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 const struct dev_pm_ops host1x_device_pm_ops = {
 318         .suspend = pm_generic_suspend,
 319         .resume = pm_generic_resume,
 320         .freeze = pm_generic_freeze,
 321         .thaw = pm_generic_thaw,
 322         .poweroff = pm_generic_poweroff,
 323         .restore = pm_generic_restore,
 324 };
 325
 326 struct bus_type host1x_bus_type = {
 327         .name = "host1x",
 328         .match = host1x_device_match,
 329         .pm = &host1x_device_pm_ops,
 330         .force_dma = true,
 331 };
 332
 333 static void __host1x_device_del(struct host1x_device *device)
 334 {
 335         struct host1x_subdev *subdev, *sd;
 336         struct host1x_client *client, *cl;
 337
 338         mutex_lock(&device->subdevs_lock);
 339
 340         /* unregister subdevices */
 341         list_for_each_entry_safe(subdev, sd, &device->active, list) {
 342                 /*
 343                  * host1x_subdev_unregister() will remove the client from
 344                  * any lists, so we'll need to manually add it back to the
 345                  * list of idle clients.
 346                  *
 347                  * XXX: Alternatively, perhaps don't remove the client from
 348                  * any lists in host1x_subdev_unregister() and instead do
 349                  * that explicitly from host1x_unregister_client()?
 350                  */
 351                 client = subdev->client;
 352
 353                 __host1x_subdev_unregister(device, subdev);
 354
 355                 /* add the client to the list of idle clients */
 356                 mutex_lock(&clients_lock);
 357                 list_add_tail(&client->list, &clients);
 358                 mutex_unlock(&clients_lock);
 359         }
 360
 361         /* remove subdevices */
 362         list_for_each_entry_safe(subdev, sd, &device->subdevs, list)
 363                 host1x_subdev_del(subdev);
 364
 365         mutex_unlock(&device->subdevs_lock);
 366
 367         /* move clients to idle list */
 368         mutex_lock(&clients_lock);
 369         mutex_lock(&device->clients_lock);
 370
 371         list_for_each_entry_safe(client, cl, &device->clients, list)
 372                 list_move_tail(&client->list, &clients);
 373
 374         mutex_unlock(&device->clients_lock);
 375         mutex_unlock(&clients_lock);
 376
 377         /* finally remove the device */
 378         list_del_init(&device->list);
 379 }
 380
 381 static void host1x_device_release(struct device *dev)
 382 {
 383         struct host1x_device *device = to_host1x_device(dev);
 384
 385         __host1x_device_del(device);
 386         kfree(device);
 387 }
 388
 389 static int host1x_device_add(struct host1x *host1x,
 390                              struct host1x_driver *driver)
 391 {
 392         struct host1x_client *client, *tmp;
 393         struct host1x_subdev *subdev;
 394         struct host1x_device *device;
 395         int err;
 396
 397         device = kzalloc(sizeof(*device), GFP_KERNEL);
 398         if (!device)
 399                 return -ENOMEM;
 400
 401         device_initialize(&device->dev);
 402
 403         mutex_init(&device->subdevs_lock);
 404         INIT_LIST_HEAD(&device->subdevs);
 405         INIT_LIST_HEAD(&device->active);
 406         mutex_init(&device->clients_lock);
 407         INIT_LIST_HEAD(&device->clients);
 408         INIT_LIST_HEAD(&device->list);
 409         device->driver = driver;
 410
 411         device->dev.coherent_dma_mask = host1x->dev->coherent_dma_mask;
 412         device->dev.dma_mask = &device->dev.coherent_dma_mask;
 413         dev_set_name(&device->dev, "%s", driver->driver.name);
 414         device->dev.release = host1x_device_release;
 415         device->dev.of_node = host1x->dev->of_node;
 416         device->dev.bus = &host1x_bus_type;
 417         device->dev.parent = host1x->dev;
 418
 419         of_dma_configure(&device->dev, host1x->dev->of_node);
 420
 421         err = host1x_device_parse_dt(device, driver);
 422         if (err < 0) {
 423                 kfree(device);
 424                 return err;
 425         }
 426
 427         list_add_tail(&device->list, &host1x->devices);
 428
 429         mutex_lock(&clients_lock);
 430
 431         list_for_each_entry_safe(client, tmp, &clients, list) {
 432                 list_for_each_entry(subdev, &device->subdevs, list) {
 433                         if (subdev->np == client->dev->of_node) {
 434                                 host1x_subdev_register(device, subdev, client);
 435                                 break;
 436                         }
 437                 }
 438         }
 439
 440         mutex_unlock(&clients_lock);
 441
 442         return 0;
 443 }
 444
 445 /*
 446  * Removes a device by first unregistering any subdevices and then removing
 447  * itself from the list of devices.
 448  *
 449  * This function must be called with the host1x->devices_lock held.
 450  */
 451 static void host1x_device_del(struct host1x *host1x,
 452                               struct host1x_device *device)
 453 {
 454         if (device->registered) {
 455                 device->registered = false;
 456                 device_del(&device->dev);
 457         }
 458
 459         put_device(&device->dev);
 460 }
 461
 462 static void host1x_attach_driver(struct host1x *host1x,
 463                                  struct host1x_driver *driver)
 464 {
 465         struct host1x_device *device;
 466         int err;
 467
 468         mutex_lock(&host1x->devices_lock);
 469
 470         list_for_each_entry(device, &host1x->devices, list) {
 471                 if (device->driver == driver) {
 472                         mutex_unlock(&host1x->devices_lock);
 473                         return;
 474                 }
 475         }
 476
 477         err = host1x_device_add(host1x, driver);
 478         if (err < 0)
 479                 dev_err(host1x->dev, "failed to allocate device: %d\n", err);
 480
 481         mutex_unlock(&host1x->devices_lock);
 482 }
 483
 484 static void host1x_detach_driver(struct host1x *host1x,
 485                                  struct host1x_driver *driver)
 486 {
 487         struct host1x_device *device, *tmp;
 488
 489         mutex_lock(&host1x->devices_lock);
 490
 491         list_for_each_entry_safe(device, tmp, &host1x->devices, list)
 492                 if (device->driver == driver)
 493                         host1x_device_del(host1x, device);
 494
 495         mutex_unlock(&host1x->devices_lock);
 496 }
 497
 498 /**
 499  * host1x_register() - register a host1x controller
 500  * @host1x: host1x controller
 501  *
 502  * The host1x controller driver uses this to register a host1x controller with
 503  * the infrastructure. Note that all Tegra SoC generations have only ever come
 504  * with a single host1x instance, so this function is somewhat academic.
 505  */
 506 int host1x_register(struct host1x *host1x)
 507 {
 508         struct host1x_driver *driver;
 509
 510         mutex_lock(&devices_lock);
 511         list_add_tail(&host1x->list, &devices);
 512         mutex_unlock(&devices_lock);
 513
 514         mutex_lock(&drivers_lock);
 515
 516         list_for_each_entry(driver, &drivers, list)
 517                 host1x_attach_driver(host1x, driver);
 518
 519         mutex_unlock(&drivers_lock);
 520
 521         return 0;
 522 }
 523
 524 /**
 525  * host1x_unregister() - unregister a host1x controller
 526  * @host1x: host1x controller
 527  *
 528  * The host1x controller driver uses this to remove a host1x controller from
 529  * the infrastructure.
 530  */
 531 int host1x_unregister(struct host1x *host1x)
 532 {
 533         struct host1x_driver *driver;
 534
 535         mutex_lock(&drivers_lock);
 536
 537         list_for_each_entry(driver, &drivers, list)
 538                 host1x_detach_driver(host1x, driver);
 539
 540         mutex_unlock(&drivers_lock);
 541
 542         mutex_lock(&devices_lock);
 543         list_del_init(&host1x->list);
 544         mutex_unlock(&devices_lock);
 545
 546         return 0;
 547 }
 548
 549 static int host1x_device_probe(struct device *dev)
 550 {
 551         struct host1x_driver *driver = to_host1x_driver(dev->driver);
 552         struct host1x_device *device = to_host1x_device(dev);
 553
 554         if (driver->probe)
 555                 return driver->probe(device);
 556
 557         return 0;
 558 }
 559
 560 static int host1x_device_remove(struct device *dev)
 561 {
 562         struct host1x_driver *driver = to_host1x_driver(dev->driver);
 563         struct host1x_device *device = to_host1x_device(dev);
 564
 565         if (driver->remove)
 566                 return driver->remove(device);
 567
 568         return 0;
 569 }
 570
 571 static void host1x_device_shutdown(struct device *dev)
 572 {
 573         struct host1x_driver *driver = to_host1x_driver(dev->driver);
 574         struct host1x_device *device = to_host1x_device(dev);
 575
 576         if (driver->shutdown)
 577                 driver->shutdown(device);
 578 }
 579
 580 /**
 581  * host1x_driver_register_full() - register a host1x driver
 582  * @driver: host1x driver
 583  * @owner: owner module
 584  *
 585  * Drivers for host1x logical devices call this function to register a driver
 586  * with the infrastructure. Note that since these drive logical devices, the
 587  * registration of the driver actually triggers tho logical device creation.
 588  * A logical device will be created for each host1x instance.
 589  */
 590 int host1x_driver_register_full(struct host1x_driver *driver,
 591                                 struct module *owner)
 592 {
 593         struct host1x *host1x;
 594
 595         INIT_LIST_HEAD(&driver->list);
 596
 597         mutex_lock(&drivers_lock);
 598         list_add_tail(&driver->list, &drivers);
 599         mutex_unlock(&drivers_lock);
 600
 601         mutex_lock(&devices_lock);
 602
 603         list_for_each_entry(host1x, &devices, list)
 604                 host1x_attach_driver(host1x, driver);
 605
 606         mutex_unlock(&devices_lock);
 607
 608         driver->driver.bus = &host1x_bus_type;
 609         driver->driver.owner = owner;
 610         driver->driver.probe = host1x_device_probe;
 611         driver->driver.remove = host1x_device_remove;
 612         driver->driver.shutdown = host1x_device_shutdown;
 613
 614         return driver_register(&driver->driver);
 615 }
 616 EXPORT_SYMBOL(host1x_driver_register_full);
 617
 618 /**
 619  * host1x_driver_unregister() - unregister a host1x driver
 620  * @driver: host1x driver
 621  *
 622  * Unbinds the driver from each of the host1x logical devices that it is
 623  * bound to, effectively removing the subsystem devices that they represent.
 624  */
 625 void host1x_driver_unregister(struct host1x_driver *driver)
 626 {
 627         driver_unregister(&driver->driver);
 628
 629         mutex_lock(&drivers_lock);
 630         list_del_init(&driver->list);
 631         mutex_unlock(&drivers_lock);
 632 }
 633 EXPORT_SYMBOL(host1x_driver_unregister);
 634
 635 /**
 636  * host1x_client_register() - register a host1x client
 637  * @client: host1x client
 638  *
 639  * Registers a host1x client with each host1x controller instance. Note that
 640  * each client will only match their parent host1x controller and will only be
 641  * associated with that instance. Once all clients have been registered with
 642  * their parent host1x controller, the infrastructure will set up the logical
 643  * device and call host1x_device_init(), which will in turn call each client's
 644  * &host1x_client_ops.init implementation.
 645  */
 646 int host1x_client_register(struct host1x_client *client)
 647 {
 648         struct host1x *host1x;
 649         int err;
 650
 651         mutex_lock(&devices_lock);
 652
 653         list_for_each_entry(host1x, &devices, list) {
 654                 err = host1x_add_client(host1x, client);
 655                 if (!err) {
 656                         mutex_unlock(&devices_lock);
 657                         return 0;
 658                 }
 659         }
 660
 661         mutex_unlock(&devices_lock);
 662
 663         mutex_lock(&clients_lock);
 664         list_add_tail(&client->list, &clients);
 665         mutex_unlock(&clients_lock);
 666
 667         return 0;
 668 }
 669 EXPORT_SYMBOL(host1x_client_register);
 670
 671 /**
 672  * host1x_client_unregister() - unregister a host1x client
 673  * @client: host1x client
 674  *
 675  * Removes a host1x client from its host1x controller instance. If a logical
 676  * device has already been initialized, it will be torn down.
 677  */
 678 int host1x_client_unregister(struct host1x_client *client)
 679 {
 680         struct host1x_client *c;
 681         struct host1x *host1x;
 682         int err;
 683
 684         mutex_lock(&devices_lock);
 685
 686         list_for_each_entry(host1x, &devices, list) {
 687                 err = host1x_del_client(host1x, client);
 688                 if (!err) {
 689                         mutex_unlock(&devices_lock);
 690                         return 0;
 691                 }
 692         }
 693
 694         mutex_unlock(&devices_lock);
 695         mutex_lock(&clients_lock);
 696
 697         list_for_each_entry(c, &clients, list) {
 698                 if (c == client) {
 699                         list_del_init(&c->list);
 700                         break;
 701                 }
 702         }
 703
 704         mutex_unlock(&clients_lock);
 705
 706         return 0;
 707 }
 708 EXPORT_SYMBOL(host1x_client_unregister);