xref: /linux/drivers/gpu/drm/drm_plane_helper.c (revision 260f6f4fda93c8485c8037865c941b42b9cba5d2)
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  */
65 static 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, &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(&conn_iter);
91 
92 	return count;
93 }
94 
95 static 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(src),
114 		.src_h = drm_rect_height(src),
115 		.crtc_x = dst->x1,
116 		.crtc_y = dst->y1,
117 		.crtc_w = drm_rect_width(dst),
118 		.crtc_h = drm_rect_height(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, &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  */
165 int 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, &dest,
202 					    DRM_MODE_ROTATE_0,
203 					    DRM_PLANE_NO_SCALING,
204 					    DRM_PLANE_NO_SCALING,
205 					    false, false, &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, 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(connector_list);
240 	return ret;
241 }
242 EXPORT_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  */
258 int 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 }
267 EXPORT_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  */
277 void drm_plane_helper_destroy(struct drm_plane *plane)
278 {
279 	drm_plane_cleanup(plane);
280 	kfree(plane);
281 }
282 EXPORT_SYMBOL(drm_plane_helper_destroy);
283