xref: /openbmc/linux/drivers/gpu/drm/drm_blend.c (revision 293d5b43)
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_crtc.h>
29 #include <linux/export.h>
30 #include <linux/slab.h>
31 #include <linux/sort.h>
32 
33 #include "drm_internal.h"
34 
35 /**
36  * drm_plane_create_zpos_property - create mutable zpos property
37  * @plane: drm plane
38  * @zpos: initial value of zpos property
39  * @min: minimal possible value of zpos property
40  * @max: maximal possible value of zpos property
41  *
42  * This function initializes generic mutable zpos property and enables support
43  * for it in drm core. Drivers can then attach this property to planes to enable
44  * support for configurable planes arrangement during blending operation.
45  * Once mutable zpos property has been enabled, the DRM core will automatically
46  * calculate drm_plane_state->normalized_zpos values. Usually min should be set
47  * to 0 and max to maximal number of planes for given crtc - 1.
48  *
49  * If zpos of some planes cannot be changed (like fixed background or
50  * cursor/topmost planes), driver should adjust min/max values and assign those
51  * planes immutable zpos property with lower or higher values (for more
52  * information, see drm_mode_create_zpos_immutable_property() function). In such
53  * case driver should also assign proper initial zpos values for all planes in
54  * its plane_reset() callback, so the planes will be always sorted properly.
55  *
56  * Returns:
57  * Zero on success, negative errno on failure.
58  */
59 int drm_plane_create_zpos_property(struct drm_plane *plane,
60 				   unsigned int zpos,
61 				   unsigned int min, unsigned int max)
62 {
63 	struct drm_property *prop;
64 
65 	prop = drm_property_create_range(plane->dev, 0, "zpos", min, max);
66 	if (!prop)
67 		return -ENOMEM;
68 
69 	drm_object_attach_property(&plane->base, prop, zpos);
70 
71 	plane->zpos_property = prop;
72 
73 	if (plane->state) {
74 		plane->state->zpos = zpos;
75 		plane->state->normalized_zpos = zpos;
76 	}
77 
78 	return 0;
79 }
80 EXPORT_SYMBOL(drm_plane_create_zpos_property);
81 
82 /**
83  * drm_plane_create_zpos_immutable_property - create immuttable zpos property
84  * @plane: drm plane
85  * @zpos: value of zpos property
86  *
87  * This function initializes generic immutable zpos property and enables
88  * support for it in drm core. Using this property driver lets userspace
89  * to get the arrangement of the planes for blending operation and notifies
90  * it that the hardware (or driver) doesn't support changing of the planes'
91  * order.
92  *
93  * Returns:
94  * Zero on success, negative errno on failure.
95  */
96 int drm_plane_create_zpos_immutable_property(struct drm_plane *plane,
97 					     unsigned int zpos)
98 {
99 	struct drm_property *prop;
100 
101 	prop = drm_property_create_range(plane->dev, DRM_MODE_PROP_IMMUTABLE,
102 					 "zpos", zpos, zpos);
103 	if (!prop)
104 		return -ENOMEM;
105 
106 	drm_object_attach_property(&plane->base, prop, zpos);
107 
108 	plane->zpos_property = prop;
109 
110 	if (plane->state) {
111 		plane->state->zpos = zpos;
112 		plane->state->normalized_zpos = zpos;
113 	}
114 
115 	return 0;
116 }
117 EXPORT_SYMBOL(drm_plane_create_zpos_immutable_property);
118 
119 static int drm_atomic_state_zpos_cmp(const void *a, const void *b)
120 {
121 	const struct drm_plane_state *sa = *(struct drm_plane_state **)a;
122 	const struct drm_plane_state *sb = *(struct drm_plane_state **)b;
123 
124 	if (sa->zpos != sb->zpos)
125 		return sa->zpos - sb->zpos;
126 	else
127 		return sa->plane->base.id - sb->plane->base.id;
128 }
129 
130 /**
131  * drm_atomic_helper_crtc_normalize_zpos - calculate normalized zpos values
132  * @crtc: crtc with planes, which have to be considered for normalization
133  * @crtc_state: new atomic state to apply
134  *
135  * This function checks new states of all planes assigned to given crtc and
136  * calculates normalized zpos value for them. Planes are compared first by their
137  * zpos values, then by plane id (if zpos equals). Plane with lowest zpos value
138  * is at the bottom. The plane_state->normalized_zpos is then filled with unique
139  * values from 0 to number of active planes in crtc minus one.
140  *
141  * RETURNS
142  * Zero for success or -errno
143  */
144 static int drm_atomic_helper_crtc_normalize_zpos(struct drm_crtc *crtc,
145 					  struct drm_crtc_state *crtc_state)
146 {
147 	struct drm_atomic_state *state = crtc_state->state;
148 	struct drm_device *dev = crtc->dev;
149 	int total_planes = dev->mode_config.num_total_plane;
150 	struct drm_plane_state **states;
151 	struct drm_plane *plane;
152 	int i, n = 0;
153 	int ret = 0;
154 
155 	DRM_DEBUG_ATOMIC("[CRTC:%d:%s] calculating normalized zpos values\n",
156 			 crtc->base.id, crtc->name);
157 
158 	states = kmalloc_array(total_planes, sizeof(*states), GFP_TEMPORARY);
159 	if (!states)
160 		return -ENOMEM;
161 
162 	/*
163 	 * Normalization process might create new states for planes which
164 	 * normalized_zpos has to be recalculated.
165 	 */
166 	drm_for_each_plane_mask(plane, dev, crtc_state->plane_mask) {
167 		struct drm_plane_state *plane_state =
168 			drm_atomic_get_plane_state(state, plane);
169 		if (IS_ERR(plane_state)) {
170 			ret = PTR_ERR(plane_state);
171 			goto done;
172 		}
173 		states[n++] = plane_state;
174 		DRM_DEBUG_ATOMIC("[PLANE:%d:%s] processing zpos value %d\n",
175 				 plane->base.id, plane->name,
176 				 plane_state->zpos);
177 	}
178 
179 	sort(states, n, sizeof(*states), drm_atomic_state_zpos_cmp, NULL);
180 
181 	for (i = 0; i < n; i++) {
182 		plane = states[i]->plane;
183 
184 		states[i]->normalized_zpos = i;
185 		DRM_DEBUG_ATOMIC("[PLANE:%d:%s] normalized zpos value %d\n",
186 				 plane->base.id, plane->name, i);
187 	}
188 	crtc_state->zpos_changed = true;
189 
190 done:
191 	kfree(states);
192 	return ret;
193 }
194 
195 /**
196  * drm_atomic_helper_normalize_zpos - calculate normalized zpos values for all
197  *				      crtcs
198  * @dev: DRM device
199  * @state: atomic state of DRM device
200  *
201  * This function calculates normalized zpos value for all modified planes in
202  * the provided atomic state of DRM device. For more information, see
203  * drm_atomic_helper_crtc_normalize_zpos() function.
204  *
205  * RETURNS
206  * Zero for success or -errno
207  */
208 int drm_atomic_helper_normalize_zpos(struct drm_device *dev,
209 				     struct drm_atomic_state *state)
210 {
211 	struct drm_crtc *crtc;
212 	struct drm_crtc_state *crtc_state;
213 	struct drm_plane *plane;
214 	struct drm_plane_state *plane_state;
215 	int i, ret = 0;
216 
217 	for_each_plane_in_state(state, plane, plane_state, i) {
218 		crtc = plane_state->crtc;
219 		if (!crtc)
220 			continue;
221 		if (plane->state->zpos != plane_state->zpos) {
222 			crtc_state =
223 				drm_atomic_get_existing_crtc_state(state, crtc);
224 			crtc_state->zpos_changed = true;
225 		}
226 	}
227 
228 	for_each_crtc_in_state(state, crtc, crtc_state, i) {
229 		if (crtc_state->plane_mask != crtc->state->plane_mask ||
230 		    crtc_state->zpos_changed) {
231 			ret = drm_atomic_helper_crtc_normalize_zpos(crtc,
232 								    crtc_state);
233 			if (ret)
234 				return ret;
235 		}
236 	}
237 	return 0;
238 }
239