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1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Presonus Studio 1810c driver for ALSA
4  * Copyright (C) 2019 Nick Kossifidis <mickflemm@gmail.com>
5  *
6  * Based on reverse engineering of the communication protocol
7  * between the windows driver / Univeral Control (UC) program
8  * and the device, through usbmon.
9  *
10  * For now this bypasses the mixer, with all channels split,
11  * so that the software can mix with greater flexibility.
12  * It also adds controls for the 4 buttons on the front of
13  * the device.
14  */
15 
16 #include <linux/usb.h>
17 #include <linux/usb/audio-v2.h>
18 #include <linux/slab.h>
19 #include <sound/core.h>
20 #include <sound/control.h>
21 
22 #include "usbaudio.h"
23 #include "mixer.h"
24 #include "mixer_quirks.h"
25 #include "helper.h"
26 #include "mixer_s1810c.h"
27 
28 #define SC1810C_CMD_REQ	160
29 #define SC1810C_CMD_REQTYPE \
30 	(USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT)
31 #define SC1810C_CMD_F1		0x50617269
32 #define SC1810C_CMD_F2		0x14
33 
34 /*
35  * DISCLAIMER: These are just guesses based on the
36  * dumps I got.
37  *
38  * It seems like a selects between
39  * device (0), mixer (0x64) and output (0x65)
40  *
41  * For mixer (0x64):
42  *  * b selects an input channel (see below).
43  *  * c selects an output channel pair (see below).
44  *  * d selects left (0) or right (1) of that pair.
45  *  * e 0-> disconnect, 0x01000000-> connect,
46  *	0x0109-> used for stereo-linking channels,
47  *	e is also used for setting volume levels
48  *	in which case b is also set so I guess
49  *	this way it is possible to set the volume
50  *	level from the specified input to the
51  *	specified output.
52  *
53  * IN Channels:
54  * 0  - 7  Mic/Inst/Line (Analog inputs)
55  * 8  - 9  S/PDIF
56  * 10 - 17 ADAT
57  * 18 - 35 DAW (Inputs from the host)
58  *
59  * OUT Channels (pairs):
60  * 0 -> Main out
61  * 1 -> Line1/2
62  * 2 -> Line3/4
63  * 3 -> S/PDIF
64  * 4 -> ADAT?
65  *
66  * For device (0):
67  *  * b and c are not used, at least not on the
68  *    dumps I got.
69  *  * d sets the control id to be modified
70  *    (see below).
71  *  * e sets the setting for that control.
72  *    (so for the switches I was interested
73  *    in it's 0/1)
74  *
75  * For output (0x65):
76  *   * b is the output channel (see above).
77  *   * c is zero.
78  *   * e I guess the same as with mixer except 0x0109
79  *	 which I didn't see in my dumps.
80  *
81  * The two fixed fields have the same values for
82  * mixer and output but a different set for device.
83  */
84 struct s1810c_ctl_packet {
85 	u32 a;
86 	u32 b;
87 	u32 fixed1;
88 	u32 fixed2;
89 	u32 c;
90 	u32 d;
91 	u32 e;
92 };
93 
94 #define SC1810C_CTL_LINE_SW	0
95 #define SC1810C_CTL_MUTE_SW	1
96 #define SC1810C_CTL_AB_SW	3
97 #define SC1810C_CTL_48V_SW	4
98 
99 #define SC1810C_SET_STATE_REQ	161
100 #define SC1810C_SET_STATE_REQTYPE SC1810C_CMD_REQTYPE
101 #define SC1810C_SET_STATE_F1	0x64656D73
102 #define SC1810C_SET_STATE_F2	0xF4
103 
104 #define SC1810C_GET_STATE_REQ	162
105 #define SC1810C_GET_STATE_REQTYPE \
106 	(USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN)
107 #define SC1810C_GET_STATE_F1	SC1810C_SET_STATE_F1
108 #define SC1810C_GET_STATE_F2	SC1810C_SET_STATE_F2
109 
110 #define SC1810C_STATE_F1_IDX	2
111 #define SC1810C_STATE_F2_IDX	3
112 
113 /*
114  * This packet includes mixer volumes and
115  * various other fields, it's an extended
116  * version of ctl_packet, with a and b
117  * being zero and different f1/f2.
118  */
119 struct s1810c_state_packet {
120 	u32 fields[63];
121 };
122 
123 #define SC1810C_STATE_48V_SW	58
124 #define SC1810C_STATE_LINE_SW	59
125 #define SC1810C_STATE_MUTE_SW	60
126 #define SC1810C_STATE_AB_SW	62
127 
128 struct s1810_mixer_state {
129 	uint16_t seqnum;
130 	struct mutex usb_mutex;
131 	struct mutex data_mutex;
132 };
133 
134 static int
snd_s1810c_send_ctl_packet(struct usb_device * dev,u32 a,u32 b,u32 c,u32 d,u32 e)135 snd_s1810c_send_ctl_packet(struct usb_device *dev, u32 a,
136 			   u32 b, u32 c, u32 d, u32 e)
137 {
138 	struct s1810c_ctl_packet pkt = { 0 };
139 	int ret = 0;
140 
141 	pkt.fixed1 = SC1810C_CMD_F1;
142 	pkt.fixed2 = SC1810C_CMD_F2;
143 
144 	pkt.a = a;
145 	pkt.b = b;
146 	pkt.c = c;
147 	pkt.d = d;
148 	/*
149 	 * Value for settings 0/1 for this
150 	 * output channel is always 0 (probably because
151 	 * there is no ADAT output on 1810c)
152 	 */
153 	pkt.e = (c == 4) ? 0 : e;
154 
155 	ret = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
156 			      SC1810C_CMD_REQ,
157 			      SC1810C_CMD_REQTYPE, 0, 0, &pkt, sizeof(pkt));
158 	if (ret < 0) {
159 		dev_warn(&dev->dev, "could not send ctl packet\n");
160 		return ret;
161 	}
162 	return 0;
163 }
164 
165 /*
166  * When opening Universal Control the program periodicaly
167  * sends and receives state packets for syncinc state between
168  * the device and the host.
169  *
170  * Note that if we send only the request to get data back we'll
171  * get an error, we need to first send an empty state packet and
172  * then ask to receive a filled. Their seqnumbers must also match.
173  */
174 static int
snd_sc1810c_get_status_field(struct usb_device * dev,u32 * field,int field_idx,uint16_t * seqnum)175 snd_sc1810c_get_status_field(struct usb_device *dev,
176 			     u32 *field, int field_idx, uint16_t *seqnum)
177 {
178 	struct s1810c_state_packet pkt_out = { { 0 } };
179 	struct s1810c_state_packet pkt_in = { { 0 } };
180 	int ret = 0;
181 
182 	pkt_out.fields[SC1810C_STATE_F1_IDX] = SC1810C_SET_STATE_F1;
183 	pkt_out.fields[SC1810C_STATE_F2_IDX] = SC1810C_SET_STATE_F2;
184 	ret = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0),
185 			      SC1810C_SET_STATE_REQ,
186 			      SC1810C_SET_STATE_REQTYPE,
187 			      (*seqnum), 0, &pkt_out, sizeof(pkt_out));
188 	if (ret < 0) {
189 		dev_warn(&dev->dev, "could not send state packet (%d)\n", ret);
190 		return ret;
191 	}
192 
193 	ret = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0),
194 			      SC1810C_GET_STATE_REQ,
195 			      SC1810C_GET_STATE_REQTYPE,
196 			      (*seqnum), 0, &pkt_in, sizeof(pkt_in));
197 	if (ret < 0) {
198 		dev_warn(&dev->dev, "could not get state field %u (%d)\n",
199 			 field_idx, ret);
200 		return ret;
201 	}
202 
203 	(*field) = pkt_in.fields[field_idx];
204 	(*seqnum)++;
205 	return 0;
206 }
207 
208 /*
209  * This is what I got when bypassing the mixer with
210  * all channels split. I'm not 100% sure of what's going
211  * on, I could probably clean this up based on my observations
212  * but I prefer to keep the same behavior as the windows driver.
213  */
snd_s1810c_init_mixer_maps(struct snd_usb_audio * chip)214 static int snd_s1810c_init_mixer_maps(struct snd_usb_audio *chip)
215 {
216 	u32 a, b, c, e, n, off;
217 	struct usb_device *dev = chip->dev;
218 
219 	/* Set initial volume levels ? */
220 	a = 0x64;
221 	e = 0xbc;
222 	for (n = 0; n < 2; n++) {
223 		off = n * 18;
224 		for (b = off, c = 0; b < 18 + off; b++) {
225 			/* This channel to all outputs ? */
226 			for (c = 0; c <= 8; c++) {
227 				snd_s1810c_send_ctl_packet(dev, a, b, c, 0, e);
228 				snd_s1810c_send_ctl_packet(dev, a, b, c, 1, e);
229 			}
230 			/* This channel to main output (again) */
231 			snd_s1810c_send_ctl_packet(dev, a, b, 0, 0, e);
232 			snd_s1810c_send_ctl_packet(dev, a, b, 0, 1, e);
233 		}
234 		/*
235 		 * I noticed on UC that DAW channels have different
236 		 * initial volumes, so this makes sense.
237 		 */
238 		e = 0xb53bf0;
239 	}
240 
241 	/* Connect analog outputs ? */
242 	a = 0x65;
243 	e = 0x01000000;
244 	for (b = 1; b < 3; b++) {
245 		snd_s1810c_send_ctl_packet(dev, a, b, 0, 0, e);
246 		snd_s1810c_send_ctl_packet(dev, a, b, 0, 1, e);
247 	}
248 	snd_s1810c_send_ctl_packet(dev, a, 0, 0, 0, e);
249 	snd_s1810c_send_ctl_packet(dev, a, 0, 0, 1, e);
250 
251 	/* Set initial volume levels for S/PDIF mappings ? */
252 	a = 0x64;
253 	e = 0xbc;
254 	c = 3;
255 	for (n = 0; n < 2; n++) {
256 		off = n * 18;
257 		for (b = off; b < 18 + off; b++) {
258 			snd_s1810c_send_ctl_packet(dev, a, b, c, 0, e);
259 			snd_s1810c_send_ctl_packet(dev, a, b, c, 1, e);
260 		}
261 		e = 0xb53bf0;
262 	}
263 
264 	/* Connect S/PDIF output ? */
265 	a = 0x65;
266 	e = 0x01000000;
267 	snd_s1810c_send_ctl_packet(dev, a, 3, 0, 0, e);
268 	snd_s1810c_send_ctl_packet(dev, a, 3, 0, 1, e);
269 
270 	/* Connect all outputs (again) ? */
271 	a = 0x65;
272 	e = 0x01000000;
273 	for (b = 0; b < 4; b++) {
274 		snd_s1810c_send_ctl_packet(dev, a, b, 0, 0, e);
275 		snd_s1810c_send_ctl_packet(dev, a, b, 0, 1, e);
276 	}
277 
278 	/* Basic routing to get sound out of the device */
279 	a = 0x64;
280 	e = 0x01000000;
281 	for (c = 0; c < 4; c++) {
282 		for (b = 0; b < 36; b++) {
283 			if ((c == 0 && b == 18) ||	/* DAW1/2 -> Main */
284 			    (c == 1 && b == 20) ||	/* DAW3/4 -> Line3/4 */
285 			    (c == 2 && b == 22) ||	/* DAW4/5 -> Line5/6 */
286 			    (c == 3 && b == 24)) {	/* DAW5/6 -> S/PDIF */
287 				/* Left */
288 				snd_s1810c_send_ctl_packet(dev, a, b, c, 0, e);
289 				snd_s1810c_send_ctl_packet(dev, a, b, c, 1, 0);
290 				b++;
291 				/* Right */
292 				snd_s1810c_send_ctl_packet(dev, a, b, c, 0, 0);
293 				snd_s1810c_send_ctl_packet(dev, a, b, c, 1, e);
294 			} else {
295 				/* Leave the rest disconnected */
296 				snd_s1810c_send_ctl_packet(dev, a, b, c, 0, 0);
297 				snd_s1810c_send_ctl_packet(dev, a, b, c, 1, 0);
298 			}
299 		}
300 	}
301 
302 	/* Set initial volume levels for S/PDIF (again) ? */
303 	a = 0x64;
304 	e = 0xbc;
305 	c = 3;
306 	for (n = 0; n < 2; n++) {
307 		off = n * 18;
308 		for (b = off; b < 18 + off; b++) {
309 			snd_s1810c_send_ctl_packet(dev, a, b, c, 0, e);
310 			snd_s1810c_send_ctl_packet(dev, a, b, c, 1, e);
311 		}
312 		e = 0xb53bf0;
313 	}
314 
315 	/* Connect S/PDIF outputs (again) ? */
316 	a = 0x65;
317 	e = 0x01000000;
318 	snd_s1810c_send_ctl_packet(dev, a, 3, 0, 0, e);
319 	snd_s1810c_send_ctl_packet(dev, a, 3, 0, 1, e);
320 
321 	/* Again ? */
322 	snd_s1810c_send_ctl_packet(dev, a, 3, 0, 0, e);
323 	snd_s1810c_send_ctl_packet(dev, a, 3, 0, 1, e);
324 
325 	return 0;
326 }
327 
328 /*
329  * Sync state with the device and retrieve the requested field,
330  * whose index is specified in (kctl->private_value & 0xFF),
331  * from the received fields array.
332  */
333 static int
snd_s1810c_get_switch_state(struct usb_mixer_interface * mixer,struct snd_kcontrol * kctl,u32 * state)334 snd_s1810c_get_switch_state(struct usb_mixer_interface *mixer,
335 			    struct snd_kcontrol *kctl, u32 *state)
336 {
337 	struct snd_usb_audio *chip = mixer->chip;
338 	struct s1810_mixer_state *private = mixer->private_data;
339 	u32 field = 0;
340 	u32 ctl_idx = (u32) (kctl->private_value & 0xFF);
341 	int ret = 0;
342 
343 	mutex_lock(&private->usb_mutex);
344 	ret = snd_sc1810c_get_status_field(chip->dev, &field,
345 					   ctl_idx, &private->seqnum);
346 	if (ret < 0)
347 		goto unlock;
348 
349 	*state = field;
350  unlock:
351 	mutex_unlock(&private->usb_mutex);
352 	return ret ? ret : 0;
353 }
354 
355 /*
356  * Send a control packet to the device for the control id
357  * specified in (kctl->private_value >> 8) with value
358  * specified in (kctl->private_value >> 16).
359  */
360 static int
snd_s1810c_set_switch_state(struct usb_mixer_interface * mixer,struct snd_kcontrol * kctl)361 snd_s1810c_set_switch_state(struct usb_mixer_interface *mixer,
362 			    struct snd_kcontrol *kctl)
363 {
364 	struct snd_usb_audio *chip = mixer->chip;
365 	struct s1810_mixer_state *private = mixer->private_data;
366 	u32 pval = (u32) kctl->private_value;
367 	u32 ctl_id = (pval >> 8) & 0xFF;
368 	u32 ctl_val = (pval >> 16) & 0x1;
369 	int ret = 0;
370 
371 	mutex_lock(&private->usb_mutex);
372 	ret = snd_s1810c_send_ctl_packet(chip->dev, 0, 0, 0, ctl_id, ctl_val);
373 	mutex_unlock(&private->usb_mutex);
374 	return ret;
375 }
376 
377 /* Generic get/set/init functions for switch controls */
378 
379 static int
snd_s1810c_switch_get(struct snd_kcontrol * kctl,struct snd_ctl_elem_value * ctl_elem)380 snd_s1810c_switch_get(struct snd_kcontrol *kctl,
381 		      struct snd_ctl_elem_value *ctl_elem)
382 {
383 	struct usb_mixer_elem_list *list = snd_kcontrol_chip(kctl);
384 	struct usb_mixer_interface *mixer = list->mixer;
385 	struct s1810_mixer_state *private = mixer->private_data;
386 	u32 pval = (u32) kctl->private_value;
387 	u32 ctl_idx = pval & 0xFF;
388 	u32 state = 0;
389 	int ret = 0;
390 
391 	mutex_lock(&private->data_mutex);
392 	ret = snd_s1810c_get_switch_state(mixer, kctl, &state);
393 	if (ret < 0)
394 		goto unlock;
395 
396 	switch (ctl_idx) {
397 	case SC1810C_STATE_LINE_SW:
398 	case SC1810C_STATE_AB_SW:
399 		ctl_elem->value.enumerated.item[0] = (int)state;
400 		break;
401 	default:
402 		ctl_elem->value.integer.value[0] = (long)state;
403 	}
404 
405  unlock:
406 	mutex_unlock(&private->data_mutex);
407 	return (ret < 0) ? ret : 0;
408 }
409 
410 static int
snd_s1810c_switch_set(struct snd_kcontrol * kctl,struct snd_ctl_elem_value * ctl_elem)411 snd_s1810c_switch_set(struct snd_kcontrol *kctl,
412 		      struct snd_ctl_elem_value *ctl_elem)
413 {
414 	struct usb_mixer_elem_list *list = snd_kcontrol_chip(kctl);
415 	struct usb_mixer_interface *mixer = list->mixer;
416 	struct s1810_mixer_state *private = mixer->private_data;
417 	u32 pval = (u32) kctl->private_value;
418 	u32 ctl_idx = pval & 0xFF;
419 	u32 curval = 0;
420 	u32 newval = 0;
421 	int ret = 0;
422 
423 	mutex_lock(&private->data_mutex);
424 	ret = snd_s1810c_get_switch_state(mixer, kctl, &curval);
425 	if (ret < 0)
426 		goto unlock;
427 
428 	switch (ctl_idx) {
429 	case SC1810C_STATE_LINE_SW:
430 	case SC1810C_STATE_AB_SW:
431 		newval = (u32) ctl_elem->value.enumerated.item[0];
432 		break;
433 	default:
434 		newval = (u32) ctl_elem->value.integer.value[0];
435 	}
436 
437 	if (curval == newval)
438 		goto unlock;
439 
440 	kctl->private_value &= ~(0x1 << 16);
441 	kctl->private_value |= (unsigned int)(newval & 0x1) << 16;
442 	ret = snd_s1810c_set_switch_state(mixer, kctl);
443 
444  unlock:
445 	mutex_unlock(&private->data_mutex);
446 	return (ret < 0) ? 0 : 1;
447 }
448 
449 static int
snd_s1810c_switch_init(struct usb_mixer_interface * mixer,const struct snd_kcontrol_new * new_kctl)450 snd_s1810c_switch_init(struct usb_mixer_interface *mixer,
451 		       const struct snd_kcontrol_new *new_kctl)
452 {
453 	struct snd_kcontrol *kctl;
454 	struct usb_mixer_elem_info *elem;
455 
456 	elem = kzalloc(sizeof(struct usb_mixer_elem_info), GFP_KERNEL);
457 	if (!elem)
458 		return -ENOMEM;
459 
460 	elem->head.mixer = mixer;
461 	elem->control = 0;
462 	elem->head.id = 0;
463 	elem->channels = 1;
464 
465 	kctl = snd_ctl_new1(new_kctl, elem);
466 	if (!kctl) {
467 		kfree(elem);
468 		return -ENOMEM;
469 	}
470 	kctl->private_free = snd_usb_mixer_elem_free;
471 
472 	return snd_usb_mixer_add_control(&elem->head, kctl);
473 }
474 
475 static int
snd_s1810c_line_sw_info(struct snd_kcontrol * kctl,struct snd_ctl_elem_info * uinfo)476 snd_s1810c_line_sw_info(struct snd_kcontrol *kctl,
477 			struct snd_ctl_elem_info *uinfo)
478 {
479 	static const char *const texts[2] = {
480 		"Preamp On (Mic/Inst)",
481 		"Preamp Off (Line in)"
482 	};
483 
484 	return snd_ctl_enum_info(uinfo, 1, ARRAY_SIZE(texts), texts);
485 }
486 
487 static const struct snd_kcontrol_new snd_s1810c_line_sw = {
488 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
489 	.name = "Line 1/2 Source Type",
490 	.info = snd_s1810c_line_sw_info,
491 	.get = snd_s1810c_switch_get,
492 	.put = snd_s1810c_switch_set,
493 	.private_value = (SC1810C_STATE_LINE_SW | SC1810C_CTL_LINE_SW << 8)
494 };
495 
496 static const struct snd_kcontrol_new snd_s1810c_mute_sw = {
497 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
498 	.name = "Mute Main Out Switch",
499 	.info = snd_ctl_boolean_mono_info,
500 	.get = snd_s1810c_switch_get,
501 	.put = snd_s1810c_switch_set,
502 	.private_value = (SC1810C_STATE_MUTE_SW | SC1810C_CTL_MUTE_SW << 8)
503 };
504 
505 static const struct snd_kcontrol_new snd_s1810c_48v_sw = {
506 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
507 	.name = "48V Phantom Power On Mic Inputs Switch",
508 	.info = snd_ctl_boolean_mono_info,
509 	.get = snd_s1810c_switch_get,
510 	.put = snd_s1810c_switch_set,
511 	.private_value = (SC1810C_STATE_48V_SW | SC1810C_CTL_48V_SW << 8)
512 };
513 
514 static int
snd_s1810c_ab_sw_info(struct snd_kcontrol * kctl,struct snd_ctl_elem_info * uinfo)515 snd_s1810c_ab_sw_info(struct snd_kcontrol *kctl,
516 		      struct snd_ctl_elem_info *uinfo)
517 {
518 	static const char *const texts[2] = {
519 		"1/2",
520 		"3/4"
521 	};
522 
523 	return snd_ctl_enum_info(uinfo, 1, ARRAY_SIZE(texts), texts);
524 }
525 
526 static const struct snd_kcontrol_new snd_s1810c_ab_sw = {
527 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
528 	.name = "Headphone 1 Source Route",
529 	.info = snd_s1810c_ab_sw_info,
530 	.get = snd_s1810c_switch_get,
531 	.put = snd_s1810c_switch_set,
532 	.private_value = (SC1810C_STATE_AB_SW | SC1810C_CTL_AB_SW << 8)
533 };
534 
snd_sc1810_mixer_state_free(struct usb_mixer_interface * mixer)535 static void snd_sc1810_mixer_state_free(struct usb_mixer_interface *mixer)
536 {
537 	struct s1810_mixer_state *private = mixer->private_data;
538 	kfree(private);
539 	mixer->private_data = NULL;
540 }
541 
542 /* Entry point, called from mixer_quirks.c */
snd_sc1810_init_mixer(struct usb_mixer_interface * mixer)543 int snd_sc1810_init_mixer(struct usb_mixer_interface *mixer)
544 {
545 	struct s1810_mixer_state *private = NULL;
546 	struct snd_usb_audio *chip = mixer->chip;
547 	struct usb_device *dev = chip->dev;
548 	int ret = 0;
549 
550 	/* Run this only once */
551 	if (!list_empty(&chip->mixer_list))
552 		return 0;
553 
554 	dev_info(&dev->dev,
555 		 "Presonus Studio 1810c, device_setup: %u\n", chip->setup);
556 	if (chip->setup == 1)
557 		dev_info(&dev->dev, "(8out/18in @ 48kHz)\n");
558 	else if (chip->setup == 2)
559 		dev_info(&dev->dev, "(6out/8in @ 192kHz)\n");
560 	else
561 		dev_info(&dev->dev, "(8out/14in @ 96kHz)\n");
562 
563 	ret = snd_s1810c_init_mixer_maps(chip);
564 	if (ret < 0)
565 		return ret;
566 
567 	private = kzalloc(sizeof(struct s1810_mixer_state), GFP_KERNEL);
568 	if (!private)
569 		return -ENOMEM;
570 
571 	mutex_init(&private->usb_mutex);
572 	mutex_init(&private->data_mutex);
573 
574 	mixer->private_data = private;
575 	mixer->private_free = snd_sc1810_mixer_state_free;
576 
577 	private->seqnum = 1;
578 
579 	ret = snd_s1810c_switch_init(mixer, &snd_s1810c_line_sw);
580 	if (ret < 0)
581 		return ret;
582 
583 	ret = snd_s1810c_switch_init(mixer, &snd_s1810c_mute_sw);
584 	if (ret < 0)
585 		return ret;
586 
587 	ret = snd_s1810c_switch_init(mixer, &snd_s1810c_48v_sw);
588 	if (ret < 0)
589 		return ret;
590 
591 	ret = snd_s1810c_switch_init(mixer, &snd_s1810c_ab_sw);
592 	if (ret < 0)
593 		return ret;
594 	return ret;
595 }
596