1/*
  2 * Copyright (C) 2016 Samsung Electronics Co.Ltd
  3 * Authors:
  4 *	Marek Szyprowski <m.szyprowski@samsung.com>
  5 *
  6 * DRM core plane blending related functions
  7 *
  8 * Permission to use, copy, modify, distribute, and sell this software and its
  9 * documentation for any purpose is hereby granted without fee, provided that
 10 * the above copyright notice appear in all copies and that both that copyright
 11 * notice and this permission notice appear in supporting documentation, and
 12 * that the name of the copyright holders not be used in advertising or
 13 * publicity pertaining to distribution of the software without specific,
 14 * written prior permission.  The copyright holders make no representations
 15 * about the suitability of this software for any purpose.  It is provided "as
 16 * is" without express or implied warranty.
 17 *
 18 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 19 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 20 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 21 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 22 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 23 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 24 * OF THIS SOFTWARE.
 25 */
 26#include <drm/drmP.h>
 27#include <drm/drm_atomic.h>
 28#include <drm/drm_blend.h>
 29#include <linux/export.h>
 30#include <linux/slab.h>
 31#include <linux/sort.h>
 32
 33#include "drm_crtc_internal.h"
 34
 35/**
 36 * DOC: overview
 37 *
 38 * The basic plane composition model supported by standard plane properties only
 39 * has a source rectangle (in logical pixels within the &drm_framebuffer), with
 40 * sub-pixel accuracy, which is scaled up to a pixel-aligned destination
 41 * rectangle in the visible area of a &drm_crtc. The visible area of a CRTC is
 42 * defined by the horizontal and vertical visible pixels (stored in @hdisplay
 43 * and @vdisplay) of the requested mode (stored in @mode in the
 44 * &drm_crtc_state). These two rectangles are both stored in the
 45 * &drm_plane_state.
 46 *
 47 * For the atomic ioctl the following standard (atomic) properties on the plane object
 48 * encode the basic plane composition model:
 49 *
 50 * SRC_X:
 51 * 	X coordinate offset for the source rectangle within the
 52 * 	&drm_framebuffer, in 16.16 fixed point. Must be positive.
 53 * SRC_Y:
 54 * 	Y coordinate offset for the source rectangle within the
 55 * 	&drm_framebuffer, in 16.16 fixed point. Must be positive.
 56 * SRC_W:
 57 * 	Width for the source rectangle within the &drm_framebuffer, in 16.16
 58 * 	fixed point. SRC_X plus SRC_W must be within the width of the source
 59 * 	framebuffer. Must be positive.
 60 * SRC_H:
 61 * 	Height for the source rectangle within the &drm_framebuffer, in 16.16
 62 * 	fixed point. SRC_Y plus SRC_H must be within the height of the source
 63 * 	framebuffer. Must be positive.
 64 * CRTC_X:
 65 * 	X coordinate offset for the destination rectangle. Can be negative.
 66 * CRTC_Y:
 67 * 	Y coordinate offset for the destination rectangle. Can be negative.
 68 * CRTC_W:
 69 * 	Width for the destination rectangle. CRTC_X plus CRTC_W can extend past
 70 * 	the currently visible horizontal area of the &drm_crtc.
 71 * CRTC_H:
 72 * 	Height for the destination rectangle. CRTC_Y plus CRTC_H can extend past
 73 * 	the currently visible vertical area of the &drm_crtc.
 74 * FB_ID:
 75 * 	Mode object ID of the &drm_framebuffer this plane should scan out.
 76 * CRTC_ID:
 77 * 	Mode object ID of the &drm_crtc this plane should be connected to.
 78 *
 79 * Note that the source rectangle must fully lie within the bounds of the
 80 * &drm_framebuffer. The destination rectangle can lie outside of the visible
 81 * area of the current mode of the CRTC. It must be apprpriately clipped by the
 82 * driver, which can be done by calling drm_plane_helper_check_update(). Drivers
 83 * are also allowed to round the subpixel sampling positions appropriately, but
 84 * only to the next full pixel. No pixel outside of the source rectangle may
 85 * ever be sampled, which is important when applying more sophisticated
 86 * filtering than just a bilinear one when scaling. The filtering mode when
 87 * scaling is unspecified.
 88 *
 89 * On top of this basic transformation additional properties can be exposed by
 90 * the driver:
 91 *
 92 * - Rotation is set up with drm_plane_create_rotation_property(). It adds a
 93 *   rotation and reflection step between the source and destination rectangles.
 94 *   Without this property the rectangle is only scaled, but not rotated or
 95 *   reflected.
 96 *
 97 * - Z position is set up with drm_plane_create_zpos_immutable_property() and
 98 *   drm_plane_create_zpos_property(). It controls the visibility of overlapping
 99 *   planes. Without this property the primary plane is always below the cursor
100 *   plane, and ordering between all other planes is undefined.
101 *
102 * Note that all the property extensions described here apply either to the
103 * plane or the CRTC (e.g. for the background color, which currently is not
104 * exposed and assumed to be black).
105 */
106
107/**
108 * drm_plane_create_rotation_property - create a new rotation property
109 * @plane: drm plane
110 * @rotation: initial value of the rotation property
111 * @supported_rotations: bitmask of supported rotations and reflections
112 *
113 * This creates a new property with the selected support for transformations.
114 *
115 * Since a rotation by 180° degress is the same as reflecting both along the x
116 * and the y axis the rotation property is somewhat redundant. Drivers can use
117 * drm_rotation_simplify() to normalize values of this property.
118 *
119 * The property exposed to userspace is a bitmask property (see
120 * drm_property_create_bitmask()) called "rotation" and has the following
121 * bitmask enumaration values:
122 *
123 * DRM_ROTATE_0:
124 * 	"rotate-0"
125 * DRM_ROTATE_90:
126 * 	"rotate-90"
127 * DRM_ROTATE_180:
128 * 	"rotate-180"
129 * DRM_ROTATE_270:
130 * 	"rotate-270"
131 * DRM_REFLECT_X:
132 * 	"reflect-x"
133 * DRM_REFELCT_Y:
134 * 	"reflect-y"
135 *
136 * Rotation is the specified amount in degrees in counter clockwise direction,
137 * the X and Y axis are within the source rectangle, i.e.  the X/Y axis before
138 * rotation. After reflection, the rotation is applied to the image sampled from
139 * the source rectangle, before scaling it to fit the destination rectangle.
140 */
141int drm_plane_create_rotation_property(struct drm_plane *plane,
142				       unsigned int rotation,
143				       unsigned int supported_rotations)
144{
145	static const struct drm_prop_enum_list props[] = {
146		{ __builtin_ffs(DRM_ROTATE_0) - 1,   "rotate-0" },
147		{ __builtin_ffs(DRM_ROTATE_90) - 1,  "rotate-90" },
148		{ __builtin_ffs(DRM_ROTATE_180) - 1, "rotate-180" },
149		{ __builtin_ffs(DRM_ROTATE_270) - 1, "rotate-270" },
150		{ __builtin_ffs(DRM_REFLECT_X) - 1,  "reflect-x" },
151		{ __builtin_ffs(DRM_REFLECT_Y) - 1,  "reflect-y" },
152	};
153	struct drm_property *prop;
154
155	WARN_ON((supported_rotations & DRM_ROTATE_MASK) == 0);
156	WARN_ON(!is_power_of_2(rotation & DRM_ROTATE_MASK));
157	WARN_ON(rotation & ~supported_rotations);
158
159	prop = drm_property_create_bitmask(plane->dev, 0, "rotation",
160					   props, ARRAY_SIZE(props),
161					   supported_rotations);
162	if (!prop)
163		return -ENOMEM;
164
165	drm_object_attach_property(&plane->base, prop, rotation);
166
167	if (plane->state)
168		plane->state->rotation = rotation;
169
170	plane->rotation_property = prop;
171
172	return 0;
173}
174EXPORT_SYMBOL(drm_plane_create_rotation_property);
175
176/**
177 * drm_rotation_simplify() - Try to simplify the rotation
178 * @rotation: Rotation to be simplified
179 * @supported_rotations: Supported rotations
180 *
181 * Attempt to simplify the rotation to a form that is supported.
182 * Eg. if the hardware supports everything except DRM_REFLECT_X
183 * one could call this function like this:
184 *
185 * drm_rotation_simplify(rotation, DRM_ROTATE_0 |
186 *                       DRM_ROTATE_90 | DRM_ROTATE_180 |
187 *                       DRM_ROTATE_270 | DRM_REFLECT_Y);
188 *
189 * to eliminate the DRM_ROTATE_X flag. Depending on what kind of
190 * transforms the hardware supports, this function may not
191 * be able to produce a supported transform, so the caller should
192 * check the result afterwards.
193 */
194unsigned int drm_rotation_simplify(unsigned int rotation,
195				   unsigned int supported_rotations)
196{
197	if (rotation & ~supported_rotations) {
198		rotation ^= DRM_REFLECT_X | DRM_REFLECT_Y;
199		rotation = (rotation & DRM_REFLECT_MASK) |
200		           BIT((ffs(rotation & DRM_ROTATE_MASK) + 1) % 4);
201	}
202
203	return rotation;
204}
205EXPORT_SYMBOL(drm_rotation_simplify);
206
207/**
208 * drm_plane_create_zpos_property - create mutable zpos property
209 * @plane: drm plane
210 * @zpos: initial value of zpos property
211 * @min: minimal possible value of zpos property
212 * @max: maximal possible value of zpos property
213 *
214 * This function initializes generic mutable zpos property and enables support
215 * for it in drm core. Drivers can then attach this property to planes to enable
216 * support for configurable planes arrangement during blending operation.
217 * Once mutable zpos property has been enabled, the DRM core will automatically
218 * calculate drm_plane_state->normalized_zpos values. Usually min should be set
219 * to 0 and max to maximal number of planes for given crtc - 1.
220 *
221 * If zpos of some planes cannot be changed (like fixed background or
222 * cursor/topmost planes), driver should adjust min/max values and assign those
223 * planes immutable zpos property with lower or higher values (for more
224 * information, see drm_plane_create_zpos_immutable_property() function). In such
225 * case driver should also assign proper initial zpos values for all planes in
226 * its plane_reset() callback, so the planes will be always sorted properly.
227 *
228 * See also drm_atomic_normalize_zpos().
229 *
230 * The property exposed to userspace is called "zpos".
231 *
232 * Returns:
233 * Zero on success, negative errno on failure.
234 */
235int drm_plane_create_zpos_property(struct drm_plane *plane,
236				   unsigned int zpos,
237				   unsigned int min, unsigned int max)
238{
239	struct drm_property *prop;
240
241	prop = drm_property_create_range(plane->dev, 0, "zpos", min, max);
242	if (!prop)
243		return -ENOMEM;
244
245	drm_object_attach_property(&plane->base, prop, zpos);
246
247	plane->zpos_property = prop;
248
249	if (plane->state) {
250		plane->state->zpos = zpos;
251		plane->state->normalized_zpos = zpos;
252	}
253
254	return 0;
255}
256EXPORT_SYMBOL(drm_plane_create_zpos_property);
257
258/**
259 * drm_plane_create_zpos_immutable_property - create immuttable zpos property
260 * @plane: drm plane
261 * @zpos: value of zpos property
262 *
263 * This function initializes generic immutable zpos property and enables
264 * support for it in drm core. Using this property driver lets userspace
265 * to get the arrangement of the planes for blending operation and notifies
266 * it that the hardware (or driver) doesn't support changing of the planes'
267 * order. For mutable zpos see drm_plane_create_zpos_property().
268 *
269 * The property exposed to userspace is called "zpos".
270 *
271 * Returns:
272 * Zero on success, negative errno on failure.
273 */
274int drm_plane_create_zpos_immutable_property(struct drm_plane *plane,
275					     unsigned int zpos)
276{
277	struct drm_property *prop;
278
279	prop = drm_property_create_range(plane->dev, DRM_MODE_PROP_IMMUTABLE,
280					 "zpos", zpos, zpos);
281	if (!prop)
282		return -ENOMEM;
283
284	drm_object_attach_property(&plane->base, prop, zpos);
285
286	plane->zpos_property = prop;
287
288	if (plane->state) {
289		plane->state->zpos = zpos;
290		plane->state->normalized_zpos = zpos;
291	}
292
293	return 0;
294}
295EXPORT_SYMBOL(drm_plane_create_zpos_immutable_property);
296
297static int drm_atomic_state_zpos_cmp(const void *a, const void *b)
298{
299	const struct drm_plane_state *sa = *(struct drm_plane_state **)a;
300	const struct drm_plane_state *sb = *(struct drm_plane_state **)b;
301
302	if (sa->zpos != sb->zpos)
303		return sa->zpos - sb->zpos;
304	else
305		return sa->plane->base.id - sb->plane->base.id;
306}
307
308static int drm_atomic_helper_crtc_normalize_zpos(struct drm_crtc *crtc,
309					  struct drm_crtc_state *crtc_state)
310{
311	struct drm_atomic_state *state = crtc_state->state;
312	struct drm_device *dev = crtc->dev;
313	int total_planes = dev->mode_config.num_total_plane;
314	struct drm_plane_state **states;
315	struct drm_plane *plane;
316	int i, n = 0;
317	int ret = 0;
318
319	DRM_DEBUG_ATOMIC("[CRTC:%d:%s] calculating normalized zpos values\n",
320			 crtc->base.id, crtc->name);
321
322	states = kmalloc_array(total_planes, sizeof(*states), GFP_TEMPORARY);
323	if (!states)
324		return -ENOMEM;
325
326	/*
327	 * Normalization process might create new states for planes which
328	 * normalized_zpos has to be recalculated.
329	 */
330	drm_for_each_plane_mask(plane, dev, crtc_state->plane_mask) {
331		struct drm_plane_state *plane_state =
332			drm_atomic_get_plane_state(state, plane);
333		if (IS_ERR(plane_state)) {
334			ret = PTR_ERR(plane_state);
335			goto done;
336		}
337		states[n++] = plane_state;
338		DRM_DEBUG_ATOMIC("[PLANE:%d:%s] processing zpos value %d\n",
339				 plane->base.id, plane->name,
340				 plane_state->zpos);
341	}
342
343	sort(states, n, sizeof(*states), drm_atomic_state_zpos_cmp, NULL);
344
345	for (i = 0; i < n; i++) {
346		plane = states[i]->plane;
347
348		states[i]->normalized_zpos = i;
349		DRM_DEBUG_ATOMIC("[PLANE:%d:%s] normalized zpos value %d\n",
350				 plane->base.id, plane->name, i);
351	}
352	crtc_state->zpos_changed = true;
353
354done:
355	kfree(states);
356	return ret;
357}
358
359/**
360 * drm_atomic_normalize_zpos - calculate normalized zpos values for all crtcs
361 * @dev: DRM device
362 * @state: atomic state of DRM device
363 *
364 * This function calculates normalized zpos value for all modified planes in
365 * the provided atomic state of DRM device.
366 *
367 * For every CRTC this function checks new states of all planes assigned to
368 * it and calculates normalized zpos value for these planes. Planes are compared
369 * first by their zpos values, then by plane id (if zpos is equal). The plane
370 * with lowest zpos value is at the bottom. The plane_state->normalized_zpos is
371 * then filled with unique values from 0 to number of active planes in crtc
372 * minus one.
373 *
374 * RETURNS
375 * Zero for success or -errno
376 */
377int drm_atomic_normalize_zpos(struct drm_device *dev,
378			      struct drm_atomic_state *state)
379{
380	struct drm_crtc *crtc;
381	struct drm_crtc_state *crtc_state;
382	struct drm_plane *plane;
383	struct drm_plane_state *plane_state;
384	int i, ret = 0;
385
386	for_each_plane_in_state(state, plane, plane_state, i) {
387		crtc = plane_state->crtc;
388		if (!crtc)
389			continue;
390		if (plane->state->zpos != plane_state->zpos) {
391			crtc_state =
392				drm_atomic_get_existing_crtc_state(state, crtc);
393			crtc_state->zpos_changed = true;
394		}
395	}
396
397	for_each_crtc_in_state(state, crtc, crtc_state, i) {
398		if (crtc_state->plane_mask != crtc->state->plane_mask ||
399		    crtc_state->zpos_changed) {
400			ret = drm_atomic_helper_crtc_normalize_zpos(crtc,
401								    crtc_state);
402			if (ret)
403				return ret;
404		}
405	}
406	return 0;
407}
408EXPORT_SYMBOL(drm_atomic_normalize_zpos);