ALSA: us122l: add snd_us122l_free()
[safe/jmp/linux-2.6] / sound / usb / usx2y / us122l.c
1 /*
2  * Copyright (C) 2007, 2008 Karsten Wiese <fzu@wemgehoertderstaat.de>
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms of the GNU General Public License as published by the
6  * Free Software Foundation; either version 2 of the License, or (at your
7  * option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful, but
10  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
11  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12  * for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software Foundation,
16  * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17  */
18
19 #include <sound/core.h>
20 #include <sound/hwdep.h>
21 #include <sound/pcm.h>
22 #include <sound/initval.h>
23 #define MODNAME "US122L"
24 #include "usb_stream.c"
25 #include "../usbaudio.h"
26 #include "us122l.h"
27
28 MODULE_AUTHOR("Karsten Wiese <fzu@wemgehoertderstaat.de>");
29 MODULE_DESCRIPTION("TASCAM "NAME_ALLCAPS" Version 0.5");
30 MODULE_LICENSE("GPL");
31
32 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;      /* Index 0-max */
33 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;       /* Id for this card */
34                                                         /* Enable this card */
35 static int enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;
36
37 module_param_array(index, int, NULL, 0444);
38 MODULE_PARM_DESC(index, "Index value for "NAME_ALLCAPS".");
39 module_param_array(id, charp, NULL, 0444);
40 MODULE_PARM_DESC(id, "ID string for "NAME_ALLCAPS".");
41 module_param_array(enable, bool, NULL, 0444);
42 MODULE_PARM_DESC(enable, "Enable "NAME_ALLCAPS".");
43
44 static int snd_us122l_card_used[SNDRV_CARDS];
45
46
47 static int us122l_create_usbmidi(struct snd_card *card)
48 {
49         static struct snd_usb_midi_endpoint_info quirk_data = {
50                 .out_ep = 4,
51                 .in_ep = 3,
52                 .out_cables =   0x001,
53                 .in_cables =    0x001
54         };
55         static struct snd_usb_audio_quirk quirk = {
56                 .vendor_name =  "US122L",
57                 .product_name = NAME_ALLCAPS,
58                 .ifnum =        1,
59                 .type = QUIRK_MIDI_US122L,
60                 .data = &quirk_data
61         };
62         struct usb_device *dev = US122L(card)->chip.dev;
63         struct usb_interface *iface = usb_ifnum_to_if(dev, 1);
64
65         return snd_usb_create_midi_interface(&US122L(card)->chip,
66                                              iface, &quirk);
67 }
68
69 /*
70  * Wrapper for usb_control_msg().
71  * Allocates a temp buffer to prevent dmaing from/to the stack.
72  */
73 static int us122l_ctl_msg(struct usb_device *dev, unsigned int pipe,
74                           __u8 request, __u8 requesttype,
75                           __u16 value, __u16 index, void *data,
76                           __u16 size, int timeout)
77 {
78         int err;
79         void *buf = NULL;
80
81         if (size > 0) {
82                 buf = kmemdup(data, size, GFP_KERNEL);
83                 if (!buf)
84                         return -ENOMEM;
85         }
86         err = usb_control_msg(dev, pipe, request, requesttype,
87                               value, index, buf, size, timeout);
88         if (size > 0) {
89                 memcpy(data, buf, size);
90                 kfree(buf);
91         }
92         return err;
93 }
94
95 static void pt_info_set(struct usb_device *dev, u8 v)
96 {
97         int ret;
98
99         ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
100                               'I',
101                               USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
102                               v, 0, NULL, 0, 1000);
103         snd_printdd(KERN_DEBUG "%i\n", ret);
104 }
105
106 static void usb_stream_hwdep_vm_open(struct vm_area_struct *area)
107 {
108         struct us122l *us122l = area->vm_private_data;
109         atomic_inc(&us122l->mmap_count);
110         snd_printdd(KERN_DEBUG "%i\n", atomic_read(&us122l->mmap_count));
111 }
112
113 static int usb_stream_hwdep_vm_fault(struct vm_area_struct *area,
114                                      struct vm_fault *vmf)
115 {
116         unsigned long offset;
117         struct page *page;
118         void *vaddr;
119         struct us122l *us122l = area->vm_private_data;
120         struct usb_stream *s;
121
122         mutex_lock(&us122l->mutex);
123         s = us122l->sk.s;
124         if (!s)
125                 goto unlock;
126
127         offset = vmf->pgoff << PAGE_SHIFT;
128         if (offset < PAGE_ALIGN(s->read_size))
129                 vaddr = (char *)s + offset;
130         else {
131                 offset -= PAGE_ALIGN(s->read_size);
132                 if (offset >= PAGE_ALIGN(s->write_size))
133                         goto unlock;
134
135                 vaddr = us122l->sk.write_page + offset;
136         }
137         page = virt_to_page(vaddr);
138
139         get_page(page);
140         mutex_unlock(&us122l->mutex);
141
142         vmf->page = page;
143
144         return 0;
145 unlock:
146         mutex_unlock(&us122l->mutex);
147         return VM_FAULT_SIGBUS;
148 }
149
150 static void usb_stream_hwdep_vm_close(struct vm_area_struct *area)
151 {
152         struct us122l *us122l = area->vm_private_data;
153         atomic_dec(&us122l->mmap_count);
154         snd_printdd(KERN_DEBUG "%i\n", atomic_read(&us122l->mmap_count));
155 }
156
157 static struct vm_operations_struct usb_stream_hwdep_vm_ops = {
158         .open = usb_stream_hwdep_vm_open,
159         .fault = usb_stream_hwdep_vm_fault,
160         .close = usb_stream_hwdep_vm_close,
161 };
162
163
164 static int usb_stream_hwdep_open(struct snd_hwdep *hw, struct file *file)
165 {
166         struct us122l   *us122l = hw->private_data;
167         struct usb_interface *iface;
168         snd_printdd(KERN_DEBUG "%p %p\n", hw, file);
169         if (hw->used >= 2)
170                 return -EBUSY;
171
172         if (!us122l->first)
173                 us122l->first = file;
174         iface = usb_ifnum_to_if(us122l->chip.dev, 1);
175         usb_autopm_get_interface(iface);
176         return 0;
177 }
178
179 static int usb_stream_hwdep_release(struct snd_hwdep *hw, struct file *file)
180 {
181         struct us122l   *us122l = hw->private_data;
182         struct usb_interface *iface = usb_ifnum_to_if(us122l->chip.dev, 1);
183         snd_printdd(KERN_DEBUG "%p %p\n", hw, file);
184         usb_autopm_put_interface(iface);
185         if (us122l->first == file)
186                 us122l->first = NULL;
187         mutex_lock(&us122l->mutex);
188         if (us122l->master == file)
189                 us122l->master = us122l->slave;
190
191         us122l->slave = NULL;
192         mutex_unlock(&us122l->mutex);
193         return 0;
194 }
195
196 static int usb_stream_hwdep_mmap(struct snd_hwdep *hw,
197                                  struct file *filp, struct vm_area_struct *area)
198 {
199         unsigned long   size = area->vm_end - area->vm_start;
200         struct us122l   *us122l = hw->private_data;
201         unsigned long offset;
202         struct usb_stream *s;
203         int err = 0;
204         bool read;
205
206         offset = area->vm_pgoff << PAGE_SHIFT;
207         mutex_lock(&us122l->mutex);
208         s = us122l->sk.s;
209         read = offset < s->read_size;
210         if (read && area->vm_flags & VM_WRITE) {
211                 err = -EPERM;
212                 goto out;
213         }
214         snd_printdd(KERN_DEBUG "%lu %u\n", size,
215                     read ? s->read_size : s->write_size);
216         /* if userspace tries to mmap beyond end of our buffer, fail */
217         if (size > PAGE_ALIGN(read ? s->read_size : s->write_size)) {
218                 snd_printk(KERN_WARNING "%lu > %u\n", size,
219                            read ? s->read_size : s->write_size);
220                 err = -EINVAL;
221                 goto out;
222         }
223
224         area->vm_ops = &usb_stream_hwdep_vm_ops;
225         area->vm_flags |= VM_RESERVED;
226         area->vm_private_data = us122l;
227         atomic_inc(&us122l->mmap_count);
228 out:
229         mutex_unlock(&us122l->mutex);
230         return err;
231 }
232
233 static unsigned int usb_stream_hwdep_poll(struct snd_hwdep *hw,
234                                           struct file *file, poll_table *wait)
235 {
236         struct us122l   *us122l = hw->private_data;
237         struct usb_stream *s = us122l->sk.s;
238         unsigned        *polled;
239         unsigned int    mask;
240
241         poll_wait(file, &us122l->sk.sleep, wait);
242
243         switch (s->state) {
244         case usb_stream_ready:
245                 if (us122l->first == file)
246                         polled = &s->periods_polled;
247                 else
248                         polled = &us122l->second_periods_polled;
249                 if (*polled != s->periods_done) {
250                         *polled = s->periods_done;
251                         mask = POLLIN | POLLOUT | POLLWRNORM;
252                         break;
253                 }
254                 /* Fall through */
255                 mask = 0;
256                 break;
257         default:
258                 mask = POLLIN | POLLOUT | POLLWRNORM | POLLERR;
259                 break;
260         }
261         return mask;
262 }
263
264 static void us122l_stop(struct us122l *us122l)
265 {
266         struct list_head *p;
267         list_for_each(p, &us122l->chip.midi_list)
268                 snd_usbmidi_input_stop(p);
269
270         usb_stream_stop(&us122l->sk);
271         usb_stream_free(&us122l->sk);
272 }
273
274 static int us122l_set_sample_rate(struct usb_device *dev, int rate)
275 {
276         unsigned int ep = 0x81;
277         unsigned char data[3];
278         int err;
279
280         data[0] = rate;
281         data[1] = rate >> 8;
282         data[2] = rate >> 16;
283         err = us122l_ctl_msg(dev, usb_sndctrlpipe(dev, 0), SET_CUR,
284                              USB_TYPE_CLASS|USB_RECIP_ENDPOINT|USB_DIR_OUT,
285                              SAMPLING_FREQ_CONTROL << 8, ep, data, 3, 1000);
286         if (err < 0)
287                 snd_printk(KERN_ERR "%d: cannot set freq %d to ep 0x%x\n",
288                            dev->devnum, rate, ep);
289         return err;
290 }
291
292 static bool us122l_start(struct us122l *us122l,
293                          unsigned rate, unsigned period_frames)
294 {
295         struct list_head *p;
296         int err;
297         unsigned use_packsize = 0;
298         bool success = false;
299
300         if (us122l->chip.dev->speed == USB_SPEED_HIGH) {
301                 /* The us-122l's descriptor defaults to iso max_packsize 78,
302                    which isn't needed for samplerates <= 48000.
303                    Lets save some memory:
304                 */
305                 switch (rate) {
306                 case 44100:
307                         use_packsize = 36;
308                         break;
309                 case 48000:
310                         use_packsize = 42;
311                         break;
312                 case 88200:
313                         use_packsize = 72;
314                         break;
315                 }
316         }
317         if (!usb_stream_new(&us122l->sk, us122l->chip.dev, 1, 2,
318                             rate, use_packsize, period_frames, 6))
319                 goto out;
320
321         err = us122l_set_sample_rate(us122l->chip.dev, rate);
322         if (err < 0) {
323                 us122l_stop(us122l);
324                 snd_printk(KERN_ERR "us122l_set_sample_rate error \n");
325                 goto out;
326         }
327         err = usb_stream_start(&us122l->sk);
328         if (err < 0) {
329                 us122l_stop(us122l);
330                 snd_printk(KERN_ERR "us122l_start error %i \n", err);
331                 goto out;
332         }
333         list_for_each(p, &us122l->chip.midi_list)
334                 snd_usbmidi_input_start(p);
335         success = true;
336 out:
337         return success;
338 }
339
340 static int usb_stream_hwdep_ioctl(struct snd_hwdep *hw, struct file *file,
341                                   unsigned cmd, unsigned long arg)
342 {
343         struct usb_stream_config *cfg;
344         struct us122l *us122l = hw->private_data;
345         unsigned min_period_frames;
346         int err = 0;
347         bool high_speed;
348
349         if (cmd != SNDRV_USB_STREAM_IOCTL_SET_PARAMS)
350                 return -ENOTTY;
351
352         cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
353         if (!cfg)
354                 return -ENOMEM;
355
356         if (copy_from_user(cfg, (void *)arg, sizeof(*cfg))) {
357                 err = -EFAULT;
358                 goto free;
359         }
360         if (cfg->version != USB_STREAM_INTERFACE_VERSION) {
361                 err = -ENXIO;
362                 goto free;
363         }
364         high_speed = us122l->chip.dev->speed == USB_SPEED_HIGH;
365         if ((cfg->sample_rate != 44100 && cfg->sample_rate != 48000  &&
366              (!high_speed ||
367               (cfg->sample_rate != 88200 && cfg->sample_rate != 96000))) ||
368             cfg->frame_size != 6 ||
369             cfg->period_frames > 0x3000) {
370                 err = -EINVAL;
371                 goto free;
372         }
373         switch (cfg->sample_rate) {
374         case 44100:
375                 min_period_frames = 48;
376                 break;
377         case 48000:
378                 min_period_frames = 52;
379                 break;
380         default:
381                 min_period_frames = 104;
382                 break;
383         }
384         if (!high_speed)
385                 min_period_frames <<= 1;
386         if (cfg->period_frames < min_period_frames) {
387                 err = -EINVAL;
388                 goto free;
389         }
390
391         snd_power_wait(hw->card, SNDRV_CTL_POWER_D0);
392
393         mutex_lock(&us122l->mutex);
394         if (!us122l->master)
395                 us122l->master = file;
396         else if (us122l->master != file) {
397                 if (memcmp(cfg, &us122l->sk.s->cfg, sizeof(*cfg))) {
398                         err = -EIO;
399                         goto unlock;
400                 }
401                 us122l->slave = file;
402         }
403         if (!us122l->sk.s ||
404             memcmp(cfg, &us122l->sk.s->cfg, sizeof(*cfg)) ||
405             us122l->sk.s->state == usb_stream_xrun) {
406                 us122l_stop(us122l);
407                 if (!us122l_start(us122l, cfg->sample_rate, cfg->period_frames))
408                         err = -EIO;
409                 else
410                         err = 1;
411         }
412 unlock:
413         mutex_unlock(&us122l->mutex);
414 free:
415         kfree(cfg);
416         return err;
417 }
418
419 #define SND_USB_STREAM_ID "USB STREAM"
420 static int usb_stream_hwdep_new(struct snd_card *card)
421 {
422         int err;
423         struct snd_hwdep *hw;
424         struct usb_device *dev = US122L(card)->chip.dev;
425
426         err = snd_hwdep_new(card, SND_USB_STREAM_ID, 0, &hw);
427         if (err < 0)
428                 return err;
429
430         hw->iface = SNDRV_HWDEP_IFACE_USB_STREAM;
431         hw->private_data = US122L(card);
432         hw->ops.open = usb_stream_hwdep_open;
433         hw->ops.release = usb_stream_hwdep_release;
434         hw->ops.ioctl = usb_stream_hwdep_ioctl;
435         hw->ops.ioctl_compat = usb_stream_hwdep_ioctl;
436         hw->ops.mmap = usb_stream_hwdep_mmap;
437         hw->ops.poll = usb_stream_hwdep_poll;
438
439         sprintf(hw->name, "/proc/bus/usb/%03d/%03d/hwdeppcm",
440                 dev->bus->busnum, dev->devnum);
441         return 0;
442 }
443
444
445 static bool us122l_create_card(struct snd_card *card)
446 {
447         int err;
448         struct us122l *us122l = US122L(card);
449
450         err = usb_set_interface(us122l->chip.dev, 1, 1);
451         if (err) {
452                 snd_printk(KERN_ERR "usb_set_interface error \n");
453                 return false;
454         }
455
456         pt_info_set(us122l->chip.dev, 0x11);
457         pt_info_set(us122l->chip.dev, 0x10);
458
459         if (!us122l_start(us122l, 44100, 256))
460                 return false;
461
462         err = us122l_create_usbmidi(card);
463         if (err < 0) {
464                 snd_printk(KERN_ERR "us122l_create_usbmidi error %i \n", err);
465                 us122l_stop(us122l);
466                 return false;
467         }
468         err = usb_stream_hwdep_new(card);
469         if (err < 0) {
470 /* release the midi resources */
471                 struct list_head *p;
472                 list_for_each(p, &us122l->chip.midi_list)
473                         snd_usbmidi_disconnect(p);
474
475                 us122l_stop(us122l);
476                 return false;
477         }
478         return true;
479 }
480
481 static void snd_us122l_free(struct snd_card *card)
482 {
483         struct us122l   *us122l = US122L(card);
484         int             index = us122l->chip.index;
485         if (index >= 0  &&  index < SNDRV_CARDS)
486                 snd_us122l_card_used[index] = 0;
487 }
488
489 static int usx2y_create_card(struct usb_device *device, struct snd_card **cardp)
490 {
491         int             dev;
492         struct snd_card *card;
493         int err;
494
495         for (dev = 0; dev < SNDRV_CARDS; ++dev)
496                 if (enable[dev] && !snd_us122l_card_used[dev])
497                         break;
498         if (dev >= SNDRV_CARDS)
499                 return -ENODEV;
500         err = snd_card_create(index[dev], id[dev], THIS_MODULE,
501                               sizeof(struct us122l), &card);
502         if (err < 0)
503                 return err;
504         snd_us122l_card_used[US122L(card)->chip.index = dev] = 1;
505         card->private_free = snd_us122l_free;
506         US122L(card)->chip.dev = device;
507         US122L(card)->chip.card = card;
508         mutex_init(&US122L(card)->mutex);
509         init_waitqueue_head(&US122L(card)->sk.sleep);
510         INIT_LIST_HEAD(&US122L(card)->chip.midi_list);
511         strcpy(card->driver, "USB "NAME_ALLCAPS"");
512         sprintf(card->shortname, "TASCAM "NAME_ALLCAPS"");
513         sprintf(card->longname, "%s (%x:%x if %d at %03d/%03d)",
514                 card->shortname,
515                 le16_to_cpu(device->descriptor.idVendor),
516                 le16_to_cpu(device->descriptor.idProduct),
517                 0,
518                 US122L(card)->chip.dev->bus->busnum,
519                 US122L(card)->chip.dev->devnum
520                 );
521         snd_card_set_dev(card, &device->dev);
522         *cardp = card;
523         return 0;
524 }
525
526 static int us122l_usb_probe(struct usb_interface *intf,
527                             const struct usb_device_id *device_id,
528                             struct snd_card **cardp)
529 {
530         struct usb_device *device = interface_to_usbdev(intf);
531         struct snd_card *card;
532         int err;
533
534         err = usx2y_create_card(device, &card);
535         if (err < 0)
536                 return err;
537
538         if (!us122l_create_card(card)) {
539                 snd_card_free(card);
540                 return -EINVAL;
541         }
542
543         err = snd_card_register(card);
544         if (err < 0) {
545                 snd_card_free(card);
546                 return err;
547         }
548
549         usb_get_dev(device);
550         *cardp = card;
551         return 0;
552 }
553
554 static int snd_us122l_probe(struct usb_interface *intf,
555                             const struct usb_device_id *id)
556 {
557         struct snd_card *card;
558         int err;
559
560         snd_printdd(KERN_DEBUG"%p:%i\n",
561                     intf, intf->cur_altsetting->desc.bInterfaceNumber);
562         if (intf->cur_altsetting->desc.bInterfaceNumber != 1)
563                 return 0;
564
565         err = us122l_usb_probe(usb_get_intf(intf), id, &card);
566         if (err < 0) {
567                 usb_put_intf(intf);
568                 return err;
569         }
570
571         usb_set_intfdata(intf, card);
572         return 0;
573 }
574
575 static void snd_us122l_disconnect(struct usb_interface *intf)
576 {
577         struct snd_card *card;
578         struct us122l *us122l;
579         struct list_head *p;
580
581         card = usb_get_intfdata(intf);
582         if (!card)
583                 return;
584
585         snd_card_disconnect(card);
586
587         us122l = US122L(card);
588         mutex_lock(&us122l->mutex);
589         us122l_stop(us122l);
590         mutex_unlock(&us122l->mutex);
591         us122l->chip.shutdown = 1;
592
593 /* release the midi resources */
594         list_for_each(p, &us122l->chip.midi_list) {
595                 snd_usbmidi_disconnect(p);
596         }
597
598         usb_put_intf(intf);
599         usb_put_dev(us122l->chip.dev);
600
601         while (atomic_read(&us122l->mmap_count))
602                 msleep(500);
603
604         snd_card_free(card);
605 }
606
607 static int snd_us122l_suspend(struct usb_interface *intf, pm_message_t message)
608 {
609         struct snd_card *card;
610         struct us122l *us122l;
611         struct list_head *p;
612
613         card = usb_get_intfdata(intf);
614         if (!card)
615                 return 0;
616         snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
617
618         us122l = US122L(card);
619         if (!us122l)
620                 return 0;
621
622         list_for_each(p, &us122l->chip.midi_list)
623                 snd_usbmidi_input_stop(p);
624
625         mutex_lock(&us122l->mutex);
626         usb_stream_stop(&us122l->sk);
627         mutex_unlock(&us122l->mutex);
628
629         return 0;
630 }
631
632 static int snd_us122l_resume(struct usb_interface *intf)
633 {
634         struct snd_card *card;
635         struct us122l *us122l;
636         struct list_head *p;
637         int err;
638
639         card = usb_get_intfdata(intf);
640         if (!card)
641                 return 0;
642
643         us122l = US122L(card);
644         if (!us122l)
645                 return 0;
646
647         mutex_lock(&us122l->mutex);
648         /* needed, doesn't restart without: */
649         err = usb_set_interface(us122l->chip.dev, 1, 1);
650         if (err) {
651                 snd_printk(KERN_ERR "usb_set_interface error \n");
652                 goto unlock;
653         }
654
655         pt_info_set(us122l->chip.dev, 0x11);
656         pt_info_set(us122l->chip.dev, 0x10);
657
658         err = us122l_set_sample_rate(us122l->chip.dev,
659                                      us122l->sk.s->cfg.sample_rate);
660         if (err < 0) {
661                 snd_printk(KERN_ERR "us122l_set_sample_rate error \n");
662                 goto unlock;
663         }
664         err = usb_stream_start(&us122l->sk);
665         if (err)
666                 goto unlock;
667
668         list_for_each(p, &us122l->chip.midi_list)
669                 snd_usbmidi_input_start(p);
670 unlock:
671         mutex_unlock(&us122l->mutex);
672         snd_power_change_state(card, SNDRV_CTL_POWER_D0);
673         return err;
674 }
675
676 static struct usb_device_id snd_us122l_usb_id_table[] = {
677         {
678                 .match_flags =  USB_DEVICE_ID_MATCH_DEVICE,
679                 .idVendor =     0x0644,
680                 .idProduct =    USB_ID_US122L
681         },
682 /*      { */            /* US-144 maybe works when @USB1.1. Untested. */
683 /*              .match_flags =  USB_DEVICE_ID_MATCH_DEVICE, */
684 /*              .idVendor =     0x0644, */
685 /*              .idProduct =    USB_ID_US144 */
686 /*      }, */
687         { /* terminator */ }
688 };
689
690 MODULE_DEVICE_TABLE(usb, snd_us122l_usb_id_table);
691 static struct usb_driver snd_us122l_usb_driver = {
692         .name =         "snd-usb-us122l",
693         .probe =        snd_us122l_probe,
694         .disconnect =   snd_us122l_disconnect,
695         .suspend =      snd_us122l_suspend,
696         .resume =       snd_us122l_resume,
697         .reset_resume = snd_us122l_resume,
698         .id_table =     snd_us122l_usb_id_table,
699         .supports_autosuspend = 1
700 };
701
702
703 static int __init snd_us122l_module_init(void)
704 {
705         return usb_register(&snd_us122l_usb_driver);
706 }
707
708 static void __exit snd_us122l_module_exit(void)
709 {
710         usb_deregister(&snd_us122l_usb_driver);
711 }
712
713 module_init(snd_us122l_module_init)
714 module_exit(snd_us122l_module_exit)