1 /* $NetBSD: drm_plane_helper.c,v 1.6 2021/12/19 09:49:56 riastradh Exp $ */
2
3 /*
4 * Copyright (C) 2014 Intel Corporation
5 *
6 * DRM universal plane helper functions
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a
9 * copy of this software and associated documentation files (the "Software"),
10 * to deal in the Software without restriction, including without limitation
11 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
12 * and/or sell copies of the Software, and to permit persons to whom the
13 * Software is furnished to do so, subject to the following conditions:
14 *
15 * The above copyright notice and this permission notice (including the next
16 * paragraph) shall be included in all copies or substantial portions of the
17 * Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
22 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
23 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
24 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
25 * SOFTWARE.
26 */
27
28 #include <sys/cdefs.h>
29 __KERNEL_RCSID(0, "$NetBSD: drm_plane_helper.c,v 1.6 2021/12/19 09:49:56 riastradh Exp $");
30
31 #include <linux/list.h>
32
33 #include <drm/drm_atomic.h>
34 #include <drm/drm_atomic_helper.h>
35 #include <drm/drm_atomic_uapi.h>
36 #include <drm/drm_crtc_helper.h>
37 #include <drm/drm_device.h>
38 #include <drm/drm_encoder.h>
39 #include <drm/drm_plane_helper.h>
40 #include <drm/drm_rect.h>
41
42 /**
43 * DOC: overview
44 *
45 * This helper library has two parts. The first part has support to implement
46 * primary plane support on top of the normal CRTC configuration interface.
47 * Since the legacy &drm_mode_config_funcs.set_config interface ties the primary
48 * plane together with the CRTC state this does not allow userspace to disable
49 * the primary plane itself. The default primary plane only expose XRBG8888 and
50 * ARGB8888 as valid pixel formats for the attached framebuffer.
51 *
52 * Drivers are highly recommended to implement proper support for primary
53 * planes, and newly merged drivers must not rely upon these transitional
54 * helpers.
55 *
56 * The second part also implements transitional helpers which allow drivers to
57 * gradually switch to the atomic helper infrastructure for plane updates. Once
58 * that switch is complete drivers shouldn't use these any longer, instead using
59 * the proper legacy implementations for update and disable plane hooks provided
60 * by the atomic helpers.
61 *
62 * Again drivers are strongly urged to switch to the new interfaces.
63 *
64 * The plane helpers share the function table structures with other helpers,
65 * specifically also the atomic helpers. See &struct drm_plane_helper_funcs for
66 * the details.
67 */
68
69 /*
70 * Returns the connectors currently associated with a CRTC. This function
71 * should be called twice: once with a NULL connector list to retrieve
72 * the list size, and once with the properly allocated list to be filled in.
73 */
get_connectors_for_crtc(struct drm_crtc * crtc,struct drm_connector ** connector_list,int num_connectors)74 static int get_connectors_for_crtc(struct drm_crtc *crtc,
75 struct drm_connector **connector_list,
76 int num_connectors)
77 {
78 struct drm_device *dev = crtc->dev;
79 struct drm_connector *connector;
80 struct drm_connector_list_iter conn_iter;
81 int count = 0;
82
83 /*
84 * Note: Once we change the plane hooks to more fine-grained locking we
85 * need to grab the connection_mutex here to be able to make these
86 * checks.
87 */
88 WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
89
90 drm_connector_list_iter_begin(dev, &conn_iter);
91 drm_for_each_connector_iter(connector, &conn_iter) {
92 if (connector->encoder && connector->encoder->crtc == crtc) {
93 if (connector_list != NULL && count < num_connectors)
94 *(connector_list++) = connector;
95
96 count++;
97 }
98 }
99 drm_connector_list_iter_end(&conn_iter);
100
101 return count;
102 }
103
drm_plane_helper_check_update(struct drm_plane * plane,struct drm_crtc * crtc,struct drm_framebuffer * fb,struct drm_rect * src,struct drm_rect * dst,unsigned int rotation,int min_scale,int max_scale,bool can_position,bool can_update_disabled,bool * visible)104 static int drm_plane_helper_check_update(struct drm_plane *plane,
105 struct drm_crtc *crtc,
106 struct drm_framebuffer *fb,
107 struct drm_rect *src,
108 struct drm_rect *dst,
109 unsigned int rotation,
110 int min_scale,
111 int max_scale,
112 bool can_position,
113 bool can_update_disabled,
114 bool *visible)
115 {
116 struct drm_plane_state plane_state = {
117 .plane = plane,
118 .crtc = crtc,
119 .fb = fb,
120 .src_x = src->x1,
121 .src_y = src->y1,
122 .src_w = drm_rect_width(src),
123 .src_h = drm_rect_height(src),
124 .crtc_x = dst->x1,
125 .crtc_y = dst->y1,
126 .crtc_w = drm_rect_width(dst),
127 .crtc_h = drm_rect_height(dst),
128 .rotation = rotation,
129 .visible = *visible,
130 };
131 struct drm_crtc_state crtc_state = {
132 .crtc = crtc,
133 .enable = crtc->enabled,
134 .mode = crtc->mode,
135 };
136 int ret;
137
138 ret = drm_atomic_helper_check_plane_state(&plane_state, &crtc_state,
139 min_scale, max_scale,
140 can_position,
141 can_update_disabled);
142 if (ret)
143 return ret;
144
145 *src = plane_state.src;
146 *dst = plane_state.dst;
147 *visible = plane_state.visible;
148
149 return 0;
150 }
151
drm_primary_helper_update(struct drm_plane * plane,struct drm_crtc * crtc,struct drm_framebuffer * fb,int crtc_x,int crtc_y,unsigned int crtc_w,unsigned int crtc_h,uint32_t src_x,uint32_t src_y,uint32_t src_w,uint32_t src_h,struct drm_modeset_acquire_ctx * ctx)152 static int drm_primary_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
153 struct drm_framebuffer *fb,
154 int crtc_x, int crtc_y,
155 unsigned int crtc_w, unsigned int crtc_h,
156 uint32_t src_x, uint32_t src_y,
157 uint32_t src_w, uint32_t src_h,
158 struct drm_modeset_acquire_ctx *ctx)
159 {
160 struct drm_mode_set set = {
161 .crtc = crtc,
162 .fb = fb,
163 .mode = &crtc->mode,
164 .x = src_x >> 16,
165 .y = src_y >> 16,
166 };
167 struct drm_rect src = {
168 .x1 = src_x,
169 .y1 = src_y,
170 .x2 = src_x + src_w,
171 .y2 = src_y + src_h,
172 };
173 struct drm_rect dest = {
174 .x1 = crtc_x,
175 .y1 = crtc_y,
176 .x2 = crtc_x + crtc_w,
177 .y2 = crtc_y + crtc_h,
178 };
179 struct drm_connector **connector_list;
180 int num_connectors, ret;
181 bool visible = false; /* XXX wasn't initialized normally. Looks like bug. */
182
183 ret = drm_plane_helper_check_update(plane, crtc, fb,
184 &src, &dest,
185 DRM_MODE_ROTATE_0,
186 DRM_PLANE_HELPER_NO_SCALING,
187 DRM_PLANE_HELPER_NO_SCALING,
188 false, false, &visible);
189 if (ret)
190 return ret;
191
192 if (!visible)
193 /*
194 * Primary plane isn't visible. Note that unless a driver
195 * provides their own disable function, this will just
196 * wind up returning -EINVAL to userspace.
197 */
198 return plane->funcs->disable_plane(plane, ctx);
199
200 /* Find current connectors for CRTC */
201 num_connectors = get_connectors_for_crtc(crtc, NULL, 0);
202 BUG_ON(num_connectors == 0);
203 connector_list = kcalloc(num_connectors, sizeof(*connector_list),
204 GFP_KERNEL);
205 if (!connector_list)
206 return -ENOMEM;
207 get_connectors_for_crtc(crtc, connector_list, num_connectors);
208
209 set.connectors = connector_list;
210 set.num_connectors = num_connectors;
211
212 /*
213 * We call set_config() directly here rather than using
214 * drm_mode_set_config_internal. We're reprogramming the same
215 * connectors that were already in use, so we shouldn't need the extra
216 * cross-CRTC fb refcounting to accomodate stealing connectors.
217 * drm_mode_setplane() already handles the basic refcounting for the
218 * framebuffers involved in this operation.
219 */
220 ret = crtc->funcs->set_config(&set, ctx);
221
222 kfree(connector_list);
223 return ret;
224 }
225
drm_primary_helper_disable(struct drm_plane * plane,struct drm_modeset_acquire_ctx * ctx)226 static int drm_primary_helper_disable(struct drm_plane *plane,
227 struct drm_modeset_acquire_ctx *ctx)
228 {
229 return -EINVAL;
230 }
231
232 /**
233 * drm_primary_helper_destroy() - Helper for primary plane destruction
234 * @plane: plane to destroy
235 *
236 * Provides a default plane destroy handler for primary planes. This handler
237 * is called during CRTC destruction. We disable the primary plane, remove
238 * it from the DRM plane list, and deallocate the plane structure.
239 */
drm_primary_helper_destroy(struct drm_plane * plane)240 void drm_primary_helper_destroy(struct drm_plane *plane)
241 {
242 drm_plane_cleanup(plane);
243 kfree(plane);
244 }
245 EXPORT_SYMBOL(drm_primary_helper_destroy);
246
247 const struct drm_plane_funcs drm_primary_helper_funcs = {
248 .update_plane = drm_primary_helper_update,
249 .disable_plane = drm_primary_helper_disable,
250 .destroy = drm_primary_helper_destroy,
251 };
252 EXPORT_SYMBOL(drm_primary_helper_funcs);
253