2 * Copyright (C) 2016 Samsung Electronics Co.Ltd
4 * Marek Szyprowski <m.szyprowski@samsung.com>
6 * DRM core plane blending related functions
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.
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
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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
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>
33 #include "drm_crtc_internal.h"
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.
46 * For the atomic ioctl the following standard (atomic) properties on the plane object
47 * encode the basic plane composition model:
50 * X coordinate offset for the source rectangle within the
51 * &drm_framebuffer, in 16.16 fixed point. Must be positive.
53 * Y coordinate offset for the source rectangle within the
54 * &drm_framebuffer, in 16.16 fixed point. Must be positive.
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.
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.
64 * X coordinate offset for the destination rectangle. Can be negative.
66 * Y coordinate offset for the destination rectangle. Can be negative.
68 * Width for the destination rectangle. CRTC_X plus CRTC_W can extend past
69 * the currently visible horizontal area of the &drm_crtc.
71 * Height for the destination rectangle. CRTC_Y plus CRTC_H can extend past
72 * the currently visible vertical area of the &drm_crtc.
74 * Mode object ID of the &drm_framebuffer this plane should scan out.
76 * Mode object ID of the &drm_crtc this plane should be connected to.
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.
88 * On top of this basic transformation additional properties can be exposed by
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.
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
106 * "rotate-<degrees>":
107 * Signals that a drm plane is rotated <degrees> degrees in counter
108 * clockwise direction.
111 * Signals that the contents of a drm plane is reflected along the
112 * <axis> axis, in the same way as mirroring.
127 * Z position is set up with drm_plane_create_zpos_immutable_property() and
128 * drm_plane_create_zpos_property(). It controls the visibility of overlapping
129 * planes. Without this property the primary plane is always below the cursor
130 * plane, and ordering between all other planes is undefined.
133 * Pixel blend mode is set up with drm_plane_create_blend_mode_property().
134 * It adds a blend mode for alpha blending equation selection, describing
135 * how the pixels from the current plane are composited with the
138 * Three alpha blending equations are defined:
141 * Blend formula that ignores the pixel alpha::
143 * out.rgb = plane_alpha * fg.rgb +
144 * (1 - plane_alpha) * bg.rgb
147 * Blend formula that assumes the pixel color values
148 * have been already pre-multiplied with the alpha
151 * out.rgb = plane_alpha * fg.rgb +
152 * (1 - (plane_alpha * fg.alpha)) * bg.rgb
155 * Blend formula that assumes the pixel color values have not
156 * been pre-multiplied and will do so when blending them to the
157 * background color values::
159 * out.rgb = plane_alpha * fg.alpha * fg.rgb +
160 * (1 - (plane_alpha * fg.alpha)) * bg.rgb
162 * Using the following symbols:
165 * Each of the RGB component values from the plane's pixel
167 * Alpha component value from the plane's pixel. If the plane's
168 * pixel format has no alpha component, then this is assumed to be
169 * 1.0. In these cases, this property has no effect, as all three
170 * equations become equivalent.
172 * Each of the RGB component values from the background
174 * Plane alpha value set by the plane "alpha" property. If the
175 * plane does not expose the "alpha" property, then this is
178 * Note that all the property extensions described here apply either to the
179 * plane or the CRTC (e.g. for the background color, which currently is not
180 * exposed and assumed to be black).
184 * drm_plane_create_alpha_property - create a new alpha property
187 * This function creates a generic, mutable, alpha property and enables support
188 * for it in the DRM core. It is attached to @plane.
190 * The alpha property will be allowed to be within the bounds of 0
191 * (transparent) to 0xffff (opaque).
194 * 0 on success, negative error code on failure.
196 int drm_plane_create_alpha_property(struct drm_plane
*plane
)
198 struct drm_property
*prop
;
200 prop
= drm_property_create_range(plane
->dev
, 0, "alpha",
201 0, DRM_BLEND_ALPHA_OPAQUE
);
205 drm_object_attach_property(&plane
->base
, prop
, DRM_BLEND_ALPHA_OPAQUE
);
206 plane
->alpha_property
= prop
;
209 plane
->state
->alpha
= DRM_BLEND_ALPHA_OPAQUE
;
213 EXPORT_SYMBOL(drm_plane_create_alpha_property
);
216 * drm_plane_create_rotation_property - create a new rotation property
218 * @rotation: initial value of the rotation property
219 * @supported_rotations: bitmask of supported rotations and reflections
221 * This creates a new property with the selected support for transformations.
223 * Since a rotation by 180° degress is the same as reflecting both along the x
224 * and the y axis the rotation property is somewhat redundant. Drivers can use
225 * drm_rotation_simplify() to normalize values of this property.
227 * The property exposed to userspace is a bitmask property (see
228 * drm_property_create_bitmask()) called "rotation" and has the following
229 * bitmask enumaration values:
233 * DRM_MODE_ROTATE_90:
235 * DRM_MODE_ROTATE_180:
237 * DRM_MODE_ROTATE_270:
239 * DRM_MODE_REFLECT_X:
241 * DRM_MODE_REFLECT_Y:
244 * Rotation is the specified amount in degrees in counter clockwise direction,
245 * the X and Y axis are within the source rectangle, i.e. the X/Y axis before
246 * rotation. After reflection, the rotation is applied to the image sampled from
247 * the source rectangle, before scaling it to fit the destination rectangle.
249 int drm_plane_create_rotation_property(struct drm_plane
*plane
,
250 unsigned int rotation
,
251 unsigned int supported_rotations
)
253 static const struct drm_prop_enum_list props
[] = {
254 { __builtin_ffs(DRM_MODE_ROTATE_0
) - 1, "rotate-0" },
255 { __builtin_ffs(DRM_MODE_ROTATE_90
) - 1, "rotate-90" },
256 { __builtin_ffs(DRM_MODE_ROTATE_180
) - 1, "rotate-180" },
257 { __builtin_ffs(DRM_MODE_ROTATE_270
) - 1, "rotate-270" },
258 { __builtin_ffs(DRM_MODE_REFLECT_X
) - 1, "reflect-x" },
259 { __builtin_ffs(DRM_MODE_REFLECT_Y
) - 1, "reflect-y" },
261 struct drm_property
*prop
;
263 WARN_ON((supported_rotations
& DRM_MODE_ROTATE_MASK
) == 0);
264 WARN_ON(!is_power_of_2(rotation
& DRM_MODE_ROTATE_MASK
));
265 WARN_ON(rotation
& ~supported_rotations
);
267 prop
= drm_property_create_bitmask(plane
->dev
, 0, "rotation",
268 props
, ARRAY_SIZE(props
),
269 supported_rotations
);
273 drm_object_attach_property(&plane
->base
, prop
, rotation
);
276 plane
->state
->rotation
= rotation
;
278 plane
->rotation_property
= prop
;
282 EXPORT_SYMBOL(drm_plane_create_rotation_property
);
285 * drm_rotation_simplify() - Try to simplify the rotation
286 * @rotation: Rotation to be simplified
287 * @supported_rotations: Supported rotations
289 * Attempt to simplify the rotation to a form that is supported.
290 * Eg. if the hardware supports everything except DRM_MODE_REFLECT_X
291 * one could call this function like this:
293 * drm_rotation_simplify(rotation, DRM_MODE_ROTATE_0 |
294 * DRM_MODE_ROTATE_90 | DRM_MODE_ROTATE_180 |
295 * DRM_MODE_ROTATE_270 | DRM_MODE_REFLECT_Y);
297 * to eliminate the DRM_MODE_ROTATE_X flag. Depending on what kind of
298 * transforms the hardware supports, this function may not
299 * be able to produce a supported transform, so the caller should
300 * check the result afterwards.
302 unsigned int drm_rotation_simplify(unsigned int rotation
,
303 unsigned int supported_rotations
)
305 if (rotation
& ~supported_rotations
) {
306 rotation
^= DRM_MODE_REFLECT_X
| DRM_MODE_REFLECT_Y
;
307 rotation
= (rotation
& DRM_MODE_REFLECT_MASK
) |
308 BIT((ffs(rotation
& DRM_MODE_ROTATE_MASK
) + 1)
314 EXPORT_SYMBOL(drm_rotation_simplify
);
317 * drm_plane_create_zpos_property - create mutable zpos property
319 * @zpos: initial value of zpos property
320 * @min: minimal possible value of zpos property
321 * @max: maximal possible value of zpos property
323 * This function initializes generic mutable zpos property and enables support
324 * for it in drm core. Drivers can then attach this property to planes to enable
325 * support for configurable planes arrangement during blending operation.
326 * Drivers that attach a mutable zpos property to any plane should call the
327 * drm_atomic_normalize_zpos() helper during their implementation of
328 * &drm_mode_config_funcs.atomic_check(), which will update the normalized zpos
329 * values and store them in &drm_plane_state.normalized_zpos. Usually min
330 * should be set to 0 and max to maximal number of planes for given crtc - 1.
332 * If zpos of some planes cannot be changed (like fixed background or
333 * cursor/topmost planes), driver should adjust min/max values and assign those
334 * planes immutable zpos property with lower or higher values (for more
335 * information, see drm_plane_create_zpos_immutable_property() function). In such
336 * case driver should also assign proper initial zpos values for all planes in
337 * its plane_reset() callback, so the planes will be always sorted properly.
339 * See also drm_atomic_normalize_zpos().
341 * The property exposed to userspace is called "zpos".
344 * Zero on success, negative errno on failure.
346 int drm_plane_create_zpos_property(struct drm_plane
*plane
,
348 unsigned int min
, unsigned int max
)
350 struct drm_property
*prop
;
352 prop
= drm_property_create_range(plane
->dev
, 0, "zpos", min
, max
);
356 drm_object_attach_property(&plane
->base
, prop
, zpos
);
358 plane
->zpos_property
= prop
;
361 plane
->state
->zpos
= zpos
;
362 plane
->state
->normalized_zpos
= zpos
;
367 EXPORT_SYMBOL(drm_plane_create_zpos_property
);
370 * drm_plane_create_zpos_immutable_property - create immuttable zpos property
372 * @zpos: value of zpos property
374 * This function initializes generic immutable zpos property and enables
375 * support for it in drm core. Using this property driver lets userspace
376 * to get the arrangement of the planes for blending operation and notifies
377 * it that the hardware (or driver) doesn't support changing of the planes'
378 * order. For mutable zpos see drm_plane_create_zpos_property().
380 * The property exposed to userspace is called "zpos".
383 * Zero on success, negative errno on failure.
385 int drm_plane_create_zpos_immutable_property(struct drm_plane
*plane
,
388 struct drm_property
*prop
;
390 prop
= drm_property_create_range(plane
->dev
, DRM_MODE_PROP_IMMUTABLE
,
395 drm_object_attach_property(&plane
->base
, prop
, zpos
);
397 plane
->zpos_property
= prop
;
400 plane
->state
->zpos
= zpos
;
401 plane
->state
->normalized_zpos
= zpos
;
406 EXPORT_SYMBOL(drm_plane_create_zpos_immutable_property
);
408 static int drm_atomic_state_zpos_cmp(const void *a
, const void *b
)
410 const struct drm_plane_state
*sa
= *(struct drm_plane_state
**)a
;
411 const struct drm_plane_state
*sb
= *(struct drm_plane_state
**)b
;
413 if (sa
->zpos
!= sb
->zpos
)
414 return sa
->zpos
- sb
->zpos
;
416 return sa
->plane
->base
.id
- sb
->plane
->base
.id
;
419 static int drm_atomic_helper_crtc_normalize_zpos(struct drm_crtc
*crtc
,
420 struct drm_crtc_state
*crtc_state
)
422 struct drm_atomic_state
*state
= crtc_state
->state
;
423 struct drm_device
*dev
= crtc
->dev
;
424 int total_planes
= dev
->mode_config
.num_total_plane
;
425 struct drm_plane_state
**states
;
426 struct drm_plane
*plane
;
430 DRM_DEBUG_ATOMIC("[CRTC:%d:%s] calculating normalized zpos values\n",
431 crtc
->base
.id
, crtc
->name
);
433 states
= kmalloc_array(total_planes
, sizeof(*states
), GFP_KERNEL
);
438 * Normalization process might create new states for planes which
439 * normalized_zpos has to be recalculated.
441 drm_for_each_plane_mask(plane
, dev
, crtc_state
->plane_mask
) {
442 struct drm_plane_state
*plane_state
=
443 drm_atomic_get_plane_state(state
, plane
);
444 if (IS_ERR(plane_state
)) {
445 ret
= PTR_ERR(plane_state
);
448 states
[n
++] = plane_state
;
449 DRM_DEBUG_ATOMIC("[PLANE:%d:%s] processing zpos value %d\n",
450 plane
->base
.id
, plane
->name
,
454 sort(states
, n
, sizeof(*states
), drm_atomic_state_zpos_cmp
, NULL
);
456 for (i
= 0; i
< n
; i
++) {
457 plane
= states
[i
]->plane
;
459 states
[i
]->normalized_zpos
= i
;
460 DRM_DEBUG_ATOMIC("[PLANE:%d:%s] normalized zpos value %d\n",
461 plane
->base
.id
, plane
->name
, i
);
463 crtc_state
->zpos_changed
= true;
471 * drm_atomic_normalize_zpos - calculate normalized zpos values for all crtcs
473 * @state: atomic state of DRM device
475 * This function calculates normalized zpos value for all modified planes in
476 * the provided atomic state of DRM device.
478 * For every CRTC this function checks new states of all planes assigned to
479 * it and calculates normalized zpos value for these planes. Planes are compared
480 * first by their zpos values, then by plane id (if zpos is equal). The plane
481 * with lowest zpos value is at the bottom. The &drm_plane_state.normalized_zpos
482 * is then filled with unique values from 0 to number of active planes in crtc
486 * Zero for success or -errno
488 int drm_atomic_normalize_zpos(struct drm_device
*dev
,
489 struct drm_atomic_state
*state
)
491 struct drm_crtc
*crtc
;
492 struct drm_crtc_state
*old_crtc_state
, *new_crtc_state
;
493 struct drm_plane
*plane
;
494 struct drm_plane_state
*old_plane_state
, *new_plane_state
;
497 for_each_oldnew_plane_in_state(state
, plane
, old_plane_state
, new_plane_state
, i
) {
498 crtc
= new_plane_state
->crtc
;
501 if (old_plane_state
->zpos
!= new_plane_state
->zpos
) {
502 new_crtc_state
= drm_atomic_get_new_crtc_state(state
, crtc
);
503 new_crtc_state
->zpos_changed
= true;
507 for_each_oldnew_crtc_in_state(state
, crtc
, old_crtc_state
, new_crtc_state
, i
) {
508 if (old_crtc_state
->plane_mask
!= new_crtc_state
->plane_mask
||
509 new_crtc_state
->zpos_changed
) {
510 ret
= drm_atomic_helper_crtc_normalize_zpos(crtc
,
518 EXPORT_SYMBOL(drm_atomic_normalize_zpos
);
521 * drm_plane_create_blend_mode_property - create a new blend mode property
523 * @supported_modes: bitmask of supported modes, must include
524 * BIT(DRM_MODE_BLEND_PREMULTI). Current DRM assumption is
525 * that alpha is premultiplied, and old userspace can break if
526 * the property defaults to anything else.
528 * This creates a new property describing the blend mode.
530 * The property exposed to userspace is an enumeration property (see
531 * drm_property_create_enum()) called "pixel blend mode" and has the
532 * following enumeration values:
535 * Blend formula that ignores the pixel alpha.
538 * Blend formula that assumes the pixel color values have been already
539 * pre-multiplied with the alpha channel values.
542 * Blend formula that assumes the pixel color values have not been
543 * pre-multiplied and will do so when blending them to the background color
547 * Zero for success or -errno
549 int drm_plane_create_blend_mode_property(struct drm_plane
*plane
,
550 unsigned int supported_modes
)
552 struct drm_device
*dev
= plane
->dev
;
553 struct drm_property
*prop
;
554 static const struct drm_prop_enum_list props
[] = {
555 { DRM_MODE_BLEND_PIXEL_NONE
, "None" },
556 { DRM_MODE_BLEND_PREMULTI
, "Pre-multiplied" },
557 { DRM_MODE_BLEND_COVERAGE
, "Coverage" },
559 unsigned int valid_mode_mask
= BIT(DRM_MODE_BLEND_PIXEL_NONE
) |
560 BIT(DRM_MODE_BLEND_PREMULTI
) |
561 BIT(DRM_MODE_BLEND_COVERAGE
);
564 if (WARN_ON((supported_modes
& ~valid_mode_mask
) ||
565 ((supported_modes
& BIT(DRM_MODE_BLEND_PREMULTI
)) == 0)))
568 prop
= drm_property_create(dev
, DRM_MODE_PROP_ENUM
,
570 hweight32(supported_modes
));
574 for (i
= 0; i
< ARRAY_SIZE(props
); i
++) {
577 if (!(BIT(props
[i
].type
) & supported_modes
))
580 ret
= drm_property_add_enum(prop
, props
[i
].type
,
584 drm_property_destroy(dev
, prop
);
590 drm_object_attach_property(&plane
->base
, prop
, DRM_MODE_BLEND_PREMULTI
);
591 plane
->blend_mode_property
= prop
;
595 EXPORT_SYMBOL(drm_plane_create_blend_mode_property
);