xref: /openbmc/linux/include/drm/drm_crtc.h (revision a6ca5ac746d104019e76c29e69c2a1fc6dd2b29f)
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  *
7  * Permission is hereby granted, free of charge, to any person obtaining a
8  * copy of this software and associated documentation files (the "Software"),
9  * to deal in the Software without restriction, including without limitation
10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11  * and/or sell copies of the Software, and to permit persons to whom the
12  * Software is furnished to do so, subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice shall be included in
15  * all copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
20  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
21  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
22  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
23  * OTHER DEALINGS IN THE SOFTWARE.
24  */
25 #ifndef __DRM_CRTC_H__
26 #define __DRM_CRTC_H__
27 
28 #include <linux/i2c.h>
29 #include <linux/spinlock.h>
30 #include <linux/types.h>
31 #include <linux/fb.h>
32 #include <linux/hdmi.h>
33 #include <linux/media-bus-format.h>
34 #include <uapi/drm/drm_mode.h>
35 #include <uapi/drm/drm_fourcc.h>
36 #include <drm/drm_modeset_lock.h>
37 #include <drm/drm_rect.h>
38 #include <drm/drm_mode_object.h>
39 #include <drm/drm_framebuffer.h>
40 #include <drm/drm_modes.h>
41 #include <drm/drm_connector.h>
42 #include <drm/drm_property.h>
43 #include <drm/drm_bridge.h>
44 #include <drm/drm_edid.h>
45 #include <drm/drm_plane.h>
46 #include <drm/drm_blend.h>
47 #include <drm/drm_color_mgmt.h>
48 #include <drm/drm_debugfs_crc.h>
49 #include <drm/drm_mode_config.h>
50 
51 struct drm_device;
52 struct drm_mode_set;
53 struct drm_file;
54 struct drm_clip_rect;
55 struct drm_printer;
56 struct device_node;
57 struct dma_fence;
58 struct edid;
59 
60 static inline int64_t U642I64(uint64_t val)
61 {
62 	return (int64_t)*((int64_t *)&val);
63 }
64 static inline uint64_t I642U64(int64_t val)
65 {
66 	return (uint64_t)*((uint64_t *)&val);
67 }
68 
69 struct drm_crtc;
70 struct drm_pending_vblank_event;
71 struct drm_plane;
72 struct drm_bridge;
73 struct drm_atomic_state;
74 
75 struct drm_crtc_helper_funcs;
76 struct drm_plane_helper_funcs;
77 
78 /**
79  * struct drm_crtc_state - mutable CRTC state
80  * @crtc: backpointer to the CRTC
81  * @enable: whether the CRTC should be enabled, gates all other state
82  * @active: whether the CRTC is actively displaying (used for DPMS)
83  * @planes_changed: planes on this crtc are updated
84  * @mode_changed: @mode or @enable has been changed
85  * @active_changed: @active has been toggled.
86  * @connectors_changed: connectors to this crtc have been updated
87  * @zpos_changed: zpos values of planes on this crtc have been updated
88  * @color_mgmt_changed: color management properties have changed (degamma or
89  *	gamma LUT or CSC matrix)
90  * @plane_mask: bitmask of (1 << drm_plane_index(plane)) of attached planes
91  * @connector_mask: bitmask of (1 << drm_connector_index(connector)) of attached connectors
92  * @encoder_mask: bitmask of (1 << drm_encoder_index(encoder)) of attached encoders
93  * @adjusted_mode: for use by helpers and drivers to compute adjusted mode timings
94  * @mode: current mode timings
95  * @mode_blob: &drm_property_blob for @mode
96  * @state: backpointer to global drm_atomic_state
97  *
98  * Note that the distinction between @enable and @active is rather subtile:
99  * Flipping @active while @enable is set without changing anything else may
100  * never return in a failure from the &drm_mode_config_funcs.atomic_check
101  * callback. Userspace assumes that a DPMS On will always succeed. In other
102  * words: @enable controls resource assignment, @active controls the actual
103  * hardware state.
104  *
105  * The three booleans active_changed, connectors_changed and mode_changed are
106  * intended to indicate whether a full modeset is needed, rather than strictly
107  * describing what has changed in a commit.
108  * See also: drm_atomic_crtc_needs_modeset()
109  */
110 struct drm_crtc_state {
111 	struct drm_crtc *crtc;
112 
113 	bool enable;
114 	bool active;
115 
116 	/* computed state bits used by helpers and drivers */
117 	bool planes_changed : 1;
118 	bool mode_changed : 1;
119 	bool active_changed : 1;
120 	bool connectors_changed : 1;
121 	bool zpos_changed : 1;
122 	bool color_mgmt_changed : 1;
123 
124 	/* attached planes bitmask:
125 	 * WARNING: transitional helpers do not maintain plane_mask so
126 	 * drivers not converted over to atomic helpers should not rely
127 	 * on plane_mask being accurate!
128 	 */
129 	u32 plane_mask;
130 
131 	u32 connector_mask;
132 	u32 encoder_mask;
133 
134 	/* adjusted_mode: for use by helpers and drivers */
135 	struct drm_display_mode adjusted_mode;
136 
137 	struct drm_display_mode mode;
138 
139 	/* blob property to expose current mode to atomic userspace */
140 	struct drm_property_blob *mode_blob;
141 
142 	/**
143 	 * @degamma_lut:
144 	 *
145 	 * Lookup table for converting framebuffer pixel data before apply the
146 	 * color conversion matrix @ctm. See drm_crtc_enable_color_mgmt(). The
147 	 * blob (if not NULL) is an array of &struct drm_color_lut.
148 	 */
149 	struct drm_property_blob *degamma_lut;
150 
151 	/**
152 	 * @ctm:
153 	 *
154 	 * Color transformation matrix. See drm_crtc_enable_color_mgmt(). The
155 	 * blob (if not NULL) is a &struct drm_color_ctm.
156 	 */
157 	struct drm_property_blob *ctm;
158 
159 	/**
160 	 * @gamma_lut:
161 	 *
162 	 * Lookup table for converting pixel data after the color conversion
163 	 * matrix @ctm.  See drm_crtc_enable_color_mgmt(). The blob (if not
164 	 * NULL) is an array of &struct drm_color_lut.
165 	 */
166 	struct drm_property_blob *gamma_lut;
167 
168 	/**
169 	 * @target_vblank:
170 	 *
171 	 * Target vertical blank period when a page flip
172 	 * should take effect.
173 	 */
174 	u32 target_vblank;
175 
176 	/**
177 	 * @pageflip_flags:
178 	 *
179 	 * DRM_MODE_PAGE_FLIP_* flags, as passed to the page flip ioctl.
180 	 * Zero in any other case.
181 	 */
182 	u32 pageflip_flags;
183 
184 	/**
185 	 * @event:
186 	 *
187 	 * Optional pointer to a DRM event to signal upon completion of the
188 	 * state update. The driver must send out the event when the atomic
189 	 * commit operation completes. There are two cases:
190 	 *
191 	 *  - The event is for a CRTC which is being disabled through this
192 	 *    atomic commit. In that case the event can be send out any time
193 	 *    after the hardware has stopped scanning out the current
194 	 *    framebuffers. It should contain the timestamp and counter for the
195 	 *    last vblank before the display pipeline was shut off.
196 	 *
197 	 *  - For a CRTC which is enabled at the end of the commit (even when it
198 	 *    undergoes an full modeset) the vblank timestamp and counter must
199 	 *    be for the vblank right before the first frame that scans out the
200 	 *    new set of buffers. Again the event can only be sent out after the
201 	 *    hardware has stopped scanning out the old buffers.
202 	 *
203 	 *  - Events for disabled CRTCs are not allowed, and drivers can ignore
204 	 *    that case.
205 	 *
206 	 * This can be handled by the drm_crtc_send_vblank_event() function,
207 	 * which the driver should call on the provided event upon completion of
208 	 * the atomic commit. Note that if the driver supports vblank signalling
209 	 * and timestamping the vblank counters and timestamps must agree with
210 	 * the ones returned from page flip events. With the current vblank
211 	 * helper infrastructure this can be achieved by holding a vblank
212 	 * reference while the page flip is pending, acquired through
213 	 * drm_crtc_vblank_get() and released with drm_crtc_vblank_put().
214 	 * Drivers are free to implement their own vblank counter and timestamp
215 	 * tracking though, e.g. if they have accurate timestamp registers in
216 	 * hardware.
217 	 *
218 	 * For hardware which supports some means to synchronize vblank
219 	 * interrupt delivery with committing display state there's also
220 	 * drm_crtc_arm_vblank_event(). See the documentation of that function
221 	 * for a detailed discussion of the constraints it needs to be used
222 	 * safely.
223 	 *
224 	 * If the device can't notify of flip completion in a race-free way
225 	 * at all, then the event should be armed just after the page flip is
226 	 * committed. In the worst case the driver will send the event to
227 	 * userspace one frame too late. This doesn't allow for a real atomic
228 	 * update, but it should avoid tearing.
229 	 */
230 	struct drm_pending_vblank_event *event;
231 
232 	struct drm_atomic_state *state;
233 };
234 
235 /**
236  * struct drm_crtc_funcs - control CRTCs for a given device
237  *
238  * The drm_crtc_funcs structure is the central CRTC management structure
239  * in the DRM.  Each CRTC controls one or more connectors (note that the name
240  * CRTC is simply historical, a CRTC may control LVDS, VGA, DVI, TV out, etc.
241  * connectors, not just CRTs).
242  *
243  * Each driver is responsible for filling out this structure at startup time,
244  * in addition to providing other modesetting features, like i2c and DDC
245  * bus accessors.
246  */
247 struct drm_crtc_funcs {
248 	/**
249 	 * @reset:
250 	 *
251 	 * Reset CRTC hardware and software state to off. This function isn't
252 	 * called by the core directly, only through drm_mode_config_reset().
253 	 * It's not a helper hook only for historical reasons.
254 	 *
255 	 * Atomic drivers can use drm_atomic_helper_crtc_reset() to reset
256 	 * atomic state using this hook.
257 	 */
258 	void (*reset)(struct drm_crtc *crtc);
259 
260 	/**
261 	 * @cursor_set:
262 	 *
263 	 * Update the cursor image. The cursor position is relative to the CRTC
264 	 * and can be partially or fully outside of the visible area.
265 	 *
266 	 * Note that contrary to all other KMS functions the legacy cursor entry
267 	 * points don't take a framebuffer object, but instead take directly a
268 	 * raw buffer object id from the driver's buffer manager (which is
269 	 * either GEM or TTM for current drivers).
270 	 *
271 	 * This entry point is deprecated, drivers should instead implement
272 	 * universal plane support and register a proper cursor plane using
273 	 * drm_crtc_init_with_planes().
274 	 *
275 	 * This callback is optional
276 	 *
277 	 * RETURNS:
278 	 *
279 	 * 0 on success or a negative error code on failure.
280 	 */
281 	int (*cursor_set)(struct drm_crtc *crtc, struct drm_file *file_priv,
282 			  uint32_t handle, uint32_t width, uint32_t height);
283 
284 	/**
285 	 * @cursor_set2:
286 	 *
287 	 * Update the cursor image, including hotspot information. The hotspot
288 	 * must not affect the cursor position in CRTC coordinates, but is only
289 	 * meant as a hint for virtualized display hardware to coordinate the
290 	 * guests and hosts cursor position. The cursor hotspot is relative to
291 	 * the cursor image. Otherwise this works exactly like @cursor_set.
292 	 *
293 	 * This entry point is deprecated, drivers should instead implement
294 	 * universal plane support and register a proper cursor plane using
295 	 * drm_crtc_init_with_planes().
296 	 *
297 	 * This callback is optional.
298 	 *
299 	 * RETURNS:
300 	 *
301 	 * 0 on success or a negative error code on failure.
302 	 */
303 	int (*cursor_set2)(struct drm_crtc *crtc, struct drm_file *file_priv,
304 			   uint32_t handle, uint32_t width, uint32_t height,
305 			   int32_t hot_x, int32_t hot_y);
306 
307 	/**
308 	 * @cursor_move:
309 	 *
310 	 * Update the cursor position. The cursor does not need to be visible
311 	 * when this hook is called.
312 	 *
313 	 * This entry point is deprecated, drivers should instead implement
314 	 * universal plane support and register a proper cursor plane using
315 	 * drm_crtc_init_with_planes().
316 	 *
317 	 * This callback is optional.
318 	 *
319 	 * RETURNS:
320 	 *
321 	 * 0 on success or a negative error code on failure.
322 	 */
323 	int (*cursor_move)(struct drm_crtc *crtc, int x, int y);
324 
325 	/**
326 	 * @gamma_set:
327 	 *
328 	 * Set gamma on the CRTC.
329 	 *
330 	 * This callback is optional.
331 	 *
332 	 * Atomic drivers who want to support gamma tables should implement the
333 	 * atomic color management support, enabled by calling
334 	 * drm_crtc_enable_color_mgmt(), which then supports the legacy gamma
335 	 * interface through the drm_atomic_helper_legacy_gamma_set()
336 	 * compatibility implementation.
337 	 *
338 	 * NOTE:
339 	 *
340 	 * Drivers that support gamma tables and also fbdev emulation through
341 	 * the provided helper library need to take care to fill out the gamma
342 	 * hooks for both. Currently there's a bit an unfortunate duplication
343 	 * going on, which should eventually be unified to just one set of
344 	 * hooks.
345 	 */
346 	int (*gamma_set)(struct drm_crtc *crtc, u16 *r, u16 *g, u16 *b,
347 			 uint32_t size,
348 			 struct drm_modeset_acquire_ctx *ctx);
349 
350 	/**
351 	 * @destroy:
352 	 *
353 	 * Clean up plane resources. This is only called at driver unload time
354 	 * through drm_mode_config_cleanup() since a CRTC cannot be hotplugged
355 	 * in DRM.
356 	 */
357 	void (*destroy)(struct drm_crtc *crtc);
358 
359 	/**
360 	 * @set_config:
361 	 *
362 	 * This is the main legacy entry point to change the modeset state on a
363 	 * CRTC. All the details of the desired configuration are passed in a
364 	 * &struct drm_mode_set - see there for details.
365 	 *
366 	 * Drivers implementing atomic modeset should use
367 	 * drm_atomic_helper_set_config() to implement this hook.
368 	 *
369 	 * RETURNS:
370 	 *
371 	 * 0 on success or a negative error code on failure.
372 	 */
373 	int (*set_config)(struct drm_mode_set *set,
374 			  struct drm_modeset_acquire_ctx *ctx);
375 
376 	/**
377 	 * @page_flip:
378 	 *
379 	 * Legacy entry point to schedule a flip to the given framebuffer.
380 	 *
381 	 * Page flipping is a synchronization mechanism that replaces the frame
382 	 * buffer being scanned out by the CRTC with a new frame buffer during
383 	 * vertical blanking, avoiding tearing (except when requested otherwise
384 	 * through the DRM_MODE_PAGE_FLIP_ASYNC flag). When an application
385 	 * requests a page flip the DRM core verifies that the new frame buffer
386 	 * is large enough to be scanned out by the CRTC in the currently
387 	 * configured mode and then calls this hook with a pointer to the new
388 	 * frame buffer.
389 	 *
390 	 * The driver must wait for any pending rendering to the new framebuffer
391 	 * to complete before executing the flip. It should also wait for any
392 	 * pending rendering from other drivers if the underlying buffer is a
393 	 * shared dma-buf.
394 	 *
395 	 * An application can request to be notified when the page flip has
396 	 * completed. The drm core will supply a &struct drm_event in the event
397 	 * parameter in this case. This can be handled by the
398 	 * drm_crtc_send_vblank_event() function, which the driver should call on
399 	 * the provided event upon completion of the flip. Note that if
400 	 * the driver supports vblank signalling and timestamping the vblank
401 	 * counters and timestamps must agree with the ones returned from page
402 	 * flip events. With the current vblank helper infrastructure this can
403 	 * be achieved by holding a vblank reference while the page flip is
404 	 * pending, acquired through drm_crtc_vblank_get() and released with
405 	 * drm_crtc_vblank_put(). Drivers are free to implement their own vblank
406 	 * counter and timestamp tracking though, e.g. if they have accurate
407 	 * timestamp registers in hardware.
408 	 *
409 	 * This callback is optional.
410 	 *
411 	 * NOTE:
412 	 *
413 	 * Very early versions of the KMS ABI mandated that the driver must
414 	 * block (but not reject) any rendering to the old framebuffer until the
415 	 * flip operation has completed and the old framebuffer is no longer
416 	 * visible. This requirement has been lifted, and userspace is instead
417 	 * expected to request delivery of an event and wait with recycling old
418 	 * buffers until such has been received.
419 	 *
420 	 * RETURNS:
421 	 *
422 	 * 0 on success or a negative error code on failure. Note that if a
423 	 * page flip operation is already pending the callback should return
424 	 * -EBUSY. Pageflips on a disabled CRTC (either by setting a NULL mode
425 	 * or just runtime disabled through DPMS respectively the new atomic
426 	 * "ACTIVE" state) should result in an -EINVAL error code. Note that
427 	 * drm_atomic_helper_page_flip() checks this already for atomic drivers.
428 	 */
429 	int (*page_flip)(struct drm_crtc *crtc,
430 			 struct drm_framebuffer *fb,
431 			 struct drm_pending_vblank_event *event,
432 			 uint32_t flags,
433 			 struct drm_modeset_acquire_ctx *ctx);
434 
435 	/**
436 	 * @page_flip_target:
437 	 *
438 	 * Same as @page_flip but with an additional parameter specifying the
439 	 * absolute target vertical blank period (as reported by
440 	 * drm_crtc_vblank_count()) when the flip should take effect.
441 	 *
442 	 * Note that the core code calls drm_crtc_vblank_get before this entry
443 	 * point, and will call drm_crtc_vblank_put if this entry point returns
444 	 * any non-0 error code. It's the driver's responsibility to call
445 	 * drm_crtc_vblank_put after this entry point returns 0, typically when
446 	 * the flip completes.
447 	 */
448 	int (*page_flip_target)(struct drm_crtc *crtc,
449 				struct drm_framebuffer *fb,
450 				struct drm_pending_vblank_event *event,
451 				uint32_t flags, uint32_t target,
452 				struct drm_modeset_acquire_ctx *ctx);
453 
454 	/**
455 	 * @set_property:
456 	 *
457 	 * This is the legacy entry point to update a property attached to the
458 	 * CRTC.
459 	 *
460 	 * Drivers implementing atomic modeset should use
461 	 * drm_atomic_helper_crtc_set_property() to implement this hook.
462 	 *
463 	 * This callback is optional if the driver does not support any legacy
464 	 * driver-private properties.
465 	 *
466 	 * RETURNS:
467 	 *
468 	 * 0 on success or a negative error code on failure.
469 	 */
470 	int (*set_property)(struct drm_crtc *crtc,
471 			    struct drm_property *property, uint64_t val);
472 
473 	/**
474 	 * @atomic_duplicate_state:
475 	 *
476 	 * Duplicate the current atomic state for this CRTC and return it.
477 	 * The core and helpers guarantee that any atomic state duplicated with
478 	 * this hook and still owned by the caller (i.e. not transferred to the
479 	 * driver by calling &drm_mode_config_funcs.atomic_commit) will be
480 	 * cleaned up by calling the @atomic_destroy_state hook in this
481 	 * structure.
482 	 *
483 	 * Atomic drivers which don't subclass &struct drm_crtc_state should use
484 	 * drm_atomic_helper_crtc_duplicate_state(). Drivers that subclass the
485 	 * state structure to extend it with driver-private state should use
486 	 * __drm_atomic_helper_crtc_duplicate_state() to make sure shared state is
487 	 * duplicated in a consistent fashion across drivers.
488 	 *
489 	 * It is an error to call this hook before &drm_crtc.state has been
490 	 * initialized correctly.
491 	 *
492 	 * NOTE:
493 	 *
494 	 * If the duplicate state references refcounted resources this hook must
495 	 * acquire a reference for each of them. The driver must release these
496 	 * references again in @atomic_destroy_state.
497 	 *
498 	 * RETURNS:
499 	 *
500 	 * Duplicated atomic state or NULL when the allocation failed.
501 	 */
502 	struct drm_crtc_state *(*atomic_duplicate_state)(struct drm_crtc *crtc);
503 
504 	/**
505 	 * @atomic_destroy_state:
506 	 *
507 	 * Destroy a state duplicated with @atomic_duplicate_state and release
508 	 * or unreference all resources it references
509 	 */
510 	void (*atomic_destroy_state)(struct drm_crtc *crtc,
511 				     struct drm_crtc_state *state);
512 
513 	/**
514 	 * @atomic_set_property:
515 	 *
516 	 * Decode a driver-private property value and store the decoded value
517 	 * into the passed-in state structure. Since the atomic core decodes all
518 	 * standardized properties (even for extensions beyond the core set of
519 	 * properties which might not be implemented by all drivers) this
520 	 * requires drivers to subclass the state structure.
521 	 *
522 	 * Such driver-private properties should really only be implemented for
523 	 * truly hardware/vendor specific state. Instead it is preferred to
524 	 * standardize atomic extension and decode the properties used to expose
525 	 * such an extension in the core.
526 	 *
527 	 * Do not call this function directly, use
528 	 * drm_atomic_crtc_set_property() instead.
529 	 *
530 	 * This callback is optional if the driver does not support any
531 	 * driver-private atomic properties.
532 	 *
533 	 * NOTE:
534 	 *
535 	 * This function is called in the state assembly phase of atomic
536 	 * modesets, which can be aborted for any reason (including on
537 	 * userspace's request to just check whether a configuration would be
538 	 * possible). Drivers MUST NOT touch any persistent state (hardware or
539 	 * software) or data structures except the passed in @state parameter.
540 	 *
541 	 * Also since userspace controls in which order properties are set this
542 	 * function must not do any input validation (since the state update is
543 	 * incomplete and hence likely inconsistent). Instead any such input
544 	 * validation must be done in the various atomic_check callbacks.
545 	 *
546 	 * RETURNS:
547 	 *
548 	 * 0 if the property has been found, -EINVAL if the property isn't
549 	 * implemented by the driver (which should never happen, the core only
550 	 * asks for properties attached to this CRTC). No other validation is
551 	 * allowed by the driver. The core already checks that the property
552 	 * value is within the range (integer, valid enum value, ...) the driver
553 	 * set when registering the property.
554 	 */
555 	int (*atomic_set_property)(struct drm_crtc *crtc,
556 				   struct drm_crtc_state *state,
557 				   struct drm_property *property,
558 				   uint64_t val);
559 	/**
560 	 * @atomic_get_property:
561 	 *
562 	 * Reads out the decoded driver-private property. This is used to
563 	 * implement the GETCRTC IOCTL.
564 	 *
565 	 * Do not call this function directly, use
566 	 * drm_atomic_crtc_get_property() instead.
567 	 *
568 	 * This callback is optional if the driver does not support any
569 	 * driver-private atomic properties.
570 	 *
571 	 * RETURNS:
572 	 *
573 	 * 0 on success, -EINVAL if the property isn't implemented by the
574 	 * driver (which should never happen, the core only asks for
575 	 * properties attached to this CRTC).
576 	 */
577 	int (*atomic_get_property)(struct drm_crtc *crtc,
578 				   const struct drm_crtc_state *state,
579 				   struct drm_property *property,
580 				   uint64_t *val);
581 
582 	/**
583 	 * @late_register:
584 	 *
585 	 * This optional hook can be used to register additional userspace
586 	 * interfaces attached to the crtc like debugfs interfaces.
587 	 * It is called late in the driver load sequence from drm_dev_register().
588 	 * Everything added from this callback should be unregistered in
589 	 * the early_unregister callback.
590 	 *
591 	 * Returns:
592 	 *
593 	 * 0 on success, or a negative error code on failure.
594 	 */
595 	int (*late_register)(struct drm_crtc *crtc);
596 
597 	/**
598 	 * @early_unregister:
599 	 *
600 	 * This optional hook should be used to unregister the additional
601 	 * userspace interfaces attached to the crtc from
602 	 * @late_register. It is called from drm_dev_unregister(),
603 	 * early in the driver unload sequence to disable userspace access
604 	 * before data structures are torndown.
605 	 */
606 	void (*early_unregister)(struct drm_crtc *crtc);
607 
608 	/**
609 	 * @set_crc_source:
610 	 *
611 	 * Changes the source of CRC checksums of frames at the request of
612 	 * userspace, typically for testing purposes. The sources available are
613 	 * specific of each driver and a %NULL value indicates that CRC
614 	 * generation is to be switched off.
615 	 *
616 	 * When CRC generation is enabled, the driver should call
617 	 * drm_crtc_add_crc_entry() at each frame, providing any information
618 	 * that characterizes the frame contents in the crcN arguments, as
619 	 * provided from the configured source. Drivers must accept an "auto"
620 	 * source name that will select a default source for this CRTC.
621 	 *
622 	 * Note that "auto" can depend upon the current modeset configuration,
623 	 * e.g. it could pick an encoder or output specific CRC sampling point.
624 	 *
625 	 * This callback is optional if the driver does not support any CRC
626 	 * generation functionality.
627 	 *
628 	 * RETURNS:
629 	 *
630 	 * 0 on success or a negative error code on failure.
631 	 */
632 	int (*set_crc_source)(struct drm_crtc *crtc, const char *source,
633 			      size_t *values_cnt);
634 
635 	/**
636 	 * @atomic_print_state:
637 	 *
638 	 * If driver subclasses &struct drm_crtc_state, it should implement
639 	 * this optional hook for printing additional driver specific state.
640 	 *
641 	 * Do not call this directly, use drm_atomic_crtc_print_state()
642 	 * instead.
643 	 */
644 	void (*atomic_print_state)(struct drm_printer *p,
645 				   const struct drm_crtc_state *state);
646 
647 	/**
648 	 * @get_vblank_counter:
649 	 *
650 	 * Driver callback for fetching a raw hardware vblank counter for the
651 	 * CRTC. It's meant to be used by new drivers as the replacement of
652 	 * &drm_driver.get_vblank_counter hook.
653 	 *
654 	 * This callback is optional. If a device doesn't have a hardware
655 	 * counter, the driver can simply leave the hook as NULL. The DRM core
656 	 * will account for missed vblank events while interrupts where disabled
657 	 * based on system timestamps.
658 	 *
659 	 * Wraparound handling and loss of events due to modesetting is dealt
660 	 * with in the DRM core code, as long as drivers call
661 	 * drm_crtc_vblank_off() and drm_crtc_vblank_on() when disabling or
662 	 * enabling a CRTC.
663 	 *
664 	 * Returns:
665 	 *
666 	 * Raw vblank counter value.
667 	 */
668 	u32 (*get_vblank_counter)(struct drm_crtc *crtc);
669 
670 	/**
671 	 * @enable_vblank:
672 	 *
673 	 * Enable vblank interrupts for the CRTC. It's meant to be used by
674 	 * new drivers as the replacement of &drm_driver.enable_vblank hook.
675 	 *
676 	 * Returns:
677 	 *
678 	 * Zero on success, appropriate errno if the vblank interrupt cannot
679 	 * be enabled.
680 	 */
681 	int (*enable_vblank)(struct drm_crtc *crtc);
682 
683 	/**
684 	 * @disable_vblank:
685 	 *
686 	 * Disable vblank interrupts for the CRTC. It's meant to be used by
687 	 * new drivers as the replacement of &drm_driver.disable_vblank hook.
688 	 */
689 	void (*disable_vblank)(struct drm_crtc *crtc);
690 };
691 
692 /**
693  * struct drm_crtc - central CRTC control structure
694  * @dev: parent DRM device
695  * @port: OF node used by drm_of_find_possible_crtcs()
696  * @head: list management
697  * @name: human readable name, can be overwritten by the driver
698  * @mutex: per-CRTC locking
699  * @base: base KMS object for ID tracking etc.
700  * @primary: primary plane for this CRTC
701  * @cursor: cursor plane for this CRTC
702  * @cursor_x: current x position of the cursor, used for universal cursor planes
703  * @cursor_y: current y position of the cursor, used for universal cursor planes
704  * @enabled: is this CRTC enabled?
705  * @mode: current mode timings
706  * @hwmode: mode timings as programmed to hw regs
707  * @x: x position on screen
708  * @y: y position on screen
709  * @funcs: CRTC control functions
710  * @gamma_size: size of gamma ramp
711  * @gamma_store: gamma ramp values
712  * @helper_private: mid-layer private data
713  * @properties: property tracking for this CRTC
714  *
715  * Each CRTC may have one or more connectors associated with it.  This structure
716  * allows the CRTC to be controlled.
717  */
718 struct drm_crtc {
719 	struct drm_device *dev;
720 	struct device_node *port;
721 	struct list_head head;
722 
723 	char *name;
724 
725 	/**
726 	 * @mutex:
727 	 *
728 	 * This provides a read lock for the overall CRTC state (mode, dpms
729 	 * state, ...) and a write lock for everything which can be update
730 	 * without a full modeset (fb, cursor data, CRTC properties ...). A full
731 	 * modeset also need to grab &drm_mode_config.connection_mutex.
732 	 *
733 	 * For atomic drivers specifically this protects @state.
734 	 */
735 	struct drm_modeset_lock mutex;
736 
737 	struct drm_mode_object base;
738 
739 	/* primary and cursor planes for CRTC */
740 	struct drm_plane *primary;
741 	struct drm_plane *cursor;
742 
743 	/**
744 	 * @index: Position inside the mode_config.list, can be used as an array
745 	 * index. It is invariant over the lifetime of the CRTC.
746 	 */
747 	unsigned index;
748 
749 	/* position of cursor plane on crtc */
750 	int cursor_x;
751 	int cursor_y;
752 
753 	bool enabled;
754 
755 	/* Requested mode from modesetting. */
756 	struct drm_display_mode mode;
757 
758 	/* Programmed mode in hw, after adjustments for encoders,
759 	 * crtc, panel scaling etc. Needed for timestamping etc.
760 	 */
761 	struct drm_display_mode hwmode;
762 
763 	int x, y;
764 	const struct drm_crtc_funcs *funcs;
765 
766 	/* Legacy FB CRTC gamma size for reporting to userspace */
767 	uint32_t gamma_size;
768 	uint16_t *gamma_store;
769 
770 	/* if you are using the helper */
771 	const struct drm_crtc_helper_funcs *helper_private;
772 
773 	struct drm_object_properties properties;
774 
775 	/**
776 	 * @state:
777 	 *
778 	 * Current atomic state for this CRTC.
779 	 *
780 	 * This is protected by @mutex. Note that nonblocking atomic commits
781 	 * access the current CRTC state without taking locks. Either by going
782 	 * through the &struct drm_atomic_state pointers, see
783 	 * for_each_crtc_in_state(), for_each_oldnew_crtc_in_state(),
784 	 * for_each_old_crtc_in_state() and for_each_new_crtc_in_state(). Or
785 	 * through careful ordering of atomic commit operations as implemented
786 	 * in the atomic helpers, see &struct drm_crtc_commit.
787 	 */
788 	struct drm_crtc_state *state;
789 
790 	/**
791 	 * @commit_list:
792 	 *
793 	 * List of &drm_crtc_commit structures tracking pending commits.
794 	 * Protected by @commit_lock. This list doesn't hold its own full
795 	 * reference, but burrows it from the ongoing commit. Commit entries
796 	 * must be removed from this list once the commit is fully completed,
797 	 * but before it's correspoding &drm_atomic_state gets destroyed.
798 	 */
799 	struct list_head commit_list;
800 
801 	/**
802 	 * @commit_lock:
803 	 *
804 	 * Spinlock to protect @commit_list.
805 	 */
806 	spinlock_t commit_lock;
807 
808 #ifdef CONFIG_DEBUG_FS
809 	/**
810 	 * @debugfs_entry:
811 	 *
812 	 * Debugfs directory for this CRTC.
813 	 */
814 	struct dentry *debugfs_entry;
815 #endif
816 
817 	/**
818 	 * @crc:
819 	 *
820 	 * Configuration settings of CRC capture.
821 	 */
822 	struct drm_crtc_crc crc;
823 
824 	/**
825 	 * @fence_context:
826 	 *
827 	 * timeline context used for fence operations.
828 	 */
829 	unsigned int fence_context;
830 
831 	/**
832 	 * @fence_lock:
833 	 *
834 	 * spinlock to protect the fences in the fence_context.
835 	 */
836 
837 	spinlock_t fence_lock;
838 	/**
839 	 * @fence_seqno:
840 	 *
841 	 * Seqno variable used as monotonic counter for the fences
842 	 * created on the CRTC's timeline.
843 	 */
844 	unsigned long fence_seqno;
845 
846 	/**
847 	 * @timeline_name:
848 	 *
849 	 * The name of the CRTC's fence timeline.
850 	 */
851 	char timeline_name[32];
852 };
853 
854 /**
855  * struct drm_mode_set - new values for a CRTC config change
856  * @fb: framebuffer to use for new config
857  * @crtc: CRTC whose configuration we're about to change
858  * @mode: mode timings to use
859  * @x: position of this CRTC relative to @fb
860  * @y: position of this CRTC relative to @fb
861  * @connectors: array of connectors to drive with this CRTC if possible
862  * @num_connectors: size of @connectors array
863  *
864  * This represents a modeset configuration for the legacy SETCRTC ioctl and is
865  * also used internally. Atomic drivers instead use &drm_atomic_state.
866  */
867 struct drm_mode_set {
868 	struct drm_framebuffer *fb;
869 	struct drm_crtc *crtc;
870 	struct drm_display_mode *mode;
871 
872 	uint32_t x;
873 	uint32_t y;
874 
875 	struct drm_connector **connectors;
876 	size_t num_connectors;
877 };
878 
879 #define obj_to_crtc(x) container_of(x, struct drm_crtc, base)
880 
881 __printf(6, 7)
882 int drm_crtc_init_with_planes(struct drm_device *dev,
883 			      struct drm_crtc *crtc,
884 			      struct drm_plane *primary,
885 			      struct drm_plane *cursor,
886 			      const struct drm_crtc_funcs *funcs,
887 			      const char *name, ...);
888 void drm_crtc_cleanup(struct drm_crtc *crtc);
889 
890 /**
891  * drm_crtc_index - find the index of a registered CRTC
892  * @crtc: CRTC to find index for
893  *
894  * Given a registered CRTC, return the index of that CRTC within a DRM
895  * device's list of CRTCs.
896  */
897 static inline unsigned int drm_crtc_index(const struct drm_crtc *crtc)
898 {
899 	return crtc->index;
900 }
901 
902 /**
903  * drm_crtc_mask - find the mask of a registered CRTC
904  * @crtc: CRTC to find mask for
905  *
906  * Given a registered CRTC, return the mask bit of that CRTC for an
907  * encoder's possible_crtcs field.
908  */
909 static inline uint32_t drm_crtc_mask(const struct drm_crtc *crtc)
910 {
911 	return 1 << drm_crtc_index(crtc);
912 }
913 
914 int drm_crtc_force_disable(struct drm_crtc *crtc);
915 int drm_crtc_force_disable_all(struct drm_device *dev);
916 
917 int drm_mode_set_config_internal(struct drm_mode_set *set);
918 struct drm_crtc *drm_crtc_from_index(struct drm_device *dev, int idx);
919 
920 /**
921  * drm_crtc_find - look up a CRTC object from its ID
922  * @dev: DRM device
923  * @id: &drm_mode_object ID
924  *
925  * This can be used to look up a CRTC from its userspace ID. Only used by
926  * drivers for legacy IOCTLs and interface, nowadays extensions to the KMS
927  * userspace interface should be done using &drm_property.
928  */
929 static inline struct drm_crtc *drm_crtc_find(struct drm_device *dev,
930 	uint32_t id)
931 {
932 	struct drm_mode_object *mo;
933 	mo = drm_mode_object_find(dev, id, DRM_MODE_OBJECT_CRTC);
934 	return mo ? obj_to_crtc(mo) : NULL;
935 }
936 
937 /**
938  * drm_for_each_crtc - iterate over all CRTCs
939  * @crtc: a &struct drm_crtc as the loop cursor
940  * @dev: the &struct drm_device
941  *
942  * Iterate over all CRTCs of @dev.
943  */
944 #define drm_for_each_crtc(crtc, dev) \
945 	list_for_each_entry(crtc, &(dev)->mode_config.crtc_list, head)
946 
947 #endif /* __DRM_CRTC_H__ */
948