2 * Copyright (C) 2016 Samsung Electronics Co.Ltd
4 * Marek Szyprowski <m.szyprowski@samsung.com>
6 * DRM core plane blending related functions
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9 * documentation for any purpose is hereby granted without fee, provided that
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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 @mode in the
44 * &drm_crtc_state). These two rectangles are both stored in the
47 * For the atomic ioctl the following standard (atomic) properties on the plane object
48 * encode the basic plane composition model:
51 * X coordinate offset for the source rectangle within the
52 * &drm_framebuffer, in 16.16 fixed point. Must be positive.
54 * Y coordinate offset for the source rectangle within the
55 * &drm_framebuffer, in 16.16 fixed point. Must be positive.
57 * Width for the source rectangle within the &drm_framebuffer, in 16.16
58 * fixed point. SRC_X plus SRC_W must be within the width of the source
59 * framebuffer. Must be positive.
61 * Height for the source rectangle within the &drm_framebuffer, in 16.16
62 * fixed point. SRC_Y plus SRC_H must be within the height of the source
63 * framebuffer. Must be positive.
65 * X coordinate offset for the destination rectangle. Can be negative.
67 * Y coordinate offset for the destination rectangle. Can be negative.
69 * Width for the destination rectangle. CRTC_X plus CRTC_W can extend past
70 * the currently visible horizontal area of the &drm_crtc.
72 * Height for the destination rectangle. CRTC_Y plus CRTC_H can extend past
73 * the currently visible vertical area of the &drm_crtc.
75 * Mode object ID of the &drm_framebuffer this plane should scan out.
77 * Mode object ID of the &drm_crtc this plane should be connected to.
79 * Note that the source rectangle must fully lie within the bounds of the
80 * &drm_framebuffer. The destination rectangle can lie outside of the visible
81 * area of the current mode of the CRTC. It must be apprpriately clipped by the
82 * driver, which can be done by calling drm_plane_helper_check_update(). Drivers
83 * are also allowed to round the subpixel sampling positions appropriately, but
84 * only to the next full pixel. No pixel outside of the source rectangle may
85 * ever be sampled, which is important when applying more sophisticated
86 * filtering than just a bilinear one when scaling. The filtering mode when
87 * scaling is unspecified.
89 * On top of this basic transformation additional properties can be exposed by
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
97 * - Z position is set up with drm_plane_create_zpos_immutable_property() and
98 * drm_plane_create_zpos_property(). It controls the visibility of overlapping
99 * planes. Without this property the primary plane is always below the cursor
100 * plane, and ordering between all other planes is undefined.
102 * Note that all the property extensions described here apply either to the
103 * plane or the CRTC (e.g. for the background color, which currently is not
104 * exposed and assumed to be black).
108 * drm_plane_create_rotation_property - create a new rotation property
110 * @rotation: initial value of the rotation property
111 * @supported_rotations: bitmask of supported rotations and reflections
113 * This creates a new property with the selected support for transformations.
115 * Since a rotation by 180° degress is the same as reflecting both along the x
116 * and the y axis the rotation property is somewhat redundant. Drivers can use
117 * drm_rotation_simplify() to normalize values of this property.
119 * The property exposed to userspace is a bitmask property (see
120 * drm_property_create_bitmask()) called "rotation" and has the following
121 * bitmask enumaration values:
136 * Rotation is the specified amount in degrees in counter clockwise direction,
137 * the X and Y axis are within the source rectangle, i.e. the X/Y axis before
138 * rotation. After reflection, the rotation is applied to the image sampled from
139 * the source rectangle, before scaling it to fit the destination rectangle.
141 int drm_plane_create_rotation_property(struct drm_plane *plane,
142 unsigned int rotation,
143 unsigned int supported_rotations)
145 static const struct drm_prop_enum_list props[] = {
146 { __builtin_ffs(DRM_ROTATE_0) - 1, "rotate-0" },
147 { __builtin_ffs(DRM_ROTATE_90) - 1, "rotate-90" },
148 { __builtin_ffs(DRM_ROTATE_180) - 1, "rotate-180" },
149 { __builtin_ffs(DRM_ROTATE_270) - 1, "rotate-270" },
150 { __builtin_ffs(DRM_REFLECT_X) - 1, "reflect-x" },
151 { __builtin_ffs(DRM_REFLECT_Y) - 1, "reflect-y" },
153 struct drm_property *prop;
155 WARN_ON((supported_rotations & DRM_ROTATE_MASK) == 0);
156 WARN_ON(!is_power_of_2(rotation & DRM_ROTATE_MASK));
157 WARN_ON(rotation & ~supported_rotations);
159 prop = drm_property_create_bitmask(plane->dev, 0, "rotation",
160 props, ARRAY_SIZE(props),
161 supported_rotations);
165 drm_object_attach_property(&plane->base, prop, rotation);
168 plane->state->rotation = rotation;
170 plane->rotation_property = prop;
174 EXPORT_SYMBOL(drm_plane_create_rotation_property);
177 * drm_rotation_simplify() - Try to simplify the rotation
178 * @rotation: Rotation to be simplified
179 * @supported_rotations: Supported rotations
181 * Attempt to simplify the rotation to a form that is supported.
182 * Eg. if the hardware supports everything except DRM_REFLECT_X
183 * one could call this function like this:
185 * drm_rotation_simplify(rotation, DRM_ROTATE_0 |
186 * DRM_ROTATE_90 | DRM_ROTATE_180 |
187 * DRM_ROTATE_270 | DRM_REFLECT_Y);
189 * to eliminate the DRM_ROTATE_X flag. Depending on what kind of
190 * transforms the hardware supports, this function may not
191 * be able to produce a supported transform, so the caller should
192 * check the result afterwards.
194 unsigned int drm_rotation_simplify(unsigned int rotation,
195 unsigned int supported_rotations)
197 if (rotation & ~supported_rotations) {
198 rotation ^= DRM_REFLECT_X | DRM_REFLECT_Y;
199 rotation = (rotation & DRM_REFLECT_MASK) |
200 BIT((ffs(rotation & DRM_ROTATE_MASK) + 1) % 4);
205 EXPORT_SYMBOL(drm_rotation_simplify);
208 * drm_plane_create_zpos_property - create mutable zpos property
210 * @zpos: initial value of zpos property
211 * @min: minimal possible value of zpos property
212 * @max: maximal possible value of zpos property
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 * Once mutable zpos property has been enabled, the DRM core will automatically
218 * calculate drm_plane_state->normalized_zpos values. Usually min should be set
219 * to 0 and max to maximal number of planes for given crtc - 1.
221 * If zpos of some planes cannot be changed (like fixed background or
222 * cursor/topmost planes), driver should adjust min/max values and assign those
223 * planes immutable zpos property with lower or higher values (for more
224 * information, see drm_plane_create_zpos_immutable_property() function). In such
225 * case driver should also assign proper initial zpos values for all planes in
226 * its plane_reset() callback, so the planes will be always sorted properly.
228 * See also drm_atomic_normalize_zpos().
230 * The property exposed to userspace is called "zpos".
233 * Zero on success, negative errno on failure.
235 int drm_plane_create_zpos_property(struct drm_plane *plane,
237 unsigned int min, unsigned int max)
239 struct drm_property *prop;
241 prop = drm_property_create_range(plane->dev, 0, "zpos", min, max);
245 drm_object_attach_property(&plane->base, prop, zpos);
247 plane->zpos_property = prop;
250 plane->state->zpos = zpos;
251 plane->state->normalized_zpos = zpos;
256 EXPORT_SYMBOL(drm_plane_create_zpos_property);
259 * drm_plane_create_zpos_immutable_property - create immuttable zpos property
261 * @zpos: value of zpos property
263 * This function initializes generic immutable zpos property and enables
264 * support for it in drm core. Using this property driver lets userspace
265 * to get the arrangement of the planes for blending operation and notifies
266 * it that the hardware (or driver) doesn't support changing of the planes'
267 * order. For mutable zpos see drm_plane_create_zpos_property().
269 * The property exposed to userspace is called "zpos".
272 * Zero on success, negative errno on failure.
274 int drm_plane_create_zpos_immutable_property(struct drm_plane *plane,
277 struct drm_property *prop;
279 prop = drm_property_create_range(plane->dev, DRM_MODE_PROP_IMMUTABLE,
284 drm_object_attach_property(&plane->base, prop, zpos);
286 plane->zpos_property = prop;
289 plane->state->zpos = zpos;
290 plane->state->normalized_zpos = zpos;
295 EXPORT_SYMBOL(drm_plane_create_zpos_immutable_property);
297 static int drm_atomic_state_zpos_cmp(const void *a, const void *b)
299 const struct drm_plane_state *sa = *(struct drm_plane_state **)a;
300 const struct drm_plane_state *sb = *(struct drm_plane_state **)b;
302 if (sa->zpos != sb->zpos)
303 return sa->zpos - sb->zpos;
305 return sa->plane->base.id - sb->plane->base.id;
308 static int drm_atomic_helper_crtc_normalize_zpos(struct drm_crtc *crtc,
309 struct drm_crtc_state *crtc_state)
311 struct drm_atomic_state *state = crtc_state->state;
312 struct drm_device *dev = crtc->dev;
313 int total_planes = dev->mode_config.num_total_plane;
314 struct drm_plane_state **states;
315 struct drm_plane *plane;
319 DRM_DEBUG_ATOMIC("[CRTC:%d:%s] calculating normalized zpos values\n",
320 crtc->base.id, crtc->name);
322 states = kmalloc_array(total_planes, sizeof(*states), GFP_TEMPORARY);
327 * Normalization process might create new states for planes which
328 * normalized_zpos has to be recalculated.
330 drm_for_each_plane_mask(plane, dev, crtc_state->plane_mask) {
331 struct drm_plane_state *plane_state =
332 drm_atomic_get_plane_state(state, plane);
333 if (IS_ERR(plane_state)) {
334 ret = PTR_ERR(plane_state);
337 states[n++] = plane_state;
338 DRM_DEBUG_ATOMIC("[PLANE:%d:%s] processing zpos value %d\n",
339 plane->base.id, plane->name,
343 sort(states, n, sizeof(*states), drm_atomic_state_zpos_cmp, NULL);
345 for (i = 0; i < n; i++) {
346 plane = states[i]->plane;
348 states[i]->normalized_zpos = i;
349 DRM_DEBUG_ATOMIC("[PLANE:%d:%s] normalized zpos value %d\n",
350 plane->base.id, plane->name, i);
352 crtc_state->zpos_changed = true;
360 * drm_atomic_normalize_zpos - calculate normalized zpos values for all crtcs
362 * @state: atomic state of DRM device
364 * This function calculates normalized zpos value for all modified planes in
365 * the provided atomic state of DRM device.
367 * For every CRTC this function checks new states of all planes assigned to
368 * it and calculates normalized zpos value for these planes. Planes are compared
369 * first by their zpos values, then by plane id (if zpos is equal). The plane
370 * with lowest zpos value is at the bottom. The plane_state->normalized_zpos is
371 * then filled with unique values from 0 to number of active planes in crtc
375 * Zero for success or -errno
377 int drm_atomic_normalize_zpos(struct drm_device *dev,
378 struct drm_atomic_state *state)
380 struct drm_crtc *crtc;
381 struct drm_crtc_state *crtc_state;
382 struct drm_plane *plane;
383 struct drm_plane_state *plane_state;
386 for_each_plane_in_state(state, plane, plane_state, i) {
387 crtc = plane_state->crtc;
390 if (plane->state->zpos != plane_state->zpos) {
392 drm_atomic_get_existing_crtc_state(state, crtc);
393 crtc_state->zpos_changed = true;
397 for_each_crtc_in_state(state, crtc, crtc_state, i) {
398 if (crtc_state->plane_mask != crtc->state->plane_mask ||
399 crtc_state->zpos_changed) {
400 ret = drm_atomic_helper_crtc_normalize_zpos(crtc,
408 EXPORT_SYMBOL(drm_atomic_normalize_zpos);