xref: /openbmc/linux/drivers/usb/serial/usb-serial.c (revision 95713967)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * USB Serial Converter driver
4  *
5  * Copyright (C) 2009 - 2013 Johan Hovold (jhovold@gmail.com)
6  * Copyright (C) 1999 - 2012 Greg Kroah-Hartman (greg@kroah.com)
7  * Copyright (C) 2000 Peter Berger (pberger@brimson.com)
8  * Copyright (C) 2000 Al Borchers (borchers@steinerpoint.com)
9  *
10  * This driver was originally based on the ACM driver by Armin Fuerst (which was
11  * based on a driver by Brad Keryan)
12  *
13  * See Documentation/usb/usb-serial.rst for more information on using this
14  * driver
15  */
16 
17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18 
19 #include <linux/kernel.h>
20 #include <linux/errno.h>
21 #include <linux/init.h>
22 #include <linux/slab.h>
23 #include <linux/tty.h>
24 #include <linux/tty_driver.h>
25 #include <linux/tty_flip.h>
26 #include <linux/module.h>
27 #include <linux/moduleparam.h>
28 #include <linux/seq_file.h>
29 #include <linux/spinlock.h>
30 #include <linux/mutex.h>
31 #include <linux/list.h>
32 #include <linux/uaccess.h>
33 #include <linux/serial.h>
34 #include <linux/usb.h>
35 #include <linux/usb/serial.h>
36 #include <linux/kfifo.h>
37 #include <linux/idr.h>
38 
39 #define DRIVER_AUTHOR "Greg Kroah-Hartman <gregkh@linuxfoundation.org>"
40 #define DRIVER_DESC "USB Serial Driver core"
41 
42 #define USB_SERIAL_TTY_MAJOR	188
43 #define USB_SERIAL_TTY_MINORS	512	/* should be enough for a while */
44 
45 /* There is no MODULE_DEVICE_TABLE for usbserial.c.  Instead
46    the MODULE_DEVICE_TABLE declarations in each serial driver
47    cause the "hotplug" program to pull in whatever module is necessary
48    via modprobe, and modprobe will load usbserial because the serial
49    drivers depend on it.
50 */
51 
52 static DEFINE_IDR(serial_minors);
53 static DEFINE_MUTEX(table_lock);
54 static LIST_HEAD(usb_serial_driver_list);
55 
56 /*
57  * Look up the serial port structure.  If it is found and it hasn't been
58  * disconnected, return with the parent usb_serial structure's disc_mutex held
59  * and its refcount incremented.  Otherwise return NULL.
60  */
usb_serial_port_get_by_minor(unsigned minor)61 struct usb_serial_port *usb_serial_port_get_by_minor(unsigned minor)
62 {
63 	struct usb_serial *serial;
64 	struct usb_serial_port *port;
65 
66 	mutex_lock(&table_lock);
67 	port = idr_find(&serial_minors, minor);
68 	if (!port)
69 		goto exit;
70 
71 	serial = port->serial;
72 	mutex_lock(&serial->disc_mutex);
73 	if (serial->disconnected) {
74 		mutex_unlock(&serial->disc_mutex);
75 		port = NULL;
76 	} else {
77 		kref_get(&serial->kref);
78 	}
79 exit:
80 	mutex_unlock(&table_lock);
81 	return port;
82 }
83 
allocate_minors(struct usb_serial * serial,int num_ports)84 static int allocate_minors(struct usb_serial *serial, int num_ports)
85 {
86 	struct usb_serial_port *port;
87 	unsigned int i, j;
88 	int minor;
89 
90 	dev_dbg(&serial->interface->dev, "%s %d\n", __func__, num_ports);
91 
92 	mutex_lock(&table_lock);
93 	for (i = 0; i < num_ports; ++i) {
94 		port = serial->port[i];
95 		minor = idr_alloc(&serial_minors, port, 0,
96 					USB_SERIAL_TTY_MINORS, GFP_KERNEL);
97 		if (minor < 0)
98 			goto error;
99 		port->minor = minor;
100 		port->port_number = i;
101 	}
102 	serial->minors_reserved = 1;
103 	mutex_unlock(&table_lock);
104 	return 0;
105 error:
106 	/* unwind the already allocated minors */
107 	for (j = 0; j < i; ++j)
108 		idr_remove(&serial_minors, serial->port[j]->minor);
109 	mutex_unlock(&table_lock);
110 	return minor;
111 }
112 
release_minors(struct usb_serial * serial)113 static void release_minors(struct usb_serial *serial)
114 {
115 	int i;
116 
117 	mutex_lock(&table_lock);
118 	for (i = 0; i < serial->num_ports; ++i)
119 		idr_remove(&serial_minors, serial->port[i]->minor);
120 	mutex_unlock(&table_lock);
121 	serial->minors_reserved = 0;
122 }
123 
usb_serial_claim_interface(struct usb_serial * serial,struct usb_interface * intf)124 int usb_serial_claim_interface(struct usb_serial *serial, struct usb_interface *intf)
125 {
126 	struct usb_driver *driver = serial->type->usb_driver;
127 	int ret;
128 
129 	if (serial->sibling)
130 		return -EBUSY;
131 
132 	ret = usb_driver_claim_interface(driver, intf, serial);
133 	if (ret) {
134 		dev_err(&serial->interface->dev,
135 				"failed to claim sibling interface: %d\n", ret);
136 		return ret;
137 	}
138 
139 	serial->sibling = intf;
140 
141 	return 0;
142 }
143 EXPORT_SYMBOL_GPL(usb_serial_claim_interface);
144 
release_sibling(struct usb_serial * serial,struct usb_interface * intf)145 static void release_sibling(struct usb_serial *serial, struct usb_interface *intf)
146 {
147 	struct usb_driver *driver = serial->type->usb_driver;
148 	struct usb_interface *sibling;
149 
150 	if (!serial->sibling)
151 		return;
152 
153 	if (intf == serial->sibling)
154 		sibling = serial->interface;
155 	else
156 		sibling = serial->sibling;
157 
158 	usb_set_intfdata(sibling, NULL);
159 	usb_driver_release_interface(driver, sibling);
160 }
161 
destroy_serial(struct kref * kref)162 static void destroy_serial(struct kref *kref)
163 {
164 	struct usb_serial *serial;
165 	struct usb_serial_port *port;
166 	int i;
167 
168 	serial = to_usb_serial(kref);
169 
170 	/* return the minor range that this device had */
171 	if (serial->minors_reserved)
172 		release_minors(serial);
173 
174 	if (serial->attached && serial->type->release)
175 		serial->type->release(serial);
176 
177 	/* Now that nothing is using the ports, they can be freed */
178 	for (i = 0; i < serial->num_port_pointers; ++i) {
179 		port = serial->port[i];
180 		if (port) {
181 			port->serial = NULL;
182 			put_device(&port->dev);
183 		}
184 	}
185 
186 	usb_put_intf(serial->interface);
187 	usb_put_dev(serial->dev);
188 	kfree(serial);
189 }
190 
usb_serial_put(struct usb_serial * serial)191 void usb_serial_put(struct usb_serial *serial)
192 {
193 	kref_put(&serial->kref, destroy_serial);
194 }
195 
196 /*****************************************************************************
197  * Driver tty interface functions
198  *****************************************************************************/
199 
200 /**
201  * serial_install - install tty
202  * @driver: the driver (USB in our case)
203  * @tty: the tty being created
204  *
205  * Initialise the termios structure for this tty.  We use the default
206  * USB serial settings but permit them to be overridden by
207  * serial->type->init_termios on first open.
208  *
209  * This is the first place a new tty gets used.  Hence this is where we
210  * acquire references to the usb_serial structure and the driver module,
211  * where we store a pointer to the port.  All these actions are reversed
212  * in serial_cleanup().
213  */
serial_install(struct tty_driver * driver,struct tty_struct * tty)214 static int serial_install(struct tty_driver *driver, struct tty_struct *tty)
215 {
216 	int idx = tty->index;
217 	struct usb_serial *serial;
218 	struct usb_serial_port *port;
219 	bool init_termios;
220 	int retval = -ENODEV;
221 
222 	port = usb_serial_port_get_by_minor(idx);
223 	if (!port)
224 		return retval;
225 
226 	serial = port->serial;
227 	if (!try_module_get(serial->type->driver.owner))
228 		goto err_put_serial;
229 
230 	init_termios = (driver->termios[idx] == NULL);
231 
232 	retval = tty_standard_install(driver, tty);
233 	if (retval)
234 		goto err_put_module;
235 
236 	mutex_unlock(&serial->disc_mutex);
237 
238 	/* allow the driver to update the initial settings */
239 	if (init_termios && serial->type->init_termios)
240 		serial->type->init_termios(tty);
241 
242 	tty->driver_data = port;
243 
244 	return retval;
245 
246 err_put_module:
247 	module_put(serial->type->driver.owner);
248 err_put_serial:
249 	usb_serial_put(serial);
250 	mutex_unlock(&serial->disc_mutex);
251 	return retval;
252 }
253 
serial_port_activate(struct tty_port * tport,struct tty_struct * tty)254 static int serial_port_activate(struct tty_port *tport, struct tty_struct *tty)
255 {
256 	struct usb_serial_port *port =
257 		container_of(tport, struct usb_serial_port, port);
258 	struct usb_serial *serial = port->serial;
259 	int retval;
260 
261 	mutex_lock(&serial->disc_mutex);
262 	if (serial->disconnected) {
263 		retval = -ENODEV;
264 		goto out_unlock;
265 	}
266 
267 	retval = usb_autopm_get_interface(serial->interface);
268 	if (retval)
269 		goto out_unlock;
270 
271 	retval = port->serial->type->open(tty, port);
272 	if (retval)
273 		usb_autopm_put_interface(serial->interface);
274 out_unlock:
275 	mutex_unlock(&serial->disc_mutex);
276 
277 	if (retval < 0)
278 		retval = usb_translate_errors(retval);
279 
280 	return retval;
281 }
282 
serial_open(struct tty_struct * tty,struct file * filp)283 static int serial_open(struct tty_struct *tty, struct file *filp)
284 {
285 	struct usb_serial_port *port = tty->driver_data;
286 
287 	dev_dbg(&port->dev, "%s\n", __func__);
288 
289 	return tty_port_open(&port->port, tty, filp);
290 }
291 
292 /**
293  * serial_port_shutdown - shut down hardware
294  * @tport: tty port to shut down
295  *
296  * Shut down a USB serial port. Serialized against activate by the
297  * tport mutex and kept to matching open/close pairs
298  * of calls by the tty-port initialized flag.
299  *
300  * Not called if tty is console.
301  */
serial_port_shutdown(struct tty_port * tport)302 static void serial_port_shutdown(struct tty_port *tport)
303 {
304 	struct usb_serial_port *port =
305 		container_of(tport, struct usb_serial_port, port);
306 	struct usb_serial_driver *drv = port->serial->type;
307 
308 	if (drv->close)
309 		drv->close(port);
310 
311 	usb_autopm_put_interface(port->serial->interface);
312 }
313 
serial_hangup(struct tty_struct * tty)314 static void serial_hangup(struct tty_struct *tty)
315 {
316 	struct usb_serial_port *port = tty->driver_data;
317 
318 	dev_dbg(&port->dev, "%s\n", __func__);
319 
320 	tty_port_hangup(&port->port);
321 }
322 
serial_close(struct tty_struct * tty,struct file * filp)323 static void serial_close(struct tty_struct *tty, struct file *filp)
324 {
325 	struct usb_serial_port *port = tty->driver_data;
326 
327 	dev_dbg(&port->dev, "%s\n", __func__);
328 
329 	tty_port_close(&port->port, tty, filp);
330 }
331 
332 /**
333  * serial_cleanup - free resources post close/hangup
334  * @tty: tty to clean up
335  *
336  * Do the resource freeing and refcount dropping for the port.
337  * Avoid freeing the console.
338  *
339  * Called asynchronously after the last tty kref is dropped.
340  */
serial_cleanup(struct tty_struct * tty)341 static void serial_cleanup(struct tty_struct *tty)
342 {
343 	struct usb_serial_port *port = tty->driver_data;
344 	struct usb_serial *serial;
345 	struct module *owner;
346 
347 	dev_dbg(&port->dev, "%s\n", __func__);
348 
349 	/* The console is magical.  Do not hang up the console hardware
350 	 * or there will be tears.
351 	 */
352 	if (port->port.console)
353 		return;
354 
355 	tty->driver_data = NULL;
356 
357 	serial = port->serial;
358 	owner = serial->type->driver.owner;
359 
360 	usb_serial_put(serial);
361 	module_put(owner);
362 }
363 
serial_write(struct tty_struct * tty,const u8 * buf,size_t count)364 static ssize_t serial_write(struct tty_struct *tty, const u8 *buf, size_t count)
365 {
366 	struct usb_serial_port *port = tty->driver_data;
367 	int retval = -ENODEV;
368 
369 	if (port->serial->dev->state == USB_STATE_NOTATTACHED)
370 		goto exit;
371 
372 	dev_dbg(&port->dev, "%s - %zu byte(s)\n", __func__, count);
373 
374 	retval = port->serial->type->write(tty, port, buf, count);
375 	if (retval < 0)
376 		retval = usb_translate_errors(retval);
377 exit:
378 	return retval;
379 }
380 
serial_write_room(struct tty_struct * tty)381 static unsigned int serial_write_room(struct tty_struct *tty)
382 {
383 	struct usb_serial_port *port = tty->driver_data;
384 
385 	dev_dbg(&port->dev, "%s\n", __func__);
386 
387 	return port->serial->type->write_room(tty);
388 }
389 
serial_chars_in_buffer(struct tty_struct * tty)390 static unsigned int serial_chars_in_buffer(struct tty_struct *tty)
391 {
392 	struct usb_serial_port *port = tty->driver_data;
393 	struct usb_serial *serial = port->serial;
394 
395 	dev_dbg(&port->dev, "%s\n", __func__);
396 
397 	if (serial->disconnected)
398 		return 0;
399 
400 	return serial->type->chars_in_buffer(tty);
401 }
402 
serial_wait_until_sent(struct tty_struct * tty,int timeout)403 static void serial_wait_until_sent(struct tty_struct *tty, int timeout)
404 {
405 	struct usb_serial_port *port = tty->driver_data;
406 	struct usb_serial *serial = port->serial;
407 
408 	dev_dbg(&port->dev, "%s\n", __func__);
409 
410 	if (!port->serial->type->wait_until_sent)
411 		return;
412 
413 	mutex_lock(&serial->disc_mutex);
414 	if (!serial->disconnected)
415 		port->serial->type->wait_until_sent(tty, timeout);
416 	mutex_unlock(&serial->disc_mutex);
417 }
418 
serial_throttle(struct tty_struct * tty)419 static void serial_throttle(struct tty_struct *tty)
420 {
421 	struct usb_serial_port *port = tty->driver_data;
422 
423 	dev_dbg(&port->dev, "%s\n", __func__);
424 
425 	if (port->serial->type->throttle)
426 		port->serial->type->throttle(tty);
427 }
428 
serial_unthrottle(struct tty_struct * tty)429 static void serial_unthrottle(struct tty_struct *tty)
430 {
431 	struct usb_serial_port *port = tty->driver_data;
432 
433 	dev_dbg(&port->dev, "%s\n", __func__);
434 
435 	if (port->serial->type->unthrottle)
436 		port->serial->type->unthrottle(tty);
437 }
438 
serial_get_serial(struct tty_struct * tty,struct serial_struct * ss)439 static int serial_get_serial(struct tty_struct *tty, struct serial_struct *ss)
440 {
441 	struct usb_serial_port *port = tty->driver_data;
442 	struct tty_port *tport = &port->port;
443 	unsigned int close_delay, closing_wait;
444 
445 	mutex_lock(&tport->mutex);
446 
447 	close_delay = jiffies_to_msecs(tport->close_delay) / 10;
448 	closing_wait = tport->closing_wait;
449 	if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
450 		closing_wait = jiffies_to_msecs(closing_wait) / 10;
451 
452 	ss->line = port->minor;
453 	ss->close_delay = close_delay;
454 	ss->closing_wait = closing_wait;
455 
456 	if (port->serial->type->get_serial)
457 		port->serial->type->get_serial(tty, ss);
458 
459 	mutex_unlock(&tport->mutex);
460 
461 	return 0;
462 }
463 
serial_set_serial(struct tty_struct * tty,struct serial_struct * ss)464 static int serial_set_serial(struct tty_struct *tty, struct serial_struct *ss)
465 {
466 	struct usb_serial_port *port = tty->driver_data;
467 	struct tty_port *tport = &port->port;
468 	unsigned int close_delay, closing_wait;
469 	int ret = 0;
470 
471 	close_delay = msecs_to_jiffies(ss->close_delay * 10);
472 	closing_wait = ss->closing_wait;
473 	if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
474 		closing_wait = msecs_to_jiffies(closing_wait * 10);
475 
476 	mutex_lock(&tport->mutex);
477 
478 	if (!capable(CAP_SYS_ADMIN)) {
479 		if (close_delay != tport->close_delay ||
480 				closing_wait != tport->closing_wait) {
481 			ret = -EPERM;
482 			goto out_unlock;
483 		}
484 	}
485 
486 	if (port->serial->type->set_serial) {
487 		ret = port->serial->type->set_serial(tty, ss);
488 		if (ret)
489 			goto out_unlock;
490 	}
491 
492 	tport->close_delay = close_delay;
493 	tport->closing_wait = closing_wait;
494 out_unlock:
495 	mutex_unlock(&tport->mutex);
496 
497 	return ret;
498 }
499 
serial_ioctl(struct tty_struct * tty,unsigned int cmd,unsigned long arg)500 static int serial_ioctl(struct tty_struct *tty,
501 					unsigned int cmd, unsigned long arg)
502 {
503 	struct usb_serial_port *port = tty->driver_data;
504 	int retval = -ENOIOCTLCMD;
505 
506 	dev_dbg(&port->dev, "%s - cmd 0x%04x\n", __func__, cmd);
507 
508 	switch (cmd) {
509 	case TIOCMIWAIT:
510 		if (port->serial->type->tiocmiwait)
511 			retval = port->serial->type->tiocmiwait(tty, arg);
512 		break;
513 	default:
514 		if (port->serial->type->ioctl)
515 			retval = port->serial->type->ioctl(tty, cmd, arg);
516 	}
517 
518 	return retval;
519 }
520 
serial_set_termios(struct tty_struct * tty,const struct ktermios * old)521 static void serial_set_termios(struct tty_struct *tty,
522 		               const struct ktermios *old)
523 {
524 	struct usb_serial_port *port = tty->driver_data;
525 
526 	dev_dbg(&port->dev, "%s\n", __func__);
527 
528 	if (port->serial->type->set_termios)
529 		port->serial->type->set_termios(tty, port, old);
530 	else
531 		tty_termios_copy_hw(&tty->termios, old);
532 }
533 
serial_break(struct tty_struct * tty,int break_state)534 static int serial_break(struct tty_struct *tty, int break_state)
535 {
536 	struct usb_serial_port *port = tty->driver_data;
537 
538 	dev_dbg(&port->dev, "%s\n", __func__);
539 
540 	if (port->serial->type->break_ctl)
541 		return port->serial->type->break_ctl(tty, break_state);
542 
543 	return -ENOTTY;
544 }
545 
serial_proc_show(struct seq_file * m,void * v)546 static int serial_proc_show(struct seq_file *m, void *v)
547 {
548 	struct usb_serial *serial;
549 	struct usb_serial_port *port;
550 	int i;
551 	char tmp[40];
552 
553 	seq_puts(m, "usbserinfo:1.0 driver:2.0\n");
554 	for (i = 0; i < USB_SERIAL_TTY_MINORS; ++i) {
555 		port = usb_serial_port_get_by_minor(i);
556 		if (port == NULL)
557 			continue;
558 		serial = port->serial;
559 
560 		seq_printf(m, "%d:", i);
561 		if (serial->type->driver.owner)
562 			seq_printf(m, " module:%s",
563 				module_name(serial->type->driver.owner));
564 		seq_printf(m, " name:\"%s\"",
565 				serial->type->description);
566 		seq_printf(m, " vendor:%04x product:%04x",
567 			le16_to_cpu(serial->dev->descriptor.idVendor),
568 			le16_to_cpu(serial->dev->descriptor.idProduct));
569 		seq_printf(m, " num_ports:%d", serial->num_ports);
570 		seq_printf(m, " port:%d", port->port_number);
571 		usb_make_path(serial->dev, tmp, sizeof(tmp));
572 		seq_printf(m, " path:%s", tmp);
573 
574 		seq_putc(m, '\n');
575 		usb_serial_put(serial);
576 		mutex_unlock(&serial->disc_mutex);
577 	}
578 	return 0;
579 }
580 
serial_tiocmget(struct tty_struct * tty)581 static int serial_tiocmget(struct tty_struct *tty)
582 {
583 	struct usb_serial_port *port = tty->driver_data;
584 
585 	dev_dbg(&port->dev, "%s\n", __func__);
586 
587 	if (port->serial->type->tiocmget)
588 		return port->serial->type->tiocmget(tty);
589 	return -ENOTTY;
590 }
591 
serial_tiocmset(struct tty_struct * tty,unsigned int set,unsigned int clear)592 static int serial_tiocmset(struct tty_struct *tty,
593 			    unsigned int set, unsigned int clear)
594 {
595 	struct usb_serial_port *port = tty->driver_data;
596 
597 	dev_dbg(&port->dev, "%s\n", __func__);
598 
599 	if (port->serial->type->tiocmset)
600 		return port->serial->type->tiocmset(tty, set, clear);
601 	return -ENOTTY;
602 }
603 
serial_get_icount(struct tty_struct * tty,struct serial_icounter_struct * icount)604 static int serial_get_icount(struct tty_struct *tty,
605 				struct serial_icounter_struct *icount)
606 {
607 	struct usb_serial_port *port = tty->driver_data;
608 
609 	dev_dbg(&port->dev, "%s\n", __func__);
610 
611 	if (port->serial->type->get_icount)
612 		return port->serial->type->get_icount(tty, icount);
613 	return -ENOTTY;
614 }
615 
616 /*
617  * We would be calling tty_wakeup here, but unfortunately some line
618  * disciplines have an annoying habit of calling tty->write from
619  * the write wakeup callback (e.g. n_hdlc.c).
620  */
usb_serial_port_softint(struct usb_serial_port * port)621 void usb_serial_port_softint(struct usb_serial_port *port)
622 {
623 	schedule_work(&port->work);
624 }
625 EXPORT_SYMBOL_GPL(usb_serial_port_softint);
626 
usb_serial_port_work(struct work_struct * work)627 static void usb_serial_port_work(struct work_struct *work)
628 {
629 	struct usb_serial_port *port =
630 		container_of(work, struct usb_serial_port, work);
631 
632 	tty_port_tty_wakeup(&port->port);
633 }
634 
usb_serial_port_poison_urbs(struct usb_serial_port * port)635 static void usb_serial_port_poison_urbs(struct usb_serial_port *port)
636 {
637 	int i;
638 
639 	for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i)
640 		usb_poison_urb(port->read_urbs[i]);
641 	for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
642 		usb_poison_urb(port->write_urbs[i]);
643 
644 	usb_poison_urb(port->interrupt_in_urb);
645 	usb_poison_urb(port->interrupt_out_urb);
646 }
647 
usb_serial_port_unpoison_urbs(struct usb_serial_port * port)648 static void usb_serial_port_unpoison_urbs(struct usb_serial_port *port)
649 {
650 	int i;
651 
652 	for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i)
653 		usb_unpoison_urb(port->read_urbs[i]);
654 	for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
655 		usb_unpoison_urb(port->write_urbs[i]);
656 
657 	usb_unpoison_urb(port->interrupt_in_urb);
658 	usb_unpoison_urb(port->interrupt_out_urb);
659 }
660 
usb_serial_port_release(struct device * dev)661 static void usb_serial_port_release(struct device *dev)
662 {
663 	struct usb_serial_port *port = to_usb_serial_port(dev);
664 	int i;
665 
666 	dev_dbg(dev, "%s\n", __func__);
667 
668 	usb_free_urb(port->interrupt_in_urb);
669 	usb_free_urb(port->interrupt_out_urb);
670 	for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {
671 		usb_free_urb(port->read_urbs[i]);
672 		kfree(port->bulk_in_buffers[i]);
673 	}
674 	for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i) {
675 		usb_free_urb(port->write_urbs[i]);
676 		kfree(port->bulk_out_buffers[i]);
677 	}
678 	kfifo_free(&port->write_fifo);
679 	kfree(port->interrupt_in_buffer);
680 	kfree(port->interrupt_out_buffer);
681 	tty_port_destroy(&port->port);
682 	kfree(port);
683 }
684 
create_serial(struct usb_device * dev,struct usb_interface * interface,struct usb_serial_driver * driver)685 static struct usb_serial *create_serial(struct usb_device *dev,
686 					struct usb_interface *interface,
687 					struct usb_serial_driver *driver)
688 {
689 	struct usb_serial *serial;
690 
691 	serial = kzalloc(sizeof(*serial), GFP_KERNEL);
692 	if (!serial)
693 		return NULL;
694 	serial->dev = usb_get_dev(dev);
695 	serial->type = driver;
696 	serial->interface = usb_get_intf(interface);
697 	kref_init(&serial->kref);
698 	mutex_init(&serial->disc_mutex);
699 	serial->minors_reserved = 0;
700 
701 	return serial;
702 }
703 
match_dynamic_id(struct usb_interface * intf,struct usb_serial_driver * drv)704 static const struct usb_device_id *match_dynamic_id(struct usb_interface *intf,
705 					    struct usb_serial_driver *drv)
706 {
707 	struct usb_dynid *dynid;
708 
709 	spin_lock(&drv->dynids.lock);
710 	list_for_each_entry(dynid, &drv->dynids.list, node) {
711 		if (usb_match_one_id(intf, &dynid->id)) {
712 			spin_unlock(&drv->dynids.lock);
713 			return &dynid->id;
714 		}
715 	}
716 	spin_unlock(&drv->dynids.lock);
717 	return NULL;
718 }
719 
get_iface_id(struct usb_serial_driver * drv,struct usb_interface * intf)720 static const struct usb_device_id *get_iface_id(struct usb_serial_driver *drv,
721 						struct usb_interface *intf)
722 {
723 	const struct usb_device_id *id;
724 
725 	id = usb_match_id(intf, drv->id_table);
726 	if (id) {
727 		dev_dbg(&intf->dev, "static descriptor matches\n");
728 		goto exit;
729 	}
730 	id = match_dynamic_id(intf, drv);
731 	if (id)
732 		dev_dbg(&intf->dev, "dynamic descriptor matches\n");
733 exit:
734 	return id;
735 }
736 
737 /* Caller must hold table_lock */
search_serial_device(struct usb_interface * iface)738 static struct usb_serial_driver *search_serial_device(
739 					struct usb_interface *iface)
740 {
741 	const struct usb_device_id *id = NULL;
742 	struct usb_serial_driver *drv;
743 	struct usb_driver *driver = to_usb_driver(iface->dev.driver);
744 
745 	/* Check if the usb id matches a known device */
746 	list_for_each_entry(drv, &usb_serial_driver_list, driver_list) {
747 		if (drv->usb_driver == driver)
748 			id = get_iface_id(drv, iface);
749 		if (id)
750 			return drv;
751 	}
752 
753 	return NULL;
754 }
755 
serial_port_carrier_raised(struct tty_port * port)756 static bool serial_port_carrier_raised(struct tty_port *port)
757 {
758 	struct usb_serial_port *p = container_of(port, struct usb_serial_port, port);
759 	struct usb_serial_driver *drv = p->serial->type;
760 
761 	if (drv->carrier_raised)
762 		return drv->carrier_raised(p);
763 	/* No carrier control - don't block */
764 	return true;
765 }
766 
serial_port_dtr_rts(struct tty_port * port,bool on)767 static void serial_port_dtr_rts(struct tty_port *port, bool on)
768 {
769 	struct usb_serial_port *p = container_of(port, struct usb_serial_port, port);
770 	struct usb_serial_driver *drv = p->serial->type;
771 
772 	if (drv->dtr_rts)
773 		drv->dtr_rts(p, on);
774 }
775 
port_number_show(struct device * dev,struct device_attribute * attr,char * buf)776 static ssize_t port_number_show(struct device *dev,
777 				struct device_attribute *attr, char *buf)
778 {
779 	struct usb_serial_port *port = to_usb_serial_port(dev);
780 
781 	return sprintf(buf, "%u\n", port->port_number);
782 }
783 static DEVICE_ATTR_RO(port_number);
784 
785 static struct attribute *usb_serial_port_attrs[] = {
786 	&dev_attr_port_number.attr,
787 	NULL
788 };
789 ATTRIBUTE_GROUPS(usb_serial_port);
790 
791 static const struct tty_port_operations serial_port_ops = {
792 	.carrier_raised		= serial_port_carrier_raised,
793 	.dtr_rts		= serial_port_dtr_rts,
794 	.activate		= serial_port_activate,
795 	.shutdown		= serial_port_shutdown,
796 };
797 
store_endpoint(struct usb_serial * serial,struct usb_serial_endpoints * epds,struct usb_endpoint_descriptor * epd)798 static void store_endpoint(struct usb_serial *serial,
799 					struct usb_serial_endpoints *epds,
800 					struct usb_endpoint_descriptor *epd)
801 {
802 	struct device *dev = &serial->interface->dev;
803 	u8 addr = epd->bEndpointAddress;
804 
805 	if (usb_endpoint_is_bulk_in(epd)) {
806 		if (epds->num_bulk_in == ARRAY_SIZE(epds->bulk_in))
807 			return;
808 		dev_dbg(dev, "found bulk in endpoint %02x\n", addr);
809 		epds->bulk_in[epds->num_bulk_in++] = epd;
810 	} else if (usb_endpoint_is_bulk_out(epd)) {
811 		if (epds->num_bulk_out == ARRAY_SIZE(epds->bulk_out))
812 			return;
813 		dev_dbg(dev, "found bulk out endpoint %02x\n", addr);
814 		epds->bulk_out[epds->num_bulk_out++] = epd;
815 	} else if (usb_endpoint_is_int_in(epd)) {
816 		if (epds->num_interrupt_in == ARRAY_SIZE(epds->interrupt_in))
817 			return;
818 		dev_dbg(dev, "found interrupt in endpoint %02x\n", addr);
819 		epds->interrupt_in[epds->num_interrupt_in++] = epd;
820 	} else if (usb_endpoint_is_int_out(epd)) {
821 		if (epds->num_interrupt_out == ARRAY_SIZE(epds->interrupt_out))
822 			return;
823 		dev_dbg(dev, "found interrupt out endpoint %02x\n", addr);
824 		epds->interrupt_out[epds->num_interrupt_out++] = epd;
825 	}
826 }
827 
find_endpoints(struct usb_serial * serial,struct usb_serial_endpoints * epds,struct usb_interface * intf)828 static void find_endpoints(struct usb_serial *serial,
829 					struct usb_serial_endpoints *epds,
830 					struct usb_interface *intf)
831 {
832 	struct usb_host_interface *iface_desc;
833 	struct usb_endpoint_descriptor *epd;
834 	unsigned int i;
835 
836 	iface_desc = intf->cur_altsetting;
837 	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
838 		epd = &iface_desc->endpoint[i].desc;
839 		store_endpoint(serial, epds, epd);
840 	}
841 }
842 
setup_port_bulk_in(struct usb_serial_port * port,struct usb_endpoint_descriptor * epd)843 static int setup_port_bulk_in(struct usb_serial_port *port,
844 					struct usb_endpoint_descriptor *epd)
845 {
846 	struct usb_serial_driver *type = port->serial->type;
847 	struct usb_device *udev = port->serial->dev;
848 	int buffer_size;
849 	int i;
850 
851 	buffer_size = max_t(int, type->bulk_in_size, usb_endpoint_maxp(epd));
852 	port->bulk_in_size = buffer_size;
853 	port->bulk_in_endpointAddress = epd->bEndpointAddress;
854 
855 	for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {
856 		set_bit(i, &port->read_urbs_free);
857 		port->read_urbs[i] = usb_alloc_urb(0, GFP_KERNEL);
858 		if (!port->read_urbs[i])
859 			return -ENOMEM;
860 		port->bulk_in_buffers[i] = kmalloc(buffer_size, GFP_KERNEL);
861 		if (!port->bulk_in_buffers[i])
862 			return -ENOMEM;
863 		usb_fill_bulk_urb(port->read_urbs[i], udev,
864 				usb_rcvbulkpipe(udev, epd->bEndpointAddress),
865 				port->bulk_in_buffers[i], buffer_size,
866 				type->read_bulk_callback, port);
867 	}
868 
869 	port->read_urb = port->read_urbs[0];
870 	port->bulk_in_buffer = port->bulk_in_buffers[0];
871 
872 	return 0;
873 }
874 
setup_port_bulk_out(struct usb_serial_port * port,struct usb_endpoint_descriptor * epd)875 static int setup_port_bulk_out(struct usb_serial_port *port,
876 					struct usb_endpoint_descriptor *epd)
877 {
878 	struct usb_serial_driver *type = port->serial->type;
879 	struct usb_device *udev = port->serial->dev;
880 	int buffer_size;
881 	int i;
882 
883 	if (kfifo_alloc(&port->write_fifo, PAGE_SIZE, GFP_KERNEL))
884 		return -ENOMEM;
885 	if (type->bulk_out_size)
886 		buffer_size = type->bulk_out_size;
887 	else
888 		buffer_size = usb_endpoint_maxp(epd);
889 	port->bulk_out_size = buffer_size;
890 	port->bulk_out_endpointAddress = epd->bEndpointAddress;
891 
892 	for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i) {
893 		set_bit(i, &port->write_urbs_free);
894 		port->write_urbs[i] = usb_alloc_urb(0, GFP_KERNEL);
895 		if (!port->write_urbs[i])
896 			return -ENOMEM;
897 		port->bulk_out_buffers[i] = kmalloc(buffer_size, GFP_KERNEL);
898 		if (!port->bulk_out_buffers[i])
899 			return -ENOMEM;
900 		usb_fill_bulk_urb(port->write_urbs[i], udev,
901 				usb_sndbulkpipe(udev, epd->bEndpointAddress),
902 				port->bulk_out_buffers[i], buffer_size,
903 				type->write_bulk_callback, port);
904 	}
905 
906 	port->write_urb = port->write_urbs[0];
907 	port->bulk_out_buffer = port->bulk_out_buffers[0];
908 
909 	return 0;
910 }
911 
setup_port_interrupt_in(struct usb_serial_port * port,struct usb_endpoint_descriptor * epd)912 static int setup_port_interrupt_in(struct usb_serial_port *port,
913 					struct usb_endpoint_descriptor *epd)
914 {
915 	struct usb_serial_driver *type = port->serial->type;
916 	struct usb_device *udev = port->serial->dev;
917 	int buffer_size;
918 
919 	port->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
920 	if (!port->interrupt_in_urb)
921 		return -ENOMEM;
922 	buffer_size = usb_endpoint_maxp(epd);
923 	port->interrupt_in_endpointAddress = epd->bEndpointAddress;
924 	port->interrupt_in_buffer = kmalloc(buffer_size, GFP_KERNEL);
925 	if (!port->interrupt_in_buffer)
926 		return -ENOMEM;
927 	usb_fill_int_urb(port->interrupt_in_urb, udev,
928 			usb_rcvintpipe(udev, epd->bEndpointAddress),
929 			port->interrupt_in_buffer, buffer_size,
930 			type->read_int_callback, port,
931 			epd->bInterval);
932 
933 	return 0;
934 }
935 
setup_port_interrupt_out(struct usb_serial_port * port,struct usb_endpoint_descriptor * epd)936 static int setup_port_interrupt_out(struct usb_serial_port *port,
937 					struct usb_endpoint_descriptor *epd)
938 {
939 	struct usb_serial_driver *type = port->serial->type;
940 	struct usb_device *udev = port->serial->dev;
941 	int buffer_size;
942 
943 	port->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
944 	if (!port->interrupt_out_urb)
945 		return -ENOMEM;
946 	buffer_size = usb_endpoint_maxp(epd);
947 	port->interrupt_out_size = buffer_size;
948 	port->interrupt_out_endpointAddress = epd->bEndpointAddress;
949 	port->interrupt_out_buffer = kmalloc(buffer_size, GFP_KERNEL);
950 	if (!port->interrupt_out_buffer)
951 		return -ENOMEM;
952 	usb_fill_int_urb(port->interrupt_out_urb, udev,
953 			usb_sndintpipe(udev, epd->bEndpointAddress),
954 			port->interrupt_out_buffer, buffer_size,
955 			type->write_int_callback, port,
956 			epd->bInterval);
957 
958 	return 0;
959 }
960 
usb_serial_probe(struct usb_interface * interface,const struct usb_device_id * id)961 static int usb_serial_probe(struct usb_interface *interface,
962 			       const struct usb_device_id *id)
963 {
964 	struct device *ddev = &interface->dev;
965 	struct usb_device *dev = interface_to_usbdev(interface);
966 	struct usb_serial *serial = NULL;
967 	struct usb_serial_port *port;
968 	struct usb_serial_endpoints *epds;
969 	struct usb_serial_driver *type = NULL;
970 	int retval;
971 	int i;
972 	int num_ports = 0;
973 	unsigned char max_endpoints;
974 
975 	mutex_lock(&table_lock);
976 	type = search_serial_device(interface);
977 	if (!type) {
978 		mutex_unlock(&table_lock);
979 		dev_dbg(ddev, "none matched\n");
980 		return -ENODEV;
981 	}
982 
983 	if (!try_module_get(type->driver.owner)) {
984 		mutex_unlock(&table_lock);
985 		dev_err(ddev, "module get failed, exiting\n");
986 		return -EIO;
987 	}
988 	mutex_unlock(&table_lock);
989 
990 	serial = create_serial(dev, interface, type);
991 	if (!serial) {
992 		retval = -ENOMEM;
993 		goto err_put_module;
994 	}
995 
996 	/* if this device type has a probe function, call it */
997 	if (type->probe) {
998 		const struct usb_device_id *id;
999 
1000 		id = get_iface_id(type, interface);
1001 		retval = type->probe(serial, id);
1002 
1003 		if (retval) {
1004 			dev_dbg(ddev, "sub driver rejected device\n");
1005 			goto err_release_sibling;
1006 		}
1007 	}
1008 
1009 	/* descriptor matches, let's find the endpoints needed */
1010 	epds = kzalloc(sizeof(*epds), GFP_KERNEL);
1011 	if (!epds) {
1012 		retval = -ENOMEM;
1013 		goto err_release_sibling;
1014 	}
1015 
1016 	find_endpoints(serial, epds, interface);
1017 	if (serial->sibling)
1018 		find_endpoints(serial, epds, serial->sibling);
1019 
1020 	if (epds->num_bulk_in < type->num_bulk_in ||
1021 			epds->num_bulk_out < type->num_bulk_out ||
1022 			epds->num_interrupt_in < type->num_interrupt_in ||
1023 			epds->num_interrupt_out < type->num_interrupt_out) {
1024 		dev_err(ddev, "required endpoints missing\n");
1025 		retval = -ENODEV;
1026 		goto err_free_epds;
1027 	}
1028 
1029 	if (type->calc_num_ports) {
1030 		retval = type->calc_num_ports(serial, epds);
1031 		if (retval < 0)
1032 			goto err_free_epds;
1033 		num_ports = retval;
1034 	}
1035 
1036 	if (!num_ports)
1037 		num_ports = type->num_ports;
1038 
1039 	if (num_ports > MAX_NUM_PORTS) {
1040 		dev_warn(ddev, "too many ports requested: %d\n", num_ports);
1041 		num_ports = MAX_NUM_PORTS;
1042 	}
1043 
1044 	serial->num_ports = (unsigned char)num_ports;
1045 	serial->num_bulk_in = epds->num_bulk_in;
1046 	serial->num_bulk_out = epds->num_bulk_out;
1047 	serial->num_interrupt_in = epds->num_interrupt_in;
1048 	serial->num_interrupt_out = epds->num_interrupt_out;
1049 
1050 	/* found all that we need */
1051 	dev_info(ddev, "%s converter detected\n", type->description);
1052 
1053 	/* create our ports, we need as many as the max endpoints */
1054 	/* we don't use num_ports here because some devices have more
1055 	   endpoint pairs than ports */
1056 	max_endpoints = max(epds->num_bulk_in, epds->num_bulk_out);
1057 	max_endpoints = max(max_endpoints, epds->num_interrupt_in);
1058 	max_endpoints = max(max_endpoints, epds->num_interrupt_out);
1059 	max_endpoints = max(max_endpoints, serial->num_ports);
1060 	serial->num_port_pointers = max_endpoints;
1061 
1062 	dev_dbg(ddev, "setting up %d port structure(s)\n", max_endpoints);
1063 	for (i = 0; i < max_endpoints; ++i) {
1064 		port = kzalloc(sizeof(struct usb_serial_port), GFP_KERNEL);
1065 		if (!port) {
1066 			retval = -ENOMEM;
1067 			goto err_free_epds;
1068 		}
1069 		tty_port_init(&port->port);
1070 		port->port.ops = &serial_port_ops;
1071 		port->serial = serial;
1072 		spin_lock_init(&port->lock);
1073 		/* Keep this for private driver use for the moment but
1074 		   should probably go away */
1075 		INIT_WORK(&port->work, usb_serial_port_work);
1076 		serial->port[i] = port;
1077 		port->dev.parent = &interface->dev;
1078 		port->dev.driver = NULL;
1079 		port->dev.bus = &usb_serial_bus_type;
1080 		port->dev.release = &usb_serial_port_release;
1081 		port->dev.groups = usb_serial_port_groups;
1082 		device_initialize(&port->dev);
1083 	}
1084 
1085 	/* set up the endpoint information */
1086 	for (i = 0; i < epds->num_bulk_in; ++i) {
1087 		retval = setup_port_bulk_in(serial->port[i], epds->bulk_in[i]);
1088 		if (retval)
1089 			goto err_free_epds;
1090 	}
1091 
1092 	for (i = 0; i < epds->num_bulk_out; ++i) {
1093 		retval = setup_port_bulk_out(serial->port[i],
1094 				epds->bulk_out[i]);
1095 		if (retval)
1096 			goto err_free_epds;
1097 	}
1098 
1099 	if (serial->type->read_int_callback) {
1100 		for (i = 0; i < epds->num_interrupt_in; ++i) {
1101 			retval = setup_port_interrupt_in(serial->port[i],
1102 					epds->interrupt_in[i]);
1103 			if (retval)
1104 				goto err_free_epds;
1105 		}
1106 	} else if (epds->num_interrupt_in) {
1107 		dev_dbg(ddev, "The device claims to support interrupt in transfers, but read_int_callback is not defined\n");
1108 	}
1109 
1110 	if (serial->type->write_int_callback) {
1111 		for (i = 0; i < epds->num_interrupt_out; ++i) {
1112 			retval = setup_port_interrupt_out(serial->port[i],
1113 					epds->interrupt_out[i]);
1114 			if (retval)
1115 				goto err_free_epds;
1116 		}
1117 	} else if (epds->num_interrupt_out) {
1118 		dev_dbg(ddev, "The device claims to support interrupt out transfers, but write_int_callback is not defined\n");
1119 	}
1120 
1121 	usb_set_intfdata(interface, serial);
1122 
1123 	/* if this device type has an attach function, call it */
1124 	if (type->attach) {
1125 		retval = type->attach(serial);
1126 		if (retval < 0)
1127 			goto err_free_epds;
1128 		serial->attached = 1;
1129 		if (retval > 0) {
1130 			/* quietly accept this device, but don't bind to a
1131 			   serial port as it's about to disappear */
1132 			serial->num_ports = 0;
1133 			goto exit;
1134 		}
1135 	} else {
1136 		serial->attached = 1;
1137 	}
1138 
1139 	retval = allocate_minors(serial, num_ports);
1140 	if (retval) {
1141 		dev_err(ddev, "No more free serial minor numbers\n");
1142 		goto err_free_epds;
1143 	}
1144 
1145 	/* register all of the individual ports with the driver core */
1146 	for (i = 0; i < num_ports; ++i) {
1147 		port = serial->port[i];
1148 		dev_set_name(&port->dev, "ttyUSB%d", port->minor);
1149 		dev_dbg(ddev, "registering %s\n", dev_name(&port->dev));
1150 		device_enable_async_suspend(&port->dev);
1151 
1152 		retval = device_add(&port->dev);
1153 		if (retval)
1154 			dev_err(ddev, "Error registering port device, continuing\n");
1155 	}
1156 
1157 	if (num_ports > 0)
1158 		usb_serial_console_init(serial->port[0]->minor);
1159 exit:
1160 	kfree(epds);
1161 	module_put(type->driver.owner);
1162 	return 0;
1163 
1164 err_free_epds:
1165 	kfree(epds);
1166 err_release_sibling:
1167 	release_sibling(serial, interface);
1168 	usb_serial_put(serial);
1169 err_put_module:
1170 	module_put(type->driver.owner);
1171 
1172 	return retval;
1173 }
1174 
usb_serial_disconnect(struct usb_interface * interface)1175 static void usb_serial_disconnect(struct usb_interface *interface)
1176 {
1177 	int i;
1178 	struct usb_serial *serial = usb_get_intfdata(interface);
1179 	struct device *dev = &interface->dev;
1180 	struct usb_serial_port *port;
1181 	struct tty_struct *tty;
1182 
1183 	/* sibling interface is cleaning up */
1184 	if (!serial)
1185 		return;
1186 
1187 	usb_serial_console_disconnect(serial);
1188 
1189 	mutex_lock(&serial->disc_mutex);
1190 	/* must set a flag, to signal subdrivers */
1191 	serial->disconnected = 1;
1192 	mutex_unlock(&serial->disc_mutex);
1193 
1194 	for (i = 0; i < serial->num_ports; ++i) {
1195 		port = serial->port[i];
1196 		tty = tty_port_tty_get(&port->port);
1197 		if (tty) {
1198 			tty_vhangup(tty);
1199 			tty_kref_put(tty);
1200 		}
1201 		usb_serial_port_poison_urbs(port);
1202 		wake_up_interruptible(&port->port.delta_msr_wait);
1203 		cancel_work_sync(&port->work);
1204 		if (device_is_registered(&port->dev))
1205 			device_del(&port->dev);
1206 	}
1207 	if (serial->type->disconnect)
1208 		serial->type->disconnect(serial);
1209 
1210 	release_sibling(serial, interface);
1211 
1212 	/* let the last holder of this object cause it to be cleaned up */
1213 	usb_serial_put(serial);
1214 	dev_info(dev, "device disconnected\n");
1215 }
1216 
usb_serial_suspend(struct usb_interface * intf,pm_message_t message)1217 int usb_serial_suspend(struct usb_interface *intf, pm_message_t message)
1218 {
1219 	struct usb_serial *serial = usb_get_intfdata(intf);
1220 	int i, r;
1221 
1222 	/* suspend when called for first sibling interface */
1223 	if (serial->suspend_count++)
1224 		return 0;
1225 
1226 	/*
1227 	 * serial->type->suspend() MUST return 0 in system sleep context,
1228 	 * otherwise, the resume callback has to recover device from
1229 	 * previous suspend failure.
1230 	 */
1231 	if (serial->type->suspend) {
1232 		r = serial->type->suspend(serial, message);
1233 		if (r < 0) {
1234 			serial->suspend_count--;
1235 			return r;
1236 		}
1237 	}
1238 
1239 	for (i = 0; i < serial->num_ports; ++i)
1240 		usb_serial_port_poison_urbs(serial->port[i]);
1241 
1242 	return 0;
1243 }
1244 EXPORT_SYMBOL(usb_serial_suspend);
1245 
usb_serial_unpoison_port_urbs(struct usb_serial * serial)1246 static void usb_serial_unpoison_port_urbs(struct usb_serial *serial)
1247 {
1248 	int i;
1249 
1250 	for (i = 0; i < serial->num_ports; ++i)
1251 		usb_serial_port_unpoison_urbs(serial->port[i]);
1252 }
1253 
usb_serial_resume(struct usb_interface * intf)1254 int usb_serial_resume(struct usb_interface *intf)
1255 {
1256 	struct usb_serial *serial = usb_get_intfdata(intf);
1257 	int rv;
1258 
1259 	/* resume when called for last sibling interface */
1260 	if (--serial->suspend_count)
1261 		return 0;
1262 
1263 	usb_serial_unpoison_port_urbs(serial);
1264 
1265 	if (serial->type->resume)
1266 		rv = serial->type->resume(serial);
1267 	else
1268 		rv = usb_serial_generic_resume(serial);
1269 
1270 	return rv;
1271 }
1272 EXPORT_SYMBOL(usb_serial_resume);
1273 
usb_serial_reset_resume(struct usb_interface * intf)1274 static int usb_serial_reset_resume(struct usb_interface *intf)
1275 {
1276 	struct usb_serial *serial = usb_get_intfdata(intf);
1277 	int rv;
1278 
1279 	/* resume when called for last sibling interface */
1280 	if (--serial->suspend_count)
1281 		return 0;
1282 
1283 	usb_serial_unpoison_port_urbs(serial);
1284 
1285 	if (serial->type->reset_resume) {
1286 		rv = serial->type->reset_resume(serial);
1287 	} else {
1288 		rv = -EOPNOTSUPP;
1289 		intf->needs_binding = 1;
1290 	}
1291 
1292 	return rv;
1293 }
1294 
1295 static const struct tty_operations serial_ops = {
1296 	.open =			serial_open,
1297 	.close =		serial_close,
1298 	.write =		serial_write,
1299 	.hangup =		serial_hangup,
1300 	.write_room =		serial_write_room,
1301 	.ioctl =		serial_ioctl,
1302 	.set_termios =		serial_set_termios,
1303 	.throttle =		serial_throttle,
1304 	.unthrottle =		serial_unthrottle,
1305 	.break_ctl =		serial_break,
1306 	.chars_in_buffer =	serial_chars_in_buffer,
1307 	.wait_until_sent =	serial_wait_until_sent,
1308 	.tiocmget =		serial_tiocmget,
1309 	.tiocmset =		serial_tiocmset,
1310 	.get_icount =		serial_get_icount,
1311 	.set_serial =		serial_set_serial,
1312 	.get_serial =		serial_get_serial,
1313 	.cleanup =		serial_cleanup,
1314 	.install =		serial_install,
1315 	.proc_show =		serial_proc_show,
1316 };
1317 
1318 
1319 struct tty_driver *usb_serial_tty_driver;
1320 
usb_serial_init(void)1321 static int __init usb_serial_init(void)
1322 {
1323 	int result;
1324 
1325 	usb_serial_tty_driver = tty_alloc_driver(USB_SERIAL_TTY_MINORS,
1326 			TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV);
1327 	if (IS_ERR(usb_serial_tty_driver))
1328 		return PTR_ERR(usb_serial_tty_driver);
1329 
1330 	/* Initialize our global data */
1331 	result = bus_register(&usb_serial_bus_type);
1332 	if (result) {
1333 		pr_err("%s - registering bus driver failed\n", __func__);
1334 		goto err_put_driver;
1335 	}
1336 
1337 	usb_serial_tty_driver->driver_name = "usbserial";
1338 	usb_serial_tty_driver->name = "ttyUSB";
1339 	usb_serial_tty_driver->major = USB_SERIAL_TTY_MAJOR;
1340 	usb_serial_tty_driver->minor_start = 0;
1341 	usb_serial_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
1342 	usb_serial_tty_driver->subtype = SERIAL_TYPE_NORMAL;
1343 	usb_serial_tty_driver->init_termios = tty_std_termios;
1344 	usb_serial_tty_driver->init_termios.c_cflag = B9600 | CS8 | CREAD
1345 							| HUPCL | CLOCAL;
1346 	usb_serial_tty_driver->init_termios.c_ispeed = 9600;
1347 	usb_serial_tty_driver->init_termios.c_ospeed = 9600;
1348 	tty_set_operations(usb_serial_tty_driver, &serial_ops);
1349 	result = tty_register_driver(usb_serial_tty_driver);
1350 	if (result) {
1351 		pr_err("%s - tty_register_driver failed\n", __func__);
1352 		goto err_unregister_bus;
1353 	}
1354 
1355 	/* register the generic driver, if we should */
1356 	result = usb_serial_generic_register();
1357 	if (result < 0) {
1358 		pr_err("%s - registering generic driver failed\n", __func__);
1359 		goto err_unregister_driver;
1360 	}
1361 
1362 	return result;
1363 
1364 err_unregister_driver:
1365 	tty_unregister_driver(usb_serial_tty_driver);
1366 err_unregister_bus:
1367 	bus_unregister(&usb_serial_bus_type);
1368 err_put_driver:
1369 	pr_err("%s - returning with error %d\n", __func__, result);
1370 	tty_driver_kref_put(usb_serial_tty_driver);
1371 	return result;
1372 }
1373 
1374 
usb_serial_exit(void)1375 static void __exit usb_serial_exit(void)
1376 {
1377 	usb_serial_console_exit();
1378 
1379 	usb_serial_generic_deregister();
1380 
1381 	tty_unregister_driver(usb_serial_tty_driver);
1382 	tty_driver_kref_put(usb_serial_tty_driver);
1383 	bus_unregister(&usb_serial_bus_type);
1384 	idr_destroy(&serial_minors);
1385 }
1386 
1387 
1388 module_init(usb_serial_init);
1389 module_exit(usb_serial_exit);
1390 
1391 #define set_to_generic_if_null(type, function)				\
1392 	do {								\
1393 		if (!type->function) {					\
1394 			type->function = usb_serial_generic_##function;	\
1395 			pr_debug("%s: using generic " #function	"\n",	\
1396 						type->driver.name);	\
1397 		}							\
1398 	} while (0)
1399 
usb_serial_operations_init(struct usb_serial_driver * device)1400 static void usb_serial_operations_init(struct usb_serial_driver *device)
1401 {
1402 	set_to_generic_if_null(device, open);
1403 	set_to_generic_if_null(device, write);
1404 	set_to_generic_if_null(device, close);
1405 	set_to_generic_if_null(device, write_room);
1406 	set_to_generic_if_null(device, chars_in_buffer);
1407 	if (device->tx_empty)
1408 		set_to_generic_if_null(device, wait_until_sent);
1409 	set_to_generic_if_null(device, read_bulk_callback);
1410 	set_to_generic_if_null(device, write_bulk_callback);
1411 	set_to_generic_if_null(device, process_read_urb);
1412 	set_to_generic_if_null(device, prepare_write_buffer);
1413 }
1414 
usb_serial_register(struct usb_serial_driver * driver)1415 static int usb_serial_register(struct usb_serial_driver *driver)
1416 {
1417 	int retval;
1418 
1419 	if (usb_disabled())
1420 		return -ENODEV;
1421 
1422 	if (!driver->description)
1423 		driver->description = driver->driver.name;
1424 	if (!driver->usb_driver) {
1425 		WARN(1, "Serial driver %s has no usb_driver\n",
1426 				driver->description);
1427 		return -EINVAL;
1428 	}
1429 
1430 	/* Prevent individual ports from being unbound. */
1431 	driver->driver.suppress_bind_attrs = true;
1432 
1433 	usb_serial_operations_init(driver);
1434 
1435 	/* Add this device to our list of devices */
1436 	mutex_lock(&table_lock);
1437 	list_add(&driver->driver_list, &usb_serial_driver_list);
1438 
1439 	retval = usb_serial_bus_register(driver);
1440 	if (retval) {
1441 		pr_err("problem %d when registering driver %s\n", retval, driver->description);
1442 		list_del(&driver->driver_list);
1443 	} else {
1444 		pr_info("USB Serial support registered for %s\n", driver->description);
1445 	}
1446 	mutex_unlock(&table_lock);
1447 	return retval;
1448 }
1449 
usb_serial_deregister(struct usb_serial_driver * device)1450 static void usb_serial_deregister(struct usb_serial_driver *device)
1451 {
1452 	pr_info("USB Serial deregistering driver %s\n", device->description);
1453 
1454 	mutex_lock(&table_lock);
1455 	list_del(&device->driver_list);
1456 	mutex_unlock(&table_lock);
1457 
1458 	usb_serial_bus_deregister(device);
1459 }
1460 
1461 /**
1462  * usb_serial_register_drivers - register drivers for a usb-serial module
1463  * @serial_drivers: NULL-terminated array of pointers to drivers to be registered
1464  * @name: name of the usb_driver for this set of @serial_drivers
1465  * @id_table: list of all devices this @serial_drivers set binds to
1466  *
1467  * Registers all the drivers in the @serial_drivers array, and dynamically
1468  * creates a struct usb_driver with the name @name and id_table of @id_table.
1469  */
usb_serial_register_drivers(struct usb_serial_driver * const serial_drivers[],const char * name,const struct usb_device_id * id_table)1470 int usb_serial_register_drivers(struct usb_serial_driver *const serial_drivers[],
1471 				const char *name,
1472 				const struct usb_device_id *id_table)
1473 {
1474 	int rc;
1475 	struct usb_driver *udriver;
1476 	struct usb_serial_driver * const *sd;
1477 
1478 	/*
1479 	 * udriver must be registered before any of the serial drivers,
1480 	 * because the store_new_id() routine for the serial drivers (in
1481 	 * bus.c) probes udriver.
1482 	 *
1483 	 * Performance hack: We don't want udriver to be probed until
1484 	 * the serial drivers are registered, because the probe would
1485 	 * simply fail for lack of a matching serial driver.
1486 	 * So we leave udriver's id_table set to NULL until we are all set.
1487 	 *
1488 	 * Suspend/resume support is implemented in the usb-serial core,
1489 	 * so fill in the PM-related fields in udriver.
1490 	 */
1491 	udriver = kzalloc(sizeof(*udriver), GFP_KERNEL);
1492 	if (!udriver)
1493 		return -ENOMEM;
1494 
1495 	udriver->name = name;
1496 	udriver->no_dynamic_id = 1;
1497 	udriver->supports_autosuspend = 1;
1498 	udriver->suspend = usb_serial_suspend;
1499 	udriver->resume = usb_serial_resume;
1500 	udriver->probe = usb_serial_probe;
1501 	udriver->disconnect = usb_serial_disconnect;
1502 
1503 	/* we only set the reset_resume field if the serial_driver has one */
1504 	for (sd = serial_drivers; *sd; ++sd) {
1505 		if ((*sd)->reset_resume) {
1506 			udriver->reset_resume = usb_serial_reset_resume;
1507 			break;
1508 		}
1509 	}
1510 
1511 	rc = usb_register(udriver);
1512 	if (rc)
1513 		goto err_free_driver;
1514 
1515 	for (sd = serial_drivers; *sd; ++sd) {
1516 		(*sd)->usb_driver = udriver;
1517 		rc = usb_serial_register(*sd);
1518 		if (rc)
1519 			goto err_deregister_drivers;
1520 	}
1521 
1522 	/* Now set udriver's id_table and look for matches */
1523 	udriver->id_table = id_table;
1524 	rc = driver_attach(&udriver->drvwrap.driver);
1525 	return 0;
1526 
1527 err_deregister_drivers:
1528 	while (sd-- > serial_drivers)
1529 		usb_serial_deregister(*sd);
1530 	usb_deregister(udriver);
1531 err_free_driver:
1532 	kfree(udriver);
1533 	return rc;
1534 }
1535 EXPORT_SYMBOL_GPL(usb_serial_register_drivers);
1536 
1537 /**
1538  * usb_serial_deregister_drivers - deregister drivers for a usb-serial module
1539  * @serial_drivers: NULL-terminated array of pointers to drivers to be deregistered
1540  *
1541  * Deregisters all the drivers in the @serial_drivers array and deregisters and
1542  * frees the struct usb_driver that was created by the call to
1543  * usb_serial_register_drivers().
1544  */
usb_serial_deregister_drivers(struct usb_serial_driver * const serial_drivers[])1545 void usb_serial_deregister_drivers(struct usb_serial_driver *const serial_drivers[])
1546 {
1547 	struct usb_driver *udriver = (*serial_drivers)->usb_driver;
1548 
1549 	for (; *serial_drivers; ++serial_drivers)
1550 		usb_serial_deregister(*serial_drivers);
1551 	usb_deregister(udriver);
1552 	kfree(udriver);
1553 }
1554 EXPORT_SYMBOL_GPL(usb_serial_deregister_drivers);
1555 
1556 MODULE_AUTHOR(DRIVER_AUTHOR);
1557 MODULE_DESCRIPTION(DRIVER_DESC);
1558 MODULE_LICENSE("GPL v2");
1559