xref: /openbmc/linux/drivers/gpu/drm/drm_blend.c (revision 93f5715e)
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 #include <drm/drmP.h>
27 #include <drm/drm_atomic.h>
28 #include <drm/drm_blend.h>
29 #include <linux/export.h>
30 #include <linux/slab.h>
31 #include <linux/sort.h>
32 
33 #include "drm_crtc_internal.h"
34 
35 /**
36  * DOC: overview
37  *
38  * The basic plane composition model supported by standard plane properties only
39  * has a source rectangle (in logical pixels within the &drm_framebuffer), with
40  * sub-pixel accuracy, which is scaled up to a pixel-aligned destination
41  * rectangle in the visible area of a &drm_crtc. The visible area of a CRTC is
42  * defined by the horizontal and vertical visible pixels (stored in @hdisplay
43  * and @vdisplay) of the requested mode (stored in &drm_crtc_state.mode). These
44  * two rectangles are both stored in the &drm_plane_state.
45  *
46  * For the atomic ioctl the following standard (atomic) properties on the plane object
47  * encode the basic plane composition model:
48  *
49  * SRC_X:
50  * 	X coordinate offset for the source rectangle within the
51  * 	&drm_framebuffer, in 16.16 fixed point. Must be positive.
52  * SRC_Y:
53  * 	Y coordinate offset for the source rectangle within the
54  * 	&drm_framebuffer, in 16.16 fixed point. Must be positive.
55  * SRC_W:
56  * 	Width for the source rectangle within the &drm_framebuffer, in 16.16
57  * 	fixed point. SRC_X plus SRC_W must be within the width of the source
58  * 	framebuffer. Must be positive.
59  * SRC_H:
60  * 	Height for the source rectangle within the &drm_framebuffer, in 16.16
61  * 	fixed point. SRC_Y plus SRC_H must be within the height of the source
62  * 	framebuffer. Must be positive.
63  * CRTC_X:
64  * 	X coordinate offset for the destination rectangle. Can be negative.
65  * CRTC_Y:
66  * 	Y coordinate offset for the destination rectangle. Can be negative.
67  * CRTC_W:
68  * 	Width for the destination rectangle. CRTC_X plus CRTC_W can extend past
69  * 	the currently visible horizontal area of the &drm_crtc.
70  * CRTC_H:
71  * 	Height for the destination rectangle. CRTC_Y plus CRTC_H can extend past
72  * 	the currently visible vertical area of the &drm_crtc.
73  * FB_ID:
74  * 	Mode object ID of the &drm_framebuffer this plane should scan out.
75  * CRTC_ID:
76  * 	Mode object ID of the &drm_crtc this plane should be connected to.
77  *
78  * Note that the source rectangle must fully lie within the bounds of the
79  * &drm_framebuffer. The destination rectangle can lie outside of the visible
80  * area of the current mode of the CRTC. It must be apprpriately clipped by the
81  * driver, which can be done by calling drm_plane_helper_check_update(). Drivers
82  * are also allowed to round the subpixel sampling positions appropriately, but
83  * only to the next full pixel. No pixel outside of the source rectangle may
84  * ever be sampled, which is important when applying more sophisticated
85  * filtering than just a bilinear one when scaling. The filtering mode when
86  * scaling is unspecified.
87  *
88  * On top of this basic transformation additional properties can be exposed by
89  * the driver:
90  *
91  * alpha:
92  * 	Alpha is setup with drm_plane_create_alpha_property(). It controls the
93  * 	plane-wide opacity, from transparent (0) to opaque (0xffff). It can be
94  * 	combined with pixel alpha.
95  *	The pixel values in the framebuffers are expected to not be
96  *	pre-multiplied by the global alpha associated to the plane.
97  *
98  * rotation:
99  *	Rotation is set up with drm_plane_create_rotation_property(). It adds a
100  *	rotation and reflection step between the source and destination rectangles.
101  *	Without this property the rectangle is only scaled, but not rotated or
102  *	reflected.
103  *
104  * zpos:
105  *	Z position is set up with drm_plane_create_zpos_immutable_property() and
106  *	drm_plane_create_zpos_property(). It controls the visibility of overlapping
107  *	planes. Without this property the primary plane is always below the cursor
108  *	plane, and ordering between all other planes is undefined.
109  *
110  * Note that all the property extensions described here apply either to the
111  * plane or the CRTC (e.g. for the background color, which currently is not
112  * exposed and assumed to be black).
113  */
114 
115 /**
116  * drm_plane_create_alpha_property - create a new alpha property
117  * @plane: drm plane
118  *
119  * This function creates a generic, mutable, alpha property and enables support
120  * for it in the DRM core. It is attached to @plane.
121  *
122  * The alpha property will be allowed to be within the bounds of 0
123  * (transparent) to 0xffff (opaque).
124  *
125  * Returns:
126  * 0 on success, negative error code on failure.
127  */
128 int drm_plane_create_alpha_property(struct drm_plane *plane)
129 {
130 	struct drm_property *prop;
131 
132 	prop = drm_property_create_range(plane->dev, 0, "alpha",
133 					 0, DRM_BLEND_ALPHA_OPAQUE);
134 	if (!prop)
135 		return -ENOMEM;
136 
137 	drm_object_attach_property(&plane->base, prop, DRM_BLEND_ALPHA_OPAQUE);
138 	plane->alpha_property = prop;
139 
140 	if (plane->state)
141 		plane->state->alpha = DRM_BLEND_ALPHA_OPAQUE;
142 
143 	return 0;
144 }
145 EXPORT_SYMBOL(drm_plane_create_alpha_property);
146 
147 /**
148  * drm_plane_create_rotation_property - create a new rotation property
149  * @plane: drm plane
150  * @rotation: initial value of the rotation property
151  * @supported_rotations: bitmask of supported rotations and reflections
152  *
153  * This creates a new property with the selected support for transformations.
154  *
155  * Since a rotation by 180° degress is the same as reflecting both along the x
156  * and the y axis the rotation property is somewhat redundant. Drivers can use
157  * drm_rotation_simplify() to normalize values of this property.
158  *
159  * The property exposed to userspace is a bitmask property (see
160  * drm_property_create_bitmask()) called "rotation" and has the following
161  * bitmask enumaration values:
162  *
163  * DRM_MODE_ROTATE_0:
164  * 	"rotate-0"
165  * DRM_MODE_ROTATE_90:
166  * 	"rotate-90"
167  * DRM_MODE_ROTATE_180:
168  * 	"rotate-180"
169  * DRM_MODE_ROTATE_270:
170  * 	"rotate-270"
171  * DRM_MODE_REFLECT_X:
172  * 	"reflect-x"
173  * DRM_MODE_REFLECT_Y:
174  * 	"reflect-y"
175  *
176  * Rotation is the specified amount in degrees in counter clockwise direction,
177  * the X and Y axis are within the source rectangle, i.e.  the X/Y axis before
178  * rotation. After reflection, the rotation is applied to the image sampled from
179  * the source rectangle, before scaling it to fit the destination rectangle.
180  */
181 int drm_plane_create_rotation_property(struct drm_plane *plane,
182 				       unsigned int rotation,
183 				       unsigned int supported_rotations)
184 {
185 	static const struct drm_prop_enum_list props[] = {
186 		{ __builtin_ffs(DRM_MODE_ROTATE_0) - 1,   "rotate-0" },
187 		{ __builtin_ffs(DRM_MODE_ROTATE_90) - 1,  "rotate-90" },
188 		{ __builtin_ffs(DRM_MODE_ROTATE_180) - 1, "rotate-180" },
189 		{ __builtin_ffs(DRM_MODE_ROTATE_270) - 1, "rotate-270" },
190 		{ __builtin_ffs(DRM_MODE_REFLECT_X) - 1,  "reflect-x" },
191 		{ __builtin_ffs(DRM_MODE_REFLECT_Y) - 1,  "reflect-y" },
192 	};
193 	struct drm_property *prop;
194 
195 	WARN_ON((supported_rotations & DRM_MODE_ROTATE_MASK) == 0);
196 	WARN_ON(!is_power_of_2(rotation & DRM_MODE_ROTATE_MASK));
197 	WARN_ON(rotation & ~supported_rotations);
198 
199 	prop = drm_property_create_bitmask(plane->dev, 0, "rotation",
200 					   props, ARRAY_SIZE(props),
201 					   supported_rotations);
202 	if (!prop)
203 		return -ENOMEM;
204 
205 	drm_object_attach_property(&plane->base, prop, rotation);
206 
207 	if (plane->state)
208 		plane->state->rotation = rotation;
209 
210 	plane->rotation_property = prop;
211 
212 	return 0;
213 }
214 EXPORT_SYMBOL(drm_plane_create_rotation_property);
215 
216 /**
217  * drm_rotation_simplify() - Try to simplify the rotation
218  * @rotation: Rotation to be simplified
219  * @supported_rotations: Supported rotations
220  *
221  * Attempt to simplify the rotation to a form that is supported.
222  * Eg. if the hardware supports everything except DRM_MODE_REFLECT_X
223  * one could call this function like this:
224  *
225  * drm_rotation_simplify(rotation, DRM_MODE_ROTATE_0 |
226  *                       DRM_MODE_ROTATE_90 | DRM_MODE_ROTATE_180 |
227  *                       DRM_MODE_ROTATE_270 | DRM_MODE_REFLECT_Y);
228  *
229  * to eliminate the DRM_MODE_ROTATE_X flag. Depending on what kind of
230  * transforms the hardware supports, this function may not
231  * be able to produce a supported transform, so the caller should
232  * check the result afterwards.
233  */
234 unsigned int drm_rotation_simplify(unsigned int rotation,
235 				   unsigned int supported_rotations)
236 {
237 	if (rotation & ~supported_rotations) {
238 		rotation ^= DRM_MODE_REFLECT_X | DRM_MODE_REFLECT_Y;
239 		rotation = (rotation & DRM_MODE_REFLECT_MASK) |
240 		           BIT((ffs(rotation & DRM_MODE_ROTATE_MASK) + 1)
241 		           % 4);
242 	}
243 
244 	return rotation;
245 }
246 EXPORT_SYMBOL(drm_rotation_simplify);
247 
248 /**
249  * drm_plane_create_zpos_property - create mutable zpos property
250  * @plane: drm plane
251  * @zpos: initial value of zpos property
252  * @min: minimal possible value of zpos property
253  * @max: maximal possible value of zpos property
254  *
255  * This function initializes generic mutable zpos property and enables support
256  * for it in drm core. Drivers can then attach this property to planes to enable
257  * support for configurable planes arrangement during blending operation.
258  * Drivers that attach a mutable zpos property to any plane should call the
259  * drm_atomic_normalize_zpos() helper during their implementation of
260  * &drm_mode_config_funcs.atomic_check(), which will update the normalized zpos
261  * values and store them in &drm_plane_state.normalized_zpos. Usually min
262  * should be set to 0 and max to maximal number of planes for given crtc - 1.
263  *
264  * If zpos of some planes cannot be changed (like fixed background or
265  * cursor/topmost planes), driver should adjust min/max values and assign those
266  * planes immutable zpos property with lower or higher values (for more
267  * information, see drm_plane_create_zpos_immutable_property() function). In such
268  * case driver should also assign proper initial zpos values for all planes in
269  * its plane_reset() callback, so the planes will be always sorted properly.
270  *
271  * See also drm_atomic_normalize_zpos().
272  *
273  * The property exposed to userspace is called "zpos".
274  *
275  * Returns:
276  * Zero on success, negative errno on failure.
277  */
278 int drm_plane_create_zpos_property(struct drm_plane *plane,
279 				   unsigned int zpos,
280 				   unsigned int min, unsigned int max)
281 {
282 	struct drm_property *prop;
283 
284 	prop = drm_property_create_range(plane->dev, 0, "zpos", min, max);
285 	if (!prop)
286 		return -ENOMEM;
287 
288 	drm_object_attach_property(&plane->base, prop, zpos);
289 
290 	plane->zpos_property = prop;
291 
292 	if (plane->state) {
293 		plane->state->zpos = zpos;
294 		plane->state->normalized_zpos = zpos;
295 	}
296 
297 	return 0;
298 }
299 EXPORT_SYMBOL(drm_plane_create_zpos_property);
300 
301 /**
302  * drm_plane_create_zpos_immutable_property - create immuttable zpos property
303  * @plane: drm plane
304  * @zpos: value of zpos property
305  *
306  * This function initializes generic immutable zpos property and enables
307  * support for it in drm core. Using this property driver lets userspace
308  * to get the arrangement of the planes for blending operation and notifies
309  * it that the hardware (or driver) doesn't support changing of the planes'
310  * order. For mutable zpos see drm_plane_create_zpos_property().
311  *
312  * The property exposed to userspace is called "zpos".
313  *
314  * Returns:
315  * Zero on success, negative errno on failure.
316  */
317 int drm_plane_create_zpos_immutable_property(struct drm_plane *plane,
318 					     unsigned int zpos)
319 {
320 	struct drm_property *prop;
321 
322 	prop = drm_property_create_range(plane->dev, DRM_MODE_PROP_IMMUTABLE,
323 					 "zpos", zpos, zpos);
324 	if (!prop)
325 		return -ENOMEM;
326 
327 	drm_object_attach_property(&plane->base, prop, zpos);
328 
329 	plane->zpos_property = prop;
330 
331 	if (plane->state) {
332 		plane->state->zpos = zpos;
333 		plane->state->normalized_zpos = zpos;
334 	}
335 
336 	return 0;
337 }
338 EXPORT_SYMBOL(drm_plane_create_zpos_immutable_property);
339 
340 static int drm_atomic_state_zpos_cmp(const void *a, const void *b)
341 {
342 	const struct drm_plane_state *sa = *(struct drm_plane_state **)a;
343 	const struct drm_plane_state *sb = *(struct drm_plane_state **)b;
344 
345 	if (sa->zpos != sb->zpos)
346 		return sa->zpos - sb->zpos;
347 	else
348 		return sa->plane->base.id - sb->plane->base.id;
349 }
350 
351 static int drm_atomic_helper_crtc_normalize_zpos(struct drm_crtc *crtc,
352 					  struct drm_crtc_state *crtc_state)
353 {
354 	struct drm_atomic_state *state = crtc_state->state;
355 	struct drm_device *dev = crtc->dev;
356 	int total_planes = dev->mode_config.num_total_plane;
357 	struct drm_plane_state **states;
358 	struct drm_plane *plane;
359 	int i, n = 0;
360 	int ret = 0;
361 
362 	DRM_DEBUG_ATOMIC("[CRTC:%d:%s] calculating normalized zpos values\n",
363 			 crtc->base.id, crtc->name);
364 
365 	states = kmalloc_array(total_planes, sizeof(*states), GFP_KERNEL);
366 	if (!states)
367 		return -ENOMEM;
368 
369 	/*
370 	 * Normalization process might create new states for planes which
371 	 * normalized_zpos has to be recalculated.
372 	 */
373 	drm_for_each_plane_mask(plane, dev, crtc_state->plane_mask) {
374 		struct drm_plane_state *plane_state =
375 			drm_atomic_get_plane_state(state, plane);
376 		if (IS_ERR(plane_state)) {
377 			ret = PTR_ERR(plane_state);
378 			goto done;
379 		}
380 		states[n++] = plane_state;
381 		DRM_DEBUG_ATOMIC("[PLANE:%d:%s] processing zpos value %d\n",
382 				 plane->base.id, plane->name,
383 				 plane_state->zpos);
384 	}
385 
386 	sort(states, n, sizeof(*states), drm_atomic_state_zpos_cmp, NULL);
387 
388 	for (i = 0; i < n; i++) {
389 		plane = states[i]->plane;
390 
391 		states[i]->normalized_zpos = i;
392 		DRM_DEBUG_ATOMIC("[PLANE:%d:%s] normalized zpos value %d\n",
393 				 plane->base.id, plane->name, i);
394 	}
395 	crtc_state->zpos_changed = true;
396 
397 done:
398 	kfree(states);
399 	return ret;
400 }
401 
402 /**
403  * drm_atomic_normalize_zpos - calculate normalized zpos values for all crtcs
404  * @dev: DRM device
405  * @state: atomic state of DRM device
406  *
407  * This function calculates normalized zpos value for all modified planes in
408  * the provided atomic state of DRM device.
409  *
410  * For every CRTC this function checks new states of all planes assigned to
411  * it and calculates normalized zpos value for these planes. Planes are compared
412  * first by their zpos values, then by plane id (if zpos is equal). The plane
413  * with lowest zpos value is at the bottom. The &drm_plane_state.normalized_zpos
414  * is then filled with unique values from 0 to number of active planes in crtc
415  * minus one.
416  *
417  * RETURNS
418  * Zero for success or -errno
419  */
420 int drm_atomic_normalize_zpos(struct drm_device *dev,
421 			      struct drm_atomic_state *state)
422 {
423 	struct drm_crtc *crtc;
424 	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
425 	struct drm_plane *plane;
426 	struct drm_plane_state *old_plane_state, *new_plane_state;
427 	int i, ret = 0;
428 
429 	for_each_oldnew_plane_in_state(state, plane, old_plane_state, new_plane_state, i) {
430 		crtc = new_plane_state->crtc;
431 		if (!crtc)
432 			continue;
433 		if (old_plane_state->zpos != new_plane_state->zpos) {
434 			new_crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
435 			new_crtc_state->zpos_changed = true;
436 		}
437 	}
438 
439 	for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
440 		if (old_crtc_state->plane_mask != new_crtc_state->plane_mask ||
441 		    new_crtc_state->zpos_changed) {
442 			ret = drm_atomic_helper_crtc_normalize_zpos(crtc,
443 								    new_crtc_state);
444 			if (ret)
445 				return ret;
446 		}
447 	}
448 	return 0;
449 }
450 EXPORT_SYMBOL(drm_atomic_normalize_zpos);
451