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1/*
2 * USB Serial Converter Generic functions
3 *
4 * Copyright (C) 2010 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 int generic_probe(struct usb_interface *interface,
32 const struct usb_device_id *id);
33
34static __u16 vendor = 0x05f9;
35static __u16 product = 0xffff;
36
37module_param(vendor, ushort, 0);
38MODULE_PARM_DESC(vendor, "User specified USB idVendor");
39
40module_param(product, ushort, 0);
41MODULE_PARM_DESC(product, "User specified USB idProduct");
42
43static struct usb_device_id generic_device_ids[2]; /* Initially all zeroes. */
44
45/* we want to look at all devices, as the vendor/product id can change
46 * depending on the command line argument */
47static const struct usb_device_id generic_serial_ids[] = {
48 {.driver_info = 42},
49 {}
50};
51
52static struct usb_driver generic_driver = {
53 .name = "usbserial_generic",
54 .probe = generic_probe,
55 .disconnect = usb_serial_disconnect,
56 .id_table = generic_serial_ids,
57 .no_dynamic_id = 1,
58};
59
60/* All of the device info needed for the Generic Serial Converter */
61struct usb_serial_driver usb_serial_generic_device = {
62 .driver = {
63 .owner = THIS_MODULE,
64 .name = "generic",
65 },
66 .id_table = generic_device_ids,
67 .usb_driver = &generic_driver,
68 .num_ports = 1,
69 .disconnect = usb_serial_generic_disconnect,
70 .release = usb_serial_generic_release,
71 .throttle = usb_serial_generic_throttle,
72 .unthrottle = usb_serial_generic_unthrottle,
73 .resume = usb_serial_generic_resume,
74};
75
76static int generic_probe(struct usb_interface *interface,
77 const struct usb_device_id *id)
78{
79 const struct usb_device_id *id_pattern;
80
81 id_pattern = usb_match_id(interface, generic_device_ids);
82 if (id_pattern != NULL)
83 return usb_serial_probe(interface, id);
84 return -ENODEV;
85}
86#endif
87
88int usb_serial_generic_register(int _debug)
89{
90 int retval = 0;
91
92 debug = _debug;
93#ifdef CONFIG_USB_SERIAL_GENERIC
94 generic_device_ids[0].idVendor = vendor;
95 generic_device_ids[0].idProduct = product;
96 generic_device_ids[0].match_flags =
97 USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT;
98
99 /* register our generic driver with ourselves */
100 retval = usb_serial_register(&usb_serial_generic_device);
101 if (retval)
102 goto exit;
103 retval = usb_register(&generic_driver);
104 if (retval)
105 usb_serial_deregister(&usb_serial_generic_device);
106exit:
107#endif
108 return retval;
109}
110
111void usb_serial_generic_deregister(void)
112{
113#ifdef CONFIG_USB_SERIAL_GENERIC
114 /* remove our generic driver */
115 usb_deregister(&generic_driver);
116 usb_serial_deregister(&usb_serial_generic_device);
117#endif
118}
119
120int usb_serial_generic_open(struct tty_struct *tty, struct usb_serial_port *port)
121{
122 int result = 0;
123 unsigned long flags;
124
125 dbg("%s - port %d", __func__, port->number);
126
127 /* clear the throttle flags */
128 spin_lock_irqsave(&port->lock, flags);
129 port->throttled = 0;
130 port->throttle_req = 0;
131 spin_unlock_irqrestore(&port->lock, flags);
132
133 /* if we have a bulk endpoint, start reading from it */
134 if (port->bulk_in_size)
135 result = usb_serial_generic_submit_read_urb(port, GFP_KERNEL);
136
137 return result;
138}
139EXPORT_SYMBOL_GPL(usb_serial_generic_open);
140
141static void generic_cleanup(struct usb_serial_port *port)
142{
143 struct usb_serial *serial = port->serial;
144 unsigned long flags;
145 int i;
146
147 dbg("%s - port %d", __func__, port->number);
148
149 if (serial->dev) {
150 /* shutdown any bulk transfers that might be going on */
151 if (port->bulk_out_size) {
152 usb_kill_urb(port->write_urb);
153 for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
154 usb_kill_urb(port->write_urbs[i]);
155
156 spin_lock_irqsave(&port->lock, flags);
157 kfifo_reset_out(&port->write_fifo);
158 spin_unlock_irqrestore(&port->lock, flags);
159 }
160 if (port->bulk_in_size)
161 usb_kill_urb(port->read_urb);
162 }
163}
164
165void usb_serial_generic_close(struct usb_serial_port *port)
166{
167 dbg("%s - port %d", __func__, port->number);
168 generic_cleanup(port);
169}
170EXPORT_SYMBOL_GPL(usb_serial_generic_close);
171
172int usb_serial_generic_prepare_write_buffer(struct usb_serial_port *port,
173 void *dest, size_t size)
174{
175 return kfifo_out_locked(&port->write_fifo, dest, size, &port->lock);
176}
177
178/**
179 * usb_serial_generic_write_start - kick off an URB write
180 * @port: Pointer to the &struct usb_serial_port data
181 *
182 * Returns zero on success, or a negative errno value
183 */
184static int usb_serial_generic_write_start(struct usb_serial_port *port)
185{
186 struct urb *urb;
187 int count, result;
188 unsigned long flags;
189 int i;
190
191 if (test_and_set_bit_lock(USB_SERIAL_WRITE_BUSY, &port->flags))
192 return 0;
193retry:
194 spin_lock_irqsave(&port->lock, flags);
195 if (!port->write_urbs_free || !kfifo_len(&port->write_fifo)) {
196 clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
197 spin_unlock_irqrestore(&port->lock, flags);
198 return 0;
199 }
200 i = (int)find_first_bit(&port->write_urbs_free,
201 ARRAY_SIZE(port->write_urbs));
202 spin_unlock_irqrestore(&port->lock, flags);
203
204 urb = port->write_urbs[i];
205 count = port->serial->type->prepare_write_buffer(port,
206 urb->transfer_buffer,
207 port->bulk_out_size);
208 urb->transfer_buffer_length = count;
209 usb_serial_debug_data(debug, &port->dev, __func__, count,
210 urb->transfer_buffer);
211 spin_lock_irqsave(&port->lock, flags);
212 port->tx_bytes += count;
213 spin_unlock_irqrestore(&port->lock, flags);
214
215 clear_bit(i, &port->write_urbs_free);
216 result = usb_submit_urb(urb, GFP_ATOMIC);
217 if (result) {
218 dev_err(&port->dev, "%s - error submitting urb: %d\n",
219 __func__, result);
220 set_bit(i, &port->write_urbs_free);
221 spin_lock_irqsave(&port->lock, flags);
222 port->tx_bytes -= count;
223 spin_unlock_irqrestore(&port->lock, flags);
224
225 clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
226 return result;
227 }
228
229 /* Try sending off another urb, unless in irq context (in which case
230 * there will be no free urb). */
231 if (!in_irq())
232 goto retry;
233
234 clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
235
236 return 0;
237}
238
239/**
240 * usb_serial_generic_write - generic write function for serial USB devices
241 * @tty: Pointer to &struct tty_struct for the device
242 * @port: Pointer to the &usb_serial_port structure for the device
243 * @buf: Pointer to the data to write
244 * @count: Number of bytes to write
245 *
246 * Returns the number of characters actually written, which may be anything
247 * from zero to @count. If an error occurs, it returns the negative errno
248 * value.
249 */
250int usb_serial_generic_write(struct tty_struct *tty,
251 struct usb_serial_port *port, const unsigned char *buf, int count)
252{
253 int result;
254
255 dbg("%s - port %d", __func__, port->number);
256
257 /* only do something if we have a bulk out endpoint */
258 if (!port->bulk_out_size)
259 return -ENODEV;
260
261 if (!count)
262 return 0;
263
264 count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
265 result = usb_serial_generic_write_start(port);
266 if (result)
267 return result;
268
269 return count;
270}
271EXPORT_SYMBOL_GPL(usb_serial_generic_write);
272
273int usb_serial_generic_write_room(struct tty_struct *tty)
274{
275 struct usb_serial_port *port = tty->driver_data;
276 unsigned long flags;
277 int room;
278
279 dbg("%s - port %d", __func__, port->number);
280
281 if (!port->bulk_out_size)
282 return 0;
283
284 spin_lock_irqsave(&port->lock, flags);
285 room = kfifo_avail(&port->write_fifo);
286 spin_unlock_irqrestore(&port->lock, flags);
287
288 dbg("%s - returns %d", __func__, room);
289 return room;
290}
291
292int usb_serial_generic_chars_in_buffer(struct tty_struct *tty)
293{
294 struct usb_serial_port *port = tty->driver_data;
295 unsigned long flags;
296 int chars;
297
298 dbg("%s - port %d", __func__, port->number);
299
300 if (!port->bulk_out_size)
301 return 0;
302
303 spin_lock_irqsave(&port->lock, flags);
304 chars = kfifo_len(&port->write_fifo) + port->tx_bytes;
305 spin_unlock_irqrestore(&port->lock, flags);
306
307 dbg("%s - returns %d", __func__, chars);
308 return chars;
309}
310
311int usb_serial_generic_submit_read_urb(struct usb_serial_port *port,
312 gfp_t mem_flags)
313{
314 int result;
315
316 result = usb_submit_urb(port->read_urb, mem_flags);
317 if (result && result != -EPERM) {
318 dev_err(&port->dev, "%s - error submitting urb: %d\n",
319 __func__, result);
320 }
321 return result;
322}
323EXPORT_SYMBOL_GPL(usb_serial_generic_submit_read_urb);
324
325void usb_serial_generic_process_read_urb(struct urb *urb)
326{
327 struct usb_serial_port *port = urb->context;
328 struct tty_struct *tty;
329 char *ch = (char *)urb->transfer_buffer;
330 int i;
331
332 if (!urb->actual_length)
333 return;
334
335 tty = tty_port_tty_get(&port->port);
336 if (!tty)
337 return;
338
339 /* The per character mucking around with sysrq path it too slow for
340 stuff like 3G modems, so shortcircuit it in the 99.9999999% of cases
341 where the USB serial is not a console anyway */
342 if (!port->port.console || !port->sysrq)
343 tty_insert_flip_string(tty, ch, urb->actual_length);
344 else {
345 for (i = 0; i < urb->actual_length; i++, ch++) {
346 if (!usb_serial_handle_sysrq_char(port, *ch))
347 tty_insert_flip_char(tty, *ch, TTY_NORMAL);
348 }
349 }
350 tty_flip_buffer_push(tty);
351 tty_kref_put(tty);
352}
353EXPORT_SYMBOL_GPL(usb_serial_generic_process_read_urb);
354
355void usb_serial_generic_read_bulk_callback(struct urb *urb)
356{
357 struct usb_serial_port *port = urb->context;
358 unsigned char *data = urb->transfer_buffer;
359 int status = urb->status;
360 unsigned long flags;
361
362 dbg("%s - port %d", __func__, port->number);
363
364 if (unlikely(status != 0)) {
365 dbg("%s - nonzero read bulk status received: %d",
366 __func__, status);
367 return;
368 }
369
370 usb_serial_debug_data(debug, &port->dev, __func__,
371 urb->actual_length, data);
372 port->serial->type->process_read_urb(urb);
373
374 /* Throttle the device if requested by tty */
375 spin_lock_irqsave(&port->lock, flags);
376 port->throttled = port->throttle_req;
377 if (!port->throttled) {
378 spin_unlock_irqrestore(&port->lock, flags);
379 usb_serial_generic_submit_read_urb(port, GFP_ATOMIC);
380 } else
381 spin_unlock_irqrestore(&port->lock, flags);
382}
383EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
384
385void usb_serial_generic_write_bulk_callback(struct urb *urb)
386{
387 unsigned long flags;
388 struct usb_serial_port *port = urb->context;
389 int status = urb->status;
390 int i;
391
392 dbg("%s - port %d", __func__, port->number);
393
394 for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
395 if (port->write_urbs[i] == urb)
396 break;
397
398 spin_lock_irqsave(&port->lock, flags);
399 port->tx_bytes -= urb->transfer_buffer_length;
400 set_bit(i, &port->write_urbs_free);
401 spin_unlock_irqrestore(&port->lock, flags);
402
403 if (status) {
404 dbg("%s - non-zero urb status: %d", __func__, status);
405
406 spin_lock_irqsave(&port->lock, flags);
407 kfifo_reset_out(&port->write_fifo);
408 spin_unlock_irqrestore(&port->lock, flags);
409 } else {
410 usb_serial_generic_write_start(port);
411 }
412
413 usb_serial_port_softint(port);
414}
415EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
416
417void usb_serial_generic_throttle(struct tty_struct *tty)
418{
419 struct usb_serial_port *port = tty->driver_data;
420 unsigned long flags;
421
422 dbg("%s - port %d", __func__, port->number);
423
424 /* Set the throttle request flag. It will be picked up
425 * by usb_serial_generic_read_bulk_callback(). */
426 spin_lock_irqsave(&port->lock, flags);
427 port->throttle_req = 1;
428 spin_unlock_irqrestore(&port->lock, flags);
429}
430EXPORT_SYMBOL_GPL(usb_serial_generic_throttle);
431
432void usb_serial_generic_unthrottle(struct tty_struct *tty)
433{
434 struct usb_serial_port *port = tty->driver_data;
435 int was_throttled;
436
437 dbg("%s - port %d", __func__, port->number);
438
439 /* Clear the throttle flags */
440 spin_lock_irq(&port->lock);
441 was_throttled = port->throttled;
442 port->throttled = port->throttle_req = 0;
443 spin_unlock_irq(&port->lock);
444
445 if (was_throttled)
446 usb_serial_generic_submit_read_urb(port, GFP_KERNEL);
447}
448EXPORT_SYMBOL_GPL(usb_serial_generic_unthrottle);
449
450#ifdef CONFIG_MAGIC_SYSRQ
451int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
452{
453 if (port->sysrq && port->port.console) {
454 if (ch && time_before(jiffies, port->sysrq)) {
455 handle_sysrq(ch);
456 port->sysrq = 0;
457 return 1;
458 }
459 port->sysrq = 0;
460 }
461 return 0;
462}
463#else
464int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
465{
466 return 0;
467}
468#endif
469EXPORT_SYMBOL_GPL(usb_serial_handle_sysrq_char);
470
471int usb_serial_handle_break(struct usb_serial_port *port)
472{
473 if (!port->sysrq) {
474 port->sysrq = jiffies + HZ*5;
475 return 1;
476 }
477 port->sysrq = 0;
478 return 0;
479}
480EXPORT_SYMBOL_GPL(usb_serial_handle_break);
481
482/**
483 * usb_serial_handle_dcd_change - handle a change of carrier detect state
484 * @port: usb_serial_port structure for the open port
485 * @tty: tty_struct structure for the port
486 * @status: new carrier detect status, nonzero if active
487 */
488void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port,
489 struct tty_struct *tty, unsigned int status)
490{
491 struct tty_port *port = &usb_port->port;
492
493 dbg("%s - port %d, status %d", __func__, usb_port->number, status);
494
495 if (status)
496 wake_up_interruptible(&port->open_wait);
497 else if (tty && !C_CLOCAL(tty))
498 tty_hangup(tty);
499}
500EXPORT_SYMBOL_GPL(usb_serial_handle_dcd_change);
501
502int usb_serial_generic_resume(struct usb_serial *serial)
503{
504 struct usb_serial_port *port;
505 int i, c = 0, r;
506
507 for (i = 0; i < serial->num_ports; i++) {
508 port = serial->port[i];
509 if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags))
510 continue;
511
512 if (port->read_urb) {
513 r = usb_submit_urb(port->read_urb, GFP_NOIO);
514 if (r < 0)
515 c++;
516 }
517
518 if (port->bulk_out_size) {
519 r = usb_serial_generic_write_start(port);
520 if (r < 0)
521 c++;
522 }
523 }
524
525 return c ? -EIO : 0;
526}
527EXPORT_SYMBOL_GPL(usb_serial_generic_resume);
528
529void usb_serial_generic_disconnect(struct usb_serial *serial)
530{
531 int i;
532
533 dbg("%s", __func__);
534
535 /* stop reads and writes on all ports */
536 for (i = 0; i < serial->num_ports; ++i)
537 generic_cleanup(serial->port[i]);
538}
539EXPORT_SYMBOL_GPL(usb_serial_generic_disconnect);
540
541void usb_serial_generic_release(struct usb_serial *serial)
542{
543 dbg("%s", __func__);
544}
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}