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
  22 #include "bus.h"
  23 #include "dev.h"
  24
  25 static DEFINE_MUTEX(clients_lock);
  26 static LIST_HEAD(clients);
  27
  28 static DEFINE_MUTEX(drivers_lock);
  29 static LIST_HEAD(drivers);
  30
  31 static DEFINE_MUTEX(devices_lock);
  32 static LIST_HEAD(devices);
  33
  34 struct host1x_subdev {
  35         struct host1x_client *client;
  36         struct device_node *np;
  37         struct list_head list;
  38 };
  39
  40 /**
  41  * host1x_subdev_add() - add a new subdevice with an associated device node
  42  */
  43 static int host1x_subdev_add(struct host1x_device *device,
  44                              struct device_node *np)
  45 {
  46         struct host1x_subdev *subdev;
  47
  48         subdev = kzalloc(sizeof(*subdev), GFP_KERNEL);
  49         if (!subdev)
  50                 return -ENOMEM;
  51
  52         INIT_LIST_HEAD(&subdev->list);
  53         subdev->np = of_node_get(np);
  54
  55         mutex_lock(&device->subdevs_lock);
  56         list_add_tail(&subdev->list, &device->subdevs);
  57         mutex_unlock(&device->subdevs_lock);
  58
  59         return 0;
  60 }
  61
  62 /**
  63  * host1x_subdev_del() - remove subdevice
  64  */
  65 static void host1x_subdev_del(struct host1x_subdev *subdev)
  66 {
  67         list_del(&subdev->list);
  68         of_node_put(subdev->np);
  69         kfree(subdev);
  70 }
  71
  72 /**
  73  * host1x_device_parse_dt() - scan device tree and add matching subdevices
  74  */
  75 static int host1x_device_parse_dt(struct host1x_device *device)
  76 {
  77         struct device_node *np;
  78         int err;
  79
  80         for_each_child_of_node(device->dev.parent->of_node, np) {
  81                 if (of_match_node(device->driver->subdevs, np) &&
  82                     of_device_is_available(np)) {
  83                         err = host1x_subdev_add(device, np);
  84                         if (err < 0)
  85                                 return err;
  86                 }
  87         }
  88
  89         return 0;
  90 }
  91
  92 static void host1x_subdev_register(struct host1x_device *device,
  93                                    struct host1x_subdev *subdev,
  94                                    struct host1x_client *client)
  95 {
  96         int err;
  97
  98         /*
  99          * Move the subdevice to the list of active (registered) subdevices
 100          * and associate it with a client. At the same time, associate the
 101          * client with its parent device.
 102          */
 103         mutex_lock(&device->subdevs_lock);
 104         mutex_lock(&device->clients_lock);
 105         list_move_tail(&client->list, &device->clients);
 106         list_move_tail(&subdev->list, &device->active);
 107         client->parent = &device->dev;
 108         subdev->client = client;
 109         mutex_unlock(&device->clients_lock);
 110         mutex_unlock(&device->subdevs_lock);
 111
 112         /*
 113          * When all subdevices have been registered, the composite device is
 114          * ready to be probed.
 115          */
 116         if (list_empty(&device->subdevs)) {
 117                 err = device->driver->probe(device);
 118                 if (err < 0)
 119                         dev_err(&device->dev, "probe failed: %d\n", err);
 120         }
 121 }
 122
 123 static void __host1x_subdev_unregister(struct host1x_device *device,
 124                                        struct host1x_subdev *subdev)
 125 {
 126         struct host1x_client *client = subdev->client;
 127         int err;
 128
 129         /*
 130          * If all subdevices have been activated, we're about to remove the
 131          * first active subdevice, so unload the driver first.
 132          */
 133         if (list_empty(&device->subdevs)) {
 134                 err = device->driver->remove(device);
 135                 if (err < 0)
 136                         dev_err(&device->dev, "remove failed: %d\n", err);
 137         }
 138
 139         /*
 140          * Move the subdevice back to the list of idle subdevices and remove
 141          * it from list of clients.
 142          */
 143         mutex_lock(&device->clients_lock);
 144         subdev->client = NULL;
 145         client->parent = NULL;
 146         list_move_tail(&subdev->list, &device->subdevs);
 147         /*
 148          * XXX: Perhaps don't do this here, but rather explicitly remove it
 149          * when the device is about to be deleted.
 150          *
 151          * This is somewhat complicated by the fact that this function is
 152          * used to remove the subdevice when a client is unregistered but
 153          * also when the composite device is about to be removed.
 154          */
 155         list_del_init(&client->list);
 156         mutex_unlock(&device->clients_lock);
 157 }
 158
 159 static void host1x_subdev_unregister(struct host1x_device *device,
 160                                      struct host1x_subdev *subdev)
 161 {
 162         mutex_lock(&device->subdevs_lock);
 163         __host1x_subdev_unregister(device, subdev);
 164         mutex_unlock(&device->subdevs_lock);
 165 }
 166
 167 int host1x_device_init(struct host1x_device *device)
 168 {
 169         struct host1x_client *client;
 170         int err;
 171
 172         mutex_lock(&device->clients_lock);
 173
 174         list_for_each_entry(client, &device->clients, list) {
 175                 if (client->ops && client->ops->init) {
 176                         err = client->ops->init(client);
 177                         if (err < 0) {
 178                                 dev_err(&device->dev,
 179                                         "failed to initialize %s: %d\n",
 180                                         dev_name(client->dev), err);
 181                                 mutex_unlock(&device->clients_lock);
 182                                 return err;
 183                         }
 184                 }
 185         }
 186
 187         mutex_unlock(&device->clients_lock);
 188
 189         return 0;
 190 }
 191 EXPORT_SYMBOL(host1x_device_init);
 192
 193 int host1x_device_exit(struct host1x_device *device)
 194 {
 195         struct host1x_client *client;
 196         int err;
 197
 198         mutex_lock(&device->clients_lock);
 199
 200         list_for_each_entry_reverse(client, &device->clients, list) {
 201                 if (client->ops && client->ops->exit) {
 202                         err = client->ops->exit(client);
 203                         if (err < 0) {
 204                                 dev_err(&device->dev,
 205                                         "failed to cleanup %s: %d\n",
 206                                         dev_name(client->dev), err);
 207                                 mutex_unlock(&device->clients_lock);
 208                                 return err;
 209                         }
 210                 }
 211         }
 212
 213         mutex_unlock(&device->clients_lock);
 214
 215         return 0;
 216 }
 217 EXPORT_SYMBOL(host1x_device_exit);
 218
 219 static int host1x_add_client(struct host1x *host1x,
 220                              struct host1x_client *client)
 221 {
 222         struct host1x_device *device;
 223         struct host1x_subdev *subdev;
 224
 225         mutex_lock(&host1x->devices_lock);
 226
 227         list_for_each_entry(device, &host1x->devices, list) {
 228                 list_for_each_entry(subdev, &device->subdevs, list) {
 229                         if (subdev->np == client->dev->of_node) {
 230                                 host1x_subdev_register(device, subdev, client);
 231                                 mutex_unlock(&host1x->devices_lock);
 232                                 return 0;
 233                         }
 234                 }
 235         }
 236
 237         mutex_unlock(&host1x->devices_lock);
 238         return -ENODEV;
 239 }
 240
 241 static int host1x_del_client(struct host1x *host1x,
 242                              struct host1x_client *client)
 243 {
 244         struct host1x_device *device, *dt;
 245         struct host1x_subdev *subdev;
 246
 247         mutex_lock(&host1x->devices_lock);
 248
 249         list_for_each_entry_safe(device, dt, &host1x->devices, list) {
 250                 list_for_each_entry(subdev, &device->active, list) {
 251                         if (subdev->client == client) {
 252                                 host1x_subdev_unregister(device, subdev);
 253                                 mutex_unlock(&host1x->devices_lock);
 254                                 return 0;
 255                         }
 256                 }
 257         }
 258
 259         mutex_unlock(&host1x->devices_lock);
 260         return -ENODEV;
 261 }
 262
 263 static struct bus_type host1x_bus_type = {
 264         .name = "host1x",
 265 };
 266
 267 int host1x_bus_init(void)
 268 {
 269         return bus_register(&host1x_bus_type);
 270 }
 271
 272 void host1x_bus_exit(void)
 273 {
 274         bus_unregister(&host1x_bus_type);
 275 }
 276
 277 static void host1x_device_release(struct device *dev)
 278 {
 279         struct host1x_device *device = to_host1x_device(dev);
 280
 281         kfree(device);
 282 }
 283
 284 static int host1x_device_add(struct host1x *host1x,
 285                              struct host1x_driver *driver)
 286 {
 287         struct host1x_client *client, *tmp;
 288         struct host1x_subdev *subdev;
 289         struct host1x_device *device;
 290         int err;
 291
 292         device = kzalloc(sizeof(*device), GFP_KERNEL);
 293         if (!device)
 294                 return -ENOMEM;
 295
 296         mutex_init(&device->subdevs_lock);
 297         INIT_LIST_HEAD(&device->subdevs);
 298         INIT_LIST_HEAD(&device->active);
 299         mutex_init(&device->clients_lock);
 300         INIT_LIST_HEAD(&device->clients);
 301         INIT_LIST_HEAD(&device->list);
 302         device->driver = driver;
 303
 304         device->dev.coherent_dma_mask = host1x->dev->coherent_dma_mask;
 305         device->dev.dma_mask = &device->dev.coherent_dma_mask;
 306         device->dev.release = host1x_device_release;
 307         dev_set_name(&device->dev, "%s", driver->name);
 308         device->dev.bus = &host1x_bus_type;
 309         device->dev.parent = host1x->dev;
 310
 311         err = device_register(&device->dev);
 312         if (err < 0)
 313                 return err;
 314
 315         err = host1x_device_parse_dt(device);
 316         if (err < 0) {
 317                 device_unregister(&device->dev);
 318                 return err;
 319         }
 320
 321         mutex_lock(&host1x->devices_lock);
 322         list_add_tail(&device->list, &host1x->devices);
 323         mutex_unlock(&host1x->devices_lock);
 324
 325         mutex_lock(&clients_lock);
 326
 327         list_for_each_entry_safe(client, tmp, &clients, list) {
 328                 list_for_each_entry(subdev, &device->subdevs, list) {
 329                         if (subdev->np == client->dev->of_node) {
 330                                 host1x_subdev_register(device, subdev, client);
 331                                 break;
 332                         }
 333                 }
 334         }
 335
 336         mutex_unlock(&clients_lock);
 337
 338         return 0;
 339 }
 340
 341 /*
 342  * Removes a device by first unregistering any subdevices and then removing
 343  * itself from the list of devices.
 344  *
 345  * This function must be called with the host1x->devices_lock held.
 346  */
 347 static void host1x_device_del(struct host1x *host1x,
 348                               struct host1x_device *device)
 349 {
 350         struct host1x_subdev *subdev, *sd;
 351         struct host1x_client *client, *cl;
 352
 353         mutex_lock(&device->subdevs_lock);
 354
 355         /* unregister subdevices */
 356         list_for_each_entry_safe(subdev, sd, &device->active, list) {
 357                 /*
 358                  * host1x_subdev_unregister() will remove the client from
 359                  * any lists, so we'll need to manually add it back to the
 360                  * list of idle clients.
 361                  *
 362                  * XXX: Alternatively, perhaps don't remove the client from
 363                  * any lists in host1x_subdev_unregister() and instead do
 364                  * that explicitly from host1x_unregister_client()?
 365                  */
 366                 client = subdev->client;
 367
 368                 __host1x_subdev_unregister(device, subdev);
 369
 370                 /* add the client to the list of idle clients */
 371                 mutex_lock(&clients_lock);
 372                 list_add_tail(&client->list, &clients);
 373                 mutex_unlock(&clients_lock);
 374         }
 375
 376         /* remove subdevices */
 377         list_for_each_entry_safe(subdev, sd, &device->subdevs, list)
 378                 host1x_subdev_del(subdev);
 379
 380         mutex_unlock(&device->subdevs_lock);
 381
 382         /* move clients to idle list */
 383         mutex_lock(&clients_lock);
 384         mutex_lock(&device->clients_lock);
 385
 386         list_for_each_entry_safe(client, cl, &device->clients, list)
 387                 list_move_tail(&client->list, &clients);
 388
 389         mutex_unlock(&device->clients_lock);
 390         mutex_unlock(&clients_lock);
 391
 392         /* finally remove the device */
 393         list_del_init(&device->list);
 394         device_unregister(&device->dev);
 395 }
 396
 397 static void host1x_attach_driver(struct host1x *host1x,
 398                                  struct host1x_driver *driver)
 399 {
 400         struct host1x_device *device;
 401         int err;
 402
 403         mutex_lock(&host1x->devices_lock);
 404
 405         list_for_each_entry(device, &host1x->devices, list) {
 406                 if (device->driver == driver) {
 407                         mutex_unlock(&host1x->devices_lock);
 408                         return;
 409                 }
 410         }
 411
 412         mutex_unlock(&host1x->devices_lock);
 413
 414         err = host1x_device_add(host1x, driver);
 415         if (err < 0)
 416                 dev_err(host1x->dev, "failed to allocate device: %d\n", err);
 417 }
 418
 419 static void host1x_detach_driver(struct host1x *host1x,
 420                                  struct host1x_driver *driver)
 421 {
 422         struct host1x_device *device, *tmp;
 423
 424         mutex_lock(&host1x->devices_lock);
 425
 426         list_for_each_entry_safe(device, tmp, &host1x->devices, list)
 427                 if (device->driver == driver)
 428                         host1x_device_del(host1x, device);
 429
 430         mutex_unlock(&host1x->devices_lock);
 431 }
 432
 433 int host1x_register(struct host1x *host1x)
 434 {
 435         struct host1x_driver *driver;
 436
 437         mutex_lock(&devices_lock);
 438         list_add_tail(&host1x->list, &devices);
 439         mutex_unlock(&devices_lock);
 440
 441         mutex_lock(&drivers_lock);
 442
 443         list_for_each_entry(driver, &drivers, list)
 444                 host1x_attach_driver(host1x, driver);
 445
 446         mutex_unlock(&drivers_lock);
 447
 448         return 0;
 449 }
 450
 451 int host1x_unregister(struct host1x *host1x)
 452 {
 453         struct host1x_driver *driver;
 454
 455         mutex_lock(&drivers_lock);
 456
 457         list_for_each_entry(driver, &drivers, list)
 458                 host1x_detach_driver(host1x, driver);
 459
 460         mutex_unlock(&drivers_lock);
 461
 462         mutex_lock(&devices_lock);
 463         list_del_init(&host1x->list);
 464         mutex_unlock(&devices_lock);
 465
 466         return 0;
 467 }
 468
 469 int host1x_driver_register(struct host1x_driver *driver)
 470 {
 471         struct host1x *host1x;
 472
 473         INIT_LIST_HEAD(&driver->list);
 474
 475         mutex_lock(&drivers_lock);
 476         list_add_tail(&driver->list, &drivers);
 477         mutex_unlock(&drivers_lock);
 478
 479         mutex_lock(&devices_lock);
 480
 481         list_for_each_entry(host1x, &devices, list)
 482                 host1x_attach_driver(host1x, driver);
 483
 484         mutex_unlock(&devices_lock);
 485
 486         return 0;
 487 }
 488 EXPORT_SYMBOL(host1x_driver_register);
 489
 490 void host1x_driver_unregister(struct host1x_driver *driver)
 491 {
 492         mutex_lock(&drivers_lock);
 493         list_del_init(&driver->list);
 494         mutex_unlock(&drivers_lock);
 495 }
 496 EXPORT_SYMBOL(host1x_driver_unregister);
 497
 498 int host1x_client_register(struct host1x_client *client)
 499 {
 500         struct host1x *host1x;
 501         int err;
 502
 503         mutex_lock(&devices_lock);
 504
 505         list_for_each_entry(host1x, &devices, list) {
 506                 err = host1x_add_client(host1x, client);
 507                 if (!err) {
 508                         mutex_unlock(&devices_lock);
 509                         return 0;
 510                 }
 511         }
 512
 513         mutex_unlock(&devices_lock);
 514
 515         mutex_lock(&clients_lock);
 516         list_add_tail(&client->list, &clients);
 517         mutex_unlock(&clients_lock);
 518
 519         return 0;
 520 }
 521 EXPORT_SYMBOL(host1x_client_register);
 522
 523 int host1x_client_unregister(struct host1x_client *client)
 524 {
 525         struct host1x_client *c;
 526         struct host1x *host1x;
 527         int err;
 528
 529         mutex_lock(&devices_lock);
 530
 531         list_for_each_entry(host1x, &devices, list) {
 532                 err = host1x_del_client(host1x, client);
 533                 if (!err) {
 534                         mutex_unlock(&devices_lock);
 535                         return 0;
 536                 }
 537         }
 538
 539         mutex_unlock(&devices_lock);
 540         mutex_lock(&clients_lock);
 541
 542         list_for_each_entry(c, &clients, list) {
 543                 if (c == client) {
 544                         list_del_init(&c->list);
 545                         break;
 546                 }
 547         }
 548
 549         mutex_unlock(&clients_lock);
 550
 551         return 0;
 552 }
 553 EXPORT_SYMBOL(host1x_client_unregister);