xref: /openbmc/linux/drivers/gpu/drm/drm_blend.c (revision 45cc842d5b75ba8f9a958f2dd12b95c6dd0452bd)
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  * - Rotation is set up with drm_plane_create_rotation_property(). It adds a
92  *   rotation and reflection step between the source and destination rectangles.
93  *   Without this property the rectangle is only scaled, but not rotated or
94  *   reflected.
95  *
96  * - Z position is set up with drm_plane_create_zpos_immutable_property() and
97  *   drm_plane_create_zpos_property(). It controls the visibility of overlapping
98  *   planes. Without this property the primary plane is always below the cursor
99  *   plane, and ordering between all other planes is undefined.
100  *
101  * Note that all the property extensions described here apply either to the
102  * plane or the CRTC (e.g. for the background color, which currently is not
103  * exposed and assumed to be black).
104  */
105 
106 /**
107  * drm_plane_create_rotation_property - create a new rotation property
108  * @plane: drm plane
109  * @rotation: initial value of the rotation property
110  * @supported_rotations: bitmask of supported rotations and reflections
111  *
112  * This creates a new property with the selected support for transformations.
113  *
114  * Since a rotation by 180° degress is the same as reflecting both along the x
115  * and the y axis the rotation property is somewhat redundant. Drivers can use
116  * drm_rotation_simplify() to normalize values of this property.
117  *
118  * The property exposed to userspace is a bitmask property (see
119  * drm_property_create_bitmask()) called "rotation" and has the following
120  * bitmask enumaration values:
121  *
122  * DRM_MODE_ROTATE_0:
123  * 	"rotate-0"
124  * DRM_MODE_ROTATE_90:
125  * 	"rotate-90"
126  * DRM_MODE_ROTATE_180:
127  * 	"rotate-180"
128  * DRM_MODE_ROTATE_270:
129  * 	"rotate-270"
130  * DRM_MODE_REFLECT_X:
131  * 	"reflect-x"
132  * DRM_MODE_REFLECT_Y:
133  * 	"reflect-y"
134  *
135  * Rotation is the specified amount in degrees in counter clockwise direction,
136  * the X and Y axis are within the source rectangle, i.e.  the X/Y axis before
137  * rotation. After reflection, the rotation is applied to the image sampled from
138  * the source rectangle, before scaling it to fit the destination rectangle.
139  */
140 int drm_plane_create_rotation_property(struct drm_plane *plane,
141 				       unsigned int rotation,
142 				       unsigned int supported_rotations)
143 {
144 	static const struct drm_prop_enum_list props[] = {
145 		{ __builtin_ffs(DRM_MODE_ROTATE_0) - 1,   "rotate-0" },
146 		{ __builtin_ffs(DRM_MODE_ROTATE_90) - 1,  "rotate-90" },
147 		{ __builtin_ffs(DRM_MODE_ROTATE_180) - 1, "rotate-180" },
148 		{ __builtin_ffs(DRM_MODE_ROTATE_270) - 1, "rotate-270" },
149 		{ __builtin_ffs(DRM_MODE_REFLECT_X) - 1,  "reflect-x" },
150 		{ __builtin_ffs(DRM_MODE_REFLECT_Y) - 1,  "reflect-y" },
151 	};
152 	struct drm_property *prop;
153 
154 	WARN_ON((supported_rotations & DRM_MODE_ROTATE_MASK) == 0);
155 	WARN_ON(!is_power_of_2(rotation & DRM_MODE_ROTATE_MASK));
156 	WARN_ON(rotation & ~supported_rotations);
157 
158 	prop = drm_property_create_bitmask(plane->dev, 0, "rotation",
159 					   props, ARRAY_SIZE(props),
160 					   supported_rotations);
161 	if (!prop)
162 		return -ENOMEM;
163 
164 	drm_object_attach_property(&plane->base, prop, rotation);
165 
166 	if (plane->state)
167 		plane->state->rotation = rotation;
168 
169 	plane->rotation_property = prop;
170 
171 	return 0;
172 }
173 EXPORT_SYMBOL(drm_plane_create_rotation_property);
174 
175 /**
176  * drm_rotation_simplify() - Try to simplify the rotation
177  * @rotation: Rotation to be simplified
178  * @supported_rotations: Supported rotations
179  *
180  * Attempt to simplify the rotation to a form that is supported.
181  * Eg. if the hardware supports everything except DRM_MODE_REFLECT_X
182  * one could call this function like this:
183  *
184  * drm_rotation_simplify(rotation, DRM_MODE_ROTATE_0 |
185  *                       DRM_MODE_ROTATE_90 | DRM_MODE_ROTATE_180 |
186  *                       DRM_MODE_ROTATE_270 | DRM_MODE_REFLECT_Y);
187  *
188  * to eliminate the DRM_MODE_ROTATE_X flag. Depending on what kind of
189  * transforms the hardware supports, this function may not
190  * be able to produce a supported transform, so the caller should
191  * check the result afterwards.
192  */
193 unsigned int drm_rotation_simplify(unsigned int rotation,
194 				   unsigned int supported_rotations)
195 {
196 	if (rotation & ~supported_rotations) {
197 		rotation ^= DRM_MODE_REFLECT_X | DRM_MODE_REFLECT_Y;
198 		rotation = (rotation & DRM_MODE_REFLECT_MASK) |
199 		           BIT((ffs(rotation & DRM_MODE_ROTATE_MASK) + 1)
200 		           % 4);
201 	}
202 
203 	return rotation;
204 }
205 EXPORT_SYMBOL(drm_rotation_simplify);
206 
207 /**
208  * drm_plane_create_zpos_property - create mutable zpos property
209  * @plane: drm plane
210  * @zpos: initial value of zpos property
211  * @min: minimal possible value of zpos property
212  * @max: maximal possible value of zpos property
213  *
214  * This function initializes generic mutable zpos property and enables support
215  * for it in drm core. Drivers can then attach this property to planes to enable
216  * support for configurable planes arrangement during blending operation.
217  * Drivers that attach a mutable zpos property to any plane should call the
218  * drm_atomic_normalize_zpos() helper during their implementation of
219  * &drm_mode_config_funcs.atomic_check(), which will update the normalized zpos
220  * values and store them in &drm_plane_state.normalized_zpos. Usually min
221  * should be set to 0 and max to maximal number of planes for given crtc - 1.
222  *
223  * If zpos of some planes cannot be changed (like fixed background or
224  * cursor/topmost planes), driver should adjust min/max values and assign those
225  * planes immutable zpos property with lower or higher values (for more
226  * information, see drm_plane_create_zpos_immutable_property() function). In such
227  * case driver should also assign proper initial zpos values for all planes in
228  * its plane_reset() callback, so the planes will be always sorted properly.
229  *
230  * See also drm_atomic_normalize_zpos().
231  *
232  * The property exposed to userspace is called "zpos".
233  *
234  * Returns:
235  * Zero on success, negative errno on failure.
236  */
237 int drm_plane_create_zpos_property(struct drm_plane *plane,
238 				   unsigned int zpos,
239 				   unsigned int min, unsigned int max)
240 {
241 	struct drm_property *prop;
242 
243 	prop = drm_property_create_range(plane->dev, 0, "zpos", min, max);
244 	if (!prop)
245 		return -ENOMEM;
246 
247 	drm_object_attach_property(&plane->base, prop, zpos);
248 
249 	plane->zpos_property = prop;
250 
251 	if (plane->state) {
252 		plane->state->zpos = zpos;
253 		plane->state->normalized_zpos = zpos;
254 	}
255 
256 	return 0;
257 }
258 EXPORT_SYMBOL(drm_plane_create_zpos_property);
259 
260 /**
261  * drm_plane_create_zpos_immutable_property - create immuttable zpos property
262  * @plane: drm plane
263  * @zpos: value of zpos property
264  *
265  * This function initializes generic immutable zpos property and enables
266  * support for it in drm core. Using this property driver lets userspace
267  * to get the arrangement of the planes for blending operation and notifies
268  * it that the hardware (or driver) doesn't support changing of the planes'
269  * order. For mutable zpos see drm_plane_create_zpos_property().
270  *
271  * The property exposed to userspace is called "zpos".
272  *
273  * Returns:
274  * Zero on success, negative errno on failure.
275  */
276 int drm_plane_create_zpos_immutable_property(struct drm_plane *plane,
277 					     unsigned int zpos)
278 {
279 	struct drm_property *prop;
280 
281 	prop = drm_property_create_range(plane->dev, DRM_MODE_PROP_IMMUTABLE,
282 					 "zpos", zpos, zpos);
283 	if (!prop)
284 		return -ENOMEM;
285 
286 	drm_object_attach_property(&plane->base, prop, zpos);
287 
288 	plane->zpos_property = prop;
289 
290 	if (plane->state) {
291 		plane->state->zpos = zpos;
292 		plane->state->normalized_zpos = zpos;
293 	}
294 
295 	return 0;
296 }
297 EXPORT_SYMBOL(drm_plane_create_zpos_immutable_property);
298 
299 static int drm_atomic_state_zpos_cmp(const void *a, const void *b)
300 {
301 	const struct drm_plane_state *sa = *(struct drm_plane_state **)a;
302 	const struct drm_plane_state *sb = *(struct drm_plane_state **)b;
303 
304 	if (sa->zpos != sb->zpos)
305 		return sa->zpos - sb->zpos;
306 	else
307 		return sa->plane->base.id - sb->plane->base.id;
308 }
309 
310 static int drm_atomic_helper_crtc_normalize_zpos(struct drm_crtc *crtc,
311 					  struct drm_crtc_state *crtc_state)
312 {
313 	struct drm_atomic_state *state = crtc_state->state;
314 	struct drm_device *dev = crtc->dev;
315 	int total_planes = dev->mode_config.num_total_plane;
316 	struct drm_plane_state **states;
317 	struct drm_plane *plane;
318 	int i, n = 0;
319 	int ret = 0;
320 
321 	DRM_DEBUG_ATOMIC("[CRTC:%d:%s] calculating normalized zpos values\n",
322 			 crtc->base.id, crtc->name);
323 
324 	states = kmalloc_array(total_planes, sizeof(*states), GFP_KERNEL);
325 	if (!states)
326 		return -ENOMEM;
327 
328 	/*
329 	 * Normalization process might create new states for planes which
330 	 * normalized_zpos has to be recalculated.
331 	 */
332 	drm_for_each_plane_mask(plane, dev, crtc_state->plane_mask) {
333 		struct drm_plane_state *plane_state =
334 			drm_atomic_get_plane_state(state, plane);
335 		if (IS_ERR(plane_state)) {
336 			ret = PTR_ERR(plane_state);
337 			goto done;
338 		}
339 		states[n++] = plane_state;
340 		DRM_DEBUG_ATOMIC("[PLANE:%d:%s] processing zpos value %d\n",
341 				 plane->base.id, plane->name,
342 				 plane_state->zpos);
343 	}
344 
345 	sort(states, n, sizeof(*states), drm_atomic_state_zpos_cmp, NULL);
346 
347 	for (i = 0; i < n; i++) {
348 		plane = states[i]->plane;
349 
350 		states[i]->normalized_zpos = i;
351 		DRM_DEBUG_ATOMIC("[PLANE:%d:%s] normalized zpos value %d\n",
352 				 plane->base.id, plane->name, i);
353 	}
354 	crtc_state->zpos_changed = true;
355 
356 done:
357 	kfree(states);
358 	return ret;
359 }
360 
361 /**
362  * drm_atomic_normalize_zpos - calculate normalized zpos values for all crtcs
363  * @dev: DRM device
364  * @state: atomic state of DRM device
365  *
366  * This function calculates normalized zpos value for all modified planes in
367  * the provided atomic state of DRM device.
368  *
369  * For every CRTC this function checks new states of all planes assigned to
370  * it and calculates normalized zpos value for these planes. Planes are compared
371  * first by their zpos values, then by plane id (if zpos is equal). The plane
372  * with lowest zpos value is at the bottom. The &drm_plane_state.normalized_zpos
373  * is then filled with unique values from 0 to number of active planes in crtc
374  * minus one.
375  *
376  * RETURNS
377  * Zero for success or -errno
378  */
379 int drm_atomic_normalize_zpos(struct drm_device *dev,
380 			      struct drm_atomic_state *state)
381 {
382 	struct drm_crtc *crtc;
383 	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
384 	struct drm_plane *plane;
385 	struct drm_plane_state *old_plane_state, *new_plane_state;
386 	int i, ret = 0;
387 
388 	for_each_oldnew_plane_in_state(state, plane, old_plane_state, new_plane_state, i) {
389 		crtc = new_plane_state->crtc;
390 		if (!crtc)
391 			continue;
392 		if (old_plane_state->zpos != new_plane_state->zpos) {
393 			new_crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
394 			new_crtc_state->zpos_changed = true;
395 		}
396 	}
397 
398 	for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
399 		if (old_crtc_state->plane_mask != new_crtc_state->plane_mask ||
400 		    new_crtc_state->zpos_changed) {
401 			ret = drm_atomic_helper_crtc_normalize_zpos(crtc,
402 								    new_crtc_state);
403 			if (ret)
404 				return ret;
405 		}
406 	}
407 	return 0;
408 }
409 EXPORT_SYMBOL(drm_atomic_normalize_zpos);
410