1// SPDX-License-Identifier: GPL-2.0-or-later
2//
3// Special handling for implicit feedback mode
4//
5
6#include <linux/init.h>
7#include <linux/usb.h>
8#include <linux/usb/audio.h>
9#include <linux/usb/audio-v2.h>
10
11#include <sound/core.h>
12#include <sound/pcm.h>
13#include <sound/pcm_params.h>
14
15#include "usbaudio.h"
16#include "card.h"
17#include "helper.h"
18#include "pcm.h"
19#include "implicit.h"
20
21enum {
22 IMPLICIT_FB_NONE,
23 IMPLICIT_FB_GENERIC,
24 IMPLICIT_FB_FIXED,
25 IMPLICIT_FB_BOTH, /* generic playback + capture (for BOSS) */
26};
27
28struct snd_usb_implicit_fb_match {
29 unsigned int id;
30 unsigned int iface_class;
31 unsigned int ep_num;
32 unsigned int iface;
33 int type;
34};
35
36#define IMPLICIT_FB_GENERIC_DEV(vend, prod) \
37 { .id = USB_ID(vend, prod), .type = IMPLICIT_FB_GENERIC }
38#define IMPLICIT_FB_FIXED_DEV(vend, prod, ep, ifnum) \
39 { .id = USB_ID(vend, prod), .type = IMPLICIT_FB_FIXED, .ep_num = (ep),\
40 .iface = (ifnum) }
41#define IMPLICIT_FB_BOTH_DEV(vend, prod, ep, ifnum) \
42 { .id = USB_ID(vend, prod), .type = IMPLICIT_FB_BOTH, .ep_num = (ep),\
43 .iface = (ifnum) }
44#define IMPLICIT_FB_SKIP_DEV(vend, prod) \
45 { .id = USB_ID(vend, prod), .type = IMPLICIT_FB_NONE }
46
47/* Implicit feedback quirk table for playback */
48static const struct snd_usb_implicit_fb_match playback_implicit_fb_quirks[] = {
49 /* Fixed EP */
50 /* FIXME: check the availability of generic matching */
51 IMPLICIT_FB_FIXED_DEV(0x0763, 0x2030, 0x81, 3), /* M-Audio Fast Track C400 */
52 IMPLICIT_FB_FIXED_DEV(0x0763, 0x2031, 0x81, 3), /* M-Audio Fast Track C600 */
53 IMPLICIT_FB_FIXED_DEV(0x0763, 0x2080, 0x81, 2), /* M-Audio FastTrack Ultra */
54 IMPLICIT_FB_FIXED_DEV(0x0763, 0x2081, 0x81, 2), /* M-Audio FastTrack Ultra */
55 IMPLICIT_FB_FIXED_DEV(0x2466, 0x8010, 0x81, 2), /* Fractal Audio Axe-Fx III */
56 IMPLICIT_FB_FIXED_DEV(0x31e9, 0x0001, 0x81, 2), /* Solid State Logic SSL2 */
57 IMPLICIT_FB_FIXED_DEV(0x31e9, 0x0002, 0x81, 2), /* Solid State Logic SSL2+ */
58 IMPLICIT_FB_FIXED_DEV(0x0499, 0x172f, 0x81, 2), /* Steinberg UR22C */
59 IMPLICIT_FB_FIXED_DEV(0x0d9a, 0x00df, 0x81, 2), /* RTX6001 */
60 IMPLICIT_FB_FIXED_DEV(0x22f0, 0x0006, 0x81, 3), /* Allen&Heath Qu-16 */
61 IMPLICIT_FB_FIXED_DEV(0x1686, 0xf029, 0x82, 2), /* Zoom UAC-2 */
62 IMPLICIT_FB_FIXED_DEV(0x2466, 0x8003, 0x86, 2), /* Fractal Audio Axe-Fx II */
63 IMPLICIT_FB_FIXED_DEV(0x0499, 0x172a, 0x86, 2), /* Yamaha MODX */
64
65 /* Special matching */
66 { .id = USB_ID(0x07fd, 0x0004), .iface_class = USB_CLASS_AUDIO,
67 .type = IMPLICIT_FB_NONE }, /* MicroBook IIc */
68 /* ep = 0x84, ifnum = 0 */
69 { .id = USB_ID(0x07fd, 0x0004), .iface_class = USB_CLASS_VENDOR_SPEC,
70 .type = IMPLICIT_FB_FIXED,
71 .ep_num = 0x84, .iface = 0 }, /* MOTU MicroBook II */
72
73 {} /* terminator */
74};
75
76/* Implicit feedback quirk table for capture: only FIXED type */
77static const struct snd_usb_implicit_fb_match capture_implicit_fb_quirks[] = {
78 {} /* terminator */
79};
80
81/* set up sync EP information on the audioformat */
82static int add_implicit_fb_sync_ep(struct snd_usb_audio *chip,
83 struct audioformat *fmt,
84 int ep, int ep_idx, int ifnum,
85 const struct usb_host_interface *alts)
86{
87 struct usb_interface *iface;
88
89 if (!alts) {
90 iface = usb_ifnum_to_if(dev: chip->dev, ifnum);
91 if (!iface || iface->num_altsetting < 2)
92 return 0;
93 alts = &iface->altsetting[1];
94 }
95
96 fmt->sync_ep = ep;
97 fmt->sync_iface = ifnum;
98 fmt->sync_altsetting = alts->desc.bAlternateSetting;
99 fmt->sync_ep_idx = ep_idx;
100 fmt->implicit_fb = 1;
101 usb_audio_dbg(chip,
102 "%d:%d: added %s implicit_fb sync_ep %x, iface %d:%d\n",
103 fmt->iface, fmt->altsetting,
104 (ep & USB_DIR_IN) ? "playback" : "capture",
105 fmt->sync_ep, fmt->sync_iface, fmt->sync_altsetting);
106 return 1;
107}
108
109/* Check whether the given UAC2 iface:altset points to an implicit fb source */
110static int add_generic_uac2_implicit_fb(struct snd_usb_audio *chip,
111 struct audioformat *fmt,
112 unsigned int ifnum,
113 unsigned int altsetting)
114{
115 struct usb_host_interface *alts;
116 struct usb_endpoint_descriptor *epd;
117
118 alts = snd_usb_get_host_interface(chip, ifnum, altsetting);
119 if (!alts)
120 return 0;
121 if (alts->desc.bInterfaceClass != USB_CLASS_AUDIO ||
122 alts->desc.bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING ||
123 alts->desc.bInterfaceProtocol != UAC_VERSION_2 ||
124 alts->desc.bNumEndpoints < 1)
125 return 0;
126 epd = get_endpoint(alts, 0);
127 if (!usb_endpoint_is_isoc_in(epd) ||
128 (epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) !=
129 USB_ENDPOINT_USAGE_IMPLICIT_FB)
130 return 0;
131 return add_implicit_fb_sync_ep(chip, fmt, ep: epd->bEndpointAddress, ep_idx: 0,
132 ifnum, alts);
133}
134
135static bool roland_sanity_check_iface(struct usb_host_interface *alts)
136{
137 if (alts->desc.bInterfaceClass != USB_CLASS_VENDOR_SPEC ||
138 (alts->desc.bInterfaceSubClass != 2 &&
139 alts->desc.bInterfaceProtocol != 2) ||
140 alts->desc.bNumEndpoints < 1)
141 return false;
142 return true;
143}
144
145/* Like the UAC2 case above, but specific to Roland with vendor class and hack */
146static int add_roland_implicit_fb(struct snd_usb_audio *chip,
147 struct audioformat *fmt,
148 struct usb_host_interface *alts)
149{
150 struct usb_endpoint_descriptor *epd;
151
152 if (!roland_sanity_check_iface(alts))
153 return 0;
154 /* only when both streams are with ASYNC type */
155 epd = get_endpoint(alts, 0);
156 if (!usb_endpoint_is_isoc_out(epd) ||
157 (epd->bmAttributes & USB_ENDPOINT_SYNCTYPE) != USB_ENDPOINT_SYNC_ASYNC)
158 return 0;
159
160 /* check capture EP */
161 alts = snd_usb_get_host_interface(chip,
162 ifnum: alts->desc.bInterfaceNumber + 1,
163 altsetting: alts->desc.bAlternateSetting);
164 if (!alts || !roland_sanity_check_iface(alts))
165 return 0;
166 epd = get_endpoint(alts, 0);
167 if (!usb_endpoint_is_isoc_in(epd) ||
168 (epd->bmAttributes & USB_ENDPOINT_SYNCTYPE) != USB_ENDPOINT_SYNC_ASYNC)
169 return 0;
170 chip->quirk_flags |= QUIRK_FLAG_PLAYBACK_FIRST;
171 return add_implicit_fb_sync_ep(chip, fmt, ep: epd->bEndpointAddress, ep_idx: 0,
172 ifnum: alts->desc.bInterfaceNumber, alts);
173}
174
175/* capture quirk for Roland device; always full-duplex */
176static int add_roland_capture_quirk(struct snd_usb_audio *chip,
177 struct audioformat *fmt,
178 struct usb_host_interface *alts)
179{
180 struct usb_endpoint_descriptor *epd;
181
182 if (!roland_sanity_check_iface(alts))
183 return 0;
184 epd = get_endpoint(alts, 0);
185 if (!usb_endpoint_is_isoc_in(epd) ||
186 (epd->bmAttributes & USB_ENDPOINT_SYNCTYPE) != USB_ENDPOINT_SYNC_ASYNC)
187 return 0;
188
189 alts = snd_usb_get_host_interface(chip,
190 ifnum: alts->desc.bInterfaceNumber - 1,
191 altsetting: alts->desc.bAlternateSetting);
192 if (!alts || !roland_sanity_check_iface(alts))
193 return 0;
194 epd = get_endpoint(alts, 0);
195 if (!usb_endpoint_is_isoc_out(epd))
196 return 0;
197 return add_implicit_fb_sync_ep(chip, fmt, ep: epd->bEndpointAddress, ep_idx: 0,
198 ifnum: alts->desc.bInterfaceNumber, alts);
199}
200
201/* Playback and capture EPs on Pioneer devices share the same iface/altset
202 * for the implicit feedback operation
203 */
204static bool is_pioneer_implicit_fb(struct snd_usb_audio *chip,
205 struct usb_host_interface *alts)
206
207{
208 struct usb_endpoint_descriptor *epd;
209
210 if (USB_ID_VENDOR(chip->usb_id) != 0x2b73 &&
211 USB_ID_VENDOR(chip->usb_id) != 0x08e4)
212 return false;
213 if (alts->desc.bInterfaceClass != USB_CLASS_VENDOR_SPEC)
214 return false;
215 if (alts->desc.bNumEndpoints != 2)
216 return false;
217
218 epd = get_endpoint(alts, 0);
219 if (!usb_endpoint_is_isoc_out(epd) ||
220 (epd->bmAttributes & USB_ENDPOINT_SYNCTYPE) != USB_ENDPOINT_SYNC_ASYNC)
221 return false;
222
223 epd = get_endpoint(alts, 1);
224 if (!usb_endpoint_is_isoc_in(epd) ||
225 (epd->bmAttributes & USB_ENDPOINT_SYNCTYPE) != USB_ENDPOINT_SYNC_ASYNC ||
226 ((epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) !=
227 USB_ENDPOINT_USAGE_DATA &&
228 (epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) !=
229 USB_ENDPOINT_USAGE_IMPLICIT_FB))
230 return false;
231
232 return true;
233}
234
235static int __add_generic_implicit_fb(struct snd_usb_audio *chip,
236 struct audioformat *fmt,
237 int iface, int altset)
238{
239 struct usb_host_interface *alts;
240 struct usb_endpoint_descriptor *epd;
241
242 alts = snd_usb_get_host_interface(chip, ifnum: iface, altsetting: altset);
243 if (!alts)
244 return 0;
245
246 if ((alts->desc.bInterfaceClass != USB_CLASS_VENDOR_SPEC &&
247 alts->desc.bInterfaceClass != USB_CLASS_AUDIO) ||
248 alts->desc.bNumEndpoints < 1)
249 return 0;
250 epd = get_endpoint(alts, 0);
251 if (!usb_endpoint_is_isoc_in(epd) ||
252 (epd->bmAttributes & USB_ENDPOINT_SYNCTYPE) != USB_ENDPOINT_SYNC_ASYNC)
253 return 0;
254 return add_implicit_fb_sync_ep(chip, fmt, ep: epd->bEndpointAddress, ep_idx: 0,
255 ifnum: iface, alts);
256}
257
258/* More generic quirk: look for the sync EP next to the data EP */
259static int add_generic_implicit_fb(struct snd_usb_audio *chip,
260 struct audioformat *fmt,
261 struct usb_host_interface *alts)
262{
263 if ((fmt->ep_attr & USB_ENDPOINT_SYNCTYPE) != USB_ENDPOINT_SYNC_ASYNC)
264 return 0;
265
266 if (__add_generic_implicit_fb(chip, fmt,
267 iface: alts->desc.bInterfaceNumber + 1,
268 altset: alts->desc.bAlternateSetting))
269 return 1;
270 return __add_generic_implicit_fb(chip, fmt,
271 iface: alts->desc.bInterfaceNumber - 1,
272 altset: alts->desc.bAlternateSetting);
273}
274
275static const struct snd_usb_implicit_fb_match *
276find_implicit_fb_entry(struct snd_usb_audio *chip,
277 const struct snd_usb_implicit_fb_match *match,
278 const struct usb_host_interface *alts)
279{
280 for (; match->id; match++)
281 if (match->id == chip->usb_id &&
282 (!match->iface_class ||
283 (alts->desc.bInterfaceClass == match->iface_class)))
284 return match;
285
286 return NULL;
287}
288
289/* Setup an implicit feedback endpoint from a quirk. Returns 0 if no quirk
290 * applies. Returns 1 if a quirk was found.
291 */
292static int audioformat_implicit_fb_quirk(struct snd_usb_audio *chip,
293 struct audioformat *fmt,
294 struct usb_host_interface *alts)
295{
296 const struct snd_usb_implicit_fb_match *p;
297 unsigned int attr = fmt->ep_attr & USB_ENDPOINT_SYNCTYPE;
298
299 p = find_implicit_fb_entry(chip, match: playback_implicit_fb_quirks, alts);
300 if (p) {
301 switch (p->type) {
302 case IMPLICIT_FB_GENERIC:
303 return add_generic_implicit_fb(chip, fmt, alts);
304 case IMPLICIT_FB_NONE:
305 return 0; /* No quirk */
306 case IMPLICIT_FB_FIXED:
307 return add_implicit_fb_sync_ep(chip, fmt, ep: p->ep_num, ep_idx: 0,
308 ifnum: p->iface, NULL);
309 }
310 }
311
312 /* Special handling for devices with capture quirks */
313 p = find_implicit_fb_entry(chip, match: capture_implicit_fb_quirks, alts);
314 if (p) {
315 switch (p->type) {
316 case IMPLICIT_FB_FIXED:
317 return 0; /* no quirk */
318 case IMPLICIT_FB_BOTH:
319 chip->quirk_flags |= QUIRK_FLAG_PLAYBACK_FIRST;
320 return add_generic_implicit_fb(chip, fmt, alts);
321 }
322 }
323
324 /* Generic UAC2 implicit feedback */
325 if (attr == USB_ENDPOINT_SYNC_ASYNC &&
326 alts->desc.bInterfaceClass == USB_CLASS_AUDIO &&
327 alts->desc.bInterfaceProtocol == UAC_VERSION_2 &&
328 alts->desc.bNumEndpoints == 1) {
329 if (add_generic_uac2_implicit_fb(chip, fmt,
330 ifnum: alts->desc.bInterfaceNumber + 1,
331 altsetting: alts->desc.bAlternateSetting))
332 return 1;
333 }
334
335 /* Roland/BOSS implicit feedback with vendor spec class */
336 if (USB_ID_VENDOR(chip->usb_id) == 0x0582) {
337 if (add_roland_implicit_fb(chip, fmt, alts) > 0)
338 return 1;
339 }
340
341 /* Pioneer devices with vendor spec class */
342 if (is_pioneer_implicit_fb(chip, alts)) {
343 chip->quirk_flags |= QUIRK_FLAG_PLAYBACK_FIRST;
344 return add_implicit_fb_sync_ep(chip, fmt,
345 get_endpoint(alts, 1)->bEndpointAddress,
346 ep_idx: 1, ifnum: alts->desc.bInterfaceNumber,
347 alts);
348 }
349
350 /* Try the generic implicit fb if available */
351 if (chip->generic_implicit_fb ||
352 (chip->quirk_flags & QUIRK_FLAG_GENERIC_IMPLICIT_FB))
353 return add_generic_implicit_fb(chip, fmt, alts);
354
355 /* No quirk */
356 return 0;
357}
358
359/* same for capture, but only handling FIXED entry */
360static int audioformat_capture_quirk(struct snd_usb_audio *chip,
361 struct audioformat *fmt,
362 struct usb_host_interface *alts)
363{
364 const struct snd_usb_implicit_fb_match *p;
365
366 p = find_implicit_fb_entry(chip, match: capture_implicit_fb_quirks, alts);
367 if (p && (p->type == IMPLICIT_FB_FIXED || p->type == IMPLICIT_FB_BOTH))
368 return add_implicit_fb_sync_ep(chip, fmt, ep: p->ep_num, ep_idx: 0,
369 ifnum: p->iface, NULL);
370
371 /* Roland/BOSS need full-duplex streams */
372 if (USB_ID_VENDOR(chip->usb_id) == 0x0582) {
373 if (add_roland_capture_quirk(chip, fmt, alts) > 0)
374 return 1;
375 }
376
377 if (is_pioneer_implicit_fb(chip, alts))
378 return 1; /* skip the quirk, also don't handle generic sync EP */
379 return 0;
380}
381
382/*
383 * Parse altset and set up implicit feedback endpoint on the audioformat
384 */
385int snd_usb_parse_implicit_fb_quirk(struct snd_usb_audio *chip,
386 struct audioformat *fmt,
387 struct usb_host_interface *alts)
388{
389 if (chip->quirk_flags & QUIRK_FLAG_SKIP_IMPLICIT_FB)
390 return 0;
391 if (fmt->endpoint & USB_DIR_IN)
392 return audioformat_capture_quirk(chip, fmt, alts);
393 else
394 return audioformat_implicit_fb_quirk(chip, fmt, alts);
395}
396
397/*
398 * Return the score of matching two audioformats.
399 * Veto the audioformat if:
400 * - It has no channels for some reason.
401 * - Requested PCM format is not supported.
402 * - Requested sample rate is not supported.
403 */
404static int match_endpoint_audioformats(struct snd_usb_substream *subs,
405 const struct audioformat *fp,
406 int rate, int channels,
407 snd_pcm_format_t pcm_format)
408{
409 int i, score;
410
411 if (fp->channels < 1)
412 return 0;
413
414 if (!(fp->formats & pcm_format_to_bits(pcm_format)))
415 return 0;
416
417 if (fp->rates & SNDRV_PCM_RATE_CONTINUOUS) {
418 if (rate < fp->rate_min || rate > fp->rate_max)
419 return 0;
420 } else {
421 for (i = 0; i < fp->nr_rates; i++) {
422 if (fp->rate_table[i] == rate)
423 break;
424 }
425 if (i >= fp->nr_rates)
426 return 0;
427 }
428
429 score = 1;
430 if (fp->channels == channels)
431 score++;
432
433 return score;
434}
435
436static struct snd_usb_substream *
437find_matching_substream(struct snd_usb_audio *chip, int stream, int ep_num,
438 int fmt_type)
439{
440 struct snd_usb_stream *as;
441 struct snd_usb_substream *subs;
442
443 list_for_each_entry(as, &chip->pcm_list, list) {
444 subs = &as->substream[stream];
445 if (as->fmt_type == fmt_type && subs->ep_num == ep_num)
446 return subs;
447 }
448
449 return NULL;
450}
451
452/*
453 * Return the audioformat that is suitable for the implicit fb
454 */
455const struct audioformat *
456snd_usb_find_implicit_fb_sync_format(struct snd_usb_audio *chip,
457 const struct audioformat *target,
458 const struct snd_pcm_hw_params *params,
459 int stream,
460 bool *fixed_rate)
461{
462 struct snd_usb_substream *subs;
463 const struct audioformat *fp, *sync_fmt = NULL;
464 int score, high_score;
465
466 /* Use the original audioformat as fallback for the shared altset */
467 if (target->iface == target->sync_iface &&
468 target->altsetting == target->sync_altsetting)
469 sync_fmt = target;
470
471 subs = find_matching_substream(chip, stream, ep_num: target->sync_ep,
472 fmt_type: target->fmt_type);
473 if (!subs)
474 goto end;
475
476 high_score = 0;
477 list_for_each_entry(fp, &subs->fmt_list, list) {
478 score = match_endpoint_audioformats(subs, fp,
479 rate: params_rate(p: params),
480 channels: params_channels(p: params),
481 pcm_format: params_format(p: params));
482 if (score > high_score) {
483 sync_fmt = fp;
484 high_score = score;
485 }
486 }
487
488 end:
489 if (fixed_rate)
490 *fixed_rate = snd_usb_pcm_has_fixed_rate(as: subs);
491 return sync_fmt;
492}
493
494

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