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->bLength == sizeof(*cs) && 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->bLength == sizeof(*cs) && 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->bLength >= sizeof(*cs) && cs->bClockID == id && 54 cs->bLength == 7 + cs->bNrInPins; 55 } 56 57 static bool validate_clock_selector_v3(void *p, int id) 58 { 59 struct uac3_clock_selector_descriptor *cs = p; 60 return cs->bLength >= sizeof(*cs) && cs->bClockID == id && 61 cs->bLength == 11 + cs->bNrInPins; 62 } 63 64 static bool validate_clock_multiplier_v2(void *p, int id) 65 { 66 struct uac_clock_multiplier_descriptor *cs = p; 67 return cs->bLength == sizeof(*cs) && cs->bClockID == id; 68 } 69 70 static bool validate_clock_multiplier_v3(void *p, int id) 71 { 72 struct uac3_clock_multiplier_descriptor *cs = p; 73 return cs->bLength == sizeof(*cs) && cs->bClockID == id; 74 } 75 76 #define DEFINE_FIND_HELPER(name, obj, validator, type) \ 77 static obj *name(struct usb_host_interface *iface, int id) \ 78 { \ 79 return find_uac_clock_desc(iface, id, validator, type); \ 80 } 81 82 DEFINE_FIND_HELPER(snd_usb_find_clock_source, 83 struct uac_clock_source_descriptor, 84 validate_clock_source_v2, UAC2_CLOCK_SOURCE); 85 DEFINE_FIND_HELPER(snd_usb_find_clock_source_v3, 86 struct uac3_clock_source_descriptor, 87 validate_clock_source_v3, UAC3_CLOCK_SOURCE); 88 89 DEFINE_FIND_HELPER(snd_usb_find_clock_selector, 90 struct uac_clock_selector_descriptor, 91 validate_clock_selector_v2, UAC2_CLOCK_SELECTOR); 92 DEFINE_FIND_HELPER(snd_usb_find_clock_selector_v3, 93 struct uac3_clock_selector_descriptor, 94 validate_clock_selector_v3, UAC3_CLOCK_SELECTOR); 95 96 DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier, 97 struct uac_clock_multiplier_descriptor, 98 validate_clock_multiplier_v2, UAC2_CLOCK_MULTIPLIER); 99 DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier_v3, 100 struct uac3_clock_multiplier_descriptor, 101 validate_clock_multiplier_v3, UAC3_CLOCK_MULTIPLIER); 102 103 static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id) 104 { 105 unsigned char buf; 106 int ret; 107 108 ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0), 109 UAC2_CS_CUR, 110 USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN, 111 UAC2_CX_CLOCK_SELECTOR << 8, 112 snd_usb_ctrl_intf(chip) | (selector_id << 8), 113 &buf, sizeof(buf)); 114 115 if (ret < 0) 116 return ret; 117 118 return buf; 119 } 120 121 static int uac_clock_selector_set_val(struct snd_usb_audio *chip, int selector_id, 122 unsigned char pin) 123 { 124 int ret; 125 126 ret = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0), 127 UAC2_CS_CUR, 128 USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT, 129 UAC2_CX_CLOCK_SELECTOR << 8, 130 snd_usb_ctrl_intf(chip) | (selector_id << 8), 131 &pin, sizeof(pin)); 132 if (ret < 0) 133 return ret; 134 135 if (ret != sizeof(pin)) { 136 usb_audio_err(chip, 137 "setting selector (id %d) unexpected length %d\n", 138 selector_id, ret); 139 return -EINVAL; 140 } 141 142 ret = uac_clock_selector_get_val(chip, selector_id); 143 if (ret < 0) 144 return ret; 145 146 if (ret != pin) { 147 usb_audio_err(chip, 148 "setting selector (id %d) to %x failed (current: %d)\n", 149 selector_id, pin, ret); 150 return -EINVAL; 151 } 152 153 return ret; 154 } 155 156 static bool uac_clock_source_is_valid(struct snd_usb_audio *chip, 157 int protocol, 158 int source_id) 159 { 160 int err; 161 unsigned char data; 162 struct usb_device *dev = chip->dev; 163 u32 bmControls; 164 165 if (protocol == UAC_VERSION_3) { 166 struct uac3_clock_source_descriptor *cs_desc = 167 snd_usb_find_clock_source_v3(chip->ctrl_intf, source_id); 168 169 if (!cs_desc) 170 return 0; 171 bmControls = le32_to_cpu(cs_desc->bmControls); 172 } else { /* UAC_VERSION_1/2 */ 173 struct uac_clock_source_descriptor *cs_desc = 174 snd_usb_find_clock_source(chip->ctrl_intf, source_id); 175 176 if (!cs_desc) 177 return 0; 178 bmControls = cs_desc->bmControls; 179 } 180 181 /* If a clock source can't tell us whether it's valid, we assume it is */ 182 if (!uac_v2v3_control_is_readable(bmControls, 183 UAC2_CS_CONTROL_CLOCK_VALID)) 184 return 1; 185 186 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR, 187 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN, 188 UAC2_CS_CONTROL_CLOCK_VALID << 8, 189 snd_usb_ctrl_intf(chip) | (source_id << 8), 190 &data, sizeof(data)); 191 192 if (err < 0) { 193 dev_warn(&dev->dev, 194 "%s(): cannot get clock validity for id %d\n", 195 __func__, source_id); 196 return 0; 197 } 198 199 return !!data; 200 } 201 202 static int __uac_clock_find_source(struct snd_usb_audio *chip, int entity_id, 203 unsigned long *visited, bool validate) 204 { 205 struct uac_clock_source_descriptor *source; 206 struct uac_clock_selector_descriptor *selector; 207 struct uac_clock_multiplier_descriptor *multiplier; 208 209 entity_id &= 0xff; 210 211 if (test_and_set_bit(entity_id, visited)) { 212 usb_audio_warn(chip, 213 "%s(): recursive clock topology detected, id %d.\n", 214 __func__, entity_id); 215 return -EINVAL; 216 } 217 218 /* first, see if the ID we're looking for is a clock source already */ 219 source = snd_usb_find_clock_source(chip->ctrl_intf, entity_id); 220 if (source) { 221 entity_id = source->bClockID; 222 if (validate && !uac_clock_source_is_valid(chip, UAC_VERSION_2, 223 entity_id)) { 224 usb_audio_err(chip, 225 "clock source %d is not valid, cannot use\n", 226 entity_id); 227 return -ENXIO; 228 } 229 return entity_id; 230 } 231 232 selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id); 233 if (selector) { 234 int ret, i, cur; 235 236 /* the entity ID we are looking for is a selector. 237 * find out what it currently selects */ 238 ret = uac_clock_selector_get_val(chip, selector->bClockID); 239 if (ret < 0) 240 return ret; 241 242 /* Selector values are one-based */ 243 244 if (ret > selector->bNrInPins || ret < 1) { 245 usb_audio_err(chip, 246 "%s(): selector reported illegal value, id %d, ret %d\n", 247 __func__, selector->bClockID, ret); 248 249 return -EINVAL; 250 } 251 252 cur = ret; 253 ret = __uac_clock_find_source(chip, selector->baCSourceID[ret - 1], 254 visited, validate); 255 if (!validate || ret > 0 || !chip->autoclock) 256 return ret; 257 258 /* The current clock source is invalid, try others. */ 259 for (i = 1; i <= selector->bNrInPins; i++) { 260 int err; 261 262 if (i == cur) 263 continue; 264 265 ret = __uac_clock_find_source(chip, selector->baCSourceID[i - 1], 266 visited, true); 267 if (ret < 0) 268 continue; 269 270 err = uac_clock_selector_set_val(chip, entity_id, i); 271 if (err < 0) 272 continue; 273 274 usb_audio_info(chip, 275 "found and selected valid clock source %d\n", 276 ret); 277 return ret; 278 } 279 280 return -ENXIO; 281 } 282 283 /* FIXME: multipliers only act as pass-thru element for now */ 284 multiplier = snd_usb_find_clock_multiplier(chip->ctrl_intf, entity_id); 285 if (multiplier) 286 return __uac_clock_find_source(chip, multiplier->bCSourceID, 287 visited, validate); 288 289 return -EINVAL; 290 } 291 292 static int __uac3_clock_find_source(struct snd_usb_audio *chip, int entity_id, 293 unsigned long *visited, bool validate) 294 { 295 struct uac3_clock_source_descriptor *source; 296 struct uac3_clock_selector_descriptor *selector; 297 struct uac3_clock_multiplier_descriptor *multiplier; 298 299 entity_id &= 0xff; 300 301 if (test_and_set_bit(entity_id, visited)) { 302 usb_audio_warn(chip, 303 "%s(): recursive clock topology detected, id %d.\n", 304 __func__, entity_id); 305 return -EINVAL; 306 } 307 308 /* first, see if the ID we're looking for is a clock source already */ 309 source = snd_usb_find_clock_source_v3(chip->ctrl_intf, entity_id); 310 if (source) { 311 entity_id = source->bClockID; 312 if (validate && !uac_clock_source_is_valid(chip, UAC_VERSION_3, 313 entity_id)) { 314 usb_audio_err(chip, 315 "clock source %d is not valid, cannot use\n", 316 entity_id); 317 return -ENXIO; 318 } 319 return entity_id; 320 } 321 322 selector = snd_usb_find_clock_selector_v3(chip->ctrl_intf, entity_id); 323 if (selector) { 324 int ret, i, cur; 325 326 /* the entity ID we are looking for is a selector. 327 * find out what it currently selects */ 328 ret = uac_clock_selector_get_val(chip, selector->bClockID); 329 if (ret < 0) 330 return ret; 331 332 /* Selector values are one-based */ 333 334 if (ret > selector->bNrInPins || ret < 1) { 335 usb_audio_err(chip, 336 "%s(): selector reported illegal value, id %d, ret %d\n", 337 __func__, selector->bClockID, ret); 338 339 return -EINVAL; 340 } 341 342 cur = ret; 343 ret = __uac3_clock_find_source(chip, selector->baCSourceID[ret - 1], 344 visited, validate); 345 if (!validate || ret > 0 || !chip->autoclock) 346 return ret; 347 348 /* The current clock source is invalid, try others. */ 349 for (i = 1; i <= selector->bNrInPins; i++) { 350 int err; 351 352 if (i == cur) 353 continue; 354 355 ret = __uac3_clock_find_source(chip, selector->baCSourceID[i - 1], 356 visited, true); 357 if (ret < 0) 358 continue; 359 360 err = uac_clock_selector_set_val(chip, entity_id, i); 361 if (err < 0) 362 continue; 363 364 usb_audio_info(chip, 365 "found and selected valid clock source %d\n", 366 ret); 367 return ret; 368 } 369 370 return -ENXIO; 371 } 372 373 /* FIXME: multipliers only act as pass-thru element for now */ 374 multiplier = snd_usb_find_clock_multiplier_v3(chip->ctrl_intf, 375 entity_id); 376 if (multiplier) 377 return __uac3_clock_find_source(chip, multiplier->bCSourceID, 378 visited, validate); 379 380 return -EINVAL; 381 } 382 383 /* 384 * For all kinds of sample rate settings and other device queries, 385 * the clock source (end-leaf) must be used. However, clock selectors, 386 * clock multipliers and sample rate converters may be specified as 387 * clock source input to terminal. This functions walks the clock path 388 * to its end and tries to find the source. 389 * 390 * The 'visited' bitfield is used internally to detect recursive loops. 391 * 392 * Returns the clock source UnitID (>=0) on success, or an error. 393 */ 394 int snd_usb_clock_find_source(struct snd_usb_audio *chip, int protocol, 395 int entity_id, bool validate) 396 { 397 DECLARE_BITMAP(visited, 256); 398 memset(visited, 0, sizeof(visited)); 399 400 switch (protocol) { 401 case UAC_VERSION_2: 402 return __uac_clock_find_source(chip, entity_id, visited, 403 validate); 404 case UAC_VERSION_3: 405 return __uac3_clock_find_source(chip, entity_id, visited, 406 validate); 407 default: 408 return -EINVAL; 409 } 410 } 411 412 static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface, 413 struct usb_host_interface *alts, 414 struct audioformat *fmt, int rate) 415 { 416 struct usb_device *dev = chip->dev; 417 unsigned int ep; 418 unsigned char data[3]; 419 int err, crate; 420 421 if (get_iface_desc(alts)->bNumEndpoints < 1) 422 return -EINVAL; 423 ep = get_endpoint(alts, 0)->bEndpointAddress; 424 425 /* if endpoint doesn't have sampling rate control, bail out */ 426 if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE)) 427 return 0; 428 429 data[0] = rate; 430 data[1] = rate >> 8; 431 data[2] = rate >> 16; 432 err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR, 433 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT, 434 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep, 435 data, sizeof(data)); 436 if (err < 0) { 437 dev_err(&dev->dev, "%d:%d: cannot set freq %d to ep %#x\n", 438 iface, fmt->altsetting, rate, ep); 439 return err; 440 } 441 442 /* Don't check the sample rate for devices which we know don't 443 * support reading */ 444 if (snd_usb_get_sample_rate_quirk(chip)) 445 return 0; 446 /* the firmware is likely buggy, don't repeat to fail too many times */ 447 if (chip->sample_rate_read_error > 2) 448 return 0; 449 450 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR, 451 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN, 452 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep, 453 data, sizeof(data)); 454 if (err < 0) { 455 dev_err(&dev->dev, "%d:%d: cannot get freq at ep %#x\n", 456 iface, fmt->altsetting, ep); 457 chip->sample_rate_read_error++; 458 return 0; /* some devices don't support reading */ 459 } 460 461 crate = data[0] | (data[1] << 8) | (data[2] << 16); 462 if (crate != rate) { 463 dev_warn(&dev->dev, "current rate %d is different from the runtime rate %d\n", crate, rate); 464 // runtime->rate = crate; 465 } 466 467 return 0; 468 } 469 470 static int get_sample_rate_v2v3(struct snd_usb_audio *chip, int iface, 471 int altsetting, int clock) 472 { 473 struct usb_device *dev = chip->dev; 474 __le32 data; 475 int err; 476 477 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR, 478 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN, 479 UAC2_CS_CONTROL_SAM_FREQ << 8, 480 snd_usb_ctrl_intf(chip) | (clock << 8), 481 &data, sizeof(data)); 482 if (err < 0) { 483 dev_warn(&dev->dev, "%d:%d: cannot get freq (v2/v3): err %d\n", 484 iface, altsetting, err); 485 return 0; 486 } 487 488 return le32_to_cpu(data); 489 } 490 491 static int set_sample_rate_v2v3(struct snd_usb_audio *chip, int iface, 492 struct usb_host_interface *alts, 493 struct audioformat *fmt, int rate) 494 { 495 struct usb_device *dev = chip->dev; 496 __le32 data; 497 int err, cur_rate, prev_rate; 498 int clock; 499 bool writeable; 500 u32 bmControls; 501 502 /* First, try to find a valid clock. This may trigger 503 * automatic clock selection if the current clock is not 504 * valid. 505 */ 506 clock = snd_usb_clock_find_source(chip, fmt->protocol, 507 fmt->clock, true); 508 if (clock < 0) { 509 /* We did not find a valid clock, but that might be 510 * because the current sample rate does not match an 511 * external clock source. Try again without validation 512 * and we will do another validation after setting the 513 * rate. 514 */ 515 clock = snd_usb_clock_find_source(chip, fmt->protocol, 516 fmt->clock, false); 517 if (clock < 0) 518 return clock; 519 } 520 521 prev_rate = get_sample_rate_v2v3(chip, iface, fmt->altsetting, clock); 522 if (prev_rate == rate) 523 goto validation; 524 525 if (fmt->protocol == UAC_VERSION_3) { 526 struct uac3_clock_source_descriptor *cs_desc; 527 528 cs_desc = snd_usb_find_clock_source_v3(chip->ctrl_intf, clock); 529 bmControls = le32_to_cpu(cs_desc->bmControls); 530 } else { 531 struct uac_clock_source_descriptor *cs_desc; 532 533 cs_desc = snd_usb_find_clock_source(chip->ctrl_intf, clock); 534 bmControls = cs_desc->bmControls; 535 } 536 537 writeable = uac_v2v3_control_is_writeable(bmControls, 538 UAC2_CS_CONTROL_SAM_FREQ); 539 if (writeable) { 540 data = cpu_to_le32(rate); 541 err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR, 542 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT, 543 UAC2_CS_CONTROL_SAM_FREQ << 8, 544 snd_usb_ctrl_intf(chip) | (clock << 8), 545 &data, sizeof(data)); 546 if (err < 0) { 547 usb_audio_err(chip, 548 "%d:%d: cannot set freq %d (v2/v3): err %d\n", 549 iface, fmt->altsetting, rate, err); 550 return err; 551 } 552 553 cur_rate = get_sample_rate_v2v3(chip, iface, 554 fmt->altsetting, clock); 555 } else { 556 cur_rate = prev_rate; 557 } 558 559 if (cur_rate != rate) { 560 if (!writeable) { 561 usb_audio_warn(chip, 562 "%d:%d: freq mismatch (RO clock): req %d, clock runs @%d\n", 563 iface, fmt->altsetting, rate, cur_rate); 564 return -ENXIO; 565 } 566 usb_audio_dbg(chip, 567 "current rate %d is different from the runtime rate %d\n", 568 cur_rate, rate); 569 } 570 571 /* Some devices doesn't respond to sample rate changes while the 572 * interface is active. */ 573 if (rate != prev_rate) { 574 usb_set_interface(dev, iface, 0); 575 snd_usb_set_interface_quirk(dev); 576 usb_set_interface(dev, iface, fmt->altsetting); 577 snd_usb_set_interface_quirk(dev); 578 } 579 580 validation: 581 /* validate clock after rate change */ 582 if (!uac_clock_source_is_valid(chip, fmt->protocol, clock)) 583 return -ENXIO; 584 return 0; 585 } 586 587 int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface, 588 struct usb_host_interface *alts, 589 struct audioformat *fmt, int rate) 590 { 591 switch (fmt->protocol) { 592 case UAC_VERSION_1: 593 default: 594 return set_sample_rate_v1(chip, iface, alts, fmt, rate); 595 596 case UAC_VERSION_3: 597 if (chip->badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) { 598 if (rate != UAC3_BADD_SAMPLING_RATE) 599 return -ENXIO; 600 else 601 return 0; 602 } 603 /* fall through */ 604 case UAC_VERSION_2: 605 return set_sample_rate_v2v3(chip, iface, alts, fmt, rate); 606 } 607 } 608 609