xref: /openbmc/linux/sound/usb/6fire/control.c (revision 95e9fd10)
1 /*
2  * Linux driver for TerraTec DMX 6Fire USB
3  *
4  * Mixer control
5  *
6  * Author:	Torsten Schenk <torsten.schenk@zoho.com>
7  * Created:	Jan 01, 2011
8  * Copyright:	(C) Torsten Schenk
9  *
10  * Thanks to:
11  * - Holger Ruckdeschel: he found out how to control individual channel
12  *   volumes and introduced mute switch
13  *
14  * This program is free software; you can redistribute it and/or modify
15  * it under the terms of the GNU General Public License as published by
16  * the Free Software Foundation; either version 2 of the License, or
17  * (at your option) any later version.
18  */
19 
20 #include <linux/interrupt.h>
21 #include <sound/control.h>
22 #include <sound/tlv.h>
23 
24 #include "control.h"
25 #include "comm.h"
26 #include "chip.h"
27 
28 static char *opt_coax_texts[2] = { "Optical", "Coax" };
29 static char *line_phono_texts[2] = { "Line", "Phono" };
30 
31 /*
32  * data that needs to be sent to device. sets up card internal stuff.
33  * values dumped from windows driver and filtered by trial'n'error.
34  */
35 static const struct {
36 	u8 type;
37 	u8 reg;
38 	u8 value;
39 }
40 init_data[] = {
41 	{ 0x22, 0x00, 0x00 }, { 0x20, 0x00, 0x08 }, { 0x22, 0x01, 0x01 },
42 	{ 0x20, 0x01, 0x08 }, { 0x22, 0x02, 0x00 }, { 0x20, 0x02, 0x08 },
43 	{ 0x22, 0x03, 0x00 }, { 0x20, 0x03, 0x08 }, { 0x22, 0x04, 0x00 },
44 	{ 0x20, 0x04, 0x08 }, { 0x22, 0x05, 0x01 }, { 0x20, 0x05, 0x08 },
45 	{ 0x22, 0x04, 0x01 }, { 0x12, 0x04, 0x00 }, { 0x12, 0x05, 0x00 },
46 	{ 0x12, 0x0d, 0x38 }, { 0x12, 0x21, 0x82 }, { 0x12, 0x22, 0x80 },
47 	{ 0x12, 0x23, 0x00 }, { 0x12, 0x06, 0x02 }, { 0x12, 0x03, 0x00 },
48 	{ 0x12, 0x02, 0x00 }, { 0x22, 0x03, 0x01 },
49 	{ 0 } /* TERMINATING ENTRY */
50 };
51 
52 static const int rates_altsetting[] = { 1, 1, 2, 2, 3, 3 };
53 /* values to write to soundcard register for all samplerates */
54 static const u16 rates_6fire_vl[] = {0x00, 0x01, 0x00, 0x01, 0x00, 0x01};
55 static const u16 rates_6fire_vh[] = {0x11, 0x11, 0x10, 0x10, 0x00, 0x00};
56 
57 static DECLARE_TLV_DB_MINMAX(tlv_output, -9000, 0);
58 static DECLARE_TLV_DB_MINMAX(tlv_input, -1500, 1500);
59 
60 enum {
61 	DIGITAL_THRU_ONLY_SAMPLERATE = 3
62 };
63 
64 static void usb6fire_control_output_vol_update(struct control_runtime *rt)
65 {
66 	struct comm_runtime *comm_rt = rt->chip->comm;
67 	int i;
68 
69 	if (comm_rt)
70 		for (i = 0; i < 6; i++)
71 			if (!(rt->ovol_updated & (1 << i))) {
72 				comm_rt->write8(comm_rt, 0x12, 0x0f + i,
73 					180 - rt->output_vol[i]);
74 				rt->ovol_updated |= 1 << i;
75 			}
76 }
77 
78 static void usb6fire_control_output_mute_update(struct control_runtime *rt)
79 {
80 	struct comm_runtime *comm_rt = rt->chip->comm;
81 
82 	if (comm_rt)
83 		comm_rt->write8(comm_rt, 0x12, 0x0e, ~rt->output_mute);
84 }
85 
86 static void usb6fire_control_input_vol_update(struct control_runtime *rt)
87 {
88 	struct comm_runtime *comm_rt = rt->chip->comm;
89 	int i;
90 
91 	if (comm_rt)
92 		for (i = 0; i < 2; i++)
93 			if (!(rt->ivol_updated & (1 << i))) {
94 				comm_rt->write8(comm_rt, 0x12, 0x1c + i,
95 					rt->input_vol[i] & 0x3f);
96 				rt->ivol_updated |= 1 << i;
97 			}
98 }
99 
100 static void usb6fire_control_line_phono_update(struct control_runtime *rt)
101 {
102 	struct comm_runtime *comm_rt = rt->chip->comm;
103 	if (comm_rt) {
104 		comm_rt->write8(comm_rt, 0x22, 0x02, rt->line_phono_switch);
105 		comm_rt->write8(comm_rt, 0x21, 0x02, rt->line_phono_switch);
106 	}
107 }
108 
109 static void usb6fire_control_opt_coax_update(struct control_runtime *rt)
110 {
111 	struct comm_runtime *comm_rt = rt->chip->comm;
112 	if (comm_rt) {
113 		comm_rt->write8(comm_rt, 0x22, 0x00, rt->opt_coax_switch);
114 		comm_rt->write8(comm_rt, 0x21, 0x00, rt->opt_coax_switch);
115 	}
116 }
117 
118 static int usb6fire_control_set_rate(struct control_runtime *rt, int rate)
119 {
120 	int ret;
121 	struct usb_device *device = rt->chip->dev;
122 	struct comm_runtime *comm_rt = rt->chip->comm;
123 
124 	if (rate < 0 || rate >= CONTROL_N_RATES)
125 		return -EINVAL;
126 
127 	ret = usb_set_interface(device, 1, rates_altsetting[rate]);
128 	if (ret < 0)
129 		return ret;
130 
131 	/* set soundcard clock */
132 	ret = comm_rt->write16(comm_rt, 0x02, 0x01, rates_6fire_vl[rate],
133 			rates_6fire_vh[rate]);
134 	if (ret < 0)
135 		return ret;
136 
137 	return 0;
138 }
139 
140 static int usb6fire_control_set_channels(
141 	struct control_runtime *rt, int n_analog_out,
142 	int n_analog_in, bool spdif_out, bool spdif_in)
143 {
144 	int ret;
145 	struct comm_runtime *comm_rt = rt->chip->comm;
146 
147 	/* enable analog inputs and outputs
148 	 * (one bit per stereo-channel) */
149 	ret = comm_rt->write16(comm_rt, 0x02, 0x02,
150 			(1 << (n_analog_out / 2)) - 1,
151 			(1 << (n_analog_in / 2)) - 1);
152 	if (ret < 0)
153 		return ret;
154 
155 	/* disable digital inputs and outputs */
156 	/* TODO: use spdif_x to enable/disable digital channels */
157 	ret = comm_rt->write16(comm_rt, 0x02, 0x03, 0x00, 0x00);
158 	if (ret < 0)
159 		return ret;
160 
161 	return 0;
162 }
163 
164 static int usb6fire_control_streaming_update(struct control_runtime *rt)
165 {
166 	struct comm_runtime *comm_rt = rt->chip->comm;
167 
168 	if (comm_rt) {
169 		if (!rt->usb_streaming && rt->digital_thru_switch)
170 			usb6fire_control_set_rate(rt,
171 				DIGITAL_THRU_ONLY_SAMPLERATE);
172 		return comm_rt->write16(comm_rt, 0x02, 0x00, 0x00,
173 			(rt->usb_streaming ? 0x01 : 0x00) |
174 			(rt->digital_thru_switch ? 0x08 : 0x00));
175 	}
176 	return -EINVAL;
177 }
178 
179 static int usb6fire_control_output_vol_info(struct snd_kcontrol *kcontrol,
180 		struct snd_ctl_elem_info *uinfo)
181 {
182 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
183 	uinfo->count = 2;
184 	uinfo->value.integer.min = 0;
185 	uinfo->value.integer.max = 180;
186 	return 0;
187 }
188 
189 static int usb6fire_control_output_vol_put(struct snd_kcontrol *kcontrol,
190 		struct snd_ctl_elem_value *ucontrol)
191 {
192 	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
193 	unsigned int ch = kcontrol->private_value;
194 	int changed = 0;
195 
196 	if (ch > 4) {
197 		snd_printk(KERN_ERR PREFIX "Invalid channel in volume control.");
198 		return -EINVAL;
199 	}
200 
201 	if (rt->output_vol[ch] != ucontrol->value.integer.value[0]) {
202 		rt->output_vol[ch] = ucontrol->value.integer.value[0];
203 		rt->ovol_updated &= ~(1 << ch);
204 		changed = 1;
205 	}
206 	if (rt->output_vol[ch + 1] != ucontrol->value.integer.value[1]) {
207 		rt->output_vol[ch + 1] = ucontrol->value.integer.value[1];
208 		rt->ovol_updated &= ~(2 << ch);
209 		changed = 1;
210 	}
211 
212 	if (changed)
213 		usb6fire_control_output_vol_update(rt);
214 
215 	return changed;
216 }
217 
218 static int usb6fire_control_output_vol_get(struct snd_kcontrol *kcontrol,
219 		struct snd_ctl_elem_value *ucontrol)
220 {
221 	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
222 	unsigned int ch = kcontrol->private_value;
223 
224 	if (ch > 4) {
225 		snd_printk(KERN_ERR PREFIX "Invalid channel in volume control.");
226 		return -EINVAL;
227 	}
228 
229 	ucontrol->value.integer.value[0] = rt->output_vol[ch];
230 	ucontrol->value.integer.value[1] = rt->output_vol[ch + 1];
231 	return 0;
232 }
233 
234 static int usb6fire_control_output_mute_put(struct snd_kcontrol *kcontrol,
235 	struct snd_ctl_elem_value *ucontrol)
236 {
237 	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
238 	unsigned int ch = kcontrol->private_value;
239 	u8 old = rt->output_mute;
240 	u8 value = 0;
241 
242 	if (ch > 4) {
243 		snd_printk(KERN_ERR PREFIX "Invalid channel in volume control.");
244 		return -EINVAL;
245 	}
246 
247 	rt->output_mute &= ~(3 << ch);
248 	if (ucontrol->value.integer.value[0])
249 		value |= 1;
250 	if (ucontrol->value.integer.value[1])
251 		value |= 2;
252 	rt->output_mute |= value << ch;
253 
254 	if (rt->output_mute != old)
255 		usb6fire_control_output_mute_update(rt);
256 
257 	return rt->output_mute != old;
258 }
259 
260 static int usb6fire_control_output_mute_get(struct snd_kcontrol *kcontrol,
261 	struct snd_ctl_elem_value *ucontrol)
262 {
263 	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
264 	unsigned int ch = kcontrol->private_value;
265 	u8 value = rt->output_mute >> ch;
266 
267 	if (ch > 4) {
268 		snd_printk(KERN_ERR PREFIX "Invalid channel in volume control.");
269 		return -EINVAL;
270 	}
271 
272 	ucontrol->value.integer.value[0] = 1 & value;
273 	value >>= 1;
274 	ucontrol->value.integer.value[1] = 1 & value;
275 
276 	return 0;
277 }
278 
279 static int usb6fire_control_input_vol_info(struct snd_kcontrol *kcontrol,
280 		struct snd_ctl_elem_info *uinfo)
281 {
282 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
283 	uinfo->count = 2;
284 	uinfo->value.integer.min = 0;
285 	uinfo->value.integer.max = 30;
286 	return 0;
287 }
288 
289 static int usb6fire_control_input_vol_put(struct snd_kcontrol *kcontrol,
290 		struct snd_ctl_elem_value *ucontrol)
291 {
292 	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
293 	int changed = 0;
294 
295 	if (rt->input_vol[0] != ucontrol->value.integer.value[0]) {
296 		rt->input_vol[0] = ucontrol->value.integer.value[0] - 15;
297 		rt->ivol_updated &= ~(1 << 0);
298 		changed = 1;
299 	}
300 	if (rt->input_vol[1] != ucontrol->value.integer.value[1]) {
301 		rt->input_vol[1] = ucontrol->value.integer.value[1] - 15;
302 		rt->ivol_updated &= ~(1 << 1);
303 		changed = 1;
304 	}
305 
306 	if (changed)
307 		usb6fire_control_input_vol_update(rt);
308 
309 	return changed;
310 }
311 
312 static int usb6fire_control_input_vol_get(struct snd_kcontrol *kcontrol,
313 		struct snd_ctl_elem_value *ucontrol)
314 {
315 	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
316 
317 	ucontrol->value.integer.value[0] = rt->input_vol[0] + 15;
318 	ucontrol->value.integer.value[1] = rt->input_vol[1] + 15;
319 
320 	return 0;
321 }
322 
323 static int usb6fire_control_line_phono_info(struct snd_kcontrol *kcontrol,
324 		struct snd_ctl_elem_info *uinfo)
325 {
326 	uinfo->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
327 	uinfo->count = 1;
328 	uinfo->value.enumerated.items = 2;
329 	if (uinfo->value.enumerated.item > 1)
330 		uinfo->value.enumerated.item = 1;
331 	strcpy(uinfo->value.enumerated.name,
332 			line_phono_texts[uinfo->value.enumerated.item]);
333 	return 0;
334 }
335 
336 static int usb6fire_control_line_phono_put(struct snd_kcontrol *kcontrol,
337 		struct snd_ctl_elem_value *ucontrol)
338 {
339 	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
340 	int changed = 0;
341 	if (rt->line_phono_switch != ucontrol->value.integer.value[0]) {
342 		rt->line_phono_switch = ucontrol->value.integer.value[0];
343 		usb6fire_control_line_phono_update(rt);
344 		changed = 1;
345 	}
346 	return changed;
347 }
348 
349 static int usb6fire_control_line_phono_get(struct snd_kcontrol *kcontrol,
350 		struct snd_ctl_elem_value *ucontrol)
351 {
352 	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
353 	ucontrol->value.integer.value[0] = rt->line_phono_switch;
354 	return 0;
355 }
356 
357 static int usb6fire_control_opt_coax_info(struct snd_kcontrol *kcontrol,
358 		struct snd_ctl_elem_info *uinfo)
359 {
360 	uinfo->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
361 	uinfo->count = 1;
362 	uinfo->value.enumerated.items = 2;
363 	if (uinfo->value.enumerated.item > 1)
364 		uinfo->value.enumerated.item = 1;
365 	strcpy(uinfo->value.enumerated.name,
366 			opt_coax_texts[uinfo->value.enumerated.item]);
367 	return 0;
368 }
369 
370 static int usb6fire_control_opt_coax_put(struct snd_kcontrol *kcontrol,
371 		struct snd_ctl_elem_value *ucontrol)
372 {
373 	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
374 	int changed = 0;
375 
376 	if (rt->opt_coax_switch != ucontrol->value.enumerated.item[0]) {
377 		rt->opt_coax_switch = ucontrol->value.enumerated.item[0];
378 		usb6fire_control_opt_coax_update(rt);
379 		changed = 1;
380 	}
381 	return changed;
382 }
383 
384 static int usb6fire_control_opt_coax_get(struct snd_kcontrol *kcontrol,
385 		struct snd_ctl_elem_value *ucontrol)
386 {
387 	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
388 	ucontrol->value.enumerated.item[0] = rt->opt_coax_switch;
389 	return 0;
390 }
391 
392 static int usb6fire_control_digital_thru_put(struct snd_kcontrol *kcontrol,
393 		struct snd_ctl_elem_value *ucontrol)
394 {
395 	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
396 	int changed = 0;
397 
398 	if (rt->digital_thru_switch != ucontrol->value.integer.value[0]) {
399 		rt->digital_thru_switch = ucontrol->value.integer.value[0];
400 		usb6fire_control_streaming_update(rt);
401 		changed = 1;
402 	}
403 	return changed;
404 }
405 
406 static int usb6fire_control_digital_thru_get(struct snd_kcontrol *kcontrol,
407 		struct snd_ctl_elem_value *ucontrol)
408 {
409 	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
410 	ucontrol->value.integer.value[0] = rt->digital_thru_switch;
411 	return 0;
412 }
413 
414 static struct __devinitdata snd_kcontrol_new vol_elements[] = {
415 	{
416 		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
417 		.name = "Analog Playback Volume",
418 		.index = 0,
419 		.private_value = 0,
420 		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
421 			SNDRV_CTL_ELEM_ACCESS_TLV_READ,
422 		.info = usb6fire_control_output_vol_info,
423 		.get = usb6fire_control_output_vol_get,
424 		.put = usb6fire_control_output_vol_put,
425 		.tlv = { .p = tlv_output }
426 	},
427 	{
428 		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
429 		.name = "Analog Playback Volume",
430 		.index = 1,
431 		.private_value = 2,
432 		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
433 			SNDRV_CTL_ELEM_ACCESS_TLV_READ,
434 		.info = usb6fire_control_output_vol_info,
435 		.get = usb6fire_control_output_vol_get,
436 		.put = usb6fire_control_output_vol_put,
437 		.tlv = { .p = tlv_output }
438 	},
439 	{
440 		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
441 		.name = "Analog Playback Volume",
442 		.index = 2,
443 		.private_value = 4,
444 		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
445 			SNDRV_CTL_ELEM_ACCESS_TLV_READ,
446 		.info = usb6fire_control_output_vol_info,
447 		.get = usb6fire_control_output_vol_get,
448 		.put = usb6fire_control_output_vol_put,
449 		.tlv = { .p = tlv_output }
450 	},
451 	{}
452 };
453 
454 static struct __devinitdata snd_kcontrol_new mute_elements[] = {
455 	{
456 		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
457 		.name = "Analog Playback Switch",
458 		.index = 0,
459 		.private_value = 0,
460 		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
461 		.info = snd_ctl_boolean_stereo_info,
462 		.get = usb6fire_control_output_mute_get,
463 		.put = usb6fire_control_output_mute_put,
464 	},
465 	{
466 		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
467 		.name = "Analog Playback Switch",
468 		.index = 1,
469 		.private_value = 2,
470 		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
471 		.info = snd_ctl_boolean_stereo_info,
472 		.get = usb6fire_control_output_mute_get,
473 		.put = usb6fire_control_output_mute_put,
474 	},
475 	{
476 		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
477 		.name = "Analog Playback Switch",
478 		.index = 2,
479 		.private_value = 4,
480 		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
481 		.info = snd_ctl_boolean_stereo_info,
482 		.get = usb6fire_control_output_mute_get,
483 		.put = usb6fire_control_output_mute_put,
484 	},
485 	{}
486 };
487 
488 static struct __devinitdata snd_kcontrol_new elements[] = {
489 	{
490 		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
491 		.name = "Line/Phono Capture Route",
492 		.index = 0,
493 		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
494 		.info = usb6fire_control_line_phono_info,
495 		.get = usb6fire_control_line_phono_get,
496 		.put = usb6fire_control_line_phono_put
497 	},
498 	{
499 		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
500 		.name = "Opt/Coax Capture Route",
501 		.index = 0,
502 		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
503 		.info = usb6fire_control_opt_coax_info,
504 		.get = usb6fire_control_opt_coax_get,
505 		.put = usb6fire_control_opt_coax_put
506 	},
507 	{
508 		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
509 		.name = "Digital Thru Playback Route",
510 		.index = 0,
511 		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
512 		.info = snd_ctl_boolean_mono_info,
513 		.get = usb6fire_control_digital_thru_get,
514 		.put = usb6fire_control_digital_thru_put
515 	},
516 	{
517 		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
518 		.name = "Analog Capture Volume",
519 		.index = 0,
520 		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
521 			SNDRV_CTL_ELEM_ACCESS_TLV_READ,
522 		.info = usb6fire_control_input_vol_info,
523 		.get = usb6fire_control_input_vol_get,
524 		.put = usb6fire_control_input_vol_put,
525 		.tlv = { .p = tlv_input }
526 	},
527 	{}
528 };
529 
530 static int usb6fire_control_add_virtual(
531 	struct control_runtime *rt,
532 	struct snd_card *card,
533 	char *name,
534 	struct snd_kcontrol_new *elems)
535 {
536 	int ret;
537 	int i;
538 	struct snd_kcontrol *vmaster =
539 		snd_ctl_make_virtual_master(name, tlv_output);
540 	struct snd_kcontrol *control;
541 
542 	if (!vmaster)
543 		return -ENOMEM;
544 	ret = snd_ctl_add(card, vmaster);
545 	if (ret < 0)
546 		return ret;
547 
548 	i = 0;
549 	while (elems[i].name) {
550 		control = snd_ctl_new1(&elems[i], rt);
551 		if (!control)
552 			return -ENOMEM;
553 		ret = snd_ctl_add(card, control);
554 		if (ret < 0)
555 			return ret;
556 		ret = snd_ctl_add_slave(vmaster, control);
557 		if (ret < 0)
558 			return ret;
559 		i++;
560 	}
561 	return 0;
562 }
563 
564 int __devinit usb6fire_control_init(struct sfire_chip *chip)
565 {
566 	int i;
567 	int ret;
568 	struct control_runtime *rt = kzalloc(sizeof(struct control_runtime),
569 			GFP_KERNEL);
570 	struct comm_runtime *comm_rt = chip->comm;
571 
572 	if (!rt)
573 		return -ENOMEM;
574 
575 	rt->chip = chip;
576 	rt->update_streaming = usb6fire_control_streaming_update;
577 	rt->set_rate = usb6fire_control_set_rate;
578 	rt->set_channels = usb6fire_control_set_channels;
579 
580 	i = 0;
581 	while (init_data[i].type) {
582 		comm_rt->write8(comm_rt, init_data[i].type, init_data[i].reg,
583 				init_data[i].value);
584 		i++;
585 	}
586 
587 	usb6fire_control_opt_coax_update(rt);
588 	usb6fire_control_line_phono_update(rt);
589 	usb6fire_control_output_vol_update(rt);
590 	usb6fire_control_output_mute_update(rt);
591 	usb6fire_control_input_vol_update(rt);
592 	usb6fire_control_streaming_update(rt);
593 
594 	ret = usb6fire_control_add_virtual(rt, chip->card,
595 		"Master Playback Volume", vol_elements);
596 	if (ret) {
597 		snd_printk(KERN_ERR PREFIX "cannot add control.\n");
598 		kfree(rt);
599 		return ret;
600 	}
601 	ret = usb6fire_control_add_virtual(rt, chip->card,
602 		"Master Playback Switch", mute_elements);
603 	if (ret) {
604 		snd_printk(KERN_ERR PREFIX "cannot add control.\n");
605 		kfree(rt);
606 		return ret;
607 	}
608 
609 	i = 0;
610 	while (elements[i].name) {
611 		ret = snd_ctl_add(chip->card, snd_ctl_new1(&elements[i], rt));
612 		if (ret < 0) {
613 			kfree(rt);
614 			snd_printk(KERN_ERR PREFIX "cannot add control.\n");
615 			return ret;
616 		}
617 		i++;
618 	}
619 
620 	chip->control = rt;
621 	return 0;
622 }
623 
624 void usb6fire_control_abort(struct sfire_chip *chip)
625 {}
626 
627 void usb6fire_control_destroy(struct sfire_chip *chip)
628 {
629 	kfree(chip->control);
630 	chip->control = NULL;
631 }
632