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