drivers/gpu/host1x/bus.c

   1 /*
   2  * Copyright (C) 2012 Avionic Design GmbH
   3  * Copyright (C) 2012-2013, NVIDIA Corporation
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <linux/host1x.h>
  19 #include <linux/of.h>
  20 #include <linux/slab.h>
  21 #include <linux/of_device.h>
  22
  23 #include "bus.h"
  24 #include "dev.h"
  25
  26 static DEFINE_MUTEX(clients_lock);
  27 static LIST_HEAD(clients);
  28
  29 static DEFINE_MUTEX(drivers_lock);
  30 static LIST_HEAD(drivers);
  31
  32 static DEFINE_MUTEX(devices_lock);
  33 static LIST_HEAD(devices);
  34
  35 struct host1x_subdev {
  36         struct host1x_client *client;
  37         struct device_node *np;
  38         struct list_head list;
  39 };
  40
  41 /**
  42  * host1x_subdev_add() - add a new subdevice with an associated device node
  43  * @device: host1x device to add the subdevice to
  44  * @np: device node
  45  */
  46 static int host1x_subdev_add(struct host1x_device *device,
  47                              struct host1x_driver *driver,
  48                              struct device_node *np)
  49 {
  50         struct host1x_subdev *subdev;
  51         struct device_node *child;
  52         int err;
  53
  54         subdev = kzalloc(sizeof(*subdev), GFP_KERNEL);
  55         if (!subdev)
  56                 return -ENOMEM;
  57
  58         INIT_LIST_HEAD(&subdev->list);
  59         subdev->np = of_node_get(np);
  60
  61         mutex_lock(&device->subdevs_lock);
  62         list_add_tail(&subdev->list, &device->subdevs);
  63         mutex_unlock(&device->subdevs_lock);
  64
  65         /* recursively add children */
  66         for_each_child_of_node(np, child) {
  67                 if (of_match_node(driver->subdevs, child) &&
  68                     of_device_is_available(child)) {
  69                         err = host1x_subdev_add(device, driver, child);
  70                         if (err < 0) {
  71                                 /* XXX cleanup? */
  72                                 of_node_put(child);
  73                                 return err;
  74                         }
  75                 }
  76         }
  77
  78         return 0;
  79 }
  80
  81 /**
  82  * host1x_subdev_del() - remove subdevice
  83  * @subdev: subdevice to remove
  84  */
  85 static void host1x_subdev_del(struct host1x_subdev *subdev)
  86 {
  87         list_del(&subdev->list);
  88         of_node_put(subdev->np);
  89         kfree(subdev);
  90 }
  91
  92 /**
  93  * host1x_device_parse_dt() - scan device tree and add matching subdevices
  94  * @device: host1x logical device
  95  * @driver: host1x driver
  96  */
  97 static int host1x_device_parse_dt(struct host1x_device *device,
  98                                   struct host1x_driver *driver)
  99 {
 100         struct device_node *np;
 101         int err;
 102
 103         for_each_child_of_node(device->dev.parent->of_node, np) {
 104                 if (of_match_node(driver->subdevs, np) &&
 105                     of_device_is_available(np)) {
 106                         err = host1x_subdev_add(device, driver, np);
 107                         if (err < 0) {
 108                                 of_node_put(np);
 109                                 return err;
 110                         }
 111                 }
 112         }
 113
 114         return 0;
 115 }
 116
 117 static void host1x_subdev_register(struct host1x_device *device,
 118                                    struct host1x_subdev *subdev,
 119                                    struct host1x_client *client)
 120 {
 121         int err;
 122
 123         /*
 124          * Move the subdevice to the list of active (registered) subdevices
 125          * and associate it with a client. At the same time, associate the
 126          * client with its parent device.
 127          */
 128         mutex_lock(&device->subdevs_lock);
 129         mutex_lock(&device->clients_lock);
 130         list_move_tail(&client->list, &device->clients);
 131         list_move_tail(&subdev->list, &device->active);
 132         client->parent = &device->dev;
 133         subdev->client = client;
 134         mutex_unlock(&device->clients_lock);
 135         mutex_unlock(&device->subdevs_lock);
 136
 137         if (list_empty(&device->subdevs)) {
 138                 err = device_add(&device->dev);
 139                 if (err < 0)
 140                         dev_err(&device->dev, "failed to add: %d\n", err);
 141                 else
 142                         device->registered = true;
 143         }
 144 }
 145
 146 static void __host1x_subdev_unregister(struct host1x_device *device,
 147                                        struct host1x_subdev *subdev)
 148 {
 149         struct host1x_client *client = subdev->client;
 150
 151         /*
 152          * If all subdevices have been activated, we're about to remove the
 153          * first active subdevice, so unload the driver first.
 154          */
 155         if (list_empty(&device->subdevs)) {
 156                 if (device->registered) {
 157                         device->registered = false;
 158                         device_del(&device->dev);
 159                 }
 160         }
 161
 162         /*
 163          * Move the subdevice back to the list of idle subdevices and remove
 164          * it from list of clients.
 165          */
 166         mutex_lock(&device->clients_lock);
 167         subdev->client = NULL;
 168         client->parent = NULL;
 169         list_move_tail(&subdev->list, &device->subdevs);
 170         /*
 171          * XXX: Perhaps don't do this here, but rather explicitly remove it
 172          * when the device is about to be deleted.
 173          *
 174          * This is somewhat complicated by the fact that this function is
 175          * used to remove the subdevice when a client is unregistered but
 176          * also when the composite device is about to be removed.
 177          */
 178         list_del_init(&client->list);
 179         mutex_unlock(&device->clients_lock);
 180 }
 181
 182 static void host1x_subdev_unregister(struct host1x_device *device,
 183                                      struct host1x_subdev *subdev)
 184 {
 185         mutex_lock(&device->subdevs_lock);
 186         __host1x_subdev_unregister(device, subdev);
 187         mutex_unlock(&device->subdevs_lock);
 188 }
 189
 190 /**
 191  * host1x_device_init() - initialize a host1x logical device
 192  * @device: host1x logical device
 193  *
 194  * The driver for the host1x logical device can call this during execution of
 195  * its &host1x_driver.probe implementation to initialize each of its clients.
 196  * The client drivers access the subsystem specific driver data using the
 197  * &host1x_client.parent field and driver data associated with it (usually by
 198  * calling dev_get_drvdata()).
 199  */
 200 int host1x_device_init(struct host1x_device *device)
 201 {
 202         struct host1x_client *client;
 203         int err;
 204
 205         mutex_lock(&device->clients_lock);
 206
 207         list_for_each_entry(client, &device->clients, list) {
 208                 if (client->ops && client->ops->init) {
 209                         err = client->ops->init(client);
 210                         if (err < 0) {
 211                                 dev_err(&device->dev,
 212                                         "failed to initialize %s: %d\n",
 213                                         dev_name(client->dev), err);
 214                                 goto teardown;
 215                         }
 216                 }
 217         }
 218
 219         mutex_unlock(&device->clients_lock);
 220
 221         return 0;
 222
 223 teardown:
 224         list_for_each_entry_continue_reverse(client, &device->clients, list)
 225                 if (client->ops->exit)
 226                         client->ops->exit(client);
 227
 228         mutex_unlock(&device->clients_lock);
 229         return err;
 230 }
 231 EXPORT_SYMBOL(host1x_device_init);
 232
 233 /**
 234  * host1x_device_exit() - uninitialize host1x logical device
 235  * @device: host1x logical device
 236  *
 237  * When the driver for a host1x logical device is unloaded, it can call this
 238  * function to tear down each of its clients. Typically this is done after a
 239  * subsystem-specific data structure is removed and the functionality can no
 240  * longer be used.
 241  */
 242 int host1x_device_exit(struct host1x_device *device)
 243 {
 244         struct host1x_client *client;
 245         int err;
 246
 247         mutex_lock(&device->clients_lock);
 248
 249         list_for_each_entry_reverse(client, &device->clients, list) {
 250                 if (client->ops && client->ops->exit) {
 251                         err = client->ops->exit(client);
 252                         if (err < 0) {
 253                                 dev_err(&device->dev,
 254                                         "failed to cleanup %s: %d\n",
 255                                         dev_name(client->dev), err);
 256                                 mutex_unlock(&device->clients_lock);
 257                                 return err;
 258                         }
 259                 }
 260         }
 261
 262         mutex_unlock(&device->clients_lock);
 263
 264         return 0;
 265 }
 266 EXPORT_SYMBOL(host1x_device_exit);
 267
 268 static int host1x_add_client(struct host1x *host1x,
 269                              struct host1x_client *client)
 270 {
 271         struct host1x_device *device;
 272         struct host1x_subdev *subdev;
 273
 274         mutex_lock(&host1x->devices_lock);
 275
 276         list_for_each_entry(device, &host1x->devices, list) {
 277                 list_for_each_entry(subdev, &device->subdevs, list) {
 278                         if (subdev->np == client->dev->of_node) {
 279                                 host1x_subdev_register(device, subdev, client);
 280                                 mutex_unlock(&host1x->devices_lock);
 281                                 return 0;
 282                         }
 283                 }
 284         }
 285
 286         mutex_unlock(&host1x->devices_lock);
 287         return -ENODEV;
 288 }
 289
 290 static int host1x_del_client(struct host1x *host1x,
 291                              struct host1x_client *client)
 292 {
 293         struct host1x_device *device, *dt;
 294         struct host1x_subdev *subdev;
 295
 296         mutex_lock(&host1x->devices_lock);
 297
 298         list_for_each_entry_safe(device, dt, &host1x->devices, list) {
 299                 list_for_each_entry(subdev, &device->active, list) {
 300                         if (subdev->client == client) {
 301                                 host1x_subdev_unregister(device, subdev);
 302                                 mutex_unlock(&host1x->devices_lock);
 303                                 return 0;
 304                         }
 305                 }
 306         }
 307
 308         mutex_unlock(&host1x->devices_lock);
 309         return -ENODEV;
 310 }
 311
 312 static int host1x_device_match(struct device *dev, struct device_driver *drv)
 313 {
 314         return strcmp(dev_name(dev), drv->name) == 0;
 315 }
 316
 317 static int host1x_dma_configure(struct device *dev)
 318 {
 319         return of_dma_configure(dev, dev->of_node, true);
 320 }
 321
 322 static const struct dev_pm_ops host1x_device_pm_ops = {
 323         .suspend = pm_generic_suspend,
 324         .resume = pm_generic_resume,
 325         .freeze = pm_generic_freeze,
 326         .thaw = pm_generic_thaw,
 327         .poweroff = pm_generic_poweroff,
 328         .restore = pm_generic_restore,
 329 };
 330
 331 struct bus_type host1x_bus_type = {
 332         .name = "host1x",
 333         .match = host1x_device_match,
 334         .dma_configure = host1x_dma_configure,
 335         .pm = &host1x_device_pm_ops,
 336 };
 337
 338 static void __host1x_device_del(struct host1x_device *device)
 339 {
 340         struct host1x_subdev *subdev, *sd;
 341         struct host1x_client *client, *cl;
 342
 343         mutex_lock(&device->subdevs_lock);
 344
 345         /* unregister subdevices */
 346         list_for_each_entry_safe(subdev, sd, &device->active, list) {
 347                 /*
 348                  * host1x_subdev_unregister() will remove the client from
 349                  * any lists, so we'll need to manually add it back to the
 350                  * list of idle clients.
 351                  *
 352                  * XXX: Alternatively, perhaps don't remove the client from
 353                  * any lists in host1x_subdev_unregister() and instead do
 354                  * that explicitly from host1x_unregister_client()?
 355                  */
 356                 client = subdev->client;
 357
 358                 __host1x_subdev_unregister(device, subdev);
 359
 360                 /* add the client to the list of idle clients */
 361                 mutex_lock(&clients_lock);
 362                 list_add_tail(&client->list, &clients);
 363                 mutex_unlock(&clients_lock);
 364         }
 365
 366         /* remove subdevices */
 367         list_for_each_entry_safe(subdev, sd, &device->subdevs, list)
 368                 host1x_subdev_del(subdev);
 369
 370         mutex_unlock(&device->subdevs_lock);
 371
 372         /* move clients to idle list */
 373         mutex_lock(&clients_lock);
 374         mutex_lock(&device->clients_lock);
 375
 376         list_for_each_entry_safe(client, cl, &device->clients, list)
 377                 list_move_tail(&client->list, &clients);
 378
 379         mutex_unlock(&device->clients_lock);
 380         mutex_unlock(&clients_lock);
 381
 382         /* finally remove the device */
 383         list_del_init(&device->list);
 384 }
 385
 386 static void host1x_device_release(struct device *dev)
 387 {
 388         struct host1x_device *device = to_host1x_device(dev);
 389
 390         __host1x_device_del(device);
 391         kfree(device);
 392 }
 393
 394 static int host1x_device_add(struct host1x *host1x,
 395                              struct host1x_driver *driver)
 396 {
 397         struct host1x_client *client, *tmp;
 398         struct host1x_subdev *subdev;
 399         struct host1x_device *device;
 400         int err;
 401
 402         device = kzalloc(sizeof(*device), GFP_KERNEL);
 403         if (!device)
 404                 return -ENOMEM;
 405
 406         device_initialize(&device->dev);
 407
 408         mutex_init(&device->subdevs_lock);
 409         INIT_LIST_HEAD(&device->subdevs);
 410         INIT_LIST_HEAD(&device->active);
 411         mutex_init(&device->clients_lock);
 412         INIT_LIST_HEAD(&device->clients);
 413         INIT_LIST_HEAD(&device->list);
 414         device->driver = driver;
 415
 416         device->dev.coherent_dma_mask = host1x->dev->coherent_dma_mask;
 417         device->dev.dma_mask = &device->dev.coherent_dma_mask;
 418         dev_set_name(&device->dev, "%s", driver->driver.name);
 419         device->dev.release = host1x_device_release;
 420         device->dev.of_node = host1x->dev->of_node;
 421         device->dev.bus = &host1x_bus_type;
 422         device->dev.parent = host1x->dev;
 423
 424         of_dma_configure(&device->dev, host1x->dev->of_node, true);
 425
 426         err = host1x_device_parse_dt(device, driver);
 427         if (err < 0) {
 428                 kfree(device);
 429                 return err;
 430         }
 431
 432         list_add_tail(&device->list, &host1x->devices);
 433
 434         mutex_lock(&clients_lock);
 435
 436         list_for_each_entry_safe(client, tmp, &clients, list) {
 437                 list_for_each_entry(subdev, &device->subdevs, list) {
 438                         if (subdev->np == client->dev->of_node) {
 439                                 host1x_subdev_register(device, subdev, client);
 440                                 break;
 441                         }
 442                 }
 443         }
 444
 445         mutex_unlock(&clients_lock);
 446
 447         return 0;
 448 }
 449
 450 /*
 451  * Removes a device by first unregistering any subdevices and then removing
 452  * itself from the list of devices.
 453  *
 454  * This function must be called with the host1x->devices_lock held.
 455  */
 456 static void host1x_device_del(struct host1x *host1x,
 457                               struct host1x_device *device)
 458 {
 459         if (device->registered) {
 460                 device->registered = false;
 461                 device_del(&device->dev);
 462         }
 463
 464         put_device(&device->dev);
 465 }
 466
 467 static void host1x_attach_driver(struct host1x *host1x,
 468                                  struct host1x_driver *driver)
 469 {
 470         struct host1x_device *device;
 471         int err;
 472
 473         mutex_lock(&host1x->devices_lock);
 474
 475         list_for_each_entry(device, &host1x->devices, list) {
 476                 if (device->driver == driver) {
 477                         mutex_unlock(&host1x->devices_lock);
 478                         return;
 479                 }
 480         }
 481
 482         err = host1x_device_add(host1x, driver);
 483         if (err < 0)
 484                 dev_err(host1x->dev, "failed to allocate device: %d\n", err);
 485
 486         mutex_unlock(&host1x->devices_lock);
 487 }
 488
 489 static void host1x_detach_driver(struct host1x *host1x,
 490                                  struct host1x_driver *driver)
 491 {
 492         struct host1x_device *device, *tmp;
 493
 494         mutex_lock(&host1x->devices_lock);
 495
 496         list_for_each_entry_safe(device, tmp, &host1x->devices, list)
 497                 if (device->driver == driver)
 498                         host1x_device_del(host1x, device);
 499
 500         mutex_unlock(&host1x->devices_lock);
 501 }
 502
 503 /**
 504  * host1x_register() - register a host1x controller
 505  * @host1x: host1x controller
 506  *
 507  * The host1x controller driver uses this to register a host1x controller with
 508  * the infrastructure. Note that all Tegra SoC generations have only ever come
 509  * with a single host1x instance, so this function is somewhat academic.
 510  */
 511 int host1x_register(struct host1x *host1x)
 512 {
 513         struct host1x_driver *driver;
 514
 515         mutex_lock(&devices_lock);
 516         list_add_tail(&host1x->list, &devices);
 517         mutex_unlock(&devices_lock);
 518
 519         mutex_lock(&drivers_lock);
 520
 521         list_for_each_entry(driver, &drivers, list)
 522                 host1x_attach_driver(host1x, driver);
 523
 524         mutex_unlock(&drivers_lock);
 525
 526         return 0;
 527 }
 528
 529 /**
 530  * host1x_unregister() - unregister a host1x controller
 531  * @host1x: host1x controller
 532  *
 533  * The host1x controller driver uses this to remove a host1x controller from
 534  * the infrastructure.
 535  */
 536 int host1x_unregister(struct host1x *host1x)
 537 {
 538         struct host1x_driver *driver;
 539
 540         mutex_lock(&drivers_lock);
 541
 542         list_for_each_entry(driver, &drivers, list)
 543                 host1x_detach_driver(host1x, driver);
 544
 545         mutex_unlock(&drivers_lock);
 546
 547         mutex_lock(&devices_lock);
 548         list_del_init(&host1x->list);
 549         mutex_unlock(&devices_lock);
 550
 551         return 0;
 552 }
 553
 554 static int host1x_device_probe(struct device *dev)
 555 {
 556         struct host1x_driver *driver = to_host1x_driver(dev->driver);
 557         struct host1x_device *device = to_host1x_device(dev);
 558
 559         if (driver->probe)
 560                 return driver->probe(device);
 561
 562         return 0;
 563 }
 564
 565 static int host1x_device_remove(struct device *dev)
 566 {
 567         struct host1x_driver *driver = to_host1x_driver(dev->driver);
 568         struct host1x_device *device = to_host1x_device(dev);
 569
 570         if (driver->remove)
 571                 return driver->remove(device);
 572
 573         return 0;
 574 }
 575
 576 static void host1x_device_shutdown(struct device *dev)
 577 {
 578         struct host1x_driver *driver = to_host1x_driver(dev->driver);
 579         struct host1x_device *device = to_host1x_device(dev);
 580
 581         if (driver->shutdown)
 582                 driver->shutdown(device);
 583 }
 584
 585 /**
 586  * host1x_driver_register_full() - register a host1x driver
 587  * @driver: host1x driver
 588  * @owner: owner module
 589  *
 590  * Drivers for host1x logical devices call this function to register a driver
 591  * with the infrastructure. Note that since these drive logical devices, the
 592  * registration of the driver actually triggers tho logical device creation.
 593  * A logical device will be created for each host1x instance.
 594  */
 595 int host1x_driver_register_full(struct host1x_driver *driver,
 596                                 struct module *owner)
 597 {
 598         struct host1x *host1x;
 599
 600         INIT_LIST_HEAD(&driver->list);
 601
 602         mutex_lock(&drivers_lock);
 603         list_add_tail(&driver->list, &drivers);
 604         mutex_unlock(&drivers_lock);
 605
 606         mutex_lock(&devices_lock);
 607
 608         list_for_each_entry(host1x, &devices, list)
 609                 host1x_attach_driver(host1x, driver);
 610
 611         mutex_unlock(&devices_lock);
 612
 613         driver->driver.bus = &host1x_bus_type;
 614         driver->driver.owner = owner;
 615         driver->driver.probe = host1x_device_probe;
 616         driver->driver.remove = host1x_device_remove;
 617         driver->driver.shutdown = host1x_device_shutdown;
 618
 619         return driver_register(&driver->driver);
 620 }
 621 EXPORT_SYMBOL(host1x_driver_register_full);
 622
 623 /**
 624  * host1x_driver_unregister() - unregister a host1x driver
 625  * @driver: host1x driver
 626  *
 627  * Unbinds the driver from each of the host1x logical devices that it is
 628  * bound to, effectively removing the subsystem devices that they represent.
 629  */
 630 void host1x_driver_unregister(struct host1x_driver *driver)
 631 {
 632         driver_unregister(&driver->driver);
 633
 634         mutex_lock(&drivers_lock);
 635         list_del_init(&driver->list);
 636         mutex_unlock(&drivers_lock);
 637 }
 638 EXPORT_SYMBOL(host1x_driver_unregister);
 639
 640 /**
 641  * host1x_client_register() - register a host1x client
 642  * @client: host1x client
 643  *
 644  * Registers a host1x client with each host1x controller instance. Note that
 645  * each client will only match their parent host1x controller and will only be
 646  * associated with that instance. Once all clients have been registered with
 647  * their parent host1x controller, the infrastructure will set up the logical
 648  * device and call host1x_device_init(), which will in turn call each client's
 649  * &host1x_client_ops.init implementation.
 650  */
 651 int host1x_client_register(struct host1x_client *client)
 652 {
 653         struct host1x *host1x;
 654         int err;
 655
 656         mutex_lock(&devices_lock);
 657
 658         list_for_each_entry(host1x, &devices, list) {
 659                 err = host1x_add_client(host1x, client);
 660                 if (!err) {
 661                         mutex_unlock(&devices_lock);
 662                         return 0;
 663                 }
 664         }
 665
 666         mutex_unlock(&devices_lock);
 667
 668         mutex_lock(&clients_lock);
 669         list_add_tail(&client->list, &clients);
 670         mutex_unlock(&clients_lock);
 671
 672         return 0;
 673 }
 674 EXPORT_SYMBOL(host1x_client_register);
 675
 676 /**
 677  * host1x_client_unregister() - unregister a host1x client
 678  * @client: host1x client
 679  *
 680  * Removes a host1x client from its host1x controller instance. If a logical
 681  * device has already been initialized, it will be torn down.
 682  */
 683 int host1x_client_unregister(struct host1x_client *client)
 684 {
 685         struct host1x_client *c;
 686         struct host1x *host1x;
 687         int err;
 688
 689         mutex_lock(&devices_lock);
 690
 691         list_for_each_entry(host1x, &devices, list) {
 692                 err = host1x_del_client(host1x, client);
 693                 if (!err) {
 694                         mutex_unlock(&devices_lock);
 695                         return 0;
 696                 }
 697         }
 698
 699         mutex_unlock(&devices_lock);
 700         mutex_lock(&clients_lock);
 701
 702         list_for_each_entry(c, &clients, list) {
 703                 if (c == client) {
 704                         list_del_init(&c->list);
 705                         break;
 706                 }
 707         }
 708
 709         mutex_unlock(&clients_lock);
 710
 711         return 0;
 712 }
 713 EXPORT_SYMBOL(host1x_client_unregister);