2 * Copyright (C) 2014 Intel Corporation
4 * DRM universal plane helper functions
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26 #include <linux/list.h>
28 #include <drm/drm_plane_helper.h>
29 #include <drm/drm_rect.h>
30 #include <drm/drm_atomic.h>
31 #include <drm/drm_atomic_uapi.h>
32 #include <drm/drm_crtc_helper.h>
33 #include <drm/drm_encoder.h>
34 #include <drm/drm_atomic_helper.h>
36 #define SUBPIXEL_MASK 0xffff
41 * This helper library has two parts. The first part has support to implement
42 * primary plane support on top of the normal CRTC configuration interface.
43 * Since the legacy &drm_mode_config_funcs.set_config interface ties the primary
44 * plane together with the CRTC state this does not allow userspace to disable
45 * the primary plane itself. To avoid too much duplicated code use
46 * drm_plane_helper_check_update() which can be used to enforce the same
47 * restrictions as primary planes had thus. The default primary plane only
48 * expose XRBG8888 and ARGB8888 as valid pixel formats for the attached
51 * Drivers are highly recommended to implement proper support for primary
52 * planes, and newly merged drivers must not rely upon these transitional
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.
61 * Again drivers are strongly urged to switch to the new interfaces.
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
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.
73 static int get_connectors_for_crtc(struct drm_crtc *crtc,
74 struct drm_connector **connector_list,
77 struct drm_device *dev = crtc->dev;
78 struct drm_connector *connector;
79 struct drm_connector_list_iter conn_iter;
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
87 WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
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;
98 drm_connector_list_iter_end(&conn_iter);
104 * drm_plane_helper_check_update() - Check plane update for validity
105 * @plane: plane object to update
106 * @crtc: owning CRTC of owning plane
107 * @fb: framebuffer to flip onto plane
108 * @src: source coordinates in 16.16 fixed point
109 * @dst: integer destination coordinates
110 * @rotation: plane rotation
111 * @min_scale: minimum @src:@dest scaling factor in 16.16 fixed point
112 * @max_scale: maximum @src:@dest scaling factor in 16.16 fixed point
113 * @can_position: is it legal to position the plane such that it
114 * doesn't cover the entire crtc? This will generally
115 * only be false for primary planes.
116 * @can_update_disabled: can the plane be updated while the crtc
118 * @visible: output parameter indicating whether plane is still visible after
121 * Checks that a desired plane update is valid. Drivers that provide
122 * their own plane handling rather than helper-provided implementations may
123 * still wish to call this function to avoid duplication of error checking
127 * Zero if update appears valid, error code on failure
129 int drm_plane_helper_check_update(struct drm_plane *plane,
130 struct drm_crtc *crtc,
131 struct drm_framebuffer *fb,
132 struct drm_rect *src,
133 struct drm_rect *dst,
134 unsigned int rotation,
138 bool can_update_disabled,
141 struct drm_plane_state plane_state = {
147 .src_w = drm_rect_width(src),
148 .src_h = drm_rect_height(src),
151 .crtc_w = drm_rect_width(dst),
152 .crtc_h = drm_rect_height(dst),
153 .rotation = rotation,
156 struct drm_crtc_state crtc_state = {
158 .enable = crtc->enabled,
163 ret = drm_atomic_helper_check_plane_state(&plane_state, &crtc_state,
164 min_scale, max_scale,
166 can_update_disabled);
170 *src = plane_state.src;
171 *dst = plane_state.dst;
172 *visible = plane_state.visible;
176 EXPORT_SYMBOL(drm_plane_helper_check_update);
179 * drm_primary_helper_update() - Helper for primary plane update
180 * @plane: plane object to update
181 * @crtc: owning CRTC of owning plane
182 * @fb: framebuffer to flip onto plane
183 * @crtc_x: x offset of primary plane on crtc
184 * @crtc_y: y offset of primary plane on crtc
185 * @crtc_w: width of primary plane rectangle on crtc
186 * @crtc_h: height of primary plane rectangle on crtc
187 * @src_x: x offset of @fb for panning
188 * @src_y: y offset of @fb for panning
189 * @src_w: width of source rectangle in @fb
190 * @src_h: height of source rectangle in @fb
191 * @ctx: lock acquire context, not used here
193 * Provides a default plane update handler for primary planes. This is handler
194 * is called in response to a userspace SetPlane operation on the plane with a
195 * non-NULL framebuffer. We call the driver's modeset handler to update the
198 * SetPlane() on a primary plane of a disabled CRTC is not supported, and will
201 * Note that we make some assumptions about hardware limitations that may not be
202 * true for all hardware --
204 * 1. Primary plane cannot be repositioned.
205 * 2. Primary plane cannot be scaled.
206 * 3. Primary plane must cover the entire CRTC.
207 * 4. Subpixel positioning is not supported.
209 * Drivers for hardware that don't have these restrictions can provide their
210 * own implementation rather than using this helper.
213 * Zero on success, error code on failure
215 int drm_primary_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
216 struct drm_framebuffer *fb,
217 int crtc_x, int crtc_y,
218 unsigned int crtc_w, unsigned int crtc_h,
219 uint32_t src_x, uint32_t src_y,
220 uint32_t src_w, uint32_t src_h,
221 struct drm_modeset_acquire_ctx *ctx)
223 struct drm_mode_set set = {
230 struct drm_rect src = {
236 struct drm_rect dest = {
239 .x2 = crtc_x + crtc_w,
240 .y2 = crtc_y + crtc_h,
242 struct drm_connector **connector_list;
243 int num_connectors, ret;
246 ret = drm_plane_helper_check_update(plane, crtc, fb,
249 DRM_PLANE_HELPER_NO_SCALING,
250 DRM_PLANE_HELPER_NO_SCALING,
251 false, false, &visible);
257 * Primary plane isn't visible. Note that unless a driver
258 * provides their own disable function, this will just
259 * wind up returning -EINVAL to userspace.
261 return plane->funcs->disable_plane(plane, ctx);
263 /* Find current connectors for CRTC */
264 num_connectors = get_connectors_for_crtc(crtc, NULL, 0);
265 BUG_ON(num_connectors == 0);
266 connector_list = kcalloc(num_connectors, sizeof(*connector_list),
270 get_connectors_for_crtc(crtc, connector_list, num_connectors);
272 set.connectors = connector_list;
273 set.num_connectors = num_connectors;
276 * We call set_config() directly here rather than using
277 * drm_mode_set_config_internal. We're reprogramming the same
278 * connectors that were already in use, so we shouldn't need the extra
279 * cross-CRTC fb refcounting to accomodate stealing connectors.
280 * drm_mode_setplane() already handles the basic refcounting for the
281 * framebuffers involved in this operation.
283 ret = crtc->funcs->set_config(&set, ctx);
285 kfree(connector_list);
288 EXPORT_SYMBOL(drm_primary_helper_update);
291 * drm_primary_helper_disable() - Helper for primary plane disable
292 * @plane: plane to disable
293 * @ctx: lock acquire context, not used here
295 * Provides a default plane disable handler for primary planes. This is handler
296 * is called in response to a userspace SetPlane operation on the plane with a
297 * NULL framebuffer parameter. It unconditionally fails the disable call with
298 * -EINVAL the only way to disable the primary plane without driver support is
299 * to disable the entire CRTC. Which does not match the plane
300 * &drm_plane_funcs.disable_plane hook.
302 * Note that some hardware may be able to disable the primary plane without
303 * disabling the whole CRTC. Drivers for such hardware should provide their
304 * own disable handler that disables just the primary plane (and they'll likely
305 * need to provide their own update handler as well to properly re-enable a
306 * disabled primary plane).
309 * Unconditionally returns -EINVAL.
311 int drm_primary_helper_disable(struct drm_plane *plane,
312 struct drm_modeset_acquire_ctx *ctx)
316 EXPORT_SYMBOL(drm_primary_helper_disable);
319 * drm_primary_helper_destroy() - Helper for primary plane destruction
320 * @plane: plane to destroy
322 * Provides a default plane destroy handler for primary planes. This handler
323 * is called during CRTC destruction. We disable the primary plane, remove
324 * it from the DRM plane list, and deallocate the plane structure.
326 void drm_primary_helper_destroy(struct drm_plane *plane)
328 drm_plane_cleanup(plane);
331 EXPORT_SYMBOL(drm_primary_helper_destroy);
333 const struct drm_plane_funcs drm_primary_helper_funcs = {
334 .update_plane = drm_primary_helper_update,
335 .disable_plane = drm_primary_helper_disable,
336 .destroy = drm_primary_helper_destroy,
338 EXPORT_SYMBOL(drm_primary_helper_funcs);
340 int drm_plane_helper_commit(struct drm_plane *plane,
341 struct drm_plane_state *plane_state,
342 struct drm_framebuffer *old_fb)
344 const struct drm_plane_helper_funcs *plane_funcs;
345 struct drm_crtc *crtc[2];
346 const struct drm_crtc_helper_funcs *crtc_funcs[2];
349 plane_funcs = plane->helper_private;
351 /* Since this is a transitional helper we can't assume that plane->state
352 * is always valid. Hence we need to use plane->crtc instead of
353 * plane->state->crtc as the old crtc. */
354 crtc[0] = plane->crtc;
355 crtc[1] = crtc[0] != plane_state->crtc ? plane_state->crtc : NULL;
357 for (i = 0; i < 2; i++)
358 crtc_funcs[i] = crtc[i] ? crtc[i]->helper_private : NULL;
360 if (plane_funcs->atomic_check) {
361 ret = plane_funcs->atomic_check(plane, plane_state);
366 if (plane_funcs->prepare_fb && plane_state->fb != old_fb) {
367 ret = plane_funcs->prepare_fb(plane,
373 /* Point of no return, commit sw state. */
374 swap(plane->state, plane_state);
376 for (i = 0; i < 2; i++) {
377 if (crtc_funcs[i] && crtc_funcs[i]->atomic_begin)
378 crtc_funcs[i]->atomic_begin(crtc[i], crtc[i]->state);
382 * Drivers may optionally implement the ->atomic_disable callback, so
383 * special-case that here.
385 if (drm_atomic_plane_disabling(plane_state, plane->state) &&
386 plane_funcs->atomic_disable)
387 plane_funcs->atomic_disable(plane, plane_state);
389 plane_funcs->atomic_update(plane, plane_state);
391 for (i = 0; i < 2; i++) {
392 if (crtc_funcs[i] && crtc_funcs[i]->atomic_flush)
393 crtc_funcs[i]->atomic_flush(crtc[i], crtc[i]->state);
397 * If we only moved the plane and didn't change fb's, there's no need to
400 if (plane->state->fb == old_fb)
403 for (i = 0; i < 2; i++) {
407 if (crtc[i]->cursor == plane)
410 /* There's no other way to figure out whether the crtc is running. */
411 ret = drm_crtc_vblank_get(crtc[i]);
413 drm_crtc_wait_one_vblank(crtc[i]);
414 drm_crtc_vblank_put(crtc[i]);
420 if (plane_funcs->cleanup_fb)
421 plane_funcs->cleanup_fb(plane, plane_state);
423 if (plane->funcs->atomic_destroy_state)
424 plane->funcs->atomic_destroy_state(plane, plane_state);
426 drm_atomic_helper_plane_destroy_state(plane, plane_state);
432 * drm_plane_helper_update() - Transitional helper for plane update
433 * @plane: plane object to update
434 * @crtc: owning CRTC of owning plane
435 * @fb: framebuffer to flip onto plane
436 * @crtc_x: x offset of primary plane on crtc
437 * @crtc_y: y offset of primary plane on crtc
438 * @crtc_w: width of primary plane rectangle on crtc
439 * @crtc_h: height of primary plane rectangle on crtc
440 * @src_x: x offset of @fb for panning
441 * @src_y: y offset of @fb for panning
442 * @src_w: width of source rectangle in @fb
443 * @src_h: height of source rectangle in @fb
444 * @ctx: lock acquire context, not used here
446 * Provides a default plane update handler using the atomic plane update
447 * functions. It is fully left to the driver to check plane constraints and
448 * handle corner-cases like a fully occluded or otherwise invisible plane.
450 * This is useful for piecewise transitioning of a driver to the atomic helpers.
453 * Zero on success, error code on failure
455 int drm_plane_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
456 struct drm_framebuffer *fb,
457 int crtc_x, int crtc_y,
458 unsigned int crtc_w, unsigned int crtc_h,
459 uint32_t src_x, uint32_t src_y,
460 uint32_t src_w, uint32_t src_h,
461 struct drm_modeset_acquire_ctx *ctx)
463 struct drm_plane_state *plane_state;
465 if (plane->funcs->atomic_duplicate_state)
466 plane_state = plane->funcs->atomic_duplicate_state(plane);
469 drm_atomic_helper_plane_reset(plane);
471 plane_state = drm_atomic_helper_plane_duplicate_state(plane);
475 plane_state->plane = plane;
477 plane_state->crtc = crtc;
478 drm_atomic_set_fb_for_plane(plane_state, fb);
479 plane_state->crtc_x = crtc_x;
480 plane_state->crtc_y = crtc_y;
481 plane_state->crtc_h = crtc_h;
482 plane_state->crtc_w = crtc_w;
483 plane_state->src_x = src_x;
484 plane_state->src_y = src_y;
485 plane_state->src_h = src_h;
486 plane_state->src_w = src_w;
488 return drm_plane_helper_commit(plane, plane_state, plane->fb);
490 EXPORT_SYMBOL(drm_plane_helper_update);
493 * drm_plane_helper_disable() - Transitional helper for plane disable
494 * @plane: plane to disable
495 * @ctx: lock acquire context, not used here
497 * Provides a default plane disable handler using the atomic plane update
498 * functions. It is fully left to the driver to check plane constraints and
499 * handle corner-cases like a fully occluded or otherwise invisible plane.
501 * This is useful for piecewise transitioning of a driver to the atomic helpers.
504 * Zero on success, error code on failure
506 int drm_plane_helper_disable(struct drm_plane *plane,
507 struct drm_modeset_acquire_ctx *ctx)
509 struct drm_plane_state *plane_state;
510 struct drm_framebuffer *old_fb;
512 /* crtc helpers love to call disable functions for already disabled hw
513 * functions. So cope with that. */
517 if (plane->funcs->atomic_duplicate_state)
518 plane_state = plane->funcs->atomic_duplicate_state(plane);
521 drm_atomic_helper_plane_reset(plane);
523 plane_state = drm_atomic_helper_plane_duplicate_state(plane);
527 plane_state->plane = plane;
529 plane_state->crtc = NULL;
530 old_fb = plane_state->fb;
531 drm_atomic_set_fb_for_plane(plane_state, NULL);
533 return drm_plane_helper_commit(plane, plane_state, old_fb);
535 EXPORT_SYMBOL(drm_plane_helper_disable);