1 /*
2  * Copyright (C) 2014 Intel Corporation
3  *
4  * DRM universal plane helper functions
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the "Software"),
8  * to deal in the Software without restriction, including without limitation
9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10  * and/or sell copies of the Software, and to permit persons to whom the
11  * Software is furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice (including the next
14  * paragraph) shall be included in all copies or substantial portions of the
15  * Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23  * SOFTWARE.
24  */
25 
26 #include <linux/list.h>
27 #include <drm/drmP.h>
28 #include <drm/drm_plane_helper.h>
29 #include <drm/drm_rect.h>
30 #include <drm/drm_atomic.h>
31 #include <drm/drm_crtc_helper.h>
32 #include <drm/drm_atomic_helper.h>
33 
34 #define SUBPIXEL_MASK 0xffff
35 
36 /**
37  * DOC: overview
38  *
39  * This helper library has two parts. The first part has support to implement
40  * primary plane support on top of the normal CRTC configuration interface.
41  * Since the legacy ->set_config interface ties the primary plane together with
42  * the CRTC state this does not allow userspace to disable the primary plane
43  * itself.  To avoid too much duplicated code use
44  * drm_plane_helper_check_update() which can be used to enforce the same
45  * restrictions as primary planes had thus. The default primary plane only
46  * expose XRBG8888 and ARGB8888 as valid pixel formats for the attached
47  * framebuffer.
48  *
49  * Drivers are highly recommended to implement proper support for primary
50  * planes, and newly merged drivers must not rely upon these transitional
51  * helpers.
52  *
53  * The second part also implements transitional helpers which allow drivers to
54  * gradually switch to the atomic helper infrastructure for plane updates. Once
55  * that switch is complete drivers shouldn't use these any longer, instead using
56  * the proper legacy implementations for update and disable plane hooks provided
57  * by the atomic helpers.
58  *
59  * Again drivers are strongly urged to switch to the new interfaces.
60  */
61 
62 /*
63  * This is the minimal list of formats that seem to be safe for modeset use
64  * with all current DRM drivers.  Most hardware can actually support more
65  * formats than this and drivers may specify a more accurate list when
66  * creating the primary plane.  However drivers that still call
67  * drm_plane_init() will use this minimal format list as the default.
68  */
69 static const uint32_t safe_modeset_formats[] = {
70 	DRM_FORMAT_XRGB8888,
71 	DRM_FORMAT_ARGB8888,
72 };
73 
74 /*
75  * Returns the connectors currently associated with a CRTC.  This function
76  * should be called twice:  once with a NULL connector list to retrieve
77  * the list size, and once with the properly allocated list to be filled in.
78  */
79 static int get_connectors_for_crtc(struct drm_crtc *crtc,
80 				   struct drm_connector **connector_list,
81 				   int num_connectors)
82 {
83 	struct drm_device *dev = crtc->dev;
84 	struct drm_connector *connector;
85 	int count = 0;
86 
87 	/*
88 	 * Note: Once we change the plane hooks to more fine-grained locking we
89 	 * need to grab the connection_mutex here to be able to make these
90 	 * checks.
91 	 */
92 	WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
93 
94 	drm_for_each_connector(connector, dev) {
95 		if (connector->encoder && connector->encoder->crtc == crtc) {
96 			if (connector_list != NULL && count < num_connectors)
97 				*(connector_list++) = connector;
98 
99 			count++;
100 		}
101 	}
102 
103 	return count;
104 }
105 
106 /**
107  * drm_plane_helper_check_update() - Check plane update for validity
108  * @plane: plane object to update
109  * @crtc: owning CRTC of owning plane
110  * @fb: framebuffer to flip onto plane
111  * @src: source coordinates in 16.16 fixed point
112  * @dest: integer destination coordinates
113  * @clip: integer clipping coordinates
114  * @min_scale: minimum @src:@dest scaling factor in 16.16 fixed point
115  * @max_scale: maximum @src:@dest scaling factor in 16.16 fixed point
116  * @can_position: is it legal to position the plane such that it
117  *                doesn't cover the entire crtc?  This will generally
118  *                only be false for primary planes.
119  * @can_update_disabled: can the plane be updated while the crtc
120  *                       is disabled?
121  * @visible: output parameter indicating whether plane is still visible after
122  *           clipping
123  *
124  * Checks that a desired plane update is valid.  Drivers that provide
125  * their own plane handling rather than helper-provided implementations may
126  * still wish to call this function to avoid duplication of error checking
127  * code.
128  *
129  * RETURNS:
130  * Zero if update appears valid, error code on failure
131  */
132 int drm_plane_helper_check_update(struct drm_plane *plane,
133 				    struct drm_crtc *crtc,
134 				    struct drm_framebuffer *fb,
135 				    struct drm_rect *src,
136 				    struct drm_rect *dest,
137 				    const struct drm_rect *clip,
138 				    int min_scale,
139 				    int max_scale,
140 				    bool can_position,
141 				    bool can_update_disabled,
142 				    bool *visible)
143 {
144 	int hscale, vscale;
145 
146 	if (!fb) {
147 		*visible = false;
148 		return 0;
149 	}
150 
151 	/* crtc should only be NULL when disabling (i.e., !fb) */
152 	if (WARN_ON(!crtc)) {
153 		*visible = false;
154 		return 0;
155 	}
156 
157 	if (!crtc->enabled && !can_update_disabled) {
158 		DRM_DEBUG_KMS("Cannot update plane of a disabled CRTC.\n");
159 		return -EINVAL;
160 	}
161 
162 	/* Check scaling */
163 	hscale = drm_rect_calc_hscale(src, dest, min_scale, max_scale);
164 	vscale = drm_rect_calc_vscale(src, dest, min_scale, max_scale);
165 	if (hscale < 0 || vscale < 0) {
166 		DRM_DEBUG_KMS("Invalid scaling of plane\n");
167 		return -ERANGE;
168 	}
169 
170 	*visible = drm_rect_clip_scaled(src, dest, clip, hscale, vscale);
171 	if (!*visible)
172 		/*
173 		 * Plane isn't visible; some drivers can handle this
174 		 * so we just return success here.  Drivers that can't
175 		 * (including those that use the primary plane helper's
176 		 * update function) will return an error from their
177 		 * update_plane handler.
178 		 */
179 		return 0;
180 
181 	if (!can_position && !drm_rect_equals(dest, clip)) {
182 		DRM_DEBUG_KMS("Plane must cover entire CRTC\n");
183 		return -EINVAL;
184 	}
185 
186 	return 0;
187 }
188 EXPORT_SYMBOL(drm_plane_helper_check_update);
189 
190 /**
191  * drm_primary_helper_update() - Helper for primary plane update
192  * @plane: plane object to update
193  * @crtc: owning CRTC of owning plane
194  * @fb: framebuffer to flip onto plane
195  * @crtc_x: x offset of primary plane on crtc
196  * @crtc_y: y offset of primary plane on crtc
197  * @crtc_w: width of primary plane rectangle on crtc
198  * @crtc_h: height of primary plane rectangle on crtc
199  * @src_x: x offset of @fb for panning
200  * @src_y: y offset of @fb for panning
201  * @src_w: width of source rectangle in @fb
202  * @src_h: height of source rectangle in @fb
203  *
204  * Provides a default plane update handler for primary planes.  This is handler
205  * is called in response to a userspace SetPlane operation on the plane with a
206  * non-NULL framebuffer.  We call the driver's modeset handler to update the
207  * framebuffer.
208  *
209  * SetPlane() on a primary plane of a disabled CRTC is not supported, and will
210  * return an error.
211  *
212  * Note that we make some assumptions about hardware limitations that may not be
213  * true for all hardware --
214  *   1) Primary plane cannot be repositioned.
215  *   2) Primary plane cannot be scaled.
216  *   3) Primary plane must cover the entire CRTC.
217  *   4) Subpixel positioning is not supported.
218  * Drivers for hardware that don't have these restrictions can provide their
219  * own implementation rather than using this helper.
220  *
221  * RETURNS:
222  * Zero on success, error code on failure
223  */
224 int drm_primary_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
225 			      struct drm_framebuffer *fb,
226 			      int crtc_x, int crtc_y,
227 			      unsigned int crtc_w, unsigned int crtc_h,
228 			      uint32_t src_x, uint32_t src_y,
229 			      uint32_t src_w, uint32_t src_h)
230 {
231 	struct drm_mode_set set = {
232 		.crtc = crtc,
233 		.fb = fb,
234 		.mode = &crtc->mode,
235 		.x = src_x >> 16,
236 		.y = src_y >> 16,
237 	};
238 	struct drm_rect src = {
239 		.x1 = src_x,
240 		.y1 = src_y,
241 		.x2 = src_x + src_w,
242 		.y2 = src_y + src_h,
243 	};
244 	struct drm_rect dest = {
245 		.x1 = crtc_x,
246 		.y1 = crtc_y,
247 		.x2 = crtc_x + crtc_w,
248 		.y2 = crtc_y + crtc_h,
249 	};
250 	const struct drm_rect clip = {
251 		.x2 = crtc->mode.hdisplay,
252 		.y2 = crtc->mode.vdisplay,
253 	};
254 	struct drm_connector **connector_list;
255 	int num_connectors, ret;
256 	bool visible;
257 
258 	ret = drm_plane_helper_check_update(plane, crtc, fb,
259 					    &src, &dest, &clip,
260 					    DRM_PLANE_HELPER_NO_SCALING,
261 					    DRM_PLANE_HELPER_NO_SCALING,
262 					    false, false, &visible);
263 	if (ret)
264 		return ret;
265 
266 	if (!visible)
267 		/*
268 		 * Primary plane isn't visible.  Note that unless a driver
269 		 * provides their own disable function, this will just
270 		 * wind up returning -EINVAL to userspace.
271 		 */
272 		return plane->funcs->disable_plane(plane);
273 
274 	/* Find current connectors for CRTC */
275 	num_connectors = get_connectors_for_crtc(crtc, NULL, 0);
276 	BUG_ON(num_connectors == 0);
277 	connector_list = kzalloc(num_connectors * sizeof(*connector_list),
278 				 GFP_KERNEL);
279 	if (!connector_list)
280 		return -ENOMEM;
281 	get_connectors_for_crtc(crtc, connector_list, num_connectors);
282 
283 	set.connectors = connector_list;
284 	set.num_connectors = num_connectors;
285 
286 	/*
287 	 * We call set_config() directly here rather than using
288 	 * drm_mode_set_config_internal.  We're reprogramming the same
289 	 * connectors that were already in use, so we shouldn't need the extra
290 	 * cross-CRTC fb refcounting to accomodate stealing connectors.
291 	 * drm_mode_setplane() already handles the basic refcounting for the
292 	 * framebuffers involved in this operation.
293 	 */
294 	ret = crtc->funcs->set_config(&set);
295 
296 	kfree(connector_list);
297 	return ret;
298 }
299 EXPORT_SYMBOL(drm_primary_helper_update);
300 
301 /**
302  * drm_primary_helper_disable() - Helper for primary plane disable
303  * @plane: plane to disable
304  *
305  * Provides a default plane disable handler for primary planes.  This is handler
306  * is called in response to a userspace SetPlane operation on the plane with a
307  * NULL framebuffer parameter.  It unconditionally fails the disable call with
308  * -EINVAL the only way to disable the primary plane without driver support is
309  * to disable the entier CRTC. Which does not match the plane ->disable hook.
310  *
311  * Note that some hardware may be able to disable the primary plane without
312  * disabling the whole CRTC.  Drivers for such hardware should provide their
313  * own disable handler that disables just the primary plane (and they'll likely
314  * need to provide their own update handler as well to properly re-enable a
315  * disabled primary plane).
316  *
317  * RETURNS:
318  * Unconditionally returns -EINVAL.
319  */
320 int drm_primary_helper_disable(struct drm_plane *plane)
321 {
322 	return -EINVAL;
323 }
324 EXPORT_SYMBOL(drm_primary_helper_disable);
325 
326 /**
327  * drm_primary_helper_destroy() - Helper for primary plane destruction
328  * @plane: plane to destroy
329  *
330  * Provides a default plane destroy handler for primary planes.  This handler
331  * is called during CRTC destruction.  We disable the primary plane, remove
332  * it from the DRM plane list, and deallocate the plane structure.
333  */
334 void drm_primary_helper_destroy(struct drm_plane *plane)
335 {
336 	drm_plane_cleanup(plane);
337 	kfree(plane);
338 }
339 EXPORT_SYMBOL(drm_primary_helper_destroy);
340 
341 const struct drm_plane_funcs drm_primary_helper_funcs = {
342 	.update_plane = drm_primary_helper_update,
343 	.disable_plane = drm_primary_helper_disable,
344 	.destroy = drm_primary_helper_destroy,
345 };
346 EXPORT_SYMBOL(drm_primary_helper_funcs);
347 
348 static struct drm_plane *create_primary_plane(struct drm_device *dev)
349 {
350 	struct drm_plane *primary;
351 	int ret;
352 
353 	primary = kzalloc(sizeof(*primary), GFP_KERNEL);
354 	if (primary == NULL) {
355 		DRM_DEBUG_KMS("Failed to allocate primary plane\n");
356 		return NULL;
357 	}
358 
359 	/*
360 	 * Remove the format_default field from drm_plane when dropping
361 	 * this helper.
362 	 */
363 	primary->format_default = true;
364 
365 	/* possible_crtc's will be filled in later by crtc_init */
366 	ret = drm_universal_plane_init(dev, primary, 0,
367 				       &drm_primary_helper_funcs,
368 				       safe_modeset_formats,
369 				       ARRAY_SIZE(safe_modeset_formats),
370 				       DRM_PLANE_TYPE_PRIMARY);
371 	if (ret) {
372 		kfree(primary);
373 		primary = NULL;
374 	}
375 
376 	return primary;
377 }
378 
379 /**
380  * drm_crtc_init - Legacy CRTC initialization function
381  * @dev: DRM device
382  * @crtc: CRTC object to init
383  * @funcs: callbacks for the new CRTC
384  *
385  * Initialize a CRTC object with a default helper-provided primary plane and no
386  * cursor plane.
387  *
388  * Returns:
389  * Zero on success, error code on failure.
390  */
391 int drm_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
392 		  const struct drm_crtc_funcs *funcs)
393 {
394 	struct drm_plane *primary;
395 
396 	primary = create_primary_plane(dev);
397 	return drm_crtc_init_with_planes(dev, crtc, primary, NULL, funcs);
398 }
399 EXPORT_SYMBOL(drm_crtc_init);
400 
401 int drm_plane_helper_commit(struct drm_plane *plane,
402 			    struct drm_plane_state *plane_state,
403 			    struct drm_framebuffer *old_fb)
404 {
405 	const struct drm_plane_helper_funcs *plane_funcs;
406 	struct drm_crtc *crtc[2];
407 	const struct drm_crtc_helper_funcs *crtc_funcs[2];
408 	int i, ret = 0;
409 
410 	plane_funcs = plane->helper_private;
411 
412 	/* Since this is a transitional helper we can't assume that plane->state
413 	 * is always valid. Hence we need to use plane->crtc instead of
414 	 * plane->state->crtc as the old crtc. */
415 	crtc[0] = plane->crtc;
416 	crtc[1] = crtc[0] != plane_state->crtc ? plane_state->crtc : NULL;
417 
418 	for (i = 0; i < 2; i++)
419 		crtc_funcs[i] = crtc[i] ? crtc[i]->helper_private : NULL;
420 
421 	if (plane_funcs->atomic_check) {
422 		ret = plane_funcs->atomic_check(plane, plane_state);
423 		if (ret)
424 			goto out;
425 	}
426 
427 	if (plane_funcs->prepare_fb && plane_state->fb &&
428 	    plane_state->fb != old_fb) {
429 		ret = plane_funcs->prepare_fb(plane, plane_state->fb,
430 					      plane_state);
431 		if (ret)
432 			goto out;
433 	}
434 
435 	/* Point of no return, commit sw state. */
436 	swap(plane->state, plane_state);
437 
438 	for (i = 0; i < 2; i++) {
439 		if (crtc_funcs[i] && crtc_funcs[i]->atomic_begin)
440 			crtc_funcs[i]->atomic_begin(crtc[i], crtc[i]->state);
441 	}
442 
443 	/*
444 	 * Drivers may optionally implement the ->atomic_disable callback, so
445 	 * special-case that here.
446 	 */
447 	if (drm_atomic_plane_disabling(plane, plane_state) &&
448 	    plane_funcs->atomic_disable)
449 		plane_funcs->atomic_disable(plane, plane_state);
450 	else
451 		plane_funcs->atomic_update(plane, plane_state);
452 
453 	for (i = 0; i < 2; i++) {
454 		if (crtc_funcs[i] && crtc_funcs[i]->atomic_flush)
455 			crtc_funcs[i]->atomic_flush(crtc[i], crtc[i]->state);
456 	}
457 
458 	/*
459 	 * If we only moved the plane and didn't change fb's, there's no need to
460 	 * wait for vblank.
461 	 */
462 	if (plane->state->fb == old_fb)
463 		goto out;
464 
465 	for (i = 0; i < 2; i++) {
466 		if (!crtc[i])
467 			continue;
468 
469 		if (crtc[i]->cursor == plane)
470 			continue;
471 
472 		/* There's no other way to figure out whether the crtc is running. */
473 		ret = drm_crtc_vblank_get(crtc[i]);
474 		if (ret == 0) {
475 			drm_crtc_wait_one_vblank(crtc[i]);
476 			drm_crtc_vblank_put(crtc[i]);
477 		}
478 
479 		ret = 0;
480 	}
481 
482 	if (plane_funcs->cleanup_fb && old_fb)
483 		plane_funcs->cleanup_fb(plane, old_fb, plane_state);
484 out:
485 	if (plane_state) {
486 		if (plane->funcs->atomic_destroy_state)
487 			plane->funcs->atomic_destroy_state(plane, plane_state);
488 		else
489 			drm_atomic_helper_plane_destroy_state(plane, plane_state);
490 	}
491 
492 	return ret;
493 }
494 
495 /**
496  * drm_plane_helper_update() - Transitional helper for plane update
497  * @plane: plane object to update
498  * @crtc: owning CRTC of owning plane
499  * @fb: framebuffer to flip onto plane
500  * @crtc_x: x offset of primary plane on crtc
501  * @crtc_y: y offset of primary plane on crtc
502  * @crtc_w: width of primary plane rectangle on crtc
503  * @crtc_h: height of primary plane rectangle on crtc
504  * @src_x: x offset of @fb for panning
505  * @src_y: y offset of @fb for panning
506  * @src_w: width of source rectangle in @fb
507  * @src_h: height of source rectangle in @fb
508  *
509  * Provides a default plane update handler using the atomic plane update
510  * functions. It is fully left to the driver to check plane constraints and
511  * handle corner-cases like a fully occluded or otherwise invisible plane.
512  *
513  * This is useful for piecewise transitioning of a driver to the atomic helpers.
514  *
515  * RETURNS:
516  * Zero on success, error code on failure
517  */
518 int drm_plane_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
519 			    struct drm_framebuffer *fb,
520 			    int crtc_x, int crtc_y,
521 			    unsigned int crtc_w, unsigned int crtc_h,
522 			    uint32_t src_x, uint32_t src_y,
523 			    uint32_t src_w, uint32_t src_h)
524 {
525 	struct drm_plane_state *plane_state;
526 
527 	if (plane->funcs->atomic_duplicate_state)
528 		plane_state = plane->funcs->atomic_duplicate_state(plane);
529 	else {
530 		if (!plane->state)
531 			drm_atomic_helper_plane_reset(plane);
532 
533 		plane_state = drm_atomic_helper_plane_duplicate_state(plane);
534 	}
535 	if (!plane_state)
536 		return -ENOMEM;
537 	plane_state->plane = plane;
538 
539 	plane_state->crtc = crtc;
540 	drm_atomic_set_fb_for_plane(plane_state, fb);
541 	plane_state->crtc_x = crtc_x;
542 	plane_state->crtc_y = crtc_y;
543 	plane_state->crtc_h = crtc_h;
544 	plane_state->crtc_w = crtc_w;
545 	plane_state->src_x = src_x;
546 	plane_state->src_y = src_y;
547 	plane_state->src_h = src_h;
548 	plane_state->src_w = src_w;
549 
550 	return drm_plane_helper_commit(plane, plane_state, plane->fb);
551 }
552 EXPORT_SYMBOL(drm_plane_helper_update);
553 
554 /**
555  * drm_plane_helper_disable() - Transitional helper for plane disable
556  * @plane: plane to disable
557  *
558  * Provides a default plane disable handler using the atomic plane update
559  * functions. It is fully left to the driver to check plane constraints and
560  * handle corner-cases like a fully occluded or otherwise invisible plane.
561  *
562  * This is useful for piecewise transitioning of a driver to the atomic helpers.
563  *
564  * RETURNS:
565  * Zero on success, error code on failure
566  */
567 int drm_plane_helper_disable(struct drm_plane *plane)
568 {
569 	struct drm_plane_state *plane_state;
570 
571 	/* crtc helpers love to call disable functions for already disabled hw
572 	 * functions. So cope with that. */
573 	if (!plane->crtc)
574 		return 0;
575 
576 	if (plane->funcs->atomic_duplicate_state)
577 		plane_state = plane->funcs->atomic_duplicate_state(plane);
578 	else {
579 		if (!plane->state)
580 			drm_atomic_helper_plane_reset(plane);
581 
582 		plane_state = drm_atomic_helper_plane_duplicate_state(plane);
583 	}
584 	if (!plane_state)
585 		return -ENOMEM;
586 	plane_state->plane = plane;
587 
588 	plane_state->crtc = NULL;
589 	drm_atomic_set_fb_for_plane(plane_state, NULL);
590 
591 	return drm_plane_helper_commit(plane, plane_state, plane->fb);
592 }
593 EXPORT_SYMBOL(drm_plane_helper_disable);
594