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/serial.h>
33 #include <linux/serial.h>
34 #include "usb-wwan.h"
35
36 /*
37 * Generate DTR/RTS signals on the port using the SET_CONTROL_LINE_STATE request
38 * in CDC ACM.
39 */
usb_wwan_send_setup(struct usb_serial_port * port)40 static int usb_wwan_send_setup(struct usb_serial_port *port)
41 {
42 struct usb_serial *serial = port->serial;
43 struct usb_wwan_port_private *portdata;
44 int val = 0;
45 int ifnum;
46 int res;
47
48 portdata = usb_get_serial_port_data(port);
49
50 if (portdata->dtr_state)
51 val |= 0x01;
52 if (portdata->rts_state)
53 val |= 0x02;
54
55 ifnum = serial->interface->cur_altsetting->desc.bInterfaceNumber;
56
57 res = usb_autopm_get_interface(serial->interface);
58 if (res)
59 return res;
60
61 res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
62 0x22, 0x21, val, ifnum, NULL, 0,
63 USB_CTRL_SET_TIMEOUT);
64
65 usb_autopm_put_interface(port->serial->interface);
66
67 return res;
68 }
69
usb_wwan_dtr_rts(struct usb_serial_port * port,int on)70 void usb_wwan_dtr_rts(struct usb_serial_port *port, int on)
71 {
72 struct usb_wwan_port_private *portdata;
73 struct usb_wwan_intf_private *intfdata;
74
75 intfdata = usb_get_serial_data(port->serial);
76
77 if (!intfdata->use_send_setup)
78 return;
79
80 portdata = usb_get_serial_port_data(port);
81 /* FIXME: locking */
82 portdata->rts_state = on;
83 portdata->dtr_state = on;
84
85 usb_wwan_send_setup(port);
86 }
87 EXPORT_SYMBOL(usb_wwan_dtr_rts);
88
usb_wwan_tiocmget(struct tty_struct * tty)89 int usb_wwan_tiocmget(struct tty_struct *tty)
90 {
91 struct usb_serial_port *port = tty->driver_data;
92 unsigned int value;
93 struct usb_wwan_port_private *portdata;
94
95 portdata = usb_get_serial_port_data(port);
96
97 value = ((portdata->rts_state) ? TIOCM_RTS : 0) |
98 ((portdata->dtr_state) ? TIOCM_DTR : 0) |
99 ((portdata->cts_state) ? TIOCM_CTS : 0) |
100 ((portdata->dsr_state) ? TIOCM_DSR : 0) |
101 ((portdata->dcd_state) ? TIOCM_CAR : 0) |
102 ((portdata->ri_state) ? TIOCM_RNG : 0);
103
104 return value;
105 }
106 EXPORT_SYMBOL(usb_wwan_tiocmget);
107
usb_wwan_tiocmset(struct tty_struct * tty,unsigned int set,unsigned int clear)108 int usb_wwan_tiocmset(struct tty_struct *tty,
109 unsigned int set, unsigned int clear)
110 {
111 struct usb_serial_port *port = tty->driver_data;
112 struct usb_wwan_port_private *portdata;
113 struct usb_wwan_intf_private *intfdata;
114
115 portdata = usb_get_serial_port_data(port);
116 intfdata = usb_get_serial_data(port->serial);
117
118 if (!intfdata->use_send_setup)
119 return -EINVAL;
120
121 /* FIXME: what locks portdata fields ? */
122 if (set & TIOCM_RTS)
123 portdata->rts_state = 1;
124 if (set & TIOCM_DTR)
125 portdata->dtr_state = 1;
126
127 if (clear & TIOCM_RTS)
128 portdata->rts_state = 0;
129 if (clear & TIOCM_DTR)
130 portdata->dtr_state = 0;
131 return usb_wwan_send_setup(port);
132 }
133 EXPORT_SYMBOL(usb_wwan_tiocmset);
134
usb_wwan_write(struct tty_struct * tty,struct usb_serial_port * port,const unsigned char * buf,int count)135 int usb_wwan_write(struct tty_struct *tty, struct usb_serial_port *port,
136 const unsigned char *buf, int count)
137 {
138 struct usb_wwan_port_private *portdata;
139 struct usb_wwan_intf_private *intfdata;
140 int i;
141 int left, todo;
142 struct urb *this_urb = NULL; /* spurious */
143 int err;
144 unsigned long flags;
145
146 portdata = usb_get_serial_port_data(port);
147 intfdata = usb_get_serial_data(port->serial);
148
149 dev_dbg(&port->dev, "%s: write (%d chars)\n", __func__, count);
150
151 i = 0;
152 left = count;
153 for (i = 0; left > 0 && i < N_OUT_URB; i++) {
154 todo = left;
155 if (todo > OUT_BUFLEN)
156 todo = OUT_BUFLEN;
157
158 this_urb = portdata->out_urbs[i];
159 if (test_and_set_bit(i, &portdata->out_busy)) {
160 if (time_before(jiffies,
161 portdata->tx_start_time[i] + 10 * HZ))
162 continue;
163 usb_unlink_urb(this_urb);
164 continue;
165 }
166 dev_dbg(&port->dev, "%s: endpoint %d buf %d\n", __func__,
167 usb_pipeendpoint(this_urb->pipe), i);
168
169 err = usb_autopm_get_interface_async(port->serial->interface);
170 if (err < 0) {
171 clear_bit(i, &portdata->out_busy);
172 break;
173 }
174
175 /* send the data */
176 memcpy(this_urb->transfer_buffer, buf, todo);
177 this_urb->transfer_buffer_length = todo;
178
179 spin_lock_irqsave(&intfdata->susp_lock, flags);
180 if (intfdata->suspended) {
181 usb_anchor_urb(this_urb, &portdata->delayed);
182 spin_unlock_irqrestore(&intfdata->susp_lock, flags);
183 } else {
184 intfdata->in_flight++;
185 spin_unlock_irqrestore(&intfdata->susp_lock, flags);
186 err = usb_submit_urb(this_urb, GFP_ATOMIC);
187 if (err) {
188 dev_err(&port->dev,
189 "%s: submit urb %d failed: %d\n",
190 __func__, i, err);
191 clear_bit(i, &portdata->out_busy);
192 spin_lock_irqsave(&intfdata->susp_lock, flags);
193 intfdata->in_flight--;
194 spin_unlock_irqrestore(&intfdata->susp_lock,
195 flags);
196 usb_autopm_put_interface_async(port->serial->interface);
197 break;
198 }
199 }
200
201 portdata->tx_start_time[i] = jiffies;
202 buf += todo;
203 left -= todo;
204 }
205
206 count -= left;
207 dev_dbg(&port->dev, "%s: wrote (did %d)\n", __func__, count);
208 return count;
209 }
210 EXPORT_SYMBOL(usb_wwan_write);
211
usb_wwan_indat_callback(struct urb * urb)212 static void usb_wwan_indat_callback(struct urb *urb)
213 {
214 int err;
215 int endpoint;
216 struct usb_serial_port *port;
217 struct device *dev;
218 unsigned char *data = urb->transfer_buffer;
219 int status = urb->status;
220
221 endpoint = usb_pipeendpoint(urb->pipe);
222 port = urb->context;
223 dev = &port->dev;
224
225 if (status) {
226 dev_dbg(dev, "%s: nonzero status: %d on endpoint %02x.\n",
227 __func__, status, endpoint);
228
229 /* don't resubmit on fatal errors */
230 if (status == -ESHUTDOWN || status == -ENOENT)
231 return;
232 } else {
233 if (urb->actual_length) {
234 tty_insert_flip_string(&port->port, data,
235 urb->actual_length);
236 tty_flip_buffer_push(&port->port);
237 } else
238 dev_dbg(dev, "%s: empty read urb received\n", __func__);
239 }
240 /* Resubmit urb so we continue receiving */
241 err = usb_submit_urb(urb, GFP_ATOMIC);
242 if (err) {
243 if (err != -EPERM && err != -ENODEV) {
244 dev_err(dev, "%s: resubmit read urb failed. (%d)\n",
245 __func__, err);
246 /* busy also in error unless we are killed */
247 usb_mark_last_busy(port->serial->dev);
248 }
249 } else {
250 usb_mark_last_busy(port->serial->dev);
251 }
252 }
253
usb_wwan_outdat_callback(struct urb * urb)254 static void usb_wwan_outdat_callback(struct urb *urb)
255 {
256 struct usb_serial_port *port;
257 struct usb_wwan_port_private *portdata;
258 struct usb_wwan_intf_private *intfdata;
259 unsigned long flags;
260 int i;
261
262 port = urb->context;
263 intfdata = usb_get_serial_data(port->serial);
264
265 usb_serial_port_softint(port);
266 usb_autopm_put_interface_async(port->serial->interface);
267 portdata = usb_get_serial_port_data(port);
268 spin_lock_irqsave(&intfdata->susp_lock, flags);
269 intfdata->in_flight--;
270 spin_unlock_irqrestore(&intfdata->susp_lock, flags);
271
272 for (i = 0; i < N_OUT_URB; ++i) {
273 if (portdata->out_urbs[i] == urb) {
274 smp_mb__before_atomic();
275 clear_bit(i, &portdata->out_busy);
276 break;
277 }
278 }
279 }
280
usb_wwan_write_room(struct tty_struct * tty)281 unsigned int usb_wwan_write_room(struct tty_struct *tty)
282 {
283 struct usb_serial_port *port = tty->driver_data;
284 struct usb_wwan_port_private *portdata;
285 int i;
286 unsigned int data_len = 0;
287 struct urb *this_urb;
288
289 portdata = usb_get_serial_port_data(port);
290
291 for (i = 0; i < N_OUT_URB; i++) {
292 this_urb = portdata->out_urbs[i];
293 if (this_urb && !test_bit(i, &portdata->out_busy))
294 data_len += OUT_BUFLEN;
295 }
296
297 dev_dbg(&port->dev, "%s: %u\n", __func__, data_len);
298 return data_len;
299 }
300 EXPORT_SYMBOL(usb_wwan_write_room);
301
usb_wwan_chars_in_buffer(struct tty_struct * tty)302 unsigned int usb_wwan_chars_in_buffer(struct tty_struct *tty)
303 {
304 struct usb_serial_port *port = tty->driver_data;
305 struct usb_wwan_port_private *portdata;
306 int i;
307 unsigned int data_len = 0;
308 struct urb *this_urb;
309
310 portdata = usb_get_serial_port_data(port);
311
312 for (i = 0; i < N_OUT_URB; i++) {
313 this_urb = portdata->out_urbs[i];
314 /* FIXME: This locking is insufficient as this_urb may
315 go unused during the test */
316 if (this_urb && test_bit(i, &portdata->out_busy))
317 data_len += this_urb->transfer_buffer_length;
318 }
319 dev_dbg(&port->dev, "%s: %u\n", __func__, data_len);
320 return data_len;
321 }
322 EXPORT_SYMBOL(usb_wwan_chars_in_buffer);
323
usb_wwan_open(struct tty_struct * tty,struct usb_serial_port * port)324 int usb_wwan_open(struct tty_struct *tty, struct usb_serial_port *port)
325 {
326 struct usb_wwan_port_private *portdata;
327 struct usb_wwan_intf_private *intfdata;
328 struct usb_serial *serial = port->serial;
329 int i, err;
330 struct urb *urb;
331
332 portdata = usb_get_serial_port_data(port);
333 intfdata = usb_get_serial_data(serial);
334
335 if (port->interrupt_in_urb) {
336 err = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
337 if (err) {
338 dev_err(&port->dev, "%s: submit int urb failed: %d\n",
339 __func__, err);
340 }
341 }
342
343 /* Start reading from the IN endpoint */
344 for (i = 0; i < N_IN_URB; i++) {
345 urb = portdata->in_urbs[i];
346 if (!urb)
347 continue;
348 err = usb_submit_urb(urb, GFP_KERNEL);
349 if (err) {
350 dev_err(&port->dev,
351 "%s: submit read urb %d failed: %d\n",
352 __func__, i, err);
353 }
354 }
355
356 spin_lock_irq(&intfdata->susp_lock);
357 if (++intfdata->open_ports == 1)
358 serial->interface->needs_remote_wakeup = 1;
359 spin_unlock_irq(&intfdata->susp_lock);
360 /* this balances a get in the generic USB serial code */
361 usb_autopm_put_interface(serial->interface);
362
363 return 0;
364 }
365 EXPORT_SYMBOL(usb_wwan_open);
366
unbusy_queued_urb(struct urb * urb,struct usb_wwan_port_private * portdata)367 static void unbusy_queued_urb(struct urb *urb,
368 struct usb_wwan_port_private *portdata)
369 {
370 int i;
371
372 for (i = 0; i < N_OUT_URB; i++) {
373 if (urb == portdata->out_urbs[i]) {
374 clear_bit(i, &portdata->out_busy);
375 break;
376 }
377 }
378 }
379
usb_wwan_close(struct usb_serial_port * port)380 void usb_wwan_close(struct usb_serial_port *port)
381 {
382 int i;
383 struct usb_serial *serial = port->serial;
384 struct usb_wwan_port_private *portdata;
385 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
386 struct urb *urb;
387
388 portdata = usb_get_serial_port_data(port);
389
390 /*
391 * Need to take susp_lock to make sure port is not already being
392 * resumed, but no need to hold it due to initialized
393 */
394 spin_lock_irq(&intfdata->susp_lock);
395 if (--intfdata->open_ports == 0)
396 serial->interface->needs_remote_wakeup = 0;
397 spin_unlock_irq(&intfdata->susp_lock);
398
399 for (;;) {
400 urb = usb_get_from_anchor(&portdata->delayed);
401 if (!urb)
402 break;
403 unbusy_queued_urb(urb, portdata);
404 usb_autopm_put_interface_async(serial->interface);
405 }
406
407 for (i = 0; i < N_IN_URB; i++)
408 usb_kill_urb(portdata->in_urbs[i]);
409 for (i = 0; i < N_OUT_URB; i++)
410 usb_kill_urb(portdata->out_urbs[i]);
411 usb_kill_urb(port->interrupt_in_urb);
412
413 usb_autopm_get_interface_no_resume(serial->interface);
414 }
415 EXPORT_SYMBOL(usb_wwan_close);
416
usb_wwan_setup_urb(struct usb_serial_port * port,int endpoint,int dir,void * ctx,char * buf,int len,void (* callback)(struct urb *))417 static struct urb *usb_wwan_setup_urb(struct usb_serial_port *port,
418 int endpoint,
419 int dir, void *ctx, char *buf, int len,
420 void (*callback) (struct urb *))
421 {
422 struct usb_serial *serial = port->serial;
423 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
424 struct urb *urb;
425
426 urb = usb_alloc_urb(0, GFP_KERNEL); /* No ISO */
427 if (!urb)
428 return NULL;
429
430 usb_fill_bulk_urb(urb, serial->dev,
431 usb_sndbulkpipe(serial->dev, endpoint) | dir,
432 buf, len, callback, ctx);
433
434 if (intfdata->use_zlp && dir == USB_DIR_OUT)
435 urb->transfer_flags |= URB_ZERO_PACKET;
436
437 return urb;
438 }
439
usb_wwan_port_probe(struct usb_serial_port * port)440 int usb_wwan_port_probe(struct usb_serial_port *port)
441 {
442 struct usb_wwan_port_private *portdata;
443 struct urb *urb;
444 u8 *buffer;
445 int i;
446
447 if (!port->bulk_in_size || !port->bulk_out_size)
448 return -ENODEV;
449
450 portdata = kzalloc(sizeof(*portdata), GFP_KERNEL);
451 if (!portdata)
452 return -ENOMEM;
453
454 init_usb_anchor(&portdata->delayed);
455
456 for (i = 0; i < N_IN_URB; i++) {
457 buffer = (u8 *)__get_free_page(GFP_KERNEL);
458 if (!buffer)
459 goto bail_out_error;
460 portdata->in_buffer[i] = buffer;
461
462 urb = usb_wwan_setup_urb(port, port->bulk_in_endpointAddress,
463 USB_DIR_IN, port,
464 buffer, IN_BUFLEN,
465 usb_wwan_indat_callback);
466 portdata->in_urbs[i] = urb;
467 }
468
469 for (i = 0; i < N_OUT_URB; i++) {
470 buffer = kmalloc(OUT_BUFLEN, GFP_KERNEL);
471 if (!buffer)
472 goto bail_out_error2;
473 portdata->out_buffer[i] = buffer;
474
475 urb = usb_wwan_setup_urb(port, port->bulk_out_endpointAddress,
476 USB_DIR_OUT, port,
477 buffer, OUT_BUFLEN,
478 usb_wwan_outdat_callback);
479 portdata->out_urbs[i] = urb;
480 }
481
482 usb_set_serial_port_data(port, portdata);
483
484 return 0;
485
486 bail_out_error2:
487 for (i = 0; i < N_OUT_URB; i++) {
488 usb_free_urb(portdata->out_urbs[i]);
489 kfree(portdata->out_buffer[i]);
490 }
491 bail_out_error:
492 for (i = 0; i < N_IN_URB; i++) {
493 usb_free_urb(portdata->in_urbs[i]);
494 free_page((unsigned long)portdata->in_buffer[i]);
495 }
496 kfree(portdata);
497
498 return -ENOMEM;
499 }
500 EXPORT_SYMBOL_GPL(usb_wwan_port_probe);
501
usb_wwan_port_remove(struct usb_serial_port * port)502 void usb_wwan_port_remove(struct usb_serial_port *port)
503 {
504 int i;
505 struct usb_wwan_port_private *portdata;
506
507 portdata = usb_get_serial_port_data(port);
508 usb_set_serial_port_data(port, NULL);
509
510 for (i = 0; i < N_IN_URB; i++) {
511 usb_free_urb(portdata->in_urbs[i]);
512 free_page((unsigned long)portdata->in_buffer[i]);
513 }
514 for (i = 0; i < N_OUT_URB; i++) {
515 usb_free_urb(portdata->out_urbs[i]);
516 kfree(portdata->out_buffer[i]);
517 }
518
519 kfree(portdata);
520 }
521 EXPORT_SYMBOL(usb_wwan_port_remove);
522
523 #ifdef CONFIG_PM
stop_urbs(struct usb_serial * serial)524 static void stop_urbs(struct usb_serial *serial)
525 {
526 int i, j;
527 struct usb_serial_port *port;
528 struct usb_wwan_port_private *portdata;
529
530 for (i = 0; i < serial->num_ports; ++i) {
531 port = serial->port[i];
532 portdata = usb_get_serial_port_data(port);
533 if (!portdata)
534 continue;
535 for (j = 0; j < N_IN_URB; j++)
536 usb_kill_urb(portdata->in_urbs[j]);
537 for (j = 0; j < N_OUT_URB; j++)
538 usb_kill_urb(portdata->out_urbs[j]);
539 usb_kill_urb(port->interrupt_in_urb);
540 }
541 }
542
usb_wwan_suspend(struct usb_serial * serial,pm_message_t message)543 int usb_wwan_suspend(struct usb_serial *serial, pm_message_t message)
544 {
545 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
546
547 spin_lock_irq(&intfdata->susp_lock);
548 if (PMSG_IS_AUTO(message)) {
549 if (intfdata->in_flight) {
550 spin_unlock_irq(&intfdata->susp_lock);
551 return -EBUSY;
552 }
553 }
554 intfdata->suspended = 1;
555 spin_unlock_irq(&intfdata->susp_lock);
556
557 stop_urbs(serial);
558
559 return 0;
560 }
561 EXPORT_SYMBOL(usb_wwan_suspend);
562
563 /* Caller must hold susp_lock. */
usb_wwan_submit_delayed_urbs(struct usb_serial_port * port)564 static int usb_wwan_submit_delayed_urbs(struct usb_serial_port *port)
565 {
566 struct usb_serial *serial = port->serial;
567 struct usb_wwan_intf_private *data = usb_get_serial_data(serial);
568 struct usb_wwan_port_private *portdata;
569 struct urb *urb;
570 int err_count = 0;
571 int err;
572
573 portdata = usb_get_serial_port_data(port);
574
575 for (;;) {
576 urb = usb_get_from_anchor(&portdata->delayed);
577 if (!urb)
578 break;
579
580 err = usb_submit_urb(urb, GFP_ATOMIC);
581 if (err) {
582 dev_err(&port->dev, "%s: submit urb failed: %d\n",
583 __func__, err);
584 err_count++;
585 unbusy_queued_urb(urb, portdata);
586 usb_autopm_put_interface_async(serial->interface);
587 continue;
588 }
589 data->in_flight++;
590 }
591
592 if (err_count)
593 return -EIO;
594
595 return 0;
596 }
597
usb_wwan_resume(struct usb_serial * serial)598 int usb_wwan_resume(struct usb_serial *serial)
599 {
600 int i, j;
601 struct usb_serial_port *port;
602 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
603 struct usb_wwan_port_private *portdata;
604 struct urb *urb;
605 int err;
606 int err_count = 0;
607
608 spin_lock_irq(&intfdata->susp_lock);
609 for (i = 0; i < serial->num_ports; i++) {
610 port = serial->port[i];
611
612 if (!tty_port_initialized(&port->port))
613 continue;
614
615 portdata = usb_get_serial_port_data(port);
616
617 if (port->interrupt_in_urb) {
618 err = usb_submit_urb(port->interrupt_in_urb,
619 GFP_ATOMIC);
620 if (err) {
621 dev_err(&port->dev,
622 "%s: submit int urb failed: %d\n",
623 __func__, err);
624 err_count++;
625 }
626 }
627
628 err = usb_wwan_submit_delayed_urbs(port);
629 if (err)
630 err_count++;
631
632 for (j = 0; j < N_IN_URB; j++) {
633 urb = portdata->in_urbs[j];
634 err = usb_submit_urb(urb, GFP_ATOMIC);
635 if (err < 0) {
636 dev_err(&port->dev,
637 "%s: submit read urb %d failed: %d\n",
638 __func__, i, err);
639 err_count++;
640 }
641 }
642 }
643 intfdata->suspended = 0;
644 spin_unlock_irq(&intfdata->susp_lock);
645
646 if (err_count)
647 return -EIO;
648
649 return 0;
650 }
651 EXPORT_SYMBOL(usb_wwan_resume);
652 #endif
653
654 MODULE_AUTHOR(DRIVER_AUTHOR);
655 MODULE_DESCRIPTION(DRIVER_DESC);
656 MODULE_LICENSE("GPL v2");
657
