xref: /linux/drivers/usb/serial/usb-serial.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /*
2  * USB Serial Converter driver
3  *
4  * Copyright (C) 2009 - 2013 Johan Hovold (jhovold@gmail.com)
5  * Copyright (C) 1999 - 2012 Greg Kroah-Hartman (greg@kroah.com)
6  * Copyright (C) 2000 Peter Berger (pberger@brimson.com)
7  * Copyright (C) 2000 Al Borchers (borchers@steinerpoint.com)
8  *
9  *	This program is free software; you can redistribute it and/or
10  *	modify it under the terms of the GNU General Public License version
11  *	2 as published by the Free Software Foundation.
12  *
13  * This driver was originally based on the ACM driver by Armin Fuerst (which was
14  * based on a driver by Brad Keryan)
15  *
16  * See Documentation/usb/usb-serial.txt for more information on using this
17  * driver
18  */
19 
20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21 
22 #include <linux/kernel.h>
23 #include <linux/errno.h>
24 #include <linux/init.h>
25 #include <linux/slab.h>
26 #include <linux/tty.h>
27 #include <linux/tty_driver.h>
28 #include <linux/tty_flip.h>
29 #include <linux/module.h>
30 #include <linux/moduleparam.h>
31 #include <linux/seq_file.h>
32 #include <linux/spinlock.h>
33 #include <linux/mutex.h>
34 #include <linux/list.h>
35 #include <linux/uaccess.h>
36 #include <linux/serial.h>
37 #include <linux/usb.h>
38 #include <linux/usb/serial.h>
39 #include <linux/kfifo.h>
40 #include <linux/idr.h>
41 #include "pl2303.h"
42 
43 #define DRIVER_AUTHOR "Greg Kroah-Hartman <gregkh@linuxfoundation.org>"
44 #define DRIVER_DESC "USB Serial Driver core"
45 
46 #define USB_SERIAL_TTY_MAJOR	188
47 #define USB_SERIAL_TTY_MINORS	512	/* should be enough for a while */
48 
49 /* There is no MODULE_DEVICE_TABLE for usbserial.c.  Instead
50    the MODULE_DEVICE_TABLE declarations in each serial driver
51    cause the "hotplug" program to pull in whatever module is necessary
52    via modprobe, and modprobe will load usbserial because the serial
53    drivers depend on it.
54 */
55 
56 static DEFINE_IDR(serial_minors);
57 static DEFINE_MUTEX(table_lock);
58 static LIST_HEAD(usb_serial_driver_list);
59 
60 /*
61  * Look up the serial port structure.  If it is found and it hasn't been
62  * disconnected, return with the parent usb_serial structure's disc_mutex held
63  * and its refcount incremented.  Otherwise return NULL.
64  */
65 struct usb_serial_port *usb_serial_port_get_by_minor(unsigned minor)
66 {
67 	struct usb_serial *serial;
68 	struct usb_serial_port *port;
69 
70 	mutex_lock(&table_lock);
71 	port = idr_find(&serial_minors, minor);
72 	if (!port)
73 		goto exit;
74 
75 	serial = port->serial;
76 	mutex_lock(&serial->disc_mutex);
77 	if (serial->disconnected) {
78 		mutex_unlock(&serial->disc_mutex);
79 		port = NULL;
80 	} else {
81 		kref_get(&serial->kref);
82 	}
83 exit:
84 	mutex_unlock(&table_lock);
85 	return port;
86 }
87 
88 static int allocate_minors(struct usb_serial *serial, int num_ports)
89 {
90 	struct usb_serial_port *port;
91 	unsigned int i, j;
92 	int minor;
93 
94 	dev_dbg(&serial->interface->dev, "%s %d\n", __func__, num_ports);
95 
96 	mutex_lock(&table_lock);
97 	for (i = 0; i < num_ports; ++i) {
98 		port = serial->port[i];
99 		minor = idr_alloc(&serial_minors, port, 0, 0, GFP_KERNEL);
100 		if (minor < 0)
101 			goto error;
102 		port->minor = minor;
103 		port->port_number = i;
104 	}
105 	serial->minors_reserved = 1;
106 	mutex_unlock(&table_lock);
107 	return 0;
108 error:
109 	/* unwind the already allocated minors */
110 	for (j = 0; j < i; ++j)
111 		idr_remove(&serial_minors, serial->port[j]->minor);
112 	mutex_unlock(&table_lock);
113 	return minor;
114 }
115 
116 static void release_minors(struct usb_serial *serial)
117 {
118 	int i;
119 
120 	mutex_lock(&table_lock);
121 	for (i = 0; i < serial->num_ports; ++i)
122 		idr_remove(&serial_minors, serial->port[i]->minor);
123 	mutex_unlock(&table_lock);
124 	serial->minors_reserved = 0;
125 }
126 
127 static void destroy_serial(struct kref *kref)
128 {
129 	struct usb_serial *serial;
130 	struct usb_serial_port *port;
131 	int i;
132 
133 	serial = to_usb_serial(kref);
134 
135 	/* return the minor range that this device had */
136 	if (serial->minors_reserved)
137 		release_minors(serial);
138 
139 	if (serial->attached && serial->type->release)
140 		serial->type->release(serial);
141 
142 	/* Now that nothing is using the ports, they can be freed */
143 	for (i = 0; i < serial->num_port_pointers; ++i) {
144 		port = serial->port[i];
145 		if (port) {
146 			port->serial = NULL;
147 			put_device(&port->dev);
148 		}
149 	}
150 
151 	usb_put_intf(serial->interface);
152 	usb_put_dev(serial->dev);
153 	kfree(serial);
154 }
155 
156 void usb_serial_put(struct usb_serial *serial)
157 {
158 	kref_put(&serial->kref, destroy_serial);
159 }
160 
161 /*****************************************************************************
162  * Driver tty interface functions
163  *****************************************************************************/
164 
165 /**
166  * serial_install - install tty
167  * @driver: the driver (USB in our case)
168  * @tty: the tty being created
169  *
170  * Create the termios objects for this tty.  We use the default
171  * USB serial settings but permit them to be overridden by
172  * serial->type->init_termios.
173  *
174  * This is the first place a new tty gets used.  Hence this is where we
175  * acquire references to the usb_serial structure and the driver module,
176  * where we store a pointer to the port, and where we do an autoresume.
177  * All these actions are reversed in serial_cleanup().
178  */
179 static int serial_install(struct tty_driver *driver, struct tty_struct *tty)
180 {
181 	int idx = tty->index;
182 	struct usb_serial *serial;
183 	struct usb_serial_port *port;
184 	int retval = -ENODEV;
185 
186 	port = usb_serial_port_get_by_minor(idx);
187 	if (!port)
188 		return retval;
189 
190 	serial = port->serial;
191 	if (!try_module_get(serial->type->driver.owner))
192 		goto error_module_get;
193 
194 	retval = usb_autopm_get_interface(serial->interface);
195 	if (retval)
196 		goto error_get_interface;
197 
198 	retval = tty_port_install(&port->port, driver, tty);
199 	if (retval)
200 		goto error_init_termios;
201 
202 	mutex_unlock(&serial->disc_mutex);
203 
204 	/* allow the driver to update the settings */
205 	if (serial->type->init_termios)
206 		serial->type->init_termios(tty);
207 
208 	tty->driver_data = port;
209 
210 	return retval;
211 
212  error_init_termios:
213 	usb_autopm_put_interface(serial->interface);
214  error_get_interface:
215 	module_put(serial->type->driver.owner);
216  error_module_get:
217 	usb_serial_put(serial);
218 	mutex_unlock(&serial->disc_mutex);
219 	return retval;
220 }
221 
222 static int serial_port_activate(struct tty_port *tport, struct tty_struct *tty)
223 {
224 	struct usb_serial_port *port =
225 		container_of(tport, struct usb_serial_port, port);
226 	struct usb_serial *serial = port->serial;
227 	int retval;
228 
229 	mutex_lock(&serial->disc_mutex);
230 	if (serial->disconnected)
231 		retval = -ENODEV;
232 	else
233 		retval = port->serial->type->open(tty, port);
234 	mutex_unlock(&serial->disc_mutex);
235 
236 	if (retval < 0)
237 		retval = usb_translate_errors(retval);
238 
239 	return retval;
240 }
241 
242 static int serial_open(struct tty_struct *tty, struct file *filp)
243 {
244 	struct usb_serial_port *port = tty->driver_data;
245 
246 	dev_dbg(tty->dev, "%s\n", __func__);
247 
248 	return tty_port_open(&port->port, tty, filp);
249 }
250 
251 /**
252  * serial_port_shutdown - shut down hardware
253  * @tport: tty port to shut down
254  *
255  * Shut down a USB serial port. Serialized against activate by the
256  * tport mutex and kept to matching open/close pairs
257  * of calls by the ASYNCB_INITIALIZED flag.
258  *
259  * Not called if tty is console.
260  */
261 static void serial_port_shutdown(struct tty_port *tport)
262 {
263 	struct usb_serial_port *port =
264 		container_of(tport, struct usb_serial_port, port);
265 	struct usb_serial_driver *drv = port->serial->type;
266 
267 	if (drv->close)
268 		drv->close(port);
269 }
270 
271 static void serial_hangup(struct tty_struct *tty)
272 {
273 	struct usb_serial_port *port = tty->driver_data;
274 
275 	dev_dbg(tty->dev, "%s\n", __func__);
276 
277 	tty_port_hangup(&port->port);
278 }
279 
280 static void serial_close(struct tty_struct *tty, struct file *filp)
281 {
282 	struct usb_serial_port *port = tty->driver_data;
283 
284 	dev_dbg(tty->dev, "%s\n", __func__);
285 
286 	tty_port_close(&port->port, tty, filp);
287 }
288 
289 /**
290  * serial_cleanup - free resources post close/hangup
291  * @port: port to free up
292  *
293  * Do the resource freeing and refcount dropping for the port.
294  * Avoid freeing the console.
295  *
296  * Called asynchronously after the last tty kref is dropped.
297  */
298 static void serial_cleanup(struct tty_struct *tty)
299 {
300 	struct usb_serial_port *port = tty->driver_data;
301 	struct usb_serial *serial;
302 	struct module *owner;
303 
304 	dev_dbg(tty->dev, "%s\n", __func__);
305 
306 	/* The console is magical.  Do not hang up the console hardware
307 	 * or there will be tears.
308 	 */
309 	if (port->port.console)
310 		return;
311 
312 	tty->driver_data = NULL;
313 
314 	serial = port->serial;
315 	owner = serial->type->driver.owner;
316 
317 	mutex_lock(&serial->disc_mutex);
318 	if (!serial->disconnected)
319 		usb_autopm_put_interface(serial->interface);
320 	mutex_unlock(&serial->disc_mutex);
321 
322 	usb_serial_put(serial);
323 	module_put(owner);
324 }
325 
326 static int serial_write(struct tty_struct *tty, const unsigned char *buf,
327 								int count)
328 {
329 	struct usb_serial_port *port = tty->driver_data;
330 	int retval = -ENODEV;
331 
332 	if (port->serial->dev->state == USB_STATE_NOTATTACHED)
333 		goto exit;
334 
335 	dev_dbg(tty->dev, "%s - %d byte(s)\n", __func__, count);
336 
337 	retval = port->serial->type->write(tty, port, buf, count);
338 	if (retval < 0)
339 		retval = usb_translate_errors(retval);
340 exit:
341 	return retval;
342 }
343 
344 static int serial_write_room(struct tty_struct *tty)
345 {
346 	struct usb_serial_port *port = tty->driver_data;
347 
348 	dev_dbg(tty->dev, "%s\n", __func__);
349 
350 	return port->serial->type->write_room(tty);
351 }
352 
353 static int serial_chars_in_buffer(struct tty_struct *tty)
354 {
355 	struct usb_serial_port *port = tty->driver_data;
356 	struct usb_serial *serial = port->serial;
357 
358 	dev_dbg(tty->dev, "%s\n", __func__);
359 
360 	if (serial->disconnected)
361 		return 0;
362 
363 	return serial->type->chars_in_buffer(tty);
364 }
365 
366 static void serial_wait_until_sent(struct tty_struct *tty, int timeout)
367 {
368 	struct usb_serial_port *port = tty->driver_data;
369 	struct usb_serial *serial = port->serial;
370 
371 	dev_dbg(tty->dev, "%s\n", __func__);
372 
373 	if (!port->serial->type->wait_until_sent)
374 		return;
375 
376 	mutex_lock(&serial->disc_mutex);
377 	if (!serial->disconnected)
378 		port->serial->type->wait_until_sent(tty, timeout);
379 	mutex_unlock(&serial->disc_mutex);
380 }
381 
382 static void serial_throttle(struct tty_struct *tty)
383 {
384 	struct usb_serial_port *port = tty->driver_data;
385 
386 	dev_dbg(tty->dev, "%s\n", __func__);
387 
388 	if (port->serial->type->throttle)
389 		port->serial->type->throttle(tty);
390 }
391 
392 static void serial_unthrottle(struct tty_struct *tty)
393 {
394 	struct usb_serial_port *port = tty->driver_data;
395 
396 	dev_dbg(tty->dev, "%s\n", __func__);
397 
398 	if (port->serial->type->unthrottle)
399 		port->serial->type->unthrottle(tty);
400 }
401 
402 static int serial_ioctl(struct tty_struct *tty,
403 					unsigned int cmd, unsigned long arg)
404 {
405 	struct usb_serial_port *port = tty->driver_data;
406 	int retval = -ENOIOCTLCMD;
407 
408 	dev_dbg(tty->dev, "%s - cmd 0x%04x\n", __func__, cmd);
409 
410 	switch (cmd) {
411 	case TIOCMIWAIT:
412 		if (port->serial->type->tiocmiwait)
413 			retval = port->serial->type->tiocmiwait(tty, arg);
414 		break;
415 	default:
416 		if (port->serial->type->ioctl)
417 			retval = port->serial->type->ioctl(tty, cmd, arg);
418 	}
419 
420 	return retval;
421 }
422 
423 static void serial_set_termios(struct tty_struct *tty, struct ktermios *old)
424 {
425 	struct usb_serial_port *port = tty->driver_data;
426 
427 	dev_dbg(tty->dev, "%s\n", __func__);
428 
429 	if (port->serial->type->set_termios)
430 		port->serial->type->set_termios(tty, port, old);
431 	else
432 		tty_termios_copy_hw(&tty->termios, old);
433 }
434 
435 static int serial_break(struct tty_struct *tty, int break_state)
436 {
437 	struct usb_serial_port *port = tty->driver_data;
438 
439 	dev_dbg(tty->dev, "%s\n", __func__);
440 
441 	if (port->serial->type->break_ctl)
442 		port->serial->type->break_ctl(tty, break_state);
443 
444 	return 0;
445 }
446 
447 static int serial_proc_show(struct seq_file *m, void *v)
448 {
449 	struct usb_serial *serial;
450 	struct usb_serial_port *port;
451 	int i;
452 	char tmp[40];
453 
454 	seq_puts(m, "usbserinfo:1.0 driver:2.0\n");
455 	for (i = 0; i < USB_SERIAL_TTY_MINORS; ++i) {
456 		port = usb_serial_port_get_by_minor(i);
457 		if (port == NULL)
458 			continue;
459 		serial = port->serial;
460 
461 		seq_printf(m, "%d:", i);
462 		if (serial->type->driver.owner)
463 			seq_printf(m, " module:%s",
464 				module_name(serial->type->driver.owner));
465 		seq_printf(m, " name:\"%s\"",
466 				serial->type->description);
467 		seq_printf(m, " vendor:%04x product:%04x",
468 			le16_to_cpu(serial->dev->descriptor.idVendor),
469 			le16_to_cpu(serial->dev->descriptor.idProduct));
470 		seq_printf(m, " num_ports:%d", serial->num_ports);
471 		seq_printf(m, " port:%d", port->port_number);
472 		usb_make_path(serial->dev, tmp, sizeof(tmp));
473 		seq_printf(m, " path:%s", tmp);
474 
475 		seq_putc(m, '\n');
476 		usb_serial_put(serial);
477 		mutex_unlock(&serial->disc_mutex);
478 	}
479 	return 0;
480 }
481 
482 static int serial_proc_open(struct inode *inode, struct file *file)
483 {
484 	return single_open(file, serial_proc_show, NULL);
485 }
486 
487 static const struct file_operations serial_proc_fops = {
488 	.owner		= THIS_MODULE,
489 	.open		= serial_proc_open,
490 	.read		= seq_read,
491 	.llseek		= seq_lseek,
492 	.release	= single_release,
493 };
494 
495 static int serial_tiocmget(struct tty_struct *tty)
496 {
497 	struct usb_serial_port *port = tty->driver_data;
498 
499 	dev_dbg(tty->dev, "%s\n", __func__);
500 
501 	if (port->serial->type->tiocmget)
502 		return port->serial->type->tiocmget(tty);
503 	return -EINVAL;
504 }
505 
506 static int serial_tiocmset(struct tty_struct *tty,
507 			    unsigned int set, unsigned int clear)
508 {
509 	struct usb_serial_port *port = tty->driver_data;
510 
511 	dev_dbg(tty->dev, "%s\n", __func__);
512 
513 	if (port->serial->type->tiocmset)
514 		return port->serial->type->tiocmset(tty, set, clear);
515 	return -EINVAL;
516 }
517 
518 static int serial_get_icount(struct tty_struct *tty,
519 				struct serial_icounter_struct *icount)
520 {
521 	struct usb_serial_port *port = tty->driver_data;
522 
523 	dev_dbg(tty->dev, "%s\n", __func__);
524 
525 	if (port->serial->type->get_icount)
526 		return port->serial->type->get_icount(tty, icount);
527 	return -EINVAL;
528 }
529 
530 /*
531  * We would be calling tty_wakeup here, but unfortunately some line
532  * disciplines have an annoying habit of calling tty->write from
533  * the write wakeup callback (e.g. n_hdlc.c).
534  */
535 void usb_serial_port_softint(struct usb_serial_port *port)
536 {
537 	schedule_work(&port->work);
538 }
539 EXPORT_SYMBOL_GPL(usb_serial_port_softint);
540 
541 static void usb_serial_port_work(struct work_struct *work)
542 {
543 	struct usb_serial_port *port =
544 		container_of(work, struct usb_serial_port, work);
545 
546 	tty_port_tty_wakeup(&port->port);
547 }
548 
549 static void usb_serial_port_poison_urbs(struct usb_serial_port *port)
550 {
551 	int i;
552 
553 	for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i)
554 		usb_poison_urb(port->read_urbs[i]);
555 	for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
556 		usb_poison_urb(port->write_urbs[i]);
557 
558 	usb_poison_urb(port->interrupt_in_urb);
559 	usb_poison_urb(port->interrupt_out_urb);
560 }
561 
562 static void usb_serial_port_unpoison_urbs(struct usb_serial_port *port)
563 {
564 	int i;
565 
566 	for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i)
567 		usb_unpoison_urb(port->read_urbs[i]);
568 	for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
569 		usb_unpoison_urb(port->write_urbs[i]);
570 
571 	usb_unpoison_urb(port->interrupt_in_urb);
572 	usb_unpoison_urb(port->interrupt_out_urb);
573 }
574 
575 static void usb_serial_port_release(struct device *dev)
576 {
577 	struct usb_serial_port *port = to_usb_serial_port(dev);
578 	int i;
579 
580 	dev_dbg(dev, "%s\n", __func__);
581 
582 	usb_free_urb(port->interrupt_in_urb);
583 	usb_free_urb(port->interrupt_out_urb);
584 	for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {
585 		usb_free_urb(port->read_urbs[i]);
586 		kfree(port->bulk_in_buffers[i]);
587 	}
588 	for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i) {
589 		usb_free_urb(port->write_urbs[i]);
590 		kfree(port->bulk_out_buffers[i]);
591 	}
592 	kfifo_free(&port->write_fifo);
593 	kfree(port->interrupt_in_buffer);
594 	kfree(port->interrupt_out_buffer);
595 	tty_port_destroy(&port->port);
596 	kfree(port);
597 }
598 
599 static struct usb_serial *create_serial(struct usb_device *dev,
600 					struct usb_interface *interface,
601 					struct usb_serial_driver *driver)
602 {
603 	struct usb_serial *serial;
604 
605 	serial = kzalloc(sizeof(*serial), GFP_KERNEL);
606 	if (!serial)
607 		return NULL;
608 	serial->dev = usb_get_dev(dev);
609 	serial->type = driver;
610 	serial->interface = usb_get_intf(interface);
611 	kref_init(&serial->kref);
612 	mutex_init(&serial->disc_mutex);
613 	serial->minors_reserved = 0;
614 
615 	return serial;
616 }
617 
618 static const struct usb_device_id *match_dynamic_id(struct usb_interface *intf,
619 					    struct usb_serial_driver *drv)
620 {
621 	struct usb_dynid *dynid;
622 
623 	spin_lock(&drv->dynids.lock);
624 	list_for_each_entry(dynid, &drv->dynids.list, node) {
625 		if (usb_match_one_id(intf, &dynid->id)) {
626 			spin_unlock(&drv->dynids.lock);
627 			return &dynid->id;
628 		}
629 	}
630 	spin_unlock(&drv->dynids.lock);
631 	return NULL;
632 }
633 
634 static const struct usb_device_id *get_iface_id(struct usb_serial_driver *drv,
635 						struct usb_interface *intf)
636 {
637 	const struct usb_device_id *id;
638 
639 	id = usb_match_id(intf, drv->id_table);
640 	if (id) {
641 		dev_dbg(&intf->dev, "static descriptor matches\n");
642 		goto exit;
643 	}
644 	id = match_dynamic_id(intf, drv);
645 	if (id)
646 		dev_dbg(&intf->dev, "dynamic descriptor matches\n");
647 exit:
648 	return id;
649 }
650 
651 /* Caller must hold table_lock */
652 static struct usb_serial_driver *search_serial_device(
653 					struct usb_interface *iface)
654 {
655 	const struct usb_device_id *id = NULL;
656 	struct usb_serial_driver *drv;
657 	struct usb_driver *driver = to_usb_driver(iface->dev.driver);
658 
659 	/* Check if the usb id matches a known device */
660 	list_for_each_entry(drv, &usb_serial_driver_list, driver_list) {
661 		if (drv->usb_driver == driver)
662 			id = get_iface_id(drv, iface);
663 		if (id)
664 			return drv;
665 	}
666 
667 	return NULL;
668 }
669 
670 static int serial_port_carrier_raised(struct tty_port *port)
671 {
672 	struct usb_serial_port *p = container_of(port, struct usb_serial_port, port);
673 	struct usb_serial_driver *drv = p->serial->type;
674 
675 	if (drv->carrier_raised)
676 		return drv->carrier_raised(p);
677 	/* No carrier control - don't block */
678 	return 1;
679 }
680 
681 static void serial_port_dtr_rts(struct tty_port *port, int on)
682 {
683 	struct usb_serial_port *p = container_of(port, struct usb_serial_port, port);
684 	struct usb_serial_driver *drv = p->serial->type;
685 
686 	if (drv->dtr_rts)
687 		drv->dtr_rts(p, on);
688 }
689 
690 static ssize_t port_number_show(struct device *dev,
691 				struct device_attribute *attr, char *buf)
692 {
693 	struct usb_serial_port *port = to_usb_serial_port(dev);
694 
695 	return sprintf(buf, "%u\n", port->port_number);
696 }
697 static DEVICE_ATTR_RO(port_number);
698 
699 static struct attribute *usb_serial_port_attrs[] = {
700 	&dev_attr_port_number.attr,
701 	NULL
702 };
703 ATTRIBUTE_GROUPS(usb_serial_port);
704 
705 static const struct tty_port_operations serial_port_ops = {
706 	.carrier_raised		= serial_port_carrier_raised,
707 	.dtr_rts		= serial_port_dtr_rts,
708 	.activate		= serial_port_activate,
709 	.shutdown		= serial_port_shutdown,
710 };
711 
712 static int usb_serial_probe(struct usb_interface *interface,
713 			       const struct usb_device_id *id)
714 {
715 	struct device *ddev = &interface->dev;
716 	struct usb_device *dev = interface_to_usbdev(interface);
717 	struct usb_serial *serial = NULL;
718 	struct usb_serial_port *port;
719 	struct usb_host_interface *iface_desc;
720 	struct usb_endpoint_descriptor *endpoint;
721 	struct usb_endpoint_descriptor *interrupt_in_endpoint[MAX_NUM_PORTS];
722 	struct usb_endpoint_descriptor *interrupt_out_endpoint[MAX_NUM_PORTS];
723 	struct usb_endpoint_descriptor *bulk_in_endpoint[MAX_NUM_PORTS];
724 	struct usb_endpoint_descriptor *bulk_out_endpoint[MAX_NUM_PORTS];
725 	struct usb_serial_driver *type = NULL;
726 	int retval;
727 	int buffer_size;
728 	int i;
729 	int j;
730 	int num_interrupt_in = 0;
731 	int num_interrupt_out = 0;
732 	int num_bulk_in = 0;
733 	int num_bulk_out = 0;
734 	int num_ports = 0;
735 	int max_endpoints;
736 
737 	mutex_lock(&table_lock);
738 	type = search_serial_device(interface);
739 	if (!type) {
740 		mutex_unlock(&table_lock);
741 		dev_dbg(ddev, "none matched\n");
742 		return -ENODEV;
743 	}
744 
745 	if (!try_module_get(type->driver.owner)) {
746 		mutex_unlock(&table_lock);
747 		dev_err(ddev, "module get failed, exiting\n");
748 		return -EIO;
749 	}
750 	mutex_unlock(&table_lock);
751 
752 	serial = create_serial(dev, interface, type);
753 	if (!serial) {
754 		module_put(type->driver.owner);
755 		return -ENOMEM;
756 	}
757 
758 	/* if this device type has a probe function, call it */
759 	if (type->probe) {
760 		const struct usb_device_id *id;
761 
762 		id = get_iface_id(type, interface);
763 		retval = type->probe(serial, id);
764 
765 		if (retval) {
766 			dev_dbg(ddev, "sub driver rejected device\n");
767 			usb_serial_put(serial);
768 			module_put(type->driver.owner);
769 			return retval;
770 		}
771 	}
772 
773 	/* descriptor matches, let's find the endpoints needed */
774 	/* check out the endpoints */
775 	iface_desc = interface->cur_altsetting;
776 	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
777 		endpoint = &iface_desc->endpoint[i].desc;
778 
779 		if (usb_endpoint_is_bulk_in(endpoint)) {
780 			/* we found a bulk in endpoint */
781 			dev_dbg(ddev, "found bulk in on endpoint %d\n", i);
782 			if (num_bulk_in < MAX_NUM_PORTS) {
783 				bulk_in_endpoint[num_bulk_in] = endpoint;
784 				++num_bulk_in;
785 			}
786 		}
787 
788 		if (usb_endpoint_is_bulk_out(endpoint)) {
789 			/* we found a bulk out endpoint */
790 			dev_dbg(ddev, "found bulk out on endpoint %d\n", i);
791 			if (num_bulk_out < MAX_NUM_PORTS) {
792 				bulk_out_endpoint[num_bulk_out] = endpoint;
793 				++num_bulk_out;
794 			}
795 		}
796 
797 		if (usb_endpoint_is_int_in(endpoint)) {
798 			/* we found a interrupt in endpoint */
799 			dev_dbg(ddev, "found interrupt in on endpoint %d\n", i);
800 			if (num_interrupt_in < MAX_NUM_PORTS) {
801 				interrupt_in_endpoint[num_interrupt_in] =
802 						endpoint;
803 				++num_interrupt_in;
804 			}
805 		}
806 
807 		if (usb_endpoint_is_int_out(endpoint)) {
808 			/* we found an interrupt out endpoint */
809 			dev_dbg(ddev, "found interrupt out on endpoint %d\n", i);
810 			if (num_interrupt_out < MAX_NUM_PORTS) {
811 				interrupt_out_endpoint[num_interrupt_out] =
812 						endpoint;
813 				++num_interrupt_out;
814 			}
815 		}
816 	}
817 
818 #if defined(CONFIG_USB_SERIAL_PL2303) || defined(CONFIG_USB_SERIAL_PL2303_MODULE)
819 	/* BEGIN HORRIBLE HACK FOR PL2303 */
820 	/* this is needed due to the looney way its endpoints are set up */
821 	if (((le16_to_cpu(dev->descriptor.idVendor) == PL2303_VENDOR_ID) &&
822 	     (le16_to_cpu(dev->descriptor.idProduct) == PL2303_PRODUCT_ID)) ||
823 	    ((le16_to_cpu(dev->descriptor.idVendor) == ATEN_VENDOR_ID) &&
824 	     (le16_to_cpu(dev->descriptor.idProduct) == ATEN_PRODUCT_ID)) ||
825 	    ((le16_to_cpu(dev->descriptor.idVendor) == ALCOR_VENDOR_ID) &&
826 	     (le16_to_cpu(dev->descriptor.idProduct) == ALCOR_PRODUCT_ID)) ||
827 	    ((le16_to_cpu(dev->descriptor.idVendor) == SIEMENS_VENDOR_ID) &&
828 	     (le16_to_cpu(dev->descriptor.idProduct) == SIEMENS_PRODUCT_ID_EF81))) {
829 		if (interface != dev->actconfig->interface[0]) {
830 			/* check out the endpoints of the other interface*/
831 			iface_desc = dev->actconfig->interface[0]->cur_altsetting;
832 			for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
833 				endpoint = &iface_desc->endpoint[i].desc;
834 				if (usb_endpoint_is_int_in(endpoint)) {
835 					/* we found a interrupt in endpoint */
836 					dev_dbg(ddev, "found interrupt in for Prolific device on separate interface\n");
837 					if (num_interrupt_in < MAX_NUM_PORTS) {
838 						interrupt_in_endpoint[num_interrupt_in] = endpoint;
839 						++num_interrupt_in;
840 					}
841 				}
842 			}
843 		}
844 
845 		/* Now make sure the PL-2303 is configured correctly.
846 		 * If not, give up now and hope this hack will work
847 		 * properly during a later invocation of usb_serial_probe
848 		 */
849 		if (num_bulk_in == 0 || num_bulk_out == 0) {
850 			dev_info(ddev, "PL-2303 hack: descriptors matched but endpoints did not\n");
851 			usb_serial_put(serial);
852 			module_put(type->driver.owner);
853 			return -ENODEV;
854 		}
855 	}
856 	/* END HORRIBLE HACK FOR PL2303 */
857 #endif
858 
859 #ifdef CONFIG_USB_SERIAL_GENERIC
860 	if (type == &usb_serial_generic_device) {
861 		num_ports = num_bulk_out;
862 		if (num_ports == 0) {
863 			dev_err(ddev, "Generic device with no bulk out, not allowed.\n");
864 			usb_serial_put(serial);
865 			module_put(type->driver.owner);
866 			return -EIO;
867 		}
868 		dev_info(ddev, "The \"generic\" usb-serial driver is only for testing and one-off prototypes.\n");
869 		dev_info(ddev, "Tell linux-usb@vger.kernel.org to add your device to a proper driver.\n");
870 	}
871 #endif
872 	if (!num_ports) {
873 		/* if this device type has a calc_num_ports function, call it */
874 		if (type->calc_num_ports)
875 			num_ports = type->calc_num_ports(serial);
876 		if (!num_ports)
877 			num_ports = type->num_ports;
878 	}
879 
880 	if (num_ports > MAX_NUM_PORTS) {
881 		dev_warn(ddev, "too many ports requested: %d\n", num_ports);
882 		num_ports = MAX_NUM_PORTS;
883 	}
884 
885 	serial->num_ports = num_ports;
886 	serial->num_bulk_in = num_bulk_in;
887 	serial->num_bulk_out = num_bulk_out;
888 	serial->num_interrupt_in = num_interrupt_in;
889 	serial->num_interrupt_out = num_interrupt_out;
890 
891 	/* found all that we need */
892 	dev_info(ddev, "%s converter detected\n", type->description);
893 
894 	/* create our ports, we need as many as the max endpoints */
895 	/* we don't use num_ports here because some devices have more
896 	   endpoint pairs than ports */
897 	max_endpoints = max(num_bulk_in, num_bulk_out);
898 	max_endpoints = max(max_endpoints, num_interrupt_in);
899 	max_endpoints = max(max_endpoints, num_interrupt_out);
900 	max_endpoints = max(max_endpoints, (int)serial->num_ports);
901 	serial->num_port_pointers = max_endpoints;
902 
903 	dev_dbg(ddev, "setting up %d port structure(s)\n", max_endpoints);
904 	for (i = 0; i < max_endpoints; ++i) {
905 		port = kzalloc(sizeof(struct usb_serial_port), GFP_KERNEL);
906 		if (!port)
907 			goto probe_error;
908 		tty_port_init(&port->port);
909 		port->port.ops = &serial_port_ops;
910 		port->serial = serial;
911 		spin_lock_init(&port->lock);
912 		/* Keep this for private driver use for the moment but
913 		   should probably go away */
914 		INIT_WORK(&port->work, usb_serial_port_work);
915 		serial->port[i] = port;
916 		port->dev.parent = &interface->dev;
917 		port->dev.driver = NULL;
918 		port->dev.bus = &usb_serial_bus_type;
919 		port->dev.release = &usb_serial_port_release;
920 		port->dev.groups = usb_serial_port_groups;
921 		device_initialize(&port->dev);
922 	}
923 
924 	/* set up the endpoint information */
925 	for (i = 0; i < num_bulk_in; ++i) {
926 		endpoint = bulk_in_endpoint[i];
927 		port = serial->port[i];
928 		buffer_size = max_t(int, serial->type->bulk_in_size,
929 				usb_endpoint_maxp(endpoint));
930 		port->bulk_in_size = buffer_size;
931 		port->bulk_in_endpointAddress = endpoint->bEndpointAddress;
932 
933 		for (j = 0; j < ARRAY_SIZE(port->read_urbs); ++j) {
934 			set_bit(j, &port->read_urbs_free);
935 			port->read_urbs[j] = usb_alloc_urb(0, GFP_KERNEL);
936 			if (!port->read_urbs[j])
937 				goto probe_error;
938 			port->bulk_in_buffers[j] = kmalloc(buffer_size,
939 								GFP_KERNEL);
940 			if (!port->bulk_in_buffers[j])
941 				goto probe_error;
942 			usb_fill_bulk_urb(port->read_urbs[j], dev,
943 					usb_rcvbulkpipe(dev,
944 						endpoint->bEndpointAddress),
945 					port->bulk_in_buffers[j], buffer_size,
946 					serial->type->read_bulk_callback,
947 					port);
948 		}
949 
950 		port->read_urb = port->read_urbs[0];
951 		port->bulk_in_buffer = port->bulk_in_buffers[0];
952 	}
953 
954 	for (i = 0; i < num_bulk_out; ++i) {
955 		endpoint = bulk_out_endpoint[i];
956 		port = serial->port[i];
957 		if (kfifo_alloc(&port->write_fifo, PAGE_SIZE, GFP_KERNEL))
958 			goto probe_error;
959 		buffer_size = serial->type->bulk_out_size;
960 		if (!buffer_size)
961 			buffer_size = usb_endpoint_maxp(endpoint);
962 		port->bulk_out_size = buffer_size;
963 		port->bulk_out_endpointAddress = endpoint->bEndpointAddress;
964 
965 		for (j = 0; j < ARRAY_SIZE(port->write_urbs); ++j) {
966 			set_bit(j, &port->write_urbs_free);
967 			port->write_urbs[j] = usb_alloc_urb(0, GFP_KERNEL);
968 			if (!port->write_urbs[j])
969 				goto probe_error;
970 			port->bulk_out_buffers[j] = kmalloc(buffer_size,
971 								GFP_KERNEL);
972 			if (!port->bulk_out_buffers[j])
973 				goto probe_error;
974 			usb_fill_bulk_urb(port->write_urbs[j], dev,
975 					usb_sndbulkpipe(dev,
976 						endpoint->bEndpointAddress),
977 					port->bulk_out_buffers[j], buffer_size,
978 					serial->type->write_bulk_callback,
979 					port);
980 		}
981 
982 		port->write_urb = port->write_urbs[0];
983 		port->bulk_out_buffer = port->bulk_out_buffers[0];
984 	}
985 
986 	if (serial->type->read_int_callback) {
987 		for (i = 0; i < num_interrupt_in; ++i) {
988 			endpoint = interrupt_in_endpoint[i];
989 			port = serial->port[i];
990 			port->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
991 			if (!port->interrupt_in_urb)
992 				goto probe_error;
993 			buffer_size = usb_endpoint_maxp(endpoint);
994 			port->interrupt_in_endpointAddress =
995 						endpoint->bEndpointAddress;
996 			port->interrupt_in_buffer = kmalloc(buffer_size,
997 								GFP_KERNEL);
998 			if (!port->interrupt_in_buffer)
999 				goto probe_error;
1000 			usb_fill_int_urb(port->interrupt_in_urb, dev,
1001 				usb_rcvintpipe(dev,
1002 						endpoint->bEndpointAddress),
1003 				port->interrupt_in_buffer, buffer_size,
1004 				serial->type->read_int_callback, port,
1005 				endpoint->bInterval);
1006 		}
1007 	} else if (num_interrupt_in) {
1008 		dev_dbg(ddev, "The device claims to support interrupt in transfers, but read_int_callback is not defined\n");
1009 	}
1010 
1011 	if (serial->type->write_int_callback) {
1012 		for (i = 0; i < num_interrupt_out; ++i) {
1013 			endpoint = interrupt_out_endpoint[i];
1014 			port = serial->port[i];
1015 			port->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
1016 			if (!port->interrupt_out_urb)
1017 				goto probe_error;
1018 			buffer_size = usb_endpoint_maxp(endpoint);
1019 			port->interrupt_out_size = buffer_size;
1020 			port->interrupt_out_endpointAddress =
1021 						endpoint->bEndpointAddress;
1022 			port->interrupt_out_buffer = kmalloc(buffer_size,
1023 								GFP_KERNEL);
1024 			if (!port->interrupt_out_buffer)
1025 				goto probe_error;
1026 			usb_fill_int_urb(port->interrupt_out_urb, dev,
1027 				usb_sndintpipe(dev,
1028 						  endpoint->bEndpointAddress),
1029 				port->interrupt_out_buffer, buffer_size,
1030 				serial->type->write_int_callback, port,
1031 				endpoint->bInterval);
1032 		}
1033 	} else if (num_interrupt_out) {
1034 		dev_dbg(ddev, "The device claims to support interrupt out transfers, but write_int_callback is not defined\n");
1035 	}
1036 
1037 	usb_set_intfdata(interface, serial);
1038 
1039 	/* if this device type has an attach function, call it */
1040 	if (type->attach) {
1041 		retval = type->attach(serial);
1042 		if (retval < 0)
1043 			goto probe_error;
1044 		serial->attached = 1;
1045 		if (retval > 0) {
1046 			/* quietly accept this device, but don't bind to a
1047 			   serial port as it's about to disappear */
1048 			serial->num_ports = 0;
1049 			goto exit;
1050 		}
1051 	} else {
1052 		serial->attached = 1;
1053 	}
1054 
1055 	/* Avoid race with tty_open and serial_install by setting the
1056 	 * disconnected flag and not clearing it until all ports have been
1057 	 * registered.
1058 	 */
1059 	serial->disconnected = 1;
1060 
1061 	if (allocate_minors(serial, num_ports)) {
1062 		dev_err(ddev, "No more free serial minor numbers\n");
1063 		goto probe_error;
1064 	}
1065 
1066 	/* register all of the individual ports with the driver core */
1067 	for (i = 0; i < num_ports; ++i) {
1068 		port = serial->port[i];
1069 		dev_set_name(&port->dev, "ttyUSB%d", port->minor);
1070 		dev_dbg(ddev, "registering %s\n", dev_name(&port->dev));
1071 		device_enable_async_suspend(&port->dev);
1072 
1073 		retval = device_add(&port->dev);
1074 		if (retval)
1075 			dev_err(ddev, "Error registering port device, continuing\n");
1076 	}
1077 
1078 	serial->disconnected = 0;
1079 
1080 	usb_serial_console_init(serial->port[0]->minor);
1081 exit:
1082 	module_put(type->driver.owner);
1083 	return 0;
1084 
1085 probe_error:
1086 	usb_serial_put(serial);
1087 	module_put(type->driver.owner);
1088 	return -EIO;
1089 }
1090 
1091 static void usb_serial_disconnect(struct usb_interface *interface)
1092 {
1093 	int i;
1094 	struct usb_serial *serial = usb_get_intfdata(interface);
1095 	struct device *dev = &interface->dev;
1096 	struct usb_serial_port *port;
1097 	struct tty_struct *tty;
1098 
1099 	usb_serial_console_disconnect(serial);
1100 
1101 	mutex_lock(&serial->disc_mutex);
1102 	/* must set a flag, to signal subdrivers */
1103 	serial->disconnected = 1;
1104 	mutex_unlock(&serial->disc_mutex);
1105 
1106 	for (i = 0; i < serial->num_ports; ++i) {
1107 		port = serial->port[i];
1108 		tty = tty_port_tty_get(&port->port);
1109 		if (tty) {
1110 			tty_vhangup(tty);
1111 			tty_kref_put(tty);
1112 		}
1113 		usb_serial_port_poison_urbs(port);
1114 		wake_up_interruptible(&port->port.delta_msr_wait);
1115 		cancel_work_sync(&port->work);
1116 		if (device_is_registered(&port->dev))
1117 			device_del(&port->dev);
1118 	}
1119 	if (serial->type->disconnect)
1120 		serial->type->disconnect(serial);
1121 
1122 	/* let the last holder of this object cause it to be cleaned up */
1123 	usb_serial_put(serial);
1124 	dev_info(dev, "device disconnected\n");
1125 }
1126 
1127 int usb_serial_suspend(struct usb_interface *intf, pm_message_t message)
1128 {
1129 	struct usb_serial *serial = usb_get_intfdata(intf);
1130 	int i, r = 0;
1131 
1132 	serial->suspending = 1;
1133 
1134 	/*
1135 	 * serial->type->suspend() MUST return 0 in system sleep context,
1136 	 * otherwise, the resume callback has to recover device from
1137 	 * previous suspend failure.
1138 	 */
1139 	if (serial->type->suspend) {
1140 		r = serial->type->suspend(serial, message);
1141 		if (r < 0) {
1142 			serial->suspending = 0;
1143 			goto err_out;
1144 		}
1145 	}
1146 
1147 	for (i = 0; i < serial->num_ports; ++i)
1148 		usb_serial_port_poison_urbs(serial->port[i]);
1149 err_out:
1150 	return r;
1151 }
1152 EXPORT_SYMBOL(usb_serial_suspend);
1153 
1154 static void usb_serial_unpoison_port_urbs(struct usb_serial *serial)
1155 {
1156 	int i;
1157 
1158 	for (i = 0; i < serial->num_ports; ++i)
1159 		usb_serial_port_unpoison_urbs(serial->port[i]);
1160 }
1161 
1162 int usb_serial_resume(struct usb_interface *intf)
1163 {
1164 	struct usb_serial *serial = usb_get_intfdata(intf);
1165 	int rv;
1166 
1167 	usb_serial_unpoison_port_urbs(serial);
1168 
1169 	serial->suspending = 0;
1170 	if (serial->type->resume)
1171 		rv = serial->type->resume(serial);
1172 	else
1173 		rv = usb_serial_generic_resume(serial);
1174 
1175 	return rv;
1176 }
1177 EXPORT_SYMBOL(usb_serial_resume);
1178 
1179 static int usb_serial_reset_resume(struct usb_interface *intf)
1180 {
1181 	struct usb_serial *serial = usb_get_intfdata(intf);
1182 	int rv;
1183 
1184 	usb_serial_unpoison_port_urbs(serial);
1185 
1186 	serial->suspending = 0;
1187 	if (serial->type->reset_resume) {
1188 		rv = serial->type->reset_resume(serial);
1189 	} else {
1190 		rv = -EOPNOTSUPP;
1191 		intf->needs_binding = 1;
1192 	}
1193 
1194 	return rv;
1195 }
1196 
1197 static const struct tty_operations serial_ops = {
1198 	.open =			serial_open,
1199 	.close =		serial_close,
1200 	.write =		serial_write,
1201 	.hangup =		serial_hangup,
1202 	.write_room =		serial_write_room,
1203 	.ioctl =		serial_ioctl,
1204 	.set_termios =		serial_set_termios,
1205 	.throttle =		serial_throttle,
1206 	.unthrottle =		serial_unthrottle,
1207 	.break_ctl =		serial_break,
1208 	.chars_in_buffer =	serial_chars_in_buffer,
1209 	.wait_until_sent =	serial_wait_until_sent,
1210 	.tiocmget =		serial_tiocmget,
1211 	.tiocmset =		serial_tiocmset,
1212 	.get_icount =		serial_get_icount,
1213 	.cleanup =		serial_cleanup,
1214 	.install =		serial_install,
1215 	.proc_fops =		&serial_proc_fops,
1216 };
1217 
1218 
1219 struct tty_driver *usb_serial_tty_driver;
1220 
1221 /* Driver structure we register with the USB core */
1222 static struct usb_driver usb_serial_driver = {
1223 	.name =		"usbserial",
1224 	.probe =	usb_serial_probe,
1225 	.disconnect =	usb_serial_disconnect,
1226 	.suspend =	usb_serial_suspend,
1227 	.resume =	usb_serial_resume,
1228 	.no_dynamic_id =	1,
1229 	.supports_autosuspend =	1,
1230 };
1231 
1232 static int __init usb_serial_init(void)
1233 {
1234 	int result;
1235 
1236 	usb_serial_tty_driver = alloc_tty_driver(USB_SERIAL_TTY_MINORS);
1237 	if (!usb_serial_tty_driver)
1238 		return -ENOMEM;
1239 
1240 	/* Initialize our global data */
1241 	result = bus_register(&usb_serial_bus_type);
1242 	if (result) {
1243 		pr_err("%s - registering bus driver failed\n", __func__);
1244 		goto exit_bus;
1245 	}
1246 
1247 	usb_serial_tty_driver->driver_name = "usbserial";
1248 	usb_serial_tty_driver->name = "ttyUSB";
1249 	usb_serial_tty_driver->major = USB_SERIAL_TTY_MAJOR;
1250 	usb_serial_tty_driver->minor_start = 0;
1251 	usb_serial_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
1252 	usb_serial_tty_driver->subtype = SERIAL_TYPE_NORMAL;
1253 	usb_serial_tty_driver->flags = TTY_DRIVER_REAL_RAW |
1254 						TTY_DRIVER_DYNAMIC_DEV;
1255 	usb_serial_tty_driver->init_termios = tty_std_termios;
1256 	usb_serial_tty_driver->init_termios.c_cflag = B9600 | CS8 | CREAD
1257 							| HUPCL | CLOCAL;
1258 	usb_serial_tty_driver->init_termios.c_ispeed = 9600;
1259 	usb_serial_tty_driver->init_termios.c_ospeed = 9600;
1260 	tty_set_operations(usb_serial_tty_driver, &serial_ops);
1261 	result = tty_register_driver(usb_serial_tty_driver);
1262 	if (result) {
1263 		pr_err("%s - tty_register_driver failed\n", __func__);
1264 		goto exit_reg_driver;
1265 	}
1266 
1267 	/* register the USB driver */
1268 	result = usb_register(&usb_serial_driver);
1269 	if (result < 0) {
1270 		pr_err("%s - usb_register failed\n", __func__);
1271 		goto exit_tty;
1272 	}
1273 
1274 	/* register the generic driver, if we should */
1275 	result = usb_serial_generic_register();
1276 	if (result < 0) {
1277 		pr_err("%s - registering generic driver failed\n", __func__);
1278 		goto exit_generic;
1279 	}
1280 
1281 	return result;
1282 
1283 exit_generic:
1284 	usb_deregister(&usb_serial_driver);
1285 
1286 exit_tty:
1287 	tty_unregister_driver(usb_serial_tty_driver);
1288 
1289 exit_reg_driver:
1290 	bus_unregister(&usb_serial_bus_type);
1291 
1292 exit_bus:
1293 	pr_err("%s - returning with error %d\n", __func__, result);
1294 	put_tty_driver(usb_serial_tty_driver);
1295 	return result;
1296 }
1297 
1298 
1299 static void __exit usb_serial_exit(void)
1300 {
1301 	usb_serial_console_exit();
1302 
1303 	usb_serial_generic_deregister();
1304 
1305 	usb_deregister(&usb_serial_driver);
1306 	tty_unregister_driver(usb_serial_tty_driver);
1307 	put_tty_driver(usb_serial_tty_driver);
1308 	bus_unregister(&usb_serial_bus_type);
1309 	idr_destroy(&serial_minors);
1310 }
1311 
1312 
1313 module_init(usb_serial_init);
1314 module_exit(usb_serial_exit);
1315 
1316 #define set_to_generic_if_null(type, function)				\
1317 	do {								\
1318 		if (!type->function) {					\
1319 			type->function = usb_serial_generic_##function;	\
1320 			pr_debug("%s: using generic " #function	"\n",	\
1321 						type->driver.name);	\
1322 		}							\
1323 	} while (0)
1324 
1325 static void usb_serial_operations_init(struct usb_serial_driver *device)
1326 {
1327 	set_to_generic_if_null(device, open);
1328 	set_to_generic_if_null(device, write);
1329 	set_to_generic_if_null(device, close);
1330 	set_to_generic_if_null(device, write_room);
1331 	set_to_generic_if_null(device, chars_in_buffer);
1332 	if (device->tx_empty)
1333 		set_to_generic_if_null(device, wait_until_sent);
1334 	set_to_generic_if_null(device, read_bulk_callback);
1335 	set_to_generic_if_null(device, write_bulk_callback);
1336 	set_to_generic_if_null(device, process_read_urb);
1337 	set_to_generic_if_null(device, prepare_write_buffer);
1338 }
1339 
1340 static int usb_serial_register(struct usb_serial_driver *driver)
1341 {
1342 	int retval;
1343 
1344 	if (usb_disabled())
1345 		return -ENODEV;
1346 
1347 	if (!driver->description)
1348 		driver->description = driver->driver.name;
1349 	if (!driver->usb_driver) {
1350 		WARN(1, "Serial driver %s has no usb_driver\n",
1351 				driver->description);
1352 		return -EINVAL;
1353 	}
1354 
1355 	usb_serial_operations_init(driver);
1356 
1357 	/* Add this device to our list of devices */
1358 	mutex_lock(&table_lock);
1359 	list_add(&driver->driver_list, &usb_serial_driver_list);
1360 
1361 	retval = usb_serial_bus_register(driver);
1362 	if (retval) {
1363 		pr_err("problem %d when registering driver %s\n", retval, driver->description);
1364 		list_del(&driver->driver_list);
1365 	} else {
1366 		pr_info("USB Serial support registered for %s\n", driver->description);
1367 	}
1368 	mutex_unlock(&table_lock);
1369 	return retval;
1370 }
1371 
1372 static void usb_serial_deregister(struct usb_serial_driver *device)
1373 {
1374 	pr_info("USB Serial deregistering driver %s\n", device->description);
1375 
1376 	mutex_lock(&table_lock);
1377 	list_del(&device->driver_list);
1378 	mutex_unlock(&table_lock);
1379 
1380 	usb_serial_bus_deregister(device);
1381 }
1382 
1383 /**
1384  * usb_serial_register_drivers - register drivers for a usb-serial module
1385  * @serial_drivers: NULL-terminated array of pointers to drivers to be registered
1386  * @name: name of the usb_driver for this set of @serial_drivers
1387  * @id_table: list of all devices this @serial_drivers set binds to
1388  *
1389  * Registers all the drivers in the @serial_drivers array, and dynamically
1390  * creates a struct usb_driver with the name @name and id_table of @id_table.
1391  */
1392 int usb_serial_register_drivers(struct usb_serial_driver *const serial_drivers[],
1393 				const char *name,
1394 				const struct usb_device_id *id_table)
1395 {
1396 	int rc;
1397 	struct usb_driver *udriver;
1398 	struct usb_serial_driver * const *sd;
1399 
1400 	/*
1401 	 * udriver must be registered before any of the serial drivers,
1402 	 * because the store_new_id() routine for the serial drivers (in
1403 	 * bus.c) probes udriver.
1404 	 *
1405 	 * Performance hack: We don't want udriver to be probed until
1406 	 * the serial drivers are registered, because the probe would
1407 	 * simply fail for lack of a matching serial driver.
1408 	 * So we leave udriver's id_table set to NULL until we are all set.
1409 	 *
1410 	 * Suspend/resume support is implemented in the usb-serial core,
1411 	 * so fill in the PM-related fields in udriver.
1412 	 */
1413 	udriver = kzalloc(sizeof(*udriver), GFP_KERNEL);
1414 	if (!udriver)
1415 		return -ENOMEM;
1416 
1417 	udriver->name = name;
1418 	udriver->no_dynamic_id = 1;
1419 	udriver->supports_autosuspend = 1;
1420 	udriver->suspend = usb_serial_suspend;
1421 	udriver->resume = usb_serial_resume;
1422 	udriver->probe = usb_serial_probe;
1423 	udriver->disconnect = usb_serial_disconnect;
1424 
1425 	/* we only set the reset_resume field if the serial_driver has one */
1426 	for (sd = serial_drivers; *sd; ++sd) {
1427 		if ((*sd)->reset_resume) {
1428 			udriver->reset_resume = usb_serial_reset_resume;
1429 			break;
1430 		}
1431 	}
1432 
1433 	rc = usb_register(udriver);
1434 	if (rc)
1435 		return rc;
1436 
1437 	for (sd = serial_drivers; *sd; ++sd) {
1438 		(*sd)->usb_driver = udriver;
1439 		rc = usb_serial_register(*sd);
1440 		if (rc)
1441 			goto failed;
1442 	}
1443 
1444 	/* Now set udriver's id_table and look for matches */
1445 	udriver->id_table = id_table;
1446 	rc = driver_attach(&udriver->drvwrap.driver);
1447 	return 0;
1448 
1449  failed:
1450 	while (sd-- > serial_drivers)
1451 		usb_serial_deregister(*sd);
1452 	usb_deregister(udriver);
1453 	return rc;
1454 }
1455 EXPORT_SYMBOL_GPL(usb_serial_register_drivers);
1456 
1457 /**
1458  * usb_serial_deregister_drivers - deregister drivers for a usb-serial module
1459  * @serial_drivers: NULL-terminated array of pointers to drivers to be deregistered
1460  *
1461  * Deregisters all the drivers in the @serial_drivers array and deregisters and
1462  * frees the struct usb_driver that was created by the call to
1463  * usb_serial_register_drivers().
1464  */
1465 void usb_serial_deregister_drivers(struct usb_serial_driver *const serial_drivers[])
1466 {
1467 	struct usb_driver *udriver = (*serial_drivers)->usb_driver;
1468 
1469 	for (; *serial_drivers; ++serial_drivers)
1470 		usb_serial_deregister(*serial_drivers);
1471 	usb_deregister(udriver);
1472 	kfree(udriver);
1473 }
1474 EXPORT_SYMBOL_GPL(usb_serial_deregister_drivers);
1475 
1476 MODULE_AUTHOR(DRIVER_AUTHOR);
1477 MODULE_DESCRIPTION(DRIVER_DESC);
1478 MODULE_LICENSE("GPL");
1479