xref: /openbmc/linux/sound/usb/mixer.c (revision e2f1cf25)
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 /* ignore the error value if ignore_ctl_error flag is set */
140 #define filter_error(cval, err) \
141 	((cval)->head.mixer->ignore_ctl_error ? 0 : (err))
142 
143 /* check whether the control should be ignored */
144 static inline int
145 check_ignored_ctl(const struct usbmix_name_map *p)
146 {
147 	if (!p || p->name || p->dB)
148 		return 0;
149 	return 1;
150 }
151 
152 /* dB mapping */
153 static inline void check_mapped_dB(const struct usbmix_name_map *p,
154 				   struct usb_mixer_elem_info *cval)
155 {
156 	if (p && p->dB) {
157 		cval->dBmin = p->dB->min;
158 		cval->dBmax = p->dB->max;
159 		cval->initialized = 1;
160 	}
161 }
162 
163 /* get the mapped selector source name */
164 static int check_mapped_selector_name(struct mixer_build *state, int unitid,
165 				      int index, char *buf, int buflen)
166 {
167 	const struct usbmix_selector_map *p;
168 
169 	if (!state->selector_map)
170 		return 0;
171 	for (p = state->selector_map; p->id; p++) {
172 		if (p->id == unitid && index < p->count)
173 			return strlcpy(buf, p->names[index], buflen);
174 	}
175 	return 0;
176 }
177 
178 /*
179  * find an audio control unit with the given unit id
180  */
181 static void *find_audio_control_unit(struct mixer_build *state,
182 				     unsigned char unit)
183 {
184 	/* we just parse the header */
185 	struct uac_feature_unit_descriptor *hdr = NULL;
186 
187 	while ((hdr = snd_usb_find_desc(state->buffer, state->buflen, hdr,
188 					USB_DT_CS_INTERFACE)) != NULL) {
189 		if (hdr->bLength >= 4 &&
190 		    hdr->bDescriptorSubtype >= UAC_INPUT_TERMINAL &&
191 		    hdr->bDescriptorSubtype <= UAC2_SAMPLE_RATE_CONVERTER &&
192 		    hdr->bUnitID == unit)
193 			return hdr;
194 	}
195 
196 	return NULL;
197 }
198 
199 /*
200  * copy a string with the given id
201  */
202 static int snd_usb_copy_string_desc(struct mixer_build *state,
203 				    int index, char *buf, int maxlen)
204 {
205 	int len = usb_string(state->chip->dev, index, buf, maxlen - 1);
206 	buf[len] = 0;
207 	return len;
208 }
209 
210 /*
211  * convert from the byte/word on usb descriptor to the zero-based integer
212  */
213 static int convert_signed_value(struct usb_mixer_elem_info *cval, int val)
214 {
215 	switch (cval->val_type) {
216 	case USB_MIXER_BOOLEAN:
217 		return !!val;
218 	case USB_MIXER_INV_BOOLEAN:
219 		return !val;
220 	case USB_MIXER_U8:
221 		val &= 0xff;
222 		break;
223 	case USB_MIXER_S8:
224 		val &= 0xff;
225 		if (val >= 0x80)
226 			val -= 0x100;
227 		break;
228 	case USB_MIXER_U16:
229 		val &= 0xffff;
230 		break;
231 	case USB_MIXER_S16:
232 		val &= 0xffff;
233 		if (val >= 0x8000)
234 			val -= 0x10000;
235 		break;
236 	}
237 	return val;
238 }
239 
240 /*
241  * convert from the zero-based int to the byte/word for usb descriptor
242  */
243 static int convert_bytes_value(struct usb_mixer_elem_info *cval, int val)
244 {
245 	switch (cval->val_type) {
246 	case USB_MIXER_BOOLEAN:
247 		return !!val;
248 	case USB_MIXER_INV_BOOLEAN:
249 		return !val;
250 	case USB_MIXER_S8:
251 	case USB_MIXER_U8:
252 		return val & 0xff;
253 	case USB_MIXER_S16:
254 	case USB_MIXER_U16:
255 		return val & 0xffff;
256 	}
257 	return 0; /* not reached */
258 }
259 
260 static int get_relative_value(struct usb_mixer_elem_info *cval, int val)
261 {
262 	if (!cval->res)
263 		cval->res = 1;
264 	if (val < cval->min)
265 		return 0;
266 	else if (val >= cval->max)
267 		return (cval->max - cval->min + cval->res - 1) / cval->res;
268 	else
269 		return (val - cval->min) / cval->res;
270 }
271 
272 static int get_abs_value(struct usb_mixer_elem_info *cval, int val)
273 {
274 	if (val < 0)
275 		return cval->min;
276 	if (!cval->res)
277 		cval->res = 1;
278 	val *= cval->res;
279 	val += cval->min;
280 	if (val > cval->max)
281 		return cval->max;
282 	return val;
283 }
284 
285 
286 /*
287  * retrieve a mixer value
288  */
289 
290 static int get_ctl_value_v1(struct usb_mixer_elem_info *cval, int request,
291 			    int validx, int *value_ret)
292 {
293 	struct snd_usb_audio *chip = cval->head.mixer->chip;
294 	unsigned char buf[2];
295 	int val_len = cval->val_type >= USB_MIXER_S16 ? 2 : 1;
296 	int timeout = 10;
297 	int idx = 0, err;
298 
299 	err = snd_usb_autoresume(chip);
300 	if (err < 0)
301 		return -EIO;
302 
303 	down_read(&chip->shutdown_rwsem);
304 	while (timeout-- > 0) {
305 		if (chip->shutdown)
306 			break;
307 		idx = snd_usb_ctrl_intf(chip) | (cval->head.id << 8);
308 		if (snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0), request,
309 				    USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
310 				    validx, idx, buf, val_len) >= val_len) {
311 			*value_ret = convert_signed_value(cval, snd_usb_combine_bytes(buf, val_len));
312 			err = 0;
313 			goto out;
314 		}
315 	}
316 	usb_audio_dbg(chip,
317 		"cannot get ctl value: req = %#x, wValue = %#x, wIndex = %#x, type = %d\n",
318 		request, validx, idx, cval->val_type);
319 	err = -EINVAL;
320 
321  out:
322 	up_read(&chip->shutdown_rwsem);
323 	snd_usb_autosuspend(chip);
324 	return err;
325 }
326 
327 static int get_ctl_value_v2(struct usb_mixer_elem_info *cval, int request,
328 			    int validx, int *value_ret)
329 {
330 	struct snd_usb_audio *chip = cval->head.mixer->chip;
331 	unsigned char buf[2 + 3 * sizeof(__u16)]; /* enough space for one range */
332 	unsigned char *val;
333 	int idx = 0, ret, size;
334 	__u8 bRequest;
335 
336 	if (request == UAC_GET_CUR) {
337 		bRequest = UAC2_CS_CUR;
338 		size = sizeof(__u16);
339 	} else {
340 		bRequest = UAC2_CS_RANGE;
341 		size = sizeof(buf);
342 	}
343 
344 	memset(buf, 0, sizeof(buf));
345 
346 	ret = snd_usb_autoresume(chip) ? -EIO : 0;
347 	if (ret)
348 		goto error;
349 
350 	down_read(&chip->shutdown_rwsem);
351 	if (chip->shutdown) {
352 		ret = -ENODEV;
353 	} else {
354 		idx = snd_usb_ctrl_intf(chip) | (cval->head.id << 8);
355 		ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0), bRequest,
356 			      USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
357 			      validx, idx, buf, size);
358 	}
359 	up_read(&chip->shutdown_rwsem);
360 	snd_usb_autosuspend(chip);
361 
362 	if (ret < 0) {
363 error:
364 		usb_audio_err(chip,
365 			"cannot get ctl value: req = %#x, wValue = %#x, wIndex = %#x, type = %d\n",
366 			request, validx, idx, cval->val_type);
367 		return ret;
368 	}
369 
370 	/* FIXME: how should we handle multiple triplets here? */
371 
372 	switch (request) {
373 	case UAC_GET_CUR:
374 		val = buf;
375 		break;
376 	case UAC_GET_MIN:
377 		val = buf + sizeof(__u16);
378 		break;
379 	case UAC_GET_MAX:
380 		val = buf + sizeof(__u16) * 2;
381 		break;
382 	case UAC_GET_RES:
383 		val = buf + sizeof(__u16) * 3;
384 		break;
385 	default:
386 		return -EINVAL;
387 	}
388 
389 	*value_ret = convert_signed_value(cval, snd_usb_combine_bytes(val, sizeof(__u16)));
390 
391 	return 0;
392 }
393 
394 static int get_ctl_value(struct usb_mixer_elem_info *cval, int request,
395 			 int validx, int *value_ret)
396 {
397 	validx += cval->idx_off;
398 
399 	return (cval->head.mixer->protocol == UAC_VERSION_1) ?
400 		get_ctl_value_v1(cval, request, validx, value_ret) :
401 		get_ctl_value_v2(cval, request, validx, value_ret);
402 }
403 
404 static int get_cur_ctl_value(struct usb_mixer_elem_info *cval,
405 			     int validx, int *value)
406 {
407 	return get_ctl_value(cval, UAC_GET_CUR, validx, value);
408 }
409 
410 /* channel = 0: master, 1 = first channel */
411 static inline int get_cur_mix_raw(struct usb_mixer_elem_info *cval,
412 				  int channel, int *value)
413 {
414 	return get_ctl_value(cval, UAC_GET_CUR,
415 			     (cval->control << 8) | channel,
416 			     value);
417 }
418 
419 int snd_usb_get_cur_mix_value(struct usb_mixer_elem_info *cval,
420 			     int channel, int index, int *value)
421 {
422 	int err;
423 
424 	if (cval->cached & (1 << channel)) {
425 		*value = cval->cache_val[index];
426 		return 0;
427 	}
428 	err = get_cur_mix_raw(cval, channel, value);
429 	if (err < 0) {
430 		if (!cval->head.mixer->ignore_ctl_error)
431 			usb_audio_dbg(cval->head.mixer->chip,
432 				"cannot get current value for control %d ch %d: err = %d\n",
433 				      cval->control, channel, err);
434 		return err;
435 	}
436 	cval->cached |= 1 << channel;
437 	cval->cache_val[index] = *value;
438 	return 0;
439 }
440 
441 /*
442  * set a mixer value
443  */
444 
445 int snd_usb_mixer_set_ctl_value(struct usb_mixer_elem_info *cval,
446 				int request, int validx, int value_set)
447 {
448 	struct snd_usb_audio *chip = cval->head.mixer->chip;
449 	unsigned char buf[2];
450 	int idx = 0, val_len, err, timeout = 10;
451 
452 	validx += cval->idx_off;
453 
454 	if (cval->head.mixer->protocol == UAC_VERSION_1) {
455 		val_len = cval->val_type >= USB_MIXER_S16 ? 2 : 1;
456 	} else { /* UAC_VERSION_2 */
457 		/* audio class v2 controls are always 2 bytes in size */
458 		val_len = sizeof(__u16);
459 
460 		/* FIXME */
461 		if (request != UAC_SET_CUR) {
462 			usb_audio_dbg(chip, "RANGE setting not yet supported\n");
463 			return -EINVAL;
464 		}
465 
466 		request = UAC2_CS_CUR;
467 	}
468 
469 	value_set = convert_bytes_value(cval, value_set);
470 	buf[0] = value_set & 0xff;
471 	buf[1] = (value_set >> 8) & 0xff;
472 	err = snd_usb_autoresume(chip);
473 	if (err < 0)
474 		return -EIO;
475 	down_read(&chip->shutdown_rwsem);
476 	while (timeout-- > 0) {
477 		if (chip->shutdown)
478 			break;
479 		idx = snd_usb_ctrl_intf(chip) | (cval->head.id << 8);
480 		if (snd_usb_ctl_msg(chip->dev,
481 				    usb_sndctrlpipe(chip->dev, 0), request,
482 				    USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
483 				    validx, idx, buf, val_len) >= 0) {
484 			err = 0;
485 			goto out;
486 		}
487 	}
488 	usb_audio_dbg(chip, "cannot set ctl value: req = %#x, wValue = %#x, wIndex = %#x, type = %d, data = %#x/%#x\n",
489 		      request, validx, idx, cval->val_type, buf[0], buf[1]);
490 	err = -EINVAL;
491 
492  out:
493 	up_read(&chip->shutdown_rwsem);
494 	snd_usb_autosuspend(chip);
495 	return err;
496 }
497 
498 static int set_cur_ctl_value(struct usb_mixer_elem_info *cval,
499 			     int validx, int value)
500 {
501 	return snd_usb_mixer_set_ctl_value(cval, UAC_SET_CUR, validx, value);
502 }
503 
504 int snd_usb_set_cur_mix_value(struct usb_mixer_elem_info *cval, int channel,
505 			     int index, int value)
506 {
507 	int err;
508 	unsigned int read_only = (channel == 0) ?
509 		cval->master_readonly :
510 		cval->ch_readonly & (1 << (channel - 1));
511 
512 	if (read_only) {
513 		usb_audio_dbg(cval->head.mixer->chip,
514 			      "%s(): channel %d of control %d is read_only\n",
515 			    __func__, channel, cval->control);
516 		return 0;
517 	}
518 
519 	err = snd_usb_mixer_set_ctl_value(cval,
520 					  UAC_SET_CUR, (cval->control << 8) | channel,
521 					  value);
522 	if (err < 0)
523 		return err;
524 	cval->cached |= 1 << channel;
525 	cval->cache_val[index] = value;
526 	return 0;
527 }
528 
529 /*
530  * TLV callback for mixer volume controls
531  */
532 int snd_usb_mixer_vol_tlv(struct snd_kcontrol *kcontrol, int op_flag,
533 			 unsigned int size, unsigned int __user *_tlv)
534 {
535 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
536 	DECLARE_TLV_DB_MINMAX(scale, 0, 0);
537 
538 	if (size < sizeof(scale))
539 		return -ENOMEM;
540 	scale[2] = cval->dBmin;
541 	scale[3] = cval->dBmax;
542 	if (copy_to_user(_tlv, scale, sizeof(scale)))
543 		return -EFAULT;
544 	return 0;
545 }
546 
547 /*
548  * parser routines begin here...
549  */
550 
551 static int parse_audio_unit(struct mixer_build *state, int unitid);
552 
553 
554 /*
555  * check if the input/output channel routing is enabled on the given bitmap.
556  * used for mixer unit parser
557  */
558 static int check_matrix_bitmap(unsigned char *bmap,
559 			       int ich, int och, int num_outs)
560 {
561 	int idx = ich * num_outs + och;
562 	return bmap[idx >> 3] & (0x80 >> (idx & 7));
563 }
564 
565 /*
566  * add an alsa control element
567  * search and increment the index until an empty slot is found.
568  *
569  * if failed, give up and free the control instance.
570  */
571 
572 int snd_usb_mixer_add_control(struct usb_mixer_elem_list *list,
573 			      struct snd_kcontrol *kctl)
574 {
575 	struct usb_mixer_interface *mixer = list->mixer;
576 	int err;
577 
578 	while (snd_ctl_find_id(mixer->chip->card, &kctl->id))
579 		kctl->id.index++;
580 	if ((err = snd_ctl_add(mixer->chip->card, kctl)) < 0) {
581 		usb_audio_dbg(mixer->chip, "cannot add control (err = %d)\n",
582 			      err);
583 		return err;
584 	}
585 	list->kctl = kctl;
586 	list->next_id_elem = mixer->id_elems[list->id];
587 	mixer->id_elems[list->id] = list;
588 	return 0;
589 }
590 
591 /*
592  * get a terminal name string
593  */
594 
595 static struct iterm_name_combo {
596 	int type;
597 	char *name;
598 } iterm_names[] = {
599 	{ 0x0300, "Output" },
600 	{ 0x0301, "Speaker" },
601 	{ 0x0302, "Headphone" },
602 	{ 0x0303, "HMD Audio" },
603 	{ 0x0304, "Desktop Speaker" },
604 	{ 0x0305, "Room Speaker" },
605 	{ 0x0306, "Com Speaker" },
606 	{ 0x0307, "LFE" },
607 	{ 0x0600, "External In" },
608 	{ 0x0601, "Analog In" },
609 	{ 0x0602, "Digital In" },
610 	{ 0x0603, "Line" },
611 	{ 0x0604, "Legacy In" },
612 	{ 0x0605, "IEC958 In" },
613 	{ 0x0606, "1394 DA Stream" },
614 	{ 0x0607, "1394 DV Stream" },
615 	{ 0x0700, "Embedded" },
616 	{ 0x0701, "Noise Source" },
617 	{ 0x0702, "Equalization Noise" },
618 	{ 0x0703, "CD" },
619 	{ 0x0704, "DAT" },
620 	{ 0x0705, "DCC" },
621 	{ 0x0706, "MiniDisk" },
622 	{ 0x0707, "Analog Tape" },
623 	{ 0x0708, "Phonograph" },
624 	{ 0x0709, "VCR Audio" },
625 	{ 0x070a, "Video Disk Audio" },
626 	{ 0x070b, "DVD Audio" },
627 	{ 0x070c, "TV Tuner Audio" },
628 	{ 0x070d, "Satellite Rec Audio" },
629 	{ 0x070e, "Cable Tuner Audio" },
630 	{ 0x070f, "DSS Audio" },
631 	{ 0x0710, "Radio Receiver" },
632 	{ 0x0711, "Radio Transmitter" },
633 	{ 0x0712, "Multi-Track Recorder" },
634 	{ 0x0713, "Synthesizer" },
635 	{ 0 },
636 };
637 
638 static int get_term_name(struct mixer_build *state, struct usb_audio_term *iterm,
639 			 unsigned char *name, int maxlen, int term_only)
640 {
641 	struct iterm_name_combo *names;
642 
643 	if (iterm->name)
644 		return snd_usb_copy_string_desc(state, iterm->name,
645 						name, maxlen);
646 
647 	/* virtual type - not a real terminal */
648 	if (iterm->type >> 16) {
649 		if (term_only)
650 			return 0;
651 		switch (iterm->type >> 16) {
652 		case UAC_SELECTOR_UNIT:
653 			strcpy(name, "Selector");
654 			return 8;
655 		case UAC1_PROCESSING_UNIT:
656 			strcpy(name, "Process Unit");
657 			return 12;
658 		case UAC1_EXTENSION_UNIT:
659 			strcpy(name, "Ext Unit");
660 			return 8;
661 		case UAC_MIXER_UNIT:
662 			strcpy(name, "Mixer");
663 			return 5;
664 		default:
665 			return sprintf(name, "Unit %d", iterm->id);
666 		}
667 	}
668 
669 	switch (iterm->type & 0xff00) {
670 	case 0x0100:
671 		strcpy(name, "PCM");
672 		return 3;
673 	case 0x0200:
674 		strcpy(name, "Mic");
675 		return 3;
676 	case 0x0400:
677 		strcpy(name, "Headset");
678 		return 7;
679 	case 0x0500:
680 		strcpy(name, "Phone");
681 		return 5;
682 	}
683 
684 	for (names = iterm_names; names->type; names++) {
685 		if (names->type == iterm->type) {
686 			strcpy(name, names->name);
687 			return strlen(names->name);
688 		}
689 	}
690 
691 	return 0;
692 }
693 
694 /*
695  * parse the source unit recursively until it reaches to a terminal
696  * or a branched unit.
697  */
698 static int check_input_term(struct mixer_build *state, int id,
699 			    struct usb_audio_term *term)
700 {
701 	int err;
702 	void *p1;
703 
704 	memset(term, 0, sizeof(*term));
705 	while ((p1 = find_audio_control_unit(state, id)) != NULL) {
706 		unsigned char *hdr = p1;
707 		term->id = id;
708 		switch (hdr[2]) {
709 		case UAC_INPUT_TERMINAL:
710 			if (state->mixer->protocol == UAC_VERSION_1) {
711 				struct uac_input_terminal_descriptor *d = p1;
712 				term->type = le16_to_cpu(d->wTerminalType);
713 				term->channels = d->bNrChannels;
714 				term->chconfig = le16_to_cpu(d->wChannelConfig);
715 				term->name = d->iTerminal;
716 			} else { /* UAC_VERSION_2 */
717 				struct uac2_input_terminal_descriptor *d = p1;
718 				term->type = le16_to_cpu(d->wTerminalType);
719 				term->channels = d->bNrChannels;
720 				term->chconfig = le32_to_cpu(d->bmChannelConfig);
721 				term->name = d->iTerminal;
722 
723 				/* call recursively to get the clock selectors */
724 				err = check_input_term(state, d->bCSourceID, term);
725 				if (err < 0)
726 					return err;
727 			}
728 			return 0;
729 		case UAC_FEATURE_UNIT: {
730 			/* the header is the same for v1 and v2 */
731 			struct uac_feature_unit_descriptor *d = p1;
732 			id = d->bSourceID;
733 			break; /* continue to parse */
734 		}
735 		case UAC_MIXER_UNIT: {
736 			struct uac_mixer_unit_descriptor *d = p1;
737 			term->type = d->bDescriptorSubtype << 16; /* virtual type */
738 			term->channels = uac_mixer_unit_bNrChannels(d);
739 			term->chconfig = uac_mixer_unit_wChannelConfig(d, state->mixer->protocol);
740 			term->name = uac_mixer_unit_iMixer(d);
741 			return 0;
742 		}
743 		case UAC_SELECTOR_UNIT:
744 		case UAC2_CLOCK_SELECTOR: {
745 			struct uac_selector_unit_descriptor *d = p1;
746 			/* call recursively to retrieve the channel info */
747 			err = check_input_term(state, d->baSourceID[0], term);
748 			if (err < 0)
749 				return err;
750 			term->type = d->bDescriptorSubtype << 16; /* virtual type */
751 			term->id = id;
752 			term->name = uac_selector_unit_iSelector(d);
753 			return 0;
754 		}
755 		case UAC1_PROCESSING_UNIT:
756 		case UAC1_EXTENSION_UNIT:
757 		/* UAC2_PROCESSING_UNIT_V2 */
758 		/* UAC2_EFFECT_UNIT */
759 		case UAC2_EXTENSION_UNIT_V2: {
760 			struct uac_processing_unit_descriptor *d = p1;
761 
762 			if (state->mixer->protocol == UAC_VERSION_2 &&
763 				hdr[2] == UAC2_EFFECT_UNIT) {
764 				/* UAC2/UAC1 unit IDs overlap here in an
765 				 * uncompatible way. Ignore this unit for now.
766 				 */
767 				return 0;
768 			}
769 
770 			if (d->bNrInPins) {
771 				id = d->baSourceID[0];
772 				break; /* continue to parse */
773 			}
774 			term->type = d->bDescriptorSubtype << 16; /* virtual type */
775 			term->channels = uac_processing_unit_bNrChannels(d);
776 			term->chconfig = uac_processing_unit_wChannelConfig(d, state->mixer->protocol);
777 			term->name = uac_processing_unit_iProcessing(d, state->mixer->protocol);
778 			return 0;
779 		}
780 		case UAC2_CLOCK_SOURCE: {
781 			struct uac_clock_source_descriptor *d = p1;
782 			term->type = d->bDescriptorSubtype << 16; /* virtual type */
783 			term->id = id;
784 			term->name = d->iClockSource;
785 			return 0;
786 		}
787 		default:
788 			return -ENODEV;
789 		}
790 	}
791 	return -ENODEV;
792 }
793 
794 /*
795  * Feature Unit
796  */
797 
798 /* feature unit control information */
799 struct usb_feature_control_info {
800 	const char *name;
801 	unsigned int type;	/* control type (mute, volume, etc.) */
802 };
803 
804 static struct usb_feature_control_info audio_feature_info[] = {
805 	{ "Mute",			USB_MIXER_INV_BOOLEAN },
806 	{ "Volume",			USB_MIXER_S16 },
807 	{ "Tone Control - Bass",	USB_MIXER_S8 },
808 	{ "Tone Control - Mid",		USB_MIXER_S8 },
809 	{ "Tone Control - Treble",	USB_MIXER_S8 },
810 	{ "Graphic Equalizer",		USB_MIXER_S8 }, /* FIXME: not implemeted yet */
811 	{ "Auto Gain Control",		USB_MIXER_BOOLEAN },
812 	{ "Delay Control",		USB_MIXER_U16 }, /* FIXME: U32 in UAC2 */
813 	{ "Bass Boost",			USB_MIXER_BOOLEAN },
814 	{ "Loudness",			USB_MIXER_BOOLEAN },
815 	/* UAC2 specific */
816 	{ "Input Gain Control",		USB_MIXER_S16 },
817 	{ "Input Gain Pad Control",	USB_MIXER_S16 },
818 	{ "Phase Inverter Control",	USB_MIXER_BOOLEAN },
819 };
820 
821 /* private_free callback */
822 void snd_usb_mixer_elem_free(struct snd_kcontrol *kctl)
823 {
824 	kfree(kctl->private_data);
825 	kctl->private_data = NULL;
826 }
827 
828 /*
829  * interface to ALSA control for feature/mixer units
830  */
831 
832 /* volume control quirks */
833 static void volume_control_quirks(struct usb_mixer_elem_info *cval,
834 				  struct snd_kcontrol *kctl)
835 {
836 	struct snd_usb_audio *chip = cval->head.mixer->chip;
837 	switch (chip->usb_id) {
838 	case USB_ID(0x0763, 0x2030): /* M-Audio Fast Track C400 */
839 	case USB_ID(0x0763, 0x2031): /* M-Audio Fast Track C600 */
840 		if (strcmp(kctl->id.name, "Effect Duration") == 0) {
841 			cval->min = 0x0000;
842 			cval->max = 0xffff;
843 			cval->res = 0x00e6;
844 			break;
845 		}
846 		if (strcmp(kctl->id.name, "Effect Volume") == 0 ||
847 		    strcmp(kctl->id.name, "Effect Feedback Volume") == 0) {
848 			cval->min = 0x00;
849 			cval->max = 0xff;
850 			break;
851 		}
852 		if (strstr(kctl->id.name, "Effect Return") != NULL) {
853 			cval->min = 0xb706;
854 			cval->max = 0xff7b;
855 			cval->res = 0x0073;
856 			break;
857 		}
858 		if ((strstr(kctl->id.name, "Playback Volume") != NULL) ||
859 			(strstr(kctl->id.name, "Effect Send") != NULL)) {
860 			cval->min = 0xb5fb; /* -73 dB = 0xb6ff */
861 			cval->max = 0xfcfe;
862 			cval->res = 0x0073;
863 		}
864 		break;
865 
866 	case USB_ID(0x0763, 0x2081): /* M-Audio Fast Track Ultra 8R */
867 	case USB_ID(0x0763, 0x2080): /* M-Audio Fast Track Ultra */
868 		if (strcmp(kctl->id.name, "Effect Duration") == 0) {
869 			usb_audio_info(chip,
870 				       "set quirk for FTU Effect Duration\n");
871 			cval->min = 0x0000;
872 			cval->max = 0x7f00;
873 			cval->res = 0x0100;
874 			break;
875 		}
876 		if (strcmp(kctl->id.name, "Effect Volume") == 0 ||
877 		    strcmp(kctl->id.name, "Effect Feedback Volume") == 0) {
878 			usb_audio_info(chip,
879 				       "set quirks for FTU Effect Feedback/Volume\n");
880 			cval->min = 0x00;
881 			cval->max = 0x7f;
882 			break;
883 		}
884 		break;
885 
886 	case USB_ID(0x0471, 0x0101):
887 	case USB_ID(0x0471, 0x0104):
888 	case USB_ID(0x0471, 0x0105):
889 	case USB_ID(0x0672, 0x1041):
890 	/* quirk for UDA1321/N101.
891 	 * note that detection between firmware 2.1.1.7 (N101)
892 	 * and later 2.1.1.21 is not very clear from datasheets.
893 	 * I hope that the min value is -15360 for newer firmware --jk
894 	 */
895 		if (!strcmp(kctl->id.name, "PCM Playback Volume") &&
896 		    cval->min == -15616) {
897 			usb_audio_info(chip,
898 				 "set volume quirk for UDA1321/N101 chip\n");
899 			cval->max = -256;
900 		}
901 		break;
902 
903 	case USB_ID(0x046d, 0x09a4):
904 		if (!strcmp(kctl->id.name, "Mic Capture Volume")) {
905 			usb_audio_info(chip,
906 				"set volume quirk for QuickCam E3500\n");
907 			cval->min = 6080;
908 			cval->max = 8768;
909 			cval->res = 192;
910 		}
911 		break;
912 
913 	case USB_ID(0x046d, 0x0807): /* Logitech Webcam C500 */
914 	case USB_ID(0x046d, 0x0808):
915 	case USB_ID(0x046d, 0x0809):
916 	case USB_ID(0x046d, 0x0819): /* Logitech Webcam C210 */
917 	case USB_ID(0x046d, 0x081b): /* HD Webcam c310 */
918 	case USB_ID(0x046d, 0x081d): /* HD Webcam c510 */
919 	case USB_ID(0x046d, 0x0825): /* HD Webcam c270 */
920 	case USB_ID(0x046d, 0x0826): /* HD Webcam c525 */
921 	case USB_ID(0x046d, 0x08ca): /* Logitech Quickcam Fusion */
922 	case USB_ID(0x046d, 0x0991):
923 	/* Most audio usb devices lie about volume resolution.
924 	 * Most Logitech webcams have res = 384.
925 	 * Proboly there is some logitech magic behind this number --fishor
926 	 */
927 		if (!strcmp(kctl->id.name, "Mic Capture Volume")) {
928 			usb_audio_info(chip,
929 				"set resolution quirk: cval->res = 384\n");
930 			cval->res = 384;
931 		}
932 		break;
933 	}
934 }
935 
936 /*
937  * retrieve the minimum and maximum values for the specified control
938  */
939 static int get_min_max_with_quirks(struct usb_mixer_elem_info *cval,
940 				   int default_min, struct snd_kcontrol *kctl)
941 {
942 	/* for failsafe */
943 	cval->min = default_min;
944 	cval->max = cval->min + 1;
945 	cval->res = 1;
946 	cval->dBmin = cval->dBmax = 0;
947 
948 	if (cval->val_type == USB_MIXER_BOOLEAN ||
949 	    cval->val_type == USB_MIXER_INV_BOOLEAN) {
950 		cval->initialized = 1;
951 	} else {
952 		int minchn = 0;
953 		if (cval->cmask) {
954 			int i;
955 			for (i = 0; i < MAX_CHANNELS; i++)
956 				if (cval->cmask & (1 << i)) {
957 					minchn = i + 1;
958 					break;
959 				}
960 		}
961 		if (get_ctl_value(cval, UAC_GET_MAX, (cval->control << 8) | minchn, &cval->max) < 0 ||
962 		    get_ctl_value(cval, UAC_GET_MIN, (cval->control << 8) | minchn, &cval->min) < 0) {
963 			usb_audio_err(cval->head.mixer->chip,
964 				      "%d:%d: cannot get min/max values for control %d (id %d)\n",
965 				   cval->head.id, snd_usb_ctrl_intf(cval->head.mixer->chip),
966 							       cval->control, cval->head.id);
967 			return -EINVAL;
968 		}
969 		if (get_ctl_value(cval, UAC_GET_RES,
970 				  (cval->control << 8) | minchn,
971 				  &cval->res) < 0) {
972 			cval->res = 1;
973 		} else {
974 			int last_valid_res = cval->res;
975 
976 			while (cval->res > 1) {
977 				if (snd_usb_mixer_set_ctl_value(cval, UAC_SET_RES,
978 								(cval->control << 8) | minchn,
979 								cval->res / 2) < 0)
980 					break;
981 				cval->res /= 2;
982 			}
983 			if (get_ctl_value(cval, UAC_GET_RES,
984 					  (cval->control << 8) | minchn, &cval->res) < 0)
985 				cval->res = last_valid_res;
986 		}
987 		if (cval->res == 0)
988 			cval->res = 1;
989 
990 		/* Additional checks for the proper resolution
991 		 *
992 		 * Some devices report smaller resolutions than actually
993 		 * reacting.  They don't return errors but simply clip
994 		 * to the lower aligned value.
995 		 */
996 		if (cval->min + cval->res < cval->max) {
997 			int last_valid_res = cval->res;
998 			int saved, test, check;
999 			get_cur_mix_raw(cval, minchn, &saved);
1000 			for (;;) {
1001 				test = saved;
1002 				if (test < cval->max)
1003 					test += cval->res;
1004 				else
1005 					test -= cval->res;
1006 				if (test < cval->min || test > cval->max ||
1007 				    snd_usb_set_cur_mix_value(cval, minchn, 0, test) ||
1008 				    get_cur_mix_raw(cval, minchn, &check)) {
1009 					cval->res = last_valid_res;
1010 					break;
1011 				}
1012 				if (test == check)
1013 					break;
1014 				cval->res *= 2;
1015 			}
1016 			snd_usb_set_cur_mix_value(cval, minchn, 0, saved);
1017 		}
1018 
1019 		cval->initialized = 1;
1020 	}
1021 
1022 	if (kctl)
1023 		volume_control_quirks(cval, kctl);
1024 
1025 	/* USB descriptions contain the dB scale in 1/256 dB unit
1026 	 * while ALSA TLV contains in 1/100 dB unit
1027 	 */
1028 	cval->dBmin = (convert_signed_value(cval, cval->min) * 100) / 256;
1029 	cval->dBmax = (convert_signed_value(cval, cval->max) * 100) / 256;
1030 	if (cval->dBmin > cval->dBmax) {
1031 		/* something is wrong; assume it's either from/to 0dB */
1032 		if (cval->dBmin < 0)
1033 			cval->dBmax = 0;
1034 		else if (cval->dBmin > 0)
1035 			cval->dBmin = 0;
1036 		if (cval->dBmin > cval->dBmax) {
1037 			/* totally crap, return an error */
1038 			return -EINVAL;
1039 		}
1040 	}
1041 
1042 	return 0;
1043 }
1044 
1045 #define get_min_max(cval, def)	get_min_max_with_quirks(cval, def, NULL)
1046 
1047 /* get a feature/mixer unit info */
1048 static int mixer_ctl_feature_info(struct snd_kcontrol *kcontrol,
1049 				  struct snd_ctl_elem_info *uinfo)
1050 {
1051 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1052 
1053 	if (cval->val_type == USB_MIXER_BOOLEAN ||
1054 	    cval->val_type == USB_MIXER_INV_BOOLEAN)
1055 		uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1056 	else
1057 		uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
1058 	uinfo->count = cval->channels;
1059 	if (cval->val_type == USB_MIXER_BOOLEAN ||
1060 	    cval->val_type == USB_MIXER_INV_BOOLEAN) {
1061 		uinfo->value.integer.min = 0;
1062 		uinfo->value.integer.max = 1;
1063 	} else {
1064 		if (!cval->initialized) {
1065 			get_min_max_with_quirks(cval, 0, kcontrol);
1066 			if (cval->initialized && cval->dBmin >= cval->dBmax) {
1067 				kcontrol->vd[0].access &=
1068 					~(SNDRV_CTL_ELEM_ACCESS_TLV_READ |
1069 					  SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK);
1070 				snd_ctl_notify(cval->head.mixer->chip->card,
1071 					       SNDRV_CTL_EVENT_MASK_INFO,
1072 					       &kcontrol->id);
1073 			}
1074 		}
1075 		uinfo->value.integer.min = 0;
1076 		uinfo->value.integer.max =
1077 			(cval->max - cval->min + cval->res - 1) / cval->res;
1078 	}
1079 	return 0;
1080 }
1081 
1082 /* get the current value from feature/mixer unit */
1083 static int mixer_ctl_feature_get(struct snd_kcontrol *kcontrol,
1084 				 struct snd_ctl_elem_value *ucontrol)
1085 {
1086 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1087 	int c, cnt, val, err;
1088 
1089 	ucontrol->value.integer.value[0] = cval->min;
1090 	if (cval->cmask) {
1091 		cnt = 0;
1092 		for (c = 0; c < MAX_CHANNELS; c++) {
1093 			if (!(cval->cmask & (1 << c)))
1094 				continue;
1095 			err = snd_usb_get_cur_mix_value(cval, c + 1, cnt, &val);
1096 			if (err < 0)
1097 				return filter_error(cval, err);
1098 			val = get_relative_value(cval, val);
1099 			ucontrol->value.integer.value[cnt] = val;
1100 			cnt++;
1101 		}
1102 		return 0;
1103 	} else {
1104 		/* master channel */
1105 		err = snd_usb_get_cur_mix_value(cval, 0, 0, &val);
1106 		if (err < 0)
1107 			return filter_error(cval, err);
1108 		val = get_relative_value(cval, val);
1109 		ucontrol->value.integer.value[0] = val;
1110 	}
1111 	return 0;
1112 }
1113 
1114 /* put the current value to feature/mixer unit */
1115 static int mixer_ctl_feature_put(struct snd_kcontrol *kcontrol,
1116 				 struct snd_ctl_elem_value *ucontrol)
1117 {
1118 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1119 	int c, cnt, val, oval, err;
1120 	int changed = 0;
1121 
1122 	if (cval->cmask) {
1123 		cnt = 0;
1124 		for (c = 0; c < MAX_CHANNELS; c++) {
1125 			if (!(cval->cmask & (1 << c)))
1126 				continue;
1127 			err = snd_usb_get_cur_mix_value(cval, c + 1, cnt, &oval);
1128 			if (err < 0)
1129 				return filter_error(cval, err);
1130 			val = ucontrol->value.integer.value[cnt];
1131 			val = get_abs_value(cval, val);
1132 			if (oval != val) {
1133 				snd_usb_set_cur_mix_value(cval, c + 1, cnt, val);
1134 				changed = 1;
1135 			}
1136 			cnt++;
1137 		}
1138 	} else {
1139 		/* master channel */
1140 		err = snd_usb_get_cur_mix_value(cval, 0, 0, &oval);
1141 		if (err < 0)
1142 			return filter_error(cval, err);
1143 		val = ucontrol->value.integer.value[0];
1144 		val = get_abs_value(cval, val);
1145 		if (val != oval) {
1146 			snd_usb_set_cur_mix_value(cval, 0, 0, val);
1147 			changed = 1;
1148 		}
1149 	}
1150 	return changed;
1151 }
1152 
1153 static struct snd_kcontrol_new usb_feature_unit_ctl = {
1154 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
1155 	.name = "", /* will be filled later manually */
1156 	.info = mixer_ctl_feature_info,
1157 	.get = mixer_ctl_feature_get,
1158 	.put = mixer_ctl_feature_put,
1159 };
1160 
1161 /* the read-only variant */
1162 static struct snd_kcontrol_new usb_feature_unit_ctl_ro = {
1163 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
1164 	.name = "", /* will be filled later manually */
1165 	.info = mixer_ctl_feature_info,
1166 	.get = mixer_ctl_feature_get,
1167 	.put = NULL,
1168 };
1169 
1170 /*
1171  * This symbol is exported in order to allow the mixer quirks to
1172  * hook up to the standard feature unit control mechanism
1173  */
1174 struct snd_kcontrol_new *snd_usb_feature_unit_ctl = &usb_feature_unit_ctl;
1175 
1176 /*
1177  * build a feature control
1178  */
1179 static size_t append_ctl_name(struct snd_kcontrol *kctl, const char *str)
1180 {
1181 	return strlcat(kctl->id.name, str, sizeof(kctl->id.name));
1182 }
1183 
1184 /*
1185  * A lot of headsets/headphones have a "Speaker" mixer. Make sure we
1186  * rename it to "Headphone". We determine if something is a headphone
1187  * similar to how udev determines form factor.
1188  */
1189 static void check_no_speaker_on_headset(struct snd_kcontrol *kctl,
1190 					struct snd_card *card)
1191 {
1192 	const char *names_to_check[] = {
1193 		"Headset", "headset", "Headphone", "headphone", NULL};
1194 	const char **s;
1195 	bool found = false;
1196 
1197 	if (strcmp("Speaker", kctl->id.name))
1198 		return;
1199 
1200 	for (s = names_to_check; *s; s++)
1201 		if (strstr(card->shortname, *s)) {
1202 			found = true;
1203 			break;
1204 		}
1205 
1206 	if (!found)
1207 		return;
1208 
1209 	strlcpy(kctl->id.name, "Headphone", sizeof(kctl->id.name));
1210 }
1211 
1212 static void build_feature_ctl(struct mixer_build *state, void *raw_desc,
1213 			      unsigned int ctl_mask, int control,
1214 			      struct usb_audio_term *iterm, int unitid,
1215 			      int readonly_mask)
1216 {
1217 	struct uac_feature_unit_descriptor *desc = raw_desc;
1218 	unsigned int len = 0;
1219 	int mapped_name = 0;
1220 	int nameid = uac_feature_unit_iFeature(desc);
1221 	struct snd_kcontrol *kctl;
1222 	struct usb_mixer_elem_info *cval;
1223 	const struct usbmix_name_map *map;
1224 	unsigned int range;
1225 
1226 	control++; /* change from zero-based to 1-based value */
1227 
1228 	if (control == UAC_FU_GRAPHIC_EQUALIZER) {
1229 		/* FIXME: not supported yet */
1230 		return;
1231 	}
1232 
1233 	map = find_map(state, unitid, control);
1234 	if (check_ignored_ctl(map))
1235 		return;
1236 
1237 	cval = kzalloc(sizeof(*cval), GFP_KERNEL);
1238 	if (!cval)
1239 		return;
1240 	snd_usb_mixer_elem_init_std(&cval->head, state->mixer, unitid);
1241 	cval->control = control;
1242 	cval->cmask = ctl_mask;
1243 	cval->val_type = audio_feature_info[control-1].type;
1244 	if (ctl_mask == 0) {
1245 		cval->channels = 1;	/* master channel */
1246 		cval->master_readonly = readonly_mask;
1247 	} else {
1248 		int i, c = 0;
1249 		for (i = 0; i < 16; i++)
1250 			if (ctl_mask & (1 << i))
1251 				c++;
1252 		cval->channels = c;
1253 		cval->ch_readonly = readonly_mask;
1254 	}
1255 
1256 	/*
1257 	 * If all channels in the mask are marked read-only, make the control
1258 	 * read-only. snd_usb_set_cur_mix_value() will check the mask again and won't
1259 	 * issue write commands to read-only channels.
1260 	 */
1261 	if (cval->channels == readonly_mask)
1262 		kctl = snd_ctl_new1(&usb_feature_unit_ctl_ro, cval);
1263 	else
1264 		kctl = snd_ctl_new1(&usb_feature_unit_ctl, cval);
1265 
1266 	if (!kctl) {
1267 		usb_audio_err(state->chip, "cannot malloc kcontrol\n");
1268 		kfree(cval);
1269 		return;
1270 	}
1271 	kctl->private_free = snd_usb_mixer_elem_free;
1272 
1273 	len = check_mapped_name(map, kctl->id.name, sizeof(kctl->id.name));
1274 	mapped_name = len != 0;
1275 	if (!len && nameid)
1276 		len = snd_usb_copy_string_desc(state, nameid,
1277 				kctl->id.name, sizeof(kctl->id.name));
1278 
1279 	switch (control) {
1280 	case UAC_FU_MUTE:
1281 	case UAC_FU_VOLUME:
1282 		/*
1283 		 * determine the control name.  the rule is:
1284 		 * - if a name id is given in descriptor, use it.
1285 		 * - if the connected input can be determined, then use the name
1286 		 *   of terminal type.
1287 		 * - if the connected output can be determined, use it.
1288 		 * - otherwise, anonymous name.
1289 		 */
1290 		if (!len) {
1291 			len = get_term_name(state, iterm, kctl->id.name,
1292 					    sizeof(kctl->id.name), 1);
1293 			if (!len)
1294 				len = get_term_name(state, &state->oterm,
1295 						    kctl->id.name,
1296 						    sizeof(kctl->id.name), 1);
1297 			if (!len)
1298 				snprintf(kctl->id.name, sizeof(kctl->id.name),
1299 					 "Feature %d", unitid);
1300 		}
1301 
1302 		if (!mapped_name)
1303 			check_no_speaker_on_headset(kctl, state->mixer->chip->card);
1304 
1305 		/*
1306 		 * determine the stream direction:
1307 		 * if the connected output is USB stream, then it's likely a
1308 		 * capture stream.  otherwise it should be playback (hopefully :)
1309 		 */
1310 		if (!mapped_name && !(state->oterm.type >> 16)) {
1311 			if ((state->oterm.type & 0xff00) == 0x0100)
1312 				append_ctl_name(kctl, " Capture");
1313 			else
1314 				append_ctl_name(kctl, " Playback");
1315 		}
1316 		append_ctl_name(kctl, control == UAC_FU_MUTE ?
1317 				" Switch" : " Volume");
1318 		break;
1319 	default:
1320 		if (!len)
1321 			strlcpy(kctl->id.name, audio_feature_info[control-1].name,
1322 				sizeof(kctl->id.name));
1323 		break;
1324 	}
1325 
1326 	/* get min/max values */
1327 	get_min_max_with_quirks(cval, 0, kctl);
1328 
1329 	if (control == UAC_FU_VOLUME) {
1330 		check_mapped_dB(map, cval);
1331 		if (cval->dBmin < cval->dBmax || !cval->initialized) {
1332 			kctl->tlv.c = snd_usb_mixer_vol_tlv;
1333 			kctl->vd[0].access |=
1334 				SNDRV_CTL_ELEM_ACCESS_TLV_READ |
1335 				SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1336 		}
1337 	}
1338 
1339 	range = (cval->max - cval->min) / cval->res;
1340 	/*
1341 	 * Are there devices with volume range more than 255? I use a bit more
1342 	 * to be sure. 384 is a resolution magic number found on Logitech
1343 	 * devices. It will definitively catch all buggy Logitech devices.
1344 	 */
1345 	if (range > 384) {
1346 		usb_audio_warn(state->chip,
1347 			       "Warning! Unlikely big volume range (=%u), cval->res is probably wrong.",
1348 			       range);
1349 		usb_audio_warn(state->chip,
1350 			       "[%d] FU [%s] ch = %d, val = %d/%d/%d",
1351 			       cval->head.id, kctl->id.name, cval->channels,
1352 			       cval->min, cval->max, cval->res);
1353 	}
1354 
1355 	usb_audio_dbg(state->chip, "[%d] FU [%s] ch = %d, val = %d/%d/%d\n",
1356 		      cval->head.id, kctl->id.name, cval->channels,
1357 		      cval->min, cval->max, cval->res);
1358 	snd_usb_mixer_add_control(&cval->head, kctl);
1359 }
1360 
1361 /*
1362  * parse a feature unit
1363  *
1364  * most of controls are defined here.
1365  */
1366 static int parse_audio_feature_unit(struct mixer_build *state, int unitid,
1367 				    void *_ftr)
1368 {
1369 	int channels, i, j;
1370 	struct usb_audio_term iterm;
1371 	unsigned int master_bits, first_ch_bits;
1372 	int err, csize;
1373 	struct uac_feature_unit_descriptor *hdr = _ftr;
1374 	__u8 *bmaControls;
1375 
1376 	if (state->mixer->protocol == UAC_VERSION_1) {
1377 		csize = hdr->bControlSize;
1378 		if (!csize) {
1379 			usb_audio_dbg(state->chip,
1380 				      "unit %u: invalid bControlSize == 0\n",
1381 				      unitid);
1382 			return -EINVAL;
1383 		}
1384 		channels = (hdr->bLength - 7) / csize - 1;
1385 		bmaControls = hdr->bmaControls;
1386 		if (hdr->bLength < 7 + csize) {
1387 			usb_audio_err(state->chip,
1388 				      "unit %u: invalid UAC_FEATURE_UNIT descriptor\n",
1389 				      unitid);
1390 			return -EINVAL;
1391 		}
1392 	} else {
1393 		struct uac2_feature_unit_descriptor *ftr = _ftr;
1394 		csize = 4;
1395 		channels = (hdr->bLength - 6) / 4 - 1;
1396 		bmaControls = ftr->bmaControls;
1397 		if (hdr->bLength < 6 + csize) {
1398 			usb_audio_err(state->chip,
1399 				      "unit %u: invalid UAC_FEATURE_UNIT descriptor\n",
1400 				      unitid);
1401 			return -EINVAL;
1402 		}
1403 	}
1404 
1405 	/* parse the source unit */
1406 	if ((err = parse_audio_unit(state, hdr->bSourceID)) < 0)
1407 		return err;
1408 
1409 	/* determine the input source type and name */
1410 	err = check_input_term(state, hdr->bSourceID, &iterm);
1411 	if (err < 0)
1412 		return err;
1413 
1414 	master_bits = snd_usb_combine_bytes(bmaControls, csize);
1415 	/* master configuration quirks */
1416 	switch (state->chip->usb_id) {
1417 	case USB_ID(0x08bb, 0x2702):
1418 		usb_audio_info(state->chip,
1419 			       "usbmixer: master volume quirk for PCM2702 chip\n");
1420 		/* disable non-functional volume control */
1421 		master_bits &= ~UAC_CONTROL_BIT(UAC_FU_VOLUME);
1422 		break;
1423 	case USB_ID(0x1130, 0xf211):
1424 		usb_audio_info(state->chip,
1425 			       "usbmixer: volume control quirk for Tenx TP6911 Audio Headset\n");
1426 		/* disable non-functional volume control */
1427 		channels = 0;
1428 		break;
1429 
1430 	}
1431 	if (channels > 0)
1432 		first_ch_bits = snd_usb_combine_bytes(bmaControls + csize, csize);
1433 	else
1434 		first_ch_bits = 0;
1435 
1436 	if (state->mixer->protocol == UAC_VERSION_1) {
1437 		/* check all control types */
1438 		for (i = 0; i < 10; i++) {
1439 			unsigned int ch_bits = 0;
1440 			for (j = 0; j < channels; j++) {
1441 				unsigned int mask;
1442 
1443 				mask = snd_usb_combine_bytes(bmaControls +
1444 							     csize * (j+1), csize);
1445 				if (mask & (1 << i))
1446 					ch_bits |= (1 << j);
1447 			}
1448 			/* audio class v1 controls are never read-only */
1449 
1450 			/*
1451 			 * The first channel must be set
1452 			 * (for ease of programming).
1453 			 */
1454 			if (ch_bits & 1)
1455 				build_feature_ctl(state, _ftr, ch_bits, i,
1456 						  &iterm, unitid, 0);
1457 			if (master_bits & (1 << i))
1458 				build_feature_ctl(state, _ftr, 0, i, &iterm,
1459 						  unitid, 0);
1460 		}
1461 	} else { /* UAC_VERSION_2 */
1462 		for (i = 0; i < ARRAY_SIZE(audio_feature_info); i++) {
1463 			unsigned int ch_bits = 0;
1464 			unsigned int ch_read_only = 0;
1465 
1466 			for (j = 0; j < channels; j++) {
1467 				unsigned int mask;
1468 
1469 				mask = snd_usb_combine_bytes(bmaControls +
1470 							     csize * (j+1), csize);
1471 				if (uac2_control_is_readable(mask, i)) {
1472 					ch_bits |= (1 << j);
1473 					if (!uac2_control_is_writeable(mask, i))
1474 						ch_read_only |= (1 << j);
1475 				}
1476 			}
1477 
1478 			/*
1479 			 * NOTE: build_feature_ctl() will mark the control
1480 			 * read-only if all channels are marked read-only in
1481 			 * the descriptors. Otherwise, the control will be
1482 			 * reported as writeable, but the driver will not
1483 			 * actually issue a write command for read-only
1484 			 * channels.
1485 			 */
1486 
1487 			/*
1488 			 * The first channel must be set
1489 			 * (for ease of programming).
1490 			 */
1491 			if (ch_bits & 1)
1492 				build_feature_ctl(state, _ftr, ch_bits, i,
1493 						  &iterm, unitid, ch_read_only);
1494 			if (uac2_control_is_readable(master_bits, i))
1495 				build_feature_ctl(state, _ftr, 0, i, &iterm, unitid,
1496 						  !uac2_control_is_writeable(master_bits, i));
1497 		}
1498 	}
1499 
1500 	return 0;
1501 }
1502 
1503 /*
1504  * Mixer Unit
1505  */
1506 
1507 /*
1508  * build a mixer unit control
1509  *
1510  * the callbacks are identical with feature unit.
1511  * input channel number (zero based) is given in control field instead.
1512  */
1513 static void build_mixer_unit_ctl(struct mixer_build *state,
1514 				 struct uac_mixer_unit_descriptor *desc,
1515 				 int in_pin, int in_ch, int unitid,
1516 				 struct usb_audio_term *iterm)
1517 {
1518 	struct usb_mixer_elem_info *cval;
1519 	unsigned int num_outs = uac_mixer_unit_bNrChannels(desc);
1520 	unsigned int i, len;
1521 	struct snd_kcontrol *kctl;
1522 	const struct usbmix_name_map *map;
1523 
1524 	map = find_map(state, unitid, 0);
1525 	if (check_ignored_ctl(map))
1526 		return;
1527 
1528 	cval = kzalloc(sizeof(*cval), GFP_KERNEL);
1529 	if (!cval)
1530 		return;
1531 
1532 	snd_usb_mixer_elem_init_std(&cval->head, state->mixer, unitid);
1533 	cval->control = in_ch + 1; /* based on 1 */
1534 	cval->val_type = USB_MIXER_S16;
1535 	for (i = 0; i < num_outs; i++) {
1536 		__u8 *c = uac_mixer_unit_bmControls(desc, state->mixer->protocol);
1537 
1538 		if (check_matrix_bitmap(c, in_ch, i, num_outs)) {
1539 			cval->cmask |= (1 << i);
1540 			cval->channels++;
1541 		}
1542 	}
1543 
1544 	/* get min/max values */
1545 	get_min_max(cval, 0);
1546 
1547 	kctl = snd_ctl_new1(&usb_feature_unit_ctl, cval);
1548 	if (!kctl) {
1549 		usb_audio_err(state->chip, "cannot malloc kcontrol\n");
1550 		kfree(cval);
1551 		return;
1552 	}
1553 	kctl->private_free = snd_usb_mixer_elem_free;
1554 
1555 	len = check_mapped_name(map, kctl->id.name, sizeof(kctl->id.name));
1556 	if (!len)
1557 		len = get_term_name(state, iterm, kctl->id.name,
1558 				    sizeof(kctl->id.name), 0);
1559 	if (!len)
1560 		len = sprintf(kctl->id.name, "Mixer Source %d", in_ch + 1);
1561 	append_ctl_name(kctl, " Volume");
1562 
1563 	usb_audio_dbg(state->chip, "[%d] MU [%s] ch = %d, val = %d/%d\n",
1564 		    cval->head.id, kctl->id.name, cval->channels, cval->min, cval->max);
1565 	snd_usb_mixer_add_control(&cval->head, kctl);
1566 }
1567 
1568 /*
1569  * parse a mixer unit
1570  */
1571 static int parse_audio_mixer_unit(struct mixer_build *state, int unitid,
1572 				  void *raw_desc)
1573 {
1574 	struct uac_mixer_unit_descriptor *desc = raw_desc;
1575 	struct usb_audio_term iterm;
1576 	int input_pins, num_ins, num_outs;
1577 	int pin, ich, err;
1578 
1579 	if (desc->bLength < 11 || !(input_pins = desc->bNrInPins) ||
1580 	    !(num_outs = uac_mixer_unit_bNrChannels(desc))) {
1581 		usb_audio_err(state->chip,
1582 			      "invalid MIXER UNIT descriptor %d\n",
1583 			      unitid);
1584 		return -EINVAL;
1585 	}
1586 
1587 	num_ins = 0;
1588 	ich = 0;
1589 	for (pin = 0; pin < input_pins; pin++) {
1590 		err = parse_audio_unit(state, desc->baSourceID[pin]);
1591 		if (err < 0)
1592 			continue;
1593 		/* no bmControls field (e.g. Maya44) -> ignore */
1594 		if (desc->bLength <= 10 + input_pins)
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) {
1633 		ucontrol->value.integer.value[0] = cval->min;
1634 		return filter_error(cval, err);
1635 	}
1636 	val = get_relative_value(cval, val);
1637 	ucontrol->value.integer.value[0] = val;
1638 	return 0;
1639 }
1640 
1641 /* put callback for processing/extension unit */
1642 static int mixer_ctl_procunit_put(struct snd_kcontrol *kcontrol,
1643 				  struct snd_ctl_elem_value *ucontrol)
1644 {
1645 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1646 	int val, oval, err;
1647 
1648 	err = get_cur_ctl_value(cval, cval->control << 8, &oval);
1649 	if (err < 0)
1650 		return filter_error(cval, err);
1651 	val = ucontrol->value.integer.value[0];
1652 	val = get_abs_value(cval, val);
1653 	if (val != oval) {
1654 		set_cur_ctl_value(cval, cval->control << 8, val);
1655 		return 1;
1656 	}
1657 	return 0;
1658 }
1659 
1660 /* alsa control interface for processing/extension unit */
1661 static struct snd_kcontrol_new mixer_procunit_ctl = {
1662 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
1663 	.name = "", /* will be filled later */
1664 	.info = mixer_ctl_feature_info,
1665 	.get = mixer_ctl_procunit_get,
1666 	.put = mixer_ctl_procunit_put,
1667 };
1668 
1669 /*
1670  * predefined data for processing units
1671  */
1672 struct procunit_value_info {
1673 	int control;
1674 	char *suffix;
1675 	int val_type;
1676 	int min_value;
1677 };
1678 
1679 struct procunit_info {
1680 	int type;
1681 	char *name;
1682 	struct procunit_value_info *values;
1683 };
1684 
1685 static struct procunit_value_info updown_proc_info[] = {
1686 	{ UAC_UD_ENABLE, "Switch", USB_MIXER_BOOLEAN },
1687 	{ UAC_UD_MODE_SELECT, "Mode Select", USB_MIXER_U8, 1 },
1688 	{ 0 }
1689 };
1690 static struct procunit_value_info prologic_proc_info[] = {
1691 	{ UAC_DP_ENABLE, "Switch", USB_MIXER_BOOLEAN },
1692 	{ UAC_DP_MODE_SELECT, "Mode Select", USB_MIXER_U8, 1 },
1693 	{ 0 }
1694 };
1695 static struct procunit_value_info threed_enh_proc_info[] = {
1696 	{ UAC_3D_ENABLE, "Switch", USB_MIXER_BOOLEAN },
1697 	{ UAC_3D_SPACE, "Spaciousness", USB_MIXER_U8 },
1698 	{ 0 }
1699 };
1700 static struct procunit_value_info reverb_proc_info[] = {
1701 	{ UAC_REVERB_ENABLE, "Switch", USB_MIXER_BOOLEAN },
1702 	{ UAC_REVERB_LEVEL, "Level", USB_MIXER_U8 },
1703 	{ UAC_REVERB_TIME, "Time", USB_MIXER_U16 },
1704 	{ UAC_REVERB_FEEDBACK, "Feedback", USB_MIXER_U8 },
1705 	{ 0 }
1706 };
1707 static struct procunit_value_info chorus_proc_info[] = {
1708 	{ UAC_CHORUS_ENABLE, "Switch", USB_MIXER_BOOLEAN },
1709 	{ UAC_CHORUS_LEVEL, "Level", USB_MIXER_U8 },
1710 	{ UAC_CHORUS_RATE, "Rate", USB_MIXER_U16 },
1711 	{ UAC_CHORUS_DEPTH, "Depth", USB_MIXER_U16 },
1712 	{ 0 }
1713 };
1714 static struct procunit_value_info dcr_proc_info[] = {
1715 	{ UAC_DCR_ENABLE, "Switch", USB_MIXER_BOOLEAN },
1716 	{ UAC_DCR_RATE, "Ratio", USB_MIXER_U16 },
1717 	{ UAC_DCR_MAXAMPL, "Max Amp", USB_MIXER_S16 },
1718 	{ UAC_DCR_THRESHOLD, "Threshold", USB_MIXER_S16 },
1719 	{ UAC_DCR_ATTACK_TIME, "Attack Time", USB_MIXER_U16 },
1720 	{ UAC_DCR_RELEASE_TIME, "Release Time", USB_MIXER_U16 },
1721 	{ 0 }
1722 };
1723 
1724 static struct procunit_info procunits[] = {
1725 	{ UAC_PROCESS_UP_DOWNMIX, "Up Down", updown_proc_info },
1726 	{ UAC_PROCESS_DOLBY_PROLOGIC, "Dolby Prologic", prologic_proc_info },
1727 	{ UAC_PROCESS_STEREO_EXTENDER, "3D Stereo Extender", threed_enh_proc_info },
1728 	{ UAC_PROCESS_REVERB, "Reverb", reverb_proc_info },
1729 	{ UAC_PROCESS_CHORUS, "Chorus", chorus_proc_info },
1730 	{ UAC_PROCESS_DYN_RANGE_COMP, "DCR", dcr_proc_info },
1731 	{ 0 },
1732 };
1733 /*
1734  * predefined data for extension units
1735  */
1736 static struct procunit_value_info clock_rate_xu_info[] = {
1737 	{ USB_XU_CLOCK_RATE_SELECTOR, "Selector", USB_MIXER_U8, 0 },
1738 	{ 0 }
1739 };
1740 static struct procunit_value_info clock_source_xu_info[] = {
1741 	{ USB_XU_CLOCK_SOURCE_SELECTOR, "External", USB_MIXER_BOOLEAN },
1742 	{ 0 }
1743 };
1744 static struct procunit_value_info spdif_format_xu_info[] = {
1745 	{ USB_XU_DIGITAL_FORMAT_SELECTOR, "SPDIF/AC3", USB_MIXER_BOOLEAN },
1746 	{ 0 }
1747 };
1748 static struct procunit_value_info soft_limit_xu_info[] = {
1749 	{ USB_XU_SOFT_LIMIT_SELECTOR, " ", USB_MIXER_BOOLEAN },
1750 	{ 0 }
1751 };
1752 static struct procunit_info extunits[] = {
1753 	{ USB_XU_CLOCK_RATE, "Clock rate", clock_rate_xu_info },
1754 	{ USB_XU_CLOCK_SOURCE, "DigitalIn CLK source", clock_source_xu_info },
1755 	{ USB_XU_DIGITAL_IO_STATUS, "DigitalOut format:", spdif_format_xu_info },
1756 	{ USB_XU_DEVICE_OPTIONS, "AnalogueIn Soft Limit", soft_limit_xu_info },
1757 	{ 0 }
1758 };
1759 
1760 /*
1761  * build a processing/extension unit
1762  */
1763 static int build_audio_procunit(struct mixer_build *state, int unitid,
1764 				void *raw_desc, struct procunit_info *list,
1765 				char *name)
1766 {
1767 	struct uac_processing_unit_descriptor *desc = raw_desc;
1768 	int num_ins = desc->bNrInPins;
1769 	struct usb_mixer_elem_info *cval;
1770 	struct snd_kcontrol *kctl;
1771 	int i, err, nameid, type, len;
1772 	struct procunit_info *info;
1773 	struct procunit_value_info *valinfo;
1774 	const struct usbmix_name_map *map;
1775 	static struct procunit_value_info default_value_info[] = {
1776 		{ 0x01, "Switch", USB_MIXER_BOOLEAN },
1777 		{ 0 }
1778 	};
1779 	static struct procunit_info default_info = {
1780 		0, NULL, default_value_info
1781 	};
1782 
1783 	if (desc->bLength < 13 || desc->bLength < 13 + num_ins ||
1784 	    desc->bLength < num_ins + uac_processing_unit_bControlSize(desc, state->mixer->protocol)) {
1785 		usb_audio_err(state->chip, "invalid %s descriptor (id %d)\n", name, unitid);
1786 		return -EINVAL;
1787 	}
1788 
1789 	for (i = 0; i < num_ins; i++) {
1790 		if ((err = parse_audio_unit(state, desc->baSourceID[i])) < 0)
1791 			return err;
1792 	}
1793 
1794 	type = le16_to_cpu(desc->wProcessType);
1795 	for (info = list; info && info->type; info++)
1796 		if (info->type == type)
1797 			break;
1798 	if (!info || !info->type)
1799 		info = &default_info;
1800 
1801 	for (valinfo = info->values; valinfo->control; valinfo++) {
1802 		__u8 *controls = uac_processing_unit_bmControls(desc, state->mixer->protocol);
1803 
1804 		if (!(controls[valinfo->control / 8] & (1 << ((valinfo->control % 8) - 1))))
1805 			continue;
1806 		map = find_map(state, unitid, valinfo->control);
1807 		if (check_ignored_ctl(map))
1808 			continue;
1809 		cval = kzalloc(sizeof(*cval), GFP_KERNEL);
1810 		if (!cval)
1811 			return -ENOMEM;
1812 		snd_usb_mixer_elem_init_std(&cval->head, state->mixer, unitid);
1813 		cval->control = valinfo->control;
1814 		cval->val_type = valinfo->val_type;
1815 		cval->channels = 1;
1816 
1817 		/* get min/max values */
1818 		if (type == UAC_PROCESS_UP_DOWNMIX && cval->control == UAC_UD_MODE_SELECT) {
1819 			__u8 *control_spec = uac_processing_unit_specific(desc, state->mixer->protocol);
1820 			/* FIXME: hard-coded */
1821 			cval->min = 1;
1822 			cval->max = control_spec[0];
1823 			cval->res = 1;
1824 			cval->initialized = 1;
1825 		} else {
1826 			if (type == USB_XU_CLOCK_RATE) {
1827 				/*
1828 				 * E-Mu USB 0404/0202/TrackerPre/0204
1829 				 * samplerate control quirk
1830 				 */
1831 				cval->min = 0;
1832 				cval->max = 5;
1833 				cval->res = 1;
1834 				cval->initialized = 1;
1835 			} else
1836 				get_min_max(cval, valinfo->min_value);
1837 		}
1838 
1839 		kctl = snd_ctl_new1(&mixer_procunit_ctl, cval);
1840 		if (!kctl) {
1841 			kfree(cval);
1842 			return -ENOMEM;
1843 		}
1844 		kctl->private_free = snd_usb_mixer_elem_free;
1845 
1846 		if (check_mapped_name(map, kctl->id.name, sizeof(kctl->id.name))) {
1847 			/* nothing */ ;
1848 		} else if (info->name) {
1849 			strlcpy(kctl->id.name, info->name, sizeof(kctl->id.name));
1850 		} else {
1851 			nameid = uac_processing_unit_iProcessing(desc, state->mixer->protocol);
1852 			len = 0;
1853 			if (nameid)
1854 				len = snd_usb_copy_string_desc(state, nameid,
1855 							       kctl->id.name,
1856 							       sizeof(kctl->id.name));
1857 			if (!len)
1858 				strlcpy(kctl->id.name, name, sizeof(kctl->id.name));
1859 		}
1860 		append_ctl_name(kctl, " ");
1861 		append_ctl_name(kctl, valinfo->suffix);
1862 
1863 		usb_audio_dbg(state->chip,
1864 			      "[%d] PU [%s] ch = %d, val = %d/%d\n",
1865 			      cval->head.id, kctl->id.name, cval->channels,
1866 			      cval->min, cval->max);
1867 
1868 		err = snd_usb_mixer_add_control(&cval->head, kctl);
1869 		if (err < 0)
1870 			return err;
1871 	}
1872 	return 0;
1873 }
1874 
1875 static int parse_audio_processing_unit(struct mixer_build *state, int unitid,
1876 				       void *raw_desc)
1877 {
1878 	return build_audio_procunit(state, unitid, raw_desc,
1879 				    procunits, "Processing Unit");
1880 }
1881 
1882 static int parse_audio_extension_unit(struct mixer_build *state, int unitid,
1883 				      void *raw_desc)
1884 {
1885 	/*
1886 	 * Note that we parse extension units with processing unit descriptors.
1887 	 * That's ok as the layout is the same.
1888 	 */
1889 	return build_audio_procunit(state, unitid, raw_desc,
1890 				    extunits, "Extension Unit");
1891 }
1892 
1893 /*
1894  * Selector Unit
1895  */
1896 
1897 /*
1898  * info callback for selector unit
1899  * use an enumerator type for routing
1900  */
1901 static int mixer_ctl_selector_info(struct snd_kcontrol *kcontrol,
1902 				   struct snd_ctl_elem_info *uinfo)
1903 {
1904 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1905 	const char **itemlist = (const char **)kcontrol->private_value;
1906 
1907 	if (snd_BUG_ON(!itemlist))
1908 		return -EINVAL;
1909 	return snd_ctl_enum_info(uinfo, 1, cval->max, itemlist);
1910 }
1911 
1912 /* get callback for selector unit */
1913 static int mixer_ctl_selector_get(struct snd_kcontrol *kcontrol,
1914 				  struct snd_ctl_elem_value *ucontrol)
1915 {
1916 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1917 	int val, err;
1918 
1919 	err = get_cur_ctl_value(cval, cval->control << 8, &val);
1920 	if (err < 0) {
1921 		ucontrol->value.enumerated.item[0] = 0;
1922 		return filter_error(cval, err);
1923 	}
1924 	val = get_relative_value(cval, val);
1925 	ucontrol->value.enumerated.item[0] = val;
1926 	return 0;
1927 }
1928 
1929 /* put callback for selector unit */
1930 static int mixer_ctl_selector_put(struct snd_kcontrol *kcontrol,
1931 				  struct snd_ctl_elem_value *ucontrol)
1932 {
1933 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1934 	int val, oval, err;
1935 
1936 	err = get_cur_ctl_value(cval, cval->control << 8, &oval);
1937 	if (err < 0)
1938 		return filter_error(cval, err);
1939 	val = ucontrol->value.enumerated.item[0];
1940 	val = get_abs_value(cval, val);
1941 	if (val != oval) {
1942 		set_cur_ctl_value(cval, cval->control << 8, val);
1943 		return 1;
1944 	}
1945 	return 0;
1946 }
1947 
1948 /* alsa control interface for selector unit */
1949 static struct snd_kcontrol_new mixer_selectunit_ctl = {
1950 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
1951 	.name = "", /* will be filled later */
1952 	.info = mixer_ctl_selector_info,
1953 	.get = mixer_ctl_selector_get,
1954 	.put = mixer_ctl_selector_put,
1955 };
1956 
1957 /*
1958  * private free callback.
1959  * free both private_data and private_value
1960  */
1961 static void usb_mixer_selector_elem_free(struct snd_kcontrol *kctl)
1962 {
1963 	int i, num_ins = 0;
1964 
1965 	if (kctl->private_data) {
1966 		struct usb_mixer_elem_info *cval = kctl->private_data;
1967 		num_ins = cval->max;
1968 		kfree(cval);
1969 		kctl->private_data = NULL;
1970 	}
1971 	if (kctl->private_value) {
1972 		char **itemlist = (char **)kctl->private_value;
1973 		for (i = 0; i < num_ins; i++)
1974 			kfree(itemlist[i]);
1975 		kfree(itemlist);
1976 		kctl->private_value = 0;
1977 	}
1978 }
1979 
1980 /*
1981  * parse a selector unit
1982  */
1983 static int parse_audio_selector_unit(struct mixer_build *state, int unitid,
1984 				     void *raw_desc)
1985 {
1986 	struct uac_selector_unit_descriptor *desc = raw_desc;
1987 	unsigned int i, nameid, len;
1988 	int err;
1989 	struct usb_mixer_elem_info *cval;
1990 	struct snd_kcontrol *kctl;
1991 	const struct usbmix_name_map *map;
1992 	char **namelist;
1993 
1994 	if (!desc->bNrInPins || desc->bLength < 5 + desc->bNrInPins) {
1995 		usb_audio_err(state->chip,
1996 			"invalid SELECTOR UNIT descriptor %d\n", unitid);
1997 		return -EINVAL;
1998 	}
1999 
2000 	for (i = 0; i < desc->bNrInPins; i++) {
2001 		if ((err = parse_audio_unit(state, desc->baSourceID[i])) < 0)
2002 			return err;
2003 	}
2004 
2005 	if (desc->bNrInPins == 1) /* only one ? nonsense! */
2006 		return 0;
2007 
2008 	map = find_map(state, unitid, 0);
2009 	if (check_ignored_ctl(map))
2010 		return 0;
2011 
2012 	cval = kzalloc(sizeof(*cval), GFP_KERNEL);
2013 	if (!cval)
2014 		return -ENOMEM;
2015 	snd_usb_mixer_elem_init_std(&cval->head, state->mixer, unitid);
2016 	cval->val_type = USB_MIXER_U8;
2017 	cval->channels = 1;
2018 	cval->min = 1;
2019 	cval->max = desc->bNrInPins;
2020 	cval->res = 1;
2021 	cval->initialized = 1;
2022 
2023 	if (state->mixer->protocol == UAC_VERSION_1)
2024 		cval->control = 0;
2025 	else /* UAC_VERSION_2 */
2026 		cval->control = (desc->bDescriptorSubtype == UAC2_CLOCK_SELECTOR) ?
2027 			UAC2_CX_CLOCK_SELECTOR : UAC2_SU_SELECTOR;
2028 
2029 	namelist = kmalloc(sizeof(char *) * desc->bNrInPins, GFP_KERNEL);
2030 	if (!namelist) {
2031 		kfree(cval);
2032 		return -ENOMEM;
2033 	}
2034 #define MAX_ITEM_NAME_LEN	64
2035 	for (i = 0; i < desc->bNrInPins; i++) {
2036 		struct usb_audio_term iterm;
2037 		len = 0;
2038 		namelist[i] = kmalloc(MAX_ITEM_NAME_LEN, GFP_KERNEL);
2039 		if (!namelist[i]) {
2040 			while (i--)
2041 				kfree(namelist[i]);
2042 			kfree(namelist);
2043 			kfree(cval);
2044 			return -ENOMEM;
2045 		}
2046 		len = check_mapped_selector_name(state, unitid, i, namelist[i],
2047 						 MAX_ITEM_NAME_LEN);
2048 		if (! len && check_input_term(state, desc->baSourceID[i], &iterm) >= 0)
2049 			len = get_term_name(state, &iterm, namelist[i], MAX_ITEM_NAME_LEN, 0);
2050 		if (! len)
2051 			sprintf(namelist[i], "Input %u", i);
2052 	}
2053 
2054 	kctl = snd_ctl_new1(&mixer_selectunit_ctl, cval);
2055 	if (! kctl) {
2056 		usb_audio_err(state->chip, "cannot malloc kcontrol\n");
2057 		kfree(namelist);
2058 		kfree(cval);
2059 		return -ENOMEM;
2060 	}
2061 	kctl->private_value = (unsigned long)namelist;
2062 	kctl->private_free = usb_mixer_selector_elem_free;
2063 
2064 	nameid = uac_selector_unit_iSelector(desc);
2065 	len = check_mapped_name(map, kctl->id.name, sizeof(kctl->id.name));
2066 	if (len)
2067 		;
2068 	else if (nameid)
2069 		snd_usb_copy_string_desc(state, nameid, kctl->id.name,
2070 					 sizeof(kctl->id.name));
2071 	else {
2072 		len = get_term_name(state, &state->oterm,
2073 				    kctl->id.name, sizeof(kctl->id.name), 0);
2074 		if (!len)
2075 			strlcpy(kctl->id.name, "USB", sizeof(kctl->id.name));
2076 
2077 		if (desc->bDescriptorSubtype == UAC2_CLOCK_SELECTOR)
2078 			append_ctl_name(kctl, " Clock Source");
2079 		else if ((state->oterm.type & 0xff00) == 0x0100)
2080 			append_ctl_name(kctl, " Capture Source");
2081 		else
2082 			append_ctl_name(kctl, " Playback Source");
2083 	}
2084 
2085 	usb_audio_dbg(state->chip, "[%d] SU [%s] items = %d\n",
2086 		    cval->head.id, kctl->id.name, desc->bNrInPins);
2087 	return snd_usb_mixer_add_control(&cval->head, kctl);
2088 }
2089 
2090 /*
2091  * parse an audio unit recursively
2092  */
2093 
2094 static int parse_audio_unit(struct mixer_build *state, int unitid)
2095 {
2096 	unsigned char *p1;
2097 
2098 	if (test_and_set_bit(unitid, state->unitbitmap))
2099 		return 0; /* the unit already visited */
2100 
2101 	p1 = find_audio_control_unit(state, unitid);
2102 	if (!p1) {
2103 		usb_audio_err(state->chip, "unit %d not found!\n", unitid);
2104 		return -EINVAL;
2105 	}
2106 
2107 	switch (p1[2]) {
2108 	case UAC_INPUT_TERMINAL:
2109 	case UAC2_CLOCK_SOURCE:
2110 		return 0; /* NOP */
2111 	case UAC_MIXER_UNIT:
2112 		return parse_audio_mixer_unit(state, unitid, p1);
2113 	case UAC_SELECTOR_UNIT:
2114 	case UAC2_CLOCK_SELECTOR:
2115 		return parse_audio_selector_unit(state, unitid, p1);
2116 	case UAC_FEATURE_UNIT:
2117 		return parse_audio_feature_unit(state, unitid, p1);
2118 	case UAC1_PROCESSING_UNIT:
2119 	/*   UAC2_EFFECT_UNIT has the same value */
2120 		if (state->mixer->protocol == UAC_VERSION_1)
2121 			return parse_audio_processing_unit(state, unitid, p1);
2122 		else
2123 			return 0; /* FIXME - effect units not implemented yet */
2124 	case UAC1_EXTENSION_UNIT:
2125 	/*   UAC2_PROCESSING_UNIT_V2 has the same value */
2126 		if (state->mixer->protocol == UAC_VERSION_1)
2127 			return parse_audio_extension_unit(state, unitid, p1);
2128 		else /* UAC_VERSION_2 */
2129 			return parse_audio_processing_unit(state, unitid, p1);
2130 	case UAC2_EXTENSION_UNIT_V2:
2131 		return parse_audio_extension_unit(state, unitid, p1);
2132 	default:
2133 		usb_audio_err(state->chip,
2134 			"unit %u: unexpected type 0x%02x\n", unitid, p1[2]);
2135 		return -EINVAL;
2136 	}
2137 }
2138 
2139 static void snd_usb_mixer_free(struct usb_mixer_interface *mixer)
2140 {
2141 	kfree(mixer->id_elems);
2142 	if (mixer->urb) {
2143 		kfree(mixer->urb->transfer_buffer);
2144 		usb_free_urb(mixer->urb);
2145 	}
2146 	usb_free_urb(mixer->rc_urb);
2147 	kfree(mixer->rc_setup_packet);
2148 	kfree(mixer);
2149 }
2150 
2151 static int snd_usb_mixer_dev_free(struct snd_device *device)
2152 {
2153 	struct usb_mixer_interface *mixer = device->device_data;
2154 	snd_usb_mixer_free(mixer);
2155 	return 0;
2156 }
2157 
2158 /*
2159  * create mixer controls
2160  *
2161  * walk through all UAC_OUTPUT_TERMINAL descriptors to search for mixers
2162  */
2163 static int snd_usb_mixer_controls(struct usb_mixer_interface *mixer)
2164 {
2165 	struct mixer_build state;
2166 	int err;
2167 	const struct usbmix_ctl_map *map;
2168 	void *p;
2169 
2170 	memset(&state, 0, sizeof(state));
2171 	state.chip = mixer->chip;
2172 	state.mixer = mixer;
2173 	state.buffer = mixer->hostif->extra;
2174 	state.buflen = mixer->hostif->extralen;
2175 
2176 	/* check the mapping table */
2177 	for (map = usbmix_ctl_maps; map->id; map++) {
2178 		if (map->id == state.chip->usb_id) {
2179 			state.map = map->map;
2180 			state.selector_map = map->selector_map;
2181 			mixer->ignore_ctl_error = map->ignore_ctl_error;
2182 			break;
2183 		}
2184 	}
2185 
2186 	p = NULL;
2187 	while ((p = snd_usb_find_csint_desc(mixer->hostif->extra,
2188 					    mixer->hostif->extralen,
2189 					    p, UAC_OUTPUT_TERMINAL)) != NULL) {
2190 		if (mixer->protocol == UAC_VERSION_1) {
2191 			struct uac1_output_terminal_descriptor *desc = p;
2192 
2193 			if (desc->bLength < sizeof(*desc))
2194 				continue; /* invalid descriptor? */
2195 			/* mark terminal ID as visited */
2196 			set_bit(desc->bTerminalID, state.unitbitmap);
2197 			state.oterm.id = desc->bTerminalID;
2198 			state.oterm.type = le16_to_cpu(desc->wTerminalType);
2199 			state.oterm.name = desc->iTerminal;
2200 			err = parse_audio_unit(&state, desc->bSourceID);
2201 			if (err < 0 && err != -EINVAL)
2202 				return err;
2203 		} else { /* UAC_VERSION_2 */
2204 			struct uac2_output_terminal_descriptor *desc = p;
2205 
2206 			if (desc->bLength < sizeof(*desc))
2207 				continue; /* invalid descriptor? */
2208 			/* mark terminal ID as visited */
2209 			set_bit(desc->bTerminalID, state.unitbitmap);
2210 			state.oterm.id = desc->bTerminalID;
2211 			state.oterm.type = le16_to_cpu(desc->wTerminalType);
2212 			state.oterm.name = desc->iTerminal;
2213 			err = parse_audio_unit(&state, desc->bSourceID);
2214 			if (err < 0 && err != -EINVAL)
2215 				return err;
2216 
2217 			/*
2218 			 * For UAC2, use the same approach to also add the
2219 			 * clock selectors
2220 			 */
2221 			err = parse_audio_unit(&state, desc->bCSourceID);
2222 			if (err < 0 && err != -EINVAL)
2223 				return err;
2224 		}
2225 	}
2226 
2227 	return 0;
2228 }
2229 
2230 void snd_usb_mixer_notify_id(struct usb_mixer_interface *mixer, int unitid)
2231 {
2232 	struct usb_mixer_elem_list *list;
2233 
2234 	for (list = mixer->id_elems[unitid]; list; list = list->next_id_elem)
2235 		snd_ctl_notify(mixer->chip->card, SNDRV_CTL_EVENT_MASK_VALUE,
2236 			       &list->kctl->id);
2237 }
2238 
2239 static void snd_usb_mixer_dump_cval(struct snd_info_buffer *buffer,
2240 				    struct usb_mixer_elem_list *list)
2241 {
2242 	struct usb_mixer_elem_info *cval = (struct usb_mixer_elem_info *)list;
2243 	static char *val_types[] = {"BOOLEAN", "INV_BOOLEAN",
2244 				    "S8", "U8", "S16", "U16"};
2245 	snd_iprintf(buffer, "    Info: id=%i, control=%i, cmask=0x%x, "
2246 			    "channels=%i, type=\"%s\"\n", cval->head.id,
2247 			    cval->control, cval->cmask, cval->channels,
2248 			    val_types[cval->val_type]);
2249 	snd_iprintf(buffer, "    Volume: min=%i, max=%i, dBmin=%i, dBmax=%i\n",
2250 			    cval->min, cval->max, cval->dBmin, cval->dBmax);
2251 }
2252 
2253 static void snd_usb_mixer_proc_read(struct snd_info_entry *entry,
2254 				    struct snd_info_buffer *buffer)
2255 {
2256 	struct snd_usb_audio *chip = entry->private_data;
2257 	struct usb_mixer_interface *mixer;
2258 	struct usb_mixer_elem_list *list;
2259 	int unitid;
2260 
2261 	list_for_each_entry(mixer, &chip->mixer_list, list) {
2262 		snd_iprintf(buffer,
2263 			"USB Mixer: usb_id=0x%08x, ctrlif=%i, ctlerr=%i\n",
2264 				chip->usb_id, snd_usb_ctrl_intf(chip),
2265 				mixer->ignore_ctl_error);
2266 		snd_iprintf(buffer, "Card: %s\n", chip->card->longname);
2267 		for (unitid = 0; unitid < MAX_ID_ELEMS; unitid++) {
2268 			for (list = mixer->id_elems[unitid]; list;
2269 			     list = list->next_id_elem) {
2270 				snd_iprintf(buffer, "  Unit: %i\n", list->id);
2271 				if (list->kctl)
2272 					snd_iprintf(buffer,
2273 						    "    Control: name=\"%s\", index=%i\n",
2274 						    list->kctl->id.name,
2275 						    list->kctl->id.index);
2276 				if (list->dump)
2277 					list->dump(buffer, list);
2278 			}
2279 		}
2280 	}
2281 }
2282 
2283 static void snd_usb_mixer_interrupt_v2(struct usb_mixer_interface *mixer,
2284 				       int attribute, int value, int index)
2285 {
2286 	struct usb_mixer_elem_list *list;
2287 	__u8 unitid = (index >> 8) & 0xff;
2288 	__u8 control = (value >> 8) & 0xff;
2289 	__u8 channel = value & 0xff;
2290 
2291 	if (channel >= MAX_CHANNELS) {
2292 		usb_audio_dbg(mixer->chip,
2293 			"%s(): bogus channel number %d\n",
2294 			__func__, channel);
2295 		return;
2296 	}
2297 
2298 	for (list = mixer->id_elems[unitid]; list; list = list->next_id_elem) {
2299 		struct usb_mixer_elem_info *info;
2300 
2301 		if (!list->kctl)
2302 			continue;
2303 
2304 		info = (struct usb_mixer_elem_info *)list;
2305 		if (info->control != control)
2306 			continue;
2307 
2308 		switch (attribute) {
2309 		case UAC2_CS_CUR:
2310 			/* invalidate cache, so the value is read from the device */
2311 			if (channel)
2312 				info->cached &= ~(1 << channel);
2313 			else /* master channel */
2314 				info->cached = 0;
2315 
2316 			snd_ctl_notify(mixer->chip->card, SNDRV_CTL_EVENT_MASK_VALUE,
2317 				       &info->head.kctl->id);
2318 			break;
2319 
2320 		case UAC2_CS_RANGE:
2321 			/* TODO */
2322 			break;
2323 
2324 		case UAC2_CS_MEM:
2325 			/* TODO */
2326 			break;
2327 
2328 		default:
2329 			usb_audio_dbg(mixer->chip,
2330 				"unknown attribute %d in interrupt\n",
2331 				attribute);
2332 			break;
2333 		} /* switch */
2334 	}
2335 }
2336 
2337 static void snd_usb_mixer_interrupt(struct urb *urb)
2338 {
2339 	struct usb_mixer_interface *mixer = urb->context;
2340 	int len = urb->actual_length;
2341 	int ustatus = urb->status;
2342 
2343 	if (ustatus != 0)
2344 		goto requeue;
2345 
2346 	if (mixer->protocol == UAC_VERSION_1) {
2347 		struct uac1_status_word *status;
2348 
2349 		for (status = urb->transfer_buffer;
2350 		     len >= sizeof(*status);
2351 		     len -= sizeof(*status), status++) {
2352 			dev_dbg(&urb->dev->dev, "status interrupt: %02x %02x\n",
2353 						status->bStatusType,
2354 						status->bOriginator);
2355 
2356 			/* ignore any notifications not from the control interface */
2357 			if ((status->bStatusType & UAC1_STATUS_TYPE_ORIG_MASK) !=
2358 				UAC1_STATUS_TYPE_ORIG_AUDIO_CONTROL_IF)
2359 				continue;
2360 
2361 			if (status->bStatusType & UAC1_STATUS_TYPE_MEM_CHANGED)
2362 				snd_usb_mixer_rc_memory_change(mixer, status->bOriginator);
2363 			else
2364 				snd_usb_mixer_notify_id(mixer, status->bOriginator);
2365 		}
2366 	} else { /* UAC_VERSION_2 */
2367 		struct uac2_interrupt_data_msg *msg;
2368 
2369 		for (msg = urb->transfer_buffer;
2370 		     len >= sizeof(*msg);
2371 		     len -= sizeof(*msg), msg++) {
2372 			/* drop vendor specific and endpoint requests */
2373 			if ((msg->bInfo & UAC2_INTERRUPT_DATA_MSG_VENDOR) ||
2374 			    (msg->bInfo & UAC2_INTERRUPT_DATA_MSG_EP))
2375 				continue;
2376 
2377 			snd_usb_mixer_interrupt_v2(mixer, msg->bAttribute,
2378 						   le16_to_cpu(msg->wValue),
2379 						   le16_to_cpu(msg->wIndex));
2380 		}
2381 	}
2382 
2383 requeue:
2384 	if (ustatus != -ENOENT &&
2385 	    ustatus != -ECONNRESET &&
2386 	    ustatus != -ESHUTDOWN) {
2387 		urb->dev = mixer->chip->dev;
2388 		usb_submit_urb(urb, GFP_ATOMIC);
2389 	}
2390 }
2391 
2392 /* create the handler for the optional status interrupt endpoint */
2393 static int snd_usb_mixer_status_create(struct usb_mixer_interface *mixer)
2394 {
2395 	struct usb_endpoint_descriptor *ep;
2396 	void *transfer_buffer;
2397 	int buffer_length;
2398 	unsigned int epnum;
2399 
2400 	/* we need one interrupt input endpoint */
2401 	if (get_iface_desc(mixer->hostif)->bNumEndpoints < 1)
2402 		return 0;
2403 	ep = get_endpoint(mixer->hostif, 0);
2404 	if (!usb_endpoint_dir_in(ep) || !usb_endpoint_xfer_int(ep))
2405 		return 0;
2406 
2407 	epnum = usb_endpoint_num(ep);
2408 	buffer_length = le16_to_cpu(ep->wMaxPacketSize);
2409 	transfer_buffer = kmalloc(buffer_length, GFP_KERNEL);
2410 	if (!transfer_buffer)
2411 		return -ENOMEM;
2412 	mixer->urb = usb_alloc_urb(0, GFP_KERNEL);
2413 	if (!mixer->urb) {
2414 		kfree(transfer_buffer);
2415 		return -ENOMEM;
2416 	}
2417 	usb_fill_int_urb(mixer->urb, mixer->chip->dev,
2418 			 usb_rcvintpipe(mixer->chip->dev, epnum),
2419 			 transfer_buffer, buffer_length,
2420 			 snd_usb_mixer_interrupt, mixer, ep->bInterval);
2421 	usb_submit_urb(mixer->urb, GFP_KERNEL);
2422 	return 0;
2423 }
2424 
2425 int snd_usb_create_mixer(struct snd_usb_audio *chip, int ctrlif,
2426 			 int ignore_error)
2427 {
2428 	static struct snd_device_ops dev_ops = {
2429 		.dev_free = snd_usb_mixer_dev_free
2430 	};
2431 	struct usb_mixer_interface *mixer;
2432 	struct snd_info_entry *entry;
2433 	int err;
2434 
2435 	strcpy(chip->card->mixername, "USB Mixer");
2436 
2437 	mixer = kzalloc(sizeof(*mixer), GFP_KERNEL);
2438 	if (!mixer)
2439 		return -ENOMEM;
2440 	mixer->chip = chip;
2441 	mixer->ignore_ctl_error = ignore_error;
2442 	mixer->id_elems = kcalloc(MAX_ID_ELEMS, sizeof(*mixer->id_elems),
2443 				  GFP_KERNEL);
2444 	if (!mixer->id_elems) {
2445 		kfree(mixer);
2446 		return -ENOMEM;
2447 	}
2448 
2449 	mixer->hostif = &usb_ifnum_to_if(chip->dev, ctrlif)->altsetting[0];
2450 	switch (get_iface_desc(mixer->hostif)->bInterfaceProtocol) {
2451 	case UAC_VERSION_1:
2452 	default:
2453 		mixer->protocol = UAC_VERSION_1;
2454 		break;
2455 	case UAC_VERSION_2:
2456 		mixer->protocol = UAC_VERSION_2;
2457 		break;
2458 	}
2459 
2460 	if ((err = snd_usb_mixer_controls(mixer)) < 0 ||
2461 	    (err = snd_usb_mixer_status_create(mixer)) < 0)
2462 		goto _error;
2463 
2464 	snd_usb_mixer_apply_create_quirk(mixer);
2465 
2466 	err = snd_device_new(chip->card, SNDRV_DEV_CODEC, mixer, &dev_ops);
2467 	if (err < 0)
2468 		goto _error;
2469 
2470 	if (list_empty(&chip->mixer_list) &&
2471 	    !snd_card_proc_new(chip->card, "usbmixer", &entry))
2472 		snd_info_set_text_ops(entry, chip, snd_usb_mixer_proc_read);
2473 
2474 	list_add(&mixer->list, &chip->mixer_list);
2475 	return 0;
2476 
2477 _error:
2478 	snd_usb_mixer_free(mixer);
2479 	return err;
2480 }
2481 
2482 void snd_usb_mixer_disconnect(struct usb_mixer_interface *mixer)
2483 {
2484 	usb_kill_urb(mixer->urb);
2485 	usb_kill_urb(mixer->rc_urb);
2486 }
2487 
2488 #ifdef CONFIG_PM
2489 /* stop any bus activity of a mixer */
2490 static void snd_usb_mixer_inactivate(struct usb_mixer_interface *mixer)
2491 {
2492 	usb_kill_urb(mixer->urb);
2493 	usb_kill_urb(mixer->rc_urb);
2494 }
2495 
2496 static int snd_usb_mixer_activate(struct usb_mixer_interface *mixer)
2497 {
2498 	int err;
2499 
2500 	if (mixer->urb) {
2501 		err = usb_submit_urb(mixer->urb, GFP_NOIO);
2502 		if (err < 0)
2503 			return err;
2504 	}
2505 
2506 	return 0;
2507 }
2508 
2509 int snd_usb_mixer_suspend(struct usb_mixer_interface *mixer)
2510 {
2511 	snd_usb_mixer_inactivate(mixer);
2512 	return 0;
2513 }
2514 
2515 static int restore_mixer_value(struct usb_mixer_elem_list *list)
2516 {
2517 	struct usb_mixer_elem_info *cval = (struct usb_mixer_elem_info *)list;
2518 	int c, err, idx;
2519 
2520 	if (cval->cmask) {
2521 		idx = 0;
2522 		for (c = 0; c < MAX_CHANNELS; c++) {
2523 			if (!(cval->cmask & (1 << c)))
2524 				continue;
2525 			if (cval->cached & (1 << c)) {
2526 				err = snd_usb_set_cur_mix_value(cval, c + 1, idx,
2527 							cval->cache_val[idx]);
2528 				if (err < 0)
2529 					return err;
2530 			}
2531 			idx++;
2532 		}
2533 	} else {
2534 		/* master */
2535 		if (cval->cached) {
2536 			err = snd_usb_set_cur_mix_value(cval, 0, 0, *cval->cache_val);
2537 			if (err < 0)
2538 				return err;
2539 		}
2540 	}
2541 
2542 	return 0;
2543 }
2544 
2545 int snd_usb_mixer_resume(struct usb_mixer_interface *mixer, bool reset_resume)
2546 {
2547 	struct usb_mixer_elem_list *list;
2548 	int id, err;
2549 
2550 	if (reset_resume) {
2551 		/* restore cached mixer values */
2552 		for (id = 0; id < MAX_ID_ELEMS; id++) {
2553 			for (list = mixer->id_elems[id]; list;
2554 			     list = list->next_id_elem) {
2555 				if (list->resume) {
2556 					err = list->resume(list);
2557 					if (err < 0)
2558 						return err;
2559 				}
2560 			}
2561 		}
2562 	}
2563 
2564 	return snd_usb_mixer_activate(mixer);
2565 }
2566 #endif
2567 
2568 void snd_usb_mixer_elem_init_std(struct usb_mixer_elem_list *list,
2569 				 struct usb_mixer_interface *mixer,
2570 				 int unitid)
2571 {
2572 	list->mixer = mixer;
2573 	list->id = unitid;
2574 	list->dump = snd_usb_mixer_dump_cval;
2575 #ifdef CONFIG_PM
2576 	list->resume = restore_mixer_value;
2577 #endif
2578 }
2579