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 | |
26 | static __u16 vendor = 0x05f9; |
27 | static __u16 product = 0xffff; |
28 | |
29 | module_param(vendor, ushort, 0); |
30 | MODULE_PARM_DESC(vendor, "User specified USB idVendor" ); |
31 | |
32 | module_param(product, ushort, 0); |
33 | MODULE_PARM_DESC(product, "User specified USB idProduct" ); |
34 | |
35 | static struct usb_device_id generic_device_ids[2]; /* Initially all zeroes. */ |
36 | |
37 | static 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 | |
48 | static 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 | |
64 | static 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 | |
77 | static struct usb_serial_driver * const serial_drivers[] = { |
78 | &usb_serial_generic_device, NULL |
79 | }; |
80 | |
81 | #endif |
82 | |
83 | int 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 | name: "usbserial_generic" , id_table: generic_device_ids); |
95 | #endif |
96 | return retval; |
97 | } |
98 | |
99 | void usb_serial_generic_deregister(void) |
100 | { |
101 | #ifdef CONFIG_USB_SERIAL_GENERIC |
102 | usb_serial_deregister_drivers(serial_drivers); |
103 | #endif |
104 | } |
105 | |
106 | int 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, addr: &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 | } |
117 | EXPORT_SYMBOL_GPL(usb_serial_generic_open); |
118 | |
119 | void 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(urb: port->write_urbs[i]); |
127 | |
128 | spin_lock_irqsave(&port->lock, flags); |
129 | kfifo_reset_out(&port->write_fifo); |
130 | spin_unlock_irqrestore(lock: &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(urb: port->read_urbs[i]); |
135 | } |
136 | } |
137 | EXPORT_SYMBOL_GPL(usb_serial_generic_close); |
138 | |
139 | int 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 | */ |
154 | int 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, addr: &port->flags)) |
163 | return 0; |
164 | retry: |
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, addr: &port->flags); |
168 | spin_unlock_irqrestore(lock: &port->lock, flags); |
169 | return 0; |
170 | } |
171 | i = (int)find_first_bit(addr: &port->write_urbs_free, |
172 | ARRAY_SIZE(port->write_urbs)); |
173 | spin_unlock_irqrestore(lock: &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(dev: &port->dev, function: __func__, size: count, data: urb->transfer_buffer); |
181 | spin_lock_irqsave(&port->lock, flags); |
182 | port->tx_bytes += count; |
183 | spin_unlock_irqrestore(lock: &port->lock, flags); |
184 | |
185 | clear_bit(nr: i, addr: &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(nr: i, addr: &port->write_urbs_free); |
191 | spin_lock_irqsave(&port->lock, flags); |
192 | port->tx_bytes -= count; |
193 | spin_unlock_irqrestore(lock: &port->lock, flags); |
194 | |
195 | clear_bit_unlock(USB_SERIAL_WRITE_BUSY, addr: &port->flags); |
196 | return result; |
197 | } |
198 | |
199 | goto retry; /* try sending off another urb */ |
200 | } |
201 | EXPORT_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 | */ |
213 | int 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 | } |
231 | EXPORT_SYMBOL_GPL(usb_serial_generic_write); |
232 | |
233 | unsigned 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(lock: &port->lock, flags); |
245 | |
246 | dev_dbg(&port->dev, "%s - returns %u\n" , __func__, room); |
247 | return room; |
248 | } |
249 | |
250 | unsigned 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(lock: &port->lock, flags); |
262 | |
263 | dev_dbg(&port->dev, "%s - returns %u\n" , __func__, chars); |
264 | return chars; |
265 | } |
266 | EXPORT_SYMBOL_GPL(usb_serial_generic_chars_in_buffer); |
267 | |
268 | void 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(timeout: period); |
292 | if (signal_pending(current)) |
293 | break; |
294 | if (timeout && time_after(jiffies, expire)) |
295 | break; |
296 | } |
297 | } |
298 | EXPORT_SYMBOL_GPL(usb_serial_generic_wait_until_sent); |
299 | |
300 | static 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(nr: index, addr: &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(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(nr: index, addr: &port->read_urbs_free); |
318 | return res; |
319 | } |
320 | |
321 | return 0; |
322 | } |
323 | |
324 | int 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, index: i, mem_flags); |
332 | if (res) |
333 | goto err; |
334 | } |
335 | |
336 | return 0; |
337 | err: |
338 | for (; i >= 0; --i) |
339 | usb_kill_urb(urb: port->read_urbs[i]); |
340 | |
341 | return res; |
342 | } |
343 | EXPORT_SYMBOL_GPL(usb_serial_generic_submit_read_urbs); |
344 | |
345 | void 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: *ch)) |
361 | tty_insert_flip_char(port: &port->port, ch: *ch, TTY_NORMAL); |
362 | } |
363 | } else { |
364 | tty_insert_flip_string(port: &port->port, chars: ch, size: urb->actual_length); |
365 | } |
366 | tty_flip_buffer_push(port: &port->port); |
367 | } |
368 | EXPORT_SYMBOL_GPL(usb_serial_generic_process_read_urb); |
369 | |
370 | void 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(dev: &port->dev, function: __func__, size: 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(nr: i, addr: &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, index: i, GFP_ATOMIC); |
431 | } |
432 | EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback); |
433 | |
434 | void 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(nr: i, addr: &port->write_urbs_free); |
448 | spin_unlock_irqrestore(lock: &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 | } |
472 | EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback); |
473 | |
474 | void 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, addr: &port->flags); |
479 | } |
480 | EXPORT_SYMBOL_GPL(usb_serial_generic_throttle); |
481 | |
482 | void 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, addr: &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 | } |
496 | EXPORT_SYMBOL_GPL(usb_serial_generic_unthrottle); |
497 | |
498 | static 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->port)) |
511 | return true; |
512 | |
513 | spin_lock_irqsave(&port->lock, flags); |
514 | cnow = port->icount; /* atomic copy*/ |
515 | spin_unlock_irqrestore(lock: &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 | |
527 | int 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(lock: &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->port)) |
541 | ret = -EIO; |
542 | |
543 | return ret; |
544 | } |
545 | EXPORT_SYMBOL_GPL(usb_serial_generic_tiocmiwait); |
546 | |
547 | int 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(lock: &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 | } |
572 | EXPORT_SYMBOL_GPL(usb_serial_generic_get_icount); |
573 | |
574 | #if defined(CONFIG_USB_SERIAL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) |
575 | int 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(key: ch); |
580 | port->sysrq = 0; |
581 | return 1; |
582 | } |
583 | port->sysrq = 0; |
584 | } |
585 | return 0; |
586 | } |
587 | EXPORT_SYMBOL_GPL(usb_serial_handle_sysrq_char); |
588 | |
589 | int 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 | } |
601 | EXPORT_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 | */ |
610 | void 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 | } |
630 | EXPORT_SYMBOL_GPL(usb_serial_handle_dcd_change); |
631 | |
632 | int 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->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 | } |
658 | EXPORT_SYMBOL_GPL(usb_serial_generic_resume); |
659 | |