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