1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 USB Driver layer for GSM modems
4
5 Copyright (C) 2005 Matthias Urlichs <smurf@smurf.noris.de>
6
7 Portions copied from the Keyspan driver by Hugh Blemings <hugh@blemings.org>
8
9 History: see the git log.
10
11 Work sponsored by: Sigos GmbH, Germany <info@sigos.de>
12
13 This driver exists because the "normal" serial driver doesn't work too well
14 with GSM modems. Issues:
15 - data loss -- one single Receive URB is not nearly enough
16 - controlling the baud rate doesn't make sense
17 */
18
19 #define DRIVER_AUTHOR "Matthias Urlichs <smurf@smurf.noris.de>"
20 #define DRIVER_DESC "USB Driver for GSM modems"
21
22 #include <linux/kernel.h>
23 #include <linux/jiffies.h>
24 #include <linux/errno.h>
25 #include <linux/slab.h>
26 #include <linux/tty.h>
27 #include <linux/tty_flip.h>
28 #include <linux/module.h>
29 #include <linux/bitops.h>
30 #include <linux/uaccess.h>
31 #include <linux/usb.h>
32 #include <linux/usb/cdc.h>
33 #include <linux/usb/serial.h>
34 #include <linux/serial.h>
35 #include "usb-wwan.h"
36
37 /*
38 * Generate DTR/RTS signals on the port using the SET_CONTROL_LINE_STATE request
39 * in CDC ACM.
40 */
usb_wwan_send_setup(struct usb_serial_port * port)41 static int usb_wwan_send_setup(struct usb_serial_port *port)
42 {
43 struct usb_serial *serial = port->serial;
44 struct usb_wwan_port_private *portdata;
45 int val = 0;
46 int ifnum;
47 int res;
48
49 portdata = usb_get_serial_port_data(port);
50
51 if (portdata->dtr_state)
52 val |= USB_CDC_CTRL_DTR;
53 if (portdata->rts_state)
54 val |= USB_CDC_CTRL_RTS;
55
56 ifnum = serial->interface->cur_altsetting->desc.bInterfaceNumber;
57
58 res = usb_autopm_get_interface(serial->interface);
59 if (res)
60 return res;
61
62 res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
63 USB_CDC_REQ_SET_CONTROL_LINE_STATE,
64 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
65 val, ifnum, NULL, 0, USB_CTRL_SET_TIMEOUT);
66
67 usb_autopm_put_interface(port->serial->interface);
68
69 return res;
70 }
71
usb_wwan_dtr_rts(struct usb_serial_port * port,int on)72 void usb_wwan_dtr_rts(struct usb_serial_port *port, int on)
73 {
74 struct usb_wwan_port_private *portdata;
75 struct usb_wwan_intf_private *intfdata;
76
77 intfdata = usb_get_serial_data(port->serial);
78
79 if (!intfdata->use_send_setup)
80 return;
81
82 portdata = usb_get_serial_port_data(port);
83 /* FIXME: locking */
84 portdata->rts_state = on;
85 portdata->dtr_state = on;
86
87 usb_wwan_send_setup(port);
88 }
89 EXPORT_SYMBOL(usb_wwan_dtr_rts);
90
usb_wwan_tiocmget(struct tty_struct * tty)91 int usb_wwan_tiocmget(struct tty_struct *tty)
92 {
93 struct usb_serial_port *port = tty->driver_data;
94 unsigned int value;
95 struct usb_wwan_port_private *portdata;
96
97 portdata = usb_get_serial_port_data(port);
98
99 value = ((portdata->rts_state) ? TIOCM_RTS : 0) |
100 ((portdata->dtr_state) ? TIOCM_DTR : 0) |
101 ((portdata->cts_state) ? TIOCM_CTS : 0) |
102 ((portdata->dsr_state) ? TIOCM_DSR : 0) |
103 ((portdata->dcd_state) ? TIOCM_CAR : 0) |
104 ((portdata->ri_state) ? TIOCM_RNG : 0);
105
106 return value;
107 }
108 EXPORT_SYMBOL(usb_wwan_tiocmget);
109
usb_wwan_tiocmset(struct tty_struct * tty,unsigned int set,unsigned int clear)110 int usb_wwan_tiocmset(struct tty_struct *tty,
111 unsigned int set, unsigned int clear)
112 {
113 struct usb_serial_port *port = tty->driver_data;
114 struct usb_wwan_port_private *portdata;
115 struct usb_wwan_intf_private *intfdata;
116
117 portdata = usb_get_serial_port_data(port);
118 intfdata = usb_get_serial_data(port->serial);
119
120 if (!intfdata->use_send_setup)
121 return -EINVAL;
122
123 /* FIXME: what locks portdata fields ? */
124 if (set & TIOCM_RTS)
125 portdata->rts_state = 1;
126 if (set & TIOCM_DTR)
127 portdata->dtr_state = 1;
128
129 if (clear & TIOCM_RTS)
130 portdata->rts_state = 0;
131 if (clear & TIOCM_DTR)
132 portdata->dtr_state = 0;
133 return usb_wwan_send_setup(port);
134 }
135 EXPORT_SYMBOL(usb_wwan_tiocmset);
136
usb_wwan_write(struct tty_struct * tty,struct usb_serial_port * port,const unsigned char * buf,int count)137 int usb_wwan_write(struct tty_struct *tty, struct usb_serial_port *port,
138 const unsigned char *buf, int count)
139 {
140 struct usb_wwan_port_private *portdata;
141 struct usb_wwan_intf_private *intfdata;
142 int i;
143 int left, todo;
144 struct urb *this_urb = NULL; /* spurious */
145 int err;
146 unsigned long flags;
147
148 portdata = usb_get_serial_port_data(port);
149 intfdata = usb_get_serial_data(port->serial);
150
151 dev_dbg(&port->dev, "%s: write (%d chars)\n", __func__, count);
152
153 left = count;
154 for (i = 0; left > 0 && i < N_OUT_URB; i++) {
155 todo = left;
156 if (todo > OUT_BUFLEN)
157 todo = OUT_BUFLEN;
158
159 this_urb = portdata->out_urbs[i];
160 if (test_and_set_bit(i, &portdata->out_busy)) {
161 if (time_before(jiffies,
162 portdata->tx_start_time[i] + 10 * HZ))
163 continue;
164 usb_unlink_urb(this_urb);
165 continue;
166 }
167 dev_dbg(&port->dev, "%s: endpoint %d buf %d\n", __func__,
168 usb_pipeendpoint(this_urb->pipe), i);
169
170 err = usb_autopm_get_interface_async(port->serial->interface);
171 if (err < 0) {
172 clear_bit(i, &portdata->out_busy);
173 break;
174 }
175
176 /* send the data */
177 memcpy(this_urb->transfer_buffer, buf, todo);
178 this_urb->transfer_buffer_length = todo;
179
180 spin_lock_irqsave(&intfdata->susp_lock, flags);
181 if (intfdata->suspended) {
182 usb_anchor_urb(this_urb, &portdata->delayed);
183 spin_unlock_irqrestore(&intfdata->susp_lock, flags);
184 } else {
185 intfdata->in_flight++;
186 spin_unlock_irqrestore(&intfdata->susp_lock, flags);
187 err = usb_submit_urb(this_urb, GFP_ATOMIC);
188 if (err) {
189 dev_err(&port->dev,
190 "%s: submit urb %d failed: %d\n",
191 __func__, i, err);
192 clear_bit(i, &portdata->out_busy);
193 spin_lock_irqsave(&intfdata->susp_lock, flags);
194 intfdata->in_flight--;
195 spin_unlock_irqrestore(&intfdata->susp_lock,
196 flags);
197 usb_autopm_put_interface_async(port->serial->interface);
198 break;
199 }
200 }
201
202 portdata->tx_start_time[i] = jiffies;
203 buf += todo;
204 left -= todo;
205 }
206
207 count -= left;
208 dev_dbg(&port->dev, "%s: wrote (did %d)\n", __func__, count);
209 return count;
210 }
211 EXPORT_SYMBOL(usb_wwan_write);
212
usb_wwan_indat_callback(struct urb * urb)213 static void usb_wwan_indat_callback(struct urb *urb)
214 {
215 int err;
216 int endpoint;
217 struct usb_serial_port *port;
218 struct device *dev;
219 unsigned char *data = urb->transfer_buffer;
220 int status = urb->status;
221
222 endpoint = usb_pipeendpoint(urb->pipe);
223 port = urb->context;
224 dev = &port->dev;
225
226 if (status) {
227 dev_dbg(dev, "%s: nonzero status: %d on endpoint %02x.\n",
228 __func__, status, endpoint);
229
230 /* don't resubmit on fatal errors */
231 if (status == -ESHUTDOWN || status == -ENOENT)
232 return;
233 } else {
234 if (urb->actual_length) {
235 tty_insert_flip_string(&port->port, data,
236 urb->actual_length);
237 tty_flip_buffer_push(&port->port);
238 } else
239 dev_dbg(dev, "%s: empty read urb received\n", __func__);
240 }
241 /* Resubmit urb so we continue receiving */
242 err = usb_submit_urb(urb, GFP_ATOMIC);
243 if (err) {
244 if (err != -EPERM && err != -ENODEV) {
245 dev_err(dev, "%s: resubmit read urb failed. (%d)\n",
246 __func__, err);
247 /* busy also in error unless we are killed */
248 usb_mark_last_busy(port->serial->dev);
249 }
250 } else {
251 usb_mark_last_busy(port->serial->dev);
252 }
253 }
254
usb_wwan_outdat_callback(struct urb * urb)255 static void usb_wwan_outdat_callback(struct urb *urb)
256 {
257 struct usb_serial_port *port;
258 struct usb_wwan_port_private *portdata;
259 struct usb_wwan_intf_private *intfdata;
260 unsigned long flags;
261 int i;
262
263 port = urb->context;
264 intfdata = usb_get_serial_data(port->serial);
265
266 usb_serial_port_softint(port);
267 usb_autopm_put_interface_async(port->serial->interface);
268 portdata = usb_get_serial_port_data(port);
269 spin_lock_irqsave(&intfdata->susp_lock, flags);
270 intfdata->in_flight--;
271 spin_unlock_irqrestore(&intfdata->susp_lock, flags);
272
273 for (i = 0; i < N_OUT_URB; ++i) {
274 if (portdata->out_urbs[i] == urb) {
275 smp_mb__before_atomic();
276 clear_bit(i, &portdata->out_busy);
277 break;
278 }
279 }
280 }
281
usb_wwan_write_room(struct tty_struct * tty)282 unsigned int usb_wwan_write_room(struct tty_struct *tty)
283 {
284 struct usb_serial_port *port = tty->driver_data;
285 struct usb_wwan_port_private *portdata;
286 int i;
287 unsigned int data_len = 0;
288 struct urb *this_urb;
289
290 portdata = usb_get_serial_port_data(port);
291
292 for (i = 0; i < N_OUT_URB; i++) {
293 this_urb = portdata->out_urbs[i];
294 if (this_urb && !test_bit(i, &portdata->out_busy))
295 data_len += OUT_BUFLEN;
296 }
297
298 dev_dbg(&port->dev, "%s: %u\n", __func__, data_len);
299 return data_len;
300 }
301 EXPORT_SYMBOL(usb_wwan_write_room);
302
usb_wwan_chars_in_buffer(struct tty_struct * tty)303 unsigned int usb_wwan_chars_in_buffer(struct tty_struct *tty)
304 {
305 struct usb_serial_port *port = tty->driver_data;
306 struct usb_wwan_port_private *portdata;
307 int i;
308 unsigned int data_len = 0;
309 struct urb *this_urb;
310
311 portdata = usb_get_serial_port_data(port);
312
313 for (i = 0; i < N_OUT_URB; i++) {
314 this_urb = portdata->out_urbs[i];
315 /* FIXME: This locking is insufficient as this_urb may
316 go unused during the test */
317 if (this_urb && test_bit(i, &portdata->out_busy))
318 data_len += this_urb->transfer_buffer_length;
319 }
320 dev_dbg(&port->dev, "%s: %u\n", __func__, data_len);
321 return data_len;
322 }
323 EXPORT_SYMBOL(usb_wwan_chars_in_buffer);
324
usb_wwan_open(struct tty_struct * tty,struct usb_serial_port * port)325 int usb_wwan_open(struct tty_struct *tty, struct usb_serial_port *port)
326 {
327 struct usb_wwan_port_private *portdata;
328 struct usb_wwan_intf_private *intfdata;
329 struct usb_serial *serial = port->serial;
330 int i, err;
331 struct urb *urb;
332
333 portdata = usb_get_serial_port_data(port);
334 intfdata = usb_get_serial_data(serial);
335
336 if (port->interrupt_in_urb) {
337 err = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
338 if (err) {
339 dev_err(&port->dev, "%s: submit int urb failed: %d\n",
340 __func__, err);
341 }
342 }
343
344 /* Start reading from the IN endpoint */
345 for (i = 0; i < N_IN_URB; i++) {
346 urb = portdata->in_urbs[i];
347 if (!urb)
348 continue;
349 err = usb_submit_urb(urb, GFP_KERNEL);
350 if (err) {
351 dev_err(&port->dev,
352 "%s: submit read urb %d failed: %d\n",
353 __func__, i, err);
354 }
355 }
356
357 spin_lock_irq(&intfdata->susp_lock);
358 if (++intfdata->open_ports == 1)
359 serial->interface->needs_remote_wakeup = 1;
360 spin_unlock_irq(&intfdata->susp_lock);
361 /* this balances a get in the generic USB serial code */
362 usb_autopm_put_interface(serial->interface);
363
364 return 0;
365 }
366 EXPORT_SYMBOL(usb_wwan_open);
367
unbusy_queued_urb(struct urb * urb,struct usb_wwan_port_private * portdata)368 static void unbusy_queued_urb(struct urb *urb,
369 struct usb_wwan_port_private *portdata)
370 {
371 int i;
372
373 for (i = 0; i < N_OUT_URB; i++) {
374 if (urb == portdata->out_urbs[i]) {
375 clear_bit(i, &portdata->out_busy);
376 break;
377 }
378 }
379 }
380
usb_wwan_close(struct usb_serial_port * port)381 void usb_wwan_close(struct usb_serial_port *port)
382 {
383 int i;
384 struct usb_serial *serial = port->serial;
385 struct usb_wwan_port_private *portdata;
386 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
387 struct urb *urb;
388
389 portdata = usb_get_serial_port_data(port);
390
391 /*
392 * Need to take susp_lock to make sure port is not already being
393 * resumed, but no need to hold it due to the tty-port initialized
394 * flag.
395 */
396 spin_lock_irq(&intfdata->susp_lock);
397 if (--intfdata->open_ports == 0)
398 serial->interface->needs_remote_wakeup = 0;
399 spin_unlock_irq(&intfdata->susp_lock);
400
401 for (;;) {
402 urb = usb_get_from_anchor(&portdata->delayed);
403 if (!urb)
404 break;
405 unbusy_queued_urb(urb, portdata);
406 usb_autopm_put_interface_async(serial->interface);
407 }
408
409 for (i = 0; i < N_IN_URB; i++)
410 usb_kill_urb(portdata->in_urbs[i]);
411 for (i = 0; i < N_OUT_URB; i++)
412 usb_kill_urb(portdata->out_urbs[i]);
413 usb_kill_urb(port->interrupt_in_urb);
414
415 usb_autopm_get_interface_no_resume(serial->interface);
416 }
417 EXPORT_SYMBOL(usb_wwan_close);
418
usb_wwan_setup_urb(struct usb_serial_port * port,int endpoint,int dir,void * ctx,char * buf,int len,void (* callback)(struct urb *))419 static struct urb *usb_wwan_setup_urb(struct usb_serial_port *port,
420 int endpoint,
421 int dir, void *ctx, char *buf, int len,
422 void (*callback) (struct urb *))
423 {
424 struct usb_serial *serial = port->serial;
425 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
426 struct urb *urb;
427
428 urb = usb_alloc_urb(0, GFP_KERNEL); /* No ISO */
429 if (!urb)
430 return NULL;
431
432 usb_fill_bulk_urb(urb, serial->dev,
433 usb_sndbulkpipe(serial->dev, endpoint) | dir,
434 buf, len, callback, ctx);
435
436 if (intfdata->use_zlp && dir == USB_DIR_OUT)
437 urb->transfer_flags |= URB_ZERO_PACKET;
438
439 return urb;
440 }
441
usb_wwan_port_probe(struct usb_serial_port * port)442 int usb_wwan_port_probe(struct usb_serial_port *port)
443 {
444 struct usb_wwan_port_private *portdata;
445 struct urb *urb;
446 u8 *buffer;
447 int i;
448
449 if (!port->bulk_in_size || !port->bulk_out_size)
450 return -ENODEV;
451
452 portdata = kzalloc(sizeof(*portdata), GFP_KERNEL);
453 if (!portdata)
454 return -ENOMEM;
455
456 init_usb_anchor(&portdata->delayed);
457
458 for (i = 0; i < N_IN_URB; i++) {
459 buffer = (u8 *)__get_free_page(GFP_KERNEL);
460 if (!buffer)
461 goto bail_out_error;
462 portdata->in_buffer[i] = buffer;
463
464 urb = usb_wwan_setup_urb(port, port->bulk_in_endpointAddress,
465 USB_DIR_IN, port,
466 buffer, IN_BUFLEN,
467 usb_wwan_indat_callback);
468 portdata->in_urbs[i] = urb;
469 }
470
471 for (i = 0; i < N_OUT_URB; i++) {
472 buffer = kmalloc(OUT_BUFLEN, GFP_KERNEL);
473 if (!buffer)
474 goto bail_out_error2;
475 portdata->out_buffer[i] = buffer;
476
477 urb = usb_wwan_setup_urb(port, port->bulk_out_endpointAddress,
478 USB_DIR_OUT, port,
479 buffer, OUT_BUFLEN,
480 usb_wwan_outdat_callback);
481 portdata->out_urbs[i] = urb;
482 }
483
484 usb_set_serial_port_data(port, portdata);
485
486 return 0;
487
488 bail_out_error2:
489 for (i = 0; i < N_OUT_URB; i++) {
490 usb_free_urb(portdata->out_urbs[i]);
491 kfree(portdata->out_buffer[i]);
492 }
493 bail_out_error:
494 for (i = 0; i < N_IN_URB; i++) {
495 usb_free_urb(portdata->in_urbs[i]);
496 free_page((unsigned long)portdata->in_buffer[i]);
497 }
498 kfree(portdata);
499
500 return -ENOMEM;
501 }
502 EXPORT_SYMBOL_GPL(usb_wwan_port_probe);
503
usb_wwan_port_remove(struct usb_serial_port * port)504 void usb_wwan_port_remove(struct usb_serial_port *port)
505 {
506 int i;
507 struct usb_wwan_port_private *portdata;
508
509 portdata = usb_get_serial_port_data(port);
510 usb_set_serial_port_data(port, NULL);
511
512 for (i = 0; i < N_IN_URB; i++) {
513 usb_free_urb(portdata->in_urbs[i]);
514 free_page((unsigned long)portdata->in_buffer[i]);
515 }
516 for (i = 0; i < N_OUT_URB; i++) {
517 usb_free_urb(portdata->out_urbs[i]);
518 kfree(portdata->out_buffer[i]);
519 }
520
521 kfree(portdata);
522 }
523 EXPORT_SYMBOL(usb_wwan_port_remove);
524
525 #ifdef CONFIG_PM
stop_urbs(struct usb_serial * serial)526 static void stop_urbs(struct usb_serial *serial)
527 {
528 int i, j;
529 struct usb_serial_port *port;
530 struct usb_wwan_port_private *portdata;
531
532 for (i = 0; i < serial->num_ports; ++i) {
533 port = serial->port[i];
534 portdata = usb_get_serial_port_data(port);
535 if (!portdata)
536 continue;
537 for (j = 0; j < N_IN_URB; j++)
538 usb_kill_urb(portdata->in_urbs[j]);
539 for (j = 0; j < N_OUT_URB; j++)
540 usb_kill_urb(portdata->out_urbs[j]);
541 usb_kill_urb(port->interrupt_in_urb);
542 }
543 }
544
usb_wwan_suspend(struct usb_serial * serial,pm_message_t message)545 int usb_wwan_suspend(struct usb_serial *serial, pm_message_t message)
546 {
547 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
548
549 spin_lock_irq(&intfdata->susp_lock);
550 if (PMSG_IS_AUTO(message)) {
551 if (intfdata->in_flight) {
552 spin_unlock_irq(&intfdata->susp_lock);
553 return -EBUSY;
554 }
555 }
556 intfdata->suspended = 1;
557 spin_unlock_irq(&intfdata->susp_lock);
558
559 stop_urbs(serial);
560
561 return 0;
562 }
563 EXPORT_SYMBOL(usb_wwan_suspend);
564
565 /* Caller must hold susp_lock. */
usb_wwan_submit_delayed_urbs(struct usb_serial_port * port)566 static int usb_wwan_submit_delayed_urbs(struct usb_serial_port *port)
567 {
568 struct usb_serial *serial = port->serial;
569 struct usb_wwan_intf_private *data = usb_get_serial_data(serial);
570 struct usb_wwan_port_private *portdata;
571 struct urb *urb;
572 int err_count = 0;
573 int err;
574
575 portdata = usb_get_serial_port_data(port);
576
577 for (;;) {
578 urb = usb_get_from_anchor(&portdata->delayed);
579 if (!urb)
580 break;
581
582 err = usb_submit_urb(urb, GFP_ATOMIC);
583 if (err) {
584 dev_err(&port->dev, "%s: submit urb failed: %d\n",
585 __func__, err);
586 err_count++;
587 unbusy_queued_urb(urb, portdata);
588 usb_autopm_put_interface_async(serial->interface);
589 continue;
590 }
591 data->in_flight++;
592 }
593
594 if (err_count)
595 return -EIO;
596
597 return 0;
598 }
599
usb_wwan_resume(struct usb_serial * serial)600 int usb_wwan_resume(struct usb_serial *serial)
601 {
602 int i, j;
603 struct usb_serial_port *port;
604 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
605 struct usb_wwan_port_private *portdata;
606 struct urb *urb;
607 int err;
608 int err_count = 0;
609
610 spin_lock_irq(&intfdata->susp_lock);
611 for (i = 0; i < serial->num_ports; i++) {
612 port = serial->port[i];
613
614 if (!tty_port_initialized(&port->port))
615 continue;
616
617 portdata = usb_get_serial_port_data(port);
618
619 if (port->interrupt_in_urb) {
620 err = usb_submit_urb(port->interrupt_in_urb,
621 GFP_ATOMIC);
622 if (err) {
623 dev_err(&port->dev,
624 "%s: submit int urb failed: %d\n",
625 __func__, err);
626 err_count++;
627 }
628 }
629
630 err = usb_wwan_submit_delayed_urbs(port);
631 if (err)
632 err_count++;
633
634 for (j = 0; j < N_IN_URB; j++) {
635 urb = portdata->in_urbs[j];
636 err = usb_submit_urb(urb, GFP_ATOMIC);
637 if (err < 0) {
638 dev_err(&port->dev,
639 "%s: submit read urb %d failed: %d\n",
640 __func__, i, err);
641 err_count++;
642 }
643 }
644 }
645 intfdata->suspended = 0;
646 spin_unlock_irq(&intfdata->susp_lock);
647
648 if (err_count)
649 return -EIO;
650
651 return 0;
652 }
653 EXPORT_SYMBOL(usb_wwan_resume);
654 #endif
655
656 MODULE_AUTHOR(DRIVER_AUTHOR);
657 MODULE_DESCRIPTION(DRIVER_DESC);
658 MODULE_LICENSE("GPL v2");
659