drivers/soundwire/intel_auxdevice.c

   1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
   2 // Copyright(c) 2015-22 Intel Corporation.
   3
   4 /*
   5  * Soundwire Intel Manager Driver
   6  */
   7
   8 #include <linux/acpi.h>
   9 #include <linux/debugfs.h>
  10 #include <linux/delay.h>
  11 #include <linux/module.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/io.h>
  14 #include <linux/auxiliary_bus.h>
  15 #include <sound/pcm_params.h>
  16 #include <linux/pm_runtime.h>
  17 #include <sound/soc.h>
  18 #include <linux/soundwire/sdw_registers.h>
  19 #include <linux/soundwire/sdw.h>
  20 #include <linux/soundwire/sdw_intel.h>
  21 #include "cadence_master.h"
  22 #include "bus.h"
  23 #include "intel.h"
  24 #include "intel_auxdevice.h"
  25
  26 /* IDA min selected to avoid conflicts with HDaudio/iDISP SDI values */
  27 #define INTEL_DEV_NUM_IDA_MIN           4
  28
  29 #define INTEL_MASTER_SUSPEND_DELAY_MS   3000
  30
  31 /*
  32  * debug/config flags for the Intel SoundWire Master.
  33  *
  34  * Since we may have multiple masters active, we can have up to 8
  35  * flags reused in each byte, with master0 using the ls-byte, etc.
  36  */
  37
  38 #define SDW_INTEL_MASTER_DISABLE_PM_RUNTIME             BIT(0)
  39 #define SDW_INTEL_MASTER_DISABLE_CLOCK_STOP             BIT(1)
  40 #define SDW_INTEL_MASTER_DISABLE_PM_RUNTIME_IDLE        BIT(2)
  41 #define SDW_INTEL_MASTER_DISABLE_MULTI_LINK             BIT(3)
  42
  43 static int md_flags;
  44 module_param_named(sdw_md_flags, md_flags, int, 0444);
  45 MODULE_PARM_DESC(sdw_md_flags, "SoundWire Intel Master device flags (0x0 all off)");
  46
  47 static int generic_pre_bank_switch(struct sdw_bus *bus)
  48 {
  49         struct sdw_cdns *cdns = bus_to_cdns(bus);
  50         struct sdw_intel *sdw = cdns_to_intel(cdns);
  51
  52         return sdw->link_res->hw_ops->pre_bank_switch(sdw);
  53 }
  54
  55 static int generic_post_bank_switch(struct sdw_bus *bus)
  56 {
  57         struct sdw_cdns *cdns = bus_to_cdns(bus);
  58         struct sdw_intel *sdw = cdns_to_intel(cdns);
  59
  60         return sdw->link_res->hw_ops->post_bank_switch(sdw);
  61 }
  62
  63 static void generic_new_peripheral_assigned(struct sdw_bus *bus, int dev_num)
  64 {
  65         struct sdw_cdns *cdns = bus_to_cdns(bus);
  66         struct sdw_intel *sdw = cdns_to_intel(cdns);
  67
  68         /* paranoia check, this should never happen */
  69         if (dev_num < INTEL_DEV_NUM_IDA_MIN || dev_num > SDW_MAX_DEVICES)  {
  70                 dev_err(bus->dev, "%s: invalid dev_num %d\n", __func__, dev_num);
  71                 return;
  72         }
  73
  74         if (sdw->link_res->hw_ops->program_sdi)
  75                 sdw->link_res->hw_ops->program_sdi(sdw, dev_num);
  76 }
  77
  78 static int sdw_master_read_intel_prop(struct sdw_bus *bus)
  79 {
  80         struct sdw_master_prop *prop = &bus->prop;
  81         struct fwnode_handle *link;
  82         char name[32];
  83         u32 quirk_mask;
  84
  85         /* Find master handle */
  86         snprintf(name, sizeof(name),
  87                  "mipi-sdw-link-%d-subproperties", bus->link_id);
  88
  89         link = device_get_named_child_node(bus->dev, name);
  90         if (!link) {
  91                 dev_err(bus->dev, "Master node %s not found\n", name);
  92                 return -EIO;
  93         }
  94
  95         fwnode_property_read_u32(link,
  96                                  "intel-sdw-ip-clock",
  97                                  &prop->mclk_freq);
  98
  99         /* the values reported by BIOS are the 2x clock, not the bus clock */
 100         prop->mclk_freq /= 2;
 101
 102         fwnode_property_read_u32(link,
 103                                  "intel-quirk-mask",
 104                                  &quirk_mask);
 105
 106         if (quirk_mask & SDW_INTEL_QUIRK_MASK_BUS_DISABLE)
 107                 prop->hw_disabled = true;
 108
 109         prop->quirks = SDW_MASTER_QUIRKS_CLEAR_INITIAL_CLASH |
 110                 SDW_MASTER_QUIRKS_CLEAR_INITIAL_PARITY;
 111
 112         return 0;
 113 }
 114
 115 static int intel_prop_read(struct sdw_bus *bus)
 116 {
 117         /* Initialize with default handler to read all DisCo properties */
 118         sdw_master_read_prop(bus);
 119
 120         /* read Intel-specific properties */
 121         sdw_master_read_intel_prop(bus);
 122
 123         return 0;
 124 }
 125
 126 static struct sdw_master_ops sdw_intel_ops = {
 127         .read_prop = intel_prop_read,
 128         .override_adr = sdw_dmi_override_adr,
 129         .xfer_msg = cdns_xfer_msg,
 130         .xfer_msg_defer = cdns_xfer_msg_defer,
 131         .set_bus_conf = cdns_bus_conf,
 132         .pre_bank_switch = generic_pre_bank_switch,
 133         .post_bank_switch = generic_post_bank_switch,
 134         .read_ping_status = cdns_read_ping_status,
 135         .new_peripheral_assigned = generic_new_peripheral_assigned,
 136 };
 137
 138 /*
 139  * probe and init (aux_dev_id argument is required by function prototype but not used)
 140  */
 141 static int intel_link_probe(struct auxiliary_device *auxdev,
 142                             const struct auxiliary_device_id *aux_dev_id)
 143
 144 {
 145         struct device *dev = &auxdev->dev;
 146         struct sdw_intel_link_dev *ldev = auxiliary_dev_to_sdw_intel_link_dev(auxdev);
 147         struct sdw_intel *sdw;
 148         struct sdw_cdns *cdns;
 149         struct sdw_bus *bus;
 150         int ret;
 151
 152         sdw = devm_kzalloc(dev, sizeof(*sdw), GFP_KERNEL);
 153         if (!sdw)
 154                 return -ENOMEM;
 155
 156         cdns = &sdw->cdns;
 157         bus = &cdns->bus;
 158
 159         sdw->instance = auxdev->id;
 160         sdw->link_res = &ldev->link_res;
 161         cdns->dev = dev;
 162         cdns->registers = sdw->link_res->registers;
 163         cdns->ip_offset = sdw->link_res->ip_offset;
 164         cdns->instance = sdw->instance;
 165         cdns->msg_count = 0;
 166
 167         bus->link_id = auxdev->id;
 168         bus->dev_num_ida_min = INTEL_DEV_NUM_IDA_MIN;
 169         bus->clk_stop_timeout = 1;
 170
 171         sdw_cdns_probe(cdns);
 172
 173         /* Set ops */
 174         bus->ops = &sdw_intel_ops;
 175
 176         /* set driver data, accessed by snd_soc_dai_get_drvdata() */
 177         auxiliary_set_drvdata(auxdev, cdns);
 178
 179         /* use generic bandwidth allocation algorithm */
 180         sdw->cdns.bus.compute_params = sdw_compute_params;
 181
 182         /* avoid resuming from pm_runtime suspend if it's not required */
 183         dev_pm_set_driver_flags(dev, DPM_FLAG_SMART_SUSPEND);
 184
 185         ret = sdw_bus_master_add(bus, dev, dev->fwnode);
 186         if (ret) {
 187                 dev_err(dev, "sdw_bus_master_add fail: %d\n", ret);
 188                 return ret;
 189         }
 190
 191         if (bus->prop.hw_disabled)
 192                 dev_info(dev,
 193                          "SoundWire master %d is disabled, will be ignored\n",
 194                          bus->link_id);
 195         /*
 196          * Ignore BIOS err_threshold, it's a really bad idea when dealing
 197          * with multiple hardware synchronized links
 198          */
 199         bus->prop.err_threshold = 0;
 200
 201         return 0;
 202 }
 203
 204 int intel_link_startup(struct auxiliary_device *auxdev)
 205 {
 206         struct device *dev = &auxdev->dev;
 207         struct sdw_cdns *cdns = auxiliary_get_drvdata(auxdev);
 208         struct sdw_intel *sdw = cdns_to_intel(cdns);
 209         struct sdw_bus *bus = &cdns->bus;
 210         int link_flags;
 211         bool multi_link;
 212         u32 clock_stop_quirks;
 213         int ret;
 214
 215         if (bus->prop.hw_disabled) {
 216                 dev_info(dev,
 217                          "SoundWire master %d is disabled, ignoring\n",
 218                          sdw->instance);
 219                 return 0;
 220         }
 221
 222         link_flags = md_flags >> (bus->link_id * 8);
 223         multi_link = !(link_flags & SDW_INTEL_MASTER_DISABLE_MULTI_LINK);
 224         if (!multi_link) {
 225                 dev_dbg(dev, "Multi-link is disabled\n");
 226         } else {
 227                 /*
 228                  * hardware-based synchronization is required regardless
 229                  * of the number of segments used by a stream: SSP-based
 230                  * synchronization is gated by gsync when the multi-master
 231                  * mode is set.
 232                  */
 233                 bus->hw_sync_min_links = 1;
 234         }
 235         bus->multi_link = multi_link;
 236
 237         /* Initialize shim, controller */
 238         ret = sdw_intel_link_power_up(sdw);
 239         if (ret)
 240                 goto err_init;
 241
 242         /* Register DAIs */
 243         ret = sdw_intel_register_dai(sdw);
 244         if (ret) {
 245                 dev_err(dev, "DAI registration failed: %d\n", ret);
 246                 goto err_power_up;
 247         }
 248
 249         sdw_intel_debugfs_init(sdw);
 250
 251         /* Enable runtime PM */
 252         if (!(link_flags & SDW_INTEL_MASTER_DISABLE_PM_RUNTIME)) {
 253                 pm_runtime_set_autosuspend_delay(dev,
 254                                                  INTEL_MASTER_SUSPEND_DELAY_MS);
 255                 pm_runtime_use_autosuspend(dev);
 256                 pm_runtime_mark_last_busy(dev);
 257
 258                 pm_runtime_set_active(dev);
 259                 pm_runtime_enable(dev);
 260         }
 261
 262         /* start bus */
 263         ret = sdw_intel_start_bus(sdw);
 264         if (ret) {
 265                 dev_err(dev, "bus start failed: %d\n", ret);
 266                 goto err_pm_runtime;
 267         }
 268
 269         clock_stop_quirks = sdw->link_res->clock_stop_quirks;
 270         if (clock_stop_quirks & SDW_INTEL_CLK_STOP_NOT_ALLOWED) {
 271                 /*
 272                  * To keep the clock running we need to prevent
 273                  * pm_runtime suspend from happening by increasing the
 274                  * reference count.
 275                  * This quirk is specified by the parent PCI device in
 276                  * case of specific latency requirements. It will have
 277                  * no effect if pm_runtime is disabled by the user via
 278                  * a module parameter for testing purposes.
 279                  */
 280                 pm_runtime_get_noresume(dev);
 281         }
 282
 283         /*
 284          * The runtime PM status of Slave devices is "Unsupported"
 285          * until they report as ATTACHED. If they don't, e.g. because
 286          * there are no Slave devices populated or if the power-on is
 287          * delayed or dependent on a power switch, the Master will
 288          * remain active and prevent its parent from suspending.
 289          *
 290          * Conditionally force the pm_runtime core to re-evaluate the
 291          * Master status in the absence of any Slave activity. A quirk
 292          * is provided to e.g. deal with Slaves that may be powered on
 293          * with a delay. A more complete solution would require the
 294          * definition of Master properties.
 295          */
 296         if (!(link_flags & SDW_INTEL_MASTER_DISABLE_PM_RUNTIME_IDLE)) {
 297                 pm_runtime_mark_last_busy(dev);
 298                 pm_runtime_idle(dev);
 299         }
 300
 301         sdw->startup_done = true;
 302         return 0;
 303
 304 err_pm_runtime:
 305         if (!(link_flags & SDW_INTEL_MASTER_DISABLE_PM_RUNTIME))
 306                 pm_runtime_disable(dev);
 307 err_power_up:
 308         sdw_intel_link_power_down(sdw);
 309 err_init:
 310         return ret;
 311 }
 312
 313 static void intel_link_remove(struct auxiliary_device *auxdev)
 314 {
 315         struct sdw_cdns *cdns = auxiliary_get_drvdata(auxdev);
 316         struct sdw_intel *sdw = cdns_to_intel(cdns);
 317         struct sdw_bus *bus = &cdns->bus;
 318
 319         /*
 320          * Since pm_runtime is already disabled, we don't decrease
 321          * the refcount when the clock_stop_quirk is
 322          * SDW_INTEL_CLK_STOP_NOT_ALLOWED
 323          */
 324         if (!bus->prop.hw_disabled) {
 325                 sdw_intel_debugfs_exit(sdw);
 326                 sdw_cdns_enable_interrupt(cdns, false);
 327         }
 328         sdw_bus_master_delete(bus);
 329 }
 330
 331 int intel_link_process_wakeen_event(struct auxiliary_device *auxdev)
 332 {
 333         struct device *dev = &auxdev->dev;
 334         struct sdw_intel *sdw;
 335         struct sdw_bus *bus;
 336
 337         sdw = auxiliary_get_drvdata(auxdev);
 338         bus = &sdw->cdns.bus;
 339
 340         if (bus->prop.hw_disabled || !sdw->startup_done) {
 341                 dev_dbg(dev, "SoundWire master %d is disabled or not-started, ignoring\n",
 342                         bus->link_id);
 343                 return 0;
 344         }
 345
 346         if (!sdw_intel_shim_check_wake(sdw))
 347                 return 0;
 348
 349         /* disable WAKEEN interrupt ASAP to prevent interrupt flood */
 350         sdw_intel_shim_wake(sdw, false);
 351
 352         /*
 353          * resume the Master, which will generate a bus reset and result in
 354          * Slaves re-attaching and be re-enumerated. The SoundWire physical
 355          * device which generated the wake will trigger an interrupt, which
 356          * will in turn cause the corresponding Linux Slave device to be
 357          * resumed and the Slave codec driver to check the status.
 358          */
 359         pm_request_resume(dev);
 360
 361         return 0;
 362 }
 363
 364 /*
 365  * PM calls
 366  */
 367
 368 static int intel_resume_child_device(struct device *dev, void *data)
 369 {
 370         int ret;
 371         struct sdw_slave *slave = dev_to_sdw_dev(dev);
 372
 373         if (!slave->probed) {
 374                 dev_dbg(dev, "skipping device, no probed driver\n");
 375                 return 0;
 376         }
 377         if (!slave->dev_num_sticky) {
 378                 dev_dbg(dev, "skipping device, never detected on bus\n");
 379                 return 0;
 380         }
 381
 382         ret = pm_request_resume(dev);
 383         if (ret < 0) {
 384                 dev_err(dev, "%s: pm_request_resume failed: %d\n", __func__, ret);
 385                 return ret;
 386         }
 387
 388         return 0;
 389 }
 390
 391 static int __maybe_unused intel_pm_prepare(struct device *dev)
 392 {
 393         struct sdw_cdns *cdns = dev_get_drvdata(dev);
 394         struct sdw_intel *sdw = cdns_to_intel(cdns);
 395         struct sdw_bus *bus = &cdns->bus;
 396         u32 clock_stop_quirks;
 397         int ret;
 398
 399         if (bus->prop.hw_disabled || !sdw->startup_done) {
 400                 dev_dbg(dev, "SoundWire master %d is disabled or not-started, ignoring\n",
 401                         bus->link_id);
 402                 return 0;
 403         }
 404
 405         clock_stop_quirks = sdw->link_res->clock_stop_quirks;
 406
 407         if (pm_runtime_suspended(dev) &&
 408             pm_runtime_suspended(dev->parent) &&
 409             ((clock_stop_quirks & SDW_INTEL_CLK_STOP_BUS_RESET) ||
 410              !clock_stop_quirks)) {
 411                 /*
 412                  * if we've enabled clock stop, and the parent is suspended, the SHIM registers
 413                  * are not accessible and the shim wake cannot be disabled.
 414                  * The only solution is to resume the entire bus to full power
 415                  */
 416
 417                 /*
 418                  * If any operation in this block fails, we keep going since we don't want
 419                  * to prevent system suspend from happening and errors should be recoverable
 420                  * on resume.
 421                  */
 422
 423                 /*
 424                  * first resume the device for this link. This will also by construction
 425                  * resume the PCI parent device.
 426                  */
 427                 ret = pm_request_resume(dev);
 428                 if (ret < 0) {
 429                         dev_err(dev, "%s: pm_request_resume failed: %d\n", __func__, ret);
 430                         return 0;
 431                 }
 432
 433                 /*
 434                  * Continue resuming the entire bus (parent + child devices) to exit
 435                  * the clock stop mode. If there are no devices connected on this link
 436                  * this is a no-op.
 437                  * The resume to full power could have been implemented with a .prepare
 438                  * step in SoundWire codec drivers. This would however require a lot
 439                  * of code to handle an Intel-specific corner case. It is simpler in
 440                  * practice to add a loop at the link level.
 441                  */
 442                 ret = device_for_each_child(bus->dev, NULL, intel_resume_child_device);
 443
 444                 if (ret < 0)
 445                         dev_err(dev, "%s: intel_resume_child_device failed: %d\n", __func__, ret);
 446         }
 447
 448         return 0;
 449 }
 450
 451 static int __maybe_unused intel_suspend(struct device *dev)
 452 {
 453         struct sdw_cdns *cdns = dev_get_drvdata(dev);
 454         struct sdw_intel *sdw = cdns_to_intel(cdns);
 455         struct sdw_bus *bus = &cdns->bus;
 456         u32 clock_stop_quirks;
 457         int ret;
 458
 459         if (bus->prop.hw_disabled || !sdw->startup_done) {
 460                 dev_dbg(dev, "SoundWire master %d is disabled or not-started, ignoring\n",
 461                         bus->link_id);
 462                 return 0;
 463         }
 464
 465         if (pm_runtime_suspended(dev)) {
 466                 dev_dbg(dev, "pm_runtime status: suspended\n");
 467
 468                 clock_stop_quirks = sdw->link_res->clock_stop_quirks;
 469
 470                 if ((clock_stop_quirks & SDW_INTEL_CLK_STOP_BUS_RESET) ||
 471                     !clock_stop_quirks) {
 472
 473                         if (pm_runtime_suspended(dev->parent)) {
 474                                 /*
 475                                  * paranoia check: this should not happen with the .prepare
 476                                  * resume to full power
 477                                  */
 478                                 dev_err(dev, "%s: invalid config: parent is suspended\n", __func__);
 479                         } else {
 480                                 sdw_intel_shim_wake(sdw, false);
 481                         }
 482                 }
 483
 484                 return 0;
 485         }
 486
 487         ret = sdw_intel_stop_bus(sdw, false);
 488         if (ret < 0) {
 489                 dev_err(dev, "%s: cannot stop bus: %d\n", __func__, ret);
 490                 return ret;
 491         }
 492
 493         return 0;
 494 }
 495
 496 static int __maybe_unused intel_suspend_runtime(struct device *dev)
 497 {
 498         struct sdw_cdns *cdns = dev_get_drvdata(dev);
 499         struct sdw_intel *sdw = cdns_to_intel(cdns);
 500         struct sdw_bus *bus = &cdns->bus;
 501         u32 clock_stop_quirks;
 502         int ret;
 503
 504         if (bus->prop.hw_disabled || !sdw->startup_done) {
 505                 dev_dbg(dev, "SoundWire master %d is disabled or not-started, ignoring\n",
 506                         bus->link_id);
 507                 return 0;
 508         }
 509
 510         clock_stop_quirks = sdw->link_res->clock_stop_quirks;
 511
 512         if (clock_stop_quirks & SDW_INTEL_CLK_STOP_TEARDOWN) {
 513                 ret = sdw_intel_stop_bus(sdw, false);
 514                 if (ret < 0) {
 515                         dev_err(dev, "%s: cannot stop bus during teardown: %d\n",
 516                                 __func__, ret);
 517                         return ret;
 518                 }
 519         } else if (clock_stop_quirks & SDW_INTEL_CLK_STOP_BUS_RESET || !clock_stop_quirks) {
 520                 ret = sdw_intel_stop_bus(sdw, true);
 521                 if (ret < 0) {
 522                         dev_err(dev, "%s: cannot stop bus during clock_stop: %d\n",
 523                                 __func__, ret);
 524                         return ret;
 525                 }
 526         } else {
 527                 dev_err(dev, "%s clock_stop_quirks %x unsupported\n",
 528                         __func__, clock_stop_quirks);
 529                 ret = -EINVAL;
 530         }
 531
 532         return ret;
 533 }
 534
 535 static int __maybe_unused intel_resume(struct device *dev)
 536 {
 537         struct sdw_cdns *cdns = dev_get_drvdata(dev);
 538         struct sdw_intel *sdw = cdns_to_intel(cdns);
 539         struct sdw_bus *bus = &cdns->bus;
 540         int link_flags;
 541         int ret;
 542
 543         if (bus->prop.hw_disabled || !sdw->startup_done) {
 544                 dev_dbg(dev, "SoundWire master %d is disabled or not-started, ignoring\n",
 545                         bus->link_id);
 546                 return 0;
 547         }
 548
 549         link_flags = md_flags >> (bus->link_id * 8);
 550
 551         if (pm_runtime_suspended(dev)) {
 552                 dev_dbg(dev, "pm_runtime status was suspended, forcing active\n");
 553
 554                 /* follow required sequence from runtime_pm.rst */
 555                 pm_runtime_disable(dev);
 556                 pm_runtime_set_active(dev);
 557                 pm_runtime_mark_last_busy(dev);
 558                 pm_runtime_enable(dev);
 559
 560                 link_flags = md_flags >> (bus->link_id * 8);
 561
 562                 if (!(link_flags & SDW_INTEL_MASTER_DISABLE_PM_RUNTIME_IDLE))
 563                         pm_runtime_idle(dev);
 564         }
 565
 566         ret = sdw_intel_link_power_up(sdw);
 567         if (ret) {
 568                 dev_err(dev, "%s failed: %d\n", __func__, ret);
 569                 return ret;
 570         }
 571
 572         /*
 573          * make sure all Slaves are tagged as UNATTACHED and provide
 574          * reason for reinitialization
 575          */
 576         sdw_clear_slave_status(bus, SDW_UNATTACH_REQUEST_MASTER_RESET);
 577
 578         ret = sdw_intel_start_bus(sdw);
 579         if (ret < 0) {
 580                 dev_err(dev, "cannot start bus during resume\n");
 581                 sdw_intel_link_power_down(sdw);
 582                 return ret;
 583         }
 584
 585         /*
 586          * after system resume, the pm_runtime suspend() may kick in
 587          * during the enumeration, before any children device force the
 588          * master device to remain active.  Using pm_runtime_get()
 589          * routines is not really possible, since it'd prevent the
 590          * master from suspending.
 591          * A reasonable compromise is to update the pm_runtime
 592          * counters and delay the pm_runtime suspend by several
 593          * seconds, by when all enumeration should be complete.
 594          */
 595         pm_runtime_mark_last_busy(dev);
 596
 597         return 0;
 598 }
 599
 600 static int __maybe_unused intel_resume_runtime(struct device *dev)
 601 {
 602         struct sdw_cdns *cdns = dev_get_drvdata(dev);
 603         struct sdw_intel *sdw = cdns_to_intel(cdns);
 604         struct sdw_bus *bus = &cdns->bus;
 605         u32 clock_stop_quirks;
 606         int ret;
 607
 608         if (bus->prop.hw_disabled || !sdw->startup_done) {
 609                 dev_dbg(dev, "SoundWire master %d is disabled or not-started, ignoring\n",
 610                         bus->link_id);
 611                 return 0;
 612         }
 613
 614         /* unconditionally disable WAKEEN interrupt */
 615         sdw_intel_shim_wake(sdw, false);
 616
 617         clock_stop_quirks = sdw->link_res->clock_stop_quirks;
 618
 619         if (clock_stop_quirks & SDW_INTEL_CLK_STOP_TEARDOWN) {
 620                 ret = sdw_intel_link_power_up(sdw);
 621                 if (ret) {
 622                         dev_err(dev, "%s: power_up failed after teardown: %d\n", __func__, ret);
 623                         return ret;
 624                 }
 625
 626                 /*
 627                  * make sure all Slaves are tagged as UNATTACHED and provide
 628                  * reason for reinitialization
 629                  */
 630                 sdw_clear_slave_status(bus, SDW_UNATTACH_REQUEST_MASTER_RESET);
 631
 632                 ret = sdw_intel_start_bus(sdw);
 633                 if (ret < 0) {
 634                         dev_err(dev, "%s: cannot start bus after teardown: %d\n", __func__, ret);
 635                         sdw_intel_link_power_down(sdw);
 636                         return ret;
 637                 }
 638
 639         } else if (clock_stop_quirks & SDW_INTEL_CLK_STOP_BUS_RESET) {
 640                 ret = sdw_intel_link_power_up(sdw);
 641                 if (ret) {
 642                         dev_err(dev, "%s: power_up failed after bus reset: %d\n", __func__, ret);
 643                         return ret;
 644                 }
 645
 646                 ret = sdw_intel_start_bus_after_reset(sdw);
 647                 if (ret < 0) {
 648                         dev_err(dev, "%s: cannot start bus after reset: %d\n", __func__, ret);
 649                         sdw_intel_link_power_down(sdw);
 650                         return ret;
 651                 }
 652         } else if (!clock_stop_quirks) {
 653
 654                 sdw_intel_check_clock_stop(sdw);
 655
 656                 ret = sdw_intel_link_power_up(sdw);
 657                 if (ret) {
 658                         dev_err(dev, "%s: power_up failed: %d\n", __func__, ret);
 659                         return ret;
 660                 }
 661
 662                 ret = sdw_intel_start_bus_after_clock_stop(sdw);
 663                 if (ret < 0) {
 664                         dev_err(dev, "%s: cannot start bus after clock stop: %d\n", __func__, ret);
 665                         sdw_intel_link_power_down(sdw);
 666                         return ret;
 667                 }
 668         } else {
 669                 dev_err(dev, "%s: clock_stop_quirks %x unsupported\n",
 670                         __func__, clock_stop_quirks);
 671                 ret = -EINVAL;
 672         }
 673
 674         return ret;
 675 }
 676
 677 static const struct dev_pm_ops intel_pm = {
 678         .prepare = intel_pm_prepare,
 679         SET_SYSTEM_SLEEP_PM_OPS(intel_suspend, intel_resume)
 680         SET_RUNTIME_PM_OPS(intel_suspend_runtime, intel_resume_runtime, NULL)
 681 };
 682
 683 static const struct auxiliary_device_id intel_link_id_table[] = {
 684         { .name = "soundwire_intel.link" },
 685         {},
 686 };
 687 MODULE_DEVICE_TABLE(auxiliary, intel_link_id_table);
 688
 689 static struct auxiliary_driver sdw_intel_drv = {
 690         .probe = intel_link_probe,
 691         .remove = intel_link_remove,
 692         .driver = {
 693                 /* auxiliary_driver_register() sets .name to be the modname */
 694                 .pm = &intel_pm,
 695         },
 696         .id_table = intel_link_id_table
 697 };
 698 module_auxiliary_driver(sdw_intel_drv);
 699
 700 MODULE_LICENSE("Dual BSD/GPL");
 701 MODULE_DESCRIPTION("Intel Soundwire Link Driver");