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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 if (timeout)
262 period = min_t(unsigned long, period, timeout);
263
264 dev_dbg(&port->dev, "%s - timeout = %u ms, period = %u ms\n",
265 __func__, jiffies_to_msecs(timeout),
266 jiffies_to_msecs(period));
267 expire = jiffies + timeout;
268 while (!port->serial->type->tx_empty(port)) {
269 schedule_timeout_interruptible(period);
270 if (signal_pending(current))
271 break;
272 if (timeout && time_after(jiffies, expire))
273 break;
274 }
275}
276EXPORT_SYMBOL_GPL(usb_serial_generic_wait_until_sent);
277
278static int usb_serial_generic_submit_read_urb(struct usb_serial_port *port,
279 int index, gfp_t mem_flags)
280{
281 int res;
282
283 if (!test_and_clear_bit(index, &port->read_urbs_free))
284 return 0;
285
286 dev_dbg(&port->dev, "%s - urb %d\n", __func__, index);
287
288 res = usb_submit_urb(port->read_urbs[index], mem_flags);
289 if (res) {
290 if (res != -EPERM && res != -ENODEV) {
291 dev_err(&port->dev,
292 "%s - usb_submit_urb failed: %d\n",
293 __func__, res);
294 }
295 set_bit(index, &port->read_urbs_free);
296 return res;
297 }
298
299 return 0;
300}
301
302int usb_serial_generic_submit_read_urbs(struct usb_serial_port *port,
303 gfp_t mem_flags)
304{
305 int res;
306 int i;
307
308 for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {
309 res = usb_serial_generic_submit_read_urb(port, i, mem_flags);
310 if (res)
311 goto err;
312 }
313
314 return 0;
315err:
316 for (; i >= 0; --i)
317 usb_kill_urb(port->read_urbs[i]);
318
319 return res;
320}
321EXPORT_SYMBOL_GPL(usb_serial_generic_submit_read_urbs);
322
323void usb_serial_generic_process_read_urb(struct urb *urb)
324{
325 struct usb_serial_port *port = urb->context;
326 char *ch = (char *)urb->transfer_buffer;
327 int i;
328
329 if (!urb->actual_length)
330 return;
331 /*
332 * The per character mucking around with sysrq path it too slow for
333 * stuff like 3G modems, so shortcircuit it in the 99.9999999% of
334 * cases where the USB serial is not a console anyway.
335 */
336 if (!port->port.console || !port->sysrq) {
337 tty_insert_flip_string(&port->port, ch, urb->actual_length);
338 } else {
339 for (i = 0; i < urb->actual_length; i++, ch++) {
340 if (!usb_serial_handle_sysrq_char(port, *ch))
341 tty_insert_flip_char(&port->port, *ch, TTY_NORMAL);
342 }
343 }
344 tty_flip_buffer_push(&port->port);
345}
346EXPORT_SYMBOL_GPL(usb_serial_generic_process_read_urb);
347
348void usb_serial_generic_read_bulk_callback(struct urb *urb)
349{
350 struct usb_serial_port *port = urb->context;
351 unsigned char *data = urb->transfer_buffer;
352 unsigned long flags;
353 int i;
354
355 for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {
356 if (urb == port->read_urbs[i])
357 break;
358 }
359 set_bit(i, &port->read_urbs_free);
360
361 dev_dbg(&port->dev, "%s - urb %d, len %d\n", __func__, i,
362 urb->actual_length);
363 switch (urb->status) {
364 case 0:
365 break;
366 case -ENOENT:
367 case -ECONNRESET:
368 case -ESHUTDOWN:
369 dev_dbg(&port->dev, "%s - urb stopped: %d\n",
370 __func__, urb->status);
371 return;
372 case -EPIPE:
373 dev_err(&port->dev, "%s - urb stopped: %d\n",
374 __func__, urb->status);
375 return;
376 default:
377 dev_dbg(&port->dev, "%s - nonzero urb status: %d\n",
378 __func__, urb->status);
379 goto resubmit;
380 }
381
382 usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
383 port->serial->type->process_read_urb(urb);
384
385resubmit:
386 /* Throttle the device if requested by tty */
387 spin_lock_irqsave(&port->lock, flags);
388 port->throttled = port->throttle_req;
389 if (!port->throttled) {
390 spin_unlock_irqrestore(&port->lock, flags);
391 usb_serial_generic_submit_read_urb(port, i, GFP_ATOMIC);
392 } else {
393 spin_unlock_irqrestore(&port->lock, flags);
394 }
395}
396EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
397
398void usb_serial_generic_write_bulk_callback(struct urb *urb)
399{
400 unsigned long flags;
401 struct usb_serial_port *port = urb->context;
402 int i;
403
404 for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i) {
405 if (port->write_urbs[i] == urb)
406 break;
407 }
408 spin_lock_irqsave(&port->lock, flags);
409 port->tx_bytes -= urb->transfer_buffer_length;
410 set_bit(i, &port->write_urbs_free);
411 spin_unlock_irqrestore(&port->lock, flags);
412
413 switch (urb->status) {
414 case 0:
415 break;
416 case -ENOENT:
417 case -ECONNRESET:
418 case -ESHUTDOWN:
419 dev_dbg(&port->dev, "%s - urb stopped: %d\n",
420 __func__, urb->status);
421 return;
422 case -EPIPE:
423 dev_err_console(port, "%s - urb stopped: %d\n",
424 __func__, urb->status);
425 return;
426 default:
427 dev_err_console(port, "%s - nonzero urb status: %d\n",
428 __func__, urb->status);
429 goto resubmit;
430 }
431
432resubmit:
433 usb_serial_generic_write_start(port, GFP_ATOMIC);
434 usb_serial_port_softint(port);
435}
436EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
437
438void usb_serial_generic_throttle(struct tty_struct *tty)
439{
440 struct usb_serial_port *port = tty->driver_data;
441 unsigned long flags;
442
443 spin_lock_irqsave(&port->lock, flags);
444 port->throttle_req = 1;
445 spin_unlock_irqrestore(&port->lock, flags);
446}
447EXPORT_SYMBOL_GPL(usb_serial_generic_throttle);
448
449void usb_serial_generic_unthrottle(struct tty_struct *tty)
450{
451 struct usb_serial_port *port = tty->driver_data;
452 int was_throttled;
453
454 spin_lock_irq(&port->lock);
455 was_throttled = port->throttled;
456 port->throttled = port->throttle_req = 0;
457 spin_unlock_irq(&port->lock);
458
459 if (was_throttled)
460 usb_serial_generic_submit_read_urbs(port, GFP_KERNEL);
461}
462EXPORT_SYMBOL_GPL(usb_serial_generic_unthrottle);
463
464static bool usb_serial_generic_msr_changed(struct tty_struct *tty,
465 unsigned long arg, struct async_icount *cprev)
466{
467 struct usb_serial_port *port = tty->driver_data;
468 struct async_icount cnow;
469 unsigned long flags;
470 bool ret;
471
472 /*
473 * Use tty-port initialised flag to detect all hangups including the
474 * one generated at USB-device disconnect.
475 */
476 if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags))
477 return true;
478
479 spin_lock_irqsave(&port->lock, flags);
480 cnow = port->icount; /* atomic copy*/
481 spin_unlock_irqrestore(&port->lock, flags);
482
483 ret = ((arg & TIOCM_RNG) && (cnow.rng != cprev->rng)) ||
484 ((arg & TIOCM_DSR) && (cnow.dsr != cprev->dsr)) ||
485 ((arg & TIOCM_CD) && (cnow.dcd != cprev->dcd)) ||
486 ((arg & TIOCM_CTS) && (cnow.cts != cprev->cts));
487
488 *cprev = cnow;
489
490 return ret;
491}
492
493int usb_serial_generic_tiocmiwait(struct tty_struct *tty, unsigned long arg)
494{
495 struct usb_serial_port *port = tty->driver_data;
496 struct async_icount cnow;
497 unsigned long flags;
498 int ret;
499
500 spin_lock_irqsave(&port->lock, flags);
501 cnow = port->icount; /* atomic copy */
502 spin_unlock_irqrestore(&port->lock, flags);
503
504 ret = wait_event_interruptible(port->port.delta_msr_wait,
505 usb_serial_generic_msr_changed(tty, arg, &cnow));
506 if (!ret && !test_bit(ASYNCB_INITIALIZED, &port->port.flags))
507 ret = -EIO;
508
509 return ret;
510}
511EXPORT_SYMBOL_GPL(usb_serial_generic_tiocmiwait);
512
513int usb_serial_generic_get_icount(struct tty_struct *tty,
514 struct serial_icounter_struct *icount)
515{
516 struct usb_serial_port *port = tty->driver_data;
517 struct async_icount cnow;
518 unsigned long flags;
519
520 spin_lock_irqsave(&port->lock, flags);
521 cnow = port->icount; /* atomic copy */
522 spin_unlock_irqrestore(&port->lock, flags);
523
524 icount->cts = cnow.cts;
525 icount->dsr = cnow.dsr;
526 icount->rng = cnow.rng;
527 icount->dcd = cnow.dcd;
528 icount->tx = cnow.tx;
529 icount->rx = cnow.rx;
530 icount->frame = cnow.frame;
531 icount->parity = cnow.parity;
532 icount->overrun = cnow.overrun;
533 icount->brk = cnow.brk;
534 icount->buf_overrun = cnow.buf_overrun;
535
536 return 0;
537}
538EXPORT_SYMBOL_GPL(usb_serial_generic_get_icount);
539
540#ifdef CONFIG_MAGIC_SYSRQ
541int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
542{
543 if (port->sysrq && port->port.console) {
544 if (ch && time_before(jiffies, port->sysrq)) {
545 handle_sysrq(ch);
546 port->sysrq = 0;
547 return 1;
548 }
549 port->sysrq = 0;
550 }
551 return 0;
552}
553#else
554int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
555{
556 return 0;
557}
558#endif
559EXPORT_SYMBOL_GPL(usb_serial_handle_sysrq_char);
560
561int usb_serial_handle_break(struct usb_serial_port *port)
562{
563 if (!port->sysrq) {
564 port->sysrq = jiffies + HZ*5;
565 return 1;
566 }
567 port->sysrq = 0;
568 return 0;
569}
570EXPORT_SYMBOL_GPL(usb_serial_handle_break);
571
572/**
573 * usb_serial_handle_dcd_change - handle a change of carrier detect state
574 * @port: usb-serial port
575 * @tty: tty for the port
576 * @status: new carrier detect status, nonzero if active
577 */
578void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port,
579 struct tty_struct *tty, unsigned int status)
580{
581 struct tty_port *port = &usb_port->port;
582
583 dev_dbg(&usb_port->dev, "%s - status %d\n", __func__, status);
584
585 if (tty) {
586 struct tty_ldisc *ld = tty_ldisc_ref(tty);
587
588 if (ld) {
589 if (ld->ops->dcd_change)
590 ld->ops->dcd_change(tty, status);
591 tty_ldisc_deref(ld);
592 }
593 }
594
595 if (status)
596 wake_up_interruptible(&port->open_wait);
597 else if (tty && !C_CLOCAL(tty))
598 tty_hangup(tty);
599}
600EXPORT_SYMBOL_GPL(usb_serial_handle_dcd_change);
601
602int usb_serial_generic_resume(struct usb_serial *serial)
603{
604 struct usb_serial_port *port;
605 int i, c = 0, r;
606
607 for (i = 0; i < serial->num_ports; i++) {
608 port = serial->port[i];
609 if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags))
610 continue;
611
612 if (port->bulk_in_size) {
613 r = usb_serial_generic_submit_read_urbs(port,
614 GFP_NOIO);
615 if (r < 0)
616 c++;
617 }
618
619 if (port->bulk_out_size) {
620 r = usb_serial_generic_write_start(port, GFP_NOIO);
621 if (r < 0)
622 c++;
623 }
624 }
625
626 return c ? -EIO : 0;
627}
628EXPORT_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);