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 union uac23_clock_source_desc {
  25         struct uac_clock_source_descriptor v2;
  26         struct uac3_clock_source_descriptor v3;
  27 };
  28
  29 union uac23_clock_selector_desc {
  30         struct uac_clock_selector_descriptor v2;
  31         struct uac3_clock_selector_descriptor v3;
  32 };
  33
  34 union uac23_clock_multiplier_desc {
  35         struct uac_clock_multiplier_descriptor v2;
  36         struct uac_clock_multiplier_descriptor v3;
  37 };
  38
  39 #define GET_VAL(p, proto, field) \
  40         ((proto) == UAC_VERSION_3 ? (p)->v3.field : (p)->v2.field)
  41
  42 static void *find_uac_clock_desc(struct usb_host_interface *iface, int id,
  43                                  bool (*validator)(void *, int, int),
  44                                  u8 type, int proto)
  45 {
  46         void *cs = NULL;
  47
  48         while ((cs = snd_usb_find_csint_desc(iface->extra, iface->extralen,
  49                                              cs, type))) {
  50                 if (validator(cs, id, proto))
  51                         return cs;
  52         }
  53
  54         return NULL;
  55 }
  56
  57 static bool validate_clock_source(void *p, int id, int proto)
  58 {
  59         union uac23_clock_source_desc *cs = p;
  60
  61         return GET_VAL(cs, proto, bClockID) == id;
  62 }
  63
  64 static bool validate_clock_selector(void *p, int id, int proto)
  65 {
  66         union uac23_clock_selector_desc *cs = p;
  67
  68         return GET_VAL(cs, proto, bClockID) == id;
  69 }
  70
  71 static bool validate_clock_multiplier(void *p, int id, int proto)
  72 {
  73         union uac23_clock_multiplier_desc *cs = p;
  74
  75         return GET_VAL(cs, proto, bClockID) == id;
  76 }
  77
  78 #define DEFINE_FIND_HELPER(name, obj, validator, type2, type3)          \
  79 static obj *name(struct snd_usb_audio *chip, int id, int proto) \
  80 {                                                                       \
  81         return find_uac_clock_desc(chip->ctrl_intf, id, validator,      \
  82                                    proto == UAC_VERSION_3 ? (type3) : (type2), \
  83                                    proto);                              \
  84 }
  85
  86 DEFINE_FIND_HELPER(snd_usb_find_clock_source,
  87                    union uac23_clock_source_desc, validate_clock_source,
  88                    UAC2_CLOCK_SOURCE, UAC3_CLOCK_SOURCE);
  89 DEFINE_FIND_HELPER(snd_usb_find_clock_selector,
  90                    union uac23_clock_selector_desc, validate_clock_selector,
  91                    UAC2_CLOCK_SELECTOR, UAC3_CLOCK_SELECTOR);
  92 DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier,
  93                    union uac23_clock_multiplier_desc, validate_clock_multiplier,
  94                    UAC2_CLOCK_MULTIPLIER, UAC3_CLOCK_MULTIPLIER);
  95
  96 static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id)
  97 {
  98         unsigned char buf;
  99         int ret;
 100
 101         ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
 102                               UAC2_CS_CUR,
 103                               USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
 104                               UAC2_CX_CLOCK_SELECTOR << 8,
 105                               snd_usb_ctrl_intf(chip) | (selector_id << 8),
 106                               &buf, sizeof(buf));
 107
 108         if (ret < 0)
 109                 return ret;
 110
 111         return buf;
 112 }
 113
 114 static int uac_clock_selector_set_val(struct snd_usb_audio *chip, int selector_id,
 115                                         unsigned char pin)
 116 {
 117         int ret;
 118
 119         ret = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0),
 120                               UAC2_CS_CUR,
 121                               USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
 122                               UAC2_CX_CLOCK_SELECTOR << 8,
 123                               snd_usb_ctrl_intf(chip) | (selector_id << 8),
 124                               &pin, sizeof(pin));
 125         if (ret < 0)
 126                 return ret;
 127
 128         if (ret != sizeof(pin)) {
 129                 usb_audio_err(chip,
 130                         "setting selector (id %d) unexpected length %d\n",
 131                         selector_id, ret);
 132                 return -EINVAL;
 133         }
 134
 135         ret = uac_clock_selector_get_val(chip, selector_id);
 136         if (ret < 0)
 137                 return ret;
 138
 139         if (ret != pin) {
 140                 usb_audio_err(chip,
 141                         "setting selector (id %d) to %x failed (current: %d)\n",
 142                         selector_id, pin, ret);
 143                 return -EINVAL;
 144         }
 145
 146         return ret;
 147 }
 148
 149 static bool uac_clock_source_is_valid_quirk(struct snd_usb_audio *chip,
 150                                             const struct audioformat *fmt,
 151                                             int source_id)
 152 {
 153         bool ret = false;
 154         int count;
 155         unsigned char data;
 156         struct usb_device *dev = chip->dev;
 157         union uac23_clock_source_desc *cs_desc;
 158
 159         cs_desc = snd_usb_find_clock_source(chip, source_id, fmt->protocol);
 160         if (!cs_desc)
 161                 return false;
 162
 163         if (fmt->protocol == UAC_VERSION_2) {
 164                 /*
 165                  * Assume the clock is valid if clock source supports only one
 166                  * single sample rate, the terminal is connected directly to it
 167                  * (there is no clock selector) and clock type is internal.
 168                  * This is to deal with some Denon DJ controllers that always
 169                  * reports that clock is invalid.
 170                  */
 171                 if (fmt->nr_rates == 1 &&
 172                     (fmt->clock & 0xff) == cs_desc->v2.bClockID &&
 173                     (cs_desc->v2.bmAttributes & 0x3) !=
 174                                 UAC_CLOCK_SOURCE_TYPE_EXT)
 175                         return true;
 176         }
 177
 178         /*
 179          * MOTU MicroBook IIc
 180          * Sample rate changes takes more than 2 seconds for this device. Clock
 181          * validity request returns false during that period.
 182          */
 183         if (chip->usb_id == USB_ID(0x07fd, 0x0004)) {
 184                 count = 0;
 185
 186                 while ((!ret) && (count < 50)) {
 187                         int err;
 188
 189                         msleep(100);
 190
 191                         err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
 192                                               USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
 193                                               UAC2_CS_CONTROL_CLOCK_VALID << 8,
 194                                               snd_usb_ctrl_intf(chip) | (source_id << 8),
 195                                               &data, sizeof(data));
 196                         if (err < 0) {
 197                                 dev_warn(&dev->dev,
 198                                          "%s(): cannot get clock validity for id %d\n",
 199                                            __func__, source_id);
 200                                 return false;
 201                         }
 202
 203                         ret = !!data;
 204                         count++;
 205                 }
 206         }
 207
 208         return ret;
 209 }
 210
 211 static bool uac_clock_source_is_valid(struct snd_usb_audio *chip,
 212                                       const struct audioformat *fmt,
 213                                       int source_id)
 214 {
 215         int err;
 216         unsigned char data;
 217         struct usb_device *dev = chip->dev;
 218         u32 bmControls;
 219         union uac23_clock_source_desc *cs_desc;
 220
 221         cs_desc = snd_usb_find_clock_source(chip, source_id, fmt->protocol);
 222         if (!cs_desc)
 223                 return false;
 224
 225         if (fmt->protocol == UAC_VERSION_3)
 226                 bmControls = le32_to_cpu(cs_desc->v3.bmControls);
 227         else
 228                 bmControls = cs_desc->v2.bmControls;
 229
 230         /* If a clock source can't tell us whether it's valid, we assume it is */
 231         if (!uac_v2v3_control_is_readable(bmControls,
 232                                       UAC2_CS_CONTROL_CLOCK_VALID))
 233                 return true;
 234
 235         err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
 236                               USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
 237                               UAC2_CS_CONTROL_CLOCK_VALID << 8,
 238                               snd_usb_ctrl_intf(chip) | (source_id << 8),
 239                               &data, sizeof(data));
 240
 241         if (err < 0) {
 242                 dev_warn(&dev->dev,
 243                          "%s(): cannot get clock validity for id %d\n",
 244                            __func__, source_id);
 245                 return false;
 246         }
 247
 248         if (data)
 249                 return true;
 250         else
 251                 return uac_clock_source_is_valid_quirk(chip, fmt, source_id);
 252 }
 253
 254 static int __uac_clock_find_source(struct snd_usb_audio *chip,
 255                                    const struct audioformat *fmt, int entity_id,
 256                                    unsigned long *visited, bool validate)
 257 {
 258         union uac23_clock_source_desc *source;
 259         union uac23_clock_selector_desc *selector;
 260         union uac23_clock_multiplier_desc *multiplier;
 261         int ret, i, cur, err, pins, clock_id;
 262         const u8 *sources;
 263         int proto = fmt->protocol;
 264
 265         entity_id &= 0xff;
 266
 267         if (test_and_set_bit(entity_id, visited)) {
 268                 usb_audio_warn(chip,
 269                          "%s(): recursive clock topology detected, id %d.\n",
 270                          __func__, entity_id);
 271                 return -EINVAL;
 272         }
 273
 274         /* first, see if the ID we're looking for is a clock source already */
 275         source = snd_usb_find_clock_source(chip, entity_id, proto);
 276         if (source) {
 277                 entity_id = GET_VAL(source, proto, bClockID);
 278                 if (validate && !uac_clock_source_is_valid(chip, fmt,
 279                                                                 entity_id)) {
 280                         usb_audio_err(chip,
 281                                 "clock source %d is not valid, cannot use\n",
 282                                 entity_id);
 283                         return -ENXIO;
 284                 }
 285                 return entity_id;
 286         }
 287
 288         selector = snd_usb_find_clock_selector(chip, entity_id, proto);
 289         if (selector) {
 290                 pins = GET_VAL(selector, proto, bNrInPins);
 291                 clock_id = GET_VAL(selector, proto, bClockID);
 292                 sources = GET_VAL(selector, proto, baCSourceID);
 293                 cur = 0;
 294
 295                 if (pins == 1) {
 296                         ret = 1;
 297                         goto find_source;
 298                 }
 299
 300                 /* the entity ID we are looking for is a selector.
 301                  * find out what it currently selects */
 302                 ret = uac_clock_selector_get_val(chip, clock_id);
 303                 if (ret < 0) {
 304                         if (!chip->autoclock)
 305                                 return ret;
 306                         goto find_others;
 307                 }
 308
 309                 /* Selector values are one-based */
 310
 311                 if (ret > pins || ret < 1) {
 312                         usb_audio_err(chip,
 313                                 "%s(): selector reported illegal value, id %d, ret %d\n",
 314                                 __func__, clock_id, ret);
 315
 316                         if (!chip->autoclock)
 317                                 return -EINVAL;
 318                         goto find_others;
 319                 }
 320
 321         find_source:
 322                 cur = ret;
 323                 ret = __uac_clock_find_source(chip, fmt,
 324                                               sources[ret - 1],
 325                                               visited, validate);
 326                 if (ret > 0) {
 327                         /* Skip setting clock selector again for some devices */
 328                         if (chip->quirk_flags & QUIRK_FLAG_SKIP_CLOCK_SELECTOR)
 329                                 return ret;
 330                         err = uac_clock_selector_set_val(chip, entity_id, cur);
 331                         if (err < 0)
 332                                 return err;
 333                 }
 334
 335                 if (!validate || ret > 0 || !chip->autoclock)
 336                         return ret;
 337
 338         find_others:
 339                 /* The current clock source is invalid, try others. */
 340                 for (i = 1; i <= pins; i++) {
 341                         if (i == cur)
 342                                 continue;
 343
 344                         ret = __uac_clock_find_source(chip, fmt,
 345                                                       sources[i - 1],
 346                                                       visited, true);
 347                         if (ret < 0)
 348                                 continue;
 349
 350                         err = uac_clock_selector_set_val(chip, entity_id, i);
 351                         if (err < 0)
 352                                 continue;
 353
 354                         usb_audio_info(chip,
 355                                  "found and selected valid clock source %d\n",
 356                                  ret);
 357                         return ret;
 358                 }
 359
 360                 return -ENXIO;
 361         }
 362
 363         /* FIXME: multipliers only act as pass-thru element for now */
 364         multiplier = snd_usb_find_clock_multiplier(chip, entity_id, proto);
 365         if (multiplier)
 366                 return __uac_clock_find_source(chip, fmt,
 367                                                GET_VAL(multiplier, proto, bCSourceID),
 368                                                visited, validate);
 369
 370         return -EINVAL;
 371 }
 372
 373 /*
 374  * For all kinds of sample rate settings and other device queries,
 375  * the clock source (end-leaf) must be used. However, clock selectors,
 376  * clock multipliers and sample rate converters may be specified as
 377  * clock source input to terminal. This functions walks the clock path
 378  * to its end and tries to find the source.
 379  *
 380  * The 'visited' bitfield is used internally to detect recursive loops.
 381  *
 382  * Returns the clock source UnitID (>=0) on success, or an error.
 383  */
 384 int snd_usb_clock_find_source(struct snd_usb_audio *chip,
 385                               const struct audioformat *fmt, bool validate)
 386 {
 387         DECLARE_BITMAP(visited, 256);
 388         memset(visited, 0, sizeof(visited));
 389
 390         switch (fmt->protocol) {
 391         case UAC_VERSION_2:
 392         case UAC_VERSION_3:
 393                 return __uac_clock_find_source(chip, fmt, fmt->clock, visited,
 394                                                validate);
 395         default:
 396                 return -EINVAL;
 397         }
 398 }
 399
 400 static int set_sample_rate_v1(struct snd_usb_audio *chip,
 401                               const struct audioformat *fmt, int rate)
 402 {
 403         struct usb_device *dev = chip->dev;
 404         unsigned char data[3];
 405         int err, crate;
 406
 407         /* if endpoint doesn't have sampling rate control, bail out */
 408         if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
 409                 return 0;
 410
 411         data[0] = rate;
 412         data[1] = rate >> 8;
 413         data[2] = rate >> 16;
 414         err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
 415                               USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
 416                               UAC_EP_CS_ATTR_SAMPLE_RATE << 8,
 417                               fmt->endpoint, data, sizeof(data));
 418         if (err < 0) {
 419                 dev_err(&dev->dev, "%d:%d: cannot set freq %d to ep %#x\n",
 420                         fmt->iface, fmt->altsetting, rate, fmt->endpoint);
 421                 return err;
 422         }
 423
 424         /* Don't check the sample rate for devices which we know don't
 425          * support reading */
 426         if (chip->quirk_flags & QUIRK_FLAG_GET_SAMPLE_RATE)
 427                 return 0;
 428         /* the firmware is likely buggy, don't repeat to fail too many times */
 429         if (chip->sample_rate_read_error > 2)
 430                 return 0;
 431
 432         err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
 433                               USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
 434                               UAC_EP_CS_ATTR_SAMPLE_RATE << 8,
 435                               fmt->endpoint, data, sizeof(data));
 436         if (err < 0) {
 437                 dev_err(&dev->dev, "%d:%d: cannot get freq at ep %#x\n",
 438                         fmt->iface, fmt->altsetting, fmt->endpoint);
 439                 chip->sample_rate_read_error++;
 440                 return 0; /* some devices don't support reading */
 441         }
 442
 443         crate = data[0] | (data[1] << 8) | (data[2] << 16);
 444         if (!crate) {
 445                 dev_info(&dev->dev, "failed to read current rate; disabling the check\n");
 446                 chip->sample_rate_read_error = 3; /* three strikes, see above */
 447                 return 0;
 448         }
 449
 450         if (crate != rate) {
 451                 dev_warn(&dev->dev, "current rate %d is different from the runtime rate %d\n", crate, rate);
 452                 // runtime->rate = crate;
 453         }
 454
 455         return 0;
 456 }
 457
 458 static int get_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
 459                               int altsetting, int clock)
 460 {
 461         struct usb_device *dev = chip->dev;
 462         __le32 data;
 463         int err;
 464
 465         err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
 466                               USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
 467                               UAC2_CS_CONTROL_SAM_FREQ << 8,
 468                               snd_usb_ctrl_intf(chip) | (clock << 8),
 469                               &data, sizeof(data));
 470         if (err < 0) {
 471                 dev_warn(&dev->dev, "%d:%d: cannot get freq (v2/v3): err %d\n",
 472                          iface, altsetting, err);
 473                 return 0;
 474         }
 475
 476         return le32_to_cpu(data);
 477 }
 478
 479 /*
 480  * Try to set the given sample rate:
 481  *
 482  * Return 0 if the clock source is read-only, the actual rate on success,
 483  * or a negative error code.
 484  *
 485  * This function gets called from format.c to validate each sample rate, too.
 486  * Hence no message is shown upon error
 487  */
 488 int snd_usb_set_sample_rate_v2v3(struct snd_usb_audio *chip,
 489                                  const struct audioformat *fmt,
 490                                  int clock, int rate)
 491 {
 492         bool writeable;
 493         u32 bmControls;
 494         __le32 data;
 495         int err;
 496         union uac23_clock_source_desc *cs_desc;
 497
 498         cs_desc = snd_usb_find_clock_source(chip, clock, fmt->protocol);
 499         if (fmt->protocol == UAC_VERSION_3)
 500                 bmControls = le32_to_cpu(cs_desc->v3.bmControls);
 501         else
 502                 bmControls = cs_desc->v2.bmControls;
 503
 504         writeable = uac_v2v3_control_is_writeable(bmControls,
 505                                                   UAC2_CS_CONTROL_SAM_FREQ);
 506         if (!writeable)
 507                 return 0;
 508
 509         data = cpu_to_le32(rate);
 510         err = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0), UAC2_CS_CUR,
 511                               USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
 512                               UAC2_CS_CONTROL_SAM_FREQ << 8,
 513                               snd_usb_ctrl_intf(chip) | (clock << 8),
 514                               &data, sizeof(data));
 515         if (err < 0)
 516                 return err;
 517
 518         return get_sample_rate_v2v3(chip, fmt->iface, fmt->altsetting, clock);
 519 }
 520
 521 static int set_sample_rate_v2v3(struct snd_usb_audio *chip,
 522                                 const struct audioformat *fmt, int rate)
 523 {
 524         int cur_rate, prev_rate;
 525         int clock;
 526
 527         /* First, try to find a valid clock. This may trigger
 528          * automatic clock selection if the current clock is not
 529          * valid.
 530          */
 531         clock = snd_usb_clock_find_source(chip, fmt, true);
 532         if (clock < 0) {
 533                 /* We did not find a valid clock, but that might be
 534                  * because the current sample rate does not match an
 535                  * external clock source. Try again without validation
 536                  * and we will do another validation after setting the
 537                  * rate.
 538                  */
 539                 clock = snd_usb_clock_find_source(chip, fmt, false);
 540
 541                 /* Hardcoded sample rates */
 542                 if (chip->quirk_flags & QUIRK_FLAG_IGNORE_CLOCK_SOURCE)
 543                         return 0;
 544
 545                 if (clock < 0)
 546                         return clock;
 547         }
 548
 549         prev_rate = get_sample_rate_v2v3(chip, fmt->iface, fmt->altsetting, clock);
 550         if (prev_rate == rate)
 551                 goto validation;
 552
 553         cur_rate = snd_usb_set_sample_rate_v2v3(chip, fmt, clock, rate);
 554         if (cur_rate < 0) {
 555                 usb_audio_err(chip,
 556                               "%d:%d: cannot set freq %d (v2/v3): err %d\n",
 557                               fmt->iface, fmt->altsetting, rate, cur_rate);
 558                 return cur_rate;
 559         }
 560
 561         if (!cur_rate)
 562                 cur_rate = prev_rate;
 563
 564         if (cur_rate != rate) {
 565                 usb_audio_dbg(chip,
 566                               "%d:%d: freq mismatch: req %d, clock runs @%d\n",
 567                               fmt->iface, fmt->altsetting, rate, cur_rate);
 568                 /* continue processing */
 569         }
 570
 571 validation:
 572         /* validate clock after rate change */
 573         if (!uac_clock_source_is_valid(chip, fmt, clock))
 574                 return -ENXIO;
 575         return 0;
 576 }
 577
 578 int snd_usb_init_sample_rate(struct snd_usb_audio *chip,
 579                              const struct audioformat *fmt, int rate)
 580 {
 581         usb_audio_dbg(chip, "%d:%d Set sample rate %d, clock %d\n",
 582                       fmt->iface, fmt->altsetting, rate, fmt->clock);
 583
 584         switch (fmt->protocol) {
 585         case UAC_VERSION_1:
 586         default:
 587                 return set_sample_rate_v1(chip, fmt, rate);
 588
 589         case UAC_VERSION_3:
 590                 if (chip->badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
 591                         if (rate != UAC3_BADD_SAMPLING_RATE)
 592                                 return -ENXIO;
 593                         else
 594                                 return 0;
 595                 }
 596                 fallthrough;
 597         case UAC_VERSION_2:
 598                 return set_sample_rate_v2v3(chip, fmt, rate);
 599         }
 600 }
 601