drivers/usb: Remove unnecessary return's from void functions
[firefly-linux-kernel-4.4.55.git] / drivers / usb / serial / usb_wwan.c
1 /*
2   USB Driver layer for GSM modems
3
4   Copyright (C) 2005  Matthias Urlichs <smurf@smurf.noris.de>
5
6   This driver is free software; you can redistribute it and/or modify
7   it under the terms of Version 2 of the GNU General Public License as
8   published by the Free Software Foundation.
9
10   Portions copied from the Keyspan driver by Hugh Blemings <hugh@blemings.org>
11
12   History: see the git log.
13
14   Work sponsored by: Sigos GmbH, Germany <info@sigos.de>
15
16   This driver exists because the "normal" serial driver doesn't work too well
17   with GSM modems. Issues:
18   - data loss -- one single Receive URB is not nearly enough
19   - controlling the baud rate doesn't make sense
20 */
21
22 #define DRIVER_VERSION "v0.7.2"
23 #define DRIVER_AUTHOR "Matthias Urlichs <smurf@smurf.noris.de>"
24 #define DRIVER_DESC "USB Driver for GSM modems"
25
26 #include <linux/kernel.h>
27 #include <linux/jiffies.h>
28 #include <linux/errno.h>
29 #include <linux/slab.h>
30 #include <linux/tty.h>
31 #include <linux/tty_flip.h>
32 #include <linux/module.h>
33 #include <linux/bitops.h>
34 #include <linux/usb.h>
35 #include <linux/usb/serial.h>
36 #include "usb-wwan.h"
37
38 static int debug;
39
40 void usb_wwan_dtr_rts(struct usb_serial_port *port, int on)
41 {
42         struct usb_serial *serial = port->serial;
43         struct usb_wwan_port_private *portdata;
44
45         struct usb_wwan_intf_private *intfdata;
46
47         dbg("%s", __func__);
48
49         intfdata = port->serial->private;
50
51         if (!intfdata->send_setup)
52                 return;
53
54         portdata = usb_get_serial_port_data(port);
55         mutex_lock(&serial->disc_mutex);
56         portdata->rts_state = on;
57         portdata->dtr_state = on;
58         if (serial->dev)
59                 intfdata->send_setup(port);
60         mutex_unlock(&serial->disc_mutex);
61 }
62 EXPORT_SYMBOL(usb_wwan_dtr_rts);
63
64 void usb_wwan_set_termios(struct tty_struct *tty,
65                           struct usb_serial_port *port,
66                           struct ktermios *old_termios)
67 {
68         struct usb_wwan_intf_private *intfdata = port->serial->private;
69
70         dbg("%s", __func__);
71
72         /* Doesn't support option setting */
73         tty_termios_copy_hw(tty->termios, old_termios);
74
75         if (intfdata->send_setup)
76                 intfdata->send_setup(port);
77 }
78 EXPORT_SYMBOL(usb_wwan_set_termios);
79
80 int usb_wwan_tiocmget(struct tty_struct *tty, struct file *file)
81 {
82         struct usb_serial_port *port = tty->driver_data;
83         unsigned int value;
84         struct usb_wwan_port_private *portdata;
85
86         portdata = usb_get_serial_port_data(port);
87
88         value = ((portdata->rts_state) ? TIOCM_RTS : 0) |
89             ((portdata->dtr_state) ? TIOCM_DTR : 0) |
90             ((portdata->cts_state) ? TIOCM_CTS : 0) |
91             ((portdata->dsr_state) ? TIOCM_DSR : 0) |
92             ((portdata->dcd_state) ? TIOCM_CAR : 0) |
93             ((portdata->ri_state) ? TIOCM_RNG : 0);
94
95         return value;
96 }
97 EXPORT_SYMBOL(usb_wwan_tiocmget);
98
99 int usb_wwan_tiocmset(struct tty_struct *tty, struct file *file,
100                       unsigned int set, unsigned int clear)
101 {
102         struct usb_serial_port *port = tty->driver_data;
103         struct usb_wwan_port_private *portdata;
104         struct usb_wwan_intf_private *intfdata;
105
106         portdata = usb_get_serial_port_data(port);
107         intfdata = port->serial->private;
108
109         if (!intfdata->send_setup)
110                 return -EINVAL;
111
112         /* FIXME: what locks portdata fields ? */
113         if (set & TIOCM_RTS)
114                 portdata->rts_state = 1;
115         if (set & TIOCM_DTR)
116                 portdata->dtr_state = 1;
117
118         if (clear & TIOCM_RTS)
119                 portdata->rts_state = 0;
120         if (clear & TIOCM_DTR)
121                 portdata->dtr_state = 0;
122         return intfdata->send_setup(port);
123 }
124 EXPORT_SYMBOL(usb_wwan_tiocmset);
125
126 /* Write */
127 int usb_wwan_write(struct tty_struct *tty, struct usb_serial_port *port,
128                    const unsigned char *buf, int count)
129 {
130         struct usb_wwan_port_private *portdata;
131         struct usb_wwan_intf_private *intfdata;
132         int i;
133         int left, todo;
134         struct urb *this_urb = NULL;    /* spurious */
135         int err;
136         unsigned long flags;
137
138         portdata = usb_get_serial_port_data(port);
139         intfdata = port->serial->private;
140
141         dbg("%s: write (%d chars)", __func__, count);
142
143         i = 0;
144         left = count;
145         for (i = 0; left > 0 && i < N_OUT_URB; i++) {
146                 todo = left;
147                 if (todo > OUT_BUFLEN)
148                         todo = OUT_BUFLEN;
149
150                 this_urb = portdata->out_urbs[i];
151                 if (test_and_set_bit(i, &portdata->out_busy)) {
152                         if (time_before(jiffies,
153                                         portdata->tx_start_time[i] + 10 * HZ))
154                                 continue;
155                         usb_unlink_urb(this_urb);
156                         continue;
157                 }
158                 dbg("%s: endpoint %d buf %d", __func__,
159                     usb_pipeendpoint(this_urb->pipe), i);
160
161                 err = usb_autopm_get_interface_async(port->serial->interface);
162                 if (err < 0)
163                         break;
164
165                 /* send the data */
166                 memcpy(this_urb->transfer_buffer, buf, todo);
167                 this_urb->transfer_buffer_length = todo;
168
169                 spin_lock_irqsave(&intfdata->susp_lock, flags);
170                 if (intfdata->suspended) {
171                         usb_anchor_urb(this_urb, &portdata->delayed);
172                         spin_unlock_irqrestore(&intfdata->susp_lock, flags);
173                 } else {
174                         intfdata->in_flight++;
175                         spin_unlock_irqrestore(&intfdata->susp_lock, flags);
176                         err = usb_submit_urb(this_urb, GFP_ATOMIC);
177                         if (err) {
178                                 dbg("usb_submit_urb %p (write bulk) failed "
179                                     "(%d)", this_urb, err);
180                                 clear_bit(i, &portdata->out_busy);
181                                 spin_lock_irqsave(&intfdata->susp_lock, flags);
182                                 intfdata->in_flight--;
183                                 spin_unlock_irqrestore(&intfdata->susp_lock,
184                                                        flags);
185                                 continue;
186                         }
187                 }
188
189                 portdata->tx_start_time[i] = jiffies;
190                 buf += todo;
191                 left -= todo;
192         }
193
194         count -= left;
195         dbg("%s: wrote (did %d)", __func__, count);
196         return count;
197 }
198 EXPORT_SYMBOL(usb_wwan_write);
199
200 static void usb_wwan_indat_callback(struct urb *urb)
201 {
202         int err;
203         int endpoint;
204         struct usb_serial_port *port;
205         struct tty_struct *tty;
206         unsigned char *data = urb->transfer_buffer;
207         int status = urb->status;
208
209         dbg("%s: %p", __func__, urb);
210
211         endpoint = usb_pipeendpoint(urb->pipe);
212         port = urb->context;
213
214         if (status) {
215                 dbg("%s: nonzero status: %d on endpoint %02x.",
216                     __func__, status, endpoint);
217         } else {
218                 tty = tty_port_tty_get(&port->port);
219                 if (urb->actual_length) {
220                         tty_insert_flip_string(tty, data, urb->actual_length);
221                         tty_flip_buffer_push(tty);
222                 } else
223                         dbg("%s: empty read urb received", __func__);
224                 tty_kref_put(tty);
225
226                 /* Resubmit urb so we continue receiving */
227                 if (status != -ESHUTDOWN) {
228                         err = usb_submit_urb(urb, GFP_ATOMIC);
229                         if (err && err != -EPERM)
230                                 printk(KERN_ERR "%s: resubmit read urb failed. "
231                                        "(%d)", __func__, err);
232                         else
233                                 usb_mark_last_busy(port->serial->dev);
234                 }
235
236         }
237 }
238
239 static void usb_wwan_outdat_callback(struct urb *urb)
240 {
241         struct usb_serial_port *port;
242         struct usb_wwan_port_private *portdata;
243         struct usb_wwan_intf_private *intfdata;
244         int i;
245
246         dbg("%s", __func__);
247
248         port = urb->context;
249         intfdata = port->serial->private;
250
251         usb_serial_port_softint(port);
252         usb_autopm_put_interface_async(port->serial->interface);
253         portdata = usb_get_serial_port_data(port);
254         spin_lock(&intfdata->susp_lock);
255         intfdata->in_flight--;
256         spin_unlock(&intfdata->susp_lock);
257
258         for (i = 0; i < N_OUT_URB; ++i) {
259                 if (portdata->out_urbs[i] == urb) {
260                         smp_mb__before_clear_bit();
261                         clear_bit(i, &portdata->out_busy);
262                         break;
263                 }
264         }
265 }
266
267 int usb_wwan_write_room(struct tty_struct *tty)
268 {
269         struct usb_serial_port *port = tty->driver_data;
270         struct usb_wwan_port_private *portdata;
271         int i;
272         int data_len = 0;
273         struct urb *this_urb;
274
275         portdata = usb_get_serial_port_data(port);
276
277         for (i = 0; i < N_OUT_URB; i++) {
278                 this_urb = portdata->out_urbs[i];
279                 if (this_urb && !test_bit(i, &portdata->out_busy))
280                         data_len += OUT_BUFLEN;
281         }
282
283         dbg("%s: %d", __func__, data_len);
284         return data_len;
285 }
286 EXPORT_SYMBOL(usb_wwan_write_room);
287
288 int usb_wwan_chars_in_buffer(struct tty_struct *tty)
289 {
290         struct usb_serial_port *port = tty->driver_data;
291         struct usb_wwan_port_private *portdata;
292         int i;
293         int data_len = 0;
294         struct urb *this_urb;
295
296         portdata = usb_get_serial_port_data(port);
297
298         for (i = 0; i < N_OUT_URB; i++) {
299                 this_urb = portdata->out_urbs[i];
300                 /* FIXME: This locking is insufficient as this_urb may
301                    go unused during the test */
302                 if (this_urb && test_bit(i, &portdata->out_busy))
303                         data_len += this_urb->transfer_buffer_length;
304         }
305         dbg("%s: %d", __func__, data_len);
306         return data_len;
307 }
308 EXPORT_SYMBOL(usb_wwan_chars_in_buffer);
309
310 int usb_wwan_open(struct tty_struct *tty, struct usb_serial_port *port)
311 {
312         struct usb_wwan_port_private *portdata;
313         struct usb_wwan_intf_private *intfdata;
314         struct usb_serial *serial = port->serial;
315         int i, err;
316         struct urb *urb;
317
318         portdata = usb_get_serial_port_data(port);
319         intfdata = serial->private;
320
321         dbg("%s", __func__);
322
323         /* Start reading from the IN endpoint */
324         for (i = 0; i < N_IN_URB; i++) {
325                 urb = portdata->in_urbs[i];
326                 if (!urb)
327                         continue;
328                 err = usb_submit_urb(urb, GFP_KERNEL);
329                 if (err) {
330                         dbg("%s: submit urb %d failed (%d) %d",
331                             __func__, i, err, urb->transfer_buffer_length);
332                 }
333         }
334
335         if (intfdata->send_setup)
336                 intfdata->send_setup(port);
337
338         serial->interface->needs_remote_wakeup = 1;
339         spin_lock_irq(&intfdata->susp_lock);
340         portdata->opened = 1;
341         spin_unlock_irq(&intfdata->susp_lock);
342         usb_autopm_put_interface(serial->interface);
343
344         return 0;
345 }
346 EXPORT_SYMBOL(usb_wwan_open);
347
348 void usb_wwan_close(struct usb_serial_port *port)
349 {
350         int i;
351         struct usb_serial *serial = port->serial;
352         struct usb_wwan_port_private *portdata;
353         struct usb_wwan_intf_private *intfdata = port->serial->private;
354
355         dbg("%s", __func__);
356         portdata = usb_get_serial_port_data(port);
357
358         if (serial->dev) {
359                 /* Stop reading/writing urbs */
360                 spin_lock_irq(&intfdata->susp_lock);
361                 portdata->opened = 0;
362                 spin_unlock_irq(&intfdata->susp_lock);
363
364                 for (i = 0; i < N_IN_URB; i++)
365                         usb_kill_urb(portdata->in_urbs[i]);
366                 for (i = 0; i < N_OUT_URB; i++)
367                         usb_kill_urb(portdata->out_urbs[i]);
368                 usb_autopm_get_interface(serial->interface);
369                 serial->interface->needs_remote_wakeup = 0;
370         }
371 }
372 EXPORT_SYMBOL(usb_wwan_close);
373
374 /* Helper functions used by usb_wwan_setup_urbs */
375 static struct urb *usb_wwan_setup_urb(struct usb_serial *serial, int endpoint,
376                                       int dir, void *ctx, char *buf, int len,
377                                       void (*callback) (struct urb *))
378 {
379         struct urb *urb;
380
381         if (endpoint == -1)
382                 return NULL;    /* endpoint not needed */
383
384         urb = usb_alloc_urb(0, GFP_KERNEL);     /* No ISO */
385         if (urb == NULL) {
386                 dbg("%s: alloc for endpoint %d failed.", __func__, endpoint);
387                 return NULL;
388         }
389
390         /* Fill URB using supplied data. */
391         usb_fill_bulk_urb(urb, serial->dev,
392                           usb_sndbulkpipe(serial->dev, endpoint) | dir,
393                           buf, len, callback, ctx);
394
395         return urb;
396 }
397
398 /* Setup urbs */
399 static void usb_wwan_setup_urbs(struct usb_serial *serial)
400 {
401         int i, j;
402         struct usb_serial_port *port;
403         struct usb_wwan_port_private *portdata;
404
405         dbg("%s", __func__);
406
407         for (i = 0; i < serial->num_ports; i++) {
408                 port = serial->port[i];
409                 portdata = usb_get_serial_port_data(port);
410
411                 /* Do indat endpoints first */
412                 for (j = 0; j < N_IN_URB; ++j) {
413                         portdata->in_urbs[j] = usb_wwan_setup_urb(serial,
414                                                                   port->
415                                                                   bulk_in_endpointAddress,
416                                                                   USB_DIR_IN,
417                                                                   port,
418                                                                   portdata->
419                                                                   in_buffer[j],
420                                                                   IN_BUFLEN,
421                                                                   usb_wwan_indat_callback);
422                 }
423
424                 /* outdat endpoints */
425                 for (j = 0; j < N_OUT_URB; ++j) {
426                         portdata->out_urbs[j] = usb_wwan_setup_urb(serial,
427                                                                    port->
428                                                                    bulk_out_endpointAddress,
429                                                                    USB_DIR_OUT,
430                                                                    port,
431                                                                    portdata->
432                                                                    out_buffer
433                                                                    [j],
434                                                                    OUT_BUFLEN,
435                                                                    usb_wwan_outdat_callback);
436                 }
437         }
438 }
439
440 int usb_wwan_startup(struct usb_serial *serial)
441 {
442         int i, j, err;
443         struct usb_serial_port *port;
444         struct usb_wwan_port_private *portdata;
445         u8 *buffer;
446
447         dbg("%s", __func__);
448
449         /* Now setup per port private data */
450         for (i = 0; i < serial->num_ports; i++) {
451                 port = serial->port[i];
452                 portdata = kzalloc(sizeof(*portdata), GFP_KERNEL);
453                 if (!portdata) {
454                         dbg("%s: kmalloc for usb_wwan_port_private (%d) failed!.",
455                             __func__, i);
456                         return 1;
457                 }
458                 init_usb_anchor(&portdata->delayed);
459
460                 for (j = 0; j < N_IN_URB; j++) {
461                         buffer = (u8 *) __get_free_page(GFP_KERNEL);
462                         if (!buffer)
463                                 goto bail_out_error;
464                         portdata->in_buffer[j] = buffer;
465                 }
466
467                 for (j = 0; j < N_OUT_URB; j++) {
468                         buffer = kmalloc(OUT_BUFLEN, GFP_KERNEL);
469                         if (!buffer)
470                                 goto bail_out_error2;
471                         portdata->out_buffer[j] = buffer;
472                 }
473
474                 usb_set_serial_port_data(port, portdata);
475
476                 if (!port->interrupt_in_urb)
477                         continue;
478                 err = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
479                 if (err)
480                         dbg("%s: submit irq_in urb failed %d", __func__, err);
481         }
482         usb_wwan_setup_urbs(serial);
483         return 0;
484
485 bail_out_error2:
486         for (j = 0; j < N_OUT_URB; j++)
487                 kfree(portdata->out_buffer[j]);
488 bail_out_error:
489         for (j = 0; j < N_IN_URB; j++)
490                 if (portdata->in_buffer[j])
491                         free_page((unsigned long)portdata->in_buffer[j]);
492         kfree(portdata);
493         return 1;
494 }
495 EXPORT_SYMBOL(usb_wwan_startup);
496
497 static void stop_read_write_urbs(struct usb_serial *serial)
498 {
499         int i, j;
500         struct usb_serial_port *port;
501         struct usb_wwan_port_private *portdata;
502
503         /* Stop reading/writing urbs */
504         for (i = 0; i < serial->num_ports; ++i) {
505                 port = serial->port[i];
506                 portdata = usb_get_serial_port_data(port);
507                 for (j = 0; j < N_IN_URB; j++)
508                         usb_kill_urb(portdata->in_urbs[j]);
509                 for (j = 0; j < N_OUT_URB; j++)
510                         usb_kill_urb(portdata->out_urbs[j]);
511         }
512 }
513
514 void usb_wwan_disconnect(struct usb_serial *serial)
515 {
516         dbg("%s", __func__);
517
518         stop_read_write_urbs(serial);
519 }
520 EXPORT_SYMBOL(usb_wwan_disconnect);
521
522 void usb_wwan_release(struct usb_serial *serial)
523 {
524         int i, j;
525         struct usb_serial_port *port;
526         struct usb_wwan_port_private *portdata;
527
528         dbg("%s", __func__);
529
530         /* Now free them */
531         for (i = 0; i < serial->num_ports; ++i) {
532                 port = serial->port[i];
533                 portdata = usb_get_serial_port_data(port);
534
535                 for (j = 0; j < N_IN_URB; j++) {
536                         usb_free_urb(portdata->in_urbs[j]);
537                         free_page((unsigned long)
538                                   portdata->in_buffer[j]);
539                         portdata->in_urbs[j] = NULL;
540                 }
541                 for (j = 0; j < N_OUT_URB; j++) {
542                         usb_free_urb(portdata->out_urbs[j]);
543                         kfree(portdata->out_buffer[j]);
544                         portdata->out_urbs[j] = NULL;
545                 }
546         }
547
548         /* Now free per port private data */
549         for (i = 0; i < serial->num_ports; i++) {
550                 port = serial->port[i];
551                 kfree(usb_get_serial_port_data(port));
552         }
553 }
554 EXPORT_SYMBOL(usb_wwan_release);
555
556 #ifdef CONFIG_PM
557 int usb_wwan_suspend(struct usb_serial *serial, pm_message_t message)
558 {
559         struct usb_wwan_intf_private *intfdata = serial->private;
560         int b;
561
562         dbg("%s entered", __func__);
563
564         if (message.event & PM_EVENT_AUTO) {
565                 spin_lock_irq(&intfdata->susp_lock);
566                 b = intfdata->in_flight;
567                 spin_unlock_irq(&intfdata->susp_lock);
568
569                 if (b)
570                         return -EBUSY;
571         }
572
573         spin_lock_irq(&intfdata->susp_lock);
574         intfdata->suspended = 1;
575         spin_unlock_irq(&intfdata->susp_lock);
576         stop_read_write_urbs(serial);
577
578         return 0;
579 }
580 EXPORT_SYMBOL(usb_wwan_suspend);
581
582 static void play_delayed(struct usb_serial_port *port)
583 {
584         struct usb_wwan_intf_private *data;
585         struct usb_wwan_port_private *portdata;
586         struct urb *urb;
587         int err;
588
589         portdata = usb_get_serial_port_data(port);
590         data = port->serial->private;
591         while ((urb = usb_get_from_anchor(&portdata->delayed))) {
592                 err = usb_submit_urb(urb, GFP_ATOMIC);
593                 if (!err)
594                         data->in_flight++;
595         }
596 }
597
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 = serial->private;
603         struct usb_wwan_port_private *portdata;
604         struct urb *urb;
605         int err = 0;
606
607         dbg("%s entered", __func__);
608         /* get the interrupt URBs resubmitted unconditionally */
609         for (i = 0; i < serial->num_ports; i++) {
610                 port = serial->port[i];
611                 if (!port->interrupt_in_urb) {
612                         dbg("%s: No interrupt URB for port %d", __func__, i);
613                         continue;
614                 }
615                 err = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
616                 dbg("Submitted interrupt URB for port %d (result %d)", i, err);
617                 if (err < 0) {
618                         err("%s: Error %d for interrupt URB of port%d",
619                             __func__, err, i);
620                         goto err_out;
621                 }
622         }
623
624         for (i = 0; i < serial->num_ports; i++) {
625                 /* walk all ports */
626                 port = serial->port[i];
627                 portdata = usb_get_serial_port_data(port);
628
629                 /* skip closed ports */
630                 spin_lock_irq(&intfdata->susp_lock);
631                 if (!portdata->opened) {
632                         spin_unlock_irq(&intfdata->susp_lock);
633                         continue;
634                 }
635
636                 for (j = 0; j < N_IN_URB; j++) {
637                         urb = portdata->in_urbs[j];
638                         err = usb_submit_urb(urb, GFP_ATOMIC);
639                         if (err < 0) {
640                                 err("%s: Error %d for bulk URB %d",
641                                     __func__, err, i);
642                                 spin_unlock_irq(&intfdata->susp_lock);
643                                 goto err_out;
644                         }
645                 }
646                 play_delayed(port);
647                 spin_unlock_irq(&intfdata->susp_lock);
648         }
649         spin_lock_irq(&intfdata->susp_lock);
650         intfdata->suspended = 0;
651         spin_unlock_irq(&intfdata->susp_lock);
652 err_out:
653         return err;
654 }
655 EXPORT_SYMBOL(usb_wwan_resume);
656 #endif
657
658 MODULE_AUTHOR(DRIVER_AUTHOR);
659 MODULE_DESCRIPTION(DRIVER_DESC);
660 MODULE_VERSION(DRIVER_VERSION);
661 MODULE_LICENSE("GPL");
662
663 module_param(debug, bool, S_IRUGO | S_IWUSR);
664 MODULE_PARM_DESC(debug, "Debug messages");