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_plane_helper.h>
29#include <drm/drm_rect.h>
30#include <drm/drm_atomic.h>
31#include <drm/drm_crtc_helper.h>
32#include <drm/drm_atomic_helper.h>
33
34#define SUBPIXEL_MASK 0xffff
35
36/**
37 * DOC: overview
38 *
39 * This helper library has two parts. The first part has support to implement
40 * primary plane support on top of the normal CRTC configuration interface.
41 * Since the legacy ->set_config interface ties the primary plane together with
42 * the CRTC state this does not allow userspace to disable the primary plane
43 * itself.  To avoid too much duplicated code use
44 * drm_plane_helper_check_update() which can be used to enforce the same
45 * restrictions as primary planes had thus. The default primary plane only
46 * expose XRBG8888 and ARGB8888 as valid pixel formats for the attached
47 * framebuffer.
48 *
49 * Drivers are highly recommended to implement proper support for primary
50 * planes, and newly merged drivers must not rely upon these transitional
51 * helpers.
52 *
53 * The second part also implements transitional helpers which allow drivers to
54 * gradually switch to the atomic helper infrastructure for plane updates. Once
55 * that switch is complete drivers shouldn't use these any longer, instead using
56 * the proper legacy implementations for update and disable plane hooks provided
57 * by the atomic helpers.
58 *
59 * Again drivers are strongly urged to switch to the new interfaces.
60 */
61
62/*
63 * This is the minimal list of formats that seem to be safe for modeset use
64 * with all current DRM drivers.  Most hardware can actually support more
65 * formats than this and drivers may specify a more accurate list when
66 * creating the primary plane.  However drivers that still call
67 * drm_plane_init() will use this minimal format list as the default.
68 */
69static const uint32_t safe_modeset_formats[] = {
70	DRM_FORMAT_XRGB8888,
71	DRM_FORMAT_ARGB8888,
72};
73
74/*
75 * Returns the connectors currently associated with a CRTC.  This function
76 * should be called twice:  once with a NULL connector list to retrieve
77 * the list size, and once with the properly allocated list to be filled in.
78 */
79static int get_connectors_for_crtc(struct drm_crtc *crtc,
80				   struct drm_connector **connector_list,
81				   int num_connectors)
82{
83	struct drm_device *dev = crtc->dev;
84	struct drm_connector *connector;
85	int count = 0;
86
87	/*
88	 * Note: Once we change the plane hooks to more fine-grained locking we
89	 * need to grab the connection_mutex here to be able to make these
90	 * checks.
91	 */
92	WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
93
94	list_for_each_entry(connector, &dev->mode_config.connector_list, head)
95		if (connector->encoder && connector->encoder->crtc == crtc) {
96			if (connector_list != NULL && count < num_connectors)
97				*(connector_list++) = connector;
98
99			count++;
100		}
101
102	return count;
103}
104
105/**
106 * drm_plane_helper_check_update() - Check plane update for validity
107 * @plane: plane object to update
108 * @crtc: owning CRTC of owning plane
109 * @fb: framebuffer to flip onto plane
110 * @src: source coordinates in 16.16 fixed point
111 * @dest: integer destination coordinates
112 * @clip: integer clipping coordinates
113 * @min_scale: minimum @src:@dest scaling factor in 16.16 fixed point
114 * @max_scale: maximum @src:@dest scaling factor in 16.16 fixed point
115 * @can_position: is it legal to position the plane such that it
116 *                doesn't cover the entire crtc?  This will generally
117 *                only be false for primary planes.
118 * @can_update_disabled: can the plane be updated while the crtc
119 *                       is disabled?
120 * @visible: output parameter indicating whether plane is still visible after
121 *           clipping
122 *
123 * Checks that a desired plane update is valid.  Drivers that provide
124 * their own plane handling rather than helper-provided implementations may
125 * still wish to call this function to avoid duplication of error checking
126 * code.
127 *
128 * RETURNS:
129 * Zero if update appears valid, error code on failure
130 */
131int drm_plane_helper_check_update(struct drm_plane *plane,
132				    struct drm_crtc *crtc,
133				    struct drm_framebuffer *fb,
134				    struct drm_rect *src,
135				    struct drm_rect *dest,
136				    const struct drm_rect *clip,
137				    int min_scale,
138				    int max_scale,
139				    bool can_position,
140				    bool can_update_disabled,
141				    bool *visible)
142{
143	int hscale, vscale;
144
145	if (!fb) {
146		*visible = false;
147		return 0;
148	}
149
150	/* crtc should only be NULL when disabling (i.e., !fb) */
151	if (WARN_ON(!crtc)) {
152		*visible = false;
153		return 0;
154	}
155
156	if (!crtc->enabled && !can_update_disabled) {
157		DRM_DEBUG_KMS("Cannot update plane of a disabled CRTC.\n");
158		return -EINVAL;
159	}
160
161	/* Check scaling */
162	hscale = drm_rect_calc_hscale(src, dest, min_scale, max_scale);
163	vscale = drm_rect_calc_vscale(src, dest, min_scale, max_scale);
164	if (hscale < 0 || vscale < 0) {
165		DRM_DEBUG_KMS("Invalid scaling of plane\n");
166		return -ERANGE;
167	}
168
169	*visible = drm_rect_clip_scaled(src, dest, clip, hscale, vscale);
170	if (!*visible)
171		/*
172		 * Plane isn't visible; some drivers can handle this
173		 * so we just return success here.  Drivers that can't
174		 * (including those that use the primary plane helper's
175		 * update function) will return an error from their
176		 * update_plane handler.
177		 */
178		return 0;
179
180	if (!can_position && !drm_rect_equals(dest, clip)) {
181		DRM_DEBUG_KMS("Plane must cover entire CRTC\n");
182		return -EINVAL;
183	}
184
185	return 0;
186}
187EXPORT_SYMBOL(drm_plane_helper_check_update);
188
189/**
190 * drm_primary_helper_update() - Helper for primary plane update
191 * @plane: plane object to update
192 * @crtc: owning CRTC of owning plane
193 * @fb: framebuffer to flip onto plane
194 * @crtc_x: x offset of primary plane on crtc
195 * @crtc_y: y offset of primary plane on crtc
196 * @crtc_w: width of primary plane rectangle on crtc
197 * @crtc_h: height of primary plane rectangle on crtc
198 * @src_x: x offset of @fb for panning
199 * @src_y: y offset of @fb for panning
200 * @src_w: width of source rectangle in @fb
201 * @src_h: height of source rectangle in @fb
202 *
203 * Provides a default plane update handler for primary planes.  This is handler
204 * is called in response to a userspace SetPlane operation on the plane with a
205 * non-NULL framebuffer.  We call the driver's modeset handler to update the
206 * framebuffer.
207 *
208 * SetPlane() on a primary plane of a disabled CRTC is not supported, and will
209 * return an error.
210 *
211 * Note that we make some assumptions about hardware limitations that may not be
212 * true for all hardware --
213 *   1) Primary plane cannot be repositioned.
214 *   2) Primary plane cannot be scaled.
215 *   3) Primary plane must cover the entire CRTC.
216 *   4) Subpixel positioning is not supported.
217 * Drivers for hardware that don't have these restrictions can provide their
218 * own implementation rather than using this helper.
219 *
220 * RETURNS:
221 * Zero on success, error code on failure
222 */
223int drm_primary_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
224			      struct drm_framebuffer *fb,
225			      int crtc_x, int crtc_y,
226			      unsigned int crtc_w, unsigned int crtc_h,
227			      uint32_t src_x, uint32_t src_y,
228			      uint32_t src_w, uint32_t src_h)
229{
230	struct drm_mode_set set = {
231		.crtc = crtc,
232		.fb = fb,
233		.mode = &crtc->mode,
234		.x = src_x >> 16,
235		.y = src_y >> 16,
236	};
237	struct drm_rect src = {
238		.x1 = src_x,
239		.y1 = src_y,
240		.x2 = src_x + src_w,
241		.y2 = src_y + src_h,
242	};
243	struct drm_rect dest = {
244		.x1 = crtc_x,
245		.y1 = crtc_y,
246		.x2 = crtc_x + crtc_w,
247		.y2 = crtc_y + crtc_h,
248	};
249	const struct drm_rect clip = {
250		.x2 = crtc->mode.hdisplay,
251		.y2 = crtc->mode.vdisplay,
252	};
253	struct drm_connector **connector_list;
254	int num_connectors, ret;
255	bool visible;
256
257	ret = drm_plane_helper_check_update(plane, crtc, fb,
258					    &src, &dest, &clip,
259					    DRM_PLANE_HELPER_NO_SCALING,
260					    DRM_PLANE_HELPER_NO_SCALING,
261					    false, false, &visible);
262	if (ret)
263		return ret;
264
265	if (!visible)
266		/*
267		 * Primary plane isn't visible.  Note that unless a driver
268		 * provides their own disable function, this will just
269		 * wind up returning -EINVAL to userspace.
270		 */
271		return plane->funcs->disable_plane(plane);
272
273	/* Find current connectors for CRTC */
274	num_connectors = get_connectors_for_crtc(crtc, NULL, 0);
275	BUG_ON(num_connectors == 0);
276	connector_list = kzalloc(num_connectors * sizeof(*connector_list),
277				 GFP_KERNEL);
278	if (!connector_list)
279		return -ENOMEM;
280	get_connectors_for_crtc(crtc, connector_list, num_connectors);
281
282	set.connectors = connector_list;
283	set.num_connectors = num_connectors;
284
285	/*
286	 * We call set_config() directly here rather than using
287	 * drm_mode_set_config_internal.  We're reprogramming the same
288	 * connectors that were already in use, so we shouldn't need the extra
289	 * cross-CRTC fb refcounting to accomodate stealing connectors.
290	 * drm_mode_setplane() already handles the basic refcounting for the
291	 * framebuffers involved in this operation.
292	 */
293	ret = crtc->funcs->set_config(&set);
294
295	kfree(connector_list);
296	return ret;
297}
298EXPORT_SYMBOL(drm_primary_helper_update);
299
300/**
301 * drm_primary_helper_disable() - Helper for primary plane disable
302 * @plane: plane to disable
303 *
304 * Provides a default plane disable handler for primary planes.  This is handler
305 * is called in response to a userspace SetPlane operation on the plane with a
306 * NULL framebuffer parameter.  It unconditionally fails the disable call with
307 * -EINVAL the only way to disable the primary plane without driver support is
308 * to disable the entier CRTC. Which does not match the plane ->disable hook.
309 *
310 * Note that some hardware may be able to disable the primary plane without
311 * disabling the whole CRTC.  Drivers for such hardware should provide their
312 * own disable handler that disables just the primary plane (and they'll likely
313 * need to provide their own update handler as well to properly re-enable a
314 * disabled primary plane).
315 *
316 * RETURNS:
317 * Unconditionally returns -EINVAL.
318 */
319int drm_primary_helper_disable(struct drm_plane *plane)
320{
321	return -EINVAL;
322}
323EXPORT_SYMBOL(drm_primary_helper_disable);
324
325/**
326 * drm_primary_helper_destroy() - Helper for primary plane destruction
327 * @plane: plane to destroy
328 *
329 * Provides a default plane destroy handler for primary planes.  This handler
330 * is called during CRTC destruction.  We disable the primary plane, remove
331 * it from the DRM plane list, and deallocate the plane structure.
332 */
333void drm_primary_helper_destroy(struct drm_plane *plane)
334{
335	drm_plane_cleanup(plane);
336	kfree(plane);
337}
338EXPORT_SYMBOL(drm_primary_helper_destroy);
339
340const struct drm_plane_funcs drm_primary_helper_funcs = {
341	.update_plane = drm_primary_helper_update,
342	.disable_plane = drm_primary_helper_disable,
343	.destroy = drm_primary_helper_destroy,
344};
345EXPORT_SYMBOL(drm_primary_helper_funcs);
346
347static struct drm_plane *create_primary_plane(struct drm_device *dev)
348{
349	struct drm_plane *primary;
350	int ret;
351
352	primary = kzalloc(sizeof(*primary), GFP_KERNEL);
353	if (primary == NULL) {
354		DRM_DEBUG_KMS("Failed to allocate primary plane\n");
355		return NULL;
356	}
357
358	/*
359	 * Remove the format_default field from drm_plane when dropping
360	 * this helper.
361	 */
362	primary->format_default = true;
363
364	/* possible_crtc's will be filled in later by crtc_init */
365	ret = drm_universal_plane_init(dev, primary, 0,
366				       &drm_primary_helper_funcs,
367				       safe_modeset_formats,
368				       ARRAY_SIZE(safe_modeset_formats),
369				       DRM_PLANE_TYPE_PRIMARY);
370	if (ret) {
371		kfree(primary);
372		primary = NULL;
373	}
374
375	return primary;
376}
377
378/**
379 * drm_crtc_init - Legacy CRTC initialization function
380 * @dev: DRM device
381 * @crtc: CRTC object to init
382 * @funcs: callbacks for the new CRTC
383 *
384 * Initialize a CRTC object with a default helper-provided primary plane and no
385 * cursor plane.
386 *
387 * Returns:
388 * Zero on success, error code on failure.
389 */
390int drm_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
391		  const struct drm_crtc_funcs *funcs)
392{
393	struct drm_plane *primary;
394
395	primary = create_primary_plane(dev);
396	return drm_crtc_init_with_planes(dev, crtc, primary, NULL, funcs);
397}
398EXPORT_SYMBOL(drm_crtc_init);
399
400int drm_plane_helper_commit(struct drm_plane *plane,
401			    struct drm_plane_state *plane_state,
402			    struct drm_framebuffer *old_fb)
403{
404	const struct drm_plane_helper_funcs *plane_funcs;
405	struct drm_crtc *crtc[2];
406	const struct drm_crtc_helper_funcs *crtc_funcs[2];
407	int i, ret = 0;
408
409	plane_funcs = plane->helper_private;
410
411	/* Since this is a transitional helper we can't assume that plane->state
412	 * is always valid. Hence we need to use plane->crtc instead of
413	 * plane->state->crtc as the old crtc. */
414	crtc[0] = plane->crtc;
415	crtc[1] = crtc[0] != plane_state->crtc ? plane_state->crtc : NULL;
416
417	for (i = 0; i < 2; i++)
418		crtc_funcs[i] = crtc[i] ? crtc[i]->helper_private : NULL;
419
420	if (plane_funcs->atomic_check) {
421		ret = plane_funcs->atomic_check(plane, plane_state);
422		if (ret)
423			goto out;
424	}
425
426	if (plane_funcs->prepare_fb && plane_state->fb &&
427	    plane_state->fb != old_fb) {
428		ret = plane_funcs->prepare_fb(plane, plane_state->fb,
429					      plane_state);
430		if (ret)
431			goto out;
432	}
433
434	/* Point of no return, commit sw state. */
435	swap(plane->state, plane_state);
436
437	for (i = 0; i < 2; i++) {
438		if (crtc_funcs[i] && crtc_funcs[i]->atomic_begin)
439			crtc_funcs[i]->atomic_begin(crtc[i]);
440	}
441
442	/*
443	 * Drivers may optionally implement the ->atomic_disable callback, so
444	 * special-case that here.
445	 */
446	if (drm_atomic_plane_disabling(plane, plane_state) &&
447	    plane_funcs->atomic_disable)
448		plane_funcs->atomic_disable(plane, plane_state);
449	else
450		plane_funcs->atomic_update(plane, plane_state);
451
452	for (i = 0; i < 2; i++) {
453		if (crtc_funcs[i] && crtc_funcs[i]->atomic_flush)
454			crtc_funcs[i]->atomic_flush(crtc[i]);
455	}
456
457	/*
458	 * If we only moved the plane and didn't change fb's, there's no need to
459	 * wait for vblank.
460	 */
461	if (plane->state->fb == old_fb)
462		goto out;
463
464	for (i = 0; i < 2; i++) {
465		if (!crtc[i])
466			continue;
467
468		if (crtc[i]->cursor == plane)
469			continue;
470
471		/* There's no other way to figure out whether the crtc is running. */
472		ret = drm_crtc_vblank_get(crtc[i]);
473		if (ret == 0) {
474			drm_crtc_wait_one_vblank(crtc[i]);
475			drm_crtc_vblank_put(crtc[i]);
476		}
477
478		ret = 0;
479	}
480
481	if (plane_funcs->cleanup_fb && old_fb)
482		plane_funcs->cleanup_fb(plane, old_fb, plane_state);
483out:
484	if (plane_state) {
485		if (plane->funcs->atomic_destroy_state)
486			plane->funcs->atomic_destroy_state(plane, plane_state);
487		else
488			drm_atomic_helper_plane_destroy_state(plane, plane_state);
489	}
490
491	return ret;
492}
493
494/**
495 * drm_plane_helper_update() - Transitional helper for plane update
496 * @plane: plane object to update
497 * @crtc: owning CRTC of owning plane
498 * @fb: framebuffer to flip onto plane
499 * @crtc_x: x offset of primary plane on crtc
500 * @crtc_y: y offset of primary plane on crtc
501 * @crtc_w: width of primary plane rectangle on crtc
502 * @crtc_h: height of primary plane rectangle on crtc
503 * @src_x: x offset of @fb for panning
504 * @src_y: y offset of @fb for panning
505 * @src_w: width of source rectangle in @fb
506 * @src_h: height of source rectangle in @fb
507 *
508 * Provides a default plane update handler using the atomic plane update
509 * functions. It is fully left to the driver to check plane constraints and
510 * handle corner-cases like a fully occluded or otherwise invisible plane.
511 *
512 * This is useful for piecewise transitioning of a driver to the atomic helpers.
513 *
514 * RETURNS:
515 * Zero on success, error code on failure
516 */
517int drm_plane_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
518			    struct drm_framebuffer *fb,
519			    int crtc_x, int crtc_y,
520			    unsigned int crtc_w, unsigned int crtc_h,
521			    uint32_t src_x, uint32_t src_y,
522			    uint32_t src_w, uint32_t src_h)
523{
524	struct drm_plane_state *plane_state;
525
526	if (plane->funcs->atomic_duplicate_state)
527		plane_state = plane->funcs->atomic_duplicate_state(plane);
528	else if (plane->state)
529		plane_state = drm_atomic_helper_plane_duplicate_state(plane);
530	else
531		plane_state = kzalloc(sizeof(*plane_state), GFP_KERNEL);
532	if (!plane_state)
533		return -ENOMEM;
534	plane_state->plane = plane;
535
536	plane_state->crtc = crtc;
537	drm_atomic_set_fb_for_plane(plane_state, fb);
538	plane_state->crtc_x = crtc_x;
539	plane_state->crtc_y = crtc_y;
540	plane_state->crtc_h = crtc_h;
541	plane_state->crtc_w = crtc_w;
542	plane_state->src_x = src_x;
543	plane_state->src_y = src_y;
544	plane_state->src_h = src_h;
545	plane_state->src_w = src_w;
546
547	return drm_plane_helper_commit(plane, plane_state, plane->fb);
548}
549EXPORT_SYMBOL(drm_plane_helper_update);
550
551/**
552 * drm_plane_helper_disable() - Transitional helper for plane disable
553 * @plane: plane to disable
554 *
555 * Provides a default plane disable handler using the atomic plane update
556 * functions. It is fully left to the driver to check plane constraints and
557 * handle corner-cases like a fully occluded or otherwise invisible plane.
558 *
559 * This is useful for piecewise transitioning of a driver to the atomic helpers.
560 *
561 * RETURNS:
562 * Zero on success, error code on failure
563 */
564int drm_plane_helper_disable(struct drm_plane *plane)
565{
566	struct drm_plane_state *plane_state;
567
568	/* crtc helpers love to call disable functions for already disabled hw
569	 * functions. So cope with that. */
570	if (!plane->crtc)
571		return 0;
572
573	if (plane->funcs->atomic_duplicate_state)
574		plane_state = plane->funcs->atomic_duplicate_state(plane);
575	else if (plane->state)
576		plane_state = drm_atomic_helper_plane_duplicate_state(plane);
577	else
578		plane_state = kzalloc(sizeof(*plane_state), GFP_KERNEL);
579	if (!plane_state)
580		return -ENOMEM;
581	plane_state->plane = plane;
582
583	plane_state->crtc = NULL;
584	drm_atomic_set_fb_for_plane(plane_state, NULL);
585
586	return drm_plane_helper_commit(plane, plane_state, plane->fb);
587}
588EXPORT_SYMBOL(drm_plane_helper_disable);
589