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