xref: /linux/drivers/gpu/drm/drm_plane_helper.c (revision a266ef69b890f099069cf51bb40572611c435a54)
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_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 has two parts. The first part has support to implement
45  * primary plane support on 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 second part also implements transitional helpers which allow drivers to
56  * gradually switch to the atomic helper infrastructure for plane updates. Once
57  * that switch is complete drivers shouldn't use these any longer, instead using
58  * the proper legacy implementations for update and disable plane hooks provided
59  * by the atomic helpers.
60  *
61  * Again drivers are strongly urged to switch to the new interfaces.
62  *
63  * The plane helpers share the function table structures with other helpers,
64  * specifically also the atomic helpers. See &struct drm_plane_helper_funcs for
65  * the details.
66  */
67 
68 /*
69  * Returns the connectors currently associated with a CRTC.  This function
70  * should be called twice:  once with a NULL connector list to retrieve
71  * the list size, and once with the properly allocated list to be filled in.
72  */
73 static int get_connectors_for_crtc(struct drm_crtc *crtc,
74 				   struct drm_connector **connector_list,
75 				   int num_connectors)
76 {
77 	struct drm_device *dev = crtc->dev;
78 	struct drm_connector *connector;
79 	struct drm_connector_list_iter conn_iter;
80 	int count = 0;
81 
82 	/*
83 	 * Note: Once we change the plane hooks to more fine-grained locking we
84 	 * need to grab the connection_mutex here to be able to make these
85 	 * checks.
86 	 */
87 	WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
88 
89 	drm_connector_list_iter_begin(dev, &conn_iter);
90 	drm_for_each_connector_iter(connector, &conn_iter) {
91 		if (connector->encoder && connector->encoder->crtc == crtc) {
92 			if (connector_list != NULL && count < num_connectors)
93 				*(connector_list++) = connector;
94 
95 			count++;
96 		}
97 	}
98 	drm_connector_list_iter_end(&conn_iter);
99 
100 	return count;
101 }
102 
103 static int drm_plane_helper_check_update(struct drm_plane *plane,
104 					 struct drm_crtc *crtc,
105 					 struct drm_framebuffer *fb,
106 					 struct drm_rect *src,
107 					 struct drm_rect *dst,
108 					 unsigned int rotation,
109 					 int min_scale,
110 					 int max_scale,
111 					 bool can_position,
112 					 bool can_update_disabled,
113 					 bool *visible)
114 {
115 	struct drm_plane_state plane_state = {
116 		.plane = plane,
117 		.crtc = crtc,
118 		.fb = fb,
119 		.src_x = src->x1,
120 		.src_y = src->y1,
121 		.src_w = drm_rect_width(src),
122 		.src_h = drm_rect_height(src),
123 		.crtc_x = dst->x1,
124 		.crtc_y = dst->y1,
125 		.crtc_w = drm_rect_width(dst),
126 		.crtc_h = drm_rect_height(dst),
127 		.rotation = rotation,
128 	};
129 	struct drm_crtc_state crtc_state = {
130 		.crtc = crtc,
131 		.enable = crtc->enabled,
132 		.mode = crtc->mode,
133 	};
134 	int ret;
135 
136 	ret = drm_atomic_helper_check_plane_state(&plane_state, &crtc_state,
137 						  min_scale, max_scale,
138 						  can_position,
139 						  can_update_disabled);
140 	if (ret)
141 		return ret;
142 
143 	*src = plane_state.src;
144 	*dst = plane_state.dst;
145 	*visible = plane_state.visible;
146 
147 	return 0;
148 }
149 
150 /**
151  * drm_plane_helper_update_primary - Helper for updating primary planes
152  * @plane: plane to update
153  * @crtc: the plane's new CRTC
154  * @fb: the plane's new framebuffer
155  * @crtc_x: x coordinate within CRTC
156  * @crtc_y: y coordinate within CRTC
157  * @crtc_w: width coordinate within CRTC
158  * @crtc_h: height coordinate within CRTC
159  * @src_x: x coordinate within source
160  * @src_y: y coordinate within source
161  * @src_w: width coordinate within source
162  * @src_h: height coordinate within source
163  * @ctx: modeset locking context
164  *
165  * This helper validates the given parameters and updates the primary plane.
166  *
167  * This function is only useful for non-atomic modesetting. Don't use
168  * it in new drivers.
169  *
170  * Returns:
171  * Zero on success, or an errno code otherwise.
172  */
173 int drm_plane_helper_update_primary(struct drm_plane *plane, struct drm_crtc *crtc,
174 				    struct drm_framebuffer *fb,
175 				    int crtc_x, int crtc_y,
176 				    unsigned int crtc_w, unsigned int crtc_h,
177 				    uint32_t src_x, uint32_t src_y,
178 				    uint32_t src_w, uint32_t src_h,
179 				    struct drm_modeset_acquire_ctx *ctx)
180 {
181 	struct drm_mode_set set = {
182 		.crtc = crtc,
183 		.fb = fb,
184 		.mode = &crtc->mode,
185 		.x = src_x >> 16,
186 		.y = src_y >> 16,
187 	};
188 	struct drm_rect src = {
189 		.x1 = src_x,
190 		.y1 = src_y,
191 		.x2 = src_x + src_w,
192 		.y2 = src_y + src_h,
193 	};
194 	struct drm_rect dest = {
195 		.x1 = crtc_x,
196 		.y1 = crtc_y,
197 		.x2 = crtc_x + crtc_w,
198 		.y2 = crtc_y + crtc_h,
199 	};
200 	struct drm_device *dev = plane->dev;
201 	struct drm_connector **connector_list;
202 	int num_connectors, ret;
203 	bool visible;
204 
205 	if (drm_WARN_ON_ONCE(dev, drm_drv_uses_atomic_modeset(dev)))
206 		return -EINVAL;
207 
208 	ret = drm_plane_helper_check_update(plane, crtc, fb,
209 					    &src, &dest,
210 					    DRM_MODE_ROTATE_0,
211 					    DRM_PLANE_NO_SCALING,
212 					    DRM_PLANE_NO_SCALING,
213 					    false, false, &visible);
214 	if (ret)
215 		return ret;
216 
217 	if (!visible)
218 		/*
219 		 * Primary plane isn't visible.  Note that unless a driver
220 		 * provides their own disable function, this will just
221 		 * wind up returning -EINVAL to userspace.
222 		 */
223 		return plane->funcs->disable_plane(plane, ctx);
224 
225 	/* Find current connectors for CRTC */
226 	num_connectors = get_connectors_for_crtc(crtc, NULL, 0);
227 	BUG_ON(num_connectors == 0);
228 	connector_list = kcalloc(num_connectors, sizeof(*connector_list),
229 				 GFP_KERNEL);
230 	if (!connector_list)
231 		return -ENOMEM;
232 	get_connectors_for_crtc(crtc, connector_list, num_connectors);
233 
234 	set.connectors = connector_list;
235 	set.num_connectors = num_connectors;
236 
237 	/*
238 	 * We call set_config() directly here rather than using
239 	 * drm_mode_set_config_internal.  We're reprogramming the same
240 	 * connectors that were already in use, so we shouldn't need the extra
241 	 * cross-CRTC fb refcounting to accommodate stealing connectors.
242 	 * drm_mode_setplane() already handles the basic refcounting for the
243 	 * framebuffers involved in this operation.
244 	 */
245 	ret = crtc->funcs->set_config(&set, ctx);
246 
247 	kfree(connector_list);
248 	return ret;
249 }
250 EXPORT_SYMBOL(drm_plane_helper_update_primary);
251 
252 /**
253  * drm_plane_helper_disable_primary - Helper for disabling primary planes
254  * @plane: plane to disable
255  * @ctx: modeset locking context
256  *
257  * This helper returns an error when trying to disable the primary
258  * plane.
259  *
260  * This function is only useful for non-atomic modesetting. Don't use
261  * it in new drivers.
262  *
263  * Returns:
264  * An errno code.
265  */
266 int drm_plane_helper_disable_primary(struct drm_plane *plane,
267 				     struct drm_modeset_acquire_ctx *ctx)
268 {
269 	struct drm_device *dev = plane->dev;
270 
271 	drm_WARN_ON_ONCE(dev, drm_drv_uses_atomic_modeset(dev));
272 
273 	return -EINVAL;
274 }
275 EXPORT_SYMBOL(drm_plane_helper_disable_primary);
276 
277 /**
278  * drm_plane_helper_destroy() - Helper for primary plane destruction
279  * @plane: plane to destroy
280  *
281  * Provides a default plane destroy handler for primary planes.  This handler
282  * is called during CRTC destruction.  We disable the primary plane, remove
283  * it from the DRM plane list, and deallocate the plane structure.
284  */
285 void drm_plane_helper_destroy(struct drm_plane *plane)
286 {
287 	drm_plane_cleanup(plane);
288 	kfree(plane);
289 }
290 EXPORT_SYMBOL(drm_plane_helper_destroy);
291 
292 /**
293  * drm_plane_helper_atomic_check() - Helper to check plane atomic-state
294  * @plane: plane to check
295  * @state: atomic state object
296  *
297  * Provides a default plane-state check handler for planes whose atomic-state
298  * scale and positioning are not expected to change since the plane is always
299  * a fullscreen scanout buffer.
300  *
301  * This is often the case for the primary plane of simple framebuffers. See
302  * also drm_crtc_helper_atomic_check() for the respective CRTC-state check
303  * helper function.
304  *
305  * RETURNS:
306  * Zero on success, or an errno code otherwise.
307  */
308 int drm_plane_helper_atomic_check(struct drm_plane *plane, struct drm_atomic_state *state)
309 {
310 	struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state, plane);
311 	struct drm_crtc *new_crtc = new_plane_state->crtc;
312 	struct drm_crtc_state *new_crtc_state = NULL;
313 
314 	if (new_crtc)
315 		new_crtc_state = drm_atomic_get_new_crtc_state(state, new_crtc);
316 
317 	return drm_atomic_helper_check_plane_state(new_plane_state, new_crtc_state,
318 						   DRM_PLANE_NO_SCALING,
319 						   DRM_PLANE_NO_SCALING,
320 						   false, false);
321 }
322 EXPORT_SYMBOL(drm_plane_helper_atomic_check);
323