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/export.h>
27#include <linux/list.h>
28
29#include <drm/drm_atomic.h>
30#include <drm/drm_atomic_helper.h>
31#include <drm/drm_atomic_uapi.h>
32#include <drm/drm_device.h>
33#include <drm/drm_drv.h>
34#include <drm/drm_encoder.h>
35#include <drm/drm_plane_helper.h>
36#include <drm/drm_print.h>
37#include <drm/drm_rect.h>
38
39#define SUBPIXEL_MASK 0xffff
40
41/**
42 * DOC: overview
43 *
44 * This helper library contains helpers to implement primary plane support on
45 * top of the normal CRTC configuration interface.
46 * Since the legacy &drm_mode_config_funcs.set_config interface ties the primary
47 * plane together with the CRTC state this does not allow userspace to disable
48 * the primary plane itself. The default primary plane only expose XRBG8888 and
49 * ARGB8888 as valid pixel formats for the attached framebuffer.
50 *
51 * Drivers are highly recommended to implement proper support for primary
52 * planes, and newly merged drivers must not rely upon these transitional
53 * helpers.
54 *
55 * The plane helpers share the function table structures with other helpers,
56 * specifically also the atomic helpers. See &struct drm_plane_helper_funcs for
57 * the details.
58 */
59
60/*
61 * Returns the connectors currently associated with a CRTC. This function
62 * should be called twice: once with a NULL connector list to retrieve
63 * the list size, and once with the properly allocated list to be filled in.
64 */
65static int get_connectors_for_crtc(struct drm_crtc *crtc,
66 struct drm_connector **connector_list,
67 int num_connectors)
68{
69 struct drm_device *dev = crtc->dev;
70 struct drm_connector *connector;
71 struct drm_connector_list_iter conn_iter;
72 int count = 0;
73
74 /*
75 * Note: Once we change the plane hooks to more fine-grained locking we
76 * need to grab the connection_mutex here to be able to make these
77 * checks.
78 */
79 WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
80
81 drm_connector_list_iter_begin(dev, iter: &conn_iter);
82 drm_for_each_connector_iter(connector, &conn_iter) {
83 if (connector->encoder && connector->encoder->crtc == crtc) {
84 if (connector_list != NULL && count < num_connectors)
85 *(connector_list++) = connector;
86
87 count++;
88 }
89 }
90 drm_connector_list_iter_end(iter: &conn_iter);
91
92 return count;
93}
94
95static int drm_plane_helper_check_update(struct drm_plane *plane,
96 struct drm_crtc *crtc,
97 struct drm_framebuffer *fb,
98 struct drm_rect *src,
99 struct drm_rect *dst,
100 unsigned int rotation,
101 int min_scale,
102 int max_scale,
103 bool can_position,
104 bool can_update_disabled,
105 bool *visible)
106{
107 struct drm_plane_state plane_state = {
108 .plane = plane,
109 .crtc = crtc,
110 .fb = fb,
111 .src_x = src->x1,
112 .src_y = src->y1,
113 .src_w = drm_rect_width(r: src),
114 .src_h = drm_rect_height(r: src),
115 .crtc_x = dst->x1,
116 .crtc_y = dst->y1,
117 .crtc_w = drm_rect_width(r: dst),
118 .crtc_h = drm_rect_height(r: dst),
119 .rotation = rotation,
120 };
121 struct drm_crtc_state crtc_state = {
122 .crtc = crtc,
123 .enable = crtc->enabled,
124 .mode = crtc->mode,
125 };
126 int ret;
127
128 ret = drm_atomic_helper_check_plane_state(plane_state: &plane_state, crtc_state: &crtc_state,
129 min_scale, max_scale,
130 can_position,
131 can_update_disabled);
132 if (ret)
133 return ret;
134
135 *src = plane_state.src;
136 *dst = plane_state.dst;
137 *visible = plane_state.visible;
138
139 return 0;
140}
141
142/**
143 * drm_plane_helper_update_primary - Helper for updating primary planes
144 * @plane: plane to update
145 * @crtc: the plane's new CRTC
146 * @fb: the plane's new framebuffer
147 * @crtc_x: x coordinate within CRTC
148 * @crtc_y: y coordinate within CRTC
149 * @crtc_w: width coordinate within CRTC
150 * @crtc_h: height coordinate within CRTC
151 * @src_x: x coordinate within source
152 * @src_y: y coordinate within source
153 * @src_w: width coordinate within source
154 * @src_h: height coordinate within source
155 * @ctx: modeset locking context
156 *
157 * This helper validates the given parameters and updates the primary plane.
158 *
159 * This function is only useful for non-atomic modesetting. Don't use
160 * it in new drivers.
161 *
162 * Returns:
163 * Zero on success, or an errno code otherwise.
164 */
165int drm_plane_helper_update_primary(struct drm_plane *plane, struct drm_crtc *crtc,
166 struct drm_framebuffer *fb,
167 int crtc_x, int crtc_y,
168 unsigned int crtc_w, unsigned int crtc_h,
169 uint32_t src_x, uint32_t src_y,
170 uint32_t src_w, uint32_t src_h,
171 struct drm_modeset_acquire_ctx *ctx)
172{
173 struct drm_mode_set set = {
174 .crtc = crtc,
175 .fb = fb,
176 .mode = &crtc->mode,
177 .x = src_x >> 16,
178 .y = src_y >> 16,
179 };
180 struct drm_rect src = {
181 .x1 = src_x,
182 .y1 = src_y,
183 .x2 = src_x + src_w,
184 .y2 = src_y + src_h,
185 };
186 struct drm_rect dest = {
187 .x1 = crtc_x,
188 .y1 = crtc_y,
189 .x2 = crtc_x + crtc_w,
190 .y2 = crtc_y + crtc_h,
191 };
192 struct drm_device *dev = plane->dev;
193 struct drm_connector **connector_list;
194 int num_connectors, ret;
195 bool visible;
196
197 if (drm_WARN_ON_ONCE(dev, drm_drv_uses_atomic_modeset(dev)))
198 return -EINVAL;
199
200 ret = drm_plane_helper_check_update(plane, crtc, fb,
201 src: &src, dst: &dest,
202 DRM_MODE_ROTATE_0,
203 DRM_PLANE_NO_SCALING,
204 DRM_PLANE_NO_SCALING,
205 can_position: false, can_update_disabled: false, visible: &visible);
206 if (ret)
207 return ret;
208
209 if (!visible)
210 /*
211 * Primary plane isn't visible. Note that unless a driver
212 * provides their own disable function, this will just
213 * wind up returning -EINVAL to userspace.
214 */
215 return plane->funcs->disable_plane(plane, ctx);
216
217 /* Find current connectors for CRTC */
218 num_connectors = get_connectors_for_crtc(crtc, NULL, num_connectors: 0);
219 BUG_ON(num_connectors == 0);
220 connector_list = kcalloc(num_connectors, sizeof(*connector_list),
221 GFP_KERNEL);
222 if (!connector_list)
223 return -ENOMEM;
224 get_connectors_for_crtc(crtc, connector_list, num_connectors);
225
226 set.connectors = connector_list;
227 set.num_connectors = num_connectors;
228
229 /*
230 * We call set_config() directly here rather than using
231 * drm_mode_set_config_internal. We're reprogramming the same
232 * connectors that were already in use, so we shouldn't need the extra
233 * cross-CRTC fb refcounting to accommodate stealing connectors.
234 * drm_mode_setplane() already handles the basic refcounting for the
235 * framebuffers involved in this operation.
236 */
237 ret = crtc->funcs->set_config(&set, ctx);
238
239 kfree(objp: connector_list);
240 return ret;
241}
242EXPORT_SYMBOL(drm_plane_helper_update_primary);
243
244/**
245 * drm_plane_helper_disable_primary - Helper for disabling primary planes
246 * @plane: plane to disable
247 * @ctx: modeset locking context
248 *
249 * This helper returns an error when trying to disable the primary
250 * plane.
251 *
252 * This function is only useful for non-atomic modesetting. Don't use
253 * it in new drivers.
254 *
255 * Returns:
256 * An errno code.
257 */
258int drm_plane_helper_disable_primary(struct drm_plane *plane,
259 struct drm_modeset_acquire_ctx *ctx)
260{
261 struct drm_device *dev = plane->dev;
262
263 drm_WARN_ON_ONCE(dev, drm_drv_uses_atomic_modeset(dev));
264
265 return -EINVAL;
266}
267EXPORT_SYMBOL(drm_plane_helper_disable_primary);
268
269/**
270 * drm_plane_helper_destroy() - Helper for primary plane destruction
271 * @plane: plane to destroy
272 *
273 * Provides a default plane destroy handler for primary planes. This handler
274 * is called during CRTC destruction. We disable the primary plane, remove
275 * it from the DRM plane list, and deallocate the plane structure.
276 */
277void drm_plane_helper_destroy(struct drm_plane *plane)
278{
279 drm_plane_cleanup(plane);
280 kfree(objp: plane);
281}
282EXPORT_SYMBOL(drm_plane_helper_destroy);
283

source code of linux/drivers/gpu/drm/drm_plane_helper.c