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 */
84struct 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 */
119struct 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
128struct s1810_mixer_state {
129 uint16_t seqnum;
130 struct mutex usb_mutex;
131 struct mutex data_mutex;
132};
133
134static int
135snd_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, value: 0, index: 0, data: &pkt, size: 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 periodically
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 */
174static int
175snd_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 value: (*seqnum), index: 0, data: &pkt_out, size: 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 value: (*seqnum), index: 0, data: &pkt_in, size: 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 */
214static 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; 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, d: 0, e);
228 snd_s1810c_send_ctl_packet(dev, a, b, c, d: 1, e);
229 }
230 /* This channel to main output (again) */
231 snd_s1810c_send_ctl_packet(dev, a, b, c: 0, d: 0, e);
232 snd_s1810c_send_ctl_packet(dev, a, b, c: 0, d: 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, c: 0, d: 0, e);
246 snd_s1810c_send_ctl_packet(dev, a, b, c: 0, d: 1, e);
247 }
248 snd_s1810c_send_ctl_packet(dev, a, b: 0, c: 0, d: 0, e);
249 snd_s1810c_send_ctl_packet(dev, a, b: 0, c: 0, d: 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, d: 0, e);
259 snd_s1810c_send_ctl_packet(dev, a, b, c, d: 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, b: 3, c: 0, d: 0, e);
268 snd_s1810c_send_ctl_packet(dev, a, b: 3, c: 0, d: 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, c: 0, d: 0, e);
275 snd_s1810c_send_ctl_packet(dev, a, b, c: 0, d: 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, d: 0, e);
289 snd_s1810c_send_ctl_packet(dev, a, b, c, d: 1, e: 0);
290 b++;
291 /* Right */
292 snd_s1810c_send_ctl_packet(dev, a, b, c, d: 0, e: 0);
293 snd_s1810c_send_ctl_packet(dev, a, b, c, d: 1, e);
294 } else {
295 /* Leave the rest disconnected */
296 snd_s1810c_send_ctl_packet(dev, a, b, c, d: 0, e: 0);
297 snd_s1810c_send_ctl_packet(dev, a, b, c, d: 1, e: 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, d: 0, e);
310 snd_s1810c_send_ctl_packet(dev, a, b, c, d: 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, b: 3, c: 0, d: 0, e);
319 snd_s1810c_send_ctl_packet(dev, a, b: 3, c: 0, d: 1, e);
320
321 /* Again ? */
322 snd_s1810c_send_ctl_packet(dev, a, b: 3, c: 0, d: 0, e);
323 snd_s1810c_send_ctl_packet(dev, a, b: 3, c: 0, d: 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 */
333static int
334snd_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(dev: chip->dev, field: &field,
345 field_idx: ctl_idx, seqnum: &private->seqnum);
346 if (ret < 0)
347 goto unlock;
348
349 *state = field;
350 unlock:
351 mutex_unlock(lock: &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 */
360static int
361snd_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(dev: chip->dev, a: 0, b: 0, c: 0, d: ctl_id, e: ctl_val);
373 mutex_unlock(lock: &private->usb_mutex);
374 return ret;
375}
376
377/* Generic get/set/init functions for switch controls */
378
379static int
380snd_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: &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(lock: &private->data_mutex);
407 return (ret < 0) ? ret : 0;
408}
409
410static int
411snd_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, state: &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(lock: &private->data_mutex);
446 return (ret < 0) ? 0 : 1;
447}
448
449static int
450snd_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(size: 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(kcontrolnew: new_kctl, private_data: elem);
466 if (!kctl) {
467 kfree(objp: 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
475static int
476snd_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(info: uinfo, channels: 1, ARRAY_SIZE(texts), names: texts);
485}
486
487static 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
496static 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
505static 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
514static int
515snd_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(info: uinfo, channels: 1, ARRAY_SIZE(texts), names: texts);
524}
525
526static 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
535static void snd_sc1810_mixer_state_free(struct usb_mixer_interface *mixer)
536{
537 struct s1810_mixer_state *private = mixer->private_data;
538 kfree(objp: private);
539 mixer->private_data = NULL;
540}
541
542/* Entry point, called from mixer_quirks.c */
543int 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(head: &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(size: 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, new_kctl: &snd_s1810c_line_sw);
580 if (ret < 0)
581 return ret;
582
583 ret = snd_s1810c_switch_init(mixer, new_kctl: &snd_s1810c_mute_sw);
584 if (ret < 0)
585 return ret;
586
587 ret = snd_s1810c_switch_init(mixer, new_kctl: &snd_s1810c_48v_sw);
588 if (ret < 0)
589 return ret;
590
591 ret = snd_s1810c_switch_init(mixer, new_kctl: &snd_s1810c_ab_sw);
592 if (ret < 0)
593 return ret;
594 return ret;
595}
596

source code of linux/sound/usb/mixer_s1810c.c