xref: /linux/sound/usb/mixer.c (revision 148f9bb87745ed45f7a11b2cbd3bc0f017d5d257)
1 /*
2  *   (Tentative) USB Audio Driver for ALSA
3  *
4  *   Mixer control part
5  *
6  *   Copyright (c) 2002 by Takashi Iwai <tiwai@suse.de>
7  *
8  *   Many codes borrowed from audio.c by
9  *	    Alan Cox (alan@lxorguk.ukuu.org.uk)
10  *	    Thomas Sailer (sailer@ife.ee.ethz.ch)
11  *
12  *
13  *   This program is free software; you can redistribute it and/or modify
14  *   it under the terms of the GNU General Public License as published by
15  *   the Free Software Foundation; either version 2 of the License, or
16  *   (at your option) any later version.
17  *
18  *   This program is distributed in the hope that it will be useful,
19  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
20  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21  *   GNU General Public License for more details.
22  *
23  *   You should have received a copy of the GNU General Public License
24  *   along with this program; if not, write to the Free Software
25  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
26  *
27  */
28 
29 /*
30  * TODOs, for both the mixer and the streaming interfaces:
31  *
32  *  - support for UAC2 effect units
33  *  - support for graphical equalizers
34  *  - RANGE and MEM set commands (UAC2)
35  *  - RANGE and MEM interrupt dispatchers (UAC2)
36  *  - audio channel clustering (UAC2)
37  *  - audio sample rate converter units (UAC2)
38  *  - proper handling of clock multipliers (UAC2)
39  *  - dispatch clock change notifications (UAC2)
40  *  	- stop PCM streams which use a clock that became invalid
41  *  	- stop PCM streams which use a clock selector that has changed
42  *  	- parse available sample rates again when clock sources changed
43  */
44 
45 #include <linux/bitops.h>
46 #include <linux/init.h>
47 #include <linux/list.h>
48 #include <linux/slab.h>
49 #include <linux/string.h>
50 #include <linux/usb.h>
51 #include <linux/usb/audio.h>
52 #include <linux/usb/audio-v2.h>
53 
54 #include <sound/core.h>
55 #include <sound/control.h>
56 #include <sound/hwdep.h>
57 #include <sound/info.h>
58 #include <sound/tlv.h>
59 
60 #include "usbaudio.h"
61 #include "mixer.h"
62 #include "helper.h"
63 #include "mixer_quirks.h"
64 #include "power.h"
65 
66 #define MAX_ID_ELEMS	256
67 
68 struct usb_audio_term {
69 	int id;
70 	int type;
71 	int channels;
72 	unsigned int chconfig;
73 	int name;
74 };
75 
76 struct usbmix_name_map;
77 
78 struct mixer_build {
79 	struct snd_usb_audio *chip;
80 	struct usb_mixer_interface *mixer;
81 	unsigned char *buffer;
82 	unsigned int buflen;
83 	DECLARE_BITMAP(unitbitmap, MAX_ID_ELEMS);
84 	struct usb_audio_term oterm;
85 	const struct usbmix_name_map *map;
86 	const struct usbmix_selector_map *selector_map;
87 };
88 
89 /*E-mu 0202/0404/0204 eXtension Unit(XU) control*/
90 enum {
91 	USB_XU_CLOCK_RATE 		= 0xe301,
92 	USB_XU_CLOCK_SOURCE		= 0xe302,
93 	USB_XU_DIGITAL_IO_STATUS	= 0xe303,
94 	USB_XU_DEVICE_OPTIONS		= 0xe304,
95 	USB_XU_DIRECT_MONITORING	= 0xe305,
96 	USB_XU_METERING			= 0xe306
97 };
98 enum {
99 	USB_XU_CLOCK_SOURCE_SELECTOR = 0x02,	/* clock source*/
100 	USB_XU_CLOCK_RATE_SELECTOR = 0x03,	/* clock rate */
101 	USB_XU_DIGITAL_FORMAT_SELECTOR = 0x01,	/* the spdif format */
102 	USB_XU_SOFT_LIMIT_SELECTOR = 0x03	/* soft limiter */
103 };
104 
105 /*
106  * manual mapping of mixer names
107  * if the mixer topology is too complicated and the parsed names are
108  * ambiguous, add the entries in usbmixer_maps.c.
109  */
110 #include "mixer_maps.c"
111 
112 static const struct usbmix_name_map *
113 find_map(struct mixer_build *state, int unitid, int control)
114 {
115 	const struct usbmix_name_map *p = state->map;
116 
117 	if (!p)
118 		return NULL;
119 
120 	for (p = state->map; p->id; p++) {
121 		if (p->id == unitid &&
122 		    (!control || !p->control || control == p->control))
123 			return p;
124 	}
125 	return NULL;
126 }
127 
128 /* get the mapped name if the unit matches */
129 static int
130 check_mapped_name(const struct usbmix_name_map *p, char *buf, int buflen)
131 {
132 	if (!p || !p->name)
133 		return 0;
134 
135 	buflen--;
136 	return strlcpy(buf, p->name, buflen);
137 }
138 
139 /* check whether the control should be ignored */
140 static inline int
141 check_ignored_ctl(const struct usbmix_name_map *p)
142 {
143 	if (!p || p->name || p->dB)
144 		return 0;
145 	return 1;
146 }
147 
148 /* dB mapping */
149 static inline void check_mapped_dB(const struct usbmix_name_map *p,
150 				   struct usb_mixer_elem_info *cval)
151 {
152 	if (p && p->dB) {
153 		cval->dBmin = p->dB->min;
154 		cval->dBmax = p->dB->max;
155 		cval->initialized = 1;
156 	}
157 }
158 
159 /* get the mapped selector source name */
160 static int check_mapped_selector_name(struct mixer_build *state, int unitid,
161 				      int index, char *buf, int buflen)
162 {
163 	const struct usbmix_selector_map *p;
164 
165 	if (! state->selector_map)
166 		return 0;
167 	for (p = state->selector_map; p->id; p++) {
168 		if (p->id == unitid && index < p->count)
169 			return strlcpy(buf, p->names[index], buflen);
170 	}
171 	return 0;
172 }
173 
174 /*
175  * find an audio control unit with the given unit id
176  */
177 static void *find_audio_control_unit(struct mixer_build *state, unsigned char unit)
178 {
179 	/* we just parse the header */
180 	struct uac_feature_unit_descriptor *hdr = NULL;
181 
182 	while ((hdr = snd_usb_find_desc(state->buffer, state->buflen, hdr,
183 					USB_DT_CS_INTERFACE)) != NULL) {
184 		if (hdr->bLength >= 4 &&
185 		    hdr->bDescriptorSubtype >= UAC_INPUT_TERMINAL &&
186 		    hdr->bDescriptorSubtype <= UAC2_SAMPLE_RATE_CONVERTER &&
187 		    hdr->bUnitID == unit)
188 			return hdr;
189 	}
190 
191 	return NULL;
192 }
193 
194 /*
195  * copy a string with the given id
196  */
197 static int snd_usb_copy_string_desc(struct mixer_build *state, int index, char *buf, int maxlen)
198 {
199 	int len = usb_string(state->chip->dev, index, buf, maxlen - 1);
200 	buf[len] = 0;
201 	return len;
202 }
203 
204 /*
205  * convert from the byte/word on usb descriptor to the zero-based integer
206  */
207 static int convert_signed_value(struct usb_mixer_elem_info *cval, int val)
208 {
209 	switch (cval->val_type) {
210 	case USB_MIXER_BOOLEAN:
211 		return !!val;
212 	case USB_MIXER_INV_BOOLEAN:
213 		return !val;
214 	case USB_MIXER_U8:
215 		val &= 0xff;
216 		break;
217 	case USB_MIXER_S8:
218 		val &= 0xff;
219 		if (val >= 0x80)
220 			val -= 0x100;
221 		break;
222 	case USB_MIXER_U16:
223 		val &= 0xffff;
224 		break;
225 	case USB_MIXER_S16:
226 		val &= 0xffff;
227 		if (val >= 0x8000)
228 			val -= 0x10000;
229 		break;
230 	}
231 	return val;
232 }
233 
234 /*
235  * convert from the zero-based int to the byte/word for usb descriptor
236  */
237 static int convert_bytes_value(struct usb_mixer_elem_info *cval, int val)
238 {
239 	switch (cval->val_type) {
240 	case USB_MIXER_BOOLEAN:
241 		return !!val;
242 	case USB_MIXER_INV_BOOLEAN:
243 		return !val;
244 	case USB_MIXER_S8:
245 	case USB_MIXER_U8:
246 		return val & 0xff;
247 	case USB_MIXER_S16:
248 	case USB_MIXER_U16:
249 		return val & 0xffff;
250 	}
251 	return 0; /* not reached */
252 }
253 
254 static int get_relative_value(struct usb_mixer_elem_info *cval, int val)
255 {
256 	if (! cval->res)
257 		cval->res = 1;
258 	if (val < cval->min)
259 		return 0;
260 	else if (val >= cval->max)
261 		return (cval->max - cval->min + cval->res - 1) / cval->res;
262 	else
263 		return (val - cval->min) / cval->res;
264 }
265 
266 static int get_abs_value(struct usb_mixer_elem_info *cval, int val)
267 {
268 	if (val < 0)
269 		return cval->min;
270 	if (! cval->res)
271 		cval->res = 1;
272 	val *= cval->res;
273 	val += cval->min;
274 	if (val > cval->max)
275 		return cval->max;
276 	return val;
277 }
278 
279 
280 /*
281  * retrieve a mixer value
282  */
283 
284 static int get_ctl_value_v1(struct usb_mixer_elem_info *cval, int request, int validx, int *value_ret)
285 {
286 	struct snd_usb_audio *chip = cval->mixer->chip;
287 	unsigned char buf[2];
288 	int val_len = cval->val_type >= USB_MIXER_S16 ? 2 : 1;
289 	int timeout = 10;
290 	int idx = 0, err;
291 
292 	err = snd_usb_autoresume(cval->mixer->chip);
293 	if (err < 0)
294 		return -EIO;
295 	down_read(&chip->shutdown_rwsem);
296 	while (timeout-- > 0) {
297 		if (chip->shutdown)
298 			break;
299 		idx = snd_usb_ctrl_intf(chip) | (cval->id << 8);
300 		if (snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0), request,
301 				    USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
302 				    validx, idx, buf, val_len) >= val_len) {
303 			*value_ret = convert_signed_value(cval, snd_usb_combine_bytes(buf, val_len));
304 			err = 0;
305 			goto out;
306 		}
307 	}
308 	snd_printdd(KERN_ERR "cannot get ctl value: req = %#x, wValue = %#x, wIndex = %#x, type = %d\n",
309 		    request, validx, idx, cval->val_type);
310 	err = -EINVAL;
311 
312  out:
313 	up_read(&chip->shutdown_rwsem);
314 	snd_usb_autosuspend(cval->mixer->chip);
315 	return err;
316 }
317 
318 static int get_ctl_value_v2(struct usb_mixer_elem_info *cval, int request, int validx, int *value_ret)
319 {
320 	struct snd_usb_audio *chip = cval->mixer->chip;
321 	unsigned char buf[2 + 3*sizeof(__u16)]; /* enough space for one range */
322 	unsigned char *val;
323 	int idx = 0, ret, size;
324 	__u8 bRequest;
325 
326 	if (request == UAC_GET_CUR) {
327 		bRequest = UAC2_CS_CUR;
328 		size = sizeof(__u16);
329 	} else {
330 		bRequest = UAC2_CS_RANGE;
331 		size = sizeof(buf);
332 	}
333 
334 	memset(buf, 0, sizeof(buf));
335 
336 	ret = snd_usb_autoresume(chip) ? -EIO : 0;
337 	if (ret)
338 		goto error;
339 
340 	down_read(&chip->shutdown_rwsem);
341 	if (chip->shutdown)
342 		ret = -ENODEV;
343 	else {
344 		idx = snd_usb_ctrl_intf(chip) | (cval->id << 8);
345 		ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0), bRequest,
346 			      USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
347 			      validx, idx, buf, size);
348 	}
349 	up_read(&chip->shutdown_rwsem);
350 	snd_usb_autosuspend(chip);
351 
352 	if (ret < 0) {
353 error:
354 		snd_printk(KERN_ERR "cannot get ctl value: req = %#x, wValue = %#x, wIndex = %#x, type = %d\n",
355 			   request, validx, idx, cval->val_type);
356 		return ret;
357 	}
358 
359 	/* FIXME: how should we handle multiple triplets here? */
360 
361 	switch (request) {
362 	case UAC_GET_CUR:
363 		val = buf;
364 		break;
365 	case UAC_GET_MIN:
366 		val = buf + sizeof(__u16);
367 		break;
368 	case UAC_GET_MAX:
369 		val = buf + sizeof(__u16) * 2;
370 		break;
371 	case UAC_GET_RES:
372 		val = buf + sizeof(__u16) * 3;
373 		break;
374 	default:
375 		return -EINVAL;
376 	}
377 
378 	*value_ret = convert_signed_value(cval, snd_usb_combine_bytes(val, sizeof(__u16)));
379 
380 	return 0;
381 }
382 
383 static int get_ctl_value(struct usb_mixer_elem_info *cval, int request, int validx, int *value_ret)
384 {
385 	validx += cval->idx_off;
386 
387 	return (cval->mixer->protocol == UAC_VERSION_1) ?
388 		get_ctl_value_v1(cval, request, validx, value_ret) :
389 		get_ctl_value_v2(cval, request, validx, value_ret);
390 }
391 
392 static int get_cur_ctl_value(struct usb_mixer_elem_info *cval, int validx, int *value)
393 {
394 	return get_ctl_value(cval, UAC_GET_CUR, validx, value);
395 }
396 
397 /* channel = 0: master, 1 = first channel */
398 static inline int get_cur_mix_raw(struct usb_mixer_elem_info *cval,
399 				  int channel, int *value)
400 {
401 	return get_ctl_value(cval, UAC_GET_CUR, (cval->control << 8) | channel, value);
402 }
403 
404 static int get_cur_mix_value(struct usb_mixer_elem_info *cval,
405 			     int channel, int index, int *value)
406 {
407 	int err;
408 
409 	if (cval->cached & (1 << channel)) {
410 		*value = cval->cache_val[index];
411 		return 0;
412 	}
413 	err = get_cur_mix_raw(cval, channel, value);
414 	if (err < 0) {
415 		if (!cval->mixer->ignore_ctl_error)
416 			snd_printd(KERN_ERR "cannot get current value for control %d ch %d: err = %d\n",
417 				   cval->control, channel, err);
418 		return err;
419 	}
420 	cval->cached |= 1 << channel;
421 	cval->cache_val[index] = *value;
422 	return 0;
423 }
424 
425 
426 /*
427  * set a mixer value
428  */
429 
430 int snd_usb_mixer_set_ctl_value(struct usb_mixer_elem_info *cval,
431 				int request, int validx, int value_set)
432 {
433 	struct snd_usb_audio *chip = cval->mixer->chip;
434 	unsigned char buf[2];
435 	int idx = 0, val_len, err, timeout = 10;
436 
437 	validx += cval->idx_off;
438 
439 	if (cval->mixer->protocol == UAC_VERSION_1) {
440 		val_len = cval->val_type >= USB_MIXER_S16 ? 2 : 1;
441 	} else { /* UAC_VERSION_2 */
442 		/* audio class v2 controls are always 2 bytes in size */
443 		val_len = sizeof(__u16);
444 
445 		/* FIXME */
446 		if (request != UAC_SET_CUR) {
447 			snd_printdd(KERN_WARNING "RANGE setting not yet supported\n");
448 			return -EINVAL;
449 		}
450 
451 		request = UAC2_CS_CUR;
452 	}
453 
454 	value_set = convert_bytes_value(cval, value_set);
455 	buf[0] = value_set & 0xff;
456 	buf[1] = (value_set >> 8) & 0xff;
457 	err = snd_usb_autoresume(chip);
458 	if (err < 0)
459 		return -EIO;
460 	down_read(&chip->shutdown_rwsem);
461 	while (timeout-- > 0) {
462 		if (chip->shutdown)
463 			break;
464 		idx = snd_usb_ctrl_intf(chip) | (cval->id << 8);
465 		if (snd_usb_ctl_msg(chip->dev,
466 				    usb_sndctrlpipe(chip->dev, 0), request,
467 				    USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
468 				    validx, idx, buf, val_len) >= 0) {
469 			err = 0;
470 			goto out;
471 		}
472 	}
473 	snd_printdd(KERN_ERR "cannot set ctl value: req = %#x, wValue = %#x, wIndex = %#x, type = %d, data = %#x/%#x\n",
474 		    request, validx, idx, cval->val_type, buf[0], buf[1]);
475 	err = -EINVAL;
476 
477  out:
478 	up_read(&chip->shutdown_rwsem);
479 	snd_usb_autosuspend(chip);
480 	return err;
481 }
482 
483 static int set_cur_ctl_value(struct usb_mixer_elem_info *cval, int validx, int value)
484 {
485 	return snd_usb_mixer_set_ctl_value(cval, UAC_SET_CUR, validx, value);
486 }
487 
488 static int set_cur_mix_value(struct usb_mixer_elem_info *cval, int channel,
489 			     int index, int value)
490 {
491 	int err;
492 	unsigned int read_only = (channel == 0) ?
493 		cval->master_readonly :
494 		cval->ch_readonly & (1 << (channel - 1));
495 
496 	if (read_only) {
497 		snd_printdd(KERN_INFO "%s(): channel %d of control %d is read_only\n",
498 			    __func__, channel, cval->control);
499 		return 0;
500 	}
501 
502 	err = snd_usb_mixer_set_ctl_value(cval, UAC_SET_CUR, (cval->control << 8) | channel,
503 			    value);
504 	if (err < 0)
505 		return err;
506 	cval->cached |= 1 << channel;
507 	cval->cache_val[index] = value;
508 	return 0;
509 }
510 
511 /*
512  * TLV callback for mixer volume controls
513  */
514 int snd_usb_mixer_vol_tlv(struct snd_kcontrol *kcontrol, int op_flag,
515 			 unsigned int size, unsigned int __user *_tlv)
516 {
517 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
518 	DECLARE_TLV_DB_MINMAX(scale, 0, 0);
519 
520 	if (size < sizeof(scale))
521 		return -ENOMEM;
522 	scale[2] = cval->dBmin;
523 	scale[3] = cval->dBmax;
524 	if (copy_to_user(_tlv, scale, sizeof(scale)))
525 		return -EFAULT;
526 	return 0;
527 }
528 
529 /*
530  * parser routines begin here...
531  */
532 
533 static int parse_audio_unit(struct mixer_build *state, int unitid);
534 
535 
536 /*
537  * check if the input/output channel routing is enabled on the given bitmap.
538  * used for mixer unit parser
539  */
540 static int check_matrix_bitmap(unsigned char *bmap, int ich, int och, int num_outs)
541 {
542 	int idx = ich * num_outs + och;
543 	return bmap[idx >> 3] & (0x80 >> (idx & 7));
544 }
545 
546 
547 /*
548  * add an alsa control element
549  * search and increment the index until an empty slot is found.
550  *
551  * if failed, give up and free the control instance.
552  */
553 
554 int snd_usb_mixer_add_control(struct usb_mixer_interface *mixer,
555 			      struct snd_kcontrol *kctl)
556 {
557 	struct usb_mixer_elem_info *cval = kctl->private_data;
558 	int err;
559 
560 	while (snd_ctl_find_id(mixer->chip->card, &kctl->id))
561 		kctl->id.index++;
562 	if ((err = snd_ctl_add(mixer->chip->card, kctl)) < 0) {
563 		snd_printd(KERN_ERR "cannot add control (err = %d)\n", err);
564 		return err;
565 	}
566 	cval->elem_id = &kctl->id;
567 	cval->next_id_elem = mixer->id_elems[cval->id];
568 	mixer->id_elems[cval->id] = cval;
569 	return 0;
570 }
571 
572 
573 /*
574  * get a terminal name string
575  */
576 
577 static struct iterm_name_combo {
578 	int type;
579 	char *name;
580 } iterm_names[] = {
581 	{ 0x0300, "Output" },
582 	{ 0x0301, "Speaker" },
583 	{ 0x0302, "Headphone" },
584 	{ 0x0303, "HMD Audio" },
585 	{ 0x0304, "Desktop Speaker" },
586 	{ 0x0305, "Room Speaker" },
587 	{ 0x0306, "Com Speaker" },
588 	{ 0x0307, "LFE" },
589 	{ 0x0600, "External In" },
590 	{ 0x0601, "Analog In" },
591 	{ 0x0602, "Digital In" },
592 	{ 0x0603, "Line" },
593 	{ 0x0604, "Legacy In" },
594 	{ 0x0605, "IEC958 In" },
595 	{ 0x0606, "1394 DA Stream" },
596 	{ 0x0607, "1394 DV Stream" },
597 	{ 0x0700, "Embedded" },
598 	{ 0x0701, "Noise Source" },
599 	{ 0x0702, "Equalization Noise" },
600 	{ 0x0703, "CD" },
601 	{ 0x0704, "DAT" },
602 	{ 0x0705, "DCC" },
603 	{ 0x0706, "MiniDisk" },
604 	{ 0x0707, "Analog Tape" },
605 	{ 0x0708, "Phonograph" },
606 	{ 0x0709, "VCR Audio" },
607 	{ 0x070a, "Video Disk Audio" },
608 	{ 0x070b, "DVD Audio" },
609 	{ 0x070c, "TV Tuner Audio" },
610 	{ 0x070d, "Satellite Rec Audio" },
611 	{ 0x070e, "Cable Tuner Audio" },
612 	{ 0x070f, "DSS Audio" },
613 	{ 0x0710, "Radio Receiver" },
614 	{ 0x0711, "Radio Transmitter" },
615 	{ 0x0712, "Multi-Track Recorder" },
616 	{ 0x0713, "Synthesizer" },
617 	{ 0 },
618 };
619 
620 static int get_term_name(struct mixer_build *state, struct usb_audio_term *iterm,
621 			 unsigned char *name, int maxlen, int term_only)
622 {
623 	struct iterm_name_combo *names;
624 
625 	if (iterm->name)
626 		return snd_usb_copy_string_desc(state, iterm->name, name, maxlen);
627 
628 	/* virtual type - not a real terminal */
629 	if (iterm->type >> 16) {
630 		if (term_only)
631 			return 0;
632 		switch (iterm->type >> 16) {
633 		case UAC_SELECTOR_UNIT:
634 			strcpy(name, "Selector"); return 8;
635 		case UAC1_PROCESSING_UNIT:
636 			strcpy(name, "Process Unit"); return 12;
637 		case UAC1_EXTENSION_UNIT:
638 			strcpy(name, "Ext Unit"); return 8;
639 		case UAC_MIXER_UNIT:
640 			strcpy(name, "Mixer"); return 5;
641 		default:
642 			return sprintf(name, "Unit %d", iterm->id);
643 		}
644 	}
645 
646 	switch (iterm->type & 0xff00) {
647 	case 0x0100:
648 		strcpy(name, "PCM"); return 3;
649 	case 0x0200:
650 		strcpy(name, "Mic"); return 3;
651 	case 0x0400:
652 		strcpy(name, "Headset"); return 7;
653 	case 0x0500:
654 		strcpy(name, "Phone"); return 5;
655 	}
656 
657 	for (names = iterm_names; names->type; names++)
658 		if (names->type == iterm->type) {
659 			strcpy(name, names->name);
660 			return strlen(names->name);
661 		}
662 	return 0;
663 }
664 
665 
666 /*
667  * parse the source unit recursively until it reaches to a terminal
668  * or a branched unit.
669  */
670 static int check_input_term(struct mixer_build *state, int id, struct usb_audio_term *term)
671 {
672 	int err;
673 	void *p1;
674 
675 	memset(term, 0, sizeof(*term));
676 	while ((p1 = find_audio_control_unit(state, id)) != NULL) {
677 		unsigned char *hdr = p1;
678 		term->id = id;
679 		switch (hdr[2]) {
680 		case UAC_INPUT_TERMINAL:
681 			if (state->mixer->protocol == UAC_VERSION_1) {
682 				struct uac_input_terminal_descriptor *d = p1;
683 				term->type = le16_to_cpu(d->wTerminalType);
684 				term->channels = d->bNrChannels;
685 				term->chconfig = le16_to_cpu(d->wChannelConfig);
686 				term->name = d->iTerminal;
687 			} else { /* UAC_VERSION_2 */
688 				struct uac2_input_terminal_descriptor *d = p1;
689 				term->type = le16_to_cpu(d->wTerminalType);
690 				term->channels = d->bNrChannels;
691 				term->chconfig = le32_to_cpu(d->bmChannelConfig);
692 				term->name = d->iTerminal;
693 
694 				/* call recursively to get the clock selectors */
695 				err = check_input_term(state, d->bCSourceID, term);
696 				if (err < 0)
697 					return err;
698 			}
699 			return 0;
700 		case UAC_FEATURE_UNIT: {
701 			/* the header is the same for v1 and v2 */
702 			struct uac_feature_unit_descriptor *d = p1;
703 			id = d->bSourceID;
704 			break; /* continue to parse */
705 		}
706 		case UAC_MIXER_UNIT: {
707 			struct uac_mixer_unit_descriptor *d = p1;
708 			term->type = d->bDescriptorSubtype << 16; /* virtual type */
709 			term->channels = uac_mixer_unit_bNrChannels(d);
710 			term->chconfig = uac_mixer_unit_wChannelConfig(d, state->mixer->protocol);
711 			term->name = uac_mixer_unit_iMixer(d);
712 			return 0;
713 		}
714 		case UAC_SELECTOR_UNIT:
715 		case UAC2_CLOCK_SELECTOR: {
716 			struct uac_selector_unit_descriptor *d = p1;
717 			/* call recursively to retrieve the channel info */
718 			err = check_input_term(state, d->baSourceID[0], term);
719 			if (err < 0)
720 				return err;
721 			term->type = d->bDescriptorSubtype << 16; /* virtual type */
722 			term->id = id;
723 			term->name = uac_selector_unit_iSelector(d);
724 			return 0;
725 		}
726 		case UAC1_PROCESSING_UNIT:
727 		case UAC1_EXTENSION_UNIT:
728 		/* UAC2_PROCESSING_UNIT_V2 */
729 		/* UAC2_EFFECT_UNIT */
730 		case UAC2_EXTENSION_UNIT_V2: {
731 			struct uac_processing_unit_descriptor *d = p1;
732 
733 			if (state->mixer->protocol == UAC_VERSION_2 &&
734 				hdr[2] == UAC2_EFFECT_UNIT) {
735 				/* UAC2/UAC1 unit IDs overlap here in an
736 				 * uncompatible way. Ignore this unit for now.
737 				 */
738 				return 0;
739 			}
740 
741 			if (d->bNrInPins) {
742 				id = d->baSourceID[0];
743 				break; /* continue to parse */
744 			}
745 			term->type = d->bDescriptorSubtype << 16; /* virtual type */
746 			term->channels = uac_processing_unit_bNrChannels(d);
747 			term->chconfig = uac_processing_unit_wChannelConfig(d, state->mixer->protocol);
748 			term->name = uac_processing_unit_iProcessing(d, state->mixer->protocol);
749 			return 0;
750 		}
751 		case UAC2_CLOCK_SOURCE: {
752 			struct uac_clock_source_descriptor *d = p1;
753 			term->type = d->bDescriptorSubtype << 16; /* virtual type */
754 			term->id = id;
755 			term->name = d->iClockSource;
756 			return 0;
757 		}
758 		default:
759 			return -ENODEV;
760 		}
761 	}
762 	return -ENODEV;
763 }
764 
765 
766 /*
767  * Feature Unit
768  */
769 
770 /* feature unit control information */
771 struct usb_feature_control_info {
772 	const char *name;
773 	unsigned int type;	/* control type (mute, volume, etc.) */
774 };
775 
776 static struct usb_feature_control_info audio_feature_info[] = {
777 	{ "Mute",			USB_MIXER_INV_BOOLEAN },
778 	{ "Volume",			USB_MIXER_S16 },
779 	{ "Tone Control - Bass",	USB_MIXER_S8 },
780 	{ "Tone Control - Mid",		USB_MIXER_S8 },
781 	{ "Tone Control - Treble",	USB_MIXER_S8 },
782 	{ "Graphic Equalizer",		USB_MIXER_S8 }, /* FIXME: not implemeted yet */
783 	{ "Auto Gain Control",		USB_MIXER_BOOLEAN },
784 	{ "Delay Control",		USB_MIXER_U16 },
785 	{ "Bass Boost",			USB_MIXER_BOOLEAN },
786 	{ "Loudness",			USB_MIXER_BOOLEAN },
787 	/* UAC2 specific */
788 	{ "Input Gain Control",		USB_MIXER_U16 },
789 	{ "Input Gain Pad Control",	USB_MIXER_BOOLEAN },
790 	{ "Phase Inverter Control",	USB_MIXER_BOOLEAN },
791 };
792 
793 
794 /* private_free callback */
795 static void usb_mixer_elem_free(struct snd_kcontrol *kctl)
796 {
797 	kfree(kctl->private_data);
798 	kctl->private_data = NULL;
799 }
800 
801 
802 /*
803  * interface to ALSA control for feature/mixer units
804  */
805 
806 /* volume control quirks */
807 static void volume_control_quirks(struct usb_mixer_elem_info *cval,
808 				  struct snd_kcontrol *kctl)
809 {
810 	switch (cval->mixer->chip->usb_id) {
811 	case USB_ID(0x0763, 0x2030): /* M-Audio Fast Track C400 */
812 	case USB_ID(0x0763, 0x2031): /* M-Audio Fast Track C600 */
813 		if (strcmp(kctl->id.name, "Effect Duration") == 0) {
814 			cval->min = 0x0000;
815 			cval->max = 0xffff;
816 			cval->res = 0x00e6;
817 			break;
818 		}
819 		if (strcmp(kctl->id.name, "Effect Volume") == 0 ||
820 		    strcmp(kctl->id.name, "Effect Feedback Volume") == 0) {
821 			cval->min = 0x00;
822 			cval->max = 0xff;
823 			break;
824 		}
825 		if (strstr(kctl->id.name, "Effect Return") != NULL) {
826 			cval->min = 0xb706;
827 			cval->max = 0xff7b;
828 			cval->res = 0x0073;
829 			break;
830 		}
831 		if ((strstr(kctl->id.name, "Playback Volume") != NULL) ||
832 			(strstr(kctl->id.name, "Effect Send") != NULL)) {
833 			cval->min = 0xb5fb; /* -73 dB = 0xb6ff */
834 			cval->max = 0xfcfe;
835 			cval->res = 0x0073;
836 		}
837 		break;
838 
839 	case USB_ID(0x0763, 0x2081): /* M-Audio Fast Track Ultra 8R */
840 	case USB_ID(0x0763, 0x2080): /* M-Audio Fast Track Ultra */
841 		if (strcmp(kctl->id.name, "Effect Duration") == 0) {
842 			snd_printk(KERN_INFO
843 				"usb-audio: set quirk for FTU Effect Duration\n");
844 			cval->min = 0x0000;
845 			cval->max = 0x7f00;
846 			cval->res = 0x0100;
847 			break;
848 		}
849 		if (strcmp(kctl->id.name, "Effect Volume") == 0 ||
850 		    strcmp(kctl->id.name, "Effect Feedback Volume") == 0) {
851 			snd_printk(KERN_INFO
852 				"usb-audio: set quirks for FTU Effect Feedback/Volume\n");
853 			cval->min = 0x00;
854 			cval->max = 0x7f;
855 			break;
856 		}
857 		break;
858 
859 	case USB_ID(0x0471, 0x0101):
860 	case USB_ID(0x0471, 0x0104):
861 	case USB_ID(0x0471, 0x0105):
862 	case USB_ID(0x0672, 0x1041):
863 	/* quirk for UDA1321/N101.
864 	 * note that detection between firmware 2.1.1.7 (N101)
865 	 * and later 2.1.1.21 is not very clear from datasheets.
866 	 * I hope that the min value is -15360 for newer firmware --jk
867 	 */
868 		if (!strcmp(kctl->id.name, "PCM Playback Volume") &&
869 		    cval->min == -15616) {
870 			snd_printk(KERN_INFO
871 				 "set volume quirk for UDA1321/N101 chip\n");
872 			cval->max = -256;
873 		}
874 		break;
875 
876 	case USB_ID(0x046d, 0x09a4):
877 		if (!strcmp(kctl->id.name, "Mic Capture Volume")) {
878 			snd_printk(KERN_INFO
879 				"set volume quirk for QuickCam E3500\n");
880 			cval->min = 6080;
881 			cval->max = 8768;
882 			cval->res = 192;
883 		}
884 		break;
885 
886 	case USB_ID(0x046d, 0x0808):
887 	case USB_ID(0x046d, 0x0809):
888 	case USB_ID(0x046d, 0x081b): /* HD Webcam c310 */
889 	case USB_ID(0x046d, 0x081d): /* HD Webcam c510 */
890 	case USB_ID(0x046d, 0x0825): /* HD Webcam c270 */
891 	case USB_ID(0x046d, 0x0991):
892 	/* Most audio usb devices lie about volume resolution.
893 	 * Most Logitech webcams have res = 384.
894 	 * Proboly there is some logitech magic behind this number --fishor
895 	 */
896 		if (!strcmp(kctl->id.name, "Mic Capture Volume")) {
897 			snd_printk(KERN_INFO
898 				"set resolution quirk: cval->res = 384\n");
899 			cval->res = 384;
900 		}
901 		break;
902 
903 	}
904 }
905 
906 /*
907  * retrieve the minimum and maximum values for the specified control
908  */
909 static int get_min_max_with_quirks(struct usb_mixer_elem_info *cval,
910 				   int default_min, struct snd_kcontrol *kctl)
911 {
912 	/* for failsafe */
913 	cval->min = default_min;
914 	cval->max = cval->min + 1;
915 	cval->res = 1;
916 	cval->dBmin = cval->dBmax = 0;
917 
918 	if (cval->val_type == USB_MIXER_BOOLEAN ||
919 	    cval->val_type == USB_MIXER_INV_BOOLEAN) {
920 		cval->initialized = 1;
921 	} else {
922 		int minchn = 0;
923 		if (cval->cmask) {
924 			int i;
925 			for (i = 0; i < MAX_CHANNELS; i++)
926 				if (cval->cmask & (1 << i)) {
927 					minchn = i + 1;
928 					break;
929 				}
930 		}
931 		if (get_ctl_value(cval, UAC_GET_MAX, (cval->control << 8) | minchn, &cval->max) < 0 ||
932 		    get_ctl_value(cval, UAC_GET_MIN, (cval->control << 8) | minchn, &cval->min) < 0) {
933 			snd_printd(KERN_ERR "%d:%d: cannot get min/max values for control %d (id %d)\n",
934 				   cval->id, snd_usb_ctrl_intf(cval->mixer->chip), cval->control, cval->id);
935 			return -EINVAL;
936 		}
937 		if (get_ctl_value(cval, UAC_GET_RES, (cval->control << 8) | minchn, &cval->res) < 0) {
938 			cval->res = 1;
939 		} else {
940 			int last_valid_res = cval->res;
941 
942 			while (cval->res > 1) {
943 				if (snd_usb_mixer_set_ctl_value(cval, UAC_SET_RES,
944 								(cval->control << 8) | minchn, cval->res / 2) < 0)
945 					break;
946 				cval->res /= 2;
947 			}
948 			if (get_ctl_value(cval, UAC_GET_RES, (cval->control << 8) | minchn, &cval->res) < 0)
949 				cval->res = last_valid_res;
950 		}
951 		if (cval->res == 0)
952 			cval->res = 1;
953 
954 		/* Additional checks for the proper resolution
955 		 *
956 		 * Some devices report smaller resolutions than actually
957 		 * reacting.  They don't return errors but simply clip
958 		 * to the lower aligned value.
959 		 */
960 		if (cval->min + cval->res < cval->max) {
961 			int last_valid_res = cval->res;
962 			int saved, test, check;
963 			get_cur_mix_raw(cval, minchn, &saved);
964 			for (;;) {
965 				test = saved;
966 				if (test < cval->max)
967 					test += cval->res;
968 				else
969 					test -= cval->res;
970 				if (test < cval->min || test > cval->max ||
971 				    set_cur_mix_value(cval, minchn, 0, test) ||
972 				    get_cur_mix_raw(cval, minchn, &check)) {
973 					cval->res = last_valid_res;
974 					break;
975 				}
976 				if (test == check)
977 					break;
978 				cval->res *= 2;
979 			}
980 			set_cur_mix_value(cval, minchn, 0, saved);
981 		}
982 
983 		cval->initialized = 1;
984 	}
985 
986 	if (kctl)
987 		volume_control_quirks(cval, kctl);
988 
989 	/* USB descriptions contain the dB scale in 1/256 dB unit
990 	 * while ALSA TLV contains in 1/100 dB unit
991 	 */
992 	cval->dBmin = (convert_signed_value(cval, cval->min) * 100) / 256;
993 	cval->dBmax = (convert_signed_value(cval, cval->max) * 100) / 256;
994 	if (cval->dBmin > cval->dBmax) {
995 		/* something is wrong; assume it's either from/to 0dB */
996 		if (cval->dBmin < 0)
997 			cval->dBmax = 0;
998 		else if (cval->dBmin > 0)
999 			cval->dBmin = 0;
1000 		if (cval->dBmin > cval->dBmax) {
1001 			/* totally crap, return an error */
1002 			return -EINVAL;
1003 		}
1004 	}
1005 
1006 	return 0;
1007 }
1008 
1009 #define get_min_max(cval, def)	get_min_max_with_quirks(cval, def, NULL)
1010 
1011 /* get a feature/mixer unit info */
1012 static int mixer_ctl_feature_info(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo)
1013 {
1014 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1015 
1016 	if (cval->val_type == USB_MIXER_BOOLEAN ||
1017 	    cval->val_type == USB_MIXER_INV_BOOLEAN)
1018 		uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1019 	else
1020 		uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
1021 	uinfo->count = cval->channels;
1022 	if (cval->val_type == USB_MIXER_BOOLEAN ||
1023 	    cval->val_type == USB_MIXER_INV_BOOLEAN) {
1024 		uinfo->value.integer.min = 0;
1025 		uinfo->value.integer.max = 1;
1026 	} else {
1027 		if (!cval->initialized) {
1028 			get_min_max_with_quirks(cval, 0, kcontrol);
1029 			if (cval->initialized && cval->dBmin >= cval->dBmax) {
1030 				kcontrol->vd[0].access &=
1031 					~(SNDRV_CTL_ELEM_ACCESS_TLV_READ |
1032 					  SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK);
1033 				snd_ctl_notify(cval->mixer->chip->card,
1034 					       SNDRV_CTL_EVENT_MASK_INFO,
1035 					       &kcontrol->id);
1036 			}
1037 		}
1038 		uinfo->value.integer.min = 0;
1039 		uinfo->value.integer.max =
1040 			(cval->max - cval->min + cval->res - 1) / cval->res;
1041 	}
1042 	return 0;
1043 }
1044 
1045 /* get the current value from feature/mixer unit */
1046 static int mixer_ctl_feature_get(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
1047 {
1048 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1049 	int c, cnt, val, err;
1050 
1051 	ucontrol->value.integer.value[0] = cval->min;
1052 	if (cval->cmask) {
1053 		cnt = 0;
1054 		for (c = 0; c < MAX_CHANNELS; c++) {
1055 			if (!(cval->cmask & (1 << c)))
1056 				continue;
1057 			err = get_cur_mix_value(cval, c + 1, cnt, &val);
1058 			if (err < 0)
1059 				return cval->mixer->ignore_ctl_error ? 0 : err;
1060 			val = get_relative_value(cval, val);
1061 			ucontrol->value.integer.value[cnt] = val;
1062 			cnt++;
1063 		}
1064 		return 0;
1065 	} else {
1066 		/* master channel */
1067 		err = get_cur_mix_value(cval, 0, 0, &val);
1068 		if (err < 0)
1069 			return cval->mixer->ignore_ctl_error ? 0 : err;
1070 		val = get_relative_value(cval, val);
1071 		ucontrol->value.integer.value[0] = val;
1072 	}
1073 	return 0;
1074 }
1075 
1076 /* put the current value to feature/mixer unit */
1077 static int mixer_ctl_feature_put(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
1078 {
1079 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1080 	int c, cnt, val, oval, err;
1081 	int changed = 0;
1082 
1083 	if (cval->cmask) {
1084 		cnt = 0;
1085 		for (c = 0; c < MAX_CHANNELS; c++) {
1086 			if (!(cval->cmask & (1 << c)))
1087 				continue;
1088 			err = get_cur_mix_value(cval, c + 1, cnt, &oval);
1089 			if (err < 0)
1090 				return cval->mixer->ignore_ctl_error ? 0 : err;
1091 			val = ucontrol->value.integer.value[cnt];
1092 			val = get_abs_value(cval, val);
1093 			if (oval != val) {
1094 				set_cur_mix_value(cval, c + 1, cnt, val);
1095 				changed = 1;
1096 			}
1097 			cnt++;
1098 		}
1099 	} else {
1100 		/* master channel */
1101 		err = get_cur_mix_value(cval, 0, 0, &oval);
1102 		if (err < 0)
1103 			return cval->mixer->ignore_ctl_error ? 0 : err;
1104 		val = ucontrol->value.integer.value[0];
1105 		val = get_abs_value(cval, val);
1106 		if (val != oval) {
1107 			set_cur_mix_value(cval, 0, 0, val);
1108 			changed = 1;
1109 		}
1110 	}
1111 	return changed;
1112 }
1113 
1114 static struct snd_kcontrol_new usb_feature_unit_ctl = {
1115 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
1116 	.name = "", /* will be filled later manually */
1117 	.info = mixer_ctl_feature_info,
1118 	.get = mixer_ctl_feature_get,
1119 	.put = mixer_ctl_feature_put,
1120 };
1121 
1122 /* the read-only variant */
1123 static struct snd_kcontrol_new usb_feature_unit_ctl_ro = {
1124 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
1125 	.name = "", /* will be filled later manually */
1126 	.info = mixer_ctl_feature_info,
1127 	.get = mixer_ctl_feature_get,
1128 	.put = NULL,
1129 };
1130 
1131 /* This symbol is exported in order to allow the mixer quirks to
1132  * hook up to the standard feature unit control mechanism */
1133 struct snd_kcontrol_new *snd_usb_feature_unit_ctl = &usb_feature_unit_ctl;
1134 
1135 /*
1136  * build a feature control
1137  */
1138 
1139 static size_t append_ctl_name(struct snd_kcontrol *kctl, const char *str)
1140 {
1141 	return strlcat(kctl->id.name, str, sizeof(kctl->id.name));
1142 }
1143 
1144 /* A lot of headsets/headphones have a "Speaker" mixer. Make sure we
1145    rename it to "Headphone". We determine if something is a headphone
1146    similar to how udev determines form factor. */
1147 static void check_no_speaker_on_headset(struct snd_kcontrol *kctl,
1148 					struct snd_card *card)
1149 {
1150 	const char *names_to_check[] = {
1151 		"Headset", "headset", "Headphone", "headphone", NULL};
1152 	const char **s;
1153 	bool found = 0;
1154 
1155 	if (strcmp("Speaker", kctl->id.name))
1156 		return;
1157 
1158 	for (s = names_to_check; *s; s++)
1159 		if (strstr(card->shortname, *s)) {
1160 			found = 1;
1161 			break;
1162 		}
1163 
1164 	if (!found)
1165 		return;
1166 
1167 	strlcpy(kctl->id.name, "Headphone", sizeof(kctl->id.name));
1168 }
1169 
1170 static void build_feature_ctl(struct mixer_build *state, void *raw_desc,
1171 			      unsigned int ctl_mask, int control,
1172 			      struct usb_audio_term *iterm, int unitid,
1173 			      int readonly_mask)
1174 {
1175 	struct uac_feature_unit_descriptor *desc = raw_desc;
1176 	unsigned int len = 0;
1177 	int mapped_name = 0;
1178 	int nameid = uac_feature_unit_iFeature(desc);
1179 	struct snd_kcontrol *kctl;
1180 	struct usb_mixer_elem_info *cval;
1181 	const struct usbmix_name_map *map;
1182 	unsigned int range;
1183 
1184 	control++; /* change from zero-based to 1-based value */
1185 
1186 	if (control == UAC_FU_GRAPHIC_EQUALIZER) {
1187 		/* FIXME: not supported yet */
1188 		return;
1189 	}
1190 
1191 	map = find_map(state, unitid, control);
1192 	if (check_ignored_ctl(map))
1193 		return;
1194 
1195 	cval = kzalloc(sizeof(*cval), GFP_KERNEL);
1196 	if (! cval) {
1197 		snd_printk(KERN_ERR "cannot malloc kcontrol\n");
1198 		return;
1199 	}
1200 	cval->mixer = state->mixer;
1201 	cval->id = unitid;
1202 	cval->control = control;
1203 	cval->cmask = ctl_mask;
1204 	cval->val_type = audio_feature_info[control-1].type;
1205 	if (ctl_mask == 0) {
1206 		cval->channels = 1;	/* master channel */
1207 		cval->master_readonly = readonly_mask;
1208 	} else {
1209 		int i, c = 0;
1210 		for (i = 0; i < 16; i++)
1211 			if (ctl_mask & (1 << i))
1212 				c++;
1213 		cval->channels = c;
1214 		cval->ch_readonly = readonly_mask;
1215 	}
1216 
1217 	/* if all channels in the mask are marked read-only, make the control
1218 	 * read-only. set_cur_mix_value() will check the mask again and won't
1219 	 * issue write commands to read-only channels. */
1220 	if (cval->channels == readonly_mask)
1221 		kctl = snd_ctl_new1(&usb_feature_unit_ctl_ro, cval);
1222 	else
1223 		kctl = snd_ctl_new1(&usb_feature_unit_ctl, cval);
1224 
1225 	if (! kctl) {
1226 		snd_printk(KERN_ERR "cannot malloc kcontrol\n");
1227 		kfree(cval);
1228 		return;
1229 	}
1230 	kctl->private_free = usb_mixer_elem_free;
1231 
1232 	len = check_mapped_name(map, kctl->id.name, sizeof(kctl->id.name));
1233 	mapped_name = len != 0;
1234 	if (! len && nameid)
1235 		len = snd_usb_copy_string_desc(state, nameid,
1236 				kctl->id.name, sizeof(kctl->id.name));
1237 
1238 	switch (control) {
1239 	case UAC_FU_MUTE:
1240 	case UAC_FU_VOLUME:
1241 		/* determine the control name.  the rule is:
1242 		 * - if a name id is given in descriptor, use it.
1243 		 * - if the connected input can be determined, then use the name
1244 		 *   of terminal type.
1245 		 * - if the connected output can be determined, use it.
1246 		 * - otherwise, anonymous name.
1247 		 */
1248 		if (! len) {
1249 			len = get_term_name(state, iterm, kctl->id.name, sizeof(kctl->id.name), 1);
1250 			if (! len)
1251 				len = get_term_name(state, &state->oterm, kctl->id.name, sizeof(kctl->id.name), 1);
1252 			if (! len)
1253 				len = snprintf(kctl->id.name, sizeof(kctl->id.name),
1254 					       "Feature %d", unitid);
1255 		}
1256 
1257 		if (!mapped_name)
1258 			check_no_speaker_on_headset(kctl, state->mixer->chip->card);
1259 
1260 		/* determine the stream direction:
1261 		 * if the connected output is USB stream, then it's likely a
1262 		 * capture stream.  otherwise it should be playback (hopefully :)
1263 		 */
1264 		if (! mapped_name && ! (state->oterm.type >> 16)) {
1265 			if ((state->oterm.type & 0xff00) == 0x0100) {
1266 				len = append_ctl_name(kctl, " Capture");
1267 			} else {
1268 				len = append_ctl_name(kctl, " Playback");
1269 			}
1270 		}
1271 		append_ctl_name(kctl, control == UAC_FU_MUTE ?
1272 				" Switch" : " Volume");
1273 		break;
1274 	default:
1275 		if (! len)
1276 			strlcpy(kctl->id.name, audio_feature_info[control-1].name,
1277 				sizeof(kctl->id.name));
1278 		break;
1279 	}
1280 
1281 	/* get min/max values */
1282 	get_min_max_with_quirks(cval, 0, kctl);
1283 
1284 	if (control == UAC_FU_VOLUME) {
1285 		check_mapped_dB(map, cval);
1286 		if (cval->dBmin < cval->dBmax || !cval->initialized) {
1287 			kctl->tlv.c = snd_usb_mixer_vol_tlv;
1288 			kctl->vd[0].access |=
1289 				SNDRV_CTL_ELEM_ACCESS_TLV_READ |
1290 				SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1291 		}
1292 	}
1293 
1294 	range = (cval->max - cval->min) / cval->res;
1295 	/* Are there devices with volume range more than 255? I use a bit more
1296 	 * to be sure. 384 is a resolution magic number found on Logitech
1297 	 * devices. It will definitively catch all buggy Logitech devices.
1298 	 */
1299 	if (range > 384) {
1300 		snd_printk(KERN_WARNING "usb_audio: Warning! Unlikely big "
1301 			   "volume range (=%u), cval->res is probably wrong.",
1302 			   range);
1303 		snd_printk(KERN_WARNING "usb_audio: [%d] FU [%s] ch = %d, "
1304 			   "val = %d/%d/%d", cval->id,
1305 			   kctl->id.name, cval->channels,
1306 			   cval->min, cval->max, cval->res);
1307 	}
1308 
1309 	snd_printdd(KERN_INFO "[%d] FU [%s] ch = %d, val = %d/%d/%d\n",
1310 		    cval->id, kctl->id.name, cval->channels, cval->min, cval->max, cval->res);
1311 	snd_usb_mixer_add_control(state->mixer, kctl);
1312 }
1313 
1314 
1315 
1316 /*
1317  * parse a feature unit
1318  *
1319  * most of controls are defined here.
1320  */
1321 static int parse_audio_feature_unit(struct mixer_build *state, int unitid, void *_ftr)
1322 {
1323 	int channels, i, j;
1324 	struct usb_audio_term iterm;
1325 	unsigned int master_bits, first_ch_bits;
1326 	int err, csize;
1327 	struct uac_feature_unit_descriptor *hdr = _ftr;
1328 	__u8 *bmaControls;
1329 
1330 	if (state->mixer->protocol == UAC_VERSION_1) {
1331 		csize = hdr->bControlSize;
1332 		if (!csize) {
1333 			snd_printdd(KERN_ERR "usbaudio: unit %u: "
1334 				    "invalid bControlSize == 0\n", unitid);
1335 			return -EINVAL;
1336 		}
1337 		channels = (hdr->bLength - 7) / csize - 1;
1338 		bmaControls = hdr->bmaControls;
1339 		if (hdr->bLength < 7 + csize) {
1340 			snd_printk(KERN_ERR "usbaudio: unit %u: "
1341 				   "invalid UAC_FEATURE_UNIT descriptor\n",
1342 				   unitid);
1343 			return -EINVAL;
1344 		}
1345 	} else {
1346 		struct uac2_feature_unit_descriptor *ftr = _ftr;
1347 		csize = 4;
1348 		channels = (hdr->bLength - 6) / 4 - 1;
1349 		bmaControls = ftr->bmaControls;
1350 		if (hdr->bLength < 6 + csize) {
1351 			snd_printk(KERN_ERR "usbaudio: unit %u: "
1352 				   "invalid UAC_FEATURE_UNIT descriptor\n",
1353 				   unitid);
1354 			return -EINVAL;
1355 		}
1356 	}
1357 
1358 	/* parse the source unit */
1359 	if ((err = parse_audio_unit(state, hdr->bSourceID)) < 0)
1360 		return err;
1361 
1362 	/* determine the input source type and name */
1363 	err = check_input_term(state, hdr->bSourceID, &iterm);
1364 	if (err < 0)
1365 		return err;
1366 
1367 	master_bits = snd_usb_combine_bytes(bmaControls, csize);
1368 	/* master configuration quirks */
1369 	switch (state->chip->usb_id) {
1370 	case USB_ID(0x08bb, 0x2702):
1371 		snd_printk(KERN_INFO
1372 			   "usbmixer: master volume quirk for PCM2702 chip\n");
1373 		/* disable non-functional volume control */
1374 		master_bits &= ~UAC_CONTROL_BIT(UAC_FU_VOLUME);
1375 		break;
1376 	case USB_ID(0x1130, 0xf211):
1377 		snd_printk(KERN_INFO
1378 			   "usbmixer: volume control quirk for Tenx TP6911 Audio Headset\n");
1379 		/* disable non-functional volume control */
1380 		channels = 0;
1381 		break;
1382 
1383 	}
1384 	if (channels > 0)
1385 		first_ch_bits = snd_usb_combine_bytes(bmaControls + csize, csize);
1386 	else
1387 		first_ch_bits = 0;
1388 
1389 	if (state->mixer->protocol == UAC_VERSION_1) {
1390 		/* check all control types */
1391 		for (i = 0; i < 10; i++) {
1392 			unsigned int ch_bits = 0;
1393 			for (j = 0; j < channels; j++) {
1394 				unsigned int mask = snd_usb_combine_bytes(bmaControls + csize * (j+1), csize);
1395 				if (mask & (1 << i))
1396 					ch_bits |= (1 << j);
1397 			}
1398 			/* audio class v1 controls are never read-only */
1399 			if (ch_bits & 1) /* the first channel must be set (for ease of programming) */
1400 				build_feature_ctl(state, _ftr, ch_bits, i, &iterm, unitid, 0);
1401 			if (master_bits & (1 << i))
1402 				build_feature_ctl(state, _ftr, 0, i, &iterm, unitid, 0);
1403 		}
1404 	} else { /* UAC_VERSION_2 */
1405 		for (i = 0; i < ARRAY_SIZE(audio_feature_info); i++) {
1406 			unsigned int ch_bits = 0;
1407 			unsigned int ch_read_only = 0;
1408 
1409 			for (j = 0; j < channels; j++) {
1410 				unsigned int mask = snd_usb_combine_bytes(bmaControls + csize * (j+1), csize);
1411 				if (uac2_control_is_readable(mask, i)) {
1412 					ch_bits |= (1 << j);
1413 					if (!uac2_control_is_writeable(mask, i))
1414 						ch_read_only |= (1 << j);
1415 				}
1416 			}
1417 
1418 			/* NOTE: build_feature_ctl() will mark the control read-only if all channels
1419 			 * are marked read-only in the descriptors. Otherwise, the control will be
1420 			 * reported as writeable, but the driver will not actually issue a write
1421 			 * command for read-only channels */
1422 			if (ch_bits & 1) /* the first channel must be set (for ease of programming) */
1423 				build_feature_ctl(state, _ftr, ch_bits, i, &iterm, unitid, ch_read_only);
1424 			if (uac2_control_is_readable(master_bits, i))
1425 				build_feature_ctl(state, _ftr, 0, i, &iterm, unitid,
1426 						  !uac2_control_is_writeable(master_bits, i));
1427 		}
1428 	}
1429 
1430 	return 0;
1431 }
1432 
1433 
1434 /*
1435  * Mixer Unit
1436  */
1437 
1438 /*
1439  * build a mixer unit control
1440  *
1441  * the callbacks are identical with feature unit.
1442  * input channel number (zero based) is given in control field instead.
1443  */
1444 
1445 static void build_mixer_unit_ctl(struct mixer_build *state,
1446 				 struct uac_mixer_unit_descriptor *desc,
1447 				 int in_pin, int in_ch, int unitid,
1448 				 struct usb_audio_term *iterm)
1449 {
1450 	struct usb_mixer_elem_info *cval;
1451 	unsigned int num_outs = uac_mixer_unit_bNrChannels(desc);
1452 	unsigned int i, len;
1453 	struct snd_kcontrol *kctl;
1454 	const struct usbmix_name_map *map;
1455 
1456 	map = find_map(state, unitid, 0);
1457 	if (check_ignored_ctl(map))
1458 		return;
1459 
1460 	cval = kzalloc(sizeof(*cval), GFP_KERNEL);
1461 	if (! cval)
1462 		return;
1463 
1464 	cval->mixer = state->mixer;
1465 	cval->id = unitid;
1466 	cval->control = in_ch + 1; /* based on 1 */
1467 	cval->val_type = USB_MIXER_S16;
1468 	for (i = 0; i < num_outs; i++) {
1469 		if (check_matrix_bitmap(uac_mixer_unit_bmControls(desc, state->mixer->protocol), in_ch, i, num_outs)) {
1470 			cval->cmask |= (1 << i);
1471 			cval->channels++;
1472 		}
1473 	}
1474 
1475 	/* get min/max values */
1476 	get_min_max(cval, 0);
1477 
1478 	kctl = snd_ctl_new1(&usb_feature_unit_ctl, cval);
1479 	if (! kctl) {
1480 		snd_printk(KERN_ERR "cannot malloc kcontrol\n");
1481 		kfree(cval);
1482 		return;
1483 	}
1484 	kctl->private_free = usb_mixer_elem_free;
1485 
1486 	len = check_mapped_name(map, kctl->id.name, sizeof(kctl->id.name));
1487 	if (! len)
1488 		len = get_term_name(state, iterm, kctl->id.name, sizeof(kctl->id.name), 0);
1489 	if (! len)
1490 		len = sprintf(kctl->id.name, "Mixer Source %d", in_ch + 1);
1491 	append_ctl_name(kctl, " Volume");
1492 
1493 	snd_printdd(KERN_INFO "[%d] MU [%s] ch = %d, val = %d/%d\n",
1494 		    cval->id, kctl->id.name, cval->channels, cval->min, cval->max);
1495 	snd_usb_mixer_add_control(state->mixer, kctl);
1496 }
1497 
1498 
1499 /*
1500  * parse a mixer unit
1501  */
1502 static int parse_audio_mixer_unit(struct mixer_build *state, int unitid, void *raw_desc)
1503 {
1504 	struct uac_mixer_unit_descriptor *desc = raw_desc;
1505 	struct usb_audio_term iterm;
1506 	int input_pins, num_ins, num_outs;
1507 	int pin, ich, err;
1508 
1509 	if (desc->bLength < 11 || ! (input_pins = desc->bNrInPins) || ! (num_outs = uac_mixer_unit_bNrChannels(desc))) {
1510 		snd_printk(KERN_ERR "invalid MIXER UNIT descriptor %d\n", unitid);
1511 		return -EINVAL;
1512 	}
1513 	/* no bmControls field (e.g. Maya44) -> ignore */
1514 	if (desc->bLength <= 10 + input_pins) {
1515 		snd_printdd(KERN_INFO "MU %d has no bmControls field\n", unitid);
1516 		return 0;
1517 	}
1518 
1519 	num_ins = 0;
1520 	ich = 0;
1521 	for (pin = 0; pin < input_pins; pin++) {
1522 		err = parse_audio_unit(state, desc->baSourceID[pin]);
1523 		if (err < 0)
1524 			continue;
1525 		err = check_input_term(state, desc->baSourceID[pin], &iterm);
1526 		if (err < 0)
1527 			return err;
1528 		num_ins += iterm.channels;
1529 		for (; ich < num_ins; ++ich) {
1530 			int och, ich_has_controls = 0;
1531 
1532 			for (och = 0; och < num_outs; ++och) {
1533 				if (check_matrix_bitmap(uac_mixer_unit_bmControls(desc, state->mixer->protocol),
1534 							ich, och, num_outs)) {
1535 					ich_has_controls = 1;
1536 					break;
1537 				}
1538 			}
1539 			if (ich_has_controls)
1540 				build_mixer_unit_ctl(state, desc, pin, ich,
1541 						     unitid, &iterm);
1542 		}
1543 	}
1544 	return 0;
1545 }
1546 
1547 
1548 /*
1549  * Processing Unit / Extension Unit
1550  */
1551 
1552 /* get callback for processing/extension unit */
1553 static int mixer_ctl_procunit_get(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
1554 {
1555 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1556 	int err, val;
1557 
1558 	err = get_cur_ctl_value(cval, cval->control << 8, &val);
1559 	if (err < 0 && cval->mixer->ignore_ctl_error) {
1560 		ucontrol->value.integer.value[0] = cval->min;
1561 		return 0;
1562 	}
1563 	if (err < 0)
1564 		return err;
1565 	val = get_relative_value(cval, val);
1566 	ucontrol->value.integer.value[0] = val;
1567 	return 0;
1568 }
1569 
1570 /* put callback for processing/extension unit */
1571 static int mixer_ctl_procunit_put(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
1572 {
1573 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1574 	int val, oval, err;
1575 
1576 	err = get_cur_ctl_value(cval, cval->control << 8, &oval);
1577 	if (err < 0) {
1578 		if (cval->mixer->ignore_ctl_error)
1579 			return 0;
1580 		return err;
1581 	}
1582 	val = ucontrol->value.integer.value[0];
1583 	val = get_abs_value(cval, val);
1584 	if (val != oval) {
1585 		set_cur_ctl_value(cval, cval->control << 8, val);
1586 		return 1;
1587 	}
1588 	return 0;
1589 }
1590 
1591 /* alsa control interface for processing/extension unit */
1592 static struct snd_kcontrol_new mixer_procunit_ctl = {
1593 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
1594 	.name = "", /* will be filled later */
1595 	.info = mixer_ctl_feature_info,
1596 	.get = mixer_ctl_procunit_get,
1597 	.put = mixer_ctl_procunit_put,
1598 };
1599 
1600 
1601 /*
1602  * predefined data for processing units
1603  */
1604 struct procunit_value_info {
1605 	int control;
1606 	char *suffix;
1607 	int val_type;
1608 	int min_value;
1609 };
1610 
1611 struct procunit_info {
1612 	int type;
1613 	char *name;
1614 	struct procunit_value_info *values;
1615 };
1616 
1617 static struct procunit_value_info updown_proc_info[] = {
1618 	{ UAC_UD_ENABLE, "Switch", USB_MIXER_BOOLEAN },
1619 	{ UAC_UD_MODE_SELECT, "Mode Select", USB_MIXER_U8, 1 },
1620 	{ 0 }
1621 };
1622 static struct procunit_value_info prologic_proc_info[] = {
1623 	{ UAC_DP_ENABLE, "Switch", USB_MIXER_BOOLEAN },
1624 	{ UAC_DP_MODE_SELECT, "Mode Select", USB_MIXER_U8, 1 },
1625 	{ 0 }
1626 };
1627 static struct procunit_value_info threed_enh_proc_info[] = {
1628 	{ UAC_3D_ENABLE, "Switch", USB_MIXER_BOOLEAN },
1629 	{ UAC_3D_SPACE, "Spaciousness", USB_MIXER_U8 },
1630 	{ 0 }
1631 };
1632 static struct procunit_value_info reverb_proc_info[] = {
1633 	{ UAC_REVERB_ENABLE, "Switch", USB_MIXER_BOOLEAN },
1634 	{ UAC_REVERB_LEVEL, "Level", USB_MIXER_U8 },
1635 	{ UAC_REVERB_TIME, "Time", USB_MIXER_U16 },
1636 	{ UAC_REVERB_FEEDBACK, "Feedback", USB_MIXER_U8 },
1637 	{ 0 }
1638 };
1639 static struct procunit_value_info chorus_proc_info[] = {
1640 	{ UAC_CHORUS_ENABLE, "Switch", USB_MIXER_BOOLEAN },
1641 	{ UAC_CHORUS_LEVEL, "Level", USB_MIXER_U8 },
1642 	{ UAC_CHORUS_RATE, "Rate", USB_MIXER_U16 },
1643 	{ UAC_CHORUS_DEPTH, "Depth", USB_MIXER_U16 },
1644 	{ 0 }
1645 };
1646 static struct procunit_value_info dcr_proc_info[] = {
1647 	{ UAC_DCR_ENABLE, "Switch", USB_MIXER_BOOLEAN },
1648 	{ UAC_DCR_RATE, "Ratio", USB_MIXER_U16 },
1649 	{ UAC_DCR_MAXAMPL, "Max Amp", USB_MIXER_S16 },
1650 	{ UAC_DCR_THRESHOLD, "Threshold", USB_MIXER_S16 },
1651 	{ UAC_DCR_ATTACK_TIME, "Attack Time", USB_MIXER_U16 },
1652 	{ UAC_DCR_RELEASE_TIME, "Release Time", USB_MIXER_U16 },
1653 	{ 0 }
1654 };
1655 
1656 static struct procunit_info procunits[] = {
1657 	{ UAC_PROCESS_UP_DOWNMIX, "Up Down", updown_proc_info },
1658 	{ UAC_PROCESS_DOLBY_PROLOGIC, "Dolby Prologic", prologic_proc_info },
1659 	{ UAC_PROCESS_STEREO_EXTENDER, "3D Stereo Extender", threed_enh_proc_info },
1660 	{ UAC_PROCESS_REVERB, "Reverb", reverb_proc_info },
1661 	{ UAC_PROCESS_CHORUS, "Chorus", chorus_proc_info },
1662 	{ UAC_PROCESS_DYN_RANGE_COMP, "DCR", dcr_proc_info },
1663 	{ 0 },
1664 };
1665 /*
1666  * predefined data for extension units
1667  */
1668 static struct procunit_value_info clock_rate_xu_info[] = {
1669 	{ USB_XU_CLOCK_RATE_SELECTOR, "Selector", USB_MIXER_U8, 0 },
1670 	{ 0 }
1671 };
1672 static struct procunit_value_info clock_source_xu_info[] = {
1673 	{ USB_XU_CLOCK_SOURCE_SELECTOR, "External", USB_MIXER_BOOLEAN },
1674 	{ 0 }
1675 };
1676 static struct procunit_value_info spdif_format_xu_info[] = {
1677 	{ USB_XU_DIGITAL_FORMAT_SELECTOR, "SPDIF/AC3", USB_MIXER_BOOLEAN },
1678 	{ 0 }
1679 };
1680 static struct procunit_value_info soft_limit_xu_info[] = {
1681 	{ USB_XU_SOFT_LIMIT_SELECTOR, " ", USB_MIXER_BOOLEAN },
1682 	{ 0 }
1683 };
1684 static struct procunit_info extunits[] = {
1685 	{ USB_XU_CLOCK_RATE, "Clock rate", clock_rate_xu_info },
1686 	{ USB_XU_CLOCK_SOURCE, "DigitalIn CLK source", clock_source_xu_info },
1687 	{ USB_XU_DIGITAL_IO_STATUS, "DigitalOut format:", spdif_format_xu_info },
1688 	{ USB_XU_DEVICE_OPTIONS, "AnalogueIn Soft Limit", soft_limit_xu_info },
1689 	{ 0 }
1690 };
1691 /*
1692  * build a processing/extension unit
1693  */
1694 static int build_audio_procunit(struct mixer_build *state, int unitid, void *raw_desc, struct procunit_info *list, char *name)
1695 {
1696 	struct uac_processing_unit_descriptor *desc = raw_desc;
1697 	int num_ins = desc->bNrInPins;
1698 	struct usb_mixer_elem_info *cval;
1699 	struct snd_kcontrol *kctl;
1700 	int i, err, nameid, type, len;
1701 	struct procunit_info *info;
1702 	struct procunit_value_info *valinfo;
1703 	const struct usbmix_name_map *map;
1704 	static struct procunit_value_info default_value_info[] = {
1705 		{ 0x01, "Switch", USB_MIXER_BOOLEAN },
1706 		{ 0 }
1707 	};
1708 	static struct procunit_info default_info = {
1709 		0, NULL, default_value_info
1710 	};
1711 
1712 	if (desc->bLength < 13 || desc->bLength < 13 + num_ins ||
1713 	    desc->bLength < num_ins + uac_processing_unit_bControlSize(desc, state->mixer->protocol)) {
1714 		snd_printk(KERN_ERR "invalid %s descriptor (id %d)\n", name, unitid);
1715 		return -EINVAL;
1716 	}
1717 
1718 	for (i = 0; i < num_ins; i++) {
1719 		if ((err = parse_audio_unit(state, desc->baSourceID[i])) < 0)
1720 			return err;
1721 	}
1722 
1723 	type = le16_to_cpu(desc->wProcessType);
1724 	for (info = list; info && info->type; info++)
1725 		if (info->type == type)
1726 			break;
1727 	if (! info || ! info->type)
1728 		info = &default_info;
1729 
1730 	for (valinfo = info->values; valinfo->control; valinfo++) {
1731 		__u8 *controls = uac_processing_unit_bmControls(desc, state->mixer->protocol);
1732 
1733 		if (! (controls[valinfo->control / 8] & (1 << ((valinfo->control % 8) - 1))))
1734 			continue;
1735 		map = find_map(state, unitid, valinfo->control);
1736 		if (check_ignored_ctl(map))
1737 			continue;
1738 		cval = kzalloc(sizeof(*cval), GFP_KERNEL);
1739 		if (! cval) {
1740 			snd_printk(KERN_ERR "cannot malloc kcontrol\n");
1741 			return -ENOMEM;
1742 		}
1743 		cval->mixer = state->mixer;
1744 		cval->id = unitid;
1745 		cval->control = valinfo->control;
1746 		cval->val_type = valinfo->val_type;
1747 		cval->channels = 1;
1748 
1749 		/* get min/max values */
1750 		if (type == UAC_PROCESS_UP_DOWNMIX && cval->control == UAC_UD_MODE_SELECT) {
1751 			__u8 *control_spec = uac_processing_unit_specific(desc, state->mixer->protocol);
1752 			/* FIXME: hard-coded */
1753 			cval->min = 1;
1754 			cval->max = control_spec[0];
1755 			cval->res = 1;
1756 			cval->initialized = 1;
1757 		} else {
1758 			if (type == USB_XU_CLOCK_RATE) {
1759 				/* E-Mu USB 0404/0202/TrackerPre/0204
1760 				 * samplerate control quirk
1761 				 */
1762 				cval->min = 0;
1763 				cval->max = 5;
1764 				cval->res = 1;
1765 				cval->initialized = 1;
1766 			} else
1767 				get_min_max(cval, valinfo->min_value);
1768 		}
1769 
1770 		kctl = snd_ctl_new1(&mixer_procunit_ctl, cval);
1771 		if (! kctl) {
1772 			snd_printk(KERN_ERR "cannot malloc kcontrol\n");
1773 			kfree(cval);
1774 			return -ENOMEM;
1775 		}
1776 		kctl->private_free = usb_mixer_elem_free;
1777 
1778 		if (check_mapped_name(map, kctl->id.name,
1779 						sizeof(kctl->id.name)))
1780 			/* nothing */ ;
1781 		else if (info->name)
1782 			strlcpy(kctl->id.name, info->name, sizeof(kctl->id.name));
1783 		else {
1784 			nameid = uac_processing_unit_iProcessing(desc, state->mixer->protocol);
1785 			len = 0;
1786 			if (nameid)
1787 				len = snd_usb_copy_string_desc(state, nameid, kctl->id.name, sizeof(kctl->id.name));
1788 			if (! len)
1789 				strlcpy(kctl->id.name, name, sizeof(kctl->id.name));
1790 		}
1791 		append_ctl_name(kctl, " ");
1792 		append_ctl_name(kctl, valinfo->suffix);
1793 
1794 		snd_printdd(KERN_INFO "[%d] PU [%s] ch = %d, val = %d/%d\n",
1795 			    cval->id, kctl->id.name, cval->channels, cval->min, cval->max);
1796 		if ((err = snd_usb_mixer_add_control(state->mixer, kctl)) < 0)
1797 			return err;
1798 	}
1799 	return 0;
1800 }
1801 
1802 
1803 static int parse_audio_processing_unit(struct mixer_build *state, int unitid, void *raw_desc)
1804 {
1805 	return build_audio_procunit(state, unitid, raw_desc, procunits, "Processing Unit");
1806 }
1807 
1808 static int parse_audio_extension_unit(struct mixer_build *state, int unitid, void *raw_desc)
1809 {
1810 	/* Note that we parse extension units with processing unit descriptors.
1811 	 * That's ok as the layout is the same */
1812 	return build_audio_procunit(state, unitid, raw_desc, extunits, "Extension Unit");
1813 }
1814 
1815 
1816 /*
1817  * Selector Unit
1818  */
1819 
1820 /* info callback for selector unit
1821  * use an enumerator type for routing
1822  */
1823 static int mixer_ctl_selector_info(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo)
1824 {
1825 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1826 	const char **itemlist = (const char **)kcontrol->private_value;
1827 
1828 	if (snd_BUG_ON(!itemlist))
1829 		return -EINVAL;
1830 	return snd_ctl_enum_info(uinfo, 1, cval->max, itemlist);
1831 }
1832 
1833 /* get callback for selector unit */
1834 static int mixer_ctl_selector_get(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
1835 {
1836 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1837 	int val, err;
1838 
1839 	err = get_cur_ctl_value(cval, cval->control << 8, &val);
1840 	if (err < 0) {
1841 		if (cval->mixer->ignore_ctl_error) {
1842 			ucontrol->value.enumerated.item[0] = 0;
1843 			return 0;
1844 		}
1845 		return err;
1846 	}
1847 	val = get_relative_value(cval, val);
1848 	ucontrol->value.enumerated.item[0] = val;
1849 	return 0;
1850 }
1851 
1852 /* put callback for selector unit */
1853 static int mixer_ctl_selector_put(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
1854 {
1855 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1856 	int val, oval, err;
1857 
1858 	err = get_cur_ctl_value(cval, cval->control << 8, &oval);
1859 	if (err < 0) {
1860 		if (cval->mixer->ignore_ctl_error)
1861 			return 0;
1862 		return err;
1863 	}
1864 	val = ucontrol->value.enumerated.item[0];
1865 	val = get_abs_value(cval, val);
1866 	if (val != oval) {
1867 		set_cur_ctl_value(cval, cval->control << 8, val);
1868 		return 1;
1869 	}
1870 	return 0;
1871 }
1872 
1873 /* alsa control interface for selector unit */
1874 static struct snd_kcontrol_new mixer_selectunit_ctl = {
1875 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
1876 	.name = "", /* will be filled later */
1877 	.info = mixer_ctl_selector_info,
1878 	.get = mixer_ctl_selector_get,
1879 	.put = mixer_ctl_selector_put,
1880 };
1881 
1882 
1883 /* private free callback.
1884  * free both private_data and private_value
1885  */
1886 static void usb_mixer_selector_elem_free(struct snd_kcontrol *kctl)
1887 {
1888 	int i, num_ins = 0;
1889 
1890 	if (kctl->private_data) {
1891 		struct usb_mixer_elem_info *cval = kctl->private_data;
1892 		num_ins = cval->max;
1893 		kfree(cval);
1894 		kctl->private_data = NULL;
1895 	}
1896 	if (kctl->private_value) {
1897 		char **itemlist = (char **)kctl->private_value;
1898 		for (i = 0; i < num_ins; i++)
1899 			kfree(itemlist[i]);
1900 		kfree(itemlist);
1901 		kctl->private_value = 0;
1902 	}
1903 }
1904 
1905 /*
1906  * parse a selector unit
1907  */
1908 static int parse_audio_selector_unit(struct mixer_build *state, int unitid, void *raw_desc)
1909 {
1910 	struct uac_selector_unit_descriptor *desc = raw_desc;
1911 	unsigned int i, nameid, len;
1912 	int err;
1913 	struct usb_mixer_elem_info *cval;
1914 	struct snd_kcontrol *kctl;
1915 	const struct usbmix_name_map *map;
1916 	char **namelist;
1917 
1918 	if (!desc->bNrInPins || desc->bLength < 5 + desc->bNrInPins) {
1919 		snd_printk(KERN_ERR "invalid SELECTOR UNIT descriptor %d\n", unitid);
1920 		return -EINVAL;
1921 	}
1922 
1923 	for (i = 0; i < desc->bNrInPins; i++) {
1924 		if ((err = parse_audio_unit(state, desc->baSourceID[i])) < 0)
1925 			return err;
1926 	}
1927 
1928 	if (desc->bNrInPins == 1) /* only one ? nonsense! */
1929 		return 0;
1930 
1931 	map = find_map(state, unitid, 0);
1932 	if (check_ignored_ctl(map))
1933 		return 0;
1934 
1935 	cval = kzalloc(sizeof(*cval), GFP_KERNEL);
1936 	if (! cval) {
1937 		snd_printk(KERN_ERR "cannot malloc kcontrol\n");
1938 		return -ENOMEM;
1939 	}
1940 	cval->mixer = state->mixer;
1941 	cval->id = unitid;
1942 	cval->val_type = USB_MIXER_U8;
1943 	cval->channels = 1;
1944 	cval->min = 1;
1945 	cval->max = desc->bNrInPins;
1946 	cval->res = 1;
1947 	cval->initialized = 1;
1948 
1949 	if (desc->bDescriptorSubtype == UAC2_CLOCK_SELECTOR)
1950 		cval->control = UAC2_CX_CLOCK_SELECTOR;
1951 	else
1952 		cval->control = 0;
1953 
1954 	namelist = kmalloc(sizeof(char *) * desc->bNrInPins, GFP_KERNEL);
1955 	if (! namelist) {
1956 		snd_printk(KERN_ERR "cannot malloc\n");
1957 		kfree(cval);
1958 		return -ENOMEM;
1959 	}
1960 #define MAX_ITEM_NAME_LEN	64
1961 	for (i = 0; i < desc->bNrInPins; i++) {
1962 		struct usb_audio_term iterm;
1963 		len = 0;
1964 		namelist[i] = kmalloc(MAX_ITEM_NAME_LEN, GFP_KERNEL);
1965 		if (! namelist[i]) {
1966 			snd_printk(KERN_ERR "cannot malloc\n");
1967 			while (i--)
1968 				kfree(namelist[i]);
1969 			kfree(namelist);
1970 			kfree(cval);
1971 			return -ENOMEM;
1972 		}
1973 		len = check_mapped_selector_name(state, unitid, i, namelist[i],
1974 						 MAX_ITEM_NAME_LEN);
1975 		if (! len && check_input_term(state, desc->baSourceID[i], &iterm) >= 0)
1976 			len = get_term_name(state, &iterm, namelist[i], MAX_ITEM_NAME_LEN, 0);
1977 		if (! len)
1978 			sprintf(namelist[i], "Input %d", i);
1979 	}
1980 
1981 	kctl = snd_ctl_new1(&mixer_selectunit_ctl, cval);
1982 	if (! kctl) {
1983 		snd_printk(KERN_ERR "cannot malloc kcontrol\n");
1984 		kfree(namelist);
1985 		kfree(cval);
1986 		return -ENOMEM;
1987 	}
1988 	kctl->private_value = (unsigned long)namelist;
1989 	kctl->private_free = usb_mixer_selector_elem_free;
1990 
1991 	nameid = uac_selector_unit_iSelector(desc);
1992 	len = check_mapped_name(map, kctl->id.name, sizeof(kctl->id.name));
1993 	if (len)
1994 		;
1995 	else if (nameid)
1996 		snd_usb_copy_string_desc(state, nameid, kctl->id.name, sizeof(kctl->id.name));
1997 	else {
1998 		len = get_term_name(state, &state->oterm,
1999 				    kctl->id.name, sizeof(kctl->id.name), 0);
2000 		if (! len)
2001 			strlcpy(kctl->id.name, "USB", sizeof(kctl->id.name));
2002 
2003 		if (desc->bDescriptorSubtype == UAC2_CLOCK_SELECTOR)
2004 			append_ctl_name(kctl, " Clock Source");
2005 		else if ((state->oterm.type & 0xff00) == 0x0100)
2006 			append_ctl_name(kctl, " Capture Source");
2007 		else
2008 			append_ctl_name(kctl, " Playback Source");
2009 	}
2010 
2011 	snd_printdd(KERN_INFO "[%d] SU [%s] items = %d\n",
2012 		    cval->id, kctl->id.name, desc->bNrInPins);
2013 	if ((err = snd_usb_mixer_add_control(state->mixer, kctl)) < 0)
2014 		return err;
2015 
2016 	return 0;
2017 }
2018 
2019 
2020 /*
2021  * parse an audio unit recursively
2022  */
2023 
2024 static int parse_audio_unit(struct mixer_build *state, int unitid)
2025 {
2026 	unsigned char *p1;
2027 
2028 	if (test_and_set_bit(unitid, state->unitbitmap))
2029 		return 0; /* the unit already visited */
2030 
2031 	p1 = find_audio_control_unit(state, unitid);
2032 	if (!p1) {
2033 		snd_printk(KERN_ERR "usbaudio: unit %d not found!\n", unitid);
2034 		return -EINVAL;
2035 	}
2036 
2037 	switch (p1[2]) {
2038 	case UAC_INPUT_TERMINAL:
2039 	case UAC2_CLOCK_SOURCE:
2040 		return 0; /* NOP */
2041 	case UAC_MIXER_UNIT:
2042 		return parse_audio_mixer_unit(state, unitid, p1);
2043 	case UAC_SELECTOR_UNIT:
2044 	case UAC2_CLOCK_SELECTOR:
2045 		return parse_audio_selector_unit(state, unitid, p1);
2046 	case UAC_FEATURE_UNIT:
2047 		return parse_audio_feature_unit(state, unitid, p1);
2048 	case UAC1_PROCESSING_UNIT:
2049 	/*   UAC2_EFFECT_UNIT has the same value */
2050 		if (state->mixer->protocol == UAC_VERSION_1)
2051 			return parse_audio_processing_unit(state, unitid, p1);
2052 		else
2053 			return 0; /* FIXME - effect units not implemented yet */
2054 	case UAC1_EXTENSION_UNIT:
2055 	/*   UAC2_PROCESSING_UNIT_V2 has the same value */
2056 		if (state->mixer->protocol == UAC_VERSION_1)
2057 			return parse_audio_extension_unit(state, unitid, p1);
2058 		else /* UAC_VERSION_2 */
2059 			return parse_audio_processing_unit(state, unitid, p1);
2060 	case UAC2_EXTENSION_UNIT_V2:
2061 		return parse_audio_extension_unit(state, unitid, p1);
2062 	default:
2063 		snd_printk(KERN_ERR "usbaudio: unit %u: unexpected type 0x%02x\n", unitid, p1[2]);
2064 		return -EINVAL;
2065 	}
2066 }
2067 
2068 static void snd_usb_mixer_free(struct usb_mixer_interface *mixer)
2069 {
2070 	kfree(mixer->id_elems);
2071 	if (mixer->urb) {
2072 		kfree(mixer->urb->transfer_buffer);
2073 		usb_free_urb(mixer->urb);
2074 	}
2075 	usb_free_urb(mixer->rc_urb);
2076 	kfree(mixer->rc_setup_packet);
2077 	kfree(mixer);
2078 }
2079 
2080 static int snd_usb_mixer_dev_free(struct snd_device *device)
2081 {
2082 	struct usb_mixer_interface *mixer = device->device_data;
2083 	snd_usb_mixer_free(mixer);
2084 	return 0;
2085 }
2086 
2087 /*
2088  * create mixer controls
2089  *
2090  * walk through all UAC_OUTPUT_TERMINAL descriptors to search for mixers
2091  */
2092 static int snd_usb_mixer_controls(struct usb_mixer_interface *mixer)
2093 {
2094 	struct mixer_build state;
2095 	int err;
2096 	const struct usbmix_ctl_map *map;
2097 	void *p;
2098 
2099 	memset(&state, 0, sizeof(state));
2100 	state.chip = mixer->chip;
2101 	state.mixer = mixer;
2102 	state.buffer = mixer->hostif->extra;
2103 	state.buflen = mixer->hostif->extralen;
2104 
2105 	/* check the mapping table */
2106 	for (map = usbmix_ctl_maps; map->id; map++) {
2107 		if (map->id == state.chip->usb_id) {
2108 			state.map = map->map;
2109 			state.selector_map = map->selector_map;
2110 			mixer->ignore_ctl_error = map->ignore_ctl_error;
2111 			break;
2112 		}
2113 	}
2114 
2115 	p = NULL;
2116 	while ((p = snd_usb_find_csint_desc(mixer->hostif->extra, mixer->hostif->extralen,
2117 					    p, UAC_OUTPUT_TERMINAL)) != NULL) {
2118 		if (mixer->protocol == UAC_VERSION_1) {
2119 			struct uac1_output_terminal_descriptor *desc = p;
2120 
2121 			if (desc->bLength < sizeof(*desc))
2122 				continue; /* invalid descriptor? */
2123 			set_bit(desc->bTerminalID, state.unitbitmap);  /* mark terminal ID as visited */
2124 			state.oterm.id = desc->bTerminalID;
2125 			state.oterm.type = le16_to_cpu(desc->wTerminalType);
2126 			state.oterm.name = desc->iTerminal;
2127 			err = parse_audio_unit(&state, desc->bSourceID);
2128 			if (err < 0 && err != -EINVAL)
2129 				return err;
2130 		} else { /* UAC_VERSION_2 */
2131 			struct uac2_output_terminal_descriptor *desc = p;
2132 
2133 			if (desc->bLength < sizeof(*desc))
2134 				continue; /* invalid descriptor? */
2135 			set_bit(desc->bTerminalID, state.unitbitmap);  /* mark terminal ID as visited */
2136 			state.oterm.id = desc->bTerminalID;
2137 			state.oterm.type = le16_to_cpu(desc->wTerminalType);
2138 			state.oterm.name = desc->iTerminal;
2139 			err = parse_audio_unit(&state, desc->bSourceID);
2140 			if (err < 0 && err != -EINVAL)
2141 				return err;
2142 
2143 			/* for UAC2, use the same approach to also add the clock selectors */
2144 			err = parse_audio_unit(&state, desc->bCSourceID);
2145 			if (err < 0 && err != -EINVAL)
2146 				return err;
2147 		}
2148 	}
2149 
2150 	return 0;
2151 }
2152 
2153 void snd_usb_mixer_notify_id(struct usb_mixer_interface *mixer, int unitid)
2154 {
2155 	struct usb_mixer_elem_info *info;
2156 
2157 	for (info = mixer->id_elems[unitid]; info; info = info->next_id_elem)
2158 		snd_ctl_notify(mixer->chip->card, SNDRV_CTL_EVENT_MASK_VALUE,
2159 			       info->elem_id);
2160 }
2161 
2162 static void snd_usb_mixer_dump_cval(struct snd_info_buffer *buffer,
2163 				    int unitid,
2164 				    struct usb_mixer_elem_info *cval)
2165 {
2166 	static char *val_types[] = {"BOOLEAN", "INV_BOOLEAN",
2167 				    "S8", "U8", "S16", "U16"};
2168 	snd_iprintf(buffer, "  Unit: %i\n", unitid);
2169 	if (cval->elem_id)
2170 		snd_iprintf(buffer, "    Control: name=\"%s\", index=%i\n",
2171 				cval->elem_id->name, cval->elem_id->index);
2172 	snd_iprintf(buffer, "    Info: id=%i, control=%i, cmask=0x%x, "
2173 			    "channels=%i, type=\"%s\"\n", cval->id,
2174 			    cval->control, cval->cmask, cval->channels,
2175 			    val_types[cval->val_type]);
2176 	snd_iprintf(buffer, "    Volume: min=%i, max=%i, dBmin=%i, dBmax=%i\n",
2177 			    cval->min, cval->max, cval->dBmin, cval->dBmax);
2178 }
2179 
2180 static void snd_usb_mixer_proc_read(struct snd_info_entry *entry,
2181 				    struct snd_info_buffer *buffer)
2182 {
2183 	struct snd_usb_audio *chip = entry->private_data;
2184 	struct usb_mixer_interface *mixer;
2185 	struct usb_mixer_elem_info *cval;
2186 	int unitid;
2187 
2188 	list_for_each_entry(mixer, &chip->mixer_list, list) {
2189 		snd_iprintf(buffer,
2190 			"USB Mixer: usb_id=0x%08x, ctrlif=%i, ctlerr=%i\n",
2191 				chip->usb_id, snd_usb_ctrl_intf(chip),
2192 				mixer->ignore_ctl_error);
2193 		snd_iprintf(buffer, "Card: %s\n", chip->card->longname);
2194 		for (unitid = 0; unitid < MAX_ID_ELEMS; unitid++) {
2195 			for (cval = mixer->id_elems[unitid]; cval;
2196 						cval = cval->next_id_elem)
2197 				snd_usb_mixer_dump_cval(buffer, unitid, cval);
2198 		}
2199 	}
2200 }
2201 
2202 static void snd_usb_mixer_interrupt_v2(struct usb_mixer_interface *mixer,
2203 				       int attribute, int value, int index)
2204 {
2205 	struct usb_mixer_elem_info *info;
2206 	__u8 unitid = (index >> 8) & 0xff;
2207 	__u8 control = (value >> 8) & 0xff;
2208 	__u8 channel = value & 0xff;
2209 
2210 	if (channel >= MAX_CHANNELS) {
2211 		snd_printk(KERN_DEBUG "%s(): bogus channel number %d\n",
2212 				__func__, channel);
2213 		return;
2214 	}
2215 
2216 	for (info = mixer->id_elems[unitid]; info; info = info->next_id_elem) {
2217 		if (info->control != control)
2218 			continue;
2219 
2220 		switch (attribute) {
2221 		case UAC2_CS_CUR:
2222 			/* invalidate cache, so the value is read from the device */
2223 			if (channel)
2224 				info->cached &= ~(1 << channel);
2225 			else /* master channel */
2226 				info->cached = 0;
2227 
2228 			snd_ctl_notify(mixer->chip->card, SNDRV_CTL_EVENT_MASK_VALUE,
2229 					info->elem_id);
2230 			break;
2231 
2232 		case UAC2_CS_RANGE:
2233 			/* TODO */
2234 			break;
2235 
2236 		case UAC2_CS_MEM:
2237 			/* TODO */
2238 			break;
2239 
2240 		default:
2241 			snd_printk(KERN_DEBUG "unknown attribute %d in interrupt\n",
2242 						attribute);
2243 			break;
2244 		} /* switch */
2245 	}
2246 }
2247 
2248 static void snd_usb_mixer_interrupt(struct urb *urb)
2249 {
2250 	struct usb_mixer_interface *mixer = urb->context;
2251 	int len = urb->actual_length;
2252 	int ustatus = urb->status;
2253 
2254 	if (ustatus != 0)
2255 		goto requeue;
2256 
2257 	if (mixer->protocol == UAC_VERSION_1) {
2258 		struct uac1_status_word *status;
2259 
2260 		for (status = urb->transfer_buffer;
2261 		     len >= sizeof(*status);
2262 		     len -= sizeof(*status), status++) {
2263 			snd_printd(KERN_DEBUG "status interrupt: %02x %02x\n",
2264 						status->bStatusType,
2265 						status->bOriginator);
2266 
2267 			/* ignore any notifications not from the control interface */
2268 			if ((status->bStatusType & UAC1_STATUS_TYPE_ORIG_MASK) !=
2269 				UAC1_STATUS_TYPE_ORIG_AUDIO_CONTROL_IF)
2270 				continue;
2271 
2272 			if (status->bStatusType & UAC1_STATUS_TYPE_MEM_CHANGED)
2273 				snd_usb_mixer_rc_memory_change(mixer, status->bOriginator);
2274 			else
2275 				snd_usb_mixer_notify_id(mixer, status->bOriginator);
2276 		}
2277 	} else { /* UAC_VERSION_2 */
2278 		struct uac2_interrupt_data_msg *msg;
2279 
2280 		for (msg = urb->transfer_buffer;
2281 		     len >= sizeof(*msg);
2282 		     len -= sizeof(*msg), msg++) {
2283 			/* drop vendor specific and endpoint requests */
2284 			if ((msg->bInfo & UAC2_INTERRUPT_DATA_MSG_VENDOR) ||
2285 			    (msg->bInfo & UAC2_INTERRUPT_DATA_MSG_EP))
2286 				continue;
2287 
2288 			snd_usb_mixer_interrupt_v2(mixer, msg->bAttribute,
2289 						   le16_to_cpu(msg->wValue),
2290 						   le16_to_cpu(msg->wIndex));
2291 		}
2292 	}
2293 
2294 requeue:
2295 	if (ustatus != -ENOENT && ustatus != -ECONNRESET && ustatus != -ESHUTDOWN) {
2296 		urb->dev = mixer->chip->dev;
2297 		usb_submit_urb(urb, GFP_ATOMIC);
2298 	}
2299 }
2300 
2301 /* stop any bus activity of a mixer */
2302 void snd_usb_mixer_inactivate(struct usb_mixer_interface *mixer)
2303 {
2304 	usb_kill_urb(mixer->urb);
2305 	usb_kill_urb(mixer->rc_urb);
2306 }
2307 
2308 int snd_usb_mixer_activate(struct usb_mixer_interface *mixer)
2309 {
2310 	int err;
2311 
2312 	if (mixer->urb) {
2313 		err = usb_submit_urb(mixer->urb, GFP_NOIO);
2314 		if (err < 0)
2315 			return err;
2316 	}
2317 
2318 	return 0;
2319 }
2320 
2321 /* create the handler for the optional status interrupt endpoint */
2322 static int snd_usb_mixer_status_create(struct usb_mixer_interface *mixer)
2323 {
2324 	struct usb_endpoint_descriptor *ep;
2325 	void *transfer_buffer;
2326 	int buffer_length;
2327 	unsigned int epnum;
2328 
2329 	/* we need one interrupt input endpoint */
2330 	if (get_iface_desc(mixer->hostif)->bNumEndpoints < 1)
2331 		return 0;
2332 	ep = get_endpoint(mixer->hostif, 0);
2333 	if (!usb_endpoint_dir_in(ep) || !usb_endpoint_xfer_int(ep))
2334 		return 0;
2335 
2336 	epnum = usb_endpoint_num(ep);
2337 	buffer_length = le16_to_cpu(ep->wMaxPacketSize);
2338 	transfer_buffer = kmalloc(buffer_length, GFP_KERNEL);
2339 	if (!transfer_buffer)
2340 		return -ENOMEM;
2341 	mixer->urb = usb_alloc_urb(0, GFP_KERNEL);
2342 	if (!mixer->urb) {
2343 		kfree(transfer_buffer);
2344 		return -ENOMEM;
2345 	}
2346 	usb_fill_int_urb(mixer->urb, mixer->chip->dev,
2347 			 usb_rcvintpipe(mixer->chip->dev, epnum),
2348 			 transfer_buffer, buffer_length,
2349 			 snd_usb_mixer_interrupt, mixer, ep->bInterval);
2350 	usb_submit_urb(mixer->urb, GFP_KERNEL);
2351 	return 0;
2352 }
2353 
2354 int snd_usb_create_mixer(struct snd_usb_audio *chip, int ctrlif,
2355 			 int ignore_error)
2356 {
2357 	static struct snd_device_ops dev_ops = {
2358 		.dev_free = snd_usb_mixer_dev_free
2359 	};
2360 	struct usb_mixer_interface *mixer;
2361 	struct snd_info_entry *entry;
2362 	int err;
2363 
2364 	strcpy(chip->card->mixername, "USB Mixer");
2365 
2366 	mixer = kzalloc(sizeof(*mixer), GFP_KERNEL);
2367 	if (!mixer)
2368 		return -ENOMEM;
2369 	mixer->chip = chip;
2370 	mixer->ignore_ctl_error = ignore_error;
2371 	mixer->id_elems = kcalloc(MAX_ID_ELEMS, sizeof(*mixer->id_elems),
2372 				  GFP_KERNEL);
2373 	if (!mixer->id_elems) {
2374 		kfree(mixer);
2375 		return -ENOMEM;
2376 	}
2377 
2378 	mixer->hostif = &usb_ifnum_to_if(chip->dev, ctrlif)->altsetting[0];
2379 	switch (get_iface_desc(mixer->hostif)->bInterfaceProtocol) {
2380 	case UAC_VERSION_1:
2381 	default:
2382 		mixer->protocol = UAC_VERSION_1;
2383 		break;
2384 	case UAC_VERSION_2:
2385 		mixer->protocol = UAC_VERSION_2;
2386 		break;
2387 	}
2388 
2389 	if ((err = snd_usb_mixer_controls(mixer)) < 0 ||
2390 	    (err = snd_usb_mixer_status_create(mixer)) < 0)
2391 		goto _error;
2392 
2393 	snd_usb_mixer_apply_create_quirk(mixer);
2394 
2395 	err = snd_device_new(chip->card, SNDRV_DEV_LOWLEVEL, mixer, &dev_ops);
2396 	if (err < 0)
2397 		goto _error;
2398 
2399 	if (list_empty(&chip->mixer_list) &&
2400 	    !snd_card_proc_new(chip->card, "usbmixer", &entry))
2401 		snd_info_set_text_ops(entry, chip, snd_usb_mixer_proc_read);
2402 
2403 	list_add(&mixer->list, &chip->mixer_list);
2404 	return 0;
2405 
2406 _error:
2407 	snd_usb_mixer_free(mixer);
2408 	return err;
2409 }
2410 
2411 void snd_usb_mixer_disconnect(struct list_head *p)
2412 {
2413 	struct usb_mixer_interface *mixer;
2414 
2415 	mixer = list_entry(p, struct usb_mixer_interface, list);
2416 	usb_kill_urb(mixer->urb);
2417 	usb_kill_urb(mixer->rc_urb);
2418 }
2419