1/*
  2 * Copyright (C) 2016 Samsung Electronics Co.Ltd
  3 * Authors:
  4 *	Marek Szyprowski <m.szyprowski@samsung.com>
  5 *
  6 * DRM core plane blending related functions
  7 *
  8 * Permission to use, copy, modify, distribute, and sell this software and its
  9 * documentation for any purpose is hereby granted without fee, provided that
 10 * the above copyright notice appear in all copies and that both that copyright
 11 * notice and this permission notice appear in supporting documentation, and
 12 * that the name of the copyright holders not be used in advertising or
 13 * publicity pertaining to distribution of the software without specific,
 14 * written prior permission.  The copyright holders make no representations
 15 * about the suitability of this software for any purpose.  It is provided "as
 16 * is" without express or implied warranty.
 17 *
 18 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 19 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 20 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 21 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 22 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 23 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 24 * OF THIS SOFTWARE.
 25 */
 26
 27#include <linux/export.h>
 28#include <linux/slab.h>
 29#include <linux/sort.h>
 30
 31#include <drm/drm_atomic.h>
 32#include <drm/drm_blend.h>
 33#include <drm/drm_device.h>
 34#include <drm/drm_print.h>
 35
 36#include "drm_crtc_internal.h"
 37
 38/**
 39 * DOC: overview
 40 *
 41 * The basic plane composition model supported by standard plane properties only
 42 * has a source rectangle (in logical pixels within the &drm_framebuffer), with
 43 * sub-pixel accuracy, which is scaled up to a pixel-aligned destination
 44 * rectangle in the visible area of a &drm_crtc. The visible area of a CRTC is
 45 * defined by the horizontal and vertical visible pixels (stored in @hdisplay
 46 * and @vdisplay) of the requested mode (stored in &drm_crtc_state.mode). These
 47 * two rectangles are both stored in the &drm_plane_state.
 48 *
 49 * For the atomic ioctl the following standard (atomic) properties on the plane object
 50 * encode the basic plane composition model:
 51 *
 52 * SRC_X:
 53 * 	X coordinate offset for the source rectangle within the
 54 * 	&drm_framebuffer, in 16.16 fixed point. Must be positive.
 55 * SRC_Y:
 56 * 	Y coordinate offset for the source rectangle within the
 57 * 	&drm_framebuffer, in 16.16 fixed point. Must be positive.
 58 * SRC_W:
 59 * 	Width for the source rectangle within the &drm_framebuffer, in 16.16
 60 * 	fixed point. SRC_X plus SRC_W must be within the width of the source
 61 * 	framebuffer. Must be positive.
 62 * SRC_H:
 63 * 	Height for the source rectangle within the &drm_framebuffer, in 16.16
 64 * 	fixed point. SRC_Y plus SRC_H must be within the height of the source
 65 * 	framebuffer. Must be positive.
 66 * CRTC_X:
 67 * 	X coordinate offset for the destination rectangle. Can be negative.
 68 * CRTC_Y:
 69 * 	Y coordinate offset for the destination rectangle. Can be negative.
 70 * CRTC_W:
 71 * 	Width for the destination rectangle. CRTC_X plus CRTC_W can extend past
 72 * 	the currently visible horizontal area of the &drm_crtc.
 73 * CRTC_H:
 74 * 	Height for the destination rectangle. CRTC_Y plus CRTC_H can extend past
 75 * 	the currently visible vertical area of the &drm_crtc.
 76 * FB_ID:
 77 * 	Mode object ID of the &drm_framebuffer this plane should scan out.
 78 * CRTC_ID:
 79 * 	Mode object ID of the &drm_crtc this plane should be connected to.
 80 *
 81 * Note that the source rectangle must fully lie within the bounds of the
 82 * &drm_framebuffer. The destination rectangle can lie outside of the visible
 83 * area of the current mode of the CRTC. It must be apprpriately clipped by the
 84 * driver, which can be done by calling drm_plane_helper_check_update(). Drivers
 85 * are also allowed to round the subpixel sampling positions appropriately, but
 86 * only to the next full pixel. No pixel outside of the source rectangle may
 87 * ever be sampled, which is important when applying more sophisticated
 88 * filtering than just a bilinear one when scaling. The filtering mode when
 89 * scaling is unspecified.
 90 *
 91 * On top of this basic transformation additional properties can be exposed by
 92 * the driver:
 93 *
 94 * alpha:
 95 * 	Alpha is setup with drm_plane_create_alpha_property(). It controls the
 96 * 	plane-wide opacity, from transparent (0) to opaque (0xffff). It can be
 97 * 	combined with pixel alpha.
 98 *	The pixel values in the framebuffers are expected to not be
 99 *	pre-multiplied by the global alpha associated to the plane.
100 *
101 * rotation:
102 *	Rotation is set up with drm_plane_create_rotation_property(). It adds a
103 *	rotation and reflection step between the source and destination rectangles.
104 *	Without this property the rectangle is only scaled, but not rotated or
105 *	reflected.
106 *
107 *	Possbile values:
108 *
109 *	"rotate-<degrees>":
110 *		Signals that a drm plane is rotated <degrees> degrees in counter
111 *		clockwise direction.
112 *
113 *	"reflect-<axis>":
114 *		Signals that the contents of a drm plane is reflected along the
115 *		<axis> axis, in the same way as mirroring.
116 *
117 *	reflect-x::
118 *
119 *			|o |    | o|
120 *			|  | -> |  |
121 *			| v|    |v |
122 *
123 *	reflect-y::
124 *
125 *			|o |    | ^|
126 *			|  | -> |  |
127 *			| v|    |o |
128 *
129 * zpos:
130 *	Z position is set up with drm_plane_create_zpos_immutable_property() and
131 *	drm_plane_create_zpos_property(). It controls the visibility of overlapping
132 *	planes. Without this property the primary plane is always below the cursor
133 *	plane, and ordering between all other planes is undefined.
134 *
135 * pixel blend mode:
136 *	Pixel blend mode is set up with drm_plane_create_blend_mode_property().
137 *	It adds a blend mode for alpha blending equation selection, describing
138 *	how the pixels from the current plane are composited with the
139 *	background.
140 *
141 *	 Three alpha blending equations are defined:
142 *
143 *	 "None":
144 *		 Blend formula that ignores the pixel alpha::
145 *
146 *			 out.rgb = plane_alpha * fg.rgb +
147 *				 (1 - plane_alpha) * bg.rgb
148 *
149 *	 "Pre-multiplied":
150 *		 Blend formula that assumes the pixel color values
151 *		 have been already pre-multiplied with the alpha
152 *		 channel values::
153 *
154 *			 out.rgb = plane_alpha * fg.rgb +
155 *				 (1 - (plane_alpha * fg.alpha)) * bg.rgb
156 *
157 *	 "Coverage":
158 *		 Blend formula that assumes the pixel color values have not
159 *		 been pre-multiplied and will do so when blending them to the
160 *		 background color values::
161 *
162 *			 out.rgb = plane_alpha * fg.alpha * fg.rgb +
163 *				 (1 - (plane_alpha * fg.alpha)) * bg.rgb
164 *
165 *	 Using the following symbols:
166 *
167 *	 "fg.rgb":
168 *		 Each of the RGB component values from the plane's pixel
169 *	 "fg.alpha":
170 *		 Alpha component value from the plane's pixel. If the plane's
171 *		 pixel format has no alpha component, then this is assumed to be
172 *		 1.0. In these cases, this property has no effect, as all three
173 *		 equations become equivalent.
174 *	 "bg.rgb":
175 *		 Each of the RGB component values from the background
176 *	 "plane_alpha":
177 *		 Plane alpha value set by the plane "alpha" property. If the
178 *		 plane does not expose the "alpha" property, then this is
179 *		 assumed to be 1.0
180 *
181 * Note that all the property extensions described here apply either to the
182 * plane or the CRTC (e.g. for the background color, which currently is not
183 * exposed and assumed to be black).
184 */
185
186/**
187 * drm_plane_create_alpha_property - create a new alpha property
188 * @plane: drm plane
189 *
190 * This function creates a generic, mutable, alpha property and enables support
191 * for it in the DRM core. It is attached to @plane.
192 *
193 * The alpha property will be allowed to be within the bounds of 0
194 * (transparent) to 0xffff (opaque).
195 *
196 * Returns:
197 * 0 on success, negative error code on failure.
198 */
199int drm_plane_create_alpha_property(struct drm_plane *plane)
200{
201	struct drm_property *prop;
202
203	prop = drm_property_create_range(plane->dev, 0, "alpha",
204					 0, DRM_BLEND_ALPHA_OPAQUE);
205	if (!prop)
206		return -ENOMEM;
207
208	drm_object_attach_property(&plane->base, prop, DRM_BLEND_ALPHA_OPAQUE);
209	plane->alpha_property = prop;
210
211	if (plane->state)
212		plane->state->alpha = DRM_BLEND_ALPHA_OPAQUE;
213
214	return 0;
215}
216EXPORT_SYMBOL(drm_plane_create_alpha_property);
217
218/**
219 * drm_plane_create_rotation_property - create a new rotation property
220 * @plane: drm plane
221 * @rotation: initial value of the rotation property
222 * @supported_rotations: bitmask of supported rotations and reflections
223 *
224 * This creates a new property with the selected support for transformations.
225 *
226 * Since a rotation by 180° degress is the same as reflecting both along the x
227 * and the y axis the rotation property is somewhat redundant. Drivers can use
228 * drm_rotation_simplify() to normalize values of this property.
229 *
230 * The property exposed to userspace is a bitmask property (see
231 * drm_property_create_bitmask()) called "rotation" and has the following
232 * bitmask enumaration values:
233 *
234 * DRM_MODE_ROTATE_0:
235 * 	"rotate-0"
236 * DRM_MODE_ROTATE_90:
237 * 	"rotate-90"
238 * DRM_MODE_ROTATE_180:
239 * 	"rotate-180"
240 * DRM_MODE_ROTATE_270:
241 * 	"rotate-270"
242 * DRM_MODE_REFLECT_X:
243 * 	"reflect-x"
244 * DRM_MODE_REFLECT_Y:
245 * 	"reflect-y"
246 *
247 * Rotation is the specified amount in degrees in counter clockwise direction,
248 * the X and Y axis are within the source rectangle, i.e.  the X/Y axis before
249 * rotation. After reflection, the rotation is applied to the image sampled from
250 * the source rectangle, before scaling it to fit the destination rectangle.
251 */
252int drm_plane_create_rotation_property(struct drm_plane *plane,
253				       unsigned int rotation,
254				       unsigned int supported_rotations)
255{
256	static const struct drm_prop_enum_list props[] = {
257		{ __builtin_ffs(DRM_MODE_ROTATE_0) - 1,   "rotate-0" },
258		{ __builtin_ffs(DRM_MODE_ROTATE_90) - 1,  "rotate-90" },
259		{ __builtin_ffs(DRM_MODE_ROTATE_180) - 1, "rotate-180" },
260		{ __builtin_ffs(DRM_MODE_ROTATE_270) - 1, "rotate-270" },
261		{ __builtin_ffs(DRM_MODE_REFLECT_X) - 1,  "reflect-x" },
262		{ __builtin_ffs(DRM_MODE_REFLECT_Y) - 1,  "reflect-y" },
263	};
264	struct drm_property *prop;
265
266	WARN_ON((supported_rotations & DRM_MODE_ROTATE_MASK) == 0);
267	WARN_ON(!is_power_of_2(rotation & DRM_MODE_ROTATE_MASK));
268	WARN_ON(rotation & ~supported_rotations);
269
270	prop = drm_property_create_bitmask(plane->dev, 0, "rotation",
271					   props, ARRAY_SIZE(props),
272					   supported_rotations);
273	if (!prop)
274		return -ENOMEM;
275
276	drm_object_attach_property(&plane->base, prop, rotation);
277
278	if (plane->state)
279		plane->state->rotation = rotation;
280
281	plane->rotation_property = prop;
282
283	return 0;
284}
285EXPORT_SYMBOL(drm_plane_create_rotation_property);
286
287/**
288 * drm_rotation_simplify() - Try to simplify the rotation
289 * @rotation: Rotation to be simplified
290 * @supported_rotations: Supported rotations
291 *
292 * Attempt to simplify the rotation to a form that is supported.
293 * Eg. if the hardware supports everything except DRM_MODE_REFLECT_X
294 * one could call this function like this:
295 *
296 * drm_rotation_simplify(rotation, DRM_MODE_ROTATE_0 |
297 *                       DRM_MODE_ROTATE_90 | DRM_MODE_ROTATE_180 |
298 *                       DRM_MODE_ROTATE_270 | DRM_MODE_REFLECT_Y);
299 *
300 * to eliminate the DRM_MODE_ROTATE_X flag. Depending on what kind of
301 * transforms the hardware supports, this function may not
302 * be able to produce a supported transform, so the caller should
303 * check the result afterwards.
304 */
305unsigned int drm_rotation_simplify(unsigned int rotation,
306				   unsigned int supported_rotations)
307{
308	if (rotation & ~supported_rotations) {
309		rotation ^= DRM_MODE_REFLECT_X | DRM_MODE_REFLECT_Y;
310		rotation = (rotation & DRM_MODE_REFLECT_MASK) |
311		           BIT((ffs(rotation & DRM_MODE_ROTATE_MASK) + 1)
312		           % 4);
313	}
314
315	return rotation;
316}
317EXPORT_SYMBOL(drm_rotation_simplify);
318
319/**
320 * drm_plane_create_zpos_property - create mutable zpos property
321 * @plane: drm plane
322 * @zpos: initial value of zpos property
323 * @min: minimal possible value of zpos property
324 * @max: maximal possible value of zpos property
325 *
326 * This function initializes generic mutable zpos property and enables support
327 * for it in drm core. Drivers can then attach this property to planes to enable
328 * support for configurable planes arrangement during blending operation.
329 * Drivers that attach a mutable zpos property to any plane should call the
330 * drm_atomic_normalize_zpos() helper during their implementation of
331 * &drm_mode_config_funcs.atomic_check(), which will update the normalized zpos
332 * values and store them in &drm_plane_state.normalized_zpos. Usually min
333 * should be set to 0 and max to maximal number of planes for given crtc - 1.
334 *
335 * If zpos of some planes cannot be changed (like fixed background or
336 * cursor/topmost planes), driver should adjust min/max values and assign those
337 * planes immutable zpos property with lower or higher values (for more
338 * information, see drm_plane_create_zpos_immutable_property() function). In such
339 * case driver should also assign proper initial zpos values for all planes in
340 * its plane_reset() callback, so the planes will be always sorted properly.
341 *
342 * See also drm_atomic_normalize_zpos().
343 *
344 * The property exposed to userspace is called "zpos".
345 *
346 * Returns:
347 * Zero on success, negative errno on failure.
348 */
349int drm_plane_create_zpos_property(struct drm_plane *plane,
350				   unsigned int zpos,
351				   unsigned int min, unsigned int max)
352{
353	struct drm_property *prop;
354
355	prop = drm_property_create_range(plane->dev, 0, "zpos", min, max);
356	if (!prop)
357		return -ENOMEM;
358
359	drm_object_attach_property(&plane->base, prop, zpos);
360
361	plane->zpos_property = prop;
362
363	if (plane->state) {
364		plane->state->zpos = zpos;
365		plane->state->normalized_zpos = zpos;
366	}
367
368	return 0;
369}
370EXPORT_SYMBOL(drm_plane_create_zpos_property);
371
372/**
373 * drm_plane_create_zpos_immutable_property - create immuttable zpos property
374 * @plane: drm plane
375 * @zpos: value of zpos property
376 *
377 * This function initializes generic immutable zpos property and enables
378 * support for it in drm core. Using this property driver lets userspace
379 * to get the arrangement of the planes for blending operation and notifies
380 * it that the hardware (or driver) doesn't support changing of the planes'
381 * order. For mutable zpos see drm_plane_create_zpos_property().
382 *
383 * The property exposed to userspace is called "zpos".
384 *
385 * Returns:
386 * Zero on success, negative errno on failure.
387 */
388int drm_plane_create_zpos_immutable_property(struct drm_plane *plane,
389					     unsigned int zpos)
390{
391	struct drm_property *prop;
392
393	prop = drm_property_create_range(plane->dev, DRM_MODE_PROP_IMMUTABLE,
394					 "zpos", zpos, zpos);
395	if (!prop)
396		return -ENOMEM;
397
398	drm_object_attach_property(&plane->base, prop, zpos);
399
400	plane->zpos_property = prop;
401
402	if (plane->state) {
403		plane->state->zpos = zpos;
404		plane->state->normalized_zpos = zpos;
405	}
406
407	return 0;
408}
409EXPORT_SYMBOL(drm_plane_create_zpos_immutable_property);
410
411static int drm_atomic_state_zpos_cmp(const void *a, const void *b)
412{
413	const struct drm_plane_state *sa = *(struct drm_plane_state **)a;
414	const struct drm_plane_state *sb = *(struct drm_plane_state **)b;
415
416	if (sa->zpos != sb->zpos)
417		return sa->zpos - sb->zpos;
418	else
419		return sa->plane->base.id - sb->plane->base.id;
420}
421
422static int drm_atomic_helper_crtc_normalize_zpos(struct drm_crtc *crtc,
423					  struct drm_crtc_state *crtc_state)
424{
425	struct drm_atomic_state *state = crtc_state->state;
426	struct drm_device *dev = crtc->dev;
427	int total_planes = dev->mode_config.num_total_plane;
428	struct drm_plane_state **states;
429	struct drm_plane *plane;
430	int i, n = 0;
431	int ret = 0;
432
433	DRM_DEBUG_ATOMIC("[CRTC:%d:%s] calculating normalized zpos values\n",
434			 crtc->base.id, crtc->name);
435
436	states = kmalloc_array(total_planes, sizeof(*states), GFP_KERNEL);
437	if (!states)
438		return -ENOMEM;
439
440	/*
441	 * Normalization process might create new states for planes which
442	 * normalized_zpos has to be recalculated.
443	 */
444	drm_for_each_plane_mask(plane, dev, crtc_state->plane_mask) {
445		struct drm_plane_state *plane_state =
446			drm_atomic_get_plane_state(state, plane);
447		if (IS_ERR(plane_state)) {
448			ret = PTR_ERR(plane_state);
449			goto done;
450		}
451		states[n++] = plane_state;
452		DRM_DEBUG_ATOMIC("[PLANE:%d:%s] processing zpos value %d\n",
453				 plane->base.id, plane->name,
454				 plane_state->zpos);
455	}
456
457	sort(states, n, sizeof(*states), drm_atomic_state_zpos_cmp, NULL);
458
459	for (i = 0; i < n; i++) {
460		plane = states[i]->plane;
461
462		states[i]->normalized_zpos = i;
463		DRM_DEBUG_ATOMIC("[PLANE:%d:%s] normalized zpos value %d\n",
464				 plane->base.id, plane->name, i);
465	}
466	crtc_state->zpos_changed = true;
467
468done:
469	kfree(states);
470	return ret;
471}
472
473/**
474 * drm_atomic_normalize_zpos - calculate normalized zpos values for all crtcs
475 * @dev: DRM device
476 * @state: atomic state of DRM device
477 *
478 * This function calculates normalized zpos value for all modified planes in
479 * the provided atomic state of DRM device.
480 *
481 * For every CRTC this function checks new states of all planes assigned to
482 * it and calculates normalized zpos value for these planes. Planes are compared
483 * first by their zpos values, then by plane id (if zpos is equal). The plane
484 * with lowest zpos value is at the bottom. The &drm_plane_state.normalized_zpos
485 * is then filled with unique values from 0 to number of active planes in crtc
486 * minus one.
487 *
488 * RETURNS
489 * Zero for success or -errno
490 */
491int drm_atomic_normalize_zpos(struct drm_device *dev,
492			      struct drm_atomic_state *state)
493{
494	struct drm_crtc *crtc;
495	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
496	struct drm_plane *plane;
497	struct drm_plane_state *old_plane_state, *new_plane_state;
498	int i, ret = 0;
499
500	for_each_oldnew_plane_in_state(state, plane, old_plane_state, new_plane_state, i) {
501		crtc = new_plane_state->crtc;
502		if (!crtc)
503			continue;
504		if (old_plane_state->zpos != new_plane_state->zpos) {
505			new_crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
506			new_crtc_state->zpos_changed = true;
507		}
508	}
509
510	for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
511		if (old_crtc_state->plane_mask != new_crtc_state->plane_mask ||
512		    new_crtc_state->zpos_changed) {
513			ret = drm_atomic_helper_crtc_normalize_zpos(crtc,
514								    new_crtc_state);
515			if (ret)
516				return ret;
517		}
518	}
519	return 0;
520}
521EXPORT_SYMBOL(drm_atomic_normalize_zpos);
522
523/**
524 * drm_plane_create_blend_mode_property - create a new blend mode property
525 * @plane: drm plane
526 * @supported_modes: bitmask of supported modes, must include
527 *		     BIT(DRM_MODE_BLEND_PREMULTI). Current DRM assumption is
528 *		     that alpha is premultiplied, and old userspace can break if
529 *		     the property defaults to anything else.
530 *
531 * This creates a new property describing the blend mode.
532 *
533 * The property exposed to userspace is an enumeration property (see
534 * drm_property_create_enum()) called "pixel blend mode" and has the
535 * following enumeration values:
536 *
537 * "None":
538 *	Blend formula that ignores the pixel alpha.
539 *
540 * "Pre-multiplied":
541 *	Blend formula that assumes the pixel color values have been already
542 *	pre-multiplied with the alpha channel values.
543 *
544 * "Coverage":
545 *	Blend formula that assumes the pixel color values have not been
546 *	pre-multiplied and will do so when blending them to the background color
547 *	values.
548 *
549 * RETURNS:
550 * Zero for success or -errno
551 */
552int drm_plane_create_blend_mode_property(struct drm_plane *plane,
553					 unsigned int supported_modes)
554{
555	struct drm_device *dev = plane->dev;
556	struct drm_property *prop;
557	static const struct drm_prop_enum_list props[] = {
558		{ DRM_MODE_BLEND_PIXEL_NONE, "None" },
559		{ DRM_MODE_BLEND_PREMULTI, "Pre-multiplied" },
560		{ DRM_MODE_BLEND_COVERAGE, "Coverage" },
561	};
562	unsigned int valid_mode_mask = BIT(DRM_MODE_BLEND_PIXEL_NONE) |
563				       BIT(DRM_MODE_BLEND_PREMULTI)   |
564				       BIT(DRM_MODE_BLEND_COVERAGE);
565	int i;
566
567	if (WARN_ON((supported_modes & ~valid_mode_mask) ||
568		    ((supported_modes & BIT(DRM_MODE_BLEND_PREMULTI)) == 0)))
569		return -EINVAL;
570
571	prop = drm_property_create(dev, DRM_MODE_PROP_ENUM,
572				   "pixel blend mode",
573				   hweight32(supported_modes));
574	if (!prop)
575		return -ENOMEM;
576
577	for (i = 0; i < ARRAY_SIZE(props); i++) {
578		int ret;
579
580		if (!(BIT(props[i].type) & supported_modes))
581			continue;
582
583		ret = drm_property_add_enum(prop, props[i].type,
584					    props[i].name);
585
586		if (ret) {
587			drm_property_destroy(dev, prop);
588
589			return ret;
590		}
591	}
592
593	drm_object_attach_property(&plane->base, prop, DRM_MODE_BLEND_PREMULTI);
594	plane->blend_mode_property = prop;
595
596	return 0;
597}
598EXPORT_SYMBOL(drm_plane_create_blend_mode_property);