sound/usb/clock.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *   Clock domain and sample rate management functions
   4  */
   5
   6 #include <linux/bitops.h>
   7 #include <linux/init.h>
   8 #include <linux/string.h>
   9 #include <linux/usb.h>
  10 #include <linux/usb/audio.h>
  11 #include <linux/usb/audio-v2.h>
  12 #include <linux/usb/audio-v3.h>
  13
  14 #include <sound/core.h>
  15 #include <sound/info.h>
  16 #include <sound/pcm.h>
  17
  18 #include "usbaudio.h"
  19 #include "card.h"
  20 #include "helper.h"
  21 #include "clock.h"
  22 #include "quirks.h"
  23
  24 static void *find_uac_clock_desc(struct usb_host_interface *iface, int id,
  25                                  bool (*validator)(void *, int), u8 type)
  26 {
  27         void *cs = NULL;
  28
  29         while ((cs = snd_usb_find_csint_desc(iface->extra, iface->extralen,
  30                                              cs, type))) {
  31                 if (validator(cs, id))
  32                         return cs;
  33         }
  34
  35         return NULL;
  36 }
  37
  38 static bool validate_clock_source_v2(void *p, int id)
  39 {
  40         struct uac_clock_source_descriptor *cs = p;
  41         return cs->bClockID == id;
  42 }
  43
  44 static bool validate_clock_source_v3(void *p, int id)
  45 {
  46         struct uac3_clock_source_descriptor *cs = p;
  47         return cs->bClockID == id;
  48 }
  49
  50 static bool validate_clock_selector_v2(void *p, int id)
  51 {
  52         struct uac_clock_selector_descriptor *cs = p;
  53         return cs->bClockID == id;
  54 }
  55
  56 static bool validate_clock_selector_v3(void *p, int id)
  57 {
  58         struct uac3_clock_selector_descriptor *cs = p;
  59         return cs->bClockID == id;
  60 }
  61
  62 static bool validate_clock_multiplier_v2(void *p, int id)
  63 {
  64         struct uac_clock_multiplier_descriptor *cs = p;
  65         return cs->bClockID == id;
  66 }
  67
  68 static bool validate_clock_multiplier_v3(void *p, int id)
  69 {
  70         struct uac3_clock_multiplier_descriptor *cs = p;
  71         return cs->bClockID == id;
  72 }
  73
  74 #define DEFINE_FIND_HELPER(name, obj, validator, type)          \
  75 static obj *name(struct usb_host_interface *iface, int id)      \
  76 {                                                               \
  77         return find_uac_clock_desc(iface, id, validator, type); \
  78 }
  79
  80 DEFINE_FIND_HELPER(snd_usb_find_clock_source,
  81                    struct uac_clock_source_descriptor,
  82                    validate_clock_source_v2, UAC2_CLOCK_SOURCE);
  83 DEFINE_FIND_HELPER(snd_usb_find_clock_source_v3,
  84                    struct uac3_clock_source_descriptor,
  85                    validate_clock_source_v3, UAC3_CLOCK_SOURCE);
  86
  87 DEFINE_FIND_HELPER(snd_usb_find_clock_selector,
  88                    struct uac_clock_selector_descriptor,
  89                    validate_clock_selector_v2, UAC2_CLOCK_SELECTOR);
  90 DEFINE_FIND_HELPER(snd_usb_find_clock_selector_v3,
  91                    struct uac3_clock_selector_descriptor,
  92                    validate_clock_selector_v3, UAC3_CLOCK_SELECTOR);
  93
  94 DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier,
  95                    struct uac_clock_multiplier_descriptor,
  96                    validate_clock_multiplier_v2, UAC2_CLOCK_MULTIPLIER);
  97 DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier_v3,
  98                    struct uac3_clock_multiplier_descriptor,
  99                    validate_clock_multiplier_v3, UAC3_CLOCK_MULTIPLIER);
 100
 101 static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id)
 102 {
 103         unsigned char buf;
 104         int ret;
 105
 106         ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
 107                               UAC2_CS_CUR,
 108                               USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
 109                               UAC2_CX_CLOCK_SELECTOR << 8,
 110                               snd_usb_ctrl_intf(chip) | (selector_id << 8),
 111                               &buf, sizeof(buf));
 112
 113         if (ret < 0)
 114                 return ret;
 115
 116         return buf;
 117 }
 118
 119 static int uac_clock_selector_set_val(struct snd_usb_audio *chip, int selector_id,
 120                                         unsigned char pin)
 121 {
 122         int ret;
 123
 124         ret = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0),
 125                               UAC2_CS_CUR,
 126                               USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
 127                               UAC2_CX_CLOCK_SELECTOR << 8,
 128                               snd_usb_ctrl_intf(chip) | (selector_id << 8),
 129                               &pin, sizeof(pin));
 130         if (ret < 0)
 131                 return ret;
 132
 133         if (ret != sizeof(pin)) {
 134                 usb_audio_err(chip,
 135                         "setting selector (id %d) unexpected length %d\n",
 136                         selector_id, ret);
 137                 return -EINVAL;
 138         }
 139
 140         ret = uac_clock_selector_get_val(chip, selector_id);
 141         if (ret < 0)
 142                 return ret;
 143
 144         if (ret != pin) {
 145                 usb_audio_err(chip,
 146                         "setting selector (id %d) to %x failed (current: %d)\n",
 147                         selector_id, pin, ret);
 148                 return -EINVAL;
 149         }
 150
 151         return ret;
 152 }
 153
 154 static bool uac_clock_source_is_valid(struct snd_usb_audio *chip,
 155                                       int protocol,
 156                                       int source_id)
 157 {
 158         int err;
 159         unsigned char data;
 160         struct usb_device *dev = chip->dev;
 161         u32 bmControls;
 162
 163         if (protocol == UAC_VERSION_3) {
 164                 struct uac3_clock_source_descriptor *cs_desc =
 165                         snd_usb_find_clock_source_v3(chip->ctrl_intf, source_id);
 166
 167                 if (!cs_desc)
 168                         return false;
 169                 bmControls = le32_to_cpu(cs_desc->bmControls);
 170         } else { /* UAC_VERSION_1/2 */
 171                 struct uac_clock_source_descriptor *cs_desc =
 172                         snd_usb_find_clock_source(chip->ctrl_intf, source_id);
 173
 174                 if (!cs_desc)
 175                         return false;
 176                 bmControls = cs_desc->bmControls;
 177         }
 178
 179         /* If a clock source can't tell us whether it's valid, we assume it is */
 180         if (!uac_v2v3_control_is_readable(bmControls,
 181                                       UAC2_CS_CONTROL_CLOCK_VALID))
 182                 return true;
 183
 184         err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
 185                               USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
 186                               UAC2_CS_CONTROL_CLOCK_VALID << 8,
 187                               snd_usb_ctrl_intf(chip) | (source_id << 8),
 188                               &data, sizeof(data));
 189
 190         if (err < 0) {
 191                 dev_warn(&dev->dev,
 192                          "%s(): cannot get clock validity for id %d\n",
 193                            __func__, source_id);
 194                 return false;
 195         }
 196
 197         return data ? true :  false;
 198 }
 199
 200 static int __uac_clock_find_source(struct snd_usb_audio *chip, int entity_id,
 201                                    unsigned long *visited, bool validate)
 202 {
 203         struct uac_clock_source_descriptor *source;
 204         struct uac_clock_selector_descriptor *selector;
 205         struct uac_clock_multiplier_descriptor *multiplier;
 206
 207         entity_id &= 0xff;
 208
 209         if (test_and_set_bit(entity_id, visited)) {
 210                 usb_audio_warn(chip,
 211                          "%s(): recursive clock topology detected, id %d.\n",
 212                          __func__, entity_id);
 213                 return -EINVAL;
 214         }
 215
 216         /* first, see if the ID we're looking for is a clock source already */
 217         source = snd_usb_find_clock_source(chip->ctrl_intf, entity_id);
 218         if (source) {
 219                 entity_id = source->bClockID;
 220                 if (validate && !uac_clock_source_is_valid(chip, UAC_VERSION_2,
 221                                                                 entity_id)) {
 222                         usb_audio_err(chip,
 223                                 "clock source %d is not valid, cannot use\n",
 224                                 entity_id);
 225                         return -ENXIO;
 226                 }
 227                 return entity_id;
 228         }
 229
 230         selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id);
 231         if (selector) {
 232                 int ret, i, cur;
 233
 234                 /* the entity ID we are looking for is a selector.
 235                  * find out what it currently selects */
 236                 ret = uac_clock_selector_get_val(chip, selector->bClockID);
 237                 if (ret < 0)
 238                         return ret;
 239
 240                 /* Selector values are one-based */
 241
 242                 if (ret > selector->bNrInPins || ret < 1) {
 243                         usb_audio_err(chip,
 244                                 "%s(): selector reported illegal value, id %d, ret %d\n",
 245                                 __func__, selector->bClockID, ret);
 246
 247                         return -EINVAL;
 248                 }
 249
 250                 cur = ret;
 251                 ret = __uac_clock_find_source(chip, selector->baCSourceID[ret - 1],
 252                                                visited, validate);
 253                 if (!validate || ret > 0 || !chip->autoclock)
 254                         return ret;
 255
 256                 /* The current clock source is invalid, try others. */
 257                 for (i = 1; i <= selector->bNrInPins; i++) {
 258                         int err;
 259
 260                         if (i == cur)
 261                                 continue;
 262
 263                         ret = __uac_clock_find_source(chip, selector->baCSourceID[i - 1],
 264                                 visited, true);
 265                         if (ret < 0)
 266                                 continue;
 267
 268                         err = uac_clock_selector_set_val(chip, entity_id, i);
 269                         if (err < 0)
 270                                 continue;
 271
 272                         usb_audio_info(chip,
 273                                  "found and selected valid clock source %d\n",
 274                                  ret);
 275                         return ret;
 276                 }
 277
 278                 return -ENXIO;
 279         }
 280
 281         /* FIXME: multipliers only act as pass-thru element for now */
 282         multiplier = snd_usb_find_clock_multiplier(chip->ctrl_intf, entity_id);
 283         if (multiplier)
 284                 return __uac_clock_find_source(chip, multiplier->bCSourceID,
 285                                                 visited, validate);
 286
 287         return -EINVAL;
 288 }
 289
 290 static int __uac3_clock_find_source(struct snd_usb_audio *chip, int entity_id,
 291                                    unsigned long *visited, bool validate)
 292 {
 293         struct uac3_clock_source_descriptor *source;
 294         struct uac3_clock_selector_descriptor *selector;
 295         struct uac3_clock_multiplier_descriptor *multiplier;
 296
 297         entity_id &= 0xff;
 298
 299         if (test_and_set_bit(entity_id, visited)) {
 300                 usb_audio_warn(chip,
 301                          "%s(): recursive clock topology detected, id %d.\n",
 302                          __func__, entity_id);
 303                 return -EINVAL;
 304         }
 305
 306         /* first, see if the ID we're looking for is a clock source already */
 307         source = snd_usb_find_clock_source_v3(chip->ctrl_intf, entity_id);
 308         if (source) {
 309                 entity_id = source->bClockID;
 310                 if (validate && !uac_clock_source_is_valid(chip, UAC_VERSION_3,
 311                                                                 entity_id)) {
 312                         usb_audio_err(chip,
 313                                 "clock source %d is not valid, cannot use\n",
 314                                 entity_id);
 315                         return -ENXIO;
 316                 }
 317                 return entity_id;
 318         }
 319
 320         selector = snd_usb_find_clock_selector_v3(chip->ctrl_intf, entity_id);
 321         if (selector) {
 322                 int ret, i, cur;
 323
 324                 /* the entity ID we are looking for is a selector.
 325                  * find out what it currently selects */
 326                 ret = uac_clock_selector_get_val(chip, selector->bClockID);
 327                 if (ret < 0)
 328                         return ret;
 329
 330                 /* Selector values are one-based */
 331
 332                 if (ret > selector->bNrInPins || ret < 1) {
 333                         usb_audio_err(chip,
 334                                 "%s(): selector reported illegal value, id %d, ret %d\n",
 335                                 __func__, selector->bClockID, ret);
 336
 337                         return -EINVAL;
 338                 }
 339
 340                 cur = ret;
 341                 ret = __uac3_clock_find_source(chip, selector->baCSourceID[ret - 1],
 342                                                visited, validate);
 343                 if (!validate || ret > 0 || !chip->autoclock)
 344                         return ret;
 345
 346                 /* The current clock source is invalid, try others. */
 347                 for (i = 1; i <= selector->bNrInPins; i++) {
 348                         int err;
 349
 350                         if (i == cur)
 351                                 continue;
 352
 353                         ret = __uac3_clock_find_source(chip, selector->baCSourceID[i - 1],
 354                                 visited, true);
 355                         if (ret < 0)
 356                                 continue;
 357
 358                         err = uac_clock_selector_set_val(chip, entity_id, i);
 359                         if (err < 0)
 360                                 continue;
 361
 362                         usb_audio_info(chip,
 363                                  "found and selected valid clock source %d\n",
 364                                  ret);
 365                         return ret;
 366                 }
 367
 368                 return -ENXIO;
 369         }
 370
 371         /* FIXME: multipliers only act as pass-thru element for now */
 372         multiplier = snd_usb_find_clock_multiplier_v3(chip->ctrl_intf,
 373                                                       entity_id);
 374         if (multiplier)
 375                 return __uac3_clock_find_source(chip, multiplier->bCSourceID,
 376                                                 visited, validate);
 377
 378         return -EINVAL;
 379 }
 380
 381 /*
 382  * For all kinds of sample rate settings and other device queries,
 383  * the clock source (end-leaf) must be used. However, clock selectors,
 384  * clock multipliers and sample rate converters may be specified as
 385  * clock source input to terminal. This functions walks the clock path
 386  * to its end and tries to find the source.
 387  *
 388  * The 'visited' bitfield is used internally to detect recursive loops.
 389  *
 390  * Returns the clock source UnitID (>=0) on success, or an error.
 391  */
 392 int snd_usb_clock_find_source(struct snd_usb_audio *chip, int protocol,
 393                               int entity_id, bool validate)
 394 {
 395         DECLARE_BITMAP(visited, 256);
 396         memset(visited, 0, sizeof(visited));
 397
 398         switch (protocol) {
 399         case UAC_VERSION_2:
 400                 return __uac_clock_find_source(chip, entity_id, visited,
 401                                                validate);
 402         case UAC_VERSION_3:
 403                 return __uac3_clock_find_source(chip, entity_id, visited,
 404                                                validate);
 405         default:
 406                 return -EINVAL;
 407         }
 408 }
 409
 410 static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface,
 411                               struct usb_host_interface *alts,
 412                               struct audioformat *fmt, int rate)
 413 {
 414         struct usb_device *dev = chip->dev;
 415         unsigned int ep;
 416         unsigned char data[3];
 417         int err, crate;
 418
 419         if (get_iface_desc(alts)->bNumEndpoints < 1)
 420                 return -EINVAL;
 421         ep = get_endpoint(alts, 0)->bEndpointAddress;
 422
 423         /* if endpoint doesn't have sampling rate control, bail out */
 424         if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
 425                 return 0;
 426
 427         data[0] = rate;
 428         data[1] = rate >> 8;
 429         data[2] = rate >> 16;
 430         err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
 431                               USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
 432                               UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
 433                               data, sizeof(data));
 434         if (err < 0) {
 435                 dev_err(&dev->dev, "%d:%d: cannot set freq %d to ep %#x\n",
 436                         iface, fmt->altsetting, rate, ep);
 437                 return err;
 438         }
 439
 440         /* Don't check the sample rate for devices which we know don't
 441          * support reading */
 442         if (snd_usb_get_sample_rate_quirk(chip))
 443                 return 0;
 444         /* the firmware is likely buggy, don't repeat to fail too many times */
 445         if (chip->sample_rate_read_error > 2)
 446                 return 0;
 447
 448         err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
 449                               USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
 450                               UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
 451                               data, sizeof(data));
 452         if (err < 0) {
 453                 dev_err(&dev->dev, "%d:%d: cannot get freq at ep %#x\n",
 454                         iface, fmt->altsetting, ep);
 455                 chip->sample_rate_read_error++;
 456                 return 0; /* some devices don't support reading */
 457         }
 458
 459         crate = data[0] | (data[1] << 8) | (data[2] << 16);
 460         if (crate != rate) {
 461                 dev_warn(&dev->dev, "current rate %d is different from the runtime rate %d\n", crate, rate);
 462                 // runtime->rate = crate;
 463         }
 464
 465         return 0;
 466 }
 467
 468 static int get_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
 469                               int altsetting, int clock)
 470 {
 471         struct usb_device *dev = chip->dev;
 472         __le32 data;
 473         int err;
 474
 475         err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
 476                               USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
 477                               UAC2_CS_CONTROL_SAM_FREQ << 8,
 478                               snd_usb_ctrl_intf(chip) | (clock << 8),
 479                               &data, sizeof(data));
 480         if (err < 0) {
 481                 dev_warn(&dev->dev, "%d:%d: cannot get freq (v2/v3): err %d\n",
 482                          iface, altsetting, err);
 483                 return 0;
 484         }
 485
 486         return le32_to_cpu(data);
 487 }
 488
 489 static int set_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
 490                               struct usb_host_interface *alts,
 491                               struct audioformat *fmt, int rate)
 492 {
 493         struct usb_device *dev = chip->dev;
 494         __le32 data;
 495         int err, cur_rate, prev_rate;
 496         int clock;
 497         bool writeable;
 498         u32 bmControls;
 499
 500         /* First, try to find a valid clock. This may trigger
 501          * automatic clock selection if the current clock is not
 502          * valid.
 503          */
 504         clock = snd_usb_clock_find_source(chip, fmt->protocol,
 505                                           fmt->clock, true);
 506         if (clock < 0) {
 507                 /* We did not find a valid clock, but that might be
 508                  * because the current sample rate does not match an
 509                  * external clock source. Try again without validation
 510                  * and we will do another validation after setting the
 511                  * rate.
 512                  */
 513                 clock = snd_usb_clock_find_source(chip, fmt->protocol,
 514                                                   fmt->clock, false);
 515                 if (clock < 0)
 516                         return clock;
 517         }
 518
 519         prev_rate = get_sample_rate_v2v3(chip, iface, fmt->altsetting, clock);
 520         if (prev_rate == rate)
 521                 goto validation;
 522
 523         if (fmt->protocol == UAC_VERSION_3) {
 524                 struct uac3_clock_source_descriptor *cs_desc;
 525
 526                 cs_desc = snd_usb_find_clock_source_v3(chip->ctrl_intf, clock);
 527                 bmControls = le32_to_cpu(cs_desc->bmControls);
 528         } else {
 529                 struct uac_clock_source_descriptor *cs_desc;
 530
 531                 cs_desc = snd_usb_find_clock_source(chip->ctrl_intf, clock);
 532                 bmControls = cs_desc->bmControls;
 533         }
 534
 535         writeable = uac_v2v3_control_is_writeable(bmControls,
 536                                                   UAC2_CS_CONTROL_SAM_FREQ);
 537         if (writeable) {
 538                 data = cpu_to_le32(rate);
 539                 err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
 540                                       USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
 541                                       UAC2_CS_CONTROL_SAM_FREQ << 8,
 542                                       snd_usb_ctrl_intf(chip) | (clock << 8),
 543                                       &data, sizeof(data));
 544                 if (err < 0) {
 545                         usb_audio_err(chip,
 546                                 "%d:%d: cannot set freq %d (v2/v3): err %d\n",
 547                                 iface, fmt->altsetting, rate, err);
 548                         return err;
 549                 }
 550
 551                 cur_rate = get_sample_rate_v2v3(chip, iface,
 552                                                 fmt->altsetting, clock);
 553         } else {
 554                 cur_rate = prev_rate;
 555         }
 556
 557         if (cur_rate != rate) {
 558                 if (!writeable) {
 559                         usb_audio_warn(chip,
 560                                  "%d:%d: freq mismatch (RO clock): req %d, clock runs @%d\n",
 561                                  iface, fmt->altsetting, rate, cur_rate);
 562                         return -ENXIO;
 563                 }
 564                 usb_audio_dbg(chip,
 565                         "current rate %d is different from the runtime rate %d\n",
 566                         cur_rate, rate);
 567         }
 568
 569         /* Some devices doesn't respond to sample rate changes while the
 570          * interface is active. */
 571         if (rate != prev_rate) {
 572                 usb_set_interface(dev, iface, 0);
 573                 snd_usb_set_interface_quirk(dev);
 574                 usb_set_interface(dev, iface, fmt->altsetting);
 575                 snd_usb_set_interface_quirk(dev);
 576         }
 577
 578 validation:
 579         /* validate clock after rate change */
 580         if (!uac_clock_source_is_valid(chip, fmt->protocol, clock))
 581                 return -ENXIO;
 582         return 0;
 583 }
 584
 585 int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
 586                              struct usb_host_interface *alts,
 587                              struct audioformat *fmt, int rate)
 588 {
 589         switch (fmt->protocol) {
 590         case UAC_VERSION_1:
 591         default:
 592                 return set_sample_rate_v1(chip, iface, alts, fmt, rate);
 593
 594         case UAC_VERSION_3:
 595                 if (chip->badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
 596                         if (rate != UAC3_BADD_SAMPLING_RATE)
 597                                 return -ENXIO;
 598                         else
 599                                 return 0;
 600                 }
 601         /* fall through */
 602         case UAC_VERSION_2:
 603                 return set_sample_rate_v2v3(chip, iface, alts, fmt, rate);
 604         }
 605 }
 606