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 .visible = *visible,
127 };
128 struct drm_crtc_state crtc_state = {
129 .crtc = crtc,
130 .enable = crtc->enabled,
131 .mode = crtc->mode,
132 };
133 int ret;
134
135 ret = drm_atomic_helper_check_plane_state(&plane_state, &crtc_state,
136 min_scale, max_scale,
137 can_position,
138 can_update_disabled);
139 if (ret)
140 return ret;
141
142 *src = plane_state.src;
143 *dst = plane_state.dst;
144 *visible = plane_state.visible;
145
146 return 0;
147 }
148
149 static int drm_primary_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
150 struct drm_framebuffer *fb,
151 int crtc_x, int crtc_y,
152 unsigned int crtc_w, unsigned int crtc_h,
153 uint32_t src_x, uint32_t src_y,
154 uint32_t src_w, uint32_t src_h,
155 struct drm_modeset_acquire_ctx *ctx)
156 {
157 struct drm_mode_set set = {
158 .crtc = crtc,
159 .fb = fb,
160 .mode = &crtc->mode,
161 .x = src_x >> 16,
162 .y = src_y >> 16,
163 };
164 struct drm_rect src = {
165 .x1 = src_x,
166 .y1 = src_y,
167 .x2 = src_x + src_w,
168 .y2 = src_y + src_h,
169 };
170 struct drm_rect dest = {
171 .x1 = crtc_x,
172 .y1 = crtc_y,
173 .x2 = crtc_x + crtc_w,
174 .y2 = crtc_y + crtc_h,
175 };
176 struct drm_connector **connector_list;
177 int num_connectors, ret;
178 bool visible;
179
180 ret = drm_plane_helper_check_update(plane, crtc, fb,
181 &src, &dest,
182 DRM_MODE_ROTATE_0,
183 DRM_PLANE_HELPER_NO_SCALING,
184 DRM_PLANE_HELPER_NO_SCALING,
185 false, false, &visible);
186 if (ret)
187 return ret;
188
189 if (!visible)
190 /*
191 * Primary plane isn't visible. Note that unless a driver
192 * provides their own disable function, this will just
193 * wind up returning -EINVAL to userspace.
194 */
195 return plane->funcs->disable_plane(plane, ctx);
196
197 /* Find current connectors for CRTC */
198 num_connectors = get_connectors_for_crtc(crtc, NULL, 0);
199 BUG_ON(num_connectors == 0);
200 connector_list = kcalloc(num_connectors, sizeof(*connector_list),
201 GFP_KERNEL);
202 if (!connector_list)
203 return -ENOMEM;
204 get_connectors_for_crtc(crtc, connector_list, num_connectors);
205
206 set.connectors = connector_list;
207 set.num_connectors = num_connectors;
208
209 /*
210 * We call set_config() directly here rather than using
211 * drm_mode_set_config_internal. We're reprogramming the same
212 * connectors that were already in use, so we shouldn't need the extra
213 * cross-CRTC fb refcounting to accomodate stealing connectors.
214 * drm_mode_setplane() already handles the basic refcounting for the
215 * framebuffers involved in this operation.
216 */
217 ret = crtc->funcs->set_config(&set, ctx);
218
219 kfree(connector_list);
220 return ret;
221 }
222
223 static int drm_primary_helper_disable(struct drm_plane *plane,
224 struct drm_modeset_acquire_ctx *ctx)
225 {
226 return -EINVAL;
227 }
228
229 /**
230 * drm_primary_helper_destroy() - Helper for primary plane destruction
231 * @plane: plane to destroy
232 *
233 * Provides a default plane destroy handler for primary planes. This handler
234 * is called during CRTC destruction. We disable the primary plane, remove
235 * it from the DRM plane list, and deallocate the plane structure.
236 */
237 void drm_primary_helper_destroy(struct drm_plane *plane)
238 {
239 drm_plane_cleanup(plane);
240 kfree(plane);
241 }
242 EXPORT_SYMBOL(drm_primary_helper_destroy);
243
244 const struct drm_plane_funcs drm_primary_helper_funcs = {
245 .update_plane = drm_primary_helper_update,
246 .disable_plane = drm_primary_helper_disable,
247 .destroy = drm_primary_helper_destroy,
248 };
249 EXPORT_SYMBOL(drm_primary_helper_funcs);