xref: /openbmc/linux/sound/usb/mixer.c (revision 3821a065)
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 static int uac2_ctl_value_size(int val_type)
286 {
287 	switch (val_type) {
288 	case USB_MIXER_S32:
289 	case USB_MIXER_U32:
290 		return 4;
291 	case USB_MIXER_S16:
292 	case USB_MIXER_U16:
293 		return 2;
294 	default:
295 		return 1;
296 	}
297 	return 0; /* unreachable */
298 }
299 
300 
301 /*
302  * retrieve a mixer value
303  */
304 
305 static int get_ctl_value_v1(struct usb_mixer_elem_info *cval, int request,
306 			    int validx, int *value_ret)
307 {
308 	struct snd_usb_audio *chip = cval->head.mixer->chip;
309 	unsigned char buf[2];
310 	int val_len = cval->val_type >= USB_MIXER_S16 ? 2 : 1;
311 	int timeout = 10;
312 	int idx = 0, err;
313 
314 	err = snd_usb_lock_shutdown(chip);
315 	if (err < 0)
316 		return -EIO;
317 
318 	while (timeout-- > 0) {
319 		idx = snd_usb_ctrl_intf(chip) | (cval->head.id << 8);
320 		if (snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0), request,
321 				    USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
322 				    validx, idx, buf, val_len) >= val_len) {
323 			*value_ret = convert_signed_value(cval, snd_usb_combine_bytes(buf, val_len));
324 			err = 0;
325 			goto out;
326 		}
327 	}
328 	usb_audio_dbg(chip,
329 		"cannot get ctl value: req = %#x, wValue = %#x, wIndex = %#x, type = %d\n",
330 		request, validx, idx, cval->val_type);
331 	err = -EINVAL;
332 
333  out:
334 	snd_usb_unlock_shutdown(chip);
335 	return err;
336 }
337 
338 static int get_ctl_value_v2(struct usb_mixer_elem_info *cval, int request,
339 			    int validx, int *value_ret)
340 {
341 	struct snd_usb_audio *chip = cval->head.mixer->chip;
342 	unsigned char buf[4 + 3 * sizeof(__u32)]; /* enough space for one range */
343 	unsigned char *val;
344 	int idx = 0, ret, size;
345 	__u8 bRequest;
346 
347 	if (request == UAC_GET_CUR) {
348 		bRequest = UAC2_CS_CUR;
349 		size = uac2_ctl_value_size(cval->val_type);
350 	} else {
351 		bRequest = UAC2_CS_RANGE;
352 		size = sizeof(buf);
353 	}
354 
355 	memset(buf, 0, sizeof(buf));
356 
357 	ret = snd_usb_lock_shutdown(chip) ? -EIO : 0;
358 	if (ret)
359 		goto error;
360 
361 	idx = snd_usb_ctrl_intf(chip) | (cval->head.id << 8);
362 	ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0), bRequest,
363 			      USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
364 			      validx, idx, buf, size);
365 	snd_usb_unlock_shutdown(chip);
366 
367 	if (ret < 0) {
368 error:
369 		usb_audio_err(chip,
370 			"cannot get ctl value: req = %#x, wValue = %#x, wIndex = %#x, type = %d\n",
371 			request, validx, idx, cval->val_type);
372 		return ret;
373 	}
374 
375 	/* FIXME: how should we handle multiple triplets here? */
376 
377 	switch (request) {
378 	case UAC_GET_CUR:
379 		val = buf;
380 		break;
381 	case UAC_GET_MIN:
382 		val = buf + sizeof(__u16);
383 		break;
384 	case UAC_GET_MAX:
385 		val = buf + sizeof(__u16) * 2;
386 		break;
387 	case UAC_GET_RES:
388 		val = buf + sizeof(__u16) * 3;
389 		break;
390 	default:
391 		return -EINVAL;
392 	}
393 
394 	*value_ret = convert_signed_value(cval, snd_usb_combine_bytes(val, sizeof(__u16)));
395 
396 	return 0;
397 }
398 
399 static int get_ctl_value(struct usb_mixer_elem_info *cval, int request,
400 			 int validx, int *value_ret)
401 {
402 	validx += cval->idx_off;
403 
404 	return (cval->head.mixer->protocol == UAC_VERSION_1) ?
405 		get_ctl_value_v1(cval, request, validx, value_ret) :
406 		get_ctl_value_v2(cval, request, validx, value_ret);
407 }
408 
409 static int get_cur_ctl_value(struct usb_mixer_elem_info *cval,
410 			     int validx, int *value)
411 {
412 	return get_ctl_value(cval, UAC_GET_CUR, validx, value);
413 }
414 
415 /* channel = 0: master, 1 = first channel */
416 static inline int get_cur_mix_raw(struct usb_mixer_elem_info *cval,
417 				  int channel, int *value)
418 {
419 	return get_ctl_value(cval, UAC_GET_CUR,
420 			     (cval->control << 8) | channel,
421 			     value);
422 }
423 
424 int snd_usb_get_cur_mix_value(struct usb_mixer_elem_info *cval,
425 			     int channel, int index, int *value)
426 {
427 	int err;
428 
429 	if (cval->cached & (1 << channel)) {
430 		*value = cval->cache_val[index];
431 		return 0;
432 	}
433 	err = get_cur_mix_raw(cval, channel, value);
434 	if (err < 0) {
435 		if (!cval->head.mixer->ignore_ctl_error)
436 			usb_audio_dbg(cval->head.mixer->chip,
437 				"cannot get current value for control %d ch %d: err = %d\n",
438 				      cval->control, channel, err);
439 		return err;
440 	}
441 	cval->cached |= 1 << channel;
442 	cval->cache_val[index] = *value;
443 	return 0;
444 }
445 
446 /*
447  * set a mixer value
448  */
449 
450 int snd_usb_mixer_set_ctl_value(struct usb_mixer_elem_info *cval,
451 				int request, int validx, int value_set)
452 {
453 	struct snd_usb_audio *chip = cval->head.mixer->chip;
454 	unsigned char buf[4];
455 	int idx = 0, val_len, err, timeout = 10;
456 
457 	validx += cval->idx_off;
458 
459 	if (cval->head.mixer->protocol == UAC_VERSION_1) {
460 		val_len = cval->val_type >= USB_MIXER_S16 ? 2 : 1;
461 	} else { /* UAC_VERSION_2 */
462 		val_len = uac2_ctl_value_size(cval->val_type);
463 
464 		/* FIXME */
465 		if (request != UAC_SET_CUR) {
466 			usb_audio_dbg(chip, "RANGE setting not yet supported\n");
467 			return -EINVAL;
468 		}
469 
470 		request = UAC2_CS_CUR;
471 	}
472 
473 	value_set = convert_bytes_value(cval, value_set);
474 	buf[0] = value_set & 0xff;
475 	buf[1] = (value_set >> 8) & 0xff;
476 	buf[2] = (value_set >> 16) & 0xff;
477 	buf[3] = (value_set >> 24) & 0xff;
478 
479 	err = snd_usb_lock_shutdown(chip);
480 	if (err < 0)
481 		return -EIO;
482 
483 	while (timeout-- > 0) {
484 		idx = snd_usb_ctrl_intf(chip) | (cval->head.id << 8);
485 		if (snd_usb_ctl_msg(chip->dev,
486 				    usb_sndctrlpipe(chip->dev, 0), request,
487 				    USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
488 				    validx, idx, buf, val_len) >= 0) {
489 			err = 0;
490 			goto out;
491 		}
492 	}
493 	usb_audio_dbg(chip, "cannot set ctl value: req = %#x, wValue = %#x, wIndex = %#x, type = %d, data = %#x/%#x\n",
494 		      request, validx, idx, cval->val_type, buf[0], buf[1]);
495 	err = -EINVAL;
496 
497  out:
498 	snd_usb_unlock_shutdown(chip);
499 	return err;
500 }
501 
502 static int set_cur_ctl_value(struct usb_mixer_elem_info *cval,
503 			     int validx, int value)
504 {
505 	return snd_usb_mixer_set_ctl_value(cval, UAC_SET_CUR, validx, value);
506 }
507 
508 int snd_usb_set_cur_mix_value(struct usb_mixer_elem_info *cval, int channel,
509 			     int index, int value)
510 {
511 	int err;
512 	unsigned int read_only = (channel == 0) ?
513 		cval->master_readonly :
514 		cval->ch_readonly & (1 << (channel - 1));
515 
516 	if (read_only) {
517 		usb_audio_dbg(cval->head.mixer->chip,
518 			      "%s(): channel %d of control %d is read_only\n",
519 			    __func__, channel, cval->control);
520 		return 0;
521 	}
522 
523 	err = snd_usb_mixer_set_ctl_value(cval,
524 					  UAC_SET_CUR, (cval->control << 8) | channel,
525 					  value);
526 	if (err < 0)
527 		return err;
528 	cval->cached |= 1 << channel;
529 	cval->cache_val[index] = value;
530 	return 0;
531 }
532 
533 /*
534  * TLV callback for mixer volume controls
535  */
536 int snd_usb_mixer_vol_tlv(struct snd_kcontrol *kcontrol, int op_flag,
537 			 unsigned int size, unsigned int __user *_tlv)
538 {
539 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
540 	DECLARE_TLV_DB_MINMAX(scale, 0, 0);
541 
542 	if (size < sizeof(scale))
543 		return -ENOMEM;
544 	scale[2] = cval->dBmin;
545 	scale[3] = cval->dBmax;
546 	if (copy_to_user(_tlv, scale, sizeof(scale)))
547 		return -EFAULT;
548 	return 0;
549 }
550 
551 /*
552  * parser routines begin here...
553  */
554 
555 static int parse_audio_unit(struct mixer_build *state, int unitid);
556 
557 
558 /*
559  * check if the input/output channel routing is enabled on the given bitmap.
560  * used for mixer unit parser
561  */
562 static int check_matrix_bitmap(unsigned char *bmap,
563 			       int ich, int och, int num_outs)
564 {
565 	int idx = ich * num_outs + och;
566 	return bmap[idx >> 3] & (0x80 >> (idx & 7));
567 }
568 
569 /*
570  * add an alsa control element
571  * search and increment the index until an empty slot is found.
572  *
573  * if failed, give up and free the control instance.
574  */
575 
576 int snd_usb_mixer_add_control(struct usb_mixer_elem_list *list,
577 			      struct snd_kcontrol *kctl)
578 {
579 	struct usb_mixer_interface *mixer = list->mixer;
580 	int err;
581 
582 	while (snd_ctl_find_id(mixer->chip->card, &kctl->id))
583 		kctl->id.index++;
584 	if ((err = snd_ctl_add(mixer->chip->card, kctl)) < 0) {
585 		usb_audio_dbg(mixer->chip, "cannot add control (err = %d)\n",
586 			      err);
587 		return err;
588 	}
589 	list->kctl = kctl;
590 	list->next_id_elem = mixer->id_elems[list->id];
591 	mixer->id_elems[list->id] = list;
592 	return 0;
593 }
594 
595 /*
596  * get a terminal name string
597  */
598 
599 static struct iterm_name_combo {
600 	int type;
601 	char *name;
602 } iterm_names[] = {
603 	{ 0x0300, "Output" },
604 	{ 0x0301, "Speaker" },
605 	{ 0x0302, "Headphone" },
606 	{ 0x0303, "HMD Audio" },
607 	{ 0x0304, "Desktop Speaker" },
608 	{ 0x0305, "Room Speaker" },
609 	{ 0x0306, "Com Speaker" },
610 	{ 0x0307, "LFE" },
611 	{ 0x0600, "External In" },
612 	{ 0x0601, "Analog In" },
613 	{ 0x0602, "Digital In" },
614 	{ 0x0603, "Line" },
615 	{ 0x0604, "Legacy In" },
616 	{ 0x0605, "IEC958 In" },
617 	{ 0x0606, "1394 DA Stream" },
618 	{ 0x0607, "1394 DV Stream" },
619 	{ 0x0700, "Embedded" },
620 	{ 0x0701, "Noise Source" },
621 	{ 0x0702, "Equalization Noise" },
622 	{ 0x0703, "CD" },
623 	{ 0x0704, "DAT" },
624 	{ 0x0705, "DCC" },
625 	{ 0x0706, "MiniDisk" },
626 	{ 0x0707, "Analog Tape" },
627 	{ 0x0708, "Phonograph" },
628 	{ 0x0709, "VCR Audio" },
629 	{ 0x070a, "Video Disk Audio" },
630 	{ 0x070b, "DVD Audio" },
631 	{ 0x070c, "TV Tuner Audio" },
632 	{ 0x070d, "Satellite Rec Audio" },
633 	{ 0x070e, "Cable Tuner Audio" },
634 	{ 0x070f, "DSS Audio" },
635 	{ 0x0710, "Radio Receiver" },
636 	{ 0x0711, "Radio Transmitter" },
637 	{ 0x0712, "Multi-Track Recorder" },
638 	{ 0x0713, "Synthesizer" },
639 	{ 0 },
640 };
641 
642 static int get_term_name(struct mixer_build *state, struct usb_audio_term *iterm,
643 			 unsigned char *name, int maxlen, int term_only)
644 {
645 	struct iterm_name_combo *names;
646 
647 	if (iterm->name)
648 		return snd_usb_copy_string_desc(state, iterm->name,
649 						name, maxlen);
650 
651 	/* virtual type - not a real terminal */
652 	if (iterm->type >> 16) {
653 		if (term_only)
654 			return 0;
655 		switch (iterm->type >> 16) {
656 		case UAC_SELECTOR_UNIT:
657 			strcpy(name, "Selector");
658 			return 8;
659 		case UAC1_PROCESSING_UNIT:
660 			strcpy(name, "Process Unit");
661 			return 12;
662 		case UAC1_EXTENSION_UNIT:
663 			strcpy(name, "Ext Unit");
664 			return 8;
665 		case UAC_MIXER_UNIT:
666 			strcpy(name, "Mixer");
667 			return 5;
668 		default:
669 			return sprintf(name, "Unit %d", iterm->id);
670 		}
671 	}
672 
673 	switch (iterm->type & 0xff00) {
674 	case 0x0100:
675 		strcpy(name, "PCM");
676 		return 3;
677 	case 0x0200:
678 		strcpy(name, "Mic");
679 		return 3;
680 	case 0x0400:
681 		strcpy(name, "Headset");
682 		return 7;
683 	case 0x0500:
684 		strcpy(name, "Phone");
685 		return 5;
686 	}
687 
688 	for (names = iterm_names; names->type; names++) {
689 		if (names->type == iterm->type) {
690 			strcpy(name, names->name);
691 			return strlen(names->name);
692 		}
693 	}
694 
695 	return 0;
696 }
697 
698 /*
699  * parse the source unit recursively until it reaches to a terminal
700  * or a branched unit.
701  */
702 static int check_input_term(struct mixer_build *state, int id,
703 			    struct usb_audio_term *term)
704 {
705 	int err;
706 	void *p1;
707 
708 	memset(term, 0, sizeof(*term));
709 	while ((p1 = find_audio_control_unit(state, id)) != NULL) {
710 		unsigned char *hdr = p1;
711 		term->id = id;
712 		switch (hdr[2]) {
713 		case UAC_INPUT_TERMINAL:
714 			if (state->mixer->protocol == UAC_VERSION_1) {
715 				struct uac_input_terminal_descriptor *d = p1;
716 				term->type = le16_to_cpu(d->wTerminalType);
717 				term->channels = d->bNrChannels;
718 				term->chconfig = le16_to_cpu(d->wChannelConfig);
719 				term->name = d->iTerminal;
720 			} else { /* UAC_VERSION_2 */
721 				struct uac2_input_terminal_descriptor *d = p1;
722 
723 				/* call recursively to verify that the
724 				 * referenced clock entity is valid */
725 				err = check_input_term(state, d->bCSourceID, term);
726 				if (err < 0)
727 					return err;
728 
729 				/* save input term properties after recursion,
730 				 * to ensure they are not overriden by the
731 				 * recursion calls */
732 				term->id = id;
733 				term->type = le16_to_cpu(d->wTerminalType);
734 				term->channels = d->bNrChannels;
735 				term->chconfig = le32_to_cpu(d->bmChannelConfig);
736 				term->name = d->iTerminal;
737 			}
738 			return 0;
739 		case UAC_FEATURE_UNIT: {
740 			/* the header is the same for v1 and v2 */
741 			struct uac_feature_unit_descriptor *d = p1;
742 			id = d->bSourceID;
743 			break; /* continue to parse */
744 		}
745 		case UAC_MIXER_UNIT: {
746 			struct uac_mixer_unit_descriptor *d = p1;
747 			term->type = d->bDescriptorSubtype << 16; /* virtual type */
748 			term->channels = uac_mixer_unit_bNrChannels(d);
749 			term->chconfig = uac_mixer_unit_wChannelConfig(d, state->mixer->protocol);
750 			term->name = uac_mixer_unit_iMixer(d);
751 			return 0;
752 		}
753 		case UAC_SELECTOR_UNIT:
754 		case UAC2_CLOCK_SELECTOR: {
755 			struct uac_selector_unit_descriptor *d = p1;
756 			/* call recursively to retrieve the channel info */
757 			err = check_input_term(state, d->baSourceID[0], term);
758 			if (err < 0)
759 				return err;
760 			term->type = d->bDescriptorSubtype << 16; /* virtual type */
761 			term->id = id;
762 			term->name = uac_selector_unit_iSelector(d);
763 			return 0;
764 		}
765 		case UAC1_PROCESSING_UNIT:
766 		case UAC1_EXTENSION_UNIT:
767 		/* UAC2_PROCESSING_UNIT_V2 */
768 		/* UAC2_EFFECT_UNIT */
769 		case UAC2_EXTENSION_UNIT_V2: {
770 			struct uac_processing_unit_descriptor *d = p1;
771 
772 			if (state->mixer->protocol == UAC_VERSION_2 &&
773 				hdr[2] == UAC2_EFFECT_UNIT) {
774 				/* UAC2/UAC1 unit IDs overlap here in an
775 				 * uncompatible way. Ignore this unit for now.
776 				 */
777 				return 0;
778 			}
779 
780 			if (d->bNrInPins) {
781 				id = d->baSourceID[0];
782 				break; /* continue to parse */
783 			}
784 			term->type = d->bDescriptorSubtype << 16; /* virtual type */
785 			term->channels = uac_processing_unit_bNrChannels(d);
786 			term->chconfig = uac_processing_unit_wChannelConfig(d, state->mixer->protocol);
787 			term->name = uac_processing_unit_iProcessing(d, state->mixer->protocol);
788 			return 0;
789 		}
790 		case UAC2_CLOCK_SOURCE: {
791 			struct uac_clock_source_descriptor *d = p1;
792 			term->type = d->bDescriptorSubtype << 16; /* virtual type */
793 			term->id = id;
794 			term->name = d->iClockSource;
795 			return 0;
796 		}
797 		default:
798 			return -ENODEV;
799 		}
800 	}
801 	return -ENODEV;
802 }
803 
804 /*
805  * Feature Unit
806  */
807 
808 /* feature unit control information */
809 struct usb_feature_control_info {
810 	const char *name;
811 	int type;	/* data type for uac1 */
812 	int type_uac2;	/* data type for uac2 if different from uac1, else -1 */
813 };
814 
815 static struct usb_feature_control_info audio_feature_info[] = {
816 	{ "Mute",			USB_MIXER_INV_BOOLEAN, -1 },
817 	{ "Volume",			USB_MIXER_S16, -1 },
818 	{ "Tone Control - Bass",	USB_MIXER_S8, -1 },
819 	{ "Tone Control - Mid",		USB_MIXER_S8, -1 },
820 	{ "Tone Control - Treble",	USB_MIXER_S8, -1 },
821 	{ "Graphic Equalizer",		USB_MIXER_S8, -1 }, /* FIXME: not implemeted yet */
822 	{ "Auto Gain Control",		USB_MIXER_BOOLEAN, -1 },
823 	{ "Delay Control",		USB_MIXER_U16, USB_MIXER_U32 },
824 	{ "Bass Boost",			USB_MIXER_BOOLEAN, -1 },
825 	{ "Loudness",			USB_MIXER_BOOLEAN, -1 },
826 	/* UAC2 specific */
827 	{ "Input Gain Control",		USB_MIXER_S16, -1 },
828 	{ "Input Gain Pad Control",	USB_MIXER_S16, -1 },
829 	{ "Phase Inverter Control",	USB_MIXER_BOOLEAN, -1 },
830 };
831 
832 /* private_free callback */
833 void snd_usb_mixer_elem_free(struct snd_kcontrol *kctl)
834 {
835 	kfree(kctl->private_data);
836 	kctl->private_data = NULL;
837 }
838 
839 /*
840  * interface to ALSA control for feature/mixer units
841  */
842 
843 /* volume control quirks */
844 static void volume_control_quirks(struct usb_mixer_elem_info *cval,
845 				  struct snd_kcontrol *kctl)
846 {
847 	struct snd_usb_audio *chip = cval->head.mixer->chip;
848 	switch (chip->usb_id) {
849 	case USB_ID(0x0763, 0x2030): /* M-Audio Fast Track C400 */
850 	case USB_ID(0x0763, 0x2031): /* M-Audio Fast Track C600 */
851 		if (strcmp(kctl->id.name, "Effect Duration") == 0) {
852 			cval->min = 0x0000;
853 			cval->max = 0xffff;
854 			cval->res = 0x00e6;
855 			break;
856 		}
857 		if (strcmp(kctl->id.name, "Effect Volume") == 0 ||
858 		    strcmp(kctl->id.name, "Effect Feedback Volume") == 0) {
859 			cval->min = 0x00;
860 			cval->max = 0xff;
861 			break;
862 		}
863 		if (strstr(kctl->id.name, "Effect Return") != NULL) {
864 			cval->min = 0xb706;
865 			cval->max = 0xff7b;
866 			cval->res = 0x0073;
867 			break;
868 		}
869 		if ((strstr(kctl->id.name, "Playback Volume") != NULL) ||
870 			(strstr(kctl->id.name, "Effect Send") != NULL)) {
871 			cval->min = 0xb5fb; /* -73 dB = 0xb6ff */
872 			cval->max = 0xfcfe;
873 			cval->res = 0x0073;
874 		}
875 		break;
876 
877 	case USB_ID(0x0763, 0x2081): /* M-Audio Fast Track Ultra 8R */
878 	case USB_ID(0x0763, 0x2080): /* M-Audio Fast Track Ultra */
879 		if (strcmp(kctl->id.name, "Effect Duration") == 0) {
880 			usb_audio_info(chip,
881 				       "set quirk for FTU Effect Duration\n");
882 			cval->min = 0x0000;
883 			cval->max = 0x7f00;
884 			cval->res = 0x0100;
885 			break;
886 		}
887 		if (strcmp(kctl->id.name, "Effect Volume") == 0 ||
888 		    strcmp(kctl->id.name, "Effect Feedback Volume") == 0) {
889 			usb_audio_info(chip,
890 				       "set quirks for FTU Effect Feedback/Volume\n");
891 			cval->min = 0x00;
892 			cval->max = 0x7f;
893 			break;
894 		}
895 		break;
896 
897 	case USB_ID(0x0471, 0x0101):
898 	case USB_ID(0x0471, 0x0104):
899 	case USB_ID(0x0471, 0x0105):
900 	case USB_ID(0x0672, 0x1041):
901 	/* quirk for UDA1321/N101.
902 	 * note that detection between firmware 2.1.1.7 (N101)
903 	 * and later 2.1.1.21 is not very clear from datasheets.
904 	 * I hope that the min value is -15360 for newer firmware --jk
905 	 */
906 		if (!strcmp(kctl->id.name, "PCM Playback Volume") &&
907 		    cval->min == -15616) {
908 			usb_audio_info(chip,
909 				 "set volume quirk for UDA1321/N101 chip\n");
910 			cval->max = -256;
911 		}
912 		break;
913 
914 	case USB_ID(0x046d, 0x09a4):
915 		if (!strcmp(kctl->id.name, "Mic Capture Volume")) {
916 			usb_audio_info(chip,
917 				"set volume quirk for QuickCam E3500\n");
918 			cval->min = 6080;
919 			cval->max = 8768;
920 			cval->res = 192;
921 		}
922 		break;
923 
924 	case USB_ID(0x046d, 0x0807): /* Logitech Webcam C500 */
925 	case USB_ID(0x046d, 0x0808):
926 	case USB_ID(0x046d, 0x0809):
927 	case USB_ID(0x046d, 0x0819): /* Logitech Webcam C210 */
928 	case USB_ID(0x046d, 0x081b): /* HD Webcam c310 */
929 	case USB_ID(0x046d, 0x081d): /* HD Webcam c510 */
930 	case USB_ID(0x046d, 0x0825): /* HD Webcam c270 */
931 	case USB_ID(0x046d, 0x0826): /* HD Webcam c525 */
932 	case USB_ID(0x046d, 0x08ca): /* Logitech Quickcam Fusion */
933 	case USB_ID(0x046d, 0x0991):
934 	/* Most audio usb devices lie about volume resolution.
935 	 * Most Logitech webcams have res = 384.
936 	 * Proboly there is some logitech magic behind this number --fishor
937 	 */
938 		if (!strcmp(kctl->id.name, "Mic Capture Volume")) {
939 			usb_audio_info(chip,
940 				"set resolution quirk: cval->res = 384\n");
941 			cval->res = 384;
942 		}
943 		break;
944 	}
945 }
946 
947 /*
948  * retrieve the minimum and maximum values for the specified control
949  */
950 static int get_min_max_with_quirks(struct usb_mixer_elem_info *cval,
951 				   int default_min, struct snd_kcontrol *kctl)
952 {
953 	/* for failsafe */
954 	cval->min = default_min;
955 	cval->max = cval->min + 1;
956 	cval->res = 1;
957 	cval->dBmin = cval->dBmax = 0;
958 
959 	if (cval->val_type == USB_MIXER_BOOLEAN ||
960 	    cval->val_type == USB_MIXER_INV_BOOLEAN) {
961 		cval->initialized = 1;
962 	} else {
963 		int minchn = 0;
964 		if (cval->cmask) {
965 			int i;
966 			for (i = 0; i < MAX_CHANNELS; i++)
967 				if (cval->cmask & (1 << i)) {
968 					minchn = i + 1;
969 					break;
970 				}
971 		}
972 		if (get_ctl_value(cval, UAC_GET_MAX, (cval->control << 8) | minchn, &cval->max) < 0 ||
973 		    get_ctl_value(cval, UAC_GET_MIN, (cval->control << 8) | minchn, &cval->min) < 0) {
974 			usb_audio_err(cval->head.mixer->chip,
975 				      "%d:%d: cannot get min/max values for control %d (id %d)\n",
976 				   cval->head.id, snd_usb_ctrl_intf(cval->head.mixer->chip),
977 							       cval->control, cval->head.id);
978 			return -EINVAL;
979 		}
980 		if (get_ctl_value(cval, UAC_GET_RES,
981 				  (cval->control << 8) | minchn,
982 				  &cval->res) < 0) {
983 			cval->res = 1;
984 		} else {
985 			int last_valid_res = cval->res;
986 
987 			while (cval->res > 1) {
988 				if (snd_usb_mixer_set_ctl_value(cval, UAC_SET_RES,
989 								(cval->control << 8) | minchn,
990 								cval->res / 2) < 0)
991 					break;
992 				cval->res /= 2;
993 			}
994 			if (get_ctl_value(cval, UAC_GET_RES,
995 					  (cval->control << 8) | minchn, &cval->res) < 0)
996 				cval->res = last_valid_res;
997 		}
998 		if (cval->res == 0)
999 			cval->res = 1;
1000 
1001 		/* Additional checks for the proper resolution
1002 		 *
1003 		 * Some devices report smaller resolutions than actually
1004 		 * reacting.  They don't return errors but simply clip
1005 		 * to the lower aligned value.
1006 		 */
1007 		if (cval->min + cval->res < cval->max) {
1008 			int last_valid_res = cval->res;
1009 			int saved, test, check;
1010 			get_cur_mix_raw(cval, minchn, &saved);
1011 			for (;;) {
1012 				test = saved;
1013 				if (test < cval->max)
1014 					test += cval->res;
1015 				else
1016 					test -= cval->res;
1017 				if (test < cval->min || test > cval->max ||
1018 				    snd_usb_set_cur_mix_value(cval, minchn, 0, test) ||
1019 				    get_cur_mix_raw(cval, minchn, &check)) {
1020 					cval->res = last_valid_res;
1021 					break;
1022 				}
1023 				if (test == check)
1024 					break;
1025 				cval->res *= 2;
1026 			}
1027 			snd_usb_set_cur_mix_value(cval, minchn, 0, saved);
1028 		}
1029 
1030 		cval->initialized = 1;
1031 	}
1032 
1033 	if (kctl)
1034 		volume_control_quirks(cval, kctl);
1035 
1036 	/* USB descriptions contain the dB scale in 1/256 dB unit
1037 	 * while ALSA TLV contains in 1/100 dB unit
1038 	 */
1039 	cval->dBmin = (convert_signed_value(cval, cval->min) * 100) / 256;
1040 	cval->dBmax = (convert_signed_value(cval, cval->max) * 100) / 256;
1041 	if (cval->dBmin > cval->dBmax) {
1042 		/* something is wrong; assume it's either from/to 0dB */
1043 		if (cval->dBmin < 0)
1044 			cval->dBmax = 0;
1045 		else if (cval->dBmin > 0)
1046 			cval->dBmin = 0;
1047 		if (cval->dBmin > cval->dBmax) {
1048 			/* totally crap, return an error */
1049 			return -EINVAL;
1050 		}
1051 	}
1052 
1053 	return 0;
1054 }
1055 
1056 #define get_min_max(cval, def)	get_min_max_with_quirks(cval, def, NULL)
1057 
1058 /* get a feature/mixer unit info */
1059 static int mixer_ctl_feature_info(struct snd_kcontrol *kcontrol,
1060 				  struct snd_ctl_elem_info *uinfo)
1061 {
1062 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1063 
1064 	if (cval->val_type == USB_MIXER_BOOLEAN ||
1065 	    cval->val_type == USB_MIXER_INV_BOOLEAN)
1066 		uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1067 	else
1068 		uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
1069 	uinfo->count = cval->channels;
1070 	if (cval->val_type == USB_MIXER_BOOLEAN ||
1071 	    cval->val_type == USB_MIXER_INV_BOOLEAN) {
1072 		uinfo->value.integer.min = 0;
1073 		uinfo->value.integer.max = 1;
1074 	} else {
1075 		if (!cval->initialized) {
1076 			get_min_max_with_quirks(cval, 0, kcontrol);
1077 			if (cval->initialized && cval->dBmin >= cval->dBmax) {
1078 				kcontrol->vd[0].access &=
1079 					~(SNDRV_CTL_ELEM_ACCESS_TLV_READ |
1080 					  SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK);
1081 				snd_ctl_notify(cval->head.mixer->chip->card,
1082 					       SNDRV_CTL_EVENT_MASK_INFO,
1083 					       &kcontrol->id);
1084 			}
1085 		}
1086 		uinfo->value.integer.min = 0;
1087 		uinfo->value.integer.max =
1088 			(cval->max - cval->min + cval->res - 1) / cval->res;
1089 	}
1090 	return 0;
1091 }
1092 
1093 /* get the current value from feature/mixer unit */
1094 static int mixer_ctl_feature_get(struct snd_kcontrol *kcontrol,
1095 				 struct snd_ctl_elem_value *ucontrol)
1096 {
1097 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1098 	int c, cnt, val, err;
1099 
1100 	ucontrol->value.integer.value[0] = cval->min;
1101 	if (cval->cmask) {
1102 		cnt = 0;
1103 		for (c = 0; c < MAX_CHANNELS; c++) {
1104 			if (!(cval->cmask & (1 << c)))
1105 				continue;
1106 			err = snd_usb_get_cur_mix_value(cval, c + 1, cnt, &val);
1107 			if (err < 0)
1108 				return filter_error(cval, err);
1109 			val = get_relative_value(cval, val);
1110 			ucontrol->value.integer.value[cnt] = val;
1111 			cnt++;
1112 		}
1113 		return 0;
1114 	} else {
1115 		/* master channel */
1116 		err = snd_usb_get_cur_mix_value(cval, 0, 0, &val);
1117 		if (err < 0)
1118 			return filter_error(cval, err);
1119 		val = get_relative_value(cval, val);
1120 		ucontrol->value.integer.value[0] = val;
1121 	}
1122 	return 0;
1123 }
1124 
1125 /* put the current value to feature/mixer unit */
1126 static int mixer_ctl_feature_put(struct snd_kcontrol *kcontrol,
1127 				 struct snd_ctl_elem_value *ucontrol)
1128 {
1129 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1130 	int c, cnt, val, oval, err;
1131 	int changed = 0;
1132 
1133 	if (cval->cmask) {
1134 		cnt = 0;
1135 		for (c = 0; c < MAX_CHANNELS; c++) {
1136 			if (!(cval->cmask & (1 << c)))
1137 				continue;
1138 			err = snd_usb_get_cur_mix_value(cval, c + 1, cnt, &oval);
1139 			if (err < 0)
1140 				return filter_error(cval, err);
1141 			val = ucontrol->value.integer.value[cnt];
1142 			val = get_abs_value(cval, val);
1143 			if (oval != val) {
1144 				snd_usb_set_cur_mix_value(cval, c + 1, cnt, val);
1145 				changed = 1;
1146 			}
1147 			cnt++;
1148 		}
1149 	} else {
1150 		/* master channel */
1151 		err = snd_usb_get_cur_mix_value(cval, 0, 0, &oval);
1152 		if (err < 0)
1153 			return filter_error(cval, err);
1154 		val = ucontrol->value.integer.value[0];
1155 		val = get_abs_value(cval, val);
1156 		if (val != oval) {
1157 			snd_usb_set_cur_mix_value(cval, 0, 0, val);
1158 			changed = 1;
1159 		}
1160 	}
1161 	return changed;
1162 }
1163 
1164 static struct snd_kcontrol_new usb_feature_unit_ctl = {
1165 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
1166 	.name = "", /* will be filled later manually */
1167 	.info = mixer_ctl_feature_info,
1168 	.get = mixer_ctl_feature_get,
1169 	.put = mixer_ctl_feature_put,
1170 };
1171 
1172 /* the read-only variant */
1173 static struct snd_kcontrol_new usb_feature_unit_ctl_ro = {
1174 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
1175 	.name = "", /* will be filled later manually */
1176 	.info = mixer_ctl_feature_info,
1177 	.get = mixer_ctl_feature_get,
1178 	.put = NULL,
1179 };
1180 
1181 /*
1182  * This symbol is exported in order to allow the mixer quirks to
1183  * hook up to the standard feature unit control mechanism
1184  */
1185 struct snd_kcontrol_new *snd_usb_feature_unit_ctl = &usb_feature_unit_ctl;
1186 
1187 /*
1188  * build a feature control
1189  */
1190 static size_t append_ctl_name(struct snd_kcontrol *kctl, const char *str)
1191 {
1192 	return strlcat(kctl->id.name, str, sizeof(kctl->id.name));
1193 }
1194 
1195 /*
1196  * A lot of headsets/headphones have a "Speaker" mixer. Make sure we
1197  * rename it to "Headphone". We determine if something is a headphone
1198  * similar to how udev determines form factor.
1199  */
1200 static void check_no_speaker_on_headset(struct snd_kcontrol *kctl,
1201 					struct snd_card *card)
1202 {
1203 	const char *names_to_check[] = {
1204 		"Headset", "headset", "Headphone", "headphone", NULL};
1205 	const char **s;
1206 	bool found = false;
1207 
1208 	if (strcmp("Speaker", kctl->id.name))
1209 		return;
1210 
1211 	for (s = names_to_check; *s; s++)
1212 		if (strstr(card->shortname, *s)) {
1213 			found = true;
1214 			break;
1215 		}
1216 
1217 	if (!found)
1218 		return;
1219 
1220 	strlcpy(kctl->id.name, "Headphone", sizeof(kctl->id.name));
1221 }
1222 
1223 static void build_feature_ctl(struct mixer_build *state, void *raw_desc,
1224 			      unsigned int ctl_mask, int control,
1225 			      struct usb_audio_term *iterm, int unitid,
1226 			      int readonly_mask)
1227 {
1228 	struct uac_feature_unit_descriptor *desc = raw_desc;
1229 	struct usb_feature_control_info *ctl_info;
1230 	unsigned int len = 0;
1231 	int mapped_name = 0;
1232 	int nameid = uac_feature_unit_iFeature(desc);
1233 	struct snd_kcontrol *kctl;
1234 	struct usb_mixer_elem_info *cval;
1235 	const struct usbmix_name_map *map;
1236 	unsigned int range;
1237 
1238 	control++; /* change from zero-based to 1-based value */
1239 
1240 	if (control == UAC_FU_GRAPHIC_EQUALIZER) {
1241 		/* FIXME: not supported yet */
1242 		return;
1243 	}
1244 
1245 	map = find_map(state, unitid, control);
1246 	if (check_ignored_ctl(map))
1247 		return;
1248 
1249 	cval = kzalloc(sizeof(*cval), GFP_KERNEL);
1250 	if (!cval)
1251 		return;
1252 	snd_usb_mixer_elem_init_std(&cval->head, state->mixer, unitid);
1253 	cval->control = control;
1254 	cval->cmask = ctl_mask;
1255 	ctl_info = &audio_feature_info[control-1];
1256 	if (state->mixer->protocol == UAC_VERSION_1)
1257 		cval->val_type = ctl_info->type;
1258 	else /* UAC_VERSION_2 */
1259 		cval->val_type = ctl_info->type_uac2 >= 0 ?
1260 			ctl_info->type_uac2 : ctl_info->type;
1261 
1262 	if (ctl_mask == 0) {
1263 		cval->channels = 1;	/* master channel */
1264 		cval->master_readonly = readonly_mask;
1265 	} else {
1266 		int i, c = 0;
1267 		for (i = 0; i < 16; i++)
1268 			if (ctl_mask & (1 << i))
1269 				c++;
1270 		cval->channels = c;
1271 		cval->ch_readonly = readonly_mask;
1272 	}
1273 
1274 	/*
1275 	 * If all channels in the mask are marked read-only, make the control
1276 	 * read-only. snd_usb_set_cur_mix_value() will check the mask again and won't
1277 	 * issue write commands to read-only channels.
1278 	 */
1279 	if (cval->channels == readonly_mask)
1280 		kctl = snd_ctl_new1(&usb_feature_unit_ctl_ro, cval);
1281 	else
1282 		kctl = snd_ctl_new1(&usb_feature_unit_ctl, cval);
1283 
1284 	if (!kctl) {
1285 		usb_audio_err(state->chip, "cannot malloc kcontrol\n");
1286 		kfree(cval);
1287 		return;
1288 	}
1289 	kctl->private_free = snd_usb_mixer_elem_free;
1290 
1291 	len = check_mapped_name(map, kctl->id.name, sizeof(kctl->id.name));
1292 	mapped_name = len != 0;
1293 	if (!len && nameid)
1294 		len = snd_usb_copy_string_desc(state, nameid,
1295 				kctl->id.name, sizeof(kctl->id.name));
1296 
1297 	switch (control) {
1298 	case UAC_FU_MUTE:
1299 	case UAC_FU_VOLUME:
1300 		/*
1301 		 * determine the control name.  the rule is:
1302 		 * - if a name id is given in descriptor, use it.
1303 		 * - if the connected input can be determined, then use the name
1304 		 *   of terminal type.
1305 		 * - if the connected output can be determined, use it.
1306 		 * - otherwise, anonymous name.
1307 		 */
1308 		if (!len) {
1309 			len = get_term_name(state, iterm, kctl->id.name,
1310 					    sizeof(kctl->id.name), 1);
1311 			if (!len)
1312 				len = get_term_name(state, &state->oterm,
1313 						    kctl->id.name,
1314 						    sizeof(kctl->id.name), 1);
1315 			if (!len)
1316 				snprintf(kctl->id.name, sizeof(kctl->id.name),
1317 					 "Feature %d", unitid);
1318 		}
1319 
1320 		if (!mapped_name)
1321 			check_no_speaker_on_headset(kctl, state->mixer->chip->card);
1322 
1323 		/*
1324 		 * determine the stream direction:
1325 		 * if the connected output is USB stream, then it's likely a
1326 		 * capture stream.  otherwise it should be playback (hopefully :)
1327 		 */
1328 		if (!mapped_name && !(state->oterm.type >> 16)) {
1329 			if ((state->oterm.type & 0xff00) == 0x0100)
1330 				append_ctl_name(kctl, " Capture");
1331 			else
1332 				append_ctl_name(kctl, " Playback");
1333 		}
1334 		append_ctl_name(kctl, control == UAC_FU_MUTE ?
1335 				" Switch" : " Volume");
1336 		break;
1337 	default:
1338 		if (!len)
1339 			strlcpy(kctl->id.name, audio_feature_info[control-1].name,
1340 				sizeof(kctl->id.name));
1341 		break;
1342 	}
1343 
1344 	/* get min/max values */
1345 	get_min_max_with_quirks(cval, 0, kctl);
1346 
1347 	if (control == UAC_FU_VOLUME) {
1348 		check_mapped_dB(map, cval);
1349 		if (cval->dBmin < cval->dBmax || !cval->initialized) {
1350 			kctl->tlv.c = snd_usb_mixer_vol_tlv;
1351 			kctl->vd[0].access |=
1352 				SNDRV_CTL_ELEM_ACCESS_TLV_READ |
1353 				SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1354 		}
1355 	}
1356 
1357 	range = (cval->max - cval->min) / cval->res;
1358 	/*
1359 	 * Are there devices with volume range more than 255? I use a bit more
1360 	 * to be sure. 384 is a resolution magic number found on Logitech
1361 	 * devices. It will definitively catch all buggy Logitech devices.
1362 	 */
1363 	if (range > 384) {
1364 		usb_audio_warn(state->chip,
1365 			       "Warning! Unlikely big volume range (=%u), cval->res is probably wrong.",
1366 			       range);
1367 		usb_audio_warn(state->chip,
1368 			       "[%d] FU [%s] ch = %d, val = %d/%d/%d",
1369 			       cval->head.id, kctl->id.name, cval->channels,
1370 			       cval->min, cval->max, cval->res);
1371 	}
1372 
1373 	usb_audio_dbg(state->chip, "[%d] FU [%s] ch = %d, val = %d/%d/%d\n",
1374 		      cval->head.id, kctl->id.name, cval->channels,
1375 		      cval->min, cval->max, cval->res);
1376 	snd_usb_mixer_add_control(&cval->head, kctl);
1377 }
1378 
1379 /*
1380  * parse a feature unit
1381  *
1382  * most of controls are defined here.
1383  */
1384 static int parse_audio_feature_unit(struct mixer_build *state, int unitid,
1385 				    void *_ftr)
1386 {
1387 	int channels, i, j;
1388 	struct usb_audio_term iterm;
1389 	unsigned int master_bits, first_ch_bits;
1390 	int err, csize;
1391 	struct uac_feature_unit_descriptor *hdr = _ftr;
1392 	__u8 *bmaControls;
1393 
1394 	if (state->mixer->protocol == UAC_VERSION_1) {
1395 		csize = hdr->bControlSize;
1396 		if (!csize) {
1397 			usb_audio_dbg(state->chip,
1398 				      "unit %u: invalid bControlSize == 0\n",
1399 				      unitid);
1400 			return -EINVAL;
1401 		}
1402 		channels = (hdr->bLength - 7) / csize - 1;
1403 		bmaControls = hdr->bmaControls;
1404 		if (hdr->bLength < 7 + csize) {
1405 			usb_audio_err(state->chip,
1406 				      "unit %u: invalid UAC_FEATURE_UNIT descriptor\n",
1407 				      unitid);
1408 			return -EINVAL;
1409 		}
1410 	} else {
1411 		struct uac2_feature_unit_descriptor *ftr = _ftr;
1412 		csize = 4;
1413 		channels = (hdr->bLength - 6) / 4 - 1;
1414 		bmaControls = ftr->bmaControls;
1415 		if (hdr->bLength < 6 + csize) {
1416 			usb_audio_err(state->chip,
1417 				      "unit %u: invalid UAC_FEATURE_UNIT descriptor\n",
1418 				      unitid);
1419 			return -EINVAL;
1420 		}
1421 	}
1422 
1423 	/* parse the source unit */
1424 	if ((err = parse_audio_unit(state, hdr->bSourceID)) < 0)
1425 		return err;
1426 
1427 	/* determine the input source type and name */
1428 	err = check_input_term(state, hdr->bSourceID, &iterm);
1429 	if (err < 0)
1430 		return err;
1431 
1432 	master_bits = snd_usb_combine_bytes(bmaControls, csize);
1433 	/* master configuration quirks */
1434 	switch (state->chip->usb_id) {
1435 	case USB_ID(0x08bb, 0x2702):
1436 		usb_audio_info(state->chip,
1437 			       "usbmixer: master volume quirk for PCM2702 chip\n");
1438 		/* disable non-functional volume control */
1439 		master_bits &= ~UAC_CONTROL_BIT(UAC_FU_VOLUME);
1440 		break;
1441 	case USB_ID(0x1130, 0xf211):
1442 		usb_audio_info(state->chip,
1443 			       "usbmixer: volume control quirk for Tenx TP6911 Audio Headset\n");
1444 		/* disable non-functional volume control */
1445 		channels = 0;
1446 		break;
1447 
1448 	}
1449 	if (channels > 0)
1450 		first_ch_bits = snd_usb_combine_bytes(bmaControls + csize, csize);
1451 	else
1452 		first_ch_bits = 0;
1453 
1454 	if (state->mixer->protocol == UAC_VERSION_1) {
1455 		/* check all control types */
1456 		for (i = 0; i < 10; i++) {
1457 			unsigned int ch_bits = 0;
1458 			for (j = 0; j < channels; j++) {
1459 				unsigned int mask;
1460 
1461 				mask = snd_usb_combine_bytes(bmaControls +
1462 							     csize * (j+1), csize);
1463 				if (mask & (1 << i))
1464 					ch_bits |= (1 << j);
1465 			}
1466 			/* audio class v1 controls are never read-only */
1467 
1468 			/*
1469 			 * The first channel must be set
1470 			 * (for ease of programming).
1471 			 */
1472 			if (ch_bits & 1)
1473 				build_feature_ctl(state, _ftr, ch_bits, i,
1474 						  &iterm, unitid, 0);
1475 			if (master_bits & (1 << i))
1476 				build_feature_ctl(state, _ftr, 0, i, &iterm,
1477 						  unitid, 0);
1478 		}
1479 	} else { /* UAC_VERSION_2 */
1480 		for (i = 0; i < ARRAY_SIZE(audio_feature_info); i++) {
1481 			unsigned int ch_bits = 0;
1482 			unsigned int ch_read_only = 0;
1483 
1484 			for (j = 0; j < channels; j++) {
1485 				unsigned int mask;
1486 
1487 				mask = snd_usb_combine_bytes(bmaControls +
1488 							     csize * (j+1), csize);
1489 				if (uac2_control_is_readable(mask, i)) {
1490 					ch_bits |= (1 << j);
1491 					if (!uac2_control_is_writeable(mask, i))
1492 						ch_read_only |= (1 << j);
1493 				}
1494 			}
1495 
1496 			/*
1497 			 * NOTE: build_feature_ctl() will mark the control
1498 			 * read-only if all channels are marked read-only in
1499 			 * the descriptors. Otherwise, the control will be
1500 			 * reported as writeable, but the driver will not
1501 			 * actually issue a write command for read-only
1502 			 * channels.
1503 			 */
1504 
1505 			/*
1506 			 * The first channel must be set
1507 			 * (for ease of programming).
1508 			 */
1509 			if (ch_bits & 1)
1510 				build_feature_ctl(state, _ftr, ch_bits, i,
1511 						  &iterm, unitid, ch_read_only);
1512 			if (uac2_control_is_readable(master_bits, i))
1513 				build_feature_ctl(state, _ftr, 0, i, &iterm, unitid,
1514 						  !uac2_control_is_writeable(master_bits, i));
1515 		}
1516 	}
1517 
1518 	return 0;
1519 }
1520 
1521 /*
1522  * Mixer Unit
1523  */
1524 
1525 /*
1526  * build a mixer unit control
1527  *
1528  * the callbacks are identical with feature unit.
1529  * input channel number (zero based) is given in control field instead.
1530  */
1531 static void build_mixer_unit_ctl(struct mixer_build *state,
1532 				 struct uac_mixer_unit_descriptor *desc,
1533 				 int in_pin, int in_ch, int unitid,
1534 				 struct usb_audio_term *iterm)
1535 {
1536 	struct usb_mixer_elem_info *cval;
1537 	unsigned int num_outs = uac_mixer_unit_bNrChannels(desc);
1538 	unsigned int i, len;
1539 	struct snd_kcontrol *kctl;
1540 	const struct usbmix_name_map *map;
1541 
1542 	map = find_map(state, unitid, 0);
1543 	if (check_ignored_ctl(map))
1544 		return;
1545 
1546 	cval = kzalloc(sizeof(*cval), GFP_KERNEL);
1547 	if (!cval)
1548 		return;
1549 
1550 	snd_usb_mixer_elem_init_std(&cval->head, state->mixer, unitid);
1551 	cval->control = in_ch + 1; /* based on 1 */
1552 	cval->val_type = USB_MIXER_S16;
1553 	for (i = 0; i < num_outs; i++) {
1554 		__u8 *c = uac_mixer_unit_bmControls(desc, state->mixer->protocol);
1555 
1556 		if (check_matrix_bitmap(c, in_ch, i, num_outs)) {
1557 			cval->cmask |= (1 << i);
1558 			cval->channels++;
1559 		}
1560 	}
1561 
1562 	/* get min/max values */
1563 	get_min_max(cval, 0);
1564 
1565 	kctl = snd_ctl_new1(&usb_feature_unit_ctl, cval);
1566 	if (!kctl) {
1567 		usb_audio_err(state->chip, "cannot malloc kcontrol\n");
1568 		kfree(cval);
1569 		return;
1570 	}
1571 	kctl->private_free = snd_usb_mixer_elem_free;
1572 
1573 	len = check_mapped_name(map, kctl->id.name, sizeof(kctl->id.name));
1574 	if (!len)
1575 		len = get_term_name(state, iterm, kctl->id.name,
1576 				    sizeof(kctl->id.name), 0);
1577 	if (!len)
1578 		len = sprintf(kctl->id.name, "Mixer Source %d", in_ch + 1);
1579 	append_ctl_name(kctl, " Volume");
1580 
1581 	usb_audio_dbg(state->chip, "[%d] MU [%s] ch = %d, val = %d/%d\n",
1582 		    cval->head.id, kctl->id.name, cval->channels, cval->min, cval->max);
1583 	snd_usb_mixer_add_control(&cval->head, kctl);
1584 }
1585 
1586 /*
1587  * parse a mixer unit
1588  */
1589 static int parse_audio_mixer_unit(struct mixer_build *state, int unitid,
1590 				  void *raw_desc)
1591 {
1592 	struct uac_mixer_unit_descriptor *desc = raw_desc;
1593 	struct usb_audio_term iterm;
1594 	int input_pins, num_ins, num_outs;
1595 	int pin, ich, err;
1596 
1597 	if (desc->bLength < 11 || !(input_pins = desc->bNrInPins) ||
1598 	    !(num_outs = uac_mixer_unit_bNrChannels(desc))) {
1599 		usb_audio_err(state->chip,
1600 			      "invalid MIXER UNIT descriptor %d\n",
1601 			      unitid);
1602 		return -EINVAL;
1603 	}
1604 
1605 	num_ins = 0;
1606 	ich = 0;
1607 	for (pin = 0; pin < input_pins; pin++) {
1608 		err = parse_audio_unit(state, desc->baSourceID[pin]);
1609 		if (err < 0)
1610 			continue;
1611 		/* no bmControls field (e.g. Maya44) -> ignore */
1612 		if (desc->bLength <= 10 + input_pins)
1613 			continue;
1614 		err = check_input_term(state, desc->baSourceID[pin], &iterm);
1615 		if (err < 0)
1616 			return err;
1617 		num_ins += iterm.channels;
1618 		for (; ich < num_ins; ich++) {
1619 			int och, ich_has_controls = 0;
1620 
1621 			for (och = 0; och < num_outs; och++) {
1622 				__u8 *c = uac_mixer_unit_bmControls(desc,
1623 						state->mixer->protocol);
1624 
1625 				if (check_matrix_bitmap(c, ich, och, num_outs)) {
1626 					ich_has_controls = 1;
1627 					break;
1628 				}
1629 			}
1630 			if (ich_has_controls)
1631 				build_mixer_unit_ctl(state, desc, pin, ich,
1632 						     unitid, &iterm);
1633 		}
1634 	}
1635 	return 0;
1636 }
1637 
1638 /*
1639  * Processing Unit / Extension Unit
1640  */
1641 
1642 /* get callback for processing/extension unit */
1643 static int mixer_ctl_procunit_get(struct snd_kcontrol *kcontrol,
1644 				  struct snd_ctl_elem_value *ucontrol)
1645 {
1646 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1647 	int err, val;
1648 
1649 	err = get_cur_ctl_value(cval, cval->control << 8, &val);
1650 	if (err < 0) {
1651 		ucontrol->value.integer.value[0] = cval->min;
1652 		return filter_error(cval, err);
1653 	}
1654 	val = get_relative_value(cval, val);
1655 	ucontrol->value.integer.value[0] = val;
1656 	return 0;
1657 }
1658 
1659 /* put callback for processing/extension unit */
1660 static int mixer_ctl_procunit_put(struct snd_kcontrol *kcontrol,
1661 				  struct snd_ctl_elem_value *ucontrol)
1662 {
1663 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1664 	int val, oval, err;
1665 
1666 	err = get_cur_ctl_value(cval, cval->control << 8, &oval);
1667 	if (err < 0)
1668 		return filter_error(cval, err);
1669 	val = ucontrol->value.integer.value[0];
1670 	val = get_abs_value(cval, val);
1671 	if (val != oval) {
1672 		set_cur_ctl_value(cval, cval->control << 8, val);
1673 		return 1;
1674 	}
1675 	return 0;
1676 }
1677 
1678 /* alsa control interface for processing/extension unit */
1679 static struct snd_kcontrol_new mixer_procunit_ctl = {
1680 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
1681 	.name = "", /* will be filled later */
1682 	.info = mixer_ctl_feature_info,
1683 	.get = mixer_ctl_procunit_get,
1684 	.put = mixer_ctl_procunit_put,
1685 };
1686 
1687 /*
1688  * predefined data for processing units
1689  */
1690 struct procunit_value_info {
1691 	int control;
1692 	char *suffix;
1693 	int val_type;
1694 	int min_value;
1695 };
1696 
1697 struct procunit_info {
1698 	int type;
1699 	char *name;
1700 	struct procunit_value_info *values;
1701 };
1702 
1703 static struct procunit_value_info updown_proc_info[] = {
1704 	{ UAC_UD_ENABLE, "Switch", USB_MIXER_BOOLEAN },
1705 	{ UAC_UD_MODE_SELECT, "Mode Select", USB_MIXER_U8, 1 },
1706 	{ 0 }
1707 };
1708 static struct procunit_value_info prologic_proc_info[] = {
1709 	{ UAC_DP_ENABLE, "Switch", USB_MIXER_BOOLEAN },
1710 	{ UAC_DP_MODE_SELECT, "Mode Select", USB_MIXER_U8, 1 },
1711 	{ 0 }
1712 };
1713 static struct procunit_value_info threed_enh_proc_info[] = {
1714 	{ UAC_3D_ENABLE, "Switch", USB_MIXER_BOOLEAN },
1715 	{ UAC_3D_SPACE, "Spaciousness", USB_MIXER_U8 },
1716 	{ 0 }
1717 };
1718 static struct procunit_value_info reverb_proc_info[] = {
1719 	{ UAC_REVERB_ENABLE, "Switch", USB_MIXER_BOOLEAN },
1720 	{ UAC_REVERB_LEVEL, "Level", USB_MIXER_U8 },
1721 	{ UAC_REVERB_TIME, "Time", USB_MIXER_U16 },
1722 	{ UAC_REVERB_FEEDBACK, "Feedback", USB_MIXER_U8 },
1723 	{ 0 }
1724 };
1725 static struct procunit_value_info chorus_proc_info[] = {
1726 	{ UAC_CHORUS_ENABLE, "Switch", USB_MIXER_BOOLEAN },
1727 	{ UAC_CHORUS_LEVEL, "Level", USB_MIXER_U8 },
1728 	{ UAC_CHORUS_RATE, "Rate", USB_MIXER_U16 },
1729 	{ UAC_CHORUS_DEPTH, "Depth", USB_MIXER_U16 },
1730 	{ 0 }
1731 };
1732 static struct procunit_value_info dcr_proc_info[] = {
1733 	{ UAC_DCR_ENABLE, "Switch", USB_MIXER_BOOLEAN },
1734 	{ UAC_DCR_RATE, "Ratio", USB_MIXER_U16 },
1735 	{ UAC_DCR_MAXAMPL, "Max Amp", USB_MIXER_S16 },
1736 	{ UAC_DCR_THRESHOLD, "Threshold", USB_MIXER_S16 },
1737 	{ UAC_DCR_ATTACK_TIME, "Attack Time", USB_MIXER_U16 },
1738 	{ UAC_DCR_RELEASE_TIME, "Release Time", USB_MIXER_U16 },
1739 	{ 0 }
1740 };
1741 
1742 static struct procunit_info procunits[] = {
1743 	{ UAC_PROCESS_UP_DOWNMIX, "Up Down", updown_proc_info },
1744 	{ UAC_PROCESS_DOLBY_PROLOGIC, "Dolby Prologic", prologic_proc_info },
1745 	{ UAC_PROCESS_STEREO_EXTENDER, "3D Stereo Extender", threed_enh_proc_info },
1746 	{ UAC_PROCESS_REVERB, "Reverb", reverb_proc_info },
1747 	{ UAC_PROCESS_CHORUS, "Chorus", chorus_proc_info },
1748 	{ UAC_PROCESS_DYN_RANGE_COMP, "DCR", dcr_proc_info },
1749 	{ 0 },
1750 };
1751 /*
1752  * predefined data for extension units
1753  */
1754 static struct procunit_value_info clock_rate_xu_info[] = {
1755 	{ USB_XU_CLOCK_RATE_SELECTOR, "Selector", USB_MIXER_U8, 0 },
1756 	{ 0 }
1757 };
1758 static struct procunit_value_info clock_source_xu_info[] = {
1759 	{ USB_XU_CLOCK_SOURCE_SELECTOR, "External", USB_MIXER_BOOLEAN },
1760 	{ 0 }
1761 };
1762 static struct procunit_value_info spdif_format_xu_info[] = {
1763 	{ USB_XU_DIGITAL_FORMAT_SELECTOR, "SPDIF/AC3", USB_MIXER_BOOLEAN },
1764 	{ 0 }
1765 };
1766 static struct procunit_value_info soft_limit_xu_info[] = {
1767 	{ USB_XU_SOFT_LIMIT_SELECTOR, " ", USB_MIXER_BOOLEAN },
1768 	{ 0 }
1769 };
1770 static struct procunit_info extunits[] = {
1771 	{ USB_XU_CLOCK_RATE, "Clock rate", clock_rate_xu_info },
1772 	{ USB_XU_CLOCK_SOURCE, "DigitalIn CLK source", clock_source_xu_info },
1773 	{ USB_XU_DIGITAL_IO_STATUS, "DigitalOut format:", spdif_format_xu_info },
1774 	{ USB_XU_DEVICE_OPTIONS, "AnalogueIn Soft Limit", soft_limit_xu_info },
1775 	{ 0 }
1776 };
1777 
1778 /*
1779  * build a processing/extension unit
1780  */
1781 static int build_audio_procunit(struct mixer_build *state, int unitid,
1782 				void *raw_desc, struct procunit_info *list,
1783 				char *name)
1784 {
1785 	struct uac_processing_unit_descriptor *desc = raw_desc;
1786 	int num_ins = desc->bNrInPins;
1787 	struct usb_mixer_elem_info *cval;
1788 	struct snd_kcontrol *kctl;
1789 	int i, err, nameid, type, len;
1790 	struct procunit_info *info;
1791 	struct procunit_value_info *valinfo;
1792 	const struct usbmix_name_map *map;
1793 	static struct procunit_value_info default_value_info[] = {
1794 		{ 0x01, "Switch", USB_MIXER_BOOLEAN },
1795 		{ 0 }
1796 	};
1797 	static struct procunit_info default_info = {
1798 		0, NULL, default_value_info
1799 	};
1800 
1801 	if (desc->bLength < 13 || desc->bLength < 13 + num_ins ||
1802 	    desc->bLength < num_ins + uac_processing_unit_bControlSize(desc, state->mixer->protocol)) {
1803 		usb_audio_err(state->chip, "invalid %s descriptor (id %d)\n", name, unitid);
1804 		return -EINVAL;
1805 	}
1806 
1807 	for (i = 0; i < num_ins; i++) {
1808 		if ((err = parse_audio_unit(state, desc->baSourceID[i])) < 0)
1809 			return err;
1810 	}
1811 
1812 	type = le16_to_cpu(desc->wProcessType);
1813 	for (info = list; info && info->type; info++)
1814 		if (info->type == type)
1815 			break;
1816 	if (!info || !info->type)
1817 		info = &default_info;
1818 
1819 	for (valinfo = info->values; valinfo->control; valinfo++) {
1820 		__u8 *controls = uac_processing_unit_bmControls(desc, state->mixer->protocol);
1821 
1822 		if (!(controls[valinfo->control / 8] & (1 << ((valinfo->control % 8) - 1))))
1823 			continue;
1824 		map = find_map(state, unitid, valinfo->control);
1825 		if (check_ignored_ctl(map))
1826 			continue;
1827 		cval = kzalloc(sizeof(*cval), GFP_KERNEL);
1828 		if (!cval)
1829 			return -ENOMEM;
1830 		snd_usb_mixer_elem_init_std(&cval->head, state->mixer, unitid);
1831 		cval->control = valinfo->control;
1832 		cval->val_type = valinfo->val_type;
1833 		cval->channels = 1;
1834 
1835 		/* get min/max values */
1836 		if (type == UAC_PROCESS_UP_DOWNMIX && cval->control == UAC_UD_MODE_SELECT) {
1837 			__u8 *control_spec = uac_processing_unit_specific(desc, state->mixer->protocol);
1838 			/* FIXME: hard-coded */
1839 			cval->min = 1;
1840 			cval->max = control_spec[0];
1841 			cval->res = 1;
1842 			cval->initialized = 1;
1843 		} else {
1844 			if (type == USB_XU_CLOCK_RATE) {
1845 				/*
1846 				 * E-Mu USB 0404/0202/TrackerPre/0204
1847 				 * samplerate control quirk
1848 				 */
1849 				cval->min = 0;
1850 				cval->max = 5;
1851 				cval->res = 1;
1852 				cval->initialized = 1;
1853 			} else
1854 				get_min_max(cval, valinfo->min_value);
1855 		}
1856 
1857 		kctl = snd_ctl_new1(&mixer_procunit_ctl, cval);
1858 		if (!kctl) {
1859 			kfree(cval);
1860 			return -ENOMEM;
1861 		}
1862 		kctl->private_free = snd_usb_mixer_elem_free;
1863 
1864 		if (check_mapped_name(map, kctl->id.name, sizeof(kctl->id.name))) {
1865 			/* nothing */ ;
1866 		} else if (info->name) {
1867 			strlcpy(kctl->id.name, info->name, sizeof(kctl->id.name));
1868 		} else {
1869 			nameid = uac_processing_unit_iProcessing(desc, state->mixer->protocol);
1870 			len = 0;
1871 			if (nameid)
1872 				len = snd_usb_copy_string_desc(state, nameid,
1873 							       kctl->id.name,
1874 							       sizeof(kctl->id.name));
1875 			if (!len)
1876 				strlcpy(kctl->id.name, name, sizeof(kctl->id.name));
1877 		}
1878 		append_ctl_name(kctl, " ");
1879 		append_ctl_name(kctl, valinfo->suffix);
1880 
1881 		usb_audio_dbg(state->chip,
1882 			      "[%d] PU [%s] ch = %d, val = %d/%d\n",
1883 			      cval->head.id, kctl->id.name, cval->channels,
1884 			      cval->min, cval->max);
1885 
1886 		err = snd_usb_mixer_add_control(&cval->head, kctl);
1887 		if (err < 0)
1888 			return err;
1889 	}
1890 	return 0;
1891 }
1892 
1893 static int parse_audio_processing_unit(struct mixer_build *state, int unitid,
1894 				       void *raw_desc)
1895 {
1896 	return build_audio_procunit(state, unitid, raw_desc,
1897 				    procunits, "Processing Unit");
1898 }
1899 
1900 static int parse_audio_extension_unit(struct mixer_build *state, int unitid,
1901 				      void *raw_desc)
1902 {
1903 	/*
1904 	 * Note that we parse extension units with processing unit descriptors.
1905 	 * That's ok as the layout is the same.
1906 	 */
1907 	return build_audio_procunit(state, unitid, raw_desc,
1908 				    extunits, "Extension Unit");
1909 }
1910 
1911 /*
1912  * Selector Unit
1913  */
1914 
1915 /*
1916  * info callback for selector unit
1917  * use an enumerator type for routing
1918  */
1919 static int mixer_ctl_selector_info(struct snd_kcontrol *kcontrol,
1920 				   struct snd_ctl_elem_info *uinfo)
1921 {
1922 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1923 	const char **itemlist = (const char **)kcontrol->private_value;
1924 
1925 	if (snd_BUG_ON(!itemlist))
1926 		return -EINVAL;
1927 	return snd_ctl_enum_info(uinfo, 1, cval->max, itemlist);
1928 }
1929 
1930 /* get callback for selector unit */
1931 static int mixer_ctl_selector_get(struct snd_kcontrol *kcontrol,
1932 				  struct snd_ctl_elem_value *ucontrol)
1933 {
1934 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1935 	int val, err;
1936 
1937 	err = get_cur_ctl_value(cval, cval->control << 8, &val);
1938 	if (err < 0) {
1939 		ucontrol->value.enumerated.item[0] = 0;
1940 		return filter_error(cval, err);
1941 	}
1942 	val = get_relative_value(cval, val);
1943 	ucontrol->value.enumerated.item[0] = val;
1944 	return 0;
1945 }
1946 
1947 /* put callback for selector unit */
1948 static int mixer_ctl_selector_put(struct snd_kcontrol *kcontrol,
1949 				  struct snd_ctl_elem_value *ucontrol)
1950 {
1951 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
1952 	int val, oval, err;
1953 
1954 	err = get_cur_ctl_value(cval, cval->control << 8, &oval);
1955 	if (err < 0)
1956 		return filter_error(cval, err);
1957 	val = ucontrol->value.enumerated.item[0];
1958 	val = get_abs_value(cval, val);
1959 	if (val != oval) {
1960 		set_cur_ctl_value(cval, cval->control << 8, val);
1961 		return 1;
1962 	}
1963 	return 0;
1964 }
1965 
1966 /* alsa control interface for selector unit */
1967 static struct snd_kcontrol_new mixer_selectunit_ctl = {
1968 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
1969 	.name = "", /* will be filled later */
1970 	.info = mixer_ctl_selector_info,
1971 	.get = mixer_ctl_selector_get,
1972 	.put = mixer_ctl_selector_put,
1973 };
1974 
1975 /*
1976  * private free callback.
1977  * free both private_data and private_value
1978  */
1979 static void usb_mixer_selector_elem_free(struct snd_kcontrol *kctl)
1980 {
1981 	int i, num_ins = 0;
1982 
1983 	if (kctl->private_data) {
1984 		struct usb_mixer_elem_info *cval = kctl->private_data;
1985 		num_ins = cval->max;
1986 		kfree(cval);
1987 		kctl->private_data = NULL;
1988 	}
1989 	if (kctl->private_value) {
1990 		char **itemlist = (char **)kctl->private_value;
1991 		for (i = 0; i < num_ins; i++)
1992 			kfree(itemlist[i]);
1993 		kfree(itemlist);
1994 		kctl->private_value = 0;
1995 	}
1996 }
1997 
1998 /*
1999  * parse a selector unit
2000  */
2001 static int parse_audio_selector_unit(struct mixer_build *state, int unitid,
2002 				     void *raw_desc)
2003 {
2004 	struct uac_selector_unit_descriptor *desc = raw_desc;
2005 	unsigned int i, nameid, len;
2006 	int err;
2007 	struct usb_mixer_elem_info *cval;
2008 	struct snd_kcontrol *kctl;
2009 	const struct usbmix_name_map *map;
2010 	char **namelist;
2011 
2012 	if (!desc->bNrInPins || desc->bLength < 5 + desc->bNrInPins) {
2013 		usb_audio_err(state->chip,
2014 			"invalid SELECTOR UNIT descriptor %d\n", unitid);
2015 		return -EINVAL;
2016 	}
2017 
2018 	for (i = 0; i < desc->bNrInPins; i++) {
2019 		if ((err = parse_audio_unit(state, desc->baSourceID[i])) < 0)
2020 			return err;
2021 	}
2022 
2023 	if (desc->bNrInPins == 1) /* only one ? nonsense! */
2024 		return 0;
2025 
2026 	map = find_map(state, unitid, 0);
2027 	if (check_ignored_ctl(map))
2028 		return 0;
2029 
2030 	cval = kzalloc(sizeof(*cval), GFP_KERNEL);
2031 	if (!cval)
2032 		return -ENOMEM;
2033 	snd_usb_mixer_elem_init_std(&cval->head, state->mixer, unitid);
2034 	cval->val_type = USB_MIXER_U8;
2035 	cval->channels = 1;
2036 	cval->min = 1;
2037 	cval->max = desc->bNrInPins;
2038 	cval->res = 1;
2039 	cval->initialized = 1;
2040 
2041 	if (state->mixer->protocol == UAC_VERSION_1)
2042 		cval->control = 0;
2043 	else /* UAC_VERSION_2 */
2044 		cval->control = (desc->bDescriptorSubtype == UAC2_CLOCK_SELECTOR) ?
2045 			UAC2_CX_CLOCK_SELECTOR : UAC2_SU_SELECTOR;
2046 
2047 	namelist = kmalloc(sizeof(char *) * desc->bNrInPins, GFP_KERNEL);
2048 	if (!namelist) {
2049 		kfree(cval);
2050 		return -ENOMEM;
2051 	}
2052 #define MAX_ITEM_NAME_LEN	64
2053 	for (i = 0; i < desc->bNrInPins; i++) {
2054 		struct usb_audio_term iterm;
2055 		len = 0;
2056 		namelist[i] = kmalloc(MAX_ITEM_NAME_LEN, GFP_KERNEL);
2057 		if (!namelist[i]) {
2058 			while (i--)
2059 				kfree(namelist[i]);
2060 			kfree(namelist);
2061 			kfree(cval);
2062 			return -ENOMEM;
2063 		}
2064 		len = check_mapped_selector_name(state, unitid, i, namelist[i],
2065 						 MAX_ITEM_NAME_LEN);
2066 		if (! len && check_input_term(state, desc->baSourceID[i], &iterm) >= 0)
2067 			len = get_term_name(state, &iterm, namelist[i], MAX_ITEM_NAME_LEN, 0);
2068 		if (! len)
2069 			sprintf(namelist[i], "Input %u", i);
2070 	}
2071 
2072 	kctl = snd_ctl_new1(&mixer_selectunit_ctl, cval);
2073 	if (! kctl) {
2074 		usb_audio_err(state->chip, "cannot malloc kcontrol\n");
2075 		kfree(namelist);
2076 		kfree(cval);
2077 		return -ENOMEM;
2078 	}
2079 	kctl->private_value = (unsigned long)namelist;
2080 	kctl->private_free = usb_mixer_selector_elem_free;
2081 
2082 	nameid = uac_selector_unit_iSelector(desc);
2083 	len = check_mapped_name(map, kctl->id.name, sizeof(kctl->id.name));
2084 	if (len)
2085 		;
2086 	else if (nameid)
2087 		snd_usb_copy_string_desc(state, nameid, kctl->id.name,
2088 					 sizeof(kctl->id.name));
2089 	else {
2090 		len = get_term_name(state, &state->oterm,
2091 				    kctl->id.name, sizeof(kctl->id.name), 0);
2092 		if (!len)
2093 			strlcpy(kctl->id.name, "USB", sizeof(kctl->id.name));
2094 
2095 		if (desc->bDescriptorSubtype == UAC2_CLOCK_SELECTOR)
2096 			append_ctl_name(kctl, " Clock Source");
2097 		else if ((state->oterm.type & 0xff00) == 0x0100)
2098 			append_ctl_name(kctl, " Capture Source");
2099 		else
2100 			append_ctl_name(kctl, " Playback Source");
2101 	}
2102 
2103 	usb_audio_dbg(state->chip, "[%d] SU [%s] items = %d\n",
2104 		    cval->head.id, kctl->id.name, desc->bNrInPins);
2105 	return snd_usb_mixer_add_control(&cval->head, kctl);
2106 }
2107 
2108 /*
2109  * parse an audio unit recursively
2110  */
2111 
2112 static int parse_audio_unit(struct mixer_build *state, int unitid)
2113 {
2114 	unsigned char *p1;
2115 
2116 	if (test_and_set_bit(unitid, state->unitbitmap))
2117 		return 0; /* the unit already visited */
2118 
2119 	p1 = find_audio_control_unit(state, unitid);
2120 	if (!p1) {
2121 		usb_audio_err(state->chip, "unit %d not found!\n", unitid);
2122 		return -EINVAL;
2123 	}
2124 
2125 	switch (p1[2]) {
2126 	case UAC_INPUT_TERMINAL:
2127 	case UAC2_CLOCK_SOURCE:
2128 		return 0; /* NOP */
2129 	case UAC_MIXER_UNIT:
2130 		return parse_audio_mixer_unit(state, unitid, p1);
2131 	case UAC_SELECTOR_UNIT:
2132 	case UAC2_CLOCK_SELECTOR:
2133 		return parse_audio_selector_unit(state, unitid, p1);
2134 	case UAC_FEATURE_UNIT:
2135 		return parse_audio_feature_unit(state, unitid, p1);
2136 	case UAC1_PROCESSING_UNIT:
2137 	/*   UAC2_EFFECT_UNIT has the same value */
2138 		if (state->mixer->protocol == UAC_VERSION_1)
2139 			return parse_audio_processing_unit(state, unitid, p1);
2140 		else
2141 			return 0; /* FIXME - effect units not implemented yet */
2142 	case UAC1_EXTENSION_UNIT:
2143 	/*   UAC2_PROCESSING_UNIT_V2 has the same value */
2144 		if (state->mixer->protocol == UAC_VERSION_1)
2145 			return parse_audio_extension_unit(state, unitid, p1);
2146 		else /* UAC_VERSION_2 */
2147 			return parse_audio_processing_unit(state, unitid, p1);
2148 	case UAC2_EXTENSION_UNIT_V2:
2149 		return parse_audio_extension_unit(state, unitid, p1);
2150 	default:
2151 		usb_audio_err(state->chip,
2152 			"unit %u: unexpected type 0x%02x\n", unitid, p1[2]);
2153 		return -EINVAL;
2154 	}
2155 }
2156 
2157 static void snd_usb_mixer_free(struct usb_mixer_interface *mixer)
2158 {
2159 	kfree(mixer->id_elems);
2160 	if (mixer->urb) {
2161 		kfree(mixer->urb->transfer_buffer);
2162 		usb_free_urb(mixer->urb);
2163 	}
2164 	usb_free_urb(mixer->rc_urb);
2165 	kfree(mixer->rc_setup_packet);
2166 	kfree(mixer);
2167 }
2168 
2169 static int snd_usb_mixer_dev_free(struct snd_device *device)
2170 {
2171 	struct usb_mixer_interface *mixer = device->device_data;
2172 	snd_usb_mixer_free(mixer);
2173 	return 0;
2174 }
2175 
2176 /*
2177  * create mixer controls
2178  *
2179  * walk through all UAC_OUTPUT_TERMINAL descriptors to search for mixers
2180  */
2181 static int snd_usb_mixer_controls(struct usb_mixer_interface *mixer)
2182 {
2183 	struct mixer_build state;
2184 	int err;
2185 	const struct usbmix_ctl_map *map;
2186 	void *p;
2187 
2188 	memset(&state, 0, sizeof(state));
2189 	state.chip = mixer->chip;
2190 	state.mixer = mixer;
2191 	state.buffer = mixer->hostif->extra;
2192 	state.buflen = mixer->hostif->extralen;
2193 
2194 	/* check the mapping table */
2195 	for (map = usbmix_ctl_maps; map->id; map++) {
2196 		if (map->id == state.chip->usb_id) {
2197 			state.map = map->map;
2198 			state.selector_map = map->selector_map;
2199 			mixer->ignore_ctl_error = map->ignore_ctl_error;
2200 			break;
2201 		}
2202 	}
2203 
2204 	p = NULL;
2205 	while ((p = snd_usb_find_csint_desc(mixer->hostif->extra,
2206 					    mixer->hostif->extralen,
2207 					    p, UAC_OUTPUT_TERMINAL)) != NULL) {
2208 		if (mixer->protocol == UAC_VERSION_1) {
2209 			struct uac1_output_terminal_descriptor *desc = p;
2210 
2211 			if (desc->bLength < sizeof(*desc))
2212 				continue; /* invalid descriptor? */
2213 			/* mark terminal ID as visited */
2214 			set_bit(desc->bTerminalID, state.unitbitmap);
2215 			state.oterm.id = desc->bTerminalID;
2216 			state.oterm.type = le16_to_cpu(desc->wTerminalType);
2217 			state.oterm.name = desc->iTerminal;
2218 			err = parse_audio_unit(&state, desc->bSourceID);
2219 			if (err < 0 && err != -EINVAL)
2220 				return err;
2221 		} else { /* UAC_VERSION_2 */
2222 			struct uac2_output_terminal_descriptor *desc = p;
2223 
2224 			if (desc->bLength < sizeof(*desc))
2225 				continue; /* invalid descriptor? */
2226 			/* mark terminal ID as visited */
2227 			set_bit(desc->bTerminalID, state.unitbitmap);
2228 			state.oterm.id = desc->bTerminalID;
2229 			state.oterm.type = le16_to_cpu(desc->wTerminalType);
2230 			state.oterm.name = desc->iTerminal;
2231 			err = parse_audio_unit(&state, desc->bSourceID);
2232 			if (err < 0 && err != -EINVAL)
2233 				return err;
2234 
2235 			/*
2236 			 * For UAC2, use the same approach to also add the
2237 			 * clock selectors
2238 			 */
2239 			err = parse_audio_unit(&state, desc->bCSourceID);
2240 			if (err < 0 && err != -EINVAL)
2241 				return err;
2242 		}
2243 	}
2244 
2245 	return 0;
2246 }
2247 
2248 void snd_usb_mixer_notify_id(struct usb_mixer_interface *mixer, int unitid)
2249 {
2250 	struct usb_mixer_elem_list *list;
2251 
2252 	for (list = mixer->id_elems[unitid]; list; list = list->next_id_elem)
2253 		snd_ctl_notify(mixer->chip->card, SNDRV_CTL_EVENT_MASK_VALUE,
2254 			       &list->kctl->id);
2255 }
2256 
2257 static void snd_usb_mixer_dump_cval(struct snd_info_buffer *buffer,
2258 				    struct usb_mixer_elem_list *list)
2259 {
2260 	struct usb_mixer_elem_info *cval = (struct usb_mixer_elem_info *)list;
2261 	static char *val_types[] = {"BOOLEAN", "INV_BOOLEAN",
2262 				    "S8", "U8", "S16", "U16"};
2263 	snd_iprintf(buffer, "    Info: id=%i, control=%i, cmask=0x%x, "
2264 			    "channels=%i, type=\"%s\"\n", cval->head.id,
2265 			    cval->control, cval->cmask, cval->channels,
2266 			    val_types[cval->val_type]);
2267 	snd_iprintf(buffer, "    Volume: min=%i, max=%i, dBmin=%i, dBmax=%i\n",
2268 			    cval->min, cval->max, cval->dBmin, cval->dBmax);
2269 }
2270 
2271 static void snd_usb_mixer_proc_read(struct snd_info_entry *entry,
2272 				    struct snd_info_buffer *buffer)
2273 {
2274 	struct snd_usb_audio *chip = entry->private_data;
2275 	struct usb_mixer_interface *mixer;
2276 	struct usb_mixer_elem_list *list;
2277 	int unitid;
2278 
2279 	list_for_each_entry(mixer, &chip->mixer_list, list) {
2280 		snd_iprintf(buffer,
2281 			"USB Mixer: usb_id=0x%08x, ctrlif=%i, ctlerr=%i\n",
2282 				chip->usb_id, snd_usb_ctrl_intf(chip),
2283 				mixer->ignore_ctl_error);
2284 		snd_iprintf(buffer, "Card: %s\n", chip->card->longname);
2285 		for (unitid = 0; unitid < MAX_ID_ELEMS; unitid++) {
2286 			for (list = mixer->id_elems[unitid]; list;
2287 			     list = list->next_id_elem) {
2288 				snd_iprintf(buffer, "  Unit: %i\n", list->id);
2289 				if (list->kctl)
2290 					snd_iprintf(buffer,
2291 						    "    Control: name=\"%s\", index=%i\n",
2292 						    list->kctl->id.name,
2293 						    list->kctl->id.index);
2294 				if (list->dump)
2295 					list->dump(buffer, list);
2296 			}
2297 		}
2298 	}
2299 }
2300 
2301 static void snd_usb_mixer_interrupt_v2(struct usb_mixer_interface *mixer,
2302 				       int attribute, int value, int index)
2303 {
2304 	struct usb_mixer_elem_list *list;
2305 	__u8 unitid = (index >> 8) & 0xff;
2306 	__u8 control = (value >> 8) & 0xff;
2307 	__u8 channel = value & 0xff;
2308 
2309 	if (channel >= MAX_CHANNELS) {
2310 		usb_audio_dbg(mixer->chip,
2311 			"%s(): bogus channel number %d\n",
2312 			__func__, channel);
2313 		return;
2314 	}
2315 
2316 	for (list = mixer->id_elems[unitid]; list; list = list->next_id_elem) {
2317 		struct usb_mixer_elem_info *info;
2318 
2319 		if (!list->kctl)
2320 			continue;
2321 
2322 		info = (struct usb_mixer_elem_info *)list;
2323 		if (info->control != control)
2324 			continue;
2325 
2326 		switch (attribute) {
2327 		case UAC2_CS_CUR:
2328 			/* invalidate cache, so the value is read from the device */
2329 			if (channel)
2330 				info->cached &= ~(1 << channel);
2331 			else /* master channel */
2332 				info->cached = 0;
2333 
2334 			snd_ctl_notify(mixer->chip->card, SNDRV_CTL_EVENT_MASK_VALUE,
2335 				       &info->head.kctl->id);
2336 			break;
2337 
2338 		case UAC2_CS_RANGE:
2339 			/* TODO */
2340 			break;
2341 
2342 		case UAC2_CS_MEM:
2343 			/* TODO */
2344 			break;
2345 
2346 		default:
2347 			usb_audio_dbg(mixer->chip,
2348 				"unknown attribute %d in interrupt\n",
2349 				attribute);
2350 			break;
2351 		} /* switch */
2352 	}
2353 }
2354 
2355 static void snd_usb_mixer_interrupt(struct urb *urb)
2356 {
2357 	struct usb_mixer_interface *mixer = urb->context;
2358 	int len = urb->actual_length;
2359 	int ustatus = urb->status;
2360 
2361 	if (ustatus != 0)
2362 		goto requeue;
2363 
2364 	if (mixer->protocol == UAC_VERSION_1) {
2365 		struct uac1_status_word *status;
2366 
2367 		for (status = urb->transfer_buffer;
2368 		     len >= sizeof(*status);
2369 		     len -= sizeof(*status), status++) {
2370 			dev_dbg(&urb->dev->dev, "status interrupt: %02x %02x\n",
2371 						status->bStatusType,
2372 						status->bOriginator);
2373 
2374 			/* ignore any notifications not from the control interface */
2375 			if ((status->bStatusType & UAC1_STATUS_TYPE_ORIG_MASK) !=
2376 				UAC1_STATUS_TYPE_ORIG_AUDIO_CONTROL_IF)
2377 				continue;
2378 
2379 			if (status->bStatusType & UAC1_STATUS_TYPE_MEM_CHANGED)
2380 				snd_usb_mixer_rc_memory_change(mixer, status->bOriginator);
2381 			else
2382 				snd_usb_mixer_notify_id(mixer, status->bOriginator);
2383 		}
2384 	} else { /* UAC_VERSION_2 */
2385 		struct uac2_interrupt_data_msg *msg;
2386 
2387 		for (msg = urb->transfer_buffer;
2388 		     len >= sizeof(*msg);
2389 		     len -= sizeof(*msg), msg++) {
2390 			/* drop vendor specific and endpoint requests */
2391 			if ((msg->bInfo & UAC2_INTERRUPT_DATA_MSG_VENDOR) ||
2392 			    (msg->bInfo & UAC2_INTERRUPT_DATA_MSG_EP))
2393 				continue;
2394 
2395 			snd_usb_mixer_interrupt_v2(mixer, msg->bAttribute,
2396 						   le16_to_cpu(msg->wValue),
2397 						   le16_to_cpu(msg->wIndex));
2398 		}
2399 	}
2400 
2401 requeue:
2402 	if (ustatus != -ENOENT &&
2403 	    ustatus != -ECONNRESET &&
2404 	    ustatus != -ESHUTDOWN) {
2405 		urb->dev = mixer->chip->dev;
2406 		usb_submit_urb(urb, GFP_ATOMIC);
2407 	}
2408 }
2409 
2410 /* create the handler for the optional status interrupt endpoint */
2411 static int snd_usb_mixer_status_create(struct usb_mixer_interface *mixer)
2412 {
2413 	struct usb_endpoint_descriptor *ep;
2414 	void *transfer_buffer;
2415 	int buffer_length;
2416 	unsigned int epnum;
2417 
2418 	/* we need one interrupt input endpoint */
2419 	if (get_iface_desc(mixer->hostif)->bNumEndpoints < 1)
2420 		return 0;
2421 	ep = get_endpoint(mixer->hostif, 0);
2422 	if (!usb_endpoint_dir_in(ep) || !usb_endpoint_xfer_int(ep))
2423 		return 0;
2424 
2425 	epnum = usb_endpoint_num(ep);
2426 	buffer_length = le16_to_cpu(ep->wMaxPacketSize);
2427 	transfer_buffer = kmalloc(buffer_length, GFP_KERNEL);
2428 	if (!transfer_buffer)
2429 		return -ENOMEM;
2430 	mixer->urb = usb_alloc_urb(0, GFP_KERNEL);
2431 	if (!mixer->urb) {
2432 		kfree(transfer_buffer);
2433 		return -ENOMEM;
2434 	}
2435 	usb_fill_int_urb(mixer->urb, mixer->chip->dev,
2436 			 usb_rcvintpipe(mixer->chip->dev, epnum),
2437 			 transfer_buffer, buffer_length,
2438 			 snd_usb_mixer_interrupt, mixer, ep->bInterval);
2439 	usb_submit_urb(mixer->urb, GFP_KERNEL);
2440 	return 0;
2441 }
2442 
2443 int snd_usb_create_mixer(struct snd_usb_audio *chip, int ctrlif,
2444 			 int ignore_error)
2445 {
2446 	static struct snd_device_ops dev_ops = {
2447 		.dev_free = snd_usb_mixer_dev_free
2448 	};
2449 	struct usb_mixer_interface *mixer;
2450 	struct snd_info_entry *entry;
2451 	int err;
2452 
2453 	strcpy(chip->card->mixername, "USB Mixer");
2454 
2455 	mixer = kzalloc(sizeof(*mixer), GFP_KERNEL);
2456 	if (!mixer)
2457 		return -ENOMEM;
2458 	mixer->chip = chip;
2459 	mixer->ignore_ctl_error = ignore_error;
2460 	mixer->id_elems = kcalloc(MAX_ID_ELEMS, sizeof(*mixer->id_elems),
2461 				  GFP_KERNEL);
2462 	if (!mixer->id_elems) {
2463 		kfree(mixer);
2464 		return -ENOMEM;
2465 	}
2466 
2467 	mixer->hostif = &usb_ifnum_to_if(chip->dev, ctrlif)->altsetting[0];
2468 	switch (get_iface_desc(mixer->hostif)->bInterfaceProtocol) {
2469 	case UAC_VERSION_1:
2470 	default:
2471 		mixer->protocol = UAC_VERSION_1;
2472 		break;
2473 	case UAC_VERSION_2:
2474 		mixer->protocol = UAC_VERSION_2;
2475 		break;
2476 	}
2477 
2478 	if ((err = snd_usb_mixer_controls(mixer)) < 0 ||
2479 	    (err = snd_usb_mixer_status_create(mixer)) < 0)
2480 		goto _error;
2481 
2482 	snd_usb_mixer_apply_create_quirk(mixer);
2483 
2484 	err = snd_device_new(chip->card, SNDRV_DEV_CODEC, mixer, &dev_ops);
2485 	if (err < 0)
2486 		goto _error;
2487 
2488 	if (list_empty(&chip->mixer_list) &&
2489 	    !snd_card_proc_new(chip->card, "usbmixer", &entry))
2490 		snd_info_set_text_ops(entry, chip, snd_usb_mixer_proc_read);
2491 
2492 	list_add(&mixer->list, &chip->mixer_list);
2493 	return 0;
2494 
2495 _error:
2496 	snd_usb_mixer_free(mixer);
2497 	return err;
2498 }
2499 
2500 void snd_usb_mixer_disconnect(struct usb_mixer_interface *mixer)
2501 {
2502 	usb_kill_urb(mixer->urb);
2503 	usb_kill_urb(mixer->rc_urb);
2504 }
2505 
2506 #ifdef CONFIG_PM
2507 /* stop any bus activity of a mixer */
2508 static void snd_usb_mixer_inactivate(struct usb_mixer_interface *mixer)
2509 {
2510 	usb_kill_urb(mixer->urb);
2511 	usb_kill_urb(mixer->rc_urb);
2512 }
2513 
2514 static int snd_usb_mixer_activate(struct usb_mixer_interface *mixer)
2515 {
2516 	int err;
2517 
2518 	if (mixer->urb) {
2519 		err = usb_submit_urb(mixer->urb, GFP_NOIO);
2520 		if (err < 0)
2521 			return err;
2522 	}
2523 
2524 	return 0;
2525 }
2526 
2527 int snd_usb_mixer_suspend(struct usb_mixer_interface *mixer)
2528 {
2529 	snd_usb_mixer_inactivate(mixer);
2530 	return 0;
2531 }
2532 
2533 static int restore_mixer_value(struct usb_mixer_elem_list *list)
2534 {
2535 	struct usb_mixer_elem_info *cval = (struct usb_mixer_elem_info *)list;
2536 	int c, err, idx;
2537 
2538 	if (cval->cmask) {
2539 		idx = 0;
2540 		for (c = 0; c < MAX_CHANNELS; c++) {
2541 			if (!(cval->cmask & (1 << c)))
2542 				continue;
2543 			if (cval->cached & (1 << (c + 1))) {
2544 				err = snd_usb_set_cur_mix_value(cval, c + 1, idx,
2545 							cval->cache_val[idx]);
2546 				if (err < 0)
2547 					return err;
2548 			}
2549 			idx++;
2550 		}
2551 	} else {
2552 		/* master */
2553 		if (cval->cached) {
2554 			err = snd_usb_set_cur_mix_value(cval, 0, 0, *cval->cache_val);
2555 			if (err < 0)
2556 				return err;
2557 		}
2558 	}
2559 
2560 	return 0;
2561 }
2562 
2563 int snd_usb_mixer_resume(struct usb_mixer_interface *mixer, bool reset_resume)
2564 {
2565 	struct usb_mixer_elem_list *list;
2566 	int id, err;
2567 
2568 	if (reset_resume) {
2569 		/* restore cached mixer values */
2570 		for (id = 0; id < MAX_ID_ELEMS; id++) {
2571 			for (list = mixer->id_elems[id]; list;
2572 			     list = list->next_id_elem) {
2573 				if (list->resume) {
2574 					err = list->resume(list);
2575 					if (err < 0)
2576 						return err;
2577 				}
2578 			}
2579 		}
2580 	}
2581 
2582 	return snd_usb_mixer_activate(mixer);
2583 }
2584 #endif
2585 
2586 void snd_usb_mixer_elem_init_std(struct usb_mixer_elem_list *list,
2587 				 struct usb_mixer_interface *mixer,
2588 				 int unitid)
2589 {
2590 	list->mixer = mixer;
2591 	list->id = unitid;
2592 	list->dump = snd_usb_mixer_dump_cval;
2593 #ifdef CONFIG_PM
2594 	list->resume = restore_mixer_value;
2595 #endif
2596 }
2597