rapidio/rionet: do not free skb before reading its length
[linux-2.6-microblaze.git] / drivers / usb / serial / usb_wwan.c
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  */
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
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
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
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
135 int usb_wwan_get_serial_info(struct tty_struct *tty,
136                            struct serial_struct *ss)
137 {
138         struct usb_serial_port *port = tty->driver_data;
139
140         ss->line            = port->minor;
141         ss->port            = port->port_number;
142         ss->baud_base       = tty_get_baud_rate(port->port.tty);
143         ss->close_delay     = port->port.close_delay / 10;
144         ss->closing_wait    = port->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
145                                  ASYNC_CLOSING_WAIT_NONE :
146                                  port->port.closing_wait / 10;
147         return 0;
148 }
149 EXPORT_SYMBOL(usb_wwan_get_serial_info);
150
151 int usb_wwan_set_serial_info(struct tty_struct *tty,
152                            struct serial_struct *ss)
153 {
154         struct usb_serial_port *port = tty->driver_data;
155         unsigned int closing_wait, close_delay;
156         int retval = 0;
157
158         close_delay = ss->close_delay * 10;
159         closing_wait = ss->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
160                         ASYNC_CLOSING_WAIT_NONE : ss->closing_wait * 10;
161
162         mutex_lock(&port->port.mutex);
163
164         if (!capable(CAP_SYS_ADMIN)) {
165                 if ((close_delay != port->port.close_delay) ||
166                     (closing_wait != port->port.closing_wait))
167                         retval = -EPERM;
168                 else
169                         retval = -EOPNOTSUPP;
170         } else {
171                 port->port.close_delay  = close_delay;
172                 port->port.closing_wait = closing_wait;
173         }
174
175         mutex_unlock(&port->port.mutex);
176         return retval;
177 }
178 EXPORT_SYMBOL(usb_wwan_set_serial_info);
179
180 int usb_wwan_write(struct tty_struct *tty, struct usb_serial_port *port,
181                    const unsigned char *buf, int count)
182 {
183         struct usb_wwan_port_private *portdata;
184         struct usb_wwan_intf_private *intfdata;
185         int i;
186         int left, todo;
187         struct urb *this_urb = NULL;    /* spurious */
188         int err;
189         unsigned long flags;
190
191         portdata = usb_get_serial_port_data(port);
192         intfdata = usb_get_serial_data(port->serial);
193
194         dev_dbg(&port->dev, "%s: write (%d chars)\n", __func__, count);
195
196         i = 0;
197         left = count;
198         for (i = 0; left > 0 && i < N_OUT_URB; i++) {
199                 todo = left;
200                 if (todo > OUT_BUFLEN)
201                         todo = OUT_BUFLEN;
202
203                 this_urb = portdata->out_urbs[i];
204                 if (test_and_set_bit(i, &portdata->out_busy)) {
205                         if (time_before(jiffies,
206                                         portdata->tx_start_time[i] + 10 * HZ))
207                                 continue;
208                         usb_unlink_urb(this_urb);
209                         continue;
210                 }
211                 dev_dbg(&port->dev, "%s: endpoint %d buf %d\n", __func__,
212                         usb_pipeendpoint(this_urb->pipe), i);
213
214                 err = usb_autopm_get_interface_async(port->serial->interface);
215                 if (err < 0) {
216                         clear_bit(i, &portdata->out_busy);
217                         break;
218                 }
219
220                 /* send the data */
221                 memcpy(this_urb->transfer_buffer, buf, todo);
222                 this_urb->transfer_buffer_length = todo;
223
224                 spin_lock_irqsave(&intfdata->susp_lock, flags);
225                 if (intfdata->suspended) {
226                         usb_anchor_urb(this_urb, &portdata->delayed);
227                         spin_unlock_irqrestore(&intfdata->susp_lock, flags);
228                 } else {
229                         intfdata->in_flight++;
230                         spin_unlock_irqrestore(&intfdata->susp_lock, flags);
231                         err = usb_submit_urb(this_urb, GFP_ATOMIC);
232                         if (err) {
233                                 dev_err(&port->dev,
234                                         "%s: submit urb %d failed: %d\n",
235                                         __func__, i, err);
236                                 clear_bit(i, &portdata->out_busy);
237                                 spin_lock_irqsave(&intfdata->susp_lock, flags);
238                                 intfdata->in_flight--;
239                                 spin_unlock_irqrestore(&intfdata->susp_lock,
240                                                        flags);
241                                 usb_autopm_put_interface_async(port->serial->interface);
242                                 break;
243                         }
244                 }
245
246                 portdata->tx_start_time[i] = jiffies;
247                 buf += todo;
248                 left -= todo;
249         }
250
251         count -= left;
252         dev_dbg(&port->dev, "%s: wrote (did %d)\n", __func__, count);
253         return count;
254 }
255 EXPORT_SYMBOL(usb_wwan_write);
256
257 static void usb_wwan_indat_callback(struct urb *urb)
258 {
259         int err;
260         int endpoint;
261         struct usb_serial_port *port;
262         struct device *dev;
263         unsigned char *data = urb->transfer_buffer;
264         int status = urb->status;
265
266         endpoint = usb_pipeendpoint(urb->pipe);
267         port = urb->context;
268         dev = &port->dev;
269
270         if (status) {
271                 dev_dbg(dev, "%s: nonzero status: %d on endpoint %02x.\n",
272                         __func__, status, endpoint);
273         } else {
274                 if (urb->actual_length) {
275                         tty_insert_flip_string(&port->port, data,
276                                         urb->actual_length);
277                         tty_flip_buffer_push(&port->port);
278                 } else
279                         dev_dbg(dev, "%s: empty read urb received\n", __func__);
280         }
281         /* Resubmit urb so we continue receiving */
282         err = usb_submit_urb(urb, GFP_ATOMIC);
283         if (err) {
284                 if (err != -EPERM && err != -ENODEV) {
285                         dev_err(dev, "%s: resubmit read urb failed. (%d)\n",
286                                 __func__, err);
287                         /* busy also in error unless we are killed */
288                         usb_mark_last_busy(port->serial->dev);
289                 }
290         } else {
291                 usb_mark_last_busy(port->serial->dev);
292         }
293 }
294
295 static void usb_wwan_outdat_callback(struct urb *urb)
296 {
297         struct usb_serial_port *port;
298         struct usb_wwan_port_private *portdata;
299         struct usb_wwan_intf_private *intfdata;
300         unsigned long flags;
301         int i;
302
303         port = urb->context;
304         intfdata = usb_get_serial_data(port->serial);
305
306         usb_serial_port_softint(port);
307         usb_autopm_put_interface_async(port->serial->interface);
308         portdata = usb_get_serial_port_data(port);
309         spin_lock_irqsave(&intfdata->susp_lock, flags);
310         intfdata->in_flight--;
311         spin_unlock_irqrestore(&intfdata->susp_lock, flags);
312
313         for (i = 0; i < N_OUT_URB; ++i) {
314                 if (portdata->out_urbs[i] == urb) {
315                         smp_mb__before_atomic();
316                         clear_bit(i, &portdata->out_busy);
317                         break;
318                 }
319         }
320 }
321
322 int usb_wwan_write_room(struct tty_struct *tty)
323 {
324         struct usb_serial_port *port = tty->driver_data;
325         struct usb_wwan_port_private *portdata;
326         int i;
327         int data_len = 0;
328         struct urb *this_urb;
329
330         portdata = usb_get_serial_port_data(port);
331
332         for (i = 0; i < N_OUT_URB; i++) {
333                 this_urb = portdata->out_urbs[i];
334                 if (this_urb && !test_bit(i, &portdata->out_busy))
335                         data_len += OUT_BUFLEN;
336         }
337
338         dev_dbg(&port->dev, "%s: %d\n", __func__, data_len);
339         return data_len;
340 }
341 EXPORT_SYMBOL(usb_wwan_write_room);
342
343 int usb_wwan_chars_in_buffer(struct tty_struct *tty)
344 {
345         struct usb_serial_port *port = tty->driver_data;
346         struct usb_wwan_port_private *portdata;
347         int i;
348         int data_len = 0;
349         struct urb *this_urb;
350
351         portdata = usb_get_serial_port_data(port);
352
353         for (i = 0; i < N_OUT_URB; i++) {
354                 this_urb = portdata->out_urbs[i];
355                 /* FIXME: This locking is insufficient as this_urb may
356                    go unused during the test */
357                 if (this_urb && test_bit(i, &portdata->out_busy))
358                         data_len += this_urb->transfer_buffer_length;
359         }
360         dev_dbg(&port->dev, "%s: %d\n", __func__, data_len);
361         return data_len;
362 }
363 EXPORT_SYMBOL(usb_wwan_chars_in_buffer);
364
365 int usb_wwan_open(struct tty_struct *tty, struct usb_serial_port *port)
366 {
367         struct usb_wwan_port_private *portdata;
368         struct usb_wwan_intf_private *intfdata;
369         struct usb_serial *serial = port->serial;
370         int i, err;
371         struct urb *urb;
372
373         portdata = usb_get_serial_port_data(port);
374         intfdata = usb_get_serial_data(serial);
375
376         if (port->interrupt_in_urb) {
377                 err = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
378                 if (err) {
379                         dev_err(&port->dev, "%s: submit int urb failed: %d\n",
380                                 __func__, err);
381                 }
382         }
383
384         /* Start reading from the IN endpoint */
385         for (i = 0; i < N_IN_URB; i++) {
386                 urb = portdata->in_urbs[i];
387                 if (!urb)
388                         continue;
389                 err = usb_submit_urb(urb, GFP_KERNEL);
390                 if (err) {
391                         dev_err(&port->dev,
392                                 "%s: submit read urb %d failed: %d\n",
393                                 __func__, i, err);
394                 }
395         }
396
397         spin_lock_irq(&intfdata->susp_lock);
398         if (++intfdata->open_ports == 1)
399                 serial->interface->needs_remote_wakeup = 1;
400         spin_unlock_irq(&intfdata->susp_lock);
401         /* this balances a get in the generic USB serial code */
402         usb_autopm_put_interface(serial->interface);
403
404         return 0;
405 }
406 EXPORT_SYMBOL(usb_wwan_open);
407
408 static void unbusy_queued_urb(struct urb *urb,
409                                         struct usb_wwan_port_private *portdata)
410 {
411         int i;
412
413         for (i = 0; i < N_OUT_URB; i++) {
414                 if (urb == portdata->out_urbs[i]) {
415                         clear_bit(i, &portdata->out_busy);
416                         break;
417                 }
418         }
419 }
420
421 void usb_wwan_close(struct usb_serial_port *port)
422 {
423         int i;
424         struct usb_serial *serial = port->serial;
425         struct usb_wwan_port_private *portdata;
426         struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
427         struct urb *urb;
428
429         portdata = usb_get_serial_port_data(port);
430
431         /*
432          * Need to take susp_lock to make sure port is not already being
433          * resumed, but no need to hold it due to initialized
434          */
435         spin_lock_irq(&intfdata->susp_lock);
436         if (--intfdata->open_ports == 0)
437                 serial->interface->needs_remote_wakeup = 0;
438         spin_unlock_irq(&intfdata->susp_lock);
439
440         for (;;) {
441                 urb = usb_get_from_anchor(&portdata->delayed);
442                 if (!urb)
443                         break;
444                 unbusy_queued_urb(urb, portdata);
445                 usb_autopm_put_interface_async(serial->interface);
446         }
447
448         for (i = 0; i < N_IN_URB; i++)
449                 usb_kill_urb(portdata->in_urbs[i]);
450         for (i = 0; i < N_OUT_URB; i++)
451                 usb_kill_urb(portdata->out_urbs[i]);
452         usb_kill_urb(port->interrupt_in_urb);
453
454         usb_autopm_get_interface_no_resume(serial->interface);
455 }
456 EXPORT_SYMBOL(usb_wwan_close);
457
458 static struct urb *usb_wwan_setup_urb(struct usb_serial_port *port,
459                                       int endpoint,
460                                       int dir, void *ctx, char *buf, int len,
461                                       void (*callback) (struct urb *))
462 {
463         struct usb_serial *serial = port->serial;
464         struct urb *urb;
465
466         urb = usb_alloc_urb(0, GFP_KERNEL);     /* No ISO */
467         if (!urb)
468                 return NULL;
469
470         usb_fill_bulk_urb(urb, serial->dev,
471                           usb_sndbulkpipe(serial->dev, endpoint) | dir,
472                           buf, len, callback, ctx);
473
474         return urb;
475 }
476
477 int usb_wwan_port_probe(struct usb_serial_port *port)
478 {
479         struct usb_wwan_port_private *portdata;
480         struct urb *urb;
481         u8 *buffer;
482         int i;
483
484         if (!port->bulk_in_size || !port->bulk_out_size)
485                 return -ENODEV;
486
487         portdata = kzalloc(sizeof(*portdata), GFP_KERNEL);
488         if (!portdata)
489                 return -ENOMEM;
490
491         init_usb_anchor(&portdata->delayed);
492
493         for (i = 0; i < N_IN_URB; i++) {
494                 buffer = (u8 *)__get_free_page(GFP_KERNEL);
495                 if (!buffer)
496                         goto bail_out_error;
497                 portdata->in_buffer[i] = buffer;
498
499                 urb = usb_wwan_setup_urb(port, port->bulk_in_endpointAddress,
500                                                 USB_DIR_IN, port,
501                                                 buffer, IN_BUFLEN,
502                                                 usb_wwan_indat_callback);
503                 portdata->in_urbs[i] = urb;
504         }
505
506         for (i = 0; i < N_OUT_URB; i++) {
507                 buffer = kmalloc(OUT_BUFLEN, GFP_KERNEL);
508                 if (!buffer)
509                         goto bail_out_error2;
510                 portdata->out_buffer[i] = buffer;
511
512                 urb = usb_wwan_setup_urb(port, port->bulk_out_endpointAddress,
513                                                 USB_DIR_OUT, port,
514                                                 buffer, OUT_BUFLEN,
515                                                 usb_wwan_outdat_callback);
516                 portdata->out_urbs[i] = urb;
517         }
518
519         usb_set_serial_port_data(port, portdata);
520
521         return 0;
522
523 bail_out_error2:
524         for (i = 0; i < N_OUT_URB; i++) {
525                 usb_free_urb(portdata->out_urbs[i]);
526                 kfree(portdata->out_buffer[i]);
527         }
528 bail_out_error:
529         for (i = 0; i < N_IN_URB; i++) {
530                 usb_free_urb(portdata->in_urbs[i]);
531                 free_page((unsigned long)portdata->in_buffer[i]);
532         }
533         kfree(portdata);
534
535         return -ENOMEM;
536 }
537 EXPORT_SYMBOL_GPL(usb_wwan_port_probe);
538
539 int usb_wwan_port_remove(struct usb_serial_port *port)
540 {
541         int i;
542         struct usb_wwan_port_private *portdata;
543
544         portdata = usb_get_serial_port_data(port);
545         usb_set_serial_port_data(port, NULL);
546
547         for (i = 0; i < N_IN_URB; i++) {
548                 usb_free_urb(portdata->in_urbs[i]);
549                 free_page((unsigned long)portdata->in_buffer[i]);
550         }
551         for (i = 0; i < N_OUT_URB; i++) {
552                 usb_free_urb(portdata->out_urbs[i]);
553                 kfree(portdata->out_buffer[i]);
554         }
555
556         kfree(portdata);
557
558         return 0;
559 }
560 EXPORT_SYMBOL(usb_wwan_port_remove);
561
562 #ifdef CONFIG_PM
563 static void stop_urbs(struct usb_serial *serial)
564 {
565         int i, j;
566         struct usb_serial_port *port;
567         struct usb_wwan_port_private *portdata;
568
569         for (i = 0; i < serial->num_ports; ++i) {
570                 port = serial->port[i];
571                 portdata = usb_get_serial_port_data(port);
572                 if (!portdata)
573                         continue;
574                 for (j = 0; j < N_IN_URB; j++)
575                         usb_kill_urb(portdata->in_urbs[j]);
576                 for (j = 0; j < N_OUT_URB; j++)
577                         usb_kill_urb(portdata->out_urbs[j]);
578                 usb_kill_urb(port->interrupt_in_urb);
579         }
580 }
581
582 int usb_wwan_suspend(struct usb_serial *serial, pm_message_t message)
583 {
584         struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
585
586         spin_lock_irq(&intfdata->susp_lock);
587         if (PMSG_IS_AUTO(message)) {
588                 if (intfdata->in_flight) {
589                         spin_unlock_irq(&intfdata->susp_lock);
590                         return -EBUSY;
591                 }
592         }
593         intfdata->suspended = 1;
594         spin_unlock_irq(&intfdata->susp_lock);
595
596         stop_urbs(serial);
597
598         return 0;
599 }
600 EXPORT_SYMBOL(usb_wwan_suspend);
601
602 /* Caller must hold susp_lock. */
603 static int usb_wwan_submit_delayed_urbs(struct usb_serial_port *port)
604 {
605         struct usb_serial *serial = port->serial;
606         struct usb_wwan_intf_private *data = usb_get_serial_data(serial);
607         struct usb_wwan_port_private *portdata;
608         struct urb *urb;
609         int err_count = 0;
610         int err;
611
612         portdata = usb_get_serial_port_data(port);
613
614         for (;;) {
615                 urb = usb_get_from_anchor(&portdata->delayed);
616                 if (!urb)
617                         break;
618
619                 err = usb_submit_urb(urb, GFP_ATOMIC);
620                 if (err) {
621                         dev_err(&port->dev, "%s: submit urb failed: %d\n",
622                                         __func__, err);
623                         err_count++;
624                         unbusy_queued_urb(urb, portdata);
625                         usb_autopm_put_interface_async(serial->interface);
626                         continue;
627                 }
628                 data->in_flight++;
629         }
630
631         if (err_count)
632                 return -EIO;
633
634         return 0;
635 }
636
637 int usb_wwan_resume(struct usb_serial *serial)
638 {
639         int i, j;
640         struct usb_serial_port *port;
641         struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
642         struct usb_wwan_port_private *portdata;
643         struct urb *urb;
644         int err;
645         int err_count = 0;
646
647         spin_lock_irq(&intfdata->susp_lock);
648         for (i = 0; i < serial->num_ports; i++) {
649                 port = serial->port[i];
650
651                 if (!tty_port_initialized(&port->port))
652                         continue;
653
654                 portdata = usb_get_serial_port_data(port);
655
656                 if (port->interrupt_in_urb) {
657                         err = usb_submit_urb(port->interrupt_in_urb,
658                                         GFP_ATOMIC);
659                         if (err) {
660                                 dev_err(&port->dev,
661                                         "%s: submit int urb failed: %d\n",
662                                         __func__, err);
663                                 err_count++;
664                         }
665                 }
666
667                 err = usb_wwan_submit_delayed_urbs(port);
668                 if (err)
669                         err_count++;
670
671                 for (j = 0; j < N_IN_URB; j++) {
672                         urb = portdata->in_urbs[j];
673                         err = usb_submit_urb(urb, GFP_ATOMIC);
674                         if (err < 0) {
675                                 dev_err(&port->dev,
676                                         "%s: submit read urb %d failed: %d\n",
677                                         __func__, i, err);
678                                 err_count++;
679                         }
680                 }
681         }
682         intfdata->suspended = 0;
683         spin_unlock_irq(&intfdata->susp_lock);
684
685         if (err_count)
686                 return -EIO;
687
688         return 0;
689 }
690 EXPORT_SYMBOL(usb_wwan_resume);
691 #endif
692
693 MODULE_AUTHOR(DRIVER_AUTHOR);
694 MODULE_DESCRIPTION(DRIVER_DESC);
695 MODULE_LICENSE("GPL v2");