drivers/gpu/drm/drm_plane_helper.c

   1 /*
   2  * Copyright (C) 2014 Intel Corporation
   3  *
   4  * DRM universal plane helper functions
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice (including the next
  14  * paragraph) shall be included in all copies or substantial portions of the
  15  * Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  23  * SOFTWARE.
  24  */
  25
  26 #include <linux/list.h>
  27 #include <drm/drmP.h>
  28 #include <drm/drm_plane_helper.h>
  29 #include <drm/drm_rect.h>
  30 #include <drm/drm_atomic.h>
  31 #include <drm/drm_crtc_helper.h>
  32 #include <drm/drm_atomic_helper.h>
  33
  34 #define SUBPIXEL_MASK 0xffff
  35
  36 /**
  37  * DOC: overview
  38  *
  39  * This helper library has two parts. The first part has support to implement
  40  * primary plane support on top of the normal CRTC configuration interface.
  41  * Since the legacy ->set_config interface ties the primary plane together with
  42  * the CRTC state this does not allow userspace to disable the primary plane
  43  * itself.  To avoid too much duplicated code use
  44  * drm_plane_helper_check_update() which can be used to enforce the same
  45  * restrictions as primary planes had thus. The default primary plane only
  46  * expose XRBG8888 and ARGB8888 as valid pixel formats for the attached
  47  * framebuffer.
  48  *
  49  * Drivers are highly recommended to implement proper support for primary
  50  * planes, and newly merged drivers must not rely upon these transitional
  51  * helpers.
  52  *
  53  * The second part also implements transitional helpers which allow drivers to
  54  * gradually switch to the atomic helper infrastructure for plane updates. Once
  55  * that switch is complete drivers shouldn't use these any longer, instead using
  56  * the proper legacy implementations for update and disable plane hooks provided
  57  * by the atomic helpers.
  58  *
  59  * Again drivers are strongly urged to switch to the new interfaces.
  60  */
  61
  62 /*
  63  * This is the minimal list of formats that seem to be safe for modeset use
  64  * with all current DRM drivers.  Most hardware can actually support more
  65  * formats than this and drivers may specify a more accurate list when
  66  * creating the primary plane.  However drivers that still call
  67  * drm_plane_init() will use this minimal format list as the default.
  68  */
  69 static const uint32_t safe_modeset_formats[] = {
  70         DRM_FORMAT_XRGB8888,
  71         DRM_FORMAT_ARGB8888,
  72 };
  73
  74 /*
  75  * Returns the connectors currently associated with a CRTC.  This function
  76  * should be called twice:  once with a NULL connector list to retrieve
  77  * the list size, and once with the properly allocated list to be filled in.
  78  */
  79 static int get_connectors_for_crtc(struct drm_crtc *crtc,
  80                                    struct drm_connector **connector_list,
  81                                    int num_connectors)
  82 {
  83         struct drm_device *dev = crtc->dev;
  84         struct drm_connector *connector;
  85         int count = 0;
  86
  87         /*
  88          * Note: Once we change the plane hooks to more fine-grained locking we
  89          * need to grab the connection_mutex here to be able to make these
  90          * checks.
  91          */
  92         WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
  93
  94         list_for_each_entry(connector, &dev->mode_config.connector_list, head)
  95                 if (connector->encoder && connector->encoder->crtc == crtc) {
  96                         if (connector_list != NULL && count < num_connectors)
  97                                 *(connector_list++) = connector;
  98
  99                         count++;
 100                 }
 101
 102         return count;
 103 }
 104
 105 /**
 106  * drm_plane_helper_check_update() - Check plane update for validity
 107  * @plane: plane object to update
 108  * @crtc: owning CRTC of owning plane
 109  * @fb: framebuffer to flip onto plane
 110  * @src: source coordinates in 16.16 fixed point
 111  * @dest: integer destination coordinates
 112  * @clip: integer clipping coordinates
 113  * @min_scale: minimum @src:@dest scaling factor in 16.16 fixed point
 114  * @max_scale: maximum @src:@dest scaling factor in 16.16 fixed point
 115  * @can_position: is it legal to position the plane such that it
 116  *                doesn't cover the entire crtc?  This will generally
 117  *                only be false for primary planes.
 118  * @can_update_disabled: can the plane be updated while the crtc
 119  *                       is disabled?
 120  * @visible: output parameter indicating whether plane is still visible after
 121  *           clipping
 122  *
 123  * Checks that a desired plane update is valid.  Drivers that provide
 124  * their own plane handling rather than helper-provided implementations may
 125  * still wish to call this function to avoid duplication of error checking
 126  * code.
 127  *
 128  * RETURNS:
 129  * Zero if update appears valid, error code on failure
 130  */
 131 int drm_plane_helper_check_update(struct drm_plane *plane,
 132                                     struct drm_crtc *crtc,
 133                                     struct drm_framebuffer *fb,
 134                                     struct drm_rect *src,
 135                                     struct drm_rect *dest,
 136                                     const struct drm_rect *clip,
 137                                     int min_scale,
 138                                     int max_scale,
 139                                     bool can_position,
 140                                     bool can_update_disabled,
 141                                     bool *visible)
 142 {
 143         int hscale, vscale;
 144
 145         if (!crtc->enabled && !can_update_disabled) {
 146                 DRM_DEBUG_KMS("Cannot update plane of a disabled CRTC.\n");
 147                 return -EINVAL;
 148         }
 149
 150         /* Check scaling */
 151         hscale = drm_rect_calc_hscale(src, dest, min_scale, max_scale);
 152         vscale = drm_rect_calc_vscale(src, dest, min_scale, max_scale);
 153         if (hscale < 0 || vscale < 0) {
 154                 DRM_DEBUG_KMS("Invalid scaling of plane\n");
 155                 return -ERANGE;
 156         }
 157
 158         if (!fb) {
 159                 *visible = false;
 160                 return 0;
 161         }
 162
 163         *visible = drm_rect_clip_scaled(src, dest, clip, hscale, vscale);
 164         if (!*visible)
 165                 /*
 166                  * Plane isn't visible; some drivers can handle this
 167                  * so we just return success here.  Drivers that can't
 168                  * (including those that use the primary plane helper's
 169                  * update function) will return an error from their
 170                  * update_plane handler.
 171                  */
 172                 return 0;
 173
 174         if (!can_position && !drm_rect_equals(dest, clip)) {
 175                 DRM_DEBUG_KMS("Plane must cover entire CRTC\n");
 176                 return -EINVAL;
 177         }
 178
 179         return 0;
 180 }
 181 EXPORT_SYMBOL(drm_plane_helper_check_update);
 182
 183 /**
 184  * drm_primary_helper_update() - Helper for primary plane update
 185  * @plane: plane object to update
 186  * @crtc: owning CRTC of owning plane
 187  * @fb: framebuffer to flip onto plane
 188  * @crtc_x: x offset of primary plane on crtc
 189  * @crtc_y: y offset of primary plane on crtc
 190  * @crtc_w: width of primary plane rectangle on crtc
 191  * @crtc_h: height of primary plane rectangle on crtc
 192  * @src_x: x offset of @fb for panning
 193  * @src_y: y offset of @fb for panning
 194  * @src_w: width of source rectangle in @fb
 195  * @src_h: height of source rectangle in @fb
 196  *
 197  * Provides a default plane update handler for primary planes.  This is handler
 198  * is called in response to a userspace SetPlane operation on the plane with a
 199  * non-NULL framebuffer.  We call the driver's modeset handler to update the
 200  * framebuffer.
 201  *
 202  * SetPlane() on a primary plane of a disabled CRTC is not supported, and will
 203  * return an error.
 204  *
 205  * Note that we make some assumptions about hardware limitations that may not be
 206  * true for all hardware --
 207  *   1) Primary plane cannot be repositioned.
 208  *   2) Primary plane cannot be scaled.
 209  *   3) Primary plane must cover the entire CRTC.
 210  *   4) Subpixel positioning is not supported.
 211  * Drivers for hardware that don't have these restrictions can provide their
 212  * own implementation rather than using this helper.
 213  *
 214  * RETURNS:
 215  * Zero on success, error code on failure
 216  */
 217 int drm_primary_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
 218                               struct drm_framebuffer *fb,
 219                               int crtc_x, int crtc_y,
 220                               unsigned int crtc_w, unsigned int crtc_h,
 221                               uint32_t src_x, uint32_t src_y,
 222                               uint32_t src_w, uint32_t src_h)
 223 {
 224         struct drm_mode_set set = {
 225                 .crtc = crtc,
 226                 .fb = fb,
 227                 .mode = &crtc->mode,
 228                 .x = src_x >> 16,
 229                 .y = src_y >> 16,
 230         };
 231         struct drm_rect src = {
 232                 .x1 = src_x,
 233                 .y1 = src_y,
 234                 .x2 = src_x + src_w,
 235                 .y2 = src_y + src_h,
 236         };
 237         struct drm_rect dest = {
 238                 .x1 = crtc_x,
 239                 .y1 = crtc_y,
 240                 .x2 = crtc_x + crtc_w,
 241                 .y2 = crtc_y + crtc_h,
 242         };
 243         const struct drm_rect clip = {
 244                 .x2 = crtc->mode.hdisplay,
 245                 .y2 = crtc->mode.vdisplay,
 246         };
 247         struct drm_connector **connector_list;
 248         int num_connectors, ret;
 249         bool visible;
 250
 251         ret = drm_plane_helper_check_update(plane, crtc, fb,
 252                                             &src, &dest, &clip,
 253                                             DRM_PLANE_HELPER_NO_SCALING,
 254                                             DRM_PLANE_HELPER_NO_SCALING,
 255                                             false, false, &visible);
 256         if (ret)
 257                 return ret;
 258
 259         if (!visible)
 260                 /*
 261                  * Primary plane isn't visible.  Note that unless a driver
 262                  * provides their own disable function, this will just
 263                  * wind up returning -EINVAL to userspace.
 264                  */
 265                 return plane->funcs->disable_plane(plane);
 266
 267         /* Find current connectors for CRTC */
 268         num_connectors = get_connectors_for_crtc(crtc, NULL, 0);
 269         BUG_ON(num_connectors == 0);
 270         connector_list = kzalloc(num_connectors * sizeof(*connector_list),
 271                                  GFP_KERNEL);
 272         if (!connector_list)
 273                 return -ENOMEM;
 274         get_connectors_for_crtc(crtc, connector_list, num_connectors);
 275
 276         set.connectors = connector_list;
 277         set.num_connectors = num_connectors;
 278
 279         /*
 280          * We call set_config() directly here rather than using
 281          * drm_mode_set_config_internal.  We're reprogramming the same
 282          * connectors that were already in use, so we shouldn't need the extra
 283          * cross-CRTC fb refcounting to accomodate stealing connectors.
 284          * drm_mode_setplane() already handles the basic refcounting for the
 285          * framebuffers involved in this operation.
 286          */
 287         ret = crtc->funcs->set_config(&set);
 288
 289         kfree(connector_list);
 290         return ret;
 291 }
 292 EXPORT_SYMBOL(drm_primary_helper_update);
 293
 294 /**
 295  * drm_primary_helper_disable() - Helper for primary plane disable
 296  * @plane: plane to disable
 297  *
 298  * Provides a default plane disable handler for primary planes.  This is handler
 299  * is called in response to a userspace SetPlane operation on the plane with a
 300  * NULL framebuffer parameter.  It unconditionally fails the disable call with
 301  * -EINVAL the only way to disable the primary plane without driver support is
 302  * to disable the entier CRTC. Which does not match the plane ->disable hook.
 303  *
 304  * Note that some hardware may be able to disable the primary plane without
 305  * disabling the whole CRTC.  Drivers for such hardware should provide their
 306  * own disable handler that disables just the primary plane (and they'll likely
 307  * need to provide their own update handler as well to properly re-enable a
 308  * disabled primary plane).
 309  *
 310  * RETURNS:
 311  * Unconditionally returns -EINVAL.
 312  */
 313 int drm_primary_helper_disable(struct drm_plane *plane)
 314 {
 315         return -EINVAL;
 316 }
 317 EXPORT_SYMBOL(drm_primary_helper_disable);
 318
 319 /**
 320  * drm_primary_helper_destroy() - Helper for primary plane destruction
 321  * @plane: plane to destroy
 322  *
 323  * Provides a default plane destroy handler for primary planes.  This handler
 324  * is called during CRTC destruction.  We disable the primary plane, remove
 325  * it from the DRM plane list, and deallocate the plane structure.
 326  */
 327 void drm_primary_helper_destroy(struct drm_plane *plane)
 328 {
 329         drm_plane_cleanup(plane);
 330         kfree(plane);
 331 }
 332 EXPORT_SYMBOL(drm_primary_helper_destroy);
 333
 334 const struct drm_plane_funcs drm_primary_helper_funcs = {
 335         .update_plane = drm_primary_helper_update,
 336         .disable_plane = drm_primary_helper_disable,
 337         .destroy = drm_primary_helper_destroy,
 338 };
 339 EXPORT_SYMBOL(drm_primary_helper_funcs);
 340
 341 /**
 342  * drm_primary_helper_create_plane() - Create a generic primary plane
 343  * @dev: drm device
 344  * @formats: pixel formats supported, or NULL for a default safe list
 345  * @num_formats: size of @formats; ignored if @formats is NULL
 346  *
 347  * Allocates and initializes a primary plane that can be used with the primary
 348  * plane helpers.  Drivers that wish to use driver-specific plane structures or
 349  * provide custom handler functions may perform their own allocation and
 350  * initialization rather than calling this function.
 351  */
 352 struct drm_plane *drm_primary_helper_create_plane(struct drm_device *dev,
 353                                                   const uint32_t *formats,
 354                                                   int num_formats)
 355 {
 356         struct drm_plane *primary;
 357         int ret;
 358
 359         primary = kzalloc(sizeof(*primary), GFP_KERNEL);
 360         if (primary == NULL) {
 361                 DRM_DEBUG_KMS("Failed to allocate primary plane\n");
 362                 return NULL;
 363         }
 364
 365         if (formats == NULL) {
 366                 formats = safe_modeset_formats;
 367                 num_formats = ARRAY_SIZE(safe_modeset_formats);
 368         }
 369
 370         /* possible_crtc's will be filled in later by crtc_init */
 371         ret = drm_universal_plane_init(dev, primary, 0,
 372                                        &drm_primary_helper_funcs,
 373                                        formats, num_formats,
 374                                        DRM_PLANE_TYPE_PRIMARY);
 375         if (ret) {
 376                 kfree(primary);
 377                 primary = NULL;
 378         }
 379
 380         return primary;
 381 }
 382 EXPORT_SYMBOL(drm_primary_helper_create_plane);
 383
 384 /**
 385  * drm_crtc_init - Legacy CRTC initialization function
 386  * @dev: DRM device
 387  * @crtc: CRTC object to init
 388  * @funcs: callbacks for the new CRTC
 389  *
 390  * Initialize a CRTC object with a default helper-provided primary plane and no
 391  * cursor plane.
 392  *
 393  * Returns:
 394  * Zero on success, error code on failure.
 395  */
 396 int drm_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
 397                   const struct drm_crtc_funcs *funcs)
 398 {
 399         struct drm_plane *primary;
 400
 401         primary = drm_primary_helper_create_plane(dev, NULL, 0);
 402         return drm_crtc_init_with_planes(dev, crtc, primary, NULL, funcs);
 403 }
 404 EXPORT_SYMBOL(drm_crtc_init);
 405
 406 int drm_plane_helper_commit(struct drm_plane *plane,
 407                             struct drm_plane_state *plane_state,
 408                             struct drm_framebuffer *old_fb)
 409 {
 410         struct drm_plane_helper_funcs *plane_funcs;
 411         struct drm_crtc *crtc[2];
 412         struct drm_crtc_helper_funcs *crtc_funcs[2];
 413         int i, ret = 0;
 414
 415         plane_funcs = plane->helper_private;
 416
 417         /* Since this is a transitional helper we can't assume that plane->state
 418          * is always valid. Hence we need to use plane->crtc instead of
 419          * plane->state->crtc as the old crtc. */
 420         crtc[0] = plane->crtc;
 421         crtc[1] = crtc[0] != plane_state->crtc ? plane_state->crtc : NULL;
 422
 423         for (i = 0; i < 2; i++)
 424                 crtc_funcs[i] = crtc[i] ? crtc[i]->helper_private : NULL;
 425
 426         if (plane_funcs->atomic_check) {
 427                 ret = plane_funcs->atomic_check(plane, plane_state);
 428                 if (ret)
 429                         goto out;
 430         }
 431
 432         if (plane_funcs->prepare_fb && plane_state->fb) {
 433                 ret = plane_funcs->prepare_fb(plane, plane_state->fb);
 434                 if (ret)
 435                         goto out;
 436         }
 437
 438         /* Point of no return, commit sw state. */
 439         swap(plane->state, plane_state);
 440
 441         for (i = 0; i < 2; i++) {
 442                 if (crtc_funcs[i] && crtc_funcs[i]->atomic_begin)
 443                         crtc_funcs[i]->atomic_begin(crtc[i]);
 444         }
 445
 446         plane_funcs->atomic_update(plane);
 447
 448         for (i = 0; i < 2; i++) {
 449                 if (crtc_funcs[i] && crtc_funcs[i]->atomic_flush)
 450                         crtc_funcs[i]->atomic_flush(crtc[i]);
 451         }
 452
 453         for (i = 0; i < 2; i++) {
 454                 if (!crtc[i])
 455                         continue;
 456
 457                 /* There's no other way to figure out whether the crtc is running. */
 458                 ret = drm_crtc_vblank_get(crtc[i]);
 459                 if (ret == 0) {
 460                         drm_crtc_wait_one_vblank(crtc[i]);
 461                         drm_crtc_vblank_put(crtc[i]);
 462                 }
 463
 464                 ret = 0;
 465         }
 466
 467         if (plane_funcs->cleanup_fb && old_fb)
 468                 plane_funcs->cleanup_fb(plane, old_fb);
 469 out:
 470         if (plane_state) {
 471                 if (plane->funcs->atomic_destroy_state)
 472                         plane->funcs->atomic_destroy_state(plane, plane_state);
 473                 else
 474                         drm_atomic_helper_plane_destroy_state(plane, plane_state);
 475         }
 476
 477         return ret;
 478 }
 479
 480 /**
 481  * drm_plane_helper_update() - Helper for primary plane update
 482  * @plane: plane object to update
 483  * @crtc: owning CRTC of owning plane
 484  * @fb: framebuffer to flip onto plane
 485  * @crtc_x: x offset of primary plane on crtc
 486  * @crtc_y: y offset of primary plane on crtc
 487  * @crtc_w: width of primary plane rectangle on crtc
 488  * @crtc_h: height of primary plane rectangle on crtc
 489  * @src_x: x offset of @fb for panning
 490  * @src_y: y offset of @fb for panning
 491  * @src_w: width of source rectangle in @fb
 492  * @src_h: height of source rectangle in @fb
 493  *
 494  * Provides a default plane update handler using the atomic plane update
 495  * functions. It is fully left to the driver to check plane constraints and
 496  * handle corner-cases like a fully occluded or otherwise invisible plane.
 497  *
 498  * This is useful for piecewise transitioning of a driver to the atomic helpers.
 499  *
 500  * RETURNS:
 501  * Zero on success, error code on failure
 502  */
 503 int drm_plane_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
 504                             struct drm_framebuffer *fb,
 505                             int crtc_x, int crtc_y,
 506                             unsigned int crtc_w, unsigned int crtc_h,
 507                             uint32_t src_x, uint32_t src_y,
 508                             uint32_t src_w, uint32_t src_h)
 509 {
 510         struct drm_plane_state *plane_state;
 511
 512         if (plane->funcs->atomic_duplicate_state)
 513                 plane_state = plane->funcs->atomic_duplicate_state(plane);
 514         else if (plane->state)
 515                 plane_state = drm_atomic_helper_plane_duplicate_state(plane);
 516         else
 517                 plane_state = kzalloc(sizeof(*plane_state), GFP_KERNEL);
 518         if (!plane_state)
 519                 return -ENOMEM;
 520
 521         plane_state->crtc = crtc;
 522         drm_atomic_set_fb_for_plane(plane_state, fb);
 523         plane_state->crtc_x = crtc_x;
 524         plane_state->crtc_y = crtc_y;
 525         plane_state->crtc_h = crtc_h;
 526         plane_state->crtc_w = crtc_w;
 527         plane_state->src_x = src_x;
 528         plane_state->src_y = src_y;
 529         plane_state->src_h = src_h;
 530         plane_state->src_w = src_w;
 531
 532         return drm_plane_helper_commit(plane, plane_state, plane->fb);
 533 }
 534 EXPORT_SYMBOL(drm_plane_helper_update);
 535
 536 /**
 537  * drm_plane_helper_disable() - Helper for primary plane disable
 538  * @plane: plane to disable
 539  *
 540  * Provides a default plane disable handler using the atomic plane update
 541  * functions. It is fully left to the driver to check plane constraints and
 542  * handle corner-cases like a fully occluded or otherwise invisible plane.
 543  *
 544  * This is useful for piecewise transitioning of a driver to the atomic helpers.
 545  *
 546  * RETURNS:
 547  * Zero on success, error code on failure
 548  */
 549 int drm_plane_helper_disable(struct drm_plane *plane)
 550 {
 551         struct drm_plane_state *plane_state;
 552
 553         /* crtc helpers love to call disable functions for already disabled hw
 554          * functions. So cope with that. */
 555         if (!plane->crtc)
 556                 return 0;
 557
 558         if (plane->funcs->atomic_duplicate_state)
 559                 plane_state = plane->funcs->atomic_duplicate_state(plane);
 560         else if (plane->state)
 561                 plane_state = drm_atomic_helper_plane_duplicate_state(plane);
 562         else
 563                 plane_state = kzalloc(sizeof(*plane_state), GFP_KERNEL);
 564         if (!plane_state)
 565                 return -ENOMEM;
 566
 567         plane_state->crtc = NULL;
 568         drm_atomic_set_fb_for_plane(plane_state, NULL);
 569
 570         return drm_plane_helper_commit(plane, plane_state, plane->fb);
 571 }
 572 EXPORT_SYMBOL(drm_plane_helper_disable);