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  */
  44 static int host1x_subdev_add(struct host1x_device *device,
  45                              struct device_node *np)
  46 {
  47         struct host1x_subdev *subdev;
  48
  49         subdev = kzalloc(sizeof(*subdev), GFP_KERNEL);
  50         if (!subdev)
  51                 return -ENOMEM;
  52
  53         INIT_LIST_HEAD(&subdev->list);
  54         subdev->np = of_node_get(np);
  55
  56         mutex_lock(&device->subdevs_lock);
  57         list_add_tail(&subdev->list, &device->subdevs);
  58         mutex_unlock(&device->subdevs_lock);
  59
  60         return 0;
  61 }
  62
  63 /**
  64  * host1x_subdev_del() - remove subdevice
  65  */
  66 static void host1x_subdev_del(struct host1x_subdev *subdev)
  67 {
  68         list_del(&subdev->list);
  69         of_node_put(subdev->np);
  70         kfree(subdev);
  71 }
  72
  73 /**
  74  * host1x_device_parse_dt() - scan device tree and add matching subdevices
  75  */
  76 static int host1x_device_parse_dt(struct host1x_device *device,
  77                                   struct host1x_driver *driver)
  78 {
  79         struct device_node *np;
  80         int err;
  81
  82         for_each_child_of_node(device->dev.parent->of_node, np) {
  83                 if (of_match_node(driver->subdevs, np) &&
  84                     of_device_is_available(np)) {
  85                         err = host1x_subdev_add(device, np);
  86                         if (err < 0) {
  87                                 of_node_put(np);
  88                                 return err;
  89                         }
  90                 }
  91         }
  92
  93         return 0;
  94 }
  95
  96 static void host1x_subdev_register(struct host1x_device *device,
  97                                    struct host1x_subdev *subdev,
  98                                    struct host1x_client *client)
  99 {
 100         int err;
 101
 102         /*
 103          * Move the subdevice to the list of active (registered) subdevices
 104          * and associate it with a client. At the same time, associate the
 105          * client with its parent device.
 106          */
 107         mutex_lock(&device->subdevs_lock);
 108         mutex_lock(&device->clients_lock);
 109         list_move_tail(&client->list, &device->clients);
 110         list_move_tail(&subdev->list, &device->active);
 111         client->parent = &device->dev;
 112         subdev->client = client;
 113         mutex_unlock(&device->clients_lock);
 114         mutex_unlock(&device->subdevs_lock);
 115
 116         if (list_empty(&device->subdevs)) {
 117                 err = device_add(&device->dev);
 118                 if (err < 0)
 119                         dev_err(&device->dev, "failed to add: %d\n", err);
 120                 else
 121                         device->registered = true;
 122         }
 123 }
 124
 125 static void __host1x_subdev_unregister(struct host1x_device *device,
 126                                        struct host1x_subdev *subdev)
 127 {
 128         struct host1x_client *client = subdev->client;
 129
 130         /*
 131          * If all subdevices have been activated, we're about to remove the
 132          * first active subdevice, so unload the driver first.
 133          */
 134         if (list_empty(&device->subdevs)) {
 135                 if (device->registered) {
 136                         device->registered = false;
 137                         device_del(&device->dev);
 138                 }
 139         }
 140
 141         /*
 142          * Move the subdevice back to the list of idle subdevices and remove
 143          * it from list of clients.
 144          */
 145         mutex_lock(&device->clients_lock);
 146         subdev->client = NULL;
 147         client->parent = NULL;
 148         list_move_tail(&subdev->list, &device->subdevs);
 149         /*
 150          * XXX: Perhaps don't do this here, but rather explicitly remove it
 151          * when the device is about to be deleted.
 152          *
 153          * This is somewhat complicated by the fact that this function is
 154          * used to remove the subdevice when a client is unregistered but
 155          * also when the composite device is about to be removed.
 156          */
 157         list_del_init(&client->list);
 158         mutex_unlock(&device->clients_lock);
 159 }
 160
 161 static void host1x_subdev_unregister(struct host1x_device *device,
 162                                      struct host1x_subdev *subdev)
 163 {
 164         mutex_lock(&device->subdevs_lock);
 165         __host1x_subdev_unregister(device, subdev);
 166         mutex_unlock(&device->subdevs_lock);
 167 }
 168
 169 int host1x_device_init(struct host1x_device *device)
 170 {
 171         struct host1x_client *client;
 172         int err;
 173
 174         mutex_lock(&device->clients_lock);
 175
 176         list_for_each_entry(client, &device->clients, list) {
 177                 if (client->ops && client->ops->init) {
 178                         err = client->ops->init(client);
 179                         if (err < 0) {
 180                                 dev_err(&device->dev,
 181                                         "failed to initialize %s: %d\n",
 182                                         dev_name(client->dev), err);
 183                                 mutex_unlock(&device->clients_lock);
 184                                 return err;
 185                         }
 186                 }
 187         }
 188
 189         mutex_unlock(&device->clients_lock);
 190
 191         return 0;
 192 }
 193 EXPORT_SYMBOL(host1x_device_init);
 194
 195 int host1x_device_exit(struct host1x_device *device)
 196 {
 197         struct host1x_client *client;
 198         int err;
 199
 200         mutex_lock(&device->clients_lock);
 201
 202         list_for_each_entry_reverse(client, &device->clients, list) {
 203                 if (client->ops && client->ops->exit) {
 204                         err = client->ops->exit(client);
 205                         if (err < 0) {
 206                                 dev_err(&device->dev,
 207                                         "failed to cleanup %s: %d\n",
 208                                         dev_name(client->dev), err);
 209                                 mutex_unlock(&device->clients_lock);
 210                                 return err;
 211                         }
 212                 }
 213         }
 214
 215         mutex_unlock(&device->clients_lock);
 216
 217         return 0;
 218 }
 219 EXPORT_SYMBOL(host1x_device_exit);
 220
 221 static int host1x_add_client(struct host1x *host1x,
 222                              struct host1x_client *client)
 223 {
 224         struct host1x_device *device;
 225         struct host1x_subdev *subdev;
 226
 227         mutex_lock(&host1x->devices_lock);
 228
 229         list_for_each_entry(device, &host1x->devices, list) {
 230                 list_for_each_entry(subdev, &device->subdevs, list) {
 231                         if (subdev->np == client->dev->of_node) {
 232                                 host1x_subdev_register(device, subdev, client);
 233                                 mutex_unlock(&host1x->devices_lock);
 234                                 return 0;
 235                         }
 236                 }
 237         }
 238
 239         mutex_unlock(&host1x->devices_lock);
 240         return -ENODEV;
 241 }
 242
 243 static int host1x_del_client(struct host1x *host1x,
 244                              struct host1x_client *client)
 245 {
 246         struct host1x_device *device, *dt;
 247         struct host1x_subdev *subdev;
 248
 249         mutex_lock(&host1x->devices_lock);
 250
 251         list_for_each_entry_safe(device, dt, &host1x->devices, list) {
 252                 list_for_each_entry(subdev, &device->active, list) {
 253                         if (subdev->client == client) {
 254                                 host1x_subdev_unregister(device, subdev);
 255                                 mutex_unlock(&host1x->devices_lock);
 256                                 return 0;
 257                         }
 258                 }
 259         }
 260
 261         mutex_unlock(&host1x->devices_lock);
 262         return -ENODEV;
 263 }
 264
 265 static int host1x_device_match(struct device *dev, struct device_driver *drv)
 266 {
 267         return strcmp(dev_name(dev), drv->name) == 0;
 268 }
 269
 270 static int host1x_device_probe(struct device *dev)
 271 {
 272         struct host1x_driver *driver = to_host1x_driver(dev->driver);
 273         struct host1x_device *device = to_host1x_device(dev);
 274
 275         if (driver->probe)
 276                 return driver->probe(device);
 277
 278         return 0;
 279 }
 280
 281 static int host1x_device_remove(struct device *dev)
 282 {
 283         struct host1x_driver *driver = to_host1x_driver(dev->driver);
 284         struct host1x_device *device = to_host1x_device(dev);
 285
 286         if (driver->remove)
 287                 return driver->remove(device);
 288
 289         return 0;
 290 }
 291
 292 static void host1x_device_shutdown(struct device *dev)
 293 {
 294         struct host1x_driver *driver = to_host1x_driver(dev->driver);
 295         struct host1x_device *device = to_host1x_device(dev);
 296
 297         if (driver->shutdown)
 298                 driver->shutdown(device);
 299 }
 300
 301 static const struct dev_pm_ops host1x_device_pm_ops = {
 302         .suspend = pm_generic_suspend,
 303         .resume = pm_generic_resume,
 304         .freeze = pm_generic_freeze,
 305         .thaw = pm_generic_thaw,
 306         .poweroff = pm_generic_poweroff,
 307         .restore = pm_generic_restore,
 308 };
 309
 310 struct bus_type host1x_bus_type = {
 311         .name = "host1x",
 312         .match = host1x_device_match,
 313         .probe = host1x_device_probe,
 314         .remove = host1x_device_remove,
 315         .shutdown = host1x_device_shutdown,
 316         .pm = &host1x_device_pm_ops,
 317 };
 318
 319 static void __host1x_device_del(struct host1x_device *device)
 320 {
 321         struct host1x_subdev *subdev, *sd;
 322         struct host1x_client *client, *cl;
 323
 324         mutex_lock(&device->subdevs_lock);
 325
 326         /* unregister subdevices */
 327         list_for_each_entry_safe(subdev, sd, &device->active, list) {
 328                 /*
 329                  * host1x_subdev_unregister() will remove the client from
 330                  * any lists, so we'll need to manually add it back to the
 331                  * list of idle clients.
 332                  *
 333                  * XXX: Alternatively, perhaps don't remove the client from
 334                  * any lists in host1x_subdev_unregister() and instead do
 335                  * that explicitly from host1x_unregister_client()?
 336                  */
 337                 client = subdev->client;
 338
 339                 __host1x_subdev_unregister(device, subdev);
 340
 341                 /* add the client to the list of idle clients */
 342                 mutex_lock(&clients_lock);
 343                 list_add_tail(&client->list, &clients);
 344                 mutex_unlock(&clients_lock);
 345         }
 346
 347         /* remove subdevices */
 348         list_for_each_entry_safe(subdev, sd, &device->subdevs, list)
 349                 host1x_subdev_del(subdev);
 350
 351         mutex_unlock(&device->subdevs_lock);
 352
 353         /* move clients to idle list */
 354         mutex_lock(&clients_lock);
 355         mutex_lock(&device->clients_lock);
 356
 357         list_for_each_entry_safe(client, cl, &device->clients, list)
 358                 list_move_tail(&client->list, &clients);
 359
 360         mutex_unlock(&device->clients_lock);
 361         mutex_unlock(&clients_lock);
 362
 363         /* finally remove the device */
 364         list_del_init(&device->list);
 365 }
 366
 367 static void host1x_device_release(struct device *dev)
 368 {
 369         struct host1x_device *device = to_host1x_device(dev);
 370
 371         __host1x_device_del(device);
 372         kfree(device);
 373 }
 374
 375 static int host1x_device_add(struct host1x *host1x,
 376                              struct host1x_driver *driver)
 377 {
 378         struct host1x_client *client, *tmp;
 379         struct host1x_subdev *subdev;
 380         struct host1x_device *device;
 381         int err;
 382
 383         device = kzalloc(sizeof(*device), GFP_KERNEL);
 384         if (!device)
 385                 return -ENOMEM;
 386
 387         device_initialize(&device->dev);
 388
 389         mutex_init(&device->subdevs_lock);
 390         INIT_LIST_HEAD(&device->subdevs);
 391         INIT_LIST_HEAD(&device->active);
 392         mutex_init(&device->clients_lock);
 393         INIT_LIST_HEAD(&device->clients);
 394         INIT_LIST_HEAD(&device->list);
 395         device->driver = driver;
 396
 397         device->dev.coherent_dma_mask = host1x->dev->coherent_dma_mask;
 398         device->dev.dma_mask = &device->dev.coherent_dma_mask;
 399         dev_set_name(&device->dev, "%s", driver->driver.name);
 400         of_dma_configure(&device->dev, host1x->dev->of_node);
 401         device->dev.release = host1x_device_release;
 402         device->dev.bus = &host1x_bus_type;
 403         device->dev.parent = host1x->dev;
 404
 405         err = host1x_device_parse_dt(device, driver);
 406         if (err < 0) {
 407                 kfree(device);
 408                 return err;
 409         }
 410
 411         list_add_tail(&device->list, &host1x->devices);
 412
 413         mutex_lock(&clients_lock);
 414
 415         list_for_each_entry_safe(client, tmp, &clients, list) {
 416                 list_for_each_entry(subdev, &device->subdevs, list) {
 417                         if (subdev->np == client->dev->of_node) {
 418                                 host1x_subdev_register(device, subdev, client);
 419                                 break;
 420                         }
 421                 }
 422         }
 423
 424         mutex_unlock(&clients_lock);
 425
 426         return 0;
 427 }
 428
 429 /*
 430  * Removes a device by first unregistering any subdevices and then removing
 431  * itself from the list of devices.
 432  *
 433  * This function must be called with the host1x->devices_lock held.
 434  */
 435 static void host1x_device_del(struct host1x *host1x,
 436                               struct host1x_device *device)
 437 {
 438         if (device->registered) {
 439                 device->registered = false;
 440                 device_del(&device->dev);
 441         }
 442
 443         put_device(&device->dev);
 444 }
 445
 446 static void host1x_attach_driver(struct host1x *host1x,
 447                                  struct host1x_driver *driver)
 448 {
 449         struct host1x_device *device;
 450         int err;
 451
 452         mutex_lock(&host1x->devices_lock);
 453
 454         list_for_each_entry(device, &host1x->devices, list) {
 455                 if (device->driver == driver) {
 456                         mutex_unlock(&host1x->devices_lock);
 457                         return;
 458                 }
 459         }
 460
 461         err = host1x_device_add(host1x, driver);
 462         if (err < 0)
 463                 dev_err(host1x->dev, "failed to allocate device: %d\n", err);
 464
 465         mutex_unlock(&host1x->devices_lock);
 466 }
 467
 468 static void host1x_detach_driver(struct host1x *host1x,
 469                                  struct host1x_driver *driver)
 470 {
 471         struct host1x_device *device, *tmp;
 472
 473         mutex_lock(&host1x->devices_lock);
 474
 475         list_for_each_entry_safe(device, tmp, &host1x->devices, list)
 476                 if (device->driver == driver)
 477                         host1x_device_del(host1x, device);
 478
 479         mutex_unlock(&host1x->devices_lock);
 480 }
 481
 482 int host1x_register(struct host1x *host1x)
 483 {
 484         struct host1x_driver *driver;
 485
 486         mutex_lock(&devices_lock);
 487         list_add_tail(&host1x->list, &devices);
 488         mutex_unlock(&devices_lock);
 489
 490         mutex_lock(&drivers_lock);
 491
 492         list_for_each_entry(driver, &drivers, list)
 493                 host1x_attach_driver(host1x, driver);
 494
 495         mutex_unlock(&drivers_lock);
 496
 497         return 0;
 498 }
 499
 500 int host1x_unregister(struct host1x *host1x)
 501 {
 502         struct host1x_driver *driver;
 503
 504         mutex_lock(&drivers_lock);
 505
 506         list_for_each_entry(driver, &drivers, list)
 507                 host1x_detach_driver(host1x, driver);
 508
 509         mutex_unlock(&drivers_lock);
 510
 511         mutex_lock(&devices_lock);
 512         list_del_init(&host1x->list);
 513         mutex_unlock(&devices_lock);
 514
 515         return 0;
 516 }
 517
 518 int host1x_driver_register_full(struct host1x_driver *driver,
 519                                 struct module *owner)
 520 {
 521         struct host1x *host1x;
 522
 523         INIT_LIST_HEAD(&driver->list);
 524
 525         mutex_lock(&drivers_lock);
 526         list_add_tail(&driver->list, &drivers);
 527         mutex_unlock(&drivers_lock);
 528
 529         mutex_lock(&devices_lock);
 530
 531         list_for_each_entry(host1x, &devices, list)
 532                 host1x_attach_driver(host1x, driver);
 533
 534         mutex_unlock(&devices_lock);
 535
 536         driver->driver.bus = &host1x_bus_type;
 537         driver->driver.owner = owner;
 538
 539         return driver_register(&driver->driver);
 540 }
 541 EXPORT_SYMBOL(host1x_driver_register_full);
 542
 543 void host1x_driver_unregister(struct host1x_driver *driver)
 544 {
 545         driver_unregister(&driver->driver);
 546
 547         mutex_lock(&drivers_lock);
 548         list_del_init(&driver->list);
 549         mutex_unlock(&drivers_lock);
 550 }
 551 EXPORT_SYMBOL(host1x_driver_unregister);
 552
 553 int host1x_client_register(struct host1x_client *client)
 554 {
 555         struct host1x *host1x;
 556         int err;
 557
 558         mutex_lock(&devices_lock);
 559
 560         list_for_each_entry(host1x, &devices, list) {
 561                 err = host1x_add_client(host1x, client);
 562                 if (!err) {
 563                         mutex_unlock(&devices_lock);
 564                         return 0;
 565                 }
 566         }
 567
 568         mutex_unlock(&devices_lock);
 569
 570         mutex_lock(&clients_lock);
 571         list_add_tail(&client->list, &clients);
 572         mutex_unlock(&clients_lock);
 573
 574         return 0;
 575 }
 576 EXPORT_SYMBOL(host1x_client_register);
 577
 578 int host1x_client_unregister(struct host1x_client *client)
 579 {
 580         struct host1x_client *c;
 581         struct host1x *host1x;
 582         int err;
 583
 584         mutex_lock(&devices_lock);
 585
 586         list_for_each_entry(host1x, &devices, list) {
 587                 err = host1x_del_client(host1x, client);
 588                 if (!err) {
 589                         mutex_unlock(&devices_lock);
 590                         return 0;
 591                 }
 592         }
 593
 594         mutex_unlock(&devices_lock);
 595         mutex_lock(&clients_lock);
 596
 597         list_for_each_entry(c, &clients, list) {
 598                 if (c == client) {
 599                         list_del_init(&c->list);
 600                         break;
 601                 }
 602         }
 603
 604         mutex_unlock(&clients_lock);
 605
 606         return 0;
 607 }
 608 EXPORT_SYMBOL(host1x_client_unregister);