto err_put_serial;
+
+	init_termios = (driver->termios[idx] == NULL);
+
+	retval = tty_standard_install(driver, tty);
+	if (retval)
+		goto err_put_module;
+
+	mutex_unlock(&serial->disc_mutex);
+
+	/* allow the driver to update the initial settings */
+	if (init_termios && serial->type->init_termios)
+		serial->type->init_termios(tty);
+
+	tty->driver_data = port;
+
+	return retval;
+
+err_put_module:
+	module_put(serial->type->driver.owner);
+err_put_serial:
+	usb_serial_put(serial);
+	mutex_unlock(&serial->disc_mutex);
+	return retval;
+}
+
+static int serial_port_activate(struct tty_port *tport, struct tty_struct *tty)
+{
+	struct usb_serial_port *port =
+		container_of(tport, struct usb_serial_port, port);
+	struct usb_serial *serial = port->serial;
+	int retval;
+
+	mutex_lock(&serial->disc_mutex);
+	if (serial->disconnected) {
+		retval = -ENODEV;
+		goto out_unlock;
+	}
+
+	retval = usb_autopm_get_interface(serial->interface);
+	if (retval)
+		goto out_unlock;
+
+	retval = port->serial->type->open(tty, port);
+	if (retval)
+		usb_autopm_put_interface(serial->interface);
+out_unlock:
+	mutex_unlock(&serial->disc_mutex);
+
+	if (retval < 0)
+		retval = usb_translate_errors(retval);
+
+	return retval;
+}
+
+static int serial_open(struct tty_struct *tty, struct file *filp)
+{
+	struct usb_serial_port *port = tty->driver_data;
+
+	dev_dbg(&port->dev, "%s\n", __func__);
+
+	return tty_port_open(&port->port, tty, filp);
+}
+
+/**
+ * serial_port_shutdown - shut down hardware
+ * @tport: tty port to shut down
+ *
+ * Shut down a USB serial port. Serialized against activate by the
+ * tport mutex and kept to matching open/close pairs
+ * of calls by the tty-port initialized flag.
+ *
+ * Not called if tty is console.
+ */
+static void serial_port_shutdown(struct tty_port *tport)
+{
+	struct usb_serial_port *port =
+		container_of(tport, struct usb_serial_port, port);
+	struct usb_serial_driver *drv = port->serial->type;
+
+	if (drv->close)
+		drv->close(port);
+
+	usb_autopm_put_interface(port->serial->interface);
+}
+
+static void serial_hangup(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+
+	dev_dbg(&port->dev, "%s\n", __func__);
+
+	tty_port_hangup(&port->port);
+}
+
+static void serial_close(struct tty_struct *tty, struct file *filp)
+{
+	struct usb_serial_port *port = tty->driver_data;
+
+	dev_dbg(&port->dev, "%s\n", __func__);
+
+	tty_port_close(&port->port, tty, filp);
+}
+
+/**
+ * serial_cleanup - free resources post close/hangup
+ * @tty: tty to clean up
+ *
+ * Do the resource freeing and refcount dropping for the port.
+ * Avoid freeing the console.
+ *
+ * Called asynchronously after the last tty kref is dropped.
+ */
+static void serial_cleanup(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct usb_serial *serial;
+	struct module *owner;
+
+	dev_dbg(&port->dev, "%s\n", __func__);
+
+	/* The console is magical.  Do not hang up the console hardware
+	 * or there will be tears.
+	 */
+	if (port->port.console)
+		return;
+
+	tty->driver_data = NULL;
+
+	serial = port->serial;
+	owner = serial->type->driver.owner;
+
+	usb_serial_put(serial);
+	module_put(owner);
+}
+
+static ssize_t serial_write(struct tty_struct *tty, const u8 *buf, size_t count)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	int retval = -ENODEV;
+
+	if (port->serial->dev->state == USB_STATE_NOTATTACHED)
+		goto exit;
+
+	dev_dbg(&port->dev, "%s - %zu byte(s)\n", __func__, count);
+
+	retval = port->serial->type->write(tty, port, buf, count);
+	if (retval < 0)
+		retval = usb_translate_errors(retval);
+exit:
+	return retval;
+}
+
+static unsigned int serial_write_room(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+
+	dev_dbg(&port->dev, "%s\n", __func__);
+
+	return port->serial->type->write_room(tty);
+}
+
+static unsigned int serial_chars_in_buffer(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct usb_serial *serial = port->serial;
+
+	dev_dbg(&port->dev, "%s\n", __func__);
+
+	if (serial->disconnected)
+		return 0;
+
+	return serial->type->chars_in_buffer(tty);
+}
+
+static void serial_wait_until_sent(struct tty_struct *tty, int timeout)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct usb_serial *serial = port->serial;
+
+	dev_dbg(&port->dev, "%s\n", __func__);
+
+	if (!port->serial->type->wait_until_sent)
+		return;
+
+	mutex_lock(&serial->disc_mutex);
+	if (!serial->disconnected)
+		port->serial->type->wait_until_sent(tty, timeout);
+	mutex_unlock(&serial->disc_mutex);
+}
+
+static void serial_throttle(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+
+	dev_dbg(&port->dev, "%s\n", __func__);
+
+	if (port->serial->type->throttle)
+		port->serial->type->throttle(tty);
+}
+
+static void serial_unthrottle(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+
+	dev_dbg(&port->dev, "%s\n", __func__);
+
+	if (port->serial->type->unthrottle)
+		port->serial->type->unthrottle(tty);
+}
+
+static int serial_get_serial(struct tty_struct *tty, struct serial_struct *ss)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct tty_port *tport = &port->port;
+	unsigned int close_delay, closing_wait;
+
+	mutex_lock(&tport->mutex);
+
+	close_delay = jiffies_to_msecs(tport->close_delay) / 10;
+	closing_wait = tport->closing_wait;
+	if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
+		closing_wait = jiffies_to_msecs(closing_wait) / 10;
+
+	ss->line = port->minor;
+	ss->close_delay = close_delay;
+	ss->closing_wait = closing_wait;
+
+	if (port->serial->type->get_serial)
+		port->serial->type->get_serial(tty, ss);
+
+	mutex_unlock(&tport->mutex);
+
+	return 0;
+}
+
+static int serial_set_serial(struct tty_struct *tty, struct serial_struct *ss)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct tty_port *tport = &port->port;
+	unsigned int close_delay, closing_wait;
+	int ret = 0;
+
+	close_delay = msecs_to_jiffies(ss->close_delay * 10);
+	closing_wait = ss->closing_wait;
+	if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
+		closing_wait = msecs_to_jiffies(closing_wait * 10);
+
+	mutex_lock(&tport->mutex);
+
+	if (!capable(CAP_SYS_ADMIN)) {
+		if (close_delay != tport->close_delay ||
+				closing_wait != tport->closing_wait) {
+			ret = -EPERM;
+			goto out_unlock;
+		}
+	}
+
+	if (port->serial->type->set_serial) {
+		ret = port->serial->type->set_serial(tty, ss);
+		if (ret)
+			goto out_unlock;
+	}
+
+	tport->close_delay = close_delay;
+	tport->closing_wait = closing_wait;
+out_unlock:
+	mutex_unlock(&tport->mutex);
+
+	return ret;
+}
+
+static int serial_ioctl(struct tty_struct *tty,
+					unsigned int cmd, unsigned long arg)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	int retval = -ENOIOCTLCMD;
+
+	dev_dbg(&port->dev, "%s - cmd 0x%04x\n", __func__, cmd);
+
+	switch (cmd) {
+	case TIOCMIWAIT:
+		if (port->serial->type->tiocmiwait)
+			retval = port->serial->type->tiocmiwait(tty, arg);
+		break;
+	default:
+		if (port->serial->type->ioctl)
+			retval = port->serial->type->ioctl(tty, cmd, arg);
+	}
+
+	return retval;
+}
+
+static void serial_set_termios(struct tty_struct *tty,
+		               const struct ktermios *old)
+{
+	struct usb_serial_port *port = tty->driver_data;
+
+	dev_dbg(&port->dev, "%s\n", __func__);
+
+	if (port->serial->type->set_termios)
+		port->serial->type->set_termios(tty, port, old);
+	else
+		tty_termios_copy_hw(&tty->termios, old);
+}
+
+static int serial_break(struct tty_struct *tty, int break_state)
+{
+	struct usb_serial_port *port = tty->driver_data;
+
+	dev_dbg(&port->dev, "%s\n", __func__);
+
+	if (port->serial->type->break_ctl)
+		return port->serial->type->break_ctl(tty, break_state);
+
+	return -ENOTTY;
+}
+
+static int serial_proc_show(struct seq_file *m, void *v)
+{
+	struct usb_serial *serial;
+	struct usb_serial_port *port;
+	int i;
+	char tmp[40];
+
+	seq_puts(m, "usbserinfo:1.0 driver:2.0\n");
+	for (i = 0; i < USB_SERIAL_TTY_MINORS; ++i) {
+		port = usb_serial_port_get_by_minor(i);
+		if (port == NULL)
+			continue;
+		serial = port->serial;
+
+		seq_printf(m, "%d:", i);
+		if (serial->type->driver.owner)
+			seq_printf(m, " module:%s",
+				module_name(serial->type->driver.owner));
+		seq_printf(m, " name:\"%s\"",
+				serial->type->description);
+		seq_printf(m, " vendor:%04x product:%04x",
+			le16_to_cpu(serial->dev->descriptor.idVendor),
+			le16_to_cpu(serial->dev->descriptor.idProduct));
+		seq_printf(m, " num_ports:%d", serial->num_ports);
+		seq_printf(m, " port:%d", port->port_number);
+		usb_make_path(serial->dev, tmp, sizeof(tmp));
+		seq_printf(m, " path:%s", tmp);
+
+		seq_putc(m, '\n');
+		usb_serial_put(serial);
+		mutex_unlock(&serial->disc_mutex);
+	}
+	return 0;
+}
+
+static int serial_tiocmget(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+
+	dev_dbg(&port->dev, "%s\n", __func__);
+
+	if (port->serial->type->tiocmget)
+		return port->serial->type->tiocmget(tty);
+	return -ENOTTY;
+}
+
+static int serial_tiocmset(struct tty_struct *tty,
+			    unsigned int set, unsigned int clear)
+{
+	struct usb_serial_port *port = tty->driver_data;
+
+	dev_dbg(&port->dev, "%s\n", __func__);
+
+	if (port->serial->type->tiocmset)
+		return port->serial->type->tiocmset(tty, set, clear);
+	return -ENOTTY;
+}
+
+static int serial_get_icount(struct tty_struct *tty,
+				struct serial_icounter_struct *icount)
+{
+	struct usb_serial_port *port = tty->driver_data;
+
+	dev_dbg(&port->dev, "%s\n", __func__);
+
+	if (port->serial->type->get_icount)
+		return port->serial->type->get_icount(tty, icount);
+	return -ENOTTY;
+}
+
+/*
+ * We would be calling tty_wakeup here, but unfortunately some line
+ * disciplines have an annoying habit of calling tty->write from
+ * the write wakeup callback (e.g. n_hdlc.c).
+ */
+void usb_serial_port_softint(struct usb_serial_port *port)
+{
+	schedule_work(&port->work);
+}
+EXPORT_SYMBOL_GPL(usb_serial_port_softint);
+
+static void usb_serial_port_work(struct work_struct *work)
+{
+	struct usb_serial_port *port =
+		container_of(work, struct usb_serial_port, work);
+
+	tty_port_tty_wakeup(&port->port);
+}
+
+static void usb_serial_port_poison_urbs(struct usb_serial_port *port)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i)
+		usb_poison_urb(port->read_urbs[i]);
+	for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
+		usb_poison_urb(port->write_urbs[i]);
+
+	usb_poison_urb(port->interrupt_in_urb);
+	usb_poison_urb(port->interrupt_out_urb);
+}
+
+static void usb_serial_port_unpoison_urbs(struct usb_serial_port *port)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i)
+		usb_unpoison_urb(port->read_urbs[i]);
+	for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
+		usb_unpoison_urb(port->write_urbs[i]);
+
+	usb_unpoison_urb(port->interrupt_in_urb);
+	usb_unpoison_urb(port->interrupt_out_urb);
+}
+
+static void usb_serial_port_release(struct device *dev)
+{
+	struct usb_serial_port *port = to_usb_serial_port(dev);
+	int i;
+
+	dev_dbg(dev, "%s\n", __func__);
+
+	usb_free_urb(port->interrupt_in_urb);
+	usb_free_urb(port->interrupt_out_urb);
+	for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {
+		usb_free_urb(port->read_urbs[i]);
+		kfree(port->bulk_in_buffers[i]);
+	}
+	for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i) {
+		usb_free_urb(port->write_urbs[i]);
+		kfree(port->bulk_out_buffers[i]);
+	}
+	kfifo_free(&port->write_fifo);
+	kfree(port->interrupt_in_buffer);
+	kfree(port->interrupt_out_buffer);
+	tty_port_destroy(&port->port);
+	kfree(port);
+}
+
+static struct usb_serial *create_serial(struct usb_device *dev,
+					struct usb_interface *interface,
+					struct usb_serial_driver *driver)
+{
+	struct usb_serial *serial;
+
+	serial = kzalloc(sizeof(*serial), GFP_KERNEL);
+	if (!serial)
+		return NULL;
+	serial->dev = usb_get_dev(dev);
+	serial->type = driver;
+	serial->interface = usb_get_intf(interface);
+	kref_init(&serial->kref);
+	mutex_init(&serial->disc_mutex);
+	serial->minors_reserved = 0;
+
+	return serial;
+}
+
+static const struct usb_device_id *match_dynamic_id(struct usb_interface *intf,
+					    struct usb_serial_driver *drv)
+{
+	struct usb_dynid *dynid;
+
+	spin_lock(&drv->dynids.lock);
+	list_for_each_entry(dynid, &drv->dynids.list, node) {
+		if (usb_match_one_id(intf, &dynid->id)) {
+			spin_unlock(&drv->dynids.lock);
+			return &dynid->id;
+		}
+	}
+	spin_unlock(&drv->dynids.lock);
+	return NULL;
+}
+
+static const struct usb_device_id *get_iface_id(struct usb_serial_driver *drv,
+						struct usb_interface *intf)
+{
+	const struct usb_device_id *id;
+
+	id = usb_match_id(intf, drv->id_table);
+	if (id) {
+		dev_dbg(&intf->dev, "static descriptor matches\n");
+		goto exit;
+	}
+	id = match_dynamic_id(intf, drv);
+	if (id)
+		dev_dbg(&intf->dev, "dynamic descriptor matches\n");
+exit:
+	return id;
+}
+
+/* Caller must hold table_lock */
+static struct usb_serial_driver *search_serial_device(
+					struct usb_interface *iface)
+{
+	const struct usb_device_id *id = NULL;
+	struct usb_serial_driver *drv;
+	struct usb_driver *driver = to_usb_driver(iface->dev.driver);
+
+	/* Check if the usb id matches a known device */
+	list_for_each_entry(drv, &usb_serial_driver_list, driver_list) {
+		if (drv->usb_driver == driver)
+			id = get_iface_id(drv, iface);
+		if (id)
+			return drv;
+	}
+
+	return NULL;
+}
+
+static bool serial_port_carrier_raised(struct tty_port *port)
+{
+	struct usb_serial_port *p = container_of(port, struct usb_serial_port, port);
+	struct usb_serial_driver *drv = p->serial->type;
+
+	if (drv->carrier_raised)
+		return drv->carrier_raised(p);
+	/* No carrier control - don't block */
+	return true;
+}
+
+static void serial_port_dtr_rts(struct tty_port *port, bool on)
+{
+	struct usb_serial_port *p = container_of(port, struct usb_serial_port, port);
+	struct usb_serial_driver *drv = p->serial->type;
+
+	if (drv->dtr_rts)
+		drv->dtr_rts(p, on);
+}
+
+static ssize_t port_number_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct usb_serial_port *port = to_usb_serial_port(dev);
+
+	return sprintf(buf, "%u\n", port->port_number);
+}
+static DEVICE_ATTR_RO(port_number);
+
+static struct attribute *usb_serial_port_attrs[] = {
+	&dev_attr_port_number.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(usb_serial_port);
+
+static const struct tty_port_operations serial_port_ops = {
+	.carrier_raised		= serial_port_carrier_raised,
+	.dtr_rts		= serial_port_dtr_rts,
+	.activate		= serial_port_activate,
+	.shutdown		= serial_port_shutdown,
+};
+
+static void store_endpoint(struct usb_serial *serial,
+					struct usb_serial_endpoints *epds,
+					struct usb_endpoint_descriptor *epd)
+{
+	struct device *dev = &serial->interface->dev;
+	u8 addr = epd->bEndpointAddress;
+
+	if (usb_endpoint_is_bulk_in(epd)) {
+		if (epds->num_bulk_in == ARRAY_SIZE(epds->bulk_in))
+			return;
+		dev_dbg(dev, "found bulk in endpoint %02x\n", addr);
+		epds->bulk_in[epds->num_bulk_in++] = epd;
+	} else if (usb_endpoint_is_bulk_out(epd)) {
+		if (epds->num_bulk_out == ARRAY_SIZE(epds->bulk_out))
+			return;
+		dev_dbg(dev, "found bulk out endpoint %02x\n", addr);
+		epds->bulk_out[epds->num_bulk_out++] = epd;
+	} else if (usb_endpoint_is_int_in(epd)) {
+		if (epds->num_interrupt_in == ARRAY_SIZE(epds->interrupt_in))
+			return;
+		dev_dbg(dev, "found interrupt in endpoint %02x\n", addr);
+		epds->interrupt_in[epds->num_interrupt_in++] = epd;
+	} else if (usb_endpoint_is_int_out(epd)) {
+		if (epds->num_interrupt_out == ARRAY_SIZE(epds->interrupt_out))
+			return;
+		dev_dbg(dev, "found interrupt out endpoint %02x\n", addr);
+		epds->interrupt_out[epds->num_interrupt_out++] = epd;
+	}
+}
+
+static void find_endpoints(struct usb_serial *serial,
+					struct usb_serial_endpoints *epds,
+					struct usb_interface *intf)
+{
+	struct usb_host_interface *iface_desc;
+	struct usb_endpoint_descriptor *epd;
+	unsigned int i;
+
+	iface_desc = intf->cur_altsetting;
+	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
+		epd = &iface_desc->endpoint[i].desc;
+		store_endpoint(serial, epds, epd);
+	}
+}
+
+static int setup_port_bulk_in(struct usb_serial_port *port,
+					struct usb_endpoint_descriptor *epd)
+{
+	struct usb_serial_driver *type = port->serial->type;
+	struct usb_device *udev = port->serial->dev;
+	int buffer_size;
+	int i;
+
+	buffer_size = max_t(int, type->bulk_in_size, usb_endpoint_maxp(epd));
+	port->bulk_in_size = buffer_size;
+	port->bulk_in_endpointAddress = epd->bEndpointAddress;
+
+	for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {
+		set_bit(i, &port->read_urbs_free);
+		port->read_urbs[i] = usb_alloc_urb(0, GFP_KERNEL);
+		if (!port->read_urbs[i])
+			return -ENOMEM;
+		port->bulk_in_buffers[i] = kmalloc(buffer_size, GFP_KERNEL);
+		if (!port->bulk_in_buffers[i])
+			return -ENOMEM;
+		usb_fill_bulk_urb(port->read_urbs[i], udev,
+				usb_rcvbulkpipe(udev, epd->bEndpointAddress),
+				port->bulk_in_buffers[i], buffer_size,
+				type->read_bulk_callback, port);
+	}
+
+	port->read_urb = port->read_urbs[0];
+	port->bulk_in_buffer = port->bulk_in_buffers[0];
+
+	return 0;
+}
+
+static int setup_port_bulk_out(struct usb_serial_port *port,
+					struct usb_endpoint_descriptor *epd)
+{
+	struct usb_serial_driver *type = port->serial->type;
+	struct usb_device *udev = port->serial->dev;
+	int buffer_size;
+	int i;
+
+	if (kfifo_alloc(&port->write_fifo, PAGE_SIZE, GFP_KERNEL))
+		return -ENOMEM;
+	if (type->bulk_out_size)
+		buffer_size = type->bulk_out_size;
+	else
+		buffer_size = usb_endpoint_maxp(epd);
+	port->bulk_out_size = buffer_size;
+	port->bulk_out_endpointAddress = epd->bEndpointAddress;
+
+	for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i) {
+		set_bit(i, &port->write_urbs_free);
+		port->write_urbs[i] = usb_alloc_urb(0, GFP_KERNEL);
+		if (!port->write_urbs[i])
+			return -ENOMEM;
+		port->bulk_out_buffers[i] = kmalloc(buffer_size, GFP_KERNEL);
+		if (!port->bulk_out_buffers[i])
+			return -ENOMEM;
+		usb_fill_bulk_urb(port->write_urbs[i], udev,
+				usb_sndbulkpipe(udev, epd->bEndpointAddress),
+				port->bulk_out_buffers[i], buffer_size,
+				type->write_bulk_callback, port);
+	}
+
+	port->write_urb = port->write_urbs[0];
+	port->bulk_out_buffer = port->bulk_out_buffers[0];
+
+	return 0;
+}
+
+static int setup_port_interrupt_in(struct usb_serial_port *port,
+					struct usb_endpoint_descriptor *epd)
+{
+	struct usb_serial_driver *type = port->serial->type;
+	struct usb_device *udev = port->serial->dev;
+	int buffer_size;
+
+	port->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (!port->interrupt_in_urb)
+		return -ENOMEM;
+	buffer_size = usb_endpoint_maxp(epd);
+	port->interrupt_in_endpointAddress = epd->bEndpointAddress;
+	port->interrupt_in_buffer = kmalloc(buffer_size, GFP_KERNEL);
+	if (!port->interrupt_in_buffer)
+		return -ENOMEM;
+	usb_fill_int_urb(port->interrupt_in_urb, udev,
+			usb_rcvintpipe(udev, epd->bEndpointAddress),
+			port->interrupt_in_buffer, buffer_size,
+			type->read_int_callback, port,
+			epd->bInterval);
+
+	return 0;
+}
+
+static int setup_port_interrupt_out(struct usb_serial_port *port,
+					struct usb_endpoint_descriptor *epd)
+{
+	struct usb_serial_driver *type = port->serial->type;
+	struct usb_device *udev = port->serial->dev;
+	int buffer_size;
+
+	port->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (!port->interrupt_out_urb)
+		return -ENOMEM;
+	buffer_size = usb_endpoint_maxp(epd);
+	port->interrupt_out_size = buffer_size;
+	port->interrupt_out_endpointAddress = epd->bEndpointAddress;
+	port->interrupt_out_buffer = kmalloc(buffer_size, GFP_KERNEL);
+	if (!port->interrupt_out_buffer)
+		return -ENOMEM;
+	usb_fill_int_urb(port->interrupt_out_urb, udev,
+			usb_sndintpipe(udev, epd->bEndpointAddress),
+			port->interrupt_out_buffer, buffer_size,
+			type->write_int_callback, port,
+			epd->bInterval);
+
+	return 0;
+}
+
+static int usb_serial_probe(struct usb_interface *interface,
+			       const struct usb_device_id *id)
+{
+	struct device *ddev = &interface->dev;
+	struct usb_device *dev = interface_to_usbdev(interface);
+	struct usb_serial *serial = NULL;
+	struct usb_serial_port *port;
+	struct usb_serial_endpoints *epds;
+	struct usb_serial_driver *type = NULL;
+	int retval;
+	int i;
+	int num_ports = 0;
+	unsigned char max_endpoints;
+
+	mutex_lock(&table_lock);
+	type = search_serial_device(interface);
+	if (!type) {
+		mutex_unlock(&table_lock);
+		dev_dbg(ddev, "none matched\n");
+		return -ENODEV;
+	}
+
+	if (!try_module_get(type->driver.owner)) {
+		mutex_unlock(&table_lock);
+		dev_err(ddev, "module get failed, exiting\n");
+		return -EIO;
+	}
+	mutex_unlock(&table_lock);
+
+	serial = create_serial(dev, interface, type);
+	if (!serial) {
+		retval = -ENOMEM;
+		goto err_put_module;
+	}
+
+	/* if this device type has a probe function, call it */
+	if (type->probe) {
+		const struct usb_device_id *id;
+
+		id = get_iface_id(type, interface);
+		retval = type->probe(serial, id);
+
+		if (retval) {
+			dev_dbg(ddev, "sub driver rejected device\n");
+			goto err_release_sibling;
+		}
+	}
+
+	/* descriptor matches, let's find the endpoints needed */
+	epds = kzalloc(sizeof(*epds), GFP_KERNEL);
+	if (!epds) {
+		retval = -ENOMEM;
+		goto err_release_sibling;
+	}
+
+	find_endpoints(serial, epds, interface);
+	if (serial->sibling)
+		find_endpoints(serial, epds, serial->sibling);
+
+	if (epds->num_bulk_in < type->num_bulk_in ||
+			epds->num_bulk_out < type->num_bulk_out ||
+			epds->num_interrupt_in < type->num_interrupt_in ||
+			epds->num_interrupt_out < type->num_interrupt_out) {
+		dev_err(ddev, "required endpoints missing\n");
+		retval = -ENODEV;
+		goto err_free_epds;
+	}
+
+	if (type->calc_num_ports) {
+		retval = type->calc_num_ports(serial, epds);
+		if (retval < 0)
+			goto err_free_epds;
+		num_ports = retval;
+	}
+
+	if (!num_ports)
+		num_ports = type->num_ports;
+
+	if (num_ports > MAX_NUM_PORTS) {
+		dev_warn(ddev, "too many ports requested: %d\n", num_ports);
+		num_ports = MAX_NUM_PORTS;
+	}
+
+	serial->num_ports = (unsigned char)num_ports;
+	serial->num_bulk_in = epds->num_bulk_in;
+	serial->num_bulk_out = epds->num_bulk_out;
+	serial->num_interrupt_in = epds->num_interrupt_in;
+	serial->num_interrupt_out = epds->num_interrupt_out;
+
+	/* found all that we need */
+	dev_info(ddev, "%s converter detected\n", type->description);
+
+	/* create our ports, we need as many as the max endpoints */
+	/* we don't use num_ports here because some devices have more
+	   endpoint pairs than ports */
+	max_endpoints = max(epds->num_bulk_in, epds->num_bulk_out);
+	max_endpoints = max(max_endpoints, epds->num_interrupt_in);
+	max_endpoints = max(max_endpoints, epds->num_interrupt_out);
+	max_endpoints = max(max_endpoints, serial->num_ports);
+	serial->num_port_pointers = max_endpoints;
+
+	dev_dbg(ddev, "setting up %d port structure(s)\n", max_endpoints);
+	for (i = 0; i < max_endpoints; ++i) {
+		port = kzalloc(sizeof(struct usb_serial_port), GFP_KERNEL);
+		if (!port) {
+			retval = -ENOMEM;
+			goto err_free_epds;
+		}
+		tty_port_init(&port->port);
+		port->port.ops = &serial_port_ops;
+		port->serial = serial;
+		spin_lock_init(&port->lock);
+		/* Keep this for private driver use for the moment but
+		   should probably go away */
+		INIT_WORK(&port->work, usb_serial_port_work);
+		serial->port[i] = port;
+		port->dev.parent = &interface->dev;
+		port->dev.driver = NULL;
+		port->dev.bus = &usb_serial_bus_type;
+		port->dev.release = &usb_serial_port_release;
+		port->dev.groups = usb_serial_port_groups;
+		device_initialize(&port->dev);
+	}
+
+	/* set up the endpoint information */
+	for (i = 0; i < epds->num_bulk_in; ++i) {
+		retval = setup_port_bulk_in(serial->port[i], epds->bulk_in[i]);
+		if (retval)
+			goto err_free_epds;
+	}
+
+	for (i = 0; i < epds->num_bulk_out; ++i) {
+		retval = setup_port_bulk_out(serial->port[i],
+				epds->bulk_out[i]);
+		if (retval)
+			goto err_free_epds;
+	}
+
+	if (serial->type->read_int_callback) {
+		for (i = 0; i < epds->num_interrupt_in; ++i) {
+			retval = setup_port_interrupt_in(serial->port[i],
+					epds->interrupt_in[i]);
+			if (retval)
+				goto err_free_epds;
+		}
+	} else if (epds->num_interrupt_in) {
+		dev_dbg(ddev, "The device claims to support interrupt in transfers, but read_int_callback is not defined\n");
+	}
+
+	if (serial->type->write_int_callback) {
+		for (i = 0; i < epds->num_interrupt_out; ++i) {
+			retval = setup_port_interrupt_out(serial->port[i],
+					epds->interrupt_out[i]);
+			if (retval)
+				goto err_free_epds;
+		}
+	} else if (epds->num_interrupt_out) {
+		dev_dbg(ddev, "The device claims to support interrupt out transfers, but write_int_callback is not defined\n");
+	}
+
+	usb_set_intfdata(interface, serial);
+
+	/* if this device type has an attach function, call it */
+	if (type->attach) {
+		retval = type->attach(serial);
+		if (retval < 0)
+			goto err_free_epds;
+		serial->attached = 1;
+		if (retval > 0) {
+			/* quietly accept this device, but don't bind to a
+			   serial port as it's about to disappear */
+			serial->num_ports = 0;
+			goto exit;
+		}
+	} else {
+		serial->attached = 1;
+	}
+
+	retval = allocate_minors(serial, num_ports);
+	if (retval) {
+		dev_err(ddev, "No more free serial minor numbers\n");
+		goto err_free_epds;
+	}
+
+	/* register all of the individual ports with the driver core */
+	for (i = 0; i < num_ports; ++i) {
+		port = serial->port[i];
+		dev_set_name(&port->dev, "ttyUSB%d", port->minor);
+		dev_dbg(ddev, "registering %s\n", dev_name(&port->dev));
+		device_enable_async_suspend(&port->dev);
+
+		retval = device_add(&port->dev);
+		if (retval)
+			dev_err(ddev, "Error registering port device, continuing\n");
+	}
+
+	if (num_ports > 0)
+		usb_serial_console_init(serial->port[0]->minor);
+exit:
+	kfree(epds);
+	module_put(type->driver.owner);
+	return 0;
+
+err_free_epds:
+	kfree(epds);
+err_release_sibling:
+	release_sibling(serial, interface);
+	usb_serial_put(serial);
+err_put_module:
+	module_put(type->driver.owner);
+
+	return retval;
+}
+
+static void usb_serial_disconnect(struct usb_interface *interface)
+{
+	int i;
+	struct usb_serial *serial = usb_get_intfdata(interface);
+	struct device *dev = &interface->dev;
+	struct usb_serial_port *port;
+	struct tty_struct *tty;
+
+	/* sibling interface is cleaning up */
+	if (!serial)
+		return;
+
+	usb_serial_console_disconnect(serial);
+
+	mutex_lock(&serial->disc_mutex);
+	/* must set a flag, to signal subdrivers */
+	serial->disconnected = 1;
+	mutex_unlock(&serial->disc_mutex);
+
+	for (i = 0; i < serial->num_ports; ++i) {
+		port = serial->port[i];
+		tty = tty_port_tty_get(&port->port);
+		if (tty) {
+			tty_vhangup(tty);
+			tty_kref_put(tty);
+		}
+		usb_serial_port_poison_urbs(port);
+		wake_up_interruptible(&port->port.delta_msr_wait);
+		cancel_work_sync(&port->work);
+		if (device_is_registered(&port->dev))
+			device_del(&port->dev);
+	}
+	if (serial->type->disconnect)
+		serial->type->disconnect(serial);
+
+	release_sibling(serial, interface);
+
+	/* let the last holder of this object cause it to be cleaned up */
+	usb_serial_put(serial);
+	dev_info(dev, "device disconnected\n");
+}
+
+int usb_serial_suspend(struct usb_interface *intf, pm_message_t message)
+{
+	struct usb_serial *serial = usb_get_intfdata(intf);
+	int i, r;
+
+	/* suspend when called for first sibling interface */
+	if (serial->suspend_count++)
+		return 0;
+
+	/*
+	 * serial->type->suspend() MUST return 0 in system sleep context,
+	 * otherwise, the resume callback has to recover device from
+	 * previous suspend failure.
+	 */
+	if (serial->type->suspend) {
+		r = serial->type->suspend(serial, message);
+		if (r < 0) {
+			serial->suspend_count--;
+			return r;
+		}
+	}
+
+	for (i = 0; i < serial->num_ports; ++i)
+		usb_serial_port_poison_urbs(serial->port[i]);
+
+	return 0;
+}
+EXPORT_SYMBOL(usb_serial_suspend);
+
+static void usb_serial_unpoison_port_urbs(struct usb_serial *serial)
+{
+	int i;
+
+	for (i = 0; i < serial->num_ports; ++i)
+		usb_serial_port_unpoison_urbs(serial->port[i]);
+}
+
+int usb_serial_resume(struct usb_interface *intf)
+{
+	struct usb_serial *serial = usb_get_intfdata(intf);
+	int rv;
+
+	/* resume when called for last sibling interface */
+	if (--serial->suspend_count)
+		return 0;
+
+	usb_serial_unpoison_port_urbs(serial);
+
+	if (serial->type->resume)
+		rv = serial->type->resume(serial);
+	else
+		rv = usb_serial_generic_resume(serial);
+
+	return rv;
+}
+EXPORT_SYMBOL(usb_serial_resume);
+
+static int usb_serial_reset_resume(struct usb_interface *intf)
+{
+	struct usb_serial *serial = usb_get_intfdata(intf);
+	int rv;
+
+	/* resume when called for last sibling interface */
+	if (--serial->suspend_count)
+		return 0;
+
+	usb_serial_unpoison_port_urbs(serial);
+
+	if (serial->type->reset_resume) {
+		rv = serial->type->reset_resume(serial);
+	} else {
+		rv = -EOPNOTSUPP;
+		intf->needs_binding = 1;
+	}
+
+	return rv;
+}
+
+static const struct tty_operations serial_ops = {
+	.open =			serial_open,
+	.close =		serial_close,
+	.write =		serial_write,
+	.hangup =		serial_hangup,
+	.write_room =		serial_write_room,
+	.ioctl =		serial_ioctl,
+	.set_termios =		serial_set_termios,
+	.throttle =		serial_throttle,
+	.unthrottle =		serial_unthrottle,
+	.break_ctl =		serial_break,
+	.chars_in_buffer =	serial_chars_in_buffer,
+	.wait_until_sent =	serial_wait_until_sent,
+	.tiocmget =		serial_tiocmget,
+	.tiocmset =		serial_tiocmset,
+	.get_icount =		serial_get_icount,
+	.set_serial =		serial_set_serial,
+	.get_serial =		serial_get_serial,
+	.cleanup =		serial_cleanup,
+	.install =		serial_install,
+	.proc_show =		serial_proc_show,
+};
+
+
+struct tty_driver *usb_serial_tty_driver;
+
+static int __init usb_serial_init(void)
+{
+	int result;
+
+	usb_serial_tty_driver = tty_alloc_driver(USB_SERIAL_TTY_MINORS,
+			TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV);
+	if (IS_ERR(usb_serial_tty_driver))
+		return PTR_ERR(usb_serial_tty_driver);
+
+	/* Initialize our global data */
+	result = bus_register(&usb_serial_bus_type);
+	if (result) {
+		pr_err("%s - registering bus driver failed\n", __func__);
+		goto err_put_driver;
+	}
+
+	usb_serial_tty_driver->driver_name = "usbserial";
+	usb_serial_tty_driver->name = "ttyUSB";
+	usb_serial_tty_driver->major = USB_SERIAL_TTY_MAJOR;
+	usb_serial_tty_driver->minor_start = 0;
+	usb_serial_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
+	usb_serial_tty_driver->subtype = SERIAL_TYPE_NORMAL;
+	usb_serial_tty_driver->init_termios = tty_std_termios;
+	usb_serial_tty_driver->init_termios.c_cflag = B9600 | CS8 | CREAD
+							| HUPCL | CLOCAL;
+	usb_serial_tty_driver->init_termios.c_ispeed = 9600;
+	usb_serial_tty_driver->init_termios.c_ospeed = 9600;
+	tty_set_operations(usb_serial_tty_driver, &serial_ops);
+	result = tty_register_driver(usb_serial_tty_driver);
+	if (result) {
+		pr_err("%s - tty_register_driver failed\n", __func__);
+		goto err_unregister_bus;
+	}
+
+	/* register the generic driver, if we should */
+	result = usb_serial_generic_register();
+	if (result < 0) {
+		pr_err("%s - registering generic driver failed\n", __func__);
+		goto err_unregister_driver;
+	}
+
+	return result;
+
+err_unregister_driver:
+	tty_unregister_driver(usb_serial_tty_driver);
+err_unregister_bus:
+	bus_unregister(&usb_serial_bus_type);
+err_put_driver:
+	pr_err("%s - returning with error %d\n", __func__, result);
+	tty_driver_kref_put(usb_serial_tty_driver);
+	return result;
+}
+
+
+static void __exit usb_serial_exit(void)
+{
+	usb_serial_console_exit();
+
+	usb_serial_generic_deregister();
+
+	tty_unregister_driver(usb_serial_tty_driver);
+	tty_driver_kref_put(usb_serial_tty_driver);
+	bus_unregister(&usb_serial_bus_type);
+	idr_destroy(&serial_minors);
+}
+
+
+module_init(usb_serial_init);
+module_exit(usb_serial_exit);
+
+#define set_to_generic_if_null(type, function)				\
+	do {								\
+		if (!type->function) {					\
+			type->function = usb_serial_generic_##function;	\
+			pr_debug("%s: using generic " #function	"\n",	\
+						type->driver.name);	\
+		}							\
+	} while (0)
+
+static void usb_serial_operations_init(struct usb_serial_driver *device)
+{
+	set_to_generic_if_null(device, open);
+	set_to_generic_if_null(device, write);
+	set_to_generic_if_null(device, close);
+	set_to_generic_if_null(device, write_room);
+	set_to_generic_if_null(device, chars_in_buffer);
+	if (device->tx_empty)
+		set_to_generic_if_null(device, wait_until_sent);
+	set_to_generic_if_null(device, read_bulk_callback);
+	set_to_generic_if_null(device, write_bulk_callback);
+	set_to_generic_if_null(device, process_read_urb);
+	set_to_generic_if_null(device, prepare_write_buffer);
+}
+
+static int usb_serial_register(struct usb_serial_driver *driver)
+{
+	int retval;
+
+	if (usb_disabled())
+		return -ENODEV;
+
+	if (!driver->description)
+		driver->description = driver->driver.name;
+	if (!driver->usb_driver) {
+		WARN(1, "Serial driver %s has no usb_driver\n",
+				driver->description);
+		return -EINVAL;
+	}
+
+	/* Prevent individual ports from being unbound. */
+	driver->driver.suppress_bind_attrs = true;
+
+	usb_serial_operations_init(driver);
+
+	/* Add this device to our list of devices */
+	mutex_lock(&table_lock);
+	list_add(&driver->driver_list, &usb_serial_driver_list);
+
+	retval = usb_serial_bus_register(driver);
+	if (retval) {
+		pr_err("problem %d when registering driver %s\n", retval, driver->description);
+		list_del(&driver->driver_list);
+	} else {
+		pr_info("USB Serial support registered for %s\n", driver->description);
+	}
+	mutex_unlock(&table_lock);
+	return retval;
+}
+
+static void usb_serial_deregister(struct usb_serial_driver *device)
+{
+	pr_info("USB Serial deregistering driver %s\n", device->description);
+
+	mutex_lock(&table_lock);
+	list_del(&device->driver_list);
+	mutex_unlock(&table_lock);
+
+	usb_serial_bus_deregister(device);
+}
+
+/**
+ * usb_serial_register_drivers - register drivers for a usb-serial module
+ * @serial_drivers: NULL-terminated array of pointers to drivers to be registered
+ * @name: name of the usb_driver for this set of @serial_drivers
+ * @id_table: list of all devices this @serial_drivers set binds to
+ *
+ * Registers all the drivers in the @serial_drivers array, and dynamically
+ * creates a struct usb_driver with the name @name and id_table of @id_table.
+ */
+int usb_serial_register_drivers(struct usb_serial_driver *const serial_drivers[],
+				const char *name,
+				const struct usb_device_id *id_table)
+{
+	int rc;
+	struct usb_driver *udriver;
+	struct usb_serial_driver * const *sd;
+
+	/*
+	 * udriver must be registered before any of the serial drivers,
+	 * because the store_new_id() routine for the serial drivers (in
+	 * bus.c) probes udriver.
+	 *
+	 * Performance hack: We don't want udriver to be probed until
+	 * the serial drivers are registered, because the probe would
+	 * simply fail for lack of a matching serial driver.
+	 * So we leave udriver's id_table set to NULL until we are all set.
+	 *
+	 * Suspend/resume support is implemented in the usb-serial core,
+	 * so fill in the PM-related fields in udriver.
+	 */
+	udriver = kzalloc(sizeof(*udriver), GFP_KERNEL);
+	if (!udriver)
+		return -ENOMEM;
+
+	udriver->name = name;
+	udriver->no_dynamic_id = 1;
+	udriver->supports_autosuspend = 1;
+	udriver->suspend = usb_serial_suspend;
+	udriver->resume = usb_serial_resume;
+	udriver->probe = usb_serial_probe;
+	udriver->disconnect = usb_serial_disconnect;
+
+	/* we only set the reset_resume field if the serial_driver has one */
+	for (sd = serial_drivers; *sd; ++sd) {
+		if ((*sd)->reset_resume) {
+			udriver->reset_resume = usb_serial_reset_resume;
+			break;
+		}
+	}
+
+	rc = usb_register(udriver);
+	if (rc)
+		goto err_free_driver;
+
+	for (sd = serial_drivers; *sd; ++sd) {
+		(*sd)->usb_driver = udriver;
+		rc = usb_serial_register(*sd);
+		if (rc)
+			goto err_deregister_drivers;
+	}
+
+	/* Now set udriver's id_table and look for matches */
+	udriver->id_table = id_table;
+	rc = driver_attach(&udriver->drvwrap.driver);
+	return 0;
+
+err_deregister_drivers:
+	while (sd-- > serial_drivers)
+		usb_serial_deregister(*sd);
+	usb_deregister(udriver);
+err_free_driver:
+	kfree(udriver);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(usb_serial_register_drivers);
+
+/**
+ * usb_serial_deregister_drivers - deregister drivers for a usb-serial module
+ * @serial_drivers: NULL-terminated array of pointers to drivers to be deregistered
+ *
+ * Deregisters all the drivers in the @serial_drivers array and deregisters and
+ * frees the struct usb_driver that was created by the call to
+ * usb_serial_register_drivers().
+ */
+void usb_serial_deregister_drivers(struct usb_serial_driver *const serial_drivers[])
+{
+	struct usb_driver *udriver = (*serial_drivers)->usb_driver;
+
+	for (; *serial_drivers; ++serial_drivers)
+		usb_serial_deregister(*serial_drivers);
+	usb_deregister(udriver);
+	kfree(udriver);
+}
+EXPORT_SYMBOL_GPL(usb_serial_deregister_drivers);
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL v2");