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