drivers/hwtracing/intel_th/core.c

   1 /*
   2  * Intel(R) Trace Hub driver core
   3  *
   4  * Copyright (C) 2014-2015 Intel Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms and conditions of the GNU General Public License,
   8  * version 2, as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  */
  15
  16 #define pr_fmt(fmt)     KBUILD_MODNAME ": " fmt
  17
  18 #include <linux/types.h>
  19 #include <linux/module.h>
  20 #include <linux/device.h>
  21 #include <linux/sysfs.h>
  22 #include <linux/kdev_t.h>
  23 #include <linux/debugfs.h>
  24 #include <linux/idr.h>
  25 #include <linux/pci.h>
  26 #include <linux/dma-mapping.h>
  27
  28 #include "intel_th.h"
  29 #include "debug.h"
  30
  31 static DEFINE_IDA(intel_th_ida);
  32
  33 static int intel_th_match(struct device *dev, struct device_driver *driver)
  34 {
  35         struct intel_th_driver *thdrv = to_intel_th_driver(driver);
  36         struct intel_th_device *thdev = to_intel_th_device(dev);
  37
  38         if (thdev->type == INTEL_TH_SWITCH &&
  39             (!thdrv->enable || !thdrv->disable))
  40                 return 0;
  41
  42         return !strcmp(thdev->name, driver->name);
  43 }
  44
  45 static int intel_th_child_remove(struct device *dev, void *data)
  46 {
  47         device_release_driver(dev);
  48
  49         return 0;
  50 }
  51
  52 static int intel_th_probe(struct device *dev)
  53 {
  54         struct intel_th_driver *thdrv = to_intel_th_driver(dev->driver);
  55         struct intel_th_device *thdev = to_intel_th_device(dev);
  56         struct intel_th_driver *hubdrv;
  57         struct intel_th_device *hub = NULL;
  58         int ret;
  59
  60         if (thdev->type == INTEL_TH_SWITCH)
  61                 hub = thdev;
  62         else if (dev->parent)
  63                 hub = to_intel_th_device(dev->parent);
  64
  65         if (!hub || !hub->dev.driver)
  66                 return -EPROBE_DEFER;
  67
  68         hubdrv = to_intel_th_driver(hub->dev.driver);
  69
  70         ret = thdrv->probe(to_intel_th_device(dev));
  71         if (ret)
  72                 return ret;
  73
  74         if (thdrv->attr_group) {
  75                 ret = sysfs_create_group(&thdev->dev.kobj, thdrv->attr_group);
  76                 if (ret) {
  77                         thdrv->remove(thdev);
  78
  79                         return ret;
  80                 }
  81         }
  82
  83         if (thdev->type == INTEL_TH_OUTPUT &&
  84             !intel_th_output_assigned(thdev))
  85                 ret = hubdrv->assign(hub, thdev);
  86
  87         return ret;
  88 }
  89
  90 static int intel_th_remove(struct device *dev)
  91 {
  92         struct intel_th_driver *thdrv = to_intel_th_driver(dev->driver);
  93         struct intel_th_device *thdev = to_intel_th_device(dev);
  94         struct intel_th_device *hub = to_intel_th_device(dev->parent);
  95         int err;
  96
  97         if (thdev->type == INTEL_TH_SWITCH) {
  98                 err = device_for_each_child(dev, thdev, intel_th_child_remove);
  99                 if (err)
 100                         return err;
 101         }
 102
 103         if (thdrv->attr_group)
 104                 sysfs_remove_group(&thdev->dev.kobj, thdrv->attr_group);
 105
 106         thdrv->remove(thdev);
 107
 108         if (intel_th_output_assigned(thdev)) {
 109                 struct intel_th_driver *hubdrv =
 110                         to_intel_th_driver(dev->parent->driver);
 111
 112                 if (hub->dev.driver)
 113                         hubdrv->unassign(hub, thdev);
 114         }
 115
 116         return 0;
 117 }
 118
 119 static struct bus_type intel_th_bus = {
 120         .name           = "intel_th",
 121         .dev_attrs      = NULL,
 122         .match          = intel_th_match,
 123         .probe          = intel_th_probe,
 124         .remove         = intel_th_remove,
 125 };
 126
 127 static void intel_th_device_free(struct intel_th_device *thdev);
 128
 129 static void intel_th_device_release(struct device *dev)
 130 {
 131         intel_th_device_free(to_intel_th_device(dev));
 132 }
 133
 134 static struct device_type intel_th_source_device_type = {
 135         .name           = "intel_th_source_device",
 136         .release        = intel_th_device_release,
 137 };
 138
 139 static struct intel_th *to_intel_th(struct intel_th_device *thdev)
 140 {
 141         /*
 142          * subdevice tree is flat: if this one is not a switch, its
 143          * parent must be
 144          */
 145         if (thdev->type != INTEL_TH_SWITCH)
 146                 thdev = to_intel_th_hub(thdev);
 147
 148         if (WARN_ON_ONCE(!thdev || thdev->type != INTEL_TH_SWITCH))
 149                 return NULL;
 150
 151         return dev_get_drvdata(thdev->dev.parent);
 152 }
 153
 154 static char *intel_th_output_devnode(struct device *dev, umode_t *mode,
 155                                      kuid_t *uid, kgid_t *gid)
 156 {
 157         struct intel_th_device *thdev = to_intel_th_device(dev);
 158         struct intel_th *th = to_intel_th(thdev);
 159         char *node;
 160
 161         if (thdev->id >= 0)
 162                 node = kasprintf(GFP_KERNEL, "intel_th%d/%s%d", th->id,
 163                                  thdev->name, thdev->id);
 164         else
 165                 node = kasprintf(GFP_KERNEL, "intel_th%d/%s", th->id,
 166                                  thdev->name);
 167
 168         return node;
 169 }
 170
 171 static ssize_t port_show(struct device *dev, struct device_attribute *attr,
 172                          char *buf)
 173 {
 174         struct intel_th_device *thdev = to_intel_th_device(dev);
 175
 176         if (thdev->output.port >= 0)
 177                 return scnprintf(buf, PAGE_SIZE, "%u\n", thdev->output.port);
 178
 179         return scnprintf(buf, PAGE_SIZE, "unassigned\n");
 180 }
 181
 182 static DEVICE_ATTR_RO(port);
 183
 184 static int intel_th_output_activate(struct intel_th_device *thdev)
 185 {
 186         struct intel_th_driver *thdrv = to_intel_th_driver(thdev->dev.driver);
 187
 188         if (thdrv->activate)
 189                 return thdrv->activate(thdev);
 190
 191         intel_th_trace_enable(thdev);
 192
 193         return 0;
 194 }
 195
 196 static void intel_th_output_deactivate(struct intel_th_device *thdev)
 197 {
 198         struct intel_th_driver *thdrv = to_intel_th_driver(thdev->dev.driver);
 199
 200         if (thdrv->deactivate)
 201                 thdrv->deactivate(thdev);
 202         else
 203                 intel_th_trace_disable(thdev);
 204 }
 205
 206 static ssize_t active_show(struct device *dev, struct device_attribute *attr,
 207                            char *buf)
 208 {
 209         struct intel_th_device *thdev = to_intel_th_device(dev);
 210
 211         return scnprintf(buf, PAGE_SIZE, "%d\n", thdev->output.active);
 212 }
 213
 214 static ssize_t active_store(struct device *dev, struct device_attribute *attr,
 215                             const char *buf, size_t size)
 216 {
 217         struct intel_th_device *thdev = to_intel_th_device(dev);
 218         unsigned long val;
 219         int ret;
 220
 221         ret = kstrtoul(buf, 10, &val);
 222         if (ret)
 223                 return ret;
 224
 225         if (!!val != thdev->output.active) {
 226                 if (val)
 227                         ret = intel_th_output_activate(thdev);
 228                 else
 229                         intel_th_output_deactivate(thdev);
 230         }
 231
 232         return ret ? ret : size;
 233 }
 234
 235 static DEVICE_ATTR_RW(active);
 236
 237 static struct attribute *intel_th_output_attrs[] = {
 238         &dev_attr_port.attr,
 239         &dev_attr_active.attr,
 240         NULL,
 241 };
 242
 243 ATTRIBUTE_GROUPS(intel_th_output);
 244
 245 static struct device_type intel_th_output_device_type = {
 246         .name           = "intel_th_output_device",
 247         .groups         = intel_th_output_groups,
 248         .release        = intel_th_device_release,
 249         .devnode        = intel_th_output_devnode,
 250 };
 251
 252 static struct device_type intel_th_switch_device_type = {
 253         .name           = "intel_th_switch_device",
 254         .release        = intel_th_device_release,
 255 };
 256
 257 static struct device_type *intel_th_device_type[] = {
 258         [INTEL_TH_SOURCE]       = &intel_th_source_device_type,
 259         [INTEL_TH_OUTPUT]       = &intel_th_output_device_type,
 260         [INTEL_TH_SWITCH]       = &intel_th_switch_device_type,
 261 };
 262
 263 int intel_th_driver_register(struct intel_th_driver *thdrv)
 264 {
 265         if (!thdrv->probe || !thdrv->remove)
 266                 return -EINVAL;
 267
 268         thdrv->driver.bus = &intel_th_bus;
 269
 270         return driver_register(&thdrv->driver);
 271 }
 272 EXPORT_SYMBOL_GPL(intel_th_driver_register);
 273
 274 void intel_th_driver_unregister(struct intel_th_driver *thdrv)
 275 {
 276         driver_unregister(&thdrv->driver);
 277 }
 278 EXPORT_SYMBOL_GPL(intel_th_driver_unregister);
 279
 280 static struct intel_th_device *
 281 intel_th_device_alloc(struct intel_th *th, unsigned int type, const char *name,
 282                       int id)
 283 {
 284         struct device *parent;
 285         struct intel_th_device *thdev;
 286
 287         if (type == INTEL_TH_SWITCH)
 288                 parent = th->dev;
 289         else
 290                 parent = &th->hub->dev;
 291
 292         thdev = kzalloc(sizeof(*thdev) + strlen(name) + 1, GFP_KERNEL);
 293         if (!thdev)
 294                 return NULL;
 295
 296         thdev->id = id;
 297         thdev->type = type;
 298
 299         strcpy(thdev->name, name);
 300         device_initialize(&thdev->dev);
 301         thdev->dev.bus = &intel_th_bus;
 302         thdev->dev.type = intel_th_device_type[type];
 303         thdev->dev.parent = parent;
 304         thdev->dev.dma_mask = parent->dma_mask;
 305         thdev->dev.dma_parms = parent->dma_parms;
 306         dma_set_coherent_mask(&thdev->dev, parent->coherent_dma_mask);
 307         if (id >= 0)
 308                 dev_set_name(&thdev->dev, "%d-%s%d", th->id, name, id);
 309         else
 310                 dev_set_name(&thdev->dev, "%d-%s", th->id, name);
 311
 312         return thdev;
 313 }
 314
 315 static int intel_th_device_add_resources(struct intel_th_device *thdev,
 316                                          struct resource *res, int nres)
 317 {
 318         struct resource *r;
 319
 320         r = kmemdup(res, sizeof(*res) * nres, GFP_KERNEL);
 321         if (!r)
 322                 return -ENOMEM;
 323
 324         thdev->resource = r;
 325         thdev->num_resources = nres;
 326
 327         return 0;
 328 }
 329
 330 static void intel_th_device_remove(struct intel_th_device *thdev)
 331 {
 332         device_del(&thdev->dev);
 333         put_device(&thdev->dev);
 334 }
 335
 336 static void intel_th_device_free(struct intel_th_device *thdev)
 337 {
 338         kfree(thdev->resource);
 339         kfree(thdev);
 340 }
 341
 342 /*
 343  * Intel(R) Trace Hub subdevices
 344  */
 345 static struct intel_th_subdevice {
 346         const char              *name;
 347         struct resource         res[3];
 348         unsigned                nres;
 349         unsigned                type;
 350         unsigned                otype;
 351         unsigned                scrpd;
 352         int                     id;
 353 } intel_th_subdevices[TH_SUBDEVICE_MAX] = {
 354         {
 355                 .nres   = 1,
 356                 .res    = {
 357                         {
 358                                 .start  = REG_GTH_OFFSET,
 359                                 .end    = REG_GTH_OFFSET + REG_GTH_LENGTH - 1,
 360                                 .flags  = IORESOURCE_MEM,
 361                         },
 362                 },
 363                 .name   = "gth",
 364                 .type   = INTEL_TH_SWITCH,
 365                 .id     = -1,
 366         },
 367         {
 368                 .nres   = 2,
 369                 .res    = {
 370                         {
 371                                 .start  = REG_MSU_OFFSET,
 372                                 .end    = REG_MSU_OFFSET + REG_MSU_LENGTH - 1,
 373                                 .flags  = IORESOURCE_MEM,
 374                         },
 375                         {
 376                                 .start  = BUF_MSU_OFFSET,
 377                                 .end    = BUF_MSU_OFFSET + BUF_MSU_LENGTH - 1,
 378                                 .flags  = IORESOURCE_MEM,
 379                         },
 380                 },
 381                 .name   = "msc",
 382                 .id     = 0,
 383                 .type   = INTEL_TH_OUTPUT,
 384                 .otype  = GTH_MSU,
 385                 .scrpd  = SCRPD_MEM_IS_PRIM_DEST | SCRPD_MSC0_IS_ENABLED,
 386         },
 387         {
 388                 .nres   = 2,
 389                 .res    = {
 390                         {
 391                                 .start  = REG_MSU_OFFSET,
 392                                 .end    = REG_MSU_OFFSET + REG_MSU_LENGTH - 1,
 393                                 .flags  = IORESOURCE_MEM,
 394                         },
 395                         {
 396                                 .start  = BUF_MSU_OFFSET,
 397                                 .end    = BUF_MSU_OFFSET + BUF_MSU_LENGTH - 1,
 398                                 .flags  = IORESOURCE_MEM,
 399                         },
 400                 },
 401                 .name   = "msc",
 402                 .id     = 1,
 403                 .type   = INTEL_TH_OUTPUT,
 404                 .otype  = GTH_MSU,
 405                 .scrpd  = SCRPD_MEM_IS_PRIM_DEST | SCRPD_MSC1_IS_ENABLED,
 406         },
 407         {
 408                 .nres   = 2,
 409                 .res    = {
 410                         {
 411                                 .start  = REG_STH_OFFSET,
 412                                 .end    = REG_STH_OFFSET + REG_STH_LENGTH - 1,
 413                                 .flags  = IORESOURCE_MEM,
 414                         },
 415                         {
 416                                 .start  = TH_MMIO_SW,
 417                                 .end    = 0,
 418                                 .flags  = IORESOURCE_MEM,
 419                         },
 420                 },
 421                 .id     = -1,
 422                 .name   = "sth",
 423                 .type   = INTEL_TH_SOURCE,
 424         },
 425         {
 426                 .nres   = 1,
 427                 .res    = {
 428                         {
 429                                 .start  = REG_PTI_OFFSET,
 430                                 .end    = REG_PTI_OFFSET + REG_PTI_LENGTH - 1,
 431                                 .flags  = IORESOURCE_MEM,
 432                         },
 433                 },
 434                 .id     = -1,
 435                 .name   = "pti",
 436                 .type   = INTEL_TH_OUTPUT,
 437                 .otype  = GTH_PTI,
 438                 .scrpd  = SCRPD_PTI_IS_PRIM_DEST,
 439         },
 440         {
 441                 .nres   = 1,
 442                 .res    = {
 443                         {
 444                                 .start  = REG_DCIH_OFFSET,
 445                                 .end    = REG_DCIH_OFFSET + REG_DCIH_LENGTH - 1,
 446                                 .flags  = IORESOURCE_MEM,
 447                         },
 448                 },
 449                 .id     = -1,
 450                 .name   = "dcih",
 451                 .type   = INTEL_TH_OUTPUT,
 452         },
 453 };
 454
 455 static int intel_th_populate(struct intel_th *th, struct resource *devres,
 456                              unsigned int ndevres, int irq)
 457 {
 458         struct resource res[3];
 459         unsigned int req = 0;
 460         int i, err;
 461
 462         /* create devices for each intel_th_subdevice */
 463         for (i = 0; i < ARRAY_SIZE(intel_th_subdevices); i++) {
 464                 struct intel_th_subdevice *subdev = &intel_th_subdevices[i];
 465                 struct intel_th_device *thdev;
 466                 int r;
 467
 468                 thdev = intel_th_device_alloc(th, subdev->type, subdev->name,
 469                                               subdev->id);
 470                 if (!thdev) {
 471                         err = -ENOMEM;
 472                         goto kill_subdevs;
 473                 }
 474
 475                 memcpy(res, subdev->res,
 476                        sizeof(struct resource) * subdev->nres);
 477
 478                 for (r = 0; r < subdev->nres; r++) {
 479                         int bar = TH_MMIO_CONFIG;
 480
 481                         /*
 482                          * Take .end == 0 to mean 'take the whole bar',
 483                          * .start then tells us which bar it is. Default to
 484                          * TH_MMIO_CONFIG.
 485                          */
 486                         if (!res[r].end && res[r].flags == IORESOURCE_MEM) {
 487                                 bar = res[r].start;
 488                                 res[r].start = 0;
 489                                 res[r].end = resource_size(&devres[bar]) - 1;
 490                         }
 491
 492                         if (res[r].flags & IORESOURCE_MEM) {
 493                                 res[r].start    += devres[bar].start;
 494                                 res[r].end      += devres[bar].start;
 495
 496                                 dev_dbg(th->dev, "%s:%d @ %pR\n",
 497                                         subdev->name, r, &res[r]);
 498                         } else if (res[r].flags & IORESOURCE_IRQ) {
 499                                 res[r].start    = irq;
 500                         }
 501                 }
 502
 503                 err = intel_th_device_add_resources(thdev, res, subdev->nres);
 504                 if (err) {
 505                         put_device(&thdev->dev);
 506                         goto kill_subdevs;
 507                 }
 508
 509                 if (subdev->type == INTEL_TH_OUTPUT) {
 510                         thdev->dev.devt = MKDEV(th->major, i);
 511                         thdev->output.type = subdev->otype;
 512                         thdev->output.port = -1;
 513                         thdev->output.scratchpad = subdev->scrpd;
 514                 }
 515
 516                 err = device_add(&thdev->dev);
 517                 if (err) {
 518                         put_device(&thdev->dev);
 519                         goto kill_subdevs;
 520                 }
 521
 522                 /* need switch driver to be loaded to enumerate the rest */
 523                 if (subdev->type == INTEL_TH_SWITCH && !req) {
 524                         th->hub = thdev;
 525                         err = request_module("intel_th_%s", subdev->name);
 526                         if (!err)
 527                                 req++;
 528                 }
 529
 530                 th->thdev[i] = thdev;
 531         }
 532
 533         return 0;
 534
 535 kill_subdevs:
 536         for (i-- ; i >= 0; i--)
 537                 intel_th_device_remove(th->thdev[i]);
 538
 539         return err;
 540 }
 541
 542 static int match_devt(struct device *dev, void *data)
 543 {
 544         dev_t devt = (dev_t)(unsigned long)data;
 545
 546         return dev->devt == devt;
 547 }
 548
 549 static int intel_th_output_open(struct inode *inode, struct file *file)
 550 {
 551         const struct file_operations *fops;
 552         struct intel_th_driver *thdrv;
 553         struct device *dev;
 554         int err;
 555
 556         dev = bus_find_device(&intel_th_bus, NULL,
 557                               (void *)(unsigned long)inode->i_rdev,
 558                               match_devt);
 559         if (!dev || !dev->driver)
 560                 return -ENODEV;
 561
 562         thdrv = to_intel_th_driver(dev->driver);
 563         fops = fops_get(thdrv->fops);
 564         if (!fops)
 565                 return -ENODEV;
 566
 567         replace_fops(file, fops);
 568
 569         file->private_data = to_intel_th_device(dev);
 570
 571         if (file->f_op->open) {
 572                 err = file->f_op->open(inode, file);
 573                 return err;
 574         }
 575
 576         return 0;
 577 }
 578
 579 static const struct file_operations intel_th_output_fops = {
 580         .open   = intel_th_output_open,
 581         .llseek = noop_llseek,
 582 };
 583
 584 /**
 585  * intel_th_alloc() - allocate a new Intel TH device and its subdevices
 586  * @dev:        parent device
 587  * @devres:     parent's resources
 588  * @ndevres:    number of resources
 589  * @irq:        irq number
 590  */
 591 struct intel_th *
 592 intel_th_alloc(struct device *dev, struct resource *devres,
 593                unsigned int ndevres, int irq)
 594 {
 595         struct intel_th *th;
 596         int err;
 597
 598         th = kzalloc(sizeof(*th), GFP_KERNEL);
 599         if (!th)
 600                 return ERR_PTR(-ENOMEM);
 601
 602         th->id = ida_simple_get(&intel_th_ida, 0, 0, GFP_KERNEL);
 603         if (th->id < 0) {
 604                 err = th->id;
 605                 goto err_alloc;
 606         }
 607
 608         th->major = __register_chrdev(0, 0, TH_POSSIBLE_OUTPUTS,
 609                                       "intel_th/output", &intel_th_output_fops);
 610         if (th->major < 0) {
 611                 err = th->major;
 612                 goto err_ida;
 613         }
 614         th->dev = dev;
 615
 616         dev_set_drvdata(dev, th);
 617
 618         err = intel_th_populate(th, devres, ndevres, irq);
 619         if (err)
 620                 goto err_chrdev;
 621
 622         return th;
 623
 624 err_chrdev:
 625         __unregister_chrdev(th->major, 0, TH_POSSIBLE_OUTPUTS,
 626                             "intel_th/output");
 627
 628 err_ida:
 629         ida_simple_remove(&intel_th_ida, th->id);
 630
 631 err_alloc:
 632         kfree(th);
 633
 634         return ERR_PTR(err);
 635 }
 636 EXPORT_SYMBOL_GPL(intel_th_alloc);
 637
 638 void intel_th_free(struct intel_th *th)
 639 {
 640         int i;
 641
 642         for (i = 0; i < TH_SUBDEVICE_MAX; i++)
 643                 if (th->thdev[i] != th->hub)
 644                         intel_th_device_remove(th->thdev[i]);
 645
 646         intel_th_device_remove(th->hub);
 647
 648         __unregister_chrdev(th->major, 0, TH_POSSIBLE_OUTPUTS,
 649                             "intel_th/output");
 650
 651         ida_simple_remove(&intel_th_ida, th->id);
 652
 653         kfree(th);
 654 }
 655 EXPORT_SYMBOL_GPL(intel_th_free);
 656
 657 /**
 658  * intel_th_trace_enable() - enable tracing for an output device
 659  * @thdev:      output device that requests tracing be enabled
 660  */
 661 int intel_th_trace_enable(struct intel_th_device *thdev)
 662 {
 663         struct intel_th_device *hub = to_intel_th_device(thdev->dev.parent);
 664         struct intel_th_driver *hubdrv = to_intel_th_driver(hub->dev.driver);
 665
 666         if (WARN_ON_ONCE(hub->type != INTEL_TH_SWITCH))
 667                 return -EINVAL;
 668
 669         if (WARN_ON_ONCE(thdev->type != INTEL_TH_OUTPUT))
 670                 return -EINVAL;
 671
 672         hubdrv->enable(hub, &thdev->output);
 673
 674         return 0;
 675 }
 676 EXPORT_SYMBOL_GPL(intel_th_trace_enable);
 677
 678 /**
 679  * intel_th_trace_disable() - disable tracing for an output device
 680  * @thdev:      output device that requests tracing be disabled
 681  */
 682 int intel_th_trace_disable(struct intel_th_device *thdev)
 683 {
 684         struct intel_th_device *hub = to_intel_th_device(thdev->dev.parent);
 685         struct intel_th_driver *hubdrv = to_intel_th_driver(hub->dev.driver);
 686
 687         WARN_ON_ONCE(hub->type != INTEL_TH_SWITCH);
 688         if (WARN_ON_ONCE(thdev->type != INTEL_TH_OUTPUT))
 689                 return -EINVAL;
 690
 691         hubdrv->disable(hub, &thdev->output);
 692
 693         return 0;
 694 }
 695 EXPORT_SYMBOL_GPL(intel_th_trace_disable);
 696
 697 int intel_th_set_output(struct intel_th_device *thdev,
 698                         unsigned int master)
 699 {
 700         struct intel_th_device *hub = to_intel_th_device(thdev->dev.parent);
 701         struct intel_th_driver *hubdrv = to_intel_th_driver(hub->dev.driver);
 702
 703         if (!hubdrv->set_output)
 704                 return -ENOTSUPP;
 705
 706         return hubdrv->set_output(hub, master);
 707 }
 708 EXPORT_SYMBOL_GPL(intel_th_set_output);
 709
 710 static int __init intel_th_init(void)
 711 {
 712         intel_th_debug_init();
 713
 714         return bus_register(&intel_th_bus);
 715 }
 716 subsys_initcall(intel_th_init);
 717
 718 static void __exit intel_th_exit(void)
 719 {
 720         intel_th_debug_done();
 721
 722         bus_unregister(&intel_th_bus);
 723 }
 724 module_exit(intel_th_exit);
 725
 726 MODULE_LICENSE("GPL v2");
 727 MODULE_DESCRIPTION("Intel(R) Trace Hub controller driver");
 728 MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>");