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_device.h>
32 #include <drm/drm_drv.h>
33 #include <drm/drm_encoder.h>
34 #include <drm/drm_plane_helper.h>
35 #include <drm/drm_print.h>
36 #include <drm/drm_rect.h>
37 
38 #define SUBPIXEL_MASK 0xffff
39 
40 /**
41  * DOC: overview
42  *
43  * This helper library has two parts. The first part has support to implement
44  * primary plane support on top of the normal CRTC configuration interface.
45  * Since the legacy &drm_mode_config_funcs.set_config interface ties the primary
46  * plane together with the CRTC state this does not allow userspace to disable
47  * the primary plane itself. The default primary plane only expose XRBG8888 and
48  * ARGB8888 as valid pixel formats for the attached framebuffer.
49  *
50  * Drivers are highly recommended to implement proper support for primary
51  * planes, and newly merged drivers must not rely upon these transitional
52  * helpers.
53  *
54  * The second part also implements transitional helpers which allow drivers to
55  * gradually switch to the atomic helper infrastructure for plane updates. Once
56  * that switch is complete drivers shouldn't use these any longer, instead using
57  * the proper legacy implementations for update and disable plane hooks provided
58  * by the atomic helpers.
59  *
60  * Again drivers are strongly urged to switch to the new interfaces.
61  *
62  * The plane helpers share the function table structures with other helpers,
63  * specifically also the atomic helpers. See &struct drm_plane_helper_funcs for
64  * the details.
65  */
66 
67 /*
68  * Returns the connectors currently associated with a CRTC.  This function
69  * should be called twice:  once with a NULL connector list to retrieve
70  * the list size, and once with the properly allocated list to be filled in.
71  */
get_connectors_for_crtc(struct drm_crtc * crtc,struct drm_connector ** connector_list,int num_connectors)72 static int get_connectors_for_crtc(struct drm_crtc *crtc,
73 				   struct drm_connector **connector_list,
74 				   int num_connectors)
75 {
76 	struct drm_device *dev = crtc->dev;
77 	struct drm_connector *connector;
78 	struct drm_connector_list_iter conn_iter;
79 	int count = 0;
80 
81 	/*
82 	 * Note: Once we change the plane hooks to more fine-grained locking we
83 	 * need to grab the connection_mutex here to be able to make these
84 	 * checks.
85 	 */
86 	WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
87 
88 	drm_connector_list_iter_begin(dev, &conn_iter);
89 	drm_for_each_connector_iter(connector, &conn_iter) {
90 		if (connector->encoder && connector->encoder->crtc == crtc) {
91 			if (connector_list != NULL && count < num_connectors)
92 				*(connector_list++) = connector;
93 
94 			count++;
95 		}
96 	}
97 	drm_connector_list_iter_end(&conn_iter);
98 
99 	return count;
100 }
101 
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)102 static int drm_plane_helper_check_update(struct drm_plane *plane,
103 					 struct drm_crtc *crtc,
104 					 struct drm_framebuffer *fb,
105 					 struct drm_rect *src,
106 					 struct drm_rect *dst,
107 					 unsigned int rotation,
108 					 int min_scale,
109 					 int max_scale,
110 					 bool can_position,
111 					 bool can_update_disabled,
112 					 bool *visible)
113 {
114 	struct drm_plane_state plane_state = {
115 		.plane = plane,
116 		.crtc = crtc,
117 		.fb = fb,
118 		.src_x = src->x1,
119 		.src_y = src->y1,
120 		.src_w = drm_rect_width(src),
121 		.src_h = drm_rect_height(src),
122 		.crtc_x = dst->x1,
123 		.crtc_y = dst->y1,
124 		.crtc_w = drm_rect_width(dst),
125 		.crtc_h = drm_rect_height(dst),
126 		.rotation = rotation,
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 /**
150  * drm_plane_helper_update_primary - Helper for updating primary planes
151  * @plane: plane to update
152  * @crtc: the plane's new CRTC
153  * @fb: the plane's new framebuffer
154  * @crtc_x: x coordinate within CRTC
155  * @crtc_y: y coordinate within CRTC
156  * @crtc_w: width coordinate within CRTC
157  * @crtc_h: height coordinate within CRTC
158  * @src_x: x coordinate within source
159  * @src_y: y coordinate within source
160  * @src_w: width coordinate within source
161  * @src_h: height coordinate within source
162  * @ctx: modeset locking context
163  *
164  * This helper validates the given parameters and updates the primary plane.
165  *
166  * This function is only useful for non-atomic modesetting. Don't use
167  * it in new drivers.
168  *
169  * Returns:
170  * Zero on success, or an errno code otherwise.
171  */
drm_plane_helper_update_primary(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)172 int drm_plane_helper_update_primary(struct drm_plane *plane, struct drm_crtc *crtc,
173 				    struct drm_framebuffer *fb,
174 				    int crtc_x, int crtc_y,
175 				    unsigned int crtc_w, unsigned int crtc_h,
176 				    uint32_t src_x, uint32_t src_y,
177 				    uint32_t src_w, uint32_t src_h,
178 				    struct drm_modeset_acquire_ctx *ctx)
179 {
180 	struct drm_mode_set set = {
181 		.crtc = crtc,
182 		.fb = fb,
183 		.mode = &crtc->mode,
184 		.x = src_x >> 16,
185 		.y = src_y >> 16,
186 	};
187 	struct drm_rect src = {
188 		.x1 = src_x,
189 		.y1 = src_y,
190 		.x2 = src_x + src_w,
191 		.y2 = src_y + src_h,
192 	};
193 	struct drm_rect dest = {
194 		.x1 = crtc_x,
195 		.y1 = crtc_y,
196 		.x2 = crtc_x + crtc_w,
197 		.y2 = crtc_y + crtc_h,
198 	};
199 	struct drm_device *dev = plane->dev;
200 	struct drm_connector **connector_list;
201 	int num_connectors, ret;
202 	bool visible;
203 
204 	if (drm_WARN_ON_ONCE(dev, drm_drv_uses_atomic_modeset(dev)))
205 		return -EINVAL;
206 
207 	ret = drm_plane_helper_check_update(plane, crtc, fb,
208 					    &src, &dest,
209 					    DRM_MODE_ROTATE_0,
210 					    DRM_PLANE_NO_SCALING,
211 					    DRM_PLANE_NO_SCALING,
212 					    false, false, &visible);
213 	if (ret)
214 		return ret;
215 
216 	if (!visible)
217 		/*
218 		 * Primary plane isn't visible.  Note that unless a driver
219 		 * provides their own disable function, this will just
220 		 * wind up returning -EINVAL to userspace.
221 		 */
222 		return plane->funcs->disable_plane(plane, ctx);
223 
224 	/* Find current connectors for CRTC */
225 	num_connectors = get_connectors_for_crtc(crtc, NULL, 0);
226 	BUG_ON(num_connectors == 0);
227 	connector_list = kcalloc(num_connectors, sizeof(*connector_list),
228 				 GFP_KERNEL);
229 	if (!connector_list)
230 		return -ENOMEM;
231 	get_connectors_for_crtc(crtc, connector_list, num_connectors);
232 
233 	set.connectors = connector_list;
234 	set.num_connectors = num_connectors;
235 
236 	/*
237 	 * We call set_config() directly here rather than using
238 	 * drm_mode_set_config_internal.  We're reprogramming the same
239 	 * connectors that were already in use, so we shouldn't need the extra
240 	 * cross-CRTC fb refcounting to accommodate stealing connectors.
241 	 * drm_mode_setplane() already handles the basic refcounting for the
242 	 * framebuffers involved in this operation.
243 	 */
244 	ret = crtc->funcs->set_config(&set, ctx);
245 
246 	kfree(connector_list);
247 	return ret;
248 }
249 EXPORT_SYMBOL(drm_plane_helper_update_primary);
250 
251 /**
252  * drm_plane_helper_disable_primary - Helper for disabling primary planes
253  * @plane: plane to disable
254  * @ctx: modeset locking context
255  *
256  * This helper returns an error when trying to disable the primary
257  * plane.
258  *
259  * This function is only useful for non-atomic modesetting. Don't use
260  * it in new drivers.
261  *
262  * Returns:
263  * An errno code.
264  */
drm_plane_helper_disable_primary(struct drm_plane * plane,struct drm_modeset_acquire_ctx * ctx)265 int drm_plane_helper_disable_primary(struct drm_plane *plane,
266 				     struct drm_modeset_acquire_ctx *ctx)
267 {
268 	struct drm_device *dev = plane->dev;
269 
270 	drm_WARN_ON_ONCE(dev, drm_drv_uses_atomic_modeset(dev));
271 
272 	return -EINVAL;
273 }
274 EXPORT_SYMBOL(drm_plane_helper_disable_primary);
275 
276 /**
277  * drm_plane_helper_destroy() - Helper for primary plane destruction
278  * @plane: plane to destroy
279  *
280  * Provides a default plane destroy handler for primary planes.  This handler
281  * is called during CRTC destruction.  We disable the primary plane, remove
282  * it from the DRM plane list, and deallocate the plane structure.
283  */
drm_plane_helper_destroy(struct drm_plane * plane)284 void drm_plane_helper_destroy(struct drm_plane *plane)
285 {
286 	drm_plane_cleanup(plane);
287 	kfree(plane);
288 }
289 EXPORT_SYMBOL(drm_plane_helper_destroy);
290 
291 /**
292  * drm_plane_helper_atomic_check() - Helper to check plane atomic-state
293  * @plane: plane to check
294  * @state: atomic state object
295  *
296  * Provides a default plane-state check handler for planes whose atomic-state
297  * scale and positioning are not expected to change since the plane is always
298  * a fullscreen scanout buffer.
299  *
300  * This is often the case for the primary plane of simple framebuffers. See
301  * also drm_crtc_helper_atomic_check() for the respective CRTC-state check
302  * helper function.
303  *
304  * RETURNS:
305  * Zero on success, or an errno code otherwise.
306  */
drm_plane_helper_atomic_check(struct drm_plane * plane,struct drm_atomic_state * state)307 int drm_plane_helper_atomic_check(struct drm_plane *plane, struct drm_atomic_state *state)
308 {
309 	struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state, plane);
310 	struct drm_crtc *new_crtc = new_plane_state->crtc;
311 	struct drm_crtc_state *new_crtc_state = NULL;
312 
313 	if (new_crtc)
314 		new_crtc_state = drm_atomic_get_new_crtc_state(state, new_crtc);
315 
316 	return drm_atomic_helper_check_plane_state(new_plane_state, new_crtc_state,
317 						   DRM_PLANE_NO_SCALING,
318 						   DRM_PLANE_NO_SCALING,
319 						   false, false);
320 }
321 EXPORT_SYMBOL(drm_plane_helper_atomic_check);
322