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 34 /** 35 * DOC: overview 36 * 37 * The DRM mode setting helper functions are common code for drivers to use if 38 * they wish. Drivers are not forced to use this code in their 39 * implementations but it would be useful if the code they do use at least 40 * provides a consistent interface and operation to userspace. Therefore it is 41 * highly recommended to use the provided helpers as much as possible. 42 * 43 * Because there is only one pointer per modeset object to hold a vfunc table 44 * for helper libraries they are by necessity shared among the different 45 * helpers. 46 * 47 * To make this clear all the helper vtables are pulled together in this location here. 48 */ 49 50 enum mode_set_atomic; 51 52 /** 53 * struct drm_crtc_helper_funcs - helper operations for CRTCs 54 * 55 * These hooks are used by the legacy CRTC helpers, the transitional plane 56 * helpers and the new atomic modesetting helpers. 57 */ 58 struct drm_crtc_helper_funcs { 59 /** 60 * @dpms: 61 * 62 * Callback to control power levels on the CRTC. If the mode passed in 63 * is unsupported, the provider must use the next lowest power level. 64 * This is used by the legacy CRTC helpers to implement DPMS 65 * functionality in drm_helper_connector_dpms(). 66 * 67 * This callback is also used to disable a CRTC by calling it with 68 * DRM_MODE_DPMS_OFF if the @disable hook isn't used. 69 * 70 * This callback is used by the legacy CRTC helpers. Atomic helpers 71 * also support using this hook for enabling and disabling a CRTC to 72 * facilitate transitions to atomic, but it is deprecated. Instead 73 * @enable and @disable should be used. 74 */ 75 void (*dpms)(struct drm_crtc *crtc, int mode); 76 77 /** 78 * @prepare: 79 * 80 * This callback should prepare the CRTC for a subsequent modeset, which 81 * in practice means the driver should disable the CRTC if it is 82 * running. Most drivers ended up implementing this by calling their 83 * @dpms hook with DRM_MODE_DPMS_OFF. 84 * 85 * This callback is used by the legacy CRTC helpers. Atomic helpers 86 * also support using this hook for disabling a CRTC to facilitate 87 * transitions to atomic, but it is deprecated. Instead @disable should 88 * be used. 89 */ 90 void (*prepare)(struct drm_crtc *crtc); 91 92 /** 93 * @commit: 94 * 95 * This callback should commit the new mode on the CRTC after a modeset, 96 * which in practice means the driver should enable the CRTC. Most 97 * drivers ended up implementing this by calling their @dpms hook with 98 * DRM_MODE_DPMS_ON. 99 * 100 * This callback is used by the legacy CRTC helpers. Atomic helpers 101 * also support using this hook for enabling a CRTC to facilitate 102 * transitions to atomic, but it is deprecated. Instead @enable should 103 * be used. 104 */ 105 void (*commit)(struct drm_crtc *crtc); 106 107 /** 108 * @mode_fixup: 109 * 110 * This callback is used to validate a mode. The parameter mode is the 111 * display mode that userspace requested, adjusted_mode is the mode the 112 * encoders need to be fed with. Note that this is the inverse semantics 113 * of the meaning for the &drm_encoder and &drm_bridge 114 * ->mode_fixup() functions. If the CRTC cannot support the requested 115 * conversion from mode to adjusted_mode it should reject the modeset. 116 * 117 * This function is used by both legacy CRTC helpers and atomic helpers. 118 * With atomic helpers it is optional. 119 * 120 * NOTE: 121 * 122 * This function is called in the check phase of atomic modesets, which 123 * can be aborted for any reason (including on userspace's request to 124 * just check whether a configuration would be possible). Atomic drivers 125 * MUST NOT touch any persistent state (hardware or software) or data 126 * structures except the passed in adjusted_mode parameter. 127 * 128 * This is in contrast to the legacy CRTC helpers where this was 129 * allowed. 130 * 131 * Atomic drivers which need to inspect and adjust more state should 132 * instead use the @atomic_check callback. 133 * 134 * Also beware that neither core nor helpers filter modes before 135 * passing them to the driver: While the list of modes that is 136 * advertised to userspace is filtered using the connector's 137 * ->mode_valid() callback, neither the core nor the helpers do any 138 * filtering on modes passed in from userspace when setting a mode. It 139 * is therefore possible for userspace to pass in a mode that was 140 * previously filtered out using ->mode_valid() or add a custom mode 141 * that wasn't probed from EDID or similar to begin with. Even though 142 * this is an advanced feature and rarely used nowadays, some users rely 143 * on being able to specify modes manually so drivers must be prepared 144 * to deal with it. Specifically this means that all drivers need not 145 * only validate modes in ->mode_valid() but also in ->mode_fixup() to 146 * make sure invalid modes passed in from userspace are rejected. 147 * 148 * RETURNS: 149 * 150 * True if an acceptable configuration is possible, false if the modeset 151 * operation should be rejected. 152 */ 153 bool (*mode_fixup)(struct drm_crtc *crtc, 154 const struct drm_display_mode *mode, 155 struct drm_display_mode *adjusted_mode); 156 157 /** 158 * @mode_set: 159 * 160 * This callback is used by the legacy CRTC helpers to set a new mode, 161 * position and framebuffer. Since it ties the primary plane to every 162 * mode change it is incompatible with universal plane support. And 163 * since it can't update other planes it's incompatible with atomic 164 * modeset support. 165 * 166 * This callback is only used by CRTC helpers and deprecated. 167 * 168 * RETURNS: 169 * 170 * 0 on success or a negative error code on failure. 171 */ 172 int (*mode_set)(struct drm_crtc *crtc, struct drm_display_mode *mode, 173 struct drm_display_mode *adjusted_mode, int x, int y, 174 struct drm_framebuffer *old_fb); 175 176 /** 177 * @mode_set_nofb: 178 * 179 * This callback is used to update the display mode of a CRTC without 180 * changing anything of the primary plane configuration. This fits the 181 * requirement of atomic and hence is used by the atomic helpers. It is 182 * also used by the transitional plane helpers to implement a 183 * @mode_set hook in drm_helper_crtc_mode_set(). 184 * 185 * Note that the display pipe is completely off when this function is 186 * called. Atomic drivers which need hardware to be running before they 187 * program the new display mode (e.g. because they implement runtime PM) 188 * should not use this hook. This is because the helper library calls 189 * this hook only once per mode change and not every time the display 190 * pipeline is suspended using either DPMS or the new "ACTIVE" property. 191 * Which means register values set in this callback might get reset when 192 * the CRTC is suspended, but not restored. Such drivers should instead 193 * move all their CRTC setup into the @enable callback. 194 * 195 * This callback is optional. 196 */ 197 void (*mode_set_nofb)(struct drm_crtc *crtc); 198 199 /** 200 * @mode_set_base: 201 * 202 * This callback is used by the legacy CRTC helpers to set a new 203 * framebuffer and scanout position. It is optional and used as an 204 * optimized fast-path instead of a full mode set operation with all the 205 * resulting flickering. If it is not present 206 * drm_crtc_helper_set_config() will fall back to a full modeset, using 207 * the ->mode_set() callback. Since it can't update other planes it's 208 * incompatible with atomic modeset support. 209 * 210 * This callback is only used by the CRTC helpers and deprecated. 211 * 212 * RETURNS: 213 * 214 * 0 on success or a negative error code on failure. 215 */ 216 int (*mode_set_base)(struct drm_crtc *crtc, int x, int y, 217 struct drm_framebuffer *old_fb); 218 219 /** 220 * @mode_set_base_atomic: 221 * 222 * This callback is used by the fbdev helpers to set a new framebuffer 223 * and scanout without sleeping, i.e. from an atomic calling context. It 224 * is only used to implement kgdb support. 225 * 226 * This callback is optional and only needed for kgdb support in the fbdev 227 * helpers. 228 * 229 * RETURNS: 230 * 231 * 0 on success or a negative error code on failure. 232 */ 233 int (*mode_set_base_atomic)(struct drm_crtc *crtc, 234 struct drm_framebuffer *fb, int x, int y, 235 enum mode_set_atomic); 236 237 /** 238 * @load_lut: 239 * 240 * Load a LUT prepared with the @gamma_set functions from 241 * &drm_fb_helper_funcs. 242 * 243 * This callback is optional and is only used by the fbdev emulation 244 * helpers. 245 * 246 * FIXME: 247 * 248 * This callback is functionally redundant with the core gamma table 249 * support and simply exists because the fbdev hasn't yet been 250 * refactored to use the core gamma table interfaces. 251 */ 252 void (*load_lut)(struct drm_crtc *crtc); 253 254 /** 255 * @disable: 256 * 257 * This callback should be used to disable the CRTC. With the atomic 258 * drivers it is called after all encoders connected to this CRTC have 259 * been shut off already using their own ->disable hook. If that 260 * sequence is too simple drivers can just add their own hooks and call 261 * it from this CRTC callback here by looping over all encoders 262 * connected to it using for_each_encoder_on_crtc(). 263 * 264 * This hook is used both by legacy CRTC helpers and atomic helpers. 265 * Atomic drivers don't need to implement it if there's no need to 266 * disable anything at the CRTC level. To ensure that runtime PM 267 * handling (using either DPMS or the new "ACTIVE" property) works 268 * @disable must be the inverse of @enable for atomic drivers. 269 * Atomic drivers should consider to use @atomic_disable instead of 270 * this one. 271 * 272 * NOTE: 273 * 274 * With legacy CRTC helpers there's a big semantic difference between 275 * @disable and other hooks (like @prepare or @dpms) used to shut down a 276 * CRTC: @disable is only called when also logically disabling the 277 * display pipeline and needs to release any resources acquired in 278 * @mode_set (like shared PLLs, or again release pinned framebuffers). 279 * 280 * Therefore @disable must be the inverse of @mode_set plus @commit for 281 * drivers still using legacy CRTC helpers, which is different from the 282 * rules under atomic. 283 */ 284 void (*disable)(struct drm_crtc *crtc); 285 286 /** 287 * @enable: 288 * 289 * This callback should be used to enable the CRTC. With the atomic 290 * drivers it is called before all encoders connected to this CRTC are 291 * enabled through the encoder's own ->enable hook. If that sequence is 292 * too simple drivers can just add their own hooks and call it from this 293 * CRTC callback here by looping over all encoders connected to it using 294 * for_each_encoder_on_crtc(). 295 * 296 * This hook is used only by atomic helpers, for symmetry with @disable. 297 * Atomic drivers don't need to implement it if there's no need to 298 * enable anything at the CRTC level. To ensure that runtime PM handling 299 * (using either DPMS or the new "ACTIVE" property) works 300 * @enable must be the inverse of @disable for atomic drivers. 301 */ 302 void (*enable)(struct drm_crtc *crtc); 303 304 /** 305 * @atomic_check: 306 * 307 * Drivers should check plane-update related CRTC constraints in this 308 * hook. They can also check mode related limitations but need to be 309 * aware of the calling order, since this hook is used by 310 * drm_atomic_helper_check_planes() whereas the preparations needed to 311 * check output routing and the display mode is done in 312 * drm_atomic_helper_check_modeset(). Therefore drivers that want to 313 * check output routing and display mode constraints in this callback 314 * must ensure that drm_atomic_helper_check_modeset() has been called 315 * beforehand. This is calling order used by the default helper 316 * implementation in drm_atomic_helper_check(). 317 * 318 * When using drm_atomic_helper_check_planes() CRTCs' ->atomic_check() 319 * hooks are called after the ones for planes, which allows drivers to 320 * assign shared resources requested by planes in the CRTC callback 321 * here. For more complicated dependencies the driver can call the provided 322 * check helpers multiple times until the computed state has a final 323 * configuration and everything has been checked. 324 * 325 * This function is also allowed to inspect any other object's state and 326 * can add more state objects to the atomic commit if needed. Care must 327 * be taken though to ensure that state check&compute functions for 328 * these added states are all called, and derived state in other objects 329 * all updated. Again the recommendation is to just call check helpers 330 * until a maximal configuration is reached. 331 * 332 * This callback is used by the atomic modeset helpers and by the 333 * transitional plane helpers, but it is optional. 334 * 335 * NOTE: 336 * 337 * This function is called in the check phase of an atomic update. The 338 * driver is not allowed to change anything outside of the free-standing 339 * state objects passed-in or assembled in the overall &drm_atomic_state 340 * update tracking structure. 341 * 342 * RETURNS: 343 * 344 * 0 on success, -EINVAL if the state or the transition can't be 345 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an 346 * attempt to obtain another state object ran into a &drm_modeset_lock 347 * deadlock. 348 */ 349 int (*atomic_check)(struct drm_crtc *crtc, 350 struct drm_crtc_state *state); 351 352 /** 353 * @atomic_begin: 354 * 355 * Drivers should prepare for an atomic update of multiple planes on 356 * a CRTC in this hook. Depending upon hardware this might be vblank 357 * evasion, blocking updates by setting bits or doing preparatory work 358 * for e.g. manual update display. 359 * 360 * This hook is called before any plane commit functions are called. 361 * 362 * Note that the power state of the display pipe when this function is 363 * called depends upon the exact helpers and calling sequence the driver 364 * has picked. See drm_atomic_commit_planes() for a discussion of the 365 * tradeoffs and variants of plane commit helpers. 366 * 367 * This callback is used by the atomic modeset helpers and by the 368 * transitional plane helpers, but it is optional. 369 */ 370 void (*atomic_begin)(struct drm_crtc *crtc, 371 struct drm_crtc_state *old_crtc_state); 372 /** 373 * @atomic_flush: 374 * 375 * Drivers should finalize an atomic update of multiple planes on 376 * a CRTC in this hook. Depending upon hardware this might include 377 * checking that vblank evasion was successful, unblocking updates by 378 * setting bits or setting the GO bit to flush out all updates. 379 * 380 * Simple hardware or hardware with special requirements can commit and 381 * flush out all updates for all planes from this hook and forgo all the 382 * other commit hooks for plane updates. 383 * 384 * This hook is called after any plane commit functions are called. 385 * 386 * Note that the power state of the display pipe when this function is 387 * called depends upon the exact helpers and calling sequence the driver 388 * has picked. See drm_atomic_commit_planes() for a discussion of the 389 * tradeoffs and variants of plane commit helpers. 390 * 391 * This callback is used by the atomic modeset helpers and by the 392 * transitional plane helpers, but it is optional. 393 */ 394 void (*atomic_flush)(struct drm_crtc *crtc, 395 struct drm_crtc_state *old_crtc_state); 396 397 /** 398 * @atomic_disable: 399 * 400 * This callback should be used to disable the CRTC. With the atomic 401 * drivers it is called after all encoders connected to this CRTC have 402 * been shut off already using their own ->disable hook. If that 403 * sequence is too simple drivers can just add their own hooks and call 404 * it from this CRTC callback here by looping over all encoders 405 * connected to it using for_each_encoder_on_crtc(). 406 * 407 * This hook is used only by atomic helpers. Atomic drivers don't 408 * need to implement it if there's no need to disable anything at the 409 * CRTC level. 410 * 411 * Comparing to @disable, this one provides the additional input 412 * parameter @old_crtc_state which could be used to access the old 413 * state. Atomic drivers should consider to use this one instead 414 * of @disable. 415 */ 416 void (*atomic_disable)(struct drm_crtc *crtc, 417 struct drm_crtc_state *old_crtc_state); 418 }; 419 420 /** 421 * drm_crtc_helper_add - sets the helper vtable for a crtc 422 * @crtc: DRM CRTC 423 * @funcs: helper vtable to set for @crtc 424 */ 425 static inline void drm_crtc_helper_add(struct drm_crtc *crtc, 426 const struct drm_crtc_helper_funcs *funcs) 427 { 428 crtc->helper_private = funcs; 429 } 430 431 /** 432 * struct drm_encoder_helper_funcs - helper operations for encoders 433 * 434 * These hooks are used by the legacy CRTC helpers, the transitional plane 435 * helpers and the new atomic modesetting helpers. 436 */ 437 struct drm_encoder_helper_funcs { 438 /** 439 * @dpms: 440 * 441 * Callback to control power levels on the encoder. If the mode passed in 442 * is unsupported, the provider must use the next lowest power level. 443 * This is used by the legacy encoder helpers to implement DPMS 444 * functionality in drm_helper_connector_dpms(). 445 * 446 * This callback is also used to disable an encoder by calling it with 447 * DRM_MODE_DPMS_OFF if the @disable hook isn't used. 448 * 449 * This callback is used by the legacy CRTC helpers. Atomic helpers 450 * also support using this hook for enabling and disabling an encoder to 451 * facilitate transitions to atomic, but it is deprecated. Instead 452 * @enable and @disable should be used. 453 */ 454 void (*dpms)(struct drm_encoder *encoder, int mode); 455 456 /** 457 * @mode_fixup: 458 * 459 * This callback is used to validate and adjust a mode. The parameter 460 * mode is the display mode that should be fed to the next element in 461 * the display chain, either the final &drm_connector or a &drm_bridge. 462 * The parameter adjusted_mode is the input mode the encoder requires. It 463 * can be modified by this callback and does not need to match mode. 464 * 465 * This function is used by both legacy CRTC helpers and atomic helpers. 466 * This hook is optional. 467 * 468 * NOTE: 469 * 470 * This function is called in the check phase of atomic modesets, which 471 * can be aborted for any reason (including on userspace's request to 472 * just check whether a configuration would be possible). Atomic drivers 473 * MUST NOT touch any persistent state (hardware or software) or data 474 * structures except the passed in adjusted_mode parameter. 475 * 476 * This is in contrast to the legacy CRTC helpers where this was 477 * allowed. 478 * 479 * Atomic drivers which need to inspect and adjust more state should 480 * instead use the @atomic_check callback. 481 * 482 * Also beware that neither core nor helpers filter modes before 483 * passing them to the driver: While the list of modes that is 484 * advertised to userspace is filtered using the connector's 485 * ->mode_valid() callback, neither the core nor the helpers do any 486 * filtering on modes passed in from userspace when setting a mode. It 487 * is therefore possible for userspace to pass in a mode that was 488 * previously filtered out using ->mode_valid() or add a custom mode 489 * that wasn't probed from EDID or similar to begin with. Even though 490 * this is an advanced feature and rarely used nowadays, some users rely 491 * on being able to specify modes manually so drivers must be prepared 492 * to deal with it. Specifically this means that all drivers need not 493 * only validate modes in ->mode_valid() but also in ->mode_fixup() to 494 * make sure invalid modes passed in from userspace are rejected. 495 * 496 * RETURNS: 497 * 498 * True if an acceptable configuration is possible, false if the modeset 499 * operation should be rejected. 500 */ 501 bool (*mode_fixup)(struct drm_encoder *encoder, 502 const struct drm_display_mode *mode, 503 struct drm_display_mode *adjusted_mode); 504 505 /** 506 * @prepare: 507 * 508 * This callback should prepare the encoder for a subsequent modeset, 509 * which in practice means the driver should disable the encoder if it 510 * is running. Most drivers ended up implementing this by calling their 511 * @dpms hook with DRM_MODE_DPMS_OFF. 512 * 513 * This callback is used by the legacy CRTC helpers. Atomic helpers 514 * also support using this hook for disabling an encoder to facilitate 515 * transitions to atomic, but it is deprecated. Instead @disable should 516 * be used. 517 */ 518 void (*prepare)(struct drm_encoder *encoder); 519 520 /** 521 * @commit: 522 * 523 * This callback should commit the new mode on the encoder after a modeset, 524 * which in practice means the driver should enable the encoder. Most 525 * drivers ended up implementing this by calling their @dpms hook with 526 * DRM_MODE_DPMS_ON. 527 * 528 * This callback is used by the legacy CRTC helpers. Atomic helpers 529 * also support using this hook for enabling an encoder to facilitate 530 * transitions to atomic, but it is deprecated. Instead @enable should 531 * be used. 532 */ 533 void (*commit)(struct drm_encoder *encoder); 534 535 /** 536 * @mode_set: 537 * 538 * This callback is used to update the display mode of an encoder. 539 * 540 * Note that the display pipe is completely off when this function is 541 * called. Drivers which need hardware to be running before they program 542 * the new display mode (because they implement runtime PM) should not 543 * use this hook, because the helper library calls it only once and not 544 * every time the display pipeline is suspend using either DPMS or the 545 * new "ACTIVE" property. Such drivers should instead move all their 546 * encoder setup into the ->enable() callback. 547 * 548 * This callback is used both by the legacy CRTC helpers and the atomic 549 * modeset helpers. It is optional in the atomic helpers. 550 * 551 * NOTE: 552 * 553 * If the driver uses the atomic modeset helpers and needs to inspect 554 * the connector state or connector display info during mode setting, 555 * @atomic_mode_set can be used instead. 556 */ 557 void (*mode_set)(struct drm_encoder *encoder, 558 struct drm_display_mode *mode, 559 struct drm_display_mode *adjusted_mode); 560 561 /** 562 * @atomic_mode_set: 563 * 564 * This callback is used to update the display mode of an encoder. 565 * 566 * Note that the display pipe is completely off when this function is 567 * called. Drivers which need hardware to be running before they program 568 * the new display mode (because they implement runtime PM) should not 569 * use this hook, because the helper library calls it only once and not 570 * every time the display pipeline is suspended using either DPMS or the 571 * new "ACTIVE" property. Such drivers should instead move all their 572 * encoder setup into the ->enable() callback. 573 * 574 * This callback is used by the atomic modeset helpers in place of the 575 * @mode_set callback, if set by the driver. It is optional and should 576 * be used instead of @mode_set if the driver needs to inspect the 577 * connector state or display info, since there is no direct way to 578 * go from the encoder to the current connector. 579 */ 580 void (*atomic_mode_set)(struct drm_encoder *encoder, 581 struct drm_crtc_state *crtc_state, 582 struct drm_connector_state *conn_state); 583 584 /** 585 * @get_crtc: 586 * 587 * This callback is used by the legacy CRTC helpers to work around 588 * deficiencies in its own book-keeping. 589 * 590 * Do not use, use atomic helpers instead, which get the book keeping 591 * right. 592 * 593 * FIXME: 594 * 595 * Currently only nouveau is using this, and as soon as nouveau is 596 * atomic we can ditch this hook. 597 */ 598 struct drm_crtc *(*get_crtc)(struct drm_encoder *encoder); 599 600 /** 601 * @detect: 602 * 603 * This callback can be used by drivers who want to do detection on the 604 * encoder object instead of in connector functions. 605 * 606 * It is not used by any helper and therefore has purely driver-specific 607 * semantics. New drivers shouldn't use this and instead just implement 608 * their own private callbacks. 609 * 610 * FIXME: 611 * 612 * This should just be converted into a pile of driver vfuncs. 613 * Currently radeon, amdgpu and nouveau are using it. 614 */ 615 enum drm_connector_status (*detect)(struct drm_encoder *encoder, 616 struct drm_connector *connector); 617 618 /** 619 * @disable: 620 * 621 * This callback should be used to disable the encoder. With the atomic 622 * drivers it is called before this encoder's CRTC has been shut off 623 * using the CRTC's own ->disable hook. If that sequence is too simple 624 * drivers can just add their own driver private encoder hooks and call 625 * them from CRTC's callback by looping over all encoders connected to 626 * it using for_each_encoder_on_crtc(). 627 * 628 * This hook is used both by legacy CRTC helpers and atomic helpers. 629 * Atomic drivers don't need to implement it if there's no need to 630 * disable anything at the encoder level. To ensure that runtime PM 631 * handling (using either DPMS or the new "ACTIVE" property) works 632 * @disable must be the inverse of @enable for atomic drivers. 633 * 634 * NOTE: 635 * 636 * With legacy CRTC helpers there's a big semantic difference between 637 * @disable and other hooks (like @prepare or @dpms) used to shut down a 638 * encoder: @disable is only called when also logically disabling the 639 * display pipeline and needs to release any resources acquired in 640 * @mode_set (like shared PLLs, or again release pinned framebuffers). 641 * 642 * Therefore @disable must be the inverse of @mode_set plus @commit for 643 * drivers still using legacy CRTC helpers, which is different from the 644 * rules under atomic. 645 */ 646 void (*disable)(struct drm_encoder *encoder); 647 648 /** 649 * @enable: 650 * 651 * This callback should be used to enable the encoder. With the atomic 652 * drivers it is called after this encoder's CRTC has been enabled using 653 * the CRTC's own ->enable hook. If that sequence is too simple drivers 654 * can just add their own driver private encoder hooks and call them 655 * from CRTC's callback by looping over all encoders connected to it 656 * using for_each_encoder_on_crtc(). 657 * 658 * This hook is used only by atomic helpers, for symmetry with @disable. 659 * Atomic drivers don't need to implement it if there's no need to 660 * enable anything at the encoder level. To ensure that runtime PM handling 661 * (using either DPMS or the new "ACTIVE" property) works 662 * @enable must be the inverse of @disable for atomic drivers. 663 */ 664 void (*enable)(struct drm_encoder *encoder); 665 666 /** 667 * @atomic_check: 668 * 669 * This callback is used to validate encoder state for atomic drivers. 670 * Since the encoder is the object connecting the CRTC and connector it 671 * gets passed both states, to be able to validate interactions and 672 * update the CRTC to match what the encoder needs for the requested 673 * connector. 674 * 675 * This function is used by the atomic helpers, but it is optional. 676 * 677 * NOTE: 678 * 679 * This function is called in the check phase of an atomic update. The 680 * driver is not allowed to change anything outside of the free-standing 681 * state objects passed-in or assembled in the overall &drm_atomic_state 682 * update tracking structure. 683 * 684 * RETURNS: 685 * 686 * 0 on success, -EINVAL if the state or the transition can't be 687 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an 688 * attempt to obtain another state object ran into a &drm_modeset_lock 689 * deadlock. 690 */ 691 int (*atomic_check)(struct drm_encoder *encoder, 692 struct drm_crtc_state *crtc_state, 693 struct drm_connector_state *conn_state); 694 }; 695 696 /** 697 * drm_encoder_helper_add - sets the helper vtable for an encoder 698 * @encoder: DRM encoder 699 * @funcs: helper vtable to set for @encoder 700 */ 701 static inline void drm_encoder_helper_add(struct drm_encoder *encoder, 702 const struct drm_encoder_helper_funcs *funcs) 703 { 704 encoder->helper_private = funcs; 705 } 706 707 /** 708 * struct drm_connector_helper_funcs - helper operations for connectors 709 * 710 * These functions are used by the atomic and legacy modeset helpers and by the 711 * probe helpers. 712 */ 713 struct drm_connector_helper_funcs { 714 /** 715 * @get_modes: 716 * 717 * This function should fill in all modes currently valid for the sink 718 * into the connector->probed_modes list. It should also update the 719 * EDID property by calling drm_mode_connector_update_edid_property(). 720 * 721 * The usual way to implement this is to cache the EDID retrieved in the 722 * probe callback somewhere in the driver-private connector structure. 723 * In this function drivers then parse the modes in the EDID and add 724 * them by calling drm_add_edid_modes(). But connectors that driver a 725 * fixed panel can also manually add specific modes using 726 * drm_mode_probed_add(). Drivers which manually add modes should also 727 * make sure that the @display_info, @width_mm and @height_mm fields of the 728 * struct &drm_connector are filled in. 729 * 730 * Virtual drivers that just want some standard VESA mode with a given 731 * resolution can call drm_add_modes_noedid(), and mark the preferred 732 * one using drm_set_preferred_mode(). 733 * 734 * Finally drivers that support audio probably want to update the ELD 735 * data, too, using drm_edid_to_eld(). 736 * 737 * This function is only called after the ->detect() hook has indicated 738 * that a sink is connected and when the EDID isn't overridden through 739 * sysfs or the kernel commandline. 740 * 741 * This callback is used by the probe helpers in e.g. 742 * drm_helper_probe_single_connector_modes(). 743 * 744 * RETURNS: 745 * 746 * The number of modes added by calling drm_mode_probed_add(). 747 */ 748 int (*get_modes)(struct drm_connector *connector); 749 750 /** 751 * @mode_valid: 752 * 753 * Callback to validate a mode for a connector, irrespective of the 754 * specific display configuration. 755 * 756 * This callback is used by the probe helpers to filter the mode list 757 * (which is usually derived from the EDID data block from the sink). 758 * See e.g. drm_helper_probe_single_connector_modes(). 759 * 760 * NOTE: 761 * 762 * This only filters the mode list supplied to userspace in the 763 * GETCONNECOTR IOCTL. Userspace is free to create modes of its own and 764 * ask the kernel to use them. It this case the atomic helpers or legacy 765 * CRTC helpers will not call this function. Drivers therefore must 766 * still fully validate any mode passed in in a modeset request. 767 * 768 * RETURNS: 769 * 770 * Either MODE_OK or one of the failure reasons in enum 771 * &drm_mode_status. 772 */ 773 enum drm_mode_status (*mode_valid)(struct drm_connector *connector, 774 struct drm_display_mode *mode); 775 /** 776 * @best_encoder: 777 * 778 * This function should select the best encoder for the given connector. 779 * 780 * This function is used by both the atomic helpers (in the 781 * drm_atomic_helper_check_modeset() function) and in the legacy CRTC 782 * helpers. 783 * 784 * NOTE: 785 * 786 * In atomic drivers this function is called in the check phase of an 787 * atomic update. The driver is not allowed to change or inspect 788 * anything outside of arguments passed-in. Atomic drivers which need to 789 * inspect dynamic configuration state should instead use 790 * @atomic_best_encoder. 791 * 792 * You can leave this function to NULL if the connector is only 793 * attached to a single encoder and you are using the atomic helpers. 794 * In this case, the core will call drm_atomic_helper_best_encoder() 795 * for you. 796 * 797 * RETURNS: 798 * 799 * Encoder that should be used for the given connector and connector 800 * state, or NULL if no suitable encoder exists. Note that the helpers 801 * will ensure that encoders aren't used twice, drivers should not check 802 * for this. 803 */ 804 struct drm_encoder *(*best_encoder)(struct drm_connector *connector); 805 806 /** 807 * @atomic_best_encoder: 808 * 809 * This is the atomic version of @best_encoder for atomic drivers which 810 * need to select the best encoder depending upon the desired 811 * configuration and can't select it statically. 812 * 813 * This function is used by drm_atomic_helper_check_modeset(). 814 * If it is not implemented, the core will fallback to @best_encoder 815 * (or drm_atomic_helper_best_encoder() if @best_encoder is NULL). 816 * 817 * NOTE: 818 * 819 * This function is called in the check phase of an atomic update. The 820 * driver is not allowed to change anything outside of the free-standing 821 * state objects passed-in or assembled in the overall &drm_atomic_state 822 * update tracking structure. 823 * 824 * RETURNS: 825 * 826 * Encoder that should be used for the given connector and connector 827 * state, or NULL if no suitable encoder exists. Note that the helpers 828 * will ensure that encoders aren't used twice, drivers should not check 829 * for this. 830 */ 831 struct drm_encoder *(*atomic_best_encoder)(struct drm_connector *connector, 832 struct drm_connector_state *connector_state); 833 }; 834 835 /** 836 * drm_connector_helper_add - sets the helper vtable for a connector 837 * @connector: DRM connector 838 * @funcs: helper vtable to set for @connector 839 */ 840 static inline void drm_connector_helper_add(struct drm_connector *connector, 841 const struct drm_connector_helper_funcs *funcs) 842 { 843 connector->helper_private = funcs; 844 } 845 846 /** 847 * struct drm_plane_helper_funcs - helper operations for planes 848 * 849 * These functions are used by the atomic helpers and by the transitional plane 850 * helpers. 851 */ 852 struct drm_plane_helper_funcs { 853 /** 854 * @prepare_fb: 855 * 856 * This hook is to prepare a framebuffer for scanout by e.g. pinning 857 * it's backing storage or relocating it into a contiguous block of 858 * VRAM. Other possible preparatory work includes flushing caches. 859 * 860 * This function must not block for outstanding rendering, since it is 861 * called in the context of the atomic IOCTL even for async commits to 862 * be able to return any errors to userspace. Instead the recommended 863 * way is to fill out the fence member of the passed-in 864 * &drm_plane_state. If the driver doesn't support native fences then 865 * equivalent functionality should be implemented through private 866 * members in the plane structure. 867 * 868 * The helpers will call @cleanup_fb with matching arguments for every 869 * successful call to this hook. 870 * 871 * This callback is used by the atomic modeset helpers and by the 872 * transitional plane helpers, but it is optional. 873 * 874 * RETURNS: 875 * 876 * 0 on success or one of the following negative error codes allowed by 877 * the atomic_commit hook in &drm_mode_config_funcs. When using helpers 878 * this callback is the only one which can fail an atomic commit, 879 * everything else must complete successfully. 880 */ 881 int (*prepare_fb)(struct drm_plane *plane, 882 struct drm_plane_state *new_state); 883 /** 884 * @cleanup_fb: 885 * 886 * This hook is called to clean up any resources allocated for the given 887 * framebuffer and plane configuration in @prepare_fb. 888 * 889 * This callback is used by the atomic modeset helpers and by the 890 * transitional plane helpers, but it is optional. 891 */ 892 void (*cleanup_fb)(struct drm_plane *plane, 893 struct drm_plane_state *old_state); 894 895 /** 896 * @atomic_check: 897 * 898 * Drivers should check plane specific constraints in this hook. 899 * 900 * When using drm_atomic_helper_check_planes() plane's ->atomic_check() 901 * hooks are called before the ones for CRTCs, which allows drivers to 902 * request shared resources that the CRTC controls here. For more 903 * complicated dependencies the driver can call the provided check helpers 904 * multiple times until the computed state has a final configuration and 905 * everything has been checked. 906 * 907 * This function is also allowed to inspect any other object's state and 908 * can add more state objects to the atomic commit if needed. Care must 909 * be taken though to ensure that state check&compute functions for 910 * these added states are all called, and derived state in other objects 911 * all updated. Again the recommendation is to just call check helpers 912 * until a maximal configuration is reached. 913 * 914 * This callback is used by the atomic modeset helpers and by the 915 * transitional plane helpers, but it is optional. 916 * 917 * NOTE: 918 * 919 * This function is called in the check phase of an atomic update. The 920 * driver is not allowed to change anything outside of the free-standing 921 * state objects passed-in or assembled in the overall &drm_atomic_state 922 * update tracking structure. 923 * 924 * RETURNS: 925 * 926 * 0 on success, -EINVAL if the state or the transition can't be 927 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an 928 * attempt to obtain another state object ran into a &drm_modeset_lock 929 * deadlock. 930 */ 931 int (*atomic_check)(struct drm_plane *plane, 932 struct drm_plane_state *state); 933 934 /** 935 * @atomic_update: 936 * 937 * Drivers should use this function to update the plane state. This 938 * hook is called in-between the ->atomic_begin() and 939 * ->atomic_flush() of &drm_crtc_helper_funcs. 940 * 941 * Note that the power state of the display pipe when this function is 942 * called depends upon the exact helpers and calling sequence the driver 943 * has picked. See drm_atomic_commit_planes() for a discussion of the 944 * tradeoffs and variants of plane commit helpers. 945 * 946 * This callback is used by the atomic modeset helpers and by the 947 * transitional plane helpers, but it is optional. 948 */ 949 void (*atomic_update)(struct drm_plane *plane, 950 struct drm_plane_state *old_state); 951 /** 952 * @atomic_disable: 953 * 954 * Drivers should use this function to unconditionally disable a plane. 955 * This hook is called in-between the ->atomic_begin() and 956 * ->atomic_flush() of &drm_crtc_helper_funcs. It is an alternative to 957 * @atomic_update, which will be called for disabling planes, too, if 958 * the @atomic_disable hook isn't implemented. 959 * 960 * This hook is also useful to disable planes in preparation of a modeset, 961 * by calling drm_atomic_helper_disable_planes_on_crtc() from the 962 * ->disable() hook in &drm_crtc_helper_funcs. 963 * 964 * Note that the power state of the display pipe when this function is 965 * called depends upon the exact helpers and calling sequence the driver 966 * has picked. See drm_atomic_commit_planes() for a discussion of the 967 * tradeoffs and variants of plane commit helpers. 968 * 969 * This callback is used by the atomic modeset helpers and by the 970 * transitional plane helpers, but it is optional. 971 */ 972 void (*atomic_disable)(struct drm_plane *plane, 973 struct drm_plane_state *old_state); 974 }; 975 976 /** 977 * drm_plane_helper_add - sets the helper vtable for a plane 978 * @plane: DRM plane 979 * @funcs: helper vtable to set for @plane 980 */ 981 static inline void drm_plane_helper_add(struct drm_plane *plane, 982 const struct drm_plane_helper_funcs *funcs) 983 { 984 plane->helper_private = funcs; 985 } 986 987 /** 988 * struct drm_mode_config_helper_funcs - global modeset helper operations 989 * 990 * These helper functions are used by the atomic helpers. 991 */ 992 struct drm_mode_config_helper_funcs { 993 /** 994 * @atomic_commit_tail: 995 * 996 * This hook is used by the default atomic_commit() hook implemented in 997 * drm_atomic_helper_commit() together with the nonblocking commit 998 * helpers (see drm_atomic_helper_setup_commit() for a starting point) 999 * to implement blocking and nonblocking commits easily. It is not used 1000 * by the atomic helpers 1001 * 1002 * This hook should first commit the given atomic state to the hardware. 1003 * But drivers can add more waiting calls at the start of their 1004 * implementation, e.g. to wait for driver-internal request for implicit 1005 * syncing, before starting to commit the update to the hardware. 1006 * 1007 * After the atomic update is committed to the hardware this hook needs 1008 * to call drm_atomic_helper_commit_hw_done(). Then wait for the upate 1009 * to be executed by the hardware, for example using 1010 * drm_atomic_helper_wait_for_vblanks(), and then clean up the old 1011 * framebuffers using drm_atomic_helper_cleanup_planes(). 1012 * 1013 * When disabling a CRTC this hook _must_ stall for the commit to 1014 * complete. Vblank waits don't work on disabled CRTC, hence the core 1015 * can't take care of this. And it also can't rely on the vblank event, 1016 * since that can be signalled already when the screen shows black, 1017 * which can happen much earlier than the last hardware access needed to 1018 * shut off the display pipeline completely. 1019 * 1020 * This hook is optional, the default implementation is 1021 * drm_atomic_helper_commit_tail(). 1022 */ 1023 void (*atomic_commit_tail)(struct drm_atomic_state *state); 1024 }; 1025 1026 #endif 1027