drivers/gpu/drm/drm_fb_helper.c

   1 /*
   2  * Copyright (c) 2006-2009 Red Hat Inc.
   3  * Copyright (c) 2006-2008 Intel Corporation
   4  * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
   5  *
   6  * DRM framebuffer helper functions
   7  *
   8  * Permission to use, copy, modify, distribute, and sell this software and its
   9  * documentation for any purpose is hereby granted without fee, provided that
  10  * the above copyright notice appear in all copies and that both that copyright
  11  * notice and this permission notice appear in supporting documentation, and
  12  * that the name of the copyright holders not be used in advertising or
  13  * publicity pertaining to distribution of the software without specific,
  14  * written prior permission.  The copyright holders make no representations
  15  * about the suitability of this software for any purpose.  It is provided "as
  16  * is" without express or implied warranty.
  17  *
  18  * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  19  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  20  * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  21  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
  22  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  23  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  24  * OF THIS SOFTWARE.
  25  *
  26  * Authors:
  27  *      Dave Airlie <airlied@linux.ie>
  28  *      Jesse Barnes <jesse.barnes@intel.com>
  29  */
  30 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  31
  32 #include <linux/console.h>
  33 #include <linux/kernel.h>
  34 #include <linux/sysrq.h>
  35 #include <linux/slab.h>
  36 #include <linux/module.h>
  37 #include <drm/drmP.h>
  38 #include <drm/drm_crtc.h>
  39 #include <drm/drm_fb_helper.h>
  40 #include <drm/drm_crtc_helper.h>
  41 #include <drm/drm_atomic.h>
  42 #include <drm/drm_atomic_helper.h>
  43
  44 #include "drm_crtc_helper_internal.h"
  45
  46 static bool drm_fbdev_emulation = true;
  47 module_param_named(fbdev_emulation, drm_fbdev_emulation, bool, 0600);
  48 MODULE_PARM_DESC(fbdev_emulation,
  49                  "Enable legacy fbdev emulation [default=true]");
  50
  51 static int drm_fbdev_overalloc = CONFIG_DRM_FBDEV_OVERALLOC;
  52 module_param(drm_fbdev_overalloc, int, 0444);
  53 MODULE_PARM_DESC(drm_fbdev_overalloc,
  54                  "Overallocation of the fbdev buffer (%) [default="
  55                  __MODULE_STRING(CONFIG_DRM_FBDEV_OVERALLOC) "]");
  56
  57 static LIST_HEAD(kernel_fb_helper_list);
  58 static DEFINE_MUTEX(kernel_fb_helper_lock);
  59
  60 /**
  61  * DOC: fbdev helpers
  62  *
  63  * The fb helper functions are useful to provide an fbdev on top of a drm kernel
  64  * mode setting driver. They can be used mostly independently from the crtc
  65  * helper functions used by many drivers to implement the kernel mode setting
  66  * interfaces.
  67  *
  68  * Initialization is done as a four-step process with drm_fb_helper_prepare(),
  69  * drm_fb_helper_init(), drm_fb_helper_single_add_all_connectors() and
  70  * drm_fb_helper_initial_config(). Drivers with fancier requirements than the
  71  * default behaviour can override the third step with their own code.
  72  * Teardown is done with drm_fb_helper_fini() after the fbdev device is
  73  * unregisters using drm_fb_helper_unregister_fbi().
  74  *
  75  * At runtime drivers should restore the fbdev console by calling
  76  * drm_fb_helper_restore_fbdev_mode_unlocked() from their &drm_driver.lastclose
  77  * callback.  They should also notify the fb helper code from updates to the
  78  * output configuration by calling drm_fb_helper_hotplug_event(). For easier
  79  * integration with the output polling code in drm_crtc_helper.c the modeset
  80  * code provides a &drm_mode_config_funcs.output_poll_changed callback.
  81  *
  82  * All other functions exported by the fb helper library can be used to
  83  * implement the fbdev driver interface by the driver.
  84  *
  85  * It is possible, though perhaps somewhat tricky, to implement race-free
  86  * hotplug detection using the fbdev helpers. The drm_fb_helper_prepare()
  87  * helper must be called first to initialize the minimum required to make
  88  * hotplug detection work. Drivers also need to make sure to properly set up
  89  * the &drm_mode_config.funcs member. After calling drm_kms_helper_poll_init()
  90  * it is safe to enable interrupts and start processing hotplug events. At the
  91  * same time, drivers should initialize all modeset objects such as CRTCs,
  92  * encoders and connectors. To finish up the fbdev helper initialization, the
  93  * drm_fb_helper_init() function is called. To probe for all attached displays
  94  * and set up an initial configuration using the detected hardware, drivers
  95  * should call drm_fb_helper_single_add_all_connectors() followed by
  96  * drm_fb_helper_initial_config().
  97  *
  98  * If &drm_framebuffer_funcs.dirty is set, the
  99  * drm_fb_helper_{cfb,sys}_{write,fillrect,copyarea,imageblit} functions will
 100  * accumulate changes and schedule &drm_fb_helper.dirty_work to run right
 101  * away. This worker then calls the dirty() function ensuring that it will
 102  * always run in process context since the fb_*() function could be running in
 103  * atomic context. If drm_fb_helper_deferred_io() is used as the deferred_io
 104  * callback it will also schedule dirty_work with the damage collected from the
 105  * mmap page writes.
 106  */
 107
 108 #define drm_fb_helper_for_each_connector(fbh, i__) \
 109         for (({ lockdep_assert_held(&(fbh)->lock); }), \
 110              i__ = 0; i__ < (fbh)->connector_count; i__++)
 111
 112 static int __drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper,
 113                                              struct drm_connector *connector)
 114 {
 115         struct drm_fb_helper_connector *fb_conn;
 116         struct drm_fb_helper_connector **temp;
 117         unsigned int count;
 118
 119         if (!drm_fbdev_emulation)
 120                 return 0;
 121
 122         lockdep_assert_held(&fb_helper->lock);
 123
 124         count = fb_helper->connector_count + 1;
 125
 126         if (count > fb_helper->connector_info_alloc_count) {
 127                 size_t size = count * sizeof(fb_conn);
 128
 129                 temp = krealloc(fb_helper->connector_info, size, GFP_KERNEL);
 130                 if (!temp)
 131                         return -ENOMEM;
 132
 133                 fb_helper->connector_info_alloc_count = count;
 134                 fb_helper->connector_info = temp;
 135         }
 136
 137         fb_conn = kzalloc(sizeof(*fb_conn), GFP_KERNEL);
 138         if (!fb_conn)
 139                 return -ENOMEM;
 140
 141         drm_connector_get(connector);
 142         fb_conn->connector = connector;
 143         fb_helper->connector_info[fb_helper->connector_count++] = fb_conn;
 144
 145         return 0;
 146 }
 147
 148 int drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper,
 149                                     struct drm_connector *connector)
 150 {
 151         int err;
 152
 153         mutex_lock(&fb_helper->lock);
 154         err = __drm_fb_helper_add_one_connector(fb_helper, connector);
 155         mutex_unlock(&fb_helper->lock);
 156
 157         return err;
 158 }
 159 EXPORT_SYMBOL(drm_fb_helper_add_one_connector);
 160
 161 /**
 162  * drm_fb_helper_single_add_all_connectors() - add all connectors to fbdev
 163  *                                             emulation helper
 164  * @fb_helper: fbdev initialized with drm_fb_helper_init
 165  *
 166  * This functions adds all the available connectors for use with the given
 167  * fb_helper. This is a separate step to allow drivers to freely assign
 168  * connectors to the fbdev, e.g. if some are reserved for special purposes or
 169  * not adequate to be used for the fbcon.
 170  *
 171  * This function is protected against concurrent connector hotadds/removals
 172  * using drm_fb_helper_add_one_connector() and
 173  * drm_fb_helper_remove_one_connector().
 174  */
 175 int drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper)
 176 {
 177         struct drm_device *dev = fb_helper->dev;
 178         struct drm_connector *connector;
 179         struct drm_connector_list_iter conn_iter;
 180         int i, ret = 0;
 181
 182         if (!drm_fbdev_emulation)
 183                 return 0;
 184
 185         mutex_lock(&fb_helper->lock);
 186         drm_connector_list_iter_begin(dev, &conn_iter);
 187         drm_for_each_connector_iter(connector, &conn_iter) {
 188                 ret = __drm_fb_helper_add_one_connector(fb_helper, connector);
 189                 if (ret)
 190                         goto fail;
 191         }
 192         goto out;
 193
 194 fail:
 195         drm_fb_helper_for_each_connector(fb_helper, i) {
 196                 struct drm_fb_helper_connector *fb_helper_connector =
 197                         fb_helper->connector_info[i];
 198
 199                 drm_connector_put(fb_helper_connector->connector);
 200
 201                 kfree(fb_helper_connector);
 202                 fb_helper->connector_info[i] = NULL;
 203         }
 204         fb_helper->connector_count = 0;
 205 out:
 206         drm_connector_list_iter_end(&conn_iter);
 207         mutex_unlock(&fb_helper->lock);
 208
 209         return ret;
 210 }
 211 EXPORT_SYMBOL(drm_fb_helper_single_add_all_connectors);
 212
 213 static int __drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
 214                                                 struct drm_connector *connector)
 215 {
 216         struct drm_fb_helper_connector *fb_helper_connector;
 217         int i, j;
 218
 219         if (!drm_fbdev_emulation)
 220                 return 0;
 221
 222         lockdep_assert_held(&fb_helper->lock);
 223
 224         drm_fb_helper_for_each_connector(fb_helper, i) {
 225                 if (fb_helper->connector_info[i]->connector == connector)
 226                         break;
 227         }
 228
 229         if (i == fb_helper->connector_count)
 230                 return -EINVAL;
 231         fb_helper_connector = fb_helper->connector_info[i];
 232         drm_connector_put(fb_helper_connector->connector);
 233
 234         for (j = i + 1; j < fb_helper->connector_count; j++)
 235                 fb_helper->connector_info[j - 1] = fb_helper->connector_info[j];
 236
 237         fb_helper->connector_count--;
 238         kfree(fb_helper_connector);
 239
 240         return 0;
 241 }
 242
 243 int drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
 244                                        struct drm_connector *connector)
 245 {
 246         int err;
 247
 248         mutex_lock(&fb_helper->lock);
 249         err = __drm_fb_helper_remove_one_connector(fb_helper, connector);
 250         mutex_unlock(&fb_helper->lock);
 251
 252         return err;
 253 }
 254 EXPORT_SYMBOL(drm_fb_helper_remove_one_connector);
 255
 256 static void drm_fb_helper_restore_lut_atomic(struct drm_crtc *crtc)
 257 {
 258         uint16_t *r_base, *g_base, *b_base;
 259
 260         if (crtc->funcs->gamma_set == NULL)
 261                 return;
 262
 263         r_base = crtc->gamma_store;
 264         g_base = r_base + crtc->gamma_size;
 265         b_base = g_base + crtc->gamma_size;
 266
 267         crtc->funcs->gamma_set(crtc, r_base, g_base, b_base,
 268                                crtc->gamma_size, NULL);
 269 }
 270
 271 /**
 272  * drm_fb_helper_debug_enter - implementation for &fb_ops.fb_debug_enter
 273  * @info: fbdev registered by the helper
 274  */
 275 int drm_fb_helper_debug_enter(struct fb_info *info)
 276 {
 277         struct drm_fb_helper *helper = info->par;
 278         const struct drm_crtc_helper_funcs *funcs;
 279         int i;
 280
 281         list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) {
 282                 for (i = 0; i < helper->crtc_count; i++) {
 283                         struct drm_mode_set *mode_set =
 284                                 &helper->crtc_info[i].mode_set;
 285
 286                         if (!mode_set->crtc->enabled)
 287                                 continue;
 288
 289                         funcs = mode_set->crtc->helper_private;
 290                         if (funcs->mode_set_base_atomic == NULL)
 291                                 continue;
 292
 293                         if (drm_drv_uses_atomic_modeset(mode_set->crtc->dev))
 294                                 continue;
 295
 296                         funcs->mode_set_base_atomic(mode_set->crtc,
 297                                                     mode_set->fb,
 298                                                     mode_set->x,
 299                                                     mode_set->y,
 300                                                     ENTER_ATOMIC_MODE_SET);
 301                 }
 302         }
 303
 304         return 0;
 305 }
 306 EXPORT_SYMBOL(drm_fb_helper_debug_enter);
 307
 308 /**
 309  * drm_fb_helper_debug_leave - implementation for &fb_ops.fb_debug_leave
 310  * @info: fbdev registered by the helper
 311  */
 312 int drm_fb_helper_debug_leave(struct fb_info *info)
 313 {
 314         struct drm_fb_helper *helper = info->par;
 315         struct drm_crtc *crtc;
 316         const struct drm_crtc_helper_funcs *funcs;
 317         struct drm_framebuffer *fb;
 318         int i;
 319
 320         for (i = 0; i < helper->crtc_count; i++) {
 321                 struct drm_mode_set *mode_set = &helper->crtc_info[i].mode_set;
 322
 323                 crtc = mode_set->crtc;
 324                 if (drm_drv_uses_atomic_modeset(crtc->dev))
 325                         continue;
 326
 327                 funcs = crtc->helper_private;
 328                 fb = crtc->primary->fb;
 329
 330                 if (!crtc->enabled)
 331                         continue;
 332
 333                 if (!fb) {
 334                         DRM_ERROR("no fb to restore??\n");
 335                         continue;
 336                 }
 337
 338                 if (funcs->mode_set_base_atomic == NULL)
 339                         continue;
 340
 341                 drm_fb_helper_restore_lut_atomic(mode_set->crtc);
 342                 funcs->mode_set_base_atomic(mode_set->crtc, fb, crtc->x,
 343                                             crtc->y, LEAVE_ATOMIC_MODE_SET);
 344         }
 345
 346         return 0;
 347 }
 348 EXPORT_SYMBOL(drm_fb_helper_debug_leave);
 349
 350 static int restore_fbdev_mode_atomic(struct drm_fb_helper *fb_helper, bool active)
 351 {
 352         struct drm_device *dev = fb_helper->dev;
 353         struct drm_plane *plane;
 354         struct drm_atomic_state *state;
 355         int i, ret;
 356         unsigned int plane_mask;
 357         struct drm_modeset_acquire_ctx ctx;
 358
 359         drm_modeset_acquire_init(&ctx, 0);
 360
 361         state = drm_atomic_state_alloc(dev);
 362         if (!state) {
 363                 ret = -ENOMEM;
 364                 goto out_ctx;
 365         }
 366
 367         state->acquire_ctx = &ctx;
 368 retry:
 369         plane_mask = 0;
 370         drm_for_each_plane(plane, dev) {
 371                 struct drm_plane_state *plane_state;
 372
 373                 plane_state = drm_atomic_get_plane_state(state, plane);
 374                 if (IS_ERR(plane_state)) {
 375                         ret = PTR_ERR(plane_state);
 376                         goto out_state;
 377                 }
 378
 379                 plane_state->rotation = DRM_MODE_ROTATE_0;
 380
 381                 plane->old_fb = plane->fb;
 382                 plane_mask |= 1 << drm_plane_index(plane);
 383
 384                 /* disable non-primary: */
 385                 if (plane->type == DRM_PLANE_TYPE_PRIMARY)
 386                         continue;
 387
 388                 ret = __drm_atomic_helper_disable_plane(plane, plane_state);
 389                 if (ret != 0)
 390                         goto out_state;
 391         }
 392
 393         for (i = 0; i < fb_helper->crtc_count; i++) {
 394                 struct drm_mode_set *mode_set = &fb_helper->crtc_info[i].mode_set;
 395
 396                 ret = __drm_atomic_helper_set_config(mode_set, state);
 397                 if (ret != 0)
 398                         goto out_state;
 399
 400                 /*
 401                  * __drm_atomic_helper_set_config() sets active when a
 402                  * mode is set, unconditionally clear it if we force DPMS off
 403                  */
 404                 if (!active) {
 405                         struct drm_crtc *crtc = mode_set->crtc;
 406                         struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
 407
 408                         crtc_state->active = false;
 409                 }
 410         }
 411
 412         ret = drm_atomic_commit(state);
 413
 414 out_state:
 415         drm_atomic_clean_old_fb(dev, plane_mask, ret);
 416
 417         if (ret == -EDEADLK)
 418                 goto backoff;
 419
 420         drm_atomic_state_put(state);
 421 out_ctx:
 422         drm_modeset_drop_locks(&ctx);
 423         drm_modeset_acquire_fini(&ctx);
 424
 425         return ret;
 426
 427 backoff:
 428         drm_atomic_state_clear(state);
 429         drm_modeset_backoff(&ctx);
 430
 431         goto retry;
 432 }
 433
 434 static int restore_fbdev_mode_legacy(struct drm_fb_helper *fb_helper)
 435 {
 436         struct drm_device *dev = fb_helper->dev;
 437         struct drm_plane *plane;
 438         int i, ret = 0;
 439
 440         drm_modeset_lock_all(fb_helper->dev);
 441         drm_for_each_plane(plane, dev) {
 442                 if (plane->type != DRM_PLANE_TYPE_PRIMARY)
 443                         drm_plane_force_disable(plane);
 444
 445                 if (plane->rotation_property)
 446                         drm_mode_plane_set_obj_prop(plane,
 447                                                     plane->rotation_property,
 448                                                     DRM_MODE_ROTATE_0);
 449         }
 450
 451         for (i = 0; i < fb_helper->crtc_count; i++) {
 452                 struct drm_mode_set *mode_set = &fb_helper->crtc_info[i].mode_set;
 453                 struct drm_crtc *crtc = mode_set->crtc;
 454
 455                 if (crtc->funcs->cursor_set2) {
 456                         ret = crtc->funcs->cursor_set2(crtc, NULL, 0, 0, 0, 0, 0);
 457                         if (ret)
 458                                 goto out;
 459                 } else if (crtc->funcs->cursor_set) {
 460                         ret = crtc->funcs->cursor_set(crtc, NULL, 0, 0, 0);
 461                         if (ret)
 462                                 goto out;
 463                 }
 464
 465                 ret = drm_mode_set_config_internal(mode_set);
 466                 if (ret)
 467                         goto out;
 468         }
 469 out:
 470         drm_modeset_unlock_all(fb_helper->dev);
 471
 472         return ret;
 473 }
 474
 475 static int restore_fbdev_mode(struct drm_fb_helper *fb_helper)
 476 {
 477         struct drm_device *dev = fb_helper->dev;
 478
 479         if (drm_drv_uses_atomic_modeset(dev))
 480                 return restore_fbdev_mode_atomic(fb_helper, true);
 481         else
 482                 return restore_fbdev_mode_legacy(fb_helper);
 483 }
 484
 485 /**
 486  * drm_fb_helper_restore_fbdev_mode_unlocked - restore fbdev configuration
 487  * @fb_helper: fbcon to restore
 488  *
 489  * This should be called from driver's drm &drm_driver.lastclose callback
 490  * when implementing an fbcon on top of kms using this helper. This ensures that
 491  * the user isn't greeted with a black screen when e.g. X dies.
 492  *
 493  * RETURNS:
 494  * Zero if everything went ok, negative error code otherwise.
 495  */
 496 int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
 497 {
 498         bool do_delayed;
 499         int ret;
 500
 501         if (!drm_fbdev_emulation)
 502                 return -ENODEV;
 503
 504         if (READ_ONCE(fb_helper->deferred_setup))
 505                 return 0;
 506
 507         mutex_lock(&fb_helper->lock);
 508         ret = restore_fbdev_mode(fb_helper);
 509
 510         do_delayed = fb_helper->delayed_hotplug;
 511         if (do_delayed)
 512                 fb_helper->delayed_hotplug = false;
 513         mutex_unlock(&fb_helper->lock);
 514
 515         if (do_delayed)
 516                 drm_fb_helper_hotplug_event(fb_helper);
 517
 518         return ret;
 519 }
 520 EXPORT_SYMBOL(drm_fb_helper_restore_fbdev_mode_unlocked);
 521
 522 static bool drm_fb_helper_is_bound(struct drm_fb_helper *fb_helper)
 523 {
 524         struct drm_device *dev = fb_helper->dev;
 525         struct drm_crtc *crtc;
 526         int bound = 0, crtcs_bound = 0;
 527
 528         /*
 529          * Sometimes user space wants everything disabled, so don't steal the
 530          * display if there's a master.
 531          */
 532         if (READ_ONCE(dev->master))
 533                 return false;
 534
 535         drm_for_each_crtc(crtc, dev) {
 536                 drm_modeset_lock(&crtc->mutex, NULL);
 537                 if (crtc->primary->fb)
 538                         crtcs_bound++;
 539                 if (crtc->primary->fb == fb_helper->fb)
 540                         bound++;
 541                 drm_modeset_unlock(&crtc->mutex);
 542         }
 543
 544         if (bound < crtcs_bound)
 545                 return false;
 546
 547         return true;
 548 }
 549
 550 #ifdef CONFIG_MAGIC_SYSRQ
 551 /*
 552  * restore fbcon display for all kms driver's using this helper, used for sysrq
 553  * and panic handling.
 554  */
 555 static bool drm_fb_helper_force_kernel_mode(void)
 556 {
 557         bool ret, error = false;
 558         struct drm_fb_helper *helper;
 559
 560         if (list_empty(&kernel_fb_helper_list))
 561                 return false;
 562
 563         list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) {
 564                 struct drm_device *dev = helper->dev;
 565
 566                 if (dev->switch_power_state == DRM_SWITCH_POWER_OFF)
 567                         continue;
 568
 569                 mutex_lock(&helper->lock);
 570                 ret = restore_fbdev_mode(helper);
 571                 if (ret)
 572                         error = true;
 573                 mutex_unlock(&helper->lock);
 574         }
 575         return error;
 576 }
 577
 578 static void drm_fb_helper_restore_work_fn(struct work_struct *ignored)
 579 {
 580         bool ret;
 581
 582         ret = drm_fb_helper_force_kernel_mode();
 583         if (ret == true)
 584                 DRM_ERROR("Failed to restore crtc configuration\n");
 585 }
 586 static DECLARE_WORK(drm_fb_helper_restore_work, drm_fb_helper_restore_work_fn);
 587
 588 static void drm_fb_helper_sysrq(int dummy1)
 589 {
 590         schedule_work(&drm_fb_helper_restore_work);
 591 }
 592
 593 static struct sysrq_key_op sysrq_drm_fb_helper_restore_op = {
 594         .handler = drm_fb_helper_sysrq,
 595         .help_msg = "force-fb(V)",
 596         .action_msg = "Restore framebuffer console",
 597 };
 598 #else
 599 static struct sysrq_key_op sysrq_drm_fb_helper_restore_op = { };
 600 #endif
 601
 602 static void dpms_legacy(struct drm_fb_helper *fb_helper, int dpms_mode)
 603 {
 604         struct drm_device *dev = fb_helper->dev;
 605         struct drm_crtc *crtc;
 606         struct drm_connector *connector;
 607         int i, j;
 608
 609         drm_modeset_lock_all(dev);
 610         for (i = 0; i < fb_helper->crtc_count; i++) {
 611                 crtc = fb_helper->crtc_info[i].mode_set.crtc;
 612
 613                 if (!crtc->enabled)
 614                         continue;
 615
 616                 /* Walk the connectors & encoders on this fb turning them on/off */
 617                 drm_fb_helper_for_each_connector(fb_helper, j) {
 618                         connector = fb_helper->connector_info[j]->connector;
 619                         connector->funcs->dpms(connector, dpms_mode);
 620                         drm_object_property_set_value(&connector->base,
 621                                 dev->mode_config.dpms_property, dpms_mode);
 622                 }
 623         }
 624         drm_modeset_unlock_all(dev);
 625 }
 626
 627 static void drm_fb_helper_dpms(struct fb_info *info, int dpms_mode)
 628 {
 629         struct drm_fb_helper *fb_helper = info->par;
 630
 631         /*
 632          * For each CRTC in this fb, turn the connectors on/off.
 633          */
 634         mutex_lock(&fb_helper->lock);
 635         if (!drm_fb_helper_is_bound(fb_helper)) {
 636                 mutex_unlock(&fb_helper->lock);
 637                 return;
 638         }
 639
 640         if (drm_drv_uses_atomic_modeset(fb_helper->dev))
 641                 restore_fbdev_mode_atomic(fb_helper, dpms_mode == DRM_MODE_DPMS_ON);
 642         else
 643                 dpms_legacy(fb_helper, dpms_mode);
 644         mutex_unlock(&fb_helper->lock);
 645 }
 646
 647 /**
 648  * drm_fb_helper_blank - implementation for &fb_ops.fb_blank
 649  * @blank: desired blanking state
 650  * @info: fbdev registered by the helper
 651  */
 652 int drm_fb_helper_blank(int blank, struct fb_info *info)
 653 {
 654         if (oops_in_progress)
 655                 return -EBUSY;
 656
 657         switch (blank) {
 658         /* Display: On; HSync: On, VSync: On */
 659         case FB_BLANK_UNBLANK:
 660                 drm_fb_helper_dpms(info, DRM_MODE_DPMS_ON);
 661                 break;
 662         /* Display: Off; HSync: On, VSync: On */
 663         case FB_BLANK_NORMAL:
 664                 drm_fb_helper_dpms(info, DRM_MODE_DPMS_STANDBY);
 665                 break;
 666         /* Display: Off; HSync: Off, VSync: On */
 667         case FB_BLANK_HSYNC_SUSPEND:
 668                 drm_fb_helper_dpms(info, DRM_MODE_DPMS_STANDBY);
 669                 break;
 670         /* Display: Off; HSync: On, VSync: Off */
 671         case FB_BLANK_VSYNC_SUSPEND:
 672                 drm_fb_helper_dpms(info, DRM_MODE_DPMS_SUSPEND);
 673                 break;
 674         /* Display: Off; HSync: Off, VSync: Off */
 675         case FB_BLANK_POWERDOWN:
 676                 drm_fb_helper_dpms(info, DRM_MODE_DPMS_OFF);
 677                 break;
 678         }
 679         return 0;
 680 }
 681 EXPORT_SYMBOL(drm_fb_helper_blank);
 682
 683 static void drm_fb_helper_modeset_release(struct drm_fb_helper *helper,
 684                                           struct drm_mode_set *modeset)
 685 {
 686         int i;
 687
 688         for (i = 0; i < modeset->num_connectors; i++) {
 689                 drm_connector_put(modeset->connectors[i]);
 690                 modeset->connectors[i] = NULL;
 691         }
 692         modeset->num_connectors = 0;
 693
 694         drm_mode_destroy(helper->dev, modeset->mode);
 695         modeset->mode = NULL;
 696
 697         /* FIXME should hold a ref? */
 698         modeset->fb = NULL;
 699 }
 700
 701 static void drm_fb_helper_crtc_free(struct drm_fb_helper *helper)
 702 {
 703         int i;
 704
 705         for (i = 0; i < helper->connector_count; i++) {
 706                 drm_connector_put(helper->connector_info[i]->connector);
 707                 kfree(helper->connector_info[i]);
 708         }
 709         kfree(helper->connector_info);
 710
 711         for (i = 0; i < helper->crtc_count; i++) {
 712                 struct drm_mode_set *modeset = &helper->crtc_info[i].mode_set;
 713
 714                 drm_fb_helper_modeset_release(helper, modeset);
 715                 kfree(modeset->connectors);
 716         }
 717         kfree(helper->crtc_info);
 718 }
 719
 720 static void drm_fb_helper_resume_worker(struct work_struct *work)
 721 {
 722         struct drm_fb_helper *helper = container_of(work, struct drm_fb_helper,
 723                                                     resume_work);
 724
 725         console_lock();
 726         fb_set_suspend(helper->fbdev, 0);
 727         console_unlock();
 728 }
 729
 730 static void drm_fb_helper_dirty_work(struct work_struct *work)
 731 {
 732         struct drm_fb_helper *helper = container_of(work, struct drm_fb_helper,
 733                                                     dirty_work);
 734         struct drm_clip_rect *clip = &helper->dirty_clip;
 735         struct drm_clip_rect clip_copy;
 736         unsigned long flags;
 737
 738         spin_lock_irqsave(&helper->dirty_lock, flags);
 739         clip_copy = *clip;
 740         clip->x1 = clip->y1 = ~0;
 741         clip->x2 = clip->y2 = 0;
 742         spin_unlock_irqrestore(&helper->dirty_lock, flags);
 743
 744         /* call dirty callback only when it has been really touched */
 745         if (clip_copy.x1 < clip_copy.x2 && clip_copy.y1 < clip_copy.y2)
 746                 helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, &clip_copy, 1);
 747 }
 748
 749 /**
 750  * drm_fb_helper_prepare - setup a drm_fb_helper structure
 751  * @dev: DRM device
 752  * @helper: driver-allocated fbdev helper structure to set up
 753  * @funcs: pointer to structure of functions associate with this helper
 754  *
 755  * Sets up the bare minimum to make the framebuffer helper usable. This is
 756  * useful to implement race-free initialization of the polling helpers.
 757  */
 758 void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
 759                            const struct drm_fb_helper_funcs *funcs)
 760 {
 761         INIT_LIST_HEAD(&helper->kernel_fb_list);
 762         spin_lock_init(&helper->dirty_lock);
 763         INIT_WORK(&helper->resume_work, drm_fb_helper_resume_worker);
 764         INIT_WORK(&helper->dirty_work, drm_fb_helper_dirty_work);
 765         helper->dirty_clip.x1 = helper->dirty_clip.y1 = ~0;
 766         mutex_init(&helper->lock);
 767         helper->funcs = funcs;
 768         helper->dev = dev;
 769 }
 770 EXPORT_SYMBOL(drm_fb_helper_prepare);
 771
 772 /**
 773  * drm_fb_helper_init - initialize a &struct drm_fb_helper
 774  * @dev: drm device
 775  * @fb_helper: driver-allocated fbdev helper structure to initialize
 776  * @max_conn_count: max connector count
 777  *
 778  * This allocates the structures for the fbdev helper with the given limits.
 779  * Note that this won't yet touch the hardware (through the driver interfaces)
 780  * nor register the fbdev. This is only done in drm_fb_helper_initial_config()
 781  * to allow driver writes more control over the exact init sequence.
 782  *
 783  * Drivers must call drm_fb_helper_prepare() before calling this function.
 784  *
 785  * RETURNS:
 786  * Zero if everything went ok, nonzero otherwise.
 787  */
 788 int drm_fb_helper_init(struct drm_device *dev,
 789                        struct drm_fb_helper *fb_helper,
 790                        int max_conn_count)
 791 {
 792         struct drm_crtc *crtc;
 793         struct drm_mode_config *config = &dev->mode_config;
 794         int i;
 795
 796         if (!drm_fbdev_emulation)
 797                 return 0;
 798
 799         if (!max_conn_count)
 800                 return -EINVAL;
 801
 802         fb_helper->crtc_info = kcalloc(config->num_crtc, sizeof(struct drm_fb_helper_crtc), GFP_KERNEL);
 803         if (!fb_helper->crtc_info)
 804                 return -ENOMEM;
 805
 806         fb_helper->crtc_count = config->num_crtc;
 807         fb_helper->connector_info = kcalloc(dev->mode_config.num_connector, sizeof(struct drm_fb_helper_connector *), GFP_KERNEL);
 808         if (!fb_helper->connector_info) {
 809                 kfree(fb_helper->crtc_info);
 810                 return -ENOMEM;
 811         }
 812         fb_helper->connector_info_alloc_count = dev->mode_config.num_connector;
 813         fb_helper->connector_count = 0;
 814
 815         for (i = 0; i < fb_helper->crtc_count; i++) {
 816                 fb_helper->crtc_info[i].mode_set.connectors =
 817                         kcalloc(max_conn_count,
 818                                 sizeof(struct drm_connector *),
 819                                 GFP_KERNEL);
 820
 821                 if (!fb_helper->crtc_info[i].mode_set.connectors)
 822                         goto out_free;
 823                 fb_helper->crtc_info[i].mode_set.num_connectors = 0;
 824         }
 825
 826         i = 0;
 827         drm_for_each_crtc(crtc, dev) {
 828                 fb_helper->crtc_info[i].mode_set.crtc = crtc;
 829                 i++;
 830         }
 831
 832         return 0;
 833 out_free:
 834         drm_fb_helper_crtc_free(fb_helper);
 835         return -ENOMEM;
 836 }
 837 EXPORT_SYMBOL(drm_fb_helper_init);
 838
 839 /**
 840  * drm_fb_helper_alloc_fbi - allocate fb_info and some of its members
 841  * @fb_helper: driver-allocated fbdev helper
 842  *
 843  * A helper to alloc fb_info and the members cmap and apertures. Called
 844  * by the driver within the fb_probe fb_helper callback function. Drivers do not
 845  * need to release the allocated fb_info structure themselves, this is
 846  * automatically done when calling drm_fb_helper_fini().
 847  *
 848  * RETURNS:
 849  * fb_info pointer if things went okay, pointer containing error code
 850  * otherwise
 851  */
 852 struct fb_info *drm_fb_helper_alloc_fbi(struct drm_fb_helper *fb_helper)
 853 {
 854         struct device *dev = fb_helper->dev->dev;
 855         struct fb_info *info;
 856         int ret;
 857
 858         info = framebuffer_alloc(0, dev);
 859         if (!info)
 860                 return ERR_PTR(-ENOMEM);
 861
 862         ret = fb_alloc_cmap(&info->cmap, 256, 0);
 863         if (ret)
 864                 goto err_release;
 865
 866         info->apertures = alloc_apertures(1);
 867         if (!info->apertures) {
 868                 ret = -ENOMEM;
 869                 goto err_free_cmap;
 870         }
 871
 872         fb_helper->fbdev = info;
 873
 874         return info;
 875
 876 err_free_cmap:
 877         fb_dealloc_cmap(&info->cmap);
 878 err_release:
 879         framebuffer_release(info);
 880         return ERR_PTR(ret);
 881 }
 882 EXPORT_SYMBOL(drm_fb_helper_alloc_fbi);
 883
 884 /**
 885  * drm_fb_helper_unregister_fbi - unregister fb_info framebuffer device
 886  * @fb_helper: driver-allocated fbdev helper
 887  *
 888  * A wrapper around unregister_framebuffer, to release the fb_info
 889  * framebuffer device. This must be called before releasing all resources for
 890  * @fb_helper by calling drm_fb_helper_fini().
 891  */
 892 void drm_fb_helper_unregister_fbi(struct drm_fb_helper *fb_helper)
 893 {
 894         if (fb_helper && fb_helper->fbdev)
 895                 unregister_framebuffer(fb_helper->fbdev);
 896 }
 897 EXPORT_SYMBOL(drm_fb_helper_unregister_fbi);
 898
 899 /**
 900  * drm_fb_helper_fini - finialize a &struct drm_fb_helper
 901  * @fb_helper: driver-allocated fbdev helper
 902  *
 903  * This cleans up all remaining resources associated with @fb_helper. Must be
 904  * called after drm_fb_helper_unlink_fbi() was called.
 905  */
 906 void drm_fb_helper_fini(struct drm_fb_helper *fb_helper)
 907 {
 908         struct fb_info *info;
 909
 910         if (!drm_fbdev_emulation || !fb_helper)
 911                 return;
 912
 913         info = fb_helper->fbdev;
 914         if (info) {
 915                 if (info->cmap.len)
 916                         fb_dealloc_cmap(&info->cmap);
 917                 framebuffer_release(info);
 918         }
 919         fb_helper->fbdev = NULL;
 920
 921         cancel_work_sync(&fb_helper->resume_work);
 922         cancel_work_sync(&fb_helper->dirty_work);
 923
 924         mutex_lock(&kernel_fb_helper_lock);
 925         if (!list_empty(&fb_helper->kernel_fb_list)) {
 926                 list_del(&fb_helper->kernel_fb_list);
 927                 if (list_empty(&kernel_fb_helper_list))
 928                         unregister_sysrq_key('v', &sysrq_drm_fb_helper_restore_op);
 929         }
 930         mutex_unlock(&kernel_fb_helper_lock);
 931
 932         mutex_destroy(&fb_helper->lock);
 933         drm_fb_helper_crtc_free(fb_helper);
 934
 935 }
 936 EXPORT_SYMBOL(drm_fb_helper_fini);
 937
 938 /**
 939  * drm_fb_helper_unlink_fbi - wrapper around unlink_framebuffer
 940  * @fb_helper: driver-allocated fbdev helper
 941  *
 942  * A wrapper around unlink_framebuffer implemented by fbdev core
 943  */
 944 void drm_fb_helper_unlink_fbi(struct drm_fb_helper *fb_helper)
 945 {
 946         if (fb_helper && fb_helper->fbdev)
 947                 unlink_framebuffer(fb_helper->fbdev);
 948 }
 949 EXPORT_SYMBOL(drm_fb_helper_unlink_fbi);
 950
 951 static void drm_fb_helper_dirty(struct fb_info *info, u32 x, u32 y,
 952                                 u32 width, u32 height)
 953 {
 954         struct drm_fb_helper *helper = info->par;
 955         struct drm_clip_rect *clip = &helper->dirty_clip;
 956         unsigned long flags;
 957
 958         if (!helper->fb->funcs->dirty)
 959                 return;
 960
 961         spin_lock_irqsave(&helper->dirty_lock, flags);
 962         clip->x1 = min_t(u32, clip->x1, x);
 963         clip->y1 = min_t(u32, clip->y1, y);
 964         clip->x2 = max_t(u32, clip->x2, x + width);
 965         clip->y2 = max_t(u32, clip->y2, y + height);
 966         spin_unlock_irqrestore(&helper->dirty_lock, flags);
 967
 968         schedule_work(&helper->dirty_work);
 969 }
 970
 971 /**
 972  * drm_fb_helper_deferred_io() - fbdev deferred_io callback function
 973  * @info: fb_info struct pointer
 974  * @pagelist: list of dirty mmap framebuffer pages
 975  *
 976  * This function is used as the &fb_deferred_io.deferred_io
 977  * callback function for flushing the fbdev mmap writes.
 978  */
 979 void drm_fb_helper_deferred_io(struct fb_info *info,
 980                                struct list_head *pagelist)
 981 {
 982         unsigned long start, end, min, max;
 983         struct page *page;
 984         u32 y1, y2;
 985
 986         min = ULONG_MAX;
 987         max = 0;
 988         list_for_each_entry(page, pagelist, lru) {
 989                 start = page->index << PAGE_SHIFT;
 990                 end = start + PAGE_SIZE - 1;
 991                 min = min(min, start);
 992                 max = max(max, end);
 993         }
 994
 995         if (min < max) {
 996                 y1 = min / info->fix.line_length;
 997                 y2 = min_t(u32, DIV_ROUND_UP(max, info->fix.line_length),
 998                            info->var.yres);
 999                 drm_fb_helper_dirty(info, 0, y1, info->var.xres, y2 - y1);
1000         }
1001 }
1002 EXPORT_SYMBOL(drm_fb_helper_deferred_io);
1003
1004 /**
1005  * drm_fb_helper_sys_read - wrapper around fb_sys_read
1006  * @info: fb_info struct pointer
1007  * @buf: userspace buffer to read from framebuffer memory
1008  * @count: number of bytes to read from framebuffer memory
1009  * @ppos: read offset within framebuffer memory
1010  *
1011  * A wrapper around fb_sys_read implemented by fbdev core
1012  */
1013 ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
1014                                size_t count, loff_t *ppos)
1015 {
1016         return fb_sys_read(info, buf, count, ppos);
1017 }
1018 EXPORT_SYMBOL(drm_fb_helper_sys_read);
1019
1020 /**
1021  * drm_fb_helper_sys_write - wrapper around fb_sys_write
1022  * @info: fb_info struct pointer
1023  * @buf: userspace buffer to write to framebuffer memory
1024  * @count: number of bytes to write to framebuffer memory
1025  * @ppos: write offset within framebuffer memory
1026  *
1027  * A wrapper around fb_sys_write implemented by fbdev core
1028  */
1029 ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
1030                                 size_t count, loff_t *ppos)
1031 {
1032         ssize_t ret;
1033
1034         ret = fb_sys_write(info, buf, count, ppos);
1035         if (ret > 0)
1036                 drm_fb_helper_dirty(info, 0, 0, info->var.xres,
1037                                     info->var.yres);
1038
1039         return ret;
1040 }
1041 EXPORT_SYMBOL(drm_fb_helper_sys_write);
1042
1043 /**
1044  * drm_fb_helper_sys_fillrect - wrapper around sys_fillrect
1045  * @info: fbdev registered by the helper
1046  * @rect: info about rectangle to fill
1047  *
1048  * A wrapper around sys_fillrect implemented by fbdev core
1049  */
1050 void drm_fb_helper_sys_fillrect(struct fb_info *info,
1051                                 const struct fb_fillrect *rect)
1052 {
1053         sys_fillrect(info, rect);
1054         drm_fb_helper_dirty(info, rect->dx, rect->dy,
1055                             rect->width, rect->height);
1056 }
1057 EXPORT_SYMBOL(drm_fb_helper_sys_fillrect);
1058
1059 /**
1060  * drm_fb_helper_sys_copyarea - wrapper around sys_copyarea
1061  * @info: fbdev registered by the helper
1062  * @area: info about area to copy
1063  *
1064  * A wrapper around sys_copyarea implemented by fbdev core
1065  */
1066 void drm_fb_helper_sys_copyarea(struct fb_info *info,
1067                                 const struct fb_copyarea *area)
1068 {
1069         sys_copyarea(info, area);
1070         drm_fb_helper_dirty(info, area->dx, area->dy,
1071                             area->width, area->height);
1072 }
1073 EXPORT_SYMBOL(drm_fb_helper_sys_copyarea);
1074
1075 /**
1076  * drm_fb_helper_sys_imageblit - wrapper around sys_imageblit
1077  * @info: fbdev registered by the helper
1078  * @image: info about image to blit
1079  *
1080  * A wrapper around sys_imageblit implemented by fbdev core
1081  */
1082 void drm_fb_helper_sys_imageblit(struct fb_info *info,
1083                                  const struct fb_image *image)
1084 {
1085         sys_imageblit(info, image);
1086         drm_fb_helper_dirty(info, image->dx, image->dy,
1087                             image->width, image->height);
1088 }
1089 EXPORT_SYMBOL(drm_fb_helper_sys_imageblit);
1090
1091 /**
1092  * drm_fb_helper_cfb_fillrect - wrapper around cfb_fillrect
1093  * @info: fbdev registered by the helper
1094  * @rect: info about rectangle to fill
1095  *
1096  * A wrapper around cfb_imageblit implemented by fbdev core
1097  */
1098 void drm_fb_helper_cfb_fillrect(struct fb_info *info,
1099                                 const struct fb_fillrect *rect)
1100 {
1101         cfb_fillrect(info, rect);
1102         drm_fb_helper_dirty(info, rect->dx, rect->dy,
1103                             rect->width, rect->height);
1104 }
1105 EXPORT_SYMBOL(drm_fb_helper_cfb_fillrect);
1106
1107 /**
1108  * drm_fb_helper_cfb_copyarea - wrapper around cfb_copyarea
1109  * @info: fbdev registered by the helper
1110  * @area: info about area to copy
1111  *
1112  * A wrapper around cfb_copyarea implemented by fbdev core
1113  */
1114 void drm_fb_helper_cfb_copyarea(struct fb_info *info,
1115                                 const struct fb_copyarea *area)
1116 {
1117         cfb_copyarea(info, area);
1118         drm_fb_helper_dirty(info, area->dx, area->dy,
1119                             area->width, area->height);
1120 }
1121 EXPORT_SYMBOL(drm_fb_helper_cfb_copyarea);
1122
1123 /**
1124  * drm_fb_helper_cfb_imageblit - wrapper around cfb_imageblit
1125  * @info: fbdev registered by the helper
1126  * @image: info about image to blit
1127  *
1128  * A wrapper around cfb_imageblit implemented by fbdev core
1129  */
1130 void drm_fb_helper_cfb_imageblit(struct fb_info *info,
1131                                  const struct fb_image *image)
1132 {
1133         cfb_imageblit(info, image);
1134         drm_fb_helper_dirty(info, image->dx, image->dy,
1135                             image->width, image->height);
1136 }
1137 EXPORT_SYMBOL(drm_fb_helper_cfb_imageblit);
1138
1139 /**
1140  * drm_fb_helper_set_suspend - wrapper around fb_set_suspend
1141  * @fb_helper: driver-allocated fbdev helper
1142  * @suspend: whether to suspend or resume
1143  *
1144  * A wrapper around fb_set_suspend implemented by fbdev core.
1145  * Use drm_fb_helper_set_suspend_unlocked() if you don't need to take
1146  * the lock yourself
1147  */
1148 void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool suspend)
1149 {
1150         if (fb_helper && fb_helper->fbdev)
1151                 fb_set_suspend(fb_helper->fbdev, suspend);
1152 }
1153 EXPORT_SYMBOL(drm_fb_helper_set_suspend);
1154
1155 /**
1156  * drm_fb_helper_set_suspend_unlocked - wrapper around fb_set_suspend that also
1157  *                                      takes the console lock
1158  * @fb_helper: driver-allocated fbdev helper
1159  * @suspend: whether to suspend or resume
1160  *
1161  * A wrapper around fb_set_suspend() that takes the console lock. If the lock
1162  * isn't available on resume, a worker is tasked with waiting for the lock
1163  * to become available. The console lock can be pretty contented on resume
1164  * due to all the printk activity.
1165  *
1166  * This function can be called multiple times with the same state since
1167  * &fb_info.state is checked to see if fbdev is running or not before locking.
1168  *
1169  * Use drm_fb_helper_set_suspend() if you need to take the lock yourself.
1170  */
1171 void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper,
1172                                         bool suspend)
1173 {
1174         if (!fb_helper || !fb_helper->fbdev)
1175                 return;
1176
1177         /* make sure there's no pending/ongoing resume */
1178         flush_work(&fb_helper->resume_work);
1179
1180         if (suspend) {
1181                 if (fb_helper->fbdev->state != FBINFO_STATE_RUNNING)
1182                         return;
1183
1184                 console_lock();
1185
1186         } else {
1187                 if (fb_helper->fbdev->state == FBINFO_STATE_RUNNING)
1188                         return;
1189
1190                 if (!console_trylock()) {
1191                         schedule_work(&fb_helper->resume_work);
1192                         return;
1193                 }
1194         }
1195
1196         fb_set_suspend(fb_helper->fbdev, suspend);
1197         console_unlock();
1198 }
1199 EXPORT_SYMBOL(drm_fb_helper_set_suspend_unlocked);
1200
1201 static int setcmap_pseudo_palette(struct fb_cmap *cmap, struct fb_info *info)
1202 {
1203         u32 *palette = (u32 *)info->pseudo_palette;
1204         int i;
1205
1206         if (cmap->start + cmap->len > 16)
1207                 return -EINVAL;
1208
1209         for (i = 0; i < cmap->len; ++i) {
1210                 u16 red = cmap->red[i];
1211                 u16 green = cmap->green[i];
1212                 u16 blue = cmap->blue[i];
1213                 u32 value;
1214
1215                 red >>= 16 - info->var.red.length;
1216                 green >>= 16 - info->var.green.length;
1217                 blue >>= 16 - info->var.blue.length;
1218                 value = (red << info->var.red.offset) |
1219                         (green << info->var.green.offset) |
1220                         (blue << info->var.blue.offset);
1221                 if (info->var.transp.length > 0) {
1222                         u32 mask = (1 << info->var.transp.length) - 1;
1223
1224                         mask <<= info->var.transp.offset;
1225                         value |= mask;
1226                 }
1227                 palette[cmap->start + i] = value;
1228         }
1229
1230         return 0;
1231 }
1232
1233 static int setcmap_legacy(struct fb_cmap *cmap, struct fb_info *info)
1234 {
1235         struct drm_fb_helper *fb_helper = info->par;
1236         struct drm_crtc *crtc;
1237         u16 *r, *g, *b;
1238         int i, ret = 0;
1239
1240         drm_modeset_lock_all(fb_helper->dev);
1241         for (i = 0; i < fb_helper->crtc_count; i++) {
1242                 crtc = fb_helper->crtc_info[i].mode_set.crtc;
1243                 if (!crtc->funcs->gamma_set || !crtc->gamma_size)
1244                         return -EINVAL;
1245
1246                 if (cmap->start + cmap->len > crtc->gamma_size)
1247                         return -EINVAL;
1248
1249                 r = crtc->gamma_store;
1250                 g = r + crtc->gamma_size;
1251                 b = g + crtc->gamma_size;
1252
1253                 memcpy(r + cmap->start, cmap->red, cmap->len * sizeof(*r));
1254                 memcpy(g + cmap->start, cmap->green, cmap->len * sizeof(*g));
1255                 memcpy(b + cmap->start, cmap->blue, cmap->len * sizeof(*b));
1256
1257                 ret = crtc->funcs->gamma_set(crtc, r, g, b,
1258                                              crtc->gamma_size, NULL);
1259                 if (ret)
1260                         return ret;
1261         }
1262         drm_modeset_unlock_all(fb_helper->dev);
1263
1264         return ret;
1265 }
1266
1267 static struct drm_property_blob *setcmap_new_gamma_lut(struct drm_crtc *crtc,
1268                                                        struct fb_cmap *cmap)
1269 {
1270         struct drm_device *dev = crtc->dev;
1271         struct drm_property_blob *gamma_lut;
1272         struct drm_color_lut *lut;
1273         int size = crtc->gamma_size;
1274         int i;
1275
1276         if (!size || cmap->start + cmap->len > size)
1277                 return ERR_PTR(-EINVAL);
1278
1279         gamma_lut = drm_property_create_blob(dev, sizeof(*lut) * size, NULL);
1280         if (IS_ERR(gamma_lut))
1281                 return gamma_lut;
1282
1283         lut = (struct drm_color_lut *)gamma_lut->data;
1284         if (cmap->start || cmap->len != size) {
1285                 u16 *r = crtc->gamma_store;
1286                 u16 *g = r + crtc->gamma_size;
1287                 u16 *b = g + crtc->gamma_size;
1288
1289                 for (i = 0; i < cmap->start; i++) {
1290                         lut[i].red = r[i];
1291                         lut[i].green = g[i];
1292                         lut[i].blue = b[i];
1293                 }
1294                 for (i = cmap->start + cmap->len; i < size; i++) {
1295                         lut[i].red = r[i];
1296                         lut[i].green = g[i];
1297                         lut[i].blue = b[i];
1298                 }
1299         }
1300
1301         for (i = 0; i < cmap->len; i++) {
1302                 lut[cmap->start + i].red = cmap->red[i];
1303                 lut[cmap->start + i].green = cmap->green[i];
1304                 lut[cmap->start + i].blue = cmap->blue[i];
1305         }
1306
1307         return gamma_lut;
1308 }
1309
1310 static int setcmap_atomic(struct fb_cmap *cmap, struct fb_info *info)
1311 {
1312         struct drm_fb_helper *fb_helper = info->par;
1313         struct drm_device *dev = fb_helper->dev;
1314         struct drm_property_blob *gamma_lut = NULL;
1315         struct drm_modeset_acquire_ctx ctx;
1316         struct drm_crtc_state *crtc_state;
1317         struct drm_atomic_state *state;
1318         struct drm_crtc *crtc;
1319         u16 *r, *g, *b;
1320         int i, ret = 0;
1321         bool replaced;
1322
1323         drm_modeset_acquire_init(&ctx, 0);
1324
1325         state = drm_atomic_state_alloc(dev);
1326         if (!state) {
1327                 ret = -ENOMEM;
1328                 goto out_ctx;
1329         }
1330
1331         state->acquire_ctx = &ctx;
1332 retry:
1333         for (i = 0; i < fb_helper->crtc_count; i++) {
1334                 crtc = fb_helper->crtc_info[i].mode_set.crtc;
1335
1336                 if (!gamma_lut)
1337                         gamma_lut = setcmap_new_gamma_lut(crtc, cmap);
1338                 if (IS_ERR(gamma_lut)) {
1339                         ret = PTR_ERR(gamma_lut);
1340                         gamma_lut = NULL;
1341                         goto out_state;
1342                 }
1343
1344                 crtc_state = drm_atomic_get_crtc_state(state, crtc);
1345                 if (IS_ERR(crtc_state)) {
1346                         ret = PTR_ERR(crtc_state);
1347                         goto out_state;
1348                 }
1349
1350                 replaced  = drm_property_replace_blob(&crtc_state->degamma_lut,
1351                                                       NULL);
1352                 replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL);
1353                 replaced |= drm_property_replace_blob(&crtc_state->gamma_lut,
1354                                                       gamma_lut);
1355                 crtc_state->color_mgmt_changed |= replaced;
1356         }
1357
1358         ret = drm_atomic_commit(state);
1359         if (ret)
1360                 goto out_state;
1361
1362         for (i = 0; i < fb_helper->crtc_count; i++) {
1363                 crtc = fb_helper->crtc_info[i].mode_set.crtc;
1364
1365                 r = crtc->gamma_store;
1366                 g = r + crtc->gamma_size;
1367                 b = g + crtc->gamma_size;
1368
1369                 memcpy(r + cmap->start, cmap->red, cmap->len * sizeof(*r));
1370                 memcpy(g + cmap->start, cmap->green, cmap->len * sizeof(*g));
1371                 memcpy(b + cmap->start, cmap->blue, cmap->len * sizeof(*b));
1372         }
1373
1374 out_state:
1375         if (ret == -EDEADLK)
1376                 goto backoff;
1377
1378         drm_property_blob_put(gamma_lut);
1379         drm_atomic_state_put(state);
1380 out_ctx:
1381         drm_modeset_drop_locks(&ctx);
1382         drm_modeset_acquire_fini(&ctx);
1383
1384         return ret;
1385
1386 backoff:
1387         drm_atomic_state_clear(state);
1388         drm_modeset_backoff(&ctx);
1389         goto retry;
1390 }
1391
1392 /**
1393  * drm_fb_helper_setcmap - implementation for &fb_ops.fb_setcmap
1394  * @cmap: cmap to set
1395  * @info: fbdev registered by the helper
1396  */
1397 int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
1398 {
1399         struct drm_fb_helper *fb_helper = info->par;
1400         int ret;
1401
1402         if (oops_in_progress)
1403                 return -EBUSY;
1404
1405         mutex_lock(&fb_helper->lock);
1406
1407         if (!drm_fb_helper_is_bound(fb_helper)) {
1408                 ret = -EBUSY;
1409                 goto out;
1410         }
1411
1412         if (info->fix.visual == FB_VISUAL_TRUECOLOR)
1413                 ret = setcmap_pseudo_palette(cmap, info);
1414         else if (drm_drv_uses_atomic_modeset(fb_helper->dev))
1415                 ret = setcmap_atomic(cmap, info);
1416         else
1417                 ret = setcmap_legacy(cmap, info);
1418
1419 out:
1420         mutex_unlock(&fb_helper->lock);
1421
1422         return ret;
1423 }
1424 EXPORT_SYMBOL(drm_fb_helper_setcmap);
1425
1426 /**
1427  * drm_fb_helper_ioctl - legacy ioctl implementation
1428  * @info: fbdev registered by the helper
1429  * @cmd: ioctl command
1430  * @arg: ioctl argument
1431  *
1432  * A helper to implement the standard fbdev ioctl. Only
1433  * FBIO_WAITFORVSYNC is implemented for now.
1434  */
1435 int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
1436                         unsigned long arg)
1437 {
1438         struct drm_fb_helper *fb_helper = info->par;
1439         struct drm_mode_set *mode_set;
1440         struct drm_crtc *crtc;
1441         int ret = 0;
1442
1443         mutex_lock(&fb_helper->lock);
1444         if (!drm_fb_helper_is_bound(fb_helper)) {
1445                 ret = -EBUSY;
1446                 goto unlock;
1447         }
1448
1449         switch (cmd) {
1450         case FBIO_WAITFORVSYNC:
1451                 /*
1452                  * Only consider the first CRTC.
1453                  *
1454                  * This ioctl is supposed to take the CRTC number as
1455                  * an argument, but in fbdev times, what that number
1456                  * was supposed to be was quite unclear, different
1457                  * drivers were passing that argument differently
1458                  * (some by reference, some by value), and most of the
1459                  * userspace applications were just hardcoding 0 as an
1460                  * argument.
1461                  *
1462                  * The first CRTC should be the integrated panel on
1463                  * most drivers, so this is the best choice we can
1464                  * make. If we're not smart enough here, one should
1465                  * just consider switch the userspace to KMS.
1466                  */
1467                 mode_set = &fb_helper->crtc_info[0].mode_set;
1468                 crtc = mode_set->crtc;
1469
1470                 /*
1471                  * Only wait for a vblank event if the CRTC is
1472                  * enabled, otherwise just don't do anythintg,
1473                  * not even report an error.
1474                  */
1475                 ret = drm_crtc_vblank_get(crtc);
1476                 if (!ret) {
1477                         drm_crtc_wait_one_vblank(crtc);
1478                         drm_crtc_vblank_put(crtc);
1479                 }
1480
1481                 ret = 0;
1482                 goto unlock;
1483         default:
1484                 ret = -ENOTTY;
1485         }
1486
1487 unlock:
1488         mutex_unlock(&fb_helper->lock);
1489         return ret;
1490 }
1491 EXPORT_SYMBOL(drm_fb_helper_ioctl);
1492
1493 /**
1494  * drm_fb_helper_check_var - implementation for &fb_ops.fb_check_var
1495  * @var: screeninfo to check
1496  * @info: fbdev registered by the helper
1497  */
1498 int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
1499                             struct fb_info *info)
1500 {
1501         struct drm_fb_helper *fb_helper = info->par;
1502         struct drm_framebuffer *fb = fb_helper->fb;
1503         int depth;
1504
1505         if (var->pixclock != 0 || in_dbg_master())
1506                 return -EINVAL;
1507
1508         /*
1509          * Changes struct fb_var_screeninfo are currently not pushed back
1510          * to KMS, hence fail if different settings are requested.
1511          */
1512         if (var->bits_per_pixel != fb->format->cpp[0] * 8 ||
1513             var->xres > fb->width || var->yres > fb->height ||
1514             var->xres_virtual > fb->width || var->yres_virtual > fb->height) {
1515                 DRM_DEBUG("fb requested width/height/bpp can't fit in current fb "
1516                           "request %dx%d-%d (virtual %dx%d) > %dx%d-%d\n",
1517                           var->xres, var->yres, var->bits_per_pixel,
1518                           var->xres_virtual, var->yres_virtual,
1519                           fb->width, fb->height, fb->format->cpp[0] * 8);
1520                 return -EINVAL;
1521         }
1522
1523         switch (var->bits_per_pixel) {
1524         case 16:
1525                 depth = (var->green.length == 6) ? 16 : 15;
1526                 break;
1527         case 32:
1528                 depth = (var->transp.length > 0) ? 32 : 24;
1529                 break;
1530         default:
1531                 depth = var->bits_per_pixel;
1532                 break;
1533         }
1534
1535         switch (depth) {
1536         case 8:
1537                 var->red.offset = 0;
1538                 var->green.offset = 0;
1539                 var->blue.offset = 0;
1540                 var->red.length = 8;
1541                 var->green.length = 8;
1542                 var->blue.length = 8;
1543                 var->transp.length = 0;
1544                 var->transp.offset = 0;
1545                 break;
1546         case 15:
1547                 var->red.offset = 10;
1548                 var->green.offset = 5;
1549                 var->blue.offset = 0;
1550                 var->red.length = 5;
1551                 var->green.length = 5;
1552                 var->blue.length = 5;
1553                 var->transp.length = 1;
1554                 var->transp.offset = 15;
1555                 break;
1556         case 16:
1557                 var->red.offset = 11;
1558                 var->green.offset = 5;
1559                 var->blue.offset = 0;
1560                 var->red.length = 5;
1561                 var->green.length = 6;
1562                 var->blue.length = 5;
1563                 var->transp.length = 0;
1564                 var->transp.offset = 0;
1565                 break;
1566         case 24:
1567                 var->red.offset = 16;
1568                 var->green.offset = 8;
1569                 var->blue.offset = 0;
1570                 var->red.length = 8;
1571                 var->green.length = 8;
1572                 var->blue.length = 8;
1573                 var->transp.length = 0;
1574                 var->transp.offset = 0;
1575                 break;
1576         case 32:
1577                 var->red.offset = 16;
1578                 var->green.offset = 8;
1579                 var->blue.offset = 0;
1580                 var->red.length = 8;
1581                 var->green.length = 8;
1582                 var->blue.length = 8;
1583                 var->transp.length = 8;
1584                 var->transp.offset = 24;
1585                 break;
1586         default:
1587                 return -EINVAL;
1588         }
1589         return 0;
1590 }
1591 EXPORT_SYMBOL(drm_fb_helper_check_var);
1592
1593 /**
1594  * drm_fb_helper_set_par - implementation for &fb_ops.fb_set_par
1595  * @info: fbdev registered by the helper
1596  *
1597  * This will let fbcon do the mode init and is called at initialization time by
1598  * the fbdev core when registering the driver, and later on through the hotplug
1599  * callback.
1600  */
1601 int drm_fb_helper_set_par(struct fb_info *info)
1602 {
1603         struct drm_fb_helper *fb_helper = info->par;
1604         struct fb_var_screeninfo *var = &info->var;
1605
1606         if (oops_in_progress)
1607                 return -EBUSY;
1608
1609         if (var->pixclock != 0) {
1610                 DRM_ERROR("PIXEL CLOCK SET\n");
1611                 return -EINVAL;
1612         }
1613
1614         drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper);
1615
1616         return 0;
1617 }
1618 EXPORT_SYMBOL(drm_fb_helper_set_par);
1619
1620 static void pan_set(struct drm_fb_helper *fb_helper, int x, int y)
1621 {
1622         int i;
1623
1624         for (i = 0; i < fb_helper->crtc_count; i++) {
1625                 struct drm_mode_set *mode_set;
1626
1627                 mode_set = &fb_helper->crtc_info[i].mode_set;
1628
1629                 mode_set->x = x;
1630                 mode_set->y = y;
1631         }
1632 }
1633
1634 static int pan_display_atomic(struct fb_var_screeninfo *var,
1635                               struct fb_info *info)
1636 {
1637         struct drm_fb_helper *fb_helper = info->par;
1638         int ret;
1639
1640         pan_set(fb_helper, var->xoffset, var->yoffset);
1641
1642         ret = restore_fbdev_mode_atomic(fb_helper, true);
1643         if (!ret) {
1644                 info->var.xoffset = var->xoffset;
1645                 info->var.yoffset = var->yoffset;
1646         } else
1647                 pan_set(fb_helper, info->var.xoffset, info->var.yoffset);
1648
1649         return ret;
1650 }
1651
1652 static int pan_display_legacy(struct fb_var_screeninfo *var,
1653                               struct fb_info *info)
1654 {
1655         struct drm_fb_helper *fb_helper = info->par;
1656         struct drm_mode_set *modeset;
1657         int ret = 0;
1658         int i;
1659
1660         drm_modeset_lock_all(fb_helper->dev);
1661         for (i = 0; i < fb_helper->crtc_count; i++) {
1662                 modeset = &fb_helper->crtc_info[i].mode_set;
1663
1664                 modeset->x = var->xoffset;
1665                 modeset->y = var->yoffset;
1666
1667                 if (modeset->num_connectors) {
1668                         ret = drm_mode_set_config_internal(modeset);
1669                         if (!ret) {
1670                                 info->var.xoffset = var->xoffset;
1671                                 info->var.yoffset = var->yoffset;
1672                         }
1673                 }
1674         }
1675         drm_modeset_unlock_all(fb_helper->dev);
1676
1677         return ret;
1678 }
1679
1680 /**
1681  * drm_fb_helper_pan_display - implementation for &fb_ops.fb_pan_display
1682  * @var: updated screen information
1683  * @info: fbdev registered by the helper
1684  */
1685 int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
1686                               struct fb_info *info)
1687 {
1688         struct drm_fb_helper *fb_helper = info->par;
1689         struct drm_device *dev = fb_helper->dev;
1690         int ret;
1691
1692         if (oops_in_progress)
1693                 return -EBUSY;
1694
1695         mutex_lock(&fb_helper->lock);
1696         if (!drm_fb_helper_is_bound(fb_helper)) {
1697                 mutex_unlock(&fb_helper->lock);
1698                 return -EBUSY;
1699         }
1700
1701         if (drm_drv_uses_atomic_modeset(dev))
1702                 ret = pan_display_atomic(var, info);
1703         else
1704                 ret = pan_display_legacy(var, info);
1705         mutex_unlock(&fb_helper->lock);
1706
1707         return ret;
1708 }
1709 EXPORT_SYMBOL(drm_fb_helper_pan_display);
1710
1711 /*
1712  * Allocates the backing storage and sets up the fbdev info structure through
1713  * the ->fb_probe callback.
1714  */
1715 static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
1716                                          int preferred_bpp)
1717 {
1718         int ret = 0;
1719         int crtc_count = 0;
1720         int i;
1721         struct drm_fb_helper_surface_size sizes;
1722         int gamma_size = 0;
1723
1724         memset(&sizes, 0, sizeof(struct drm_fb_helper_surface_size));
1725         sizes.surface_depth = 24;
1726         sizes.surface_bpp = 32;
1727         sizes.fb_width = (u32)-1;
1728         sizes.fb_height = (u32)-1;
1729
1730         /* if driver picks 8 or 16 by default use that for both depth/bpp */
1731         if (preferred_bpp != sizes.surface_bpp)
1732                 sizes.surface_depth = sizes.surface_bpp = preferred_bpp;
1733
1734         /* first up get a count of crtcs now in use and new min/maxes width/heights */
1735         drm_fb_helper_for_each_connector(fb_helper, i) {
1736                 struct drm_fb_helper_connector *fb_helper_conn = fb_helper->connector_info[i];
1737                 struct drm_cmdline_mode *cmdline_mode;
1738
1739                 cmdline_mode = &fb_helper_conn->connector->cmdline_mode;
1740
1741                 if (cmdline_mode->bpp_specified) {
1742                         switch (cmdline_mode->bpp) {
1743                         case 8:
1744                                 sizes.surface_depth = sizes.surface_bpp = 8;
1745                                 break;
1746                         case 15:
1747                                 sizes.surface_depth = 15;
1748                                 sizes.surface_bpp = 16;
1749                                 break;
1750                         case 16:
1751                                 sizes.surface_depth = sizes.surface_bpp = 16;
1752                                 break;
1753                         case 24:
1754                                 sizes.surface_depth = sizes.surface_bpp = 24;
1755                                 break;
1756                         case 32:
1757                                 sizes.surface_depth = 24;
1758                                 sizes.surface_bpp = 32;
1759                                 break;
1760                         }
1761                         break;
1762                 }
1763         }
1764
1765         crtc_count = 0;
1766         for (i = 0; i < fb_helper->crtc_count; i++) {
1767                 struct drm_display_mode *desired_mode;
1768                 struct drm_mode_set *mode_set;
1769                 int x, y, j;
1770                 /* in case of tile group, are we the last tile vert or horiz?
1771                  * If no tile group you are always the last one both vertically
1772                  * and horizontally
1773                  */
1774                 bool lastv = true, lasth = true;
1775
1776                 desired_mode = fb_helper->crtc_info[i].desired_mode;
1777                 mode_set = &fb_helper->crtc_info[i].mode_set;
1778
1779                 if (!desired_mode)
1780                         continue;
1781
1782                 crtc_count++;
1783
1784                 x = fb_helper->crtc_info[i].x;
1785                 y = fb_helper->crtc_info[i].y;
1786
1787                 if (gamma_size == 0)
1788                         gamma_size = fb_helper->crtc_info[i].mode_set.crtc->gamma_size;
1789
1790                 sizes.surface_width  = max_t(u32, desired_mode->hdisplay + x, sizes.surface_width);
1791                 sizes.surface_height = max_t(u32, desired_mode->vdisplay + y, sizes.surface_height);
1792
1793                 for (j = 0; j < mode_set->num_connectors; j++) {
1794                         struct drm_connector *connector = mode_set->connectors[j];
1795
1796                         if (connector->has_tile) {
1797                                 lasth = (connector->tile_h_loc == (connector->num_h_tile - 1));
1798                                 lastv = (connector->tile_v_loc == (connector->num_v_tile - 1));
1799                                 /* cloning to multiple tiles is just crazy-talk, so: */
1800                                 break;
1801                         }
1802                 }
1803
1804                 if (lasth)
1805                         sizes.fb_width  = min_t(u32, desired_mode->hdisplay + x, sizes.fb_width);
1806                 if (lastv)
1807                         sizes.fb_height = min_t(u32, desired_mode->vdisplay + y, sizes.fb_height);
1808         }
1809
1810         if (crtc_count == 0 || sizes.fb_width == -1 || sizes.fb_height == -1) {
1811                 DRM_INFO("Cannot find any crtc or sizes\n");
1812                 return -EAGAIN;
1813         }
1814
1815         /* Handle our overallocation */
1816         sizes.surface_height *= drm_fbdev_overalloc;
1817         sizes.surface_height /= 100;
1818
1819         /* push down into drivers */
1820         ret = (*fb_helper->funcs->fb_probe)(fb_helper, &sizes);
1821         if (ret < 0)
1822                 return ret;
1823
1824         return 0;
1825 }
1826
1827 /**
1828  * drm_fb_helper_fill_fix - initializes fixed fbdev information
1829  * @info: fbdev registered by the helper
1830  * @pitch: desired pitch
1831  * @depth: desired depth
1832  *
1833  * Helper to fill in the fixed fbdev information useful for a non-accelerated
1834  * fbdev emulations. Drivers which support acceleration methods which impose
1835  * additional constraints need to set up their own limits.
1836  *
1837  * Drivers should call this (or their equivalent setup code) from their
1838  * &drm_fb_helper_funcs.fb_probe callback.
1839  */
1840 void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
1841                             uint32_t depth)
1842 {
1843         info->fix.type = FB_TYPE_PACKED_PIXELS;
1844         info->fix.visual = depth == 8 ? FB_VISUAL_PSEUDOCOLOR :
1845                 FB_VISUAL_TRUECOLOR;
1846         info->fix.mmio_start = 0;
1847         info->fix.mmio_len = 0;
1848         info->fix.type_aux = 0;
1849         info->fix.xpanstep = 1; /* doing it in hw */
1850         info->fix.ypanstep = 1; /* doing it in hw */
1851         info->fix.ywrapstep = 0;
1852         info->fix.accel = FB_ACCEL_NONE;
1853
1854         info->fix.line_length = pitch;
1855 }
1856 EXPORT_SYMBOL(drm_fb_helper_fill_fix);
1857
1858 /**
1859  * drm_fb_helper_fill_var - initalizes variable fbdev information
1860  * @info: fbdev instance to set up
1861  * @fb_helper: fb helper instance to use as template
1862  * @fb_width: desired fb width
1863  * @fb_height: desired fb height
1864  *
1865  * Sets up the variable fbdev metainformation from the given fb helper instance
1866  * and the drm framebuffer allocated in &drm_fb_helper.fb.
1867  *
1868  * Drivers should call this (or their equivalent setup code) from their
1869  * &drm_fb_helper_funcs.fb_probe callback after having allocated the fbdev
1870  * backing storage framebuffer.
1871  */
1872 void drm_fb_helper_fill_var(struct fb_info *info, struct drm_fb_helper *fb_helper,
1873                             uint32_t fb_width, uint32_t fb_height)
1874 {
1875         struct drm_framebuffer *fb = fb_helper->fb;
1876
1877         info->pseudo_palette = fb_helper->pseudo_palette;
1878         info->var.xres_virtual = fb->width;
1879         info->var.yres_virtual = fb->height;
1880         info->var.bits_per_pixel = fb->format->cpp[0] * 8;
1881         info->var.accel_flags = FB_ACCELF_TEXT;
1882         info->var.xoffset = 0;
1883         info->var.yoffset = 0;
1884         info->var.activate = FB_ACTIVATE_NOW;
1885         info->var.height = -1;
1886         info->var.width = -1;
1887
1888         switch (fb->format->depth) {
1889         case 8:
1890                 info->var.red.offset = 0;
1891                 info->var.green.offset = 0;
1892                 info->var.blue.offset = 0;
1893                 info->var.red.length = 8; /* 8bit DAC */
1894                 info->var.green.length = 8;
1895                 info->var.blue.length = 8;
1896                 info->var.transp.offset = 0;
1897                 info->var.transp.length = 0;
1898                 break;
1899         case 15:
1900                 info->var.red.offset = 10;
1901                 info->var.green.offset = 5;
1902                 info->var.blue.offset = 0;
1903                 info->var.red.length = 5;
1904                 info->var.green.length = 5;
1905                 info->var.blue.length = 5;
1906                 info->var.transp.offset = 15;
1907                 info->var.transp.length = 1;
1908                 break;
1909         case 16:
1910                 info->var.red.offset = 11;
1911                 info->var.green.offset = 5;
1912                 info->var.blue.offset = 0;
1913                 info->var.red.length = 5;
1914                 info->var.green.length = 6;
1915                 info->var.blue.length = 5;
1916                 info->var.transp.offset = 0;
1917                 break;
1918         case 24:
1919                 info->var.red.offset = 16;
1920                 info->var.green.offset = 8;
1921                 info->var.blue.offset = 0;
1922                 info->var.red.length = 8;
1923                 info->var.green.length = 8;
1924                 info->var.blue.length = 8;
1925                 info->var.transp.offset = 0;
1926                 info->var.transp.length = 0;
1927                 break;
1928         case 32:
1929                 info->var.red.offset = 16;
1930                 info->var.green.offset = 8;
1931                 info->var.blue.offset = 0;
1932                 info->var.red.length = 8;
1933                 info->var.green.length = 8;
1934                 info->var.blue.length = 8;
1935                 info->var.transp.offset = 24;
1936                 info->var.transp.length = 8;
1937                 break;
1938         default:
1939                 break;
1940         }
1941
1942         info->var.xres = fb_width;
1943         info->var.yres = fb_height;
1944 }
1945 EXPORT_SYMBOL(drm_fb_helper_fill_var);
1946
1947 static int drm_fb_helper_probe_connector_modes(struct drm_fb_helper *fb_helper,
1948                                                 uint32_t maxX,
1949                                                 uint32_t maxY)
1950 {
1951         struct drm_connector *connector;
1952         int i, count = 0;
1953
1954         drm_fb_helper_for_each_connector(fb_helper, i) {
1955                 connector = fb_helper->connector_info[i]->connector;
1956                 count += connector->funcs->fill_modes(connector, maxX, maxY);
1957         }
1958
1959         return count;
1960 }
1961
1962 struct drm_display_mode *drm_has_preferred_mode(struct drm_fb_helper_connector *fb_connector, int width, int height)
1963 {
1964         struct drm_display_mode *mode;
1965
1966         list_for_each_entry(mode, &fb_connector->connector->modes, head) {
1967                 if (mode->hdisplay > width ||
1968                     mode->vdisplay > height)
1969                         continue;
1970                 if (mode->type & DRM_MODE_TYPE_PREFERRED)
1971                         return mode;
1972         }
1973         return NULL;
1974 }
1975 EXPORT_SYMBOL(drm_has_preferred_mode);
1976
1977 static bool drm_has_cmdline_mode(struct drm_fb_helper_connector *fb_connector)
1978 {
1979         return fb_connector->connector->cmdline_mode.specified;
1980 }
1981
1982 struct drm_display_mode *drm_pick_cmdline_mode(struct drm_fb_helper_connector *fb_helper_conn)
1983 {
1984         struct drm_cmdline_mode *cmdline_mode;
1985         struct drm_display_mode *mode;
1986         bool prefer_non_interlace;
1987
1988         cmdline_mode = &fb_helper_conn->connector->cmdline_mode;
1989         if (cmdline_mode->specified == false)
1990                 return NULL;
1991
1992         /* attempt to find a matching mode in the list of modes
1993          *  we have gotten so far, if not add a CVT mode that conforms
1994          */
1995         if (cmdline_mode->rb || cmdline_mode->margins)
1996                 goto create_mode;
1997
1998         prefer_non_interlace = !cmdline_mode->interlace;
1999 again:
2000         list_for_each_entry(mode, &fb_helper_conn->connector->modes, head) {
2001                 /* check width/height */
2002                 if (mode->hdisplay != cmdline_mode->xres ||
2003                     mode->vdisplay != cmdline_mode->yres)
2004                         continue;
2005
2006                 if (cmdline_mode->refresh_specified) {
2007                         if (mode->vrefresh != cmdline_mode->refresh)
2008                                 continue;
2009                 }
2010
2011                 if (cmdline_mode->interlace) {
2012                         if (!(mode->flags & DRM_MODE_FLAG_INTERLACE))
2013                                 continue;
2014                 } else if (prefer_non_interlace) {
2015                         if (mode->flags & DRM_MODE_FLAG_INTERLACE)
2016                                 continue;
2017                 }
2018                 return mode;
2019         }
2020
2021         if (prefer_non_interlace) {
2022                 prefer_non_interlace = false;
2023                 goto again;
2024         }
2025
2026 create_mode:
2027         mode = drm_mode_create_from_cmdline_mode(fb_helper_conn->connector->dev,
2028                                                  cmdline_mode);
2029         list_add(&mode->head, &fb_helper_conn->connector->modes);
2030         return mode;
2031 }
2032 EXPORT_SYMBOL(drm_pick_cmdline_mode);
2033
2034 static bool drm_connector_enabled(struct drm_connector *connector, bool strict)
2035 {
2036         bool enable;
2037
2038         if (strict)
2039                 enable = connector->status == connector_status_connected;
2040         else
2041                 enable = connector->status != connector_status_disconnected;
2042
2043         return enable;
2044 }
2045
2046 static void drm_enable_connectors(struct drm_fb_helper *fb_helper,
2047                                   bool *enabled)
2048 {
2049         bool any_enabled = false;
2050         struct drm_connector *connector;
2051         int i = 0;
2052
2053         drm_fb_helper_for_each_connector(fb_helper, i) {
2054                 connector = fb_helper->connector_info[i]->connector;
2055                 enabled[i] = drm_connector_enabled(connector, true);
2056                 DRM_DEBUG_KMS("connector %d enabled? %s\n", connector->base.id,
2057                           enabled[i] ? "yes" : "no");
2058                 any_enabled |= enabled[i];
2059         }
2060
2061         if (any_enabled)
2062                 return;
2063
2064         drm_fb_helper_for_each_connector(fb_helper, i) {
2065                 connector = fb_helper->connector_info[i]->connector;
2066                 enabled[i] = drm_connector_enabled(connector, false);
2067         }
2068 }
2069
2070 static bool drm_target_cloned(struct drm_fb_helper *fb_helper,
2071                               struct drm_display_mode **modes,
2072                               struct drm_fb_offset *offsets,
2073                               bool *enabled, int width, int height)
2074 {
2075         int count, i, j;
2076         bool can_clone = false;
2077         struct drm_fb_helper_connector *fb_helper_conn;
2078         struct drm_display_mode *dmt_mode, *mode;
2079
2080         /* only contemplate cloning in the single crtc case */
2081         if (fb_helper->crtc_count > 1)
2082                 return false;
2083
2084         count = 0;
2085         drm_fb_helper_for_each_connector(fb_helper, i) {
2086                 if (enabled[i])
2087                         count++;
2088         }
2089
2090         /* only contemplate cloning if more than one connector is enabled */
2091         if (count <= 1)
2092                 return false;
2093
2094         /* check the command line or if nothing common pick 1024x768 */
2095         can_clone = true;
2096         drm_fb_helper_for_each_connector(fb_helper, i) {
2097                 if (!enabled[i])
2098                         continue;
2099                 fb_helper_conn = fb_helper->connector_info[i];
2100                 modes[i] = drm_pick_cmdline_mode(fb_helper_conn);
2101                 if (!modes[i]) {
2102                         can_clone = false;
2103                         break;
2104                 }
2105                 for (j = 0; j < i; j++) {
2106                         if (!enabled[j])
2107                                 continue;
2108                         if (!drm_mode_equal(modes[j], modes[i]))
2109                                 can_clone = false;
2110                 }
2111         }
2112
2113         if (can_clone) {
2114                 DRM_DEBUG_KMS("can clone using command line\n");
2115                 return true;
2116         }
2117
2118         /* try and find a 1024x768 mode on each connector */
2119         can_clone = true;
2120         dmt_mode = drm_mode_find_dmt(fb_helper->dev, 1024, 768, 60, false);
2121
2122         drm_fb_helper_for_each_connector(fb_helper, i) {
2123                 if (!enabled[i])
2124                         continue;
2125
2126                 fb_helper_conn = fb_helper->connector_info[i];
2127                 list_for_each_entry(mode, &fb_helper_conn->connector->modes, head) {
2128                         if (drm_mode_equal(mode, dmt_mode))
2129                                 modes[i] = mode;
2130                 }
2131                 if (!modes[i])
2132                         can_clone = false;
2133         }
2134
2135         if (can_clone) {
2136                 DRM_DEBUG_KMS("can clone using 1024x768\n");
2137                 return true;
2138         }
2139         DRM_INFO("kms: can't enable cloning when we probably wanted to.\n");
2140         return false;
2141 }
2142
2143 static int drm_get_tile_offsets(struct drm_fb_helper *fb_helper,
2144                                 struct drm_display_mode **modes,
2145                                 struct drm_fb_offset *offsets,
2146                                 int idx,
2147                                 int h_idx, int v_idx)
2148 {
2149         struct drm_fb_helper_connector *fb_helper_conn;
2150         int i;
2151         int hoffset = 0, voffset = 0;
2152
2153         drm_fb_helper_for_each_connector(fb_helper, i) {
2154                 fb_helper_conn = fb_helper->connector_info[i];
2155                 if (!fb_helper_conn->connector->has_tile)
2156                         continue;
2157
2158                 if (!modes[i] && (h_idx || v_idx)) {
2159                         DRM_DEBUG_KMS("no modes for connector tiled %d %d\n", i,
2160                                       fb_helper_conn->connector->base.id);
2161                         continue;
2162                 }
2163                 if (fb_helper_conn->connector->tile_h_loc < h_idx)
2164                         hoffset += modes[i]->hdisplay;
2165
2166                 if (fb_helper_conn->connector->tile_v_loc < v_idx)
2167                         voffset += modes[i]->vdisplay;
2168         }
2169         offsets[idx].x = hoffset;
2170         offsets[idx].y = voffset;
2171         DRM_DEBUG_KMS("returned %d %d for %d %d\n", hoffset, voffset, h_idx, v_idx);
2172         return 0;
2173 }
2174
2175 static bool drm_target_preferred(struct drm_fb_helper *fb_helper,
2176                                  struct drm_display_mode **modes,
2177                                  struct drm_fb_offset *offsets,
2178                                  bool *enabled, int width, int height)
2179 {
2180         struct drm_fb_helper_connector *fb_helper_conn;
2181         const u64 mask = BIT_ULL(fb_helper->connector_count) - 1;
2182         u64 conn_configured = 0;
2183         int tile_pass = 0;
2184         int i;
2185
2186 retry:
2187         drm_fb_helper_for_each_connector(fb_helper, i) {
2188                 fb_helper_conn = fb_helper->connector_info[i];
2189
2190                 if (conn_configured & BIT_ULL(i))
2191                         continue;
2192
2193                 if (enabled[i] == false) {
2194                         conn_configured |= BIT_ULL(i);
2195                         continue;
2196                 }
2197
2198                 /* first pass over all the untiled connectors */
2199                 if (tile_pass == 0 && fb_helper_conn->connector->has_tile)
2200                         continue;
2201
2202                 if (tile_pass == 1) {
2203                         if (fb_helper_conn->connector->tile_h_loc != 0 ||
2204                             fb_helper_conn->connector->tile_v_loc != 0)
2205                                 continue;
2206
2207                 } else {
2208                         if (fb_helper_conn->connector->tile_h_loc != tile_pass - 1 &&
2209                             fb_helper_conn->connector->tile_v_loc != tile_pass - 1)
2210                         /* if this tile_pass doesn't cover any of the tiles - keep going */
2211                                 continue;
2212
2213                         /*
2214                          * find the tile offsets for this pass - need to find
2215                          * all tiles left and above
2216                          */
2217                         drm_get_tile_offsets(fb_helper, modes, offsets,
2218                                              i, fb_helper_conn->connector->tile_h_loc, fb_helper_conn->connector->tile_v_loc);
2219                 }
2220                 DRM_DEBUG_KMS("looking for cmdline mode on connector %d\n",
2221                               fb_helper_conn->connector->base.id);
2222
2223                 /* got for command line mode first */
2224                 modes[i] = drm_pick_cmdline_mode(fb_helper_conn);
2225                 if (!modes[i]) {
2226                         DRM_DEBUG_KMS("looking for preferred mode on connector %d %d\n",
2227                                       fb_helper_conn->connector->base.id, fb_helper_conn->connector->tile_group ? fb_helper_conn->connector->tile_group->id : 0);
2228                         modes[i] = drm_has_preferred_mode(fb_helper_conn, width, height);
2229                 }
2230                 /* No preferred modes, pick one off the list */
2231                 if (!modes[i] && !list_empty(&fb_helper_conn->connector->modes)) {
2232                         list_for_each_entry(modes[i], &fb_helper_conn->connector->modes, head)
2233                                 break;
2234                 }
2235                 DRM_DEBUG_KMS("found mode %s\n", modes[i] ? modes[i]->name :
2236                           "none");
2237                 conn_configured |= BIT_ULL(i);
2238         }
2239
2240         if ((conn_configured & mask) != mask) {
2241                 tile_pass++;
2242                 goto retry;
2243         }
2244         return true;
2245 }
2246
2247 static int drm_pick_crtcs(struct drm_fb_helper *fb_helper,
2248                           struct drm_fb_helper_crtc **best_crtcs,
2249                           struct drm_display_mode **modes,
2250                           int n, int width, int height)
2251 {
2252         int c, o;
2253         struct drm_connector *connector;
2254         const struct drm_connector_helper_funcs *connector_funcs;
2255         struct drm_encoder *encoder;
2256         int my_score, best_score, score;
2257         struct drm_fb_helper_crtc **crtcs, *crtc;
2258         struct drm_fb_helper_connector *fb_helper_conn;
2259
2260         if (n == fb_helper->connector_count)
2261                 return 0;
2262
2263         fb_helper_conn = fb_helper->connector_info[n];
2264         connector = fb_helper_conn->connector;
2265
2266         best_crtcs[n] = NULL;
2267         best_score = drm_pick_crtcs(fb_helper, best_crtcs, modes, n+1, width, height);
2268         if (modes[n] == NULL)
2269                 return best_score;
2270
2271         crtcs = kzalloc(fb_helper->connector_count *
2272                         sizeof(struct drm_fb_helper_crtc *), GFP_KERNEL);
2273         if (!crtcs)
2274                 return best_score;
2275
2276         my_score = 1;
2277         if (connector->status == connector_status_connected)
2278                 my_score++;
2279         if (drm_has_cmdline_mode(fb_helper_conn))
2280                 my_score++;
2281         if (drm_has_preferred_mode(fb_helper_conn, width, height))
2282                 my_score++;
2283
2284         connector_funcs = connector->helper_private;
2285
2286         /*
2287          * If the DRM device implements atomic hooks and ->best_encoder() is
2288          * NULL we fallback to the default drm_atomic_helper_best_encoder()
2289          * helper.
2290          */
2291         if (drm_drv_uses_atomic_modeset(fb_helper->dev) &&
2292             !connector_funcs->best_encoder)
2293                 encoder = drm_atomic_helper_best_encoder(connector);
2294         else
2295                 encoder = connector_funcs->best_encoder(connector);
2296
2297         if (!encoder)
2298                 goto out;
2299
2300         /*
2301          * select a crtc for this connector and then attempt to configure
2302          * remaining connectors
2303          */
2304         for (c = 0; c < fb_helper->crtc_count; c++) {
2305                 crtc = &fb_helper->crtc_info[c];
2306
2307                 if ((encoder->possible_crtcs & (1 << c)) == 0)
2308                         continue;
2309
2310                 for (o = 0; o < n; o++)
2311                         if (best_crtcs[o] == crtc)
2312                                 break;
2313
2314                 if (o < n) {
2315                         /* ignore cloning unless only a single crtc */
2316                         if (fb_helper->crtc_count > 1)
2317                                 continue;
2318
2319                         if (!drm_mode_equal(modes[o], modes[n]))
2320                                 continue;
2321                 }
2322
2323                 crtcs[n] = crtc;
2324                 memcpy(crtcs, best_crtcs, n * sizeof(struct drm_fb_helper_crtc *));
2325                 score = my_score + drm_pick_crtcs(fb_helper, crtcs, modes, n + 1,
2326                                                   width, height);
2327                 if (score > best_score) {
2328                         best_score = score;
2329                         memcpy(best_crtcs, crtcs,
2330                                fb_helper->connector_count *
2331                                sizeof(struct drm_fb_helper_crtc *));
2332                 }
2333         }
2334 out:
2335         kfree(crtcs);
2336         return best_score;
2337 }
2338
2339 static void drm_setup_crtcs(struct drm_fb_helper *fb_helper,
2340                             u32 width, u32 height)
2341 {
2342         struct drm_device *dev = fb_helper->dev;
2343         struct drm_fb_helper_crtc **crtcs;
2344         struct drm_display_mode **modes;
2345         struct drm_fb_offset *offsets;
2346         bool *enabled;
2347         int i;
2348
2349         DRM_DEBUG_KMS("\n");
2350         /* prevent concurrent modification of connector_count by hotplug */
2351         lockdep_assert_held(&fb_helper->lock);
2352
2353         crtcs = kcalloc(fb_helper->connector_count,
2354                         sizeof(struct drm_fb_helper_crtc *), GFP_KERNEL);
2355         modes = kcalloc(fb_helper->connector_count,
2356                         sizeof(struct drm_display_mode *), GFP_KERNEL);
2357         offsets = kcalloc(fb_helper->connector_count,
2358                           sizeof(struct drm_fb_offset), GFP_KERNEL);
2359         enabled = kcalloc(fb_helper->connector_count,
2360                           sizeof(bool), GFP_KERNEL);
2361         if (!crtcs || !modes || !enabled || !offsets) {
2362                 DRM_ERROR("Memory allocation failed\n");
2363                 goto out;
2364         }
2365
2366         mutex_lock(&fb_helper->dev->mode_config.mutex);
2367         if (drm_fb_helper_probe_connector_modes(fb_helper, width, height) == 0)
2368                 DRM_DEBUG_KMS("No connectors reported connected with modes\n");
2369         drm_enable_connectors(fb_helper, enabled);
2370
2371         if (!(fb_helper->funcs->initial_config &&
2372               fb_helper->funcs->initial_config(fb_helper, crtcs, modes,
2373                                                offsets,
2374                                                enabled, width, height))) {
2375                 memset(modes, 0, fb_helper->connector_count*sizeof(modes[0]));
2376                 memset(crtcs, 0, fb_helper->connector_count*sizeof(crtcs[0]));
2377                 memset(offsets, 0, fb_helper->connector_count*sizeof(offsets[0]));
2378
2379                 if (!drm_target_cloned(fb_helper, modes, offsets,
2380                                        enabled, width, height) &&
2381                     !drm_target_preferred(fb_helper, modes, offsets,
2382                                           enabled, width, height))
2383                         DRM_ERROR("Unable to find initial modes\n");
2384
2385                 DRM_DEBUG_KMS("picking CRTCs for %dx%d config\n",
2386                               width, height);
2387
2388                 drm_pick_crtcs(fb_helper, crtcs, modes, 0, width, height);
2389         }
2390         mutex_unlock(&fb_helper->dev->mode_config.mutex);
2391
2392         /* need to set the modesets up here for use later */
2393         /* fill out the connector<->crtc mappings into the modesets */
2394         for (i = 0; i < fb_helper->crtc_count; i++)
2395                 drm_fb_helper_modeset_release(fb_helper,
2396                                               &fb_helper->crtc_info[i].mode_set);
2397
2398         drm_fb_helper_for_each_connector(fb_helper, i) {
2399                 struct drm_display_mode *mode = modes[i];
2400                 struct drm_fb_helper_crtc *fb_crtc = crtcs[i];
2401                 struct drm_fb_offset *offset = &offsets[i];
2402
2403                 if (mode && fb_crtc) {
2404                         struct drm_mode_set *modeset = &fb_crtc->mode_set;
2405                         struct drm_connector *connector =
2406                                 fb_helper->connector_info[i]->connector;
2407
2408                         DRM_DEBUG_KMS("desired mode %s set on crtc %d (%d,%d)\n",
2409                                       mode->name, fb_crtc->mode_set.crtc->base.id, offset->x, offset->y);
2410
2411                         fb_crtc->desired_mode = mode;
2412                         fb_crtc->x = offset->x;
2413                         fb_crtc->y = offset->y;
2414                         modeset->mode = drm_mode_duplicate(dev,
2415                                                            fb_crtc->desired_mode);
2416                         drm_connector_get(connector);
2417                         modeset->connectors[modeset->num_connectors++] = connector;
2418                         modeset->x = offset->x;
2419                         modeset->y = offset->y;
2420                 }
2421         }
2422 out:
2423         kfree(crtcs);
2424         kfree(modes);
2425         kfree(offsets);
2426         kfree(enabled);
2427 }
2428
2429 /*
2430  * This is a continuation of drm_setup_crtcs() that sets up anything related
2431  * to the framebuffer. During initialization, drm_setup_crtcs() is called before
2432  * the framebuffer has been allocated (fb_helper->fb and fb_helper->fbdev).
2433  * So, any setup that touches those fields needs to be done here instead of in
2434  * drm_setup_crtcs().
2435  */
2436 static void drm_setup_crtcs_fb(struct drm_fb_helper *fb_helper)
2437 {
2438         int i;
2439
2440         for (i = 0; i < fb_helper->crtc_count; i++)
2441                 if (fb_helper->crtc_info[i].mode_set.num_connectors)
2442                         fb_helper->crtc_info[i].mode_set.fb = fb_helper->fb;
2443 }
2444
2445 /* Note: Drops fb_helper->lock before returning. */
2446 static int
2447 __drm_fb_helper_initial_config_and_unlock(struct drm_fb_helper *fb_helper,
2448                                           int bpp_sel)
2449 {
2450         struct drm_device *dev = fb_helper->dev;
2451         struct fb_info *info;
2452         unsigned int width, height;
2453         int ret;
2454
2455         width = dev->mode_config.max_width;
2456         height = dev->mode_config.max_height;
2457
2458         drm_setup_crtcs(fb_helper, width, height);
2459         ret = drm_fb_helper_single_fb_probe(fb_helper, bpp_sel);
2460         if (ret < 0) {
2461                 if (ret == -EAGAIN) {
2462                         fb_helper->preferred_bpp = bpp_sel;
2463                         fb_helper->deferred_setup = true;
2464                         ret = 0;
2465                 }
2466                 mutex_unlock(&fb_helper->lock);
2467
2468                 return ret;
2469         }
2470         drm_setup_crtcs_fb(fb_helper);
2471
2472         fb_helper->deferred_setup = false;
2473
2474         info = fb_helper->fbdev;
2475         info->var.pixclock = 0;
2476
2477         /* Need to drop locks to avoid recursive deadlock in
2478          * register_framebuffer. This is ok because the only thing left to do is
2479          * register the fbdev emulation instance in kernel_fb_helper_list. */
2480         mutex_unlock(&fb_helper->lock);
2481
2482         ret = register_framebuffer(info);
2483         if (ret < 0)
2484                 return ret;
2485
2486         dev_info(dev->dev, "fb%d: %s frame buffer device\n",
2487                  info->node, info->fix.id);
2488
2489         mutex_lock(&kernel_fb_helper_lock);
2490         if (list_empty(&kernel_fb_helper_list))
2491                 register_sysrq_key('v', &sysrq_drm_fb_helper_restore_op);
2492
2493         list_add(&fb_helper->kernel_fb_list, &kernel_fb_helper_list);
2494         mutex_unlock(&kernel_fb_helper_lock);
2495
2496         return 0;
2497 }
2498
2499 /**
2500  * drm_fb_helper_initial_config - setup a sane initial connector configuration
2501  * @fb_helper: fb_helper device struct
2502  * @bpp_sel: bpp value to use for the framebuffer configuration
2503  *
2504  * Scans the CRTCs and connectors and tries to put together an initial setup.
2505  * At the moment, this is a cloned configuration across all heads with
2506  * a new framebuffer object as the backing store.
2507  *
2508  * Note that this also registers the fbdev and so allows userspace to call into
2509  * the driver through the fbdev interfaces.
2510  *
2511  * This function will call down into the &drm_fb_helper_funcs.fb_probe callback
2512  * to let the driver allocate and initialize the fbdev info structure and the
2513  * drm framebuffer used to back the fbdev. drm_fb_helper_fill_var() and
2514  * drm_fb_helper_fill_fix() are provided as helpers to setup simple default
2515  * values for the fbdev info structure.
2516  *
2517  * HANG DEBUGGING:
2518  *
2519  * When you have fbcon support built-in or already loaded, this function will do
2520  * a full modeset to setup the fbdev console. Due to locking misdesign in the
2521  * VT/fbdev subsystem that entire modeset sequence has to be done while holding
2522  * console_lock. Until console_unlock is called no dmesg lines will be sent out
2523  * to consoles, not even serial console. This means when your driver crashes,
2524  * you will see absolutely nothing else but a system stuck in this function,
2525  * with no further output. Any kind of printk() you place within your own driver
2526  * or in the drm core modeset code will also never show up.
2527  *
2528  * Standard debug practice is to run the fbcon setup without taking the
2529  * console_lock as a hack, to be able to see backtraces and crashes on the
2530  * serial line. This can be done by setting the fb.lockless_register_fb=1 kernel
2531  * cmdline option.
2532  *
2533  * The other option is to just disable fbdev emulation since very likely the
2534  * first modeset from userspace will crash in the same way, and is even easier
2535  * to debug. This can be done by setting the drm_kms_helper.fbdev_emulation=0
2536  * kernel cmdline option.
2537  *
2538  * RETURNS:
2539  * Zero if everything went ok, nonzero otherwise.
2540  */
2541 int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper, int bpp_sel)
2542 {
2543         int ret;
2544
2545         if (!drm_fbdev_emulation)
2546                 return 0;
2547
2548         mutex_lock(&fb_helper->lock);
2549         ret = __drm_fb_helper_initial_config_and_unlock(fb_helper, bpp_sel);
2550
2551         return ret;
2552 }
2553 EXPORT_SYMBOL(drm_fb_helper_initial_config);
2554
2555 /**
2556  * drm_fb_helper_hotplug_event - respond to a hotplug notification by
2557  *                               probing all the outputs attached to the fb
2558  * @fb_helper: the drm_fb_helper
2559  *
2560  * Scan the connectors attached to the fb_helper and try to put together a
2561  * setup after notification of a change in output configuration.
2562  *
2563  * Called at runtime, takes the mode config locks to be able to check/change the
2564  * modeset configuration. Must be run from process context (which usually means
2565  * either the output polling work or a work item launched from the driver's
2566  * hotplug interrupt).
2567  *
2568  * Note that drivers may call this even before calling
2569  * drm_fb_helper_initial_config but only after drm_fb_helper_init. This allows
2570  * for a race-free fbcon setup and will make sure that the fbdev emulation will
2571  * not miss any hotplug events.
2572  *
2573  * RETURNS:
2574  * 0 on success and a non-zero error code otherwise.
2575  */
2576 int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
2577 {
2578         int err = 0;
2579
2580         if (!drm_fbdev_emulation)
2581                 return 0;
2582
2583         mutex_lock(&fb_helper->lock);
2584         if (fb_helper->deferred_setup) {
2585                 err = __drm_fb_helper_initial_config_and_unlock(fb_helper,
2586                                 fb_helper->preferred_bpp);
2587                 return err;
2588         }
2589
2590         if (!fb_helper->fb || !drm_fb_helper_is_bound(fb_helper)) {
2591                 fb_helper->delayed_hotplug = true;
2592                 mutex_unlock(&fb_helper->lock);
2593                 return err;
2594         }
2595
2596         DRM_DEBUG_KMS("\n");
2597
2598         drm_setup_crtcs(fb_helper, fb_helper->fb->width, fb_helper->fb->height);
2599         drm_setup_crtcs_fb(fb_helper);
2600         mutex_unlock(&fb_helper->lock);
2601
2602         drm_fb_helper_set_par(fb_helper->fbdev);
2603
2604         return 0;
2605 }
2606 EXPORT_SYMBOL(drm_fb_helper_hotplug_event);
2607
2608 /* The Kconfig DRM_KMS_HELPER selects FRAMEBUFFER_CONSOLE (if !EXPERT)
2609  * but the module doesn't depend on any fb console symbols.  At least
2610  * attempt to load fbcon to avoid leaving the system without a usable console.
2611  */
2612 int __init drm_fb_helper_modinit(void)
2613 {
2614 #if defined(CONFIG_FRAMEBUFFER_CONSOLE_MODULE) && !defined(CONFIG_EXPERT)
2615         const char name[] = "fbcon";
2616         struct module *fbcon;
2617
2618         mutex_lock(&module_mutex);
2619         fbcon = find_module(name);
2620         mutex_unlock(&module_mutex);
2621
2622         if (!fbcon)
2623                 request_module_nowait(name);
2624 #endif
2625         return 0;
2626 }
2627 EXPORT_SYMBOL(drm_fb_helper_modinit);