Loading...
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
110 clear_bit(USB_SERIAL_THROTTLED, &port->flags);
111
112 if (port->bulk_in_size)
113 result = usb_serial_generic_submit_read_urbs(port, GFP_KERNEL);
114
115 return result;
116}
117EXPORT_SYMBOL_GPL(usb_serial_generic_open);
118
119void usb_serial_generic_close(struct usb_serial_port *port)
120{
121 unsigned long flags;
122 int i;
123
124 if (port->bulk_out_size) {
125 for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
126 usb_kill_urb(port->write_urbs[i]);
127
128 spin_lock_irqsave(&port->lock, flags);
129 kfifo_reset_out(&port->write_fifo);
130 spin_unlock_irqrestore(&port->lock, flags);
131 }
132 if (port->bulk_in_size) {
133 for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i)
134 usb_kill_urb(port->read_urbs[i]);
135 }
136}
137EXPORT_SYMBOL_GPL(usb_serial_generic_close);
138
139int usb_serial_generic_prepare_write_buffer(struct usb_serial_port *port,
140 void *dest, size_t size)
141{
142 return kfifo_out_locked(&port->write_fifo, dest, size, &port->lock);
143}
144
145/**
146 * usb_serial_generic_write_start - start writing buffered data
147 * @port: usb-serial port
148 * @mem_flags: flags to use for memory allocations
149 *
150 * Serialised using USB_SERIAL_WRITE_BUSY flag.
151 *
152 * Return: Zero on success or if busy, otherwise a negative errno value.
153 */
154int usb_serial_generic_write_start(struct usb_serial_port *port,
155 gfp_t mem_flags)
156{
157 struct urb *urb;
158 int count, result;
159 unsigned long flags;
160 int i;
161
162 if (test_and_set_bit_lock(USB_SERIAL_WRITE_BUSY, &port->flags))
163 return 0;
164retry:
165 spin_lock_irqsave(&port->lock, flags);
166 if (!port->write_urbs_free || !kfifo_len(&port->write_fifo)) {
167 clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
168 spin_unlock_irqrestore(&port->lock, flags);
169 return 0;
170 }
171 i = (int)find_first_bit(&port->write_urbs_free,
172 ARRAY_SIZE(port->write_urbs));
173 spin_unlock_irqrestore(&port->lock, flags);
174
175 urb = port->write_urbs[i];
176 count = port->serial->type->prepare_write_buffer(port,
177 urb->transfer_buffer,
178 port->bulk_out_size);
179 urb->transfer_buffer_length = count;
180 usb_serial_debug_data(&port->dev, __func__, count, urb->transfer_buffer);
181 spin_lock_irqsave(&port->lock, flags);
182 port->tx_bytes += count;
183 spin_unlock_irqrestore(&port->lock, flags);
184
185 clear_bit(i, &port->write_urbs_free);
186 result = usb_submit_urb(urb, mem_flags);
187 if (result) {
188 dev_err_console(port, "%s - error submitting urb: %d\n",
189 __func__, result);
190 set_bit(i, &port->write_urbs_free);
191 spin_lock_irqsave(&port->lock, flags);
192 port->tx_bytes -= count;
193 spin_unlock_irqrestore(&port->lock, flags);
194
195 clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
196 return result;
197 }
198
199 goto retry; /* try sending off another urb */
200}
201EXPORT_SYMBOL_GPL(usb_serial_generic_write_start);
202
203/**
204 * usb_serial_generic_write - generic write function
205 * @tty: tty for the port
206 * @port: usb-serial port
207 * @buf: data to write
208 * @count: number of bytes to write
209 *
210 * Return: The number of characters buffered, which may be anything from
211 * zero to @count, or a negative errno value.
212 */
213int usb_serial_generic_write(struct tty_struct *tty,
214 struct usb_serial_port *port, const unsigned char *buf, int count)
215{
216 int result;
217
218 if (!port->bulk_out_size)
219 return -ENODEV;
220
221 if (!count)
222 return 0;
223
224 count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
225 result = usb_serial_generic_write_start(port, GFP_ATOMIC);
226 if (result)
227 return result;
228
229 return count;
230}
231EXPORT_SYMBOL_GPL(usb_serial_generic_write);
232
233unsigned int usb_serial_generic_write_room(struct tty_struct *tty)
234{
235 struct usb_serial_port *port = tty->driver_data;
236 unsigned long flags;
237 unsigned int room;
238
239 if (!port->bulk_out_size)
240 return 0;
241
242 spin_lock_irqsave(&port->lock, flags);
243 room = kfifo_avail(&port->write_fifo);
244 spin_unlock_irqrestore(&port->lock, flags);
245
246 dev_dbg(&port->dev, "%s - returns %u\n", __func__, room);
247 return room;
248}
249
250unsigned int usb_serial_generic_chars_in_buffer(struct tty_struct *tty)
251{
252 struct usb_serial_port *port = tty->driver_data;
253 unsigned long flags;
254 unsigned int chars;
255
256 if (!port->bulk_out_size)
257 return 0;
258
259 spin_lock_irqsave(&port->lock, flags);
260 chars = kfifo_len(&port->write_fifo) + port->tx_bytes;
261 spin_unlock_irqrestore(&port->lock, flags);
262
263 dev_dbg(&port->dev, "%s - returns %u\n", __func__, chars);
264 return chars;
265}
266EXPORT_SYMBOL_GPL(usb_serial_generic_chars_in_buffer);
267
268void usb_serial_generic_wait_until_sent(struct tty_struct *tty, long timeout)
269{
270 struct usb_serial_port *port = tty->driver_data;
271 unsigned int bps;
272 unsigned long period;
273 unsigned long expire;
274
275 bps = tty_get_baud_rate(tty);
276 if (!bps)
277 bps = 9600; /* B0 */
278 /*
279 * Use a poll-period of roughly the time it takes to send one
280 * character or at least one jiffy.
281 */
282 period = max_t(unsigned long, (10 * HZ / bps), 1);
283 if (timeout)
284 period = min_t(unsigned long, period, timeout);
285
286 dev_dbg(&port->dev, "%s - timeout = %u ms, period = %u ms\n",
287 __func__, jiffies_to_msecs(timeout),
288 jiffies_to_msecs(period));
289 expire = jiffies + timeout;
290 while (!port->serial->type->tx_empty(port)) {
291 schedule_timeout_interruptible(period);
292 if (signal_pending(current))
293 break;
294 if (timeout && time_after(jiffies, expire))
295 break;
296 }
297}
298EXPORT_SYMBOL_GPL(usb_serial_generic_wait_until_sent);
299
300static int usb_serial_generic_submit_read_urb(struct usb_serial_port *port,
301 int index, gfp_t mem_flags)
302{
303 int res;
304
305 if (!test_and_clear_bit(index, &port->read_urbs_free))
306 return 0;
307
308 dev_dbg(&port->dev, "%s - urb %d\n", __func__, index);
309
310 res = usb_submit_urb(port->read_urbs[index], mem_flags);
311 if (res) {
312 if (res != -EPERM && res != -ENODEV) {
313 dev_err(&port->dev,
314 "%s - usb_submit_urb failed: %d\n",
315 __func__, res);
316 }
317 set_bit(index, &port->read_urbs_free);
318 return res;
319 }
320
321 return 0;
322}
323
324int usb_serial_generic_submit_read_urbs(struct usb_serial_port *port,
325 gfp_t mem_flags)
326{
327 int res;
328 int i;
329
330 for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {
331 res = usb_serial_generic_submit_read_urb(port, i, mem_flags);
332 if (res)
333 goto err;
334 }
335
336 return 0;
337err:
338 for (; i >= 0; --i)
339 usb_kill_urb(port->read_urbs[i]);
340
341 return res;
342}
343EXPORT_SYMBOL_GPL(usb_serial_generic_submit_read_urbs);
344
345void usb_serial_generic_process_read_urb(struct urb *urb)
346{
347 struct usb_serial_port *port = urb->context;
348 char *ch = urb->transfer_buffer;
349 int i;
350
351 if (!urb->actual_length)
352 return;
353 /*
354 * The per character mucking around with sysrq path it too slow for
355 * stuff like 3G modems, so shortcircuit it in the 99.9999999% of
356 * cases where the USB serial is not a console anyway.
357 */
358 if (port->sysrq) {
359 for (i = 0; i < urb->actual_length; i++, ch++) {
360 if (!usb_serial_handle_sysrq_char(port, *ch))
361 tty_insert_flip_char(&port->port, *ch, TTY_NORMAL);
362 }
363 } else {
364 tty_insert_flip_string(&port->port, ch, urb->actual_length);
365 }
366 tty_flip_buffer_push(&port->port);
367}
368EXPORT_SYMBOL_GPL(usb_serial_generic_process_read_urb);
369
370void usb_serial_generic_read_bulk_callback(struct urb *urb)
371{
372 struct usb_serial_port *port = urb->context;
373 unsigned char *data = urb->transfer_buffer;
374 bool stopped = false;
375 int status = urb->status;
376 int i;
377
378 for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {
379 if (urb == port->read_urbs[i])
380 break;
381 }
382
383 dev_dbg(&port->dev, "%s - urb %d, len %d\n", __func__, i,
384 urb->actual_length);
385 switch (status) {
386 case 0:
387 usb_serial_debug_data(&port->dev, __func__, urb->actual_length,
388 data);
389 port->serial->type->process_read_urb(urb);
390 break;
391 case -ENOENT:
392 case -ECONNRESET:
393 case -ESHUTDOWN:
394 dev_dbg(&port->dev, "%s - urb stopped: %d\n",
395 __func__, status);
396 stopped = true;
397 break;
398 case -EPIPE:
399 dev_err(&port->dev, "%s - urb stopped: %d\n",
400 __func__, status);
401 stopped = true;
402 break;
403 default:
404 dev_dbg(&port->dev, "%s - nonzero urb status: %d\n",
405 __func__, status);
406 break;
407 }
408
409 /*
410 * Make sure URB processing is done before marking as free to avoid
411 * racing with unthrottle() on another CPU. Matches the barriers
412 * implied by the test_and_clear_bit() in
413 * usb_serial_generic_submit_read_urb().
414 */
415 smp_mb__before_atomic();
416 set_bit(i, &port->read_urbs_free);
417 /*
418 * Make sure URB is marked as free before checking the throttled flag
419 * to avoid racing with unthrottle() on another CPU. Matches the
420 * smp_mb__after_atomic() in unthrottle().
421 */
422 smp_mb__after_atomic();
423
424 if (stopped)
425 return;
426
427 if (test_bit(USB_SERIAL_THROTTLED, &port->flags))
428 return;
429
430 usb_serial_generic_submit_read_urb(port, i, GFP_ATOMIC);
431}
432EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
433
434void usb_serial_generic_write_bulk_callback(struct urb *urb)
435{
436 unsigned long flags;
437 struct usb_serial_port *port = urb->context;
438 int status = urb->status;
439 int i;
440
441 for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i) {
442 if (port->write_urbs[i] == urb)
443 break;
444 }
445 spin_lock_irqsave(&port->lock, flags);
446 port->tx_bytes -= urb->transfer_buffer_length;
447 set_bit(i, &port->write_urbs_free);
448 spin_unlock_irqrestore(&port->lock, flags);
449
450 switch (status) {
451 case 0:
452 break;
453 case -ENOENT:
454 case -ECONNRESET:
455 case -ESHUTDOWN:
456 dev_dbg(&port->dev, "%s - urb stopped: %d\n",
457 __func__, status);
458 return;
459 case -EPIPE:
460 dev_err_console(port, "%s - urb stopped: %d\n",
461 __func__, status);
462 return;
463 default:
464 dev_err_console(port, "%s - nonzero urb status: %d\n",
465 __func__, status);
466 break;
467 }
468
469 usb_serial_generic_write_start(port, GFP_ATOMIC);
470 usb_serial_port_softint(port);
471}
472EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
473
474void usb_serial_generic_throttle(struct tty_struct *tty)
475{
476 struct usb_serial_port *port = tty->driver_data;
477
478 set_bit(USB_SERIAL_THROTTLED, &port->flags);
479}
480EXPORT_SYMBOL_GPL(usb_serial_generic_throttle);
481
482void usb_serial_generic_unthrottle(struct tty_struct *tty)
483{
484 struct usb_serial_port *port = tty->driver_data;
485
486 clear_bit(USB_SERIAL_THROTTLED, &port->flags);
487
488 /*
489 * Matches the smp_mb__after_atomic() in
490 * usb_serial_generic_read_bulk_callback().
491 */
492 smp_mb__after_atomic();
493
494 usb_serial_generic_submit_read_urbs(port, GFP_KERNEL);
495}
496EXPORT_SYMBOL_GPL(usb_serial_generic_unthrottle);
497
498static bool usb_serial_generic_msr_changed(struct tty_struct *tty,
499 unsigned long arg, struct async_icount *cprev)
500{
501 struct usb_serial_port *port = tty->driver_data;
502 struct async_icount cnow;
503 unsigned long flags;
504 bool ret;
505
506 /*
507 * Use tty-port initialised flag to detect all hangups including the
508 * one generated at USB-device disconnect.
509 */
510 if (!tty_port_initialized(&port->port))
511 return true;
512
513 spin_lock_irqsave(&port->lock, flags);
514 cnow = port->icount; /* atomic copy*/
515 spin_unlock_irqrestore(&port->lock, flags);
516
517 ret = ((arg & TIOCM_RNG) && (cnow.rng != cprev->rng)) ||
518 ((arg & TIOCM_DSR) && (cnow.dsr != cprev->dsr)) ||
519 ((arg & TIOCM_CD) && (cnow.dcd != cprev->dcd)) ||
520 ((arg & TIOCM_CTS) && (cnow.cts != cprev->cts));
521
522 *cprev = cnow;
523
524 return ret;
525}
526
527int usb_serial_generic_tiocmiwait(struct tty_struct *tty, unsigned long arg)
528{
529 struct usb_serial_port *port = tty->driver_data;
530 struct async_icount cnow;
531 unsigned long flags;
532 int ret;
533
534 spin_lock_irqsave(&port->lock, flags);
535 cnow = port->icount; /* atomic copy */
536 spin_unlock_irqrestore(&port->lock, flags);
537
538 ret = wait_event_interruptible(port->port.delta_msr_wait,
539 usb_serial_generic_msr_changed(tty, arg, &cnow));
540 if (!ret && !tty_port_initialized(&port->port))
541 ret = -EIO;
542
543 return ret;
544}
545EXPORT_SYMBOL_GPL(usb_serial_generic_tiocmiwait);
546
547int usb_serial_generic_get_icount(struct tty_struct *tty,
548 struct serial_icounter_struct *icount)
549{
550 struct usb_serial_port *port = tty->driver_data;
551 struct async_icount cnow;
552 unsigned long flags;
553
554 spin_lock_irqsave(&port->lock, flags);
555 cnow = port->icount; /* atomic copy */
556 spin_unlock_irqrestore(&port->lock, flags);
557
558 icount->cts = cnow.cts;
559 icount->dsr = cnow.dsr;
560 icount->rng = cnow.rng;
561 icount->dcd = cnow.dcd;
562 icount->tx = cnow.tx;
563 icount->rx = cnow.rx;
564 icount->frame = cnow.frame;
565 icount->parity = cnow.parity;
566 icount->overrun = cnow.overrun;
567 icount->brk = cnow.brk;
568 icount->buf_overrun = cnow.buf_overrun;
569
570 return 0;
571}
572EXPORT_SYMBOL_GPL(usb_serial_generic_get_icount);
573
574#if defined(CONFIG_USB_SERIAL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
575int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
576{
577 if (port->sysrq) {
578 if (ch && time_before(jiffies, port->sysrq)) {
579 handle_sysrq(ch);
580 port->sysrq = 0;
581 return 1;
582 }
583 port->sysrq = 0;
584 }
585 return 0;
586}
587EXPORT_SYMBOL_GPL(usb_serial_handle_sysrq_char);
588
589int usb_serial_handle_break(struct usb_serial_port *port)
590{
591 if (!port->port.console)
592 return 0;
593
594 if (!port->sysrq) {
595 port->sysrq = jiffies + HZ*5;
596 return 1;
597 }
598 port->sysrq = 0;
599 return 0;
600}
601EXPORT_SYMBOL_GPL(usb_serial_handle_break);
602#endif
603
604/**
605 * usb_serial_handle_dcd_change - handle a change of carrier detect state
606 * @port: usb-serial port
607 * @tty: tty for the port
608 * @status: new carrier detect status, nonzero if active
609 */
610void usb_serial_handle_dcd_change(struct usb_serial_port *port,
611 struct tty_struct *tty, unsigned int status)
612{
613 dev_dbg(&port->dev, "%s - status %d\n", __func__, status);
614
615 if (tty) {
616 struct tty_ldisc *ld = tty_ldisc_ref(tty);
617
618 if (ld) {
619 if (ld->ops->dcd_change)
620 ld->ops->dcd_change(tty, status);
621 tty_ldisc_deref(ld);
622 }
623 }
624
625 if (status)
626 wake_up_interruptible(&port->port.open_wait);
627 else if (tty && !C_CLOCAL(tty))
628 tty_hangup(tty);
629}
630EXPORT_SYMBOL_GPL(usb_serial_handle_dcd_change);
631
632int usb_serial_generic_resume(struct usb_serial *serial)
633{
634 struct usb_serial_port *port;
635 int i, c = 0, r;
636
637 for (i = 0; i < serial->num_ports; i++) {
638 port = serial->port[i];
639 if (!tty_port_initialized(&port->port))
640 continue;
641
642 if (port->bulk_in_size) {
643 r = usb_serial_generic_submit_read_urbs(port,
644 GFP_NOIO);
645 if (r < 0)
646 c++;
647 }
648
649 if (port->bulk_out_size) {
650 r = usb_serial_generic_write_start(port, GFP_NOIO);
651 if (r < 0)
652 c++;
653 }
654 }
655
656 return c ? -EIO : 0;
657}
658EXPORT_SYMBOL_GPL(usb_serial_generic_resume);