xref: /dragonfly/sys/dev/drm/drm_plane_helper.c (revision 3cc0afc6)
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 #include <drm/drmP.h>
28 #include <drm/drm_rect.h>
29 #include <drm/drm_plane_helper.h>
30 
31 #define SUBPIXEL_MASK 0xffff
32 
33 /*
34  * This is the minimal list of formats that seem to be safe for modeset use
35  * with all current DRM drivers.  Most hardware can actually support more
36  * formats than this and drivers may specify a more accurate list when
37  * creating the primary plane.  However drivers that still call
38  * drm_plane_init() will use this minimal format list as the default.
39  */
40 static const uint32_t safe_modeset_formats[] = {
41 	DRM_FORMAT_XRGB8888,
42 	DRM_FORMAT_ARGB8888,
43 };
44 
45 /*
46  * Returns the connectors currently associated with a CRTC.  This function
47  * should be called twice:  once with a NULL connector list to retrieve
48  * the list size, and once with the properly allocated list to be filled in.
49  */
50 static int get_connectors_for_crtc(struct drm_crtc *crtc,
51 				   struct drm_connector **connector_list,
52 				   int num_connectors)
53 {
54 	struct drm_device *dev = crtc->dev;
55 	struct drm_connector *connector;
56 	int count = 0;
57 
58 	/*
59 	 * Note: Once we change the plane hooks to more fine-grained locking we
60 	 * need to grab the connection_mutex here to be able to make these
61 	 * checks.
62 	 */
63 	WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
64 
65 	list_for_each_entry(connector, &dev->mode_config.connector_list, head)
66 		if (connector->encoder && connector->encoder->crtc == crtc) {
67 			if (connector_list != NULL && count < num_connectors)
68 				*(connector_list++) = connector;
69 
70 			count++;
71 		}
72 
73 	return count;
74 }
75 
76 /**
77  * drm_primary_helper_update() - Helper for primary plane update
78  * @plane: plane object to update
79  * @crtc: owning CRTC of owning plane
80  * @fb: framebuffer to flip onto plane
81  * @crtc_x: x offset of primary plane on crtc
82  * @crtc_y: y offset of primary plane on crtc
83  * @crtc_w: width of primary plane rectangle on crtc
84  * @crtc_h: height of primary plane rectangle on crtc
85  * @src_x: x offset of @fb for panning
86  * @src_y: y offset of @fb for panning
87  * @src_w: width of source rectangle in @fb
88  * @src_h: height of source rectangle in @fb
89  *
90  * Provides a default plane update handler for primary planes.  This is handler
91  * is called in response to a userspace SetPlane operation on the plane with a
92  * non-NULL framebuffer.  We call the driver's modeset handler to update the
93  * framebuffer.
94  *
95  * SetPlane() on a primary plane of a disabled CRTC is not supported, and will
96  * return an error.
97  *
98  * Note that we make some assumptions about hardware limitations that may not be
99  * true for all hardware --
100  *   1) Primary plane cannot be repositioned.
101  *   2) Primary plane cannot be scaled.
102  *   3) Primary plane must cover the entire CRTC.
103  *   4) Subpixel positioning is not supported.
104  * Drivers for hardware that don't have these restrictions can provide their
105  * own implementation rather than using this helper.
106  *
107  * RETURNS:
108  * Zero on success, error code on failure
109  */
110 int drm_primary_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
111 			      struct drm_framebuffer *fb,
112 			      int crtc_x, int crtc_y,
113 			      unsigned int crtc_w, unsigned int crtc_h,
114 			      uint32_t src_x, uint32_t src_y,
115 			      uint32_t src_w, uint32_t src_h)
116 {
117 	struct drm_mode_set set = {
118 		.crtc = crtc,
119 		.fb = fb,
120 		.mode = &crtc->mode,
121 		.x = src_x >> 16,
122 		.y = src_y >> 16,
123 	};
124 	struct drm_rect dest = {
125 		.x1 = crtc_x,
126 		.y1 = crtc_y,
127 		.x2 = crtc_x + crtc_w,
128 		.y2 = crtc_y + crtc_h,
129 	};
130 	struct drm_rect clip = {
131 		.x2 = crtc->mode.hdisplay,
132 		.y2 = crtc->mode.vdisplay,
133 	};
134 	struct drm_connector **connector_list;
135 	int num_connectors, ret;
136 
137 	if (!crtc->enabled) {
138 		DRM_DEBUG_KMS("Cannot update primary plane of a disabled CRTC.\n");
139 		return -EINVAL;
140 	}
141 
142 	/* Disallow subpixel positioning */
143 	if ((src_x | src_y | src_w | src_h) & SUBPIXEL_MASK) {
144 		DRM_DEBUG_KMS("Primary plane does not support subpixel positioning\n");
145 		return -EINVAL;
146 	}
147 
148 	/* Primary planes are locked to their owning CRTC */
149 	if (plane->possible_crtcs != drm_crtc_mask(crtc)) {
150 		DRM_DEBUG_KMS("Cannot change primary plane CRTC\n");
151 		return -EINVAL;
152 	}
153 
154 	/* Disallow scaling */
155 	src_w >>= 16;
156 	src_h >>= 16;
157 	if (crtc_w != src_w || crtc_h != src_h) {
158 		DRM_DEBUG_KMS("Can't scale primary plane\n");
159 		return -EINVAL;
160 	}
161 
162 	/* Make sure primary plane covers entire CRTC */
163 	drm_rect_intersect(&dest, &clip);
164 	if (dest.x1 != 0 || dest.y1 != 0 ||
165 	    dest.x2 != crtc->mode.hdisplay || dest.y2 != crtc->mode.vdisplay) {
166 		DRM_DEBUG_KMS("Primary plane must cover entire CRTC\n");
167 		return -EINVAL;
168 	}
169 
170 	/* Framebuffer must be big enough to cover entire plane */
171 	ret = drm_crtc_check_viewport(crtc, crtc_x, crtc_y, &crtc->mode, fb);
172 	if (ret)
173 		return ret;
174 
175 	/* Find current connectors for CRTC */
176 	num_connectors = get_connectors_for_crtc(crtc, NULL, 0);
177 	BUG_ON(num_connectors == 0);
178 	connector_list = kzalloc(num_connectors * sizeof(*connector_list),
179 				 GFP_KERNEL);
180 	if (!connector_list)
181 		return -ENOMEM;
182 	get_connectors_for_crtc(crtc, connector_list, num_connectors);
183 
184 	set.connectors = connector_list;
185 	set.num_connectors = num_connectors;
186 
187 	/*
188 	 * We call set_config() directly here rather than using
189 	 * drm_mode_set_config_internal.  We're reprogramming the same
190 	 * connectors that were already in use, so we shouldn't need the extra
191 	 * cross-CRTC fb refcounting to accomodate stealing connectors.
192 	 * drm_mode_setplane() already handles the basic refcounting for the
193 	 * framebuffers involved in this operation.
194 	 */
195 	ret = crtc->funcs->set_config(&set);
196 
197 	kfree(connector_list);
198 	return ret;
199 }
200 EXPORT_SYMBOL(drm_primary_helper_update);
201 
202 /**
203  * drm_primary_helper_disable() - Helper for primary plane disable
204  * @plane: plane to disable
205  *
206  * Provides a default plane disable handler for primary planes.  This is handler
207  * is called in response to a userspace SetPlane operation on the plane with a
208  * NULL framebuffer parameter.  We call the driver's modeset handler with a NULL
209  * framebuffer to disable the CRTC if no other planes are currently enabled.
210  * If other planes are still enabled on the same CRTC, we return -EBUSY.
211  *
212  * Note that some hardware may be able to disable the primary plane without
213  * disabling the whole CRTC.  Drivers for such hardware should provide their
214  * own disable handler that disables just the primary plane (and they'll likely
215  * need to provide their own update handler as well to properly re-enable a
216  * disabled primary plane).
217  *
218  * RETURNS:
219  * Zero on success, error code on failure
220  */
221 int drm_primary_helper_disable(struct drm_plane *plane)
222 {
223 	struct drm_plane *p;
224 	struct drm_mode_set set = {
225 		.crtc = plane->crtc,
226 		.fb = NULL,
227 	};
228 
229 	if (plane->crtc == NULL || plane->fb == NULL)
230 		/* Already disabled */
231 		return 0;
232 
233 	list_for_each_entry(p, &plane->dev->mode_config.plane_list, head)
234 		if (p != plane && p->fb) {
235 			DRM_DEBUG_KMS("Cannot disable primary plane while other planes are still active on CRTC.\n");
236 			return -EBUSY;
237 		}
238 
239 	/*
240 	 * N.B.  We call set_config() directly here rather than
241 	 * drm_mode_set_config_internal() since drm_mode_setplane() already
242 	 * handles the basic refcounting and we don't need the special
243 	 * cross-CRTC refcounting (no chance of stealing connectors from
244 	 * other CRTC's with this update).
245 	 */
246 	return plane->crtc->funcs->set_config(&set);
247 }
248 EXPORT_SYMBOL(drm_primary_helper_disable);
249 
250 /**
251  * drm_primary_helper_destroy() - Helper for primary plane destruction
252  * @plane: plane to destroy
253  *
254  * Provides a default plane destroy handler for primary planes.  This handler
255  * is called during CRTC destruction.  We disable the primary plane, remove
256  * it from the DRM plane list, and deallocate the plane structure.
257  */
258 void drm_primary_helper_destroy(struct drm_plane *plane)
259 {
260 	drm_plane_cleanup(plane);
261 	kfree(plane);
262 }
263 EXPORT_SYMBOL(drm_primary_helper_destroy);
264 
265 const struct drm_plane_funcs drm_primary_helper_funcs = {
266 	.update_plane = drm_primary_helper_update,
267 	.disable_plane = drm_primary_helper_disable,
268 	.destroy = drm_primary_helper_destroy,
269 };
270 EXPORT_SYMBOL(drm_primary_helper_funcs);
271 
272 /**
273  * drm_primary_helper_create_plane() - Create a generic primary plane
274  * @dev: drm device
275  * @formats: pixel formats supported, or NULL for a default safe list
276  * @num_formats: size of @formats; ignored if @formats is NULL
277  *
278  * Allocates and initializes a primary plane that can be used with the primary
279  * plane helpers.  Drivers that wish to use driver-specific plane structures or
280  * provide custom handler functions may perform their own allocation and
281  * initialization rather than calling this function.
282  */
283 struct drm_plane *drm_primary_helper_create_plane(struct drm_device *dev,
284 						  const uint32_t *formats,
285 						  int num_formats)
286 {
287 	struct drm_plane *primary;
288 	int ret;
289 
290 	primary = kzalloc(sizeof(*primary), GFP_KERNEL);
291 	if (primary == NULL) {
292 		DRM_DEBUG_KMS("Failed to allocate primary plane\n");
293 		return NULL;
294 	}
295 
296 	if (formats == NULL) {
297 		formats = safe_modeset_formats;
298 		num_formats = ARRAY_SIZE(safe_modeset_formats);
299 	}
300 
301 	/* possible_crtc's will be filled in later by crtc_init */
302 	ret = drm_plane_init(dev, primary, 0, &drm_primary_helper_funcs,
303 			     formats, num_formats,
304 			     DRM_PLANE_TYPE_PRIMARY);
305 	if (ret) {
306 		kfree(primary);
307 		primary = NULL;
308 	}
309 
310 	return primary;
311 }
312 EXPORT_SYMBOL(drm_primary_helper_create_plane);
313 
314 /**
315  * drm_crtc_init - Legacy CRTC initialization function
316  * @dev: DRM device
317  * @crtc: CRTC object to init
318  * @funcs: callbacks for the new CRTC
319  *
320  * Initialize a CRTC object with a default helper-provided primary plane and no
321  * cursor plane.
322  *
323  * Returns:
324  * Zero on success, error code on failure.
325  */
326 int drm_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
327 		  const struct drm_crtc_funcs *funcs)
328 {
329 	struct drm_plane *primary;
330 
331 	primary = drm_primary_helper_create_plane(dev, NULL, 0);
332 	return drm_crtc_init_with_planes(dev, crtc, primary, NULL, funcs);
333 }
334 EXPORT_SYMBOL(drm_crtc_init);
335