GNU Linux-libre 5.10.219-gnu1
[releases.git] / drivers / gpu / drm / drm_plane_helper.c
1 /*
2  * Copyright (C) 2014 Intel Corporation
3  *
4  * DRM universal plane helper functions
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the "Software"),
8  * to deal in the Software without restriction, including without limitation
9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10  * and/or sell copies of the Software, and to permit persons to whom the
11  * Software is furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice (including the next
14  * paragraph) shall be included in all copies or substantial portions of the
15  * Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23  * SOFTWARE.
24  */
25
26 #include <linux/list.h>
27
28 #include <drm/drm_atomic.h>
29 #include <drm/drm_atomic_helper.h>
30 #include <drm/drm_atomic_uapi.h>
31 #include <drm/drm_crtc_helper.h>
32 #include <drm/drm_device.h>
33 #include <drm/drm_encoder.h>
34 #include <drm/drm_plane_helper.h>
35 #include <drm/drm_rect.h>
36
37 #define SUBPIXEL_MASK 0xffff
38
39 /**
40  * DOC: overview
41  *
42  * This helper library has two parts. The first part has support to implement
43  * primary plane support on top of the normal CRTC configuration interface.
44  * Since the legacy &drm_mode_config_funcs.set_config interface ties the primary
45  * plane together with the CRTC state this does not allow userspace to disable
46  * the primary plane itself. The default primary plane only expose XRBG8888 and
47  * ARGB8888 as valid pixel formats for the attached framebuffer.
48  *
49  * Drivers are highly recommended to implement proper support for primary
50  * planes, and newly merged drivers must not rely upon these transitional
51  * helpers.
52  *
53  * The second part also implements transitional helpers which allow drivers to
54  * gradually switch to the atomic helper infrastructure for plane updates. Once
55  * that switch is complete drivers shouldn't use these any longer, instead using
56  * the proper legacy implementations for update and disable plane hooks provided
57  * by the atomic helpers.
58  *
59  * Again drivers are strongly urged to switch to the new interfaces.
60  *
61  * The plane helpers share the function table structures with other helpers,
62  * specifically also the atomic helpers. See &struct drm_plane_helper_funcs for
63  * the details.
64  */
65
66 /*
67  * Returns the connectors currently associated with a CRTC.  This function
68  * should be called twice:  once with a NULL connector list to retrieve
69  * the list size, and once with the properly allocated list to be filled in.
70  */
71 static int get_connectors_for_crtc(struct drm_crtc *crtc,
72                                    struct drm_connector **connector_list,
73                                    int num_connectors)
74 {
75         struct drm_device *dev = crtc->dev;
76         struct drm_connector *connector;
77         struct drm_connector_list_iter conn_iter;
78         int count = 0;
79
80         /*
81          * Note: Once we change the plane hooks to more fine-grained locking we
82          * need to grab the connection_mutex here to be able to make these
83          * checks.
84          */
85         WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
86
87         drm_connector_list_iter_begin(dev, &conn_iter);
88         drm_for_each_connector_iter(connector, &conn_iter) {
89                 if (connector->encoder && connector->encoder->crtc == crtc) {
90                         if (connector_list != NULL && count < num_connectors)
91                                 *(connector_list++) = connector;
92
93                         count++;
94                 }
95         }
96         drm_connector_list_iter_end(&conn_iter);
97
98         return count;
99 }
100
101 static int drm_plane_helper_check_update(struct drm_plane *plane,
102                                          struct drm_crtc *crtc,
103                                          struct drm_framebuffer *fb,
104                                          struct drm_rect *src,
105                                          struct drm_rect *dst,
106                                          unsigned int rotation,
107                                          int min_scale,
108                                          int max_scale,
109                                          bool can_position,
110                                          bool can_update_disabled,
111                                          bool *visible)
112 {
113         struct drm_plane_state plane_state = {
114                 .plane = plane,
115                 .crtc = crtc,
116                 .fb = fb,
117                 .src_x = src->x1,
118                 .src_y = src->y1,
119                 .src_w = drm_rect_width(src),
120                 .src_h = drm_rect_height(src),
121                 .crtc_x = dst->x1,
122                 .crtc_y = dst->y1,
123                 .crtc_w = drm_rect_width(dst),
124                 .crtc_h = drm_rect_height(dst),
125                 .rotation = rotation,
126         };
127         struct drm_crtc_state crtc_state = {
128                 .crtc = crtc,
129                 .enable = crtc->enabled,
130                 .mode = crtc->mode,
131         };
132         int ret;
133
134         ret = drm_atomic_helper_check_plane_state(&plane_state, &crtc_state,
135                                                   min_scale, max_scale,
136                                                   can_position,
137                                                   can_update_disabled);
138         if (ret)
139                 return ret;
140
141         *src = plane_state.src;
142         *dst = plane_state.dst;
143         *visible = plane_state.visible;
144
145         return 0;
146 }
147
148 static int drm_primary_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
149                                      struct drm_framebuffer *fb,
150                                      int crtc_x, int crtc_y,
151                                      unsigned int crtc_w, unsigned int crtc_h,
152                                      uint32_t src_x, uint32_t src_y,
153                                      uint32_t src_w, uint32_t src_h,
154                                      struct drm_modeset_acquire_ctx *ctx)
155 {
156         struct drm_mode_set set = {
157                 .crtc = crtc,
158                 .fb = fb,
159                 .mode = &crtc->mode,
160                 .x = src_x >> 16,
161                 .y = src_y >> 16,
162         };
163         struct drm_rect src = {
164                 .x1 = src_x,
165                 .y1 = src_y,
166                 .x2 = src_x + src_w,
167                 .y2 = src_y + src_h,
168         };
169         struct drm_rect dest = {
170                 .x1 = crtc_x,
171                 .y1 = crtc_y,
172                 .x2 = crtc_x + crtc_w,
173                 .y2 = crtc_y + crtc_h,
174         };
175         struct drm_connector **connector_list;
176         int num_connectors, ret;
177         bool visible;
178
179         ret = drm_plane_helper_check_update(plane, crtc, fb,
180                                             &src, &dest,
181                                             DRM_MODE_ROTATE_0,
182                                             DRM_PLANE_HELPER_NO_SCALING,
183                                             DRM_PLANE_HELPER_NO_SCALING,
184                                             false, false, &visible);
185         if (ret)
186                 return ret;
187
188         if (!visible)
189                 /*
190                  * Primary plane isn't visible.  Note that unless a driver
191                  * provides their own disable function, this will just
192                  * wind up returning -EINVAL to userspace.
193                  */
194                 return plane->funcs->disable_plane(plane, ctx);
195
196         /* Find current connectors for CRTC */
197         num_connectors = get_connectors_for_crtc(crtc, NULL, 0);
198         BUG_ON(num_connectors == 0);
199         connector_list = kcalloc(num_connectors, sizeof(*connector_list),
200                                  GFP_KERNEL);
201         if (!connector_list)
202                 return -ENOMEM;
203         get_connectors_for_crtc(crtc, connector_list, num_connectors);
204
205         set.connectors = connector_list;
206         set.num_connectors = num_connectors;
207
208         /*
209          * We call set_config() directly here rather than using
210          * drm_mode_set_config_internal.  We're reprogramming the same
211          * connectors that were already in use, so we shouldn't need the extra
212          * cross-CRTC fb refcounting to accomodate stealing connectors.
213          * drm_mode_setplane() already handles the basic refcounting for the
214          * framebuffers involved in this operation.
215          */
216         ret = crtc->funcs->set_config(&set, ctx);
217
218         kfree(connector_list);
219         return ret;
220 }
221
222 static int drm_primary_helper_disable(struct drm_plane *plane,
223                                       struct drm_modeset_acquire_ctx *ctx)
224 {
225         return -EINVAL;
226 }
227
228 /**
229  * drm_primary_helper_destroy() - Helper for primary plane destruction
230  * @plane: plane to destroy
231  *
232  * Provides a default plane destroy handler for primary planes.  This handler
233  * is called during CRTC destruction.  We disable the primary plane, remove
234  * it from the DRM plane list, and deallocate the plane structure.
235  */
236 void drm_primary_helper_destroy(struct drm_plane *plane)
237 {
238         drm_plane_cleanup(plane);
239         kfree(plane);
240 }
241 EXPORT_SYMBOL(drm_primary_helper_destroy);
242
243 const struct drm_plane_funcs drm_primary_helper_funcs = {
244         .update_plane = drm_primary_helper_update,
245         .disable_plane = drm_primary_helper_disable,
246         .destroy = drm_primary_helper_destroy,
247 };
248 EXPORT_SYMBOL(drm_primary_helper_funcs);