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