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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * USB Serial Converter Generic functions
4 *
5 * Copyright (C) 2010 - 2013 Johan Hovold (jhovold@gmail.com)
6 * Copyright (C) 1999 - 2002 Greg Kroah-Hartman (greg@kroah.com)
7 */
8
9#include <linux/kernel.h>
10#include <linux/sched/signal.h>
11#include <linux/errno.h>
12#include <linux/slab.h>
13#include <linux/sysrq.h>
14#include <linux/tty.h>
15#include <linux/tty_flip.h>
16#include <linux/module.h>
17#include <linux/moduleparam.h>
18#include <linux/usb.h>
19#include <linux/usb/serial.h>
20#include <linux/uaccess.h>
21#include <linux/kfifo.h>
22#include <linux/serial.h>
23
24#ifdef CONFIG_USB_SERIAL_GENERIC
25
26static __u16 vendor = 0x05f9;
27static __u16 product = 0xffff;
28
29module_param(vendor, ushort, 0);
30MODULE_PARM_DESC(vendor, "User specified USB idVendor");
31
32module_param(product, ushort, 0);
33MODULE_PARM_DESC(product, "User specified USB idProduct");
34
35static struct usb_device_id generic_device_ids[2]; /* Initially all zeroes. */
36
37static int usb_serial_generic_probe(struct usb_serial *serial,
38 const struct usb_device_id *id)
39{
40 struct device *dev = &serial->interface->dev;
41
42 dev_info(dev, "The \"generic\" usb-serial driver is only for testing and one-off prototypes.\n");
43 dev_info(dev, "Tell linux-usb@vger.kernel.org to add your device to a proper driver.\n");
44
45 return 0;
46}
47
48static int usb_serial_generic_calc_num_ports(struct usb_serial *serial,
49 struct usb_serial_endpoints *epds)
50{
51 struct device *dev = &serial->interface->dev;
52 int num_ports;
53
54 num_ports = max(epds->num_bulk_in, epds->num_bulk_out);
55
56 if (num_ports == 0) {
57 dev_err(dev, "device has no bulk endpoints\n");
58 return -ENODEV;
59 }
60
61 return num_ports;
62}
63
64static struct usb_serial_driver usb_serial_generic_device = {
65 .driver = {
66 .name = "generic",
67 },
68 .id_table = generic_device_ids,
69 .probe = usb_serial_generic_probe,
70 .calc_num_ports = usb_serial_generic_calc_num_ports,
71 .throttle = usb_serial_generic_throttle,
72 .unthrottle = usb_serial_generic_unthrottle,
73 .resume = usb_serial_generic_resume,
74};
75
76static struct usb_serial_driver * const serial_drivers[] = {
77 &usb_serial_generic_device, NULL
78};
79
80#endif
81
82int usb_serial_generic_register(void)
83{
84 int retval = 0;
85
86#ifdef CONFIG_USB_SERIAL_GENERIC
87 generic_device_ids[0].idVendor = vendor;
88 generic_device_ids[0].idProduct = product;
89 generic_device_ids[0].match_flags =
90 USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT;
91
92 retval = usb_serial_register_drivers(serial_drivers,
93 "usbserial_generic", generic_device_ids);
94#endif
95 return retval;
96}
97
98void usb_serial_generic_deregister(void)
99{
100#ifdef CONFIG_USB_SERIAL_GENERIC
101 usb_serial_deregister_drivers(serial_drivers);
102#endif
103}
104
105int usb_serial_generic_open(struct tty_struct *tty, struct usb_serial_port *port)
106{
107 int result = 0;
108
109 clear_bit(USB_SERIAL_THROTTLED, &port->flags);
110
111 if (port->bulk_in_size)
112 result = usb_serial_generic_submit_read_urbs(port, GFP_KERNEL);
113
114 return result;
115}
116EXPORT_SYMBOL_GPL(usb_serial_generic_open);
117
118void usb_serial_generic_close(struct usb_serial_port *port)
119{
120 unsigned long flags;
121 int i;
122
123 if (port->bulk_out_size) {
124 for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
125 usb_kill_urb(port->write_urbs[i]);
126
127 spin_lock_irqsave(&port->lock, flags);
128 kfifo_reset_out(&port->write_fifo);
129 spin_unlock_irqrestore(&port->lock, flags);
130 }
131 if (port->bulk_in_size) {
132 for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i)
133 usb_kill_urb(port->read_urbs[i]);
134 }
135}
136EXPORT_SYMBOL_GPL(usb_serial_generic_close);
137
138int usb_serial_generic_prepare_write_buffer(struct usb_serial_port *port,
139 void *dest, size_t size)
140{
141 return kfifo_out_locked(&port->write_fifo, dest, size, &port->lock);
142}
143
144/**
145 * usb_serial_generic_write_start - start writing buffered data
146 * @port: usb-serial port
147 * @mem_flags: flags to use for memory allocations
148 *
149 * Serialised using USB_SERIAL_WRITE_BUSY flag.
150 *
151 * Return: Zero on success or if busy, otherwise a negative errno value.
152 */
153int usb_serial_generic_write_start(struct usb_serial_port *port,
154 gfp_t mem_flags)
155{
156 struct urb *urb;
157 int count, result;
158 unsigned long flags;
159 int i;
160
161 if (test_and_set_bit_lock(USB_SERIAL_WRITE_BUSY, &port->flags))
162 return 0;
163retry:
164 spin_lock_irqsave(&port->lock, flags);
165 if (!port->write_urbs_free || !kfifo_len(&port->write_fifo)) {
166 clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
167 spin_unlock_irqrestore(&port->lock, flags);
168 return 0;
169 }
170 i = (int)find_first_bit(&port->write_urbs_free,
171 ARRAY_SIZE(port->write_urbs));
172 spin_unlock_irqrestore(&port->lock, flags);
173
174 urb = port->write_urbs[i];
175 count = port->serial->type->prepare_write_buffer(port,
176 urb->transfer_buffer,
177 port->bulk_out_size);
178 urb->transfer_buffer_length = count;
179 usb_serial_debug_data(&port->dev, __func__, count, urb->transfer_buffer);
180 spin_lock_irqsave(&port->lock, flags);
181 port->tx_bytes += count;
182 spin_unlock_irqrestore(&port->lock, flags);
183
184 clear_bit(i, &port->write_urbs_free);
185 result = usb_submit_urb(urb, mem_flags);
186 if (result) {
187 dev_err_console(port, "%s - error submitting urb: %d\n",
188 __func__, result);
189 set_bit(i, &port->write_urbs_free);
190 spin_lock_irqsave(&port->lock, flags);
191 port->tx_bytes -= count;
192 spin_unlock_irqrestore(&port->lock, flags);
193
194 clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
195 return result;
196 }
197
198 goto retry; /* try sending off another urb */
199}
200EXPORT_SYMBOL_GPL(usb_serial_generic_write_start);
201
202/**
203 * usb_serial_generic_write - generic write function
204 * @tty: tty for the port
205 * @port: usb-serial port
206 * @buf: data to write
207 * @count: number of bytes to write
208 *
209 * Return: The number of characters buffered, which may be anything from
210 * zero to @count, or a negative errno value.
211 */
212int usb_serial_generic_write(struct tty_struct *tty,
213 struct usb_serial_port *port, const unsigned char *buf, int count)
214{
215 int result;
216
217 if (!port->bulk_out_size)
218 return -ENODEV;
219
220 if (!count)
221 return 0;
222
223 count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
224 result = usb_serial_generic_write_start(port, GFP_ATOMIC);
225 if (result)
226 return result;
227
228 return count;
229}
230EXPORT_SYMBOL_GPL(usb_serial_generic_write);
231
232unsigned int usb_serial_generic_write_room(struct tty_struct *tty)
233{
234 struct usb_serial_port *port = tty->driver_data;
235 unsigned long flags;
236 unsigned int room;
237
238 if (!port->bulk_out_size)
239 return 0;
240
241 spin_lock_irqsave(&port->lock, flags);
242 room = kfifo_avail(&port->write_fifo);
243 spin_unlock_irqrestore(&port->lock, flags);
244
245 dev_dbg(&port->dev, "%s - returns %u\n", __func__, room);
246 return room;
247}
248
249unsigned int usb_serial_generic_chars_in_buffer(struct tty_struct *tty)
250{
251 struct usb_serial_port *port = tty->driver_data;
252 unsigned long flags;
253 unsigned int chars;
254
255 if (!port->bulk_out_size)
256 return 0;
257
258 spin_lock_irqsave(&port->lock, flags);
259 chars = kfifo_len(&port->write_fifo) + port->tx_bytes;
260 spin_unlock_irqrestore(&port->lock, flags);
261
262 dev_dbg(&port->dev, "%s - returns %u\n", __func__, chars);
263 return chars;
264}
265EXPORT_SYMBOL_GPL(usb_serial_generic_chars_in_buffer);
266
267void usb_serial_generic_wait_until_sent(struct tty_struct *tty, long timeout)
268{
269 struct usb_serial_port *port = tty->driver_data;
270 unsigned int bps;
271 unsigned long period;
272 unsigned long expire;
273
274 bps = tty_get_baud_rate(tty);
275 if (!bps)
276 bps = 9600; /* B0 */
277 /*
278 * Use a poll-period of roughly the time it takes to send one
279 * character or at least one jiffy.
280 */
281 period = max_t(unsigned long, (10 * HZ / bps), 1);
282 if (timeout)
283 period = min_t(unsigned long, period, timeout);
284
285 dev_dbg(&port->dev, "%s - timeout = %u ms, period = %u ms\n",
286 __func__, jiffies_to_msecs(timeout),
287 jiffies_to_msecs(period));
288 expire = jiffies + timeout;
289 while (!port->serial->type->tx_empty(port)) {
290 schedule_timeout_interruptible(period);
291 if (signal_pending(current))
292 break;
293 if (timeout && time_after(jiffies, expire))
294 break;
295 }
296}
297EXPORT_SYMBOL_GPL(usb_serial_generic_wait_until_sent);
298
299static int usb_serial_generic_submit_read_urb(struct usb_serial_port *port,
300 int index, gfp_t mem_flags)
301{
302 int res;
303
304 if (!test_and_clear_bit(index, &port->read_urbs_free))
305 return 0;
306
307 dev_dbg(&port->dev, "%s - urb %d\n", __func__, index);
308
309 res = usb_submit_urb(port->read_urbs[index], mem_flags);
310 if (res) {
311 if (res != -EPERM && res != -ENODEV) {
312 dev_err(&port->dev,
313 "%s - usb_submit_urb failed: %d\n",
314 __func__, res);
315 }
316 set_bit(index, &port->read_urbs_free);
317 return res;
318 }
319
320 return 0;
321}
322
323int usb_serial_generic_submit_read_urbs(struct usb_serial_port *port,
324 gfp_t mem_flags)
325{
326 int res;
327 int i;
328
329 for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {
330 res = usb_serial_generic_submit_read_urb(port, i, mem_flags);
331 if (res)
332 goto err;
333 }
334
335 return 0;
336err:
337 for (; i >= 0; --i)
338 usb_kill_urb(port->read_urbs[i]);
339
340 return res;
341}
342EXPORT_SYMBOL_GPL(usb_serial_generic_submit_read_urbs);
343
344void usb_serial_generic_process_read_urb(struct urb *urb)
345{
346 struct usb_serial_port *port = urb->context;
347 char *ch = urb->transfer_buffer;
348 int i;
349
350 if (!urb->actual_length)
351 return;
352 /*
353 * The per character mucking around with sysrq path it too slow for
354 * stuff like 3G modems, so shortcircuit it in the 99.9999999% of
355 * cases where the USB serial is not a console anyway.
356 */
357 if (port->sysrq) {
358 for (i = 0; i < urb->actual_length; i++, ch++) {
359 if (!usb_serial_handle_sysrq_char(port, *ch))
360 tty_insert_flip_char(&port->port, *ch, TTY_NORMAL);
361 }
362 } else {
363 tty_insert_flip_string(&port->port, ch, urb->actual_length);
364 }
365 tty_flip_buffer_push(&port->port);
366}
367EXPORT_SYMBOL_GPL(usb_serial_generic_process_read_urb);
368
369void usb_serial_generic_read_bulk_callback(struct urb *urb)
370{
371 struct usb_serial_port *port = urb->context;
372 unsigned char *data = urb->transfer_buffer;
373 bool stopped = false;
374 int status = urb->status;
375 int i;
376
377 for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {
378 if (urb == port->read_urbs[i])
379 break;
380 }
381
382 dev_dbg(&port->dev, "%s - urb %d, len %d\n", __func__, i,
383 urb->actual_length);
384 switch (status) {
385 case 0:
386 usb_serial_debug_data(&port->dev, __func__, urb->actual_length,
387 data);
388 port->serial->type->process_read_urb(urb);
389 break;
390 case -ENOENT:
391 case -ECONNRESET:
392 case -ESHUTDOWN:
393 dev_dbg(&port->dev, "%s - urb stopped: %d\n",
394 __func__, status);
395 stopped = true;
396 break;
397 case -EPIPE:
398 dev_err(&port->dev, "%s - urb stopped: %d\n",
399 __func__, status);
400 stopped = true;
401 break;
402 default:
403 dev_dbg(&port->dev, "%s - nonzero urb status: %d\n",
404 __func__, status);
405 break;
406 }
407
408 /*
409 * Make sure URB processing is done before marking as free to avoid
410 * racing with unthrottle() on another CPU. Matches the barriers
411 * implied by the test_and_clear_bit() in
412 * usb_serial_generic_submit_read_urb().
413 */
414 smp_mb__before_atomic();
415 set_bit(i, &port->read_urbs_free);
416 /*
417 * Make sure URB is marked as free before checking the throttled flag
418 * to avoid racing with unthrottle() on another CPU. Matches the
419 * smp_mb__after_atomic() in unthrottle().
420 */
421 smp_mb__after_atomic();
422
423 if (stopped)
424 return;
425
426 if (test_bit(USB_SERIAL_THROTTLED, &port->flags))
427 return;
428
429 usb_serial_generic_submit_read_urb(port, i, GFP_ATOMIC);
430}
431EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
432
433void usb_serial_generic_write_bulk_callback(struct urb *urb)
434{
435 unsigned long flags;
436 struct usb_serial_port *port = urb->context;
437 int status = urb->status;
438 int i;
439
440 for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i) {
441 if (port->write_urbs[i] == urb)
442 break;
443 }
444 spin_lock_irqsave(&port->lock, flags);
445 port->tx_bytes -= urb->transfer_buffer_length;
446 set_bit(i, &port->write_urbs_free);
447 spin_unlock_irqrestore(&port->lock, flags);
448
449 switch (status) {
450 case 0:
451 break;
452 case -ENOENT:
453 case -ECONNRESET:
454 case -ESHUTDOWN:
455 dev_dbg(&port->dev, "%s - urb stopped: %d\n",
456 __func__, status);
457 return;
458 case -EPIPE:
459 dev_err_console(port, "%s - urb stopped: %d\n",
460 __func__, status);
461 return;
462 default:
463 dev_err_console(port, "%s - nonzero urb status: %d\n",
464 __func__, status);
465 break;
466 }
467
468 usb_serial_generic_write_start(port, GFP_ATOMIC);
469 usb_serial_port_softint(port);
470}
471EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
472
473void usb_serial_generic_throttle(struct tty_struct *tty)
474{
475 struct usb_serial_port *port = tty->driver_data;
476
477 set_bit(USB_SERIAL_THROTTLED, &port->flags);
478}
479EXPORT_SYMBOL_GPL(usb_serial_generic_throttle);
480
481void usb_serial_generic_unthrottle(struct tty_struct *tty)
482{
483 struct usb_serial_port *port = tty->driver_data;
484
485 clear_bit(USB_SERIAL_THROTTLED, &port->flags);
486
487 /*
488 * Matches the smp_mb__after_atomic() in
489 * usb_serial_generic_read_bulk_callback().
490 */
491 smp_mb__after_atomic();
492
493 usb_serial_generic_submit_read_urbs(port, GFP_KERNEL);
494}
495EXPORT_SYMBOL_GPL(usb_serial_generic_unthrottle);
496
497static bool usb_serial_generic_msr_changed(struct tty_struct *tty,
498 unsigned long arg, struct async_icount *cprev)
499{
500 struct usb_serial_port *port = tty->driver_data;
501 struct async_icount cnow;
502 unsigned long flags;
503 bool ret;
504
505 /*
506 * Use tty-port initialised flag to detect all hangups including the
507 * one generated at USB-device disconnect.
508 */
509 if (!tty_port_initialized(&port->port))
510 return true;
511
512 spin_lock_irqsave(&port->lock, flags);
513 cnow = port->icount; /* atomic copy*/
514 spin_unlock_irqrestore(&port->lock, flags);
515
516 ret = ((arg & TIOCM_RNG) && (cnow.rng != cprev->rng)) ||
517 ((arg & TIOCM_DSR) && (cnow.dsr != cprev->dsr)) ||
518 ((arg & TIOCM_CD) && (cnow.dcd != cprev->dcd)) ||
519 ((arg & TIOCM_CTS) && (cnow.cts != cprev->cts));
520
521 *cprev = cnow;
522
523 return ret;
524}
525
526int usb_serial_generic_tiocmiwait(struct tty_struct *tty, unsigned long arg)
527{
528 struct usb_serial_port *port = tty->driver_data;
529 struct async_icount cnow;
530 unsigned long flags;
531 int ret;
532
533 spin_lock_irqsave(&port->lock, flags);
534 cnow = port->icount; /* atomic copy */
535 spin_unlock_irqrestore(&port->lock, flags);
536
537 ret = wait_event_interruptible(port->port.delta_msr_wait,
538 usb_serial_generic_msr_changed(tty, arg, &cnow));
539 if (!ret && !tty_port_initialized(&port->port))
540 ret = -EIO;
541
542 return ret;
543}
544EXPORT_SYMBOL_GPL(usb_serial_generic_tiocmiwait);
545
546int usb_serial_generic_get_icount(struct tty_struct *tty,
547 struct serial_icounter_struct *icount)
548{
549 struct usb_serial_port *port = tty->driver_data;
550 struct async_icount cnow;
551 unsigned long flags;
552
553 spin_lock_irqsave(&port->lock, flags);
554 cnow = port->icount; /* atomic copy */
555 spin_unlock_irqrestore(&port->lock, flags);
556
557 icount->cts = cnow.cts;
558 icount->dsr = cnow.dsr;
559 icount->rng = cnow.rng;
560 icount->dcd = cnow.dcd;
561 icount->tx = cnow.tx;
562 icount->rx = cnow.rx;
563 icount->frame = cnow.frame;
564 icount->parity = cnow.parity;
565 icount->overrun = cnow.overrun;
566 icount->brk = cnow.brk;
567 icount->buf_overrun = cnow.buf_overrun;
568
569 return 0;
570}
571EXPORT_SYMBOL_GPL(usb_serial_generic_get_icount);
572
573#if defined(CONFIG_USB_SERIAL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
574int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
575{
576 if (port->sysrq) {
577 if (ch && time_before(jiffies, port->sysrq)) {
578 handle_sysrq(ch);
579 port->sysrq = 0;
580 return 1;
581 }
582 port->sysrq = 0;
583 }
584 return 0;
585}
586EXPORT_SYMBOL_GPL(usb_serial_handle_sysrq_char);
587
588int usb_serial_handle_break(struct usb_serial_port *port)
589{
590 if (!port->port.console)
591 return 0;
592
593 if (!port->sysrq) {
594 port->sysrq = jiffies + HZ*5;
595 return 1;
596 }
597 port->sysrq = 0;
598 return 0;
599}
600EXPORT_SYMBOL_GPL(usb_serial_handle_break);
601#endif
602
603/**
604 * usb_serial_handle_dcd_change - handle a change of carrier detect state
605 * @port: usb-serial port
606 * @tty: tty for the port
607 * @status: new carrier detect status, nonzero if active
608 */
609void usb_serial_handle_dcd_change(struct usb_serial_port *port,
610 struct tty_struct *tty, unsigned int status)
611{
612 dev_dbg(&port->dev, "%s - status %d\n", __func__, status);
613
614 if (tty) {
615 struct tty_ldisc *ld = tty_ldisc_ref(tty);
616
617 if (ld) {
618 if (ld->ops->dcd_change)
619 ld->ops->dcd_change(tty, status);
620 tty_ldisc_deref(ld);
621 }
622 }
623
624 if (status)
625 wake_up_interruptible(&port->port.open_wait);
626 else if (tty && !C_CLOCAL(tty))
627 tty_hangup(tty);
628}
629EXPORT_SYMBOL_GPL(usb_serial_handle_dcd_change);
630
631int usb_serial_generic_resume(struct usb_serial *serial)
632{
633 struct usb_serial_port *port;
634 int i, c = 0, r;
635
636 for (i = 0; i < serial->num_ports; i++) {
637 port = serial->port[i];
638 if (!tty_port_initialized(&port->port))
639 continue;
640
641 if (port->bulk_in_size) {
642 r = usb_serial_generic_submit_read_urbs(port,
643 GFP_NOIO);
644 if (r < 0)
645 c++;
646 }
647
648 if (port->bulk_out_size) {
649 r = usb_serial_generic_write_start(port, GFP_NOIO);
650 if (r < 0)
651 c++;
652 }
653 }
654
655 return c ? -EIO : 0;
656}
657EXPORT_SYMBOL_GPL(usb_serial_generic_resume);
1/*
2 * USB Serial Converter Generic functions
3 *
4 * Copyright (C) 2010 - 2011 Johan Hovold (jhovold@gmail.com)
5 * Copyright (C) 1999 - 2002 Greg Kroah-Hartman (greg@kroah.com)
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License version
9 * 2 as published by the Free Software Foundation.
10 *
11 */
12
13#include <linux/kernel.h>
14#include <linux/errno.h>
15#include <linux/slab.h>
16#include <linux/sysrq.h>
17#include <linux/tty.h>
18#include <linux/tty_flip.h>
19#include <linux/module.h>
20#include <linux/moduleparam.h>
21#include <linux/usb.h>
22#include <linux/usb/serial.h>
23#include <linux/uaccess.h>
24#include <linux/kfifo.h>
25#include <linux/serial.h>
26
27static int debug;
28
29#ifdef CONFIG_USB_SERIAL_GENERIC
30
31static __u16 vendor = 0x05f9;
32static __u16 product = 0xffff;
33
34module_param(vendor, ushort, 0);
35MODULE_PARM_DESC(vendor, "User specified USB idVendor");
36
37module_param(product, ushort, 0);
38MODULE_PARM_DESC(product, "User specified USB idProduct");
39
40static struct usb_device_id generic_device_ids[2]; /* Initially all zeroes. */
41
42/* All of the device info needed for the Generic Serial Converter */
43struct usb_serial_driver usb_serial_generic_device = {
44 .driver = {
45 .owner = THIS_MODULE,
46 .name = "generic",
47 },
48 .id_table = generic_device_ids,
49 .num_ports = 1,
50 .disconnect = usb_serial_generic_disconnect,
51 .release = usb_serial_generic_release,
52 .throttle = usb_serial_generic_throttle,
53 .unthrottle = usb_serial_generic_unthrottle,
54 .resume = usb_serial_generic_resume,
55};
56
57static struct usb_serial_driver * const serial_drivers[] = {
58 &usb_serial_generic_device, NULL
59};
60
61#endif
62
63int usb_serial_generic_register(int _debug)
64{
65 int retval = 0;
66
67 debug = _debug;
68#ifdef CONFIG_USB_SERIAL_GENERIC
69 generic_device_ids[0].idVendor = vendor;
70 generic_device_ids[0].idProduct = product;
71 generic_device_ids[0].match_flags =
72 USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT;
73
74 /* register our generic driver with ourselves */
75 retval = usb_serial_register_drivers(serial_drivers,
76 "usbserial_generic", generic_device_ids);
77#endif
78 return retval;
79}
80
81void usb_serial_generic_deregister(void)
82{
83#ifdef CONFIG_USB_SERIAL_GENERIC
84 /* remove our generic driver */
85 usb_serial_deregister_drivers(serial_drivers);
86#endif
87}
88
89int usb_serial_generic_open(struct tty_struct *tty, struct usb_serial_port *port)
90{
91 int result = 0;
92 unsigned long flags;
93
94 /* clear the throttle flags */
95 spin_lock_irqsave(&port->lock, flags);
96 port->throttled = 0;
97 port->throttle_req = 0;
98 spin_unlock_irqrestore(&port->lock, flags);
99
100 /* if we have a bulk endpoint, start reading from it */
101 if (port->bulk_in_size)
102 result = usb_serial_generic_submit_read_urbs(port, GFP_KERNEL);
103
104 return result;
105}
106EXPORT_SYMBOL_GPL(usb_serial_generic_open);
107
108static void generic_cleanup(struct usb_serial_port *port)
109{
110 struct usb_serial *serial = port->serial;
111 unsigned long flags;
112 int i;
113
114 if (serial->dev) {
115 /* shutdown any bulk transfers that might be going on */
116 if (port->bulk_out_size) {
117 for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
118 usb_kill_urb(port->write_urbs[i]);
119
120 spin_lock_irqsave(&port->lock, flags);
121 kfifo_reset_out(&port->write_fifo);
122 spin_unlock_irqrestore(&port->lock, flags);
123 }
124 if (port->bulk_in_size) {
125 for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i)
126 usb_kill_urb(port->read_urbs[i]);
127 }
128 }
129}
130
131void usb_serial_generic_close(struct usb_serial_port *port)
132{
133 generic_cleanup(port);
134}
135EXPORT_SYMBOL_GPL(usb_serial_generic_close);
136
137int usb_serial_generic_prepare_write_buffer(struct usb_serial_port *port,
138 void *dest, size_t size)
139{
140 return kfifo_out_locked(&port->write_fifo, dest, size, &port->lock);
141}
142
143/**
144 * usb_serial_generic_write_start - kick off an URB write
145 * @port: Pointer to the &struct usb_serial_port data
146 *
147 * Returns zero on success, or a negative errno value
148 */
149static int usb_serial_generic_write_start(struct usb_serial_port *port)
150{
151 struct urb *urb;
152 int count, result;
153 unsigned long flags;
154 int i;
155
156 if (test_and_set_bit_lock(USB_SERIAL_WRITE_BUSY, &port->flags))
157 return 0;
158retry:
159 spin_lock_irqsave(&port->lock, flags);
160 if (!port->write_urbs_free || !kfifo_len(&port->write_fifo)) {
161 clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
162 spin_unlock_irqrestore(&port->lock, flags);
163 return 0;
164 }
165 i = (int)find_first_bit(&port->write_urbs_free,
166 ARRAY_SIZE(port->write_urbs));
167 spin_unlock_irqrestore(&port->lock, flags);
168
169 urb = port->write_urbs[i];
170 count = port->serial->type->prepare_write_buffer(port,
171 urb->transfer_buffer,
172 port->bulk_out_size);
173 urb->transfer_buffer_length = count;
174 usb_serial_debug_data(debug, &port->dev, __func__, count,
175 urb->transfer_buffer);
176 spin_lock_irqsave(&port->lock, flags);
177 port->tx_bytes += count;
178 spin_unlock_irqrestore(&port->lock, flags);
179
180 clear_bit(i, &port->write_urbs_free);
181 result = usb_submit_urb(urb, GFP_ATOMIC);
182 if (result) {
183 dev_err_console(port, "%s - error submitting urb: %d\n",
184 __func__, result);
185 set_bit(i, &port->write_urbs_free);
186 spin_lock_irqsave(&port->lock, flags);
187 port->tx_bytes -= count;
188 spin_unlock_irqrestore(&port->lock, flags);
189
190 clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
191 return result;
192 }
193
194 /* Try sending off another urb, unless in irq context (in which case
195 * there will be no free urb). */
196 if (!in_irq())
197 goto retry;
198
199 clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
200
201 return 0;
202}
203
204/**
205 * usb_serial_generic_write - generic write function for serial USB devices
206 * @tty: Pointer to &struct tty_struct for the device
207 * @port: Pointer to the &usb_serial_port structure for the device
208 * @buf: Pointer to the data to write
209 * @count: Number of bytes to write
210 *
211 * Returns the number of characters actually written, which may be anything
212 * from zero to @count. If an error occurs, it returns the negative errno
213 * value.
214 */
215int usb_serial_generic_write(struct tty_struct *tty,
216 struct usb_serial_port *port, const unsigned char *buf, int count)
217{
218 int result;
219
220 /* only do something if we have a bulk out endpoint */
221 if (!port->bulk_out_size)
222 return -ENODEV;
223
224 if (!count)
225 return 0;
226
227 count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
228 result = usb_serial_generic_write_start(port);
229 if (result)
230 return result;
231
232 return count;
233}
234EXPORT_SYMBOL_GPL(usb_serial_generic_write);
235
236int usb_serial_generic_write_room(struct tty_struct *tty)
237{
238 struct usb_serial_port *port = tty->driver_data;
239 unsigned long flags;
240 int room;
241
242 if (!port->bulk_out_size)
243 return 0;
244
245 spin_lock_irqsave(&port->lock, flags);
246 room = kfifo_avail(&port->write_fifo);
247 spin_unlock_irqrestore(&port->lock, flags);
248
249 dev_dbg(&port->dev, "%s - returns %d\n", __func__, room);
250 return room;
251}
252
253int usb_serial_generic_chars_in_buffer(struct tty_struct *tty)
254{
255 struct usb_serial_port *port = tty->driver_data;
256 unsigned long flags;
257 int chars;
258
259 if (!port->bulk_out_size)
260 return 0;
261
262 spin_lock_irqsave(&port->lock, flags);
263 chars = kfifo_len(&port->write_fifo) + port->tx_bytes;
264 spin_unlock_irqrestore(&port->lock, flags);
265
266 dev_dbg(&port->dev, "%s - returns %d\n", __func__, chars);
267 return chars;
268}
269
270static int usb_serial_generic_submit_read_urb(struct usb_serial_port *port,
271 int index, gfp_t mem_flags)
272{
273 int res;
274
275 if (!test_and_clear_bit(index, &port->read_urbs_free))
276 return 0;
277
278 dev_dbg(&port->dev, "%s - port %d, urb %d\n", __func__,
279 port->number, index);
280
281 res = usb_submit_urb(port->read_urbs[index], mem_flags);
282 if (res) {
283 if (res != -EPERM) {
284 dev_err(&port->dev,
285 "%s - usb_submit_urb failed: %d\n",
286 __func__, res);
287 }
288 set_bit(index, &port->read_urbs_free);
289 return res;
290 }
291
292 return 0;
293}
294
295int usb_serial_generic_submit_read_urbs(struct usb_serial_port *port,
296 gfp_t mem_flags)
297{
298 int res;
299 int i;
300
301 for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {
302 res = usb_serial_generic_submit_read_urb(port, i, mem_flags);
303 if (res)
304 goto err;
305 }
306
307 return 0;
308err:
309 for (; i >= 0; --i)
310 usb_kill_urb(port->read_urbs[i]);
311
312 return res;
313}
314EXPORT_SYMBOL_GPL(usb_serial_generic_submit_read_urbs);
315
316void usb_serial_generic_process_read_urb(struct urb *urb)
317{
318 struct usb_serial_port *port = urb->context;
319 struct tty_struct *tty;
320 char *ch = (char *)urb->transfer_buffer;
321 int i;
322
323 if (!urb->actual_length)
324 return;
325
326 tty = tty_port_tty_get(&port->port);
327 if (!tty)
328 return;
329
330 /* The per character mucking around with sysrq path it too slow for
331 stuff like 3G modems, so shortcircuit it in the 99.9999999% of cases
332 where the USB serial is not a console anyway */
333 if (!port->port.console || !port->sysrq)
334 tty_insert_flip_string(tty, ch, urb->actual_length);
335 else {
336 for (i = 0; i < urb->actual_length; i++, ch++) {
337 if (!usb_serial_handle_sysrq_char(port, *ch))
338 tty_insert_flip_char(tty, *ch, TTY_NORMAL);
339 }
340 }
341 tty_flip_buffer_push(tty);
342 tty_kref_put(tty);
343}
344EXPORT_SYMBOL_GPL(usb_serial_generic_process_read_urb);
345
346void usb_serial_generic_read_bulk_callback(struct urb *urb)
347{
348 struct usb_serial_port *port = urb->context;
349 unsigned char *data = urb->transfer_buffer;
350 unsigned long flags;
351 int i;
352
353 for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {
354 if (urb == port->read_urbs[i])
355 break;
356 }
357 set_bit(i, &port->read_urbs_free);
358
359 dev_dbg(&port->dev, "%s - port %d, urb %d, len %d\n",
360 __func__, port->number, i, urb->actual_length);
361
362 if (urb->status) {
363 dev_dbg(&port->dev, "%s - non-zero urb status: %d\n",
364 __func__, urb->status);
365 return;
366 }
367
368 usb_serial_debug_data(debug, &port->dev, __func__,
369 urb->actual_length, data);
370 port->serial->type->process_read_urb(urb);
371
372 /* Throttle the device if requested by tty */
373 spin_lock_irqsave(&port->lock, flags);
374 port->throttled = port->throttle_req;
375 if (!port->throttled) {
376 spin_unlock_irqrestore(&port->lock, flags);
377 usb_serial_generic_submit_read_urb(port, i, GFP_ATOMIC);
378 } else
379 spin_unlock_irqrestore(&port->lock, flags);
380}
381EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
382
383void usb_serial_generic_write_bulk_callback(struct urb *urb)
384{
385 unsigned long flags;
386 struct usb_serial_port *port = urb->context;
387 int status = urb->status;
388 int i;
389
390 for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
391 if (port->write_urbs[i] == urb)
392 break;
393
394 spin_lock_irqsave(&port->lock, flags);
395 port->tx_bytes -= urb->transfer_buffer_length;
396 set_bit(i, &port->write_urbs_free);
397 spin_unlock_irqrestore(&port->lock, flags);
398
399 if (status) {
400 dev_dbg(&port->dev, "%s - non-zero urb status: %d\n",
401 __func__, status);
402
403 spin_lock_irqsave(&port->lock, flags);
404 kfifo_reset_out(&port->write_fifo);
405 spin_unlock_irqrestore(&port->lock, flags);
406 } else {
407 usb_serial_generic_write_start(port);
408 }
409
410 usb_serial_port_softint(port);
411}
412EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
413
414void usb_serial_generic_throttle(struct tty_struct *tty)
415{
416 struct usb_serial_port *port = tty->driver_data;
417 unsigned long flags;
418
419 /* Set the throttle request flag. It will be picked up
420 * by usb_serial_generic_read_bulk_callback(). */
421 spin_lock_irqsave(&port->lock, flags);
422 port->throttle_req = 1;
423 spin_unlock_irqrestore(&port->lock, flags);
424}
425EXPORT_SYMBOL_GPL(usb_serial_generic_throttle);
426
427void usb_serial_generic_unthrottle(struct tty_struct *tty)
428{
429 struct usb_serial_port *port = tty->driver_data;
430 int was_throttled;
431
432 /* Clear the throttle flags */
433 spin_lock_irq(&port->lock);
434 was_throttled = port->throttled;
435 port->throttled = port->throttle_req = 0;
436 spin_unlock_irq(&port->lock);
437
438 if (was_throttled)
439 usb_serial_generic_submit_read_urbs(port, GFP_KERNEL);
440}
441EXPORT_SYMBOL_GPL(usb_serial_generic_unthrottle);
442
443#ifdef CONFIG_MAGIC_SYSRQ
444int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
445{
446 if (port->sysrq && port->port.console) {
447 if (ch && time_before(jiffies, port->sysrq)) {
448 handle_sysrq(ch);
449 port->sysrq = 0;
450 return 1;
451 }
452 port->sysrq = 0;
453 }
454 return 0;
455}
456#else
457int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
458{
459 return 0;
460}
461#endif
462EXPORT_SYMBOL_GPL(usb_serial_handle_sysrq_char);
463
464int usb_serial_handle_break(struct usb_serial_port *port)
465{
466 if (!port->sysrq) {
467 port->sysrq = jiffies + HZ*5;
468 return 1;
469 }
470 port->sysrq = 0;
471 return 0;
472}
473EXPORT_SYMBOL_GPL(usb_serial_handle_break);
474
475/**
476 * usb_serial_handle_dcd_change - handle a change of carrier detect state
477 * @port: usb_serial_port structure for the open port
478 * @tty: tty_struct structure for the port
479 * @status: new carrier detect status, nonzero if active
480 */
481void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port,
482 struct tty_struct *tty, unsigned int status)
483{
484 struct tty_port *port = &usb_port->port;
485
486 dev_dbg(&usb_port->dev, "%s - port %d, status %d\n", __func__,
487 usb_port->number, status);
488
489 if (status)
490 wake_up_interruptible(&port->open_wait);
491 else if (tty && !C_CLOCAL(tty))
492 tty_hangup(tty);
493}
494EXPORT_SYMBOL_GPL(usb_serial_handle_dcd_change);
495
496int usb_serial_generic_resume(struct usb_serial *serial)
497{
498 struct usb_serial_port *port;
499 int i, c = 0, r;
500
501 for (i = 0; i < serial->num_ports; i++) {
502 port = serial->port[i];
503 if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags))
504 continue;
505
506 if (port->bulk_in_size) {
507 r = usb_serial_generic_submit_read_urbs(port,
508 GFP_NOIO);
509 if (r < 0)
510 c++;
511 }
512
513 if (port->bulk_out_size) {
514 r = usb_serial_generic_write_start(port);
515 if (r < 0)
516 c++;
517 }
518 }
519
520 return c ? -EIO : 0;
521}
522EXPORT_SYMBOL_GPL(usb_serial_generic_resume);
523
524void usb_serial_generic_disconnect(struct usb_serial *serial)
525{
526 int i;
527
528 /* stop reads and writes on all ports */
529 for (i = 0; i < serial->num_ports; ++i)
530 generic_cleanup(serial->port[i]);
531}
532EXPORT_SYMBOL_GPL(usb_serial_generic_disconnect);
533
534void usb_serial_generic_release(struct usb_serial *serial)
535{
536}