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                                 mutex_unlock(&device->clients_lock);
 215                                 return err;
 216                         }
 217                 }
 218         }
 219
 220         mutex_unlock(&device->clients_lock);
 221
 222         return 0;
 223 }
 224 EXPORT_SYMBOL(host1x_device_init);
 225
 226 /**
 227  * host1x_device_exit() - uninitialize host1x logical device
 228  * @device: host1x logical device
 229  *
 230  * When the driver for a host1x logical device is unloaded, it can call this
 231  * function to tear down each of its clients. Typically this is done after a
 232  * subsystem-specific data structure is removed and the functionality can no
 233  * longer be used.
 234  */
 235 int host1x_device_exit(struct host1x_device *device)
 236 {
 237         struct host1x_client *client;
 238         int err;
 239
 240         mutex_lock(&device->clients_lock);
 241
 242         list_for_each_entry_reverse(client, &device->clients, list) {
 243                 if (client->ops && client->ops->exit) {
 244                         err = client->ops->exit(client);
 245                         if (err < 0) {
 246                                 dev_err(&device->dev,
 247                                         "failed to cleanup %s: %d\n",
 248                                         dev_name(client->dev), err);
 249                                 mutex_unlock(&device->clients_lock);
 250                                 return err;
 251                         }
 252                 }
 253         }
 254
 255         mutex_unlock(&device->clients_lock);
 256
 257         return 0;
 258 }
 259 EXPORT_SYMBOL(host1x_device_exit);
 260
 261 static int host1x_add_client(struct host1x *host1x,
 262                              struct host1x_client *client)
 263 {
 264         struct host1x_device *device;
 265         struct host1x_subdev *subdev;
 266
 267         mutex_lock(&host1x->devices_lock);
 268
 269         list_for_each_entry(device, &host1x->devices, list) {
 270                 list_for_each_entry(subdev, &device->subdevs, list) {
 271                         if (subdev->np == client->dev->of_node) {
 272                                 host1x_subdev_register(device, subdev, client);
 273                                 mutex_unlock(&host1x->devices_lock);
 274                                 return 0;
 275                         }
 276                 }
 277         }
 278
 279         mutex_unlock(&host1x->devices_lock);
 280         return -ENODEV;
 281 }
 282
 283 static int host1x_del_client(struct host1x *host1x,
 284                              struct host1x_client *client)
 285 {
 286         struct host1x_device *device, *dt;
 287         struct host1x_subdev *subdev;
 288
 289         mutex_lock(&host1x->devices_lock);
 290
 291         list_for_each_entry_safe(device, dt, &host1x->devices, list) {
 292                 list_for_each_entry(subdev, &device->active, list) {
 293                         if (subdev->client == client) {
 294                                 host1x_subdev_unregister(device, subdev);
 295                                 mutex_unlock(&host1x->devices_lock);
 296                                 return 0;
 297                         }
 298                 }
 299         }
 300
 301         mutex_unlock(&host1x->devices_lock);
 302         return -ENODEV;
 303 }
 304
 305 static int host1x_device_match(struct device *dev, struct device_driver *drv)
 306 {
 307         return strcmp(dev_name(dev), drv->name) == 0;
 308 }
 309
 310 static const struct dev_pm_ops host1x_device_pm_ops = {
 311         .suspend = pm_generic_suspend,
 312         .resume = pm_generic_resume,
 313         .freeze = pm_generic_freeze,
 314         .thaw = pm_generic_thaw,
 315         .poweroff = pm_generic_poweroff,
 316         .restore = pm_generic_restore,
 317 };
 318
 319 struct bus_type host1x_bus_type = {
 320         .name = "host1x",
 321         .match = host1x_device_match,
 322         .pm = &host1x_device_pm_ops,
 323         .force_dma = true,
 324 };
 325
 326 static void __host1x_device_del(struct host1x_device *device)
 327 {
 328         struct host1x_subdev *subdev, *sd;
 329         struct host1x_client *client, *cl;
 330
 331         mutex_lock(&device->subdevs_lock);
 332
 333         /* unregister subdevices */
 334         list_for_each_entry_safe(subdev, sd, &device->active, list) {
 335                 /*
 336                  * host1x_subdev_unregister() will remove the client from
 337                  * any lists, so we'll need to manually add it back to the
 338                  * list of idle clients.
 339                  *
 340                  * XXX: Alternatively, perhaps don't remove the client from
 341                  * any lists in host1x_subdev_unregister() and instead do
 342                  * that explicitly from host1x_unregister_client()?
 343                  */
 344                 client = subdev->client;
 345
 346                 __host1x_subdev_unregister(device, subdev);
 347
 348                 /* add the client to the list of idle clients */
 349                 mutex_lock(&clients_lock);
 350                 list_add_tail(&client->list, &clients);
 351                 mutex_unlock(&clients_lock);
 352         }
 353
 354         /* remove subdevices */
 355         list_for_each_entry_safe(subdev, sd, &device->subdevs, list)
 356                 host1x_subdev_del(subdev);
 357
 358         mutex_unlock(&device->subdevs_lock);
 359
 360         /* move clients to idle list */
 361         mutex_lock(&clients_lock);
 362         mutex_lock(&device->clients_lock);
 363
 364         list_for_each_entry_safe(client, cl, &device->clients, list)
 365                 list_move_tail(&client->list, &clients);
 366
 367         mutex_unlock(&device->clients_lock);
 368         mutex_unlock(&clients_lock);
 369
 370         /* finally remove the device */
 371         list_del_init(&device->list);
 372 }
 373
 374 static void host1x_device_release(struct device *dev)
 375 {
 376         struct host1x_device *device = to_host1x_device(dev);
 377
 378         __host1x_device_del(device);
 379         kfree(device);
 380 }
 381
 382 static int host1x_device_add(struct host1x *host1x,
 383                              struct host1x_driver *driver)
 384 {
 385         struct host1x_client *client, *tmp;
 386         struct host1x_subdev *subdev;
 387         struct host1x_device *device;
 388         int err;
 389
 390         device = kzalloc(sizeof(*device), GFP_KERNEL);
 391         if (!device)
 392                 return -ENOMEM;
 393
 394         device_initialize(&device->dev);
 395
 396         mutex_init(&device->subdevs_lock);
 397         INIT_LIST_HEAD(&device->subdevs);
 398         INIT_LIST_HEAD(&device->active);
 399         mutex_init(&device->clients_lock);
 400         INIT_LIST_HEAD(&device->clients);
 401         INIT_LIST_HEAD(&device->list);
 402         device->driver = driver;
 403
 404         device->dev.coherent_dma_mask = host1x->dev->coherent_dma_mask;
 405         device->dev.dma_mask = &device->dev.coherent_dma_mask;
 406         dev_set_name(&device->dev, "%s", driver->driver.name);
 407         device->dev.release = host1x_device_release;
 408         device->dev.of_node = host1x->dev->of_node;
 409         device->dev.bus = &host1x_bus_type;
 410         device->dev.parent = host1x->dev;
 411
 412         of_dma_configure(&device->dev, host1x->dev->of_node);
 413
 414         err = host1x_device_parse_dt(device, driver);
 415         if (err < 0) {
 416                 kfree(device);
 417                 return err;
 418         }
 419
 420         list_add_tail(&device->list, &host1x->devices);
 421
 422         mutex_lock(&clients_lock);
 423
 424         list_for_each_entry_safe(client, tmp, &clients, list) {
 425                 list_for_each_entry(subdev, &device->subdevs, list) {
 426                         if (subdev->np == client->dev->of_node) {
 427                                 host1x_subdev_register(device, subdev, client);
 428                                 break;
 429                         }
 430                 }
 431         }
 432
 433         mutex_unlock(&clients_lock);
 434
 435         return 0;
 436 }
 437
 438 /*
 439  * Removes a device by first unregistering any subdevices and then removing
 440  * itself from the list of devices.
 441  *
 442  * This function must be called with the host1x->devices_lock held.
 443  */
 444 static void host1x_device_del(struct host1x *host1x,
 445                               struct host1x_device *device)
 446 {
 447         if (device->registered) {
 448                 device->registered = false;
 449                 device_del(&device->dev);
 450         }
 451
 452         put_device(&device->dev);
 453 }
 454
 455 static void host1x_attach_driver(struct host1x *host1x,
 456                                  struct host1x_driver *driver)
 457 {
 458         struct host1x_device *device;
 459         int err;
 460
 461         mutex_lock(&host1x->devices_lock);
 462
 463         list_for_each_entry(device, &host1x->devices, list) {
 464                 if (device->driver == driver) {
 465                         mutex_unlock(&host1x->devices_lock);
 466                         return;
 467                 }
 468         }
 469
 470         err = host1x_device_add(host1x, driver);
 471         if (err < 0)
 472                 dev_err(host1x->dev, "failed to allocate device: %d\n", err);
 473
 474         mutex_unlock(&host1x->devices_lock);
 475 }
 476
 477 static void host1x_detach_driver(struct host1x *host1x,
 478                                  struct host1x_driver *driver)
 479 {
 480         struct host1x_device *device, *tmp;
 481
 482         mutex_lock(&host1x->devices_lock);
 483
 484         list_for_each_entry_safe(device, tmp, &host1x->devices, list)
 485                 if (device->driver == driver)
 486                         host1x_device_del(host1x, device);
 487
 488         mutex_unlock(&host1x->devices_lock);
 489 }
 490
 491 /**
 492  * host1x_register() - register a host1x controller
 493  * @host1x: host1x controller
 494  *
 495  * The host1x controller driver uses this to register a host1x controller with
 496  * the infrastructure. Note that all Tegra SoC generations have only ever come
 497  * with a single host1x instance, so this function is somewhat academic.
 498  */
 499 int host1x_register(struct host1x *host1x)
 500 {
 501         struct host1x_driver *driver;
 502
 503         mutex_lock(&devices_lock);
 504         list_add_tail(&host1x->list, &devices);
 505         mutex_unlock(&devices_lock);
 506
 507         mutex_lock(&drivers_lock);
 508
 509         list_for_each_entry(driver, &drivers, list)
 510                 host1x_attach_driver(host1x, driver);
 511
 512         mutex_unlock(&drivers_lock);
 513
 514         return 0;
 515 }
 516
 517 /**
 518  * host1x_unregister() - unregister a host1x controller
 519  * @host1x: host1x controller
 520  *
 521  * The host1x controller driver uses this to remove a host1x controller from
 522  * the infrastructure.
 523  */
 524 int host1x_unregister(struct host1x *host1x)
 525 {
 526         struct host1x_driver *driver;
 527
 528         mutex_lock(&drivers_lock);
 529
 530         list_for_each_entry(driver, &drivers, list)
 531                 host1x_detach_driver(host1x, driver);
 532
 533         mutex_unlock(&drivers_lock);
 534
 535         mutex_lock(&devices_lock);
 536         list_del_init(&host1x->list);
 537         mutex_unlock(&devices_lock);
 538
 539         return 0;
 540 }
 541
 542 static int host1x_device_probe(struct device *dev)
 543 {
 544         struct host1x_driver *driver = to_host1x_driver(dev->driver);
 545         struct host1x_device *device = to_host1x_device(dev);
 546
 547         if (driver->probe)
 548                 return driver->probe(device);
 549
 550         return 0;
 551 }
 552
 553 static int host1x_device_remove(struct device *dev)
 554 {
 555         struct host1x_driver *driver = to_host1x_driver(dev->driver);
 556         struct host1x_device *device = to_host1x_device(dev);
 557
 558         if (driver->remove)
 559                 return driver->remove(device);
 560
 561         return 0;
 562 }
 563
 564 static void host1x_device_shutdown(struct device *dev)
 565 {
 566         struct host1x_driver *driver = to_host1x_driver(dev->driver);
 567         struct host1x_device *device = to_host1x_device(dev);
 568
 569         if (driver->shutdown)
 570                 driver->shutdown(device);
 571 }
 572
 573 /**
 574  * host1x_driver_register_full() - register a host1x driver
 575  * @driver: host1x driver
 576  * @owner: owner module
 577  *
 578  * Drivers for host1x logical devices call this function to register a driver
 579  * with the infrastructure. Note that since these drive logical devices, the
 580  * registration of the driver actually triggers tho logical device creation.
 581  * A logical device will be created for each host1x instance.
 582  */
 583 int host1x_driver_register_full(struct host1x_driver *driver,
 584                                 struct module *owner)
 585 {
 586         struct host1x *host1x;
 587
 588         INIT_LIST_HEAD(&driver->list);
 589
 590         mutex_lock(&drivers_lock);
 591         list_add_tail(&driver->list, &drivers);
 592         mutex_unlock(&drivers_lock);
 593
 594         mutex_lock(&devices_lock);
 595
 596         list_for_each_entry(host1x, &devices, list)
 597                 host1x_attach_driver(host1x, driver);
 598
 599         mutex_unlock(&devices_lock);
 600
 601         driver->driver.bus = &host1x_bus_type;
 602         driver->driver.owner = owner;
 603         driver->driver.probe = host1x_device_probe;
 604         driver->driver.remove = host1x_device_remove;
 605         driver->driver.shutdown = host1x_device_shutdown;
 606
 607         return driver_register(&driver->driver);
 608 }
 609 EXPORT_SYMBOL(host1x_driver_register_full);
 610
 611 /**
 612  * host1x_driver_unregister() - unregister a host1x driver
 613  * @driver: host1x driver
 614  *
 615  * Unbinds the driver from each of the host1x logical devices that it is
 616  * bound to, effectively removing the subsystem devices that they represent.
 617  */
 618 void host1x_driver_unregister(struct host1x_driver *driver)
 619 {
 620         driver_unregister(&driver->driver);
 621
 622         mutex_lock(&drivers_lock);
 623         list_del_init(&driver->list);
 624         mutex_unlock(&drivers_lock);
 625 }
 626 EXPORT_SYMBOL(host1x_driver_unregister);
 627
 628 /**
 629  * host1x_client_register() - register a host1x client
 630  * @client: host1x client
 631  *
 632  * Registers a host1x client with each host1x controller instance. Note that
 633  * each client will only match their parent host1x controller and will only be
 634  * associated with that instance. Once all clients have been registered with
 635  * their parent host1x controller, the infrastructure will set up the logical
 636  * device and call host1x_device_init(), which will in turn call each client's
 637  * &host1x_client_ops.init implementation.
 638  */
 639 int host1x_client_register(struct host1x_client *client)
 640 {
 641         struct host1x *host1x;
 642         int err;
 643
 644         mutex_lock(&devices_lock);
 645
 646         list_for_each_entry(host1x, &devices, list) {
 647                 err = host1x_add_client(host1x, client);
 648                 if (!err) {
 649                         mutex_unlock(&devices_lock);
 650                         return 0;
 651                 }
 652         }
 653
 654         mutex_unlock(&devices_lock);
 655
 656         mutex_lock(&clients_lock);
 657         list_add_tail(&client->list, &clients);
 658         mutex_unlock(&clients_lock);
 659
 660         return 0;
 661 }
 662 EXPORT_SYMBOL(host1x_client_register);
 663
 664 /**
 665  * host1x_client_unregister() - unregister a host1x client
 666  * @client: host1x client
 667  *
 668  * Removes a host1x client from its host1x controller instance. If a logical
 669  * device has already been initialized, it will be torn down.
 670  */
 671 int host1x_client_unregister(struct host1x_client *client)
 672 {
 673         struct host1x_client *c;
 674         struct host1x *host1x;
 675         int err;
 676
 677         mutex_lock(&devices_lock);
 678
 679         list_for_each_entry(host1x, &devices, list) {
 680                 err = host1x_del_client(host1x, client);
 681                 if (!err) {
 682                         mutex_unlock(&devices_lock);
 683                         return 0;
 684                 }
 685         }
 686
 687         mutex_unlock(&devices_lock);
 688         mutex_lock(&clients_lock);
 689
 690         list_for_each_entry(c, &clients, list) {
 691                 if (c == client) {
 692                         list_del_init(&c->list);
 693                         break;
 694                 }
 695         }
 696
 697         mutex_unlock(&clients_lock);
 698
 699         return 0;
 700 }
 701 EXPORT_SYMBOL(host1x_client_unregister);