Pileus Git - ~andy/linux/blob - 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 "dev.h"
  23
  24 static DEFINE_MUTEX(clients_lock);
  25 static LIST_HEAD(clients);
  26
  27 static DEFINE_MUTEX(drivers_lock);
  28 static LIST_HEAD(drivers);
  29
  30 static DEFINE_MUTEX(devices_lock);
  31 static LIST_HEAD(devices);
  32
  33 struct host1x_subdev {
  34         struct host1x_client *client;
  35         struct device_node *np;
  36         struct list_head list;
  37 };
  38
  39 /**
  40  * host1x_subdev_add() - add a new subdevice with an associated device node
  41  */
  42 static int host1x_subdev_add(struct host1x_device *device,
  43                              struct device_node *np)
  44 {
  45         struct host1x_subdev *subdev;
  46
  47         subdev = kzalloc(sizeof(*subdev), GFP_KERNEL);
  48         if (!subdev)
  49                 return -ENOMEM;
  50
  51         INIT_LIST_HEAD(&subdev->list);
  52         subdev->np = of_node_get(np);
  53
  54         mutex_lock(&device->subdevs_lock);
  55         list_add_tail(&subdev->list, &device->subdevs);
  56         mutex_unlock(&device->subdevs_lock);
  57
  58         return 0;
  59 }
  60
  61 /**
  62  * host1x_subdev_del() - remove subdevice
  63  */
  64 static void host1x_subdev_del(struct host1x_subdev *subdev)
  65 {
  66         list_del(&subdev->list);
  67         of_node_put(subdev->np);
  68         kfree(subdev);
  69 }
  70
  71 /**
  72  * host1x_device_parse_dt() - scan device tree and add matching subdevices
  73  */
  74 static int host1x_device_parse_dt(struct host1x_device *device)
  75 {
  76         struct device_node *np;
  77         int err;
  78
  79         for_each_child_of_node(device->dev.parent->of_node, np) {
  80                 if (of_match_node(device->driver->subdevs, np) &&
  81                     of_device_is_available(np)) {
  82                         err = host1x_subdev_add(device, np);
  83                         if (err < 0)
  84                                 return err;
  85                 }
  86         }
  87
  88         return 0;
  89 }
  90
  91 static void host1x_subdev_register(struct host1x_device *device,
  92                                    struct host1x_subdev *subdev,
  93                                    struct host1x_client *client)
  94 {
  95         int err;
  96
  97         /*
  98          * Move the subdevice to the list of active (registered) subdevices
  99          * and associate it with a client. At the same time, associate the
 100          * client with its parent device.
 101          */
 102         mutex_lock(&device->subdevs_lock);
 103         mutex_lock(&device->clients_lock);
 104         list_move_tail(&client->list, &device->clients);
 105         list_move_tail(&subdev->list, &device->active);
 106         client->parent = &device->dev;
 107         subdev->client = client;
 108         mutex_unlock(&device->clients_lock);
 109         mutex_unlock(&device->subdevs_lock);
 110
 111         /*
 112          * When all subdevices have been registered, the composite device is
 113          * ready to be probed.
 114          */
 115         if (list_empty(&device->subdevs)) {
 116                 err = device->driver->probe(device);
 117                 if (err < 0)
 118                         dev_err(&device->dev, "probe failed: %d\n", err);
 119         }
 120 }
 121
 122 static void __host1x_subdev_unregister(struct host1x_device *device,
 123                                        struct host1x_subdev *subdev)
 124 {
 125         struct host1x_client *client = subdev->client;
 126         int err;
 127
 128         /*
 129          * If all subdevices have been activated, we're about to remove the
 130          * first active subdevice, so unload the driver first.
 131          */
 132         if (list_empty(&device->subdevs)) {
 133                 err = device->driver->remove(device);
 134                 if (err < 0)
 135                         dev_err(&device->dev, "remove failed: %d\n", err);
 136         }
 137
 138         /*
 139          * Move the subdevice back to the list of idle subdevices and remove
 140          * it from list of clients.
 141          */
 142         mutex_lock(&device->clients_lock);
 143         subdev->client = NULL;
 144         client->parent = NULL;
 145         list_move_tail(&subdev->list, &device->subdevs);
 146         /*
 147          * XXX: Perhaps don't do this here, but rather explicitly remove it
 148          * when the device is about to be deleted.
 149          *
 150          * This is somewhat complicated by the fact that this function is
 151          * used to remove the subdevice when a client is unregistered but
 152          * also when the composite device is about to be removed.
 153          */
 154         list_del_init(&client->list);
 155         mutex_unlock(&device->clients_lock);
 156 }
 157
 158 static void host1x_subdev_unregister(struct host1x_device *device,
 159                                      struct host1x_subdev *subdev)
 160 {
 161         mutex_lock(&device->subdevs_lock);
 162         __host1x_subdev_unregister(device, subdev);
 163         mutex_unlock(&device->subdevs_lock);
 164 }
 165
 166 int host1x_device_init(struct host1x_device *device)
 167 {
 168         struct host1x_client *client;
 169         int err;
 170
 171         mutex_lock(&device->clients_lock);
 172
 173         list_for_each_entry(client, &device->clients, list) {
 174                 if (client->ops && client->ops->init) {
 175                         err = client->ops->init(client);
 176                         if (err < 0) {
 177                                 dev_err(&device->dev,
 178                                         "failed to initialize %s: %d\n",
 179                                         dev_name(client->dev), err);
 180                                 mutex_unlock(&device->clients_lock);
 181                                 return err;
 182                         }
 183                 }
 184         }
 185
 186         mutex_unlock(&device->clients_lock);
 187
 188         return 0;
 189 }
 190
 191 int host1x_device_exit(struct host1x_device *device)
 192 {
 193         struct host1x_client *client;
 194         int err;
 195
 196         mutex_lock(&device->clients_lock);
 197
 198         list_for_each_entry_reverse(client, &device->clients, list) {
 199                 if (client->ops && client->ops->exit) {
 200                         err = client->ops->exit(client);
 201                         if (err < 0) {
 202                                 dev_err(&device->dev,
 203                                         "failed to cleanup %s: %d\n",
 204                                         dev_name(client->dev), err);
 205                                 mutex_unlock(&device->clients_lock);
 206                                 return err;
 207                         }
 208                 }
 209         }
 210
 211         mutex_unlock(&device->clients_lock);
 212
 213         return 0;
 214 }
 215
 216 static int host1x_register_client(struct host1x *host1x,
 217                                   struct host1x_client *client)
 218 {
 219         struct host1x_device *device;
 220         struct host1x_subdev *subdev;
 221
 222         mutex_lock(&host1x->devices_lock);
 223
 224         list_for_each_entry(device, &host1x->devices, list) {
 225                 list_for_each_entry(subdev, &device->subdevs, list) {
 226                         if (subdev->np == client->dev->of_node) {
 227                                 host1x_subdev_register(device, subdev, client);
 228                                 mutex_unlock(&host1x->devices_lock);
 229                                 return 0;
 230                         }
 231                 }
 232         }
 233
 234         mutex_unlock(&host1x->devices_lock);
 235         return -ENODEV;
 236 }
 237
 238 static int host1x_unregister_client(struct host1x *host1x,
 239                                     struct host1x_client *client)
 240 {
 241         struct host1x_device *device, *dt;
 242         struct host1x_subdev *subdev;
 243
 244         mutex_lock(&host1x->devices_lock);
 245
 246         list_for_each_entry_safe(device, dt, &host1x->devices, list) {
 247                 list_for_each_entry(subdev, &device->active, list) {
 248                         if (subdev->client == client) {
 249                                 host1x_subdev_unregister(device, subdev);
 250                                 mutex_unlock(&host1x->devices_lock);
 251                                 return 0;
 252                         }
 253                 }
 254         }
 255
 256         mutex_unlock(&host1x->devices_lock);
 257         return -ENODEV;
 258 }
 259
 260 struct bus_type host1x_bus_type = {
 261         .name = "host1x",
 262 };
 263
 264 int host1x_bus_init(void)
 265 {
 266         return bus_register(&host1x_bus_type);
 267 }
 268
 269 void host1x_bus_exit(void)
 270 {
 271         bus_unregister(&host1x_bus_type);
 272 }
 273
 274 static void host1x_device_release(struct device *dev)
 275 {
 276         struct host1x_device *device = to_host1x_device(dev);
 277
 278         kfree(device);
 279 }
 280
 281 static int host1x_device_add(struct host1x *host1x,
 282                              struct host1x_driver *driver)
 283 {
 284         struct host1x_client *client, *tmp;
 285         struct host1x_subdev *subdev;
 286         struct host1x_device *device;
 287         int err;
 288
 289         device = kzalloc(sizeof(*device), GFP_KERNEL);
 290         if (!device)
 291                 return -ENOMEM;
 292
 293         mutex_init(&device->subdevs_lock);
 294         INIT_LIST_HEAD(&device->subdevs);
 295         INIT_LIST_HEAD(&device->active);
 296         mutex_init(&device->clients_lock);
 297         INIT_LIST_HEAD(&device->clients);
 298         INIT_LIST_HEAD(&device->list);
 299         device->driver = driver;
 300
 301         device->dev.coherent_dma_mask = host1x->dev->coherent_dma_mask;
 302         device->dev.dma_mask = &device->dev.coherent_dma_mask;
 303         device->dev.release = host1x_device_release;
 304         dev_set_name(&device->dev, driver->name);
 305         device->dev.bus = &host1x_bus_type;
 306         device->dev.parent = host1x->dev;
 307
 308         err = device_register(&device->dev);
 309         if (err < 0)
 310                 return err;
 311
 312         err = host1x_device_parse_dt(device);
 313         if (err < 0) {
 314                 device_unregister(&device->dev);
 315                 return err;
 316         }
 317
 318         mutex_lock(&host1x->devices_lock);
 319         list_add_tail(&device->list, &host1x->devices);
 320         mutex_unlock(&host1x->devices_lock);
 321
 322         mutex_lock(&clients_lock);
 323
 324         list_for_each_entry_safe(client, tmp, &clients, list) {
 325                 list_for_each_entry(subdev, &device->subdevs, list) {
 326                         if (subdev->np == client->dev->of_node) {
 327                                 host1x_subdev_register(device, subdev, client);
 328                                 break;
 329                         }
 330                 }
 331         }
 332
 333         mutex_unlock(&clients_lock);
 334
 335         return 0;
 336 }
 337
 338 /*
 339  * Removes a device by first unregistering any subdevices and then removing
 340  * itself from the list of devices.
 341  *
 342  * This function must be called with the host1x->devices_lock held.
 343  */
 344 static void host1x_device_del(struct host1x *host1x,
 345                               struct host1x_device *device)
 346 {
 347         struct host1x_subdev *subdev, *sd;
 348         struct host1x_client *client, *cl;
 349
 350         mutex_lock(&device->subdevs_lock);
 351
 352         /* unregister subdevices */
 353         list_for_each_entry_safe(subdev, sd, &device->active, list) {
 354                 /*
 355                  * host1x_subdev_unregister() will remove the client from
 356                  * any lists, so we'll need to manually add it back to the
 357                  * list of idle clients.
 358                  *
 359                  * XXX: Alternatively, perhaps don't remove the client from
 360                  * any lists in host1x_subdev_unregister() and instead do
 361                  * that explicitly from host1x_unregister_client()?
 362                  */
 363                 client = subdev->client;
 364
 365                 __host1x_subdev_unregister(device, subdev);
 366
 367                 /* add the client to the list of idle clients */
 368                 mutex_lock(&clients_lock);
 369                 list_add_tail(&client->list, &clients);
 370                 mutex_unlock(&clients_lock);
 371         }
 372
 373         /* remove subdevices */
 374         list_for_each_entry_safe(subdev, sd, &device->subdevs, list)
 375                 host1x_subdev_del(subdev);
 376
 377         mutex_unlock(&device->subdevs_lock);
 378
 379         /* move clients to idle list */
 380         mutex_lock(&clients_lock);
 381         mutex_lock(&device->clients_lock);
 382
 383         list_for_each_entry_safe(client, cl, &device->clients, list)
 384                 list_move_tail(&client->list, &clients);
 385
 386         mutex_unlock(&device->clients_lock);
 387         mutex_unlock(&clients_lock);
 388
 389         /* finally remove the device */
 390         list_del_init(&device->list);
 391         device_unregister(&device->dev);
 392 }
 393
 394 static void host1x_attach_driver(struct host1x *host1x,
 395                                  struct host1x_driver *driver)
 396 {
 397         struct host1x_device *device;
 398         int err;
 399
 400         mutex_lock(&host1x->devices_lock);
 401
 402         list_for_each_entry(device, &host1x->devices, list) {
 403                 if (device->driver == driver) {
 404                         mutex_unlock(&host1x->devices_lock);
 405                         return;
 406                 }
 407         }
 408
 409         mutex_unlock(&host1x->devices_lock);
 410
 411         err = host1x_device_add(host1x, driver);
 412         if (err < 0)
 413                 dev_err(host1x->dev, "failed to allocate device: %d\n", err);
 414 }
 415
 416 static void host1x_detach_driver(struct host1x *host1x,
 417                                  struct host1x_driver *driver)
 418 {
 419         struct host1x_device *device, *tmp;
 420
 421         mutex_lock(&host1x->devices_lock);
 422
 423         list_for_each_entry_safe(device, tmp, &host1x->devices, list)
 424                 if (device->driver == driver)
 425                         host1x_device_del(host1x, device);
 426
 427         mutex_unlock(&host1x->devices_lock);
 428 }
 429
 430 int host1x_register(struct host1x *host1x)
 431 {
 432         struct host1x_driver *driver;
 433
 434         mutex_lock(&devices_lock);
 435         list_add_tail(&host1x->list, &devices);
 436         mutex_unlock(&devices_lock);
 437
 438         mutex_lock(&drivers_lock);
 439
 440         list_for_each_entry(driver, &drivers, list)
 441                 host1x_attach_driver(host1x, driver);
 442
 443         mutex_unlock(&drivers_lock);
 444
 445         return 0;
 446 }
 447
 448 int host1x_unregister(struct host1x *host1x)
 449 {
 450         struct host1x_driver *driver;
 451
 452         mutex_lock(&drivers_lock);
 453
 454         list_for_each_entry(driver, &drivers, list)
 455                 host1x_detach_driver(host1x, driver);
 456
 457         mutex_unlock(&drivers_lock);
 458
 459         mutex_lock(&devices_lock);
 460         list_del_init(&host1x->list);
 461         mutex_unlock(&devices_lock);
 462
 463         return 0;
 464 }
 465
 466 int host1x_driver_register(struct host1x_driver *driver)
 467 {
 468         struct host1x *host1x;
 469
 470         INIT_LIST_HEAD(&driver->list);
 471
 472         mutex_lock(&drivers_lock);
 473         list_add_tail(&driver->list, &drivers);
 474         mutex_unlock(&drivers_lock);
 475
 476         mutex_lock(&devices_lock);
 477
 478         list_for_each_entry(host1x, &devices, list)
 479                 host1x_attach_driver(host1x, driver);
 480
 481         mutex_unlock(&devices_lock);
 482
 483         return 0;
 484 }
 485 EXPORT_SYMBOL(host1x_driver_register);
 486
 487 void host1x_driver_unregister(struct host1x_driver *driver)
 488 {
 489         mutex_lock(&drivers_lock);
 490         list_del_init(&driver->list);
 491         mutex_unlock(&drivers_lock);
 492 }
 493 EXPORT_SYMBOL(host1x_driver_unregister);
 494
 495 int host1x_client_register(struct host1x_client *client)
 496 {
 497         struct host1x *host1x;
 498         int err;
 499
 500         mutex_lock(&devices_lock);
 501
 502         list_for_each_entry(host1x, &devices, list) {
 503                 err = host1x_register_client(host1x, client);
 504                 if (!err) {
 505                         mutex_unlock(&devices_lock);
 506                         return 0;
 507                 }
 508         }
 509
 510         mutex_unlock(&devices_lock);
 511
 512         mutex_lock(&clients_lock);
 513         list_add_tail(&client->list, &clients);
 514         mutex_unlock(&clients_lock);
 515
 516         return 0;
 517 }
 518 EXPORT_SYMBOL(host1x_client_register);
 519
 520 int host1x_client_unregister(struct host1x_client *client)
 521 {
 522         struct host1x_client *c;
 523         struct host1x *host1x;
 524         int err;
 525
 526         mutex_lock(&devices_lock);
 527
 528         list_for_each_entry(host1x, &devices, list) {
 529                 err = host1x_unregister_client(host1x, client);
 530                 if (!err) {
 531                         mutex_unlock(&devices_lock);
 532                         return 0;
 533                 }
 534         }
 535
 536         mutex_unlock(&devices_lock);
 537         mutex_lock(&clients_lock);
 538
 539         list_for_each_entry(c, &clients, list) {
 540                 if (c == client) {
 541                         list_del_init(&c->list);
 542                         break;
 543                 }
 544         }
 545
 546         mutex_unlock(&clients_lock);
 547
 548         return 0;
 549 }
 550 EXPORT_SYMBOL(host1x_client_unregister);