linux/drivers/gpu/drm/drm_blend.c
Simon Ser 77a71abbdd
drm/doc: introduce new section for standard plane properties
Introduce a new "Standard Plane Properties" section for properties
defined in drm_plane.c. Move the mis-placed IN_FORMATS docs there.

Signed-off-by: Simon Ser <contact@emersion.fr>
Reviewed-by: Daniel Vetter <daniel@ffwll.ch>
Cc: Pekka Paalanen <ppaalanen@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201217113220.102271-3-contact@emersion.fr
2020-12-17 16:56:40 +01:00

619 lines
21 KiB
C

/*
* Copyright (C) 2016 Samsung Electronics Co.Ltd
* Authors:
* Marek Szyprowski <m.szyprowski@samsung.com>
*
* DRM core plane blending related functions
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that copyright
* notice and this permission notice appear in supporting documentation, and
* that the name of the copyright holders not be used in advertising or
* publicity pertaining to distribution of the software without specific,
* written prior permission. The copyright holders make no representations
* about the suitability of this software for any purpose. It is provided "as
* is" without express or implied warranty.
*
* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
* EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
* DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
* OF THIS SOFTWARE.
*/
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/sort.h>
#include <drm/drm_atomic.h>
#include <drm/drm_blend.h>
#include <drm/drm_device.h>
#include <drm/drm_print.h>
#include "drm_crtc_internal.h"
/**
* DOC: overview
*
* The basic plane composition model supported by standard plane properties only
* has a source rectangle (in logical pixels within the &drm_framebuffer), with
* sub-pixel accuracy, which is scaled up to a pixel-aligned destination
* rectangle in the visible area of a &drm_crtc. The visible area of a CRTC is
* defined by the horizontal and vertical visible pixels (stored in @hdisplay
* and @vdisplay) of the requested mode (stored in &drm_crtc_state.mode). These
* two rectangles are both stored in the &drm_plane_state.
*
* For the atomic ioctl the following standard (atomic) properties on the plane object
* encode the basic plane composition model:
*
* SRC_X:
* X coordinate offset for the source rectangle within the
* &drm_framebuffer, in 16.16 fixed point. Must be positive.
* SRC_Y:
* Y coordinate offset for the source rectangle within the
* &drm_framebuffer, in 16.16 fixed point. Must be positive.
* SRC_W:
* Width for the source rectangle within the &drm_framebuffer, in 16.16
* fixed point. SRC_X plus SRC_W must be within the width of the source
* framebuffer. Must be positive.
* SRC_H:
* Height for the source rectangle within the &drm_framebuffer, in 16.16
* fixed point. SRC_Y plus SRC_H must be within the height of the source
* framebuffer. Must be positive.
* CRTC_X:
* X coordinate offset for the destination rectangle. Can be negative.
* CRTC_Y:
* Y coordinate offset for the destination rectangle. Can be negative.
* CRTC_W:
* Width for the destination rectangle. CRTC_X plus CRTC_W can extend past
* the currently visible horizontal area of the &drm_crtc.
* CRTC_H:
* Height for the destination rectangle. CRTC_Y plus CRTC_H can extend past
* the currently visible vertical area of the &drm_crtc.
* FB_ID:
* Mode object ID of the &drm_framebuffer this plane should scan out.
* CRTC_ID:
* Mode object ID of the &drm_crtc this plane should be connected to.
*
* Note that the source rectangle must fully lie within the bounds of the
* &drm_framebuffer. The destination rectangle can lie outside of the visible
* area of the current mode of the CRTC. It must be apprpriately clipped by the
* driver, which can be done by calling drm_plane_helper_check_update(). Drivers
* are also allowed to round the subpixel sampling positions appropriately, but
* only to the next full pixel. No pixel outside of the source rectangle may
* ever be sampled, which is important when applying more sophisticated
* filtering than just a bilinear one when scaling. The filtering mode when
* scaling is unspecified.
*
* On top of this basic transformation additional properties can be exposed by
* the driver:
*
* alpha:
* Alpha is setup with drm_plane_create_alpha_property(). It controls the
* plane-wide opacity, from transparent (0) to opaque (0xffff). It can be
* combined with pixel alpha.
* The pixel values in the framebuffers are expected to not be
* pre-multiplied by the global alpha associated to the plane.
*
* rotation:
* Rotation is set up with drm_plane_create_rotation_property(). It adds a
* rotation and reflection step between the source and destination rectangles.
* Without this property the rectangle is only scaled, but not rotated or
* reflected.
*
* Possbile values:
*
* "rotate-<degrees>":
* Signals that a drm plane is rotated <degrees> degrees in counter
* clockwise direction.
*
* "reflect-<axis>":
* Signals that the contents of a drm plane is reflected along the
* <axis> axis, in the same way as mirroring.
*
* reflect-x::
*
* |o | | o|
* | | -> | |
* | v| |v |
*
* reflect-y::
*
* |o | | ^|
* | | -> | |
* | v| |o |
*
* zpos:
* Z position is set up with drm_plane_create_zpos_immutable_property() and
* drm_plane_create_zpos_property(). It controls the visibility of overlapping
* planes. Without this property the primary plane is always below the cursor
* plane, and ordering between all other planes is undefined. The positive
* Z axis points towards the user, i.e. planes with lower Z position values
* are underneath planes with higher Z position values. Two planes with the
* same Z position value have undefined ordering. Note that the Z position
* value can also be immutable, to inform userspace about the hard-coded
* stacking of planes, see drm_plane_create_zpos_immutable_property(). If
* any plane has a zpos property (either mutable or immutable), then all
* planes shall have a zpos property.
*
* pixel blend mode:
* Pixel blend mode is set up with drm_plane_create_blend_mode_property().
* It adds a blend mode for alpha blending equation selection, describing
* how the pixels from the current plane are composited with the
* background.
*
* Three alpha blending equations are defined:
*
* "None":
* Blend formula that ignores the pixel alpha::
*
* out.rgb = plane_alpha * fg.rgb +
* (1 - plane_alpha) * bg.rgb
*
* "Pre-multiplied":
* Blend formula that assumes the pixel color values
* have been already pre-multiplied with the alpha
* channel values::
*
* out.rgb = plane_alpha * fg.rgb +
* (1 - (plane_alpha * fg.alpha)) * bg.rgb
*
* "Coverage":
* Blend formula that assumes the pixel color values have not
* been pre-multiplied and will do so when blending them to the
* background color values::
*
* out.rgb = plane_alpha * fg.alpha * fg.rgb +
* (1 - (plane_alpha * fg.alpha)) * bg.rgb
*
* Using the following symbols:
*
* "fg.rgb":
* Each of the RGB component values from the plane's pixel
* "fg.alpha":
* Alpha component value from the plane's pixel. If the plane's
* pixel format has no alpha component, then this is assumed to be
* 1.0. In these cases, this property has no effect, as all three
* equations become equivalent.
* "bg.rgb":
* Each of the RGB component values from the background
* "plane_alpha":
* Plane alpha value set by the plane "alpha" property. If the
* plane does not expose the "alpha" property, then this is
* assumed to be 1.0
*
* Note that all the property extensions described here apply either to the
* plane or the CRTC (e.g. for the background color, which currently is not
* exposed and assumed to be black).
*
* SCALING_FILTER:
* Indicates scaling filter to be used for plane scaler
*
* The value of this property can be one of the following:
*
* Default:
* Driver's default scaling filter
* Nearest Neighbor:
* Nearest Neighbor scaling filter
*
* Drivers can set up this property for a plane by calling
* drm_plane_create_scaling_filter_property
*/
/**
* drm_plane_create_alpha_property - create a new alpha property
* @plane: drm plane
*
* This function creates a generic, mutable, alpha property and enables support
* for it in the DRM core. It is attached to @plane.
*
* The alpha property will be allowed to be within the bounds of 0
* (transparent) to 0xffff (opaque).
*
* Returns:
* 0 on success, negative error code on failure.
*/
int drm_plane_create_alpha_property(struct drm_plane *plane)
{
struct drm_property *prop;
prop = drm_property_create_range(plane->dev, 0, "alpha",
0, DRM_BLEND_ALPHA_OPAQUE);
if (!prop)
return -ENOMEM;
drm_object_attach_property(&plane->base, prop, DRM_BLEND_ALPHA_OPAQUE);
plane->alpha_property = prop;
if (plane->state)
plane->state->alpha = DRM_BLEND_ALPHA_OPAQUE;
return 0;
}
EXPORT_SYMBOL(drm_plane_create_alpha_property);
/**
* drm_plane_create_rotation_property - create a new rotation property
* @plane: drm plane
* @rotation: initial value of the rotation property
* @supported_rotations: bitmask of supported rotations and reflections
*
* This creates a new property with the selected support for transformations.
*
* Since a rotation by 180° degress is the same as reflecting both along the x
* and the y axis the rotation property is somewhat redundant. Drivers can use
* drm_rotation_simplify() to normalize values of this property.
*
* The property exposed to userspace is a bitmask property (see
* drm_property_create_bitmask()) called "rotation" and has the following
* bitmask enumaration values:
*
* DRM_MODE_ROTATE_0:
* "rotate-0"
* DRM_MODE_ROTATE_90:
* "rotate-90"
* DRM_MODE_ROTATE_180:
* "rotate-180"
* DRM_MODE_ROTATE_270:
* "rotate-270"
* DRM_MODE_REFLECT_X:
* "reflect-x"
* DRM_MODE_REFLECT_Y:
* "reflect-y"
*
* Rotation is the specified amount in degrees in counter clockwise direction,
* the X and Y axis are within the source rectangle, i.e. the X/Y axis before
* rotation. After reflection, the rotation is applied to the image sampled from
* the source rectangle, before scaling it to fit the destination rectangle.
*/
int drm_plane_create_rotation_property(struct drm_plane *plane,
unsigned int rotation,
unsigned int supported_rotations)
{
static const struct drm_prop_enum_list props[] = {
{ __builtin_ffs(DRM_MODE_ROTATE_0) - 1, "rotate-0" },
{ __builtin_ffs(DRM_MODE_ROTATE_90) - 1, "rotate-90" },
{ __builtin_ffs(DRM_MODE_ROTATE_180) - 1, "rotate-180" },
{ __builtin_ffs(DRM_MODE_ROTATE_270) - 1, "rotate-270" },
{ __builtin_ffs(DRM_MODE_REFLECT_X) - 1, "reflect-x" },
{ __builtin_ffs(DRM_MODE_REFLECT_Y) - 1, "reflect-y" },
};
struct drm_property *prop;
WARN_ON((supported_rotations & DRM_MODE_ROTATE_MASK) == 0);
WARN_ON(!is_power_of_2(rotation & DRM_MODE_ROTATE_MASK));
WARN_ON(rotation & ~supported_rotations);
prop = drm_property_create_bitmask(plane->dev, 0, "rotation",
props, ARRAY_SIZE(props),
supported_rotations);
if (!prop)
return -ENOMEM;
drm_object_attach_property(&plane->base, prop, rotation);
if (plane->state)
plane->state->rotation = rotation;
plane->rotation_property = prop;
return 0;
}
EXPORT_SYMBOL(drm_plane_create_rotation_property);
/**
* drm_rotation_simplify() - Try to simplify the rotation
* @rotation: Rotation to be simplified
* @supported_rotations: Supported rotations
*
* Attempt to simplify the rotation to a form that is supported.
* Eg. if the hardware supports everything except DRM_MODE_REFLECT_X
* one could call this function like this:
*
* drm_rotation_simplify(rotation, DRM_MODE_ROTATE_0 |
* DRM_MODE_ROTATE_90 | DRM_MODE_ROTATE_180 |
* DRM_MODE_ROTATE_270 | DRM_MODE_REFLECT_Y);
*
* to eliminate the DRM_MODE_ROTATE_X flag. Depending on what kind of
* transforms the hardware supports, this function may not
* be able to produce a supported transform, so the caller should
* check the result afterwards.
*/
unsigned int drm_rotation_simplify(unsigned int rotation,
unsigned int supported_rotations)
{
if (rotation & ~supported_rotations) {
rotation ^= DRM_MODE_REFLECT_X | DRM_MODE_REFLECT_Y;
rotation = (rotation & DRM_MODE_REFLECT_MASK) |
BIT((ffs(rotation & DRM_MODE_ROTATE_MASK) + 1)
% 4);
}
return rotation;
}
EXPORT_SYMBOL(drm_rotation_simplify);
/**
* drm_plane_create_zpos_property - create mutable zpos property
* @plane: drm plane
* @zpos: initial value of zpos property
* @min: minimal possible value of zpos property
* @max: maximal possible value of zpos property
*
* This function initializes generic mutable zpos property and enables support
* for it in drm core. Drivers can then attach this property to planes to enable
* support for configurable planes arrangement during blending operation.
* Drivers that attach a mutable zpos property to any plane should call the
* drm_atomic_normalize_zpos() helper during their implementation of
* &drm_mode_config_funcs.atomic_check(), which will update the normalized zpos
* values and store them in &drm_plane_state.normalized_zpos. Usually min
* should be set to 0 and max to maximal number of planes for given crtc - 1.
*
* If zpos of some planes cannot be changed (like fixed background or
* cursor/topmost planes), drivers shall adjust the min/max values and assign
* those planes immutable zpos properties with lower or higher values (for more
* information, see drm_plane_create_zpos_immutable_property() function). In such
* case drivers shall also assign proper initial zpos values for all planes in
* its plane_reset() callback, so the planes will be always sorted properly.
*
* See also drm_atomic_normalize_zpos().
*
* The property exposed to userspace is called "zpos".
*
* Returns:
* Zero on success, negative errno on failure.
*/
int drm_plane_create_zpos_property(struct drm_plane *plane,
unsigned int zpos,
unsigned int min, unsigned int max)
{
struct drm_property *prop;
prop = drm_property_create_range(plane->dev, 0, "zpos", min, max);
if (!prop)
return -ENOMEM;
drm_object_attach_property(&plane->base, prop, zpos);
plane->zpos_property = prop;
if (plane->state) {
plane->state->zpos = zpos;
plane->state->normalized_zpos = zpos;
}
return 0;
}
EXPORT_SYMBOL(drm_plane_create_zpos_property);
/**
* drm_plane_create_zpos_immutable_property - create immuttable zpos property
* @plane: drm plane
* @zpos: value of zpos property
*
* This function initializes generic immutable zpos property and enables
* support for it in drm core. Using this property driver lets userspace
* to get the arrangement of the planes for blending operation and notifies
* it that the hardware (or driver) doesn't support changing of the planes'
* order. For mutable zpos see drm_plane_create_zpos_property().
*
* The property exposed to userspace is called "zpos".
*
* Returns:
* Zero on success, negative errno on failure.
*/
int drm_plane_create_zpos_immutable_property(struct drm_plane *plane,
unsigned int zpos)
{
struct drm_property *prop;
prop = drm_property_create_range(plane->dev, DRM_MODE_PROP_IMMUTABLE,
"zpos", zpos, zpos);
if (!prop)
return -ENOMEM;
drm_object_attach_property(&plane->base, prop, zpos);
plane->zpos_property = prop;
if (plane->state) {
plane->state->zpos = zpos;
plane->state->normalized_zpos = zpos;
}
return 0;
}
EXPORT_SYMBOL(drm_plane_create_zpos_immutable_property);
static int drm_atomic_state_zpos_cmp(const void *a, const void *b)
{
const struct drm_plane_state *sa = *(struct drm_plane_state **)a;
const struct drm_plane_state *sb = *(struct drm_plane_state **)b;
if (sa->zpos != sb->zpos)
return sa->zpos - sb->zpos;
else
return sa->plane->base.id - sb->plane->base.id;
}
static int drm_atomic_helper_crtc_normalize_zpos(struct drm_crtc *crtc,
struct drm_crtc_state *crtc_state)
{
struct drm_atomic_state *state = crtc_state->state;
struct drm_device *dev = crtc->dev;
int total_planes = dev->mode_config.num_total_plane;
struct drm_plane_state **states;
struct drm_plane *plane;
int i, n = 0;
int ret = 0;
DRM_DEBUG_ATOMIC("[CRTC:%d:%s] calculating normalized zpos values\n",
crtc->base.id, crtc->name);
states = kmalloc_array(total_planes, sizeof(*states), GFP_KERNEL);
if (!states)
return -ENOMEM;
/*
* Normalization process might create new states for planes which
* normalized_zpos has to be recalculated.
*/
drm_for_each_plane_mask(plane, dev, crtc_state->plane_mask) {
struct drm_plane_state *plane_state =
drm_atomic_get_plane_state(state, plane);
if (IS_ERR(plane_state)) {
ret = PTR_ERR(plane_state);
goto done;
}
states[n++] = plane_state;
DRM_DEBUG_ATOMIC("[PLANE:%d:%s] processing zpos value %d\n",
plane->base.id, plane->name,
plane_state->zpos);
}
sort(states, n, sizeof(*states), drm_atomic_state_zpos_cmp, NULL);
for (i = 0; i < n; i++) {
plane = states[i]->plane;
states[i]->normalized_zpos = i;
DRM_DEBUG_ATOMIC("[PLANE:%d:%s] normalized zpos value %d\n",
plane->base.id, plane->name, i);
}
crtc_state->zpos_changed = true;
done:
kfree(states);
return ret;
}
/**
* drm_atomic_normalize_zpos - calculate normalized zpos values for all crtcs
* @dev: DRM device
* @state: atomic state of DRM device
*
* This function calculates normalized zpos value for all modified planes in
* the provided atomic state of DRM device.
*
* For every CRTC this function checks new states of all planes assigned to
* it and calculates normalized zpos value for these planes. Planes are compared
* first by their zpos values, then by plane id (if zpos is equal). The plane
* with lowest zpos value is at the bottom. The &drm_plane_state.normalized_zpos
* is then filled with unique values from 0 to number of active planes in crtc
* minus one.
*
* RETURNS
* Zero for success or -errno
*/
int drm_atomic_normalize_zpos(struct drm_device *dev,
struct drm_atomic_state *state)
{
struct drm_crtc *crtc;
struct drm_crtc_state *old_crtc_state, *new_crtc_state;
struct drm_plane *plane;
struct drm_plane_state *old_plane_state, *new_plane_state;
int i, ret = 0;
for_each_oldnew_plane_in_state(state, plane, old_plane_state, new_plane_state, i) {
crtc = new_plane_state->crtc;
if (!crtc)
continue;
if (old_plane_state->zpos != new_plane_state->zpos) {
new_crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
new_crtc_state->zpos_changed = true;
}
}
for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
if (old_crtc_state->plane_mask != new_crtc_state->plane_mask ||
new_crtc_state->zpos_changed) {
ret = drm_atomic_helper_crtc_normalize_zpos(crtc,
new_crtc_state);
if (ret)
return ret;
}
}
return 0;
}
EXPORT_SYMBOL(drm_atomic_normalize_zpos);
/**
* drm_plane_create_blend_mode_property - create a new blend mode property
* @plane: drm plane
* @supported_modes: bitmask of supported modes, must include
* BIT(DRM_MODE_BLEND_PREMULTI). Current DRM assumption is
* that alpha is premultiplied, and old userspace can break if
* the property defaults to anything else.
*
* This creates a new property describing the blend mode.
*
* The property exposed to userspace is an enumeration property (see
* drm_property_create_enum()) called "pixel blend mode" and has the
* following enumeration values:
*
* "None":
* Blend formula that ignores the pixel alpha.
*
* "Pre-multiplied":
* Blend formula that assumes the pixel color values have been already
* pre-multiplied with the alpha channel values.
*
* "Coverage":
* Blend formula that assumes the pixel color values have not been
* pre-multiplied and will do so when blending them to the background color
* values.
*
* RETURNS:
* Zero for success or -errno
*/
int drm_plane_create_blend_mode_property(struct drm_plane *plane,
unsigned int supported_modes)
{
struct drm_device *dev = plane->dev;
struct drm_property *prop;
static const struct drm_prop_enum_list props[] = {
{ DRM_MODE_BLEND_PIXEL_NONE, "None" },
{ DRM_MODE_BLEND_PREMULTI, "Pre-multiplied" },
{ DRM_MODE_BLEND_COVERAGE, "Coverage" },
};
unsigned int valid_mode_mask = BIT(DRM_MODE_BLEND_PIXEL_NONE) |
BIT(DRM_MODE_BLEND_PREMULTI) |
BIT(DRM_MODE_BLEND_COVERAGE);
int i;
if (WARN_ON((supported_modes & ~valid_mode_mask) ||
((supported_modes & BIT(DRM_MODE_BLEND_PREMULTI)) == 0)))
return -EINVAL;
prop = drm_property_create(dev, DRM_MODE_PROP_ENUM,
"pixel blend mode",
hweight32(supported_modes));
if (!prop)
return -ENOMEM;
for (i = 0; i < ARRAY_SIZE(props); i++) {
int ret;
if (!(BIT(props[i].type) & supported_modes))
continue;
ret = drm_property_add_enum(prop, props[i].type,
props[i].name);
if (ret) {
drm_property_destroy(dev, prop);
return ret;
}
}
drm_object_attach_property(&plane->base, prop, DRM_MODE_BLEND_PREMULTI);
plane->blend_mode_property = prop;
return 0;
}
EXPORT_SYMBOL(drm_plane_create_blend_mode_property);