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/dmi.h> 22 #include <linux/seq_file.h> 23 #include <linux/uaccess.h> 24 #include <linux/fs.h> 25 #include <linux/debugfs.h> 26 #include <linux/fb.h> 27 28 #include <linux/pci.h> 29 #include <linux/vga_switcheroo.h> 30 31 #include <linux/vgaarb.h> 32 33 struct vga_switcheroo_client { 34 struct pci_dev *pdev; 35 struct fb_info *fb_info; 36 int pwr_state; 37 const struct vga_switcheroo_client_ops *ops; 38 int id; 39 bool active; 40 struct list_head list; 41 }; 42 43 static DEFINE_MUTEX(vgasr_mutex); 44 45 struct vgasr_priv { 46 47 bool active; 48 bool delayed_switch_active; 49 enum vga_switcheroo_client_id delayed_client_id; 50 51 struct dentry *debugfs_root; 52 struct dentry *switch_file; 53 54 int registered_clients; 55 struct list_head clients; 56 57 struct vga_switcheroo_handler *handler; 58 }; 59 60 #define ID_BIT_AUDIO 0x100 61 #define client_is_audio(c) ((c)->id & ID_BIT_AUDIO) 62 #define client_is_vga(c) ((c)->id == -1 || !client_is_audio(c)) 63 #define client_id(c) ((c)->id & ~ID_BIT_AUDIO) 64 65 static int vga_switcheroo_debugfs_init(struct vgasr_priv *priv); 66 static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv); 67 68 /* only one switcheroo per system */ 69 static struct vgasr_priv vgasr_priv = { 70 .clients = LIST_HEAD_INIT(vgasr_priv.clients), 71 }; 72 73 static bool vga_switcheroo_ready(void) 74 { 75 /* we're ready if we get two clients + handler */ 76 return !vgasr_priv.active && 77 vgasr_priv.registered_clients == 2 && vgasr_priv.handler; 78 } 79 80 static void vga_switcheroo_enable(void) 81 { 82 int ret; 83 struct vga_switcheroo_client *client; 84 85 /* call the handler to init */ 86 if (vgasr_priv.handler->init) 87 vgasr_priv.handler->init(); 88 89 list_for_each_entry(client, &vgasr_priv.clients, list) { 90 if (client->id != -1) 91 continue; 92 ret = vgasr_priv.handler->get_client_id(client->pdev); 93 if (ret < 0) 94 return; 95 96 client->id = ret; 97 } 98 vga_switcheroo_debugfs_init(&vgasr_priv); 99 vgasr_priv.active = true; 100 } 101 102 int vga_switcheroo_register_handler(struct vga_switcheroo_handler *handler) 103 { 104 mutex_lock(&vgasr_mutex); 105 if (vgasr_priv.handler) { 106 mutex_unlock(&vgasr_mutex); 107 return -EINVAL; 108 } 109 110 vgasr_priv.handler = handler; 111 if (vga_switcheroo_ready()) { 112 printk(KERN_INFO "vga_switcheroo: enabled\n"); 113 vga_switcheroo_enable(); 114 } 115 mutex_unlock(&vgasr_mutex); 116 return 0; 117 } 118 EXPORT_SYMBOL(vga_switcheroo_register_handler); 119 120 void vga_switcheroo_unregister_handler(void) 121 { 122 mutex_lock(&vgasr_mutex); 123 vgasr_priv.handler = NULL; 124 if (vgasr_priv.active) { 125 pr_info("vga_switcheroo: disabled\n"); 126 vga_switcheroo_debugfs_fini(&vgasr_priv); 127 vgasr_priv.active = false; 128 } 129 mutex_unlock(&vgasr_mutex); 130 } 131 EXPORT_SYMBOL(vga_switcheroo_unregister_handler); 132 133 static int register_client(struct pci_dev *pdev, 134 const struct vga_switcheroo_client_ops *ops, 135 int id, bool active) 136 { 137 struct vga_switcheroo_client *client; 138 139 client = kzalloc(sizeof(*client), GFP_KERNEL); 140 if (!client) 141 return -ENOMEM; 142 143 client->pwr_state = VGA_SWITCHEROO_ON; 144 client->pdev = pdev; 145 client->ops = ops; 146 client->id = id; 147 client->active = active; 148 149 mutex_lock(&vgasr_mutex); 150 list_add_tail(&client->list, &vgasr_priv.clients); 151 if (client_is_vga(client)) 152 vgasr_priv.registered_clients++; 153 154 if (vga_switcheroo_ready()) { 155 printk(KERN_INFO "vga_switcheroo: enabled\n"); 156 vga_switcheroo_enable(); 157 } 158 mutex_unlock(&vgasr_mutex); 159 return 0; 160 } 161 162 int vga_switcheroo_register_client(struct pci_dev *pdev, 163 const struct vga_switcheroo_client_ops *ops) 164 { 165 return register_client(pdev, ops, -1, 166 pdev == vga_default_device()); 167 } 168 EXPORT_SYMBOL(vga_switcheroo_register_client); 169 170 int vga_switcheroo_register_audio_client(struct pci_dev *pdev, 171 const struct vga_switcheroo_client_ops *ops, 172 int id, bool active) 173 { 174 return register_client(pdev, ops, id | ID_BIT_AUDIO, active); 175 } 176 EXPORT_SYMBOL(vga_switcheroo_register_audio_client); 177 178 static struct vga_switcheroo_client * 179 find_client_from_pci(struct list_head *head, struct pci_dev *pdev) 180 { 181 struct vga_switcheroo_client *client; 182 list_for_each_entry(client, head, list) 183 if (client->pdev == pdev) 184 return client; 185 return NULL; 186 } 187 188 static struct vga_switcheroo_client * 189 find_client_from_id(struct list_head *head, int client_id) 190 { 191 struct vga_switcheroo_client *client; 192 list_for_each_entry(client, head, list) 193 if (client->id == client_id) 194 return client; 195 return NULL; 196 } 197 198 static struct vga_switcheroo_client * 199 find_active_client(struct list_head *head) 200 { 201 struct vga_switcheroo_client *client; 202 list_for_each_entry(client, head, list) 203 if (client->active && client_is_vga(client)) 204 return client; 205 return NULL; 206 } 207 208 int vga_switcheroo_get_client_state(struct pci_dev *pdev) 209 { 210 struct vga_switcheroo_client *client; 211 212 client = find_client_from_pci(&vgasr_priv.clients, pdev); 213 if (!client) 214 return VGA_SWITCHEROO_NOT_FOUND; 215 if (!vgasr_priv.active) 216 return VGA_SWITCHEROO_INIT; 217 return client->pwr_state; 218 } 219 EXPORT_SYMBOL(vga_switcheroo_get_client_state); 220 221 void vga_switcheroo_unregister_client(struct pci_dev *pdev) 222 { 223 struct vga_switcheroo_client *client; 224 225 mutex_lock(&vgasr_mutex); 226 client = find_client_from_pci(&vgasr_priv.clients, pdev); 227 if (client) { 228 if (client_is_vga(client)) 229 vgasr_priv.registered_clients--; 230 list_del(&client->list); 231 kfree(client); 232 } 233 if (vgasr_priv.active && vgasr_priv.registered_clients < 2) { 234 printk(KERN_INFO "vga_switcheroo: disabled\n"); 235 vga_switcheroo_debugfs_fini(&vgasr_priv); 236 vgasr_priv.active = false; 237 } 238 mutex_unlock(&vgasr_mutex); 239 } 240 EXPORT_SYMBOL(vga_switcheroo_unregister_client); 241 242 void vga_switcheroo_client_fb_set(struct pci_dev *pdev, 243 struct fb_info *info) 244 { 245 struct vga_switcheroo_client *client; 246 247 mutex_lock(&vgasr_mutex); 248 client = find_client_from_pci(&vgasr_priv.clients, pdev); 249 if (client) 250 client->fb_info = info; 251 mutex_unlock(&vgasr_mutex); 252 } 253 EXPORT_SYMBOL(vga_switcheroo_client_fb_set); 254 255 static int vga_switcheroo_show(struct seq_file *m, void *v) 256 { 257 struct vga_switcheroo_client *client; 258 int i = 0; 259 mutex_lock(&vgasr_mutex); 260 list_for_each_entry(client, &vgasr_priv.clients, list) { 261 seq_printf(m, "%d:%s%s:%c:%s:%s\n", i, 262 client_id(client) == VGA_SWITCHEROO_DIS ? "DIS" : "IGD", 263 client_is_vga(client) ? "" : "-Audio", 264 client->active ? '+' : ' ', 265 client->pwr_state ? "Pwr" : "Off", 266 pci_name(client->pdev)); 267 i++; 268 } 269 mutex_unlock(&vgasr_mutex); 270 return 0; 271 } 272 273 static int vga_switcheroo_debugfs_open(struct inode *inode, struct file *file) 274 { 275 return single_open(file, vga_switcheroo_show, NULL); 276 } 277 278 static int vga_switchon(struct vga_switcheroo_client *client) 279 { 280 if (vgasr_priv.handler->power_state) 281 vgasr_priv.handler->power_state(client->id, VGA_SWITCHEROO_ON); 282 /* call the driver callback to turn on device */ 283 client->ops->set_gpu_state(client->pdev, VGA_SWITCHEROO_ON); 284 client->pwr_state = VGA_SWITCHEROO_ON; 285 return 0; 286 } 287 288 static int vga_switchoff(struct vga_switcheroo_client *client) 289 { 290 /* call the driver callback to turn off device */ 291 client->ops->set_gpu_state(client->pdev, VGA_SWITCHEROO_OFF); 292 if (vgasr_priv.handler->power_state) 293 vgasr_priv.handler->power_state(client->id, VGA_SWITCHEROO_OFF); 294 client->pwr_state = VGA_SWITCHEROO_OFF; 295 return 0; 296 } 297 298 static void set_audio_state(int id, int state) 299 { 300 struct vga_switcheroo_client *client; 301 302 client = find_client_from_id(&vgasr_priv.clients, id | ID_BIT_AUDIO); 303 if (client && client->pwr_state != state) { 304 client->ops->set_gpu_state(client->pdev, state); 305 client->pwr_state = state; 306 } 307 } 308 309 /* stage one happens before delay */ 310 static int vga_switchto_stage1(struct vga_switcheroo_client *new_client) 311 { 312 struct vga_switcheroo_client *active; 313 314 active = find_active_client(&vgasr_priv.clients); 315 if (!active) 316 return 0; 317 318 if (new_client->pwr_state == VGA_SWITCHEROO_OFF) 319 vga_switchon(new_client); 320 321 vga_set_default_device(new_client->pdev); 322 return 0; 323 } 324 325 /* post delay */ 326 static int vga_switchto_stage2(struct vga_switcheroo_client *new_client) 327 { 328 int ret; 329 struct vga_switcheroo_client *active; 330 331 active = find_active_client(&vgasr_priv.clients); 332 if (!active) 333 return 0; 334 335 active->active = false; 336 337 set_audio_state(active->id, VGA_SWITCHEROO_OFF); 338 339 if (new_client->fb_info) { 340 struct fb_event event; 341 event.info = new_client->fb_info; 342 fb_notifier_call_chain(FB_EVENT_REMAP_ALL_CONSOLE, &event); 343 } 344 345 ret = vgasr_priv.handler->switchto(new_client->id); 346 if (ret) 347 return ret; 348 349 if (new_client->ops->reprobe) 350 new_client->ops->reprobe(new_client->pdev); 351 352 if (active->pwr_state == VGA_SWITCHEROO_ON) 353 vga_switchoff(active); 354 355 set_audio_state(new_client->id, VGA_SWITCHEROO_ON); 356 357 new_client->active = true; 358 return 0; 359 } 360 361 static bool check_can_switch(void) 362 { 363 struct vga_switcheroo_client *client; 364 365 list_for_each_entry(client, &vgasr_priv.clients, list) { 366 if (!client->ops->can_switch(client->pdev)) { 367 printk(KERN_ERR "vga_switcheroo: client %x refused switch\n", client->id); 368 return false; 369 } 370 } 371 return true; 372 } 373 374 static ssize_t 375 vga_switcheroo_debugfs_write(struct file *filp, const char __user *ubuf, 376 size_t cnt, loff_t *ppos) 377 { 378 char usercmd[64]; 379 const char *pdev_name; 380 int ret; 381 bool delay = false, can_switch; 382 bool just_mux = false; 383 int client_id = -1; 384 struct vga_switcheroo_client *client = NULL; 385 386 if (cnt > 63) 387 cnt = 63; 388 389 if (copy_from_user(usercmd, ubuf, cnt)) 390 return -EFAULT; 391 392 mutex_lock(&vgasr_mutex); 393 394 if (!vgasr_priv.active) { 395 cnt = -EINVAL; 396 goto out; 397 } 398 399 /* pwr off the device not in use */ 400 if (strncmp(usercmd, "OFF", 3) == 0) { 401 list_for_each_entry(client, &vgasr_priv.clients, list) { 402 if (client->active || client_is_audio(client)) 403 continue; 404 set_audio_state(client->id, VGA_SWITCHEROO_OFF); 405 if (client->pwr_state == VGA_SWITCHEROO_ON) 406 vga_switchoff(client); 407 } 408 goto out; 409 } 410 /* pwr on the device not in use */ 411 if (strncmp(usercmd, "ON", 2) == 0) { 412 list_for_each_entry(client, &vgasr_priv.clients, list) { 413 if (client->active || client_is_audio(client)) 414 continue; 415 if (client->pwr_state == VGA_SWITCHEROO_OFF) 416 vga_switchon(client); 417 set_audio_state(client->id, VGA_SWITCHEROO_ON); 418 } 419 goto out; 420 } 421 422 /* request a delayed switch - test can we switch now */ 423 if (strncmp(usercmd, "DIGD", 4) == 0) { 424 client_id = VGA_SWITCHEROO_IGD; 425 delay = true; 426 } 427 428 if (strncmp(usercmd, "DDIS", 4) == 0) { 429 client_id = VGA_SWITCHEROO_DIS; 430 delay = true; 431 } 432 433 if (strncmp(usercmd, "IGD", 3) == 0) 434 client_id = VGA_SWITCHEROO_IGD; 435 436 if (strncmp(usercmd, "DIS", 3) == 0) 437 client_id = VGA_SWITCHEROO_DIS; 438 439 if (strncmp(usercmd, "MIGD", 4) == 0) { 440 just_mux = true; 441 client_id = VGA_SWITCHEROO_IGD; 442 } 443 if (strncmp(usercmd, "MDIS", 4) == 0) { 444 just_mux = true; 445 client_id = VGA_SWITCHEROO_DIS; 446 } 447 448 if (client_id == -1) 449 goto out; 450 client = find_client_from_id(&vgasr_priv.clients, client_id); 451 if (!client) 452 goto out; 453 454 vgasr_priv.delayed_switch_active = false; 455 456 if (just_mux) { 457 ret = vgasr_priv.handler->switchto(client_id); 458 goto out; 459 } 460 461 if (client->active) 462 goto out; 463 464 /* okay we want a switch - test if devices are willing to switch */ 465 can_switch = check_can_switch(); 466 467 if (can_switch == false && delay == false) 468 goto out; 469 470 if (can_switch) { 471 pdev_name = pci_name(client->pdev); 472 ret = vga_switchto_stage1(client); 473 if (ret) 474 printk(KERN_ERR "vga_switcheroo: switching failed stage 1 %d\n", ret); 475 476 ret = vga_switchto_stage2(client); 477 if (ret) 478 printk(KERN_ERR "vga_switcheroo: switching failed stage 2 %d\n", ret); 479 480 } else { 481 printk(KERN_INFO "vga_switcheroo: setting delayed switch to client %d\n", client->id); 482 vgasr_priv.delayed_switch_active = true; 483 vgasr_priv.delayed_client_id = client_id; 484 485 ret = vga_switchto_stage1(client); 486 if (ret) 487 printk(KERN_ERR "vga_switcheroo: delayed switching stage 1 failed %d\n", ret); 488 } 489 490 out: 491 mutex_unlock(&vgasr_mutex); 492 return cnt; 493 } 494 495 static const struct file_operations vga_switcheroo_debugfs_fops = { 496 .owner = THIS_MODULE, 497 .open = vga_switcheroo_debugfs_open, 498 .write = vga_switcheroo_debugfs_write, 499 .read = seq_read, 500 .llseek = seq_lseek, 501 .release = single_release, 502 }; 503 504 static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv) 505 { 506 if (priv->switch_file) { 507 debugfs_remove(priv->switch_file); 508 priv->switch_file = NULL; 509 } 510 if (priv->debugfs_root) { 511 debugfs_remove(priv->debugfs_root); 512 priv->debugfs_root = NULL; 513 } 514 } 515 516 static int vga_switcheroo_debugfs_init(struct vgasr_priv *priv) 517 { 518 /* already initialised */ 519 if (priv->debugfs_root) 520 return 0; 521 priv->debugfs_root = debugfs_create_dir("vgaswitcheroo", NULL); 522 523 if (!priv->debugfs_root) { 524 printk(KERN_ERR "vga_switcheroo: Cannot create /sys/kernel/debug/vgaswitcheroo\n"); 525 goto fail; 526 } 527 528 priv->switch_file = debugfs_create_file("switch", 0644, 529 priv->debugfs_root, NULL, &vga_switcheroo_debugfs_fops); 530 if (!priv->switch_file) { 531 printk(KERN_ERR "vga_switcheroo: cannot create /sys/kernel/debug/vgaswitcheroo/switch\n"); 532 goto fail; 533 } 534 return 0; 535 fail: 536 vga_switcheroo_debugfs_fini(priv); 537 return -1; 538 } 539 540 int vga_switcheroo_process_delayed_switch(void) 541 { 542 struct vga_switcheroo_client *client; 543 const char *pdev_name; 544 int ret; 545 int err = -EINVAL; 546 547 mutex_lock(&vgasr_mutex); 548 if (!vgasr_priv.delayed_switch_active) 549 goto err; 550 551 printk(KERN_INFO "vga_switcheroo: processing delayed switch to %d\n", vgasr_priv.delayed_client_id); 552 553 client = find_client_from_id(&vgasr_priv.clients, 554 vgasr_priv.delayed_client_id); 555 if (!client || !check_can_switch()) 556 goto err; 557 558 pdev_name = pci_name(client->pdev); 559 ret = vga_switchto_stage2(client); 560 if (ret) 561 printk(KERN_ERR "vga_switcheroo: delayed switching failed stage 2 %d\n", ret); 562 563 vgasr_priv.delayed_switch_active = false; 564 err = 0; 565 err: 566 mutex_unlock(&vgasr_mutex); 567 return err; 568 } 569 EXPORT_SYMBOL(vga_switcheroo_process_delayed_switch); 570 571