xref: /linux/sound/usb/mixer_scarlett.c (revision 18f90d372cf35b387663f1567de701e5393f6eb5)
1 /*
2  *   Scarlett Driver for ALSA
3  *
4  *   Copyright (c) 2013 by Tobias Hoffmann
5  *   Copyright (c) 2013 by Robin Gareus <robin at gareus.org>
6  *   Copyright (c) 2002 by Takashi Iwai <tiwai at suse.de>
7  *   Copyright (c) 2014 by Chris J Arges <chris.j.arges at canonical.com>
8  *
9  *   Many codes borrowed from audio.c by
10  *	    Alan Cox (alan at lxorguk.ukuu.org.uk)
11  *	    Thomas Sailer (sailer at ife.ee.ethz.ch)
12  *
13  *   Code cleanup:
14  *   David Henningsson <david.henningsson at canonical.com>
15  *
16  *   This program is free software; you can redistribute it and/or modify
17  *   it under the terms of the GNU General Public License as published by
18  *   the Free Software Foundation; either version 2 of the License, or
19  *   (at your option) any later version.
20  *
21  *   This program is distributed in the hope that it will be useful,
22  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
23  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
24  *   GNU General Public License for more details.
25  *
26  */
27 
28 /*
29  * Rewritten and extended to support more models, e.g. Scarlett 18i8.
30  *
31  * Auto-detection via UAC2 is not feasible to properly discover the vast
32  * majority of features. It's related to both Linux/ALSA's UAC2 as well as
33  * Focusrite's implementation of it. Eventually quirks may be sufficient but
34  * right now it's a major headache to work arount these things.
35  *
36  * NB. Neither the OSX nor the win driver provided by Focusrite performs
37  * discovery, they seem to operate the same as this driver.
38  */
39 
40 /* Mixer Interface for the Focusrite Scarlett 18i6 audio interface.
41  *
42  * The protocol was reverse engineered by looking at communication between
43  * Scarlett MixControl (v 1.2.128.0) and the Focusrite(R) Scarlett 18i6
44  * (firmware v305) using wireshark and usbmon in January 2013.
45  * Extended in July 2013.
46  *
47  * this mixer gives complete access to all features of the device:
48  *  - change Impedance of inputs (Line-in, Mic / Instrument, Hi-Z)
49  *  - select clock source
50  *  - dynamic input to mixer-matrix assignment
51  *  - 18 x 6 mixer-matrix gain stages
52  *  - bus routing & volume control
53  *  - automatic re-initialization on connect if device was power-cycled
54  *
55  * USB URB commands overview (bRequest = 0x01 = UAC2_CS_CUR)
56  * wIndex
57  * 0x01 Analog Input line/instrument impedance switch, wValue=0x0901 +
58  *      channel, data=Line/Inst (2bytes)
59  *      pad (-10dB) switch, wValue=0x0b01 + channel, data=Off/On (2bytes)
60  *      ?? wValue=0x0803/04, ?? (2bytes)
61  * 0x0a Master Volume, wValue=0x0200+bus[0:all + only 1..4?] data(2bytes)
62  *      Bus Mute/Unmute wValue=0x0100+bus[0:all + only 1..4?], data(2bytes)
63  * 0x28 Clock source, wValue=0x0100, data={1:int,2:spdif,3:adat} (1byte)
64  * 0x29 Set Sample-rate, wValue=0x0100, data=sample-rate(4bytes)
65  * 0x32 Mixer mux, wValue=0x0600 + mixer-channel, data=input-to-connect(2bytes)
66  * 0x33 Output mux, wValue=bus, data=input-to-connect(2bytes)
67  * 0x34 Capture mux, wValue=0...18, data=input-to-connect(2bytes)
68  * 0x3c Matrix Mixer gains, wValue=mixer-node  data=gain(2bytes)
69  *      ?? [sometimes](4bytes, e.g 0x000003be 0x000003bf ...03ff)
70  *
71  * USB reads: (i.e. actually issued by original software)
72  * 0x01 wValue=0x0901+channel (1byte!!), wValue=0x0b01+channed (1byte!!)
73  * 0x29 wValue=0x0100 sample-rate(4bytes)
74  *      wValue=0x0200 ?? 1byte (only once)
75  * 0x2a wValue=0x0100 ?? 4bytes, sample-rate2 ??
76  *
77  * USB reads with bRequest = 0x03 = UAC2_CS_MEM
78  * 0x3c wValue=0x0002 1byte: sync status (locked=1)
79  *      wValue=0x0000 18*2byte: peak meter (inputs)
80  *      wValue=0x0001 8(?)*2byte: peak meter (mix)
81  *      wValue=0x0003 6*2byte: peak meter (pcm/daw)
82  *
83  * USB write with bRequest = 0x03
84  * 0x3c Save settings to hardware: wValue=0x005a, data=0xa5
85  *
86  *
87  * <ditaa>
88  *  /--------------\    18chn            6chn    /--------------\
89  *  | Hardware  in +--+-------\        /------+--+ ALSA PCM out |
90  *  \--------------/  |       |        |      |  \--------------/
91  *                    |       |        |      |
92  *                    |       v        v      |
93  *                    |   +---------------+   |
94  *                    |    \ Matrix  Mux /    |
95  *                    |     +-----+-----+     |
96  *                    |           |           |
97  *                    |           | 18chn     |
98  *                    |           v           |
99  *                    |     +-----------+     |
100  *                    |     | Mixer     |     |
101  *                    |     |    Matrix |     |
102  *                    |     |           |     |
103  *                    |     | 18x6 Gain |     |
104  *                    |     |   stages  |     |
105  *                    |     +-----+-----+     |
106  *                    |           |           |
107  *                    |           |           |
108  *                    | 18chn     | 6chn      | 6chn
109  *                    v           v           v
110  *                    =========================
111  *             +---------------+     +--—------------+
112  *              \ Output  Mux /       \ Capture Mux /
113  *               +-----+-----+         +-----+-----+
114  *                     |                     |
115  *                     | 6chn                |
116  *                     v                     |
117  *              +-------------+              |
118  *              | Master Gain |              |
119  *              +------+------+              |
120  *                     |                     |
121  *                     | 6chn                | 18chn
122  *                     | (3 stereo pairs)    |
123  *  /--------------\   |                     |   /--------------\
124  *  | Hardware out |<--/                     \-->| ALSA PCM  in |
125  *  \--------------/                             \--------------/
126  * </ditaa>
127  *
128  */
129 
130 #include <linux/slab.h>
131 #include <linux/usb.h>
132 #include <linux/usb/audio-v2.h>
133 
134 #include <sound/core.h>
135 #include <sound/control.h>
136 #include <sound/tlv.h>
137 
138 #include "usbaudio.h"
139 #include "mixer.h"
140 #include "helper.h"
141 #include "power.h"
142 
143 #include "mixer_scarlett.h"
144 
145 /* some gui mixers can't handle negative ctl values */
146 #define SND_SCARLETT_LEVEL_BIAS 128
147 #define SND_SCARLETT_MATRIX_IN_MAX 18
148 #define SND_SCARLETT_CONTROLS_MAX 10
149 #define SND_SCARLETT_OFFSETS_MAX 5
150 
151 enum {
152 	SCARLETT_OUTPUTS,
153 	SCARLETT_SWITCH_IMPEDANCE,
154 	SCARLETT_SWITCH_PAD,
155 };
156 
157 enum {
158 	SCARLETT_OFFSET_PCM = 0,
159 	SCARLETT_OFFSET_ANALOG = 1,
160 	SCARLETT_OFFSET_SPDIF = 2,
161 	SCARLETT_OFFSET_ADAT = 3,
162 	SCARLETT_OFFSET_MIX = 4,
163 };
164 
165 struct scarlett_mixer_elem_enum_info {
166 	int start;
167 	int len;
168 	int offsets[SND_SCARLETT_OFFSETS_MAX];
169 	char const * const *names;
170 };
171 
172 struct scarlett_mixer_control {
173 	unsigned char num;
174 	unsigned char type;
175 	const char *name;
176 };
177 
178 struct scarlett_device_info {
179 	int matrix_in;
180 	int matrix_out;
181 	int input_len;
182 	int output_len;
183 
184 	struct scarlett_mixer_elem_enum_info opt_master;
185 	struct scarlett_mixer_elem_enum_info opt_matrix;
186 
187 	/* initial values for matrix mux */
188 	int matrix_mux_init[SND_SCARLETT_MATRIX_IN_MAX];
189 
190 	int num_controls;	/* number of items in controls */
191 	const struct scarlett_mixer_control controls[SND_SCARLETT_CONTROLS_MAX];
192 };
193 
194 /********************** Enum Strings *************************/
195 
196 static const struct scarlett_mixer_elem_enum_info opt_pad = {
197 	.start = 0,
198 	.len = 2,
199 	.offsets = {},
200 	.names = (char const * const []){
201 		"0dB", "-10dB"
202 	}
203 };
204 
205 static const struct scarlett_mixer_elem_enum_info opt_impedance = {
206 	.start = 0,
207 	.len = 2,
208 	.offsets = {},
209 	.names = (char const * const []){
210 		"Line", "Hi-Z"
211 	}
212 };
213 
214 static const struct scarlett_mixer_elem_enum_info opt_clock = {
215 	.start = 1,
216 	.len = 3,
217 	.offsets = {},
218 	.names = (char const * const []){
219 		"Internal", "SPDIF", "ADAT"
220 	}
221 };
222 
223 static const struct scarlett_mixer_elem_enum_info opt_sync = {
224 	.start = 0,
225 	.len = 2,
226 	.offsets = {},
227 	.names = (char const * const []){
228 		"No Lock", "Locked"
229 	}
230 };
231 
232 static int scarlett_ctl_switch_info(struct snd_kcontrol *kctl,
233 		struct snd_ctl_elem_info *uinfo)
234 {
235 	struct usb_mixer_elem_info *elem = kctl->private_data;
236 
237 	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
238 	uinfo->count = elem->channels;
239 	uinfo->value.integer.min = 0;
240 	uinfo->value.integer.max = 1;
241 	return 0;
242 }
243 
244 static int scarlett_ctl_switch_get(struct snd_kcontrol *kctl,
245 		struct snd_ctl_elem_value *ucontrol)
246 {
247 	struct usb_mixer_elem_info *elem = kctl->private_data;
248 	int i, err, val;
249 
250 	for (i = 0; i < elem->channels; i++) {
251 		err = snd_usb_get_cur_mix_value(elem, i, i, &val);
252 		if (err < 0)
253 			return err;
254 
255 		val = !val; /* invert mute logic for mixer */
256 		ucontrol->value.integer.value[i] = val;
257 	}
258 
259 	return 0;
260 }
261 
262 static int scarlett_ctl_switch_put(struct snd_kcontrol *kctl,
263 		struct snd_ctl_elem_value *ucontrol)
264 {
265 	struct usb_mixer_elem_info *elem = kctl->private_data;
266 	int i, changed = 0;
267 	int err, oval, val;
268 
269 	for (i = 0; i < elem->channels; i++) {
270 		err = snd_usb_get_cur_mix_value(elem, i, i, &oval);
271 		if (err < 0)
272 			return err;
273 
274 		val = ucontrol->value.integer.value[i];
275 		val = !val;
276 		if (oval != val) {
277 			err = snd_usb_set_cur_mix_value(elem, i, i, val);
278 			if (err < 0)
279 				return err;
280 
281 			changed = 1;
282 		}
283 	}
284 
285 	return changed;
286 }
287 
288 static int scarlett_ctl_resume(struct usb_mixer_elem_list *list)
289 {
290 	struct usb_mixer_elem_info *elem = mixer_elem_list_to_info(list);
291 	int i;
292 
293 	for (i = 0; i < elem->channels; i++)
294 		if (elem->cached & (1 << i))
295 			snd_usb_set_cur_mix_value(elem, i, i,
296 						  elem->cache_val[i]);
297 	return 0;
298 }
299 
300 static int scarlett_ctl_info(struct snd_kcontrol *kctl,
301 			     struct snd_ctl_elem_info *uinfo)
302 {
303 	struct usb_mixer_elem_info *elem = kctl->private_data;
304 
305 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
306 	uinfo->count = elem->channels;
307 	uinfo->value.integer.min = 0;
308 	uinfo->value.integer.max = (int)kctl->private_value +
309 		SND_SCARLETT_LEVEL_BIAS;
310 	uinfo->value.integer.step = 1;
311 	return 0;
312 }
313 
314 static int scarlett_ctl_get(struct snd_kcontrol *kctl,
315 			    struct snd_ctl_elem_value *ucontrol)
316 {
317 	struct usb_mixer_elem_info *elem = kctl->private_data;
318 	int i, err, val;
319 
320 	for (i = 0; i < elem->channels; i++) {
321 		err = snd_usb_get_cur_mix_value(elem, i, i, &val);
322 		if (err < 0)
323 			return err;
324 
325 		val = clamp(val / 256, -128, (int)kctl->private_value) +
326 				    SND_SCARLETT_LEVEL_BIAS;
327 		ucontrol->value.integer.value[i] = val;
328 	}
329 
330 	return 0;
331 }
332 
333 static int scarlett_ctl_put(struct snd_kcontrol *kctl,
334 			    struct snd_ctl_elem_value *ucontrol)
335 {
336 	struct usb_mixer_elem_info *elem = kctl->private_data;
337 	int i, changed = 0;
338 	int err, oval, val;
339 
340 	for (i = 0; i < elem->channels; i++) {
341 		err = snd_usb_get_cur_mix_value(elem, i, i, &oval);
342 		if (err < 0)
343 			return err;
344 
345 		val = ucontrol->value.integer.value[i] -
346 			SND_SCARLETT_LEVEL_BIAS;
347 		val = val * 256;
348 		if (oval != val) {
349 			err = snd_usb_set_cur_mix_value(elem, i, i, val);
350 			if (err < 0)
351 				return err;
352 
353 			changed = 1;
354 		}
355 	}
356 
357 	return changed;
358 }
359 
360 static void scarlett_generate_name(int i, char *dst, int offsets[])
361 {
362 	if (i > offsets[SCARLETT_OFFSET_MIX])
363 		sprintf(dst, "Mix %c",
364 			'A'+(i - offsets[SCARLETT_OFFSET_MIX] - 1));
365 	else if (i > offsets[SCARLETT_OFFSET_ADAT])
366 		sprintf(dst, "ADAT %d", i - offsets[SCARLETT_OFFSET_ADAT]);
367 	else if (i > offsets[SCARLETT_OFFSET_SPDIF])
368 		sprintf(dst, "SPDIF %d", i - offsets[SCARLETT_OFFSET_SPDIF]);
369 	else if (i > offsets[SCARLETT_OFFSET_ANALOG])
370 		sprintf(dst, "Analog %d", i - offsets[SCARLETT_OFFSET_ANALOG]);
371 	else if (i > offsets[SCARLETT_OFFSET_PCM])
372 		sprintf(dst, "PCM %d", i - offsets[SCARLETT_OFFSET_PCM]);
373 	else
374 		sprintf(dst, "Off");
375 }
376 
377 static int scarlett_ctl_enum_dynamic_info(struct snd_kcontrol *kctl,
378 					  struct snd_ctl_elem_info *uinfo)
379 {
380 	struct usb_mixer_elem_info *elem = kctl->private_data;
381 	struct scarlett_mixer_elem_enum_info *opt = elem->private_data;
382 	unsigned int items = opt->len;
383 
384 	uinfo->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
385 	uinfo->count = elem->channels;
386 	uinfo->value.enumerated.items = items;
387 
388 	if (uinfo->value.enumerated.item >= items)
389 		uinfo->value.enumerated.item = items - 1;
390 
391 	/* generate name dynamically based on item number and offset info */
392 	scarlett_generate_name(uinfo->value.enumerated.item,
393 			       uinfo->value.enumerated.name,
394 			       opt->offsets);
395 
396 	return 0;
397 }
398 
399 static int scarlett_ctl_enum_info(struct snd_kcontrol *kctl,
400 				  struct snd_ctl_elem_info *uinfo)
401 {
402 	struct usb_mixer_elem_info *elem = kctl->private_data;
403 	struct scarlett_mixer_elem_enum_info *opt = elem->private_data;
404 
405 	return snd_ctl_enum_info(uinfo, elem->channels, opt->len,
406 				 (const char * const *)opt->names);
407 }
408 
409 static int scarlett_ctl_enum_get(struct snd_kcontrol *kctl,
410 				 struct snd_ctl_elem_value *ucontrol)
411 {
412 	struct usb_mixer_elem_info *elem = kctl->private_data;
413 	struct scarlett_mixer_elem_enum_info *opt = elem->private_data;
414 	int err, val;
415 
416 	err = snd_usb_get_cur_mix_value(elem, 0, 0, &val);
417 	if (err < 0)
418 		return err;
419 
420 	val = clamp(val - opt->start, 0, opt->len-1);
421 
422 	ucontrol->value.enumerated.item[0] = val;
423 
424 	return 0;
425 }
426 
427 static int scarlett_ctl_enum_put(struct snd_kcontrol *kctl,
428 				 struct snd_ctl_elem_value *ucontrol)
429 {
430 	struct usb_mixer_elem_info *elem = kctl->private_data;
431 	struct scarlett_mixer_elem_enum_info *opt = elem->private_data;
432 	int err, oval, val;
433 
434 	err = snd_usb_get_cur_mix_value(elem, 0, 0, &oval);
435 	if (err < 0)
436 		return err;
437 
438 	val = ucontrol->value.integer.value[0];
439 	val = val + opt->start;
440 	if (val != oval) {
441 		snd_usb_set_cur_mix_value(elem, 0, 0, val);
442 		return 1;
443 	}
444 	return 0;
445 }
446 
447 static int scarlett_ctl_enum_resume(struct usb_mixer_elem_list *list)
448 {
449 	struct usb_mixer_elem_info *elem = mixer_elem_list_to_info(list);
450 
451 	if (elem->cached)
452 		snd_usb_set_cur_mix_value(elem, 0, 0, *elem->cache_val);
453 	return 0;
454 }
455 
456 static int scarlett_ctl_meter_get(struct snd_kcontrol *kctl,
457 				  struct snd_ctl_elem_value *ucontrol)
458 {
459 	struct usb_mixer_elem_info *elem = kctl->private_data;
460 	struct snd_usb_audio *chip = elem->head.mixer->chip;
461 	unsigned char buf[2 * MAX_CHANNELS] = {0, };
462 	int wValue = (elem->control << 8) | elem->idx_off;
463 	int idx = snd_usb_ctrl_intf(chip) | (elem->head.id << 8);
464 	int err;
465 
466 	err = snd_usb_ctl_msg(chip->dev,
467 				usb_rcvctrlpipe(chip->dev, 0),
468 				UAC2_CS_MEM,
469 				USB_RECIP_INTERFACE | USB_TYPE_CLASS |
470 				USB_DIR_IN, wValue, idx, buf, elem->channels);
471 	if (err < 0)
472 		return err;
473 
474 	ucontrol->value.enumerated.item[0] = clamp((int)buf[0], 0, 1);
475 	return 0;
476 }
477 
478 static const struct snd_kcontrol_new usb_scarlett_ctl_switch = {
479 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
480 	.name = "",
481 	.info = scarlett_ctl_switch_info,
482 	.get =  scarlett_ctl_switch_get,
483 	.put =  scarlett_ctl_switch_put,
484 };
485 
486 static const DECLARE_TLV_DB_SCALE(db_scale_scarlett_gain, -12800, 100, 0);
487 
488 static const struct snd_kcontrol_new usb_scarlett_ctl = {
489 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
490 	.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
491 		  SNDRV_CTL_ELEM_ACCESS_TLV_READ,
492 	.name = "",
493 	.info = scarlett_ctl_info,
494 	.get =  scarlett_ctl_get,
495 	.put =  scarlett_ctl_put,
496 	.private_value = 6,  /* max value */
497 	.tlv = { .p = db_scale_scarlett_gain }
498 };
499 
500 static const struct snd_kcontrol_new usb_scarlett_ctl_master = {
501 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
502 	.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
503 		  SNDRV_CTL_ELEM_ACCESS_TLV_READ,
504 	.name = "",
505 	.info = scarlett_ctl_info,
506 	.get =  scarlett_ctl_get,
507 	.put =  scarlett_ctl_put,
508 	.private_value = 6,  /* max value */
509 	.tlv = { .p = db_scale_scarlett_gain }
510 };
511 
512 static const struct snd_kcontrol_new usb_scarlett_ctl_enum = {
513 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
514 	.name = "",
515 	.info = scarlett_ctl_enum_info,
516 	.get =  scarlett_ctl_enum_get,
517 	.put =  scarlett_ctl_enum_put,
518 };
519 
520 static const struct snd_kcontrol_new usb_scarlett_ctl_dynamic_enum = {
521 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
522 	.name = "",
523 	.info = scarlett_ctl_enum_dynamic_info,
524 	.get =  scarlett_ctl_enum_get,
525 	.put =  scarlett_ctl_enum_put,
526 };
527 
528 static const struct snd_kcontrol_new usb_scarlett_ctl_sync = {
529 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
530 	.access = SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE,
531 	.name = "",
532 	.info = scarlett_ctl_enum_info,
533 	.get =  scarlett_ctl_meter_get,
534 };
535 
536 static int add_new_ctl(struct usb_mixer_interface *mixer,
537 		       const struct snd_kcontrol_new *ncontrol,
538 		       usb_mixer_elem_resume_func_t resume,
539 		       int index, int offset, int num,
540 		       int val_type, int channels, const char *name,
541 		       const struct scarlett_mixer_elem_enum_info *opt,
542 		       struct usb_mixer_elem_info **elem_ret
543 )
544 {
545 	struct snd_kcontrol *kctl;
546 	struct usb_mixer_elem_info *elem;
547 	int err;
548 
549 	elem = kzalloc(sizeof(*elem), GFP_KERNEL);
550 	if (!elem)
551 		return -ENOMEM;
552 
553 	elem->head.mixer = mixer;
554 	elem->head.resume = resume;
555 	elem->control = offset;
556 	elem->idx_off = num;
557 	elem->head.id = index;
558 	elem->val_type = val_type;
559 
560 	elem->channels = channels;
561 
562 	/* add scarlett_mixer_elem_enum_info struct */
563 	elem->private_data = (void *)opt;
564 
565 	kctl = snd_ctl_new1(ncontrol, elem);
566 	if (!kctl) {
567 		kfree(elem);
568 		return -ENOMEM;
569 	}
570 	kctl->private_free = snd_usb_mixer_elem_free;
571 
572 	strlcpy(kctl->id.name, name, sizeof(kctl->id.name));
573 
574 	err = snd_usb_mixer_add_control(&elem->head, kctl);
575 	if (err < 0)
576 		return err;
577 
578 	if (elem_ret)
579 		*elem_ret = elem;
580 
581 	return 0;
582 }
583 
584 static int add_output_ctls(struct usb_mixer_interface *mixer,
585 			   int index, const char *name,
586 			   const struct scarlett_device_info *info)
587 {
588 	int err;
589 	char mx[SNDRV_CTL_ELEM_ID_NAME_MAXLEN];
590 	struct usb_mixer_elem_info *elem;
591 
592 	/* Add mute switch */
593 	snprintf(mx, sizeof(mx), "Master %d (%s) Playback Switch",
594 		index + 1, name);
595 	err = add_new_ctl(mixer, &usb_scarlett_ctl_switch,
596 			  scarlett_ctl_resume, 0x0a, 0x01,
597 			  2*index+1, USB_MIXER_S16, 2, mx, NULL, &elem);
598 	if (err < 0)
599 		return err;
600 
601 	/* Add volume control and initialize to 0 */
602 	snprintf(mx, sizeof(mx), "Master %d (%s) Playback Volume",
603 		index + 1, name);
604 	err = add_new_ctl(mixer, &usb_scarlett_ctl_master,
605 			  scarlett_ctl_resume, 0x0a, 0x02,
606 			  2*index+1, USB_MIXER_S16, 2, mx, NULL, &elem);
607 	if (err < 0)
608 		return err;
609 
610 	/* Add L channel source playback enumeration */
611 	snprintf(mx, sizeof(mx), "Master %dL (%s) Source Playback Enum",
612 		index + 1, name);
613 	err = add_new_ctl(mixer, &usb_scarlett_ctl_dynamic_enum,
614 			  scarlett_ctl_enum_resume, 0x33, 0x00,
615 			  2*index, USB_MIXER_S16, 1, mx, &info->opt_master,
616 			  &elem);
617 	if (err < 0)
618 		return err;
619 
620 	/* Add R channel source playback enumeration */
621 	snprintf(mx, sizeof(mx), "Master %dR (%s) Source Playback Enum",
622 		index + 1, name);
623 	err = add_new_ctl(mixer, &usb_scarlett_ctl_dynamic_enum,
624 			  scarlett_ctl_enum_resume, 0x33, 0x00,
625 			  2*index+1, USB_MIXER_S16, 1, mx, &info->opt_master,
626 			  &elem);
627 	if (err < 0)
628 		return err;
629 
630 	return 0;
631 }
632 
633 /********************** device-specific config *************************/
634 
635 /*  untested...  */
636 static struct scarlett_device_info s6i6_info = {
637 	.matrix_in = 18,
638 	.matrix_out = 8,
639 	.input_len = 6,
640 	.output_len = 6,
641 
642 	.opt_master = {
643 		.start = -1,
644 		.len = 27,
645 		.offsets = {0, 12, 16, 18, 18},
646 		.names = NULL
647 	},
648 
649 	.opt_matrix = {
650 		.start = -1,
651 		.len = 19,
652 		.offsets = {0, 12, 16, 18, 18},
653 		.names = NULL
654 	},
655 
656 	.num_controls = 9,
657 	.controls = {
658 		{ .num = 0, .type = SCARLETT_OUTPUTS, .name = "Monitor" },
659 		{ .num = 1, .type = SCARLETT_OUTPUTS, .name = "Headphone" },
660 		{ .num = 2, .type = SCARLETT_OUTPUTS, .name = "SPDIF" },
661 		{ .num = 1, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
662 		{ .num = 1, .type = SCARLETT_SWITCH_PAD, .name = NULL},
663 		{ .num = 2, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
664 		{ .num = 2, .type = SCARLETT_SWITCH_PAD, .name = NULL},
665 		{ .num = 3, .type = SCARLETT_SWITCH_PAD, .name = NULL},
666 		{ .num = 4, .type = SCARLETT_SWITCH_PAD, .name = NULL},
667 	},
668 
669 	.matrix_mux_init = {
670 		12, 13, 14, 15,                 /* Analog -> 1..4 */
671 		16, 17,                          /* SPDIF -> 5,6 */
672 		0, 1, 2, 3, 4, 5, 6, 7,     /* PCM[1..12] -> 7..18 */
673 		8, 9, 10, 11
674 	}
675 };
676 
677 /*  untested...  */
678 static struct scarlett_device_info s8i6_info = {
679 	.matrix_in = 18,
680 	.matrix_out = 6,
681 	.input_len = 8,
682 	.output_len = 6,
683 
684 	.opt_master = {
685 		.start = -1,
686 		.len = 25,
687 		.offsets = {0, 12, 16, 18, 18},
688 		.names = NULL
689 	},
690 
691 	.opt_matrix = {
692 		.start = -1,
693 		.len = 19,
694 		.offsets = {0, 12, 16, 18, 18},
695 		.names = NULL
696 	},
697 
698 	.num_controls = 7,
699 	.controls = {
700 		{ .num = 0, .type = SCARLETT_OUTPUTS, .name = "Monitor" },
701 		{ .num = 1, .type = SCARLETT_OUTPUTS, .name = "Headphone" },
702 		{ .num = 2, .type = SCARLETT_OUTPUTS, .name = "SPDIF" },
703 		{ .num = 1, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
704 		{ .num = 2, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
705 		{ .num = 3, .type = SCARLETT_SWITCH_PAD, .name = NULL},
706 		{ .num = 4, .type = SCARLETT_SWITCH_PAD, .name = NULL},
707 	},
708 
709 	.matrix_mux_init = {
710 		12, 13, 14, 15,                 /* Analog -> 1..4 */
711 		16, 17,                          /* SPDIF -> 5,6 */
712 		0, 1, 2, 3, 4, 5, 6, 7,     /* PCM[1..12] -> 7..18 */
713 		8, 9, 10, 11
714 	}
715 };
716 
717 static struct scarlett_device_info s18i6_info = {
718 	.matrix_in = 18,
719 	.matrix_out = 6,
720 	.input_len = 18,
721 	.output_len = 6,
722 
723 	.opt_master = {
724 		.start = -1,
725 		.len = 31,
726 		.offsets = {0, 6, 14, 16, 24},
727 		.names = NULL,
728 	},
729 
730 	.opt_matrix = {
731 		.start = -1,
732 		.len = 25,
733 		.offsets = {0, 6, 14, 16, 24},
734 		.names = NULL,
735 	},
736 
737 	.num_controls = 5,
738 	.controls = {
739 		{ .num = 0, .type = SCARLETT_OUTPUTS, .name = "Monitor" },
740 		{ .num = 1, .type = SCARLETT_OUTPUTS, .name = "Headphone" },
741 		{ .num = 2, .type = SCARLETT_OUTPUTS, .name = "SPDIF" },
742 		{ .num = 1, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
743 		{ .num = 2, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
744 	},
745 
746 	.matrix_mux_init = {
747 		 6,  7,  8,  9, 10, 11, 12, 13, /* Analog -> 1..8 */
748 		16, 17, 18, 19, 20, 21,     /* ADAT[1..6] -> 9..14 */
749 		14, 15,                          /* SPDIF -> 15,16 */
750 		0, 1                          /* PCM[1,2] -> 17,18 */
751 	}
752 };
753 
754 static struct scarlett_device_info s18i8_info = {
755 	.matrix_in = 18,
756 	.matrix_out = 8,
757 	.input_len = 18,
758 	.output_len = 8,
759 
760 	.opt_master = {
761 		.start = -1,
762 		.len = 35,
763 		.offsets = {0, 8, 16, 18, 26},
764 		.names = NULL
765 	},
766 
767 	.opt_matrix = {
768 		.start = -1,
769 		.len = 27,
770 		.offsets = {0, 8, 16, 18, 26},
771 		.names = NULL
772 	},
773 
774 	.num_controls = 10,
775 	.controls = {
776 		{ .num = 0, .type = SCARLETT_OUTPUTS, .name = "Monitor" },
777 		{ .num = 1, .type = SCARLETT_OUTPUTS, .name = "Headphone 1" },
778 		{ .num = 2, .type = SCARLETT_OUTPUTS, .name = "Headphone 2" },
779 		{ .num = 3, .type = SCARLETT_OUTPUTS, .name = "SPDIF" },
780 		{ .num = 1, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
781 		{ .num = 1, .type = SCARLETT_SWITCH_PAD, .name = NULL},
782 		{ .num = 2, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
783 		{ .num = 2, .type = SCARLETT_SWITCH_PAD, .name = NULL},
784 		{ .num = 3, .type = SCARLETT_SWITCH_PAD, .name = NULL},
785 		{ .num = 4, .type = SCARLETT_SWITCH_PAD, .name = NULL},
786 	},
787 
788 	.matrix_mux_init = {
789 		 8,  9, 10, 11, 12, 13, 14, 15, /* Analog -> 1..8 */
790 		18, 19, 20, 21, 22, 23,     /* ADAT[1..6] -> 9..14 */
791 		16, 17,                          /* SPDIF -> 15,16 */
792 		0, 1                          /* PCM[1,2] -> 17,18 */
793 	}
794 };
795 
796 static struct scarlett_device_info s18i20_info = {
797 	.matrix_in = 18,
798 	.matrix_out = 8,
799 	.input_len = 18,
800 	.output_len = 20,
801 
802 	.opt_master = {
803 		.start = -1,
804 		.len = 47,
805 		.offsets = {0, 20, 28, 30, 38},
806 		.names = NULL
807 	},
808 
809 	.opt_matrix = {
810 		.start = -1,
811 		.len = 39,
812 		.offsets = {0, 20, 28, 30, 38},
813 		.names = NULL
814 	},
815 
816 	.num_controls = 10,
817 	.controls = {
818 		{ .num = 0, .type = SCARLETT_OUTPUTS, .name = "Monitor" },
819 		{ .num = 1, .type = SCARLETT_OUTPUTS, .name = "Line 3/4" },
820 		{ .num = 2, .type = SCARLETT_OUTPUTS, .name = "Line 5/6" },
821 		{ .num = 3, .type = SCARLETT_OUTPUTS, .name = "Line 7/8" },
822 		{ .num = 4, .type = SCARLETT_OUTPUTS, .name = "Line 9/10" },
823 		{ .num = 5, .type = SCARLETT_OUTPUTS, .name = "SPDIF" },
824 		{ .num = 6, .type = SCARLETT_OUTPUTS, .name = "ADAT 1/2" },
825 		{ .num = 7, .type = SCARLETT_OUTPUTS, .name = "ADAT 3/4" },
826 		{ .num = 8, .type = SCARLETT_OUTPUTS, .name = "ADAT 5/6" },
827 		{ .num = 9, .type = SCARLETT_OUTPUTS, .name = "ADAT 7/8" },
828 		/*{ .num = 1, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
829 		{ .num = 1, .type = SCARLETT_SWITCH_PAD, .name = NULL},
830 		{ .num = 2, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
831 		{ .num = 2, .type = SCARLETT_SWITCH_PAD, .name = NULL},
832 		{ .num = 3, .type = SCARLETT_SWITCH_PAD, .name = NULL},
833 		{ .num = 4, .type = SCARLETT_SWITCH_PAD, .name = NULL},*/
834 	},
835 
836 	.matrix_mux_init = {
837 		20, 21, 22, 23, 24, 25, 26, 27, /* Analog -> 1..8 */
838 		30, 31, 32, 33, 34, 35,     /* ADAT[1..6] -> 9..14 */
839 		28, 29,                          /* SPDIF -> 15,16 */
840 		0, 1                          /* PCM[1,2] -> 17,18 */
841 	}
842 };
843 
844 
845 static int scarlett_controls_create_generic(struct usb_mixer_interface *mixer,
846 	struct scarlett_device_info *info)
847 {
848 	int i, err;
849 	char mx[SNDRV_CTL_ELEM_ID_NAME_MAXLEN];
850 	const struct scarlett_mixer_control *ctl;
851 	struct usb_mixer_elem_info *elem;
852 
853 	/* create master switch and playback volume */
854 	err = add_new_ctl(mixer, &usb_scarlett_ctl_switch,
855 			  scarlett_ctl_resume, 0x0a, 0x01, 0,
856 			  USB_MIXER_S16, 1, "Master Playback Switch", NULL,
857 			  &elem);
858 	if (err < 0)
859 		return err;
860 
861 	err = add_new_ctl(mixer, &usb_scarlett_ctl_master,
862 			  scarlett_ctl_resume, 0x0a, 0x02, 0,
863 			  USB_MIXER_S16, 1, "Master Playback Volume", NULL,
864 			  &elem);
865 	if (err < 0)
866 		return err;
867 
868 	/* iterate through controls in info struct and create each one */
869 	for (i = 0; i < info->num_controls; i++) {
870 		ctl = &info->controls[i];
871 
872 		switch (ctl->type) {
873 		case SCARLETT_OUTPUTS:
874 			err = add_output_ctls(mixer, ctl->num, ctl->name, info);
875 			if (err < 0)
876 				return err;
877 			break;
878 		case SCARLETT_SWITCH_IMPEDANCE:
879 			sprintf(mx, "Input %d Impedance Switch", ctl->num);
880 			err = add_new_ctl(mixer, &usb_scarlett_ctl_enum,
881 					  scarlett_ctl_enum_resume, 0x01,
882 					  0x09, ctl->num, USB_MIXER_S16, 1, mx,
883 					  &opt_impedance, &elem);
884 			if (err < 0)
885 				return err;
886 			break;
887 		case SCARLETT_SWITCH_PAD:
888 			sprintf(mx, "Input %d Pad Switch", ctl->num);
889 			err = add_new_ctl(mixer, &usb_scarlett_ctl_enum,
890 					  scarlett_ctl_enum_resume, 0x01,
891 					  0x0b, ctl->num, USB_MIXER_S16, 1, mx,
892 					  &opt_pad, &elem);
893 			if (err < 0)
894 				return err;
895 			break;
896 		}
897 	}
898 
899 	return 0;
900 }
901 
902 /*
903  * Create and initialize a mixer for the Focusrite(R) Scarlett
904  */
905 int snd_scarlett_controls_create(struct usb_mixer_interface *mixer)
906 {
907 	int err, i, o;
908 	char mx[SNDRV_CTL_ELEM_ID_NAME_MAXLEN];
909 	struct scarlett_device_info *info;
910 	struct usb_mixer_elem_info *elem;
911 	static char sample_rate_buffer[4] = { '\x80', '\xbb', '\x00', '\x00' };
912 
913 	/* only use UAC_VERSION_2 */
914 	if (!mixer->protocol)
915 		return 0;
916 
917 	switch (mixer->chip->usb_id) {
918 	case USB_ID(0x1235, 0x8012):
919 		info = &s6i6_info;
920 		break;
921 	case USB_ID(0x1235, 0x8002):
922 		info = &s8i6_info;
923 		break;
924 	case USB_ID(0x1235, 0x8004):
925 		info = &s18i6_info;
926 		break;
927 	case USB_ID(0x1235, 0x8014):
928 		info = &s18i8_info;
929 		break;
930 	case USB_ID(0x1235, 0x800c):
931 		info = &s18i20_info;
932 		break;
933 	default: /* device not (yet) supported */
934 		return -EINVAL;
935 	}
936 
937 	/* generic function to create controls */
938 	err = scarlett_controls_create_generic(mixer, info);
939 	if (err < 0)
940 		return err;
941 
942 	/* setup matrix controls */
943 	for (i = 0; i < info->matrix_in; i++) {
944 		snprintf(mx, sizeof(mx), "Matrix %02d Input Playback Route",
945 			 i+1);
946 		err = add_new_ctl(mixer, &usb_scarlett_ctl_dynamic_enum,
947 				  scarlett_ctl_enum_resume, 0x32,
948 				  0x06, i, USB_MIXER_S16, 1, mx,
949 				  &info->opt_matrix, &elem);
950 		if (err < 0)
951 			return err;
952 
953 		for (o = 0; o < info->matrix_out; o++) {
954 			sprintf(mx, "Matrix %02d Mix %c Playback Volume", i+1,
955 				o+'A');
956 			err = add_new_ctl(mixer, &usb_scarlett_ctl,
957 					  scarlett_ctl_resume, 0x3c, 0x00,
958 					  (i << 3) + (o & 0x07), USB_MIXER_S16,
959 					  1, mx, NULL, &elem);
960 			if (err < 0)
961 				return err;
962 
963 		}
964 	}
965 
966 	for (i = 0; i < info->input_len; i++) {
967 		snprintf(mx, sizeof(mx), "Input Source %02d Capture Route",
968 			 i+1);
969 		err = add_new_ctl(mixer, &usb_scarlett_ctl_dynamic_enum,
970 				  scarlett_ctl_enum_resume, 0x34,
971 				  0x00, i, USB_MIXER_S16, 1, mx,
972 				  &info->opt_master, &elem);
973 		if (err < 0)
974 			return err;
975 	}
976 
977 	/* val_len == 1 needed here */
978 	err = add_new_ctl(mixer, &usb_scarlett_ctl_enum,
979 			  scarlett_ctl_enum_resume, 0x28, 0x01, 0,
980 			  USB_MIXER_U8, 1, "Sample Clock Source",
981 			  &opt_clock, &elem);
982 	if (err < 0)
983 		return err;
984 
985 	/* val_len == 1 and UAC2_CS_MEM */
986 	err = add_new_ctl(mixer, &usb_scarlett_ctl_sync, NULL, 0x3c, 0x00, 2,
987 			  USB_MIXER_U8, 1, "Sample Clock Sync Status",
988 			  &opt_sync, &elem);
989 	if (err < 0)
990 		return err;
991 
992 	/* initialize sampling rate to 48000 */
993 	err = snd_usb_ctl_msg(mixer->chip->dev,
994 		usb_sndctrlpipe(mixer->chip->dev, 0), UAC2_CS_CUR,
995 		USB_RECIP_INTERFACE | USB_TYPE_CLASS |
996 		USB_DIR_OUT, 0x0100, snd_usb_ctrl_intf(mixer->chip) |
997 		(0x29 << 8), sample_rate_buffer, 4);
998 	if (err < 0)
999 		return err;
1000 
1001 	return err;
1002 }
1003