drivers/gpu/vga/vga_switcheroo.c

   1 /*
   2  * Copyright (c) 2010 Red Hat Inc.
   3  * Author : Dave Airlie <airlied@redhat.com>
   4  *
   5  *
   6  * Licensed under GPLv2
   7  *
   8  * vga_switcheroo.c - Support for laptop with dual GPU using one set of outputs
   9
  10  Switcher interface - methods require for ATPX and DCM
  11  - switchto - this throws the output MUX switch
  12  - discrete_set_power - sets the power state for the discrete card
  13
  14  GPU driver interface
  15  - set_gpu_state - this should do the equiv of s/r for the card
  16                   - this should *not* set the discrete power state
  17  - switch_check  - check if the device is in a position to switch now
  18  */
  19
  20 #include <linux/module.h>
  21 #include <linux/seq_file.h>
  22 #include <linux/uaccess.h>
  23 #include <linux/fs.h>
  24 #include <linux/debugfs.h>
  25 #include <linux/fb.h>
  26
  27 #include <linux/pci.h>
  28 #include <linux/console.h>
  29 #include <linux/vga_switcheroo.h>
  30 #include <linux/pm_runtime.h>
  31
  32 #include <linux/vgaarb.h>
  33
  34 struct vga_switcheroo_client {
  35         struct pci_dev *pdev;
  36         struct fb_info *fb_info;
  37         int pwr_state;
  38         const struct vga_switcheroo_client_ops *ops;
  39         int id;
  40         bool active;
  41         bool driver_power_control;
  42         struct list_head list;
  43 };
  44
  45 static DEFINE_MUTEX(vgasr_mutex);
  46
  47 struct vgasr_priv {
  48
  49         bool active;
  50         bool delayed_switch_active;
  51         enum vga_switcheroo_client_id delayed_client_id;
  52
  53         struct dentry *debugfs_root;
  54         struct dentry *switch_file;
  55
  56         int registered_clients;
  57         struct list_head clients;
  58
  59         struct vga_switcheroo_handler *handler;
  60 };
  61
  62 #define ID_BIT_AUDIO            0x100
  63 #define client_is_audio(c)      ((c)->id & ID_BIT_AUDIO)
  64 #define client_is_vga(c)        ((c)->id == -1 || !client_is_audio(c))
  65 #define client_id(c)            ((c)->id & ~ID_BIT_AUDIO)
  66
  67 static int vga_switcheroo_debugfs_init(struct vgasr_priv *priv);
  68 static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv);
  69
  70 /* only one switcheroo per system */
  71 static struct vgasr_priv vgasr_priv = {
  72         .clients = LIST_HEAD_INIT(vgasr_priv.clients),
  73 };
  74
  75 static bool vga_switcheroo_ready(void)
  76 {
  77         /* we're ready if we get two clients + handler */
  78         return !vgasr_priv.active &&
  79                vgasr_priv.registered_clients == 2 && vgasr_priv.handler;
  80 }
  81
  82 static void vga_switcheroo_enable(void)
  83 {
  84         int ret;
  85         struct vga_switcheroo_client *client;
  86
  87         /* call the handler to init */
  88         if (vgasr_priv.handler->init)
  89                 vgasr_priv.handler->init();
  90
  91         list_for_each_entry(client, &vgasr_priv.clients, list) {
  92                 if (client->id != -1)
  93                         continue;
  94                 ret = vgasr_priv.handler->get_client_id(client->pdev);
  95                 if (ret < 0)
  96                         return;
  97
  98                 client->id = ret;
  99         }
 100         vga_switcheroo_debugfs_init(&vgasr_priv);
 101         vgasr_priv.active = true;
 102 }
 103
 104 int vga_switcheroo_register_handler(struct vga_switcheroo_handler *handler)
 105 {
 106         mutex_lock(&vgasr_mutex);
 107         if (vgasr_priv.handler) {
 108                 mutex_unlock(&vgasr_mutex);
 109                 return -EINVAL;
 110         }
 111
 112         vgasr_priv.handler = handler;
 113         if (vga_switcheroo_ready()) {
 114                 printk(KERN_INFO "vga_switcheroo: enabled\n");
 115                 vga_switcheroo_enable();
 116         }
 117         mutex_unlock(&vgasr_mutex);
 118         return 0;
 119 }
 120 EXPORT_SYMBOL(vga_switcheroo_register_handler);
 121
 122 void vga_switcheroo_unregister_handler(void)
 123 {
 124         mutex_lock(&vgasr_mutex);
 125         vgasr_priv.handler = NULL;
 126         if (vgasr_priv.active) {
 127                 pr_info("vga_switcheroo: disabled\n");
 128                 vga_switcheroo_debugfs_fini(&vgasr_priv);
 129                 vgasr_priv.active = false;
 130         }
 131         mutex_unlock(&vgasr_mutex);
 132 }
 133 EXPORT_SYMBOL(vga_switcheroo_unregister_handler);
 134
 135 static int register_client(struct pci_dev *pdev,
 136                            const struct vga_switcheroo_client_ops *ops,
 137                            int id, bool active, bool driver_power_control)
 138 {
 139         struct vga_switcheroo_client *client;
 140
 141         client = kzalloc(sizeof(*client), GFP_KERNEL);
 142         if (!client)
 143                 return -ENOMEM;
 144
 145         client->pwr_state = VGA_SWITCHEROO_ON;
 146         client->pdev = pdev;
 147         client->ops = ops;
 148         client->id = id;
 149         client->active = active;
 150         client->driver_power_control = driver_power_control;
 151
 152         mutex_lock(&vgasr_mutex);
 153         list_add_tail(&client->list, &vgasr_priv.clients);
 154         if (client_is_vga(client))
 155                 vgasr_priv.registered_clients++;
 156
 157         if (vga_switcheroo_ready()) {
 158                 printk(KERN_INFO "vga_switcheroo: enabled\n");
 159                 vga_switcheroo_enable();
 160         }
 161         mutex_unlock(&vgasr_mutex);
 162         return 0;
 163 }
 164
 165 int vga_switcheroo_register_client(struct pci_dev *pdev,
 166                                    const struct vga_switcheroo_client_ops *ops,
 167                                    bool driver_power_control)
 168 {
 169         return register_client(pdev, ops, -1,
 170                                pdev == vga_default_device(), driver_power_control);
 171 }
 172 EXPORT_SYMBOL(vga_switcheroo_register_client);
 173
 174 int vga_switcheroo_register_audio_client(struct pci_dev *pdev,
 175                                          const struct vga_switcheroo_client_ops *ops,
 176                                          int id, bool active)
 177 {
 178         return register_client(pdev, ops, id | ID_BIT_AUDIO, active, false);
 179 }
 180 EXPORT_SYMBOL(vga_switcheroo_register_audio_client);
 181
 182 static struct vga_switcheroo_client *
 183 find_client_from_pci(struct list_head *head, struct pci_dev *pdev)
 184 {
 185         struct vga_switcheroo_client *client;
 186         list_for_each_entry(client, head, list)
 187                 if (client->pdev == pdev)
 188                         return client;
 189         return NULL;
 190 }
 191
 192 static struct vga_switcheroo_client *
 193 find_client_from_id(struct list_head *head, int client_id)
 194 {
 195         struct vga_switcheroo_client *client;
 196         list_for_each_entry(client, head, list)
 197                 if (client->id == client_id)
 198                         return client;
 199         return NULL;
 200 }
 201
 202 static struct vga_switcheroo_client *
 203 find_active_client(struct list_head *head)
 204 {
 205         struct vga_switcheroo_client *client;
 206         list_for_each_entry(client, head, list)
 207                 if (client->active && client_is_vga(client))
 208                         return client;
 209         return NULL;
 210 }
 211
 212 int vga_switcheroo_get_client_state(struct pci_dev *pdev)
 213 {
 214         struct vga_switcheroo_client *client;
 215
 216         client = find_client_from_pci(&vgasr_priv.clients, pdev);
 217         if (!client)
 218                 return VGA_SWITCHEROO_NOT_FOUND;
 219         if (!vgasr_priv.active)
 220                 return VGA_SWITCHEROO_INIT;
 221         return client->pwr_state;
 222 }
 223 EXPORT_SYMBOL(vga_switcheroo_get_client_state);
 224
 225 void vga_switcheroo_unregister_client(struct pci_dev *pdev)
 226 {
 227         struct vga_switcheroo_client *client;
 228
 229         mutex_lock(&vgasr_mutex);
 230         client = find_client_from_pci(&vgasr_priv.clients, pdev);
 231         if (client) {
 232                 if (client_is_vga(client))
 233                         vgasr_priv.registered_clients--;
 234                 list_del(&client->list);
 235                 kfree(client);
 236         }
 237         if (vgasr_priv.active && vgasr_priv.registered_clients < 2) {
 238                 printk(KERN_INFO "vga_switcheroo: disabled\n");
 239                 vga_switcheroo_debugfs_fini(&vgasr_priv);
 240                 vgasr_priv.active = false;
 241         }
 242         mutex_unlock(&vgasr_mutex);
 243 }
 244 EXPORT_SYMBOL(vga_switcheroo_unregister_client);
 245
 246 void vga_switcheroo_client_fb_set(struct pci_dev *pdev,
 247                                  struct fb_info *info)
 248 {
 249         struct vga_switcheroo_client *client;
 250
 251         mutex_lock(&vgasr_mutex);
 252         client = find_client_from_pci(&vgasr_priv.clients, pdev);
 253         if (client)
 254                 client->fb_info = info;
 255         mutex_unlock(&vgasr_mutex);
 256 }
 257 EXPORT_SYMBOL(vga_switcheroo_client_fb_set);
 258
 259 static int vga_switcheroo_show(struct seq_file *m, void *v)
 260 {
 261         struct vga_switcheroo_client *client;
 262         int i = 0;
 263         mutex_lock(&vgasr_mutex);
 264         list_for_each_entry(client, &vgasr_priv.clients, list) {
 265                 seq_printf(m, "%d:%s%s:%c:%s%s:%s\n", i,
 266                            client_id(client) == VGA_SWITCHEROO_DIS ? "DIS" : "IGD",
 267                            client_is_vga(client) ? "" : "-Audio",
 268                            client->active ? '+' : ' ',
 269                            client->driver_power_control ? "Dyn" : "",
 270                            client->pwr_state ? "Pwr" : "Off",
 271                            pci_name(client->pdev));
 272                 i++;
 273         }
 274         mutex_unlock(&vgasr_mutex);
 275         return 0;
 276 }
 277
 278 static int vga_switcheroo_debugfs_open(struct inode *inode, struct file *file)
 279 {
 280         return single_open(file, vga_switcheroo_show, NULL);
 281 }
 282
 283 static int vga_switchon(struct vga_switcheroo_client *client)
 284 {
 285         if (client->driver_power_control)
 286                 return 0;
 287         if (vgasr_priv.handler->power_state)
 288                 vgasr_priv.handler->power_state(client->id, VGA_SWITCHEROO_ON);
 289         /* call the driver callback to turn on device */
 290         client->ops->set_gpu_state(client->pdev, VGA_SWITCHEROO_ON);
 291         client->pwr_state = VGA_SWITCHEROO_ON;
 292         return 0;
 293 }
 294
 295 static int vga_switchoff(struct vga_switcheroo_client *client)
 296 {
 297         if (client->driver_power_control)
 298                 return 0;
 299         /* call the driver callback to turn off device */
 300         client->ops->set_gpu_state(client->pdev, VGA_SWITCHEROO_OFF);
 301         if (vgasr_priv.handler->power_state)
 302                 vgasr_priv.handler->power_state(client->id, VGA_SWITCHEROO_OFF);
 303         client->pwr_state = VGA_SWITCHEROO_OFF;
 304         return 0;
 305 }
 306
 307 static void set_audio_state(int id, int state)
 308 {
 309         struct vga_switcheroo_client *client;
 310
 311         client = find_client_from_id(&vgasr_priv.clients, id | ID_BIT_AUDIO);
 312         if (client && client->pwr_state != state) {
 313                 client->ops->set_gpu_state(client->pdev, state);
 314                 client->pwr_state = state;
 315         }
 316 }
 317
 318 /* stage one happens before delay */
 319 static int vga_switchto_stage1(struct vga_switcheroo_client *new_client)
 320 {
 321         struct vga_switcheroo_client *active;
 322
 323         active = find_active_client(&vgasr_priv.clients);
 324         if (!active)
 325                 return 0;
 326
 327         if (new_client->pwr_state == VGA_SWITCHEROO_OFF)
 328                 vga_switchon(new_client);
 329
 330         vga_set_default_device(new_client->pdev);
 331         return 0;
 332 }
 333
 334 /* post delay */
 335 static int vga_switchto_stage2(struct vga_switcheroo_client *new_client)
 336 {
 337         int ret;
 338         struct vga_switcheroo_client *active;
 339
 340         active = find_active_client(&vgasr_priv.clients);
 341         if (!active)
 342                 return 0;
 343
 344         active->active = false;
 345
 346         set_audio_state(active->id, VGA_SWITCHEROO_OFF);
 347
 348         if (new_client->fb_info) {
 349                 struct fb_event event;
 350                 console_lock();
 351                 event.info = new_client->fb_info;
 352                 fb_notifier_call_chain(FB_EVENT_REMAP_ALL_CONSOLE, &event);
 353                 console_unlock();
 354         }
 355
 356         ret = vgasr_priv.handler->switchto(new_client->id);
 357         if (ret)
 358                 return ret;
 359
 360         if (new_client->ops->reprobe)
 361                 new_client->ops->reprobe(new_client->pdev);
 362
 363         if (active->pwr_state == VGA_SWITCHEROO_ON)
 364                 vga_switchoff(active);
 365
 366         set_audio_state(new_client->id, VGA_SWITCHEROO_ON);
 367
 368         new_client->active = true;
 369         return 0;
 370 }
 371
 372 static bool check_can_switch(void)
 373 {
 374         struct vga_switcheroo_client *client;
 375
 376         list_for_each_entry(client, &vgasr_priv.clients, list) {
 377                 if (!client->ops->can_switch(client->pdev)) {
 378                         printk(KERN_ERR "vga_switcheroo: client %x refused switch\n", client->id);
 379                         return false;
 380                 }
 381         }
 382         return true;
 383 }
 384
 385 static ssize_t
 386 vga_switcheroo_debugfs_write(struct file *filp, const char __user *ubuf,
 387                              size_t cnt, loff_t *ppos)
 388 {
 389         char usercmd[64];
 390         int ret;
 391         bool delay = false, can_switch;
 392         bool just_mux = false;
 393         int client_id = -1;
 394         struct vga_switcheroo_client *client = NULL;
 395
 396         if (cnt > 63)
 397                 cnt = 63;
 398
 399         if (copy_from_user(usercmd, ubuf, cnt))
 400                 return -EFAULT;
 401
 402         mutex_lock(&vgasr_mutex);
 403
 404         if (!vgasr_priv.active) {
 405                 cnt = -EINVAL;
 406                 goto out;
 407         }
 408
 409         /* pwr off the device not in use */
 410         if (strncmp(usercmd, "OFF", 3) == 0) {
 411                 list_for_each_entry(client, &vgasr_priv.clients, list) {
 412                         if (client->active || client_is_audio(client))
 413                                 continue;
 414                         if (client->driver_power_control)
 415                                 continue;
 416                         set_audio_state(client->id, VGA_SWITCHEROO_OFF);
 417                         if (client->pwr_state == VGA_SWITCHEROO_ON)
 418                                 vga_switchoff(client);
 419                 }
 420                 goto out;
 421         }
 422         /* pwr on the device not in use */
 423         if (strncmp(usercmd, "ON", 2) == 0) {
 424                 list_for_each_entry(client, &vgasr_priv.clients, list) {
 425                         if (client->active || client_is_audio(client))
 426                                 continue;
 427                         if (client->driver_power_control)
 428                                 continue;
 429                         if (client->pwr_state == VGA_SWITCHEROO_OFF)
 430                                 vga_switchon(client);
 431                         set_audio_state(client->id, VGA_SWITCHEROO_ON);
 432                 }
 433                 goto out;
 434         }
 435
 436         /* request a delayed switch - test can we switch now */
 437         if (strncmp(usercmd, "DIGD", 4) == 0) {
 438                 client_id = VGA_SWITCHEROO_IGD;
 439                 delay = true;
 440         }
 441
 442         if (strncmp(usercmd, "DDIS", 4) == 0) {
 443                 client_id = VGA_SWITCHEROO_DIS;
 444                 delay = true;
 445         }
 446
 447         if (strncmp(usercmd, "IGD", 3) == 0)
 448                 client_id = VGA_SWITCHEROO_IGD;
 449
 450         if (strncmp(usercmd, "DIS", 3) == 0)
 451                 client_id = VGA_SWITCHEROO_DIS;
 452
 453         if (strncmp(usercmd, "MIGD", 4) == 0) {
 454                 just_mux = true;
 455                 client_id = VGA_SWITCHEROO_IGD;
 456         }
 457         if (strncmp(usercmd, "MDIS", 4) == 0) {
 458                 just_mux = true;
 459                 client_id = VGA_SWITCHEROO_DIS;
 460         }
 461
 462         if (client_id == -1)
 463                 goto out;
 464         client = find_client_from_id(&vgasr_priv.clients, client_id);
 465         if (!client)
 466                 goto out;
 467
 468         vgasr_priv.delayed_switch_active = false;
 469
 470         if (just_mux) {
 471                 ret = vgasr_priv.handler->switchto(client_id);
 472                 goto out;
 473         }
 474
 475         if (client->active)
 476                 goto out;
 477
 478         /* okay we want a switch - test if devices are willing to switch */
 479         can_switch = check_can_switch();
 480
 481         if (can_switch == false && delay == false)
 482                 goto out;
 483
 484         if (can_switch) {
 485                 ret = vga_switchto_stage1(client);
 486                 if (ret)
 487                         printk(KERN_ERR "vga_switcheroo: switching failed stage 1 %d\n", ret);
 488
 489                 ret = vga_switchto_stage2(client);
 490                 if (ret)
 491                         printk(KERN_ERR "vga_switcheroo: switching failed stage 2 %d\n", ret);
 492
 493         } else {
 494                 printk(KERN_INFO "vga_switcheroo: setting delayed switch to client %d\n", client->id);
 495                 vgasr_priv.delayed_switch_active = true;
 496                 vgasr_priv.delayed_client_id = client_id;
 497
 498                 ret = vga_switchto_stage1(client);
 499                 if (ret)
 500                         printk(KERN_ERR "vga_switcheroo: delayed switching stage 1 failed %d\n", ret);
 501         }
 502
 503 out:
 504         mutex_unlock(&vgasr_mutex);
 505         return cnt;
 506 }
 507
 508 static const struct file_operations vga_switcheroo_debugfs_fops = {
 509         .owner = THIS_MODULE,
 510         .open = vga_switcheroo_debugfs_open,
 511         .write = vga_switcheroo_debugfs_write,
 512         .read = seq_read,
 513         .llseek = seq_lseek,
 514         .release = single_release,
 515 };
 516
 517 static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv)
 518 {
 519         if (priv->switch_file) {
 520                 debugfs_remove(priv->switch_file);
 521                 priv->switch_file = NULL;
 522         }
 523         if (priv->debugfs_root) {
 524                 debugfs_remove(priv->debugfs_root);
 525                 priv->debugfs_root = NULL;
 526         }
 527 }
 528
 529 static int vga_switcheroo_debugfs_init(struct vgasr_priv *priv)
 530 {
 531         /* already initialised */
 532         if (priv->debugfs_root)
 533                 return 0;
 534         priv->debugfs_root = debugfs_create_dir("vgaswitcheroo", NULL);
 535
 536         if (!priv->debugfs_root) {
 537                 printk(KERN_ERR "vga_switcheroo: Cannot create /sys/kernel/debug/vgaswitcheroo\n");
 538                 goto fail;
 539         }
 540
 541         priv->switch_file = debugfs_create_file("switch", 0644,
 542                                                 priv->debugfs_root, NULL, &vga_switcheroo_debugfs_fops);
 543         if (!priv->switch_file) {
 544                 printk(KERN_ERR "vga_switcheroo: cannot create /sys/kernel/debug/vgaswitcheroo/switch\n");
 545                 goto fail;
 546         }
 547         return 0;
 548 fail:
 549         vga_switcheroo_debugfs_fini(priv);
 550         return -1;
 551 }
 552
 553 int vga_switcheroo_process_delayed_switch(void)
 554 {
 555         struct vga_switcheroo_client *client;
 556         int ret;
 557         int err = -EINVAL;
 558
 559         mutex_lock(&vgasr_mutex);
 560         if (!vgasr_priv.delayed_switch_active)
 561                 goto err;
 562
 563         printk(KERN_INFO "vga_switcheroo: processing delayed switch to %d\n", vgasr_priv.delayed_client_id);
 564
 565         client = find_client_from_id(&vgasr_priv.clients,
 566                                      vgasr_priv.delayed_client_id);
 567         if (!client || !check_can_switch())
 568                 goto err;
 569
 570         ret = vga_switchto_stage2(client);
 571         if (ret)
 572                 printk(KERN_ERR "vga_switcheroo: delayed switching failed stage 2 %d\n", ret);
 573
 574         vgasr_priv.delayed_switch_active = false;
 575         err = 0;
 576 err:
 577         mutex_unlock(&vgasr_mutex);
 578         return err;
 579 }
 580 EXPORT_SYMBOL(vga_switcheroo_process_delayed_switch);
 581
 582 static void vga_switcheroo_power_switch(struct pci_dev *pdev, enum vga_switcheroo_state state)
 583 {
 584         struct vga_switcheroo_client *client;
 585
 586         if (!vgasr_priv.handler->power_state)
 587                 return;
 588
 589         client = find_client_from_pci(&vgasr_priv.clients, pdev);
 590         if (!client)
 591                 return;
 592
 593         if (!client->driver_power_control)
 594                 return;
 595
 596         vgasr_priv.handler->power_state(client->id, state);
 597 }
 598
 599 /* force a PCI device to a certain state - mainly to turn off audio clients */
 600
 601 void vga_switcheroo_set_dynamic_switch(struct pci_dev *pdev, enum vga_switcheroo_state dynamic)
 602 {
 603         struct vga_switcheroo_client *client;
 604
 605         client = find_client_from_pci(&vgasr_priv.clients, pdev);
 606         if (!client)
 607                 return;
 608
 609         if (!client->driver_power_control)
 610                 return;
 611
 612         client->pwr_state = dynamic;
 613         set_audio_state(client->id, dynamic);
 614 }
 615 EXPORT_SYMBOL(vga_switcheroo_set_dynamic_switch);
 616
 617 /* switcheroo power domain */
 618 static int vga_switcheroo_runtime_suspend(struct device *dev)
 619 {
 620         struct pci_dev *pdev = to_pci_dev(dev);
 621         int ret;
 622
 623         ret = dev->bus->pm->runtime_suspend(dev);
 624         if (ret)
 625                 return ret;
 626         if (vgasr_priv.handler->switchto)
 627                 vgasr_priv.handler->switchto(VGA_SWITCHEROO_IGD);
 628         vga_switcheroo_power_switch(pdev, VGA_SWITCHEROO_OFF);
 629         return 0;
 630 }
 631
 632 static int vga_switcheroo_runtime_resume(struct device *dev)
 633 {
 634         struct pci_dev *pdev = to_pci_dev(dev);
 635         int ret;
 636
 637         vga_switcheroo_power_switch(pdev, VGA_SWITCHEROO_ON);
 638         ret = dev->bus->pm->runtime_resume(dev);
 639         if (ret)
 640                 return ret;
 641
 642         return 0;
 643 }
 644
 645 /* this version is for the case where the power switch is separate
 646    to the device being powered down. */
 647 int vga_switcheroo_init_domain_pm_ops(struct device *dev, struct dev_pm_domain *domain)
 648 {
 649         /* copy over all the bus versions */
 650         if (dev->bus && dev->bus->pm) {
 651                 domain->ops = *dev->bus->pm;
 652                 domain->ops.runtime_suspend = vga_switcheroo_runtime_suspend;
 653                 domain->ops.runtime_resume = vga_switcheroo_runtime_resume;
 654
 655                 dev->pm_domain = domain;
 656                 return 0;
 657         }
 658         dev->pm_domain = NULL;
 659         return -EINVAL;
 660 }
 661 EXPORT_SYMBOL(vga_switcheroo_init_domain_pm_ops);
 662
 663 void vga_switcheroo_fini_domain_pm_ops(struct device *dev)
 664 {
 665         dev->pm_domain = NULL;
 666 }
 667 EXPORT_SYMBOL(vga_switcheroo_fini_domain_pm_ops);
 668
 669 static int vga_switcheroo_runtime_resume_hdmi_audio(struct device *dev)
 670 {
 671         struct pci_dev *pdev = to_pci_dev(dev);
 672         int ret;
 673         struct vga_switcheroo_client *client, *found = NULL;
 674
 675         /* we need to check if we have to switch back on the video
 676            device so the audio device can come back */
 677         list_for_each_entry(client, &vgasr_priv.clients, list) {
 678                 if (PCI_SLOT(client->pdev->devfn) == PCI_SLOT(pdev->devfn) && client_is_vga(client)) {
 679                         found = client;
 680                         ret = pm_runtime_get_sync(&client->pdev->dev);
 681                         if (ret) {
 682                                 if (ret != 1)
 683                                         return ret;
 684                         }
 685                         break;
 686                 }
 687         }
 688         ret = dev->bus->pm->runtime_resume(dev);
 689
 690         /* put the reference for the gpu */
 691         if (found) {
 692                 pm_runtime_mark_last_busy(&found->pdev->dev);
 693                 pm_runtime_put_autosuspend(&found->pdev->dev);
 694         }
 695         return ret;
 696 }
 697
 698 int vga_switcheroo_init_domain_pm_optimus_hdmi_audio(struct device *dev, struct dev_pm_domain *domain)
 699 {
 700         /* copy over all the bus versions */
 701         if (dev->bus && dev->bus->pm) {
 702                 domain->ops = *dev->bus->pm;
 703                 domain->ops.runtime_resume = vga_switcheroo_runtime_resume_hdmi_audio;
 704
 705                 dev->pm_domain = domain;
 706                 return 0;
 707         }
 708         dev->pm_domain = NULL;
 709         return -EINVAL;
 710 }
 711 EXPORT_SYMBOL(vga_switcheroo_init_domain_pm_optimus_hdmi_audio);