xref: /openbmc/linux/sound/usb/mixer.c (revision 6774def6)
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,
178 				     unsigned char unit)
179 {
180 	/* we just parse the header */
181 	struct uac_feature_unit_descriptor *hdr = NULL;
182 
183 	while ((hdr = snd_usb_find_desc(state->buffer, state->buflen, hdr,
184 					USB_DT_CS_INTERFACE)) != NULL) {
185 		if (hdr->bLength >= 4 &&
186 		    hdr->bDescriptorSubtype >= UAC_INPUT_TERMINAL &&
187 		    hdr->bDescriptorSubtype <= UAC2_SAMPLE_RATE_CONVERTER &&
188 		    hdr->bUnitID == unit)
189 			return hdr;
190 	}
191 
192 	return NULL;
193 }
194 
195 /*
196  * copy a string with the given id
197  */
198 static int snd_usb_copy_string_desc(struct mixer_build *state,
199 				    int index, char *buf, int maxlen)
200 {
201 	int len = usb_string(state->chip->dev, index, buf, maxlen - 1);
202 	buf[len] = 0;
203 	return len;
204 }
205 
206 /*
207  * convert from the byte/word on usb descriptor to the zero-based integer
208  */
209 static int convert_signed_value(struct usb_mixer_elem_info *cval, int val)
210 {
211 	switch (cval->val_type) {
212 	case USB_MIXER_BOOLEAN:
213 		return !!val;
214 	case USB_MIXER_INV_BOOLEAN:
215 		return !val;
216 	case USB_MIXER_U8:
217 		val &= 0xff;
218 		break;
219 	case USB_MIXER_S8:
220 		val &= 0xff;
221 		if (val >= 0x80)
222 			val -= 0x100;
223 		break;
224 	case USB_MIXER_U16:
225 		val &= 0xffff;
226 		break;
227 	case USB_MIXER_S16:
228 		val &= 0xffff;
229 		if (val >= 0x8000)
230 			val -= 0x10000;
231 		break;
232 	}
233 	return val;
234 }
235 
236 /*
237  * convert from the zero-based int to the byte/word for usb descriptor
238  */
239 static int convert_bytes_value(struct usb_mixer_elem_info *cval, int val)
240 {
241 	switch (cval->val_type) {
242 	case USB_MIXER_BOOLEAN:
243 		return !!val;
244 	case USB_MIXER_INV_BOOLEAN:
245 		return !val;
246 	case USB_MIXER_S8:
247 	case USB_MIXER_U8:
248 		return val & 0xff;
249 	case USB_MIXER_S16:
250 	case USB_MIXER_U16:
251 		return val & 0xffff;
252 	}
253 	return 0; /* not reached */
254 }
255 
256 static int get_relative_value(struct usb_mixer_elem_info *cval, int val)
257 {
258 	if (!cval->res)
259 		cval->res = 1;
260 	if (val < cval->min)
261 		return 0;
262 	else if (val >= cval->max)
263 		return (cval->max - cval->min + cval->res - 1) / cval->res;
264 	else
265 		return (val - cval->min) / cval->res;
266 }
267 
268 static int get_abs_value(struct usb_mixer_elem_info *cval, int val)
269 {
270 	if (val < 0)
271 		return cval->min;
272 	if (!cval->res)
273 		cval->res = 1;
274 	val *= cval->res;
275 	val += cval->min;
276 	if (val > cval->max)
277 		return cval->max;
278 	return val;
279 }
280 
281 
282 /*
283  * retrieve a mixer value
284  */
285 
286 static int get_ctl_value_v1(struct usb_mixer_elem_info *cval, int request,
287 			    int validx, int *value_ret)
288 {
289 	struct snd_usb_audio *chip = cval->mixer->chip;
290 	unsigned char buf[2];
291 	int val_len = cval->val_type >= USB_MIXER_S16 ? 2 : 1;
292 	int timeout = 10;
293 	int idx = 0, err;
294 
295 	err = snd_usb_autoresume(cval->mixer->chip);
296 	if (err < 0)
297 		return -EIO;
298 
299 	down_read(&chip->shutdown_rwsem);
300 	while (timeout-- > 0) {
301 		if (chip->shutdown)
302 			break;
303 		idx = snd_usb_ctrl_intf(chip) | (cval->id << 8);
304 		if (snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0), request,
305 				    USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
306 				    validx, idx, buf, val_len) >= val_len) {
307 			*value_ret = convert_signed_value(cval, snd_usb_combine_bytes(buf, val_len));
308 			err = 0;
309 			goto out;
310 		}
311 	}
312 	usb_audio_dbg(chip,
313 		"cannot get ctl value: req = %#x, wValue = %#x, wIndex = %#x, type = %d\n",
314 		request, validx, idx, cval->val_type);
315 	err = -EINVAL;
316 
317  out:
318 	up_read(&chip->shutdown_rwsem);
319 	snd_usb_autosuspend(cval->mixer->chip);
320 	return err;
321 }
322 
323 static int get_ctl_value_v2(struct usb_mixer_elem_info *cval, int request,
324 			    int validx, int *value_ret)
325 {
326 	struct snd_usb_audio *chip = cval->mixer->chip;
327 	unsigned char buf[2 + 3 * sizeof(__u16)]; /* enough space for one range */
328 	unsigned char *val;
329 	int idx = 0, ret, size;
330 	__u8 bRequest;
331 
332 	if (request == UAC_GET_CUR) {
333 		bRequest = UAC2_CS_CUR;
334 		size = sizeof(__u16);
335 	} else {
336 		bRequest = UAC2_CS_RANGE;
337 		size = sizeof(buf);
338 	}
339 
340 	memset(buf, 0, sizeof(buf));
341 
342 	ret = snd_usb_autoresume(chip) ? -EIO : 0;
343 	if (ret)
344 		goto error;
345 
346 	down_read(&chip->shutdown_rwsem);
347 	if (chip->shutdown) {
348 		ret = -ENODEV;
349 	} else {
350 		idx = snd_usb_ctrl_intf(chip) | (cval->id << 8);
351 		ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0), bRequest,
352 			      USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
353 			      validx, idx, buf, size);
354 	}
355 	up_read(&chip->shutdown_rwsem);
356 	snd_usb_autosuspend(chip);
357 
358 	if (ret < 0) {
359 error:
360 		usb_audio_err(chip,
361 			"cannot get ctl value: req = %#x, wValue = %#x, wIndex = %#x, type = %d\n",
362 			request, validx, idx, cval->val_type);
363 		return ret;
364 	}
365 
366 	/* FIXME: how should we handle multiple triplets here? */
367 
368 	switch (request) {
369 	case UAC_GET_CUR:
370 		val = buf;
371 		break;
372 	case UAC_GET_MIN:
373 		val = buf + sizeof(__u16);
374 		break;
375 	case UAC_GET_MAX:
376 		val = buf + sizeof(__u16) * 2;
377 		break;
378 	case UAC_GET_RES:
379 		val = buf + sizeof(__u16) * 3;
380 		break;
381 	default:
382 		return -EINVAL;
383 	}
384 
385 	*value_ret = convert_signed_value(cval, snd_usb_combine_bytes(val, sizeof(__u16)));
386 
387 	return 0;
388 }
389 
390 static int get_ctl_value(struct usb_mixer_elem_info *cval, int request,
391 			 int validx, int *value_ret)
392 {
393 	validx += cval->idx_off;
394 
395 	return (cval->mixer->protocol == UAC_VERSION_1) ?
396 		get_ctl_value_v1(cval, request, validx, value_ret) :
397 		get_ctl_value_v2(cval, request, validx, value_ret);
398 }
399 
400 static int get_cur_ctl_value(struct usb_mixer_elem_info *cval,
401 			     int validx, int *value)
402 {
403 	return get_ctl_value(cval, UAC_GET_CUR, validx, value);
404 }
405 
406 /* channel = 0: master, 1 = first channel */
407 static inline int get_cur_mix_raw(struct usb_mixer_elem_info *cval,
408 				  int channel, int *value)
409 {
410 	return get_ctl_value(cval, UAC_GET_CUR,
411 			     (cval->control << 8) | channel,
412 			     value);
413 }
414 
415 static int get_cur_mix_value(struct usb_mixer_elem_info *cval,
416 			     int channel, int index, int *value)
417 {
418 	int err;
419 
420 	if (cval->cached & (1 << channel)) {
421 		*value = cval->cache_val[index];
422 		return 0;
423 	}
424 	err = get_cur_mix_raw(cval, channel, value);
425 	if (err < 0) {
426 		if (!cval->mixer->ignore_ctl_error)
427 			usb_audio_dbg(cval->mixer->chip,
428 				"cannot get current value for control %d ch %d: err = %d\n",
429 				      cval->control, channel, err);
430 		return err;
431 	}
432 	cval->cached |= 1 << channel;
433 	cval->cache_val[index] = *value;
434 	return 0;
435 }
436 
437 /*
438  * set a mixer value
439  */
440 
441 int snd_usb_mixer_set_ctl_value(struct usb_mixer_elem_info *cval,
442 				int request, int validx, int value_set)
443 {
444 	struct snd_usb_audio *chip = cval->mixer->chip;
445 	unsigned char buf[2];
446 	int idx = 0, val_len, err, timeout = 10;
447 
448 	validx += cval->idx_off;
449 
450 	if (cval->mixer->protocol == UAC_VERSION_1) {
451 		val_len = cval->val_type >= USB_MIXER_S16 ? 2 : 1;
452 	} else { /* UAC_VERSION_2 */
453 		/* audio class v2 controls are always 2 bytes in size */
454 		val_len = sizeof(__u16);
455 
456 		/* FIXME */
457 		if (request != UAC_SET_CUR) {
458 			usb_audio_dbg(chip, "RANGE setting not yet supported\n");
459 			return -EINVAL;
460 		}
461 
462 		request = UAC2_CS_CUR;
463 	}
464 
465 	value_set = convert_bytes_value(cval, value_set);
466 	buf[0] = value_set & 0xff;
467 	buf[1] = (value_set >> 8) & 0xff;
468 	err = snd_usb_autoresume(chip);
469 	if (err < 0)
470 		return -EIO;
471 	down_read(&chip->shutdown_rwsem);
472 	while (timeout-- > 0) {
473 		if (chip->shutdown)
474 			break;
475 		idx = snd_usb_ctrl_intf(chip) | (cval->id << 8);
476 		if (snd_usb_ctl_msg(chip->dev,
477 				    usb_sndctrlpipe(chip->dev, 0), request,
478 				    USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
479 				    validx, idx, buf, val_len) >= 0) {
480 			err = 0;
481 			goto out;
482 		}
483 	}
484 	usb_audio_dbg(chip, "cannot set ctl value: req = %#x, wValue = %#x, wIndex = %#x, type = %d, data = %#x/%#x\n",
485 		      request, validx, idx, cval->val_type, buf[0], buf[1]);
486 	err = -EINVAL;
487 
488  out:
489 	up_read(&chip->shutdown_rwsem);
490 	snd_usb_autosuspend(chip);
491 	return err;
492 }
493 
494 static int set_cur_ctl_value(struct usb_mixer_elem_info *cval,
495 			     int validx, int value)
496 {
497 	return snd_usb_mixer_set_ctl_value(cval, UAC_SET_CUR, validx, value);
498 }
499 
500 static int set_cur_mix_value(struct usb_mixer_elem_info *cval, int channel,
501 			     int index, int value)
502 {
503 	int err;
504 	unsigned int read_only = (channel == 0) ?
505 		cval->master_readonly :
506 		cval->ch_readonly & (1 << (channel - 1));
507 
508 	if (read_only) {
509 		usb_audio_dbg(cval->mixer->chip,
510 			      "%s(): channel %d of control %d is read_only\n",
511 			    __func__, channel, cval->control);
512 		return 0;
513 	}
514 
515 	err = snd_usb_mixer_set_ctl_value(cval,
516 					  UAC_SET_CUR, (cval->control << 8) | channel,
517 					  value);
518 	if (err < 0)
519 		return err;
520 	cval->cached |= 1 << channel;
521 	cval->cache_val[index] = value;
522 	return 0;
523 }
524 
525 /*
526  * TLV callback for mixer volume controls
527  */
528 int snd_usb_mixer_vol_tlv(struct snd_kcontrol *kcontrol, int op_flag,
529 			 unsigned int size, unsigned int __user *_tlv)
530 {
531 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
532 	DECLARE_TLV_DB_MINMAX(scale, 0, 0);
533 
534 	if (size < sizeof(scale))
535 		return -ENOMEM;
536 	scale[2] = cval->dBmin;
537 	scale[3] = cval->dBmax;
538 	if (copy_to_user(_tlv, scale, sizeof(scale)))
539 		return -EFAULT;
540 	return 0;
541 }
542 
543 /*
544  * parser routines begin here...
545  */
546 
547 static int parse_audio_unit(struct mixer_build *state, int unitid);
548 
549 
550 /*
551  * check if the input/output channel routing is enabled on the given bitmap.
552  * used for mixer unit parser
553  */
554 static int check_matrix_bitmap(unsigned char *bmap,
555 			       int ich, int och, int num_outs)
556 {
557 	int idx = ich * num_outs + och;
558 	return bmap[idx >> 3] & (0x80 >> (idx & 7));
559 }
560 
561 /*
562  * add an alsa control element
563  * search and increment the index until an empty slot is found.
564  *
565  * if failed, give up and free the control instance.
566  */
567 
568 int snd_usb_mixer_add_control(struct usb_mixer_interface *mixer,
569 			      struct snd_kcontrol *kctl)
570 {
571 	struct usb_mixer_elem_info *cval = kctl->private_data;
572 	int err;
573 
574 	while (snd_ctl_find_id(mixer->chip->card, &kctl->id))
575 		kctl->id.index++;
576 	if ((err = snd_ctl_add(mixer->chip->card, kctl)) < 0) {
577 		usb_audio_dbg(mixer->chip, "cannot add control (err = %d)\n",
578 			      err);
579 		return err;
580 	}
581 	cval->elem_id = &kctl->id;
582 	cval->next_id_elem = mixer->id_elems[cval->id];
583 	mixer->id_elems[cval->id] = cval;
584 	return 0;
585 }
586 
587 /*
588  * get a terminal name string
589  */
590 
591 static struct iterm_name_combo {
592 	int type;
593 	char *name;
594 } iterm_names[] = {
595 	{ 0x0300, "Output" },
596 	{ 0x0301, "Speaker" },
597 	{ 0x0302, "Headphone" },
598 	{ 0x0303, "HMD Audio" },
599 	{ 0x0304, "Desktop Speaker" },
600 	{ 0x0305, "Room Speaker" },
601 	{ 0x0306, "Com Speaker" },
602 	{ 0x0307, "LFE" },
603 	{ 0x0600, "External In" },
604 	{ 0x0601, "Analog In" },
605 	{ 0x0602, "Digital In" },
606 	{ 0x0603, "Line" },
607 	{ 0x0604, "Legacy In" },
608 	{ 0x0605, "IEC958 In" },
609 	{ 0x0606, "1394 DA Stream" },
610 	{ 0x0607, "1394 DV Stream" },
611 	{ 0x0700, "Embedded" },
612 	{ 0x0701, "Noise Source" },
613 	{ 0x0702, "Equalization Noise" },
614 	{ 0x0703, "CD" },
615 	{ 0x0704, "DAT" },
616 	{ 0x0705, "DCC" },
617 	{ 0x0706, "MiniDisk" },
618 	{ 0x0707, "Analog Tape" },
619 	{ 0x0708, "Phonograph" },
620 	{ 0x0709, "VCR Audio" },
621 	{ 0x070a, "Video Disk Audio" },
622 	{ 0x070b, "DVD Audio" },
623 	{ 0x070c, "TV Tuner Audio" },
624 	{ 0x070d, "Satellite Rec Audio" },
625 	{ 0x070e, "Cable Tuner Audio" },
626 	{ 0x070f, "DSS Audio" },
627 	{ 0x0710, "Radio Receiver" },
628 	{ 0x0711, "Radio Transmitter" },
629 	{ 0x0712, "Multi-Track Recorder" },
630 	{ 0x0713, "Synthesizer" },
631 	{ 0 },
632 };
633 
634 static int get_term_name(struct mixer_build *state, struct usb_audio_term *iterm,
635 			 unsigned char *name, int maxlen, int term_only)
636 {
637 	struct iterm_name_combo *names;
638 
639 	if (iterm->name)
640 		return snd_usb_copy_string_desc(state, iterm->name,
641 						name, maxlen);
642 
643 	/* virtual type - not a real terminal */
644 	if (iterm->type >> 16) {
645 		if (term_only)
646 			return 0;
647 		switch (iterm->type >> 16) {
648 		case UAC_SELECTOR_UNIT:
649 			strcpy(name, "Selector");
650 			return 8;
651 		case UAC1_PROCESSING_UNIT:
652 			strcpy(name, "Process Unit");
653 			return 12;
654 		case UAC1_EXTENSION_UNIT:
655 			strcpy(name, "Ext Unit");
656 			return 8;
657 		case UAC_MIXER_UNIT:
658 			strcpy(name, "Mixer");
659 			return 5;
660 		default:
661 			return sprintf(name, "Unit %d", iterm->id);
662 		}
663 	}
664 
665 	switch (iterm->type & 0xff00) {
666 	case 0x0100:
667 		strcpy(name, "PCM");
668 		return 3;
669 	case 0x0200:
670 		strcpy(name, "Mic");
671 		return 3;
672 	case 0x0400:
673 		strcpy(name, "Headset");
674 		return 7;
675 	case 0x0500:
676 		strcpy(name, "Phone");
677 		return 5;
678 	}
679 
680 	for (names = iterm_names; names->type; names++) {
681 		if (names->type == iterm->type) {
682 			strcpy(name, names->name);
683 			return strlen(names->name);
684 		}
685 	}
686 
687 	return 0;
688 }
689 
690 /*
691  * parse the source unit recursively until it reaches to a terminal
692  * or a branched unit.
693  */
694 static int check_input_term(struct mixer_build *state, int id,
695 			    struct usb_audio_term *term)
696 {
697 	int err;
698 	void *p1;
699 
700 	memset(term, 0, sizeof(*term));
701 	while ((p1 = find_audio_control_unit(state, id)) != NULL) {
702 		unsigned char *hdr = p1;
703 		term->id = id;
704 		switch (hdr[2]) {
705 		case UAC_INPUT_TERMINAL:
706 			if (state->mixer->protocol == UAC_VERSION_1) {
707 				struct uac_input_terminal_descriptor *d = p1;
708 				term->type = le16_to_cpu(d->wTerminalType);
709 				term->channels = d->bNrChannels;
710 				term->chconfig = le16_to_cpu(d->wChannelConfig);
711 				term->name = d->iTerminal;
712 			} else { /* UAC_VERSION_2 */
713 				struct uac2_input_terminal_descriptor *d = p1;
714 				term->type = le16_to_cpu(d->wTerminalType);
715 				term->channels = d->bNrChannels;
716 				term->chconfig = le32_to_cpu(d->bmChannelConfig);
717 				term->name = d->iTerminal;
718 
719 				/* call recursively to get the clock selectors */
720 				err = check_input_term(state, d->bCSourceID, term);
721 				if (err < 0)
722 					return err;
723 			}
724 			return 0;
725 		case UAC_FEATURE_UNIT: {
726 			/* the header is the same for v1 and v2 */
727 			struct uac_feature_unit_descriptor *d = p1;
728 			id = d->bSourceID;
729 			break; /* continue to parse */
730 		}
731 		case UAC_MIXER_UNIT: {
732 			struct uac_mixer_unit_descriptor *d = p1;
733 			term->type = d->bDescriptorSubtype << 16; /* virtual type */
734 			term->channels = uac_mixer_unit_bNrChannels(d);
735 			term->chconfig = uac_mixer_unit_wChannelConfig(d, state->mixer->protocol);
736 			term->name = uac_mixer_unit_iMixer(d);
737 			return 0;
738 		}
739 		case UAC_SELECTOR_UNIT:
740 		case UAC2_CLOCK_SELECTOR: {
741 			struct uac_selector_unit_descriptor *d = p1;
742 			/* call recursively to retrieve the channel info */
743 			err = check_input_term(state, d->baSourceID[0], term);
744 			if (err < 0)
745 				return err;
746 			term->type = d->bDescriptorSubtype << 16; /* virtual type */
747 			term->id = id;
748 			term->name = uac_selector_unit_iSelector(d);
749 			return 0;
750 		}
751 		case UAC1_PROCESSING_UNIT:
752 		case UAC1_EXTENSION_UNIT:
753 		/* UAC2_PROCESSING_UNIT_V2 */
754 		/* UAC2_EFFECT_UNIT */
755 		case UAC2_EXTENSION_UNIT_V2: {
756 			struct uac_processing_unit_descriptor *d = p1;
757 
758 			if (state->mixer->protocol == UAC_VERSION_2 &&
759 				hdr[2] == UAC2_EFFECT_UNIT) {
760 				/* UAC2/UAC1 unit IDs overlap here in an
761 				 * uncompatible way. Ignore this unit for now.
762 				 */
763 				return 0;
764 			}
765 
766 			if (d->bNrInPins) {
767 				id = d->baSourceID[0];
768 				break; /* continue to parse */
769 			}
770 			term->type = d->bDescriptorSubtype << 16; /* virtual type */
771 			term->channels = uac_processing_unit_bNrChannels(d);
772 			term->chconfig = uac_processing_unit_wChannelConfig(d, state->mixer->protocol);
773 			term->name = uac_processing_unit_iProcessing(d, state->mixer->protocol);
774 			return 0;
775 		}
776 		case UAC2_CLOCK_SOURCE: {
777 			struct uac_clock_source_descriptor *d = p1;
778 			term->type = d->bDescriptorSubtype << 16; /* virtual type */
779 			term->id = id;
780 			term->name = d->iClockSource;
781 			return 0;
782 		}
783 		default:
784 			return -ENODEV;
785 		}
786 	}
787 	return -ENODEV;
788 }
789 
790 /*
791  * Feature Unit
792  */
793 
794 /* feature unit control information */
795 struct usb_feature_control_info {
796 	const char *name;
797 	unsigned int type;	/* control type (mute, volume, etc.) */
798 };
799 
800 static struct usb_feature_control_info audio_feature_info[] = {
801 	{ "Mute",			USB_MIXER_INV_BOOLEAN },
802 	{ "Volume",			USB_MIXER_S16 },
803 	{ "Tone Control - Bass",	USB_MIXER_S8 },
804 	{ "Tone Control - Mid",		USB_MIXER_S8 },
805 	{ "Tone Control - Treble",	USB_MIXER_S8 },
806 	{ "Graphic Equalizer",		USB_MIXER_S8 }, /* FIXME: not implemeted yet */
807 	{ "Auto Gain Control",		USB_MIXER_BOOLEAN },
808 	{ "Delay Control",		USB_MIXER_U16 },
809 	{ "Bass Boost",			USB_MIXER_BOOLEAN },
810 	{ "Loudness",			USB_MIXER_BOOLEAN },
811 	/* UAC2 specific */
812 	{ "Input Gain Control",		USB_MIXER_U16 },
813 	{ "Input Gain Pad Control",	USB_MIXER_BOOLEAN },
814 	{ "Phase Inverter Control",	USB_MIXER_BOOLEAN },
815 };
816 
817 /* private_free callback */
818 static void usb_mixer_elem_free(struct snd_kcontrol *kctl)
819 {
820 	kfree(kctl->private_data);
821 	kctl->private_data = NULL;
822 }
823 
824 /*
825  * interface to ALSA control for feature/mixer units
826  */
827 
828 /* volume control quirks */
829 static void volume_control_quirks(struct usb_mixer_elem_info *cval,
830 				  struct snd_kcontrol *kctl)
831 {
832 	struct snd_usb_audio *chip = cval->mixer->chip;
833 	switch (chip->usb_id) {
834 	case USB_ID(0x0763, 0x2030): /* M-Audio Fast Track C400 */
835 	case USB_ID(0x0763, 0x2031): /* M-Audio Fast Track C600 */
836 		if (strcmp(kctl->id.name, "Effect Duration") == 0) {
837 			cval->min = 0x0000;
838 			cval->max = 0xffff;
839 			cval->res = 0x00e6;
840 			break;
841 		}
842 		if (strcmp(kctl->id.name, "Effect Volume") == 0 ||
843 		    strcmp(kctl->id.name, "Effect Feedback Volume") == 0) {
844 			cval->min = 0x00;
845 			cval->max = 0xff;
846 			break;
847 		}
848 		if (strstr(kctl->id.name, "Effect Return") != NULL) {
849 			cval->min = 0xb706;
850 			cval->max = 0xff7b;
851 			cval->res = 0x0073;
852 			break;
853 		}
854 		if ((strstr(kctl->id.name, "Playback Volume") != NULL) ||
855 			(strstr(kctl->id.name, "Effect Send") != NULL)) {
856 			cval->min = 0xb5fb; /* -73 dB = 0xb6ff */
857 			cval->max = 0xfcfe;
858 			cval->res = 0x0073;
859 		}
860 		break;
861 
862 	case USB_ID(0x0763, 0x2081): /* M-Audio Fast Track Ultra 8R */
863 	case USB_ID(0x0763, 0x2080): /* M-Audio Fast Track Ultra */
864 		if (strcmp(kctl->id.name, "Effect Duration") == 0) {
865 			usb_audio_info(chip,
866 				       "set quirk for FTU Effect Duration\n");
867 			cval->min = 0x0000;
868 			cval->max = 0x7f00;
869 			cval->res = 0x0100;
870 			break;
871 		}
872 		if (strcmp(kctl->id.name, "Effect Volume") == 0 ||
873 		    strcmp(kctl->id.name, "Effect Feedback Volume") == 0) {
874 			usb_audio_info(chip,
875 				       "set quirks for FTU Effect Feedback/Volume\n");
876 			cval->min = 0x00;
877 			cval->max = 0x7f;
878 			break;
879 		}
880 		break;
881 
882 	case USB_ID(0x0471, 0x0101):
883 	case USB_ID(0x0471, 0x0104):
884 	case USB_ID(0x0471, 0x0105):
885 	case USB_ID(0x0672, 0x1041):
886 	/* quirk for UDA1321/N101.
887 	 * note that detection between firmware 2.1.1.7 (N101)
888 	 * and later 2.1.1.21 is not very clear from datasheets.
889 	 * I hope that the min value is -15360 for newer firmware --jk
890 	 */
891 		if (!strcmp(kctl->id.name, "PCM Playback Volume") &&
892 		    cval->min == -15616) {
893 			usb_audio_info(chip,
894 				 "set volume quirk for UDA1321/N101 chip\n");
895 			cval->max = -256;
896 		}
897 		break;
898 
899 	case USB_ID(0x046d, 0x09a4):
900 		if (!strcmp(kctl->id.name, "Mic Capture Volume")) {
901 			usb_audio_info(chip,
902 				"set volume quirk for QuickCam E3500\n");
903 			cval->min = 6080;
904 			cval->max = 8768;
905 			cval->res = 192;
906 		}
907 		break;
908 
909 	case USB_ID(0x046d, 0x0807): /* Logitech Webcam C500 */
910 	case USB_ID(0x046d, 0x0808):
911 	case USB_ID(0x046d, 0x0809):
912 	case USB_ID(0x046d, 0x081b): /* HD Webcam c310 */
913 	case USB_ID(0x046d, 0x081d): /* HD Webcam c510 */
914 	case USB_ID(0x046d, 0x0825): /* HD Webcam c270 */
915 	case USB_ID(0x046d, 0x0826): /* HD Webcam c525 */
916 	case USB_ID(0x046d, 0x0991):
917 	/* Most audio usb devices lie about volume resolution.
918 	 * Most Logitech webcams have res = 384.
919 	 * Proboly there is some logitech magic behind this number --fishor
920 	 */
921 		if (!strcmp(kctl->id.name, "Mic Capture Volume")) {
922 			usb_audio_info(chip,
923 				"set resolution quirk: cval->res = 384\n");
924 			cval->res = 384;
925 		}
926 		break;
927 	}
928 }
929 
930 /*
931  * retrieve the minimum and maximum values for the specified control
932  */
933 static int get_min_max_with_quirks(struct usb_mixer_elem_info *cval,
934 				   int default_min, struct snd_kcontrol *kctl)
935 {
936 	/* for failsafe */
937 	cval->min = default_min;
938 	cval->max = cval->min + 1;
939 	cval->res = 1;
940 	cval->dBmin = cval->dBmax = 0;
941 
942 	if (cval->val_type == USB_MIXER_BOOLEAN ||
943 	    cval->val_type == USB_MIXER_INV_BOOLEAN) {
944 		cval->initialized = 1;
945 	} else {
946 		int minchn = 0;
947 		if (cval->cmask) {
948 			int i;
949 			for (i = 0; i < MAX_CHANNELS; i++)
950 				if (cval->cmask & (1 << i)) {
951 					minchn = i + 1;
952 					break;
953 				}
954 		}
955 		if (get_ctl_value(cval, UAC_GET_MAX, (cval->control << 8) | minchn, &cval->max) < 0 ||
956 		    get_ctl_value(cval, UAC_GET_MIN, (cval->control << 8) | minchn, &cval->min) < 0) {
957 			usb_audio_err(cval->mixer->chip,
958 				      "%d:%d: cannot get min/max values for control %d (id %d)\n",
959 				   cval->id, snd_usb_ctrl_intf(cval->mixer->chip),
960 							       cval->control, cval->id);
961 			return -EINVAL;
962 		}
963 		if (get_ctl_value(cval, UAC_GET_RES,
964 				  (cval->control << 8) | minchn,
965 				  &cval->res) < 0) {
966 			cval->res = 1;
967 		} else {
968 			int last_valid_res = cval->res;
969 
970 			while (cval->res > 1) {
971 				if (snd_usb_mixer_set_ctl_value(cval, UAC_SET_RES,
972 								(cval->control << 8) | minchn,
973 								cval->res / 2) < 0)
974 					break;
975 				cval->res /= 2;
976 			}
977 			if (get_ctl_value(cval, UAC_GET_RES,
978 					  (cval->control << 8) | minchn, &cval->res) < 0)
979 				cval->res = last_valid_res;
980 		}
981 		if (cval->res == 0)
982 			cval->res = 1;
983 
984 		/* Additional checks for the proper resolution
985 		 *
986 		 * Some devices report smaller resolutions than actually
987 		 * reacting.  They don't return errors but simply clip
988 		 * to the lower aligned value.
989 		 */
990 		if (cval->min + cval->res < cval->max) {
991 			int last_valid_res = cval->res;
992 			int saved, test, check;
993 			get_cur_mix_raw(cval, minchn, &saved);
994 			for (;;) {
995 				test = saved;
996 				if (test < cval->max)
997 					test += cval->res;
998 				else
999 					test -= cval->res;
1000 				if (test < cval->min || test > cval->max ||
1001 				    set_cur_mix_value(cval, minchn, 0, test) ||
1002 				    get_cur_mix_raw(cval, minchn, &check)) {
1003 					cval->res = last_valid_res;
1004 					break;
1005 				}
1006 				if (test == check)
1007 					break;
1008 				cval->res *= 2;
1009 			}
1010 			set_cur_mix_value(cval, minchn, 0, saved);
1011 		}
1012 
1013 		cval->initialized = 1;
1014 	}
1015 
1016 	if (kctl)
1017 		volume_control_quirks(cval, kctl);
1018 
1019 	/* USB descriptions contain the dB scale in 1/256 dB unit
1020 	 * while ALSA TLV contains in 1/100 dB unit
1021 	 */
1022 	cval->dBmin = (convert_signed_value(cval, cval->min) * 100) / 256;
1023 	cval->dBmax = (convert_signed_value(cval, cval->max) * 100) / 256;
1024 	if (cval->dBmin > cval->dBmax) {
1025 		/* something is wrong; assume it's either from/to 0dB */
1026 		if (cval->dBmin < 0)
1027 			cval->dBmax = 0;
1028 		else if (cval->dBmin > 0)
1029 			cval->dBmin = 0;
1030 		if (cval->dBmin > cval->dBmax) {
1031 			/* totally crap, return an error */
1032 			return -EINVAL;
1033 		}
1034 	}
1035 
1036 	return 0;
1037 }
1038 
1039 #define get_min_max(cval, def)	get_min_max_with_quirks(cval, def, NULL)
1040 
1041 /* get a feature/mixer unit info */
1042 static int mixer_ctl_feature_info(struct snd_kcontrol *kcontrol,
1043 				  struct snd_ctl_elem_info *uinfo)
1044 {
1045 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1046 
1047 	if (cval->val_type == USB_MIXER_BOOLEAN ||
1048 	    cval->val_type == USB_MIXER_INV_BOOLEAN)
1049 		uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1050 	else
1051 		uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
1052 	uinfo->count = cval->channels;
1053 	if (cval->val_type == USB_MIXER_BOOLEAN ||
1054 	    cval->val_type == USB_MIXER_INV_BOOLEAN) {
1055 		uinfo->value.integer.min = 0;
1056 		uinfo->value.integer.max = 1;
1057 	} else {
1058 		if (!cval->initialized) {
1059 			get_min_max_with_quirks(cval, 0, kcontrol);
1060 			if (cval->initialized && cval->dBmin >= cval->dBmax) {
1061 				kcontrol->vd[0].access &=
1062 					~(SNDRV_CTL_ELEM_ACCESS_TLV_READ |
1063 					  SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK);
1064 				snd_ctl_notify(cval->mixer->chip->card,
1065 					       SNDRV_CTL_EVENT_MASK_INFO,
1066 					       &kcontrol->id);
1067 			}
1068 		}
1069 		uinfo->value.integer.min = 0;
1070 		uinfo->value.integer.max =
1071 			(cval->max - cval->min + cval->res - 1) / cval->res;
1072 	}
1073 	return 0;
1074 }
1075 
1076 /* get the current value from feature/mixer unit */
1077 static int mixer_ctl_feature_get(struct snd_kcontrol *kcontrol,
1078 				 struct snd_ctl_elem_value *ucontrol)
1079 {
1080 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1081 	int c, cnt, val, err;
1082 
1083 	ucontrol->value.integer.value[0] = cval->min;
1084 	if (cval->cmask) {
1085 		cnt = 0;
1086 		for (c = 0; c < MAX_CHANNELS; c++) {
1087 			if (!(cval->cmask & (1 << c)))
1088 				continue;
1089 			err = get_cur_mix_value(cval, c + 1, cnt, &val);
1090 			if (err < 0)
1091 				return cval->mixer->ignore_ctl_error ? 0 : err;
1092 			val = get_relative_value(cval, val);
1093 			ucontrol->value.integer.value[cnt] = val;
1094 			cnt++;
1095 		}
1096 		return 0;
1097 	} else {
1098 		/* master channel */
1099 		err = get_cur_mix_value(cval, 0, 0, &val);
1100 		if (err < 0)
1101 			return cval->mixer->ignore_ctl_error ? 0 : err;
1102 		val = get_relative_value(cval, val);
1103 		ucontrol->value.integer.value[0] = val;
1104 	}
1105 	return 0;
1106 }
1107 
1108 /* put the current value to feature/mixer unit */
1109 static int mixer_ctl_feature_put(struct snd_kcontrol *kcontrol,
1110 				 struct snd_ctl_elem_value *ucontrol)
1111 {
1112 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1113 	int c, cnt, val, oval, err;
1114 	int changed = 0;
1115 
1116 	if (cval->cmask) {
1117 		cnt = 0;
1118 		for (c = 0; c < MAX_CHANNELS; c++) {
1119 			if (!(cval->cmask & (1 << c)))
1120 				continue;
1121 			err = get_cur_mix_value(cval, c + 1, cnt, &oval);
1122 			if (err < 0)
1123 				return cval->mixer->ignore_ctl_error ? 0 : err;
1124 			val = ucontrol->value.integer.value[cnt];
1125 			val = get_abs_value(cval, val);
1126 			if (oval != val) {
1127 				set_cur_mix_value(cval, c + 1, cnt, val);
1128 				changed = 1;
1129 			}
1130 			cnt++;
1131 		}
1132 	} else {
1133 		/* master channel */
1134 		err = get_cur_mix_value(cval, 0, 0, &oval);
1135 		if (err < 0)
1136 			return cval->mixer->ignore_ctl_error ? 0 : err;
1137 		val = ucontrol->value.integer.value[0];
1138 		val = get_abs_value(cval, val);
1139 		if (val != oval) {
1140 			set_cur_mix_value(cval, 0, 0, val);
1141 			changed = 1;
1142 		}
1143 	}
1144 	return changed;
1145 }
1146 
1147 static struct snd_kcontrol_new usb_feature_unit_ctl = {
1148 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
1149 	.name = "", /* will be filled later manually */
1150 	.info = mixer_ctl_feature_info,
1151 	.get = mixer_ctl_feature_get,
1152 	.put = mixer_ctl_feature_put,
1153 };
1154 
1155 /* the read-only variant */
1156 static struct snd_kcontrol_new usb_feature_unit_ctl_ro = {
1157 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
1158 	.name = "", /* will be filled later manually */
1159 	.info = mixer_ctl_feature_info,
1160 	.get = mixer_ctl_feature_get,
1161 	.put = NULL,
1162 };
1163 
1164 /*
1165  * This symbol is exported in order to allow the mixer quirks to
1166  * hook up to the standard feature unit control mechanism
1167  */
1168 struct snd_kcontrol_new *snd_usb_feature_unit_ctl = &usb_feature_unit_ctl;
1169 
1170 /*
1171  * build a feature control
1172  */
1173 static size_t append_ctl_name(struct snd_kcontrol *kctl, const char *str)
1174 {
1175 	return strlcat(kctl->id.name, str, sizeof(kctl->id.name));
1176 }
1177 
1178 /*
1179  * A lot of headsets/headphones have a "Speaker" mixer. Make sure we
1180  * rename it to "Headphone". We determine if something is a headphone
1181  * similar to how udev determines form factor.
1182  */
1183 static void check_no_speaker_on_headset(struct snd_kcontrol *kctl,
1184 					struct snd_card *card)
1185 {
1186 	const char *names_to_check[] = {
1187 		"Headset", "headset", "Headphone", "headphone", NULL};
1188 	const char **s;
1189 	bool found = false;
1190 
1191 	if (strcmp("Speaker", kctl->id.name))
1192 		return;
1193 
1194 	for (s = names_to_check; *s; s++)
1195 		if (strstr(card->shortname, *s)) {
1196 			found = true;
1197 			break;
1198 		}
1199 
1200 	if (!found)
1201 		return;
1202 
1203 	strlcpy(kctl->id.name, "Headphone", sizeof(kctl->id.name));
1204 }
1205 
1206 static void build_feature_ctl(struct mixer_build *state, void *raw_desc,
1207 			      unsigned int ctl_mask, int control,
1208 			      struct usb_audio_term *iterm, int unitid,
1209 			      int readonly_mask)
1210 {
1211 	struct uac_feature_unit_descriptor *desc = raw_desc;
1212 	unsigned int len = 0;
1213 	int mapped_name = 0;
1214 	int nameid = uac_feature_unit_iFeature(desc);
1215 	struct snd_kcontrol *kctl;
1216 	struct usb_mixer_elem_info *cval;
1217 	const struct usbmix_name_map *map;
1218 	unsigned int range;
1219 
1220 	control++; /* change from zero-based to 1-based value */
1221 
1222 	if (control == UAC_FU_GRAPHIC_EQUALIZER) {
1223 		/* FIXME: not supported yet */
1224 		return;
1225 	}
1226 
1227 	map = find_map(state, unitid, control);
1228 	if (check_ignored_ctl(map))
1229 		return;
1230 
1231 	cval = kzalloc(sizeof(*cval), GFP_KERNEL);
1232 	if (!cval)
1233 		return;
1234 	cval->mixer = state->mixer;
1235 	cval->id = unitid;
1236 	cval->control = control;
1237 	cval->cmask = ctl_mask;
1238 	cval->val_type = audio_feature_info[control-1].type;
1239 	if (ctl_mask == 0) {
1240 		cval->channels = 1;	/* master channel */
1241 		cval->master_readonly = readonly_mask;
1242 	} else {
1243 		int i, c = 0;
1244 		for (i = 0; i < 16; i++)
1245 			if (ctl_mask & (1 << i))
1246 				c++;
1247 		cval->channels = c;
1248 		cval->ch_readonly = readonly_mask;
1249 	}
1250 
1251 	/*
1252 	 * If all channels in the mask are marked read-only, make the control
1253 	 * read-only. set_cur_mix_value() will check the mask again and won't
1254 	 * issue write commands to read-only channels.
1255 	 */
1256 	if (cval->channels == readonly_mask)
1257 		kctl = snd_ctl_new1(&usb_feature_unit_ctl_ro, cval);
1258 	else
1259 		kctl = snd_ctl_new1(&usb_feature_unit_ctl, cval);
1260 
1261 	if (!kctl) {
1262 		usb_audio_err(state->chip, "cannot malloc kcontrol\n");
1263 		kfree(cval);
1264 		return;
1265 	}
1266 	kctl->private_free = usb_mixer_elem_free;
1267 
1268 	len = check_mapped_name(map, kctl->id.name, sizeof(kctl->id.name));
1269 	mapped_name = len != 0;
1270 	if (!len && nameid)
1271 		len = snd_usb_copy_string_desc(state, nameid,
1272 				kctl->id.name, sizeof(kctl->id.name));
1273 
1274 	switch (control) {
1275 	case UAC_FU_MUTE:
1276 	case UAC_FU_VOLUME:
1277 		/*
1278 		 * determine the control name.  the rule is:
1279 		 * - if a name id is given in descriptor, use it.
1280 		 * - if the connected input can be determined, then use the name
1281 		 *   of terminal type.
1282 		 * - if the connected output can be determined, use it.
1283 		 * - otherwise, anonymous name.
1284 		 */
1285 		if (!len) {
1286 			len = get_term_name(state, iterm, kctl->id.name,
1287 					    sizeof(kctl->id.name), 1);
1288 			if (!len)
1289 				len = get_term_name(state, &state->oterm,
1290 						    kctl->id.name,
1291 						    sizeof(kctl->id.name), 1);
1292 			if (!len)
1293 				len = snprintf(kctl->id.name,
1294 					       sizeof(kctl->id.name),
1295 					       "Feature %d", unitid);
1296 		}
1297 
1298 		if (!mapped_name)
1299 			check_no_speaker_on_headset(kctl, state->mixer->chip->card);
1300 
1301 		/*
1302 		 * determine the stream direction:
1303 		 * if the connected output is USB stream, then it's likely a
1304 		 * capture stream.  otherwise it should be playback (hopefully :)
1305 		 */
1306 		if (!mapped_name && !(state->oterm.type >> 16)) {
1307 			if ((state->oterm.type & 0xff00) == 0x0100)
1308 				len = append_ctl_name(kctl, " Capture");
1309 			else
1310 				len = append_ctl_name(kctl, " Playback");
1311 		}
1312 		append_ctl_name(kctl, control == UAC_FU_MUTE ?
1313 				" Switch" : " Volume");
1314 		break;
1315 	default:
1316 		if (!len)
1317 			strlcpy(kctl->id.name, audio_feature_info[control-1].name,
1318 				sizeof(kctl->id.name));
1319 		break;
1320 	}
1321 
1322 	/* get min/max values */
1323 	get_min_max_with_quirks(cval, 0, kctl);
1324 
1325 	if (control == UAC_FU_VOLUME) {
1326 		check_mapped_dB(map, cval);
1327 		if (cval->dBmin < cval->dBmax || !cval->initialized) {
1328 			kctl->tlv.c = snd_usb_mixer_vol_tlv;
1329 			kctl->vd[0].access |=
1330 				SNDRV_CTL_ELEM_ACCESS_TLV_READ |
1331 				SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1332 		}
1333 	}
1334 
1335 	range = (cval->max - cval->min) / cval->res;
1336 	/*
1337 	 * Are there devices with volume range more than 255? I use a bit more
1338 	 * to be sure. 384 is a resolution magic number found on Logitech
1339 	 * devices. It will definitively catch all buggy Logitech devices.
1340 	 */
1341 	if (range > 384) {
1342 		usb_audio_warn(state->chip,
1343 			       "Warning! Unlikely big volume range (=%u), cval->res is probably wrong.",
1344 			       range);
1345 		usb_audio_warn(state->chip,
1346 			       "[%d] FU [%s] ch = %d, val = %d/%d/%d",
1347 			       cval->id, kctl->id.name, cval->channels,
1348 			       cval->min, cval->max, cval->res);
1349 	}
1350 
1351 	usb_audio_dbg(state->chip, "[%d] FU [%s] ch = %d, val = %d/%d/%d\n",
1352 		      cval->id, kctl->id.name, cval->channels,
1353 		      cval->min, cval->max, cval->res);
1354 	snd_usb_mixer_add_control(state->mixer, kctl);
1355 }
1356 
1357 /*
1358  * parse a feature unit
1359  *
1360  * most of controls are defined here.
1361  */
1362 static int parse_audio_feature_unit(struct mixer_build *state, int unitid,
1363 				    void *_ftr)
1364 {
1365 	int channels, i, j;
1366 	struct usb_audio_term iterm;
1367 	unsigned int master_bits, first_ch_bits;
1368 	int err, csize;
1369 	struct uac_feature_unit_descriptor *hdr = _ftr;
1370 	__u8 *bmaControls;
1371 
1372 	if (state->mixer->protocol == UAC_VERSION_1) {
1373 		csize = hdr->bControlSize;
1374 		if (!csize) {
1375 			usb_audio_dbg(state->chip,
1376 				      "unit %u: invalid bControlSize == 0\n",
1377 				      unitid);
1378 			return -EINVAL;
1379 		}
1380 		channels = (hdr->bLength - 7) / csize - 1;
1381 		bmaControls = hdr->bmaControls;
1382 		if (hdr->bLength < 7 + csize) {
1383 			usb_audio_err(state->chip,
1384 				      "unit %u: invalid UAC_FEATURE_UNIT descriptor\n",
1385 				      unitid);
1386 			return -EINVAL;
1387 		}
1388 	} else {
1389 		struct uac2_feature_unit_descriptor *ftr = _ftr;
1390 		csize = 4;
1391 		channels = (hdr->bLength - 6) / 4 - 1;
1392 		bmaControls = ftr->bmaControls;
1393 		if (hdr->bLength < 6 + csize) {
1394 			usb_audio_err(state->chip,
1395 				      "unit %u: invalid UAC_FEATURE_UNIT descriptor\n",
1396 				      unitid);
1397 			return -EINVAL;
1398 		}
1399 	}
1400 
1401 	/* parse the source unit */
1402 	if ((err = parse_audio_unit(state, hdr->bSourceID)) < 0)
1403 		return err;
1404 
1405 	/* determine the input source type and name */
1406 	err = check_input_term(state, hdr->bSourceID, &iterm);
1407 	if (err < 0)
1408 		return err;
1409 
1410 	master_bits = snd_usb_combine_bytes(bmaControls, csize);
1411 	/* master configuration quirks */
1412 	switch (state->chip->usb_id) {
1413 	case USB_ID(0x08bb, 0x2702):
1414 		usb_audio_info(state->chip,
1415 			       "usbmixer: master volume quirk for PCM2702 chip\n");
1416 		/* disable non-functional volume control */
1417 		master_bits &= ~UAC_CONTROL_BIT(UAC_FU_VOLUME);
1418 		break;
1419 	case USB_ID(0x1130, 0xf211):
1420 		usb_audio_info(state->chip,
1421 			       "usbmixer: volume control quirk for Tenx TP6911 Audio Headset\n");
1422 		/* disable non-functional volume control */
1423 		channels = 0;
1424 		break;
1425 
1426 	}
1427 	if (channels > 0)
1428 		first_ch_bits = snd_usb_combine_bytes(bmaControls + csize, csize);
1429 	else
1430 		first_ch_bits = 0;
1431 
1432 	if (state->mixer->protocol == UAC_VERSION_1) {
1433 		/* check all control types */
1434 		for (i = 0; i < 10; i++) {
1435 			unsigned int ch_bits = 0;
1436 			for (j = 0; j < channels; j++) {
1437 				unsigned int mask;
1438 
1439 				mask = snd_usb_combine_bytes(bmaControls +
1440 							     csize * (j+1), csize);
1441 				if (mask & (1 << i))
1442 					ch_bits |= (1 << j);
1443 			}
1444 			/* audio class v1 controls are never read-only */
1445 
1446 			/*
1447 			 * The first channel must be set
1448 			 * (for ease of programming).
1449 			 */
1450 			if (ch_bits & 1)
1451 				build_feature_ctl(state, _ftr, ch_bits, i,
1452 						  &iterm, unitid, 0);
1453 			if (master_bits & (1 << i))
1454 				build_feature_ctl(state, _ftr, 0, i, &iterm,
1455 						  unitid, 0);
1456 		}
1457 	} else { /* UAC_VERSION_2 */
1458 		for (i = 0; i < ARRAY_SIZE(audio_feature_info); i++) {
1459 			unsigned int ch_bits = 0;
1460 			unsigned int ch_read_only = 0;
1461 
1462 			for (j = 0; j < channels; j++) {
1463 				unsigned int mask;
1464 
1465 				mask = snd_usb_combine_bytes(bmaControls +
1466 							     csize * (j+1), csize);
1467 				if (uac2_control_is_readable(mask, i)) {
1468 					ch_bits |= (1 << j);
1469 					if (!uac2_control_is_writeable(mask, i))
1470 						ch_read_only |= (1 << j);
1471 				}
1472 			}
1473 
1474 			/*
1475 			 * NOTE: build_feature_ctl() will mark the control
1476 			 * read-only if all channels are marked read-only in
1477 			 * the descriptors. Otherwise, the control will be
1478 			 * reported as writeable, but the driver will not
1479 			 * actually issue a write command for read-only
1480 			 * channels.
1481 			 */
1482 
1483 			/*
1484 			 * The first channel must be set
1485 			 * (for ease of programming).
1486 			 */
1487 			if (ch_bits & 1)
1488 				build_feature_ctl(state, _ftr, ch_bits, i,
1489 						  &iterm, unitid, ch_read_only);
1490 			if (uac2_control_is_readable(master_bits, i))
1491 				build_feature_ctl(state, _ftr, 0, i, &iterm, unitid,
1492 						  !uac2_control_is_writeable(master_bits, i));
1493 		}
1494 	}
1495 
1496 	return 0;
1497 }
1498 
1499 /*
1500  * Mixer Unit
1501  */
1502 
1503 /*
1504  * build a mixer unit control
1505  *
1506  * the callbacks are identical with feature unit.
1507  * input channel number (zero based) is given in control field instead.
1508  */
1509 static void build_mixer_unit_ctl(struct mixer_build *state,
1510 				 struct uac_mixer_unit_descriptor *desc,
1511 				 int in_pin, int in_ch, int unitid,
1512 				 struct usb_audio_term *iterm)
1513 {
1514 	struct usb_mixer_elem_info *cval;
1515 	unsigned int num_outs = uac_mixer_unit_bNrChannels(desc);
1516 	unsigned int i, len;
1517 	struct snd_kcontrol *kctl;
1518 	const struct usbmix_name_map *map;
1519 
1520 	map = find_map(state, unitid, 0);
1521 	if (check_ignored_ctl(map))
1522 		return;
1523 
1524 	cval = kzalloc(sizeof(*cval), GFP_KERNEL);
1525 	if (!cval)
1526 		return;
1527 
1528 	cval->mixer = state->mixer;
1529 	cval->id = unitid;
1530 	cval->control = in_ch + 1; /* based on 1 */
1531 	cval->val_type = USB_MIXER_S16;
1532 	for (i = 0; i < num_outs; i++) {
1533 		__u8 *c = uac_mixer_unit_bmControls(desc, state->mixer->protocol);
1534 
1535 		if (check_matrix_bitmap(c, in_ch, i, num_outs)) {
1536 			cval->cmask |= (1 << i);
1537 			cval->channels++;
1538 		}
1539 	}
1540 
1541 	/* get min/max values */
1542 	get_min_max(cval, 0);
1543 
1544 	kctl = snd_ctl_new1(&usb_feature_unit_ctl, cval);
1545 	if (!kctl) {
1546 		usb_audio_err(state->chip, "cannot malloc kcontrol\n");
1547 		kfree(cval);
1548 		return;
1549 	}
1550 	kctl->private_free = usb_mixer_elem_free;
1551 
1552 	len = check_mapped_name(map, kctl->id.name, sizeof(kctl->id.name));
1553 	if (!len)
1554 		len = get_term_name(state, iterm, kctl->id.name,
1555 				    sizeof(kctl->id.name), 0);
1556 	if (!len)
1557 		len = sprintf(kctl->id.name, "Mixer Source %d", in_ch + 1);
1558 	append_ctl_name(kctl, " Volume");
1559 
1560 	usb_audio_dbg(state->chip, "[%d] MU [%s] ch = %d, val = %d/%d\n",
1561 		    cval->id, kctl->id.name, cval->channels, cval->min, cval->max);
1562 	snd_usb_mixer_add_control(state->mixer, kctl);
1563 }
1564 
1565 /*
1566  * parse a mixer unit
1567  */
1568 static int parse_audio_mixer_unit(struct mixer_build *state, int unitid,
1569 				  void *raw_desc)
1570 {
1571 	struct uac_mixer_unit_descriptor *desc = raw_desc;
1572 	struct usb_audio_term iterm;
1573 	int input_pins, num_ins, num_outs;
1574 	int pin, ich, err;
1575 
1576 	if (desc->bLength < 11 || !(input_pins = desc->bNrInPins) ||
1577 	    !(num_outs = uac_mixer_unit_bNrChannels(desc))) {
1578 		usb_audio_err(state->chip,
1579 			      "invalid MIXER UNIT descriptor %d\n",
1580 			      unitid);
1581 		return -EINVAL;
1582 	}
1583 	/* no bmControls field (e.g. Maya44) -> ignore */
1584 	if (desc->bLength <= 10 + input_pins) {
1585 		usb_audio_dbg(state->chip, "MU %d has no bmControls field\n",
1586 			      unitid);
1587 		return 0;
1588 	}
1589 
1590 	num_ins = 0;
1591 	ich = 0;
1592 	for (pin = 0; pin < input_pins; pin++) {
1593 		err = parse_audio_unit(state, desc->baSourceID[pin]);
1594 		if (err < 0)
1595 			continue;
1596 		err = check_input_term(state, desc->baSourceID[pin], &iterm);
1597 		if (err < 0)
1598 			return err;
1599 		num_ins += iterm.channels;
1600 		for (; ich < num_ins; ich++) {
1601 			int och, ich_has_controls = 0;
1602 
1603 			for (och = 0; och < num_outs; och++) {
1604 				__u8 *c = uac_mixer_unit_bmControls(desc,
1605 						state->mixer->protocol);
1606 
1607 				if (check_matrix_bitmap(c, ich, och, num_outs)) {
1608 					ich_has_controls = 1;
1609 					break;
1610 				}
1611 			}
1612 			if (ich_has_controls)
1613 				build_mixer_unit_ctl(state, desc, pin, ich,
1614 						     unitid, &iterm);
1615 		}
1616 	}
1617 	return 0;
1618 }
1619 
1620 /*
1621  * Processing Unit / Extension Unit
1622  */
1623 
1624 /* get callback for processing/extension unit */
1625 static int mixer_ctl_procunit_get(struct snd_kcontrol *kcontrol,
1626 				  struct snd_ctl_elem_value *ucontrol)
1627 {
1628 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1629 	int err, val;
1630 
1631 	err = get_cur_ctl_value(cval, cval->control << 8, &val);
1632 	if (err < 0 && cval->mixer->ignore_ctl_error) {
1633 		ucontrol->value.integer.value[0] = cval->min;
1634 		return 0;
1635 	}
1636 	if (err < 0)
1637 		return err;
1638 	val = get_relative_value(cval, val);
1639 	ucontrol->value.integer.value[0] = val;
1640 	return 0;
1641 }
1642 
1643 /* put callback for processing/extension unit */
1644 static int mixer_ctl_procunit_put(struct snd_kcontrol *kcontrol,
1645 				  struct snd_ctl_elem_value *ucontrol)
1646 {
1647 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1648 	int val, oval, err;
1649 
1650 	err = get_cur_ctl_value(cval, cval->control << 8, &oval);
1651 	if (err < 0) {
1652 		if (cval->mixer->ignore_ctl_error)
1653 			return 0;
1654 		return err;
1655 	}
1656 	val = ucontrol->value.integer.value[0];
1657 	val = get_abs_value(cval, val);
1658 	if (val != oval) {
1659 		set_cur_ctl_value(cval, cval->control << 8, val);
1660 		return 1;
1661 	}
1662 	return 0;
1663 }
1664 
1665 /* alsa control interface for processing/extension unit */
1666 static struct snd_kcontrol_new mixer_procunit_ctl = {
1667 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
1668 	.name = "", /* will be filled later */
1669 	.info = mixer_ctl_feature_info,
1670 	.get = mixer_ctl_procunit_get,
1671 	.put = mixer_ctl_procunit_put,
1672 };
1673 
1674 /*
1675  * predefined data for processing units
1676  */
1677 struct procunit_value_info {
1678 	int control;
1679 	char *suffix;
1680 	int val_type;
1681 	int min_value;
1682 };
1683 
1684 struct procunit_info {
1685 	int type;
1686 	char *name;
1687 	struct procunit_value_info *values;
1688 };
1689 
1690 static struct procunit_value_info updown_proc_info[] = {
1691 	{ UAC_UD_ENABLE, "Switch", USB_MIXER_BOOLEAN },
1692 	{ UAC_UD_MODE_SELECT, "Mode Select", USB_MIXER_U8, 1 },
1693 	{ 0 }
1694 };
1695 static struct procunit_value_info prologic_proc_info[] = {
1696 	{ UAC_DP_ENABLE, "Switch", USB_MIXER_BOOLEAN },
1697 	{ UAC_DP_MODE_SELECT, "Mode Select", USB_MIXER_U8, 1 },
1698 	{ 0 }
1699 };
1700 static struct procunit_value_info threed_enh_proc_info[] = {
1701 	{ UAC_3D_ENABLE, "Switch", USB_MIXER_BOOLEAN },
1702 	{ UAC_3D_SPACE, "Spaciousness", USB_MIXER_U8 },
1703 	{ 0 }
1704 };
1705 static struct procunit_value_info reverb_proc_info[] = {
1706 	{ UAC_REVERB_ENABLE, "Switch", USB_MIXER_BOOLEAN },
1707 	{ UAC_REVERB_LEVEL, "Level", USB_MIXER_U8 },
1708 	{ UAC_REVERB_TIME, "Time", USB_MIXER_U16 },
1709 	{ UAC_REVERB_FEEDBACK, "Feedback", USB_MIXER_U8 },
1710 	{ 0 }
1711 };
1712 static struct procunit_value_info chorus_proc_info[] = {
1713 	{ UAC_CHORUS_ENABLE, "Switch", USB_MIXER_BOOLEAN },
1714 	{ UAC_CHORUS_LEVEL, "Level", USB_MIXER_U8 },
1715 	{ UAC_CHORUS_RATE, "Rate", USB_MIXER_U16 },
1716 	{ UAC_CHORUS_DEPTH, "Depth", USB_MIXER_U16 },
1717 	{ 0 }
1718 };
1719 static struct procunit_value_info dcr_proc_info[] = {
1720 	{ UAC_DCR_ENABLE, "Switch", USB_MIXER_BOOLEAN },
1721 	{ UAC_DCR_RATE, "Ratio", USB_MIXER_U16 },
1722 	{ UAC_DCR_MAXAMPL, "Max Amp", USB_MIXER_S16 },
1723 	{ UAC_DCR_THRESHOLD, "Threshold", USB_MIXER_S16 },
1724 	{ UAC_DCR_ATTACK_TIME, "Attack Time", USB_MIXER_U16 },
1725 	{ UAC_DCR_RELEASE_TIME, "Release Time", USB_MIXER_U16 },
1726 	{ 0 }
1727 };
1728 
1729 static struct procunit_info procunits[] = {
1730 	{ UAC_PROCESS_UP_DOWNMIX, "Up Down", updown_proc_info },
1731 	{ UAC_PROCESS_DOLBY_PROLOGIC, "Dolby Prologic", prologic_proc_info },
1732 	{ UAC_PROCESS_STEREO_EXTENDER, "3D Stereo Extender", threed_enh_proc_info },
1733 	{ UAC_PROCESS_REVERB, "Reverb", reverb_proc_info },
1734 	{ UAC_PROCESS_CHORUS, "Chorus", chorus_proc_info },
1735 	{ UAC_PROCESS_DYN_RANGE_COMP, "DCR", dcr_proc_info },
1736 	{ 0 },
1737 };
1738 /*
1739  * predefined data for extension units
1740  */
1741 static struct procunit_value_info clock_rate_xu_info[] = {
1742 	{ USB_XU_CLOCK_RATE_SELECTOR, "Selector", USB_MIXER_U8, 0 },
1743 	{ 0 }
1744 };
1745 static struct procunit_value_info clock_source_xu_info[] = {
1746 	{ USB_XU_CLOCK_SOURCE_SELECTOR, "External", USB_MIXER_BOOLEAN },
1747 	{ 0 }
1748 };
1749 static struct procunit_value_info spdif_format_xu_info[] = {
1750 	{ USB_XU_DIGITAL_FORMAT_SELECTOR, "SPDIF/AC3", USB_MIXER_BOOLEAN },
1751 	{ 0 }
1752 };
1753 static struct procunit_value_info soft_limit_xu_info[] = {
1754 	{ USB_XU_SOFT_LIMIT_SELECTOR, " ", USB_MIXER_BOOLEAN },
1755 	{ 0 }
1756 };
1757 static struct procunit_info extunits[] = {
1758 	{ USB_XU_CLOCK_RATE, "Clock rate", clock_rate_xu_info },
1759 	{ USB_XU_CLOCK_SOURCE, "DigitalIn CLK source", clock_source_xu_info },
1760 	{ USB_XU_DIGITAL_IO_STATUS, "DigitalOut format:", spdif_format_xu_info },
1761 	{ USB_XU_DEVICE_OPTIONS, "AnalogueIn Soft Limit", soft_limit_xu_info },
1762 	{ 0 }
1763 };
1764 
1765 /*
1766  * build a processing/extension unit
1767  */
1768 static int build_audio_procunit(struct mixer_build *state, int unitid,
1769 				void *raw_desc, struct procunit_info *list,
1770 				char *name)
1771 {
1772 	struct uac_processing_unit_descriptor *desc = raw_desc;
1773 	int num_ins = desc->bNrInPins;
1774 	struct usb_mixer_elem_info *cval;
1775 	struct snd_kcontrol *kctl;
1776 	int i, err, nameid, type, len;
1777 	struct procunit_info *info;
1778 	struct procunit_value_info *valinfo;
1779 	const struct usbmix_name_map *map;
1780 	static struct procunit_value_info default_value_info[] = {
1781 		{ 0x01, "Switch", USB_MIXER_BOOLEAN },
1782 		{ 0 }
1783 	};
1784 	static struct procunit_info default_info = {
1785 		0, NULL, default_value_info
1786 	};
1787 
1788 	if (desc->bLength < 13 || desc->bLength < 13 + num_ins ||
1789 	    desc->bLength < num_ins + uac_processing_unit_bControlSize(desc, state->mixer->protocol)) {
1790 		usb_audio_err(state->chip, "invalid %s descriptor (id %d)\n", name, unitid);
1791 		return -EINVAL;
1792 	}
1793 
1794 	for (i = 0; i < num_ins; i++) {
1795 		if ((err = parse_audio_unit(state, desc->baSourceID[i])) < 0)
1796 			return err;
1797 	}
1798 
1799 	type = le16_to_cpu(desc->wProcessType);
1800 	for (info = list; info && info->type; info++)
1801 		if (info->type == type)
1802 			break;
1803 	if (!info || !info->type)
1804 		info = &default_info;
1805 
1806 	for (valinfo = info->values; valinfo->control; valinfo++) {
1807 		__u8 *controls = uac_processing_unit_bmControls(desc, state->mixer->protocol);
1808 
1809 		if (!(controls[valinfo->control / 8] & (1 << ((valinfo->control % 8) - 1))))
1810 			continue;
1811 		map = find_map(state, unitid, valinfo->control);
1812 		if (check_ignored_ctl(map))
1813 			continue;
1814 		cval = kzalloc(sizeof(*cval), GFP_KERNEL);
1815 		if (!cval)
1816 			return -ENOMEM;
1817 		cval->mixer = state->mixer;
1818 		cval->id = unitid;
1819 		cval->control = valinfo->control;
1820 		cval->val_type = valinfo->val_type;
1821 		cval->channels = 1;
1822 
1823 		/* get min/max values */
1824 		if (type == UAC_PROCESS_UP_DOWNMIX && cval->control == UAC_UD_MODE_SELECT) {
1825 			__u8 *control_spec = uac_processing_unit_specific(desc, state->mixer->protocol);
1826 			/* FIXME: hard-coded */
1827 			cval->min = 1;
1828 			cval->max = control_spec[0];
1829 			cval->res = 1;
1830 			cval->initialized = 1;
1831 		} else {
1832 			if (type == USB_XU_CLOCK_RATE) {
1833 				/*
1834 				 * E-Mu USB 0404/0202/TrackerPre/0204
1835 				 * samplerate control quirk
1836 				 */
1837 				cval->min = 0;
1838 				cval->max = 5;
1839 				cval->res = 1;
1840 				cval->initialized = 1;
1841 			} else
1842 				get_min_max(cval, valinfo->min_value);
1843 		}
1844 
1845 		kctl = snd_ctl_new1(&mixer_procunit_ctl, cval);
1846 		if (!kctl) {
1847 			kfree(cval);
1848 			return -ENOMEM;
1849 		}
1850 		kctl->private_free = usb_mixer_elem_free;
1851 
1852 		if (check_mapped_name(map, kctl->id.name, sizeof(kctl->id.name))) {
1853 			/* nothing */ ;
1854 		} else if (info->name) {
1855 			strlcpy(kctl->id.name, info->name, sizeof(kctl->id.name));
1856 		} else {
1857 			nameid = uac_processing_unit_iProcessing(desc, state->mixer->protocol);
1858 			len = 0;
1859 			if (nameid)
1860 				len = snd_usb_copy_string_desc(state, nameid,
1861 							       kctl->id.name,
1862 							       sizeof(kctl->id.name));
1863 			if (!len)
1864 				strlcpy(kctl->id.name, name, sizeof(kctl->id.name));
1865 		}
1866 		append_ctl_name(kctl, " ");
1867 		append_ctl_name(kctl, valinfo->suffix);
1868 
1869 		usb_audio_dbg(state->chip,
1870 			      "[%d] PU [%s] ch = %d, val = %d/%d\n",
1871 			      cval->id, kctl->id.name, cval->channels,
1872 			      cval->min, cval->max);
1873 
1874 		err = snd_usb_mixer_add_control(state->mixer, kctl);
1875 		if (err < 0)
1876 			return err;
1877 	}
1878 	return 0;
1879 }
1880 
1881 static int parse_audio_processing_unit(struct mixer_build *state, int unitid,
1882 				       void *raw_desc)
1883 {
1884 	return build_audio_procunit(state, unitid, raw_desc,
1885 				    procunits, "Processing Unit");
1886 }
1887 
1888 static int parse_audio_extension_unit(struct mixer_build *state, int unitid,
1889 				      void *raw_desc)
1890 {
1891 	/*
1892 	 * Note that we parse extension units with processing unit descriptors.
1893 	 * That's ok as the layout is the same.
1894 	 */
1895 	return build_audio_procunit(state, unitid, raw_desc,
1896 				    extunits, "Extension Unit");
1897 }
1898 
1899 /*
1900  * Selector Unit
1901  */
1902 
1903 /*
1904  * info callback for selector unit
1905  * use an enumerator type for routing
1906  */
1907 static int mixer_ctl_selector_info(struct snd_kcontrol *kcontrol,
1908 				   struct snd_ctl_elem_info *uinfo)
1909 {
1910 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1911 	const char **itemlist = (const char **)kcontrol->private_value;
1912 
1913 	if (snd_BUG_ON(!itemlist))
1914 		return -EINVAL;
1915 	return snd_ctl_enum_info(uinfo, 1, cval->max, itemlist);
1916 }
1917 
1918 /* get callback for selector unit */
1919 static int mixer_ctl_selector_get(struct snd_kcontrol *kcontrol,
1920 				  struct snd_ctl_elem_value *ucontrol)
1921 {
1922 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1923 	int val, err;
1924 
1925 	err = get_cur_ctl_value(cval, cval->control << 8, &val);
1926 	if (err < 0) {
1927 		if (cval->mixer->ignore_ctl_error) {
1928 			ucontrol->value.enumerated.item[0] = 0;
1929 			return 0;
1930 		}
1931 		return err;
1932 	}
1933 	val = get_relative_value(cval, val);
1934 	ucontrol->value.enumerated.item[0] = val;
1935 	return 0;
1936 }
1937 
1938 /* put callback for selector unit */
1939 static int mixer_ctl_selector_put(struct snd_kcontrol *kcontrol,
1940 				  struct snd_ctl_elem_value *ucontrol)
1941 {
1942 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1943 	int val, oval, err;
1944 
1945 	err = get_cur_ctl_value(cval, cval->control << 8, &oval);
1946 	if (err < 0) {
1947 		if (cval->mixer->ignore_ctl_error)
1948 			return 0;
1949 		return err;
1950 	}
1951 	val = ucontrol->value.enumerated.item[0];
1952 	val = get_abs_value(cval, val);
1953 	if (val != oval) {
1954 		set_cur_ctl_value(cval, cval->control << 8, val);
1955 		return 1;
1956 	}
1957 	return 0;
1958 }
1959 
1960 /* alsa control interface for selector unit */
1961 static struct snd_kcontrol_new mixer_selectunit_ctl = {
1962 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
1963 	.name = "", /* will be filled later */
1964 	.info = mixer_ctl_selector_info,
1965 	.get = mixer_ctl_selector_get,
1966 	.put = mixer_ctl_selector_put,
1967 };
1968 
1969 /*
1970  * private free callback.
1971  * free both private_data and private_value
1972  */
1973 static void usb_mixer_selector_elem_free(struct snd_kcontrol *kctl)
1974 {
1975 	int i, num_ins = 0;
1976 
1977 	if (kctl->private_data) {
1978 		struct usb_mixer_elem_info *cval = kctl->private_data;
1979 		num_ins = cval->max;
1980 		kfree(cval);
1981 		kctl->private_data = NULL;
1982 	}
1983 	if (kctl->private_value) {
1984 		char **itemlist = (char **)kctl->private_value;
1985 		for (i = 0; i < num_ins; i++)
1986 			kfree(itemlist[i]);
1987 		kfree(itemlist);
1988 		kctl->private_value = 0;
1989 	}
1990 }
1991 
1992 /*
1993  * parse a selector unit
1994  */
1995 static int parse_audio_selector_unit(struct mixer_build *state, int unitid,
1996 				     void *raw_desc)
1997 {
1998 	struct uac_selector_unit_descriptor *desc = raw_desc;
1999 	unsigned int i, nameid, len;
2000 	int err;
2001 	struct usb_mixer_elem_info *cval;
2002 	struct snd_kcontrol *kctl;
2003 	const struct usbmix_name_map *map;
2004 	char **namelist;
2005 
2006 	if (!desc->bNrInPins || desc->bLength < 5 + desc->bNrInPins) {
2007 		usb_audio_err(state->chip,
2008 			"invalid SELECTOR UNIT descriptor %d\n", unitid);
2009 		return -EINVAL;
2010 	}
2011 
2012 	for (i = 0; i < desc->bNrInPins; i++) {
2013 		if ((err = parse_audio_unit(state, desc->baSourceID[i])) < 0)
2014 			return err;
2015 	}
2016 
2017 	if (desc->bNrInPins == 1) /* only one ? nonsense! */
2018 		return 0;
2019 
2020 	map = find_map(state, unitid, 0);
2021 	if (check_ignored_ctl(map))
2022 		return 0;
2023 
2024 	cval = kzalloc(sizeof(*cval), GFP_KERNEL);
2025 	if (!cval)
2026 		return -ENOMEM;
2027 	cval->mixer = state->mixer;
2028 	cval->id = unitid;
2029 	cval->val_type = USB_MIXER_U8;
2030 	cval->channels = 1;
2031 	cval->min = 1;
2032 	cval->max = desc->bNrInPins;
2033 	cval->res = 1;
2034 	cval->initialized = 1;
2035 
2036 	if (desc->bDescriptorSubtype == UAC2_CLOCK_SELECTOR)
2037 		cval->control = UAC2_CX_CLOCK_SELECTOR;
2038 	else
2039 		cval->control = 0;
2040 
2041 	namelist = kmalloc(sizeof(char *) * desc->bNrInPins, GFP_KERNEL);
2042 	if (!namelist) {
2043 		kfree(cval);
2044 		return -ENOMEM;
2045 	}
2046 #define MAX_ITEM_NAME_LEN	64
2047 	for (i = 0; i < desc->bNrInPins; i++) {
2048 		struct usb_audio_term iterm;
2049 		len = 0;
2050 		namelist[i] = kmalloc(MAX_ITEM_NAME_LEN, GFP_KERNEL);
2051 		if (!namelist[i]) {
2052 			while (i--)
2053 				kfree(namelist[i]);
2054 			kfree(namelist);
2055 			kfree(cval);
2056 			return -ENOMEM;
2057 		}
2058 		len = check_mapped_selector_name(state, unitid, i, namelist[i],
2059 						 MAX_ITEM_NAME_LEN);
2060 		if (! len && check_input_term(state, desc->baSourceID[i], &iterm) >= 0)
2061 			len = get_term_name(state, &iterm, namelist[i], MAX_ITEM_NAME_LEN, 0);
2062 		if (! len)
2063 			sprintf(namelist[i], "Input %u", i);
2064 	}
2065 
2066 	kctl = snd_ctl_new1(&mixer_selectunit_ctl, cval);
2067 	if (! kctl) {
2068 		usb_audio_err(state->chip, "cannot malloc kcontrol\n");
2069 		kfree(namelist);
2070 		kfree(cval);
2071 		return -ENOMEM;
2072 	}
2073 	kctl->private_value = (unsigned long)namelist;
2074 	kctl->private_free = usb_mixer_selector_elem_free;
2075 
2076 	nameid = uac_selector_unit_iSelector(desc);
2077 	len = check_mapped_name(map, kctl->id.name, sizeof(kctl->id.name));
2078 	if (len)
2079 		;
2080 	else if (nameid)
2081 		snd_usb_copy_string_desc(state, nameid, kctl->id.name,
2082 					 sizeof(kctl->id.name));
2083 	else {
2084 		len = get_term_name(state, &state->oterm,
2085 				    kctl->id.name, sizeof(kctl->id.name), 0);
2086 		if (!len)
2087 			strlcpy(kctl->id.name, "USB", sizeof(kctl->id.name));
2088 
2089 		if (desc->bDescriptorSubtype == UAC2_CLOCK_SELECTOR)
2090 			append_ctl_name(kctl, " Clock Source");
2091 		else if ((state->oterm.type & 0xff00) == 0x0100)
2092 			append_ctl_name(kctl, " Capture Source");
2093 		else
2094 			append_ctl_name(kctl, " Playback Source");
2095 	}
2096 
2097 	usb_audio_dbg(state->chip, "[%d] SU [%s] items = %d\n",
2098 		    cval->id, kctl->id.name, desc->bNrInPins);
2099 	if ((err = snd_usb_mixer_add_control(state->mixer, kctl)) < 0)
2100 		return err;
2101 
2102 	return 0;
2103 }
2104 
2105 /*
2106  * parse an audio unit recursively
2107  */
2108 
2109 static int parse_audio_unit(struct mixer_build *state, int unitid)
2110 {
2111 	unsigned char *p1;
2112 
2113 	if (test_and_set_bit(unitid, state->unitbitmap))
2114 		return 0; /* the unit already visited */
2115 
2116 	p1 = find_audio_control_unit(state, unitid);
2117 	if (!p1) {
2118 		usb_audio_err(state->chip, "unit %d not found!\n", unitid);
2119 		return -EINVAL;
2120 	}
2121 
2122 	switch (p1[2]) {
2123 	case UAC_INPUT_TERMINAL:
2124 	case UAC2_CLOCK_SOURCE:
2125 		return 0; /* NOP */
2126 	case UAC_MIXER_UNIT:
2127 		return parse_audio_mixer_unit(state, unitid, p1);
2128 	case UAC_SELECTOR_UNIT:
2129 	case UAC2_CLOCK_SELECTOR:
2130 		return parse_audio_selector_unit(state, unitid, p1);
2131 	case UAC_FEATURE_UNIT:
2132 		return parse_audio_feature_unit(state, unitid, p1);
2133 	case UAC1_PROCESSING_UNIT:
2134 	/*   UAC2_EFFECT_UNIT has the same value */
2135 		if (state->mixer->protocol == UAC_VERSION_1)
2136 			return parse_audio_processing_unit(state, unitid, p1);
2137 		else
2138 			return 0; /* FIXME - effect units not implemented yet */
2139 	case UAC1_EXTENSION_UNIT:
2140 	/*   UAC2_PROCESSING_UNIT_V2 has the same value */
2141 		if (state->mixer->protocol == UAC_VERSION_1)
2142 			return parse_audio_extension_unit(state, unitid, p1);
2143 		else /* UAC_VERSION_2 */
2144 			return parse_audio_processing_unit(state, unitid, p1);
2145 	case UAC2_EXTENSION_UNIT_V2:
2146 		return parse_audio_extension_unit(state, unitid, p1);
2147 	default:
2148 		usb_audio_err(state->chip,
2149 			"unit %u: unexpected type 0x%02x\n", unitid, p1[2]);
2150 		return -EINVAL;
2151 	}
2152 }
2153 
2154 static void snd_usb_mixer_free(struct usb_mixer_interface *mixer)
2155 {
2156 	kfree(mixer->id_elems);
2157 	if (mixer->urb) {
2158 		kfree(mixer->urb->transfer_buffer);
2159 		usb_free_urb(mixer->urb);
2160 	}
2161 	usb_free_urb(mixer->rc_urb);
2162 	kfree(mixer->rc_setup_packet);
2163 	kfree(mixer);
2164 }
2165 
2166 static int snd_usb_mixer_dev_free(struct snd_device *device)
2167 {
2168 	struct usb_mixer_interface *mixer = device->device_data;
2169 	snd_usb_mixer_free(mixer);
2170 	return 0;
2171 }
2172 
2173 /*
2174  * create mixer controls
2175  *
2176  * walk through all UAC_OUTPUT_TERMINAL descriptors to search for mixers
2177  */
2178 static int snd_usb_mixer_controls(struct usb_mixer_interface *mixer)
2179 {
2180 	struct mixer_build state;
2181 	int err;
2182 	const struct usbmix_ctl_map *map;
2183 	void *p;
2184 
2185 	memset(&state, 0, sizeof(state));
2186 	state.chip = mixer->chip;
2187 	state.mixer = mixer;
2188 	state.buffer = mixer->hostif->extra;
2189 	state.buflen = mixer->hostif->extralen;
2190 
2191 	/* check the mapping table */
2192 	for (map = usbmix_ctl_maps; map->id; map++) {
2193 		if (map->id == state.chip->usb_id) {
2194 			state.map = map->map;
2195 			state.selector_map = map->selector_map;
2196 			mixer->ignore_ctl_error = map->ignore_ctl_error;
2197 			break;
2198 		}
2199 	}
2200 
2201 	p = NULL;
2202 	while ((p = snd_usb_find_csint_desc(mixer->hostif->extra,
2203 					    mixer->hostif->extralen,
2204 					    p, UAC_OUTPUT_TERMINAL)) != NULL) {
2205 		if (mixer->protocol == UAC_VERSION_1) {
2206 			struct uac1_output_terminal_descriptor *desc = p;
2207 
2208 			if (desc->bLength < sizeof(*desc))
2209 				continue; /* invalid descriptor? */
2210 			/* mark terminal ID as visited */
2211 			set_bit(desc->bTerminalID, state.unitbitmap);
2212 			state.oterm.id = desc->bTerminalID;
2213 			state.oterm.type = le16_to_cpu(desc->wTerminalType);
2214 			state.oterm.name = desc->iTerminal;
2215 			err = parse_audio_unit(&state, desc->bSourceID);
2216 			if (err < 0 && err != -EINVAL)
2217 				return err;
2218 		} else { /* UAC_VERSION_2 */
2219 			struct uac2_output_terminal_descriptor *desc = p;
2220 
2221 			if (desc->bLength < sizeof(*desc))
2222 				continue; /* invalid descriptor? */
2223 			/* mark terminal ID as visited */
2224 			set_bit(desc->bTerminalID, state.unitbitmap);
2225 			state.oterm.id = desc->bTerminalID;
2226 			state.oterm.type = le16_to_cpu(desc->wTerminalType);
2227 			state.oterm.name = desc->iTerminal;
2228 			err = parse_audio_unit(&state, desc->bSourceID);
2229 			if (err < 0 && err != -EINVAL)
2230 				return err;
2231 
2232 			/*
2233 			 * For UAC2, use the same approach to also add the
2234 			 * clock selectors
2235 			 */
2236 			err = parse_audio_unit(&state, desc->bCSourceID);
2237 			if (err < 0 && err != -EINVAL)
2238 				return err;
2239 		}
2240 	}
2241 
2242 	return 0;
2243 }
2244 
2245 void snd_usb_mixer_notify_id(struct usb_mixer_interface *mixer, int unitid)
2246 {
2247 	struct usb_mixer_elem_info *info;
2248 
2249 	for (info = mixer->id_elems[unitid]; info; info = info->next_id_elem)
2250 		snd_ctl_notify(mixer->chip->card, SNDRV_CTL_EVENT_MASK_VALUE,
2251 			       info->elem_id);
2252 }
2253 
2254 static void snd_usb_mixer_dump_cval(struct snd_info_buffer *buffer,
2255 				    int unitid,
2256 				    struct usb_mixer_elem_info *cval)
2257 {
2258 	static char *val_types[] = {"BOOLEAN", "INV_BOOLEAN",
2259 				    "S8", "U8", "S16", "U16"};
2260 	snd_iprintf(buffer, "  Unit: %i\n", unitid);
2261 	if (cval->elem_id)
2262 		snd_iprintf(buffer, "    Control: name=\"%s\", index=%i\n",
2263 				cval->elem_id->name, cval->elem_id->index);
2264 	snd_iprintf(buffer, "    Info: id=%i, control=%i, cmask=0x%x, "
2265 			    "channels=%i, type=\"%s\"\n", cval->id,
2266 			    cval->control, cval->cmask, cval->channels,
2267 			    val_types[cval->val_type]);
2268 	snd_iprintf(buffer, "    Volume: min=%i, max=%i, dBmin=%i, dBmax=%i\n",
2269 			    cval->min, cval->max, cval->dBmin, cval->dBmax);
2270 }
2271 
2272 static void snd_usb_mixer_proc_read(struct snd_info_entry *entry,
2273 				    struct snd_info_buffer *buffer)
2274 {
2275 	struct snd_usb_audio *chip = entry->private_data;
2276 	struct usb_mixer_interface *mixer;
2277 	struct usb_mixer_elem_info *cval;
2278 	int unitid;
2279 
2280 	list_for_each_entry(mixer, &chip->mixer_list, list) {
2281 		snd_iprintf(buffer,
2282 			"USB Mixer: usb_id=0x%08x, ctrlif=%i, ctlerr=%i\n",
2283 				chip->usb_id, snd_usb_ctrl_intf(chip),
2284 				mixer->ignore_ctl_error);
2285 		snd_iprintf(buffer, "Card: %s\n", chip->card->longname);
2286 		for (unitid = 0; unitid < MAX_ID_ELEMS; unitid++) {
2287 			for (cval = mixer->id_elems[unitid]; cval;
2288 						cval = cval->next_id_elem)
2289 				snd_usb_mixer_dump_cval(buffer, unitid, cval);
2290 		}
2291 	}
2292 }
2293 
2294 static void snd_usb_mixer_interrupt_v2(struct usb_mixer_interface *mixer,
2295 				       int attribute, int value, int index)
2296 {
2297 	struct usb_mixer_elem_info *info;
2298 	__u8 unitid = (index >> 8) & 0xff;
2299 	__u8 control = (value >> 8) & 0xff;
2300 	__u8 channel = value & 0xff;
2301 
2302 	if (channel >= MAX_CHANNELS) {
2303 		usb_audio_dbg(mixer->chip,
2304 			"%s(): bogus channel number %d\n",
2305 			__func__, channel);
2306 		return;
2307 	}
2308 
2309 	for (info = mixer->id_elems[unitid]; info; info = info->next_id_elem) {
2310 		if (info->control != control)
2311 			continue;
2312 
2313 		switch (attribute) {
2314 		case UAC2_CS_CUR:
2315 			/* invalidate cache, so the value is read from the device */
2316 			if (channel)
2317 				info->cached &= ~(1 << channel);
2318 			else /* master channel */
2319 				info->cached = 0;
2320 
2321 			snd_ctl_notify(mixer->chip->card, SNDRV_CTL_EVENT_MASK_VALUE,
2322 					info->elem_id);
2323 			break;
2324 
2325 		case UAC2_CS_RANGE:
2326 			/* TODO */
2327 			break;
2328 
2329 		case UAC2_CS_MEM:
2330 			/* TODO */
2331 			break;
2332 
2333 		default:
2334 			usb_audio_dbg(mixer->chip,
2335 				"unknown attribute %d in interrupt\n",
2336 				attribute);
2337 			break;
2338 		} /* switch */
2339 	}
2340 }
2341 
2342 static void snd_usb_mixer_interrupt(struct urb *urb)
2343 {
2344 	struct usb_mixer_interface *mixer = urb->context;
2345 	int len = urb->actual_length;
2346 	int ustatus = urb->status;
2347 
2348 	if (ustatus != 0)
2349 		goto requeue;
2350 
2351 	if (mixer->protocol == UAC_VERSION_1) {
2352 		struct uac1_status_word *status;
2353 
2354 		for (status = urb->transfer_buffer;
2355 		     len >= sizeof(*status);
2356 		     len -= sizeof(*status), status++) {
2357 			dev_dbg(&urb->dev->dev, "status interrupt: %02x %02x\n",
2358 						status->bStatusType,
2359 						status->bOriginator);
2360 
2361 			/* ignore any notifications not from the control interface */
2362 			if ((status->bStatusType & UAC1_STATUS_TYPE_ORIG_MASK) !=
2363 				UAC1_STATUS_TYPE_ORIG_AUDIO_CONTROL_IF)
2364 				continue;
2365 
2366 			if (status->bStatusType & UAC1_STATUS_TYPE_MEM_CHANGED)
2367 				snd_usb_mixer_rc_memory_change(mixer, status->bOriginator);
2368 			else
2369 				snd_usb_mixer_notify_id(mixer, status->bOriginator);
2370 		}
2371 	} else { /* UAC_VERSION_2 */
2372 		struct uac2_interrupt_data_msg *msg;
2373 
2374 		for (msg = urb->transfer_buffer;
2375 		     len >= sizeof(*msg);
2376 		     len -= sizeof(*msg), msg++) {
2377 			/* drop vendor specific and endpoint requests */
2378 			if ((msg->bInfo & UAC2_INTERRUPT_DATA_MSG_VENDOR) ||
2379 			    (msg->bInfo & UAC2_INTERRUPT_DATA_MSG_EP))
2380 				continue;
2381 
2382 			snd_usb_mixer_interrupt_v2(mixer, msg->bAttribute,
2383 						   le16_to_cpu(msg->wValue),
2384 						   le16_to_cpu(msg->wIndex));
2385 		}
2386 	}
2387 
2388 requeue:
2389 	if (ustatus != -ENOENT &&
2390 	    ustatus != -ECONNRESET &&
2391 	    ustatus != -ESHUTDOWN) {
2392 		urb->dev = mixer->chip->dev;
2393 		usb_submit_urb(urb, GFP_ATOMIC);
2394 	}
2395 }
2396 
2397 /* create the handler for the optional status interrupt endpoint */
2398 static int snd_usb_mixer_status_create(struct usb_mixer_interface *mixer)
2399 {
2400 	struct usb_endpoint_descriptor *ep;
2401 	void *transfer_buffer;
2402 	int buffer_length;
2403 	unsigned int epnum;
2404 
2405 	/* we need one interrupt input endpoint */
2406 	if (get_iface_desc(mixer->hostif)->bNumEndpoints < 1)
2407 		return 0;
2408 	ep = get_endpoint(mixer->hostif, 0);
2409 	if (!usb_endpoint_dir_in(ep) || !usb_endpoint_xfer_int(ep))
2410 		return 0;
2411 
2412 	epnum = usb_endpoint_num(ep);
2413 	buffer_length = le16_to_cpu(ep->wMaxPacketSize);
2414 	transfer_buffer = kmalloc(buffer_length, GFP_KERNEL);
2415 	if (!transfer_buffer)
2416 		return -ENOMEM;
2417 	mixer->urb = usb_alloc_urb(0, GFP_KERNEL);
2418 	if (!mixer->urb) {
2419 		kfree(transfer_buffer);
2420 		return -ENOMEM;
2421 	}
2422 	usb_fill_int_urb(mixer->urb, mixer->chip->dev,
2423 			 usb_rcvintpipe(mixer->chip->dev, epnum),
2424 			 transfer_buffer, buffer_length,
2425 			 snd_usb_mixer_interrupt, mixer, ep->bInterval);
2426 	usb_submit_urb(mixer->urb, GFP_KERNEL);
2427 	return 0;
2428 }
2429 
2430 int snd_usb_create_mixer(struct snd_usb_audio *chip, int ctrlif,
2431 			 int ignore_error)
2432 {
2433 	static struct snd_device_ops dev_ops = {
2434 		.dev_free = snd_usb_mixer_dev_free
2435 	};
2436 	struct usb_mixer_interface *mixer;
2437 	struct snd_info_entry *entry;
2438 	int err;
2439 
2440 	strcpy(chip->card->mixername, "USB Mixer");
2441 
2442 	mixer = kzalloc(sizeof(*mixer), GFP_KERNEL);
2443 	if (!mixer)
2444 		return -ENOMEM;
2445 	mixer->chip = chip;
2446 	mixer->ignore_ctl_error = ignore_error;
2447 	mixer->id_elems = kcalloc(MAX_ID_ELEMS, sizeof(*mixer->id_elems),
2448 				  GFP_KERNEL);
2449 	if (!mixer->id_elems) {
2450 		kfree(mixer);
2451 		return -ENOMEM;
2452 	}
2453 
2454 	mixer->hostif = &usb_ifnum_to_if(chip->dev, ctrlif)->altsetting[0];
2455 	switch (get_iface_desc(mixer->hostif)->bInterfaceProtocol) {
2456 	case UAC_VERSION_1:
2457 	default:
2458 		mixer->protocol = UAC_VERSION_1;
2459 		break;
2460 	case UAC_VERSION_2:
2461 		mixer->protocol = UAC_VERSION_2;
2462 		break;
2463 	}
2464 
2465 	if ((err = snd_usb_mixer_controls(mixer)) < 0 ||
2466 	    (err = snd_usb_mixer_status_create(mixer)) < 0)
2467 		goto _error;
2468 
2469 	snd_usb_mixer_apply_create_quirk(mixer);
2470 
2471 	err = snd_device_new(chip->card, SNDRV_DEV_CODEC, mixer, &dev_ops);
2472 	if (err < 0)
2473 		goto _error;
2474 
2475 	if (list_empty(&chip->mixer_list) &&
2476 	    !snd_card_proc_new(chip->card, "usbmixer", &entry))
2477 		snd_info_set_text_ops(entry, chip, snd_usb_mixer_proc_read);
2478 
2479 	list_add(&mixer->list, &chip->mixer_list);
2480 	return 0;
2481 
2482 _error:
2483 	snd_usb_mixer_free(mixer);
2484 	return err;
2485 }
2486 
2487 void snd_usb_mixer_disconnect(struct list_head *p)
2488 {
2489 	struct usb_mixer_interface *mixer;
2490 
2491 	mixer = list_entry(p, struct usb_mixer_interface, list);
2492 	usb_kill_urb(mixer->urb);
2493 	usb_kill_urb(mixer->rc_urb);
2494 }
2495 
2496 #ifdef CONFIG_PM
2497 /* stop any bus activity of a mixer */
2498 static void snd_usb_mixer_inactivate(struct usb_mixer_interface *mixer)
2499 {
2500 	usb_kill_urb(mixer->urb);
2501 	usb_kill_urb(mixer->rc_urb);
2502 }
2503 
2504 static int snd_usb_mixer_activate(struct usb_mixer_interface *mixer)
2505 {
2506 	int err;
2507 
2508 	if (mixer->urb) {
2509 		err = usb_submit_urb(mixer->urb, GFP_NOIO);
2510 		if (err < 0)
2511 			return err;
2512 	}
2513 
2514 	return 0;
2515 }
2516 
2517 int snd_usb_mixer_suspend(struct usb_mixer_interface *mixer)
2518 {
2519 	snd_usb_mixer_inactivate(mixer);
2520 	return 0;
2521 }
2522 
2523 static int restore_mixer_value(struct usb_mixer_elem_info *cval)
2524 {
2525 	int c, err, idx;
2526 
2527 	if (cval->cmask) {
2528 		idx = 0;
2529 		for (c = 0; c < MAX_CHANNELS; c++) {
2530 			if (!(cval->cmask & (1 << c)))
2531 				continue;
2532 			if (cval->cached & (1 << c)) {
2533 				err = set_cur_mix_value(cval, c + 1, idx,
2534 							cval->cache_val[idx]);
2535 				if (err < 0)
2536 					return err;
2537 			}
2538 			idx++;
2539 		}
2540 	} else {
2541 		/* master */
2542 		if (cval->cached) {
2543 			err = set_cur_mix_value(cval, 0, 0, *cval->cache_val);
2544 			if (err < 0)
2545 				return err;
2546 		}
2547 	}
2548 
2549 	return 0;
2550 }
2551 
2552 int snd_usb_mixer_resume(struct usb_mixer_interface *mixer, bool reset_resume)
2553 {
2554 	struct usb_mixer_elem_info *cval;
2555 	int id, err;
2556 
2557 	/* FIXME: any mixer quirks? */
2558 
2559 	if (reset_resume) {
2560 		/* restore cached mixer values */
2561 		for (id = 0; id < MAX_ID_ELEMS; id++) {
2562 			for (cval = mixer->id_elems[id]; cval;
2563 			     cval = cval->next_id_elem) {
2564 				err = restore_mixer_value(cval);
2565 				if (err < 0)
2566 					return err;
2567 			}
2568 		}
2569 	}
2570 
2571 	return snd_usb_mixer_activate(mixer);
2572 }
2573 #endif
2574