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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 - 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}