xref: /openbmc/linux/drivers/gpu/drm/drm_blend.c (revision 4d10bd45)
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:
92  *	Rotation is set up with drm_plane_create_rotation_property(). It adds a
93  *	rotation and reflection step between the source and destination rectangles.
94  *	Without this property the rectangle is only scaled, but not rotated or
95  *	reflected.
96  *
97  * zpos:
98  *	Z position is set up with drm_plane_create_zpos_immutable_property() and
99  *	drm_plane_create_zpos_property(). It controls the visibility of overlapping
100  *	planes. Without this property the primary plane is always below the cursor
101  *	plane, and ordering between all other planes is undefined.
102  *
103  * Note that all the property extensions described here apply either to the
104  * plane or the CRTC (e.g. for the background color, which currently is not
105  * exposed and assumed to be black).
106  */
107 
108 /**
109  * drm_plane_create_rotation_property - create a new rotation property
110  * @plane: drm plane
111  * @rotation: initial value of the rotation property
112  * @supported_rotations: bitmask of supported rotations and reflections
113  *
114  * This creates a new property with the selected support for transformations.
115  *
116  * Since a rotation by 180° degress is the same as reflecting both along the x
117  * and the y axis the rotation property is somewhat redundant. Drivers can use
118  * drm_rotation_simplify() to normalize values of this property.
119  *
120  * The property exposed to userspace is a bitmask property (see
121  * drm_property_create_bitmask()) called "rotation" and has the following
122  * bitmask enumaration values:
123  *
124  * DRM_MODE_ROTATE_0:
125  * 	"rotate-0"
126  * DRM_MODE_ROTATE_90:
127  * 	"rotate-90"
128  * DRM_MODE_ROTATE_180:
129  * 	"rotate-180"
130  * DRM_MODE_ROTATE_270:
131  * 	"rotate-270"
132  * DRM_MODE_REFLECT_X:
133  * 	"reflect-x"
134  * DRM_MODE_REFLECT_Y:
135  * 	"reflect-y"
136  *
137  * Rotation is the specified amount in degrees in counter clockwise direction,
138  * the X and Y axis are within the source rectangle, i.e.  the X/Y axis before
139  * rotation. After reflection, the rotation is applied to the image sampled from
140  * the source rectangle, before scaling it to fit the destination rectangle.
141  */
142 int drm_plane_create_rotation_property(struct drm_plane *plane,
143 				       unsigned int rotation,
144 				       unsigned int supported_rotations)
145 {
146 	static const struct drm_prop_enum_list props[] = {
147 		{ __builtin_ffs(DRM_MODE_ROTATE_0) - 1,   "rotate-0" },
148 		{ __builtin_ffs(DRM_MODE_ROTATE_90) - 1,  "rotate-90" },
149 		{ __builtin_ffs(DRM_MODE_ROTATE_180) - 1, "rotate-180" },
150 		{ __builtin_ffs(DRM_MODE_ROTATE_270) - 1, "rotate-270" },
151 		{ __builtin_ffs(DRM_MODE_REFLECT_X) - 1,  "reflect-x" },
152 		{ __builtin_ffs(DRM_MODE_REFLECT_Y) - 1,  "reflect-y" },
153 	};
154 	struct drm_property *prop;
155 
156 	WARN_ON((supported_rotations & DRM_MODE_ROTATE_MASK) == 0);
157 	WARN_ON(!is_power_of_2(rotation & DRM_MODE_ROTATE_MASK));
158 	WARN_ON(rotation & ~supported_rotations);
159 
160 	prop = drm_property_create_bitmask(plane->dev, 0, "rotation",
161 					   props, ARRAY_SIZE(props),
162 					   supported_rotations);
163 	if (!prop)
164 		return -ENOMEM;
165 
166 	drm_object_attach_property(&plane->base, prop, rotation);
167 
168 	if (plane->state)
169 		plane->state->rotation = rotation;
170 
171 	plane->rotation_property = prop;
172 
173 	return 0;
174 }
175 EXPORT_SYMBOL(drm_plane_create_rotation_property);
176 
177 /**
178  * drm_rotation_simplify() - Try to simplify the rotation
179  * @rotation: Rotation to be simplified
180  * @supported_rotations: Supported rotations
181  *
182  * Attempt to simplify the rotation to a form that is supported.
183  * Eg. if the hardware supports everything except DRM_MODE_REFLECT_X
184  * one could call this function like this:
185  *
186  * drm_rotation_simplify(rotation, DRM_MODE_ROTATE_0 |
187  *                       DRM_MODE_ROTATE_90 | DRM_MODE_ROTATE_180 |
188  *                       DRM_MODE_ROTATE_270 | DRM_MODE_REFLECT_Y);
189  *
190  * to eliminate the DRM_MODE_ROTATE_X flag. Depending on what kind of
191  * transforms the hardware supports, this function may not
192  * be able to produce a supported transform, so the caller should
193  * check the result afterwards.
194  */
195 unsigned int drm_rotation_simplify(unsigned int rotation,
196 				   unsigned int supported_rotations)
197 {
198 	if (rotation & ~supported_rotations) {
199 		rotation ^= DRM_MODE_REFLECT_X | DRM_MODE_REFLECT_Y;
200 		rotation = (rotation & DRM_MODE_REFLECT_MASK) |
201 		           BIT((ffs(rotation & DRM_MODE_ROTATE_MASK) + 1)
202 		           % 4);
203 	}
204 
205 	return rotation;
206 }
207 EXPORT_SYMBOL(drm_rotation_simplify);
208 
209 /**
210  * drm_plane_create_zpos_property - create mutable zpos property
211  * @plane: drm plane
212  * @zpos: initial value of zpos property
213  * @min: minimal possible value of zpos property
214  * @max: maximal possible value of zpos property
215  *
216  * This function initializes generic mutable zpos property and enables support
217  * for it in drm core. Drivers can then attach this property to planes to enable
218  * support for configurable planes arrangement during blending operation.
219  * Drivers that attach a mutable zpos property to any plane should call the
220  * drm_atomic_normalize_zpos() helper during their implementation of
221  * &drm_mode_config_funcs.atomic_check(), which will update the normalized zpos
222  * values and store them in &drm_plane_state.normalized_zpos. Usually min
223  * should be set to 0 and max to maximal number of planes for given crtc - 1.
224  *
225  * If zpos of some planes cannot be changed (like fixed background or
226  * cursor/topmost planes), driver should adjust min/max values and assign those
227  * planes immutable zpos property with lower or higher values (for more
228  * information, see drm_plane_create_zpos_immutable_property() function). In such
229  * case driver should also assign proper initial zpos values for all planes in
230  * its plane_reset() callback, so the planes will be always sorted properly.
231  *
232  * See also drm_atomic_normalize_zpos().
233  *
234  * The property exposed to userspace is called "zpos".
235  *
236  * Returns:
237  * Zero on success, negative errno on failure.
238  */
239 int drm_plane_create_zpos_property(struct drm_plane *plane,
240 				   unsigned int zpos,
241 				   unsigned int min, unsigned int max)
242 {
243 	struct drm_property *prop;
244 
245 	prop = drm_property_create_range(plane->dev, 0, "zpos", min, max);
246 	if (!prop)
247 		return -ENOMEM;
248 
249 	drm_object_attach_property(&plane->base, prop, zpos);
250 
251 	plane->zpos_property = prop;
252 
253 	if (plane->state) {
254 		plane->state->zpos = zpos;
255 		plane->state->normalized_zpos = zpos;
256 	}
257 
258 	return 0;
259 }
260 EXPORT_SYMBOL(drm_plane_create_zpos_property);
261 
262 /**
263  * drm_plane_create_zpos_immutable_property - create immuttable zpos property
264  * @plane: drm plane
265  * @zpos: value of zpos property
266  *
267  * This function initializes generic immutable zpos property and enables
268  * support for it in drm core. Using this property driver lets userspace
269  * to get the arrangement of the planes for blending operation and notifies
270  * it that the hardware (or driver) doesn't support changing of the planes'
271  * order. For mutable zpos see drm_plane_create_zpos_property().
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_immutable_property(struct drm_plane *plane,
279 					     unsigned int zpos)
280 {
281 	struct drm_property *prop;
282 
283 	prop = drm_property_create_range(plane->dev, DRM_MODE_PROP_IMMUTABLE,
284 					 "zpos", zpos, zpos);
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_immutable_property);
300 
301 static int drm_atomic_state_zpos_cmp(const void *a, const void *b)
302 {
303 	const struct drm_plane_state *sa = *(struct drm_plane_state **)a;
304 	const struct drm_plane_state *sb = *(struct drm_plane_state **)b;
305 
306 	if (sa->zpos != sb->zpos)
307 		return sa->zpos - sb->zpos;
308 	else
309 		return sa->plane->base.id - sb->plane->base.id;
310 }
311 
312 static int drm_atomic_helper_crtc_normalize_zpos(struct drm_crtc *crtc,
313 					  struct drm_crtc_state *crtc_state)
314 {
315 	struct drm_atomic_state *state = crtc_state->state;
316 	struct drm_device *dev = crtc->dev;
317 	int total_planes = dev->mode_config.num_total_plane;
318 	struct drm_plane_state **states;
319 	struct drm_plane *plane;
320 	int i, n = 0;
321 	int ret = 0;
322 
323 	DRM_DEBUG_ATOMIC("[CRTC:%d:%s] calculating normalized zpos values\n",
324 			 crtc->base.id, crtc->name);
325 
326 	states = kmalloc_array(total_planes, sizeof(*states), GFP_KERNEL);
327 	if (!states)
328 		return -ENOMEM;
329 
330 	/*
331 	 * Normalization process might create new states for planes which
332 	 * normalized_zpos has to be recalculated.
333 	 */
334 	drm_for_each_plane_mask(plane, dev, crtc_state->plane_mask) {
335 		struct drm_plane_state *plane_state =
336 			drm_atomic_get_plane_state(state, plane);
337 		if (IS_ERR(plane_state)) {
338 			ret = PTR_ERR(plane_state);
339 			goto done;
340 		}
341 		states[n++] = plane_state;
342 		DRM_DEBUG_ATOMIC("[PLANE:%d:%s] processing zpos value %d\n",
343 				 plane->base.id, plane->name,
344 				 plane_state->zpos);
345 	}
346 
347 	sort(states, n, sizeof(*states), drm_atomic_state_zpos_cmp, NULL);
348 
349 	for (i = 0; i < n; i++) {
350 		plane = states[i]->plane;
351 
352 		states[i]->normalized_zpos = i;
353 		DRM_DEBUG_ATOMIC("[PLANE:%d:%s] normalized zpos value %d\n",
354 				 plane->base.id, plane->name, i);
355 	}
356 	crtc_state->zpos_changed = true;
357 
358 done:
359 	kfree(states);
360 	return ret;
361 }
362 
363 /**
364  * drm_atomic_normalize_zpos - calculate normalized zpos values for all crtcs
365  * @dev: DRM device
366  * @state: atomic state of DRM device
367  *
368  * This function calculates normalized zpos value for all modified planes in
369  * the provided atomic state of DRM device.
370  *
371  * For every CRTC this function checks new states of all planes assigned to
372  * it and calculates normalized zpos value for these planes. Planes are compared
373  * first by their zpos values, then by plane id (if zpos is equal). The plane
374  * with lowest zpos value is at the bottom. The &drm_plane_state.normalized_zpos
375  * is then filled with unique values from 0 to number of active planes in crtc
376  * minus one.
377  *
378  * RETURNS
379  * Zero for success or -errno
380  */
381 int drm_atomic_normalize_zpos(struct drm_device *dev,
382 			      struct drm_atomic_state *state)
383 {
384 	struct drm_crtc *crtc;
385 	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
386 	struct drm_plane *plane;
387 	struct drm_plane_state *old_plane_state, *new_plane_state;
388 	int i, ret = 0;
389 
390 	for_each_oldnew_plane_in_state(state, plane, old_plane_state, new_plane_state, i) {
391 		crtc = new_plane_state->crtc;
392 		if (!crtc)
393 			continue;
394 		if (old_plane_state->zpos != new_plane_state->zpos) {
395 			new_crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
396 			new_crtc_state->zpos_changed = true;
397 		}
398 	}
399 
400 	for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
401 		if (old_crtc_state->plane_mask != new_crtc_state->plane_mask ||
402 		    new_crtc_state->zpos_changed) {
403 			ret = drm_atomic_helper_crtc_normalize_zpos(crtc,
404 								    new_crtc_state);
405 			if (ret)
406 				return ret;
407 		}
408 	}
409 	return 0;
410 }
411 EXPORT_SYMBOL(drm_atomic_normalize_zpos);
412