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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 period = min_t(unsigned long, period, timeout);
262
263 dev_dbg(&port->dev, "%s - timeout = %u ms, period = %u ms\n",
264 __func__, jiffies_to_msecs(timeout),
265 jiffies_to_msecs(period));
266 expire = jiffies + timeout;
267 while (!port->serial->type->tx_empty(port)) {
268 schedule_timeout_interruptible(period);
269 if (signal_pending(current))
270 break;
271 if (time_after(jiffies, expire))
272 break;
273 }
274}
275EXPORT_SYMBOL_GPL(usb_serial_generic_wait_until_sent);
276
277static int usb_serial_generic_submit_read_urb(struct usb_serial_port *port,
278 int index, gfp_t mem_flags)
279{
280 int res;
281
282 if (!test_and_clear_bit(index, &port->read_urbs_free))
283 return 0;
284
285 dev_dbg(&port->dev, "%s - urb %d\n", __func__, index);
286
287 res = usb_submit_urb(port->read_urbs[index], mem_flags);
288 if (res) {
289 if (res != -EPERM) {
290 dev_err(&port->dev,
291 "%s - usb_submit_urb failed: %d\n",
292 __func__, res);
293 }
294 set_bit(index, &port->read_urbs_free);
295 return res;
296 }
297
298 return 0;
299}
300
301int usb_serial_generic_submit_read_urbs(struct usb_serial_port *port,
302 gfp_t mem_flags)
303{
304 int res;
305 int i;
306
307 for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {
308 res = usb_serial_generic_submit_read_urb(port, i, mem_flags);
309 if (res)
310 goto err;
311 }
312
313 return 0;
314err:
315 for (; i >= 0; --i)
316 usb_kill_urb(port->read_urbs[i]);
317
318 return res;
319}
320EXPORT_SYMBOL_GPL(usb_serial_generic_submit_read_urbs);
321
322void usb_serial_generic_process_read_urb(struct urb *urb)
323{
324 struct usb_serial_port *port = urb->context;
325 char *ch = (char *)urb->transfer_buffer;
326 int i;
327
328 if (!urb->actual_length)
329 return;
330 /*
331 * The per character mucking around with sysrq path it too slow for
332 * stuff like 3G modems, so shortcircuit it in the 99.9999999% of
333 * cases where the USB serial is not a console anyway.
334 */
335 if (!port->port.console || !port->sysrq) {
336 tty_insert_flip_string(&port->port, ch, urb->actual_length);
337 } else {
338 for (i = 0; i < urb->actual_length; i++, ch++) {
339 if (!usb_serial_handle_sysrq_char(port, *ch))
340 tty_insert_flip_char(&port->port, *ch, TTY_NORMAL);
341 }
342 }
343 tty_flip_buffer_push(&port->port);
344}
345EXPORT_SYMBOL_GPL(usb_serial_generic_process_read_urb);
346
347void usb_serial_generic_read_bulk_callback(struct urb *urb)
348{
349 struct usb_serial_port *port = urb->context;
350 unsigned char *data = urb->transfer_buffer;
351 unsigned long flags;
352 int i;
353
354 for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {
355 if (urb == port->read_urbs[i])
356 break;
357 }
358 set_bit(i, &port->read_urbs_free);
359
360 dev_dbg(&port->dev, "%s - urb %d, len %d\n", __func__, i,
361 urb->actual_length);
362 switch (urb->status) {
363 case 0:
364 break;
365 case -ENOENT:
366 case -ECONNRESET:
367 case -ESHUTDOWN:
368 dev_dbg(&port->dev, "%s - urb stopped: %d\n",
369 __func__, urb->status);
370 return;
371 case -EPIPE:
372 dev_err(&port->dev, "%s - urb stopped: %d\n",
373 __func__, urb->status);
374 return;
375 default:
376 dev_err(&port->dev, "%s - nonzero urb status: %d\n",
377 __func__, urb->status);
378 goto resubmit;
379 }
380
381 usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
382 port->serial->type->process_read_urb(urb);
383
384resubmit:
385 /* Throttle the device if requested by tty */
386 spin_lock_irqsave(&port->lock, flags);
387 port->throttled = port->throttle_req;
388 if (!port->throttled) {
389 spin_unlock_irqrestore(&port->lock, flags);
390 usb_serial_generic_submit_read_urb(port, i, GFP_ATOMIC);
391 } else {
392 spin_unlock_irqrestore(&port->lock, flags);
393 }
394}
395EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
396
397void usb_serial_generic_write_bulk_callback(struct urb *urb)
398{
399 unsigned long flags;
400 struct usb_serial_port *port = urb->context;
401 int i;
402
403 for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i) {
404 if (port->write_urbs[i] == urb)
405 break;
406 }
407 spin_lock_irqsave(&port->lock, flags);
408 port->tx_bytes -= urb->transfer_buffer_length;
409 set_bit(i, &port->write_urbs_free);
410 spin_unlock_irqrestore(&port->lock, flags);
411
412 switch (urb->status) {
413 case 0:
414 break;
415 case -ENOENT:
416 case -ECONNRESET:
417 case -ESHUTDOWN:
418 dev_dbg(&port->dev, "%s - urb stopped: %d\n",
419 __func__, urb->status);
420 return;
421 case -EPIPE:
422 dev_err_console(port, "%s - urb stopped: %d\n",
423 __func__, urb->status);
424 return;
425 default:
426 dev_err_console(port, "%s - nonzero urb status: %d\n",
427 __func__, urb->status);
428 goto resubmit;
429 }
430
431resubmit:
432 usb_serial_generic_write_start(port, GFP_ATOMIC);
433 usb_serial_port_softint(port);
434}
435EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
436
437void usb_serial_generic_throttle(struct tty_struct *tty)
438{
439 struct usb_serial_port *port = tty->driver_data;
440 unsigned long flags;
441
442 spin_lock_irqsave(&port->lock, flags);
443 port->throttle_req = 1;
444 spin_unlock_irqrestore(&port->lock, flags);
445}
446EXPORT_SYMBOL_GPL(usb_serial_generic_throttle);
447
448void usb_serial_generic_unthrottle(struct tty_struct *tty)
449{
450 struct usb_serial_port *port = tty->driver_data;
451 int was_throttled;
452
453 spin_lock_irq(&port->lock);
454 was_throttled = port->throttled;
455 port->throttled = port->throttle_req = 0;
456 spin_unlock_irq(&port->lock);
457
458 if (was_throttled)
459 usb_serial_generic_submit_read_urbs(port, GFP_KERNEL);
460}
461EXPORT_SYMBOL_GPL(usb_serial_generic_unthrottle);
462
463static bool usb_serial_generic_msr_changed(struct tty_struct *tty,
464 unsigned long arg, struct async_icount *cprev)
465{
466 struct usb_serial_port *port = tty->driver_data;
467 struct async_icount cnow;
468 unsigned long flags;
469 bool ret;
470
471 /*
472 * Use tty-port initialised flag to detect all hangups including the
473 * one generated at USB-device disconnect.
474 */
475 if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags))
476 return true;
477
478 spin_lock_irqsave(&port->lock, flags);
479 cnow = port->icount; /* atomic copy*/
480 spin_unlock_irqrestore(&port->lock, flags);
481
482 ret = ((arg & TIOCM_RNG) && (cnow.rng != cprev->rng)) ||
483 ((arg & TIOCM_DSR) && (cnow.dsr != cprev->dsr)) ||
484 ((arg & TIOCM_CD) && (cnow.dcd != cprev->dcd)) ||
485 ((arg & TIOCM_CTS) && (cnow.cts != cprev->cts));
486
487 *cprev = cnow;
488
489 return ret;
490}
491
492int usb_serial_generic_tiocmiwait(struct tty_struct *tty, unsigned long arg)
493{
494 struct usb_serial_port *port = tty->driver_data;
495 struct async_icount cnow;
496 unsigned long flags;
497 int ret;
498
499 spin_lock_irqsave(&port->lock, flags);
500 cnow = port->icount; /* atomic copy */
501 spin_unlock_irqrestore(&port->lock, flags);
502
503 ret = wait_event_interruptible(port->port.delta_msr_wait,
504 usb_serial_generic_msr_changed(tty, arg, &cnow));
505 if (!ret && !test_bit(ASYNCB_INITIALIZED, &port->port.flags))
506 ret = -EIO;
507
508 return ret;
509}
510EXPORT_SYMBOL_GPL(usb_serial_generic_tiocmiwait);
511
512int usb_serial_generic_get_icount(struct tty_struct *tty,
513 struct serial_icounter_struct *icount)
514{
515 struct usb_serial_port *port = tty->driver_data;
516 struct async_icount cnow;
517 unsigned long flags;
518
519 spin_lock_irqsave(&port->lock, flags);
520 cnow = port->icount; /* atomic copy */
521 spin_unlock_irqrestore(&port->lock, flags);
522
523 icount->cts = cnow.cts;
524 icount->dsr = cnow.dsr;
525 icount->rng = cnow.rng;
526 icount->dcd = cnow.dcd;
527 icount->tx = cnow.tx;
528 icount->rx = cnow.rx;
529 icount->frame = cnow.frame;
530 icount->parity = cnow.parity;
531 icount->overrun = cnow.overrun;
532 icount->brk = cnow.brk;
533 icount->buf_overrun = cnow.buf_overrun;
534
535 return 0;
536}
537EXPORT_SYMBOL_GPL(usb_serial_generic_get_icount);
538
539#ifdef CONFIG_MAGIC_SYSRQ
540int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
541{
542 if (port->sysrq && port->port.console) {
543 if (ch && time_before(jiffies, port->sysrq)) {
544 handle_sysrq(ch);
545 port->sysrq = 0;
546 return 1;
547 }
548 port->sysrq = 0;
549 }
550 return 0;
551}
552#else
553int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
554{
555 return 0;
556}
557#endif
558EXPORT_SYMBOL_GPL(usb_serial_handle_sysrq_char);
559
560int usb_serial_handle_break(struct usb_serial_port *port)
561{
562 if (!port->sysrq) {
563 port->sysrq = jiffies + HZ*5;
564 return 1;
565 }
566 port->sysrq = 0;
567 return 0;
568}
569EXPORT_SYMBOL_GPL(usb_serial_handle_break);
570
571/**
572 * usb_serial_handle_dcd_change - handle a change of carrier detect state
573 * @port: usb-serial port
574 * @tty: tty for the port
575 * @status: new carrier detect status, nonzero if active
576 */
577void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port,
578 struct tty_struct *tty, unsigned int status)
579{
580 struct tty_port *port = &usb_port->port;
581
582 dev_dbg(&usb_port->dev, "%s - status %d\n", __func__, status);
583
584 if (tty) {
585 struct tty_ldisc *ld = tty_ldisc_ref(tty);
586
587 if (ld) {
588 if (ld->ops->dcd_change)
589 ld->ops->dcd_change(tty, status);
590 tty_ldisc_deref(ld);
591 }
592 }
593
594 if (status)
595 wake_up_interruptible(&port->open_wait);
596 else if (tty && !C_CLOCAL(tty))
597 tty_hangup(tty);
598}
599EXPORT_SYMBOL_GPL(usb_serial_handle_dcd_change);
600
601int usb_serial_generic_resume(struct usb_serial *serial)
602{
603 struct usb_serial_port *port;
604 int i, c = 0, r;
605
606 for (i = 0; i < serial->num_ports; i++) {
607 port = serial->port[i];
608 if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags))
609 continue;
610
611 if (port->bulk_in_size) {
612 r = usb_serial_generic_submit_read_urbs(port,
613 GFP_NOIO);
614 if (r < 0)
615 c++;
616 }
617
618 if (port->bulk_out_size) {
619 r = usb_serial_generic_write_start(port, GFP_NOIO);
620 if (r < 0)
621 c++;
622 }
623 }
624
625 return c ? -EIO : 0;
626}
627EXPORT_SYMBOL_GPL(usb_serial_generic_resume);