xref: /openbmc/linux/sound/usb/mixer_scarlett.c (revision 20e2fc42)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *   Scarlett Driver for ALSA
4  *
5  *   Copyright (c) 2013 by Tobias Hoffmann
6  *   Copyright (c) 2013 by Robin Gareus <robin at gareus.org>
7  *   Copyright (c) 2002 by Takashi Iwai <tiwai at suse.de>
8  *   Copyright (c) 2014 by Chris J Arges <chris.j.arges at canonical.com>
9  *
10  *   Many codes borrowed from audio.c by
11  *	    Alan Cox (alan at lxorguk.ukuu.org.uk)
12  *	    Thomas Sailer (sailer at ife.ee.ethz.ch)
13  *
14  *   Code cleanup:
15  *   David Henningsson <david.henningsson at canonical.com>
16  */
17 
18 /*
19  * Rewritten and extended to support more models, e.g. Scarlett 18i8.
20  *
21  * Auto-detection via UAC2 is not feasible to properly discover the vast
22  * majority of features. It's related to both Linux/ALSA's UAC2 as well as
23  * Focusrite's implementation of it. Eventually quirks may be sufficient but
24  * right now it's a major headache to work arount these things.
25  *
26  * NB. Neither the OSX nor the win driver provided by Focusrite performs
27  * discovery, they seem to operate the same as this driver.
28  */
29 
30 /* Mixer Interface for the Focusrite Scarlett 18i6 audio interface.
31  *
32  * The protocol was reverse engineered by looking at communication between
33  * Scarlett MixControl (v 1.2.128.0) and the Focusrite(R) Scarlett 18i6
34  * (firmware v305) using wireshark and usbmon in January 2013.
35  * Extended in July 2013.
36  *
37  * this mixer gives complete access to all features of the device:
38  *  - change Impedance of inputs (Line-in, Mic / Instrument, Hi-Z)
39  *  - select clock source
40  *  - dynamic input to mixer-matrix assignment
41  *  - 18 x 6 mixer-matrix gain stages
42  *  - bus routing & volume control
43  *  - automatic re-initialization on connect if device was power-cycled
44  *
45  * USB URB commands overview (bRequest = 0x01 = UAC2_CS_CUR)
46  * wIndex
47  * 0x01 Analog Input line/instrument impedance switch, wValue=0x0901 +
48  *      channel, data=Line/Inst (2bytes)
49  *      pad (-10dB) switch, wValue=0x0b01 + channel, data=Off/On (2bytes)
50  *      ?? wValue=0x0803/04, ?? (2bytes)
51  * 0x0a Master Volume, wValue=0x0200+bus[0:all + only 1..4?] data(2bytes)
52  *      Bus Mute/Unmute wValue=0x0100+bus[0:all + only 1..4?], data(2bytes)
53  * 0x28 Clock source, wValue=0x0100, data={1:int,2:spdif,3:adat} (1byte)
54  * 0x29 Set Sample-rate, wValue=0x0100, data=sample-rate(4bytes)
55  * 0x32 Mixer mux, wValue=0x0600 + mixer-channel, data=input-to-connect(2bytes)
56  * 0x33 Output mux, wValue=bus, data=input-to-connect(2bytes)
57  * 0x34 Capture mux, wValue=0...18, data=input-to-connect(2bytes)
58  * 0x3c Matrix Mixer gains, wValue=mixer-node  data=gain(2bytes)
59  *      ?? [sometimes](4bytes, e.g 0x000003be 0x000003bf ...03ff)
60  *
61  * USB reads: (i.e. actually issued by original software)
62  * 0x01 wValue=0x0901+channel (1byte!!), wValue=0x0b01+channed (1byte!!)
63  * 0x29 wValue=0x0100 sample-rate(4bytes)
64  *      wValue=0x0200 ?? 1byte (only once)
65  * 0x2a wValue=0x0100 ?? 4bytes, sample-rate2 ??
66  *
67  * USB reads with bRequest = 0x03 = UAC2_CS_MEM
68  * 0x3c wValue=0x0002 1byte: sync status (locked=1)
69  *      wValue=0x0000 18*2byte: peak meter (inputs)
70  *      wValue=0x0001 8(?)*2byte: peak meter (mix)
71  *      wValue=0x0003 6*2byte: peak meter (pcm/daw)
72  *
73  * USB write with bRequest = 0x03
74  * 0x3c Save settings to hardware: wValue=0x005a, data=0xa5
75  *
76  *
77  * <ditaa>
78  *  /--------------\    18chn            6chn    /--------------\
79  *  | Hardware  in +--+-------\        /------+--+ ALSA PCM out |
80  *  \--------------/  |       |        |      |  \--------------/
81  *                    |       |        |      |
82  *                    |       v        v      |
83  *                    |   +---------------+   |
84  *                    |    \ Matrix  Mux /    |
85  *                    |     +-----+-----+     |
86  *                    |           |           |
87  *                    |           | 18chn     |
88  *                    |           v           |
89  *                    |     +-----------+     |
90  *                    |     | Mixer     |     |
91  *                    |     |    Matrix |     |
92  *                    |     |           |     |
93  *                    |     | 18x6 Gain |     |
94  *                    |     |   stages  |     |
95  *                    |     +-----+-----+     |
96  *                    |           |           |
97  *                    |           |           |
98  *                    | 18chn     | 6chn      | 6chn
99  *                    v           v           v
100  *                    =========================
101  *             +---------------+     +--—------------+
102  *              \ Output  Mux /       \ Capture Mux /
103  *               +-----+-----+         +-----+-----+
104  *                     |                     |
105  *                     | 6chn                |
106  *                     v                     |
107  *              +-------------+              |
108  *              | Master Gain |              |
109  *              +------+------+              |
110  *                     |                     |
111  *                     | 6chn                | 18chn
112  *                     | (3 stereo pairs)    |
113  *  /--------------\   |                     |   /--------------\
114  *  | Hardware out |<--/                     \-->| ALSA PCM  in |
115  *  \--------------/                             \--------------/
116  * </ditaa>
117  *
118  */
119 
120 #include <linux/slab.h>
121 #include <linux/usb.h>
122 #include <linux/usb/audio-v2.h>
123 
124 #include <sound/core.h>
125 #include <sound/control.h>
126 #include <sound/tlv.h>
127 
128 #include "usbaudio.h"
129 #include "mixer.h"
130 #include "helper.h"
131 #include "power.h"
132 
133 #include "mixer_scarlett.h"
134 
135 /* some gui mixers can't handle negative ctl values */
136 #define SND_SCARLETT_LEVEL_BIAS 128
137 #define SND_SCARLETT_MATRIX_IN_MAX 18
138 #define SND_SCARLETT_CONTROLS_MAX 10
139 #define SND_SCARLETT_OFFSETS_MAX 5
140 
141 enum {
142 	SCARLETT_OUTPUTS,
143 	SCARLETT_SWITCH_IMPEDANCE,
144 	SCARLETT_SWITCH_PAD,
145 };
146 
147 enum {
148 	SCARLETT_OFFSET_PCM = 0,
149 	SCARLETT_OFFSET_ANALOG = 1,
150 	SCARLETT_OFFSET_SPDIF = 2,
151 	SCARLETT_OFFSET_ADAT = 3,
152 	SCARLETT_OFFSET_MIX = 4,
153 };
154 
155 struct scarlett_mixer_elem_enum_info {
156 	int start;
157 	int len;
158 	int offsets[SND_SCARLETT_OFFSETS_MAX];
159 	char const * const *names;
160 };
161 
162 struct scarlett_mixer_control {
163 	unsigned char num;
164 	unsigned char type;
165 	const char *name;
166 };
167 
168 struct scarlett_device_info {
169 	int matrix_in;
170 	int matrix_out;
171 	int input_len;
172 	int output_len;
173 
174 	struct scarlett_mixer_elem_enum_info opt_master;
175 	struct scarlett_mixer_elem_enum_info opt_matrix;
176 
177 	/* initial values for matrix mux */
178 	int matrix_mux_init[SND_SCARLETT_MATRIX_IN_MAX];
179 
180 	int num_controls;	/* number of items in controls */
181 	const struct scarlett_mixer_control controls[SND_SCARLETT_CONTROLS_MAX];
182 };
183 
184 /********************** Enum Strings *************************/
185 
186 static const struct scarlett_mixer_elem_enum_info opt_pad = {
187 	.start = 0,
188 	.len = 2,
189 	.offsets = {},
190 	.names = (char const * const []){
191 		"0dB", "-10dB"
192 	}
193 };
194 
195 static const struct scarlett_mixer_elem_enum_info opt_impedance = {
196 	.start = 0,
197 	.len = 2,
198 	.offsets = {},
199 	.names = (char const * const []){
200 		"Line", "Hi-Z"
201 	}
202 };
203 
204 static const struct scarlett_mixer_elem_enum_info opt_clock = {
205 	.start = 1,
206 	.len = 3,
207 	.offsets = {},
208 	.names = (char const * const []){
209 		"Internal", "SPDIF", "ADAT"
210 	}
211 };
212 
213 static const struct scarlett_mixer_elem_enum_info opt_sync = {
214 	.start = 0,
215 	.len = 2,
216 	.offsets = {},
217 	.names = (char const * const []){
218 		"No Lock", "Locked"
219 	}
220 };
221 
222 static int scarlett_ctl_switch_info(struct snd_kcontrol *kctl,
223 		struct snd_ctl_elem_info *uinfo)
224 {
225 	struct usb_mixer_elem_info *elem = kctl->private_data;
226 
227 	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
228 	uinfo->count = elem->channels;
229 	uinfo->value.integer.min = 0;
230 	uinfo->value.integer.max = 1;
231 	return 0;
232 }
233 
234 static int scarlett_ctl_switch_get(struct snd_kcontrol *kctl,
235 		struct snd_ctl_elem_value *ucontrol)
236 {
237 	struct usb_mixer_elem_info *elem = kctl->private_data;
238 	int i, err, val;
239 
240 	for (i = 0; i < elem->channels; i++) {
241 		err = snd_usb_get_cur_mix_value(elem, i, i, &val);
242 		if (err < 0)
243 			return err;
244 
245 		val = !val; /* invert mute logic for mixer */
246 		ucontrol->value.integer.value[i] = val;
247 	}
248 
249 	return 0;
250 }
251 
252 static int scarlett_ctl_switch_put(struct snd_kcontrol *kctl,
253 		struct snd_ctl_elem_value *ucontrol)
254 {
255 	struct usb_mixer_elem_info *elem = kctl->private_data;
256 	int i, changed = 0;
257 	int err, oval, val;
258 
259 	for (i = 0; i < elem->channels; i++) {
260 		err = snd_usb_get_cur_mix_value(elem, i, i, &oval);
261 		if (err < 0)
262 			return err;
263 
264 		val = ucontrol->value.integer.value[i];
265 		val = !val;
266 		if (oval != val) {
267 			err = snd_usb_set_cur_mix_value(elem, i, i, val);
268 			if (err < 0)
269 				return err;
270 
271 			changed = 1;
272 		}
273 	}
274 
275 	return changed;
276 }
277 
278 static int scarlett_ctl_resume(struct usb_mixer_elem_list *list)
279 {
280 	struct usb_mixer_elem_info *elem = mixer_elem_list_to_info(list);
281 	int i;
282 
283 	for (i = 0; i < elem->channels; i++)
284 		if (elem->cached & (1 << i))
285 			snd_usb_set_cur_mix_value(elem, i, i,
286 						  elem->cache_val[i]);
287 	return 0;
288 }
289 
290 static int scarlett_ctl_info(struct snd_kcontrol *kctl,
291 			     struct snd_ctl_elem_info *uinfo)
292 {
293 	struct usb_mixer_elem_info *elem = kctl->private_data;
294 
295 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
296 	uinfo->count = elem->channels;
297 	uinfo->value.integer.min = 0;
298 	uinfo->value.integer.max = (int)kctl->private_value +
299 		SND_SCARLETT_LEVEL_BIAS;
300 	uinfo->value.integer.step = 1;
301 	return 0;
302 }
303 
304 static int scarlett_ctl_get(struct snd_kcontrol *kctl,
305 			    struct snd_ctl_elem_value *ucontrol)
306 {
307 	struct usb_mixer_elem_info *elem = kctl->private_data;
308 	int i, err, val;
309 
310 	for (i = 0; i < elem->channels; i++) {
311 		err = snd_usb_get_cur_mix_value(elem, i, i, &val);
312 		if (err < 0)
313 			return err;
314 
315 		val = clamp(val / 256, -128, (int)kctl->private_value) +
316 				    SND_SCARLETT_LEVEL_BIAS;
317 		ucontrol->value.integer.value[i] = val;
318 	}
319 
320 	return 0;
321 }
322 
323 static int scarlett_ctl_put(struct snd_kcontrol *kctl,
324 			    struct snd_ctl_elem_value *ucontrol)
325 {
326 	struct usb_mixer_elem_info *elem = kctl->private_data;
327 	int i, changed = 0;
328 	int err, oval, val;
329 
330 	for (i = 0; i < elem->channels; i++) {
331 		err = snd_usb_get_cur_mix_value(elem, i, i, &oval);
332 		if (err < 0)
333 			return err;
334 
335 		val = ucontrol->value.integer.value[i] -
336 			SND_SCARLETT_LEVEL_BIAS;
337 		val = val * 256;
338 		if (oval != val) {
339 			err = snd_usb_set_cur_mix_value(elem, i, i, val);
340 			if (err < 0)
341 				return err;
342 
343 			changed = 1;
344 		}
345 	}
346 
347 	return changed;
348 }
349 
350 static void scarlett_generate_name(int i, char *dst, int offsets[])
351 {
352 	if (i > offsets[SCARLETT_OFFSET_MIX])
353 		sprintf(dst, "Mix %c",
354 			'A'+(i - offsets[SCARLETT_OFFSET_MIX] - 1));
355 	else if (i > offsets[SCARLETT_OFFSET_ADAT])
356 		sprintf(dst, "ADAT %d", i - offsets[SCARLETT_OFFSET_ADAT]);
357 	else if (i > offsets[SCARLETT_OFFSET_SPDIF])
358 		sprintf(dst, "SPDIF %d", i - offsets[SCARLETT_OFFSET_SPDIF]);
359 	else if (i > offsets[SCARLETT_OFFSET_ANALOG])
360 		sprintf(dst, "Analog %d", i - offsets[SCARLETT_OFFSET_ANALOG]);
361 	else if (i > offsets[SCARLETT_OFFSET_PCM])
362 		sprintf(dst, "PCM %d", i - offsets[SCARLETT_OFFSET_PCM]);
363 	else
364 		sprintf(dst, "Off");
365 }
366 
367 static int scarlett_ctl_enum_dynamic_info(struct snd_kcontrol *kctl,
368 					  struct snd_ctl_elem_info *uinfo)
369 {
370 	struct usb_mixer_elem_info *elem = kctl->private_data;
371 	struct scarlett_mixer_elem_enum_info *opt = elem->private_data;
372 	unsigned int items = opt->len;
373 
374 	uinfo->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
375 	uinfo->count = elem->channels;
376 	uinfo->value.enumerated.items = items;
377 
378 	if (uinfo->value.enumerated.item >= items)
379 		uinfo->value.enumerated.item = items - 1;
380 
381 	/* generate name dynamically based on item number and offset info */
382 	scarlett_generate_name(uinfo->value.enumerated.item,
383 			       uinfo->value.enumerated.name,
384 			       opt->offsets);
385 
386 	return 0;
387 }
388 
389 static int scarlett_ctl_enum_info(struct snd_kcontrol *kctl,
390 				  struct snd_ctl_elem_info *uinfo)
391 {
392 	struct usb_mixer_elem_info *elem = kctl->private_data;
393 	struct scarlett_mixer_elem_enum_info *opt = elem->private_data;
394 
395 	return snd_ctl_enum_info(uinfo, elem->channels, opt->len,
396 				 (const char * const *)opt->names);
397 }
398 
399 static int scarlett_ctl_enum_get(struct snd_kcontrol *kctl,
400 				 struct snd_ctl_elem_value *ucontrol)
401 {
402 	struct usb_mixer_elem_info *elem = kctl->private_data;
403 	struct scarlett_mixer_elem_enum_info *opt = elem->private_data;
404 	int err, val;
405 
406 	err = snd_usb_get_cur_mix_value(elem, 0, 0, &val);
407 	if (err < 0)
408 		return err;
409 
410 	val = clamp(val - opt->start, 0, opt->len-1);
411 
412 	ucontrol->value.enumerated.item[0] = val;
413 
414 	return 0;
415 }
416 
417 static int scarlett_ctl_enum_put(struct snd_kcontrol *kctl,
418 				 struct snd_ctl_elem_value *ucontrol)
419 {
420 	struct usb_mixer_elem_info *elem = kctl->private_data;
421 	struct scarlett_mixer_elem_enum_info *opt = elem->private_data;
422 	int err, oval, val;
423 
424 	err = snd_usb_get_cur_mix_value(elem, 0, 0, &oval);
425 	if (err < 0)
426 		return err;
427 
428 	val = ucontrol->value.integer.value[0];
429 	val = val + opt->start;
430 	if (val != oval) {
431 		snd_usb_set_cur_mix_value(elem, 0, 0, val);
432 		return 1;
433 	}
434 	return 0;
435 }
436 
437 static int scarlett_ctl_enum_resume(struct usb_mixer_elem_list *list)
438 {
439 	struct usb_mixer_elem_info *elem = mixer_elem_list_to_info(list);
440 
441 	if (elem->cached)
442 		snd_usb_set_cur_mix_value(elem, 0, 0, *elem->cache_val);
443 	return 0;
444 }
445 
446 static int scarlett_ctl_meter_get(struct snd_kcontrol *kctl,
447 				  struct snd_ctl_elem_value *ucontrol)
448 {
449 	struct usb_mixer_elem_info *elem = kctl->private_data;
450 	struct snd_usb_audio *chip = elem->head.mixer->chip;
451 	unsigned char buf[2 * MAX_CHANNELS] = {0, };
452 	int wValue = (elem->control << 8) | elem->idx_off;
453 	int idx = snd_usb_ctrl_intf(chip) | (elem->head.id << 8);
454 	int err;
455 
456 	err = snd_usb_ctl_msg(chip->dev,
457 				usb_rcvctrlpipe(chip->dev, 0),
458 				UAC2_CS_MEM,
459 				USB_RECIP_INTERFACE | USB_TYPE_CLASS |
460 				USB_DIR_IN, wValue, idx, buf, elem->channels);
461 	if (err < 0)
462 		return err;
463 
464 	ucontrol->value.enumerated.item[0] = clamp((int)buf[0], 0, 1);
465 	return 0;
466 }
467 
468 static const struct snd_kcontrol_new usb_scarlett_ctl_switch = {
469 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
470 	.name = "",
471 	.info = scarlett_ctl_switch_info,
472 	.get =  scarlett_ctl_switch_get,
473 	.put =  scarlett_ctl_switch_put,
474 };
475 
476 static const DECLARE_TLV_DB_SCALE(db_scale_scarlett_gain, -12800, 100, 0);
477 
478 static const struct snd_kcontrol_new usb_scarlett_ctl = {
479 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
480 	.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
481 		  SNDRV_CTL_ELEM_ACCESS_TLV_READ,
482 	.name = "",
483 	.info = scarlett_ctl_info,
484 	.get =  scarlett_ctl_get,
485 	.put =  scarlett_ctl_put,
486 	.private_value = 6,  /* max value */
487 	.tlv = { .p = db_scale_scarlett_gain }
488 };
489 
490 static const struct snd_kcontrol_new usb_scarlett_ctl_master = {
491 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
492 	.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
493 		  SNDRV_CTL_ELEM_ACCESS_TLV_READ,
494 	.name = "",
495 	.info = scarlett_ctl_info,
496 	.get =  scarlett_ctl_get,
497 	.put =  scarlett_ctl_put,
498 	.private_value = 6,  /* max value */
499 	.tlv = { .p = db_scale_scarlett_gain }
500 };
501 
502 static const struct snd_kcontrol_new usb_scarlett_ctl_enum = {
503 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
504 	.name = "",
505 	.info = scarlett_ctl_enum_info,
506 	.get =  scarlett_ctl_enum_get,
507 	.put =  scarlett_ctl_enum_put,
508 };
509 
510 static const struct snd_kcontrol_new usb_scarlett_ctl_dynamic_enum = {
511 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
512 	.name = "",
513 	.info = scarlett_ctl_enum_dynamic_info,
514 	.get =  scarlett_ctl_enum_get,
515 	.put =  scarlett_ctl_enum_put,
516 };
517 
518 static const struct snd_kcontrol_new usb_scarlett_ctl_sync = {
519 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
520 	.access = SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE,
521 	.name = "",
522 	.info = scarlett_ctl_enum_info,
523 	.get =  scarlett_ctl_meter_get,
524 };
525 
526 static int add_new_ctl(struct usb_mixer_interface *mixer,
527 		       const struct snd_kcontrol_new *ncontrol,
528 		       usb_mixer_elem_resume_func_t resume,
529 		       int index, int offset, int num,
530 		       int val_type, int channels, const char *name,
531 		       const struct scarlett_mixer_elem_enum_info *opt,
532 		       struct usb_mixer_elem_info **elem_ret
533 )
534 {
535 	struct snd_kcontrol *kctl;
536 	struct usb_mixer_elem_info *elem;
537 	int err;
538 
539 	elem = kzalloc(sizeof(*elem), GFP_KERNEL);
540 	if (!elem)
541 		return -ENOMEM;
542 
543 	elem->head.mixer = mixer;
544 	elem->head.resume = resume;
545 	elem->control = offset;
546 	elem->idx_off = num;
547 	elem->head.id = index;
548 	elem->val_type = val_type;
549 
550 	elem->channels = channels;
551 
552 	/* add scarlett_mixer_elem_enum_info struct */
553 	elem->private_data = (void *)opt;
554 
555 	kctl = snd_ctl_new1(ncontrol, elem);
556 	if (!kctl) {
557 		kfree(elem);
558 		return -ENOMEM;
559 	}
560 	kctl->private_free = snd_usb_mixer_elem_free;
561 
562 	strlcpy(kctl->id.name, name, sizeof(kctl->id.name));
563 
564 	err = snd_usb_mixer_add_control(&elem->head, kctl);
565 	if (err < 0)
566 		return err;
567 
568 	if (elem_ret)
569 		*elem_ret = elem;
570 
571 	return 0;
572 }
573 
574 static int add_output_ctls(struct usb_mixer_interface *mixer,
575 			   int index, const char *name,
576 			   const struct scarlett_device_info *info)
577 {
578 	int err;
579 	char mx[SNDRV_CTL_ELEM_ID_NAME_MAXLEN];
580 	struct usb_mixer_elem_info *elem;
581 
582 	/* Add mute switch */
583 	snprintf(mx, sizeof(mx), "Master %d (%s) Playback Switch",
584 		index + 1, name);
585 	err = add_new_ctl(mixer, &usb_scarlett_ctl_switch,
586 			  scarlett_ctl_resume, 0x0a, 0x01,
587 			  2*index+1, USB_MIXER_S16, 2, mx, NULL, &elem);
588 	if (err < 0)
589 		return err;
590 
591 	/* Add volume control and initialize to 0 */
592 	snprintf(mx, sizeof(mx), "Master %d (%s) Playback Volume",
593 		index + 1, name);
594 	err = add_new_ctl(mixer, &usb_scarlett_ctl_master,
595 			  scarlett_ctl_resume, 0x0a, 0x02,
596 			  2*index+1, USB_MIXER_S16, 2, mx, NULL, &elem);
597 	if (err < 0)
598 		return err;
599 
600 	/* Add L channel source playback enumeration */
601 	snprintf(mx, sizeof(mx), "Master %dL (%s) Source Playback Enum",
602 		index + 1, name);
603 	err = add_new_ctl(mixer, &usb_scarlett_ctl_dynamic_enum,
604 			  scarlett_ctl_enum_resume, 0x33, 0x00,
605 			  2*index, USB_MIXER_S16, 1, mx, &info->opt_master,
606 			  &elem);
607 	if (err < 0)
608 		return err;
609 
610 	/* Add R channel source playback enumeration */
611 	snprintf(mx, sizeof(mx), "Master %dR (%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+1, USB_MIXER_S16, 1, mx, &info->opt_master,
616 			  &elem);
617 	if (err < 0)
618 		return err;
619 
620 	return 0;
621 }
622 
623 /********************** device-specific config *************************/
624 
625 /*  untested...  */
626 static struct scarlett_device_info s6i6_info = {
627 	.matrix_in = 18,
628 	.matrix_out = 8,
629 	.input_len = 6,
630 	.output_len = 6,
631 
632 	.opt_master = {
633 		.start = -1,
634 		.len = 27,
635 		.offsets = {0, 12, 16, 18, 18},
636 		.names = NULL
637 	},
638 
639 	.opt_matrix = {
640 		.start = -1,
641 		.len = 19,
642 		.offsets = {0, 12, 16, 18, 18},
643 		.names = NULL
644 	},
645 
646 	.num_controls = 9,
647 	.controls = {
648 		{ .num = 0, .type = SCARLETT_OUTPUTS, .name = "Monitor" },
649 		{ .num = 1, .type = SCARLETT_OUTPUTS, .name = "Headphone" },
650 		{ .num = 2, .type = SCARLETT_OUTPUTS, .name = "SPDIF" },
651 		{ .num = 1, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
652 		{ .num = 1, .type = SCARLETT_SWITCH_PAD, .name = NULL},
653 		{ .num = 2, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
654 		{ .num = 2, .type = SCARLETT_SWITCH_PAD, .name = NULL},
655 		{ .num = 3, .type = SCARLETT_SWITCH_PAD, .name = NULL},
656 		{ .num = 4, .type = SCARLETT_SWITCH_PAD, .name = NULL},
657 	},
658 
659 	.matrix_mux_init = {
660 		12, 13, 14, 15,                 /* Analog -> 1..4 */
661 		16, 17,                          /* SPDIF -> 5,6 */
662 		0, 1, 2, 3, 4, 5, 6, 7,     /* PCM[1..12] -> 7..18 */
663 		8, 9, 10, 11
664 	}
665 };
666 
667 /*  untested...  */
668 static struct scarlett_device_info s8i6_info = {
669 	.matrix_in = 18,
670 	.matrix_out = 6,
671 	.input_len = 8,
672 	.output_len = 6,
673 
674 	.opt_master = {
675 		.start = -1,
676 		.len = 25,
677 		.offsets = {0, 12, 16, 18, 18},
678 		.names = NULL
679 	},
680 
681 	.opt_matrix = {
682 		.start = -1,
683 		.len = 19,
684 		.offsets = {0, 12, 16, 18, 18},
685 		.names = NULL
686 	},
687 
688 	.num_controls = 7,
689 	.controls = {
690 		{ .num = 0, .type = SCARLETT_OUTPUTS, .name = "Monitor" },
691 		{ .num = 1, .type = SCARLETT_OUTPUTS, .name = "Headphone" },
692 		{ .num = 2, .type = SCARLETT_OUTPUTS, .name = "SPDIF" },
693 		{ .num = 1, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
694 		{ .num = 2, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
695 		{ .num = 3, .type = SCARLETT_SWITCH_PAD, .name = NULL},
696 		{ .num = 4, .type = SCARLETT_SWITCH_PAD, .name = NULL},
697 	},
698 
699 	.matrix_mux_init = {
700 		12, 13, 14, 15,                 /* Analog -> 1..4 */
701 		16, 17,                          /* SPDIF -> 5,6 */
702 		0, 1, 2, 3, 4, 5, 6, 7,     /* PCM[1..12] -> 7..18 */
703 		8, 9, 10, 11
704 	}
705 };
706 
707 static struct scarlett_device_info s18i6_info = {
708 	.matrix_in = 18,
709 	.matrix_out = 6,
710 	.input_len = 18,
711 	.output_len = 6,
712 
713 	.opt_master = {
714 		.start = -1,
715 		.len = 31,
716 		.offsets = {0, 6, 14, 16, 24},
717 		.names = NULL,
718 	},
719 
720 	.opt_matrix = {
721 		.start = -1,
722 		.len = 25,
723 		.offsets = {0, 6, 14, 16, 24},
724 		.names = NULL,
725 	},
726 
727 	.num_controls = 5,
728 	.controls = {
729 		{ .num = 0, .type = SCARLETT_OUTPUTS, .name = "Monitor" },
730 		{ .num = 1, .type = SCARLETT_OUTPUTS, .name = "Headphone" },
731 		{ .num = 2, .type = SCARLETT_OUTPUTS, .name = "SPDIF" },
732 		{ .num = 1, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
733 		{ .num = 2, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
734 	},
735 
736 	.matrix_mux_init = {
737 		 6,  7,  8,  9, 10, 11, 12, 13, /* Analog -> 1..8 */
738 		16, 17, 18, 19, 20, 21,     /* ADAT[1..6] -> 9..14 */
739 		14, 15,                          /* SPDIF -> 15,16 */
740 		0, 1                          /* PCM[1,2] -> 17,18 */
741 	}
742 };
743 
744 static struct scarlett_device_info s18i8_info = {
745 	.matrix_in = 18,
746 	.matrix_out = 8,
747 	.input_len = 18,
748 	.output_len = 8,
749 
750 	.opt_master = {
751 		.start = -1,
752 		.len = 35,
753 		.offsets = {0, 8, 16, 18, 26},
754 		.names = NULL
755 	},
756 
757 	.opt_matrix = {
758 		.start = -1,
759 		.len = 27,
760 		.offsets = {0, 8, 16, 18, 26},
761 		.names = NULL
762 	},
763 
764 	.num_controls = 10,
765 	.controls = {
766 		{ .num = 0, .type = SCARLETT_OUTPUTS, .name = "Monitor" },
767 		{ .num = 1, .type = SCARLETT_OUTPUTS, .name = "Headphone 1" },
768 		{ .num = 2, .type = SCARLETT_OUTPUTS, .name = "Headphone 2" },
769 		{ .num = 3, .type = SCARLETT_OUTPUTS, .name = "SPDIF" },
770 		{ .num = 1, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
771 		{ .num = 1, .type = SCARLETT_SWITCH_PAD, .name = NULL},
772 		{ .num = 2, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
773 		{ .num = 2, .type = SCARLETT_SWITCH_PAD, .name = NULL},
774 		{ .num = 3, .type = SCARLETT_SWITCH_PAD, .name = NULL},
775 		{ .num = 4, .type = SCARLETT_SWITCH_PAD, .name = NULL},
776 	},
777 
778 	.matrix_mux_init = {
779 		 8,  9, 10, 11, 12, 13, 14, 15, /* Analog -> 1..8 */
780 		18, 19, 20, 21, 22, 23,     /* ADAT[1..6] -> 9..14 */
781 		16, 17,                          /* SPDIF -> 15,16 */
782 		0, 1                          /* PCM[1,2] -> 17,18 */
783 	}
784 };
785 
786 static struct scarlett_device_info s18i20_info = {
787 	.matrix_in = 18,
788 	.matrix_out = 8,
789 	.input_len = 18,
790 	.output_len = 20,
791 
792 	.opt_master = {
793 		.start = -1,
794 		.len = 47,
795 		.offsets = {0, 20, 28, 30, 38},
796 		.names = NULL
797 	},
798 
799 	.opt_matrix = {
800 		.start = -1,
801 		.len = 39,
802 		.offsets = {0, 20, 28, 30, 38},
803 		.names = NULL
804 	},
805 
806 	.num_controls = 10,
807 	.controls = {
808 		{ .num = 0, .type = SCARLETT_OUTPUTS, .name = "Monitor" },
809 		{ .num = 1, .type = SCARLETT_OUTPUTS, .name = "Line 3/4" },
810 		{ .num = 2, .type = SCARLETT_OUTPUTS, .name = "Line 5/6" },
811 		{ .num = 3, .type = SCARLETT_OUTPUTS, .name = "Line 7/8" },
812 		{ .num = 4, .type = SCARLETT_OUTPUTS, .name = "Line 9/10" },
813 		{ .num = 5, .type = SCARLETT_OUTPUTS, .name = "SPDIF" },
814 		{ .num = 6, .type = SCARLETT_OUTPUTS, .name = "ADAT 1/2" },
815 		{ .num = 7, .type = SCARLETT_OUTPUTS, .name = "ADAT 3/4" },
816 		{ .num = 8, .type = SCARLETT_OUTPUTS, .name = "ADAT 5/6" },
817 		{ .num = 9, .type = SCARLETT_OUTPUTS, .name = "ADAT 7/8" },
818 		/*{ .num = 1, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
819 		{ .num = 1, .type = SCARLETT_SWITCH_PAD, .name = NULL},
820 		{ .num = 2, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
821 		{ .num = 2, .type = SCARLETT_SWITCH_PAD, .name = NULL},
822 		{ .num = 3, .type = SCARLETT_SWITCH_PAD, .name = NULL},
823 		{ .num = 4, .type = SCARLETT_SWITCH_PAD, .name = NULL},*/
824 	},
825 
826 	.matrix_mux_init = {
827 		20, 21, 22, 23, 24, 25, 26, 27, /* Analog -> 1..8 */
828 		30, 31, 32, 33, 34, 35,     /* ADAT[1..6] -> 9..14 */
829 		28, 29,                          /* SPDIF -> 15,16 */
830 		0, 1                          /* PCM[1,2] -> 17,18 */
831 	}
832 };
833 
834 
835 static int scarlett_controls_create_generic(struct usb_mixer_interface *mixer,
836 	struct scarlett_device_info *info)
837 {
838 	int i, err;
839 	char mx[SNDRV_CTL_ELEM_ID_NAME_MAXLEN];
840 	const struct scarlett_mixer_control *ctl;
841 	struct usb_mixer_elem_info *elem;
842 
843 	/* create master switch and playback volume */
844 	err = add_new_ctl(mixer, &usb_scarlett_ctl_switch,
845 			  scarlett_ctl_resume, 0x0a, 0x01, 0,
846 			  USB_MIXER_S16, 1, "Master Playback Switch", NULL,
847 			  &elem);
848 	if (err < 0)
849 		return err;
850 
851 	err = add_new_ctl(mixer, &usb_scarlett_ctl_master,
852 			  scarlett_ctl_resume, 0x0a, 0x02, 0,
853 			  USB_MIXER_S16, 1, "Master Playback Volume", NULL,
854 			  &elem);
855 	if (err < 0)
856 		return err;
857 
858 	/* iterate through controls in info struct and create each one */
859 	for (i = 0; i < info->num_controls; i++) {
860 		ctl = &info->controls[i];
861 
862 		switch (ctl->type) {
863 		case SCARLETT_OUTPUTS:
864 			err = add_output_ctls(mixer, ctl->num, ctl->name, info);
865 			if (err < 0)
866 				return err;
867 			break;
868 		case SCARLETT_SWITCH_IMPEDANCE:
869 			sprintf(mx, "Input %d Impedance Switch", ctl->num);
870 			err = add_new_ctl(mixer, &usb_scarlett_ctl_enum,
871 					  scarlett_ctl_enum_resume, 0x01,
872 					  0x09, ctl->num, USB_MIXER_S16, 1, mx,
873 					  &opt_impedance, &elem);
874 			if (err < 0)
875 				return err;
876 			break;
877 		case SCARLETT_SWITCH_PAD:
878 			sprintf(mx, "Input %d Pad Switch", ctl->num);
879 			err = add_new_ctl(mixer, &usb_scarlett_ctl_enum,
880 					  scarlett_ctl_enum_resume, 0x01,
881 					  0x0b, ctl->num, USB_MIXER_S16, 1, mx,
882 					  &opt_pad, &elem);
883 			if (err < 0)
884 				return err;
885 			break;
886 		}
887 	}
888 
889 	return 0;
890 }
891 
892 /*
893  * Create and initialize a mixer for the Focusrite(R) Scarlett
894  */
895 int snd_scarlett_controls_create(struct usb_mixer_interface *mixer)
896 {
897 	int err, i, o;
898 	char mx[SNDRV_CTL_ELEM_ID_NAME_MAXLEN];
899 	struct scarlett_device_info *info;
900 	struct usb_mixer_elem_info *elem;
901 	static char sample_rate_buffer[4] = { '\x80', '\xbb', '\x00', '\x00' };
902 
903 	/* only use UAC_VERSION_2 */
904 	if (!mixer->protocol)
905 		return 0;
906 
907 	switch (mixer->chip->usb_id) {
908 	case USB_ID(0x1235, 0x8012):
909 		info = &s6i6_info;
910 		break;
911 	case USB_ID(0x1235, 0x8002):
912 		info = &s8i6_info;
913 		break;
914 	case USB_ID(0x1235, 0x8004):
915 		info = &s18i6_info;
916 		break;
917 	case USB_ID(0x1235, 0x8014):
918 		info = &s18i8_info;
919 		break;
920 	case USB_ID(0x1235, 0x800c):
921 		info = &s18i20_info;
922 		break;
923 	default: /* device not (yet) supported */
924 		return -EINVAL;
925 	}
926 
927 	/* generic function to create controls */
928 	err = scarlett_controls_create_generic(mixer, info);
929 	if (err < 0)
930 		return err;
931 
932 	/* setup matrix controls */
933 	for (i = 0; i < info->matrix_in; i++) {
934 		snprintf(mx, sizeof(mx), "Matrix %02d Input Playback Route",
935 			 i+1);
936 		err = add_new_ctl(mixer, &usb_scarlett_ctl_dynamic_enum,
937 				  scarlett_ctl_enum_resume, 0x32,
938 				  0x06, i, USB_MIXER_S16, 1, mx,
939 				  &info->opt_matrix, &elem);
940 		if (err < 0)
941 			return err;
942 
943 		for (o = 0; o < info->matrix_out; o++) {
944 			sprintf(mx, "Matrix %02d Mix %c Playback Volume", i+1,
945 				o+'A');
946 			err = add_new_ctl(mixer, &usb_scarlett_ctl,
947 					  scarlett_ctl_resume, 0x3c, 0x00,
948 					  (i << 3) + (o & 0x07), USB_MIXER_S16,
949 					  1, mx, NULL, &elem);
950 			if (err < 0)
951 				return err;
952 
953 		}
954 	}
955 
956 	for (i = 0; i < info->input_len; i++) {
957 		snprintf(mx, sizeof(mx), "Input Source %02d Capture Route",
958 			 i+1);
959 		err = add_new_ctl(mixer, &usb_scarlett_ctl_dynamic_enum,
960 				  scarlett_ctl_enum_resume, 0x34,
961 				  0x00, i, USB_MIXER_S16, 1, mx,
962 				  &info->opt_master, &elem);
963 		if (err < 0)
964 			return err;
965 	}
966 
967 	/* val_len == 1 needed here */
968 	err = add_new_ctl(mixer, &usb_scarlett_ctl_enum,
969 			  scarlett_ctl_enum_resume, 0x28, 0x01, 0,
970 			  USB_MIXER_U8, 1, "Sample Clock Source",
971 			  &opt_clock, &elem);
972 	if (err < 0)
973 		return err;
974 
975 	/* val_len == 1 and UAC2_CS_MEM */
976 	err = add_new_ctl(mixer, &usb_scarlett_ctl_sync, NULL, 0x3c, 0x00, 2,
977 			  USB_MIXER_U8, 1, "Sample Clock Sync Status",
978 			  &opt_sync, &elem);
979 	if (err < 0)
980 		return err;
981 
982 	/* initialize sampling rate to 48000 */
983 	err = snd_usb_ctl_msg(mixer->chip->dev,
984 		usb_sndctrlpipe(mixer->chip->dev, 0), UAC2_CS_CUR,
985 		USB_RECIP_INTERFACE | USB_TYPE_CLASS |
986 		USB_DIR_OUT, 0x0100, snd_usb_ctrl_intf(mixer->chip) |
987 		(0x29 << 8), sample_rate_buffer, 4);
988 	if (err < 0)
989 		return err;
990 
991 	return err;
992 }
993