1 /* 2 * Copyright © 2006 Keith Packard 3 * Copyright © 2007-2008 Dave Airlie 4 * Copyright © 2007-2008 Intel Corporation 5 * Jesse Barnes <jesse.barnes@intel.com> 6 * Copyright © 2011-2013 Intel Corporation 7 * Copyright © 2015 Intel Corporation 8 * Daniel Vetter <daniel.vetter@ffwll.ch> 9 * 10 * Permission is hereby granted, free of charge, to any person obtaining a 11 * copy of this software and associated documentation files (the "Software"), 12 * to deal in the Software without restriction, including without limitation 13 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 14 * and/or sell copies of the Software, and to permit persons to whom the 15 * Software is furnished to do so, subject to the following conditions: 16 * 17 * The above copyright notice and this permission notice shall be included in 18 * all copies or substantial portions of the Software. 19 * 20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 23 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR 24 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 25 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 26 * OTHER DEALINGS IN THE SOFTWARE. 27 */ 28 29 #ifndef __DRM_MODESET_HELPER_VTABLES_H__ 30 #define __DRM_MODESET_HELPER_VTABLES_H__ 31 32 #include <drm/drm_crtc.h> 33 #include <drm/drm_encoder.h> 34 35 /** 36 * DOC: overview 37 * 38 * The DRM mode setting helper functions are common code for drivers to use if 39 * they wish. Drivers are not forced to use this code in their 40 * implementations but it would be useful if the code they do use at least 41 * provides a consistent interface and operation to userspace. Therefore it is 42 * highly recommended to use the provided helpers as much as possible. 43 * 44 * Because there is only one pointer per modeset object to hold a vfunc table 45 * for helper libraries they are by necessity shared among the different 46 * helpers. 47 * 48 * To make this clear all the helper vtables are pulled together in this location here. 49 */ 50 51 struct drm_scanout_buffer; 52 struct drm_writeback_connector; 53 struct drm_writeback_job; 54 55 /** 56 * struct drm_crtc_helper_funcs - helper operations for CRTCs 57 * 58 * These hooks are used by the legacy CRTC helpers and the new atomic 59 * modesetting helpers. 60 */ 61 struct drm_crtc_helper_funcs { 62 /** 63 * @dpms: 64 * 65 * Callback to control power levels on the CRTC. If the mode passed in 66 * is unsupported, the provider must use the next lowest power level. 67 * This is used by the legacy CRTC helpers to implement DPMS 68 * functionality in drm_helper_connector_dpms(). 69 * 70 * This callback is also used to disable a CRTC by calling it with 71 * DRM_MODE_DPMS_OFF if the @disable hook isn't used. 72 * 73 * This callback is used by the legacy CRTC helpers. Atomic helpers 74 * also support using this hook for enabling and disabling a CRTC to 75 * facilitate transitions to atomic, but it is deprecated. Instead 76 * @atomic_enable and @atomic_disable should be used. 77 */ 78 void (*dpms)(struct drm_crtc *crtc, int mode); 79 80 /** 81 * @prepare: 82 * 83 * This callback should prepare the CRTC for a subsequent modeset, which 84 * in practice means the driver should disable the CRTC if it is 85 * running. Most drivers ended up implementing this by calling their 86 * @dpms hook with DRM_MODE_DPMS_OFF. 87 * 88 * This callback is used by the legacy CRTC helpers. Atomic helpers 89 * also support using this hook for disabling a CRTC to facilitate 90 * transitions to atomic, but it is deprecated. Instead @atomic_disable 91 * should be used. 92 */ 93 void (*prepare)(struct drm_crtc *crtc); 94 95 /** 96 * @commit: 97 * 98 * This callback should commit the new mode on the CRTC after a modeset, 99 * which in practice means the driver should enable the CRTC. Most 100 * drivers ended up implementing this by calling their @dpms hook with 101 * DRM_MODE_DPMS_ON. 102 * 103 * This callback is used by the legacy CRTC helpers. Atomic helpers 104 * also support using this hook for enabling a CRTC to facilitate 105 * transitions to atomic, but it is deprecated. Instead @atomic_enable 106 * should be used. 107 */ 108 void (*commit)(struct drm_crtc *crtc); 109 110 /** 111 * @mode_valid: 112 * 113 * This callback is used to check if a specific mode is valid in this 114 * crtc. This should be implemented if the crtc has some sort of 115 * restriction in the modes it can display. For example, a given crtc 116 * may be responsible to set a clock value. If the clock can not 117 * produce all the values for the available modes then this callback 118 * can be used to restrict the number of modes to only the ones that 119 * can be displayed. 120 * 121 * This hook is used by the probe helpers to filter the mode list in 122 * drm_helper_probe_single_connector_modes(), and it is used by the 123 * atomic helpers to validate modes supplied by userspace in 124 * drm_atomic_helper_check_modeset(). 125 * 126 * This function is optional. 127 * 128 * NOTE: 129 * 130 * Since this function is both called from the check phase of an atomic 131 * commit, and the mode validation in the probe paths it is not allowed 132 * to look at anything else but the passed-in mode, and validate it 133 * against configuration-invariant hardware constraints. Any further 134 * limits which depend upon the configuration can only be checked in 135 * @mode_fixup or @atomic_check. 136 * 137 * RETURNS: 138 * 139 * drm_mode_status Enum 140 */ 141 enum drm_mode_status (*mode_valid)(struct drm_crtc *crtc, 142 const struct drm_display_mode *mode); 143 144 /** 145 * @mode_fixup: 146 * 147 * This callback is used to validate a mode. The parameter mode is the 148 * display mode that userspace requested, adjusted_mode is the mode the 149 * encoders need to be fed with. Note that this is the inverse semantics 150 * of the meaning for the &drm_encoder and &drm_bridge_funcs.mode_fixup 151 * vfunc. If the CRTC cannot support the requested conversion from mode 152 * to adjusted_mode it should reject the modeset. See also 153 * &drm_crtc_state.adjusted_mode for more details. 154 * 155 * This function is used by both legacy CRTC helpers and atomic helpers. 156 * With atomic helpers it is optional. 157 * 158 * NOTE: 159 * 160 * This function is called in the check phase of atomic modesets, which 161 * can be aborted for any reason (including on userspace's request to 162 * just check whether a configuration would be possible). Atomic drivers 163 * MUST NOT touch any persistent state (hardware or software) or data 164 * structures except the passed in adjusted_mode parameter. 165 * 166 * This is in contrast to the legacy CRTC helpers where this was 167 * allowed. 168 * 169 * Atomic drivers which need to inspect and adjust more state should 170 * instead use the @atomic_check callback, but note that they're not 171 * perfectly equivalent: @mode_valid is called from 172 * drm_atomic_helper_check_modeset(), but @atomic_check is called from 173 * drm_atomic_helper_check_planes(), because originally it was meant for 174 * plane update checks only. 175 * 176 * Also beware that userspace can request its own custom modes, neither 177 * core nor helpers filter modes to the list of probe modes reported by 178 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure 179 * that modes are filtered consistently put any CRTC constraints and 180 * limits checks into @mode_valid. 181 * 182 * RETURNS: 183 * 184 * True if an acceptable configuration is possible, false if the modeset 185 * operation should be rejected. 186 */ 187 bool (*mode_fixup)(struct drm_crtc *crtc, 188 const struct drm_display_mode *mode, 189 struct drm_display_mode *adjusted_mode); 190 191 /** 192 * @mode_set: 193 * 194 * This callback is used by the legacy CRTC helpers to set a new mode, 195 * position and framebuffer. Since it ties the primary plane to every 196 * mode change it is incompatible with universal plane support. And 197 * since it can't update other planes it's incompatible with atomic 198 * modeset support. 199 * 200 * This callback is only used by CRTC helpers and deprecated. 201 * 202 * RETURNS: 203 * 204 * 0 on success or a negative error code on failure. 205 */ 206 int (*mode_set)(struct drm_crtc *crtc, struct drm_display_mode *mode, 207 struct drm_display_mode *adjusted_mode, int x, int y, 208 struct drm_framebuffer *old_fb); 209 210 /** 211 * @mode_set_nofb: 212 * 213 * This callback is used to update the display mode of a CRTC without 214 * changing anything of the primary plane configuration. This fits the 215 * requirement of atomic and hence is used by the atomic helpers. 216 * 217 * Note that the display pipe is completely off when this function is 218 * called. Atomic drivers which need hardware to be running before they 219 * program the new display mode (e.g. because they implement runtime PM) 220 * should not use this hook. This is because the helper library calls 221 * this hook only once per mode change and not every time the display 222 * pipeline is suspended using either DPMS or the new "ACTIVE" property. 223 * Which means register values set in this callback might get reset when 224 * the CRTC is suspended, but not restored. Such drivers should instead 225 * move all their CRTC setup into the @atomic_enable callback. 226 * 227 * This callback is optional. 228 */ 229 void (*mode_set_nofb)(struct drm_crtc *crtc); 230 231 /** 232 * @mode_set_base: 233 * 234 * This callback is used by the legacy CRTC helpers to set a new 235 * framebuffer and scanout position. It is optional and used as an 236 * optimized fast-path instead of a full mode set operation with all the 237 * resulting flickering. If it is not present 238 * drm_crtc_helper_set_config() will fall back to a full modeset, using 239 * the @mode_set callback. Since it can't update other planes it's 240 * incompatible with atomic modeset support. 241 * 242 * This callback is only used by the CRTC helpers and deprecated. 243 * 244 * RETURNS: 245 * 246 * 0 on success or a negative error code on failure. 247 */ 248 int (*mode_set_base)(struct drm_crtc *crtc, int x, int y, 249 struct drm_framebuffer *old_fb); 250 251 /** 252 * @disable: 253 * 254 * This callback should be used to disable the CRTC. With the atomic 255 * drivers it is called after all encoders connected to this CRTC have 256 * been shut off already using their own 257 * &drm_encoder_helper_funcs.disable hook. If that sequence is too 258 * simple drivers can just add their own hooks and call it from this 259 * CRTC callback here by looping over all encoders connected to it using 260 * for_each_encoder_on_crtc(). 261 * 262 * This hook is used both by legacy CRTC helpers and atomic helpers. 263 * Atomic drivers don't need to implement it if there's no need to 264 * disable anything at the CRTC level. To ensure that runtime PM 265 * handling (using either DPMS or the new "ACTIVE" property) works 266 * @disable must be the inverse of @atomic_enable for atomic drivers. 267 * Atomic drivers should consider to use @atomic_disable instead of 268 * this one. 269 * 270 * NOTE: 271 * 272 * With legacy CRTC helpers there's a big semantic difference between 273 * @disable and other hooks (like @prepare or @dpms) used to shut down a 274 * CRTC: @disable is only called when also logically disabling the 275 * display pipeline and needs to release any resources acquired in 276 * @mode_set (like shared PLLs, or again release pinned framebuffers). 277 * 278 * Therefore @disable must be the inverse of @mode_set plus @commit for 279 * drivers still using legacy CRTC helpers, which is different from the 280 * rules under atomic. 281 */ 282 void (*disable)(struct drm_crtc *crtc); 283 284 /** 285 * @atomic_check: 286 * 287 * Drivers should check plane-update related CRTC constraints in this 288 * hook. They can also check mode related limitations but need to be 289 * aware of the calling order, since this hook is used by 290 * drm_atomic_helper_check_planes() whereas the preparations needed to 291 * check output routing and the display mode is done in 292 * drm_atomic_helper_check_modeset(). Therefore drivers that want to 293 * check output routing and display mode constraints in this callback 294 * must ensure that drm_atomic_helper_check_modeset() has been called 295 * beforehand. This is calling order used by the default helper 296 * implementation in drm_atomic_helper_check(). 297 * 298 * When using drm_atomic_helper_check_planes() this hook is called 299 * after the &drm_plane_helper_funcs.atomic_check hook for planes, which 300 * allows drivers to assign shared resources requested by planes in this 301 * callback here. For more complicated dependencies the driver can call 302 * the provided check helpers multiple times until the computed state 303 * has a final configuration and everything has been checked. 304 * 305 * This function is also allowed to inspect any other object's state and 306 * can add more state objects to the atomic commit if needed. Care must 307 * be taken though to ensure that state check and compute functions for 308 * these added states are all called, and derived state in other objects 309 * all updated. Again the recommendation is to just call check helpers 310 * until a maximal configuration is reached. 311 * 312 * This callback is used by the atomic modeset helpers, but it is 313 * optional. 314 * 315 * NOTE: 316 * 317 * This function is called in the check phase of an atomic update. The 318 * driver is not allowed to change anything outside of the free-standing 319 * state object passed-in. 320 * 321 * Also beware that userspace can request its own custom modes, neither 322 * core nor helpers filter modes to the list of probe modes reported by 323 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure 324 * that modes are filtered consistently put any CRTC constraints and 325 * limits checks into @mode_valid. 326 * 327 * RETURNS: 328 * 329 * 0 on success, -EINVAL if the state or the transition can't be 330 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an 331 * attempt to obtain another state object ran into a &drm_modeset_lock 332 * deadlock. 333 */ 334 int (*atomic_check)(struct drm_crtc *crtc, 335 struct drm_atomic_state *state); 336 337 /** 338 * @atomic_begin: 339 * 340 * Drivers should prepare for an atomic update of multiple planes on 341 * a CRTC in this hook. Depending upon hardware this might be vblank 342 * evasion, blocking updates by setting bits or doing preparatory work 343 * for e.g. manual update display. 344 * 345 * This hook is called before any plane commit functions are called. 346 * 347 * Note that the power state of the display pipe when this function is 348 * called depends upon the exact helpers and calling sequence the driver 349 * has picked. See drm_atomic_helper_commit_planes() for a discussion of 350 * the tradeoffs and variants of plane commit helpers. 351 * 352 * This callback is used by the atomic modeset helpers, but it is 353 * optional. 354 */ 355 void (*atomic_begin)(struct drm_crtc *crtc, 356 struct drm_atomic_state *state); 357 /** 358 * @atomic_flush: 359 * 360 * Drivers should finalize an atomic update of multiple planes on 361 * a CRTC in this hook. Depending upon hardware this might include 362 * checking that vblank evasion was successful, unblocking updates by 363 * setting bits or setting the GO bit to flush out all updates. 364 * 365 * Simple hardware or hardware with special requirements can commit and 366 * flush out all updates for all planes from this hook and forgo all the 367 * other commit hooks for plane updates. 368 * 369 * This hook is called after any plane commit functions are called. 370 * 371 * Note that the power state of the display pipe when this function is 372 * called depends upon the exact helpers and calling sequence the driver 373 * has picked. See drm_atomic_helper_commit_planes() for a discussion of 374 * the tradeoffs and variants of plane commit helpers. 375 * 376 * This callback is used by the atomic modeset helpers, but it is 377 * optional. 378 */ 379 void (*atomic_flush)(struct drm_crtc *crtc, 380 struct drm_atomic_state *state); 381 382 /** 383 * @atomic_enable: 384 * 385 * This callback should be used to enable the CRTC. With the atomic 386 * drivers it is called before all encoders connected to this CRTC are 387 * enabled through the encoder's own &drm_encoder_helper_funcs.enable 388 * hook. If that sequence is too simple drivers can just add their own 389 * hooks and call it from this CRTC callback here by looping over all 390 * encoders connected to it using for_each_encoder_on_crtc(). 391 * 392 * This hook is used only by atomic helpers, for symmetry with 393 * @atomic_disable. Atomic drivers don't need to implement it if there's 394 * no need to enable anything at the CRTC level. To ensure that runtime 395 * PM handling (using either DPMS or the new "ACTIVE" property) works 396 * @atomic_enable must be the inverse of @atomic_disable for atomic 397 * drivers. 398 * 399 * This function is optional. 400 */ 401 void (*atomic_enable)(struct drm_crtc *crtc, 402 struct drm_atomic_state *state); 403 404 /** 405 * @atomic_disable: 406 * 407 * This callback should be used to disable the CRTC. With the atomic 408 * drivers it is called after all encoders connected to this CRTC have 409 * been shut off already using their own 410 * &drm_encoder_helper_funcs.disable hook. If that sequence is too 411 * simple drivers can just add their own hooks and call it from this 412 * CRTC callback here by looping over all encoders connected to it using 413 * for_each_encoder_on_crtc(). 414 * 415 * This hook is used only by atomic helpers. Atomic drivers don't 416 * need to implement it if there's no need to disable anything at the 417 * CRTC level. 418 * 419 * This function is optional. 420 */ 421 void (*atomic_disable)(struct drm_crtc *crtc, 422 struct drm_atomic_state *state); 423 424 /** 425 * @get_scanout_position: 426 * 427 * Called by vblank timestamping code. 428 * 429 * Returns the current display scanout position from a CRTC and an 430 * optional accurate ktime_get() timestamp of when the position was 431 * measured. Note that this is a helper callback which is only used 432 * if a driver uses drm_crtc_vblank_helper_get_vblank_timestamp() 433 * for the @drm_crtc_funcs.get_vblank_timestamp callback. 434 * 435 * Parameters: 436 * 437 * crtc: 438 * The CRTC. 439 * in_vblank_irq: 440 * True when called from drm_crtc_handle_vblank(). Some drivers 441 * need to apply some workarounds for gpu-specific vblank irq 442 * quirks if the flag is set. 443 * vpos: 444 * Target location for current vertical scanout position. 445 * hpos: 446 * Target location for current horizontal scanout position. 447 * stime: 448 * Target location for timestamp taken immediately before 449 * scanout position query. Can be NULL to skip timestamp. 450 * etime: 451 * Target location for timestamp taken immediately after 452 * scanout position query. Can be NULL to skip timestamp. 453 * mode: 454 * Current display timings. 455 * 456 * Returns vpos as a positive number while in active scanout area. 457 * Returns vpos as a negative number inside vblank, counting the number 458 * of scanlines to go until end of vblank, e.g., -1 means "one scanline 459 * until start of active scanout / end of vblank." 460 * 461 * Returns: 462 * 463 * True on success, false if a reliable scanout position counter could 464 * not be read out. 465 */ 466 bool (*get_scanout_position)(struct drm_crtc *crtc, 467 bool in_vblank_irq, int *vpos, int *hpos, 468 ktime_t *stime, ktime_t *etime, 469 const struct drm_display_mode *mode); 470 471 /** 472 * @handle_vblank_timeout: Handles timeouts of the vblank timer. 473 * 474 * Called by CRTC's the vblank timer on each timeout. Semantics is 475 * equivalient to drm_crtc_handle_vblank(). Implementations should 476 * invoke drm_crtc_handle_vblank() as part of processing the timeout. 477 * 478 * This callback is optional. If unset, the vblank timer invokes 479 * drm_crtc_handle_vblank() directly. 480 */ 481 bool (*handle_vblank_timeout)(struct drm_crtc *crtc); 482 }; 483 484 /** 485 * drm_crtc_helper_add - sets the helper vtable for a crtc 486 * @crtc: DRM CRTC 487 * @funcs: helper vtable to set for @crtc 488 */ 489 static inline void drm_crtc_helper_add(struct drm_crtc *crtc, 490 const struct drm_crtc_helper_funcs *funcs) 491 { 492 crtc->helper_private = funcs; 493 } 494 495 /** 496 * struct drm_encoder_helper_funcs - helper operations for encoders 497 * 498 * These hooks are used by the legacy CRTC helpers and the new atomic 499 * modesetting helpers. 500 */ 501 struct drm_encoder_helper_funcs { 502 /** 503 * @dpms: 504 * 505 * Callback to control power levels on the encoder. If the mode passed in 506 * is unsupported, the provider must use the next lowest power level. 507 * This is used by the legacy encoder helpers to implement DPMS 508 * functionality in drm_helper_connector_dpms(). 509 * 510 * This callback is also used to disable an encoder by calling it with 511 * DRM_MODE_DPMS_OFF if the @disable hook isn't used. 512 * 513 * This callback is used by the legacy CRTC helpers. Atomic helpers 514 * also support using this hook for enabling and disabling an encoder to 515 * facilitate transitions to atomic, but it is deprecated. Instead 516 * @enable and @disable should be used. 517 */ 518 void (*dpms)(struct drm_encoder *encoder, int mode); 519 520 /** 521 * @mode_valid: 522 * 523 * This callback is used to check if a specific mode is valid in this 524 * encoder. This should be implemented if the encoder has some sort 525 * of restriction in the modes it can display. For example, a given 526 * encoder may be responsible to set a clock value. If the clock can 527 * not produce all the values for the available modes then this callback 528 * can be used to restrict the number of modes to only the ones that 529 * can be displayed. 530 * 531 * This hook is used by the probe helpers to filter the mode list in 532 * drm_helper_probe_single_connector_modes(), and it is used by the 533 * atomic helpers to validate modes supplied by userspace in 534 * drm_atomic_helper_check_modeset(). 535 * 536 * This function is optional. 537 * 538 * NOTE: 539 * 540 * Since this function is both called from the check phase of an atomic 541 * commit, and the mode validation in the probe paths it is not allowed 542 * to look at anything else but the passed-in mode, and validate it 543 * against configuration-invariant hardware constraints. Any further 544 * limits which depend upon the configuration can only be checked in 545 * @mode_fixup or @atomic_check. 546 * 547 * RETURNS: 548 * 549 * drm_mode_status Enum 550 */ 551 enum drm_mode_status (*mode_valid)(struct drm_encoder *crtc, 552 const struct drm_display_mode *mode); 553 554 /** 555 * @mode_fixup: 556 * 557 * This callback is used to validate and adjust a mode. The parameter 558 * mode is the display mode that should be fed to the next element in 559 * the display chain, either the final &drm_connector or a &drm_bridge. 560 * The parameter adjusted_mode is the input mode the encoder requires. It 561 * can be modified by this callback and does not need to match mode. See 562 * also &drm_crtc_state.adjusted_mode for more details. 563 * 564 * This function is used by both legacy CRTC helpers and atomic helpers. 565 * This hook is optional. 566 * 567 * NOTE: 568 * 569 * This function is called in the check phase of atomic modesets, which 570 * can be aborted for any reason (including on userspace's request to 571 * just check whether a configuration would be possible). Atomic drivers 572 * MUST NOT touch any persistent state (hardware or software) or data 573 * structures except the passed in adjusted_mode parameter. 574 * 575 * This is in contrast to the legacy CRTC helpers where this was 576 * allowed. 577 * 578 * Atomic drivers which need to inspect and adjust more state should 579 * instead use the @atomic_check callback. If @atomic_check is used, 580 * this hook isn't called since @atomic_check allows a strict superset 581 * of the functionality of @mode_fixup. 582 * 583 * Also beware that userspace can request its own custom modes, neither 584 * core nor helpers filter modes to the list of probe modes reported by 585 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure 586 * that modes are filtered consistently put any encoder constraints and 587 * limits checks into @mode_valid. 588 * 589 * RETURNS: 590 * 591 * True if an acceptable configuration is possible, false if the modeset 592 * operation should be rejected. 593 */ 594 bool (*mode_fixup)(struct drm_encoder *encoder, 595 const struct drm_display_mode *mode, 596 struct drm_display_mode *adjusted_mode); 597 598 /** 599 * @prepare: 600 * 601 * This callback should prepare the encoder for a subsequent modeset, 602 * which in practice means the driver should disable the encoder if it 603 * is running. Most drivers ended up implementing this by calling their 604 * @dpms hook with DRM_MODE_DPMS_OFF. 605 * 606 * This callback is used by the legacy CRTC helpers. Atomic helpers 607 * also support using this hook for disabling an encoder to facilitate 608 * transitions to atomic, but it is deprecated. Instead @disable should 609 * be used. 610 */ 611 void (*prepare)(struct drm_encoder *encoder); 612 613 /** 614 * @commit: 615 * 616 * This callback should commit the new mode on the encoder after a modeset, 617 * which in practice means the driver should enable the encoder. Most 618 * drivers ended up implementing this by calling their @dpms hook with 619 * DRM_MODE_DPMS_ON. 620 * 621 * This callback is used by the legacy CRTC helpers. Atomic helpers 622 * also support using this hook for enabling an encoder to facilitate 623 * transitions to atomic, but it is deprecated. Instead @enable should 624 * be used. 625 */ 626 void (*commit)(struct drm_encoder *encoder); 627 628 /** 629 * @mode_set: 630 * 631 * This callback is used to update the display mode of an encoder. 632 * 633 * Note that the display pipe is completely off when this function is 634 * called. Drivers which need hardware to be running before they program 635 * the new display mode (because they implement runtime PM) should not 636 * use this hook, because the helper library calls it only once and not 637 * every time the display pipeline is suspend using either DPMS or the 638 * new "ACTIVE" property. Such drivers should instead move all their 639 * encoder setup into the @enable callback. 640 * 641 * This callback is used both by the legacy CRTC helpers and the atomic 642 * modeset helpers. It is optional in the atomic helpers. 643 * 644 * NOTE: 645 * 646 * If the driver uses the atomic modeset helpers and needs to inspect 647 * the connector state or connector display info during mode setting, 648 * @atomic_mode_set can be used instead. 649 */ 650 void (*mode_set)(struct drm_encoder *encoder, 651 struct drm_display_mode *mode, 652 struct drm_display_mode *adjusted_mode); 653 654 /** 655 * @atomic_mode_set: 656 * 657 * This callback is used to update the display mode of an encoder. 658 * 659 * Note that the display pipe is completely off when this function is 660 * called. Drivers which need hardware to be running before they program 661 * the new display mode (because they implement runtime PM) should not 662 * use this hook, because the helper library calls it only once and not 663 * every time the display pipeline is suspended using either DPMS or the 664 * new "ACTIVE" property. Such drivers should instead move all their 665 * encoder setup into the @enable callback. 666 * 667 * This callback is used by the atomic modeset helpers in place of the 668 * @mode_set callback, if set by the driver. It is optional and should 669 * be used instead of @mode_set if the driver needs to inspect the 670 * connector state or display info, since there is no direct way to 671 * go from the encoder to the current connector. 672 */ 673 void (*atomic_mode_set)(struct drm_encoder *encoder, 674 struct drm_crtc_state *crtc_state, 675 struct drm_connector_state *conn_state); 676 677 /** 678 * @detect: 679 * 680 * This callback can be used by drivers who want to do detection on the 681 * encoder object instead of in connector functions. 682 * 683 * It is not used by any helper and therefore has purely driver-specific 684 * semantics. New drivers shouldn't use this and instead just implement 685 * their own private callbacks. 686 * 687 * FIXME: 688 * 689 * This should just be converted into a pile of driver vfuncs. 690 * Currently radeon, amdgpu and nouveau are using it. 691 */ 692 enum drm_connector_status (*detect)(struct drm_encoder *encoder, 693 struct drm_connector *connector); 694 695 /** 696 * @atomic_disable: 697 * 698 * This callback should be used to disable the encoder. With the atomic 699 * drivers it is called before this encoder's CRTC has been shut off 700 * using their own &drm_crtc_helper_funcs.atomic_disable hook. If that 701 * sequence is too simple drivers can just add their own driver private 702 * encoder hooks and call them from CRTC's callback by looping over all 703 * encoders connected to it using for_each_encoder_on_crtc(). 704 * 705 * This callback is a variant of @disable that provides the atomic state 706 * to the driver. If @atomic_disable is implemented, @disable is not 707 * called by the helpers. 708 * 709 * This hook is only used by atomic helpers. Atomic drivers don't need 710 * to implement it if there's no need to disable anything at the encoder 711 * level. To ensure that runtime PM handling (using either DPMS or the 712 * new "ACTIVE" property) works @atomic_disable must be the inverse of 713 * @atomic_enable. 714 */ 715 void (*atomic_disable)(struct drm_encoder *encoder, 716 struct drm_atomic_state *state); 717 718 /** 719 * @atomic_enable: 720 * 721 * This callback should be used to enable the encoder. It is called 722 * after this encoder's CRTC has been enabled using their own 723 * &drm_crtc_helper_funcs.atomic_enable hook. If that sequence is 724 * too simple drivers can just add their own driver private encoder 725 * hooks and call them from CRTC's callback by looping over all encoders 726 * connected to it using for_each_encoder_on_crtc(). 727 * 728 * This callback is a variant of @enable that provides the atomic state 729 * to the driver. If @atomic_enable is implemented, @enable is not 730 * called by the helpers. 731 * 732 * This hook is only used by atomic helpers, it is the opposite of 733 * @atomic_disable. Atomic drivers don't need to implement it if there's 734 * no need to enable anything at the encoder level. To ensure that 735 * runtime PM handling works @atomic_enable must be the inverse of 736 * @atomic_disable. 737 */ 738 void (*atomic_enable)(struct drm_encoder *encoder, 739 struct drm_atomic_state *state); 740 741 /** 742 * @disable: 743 * 744 * This callback should be used to disable the encoder. With the atomic 745 * drivers it is called before this encoder's CRTC has been shut off 746 * using their own &drm_crtc_helper_funcs.disable hook. If that 747 * sequence is too simple drivers can just add their own driver private 748 * encoder hooks and call them from CRTC's callback by looping over all 749 * encoders connected to it using for_each_encoder_on_crtc(). 750 * 751 * This hook is used both by legacy CRTC helpers and atomic helpers. 752 * Atomic drivers don't need to implement it if there's no need to 753 * disable anything at the encoder level. To ensure that runtime PM 754 * handling (using either DPMS or the new "ACTIVE" property) works 755 * @disable must be the inverse of @enable for atomic drivers. 756 * 757 * For atomic drivers also consider @atomic_disable and save yourself 758 * from having to read the NOTE below! 759 * 760 * NOTE: 761 * 762 * With legacy CRTC helpers there's a big semantic difference between 763 * @disable and other hooks (like @prepare or @dpms) used to shut down a 764 * encoder: @disable is only called when also logically disabling the 765 * display pipeline and needs to release any resources acquired in 766 * @mode_set (like shared PLLs, or again release pinned framebuffers). 767 * 768 * Therefore @disable must be the inverse of @mode_set plus @commit for 769 * drivers still using legacy CRTC helpers, which is different from the 770 * rules under atomic. 771 */ 772 void (*disable)(struct drm_encoder *encoder); 773 774 /** 775 * @enable: 776 * 777 * This callback should be used to enable the encoder. With the atomic 778 * drivers it is called after this encoder's CRTC has been enabled using 779 * their own &drm_crtc_helper_funcs.enable hook. If that sequence is 780 * too simple drivers can just add their own driver private encoder 781 * hooks and call them from CRTC's callback by looping over all encoders 782 * connected to it using for_each_encoder_on_crtc(). 783 * 784 * This hook is only used by atomic helpers, it is the opposite of 785 * @disable. Atomic drivers don't need to implement it if there's no 786 * need to enable anything at the encoder level. To ensure that 787 * runtime PM handling (using either DPMS or the new "ACTIVE" property) 788 * works @enable must be the inverse of @disable for atomic drivers. 789 */ 790 void (*enable)(struct drm_encoder *encoder); 791 792 /** 793 * @atomic_check: 794 * 795 * This callback is used to validate encoder state for atomic drivers. 796 * Since the encoder is the object connecting the CRTC and connector it 797 * gets passed both states, to be able to validate interactions and 798 * update the CRTC to match what the encoder needs for the requested 799 * connector. 800 * 801 * Since this provides a strict superset of the functionality of 802 * @mode_fixup (the requested and adjusted modes are both available 803 * through the passed in &struct drm_crtc_state) @mode_fixup is not 804 * called when @atomic_check is implemented. 805 * 806 * This function is used by the atomic helpers, but it is optional. 807 * 808 * NOTE: 809 * 810 * This function is called in the check phase of an atomic update. The 811 * driver is not allowed to change anything outside of the free-standing 812 * state objects passed-in or assembled in the overall &drm_atomic_state 813 * update tracking structure. 814 * 815 * Also beware that userspace can request its own custom modes, neither 816 * core nor helpers filter modes to the list of probe modes reported by 817 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure 818 * that modes are filtered consistently put any encoder constraints and 819 * limits checks into @mode_valid. 820 * 821 * RETURNS: 822 * 823 * 0 on success, -EINVAL if the state or the transition can't be 824 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an 825 * attempt to obtain another state object ran into a &drm_modeset_lock 826 * deadlock. 827 */ 828 int (*atomic_check)(struct drm_encoder *encoder, 829 struct drm_crtc_state *crtc_state, 830 struct drm_connector_state *conn_state); 831 }; 832 833 /** 834 * drm_encoder_helper_add - sets the helper vtable for an encoder 835 * @encoder: DRM encoder 836 * @funcs: helper vtable to set for @encoder 837 */ 838 static inline void drm_encoder_helper_add(struct drm_encoder *encoder, 839 const struct drm_encoder_helper_funcs *funcs) 840 { 841 encoder->helper_private = funcs; 842 } 843 844 /** 845 * struct drm_connector_helper_funcs - helper operations for connectors 846 * 847 * These functions are used by the atomic and legacy modeset helpers and by the 848 * probe helpers. 849 */ 850 struct drm_connector_helper_funcs { 851 /** 852 * @get_modes: 853 * 854 * This function should fill in all modes currently valid for the sink 855 * into the &drm_connector.probed_modes list. It should also update the 856 * EDID property by calling drm_connector_update_edid_property(). 857 * 858 * The usual way to implement this is to cache the EDID retrieved in the 859 * probe callback somewhere in the driver-private connector structure. 860 * In this function drivers then parse the modes in the EDID and add 861 * them by calling drm_add_edid_modes(). But connectors that drive a 862 * fixed panel can also manually add specific modes using 863 * drm_mode_probed_add(). Drivers which manually add modes should also 864 * make sure that the &drm_connector.display_info, 865 * &drm_connector.width_mm and &drm_connector.height_mm fields are 866 * filled in. 867 * 868 * Note that the caller function will automatically add standard VESA 869 * DMT modes up to 1024x768 if the .get_modes() helper operation returns 870 * no mode and if the connector status is connector_status_connected or 871 * connector_status_unknown. There is no need to call 872 * drm_add_modes_noedid() manually in that case. 873 * 874 * Virtual drivers that just want some standard VESA mode with a given 875 * resolution can call drm_add_modes_noedid(), and mark the preferred 876 * one using drm_set_preferred_mode(). 877 * 878 * This function is only called after the @detect hook has indicated 879 * that a sink is connected and when the EDID isn't overridden through 880 * sysfs or the kernel commandline. 881 * 882 * This callback is used by the probe helpers in e.g. 883 * drm_helper_probe_single_connector_modes(). 884 * 885 * To avoid races with concurrent connector state updates, the helper 886 * libraries always call this with the &drm_mode_config.connection_mutex 887 * held. Because of this it's safe to inspect &drm_connector->state. 888 * 889 * RETURNS: 890 * 891 * The number of modes added by calling drm_mode_probed_add(). Return 0 892 * on failures (no modes) instead of negative error codes. 893 */ 894 int (*get_modes)(struct drm_connector *connector); 895 896 /** 897 * @detect_ctx: 898 * 899 * Check to see if anything is attached to the connector. The parameter 900 * force is set to false whilst polling, true when checking the 901 * connector due to a user request. force can be used by the driver to 902 * avoid expensive, destructive operations during automated probing. 903 * 904 * This callback is optional, if not implemented the connector will be 905 * considered as always being attached. 906 * 907 * This is the atomic version of &drm_connector_funcs.detect. 908 * 909 * To avoid races against concurrent connector state updates, the 910 * helper libraries always call this with ctx set to a valid context, 911 * and &drm_mode_config.connection_mutex will always be locked with 912 * the ctx parameter set to this ctx. This allows taking additional 913 * locks as required. 914 * 915 * RETURNS: 916 * 917 * &drm_connector_status indicating the connector's status, 918 * or the error code returned by drm_modeset_lock(), -EDEADLK. 919 */ 920 int (*detect_ctx)(struct drm_connector *connector, 921 struct drm_modeset_acquire_ctx *ctx, 922 bool force); 923 924 /** 925 * @mode_valid: 926 * 927 * Callback to validate a mode for a connector, irrespective of the 928 * specific display configuration. 929 * 930 * This callback is used by the probe helpers to filter the mode list 931 * (which is usually derived from the EDID data block from the sink). 932 * See e.g. drm_helper_probe_single_connector_modes(). 933 * 934 * This function is optional. 935 * 936 * NOTE: 937 * 938 * This only filters the mode list supplied to userspace in the 939 * GETCONNECTOR IOCTL. Compared to &drm_encoder_helper_funcs.mode_valid, 940 * &drm_crtc_helper_funcs.mode_valid and &drm_bridge_funcs.mode_valid, 941 * which are also called by the atomic helpers from 942 * drm_atomic_helper_check_modeset(). This allows userspace to force and 943 * ignore sink constraint (like the pixel clock limits in the screen's 944 * EDID), which is useful for e.g. testing, or working around a broken 945 * EDID. Any source hardware constraint (which always need to be 946 * enforced) therefore should be checked in one of the above callbacks, 947 * and not this one here. 948 * 949 * To avoid races with concurrent connector state updates, the helper 950 * libraries always call this with the &drm_mode_config.connection_mutex 951 * held. Because of this it's safe to inspect &drm_connector->state. 952 * 953 * RETURNS: 954 * 955 * Either &drm_mode_status.MODE_OK or one of the failure reasons in &enum 956 * drm_mode_status. 957 */ 958 enum drm_mode_status (*mode_valid)(struct drm_connector *connector, 959 const struct drm_display_mode *mode); 960 961 /** 962 * @mode_valid_ctx: 963 * 964 * Callback to validate a mode for a connector, irrespective of the 965 * specific display configuration. 966 * 967 * This callback is used by the probe helpers to filter the mode list 968 * (which is usually derived from the EDID data block from the sink). 969 * See e.g. drm_helper_probe_single_connector_modes(). 970 * 971 * This function is optional, and is the atomic version of 972 * &drm_connector_helper_funcs.mode_valid. 973 * 974 * To allow for accessing the atomic state of modesetting objects, the 975 * helper libraries always call this with ctx set to a valid context, 976 * and &drm_mode_config.connection_mutex will always be locked with 977 * the ctx parameter set to @ctx. This allows for taking additional 978 * locks as required. 979 * 980 * Even though additional locks may be acquired, this callback is 981 * still expected not to take any constraints into account which would 982 * be influenced by the currently set display state - such constraints 983 * should be handled in the driver's atomic check. For example, if a 984 * connector shares display bandwidth with other connectors then it 985 * would be ok to validate the minimum bandwidth requirement of a mode 986 * against the maximum possible bandwidth of the connector. But it 987 * wouldn't be ok to take the current bandwidth usage of other 988 * connectors into account, as this would change depending on the 989 * display state. 990 * 991 * Returns: 992 * 0 if &drm_connector_helper_funcs.mode_valid_ctx succeeded and wrote 993 * the &enum drm_mode_status value to @status, or a negative error 994 * code otherwise. 995 * 996 */ 997 int (*mode_valid_ctx)(struct drm_connector *connector, 998 const struct drm_display_mode *mode, 999 struct drm_modeset_acquire_ctx *ctx, 1000 enum drm_mode_status *status); 1001 1002 /** 1003 * @best_encoder: 1004 * 1005 * This function should select the best encoder for the given connector. 1006 * 1007 * This function is used by both the atomic helpers (in the 1008 * drm_atomic_helper_check_modeset() function) and in the legacy CRTC 1009 * helpers. 1010 * 1011 * NOTE: 1012 * 1013 * In atomic drivers this function is called in the check phase of an 1014 * atomic update. The driver is not allowed to change or inspect 1015 * anything outside of arguments passed-in. Atomic drivers which need to 1016 * inspect dynamic configuration state should instead use 1017 * @atomic_best_encoder. 1018 * 1019 * You can leave this function to NULL if the connector is only 1020 * attached to a single encoder. In this case, the core will call 1021 * drm_connector_get_single_encoder() for you. 1022 * 1023 * RETURNS: 1024 * 1025 * Encoder that should be used for the given connector and connector 1026 * state, or NULL if no suitable encoder exists. Note that the helpers 1027 * will ensure that encoders aren't used twice, drivers should not check 1028 * for this. 1029 */ 1030 struct drm_encoder *(*best_encoder)(struct drm_connector *connector); 1031 1032 /** 1033 * @atomic_best_encoder: 1034 * 1035 * This is the atomic version of @best_encoder for atomic drivers which 1036 * need to select the best encoder depending upon the desired 1037 * configuration and can't select it statically. 1038 * 1039 * This function is used by drm_atomic_helper_check_modeset(). 1040 * If it is not implemented, the core will fallback to @best_encoder 1041 * (or drm_connector_get_single_encoder() if @best_encoder is NULL). 1042 * 1043 * NOTE: 1044 * 1045 * This function is called in the check phase of an atomic update. The 1046 * driver is not allowed to change anything outside of the 1047 * &drm_atomic_state update tracking structure passed in. 1048 * 1049 * RETURNS: 1050 * 1051 * Encoder that should be used for the given connector and connector 1052 * state, or NULL if no suitable encoder exists. Note that the helpers 1053 * will ensure that encoders aren't used twice, drivers should not check 1054 * for this. 1055 */ 1056 struct drm_encoder *(*atomic_best_encoder)(struct drm_connector *connector, 1057 struct drm_atomic_state *state); 1058 1059 /** 1060 * @atomic_check: 1061 * 1062 * This hook is used to validate connector state. This function is 1063 * called from &drm_atomic_helper_check_modeset, and is called when 1064 * a connector property is set, or a modeset on the crtc is forced. 1065 * 1066 * Because &drm_atomic_helper_check_modeset may be called multiple times, 1067 * this function should handle being called multiple times as well. 1068 * 1069 * This function is also allowed to inspect any other object's state and 1070 * can add more state objects to the atomic commit if needed. Care must 1071 * be taken though to ensure that state check and compute functions for 1072 * these added states are all called, and derived state in other objects 1073 * all updated. Again the recommendation is to just call check helpers 1074 * until a maximal configuration is reached. 1075 * 1076 * NOTE: 1077 * 1078 * This function is called in the check phase of an atomic update. The 1079 * driver is not allowed to change anything outside of the free-standing 1080 * state objects passed-in or assembled in the overall &drm_atomic_state 1081 * update tracking structure. 1082 * 1083 * RETURNS: 1084 * 1085 * 0 on success, -EINVAL if the state or the transition can't be 1086 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an 1087 * attempt to obtain another state object ran into a &drm_modeset_lock 1088 * deadlock. 1089 */ 1090 int (*atomic_check)(struct drm_connector *connector, 1091 struct drm_atomic_state *state); 1092 1093 /** 1094 * @atomic_commit: 1095 * 1096 * This hook is to be used by drivers implementing writeback connectors 1097 * that need a point when to commit the writeback job to the hardware. 1098 * The writeback_job to commit is available in the new connector state, 1099 * in &drm_connector_state.writeback_job. 1100 * 1101 * This hook is optional. 1102 * 1103 * This callback is used by the atomic modeset helpers. 1104 */ 1105 void (*atomic_commit)(struct drm_connector *connector, 1106 struct drm_atomic_state *state); 1107 1108 /** 1109 * @prepare_writeback_job: 1110 * 1111 * As writeback jobs contain a framebuffer, drivers may need to 1112 * prepare and clean them up the same way they can prepare and 1113 * clean up framebuffers for planes. This optional connector operation 1114 * is used to support the preparation of writeback jobs. The job 1115 * prepare operation is called from drm_atomic_helper_prepare_planes() 1116 * for struct &drm_writeback_connector connectors only. 1117 * 1118 * This operation is optional. 1119 * 1120 * This callback is used by the atomic modeset helpers. 1121 */ 1122 int (*prepare_writeback_job)(struct drm_writeback_connector *connector, 1123 struct drm_writeback_job *job); 1124 /** 1125 * @cleanup_writeback_job: 1126 * 1127 * This optional connector operation is used to support the 1128 * cleanup of writeback jobs. The job cleanup operation is called 1129 * from the existing drm_writeback_cleanup_job() function, invoked 1130 * both when destroying the job as part of an aborted commit, or when 1131 * the job completes. 1132 * 1133 * This operation is optional. 1134 * 1135 * This callback is used by the atomic modeset helpers. 1136 */ 1137 void (*cleanup_writeback_job)(struct drm_writeback_connector *connector, 1138 struct drm_writeback_job *job); 1139 1140 /** 1141 * @enable_hpd: 1142 * 1143 * Enable hot-plug detection for the connector. 1144 * 1145 * This operation is optional. 1146 * 1147 * This callback is used by the drm_kms_helper_poll_enable() helpers. 1148 * 1149 * This operation does not need to perform any hpd state tracking as 1150 * the DRM core handles that maintenance and ensures the calls to enable 1151 * and disable hpd are balanced. 1152 * 1153 */ 1154 void (*enable_hpd)(struct drm_connector *connector); 1155 1156 /** 1157 * @disable_hpd: 1158 * 1159 * Disable hot-plug detection for the connector. 1160 * 1161 * This operation is optional. 1162 * 1163 * This callback is used by the drm_kms_helper_poll_disable() helpers. 1164 * 1165 * This operation does not need to perform any hpd state tracking as 1166 * the DRM core handles that maintenance and ensures the calls to enable 1167 * and disable hpd are balanced. 1168 * 1169 */ 1170 void (*disable_hpd)(struct drm_connector *connector); 1171 }; 1172 1173 /** 1174 * drm_connector_helper_add - sets the helper vtable for a connector 1175 * @connector: DRM connector 1176 * @funcs: helper vtable to set for @connector 1177 */ 1178 static inline void drm_connector_helper_add(struct drm_connector *connector, 1179 const struct drm_connector_helper_funcs *funcs) 1180 { 1181 connector->helper_private = funcs; 1182 } 1183 1184 /** 1185 * struct drm_plane_helper_funcs - helper operations for planes 1186 * 1187 * These functions are used by the atomic helpers. 1188 */ 1189 struct drm_plane_helper_funcs { 1190 /** 1191 * @prepare_fb: 1192 * 1193 * This hook is to prepare a framebuffer for scanout by e.g. pinning 1194 * its backing storage or relocating it into a contiguous block of 1195 * VRAM. Other possible preparatory work includes flushing caches. 1196 * 1197 * This function must not block for outstanding rendering, since it is 1198 * called in the context of the atomic IOCTL even for async commits to 1199 * be able to return any errors to userspace. Instead the recommended 1200 * way is to fill out the &drm_plane_state.fence of the passed-in 1201 * &drm_plane_state. If the driver doesn't support native fences then 1202 * equivalent functionality should be implemented through private 1203 * members in the plane structure. 1204 * 1205 * For GEM drivers who neither have a @prepare_fb nor @cleanup_fb hook 1206 * set drm_gem_plane_helper_prepare_fb() is called automatically to 1207 * implement this. Other drivers which need additional plane processing 1208 * can call drm_gem_plane_helper_prepare_fb() from their @prepare_fb 1209 * hook. 1210 * 1211 * The resources acquired in @prepare_fb persist after the end of 1212 * the atomic commit. Resources that can be release at the commit's end 1213 * should be acquired in @begin_fb_access and released in @end_fb_access. 1214 * For example, a GEM buffer's pin operation belongs into @prepare_fb to 1215 * keep the buffer pinned after the commit. But a vmap operation for 1216 * shadow-plane helpers belongs into @begin_fb_access, so that atomic 1217 * helpers remove the mapping at the end of the commit. 1218 * 1219 * The helpers will call @cleanup_fb with matching arguments for every 1220 * successful call to this hook. 1221 * 1222 * This callback is used by the atomic modeset helpers, but it is 1223 * optional. See @begin_fb_access for preparing per-commit resources. 1224 * 1225 * RETURNS: 1226 * 1227 * 0 on success or one of the following negative error codes allowed by 1228 * the &drm_mode_config_funcs.atomic_commit vfunc. When using helpers 1229 * this callback is the only one which can fail an atomic commit, 1230 * everything else must complete successfully. 1231 */ 1232 int (*prepare_fb)(struct drm_plane *plane, 1233 struct drm_plane_state *new_state); 1234 /** 1235 * @cleanup_fb: 1236 * 1237 * This hook is called to clean up any resources allocated for the given 1238 * framebuffer and plane configuration in @prepare_fb. 1239 * 1240 * This callback is used by the atomic modeset helpers, but it is 1241 * optional. 1242 */ 1243 void (*cleanup_fb)(struct drm_plane *plane, 1244 struct drm_plane_state *old_state); 1245 1246 /** 1247 * @begin_fb_access: 1248 * 1249 * This hook prepares the plane for access during an atomic commit. 1250 * In contrast to @prepare_fb, resources acquired in @begin_fb_access, 1251 * are released at the end of the atomic commit in @end_fb_access. 1252 * 1253 * For example, with shadow-plane helpers, the GEM buffer's vmap 1254 * operation belongs into @begin_fb_access, so that the buffer's 1255 * memory will be unmapped at the end of the commit in @end_fb_access. 1256 * But a GEM buffer's pin operation belongs into @prepare_fb 1257 * to keep the buffer pinned after the commit. 1258 * 1259 * The callback is used by the atomic modeset helpers, but it is optional. 1260 * See @end_fb_cleanup for undoing the effects of @begin_fb_access and 1261 * @prepare_fb for acquiring resources until the next pageflip. 1262 * 1263 * Returns: 1264 * 0 on success, or a negative errno code otherwise. 1265 */ 1266 int (*begin_fb_access)(struct drm_plane *plane, struct drm_plane_state *new_plane_state); 1267 1268 /** 1269 * @end_fb_access: 1270 * 1271 * This hook cleans up resources allocated by @begin_fb_access. It it called 1272 * at the end of a commit for the new plane state. 1273 */ 1274 void (*end_fb_access)(struct drm_plane *plane, struct drm_plane_state *new_plane_state); 1275 1276 /** 1277 * @atomic_check: 1278 * 1279 * Drivers should check plane specific constraints in this hook. 1280 * 1281 * When using drm_atomic_helper_check_planes() plane's @atomic_check 1282 * hooks are called before the ones for CRTCs, which allows drivers to 1283 * request shared resources that the CRTC controls here. For more 1284 * complicated dependencies the driver can call the provided check helpers 1285 * multiple times until the computed state has a final configuration and 1286 * everything has been checked. 1287 * 1288 * This function is also allowed to inspect any other object's state and 1289 * can add more state objects to the atomic commit if needed. Care must 1290 * be taken though to ensure that state check and compute functions for 1291 * these added states are all called, and derived state in other objects 1292 * all updated. Again the recommendation is to just call check helpers 1293 * until a maximal configuration is reached. 1294 * 1295 * This callback is used by the atomic modeset helpers, but it is 1296 * optional. 1297 * 1298 * NOTE: 1299 * 1300 * This function is called in the check phase of an atomic update. The 1301 * driver is not allowed to change anything outside of the 1302 * &drm_atomic_state update tracking structure. 1303 * 1304 * RETURNS: 1305 * 1306 * 0 on success, -EINVAL if the state or the transition can't be 1307 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an 1308 * attempt to obtain another state object ran into a &drm_modeset_lock 1309 * deadlock. 1310 */ 1311 int (*atomic_check)(struct drm_plane *plane, 1312 struct drm_atomic_state *state); 1313 1314 /** 1315 * @atomic_update: 1316 * 1317 * Drivers should use this function to update the plane state. This 1318 * hook is called in-between the &drm_crtc_helper_funcs.atomic_begin and 1319 * drm_crtc_helper_funcs.atomic_flush callbacks. 1320 * 1321 * Note that the power state of the display pipe when this function is 1322 * called depends upon the exact helpers and calling sequence the driver 1323 * has picked. See drm_atomic_helper_commit_planes() for a discussion of 1324 * the tradeoffs and variants of plane commit helpers. 1325 * 1326 * This callback is used by the atomic modeset helpers, but it is optional. 1327 */ 1328 void (*atomic_update)(struct drm_plane *plane, 1329 struct drm_atomic_state *state); 1330 1331 /** 1332 * @atomic_enable: 1333 * 1334 * Drivers should use this function to unconditionally enable a plane. 1335 * This hook is called in-between the &drm_crtc_helper_funcs.atomic_begin 1336 * and drm_crtc_helper_funcs.atomic_flush callbacks. It is called after 1337 * @atomic_update, which will be called for all enabled planes. Drivers 1338 * that use @atomic_enable should set up a plane in @atomic_update and 1339 * afterwards enable the plane in @atomic_enable. If a plane needs to be 1340 * enabled before installing the scanout buffer, drivers can still do 1341 * so in @atomic_update. 1342 * 1343 * Note that the power state of the display pipe when this function is 1344 * called depends upon the exact helpers and calling sequence the driver 1345 * has picked. See drm_atomic_helper_commit_planes() for a discussion of 1346 * the tradeoffs and variants of plane commit helpers. 1347 * 1348 * This callback is used by the atomic modeset helpers, but it is 1349 * optional. If implemented, @atomic_enable should be the inverse of 1350 * @atomic_disable. Drivers that don't want to use either can still 1351 * implement the complete plane update in @atomic_update. 1352 */ 1353 void (*atomic_enable)(struct drm_plane *plane, 1354 struct drm_atomic_state *state); 1355 1356 /** 1357 * @atomic_disable: 1358 * 1359 * Drivers should use this function to unconditionally disable a plane. 1360 * This hook is called in-between the 1361 * &drm_crtc_helper_funcs.atomic_begin and 1362 * drm_crtc_helper_funcs.atomic_flush callbacks. It is an alternative to 1363 * @atomic_update, which will be called for disabling planes, too, if 1364 * the @atomic_disable hook isn't implemented. 1365 * 1366 * This hook is also useful to disable planes in preparation of a modeset, 1367 * by calling drm_atomic_helper_disable_planes_on_crtc() from the 1368 * &drm_crtc_helper_funcs.disable hook. 1369 * 1370 * Note that the power state of the display pipe when this function is 1371 * called depends upon the exact helpers and calling sequence the driver 1372 * has picked. See drm_atomic_helper_commit_planes() for a discussion of 1373 * the tradeoffs and variants of plane commit helpers. 1374 * 1375 * This callback is used by the atomic modeset helpers, but it is 1376 * optional. It's intended to reverse the effects of @atomic_enable. 1377 */ 1378 void (*atomic_disable)(struct drm_plane *plane, 1379 struct drm_atomic_state *state); 1380 1381 /** 1382 * @atomic_async_check: 1383 * 1384 * Drivers should set this function pointer to check if the plane's 1385 * atomic state can be updated in a async fashion. Here async means 1386 * "not vblank synchronized". 1387 * 1388 * This hook is called by drm_atomic_async_check() to establish if a 1389 * given update can be committed asynchronously, that is, if it can 1390 * jump ahead of the state currently queued for update. 1391 * 1392 * This function is also used by drm_atomic_set_property() to determine 1393 * if the plane can be flipped in async. The flip flag is used to 1394 * distinguish if the function is used for just the plane state or for a 1395 * flip. 1396 * 1397 * RETURNS: 1398 * 1399 * Return 0 on success and any error returned indicates that the update 1400 * can not be applied in asynchronous manner. 1401 */ 1402 int (*atomic_async_check)(struct drm_plane *plane, 1403 struct drm_atomic_state *state, bool flip); 1404 1405 /** 1406 * @atomic_async_update: 1407 * 1408 * Drivers should set this function pointer to perform asynchronous 1409 * updates of planes, that is, jump ahead of the currently queued 1410 * state and update the plane. Here async means "not vblank 1411 * synchronized". 1412 * 1413 * This hook is called by drm_atomic_helper_async_commit(). 1414 * 1415 * An async update will happen on legacy cursor updates. An async 1416 * update won't happen if there is an outstanding commit modifying 1417 * the same plane. 1418 * 1419 * When doing async_update drivers shouldn't replace the 1420 * &drm_plane_state but update the current one with the new plane 1421 * configurations in the new plane_state. 1422 * 1423 * Drivers should also swap the framebuffers between current plane 1424 * state (&drm_plane.state) and new_state. 1425 * This is required since cleanup for async commits is performed on 1426 * the new state, rather than old state like for traditional commits. 1427 * Since we want to give up the reference on the current (old) fb 1428 * instead of our brand new one, swap them in the driver during the 1429 * async commit. 1430 * 1431 * FIXME: 1432 * - It only works for single plane updates 1433 * - Async Pageflips are not supported yet 1434 * - Some hw might still scan out the old buffer until the next 1435 * vblank, however we let go of the fb references as soon as 1436 * we run this hook. For now drivers must implement their own workers 1437 * for deferring if needed, until a common solution is created. 1438 */ 1439 void (*atomic_async_update)(struct drm_plane *plane, 1440 struct drm_atomic_state *state); 1441 1442 /** 1443 * @get_scanout_buffer: 1444 * 1445 * Get the current scanout buffer, to display a message with drm_panic. 1446 * The driver should do the minimum changes to provide a buffer, 1447 * that can be used to display the panic screen. Currently only linear 1448 * buffers are supported. Non-linear buffer support is on the TODO list. 1449 * The device &dev.mode_config.panic_lock is taken before calling this 1450 * function, so you can safely access the &plane.state 1451 * It is called from a panic callback, and must follow its restrictions. 1452 * Please look the documentation at drm_panic_trylock() for an in-depth 1453 * discussions of what's safe and what is not allowed. 1454 * It's a best effort mode, so it's expected that in some complex cases 1455 * the panic screen won't be displayed. 1456 * The returned &drm_scanout_buffer.map must be valid if no error code is 1457 * returned. 1458 * 1459 * Return: 1460 * %0 on success, negative errno on failure. 1461 */ 1462 int (*get_scanout_buffer)(struct drm_plane *plane, 1463 struct drm_scanout_buffer *sb); 1464 1465 /** 1466 * @panic_flush: 1467 * 1468 * It is used by drm_panic, and is called after the panic screen is 1469 * drawn to the scanout buffer. In this function, the driver 1470 * can send additional commands to the hardware, to make the scanout 1471 * buffer visible. 1472 * It is only called if get_scanout_buffer() returned successfully, and 1473 * the &dev.mode_config.panic_lock is held during the entire sequence. 1474 * It is called from a panic callback, and must follow its restrictions. 1475 * Please look the documentation at drm_panic_trylock() for an in-depth 1476 * discussions of what's safe and what is not allowed. 1477 */ 1478 void (*panic_flush)(struct drm_plane *plane); 1479 }; 1480 1481 /** 1482 * drm_plane_helper_add - sets the helper vtable for a plane 1483 * @plane: DRM plane 1484 * @funcs: helper vtable to set for @plane 1485 */ 1486 static inline void drm_plane_helper_add(struct drm_plane *plane, 1487 const struct drm_plane_helper_funcs *funcs) 1488 { 1489 plane->helper_private = funcs; 1490 } 1491 1492 /** 1493 * struct drm_mode_config_helper_funcs - global modeset helper operations 1494 * 1495 * These helper functions are used by the atomic helpers. 1496 */ 1497 struct drm_mode_config_helper_funcs { 1498 /** 1499 * @atomic_commit_tail: 1500 * 1501 * This hook is used by the default atomic_commit() hook implemented in 1502 * drm_atomic_helper_commit() together with the nonblocking commit 1503 * helpers (see drm_atomic_helper_setup_commit() for a starting point) 1504 * to implement blocking and nonblocking commits easily. It is not used 1505 * by the atomic helpers 1506 * 1507 * This function is called when the new atomic state has already been 1508 * swapped into the various state pointers. The passed in state 1509 * therefore contains copies of the old/previous state. This hook should 1510 * commit the new state into hardware. Note that the helpers have 1511 * already waited for preceding atomic commits and fences, but drivers 1512 * can add more waiting calls at the start of their implementation, e.g. 1513 * to wait for driver-internal request for implicit syncing, before 1514 * starting to commit the update to the hardware. 1515 * 1516 * After the atomic update is committed to the hardware this hook needs 1517 * to call drm_atomic_helper_commit_hw_done(). Then wait for the update 1518 * to be executed by the hardware, for example using 1519 * drm_atomic_helper_wait_for_vblanks() or 1520 * drm_atomic_helper_wait_for_flip_done(), and then clean up the old 1521 * framebuffers using drm_atomic_helper_cleanup_planes(). 1522 * 1523 * When disabling a CRTC this hook _must_ stall for the commit to 1524 * complete. Vblank waits don't work on disabled CRTC, hence the core 1525 * can't take care of this. And it also can't rely on the vblank event, 1526 * since that can be signalled already when the screen shows black, 1527 * which can happen much earlier than the last hardware access needed to 1528 * shut off the display pipeline completely. 1529 * 1530 * This hook is optional, the default implementation is 1531 * drm_atomic_helper_commit_tail(). 1532 */ 1533 void (*atomic_commit_tail)(struct drm_atomic_state *state); 1534 1535 /** 1536 * @atomic_commit_setup: 1537 * 1538 * This hook is used by the default atomic_commit() hook implemented in 1539 * drm_atomic_helper_commit() together with the nonblocking helpers (see 1540 * drm_atomic_helper_setup_commit()) to extend the DRM commit setup. It 1541 * is not used by the atomic helpers. 1542 * 1543 * This function is called at the end of 1544 * drm_atomic_helper_setup_commit(), so once the commit has been 1545 * properly setup across the generic DRM object states. It allows 1546 * drivers to do some additional commit tracking that isn't related to a 1547 * CRTC, plane or connector, tracked in a &drm_private_obj structure. 1548 * 1549 * Note that the documentation of &drm_private_obj has more details on 1550 * how one should implement this. 1551 * 1552 * This hook is optional. 1553 */ 1554 int (*atomic_commit_setup)(struct drm_atomic_state *state); 1555 }; 1556 1557 #endif 1558