Add Plane Degamma as a blob property and plane degamma size as a range property.
v2: Rebase
v3: Fixed Sean, Paul's review comments. Moved the property from mode_config to drm_plane. Created a helper function to instantiate these properties and removed from drm_mode_create_standard_properties Added property documentation as suggested by Daniel, Vetter.
v4: Rebase
v5: Added "Display Color Hardware Pipeline" flow to kernel documentation as suggested by "Ville Syrjala" and "Brian Starkey". Moved the property creation to drm_color_mgmt.c file to consolidate all color operations at one place.
v6: Fixed checkpatch issues with --strict as parameter.
Signed-off-by: Uma Shankar uma.shankar@intel.com Reviewed-by: Alexandru Gheorghe alexandru-cosmin.gheorghe@arm.com --- Documentation/gpu/drm-kms.rst | 90 +++++++++++++++++++++++++++++++ drivers/gpu/drm/drm_atomic.c | 1 + drivers/gpu/drm/drm_atomic_state_helper.c | 5 ++ drivers/gpu/drm/drm_atomic_uapi.c | 10 ++++ drivers/gpu/drm/drm_color_mgmt.c | 43 +++++++++++++-- include/drm/drm_plane.h | 24 +++++++++ 6 files changed, 170 insertions(+), 3 deletions(-)
diff --git a/Documentation/gpu/drm-kms.rst b/Documentation/gpu/drm-kms.rst index 23a3c98..9e64df5 100644 --- a/Documentation/gpu/drm-kms.rst +++ b/Documentation/gpu/drm-kms.rst @@ -473,12 +473,102 @@ FB_DAMAGE_CLIPS Color Management Properties ---------------------------
+Below is how a typical hardware pipeline for color +will look like: + +.. kernel-render:: DOT + :alt: Display Color Pipeline + :caption: Display Color Pipeline Overview + + digraph "KMS" { + node [shape=box] + + subgraph cluster_static { + style=dashed + label="Display Color Hardware Blocks" + + node [bgcolor=grey style=filled] + "Plane Degamma A" -> "Plane CSC/CTM A" + "Plane CSC/CTM A" -> "Plane Gamma A" + "Pipe Blender" [color=lightblue,style=filled, width=5.25, height=0.75]; + "Plane Gamma A" -> "Pipe Blender" + "Pipe Blender" -> "Pipe DeGamma" + "Pipe DeGamma" -> "Pipe CSC/CTM" + "Pipe CSC/CTM" -> "Pipe Gamma" + "Pipe Gamma" -> "Pipe Output" + } + + subgraph cluster_static { + style=dashed + + node [shape=box] + "Plane Degamma B" -> "Plane CSC/CTM B" + "Plane CSC/CTM B" -> "Plane Gamma B" + "Plane Gamma B" -> "Pipe Blender" + } + + subgraph cluster_static { + style=dashed + + node [shape=box] + "Plane Degamma C" -> "Plane CSC/CTM C" + "Plane CSC/CTM C" -> "Plane Gamma C" + "Plane Gamma C" -> "Pipe Blender" + } + + subgraph cluster_fb { + style=dashed + label="RAM" + + node [shape=box width=1.7 height=0.2] + + "FB 1" -> "Plane Degamma A" + "FB 2" -> "Plane Degamma B" + "FB 3" -> "Plane Degamma C" + } + } + +In real world usecases, + +1. Plane Degamma can be used to linearize a non linear gamma +encoded framebuffer. This is needed to do any linear math like +color space conversion. For ex, linearize frames encoded in SRGB +or by HDR curve. + +2. Later Plane CTM block can convert the content to some different +colorspace. For ex, SRGB to BT2020 etc. + +3. Plane Gamma block can be used later to re-apply the non-linear +curve. This can also be used to apply Tone Mapping for HDR usecases. + +All the layers or framebuffers need to be converted to same color +space and format before blending. The plane color hardware blocks +can help with this. Once the Data is blended, similar color processing +can be done on blended output using pipe color hardware blocks. + +DRM Properties have been created to define and expose all these +hardware blocks to userspace. A userspace application (compositor +or any color app) can use these interfaces and define policies to +efficiently use the display hardware for such color operations. + +Pipe Color Management Properties +--------------------------------- + .. kernel-doc:: drivers/gpu/drm/drm_color_mgmt.c :doc: overview
.. kernel-doc:: drivers/gpu/drm/drm_color_mgmt.c :export:
+Plane Color Management Properties +--------------------------------- + +.. kernel-doc:: drivers/gpu/drm/drm_color_mgmt.c + :doc: Plane Color Properties + +.. kernel-doc:: drivers/gpu/drm/drm_color_mgmt.c + :doc: export + Tile Group Property -------------------
diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c index 5eb4013..6336542 100644 --- a/drivers/gpu/drm/drm_atomic.c +++ b/drivers/gpu/drm/drm_atomic.c @@ -655,6 +655,7 @@ static void drm_atomic_plane_print_state(struct drm_printer *p, drm_get_color_encoding_name(state->color_encoding)); drm_printf(p, "\tcolor-range=%s\n", drm_get_color_range_name(state->color_range)); + drm_printf(p, "\tcolor_mgmt_changed=%d\n", state->color_mgmt_changed);
if (plane->funcs->atomic_print_state) plane->funcs->atomic_print_state(p, state); diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c b/drivers/gpu/drm/drm_atomic_state_helper.c index 59ffb6b..a8fb7f9 100644 --- a/drivers/gpu/drm/drm_atomic_state_helper.c +++ b/drivers/gpu/drm/drm_atomic_state_helper.c @@ -243,6 +243,10 @@ void __drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane, state->fence = NULL; state->commit = NULL; state->fb_damage_clips = NULL; + + if (state->degamma_lut) + drm_property_blob_get(state->degamma_lut); + state->color_mgmt_changed = false; } EXPORT_SYMBOL(__drm_atomic_helper_plane_duplicate_state);
@@ -289,6 +293,7 @@ void __drm_atomic_helper_plane_destroy_state(struct drm_plane_state *state) drm_crtc_commit_put(state->commit);
drm_property_blob_put(state->fb_damage_clips); + drm_property_blob_put(state->degamma_lut); } EXPORT_SYMBOL(__drm_atomic_helper_plane_destroy_state);
diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c index ea797d4..b21fba5 100644 --- a/drivers/gpu/drm/drm_atomic_uapi.c +++ b/drivers/gpu/drm/drm_atomic_uapi.c @@ -572,6 +572,13 @@ static int drm_atomic_plane_set_property(struct drm_plane *plane, state->color_encoding = val; } else if (property == plane->color_range_property) { state->color_range = val; + } else if (property == plane->degamma_lut_property) { + ret = drm_atomic_replace_property_blob_from_id(dev, + &state->degamma_lut, + val, -1, sizeof(struct drm_color_lut), + &replaced); + state->color_mgmt_changed |= replaced; + return ret; } else if (property == config->prop_fb_damage_clips) { ret = drm_atomic_replace_property_blob_from_id(dev, &state->fb_damage_clips, @@ -635,6 +642,9 @@ static int drm_atomic_plane_set_property(struct drm_plane *plane, *val = state->color_encoding; } else if (property == plane->color_range_property) { *val = state->color_range; + } else if (property == plane->degamma_lut_property) { + *val = (state->degamma_lut) ? + state->degamma_lut->base.id : 0; } else if (property == config->prop_fb_damage_clips) { *val = (state->fb_damage_clips) ? state->fb_damage_clips->base.id : 0; diff --git a/drivers/gpu/drm/drm_color_mgmt.c b/drivers/gpu/drm/drm_color_mgmt.c index 79ff874..8ccefd8 100644 --- a/drivers/gpu/drm/drm_color_mgmt.c +++ b/drivers/gpu/drm/drm_color_mgmt.c @@ -29,11 +29,11 @@ /** * DOC: overview * - * Color management or color space adjustments is supported through a set of 5 - * properties on the &drm_crtc object. They are set up by calling + * Pipe Color management or color space adjustments is supported through a + * set of 5 properties on the &drm_crtc object. They are set up by calling * drm_crtc_enable_color_mgmt(). * - * "DEGAMMA_LUT”: + * "DEGAMMA_LUT * Blob property to set the degamma lookup table (LUT) mapping pixel data * from the framebuffer before it is given to the transformation matrix. * The data is interpreted as an array of &struct drm_color_lut elements. @@ -484,6 +484,43 @@ int drm_plane_create_color_properties(struct drm_plane *plane, EXPORT_SYMBOL(drm_plane_create_color_properties);
/** + * DOC: Plane Color Properties + * + * Plane Color management or color space adjustments is supported + * through a set of 5 properties on the &drm_plane object. + * + * degamma_lut_property: + * Blob property which allows a userspace to provide LUT values + * to apply degamma curve using the h/w plane degamma processing + * engine, thereby making the content as linear for further color + * processing. + * + * degamma_lut_size_property: + * Range Property to indicate size of the plane degamma LUT. + */ +int drm_plane_color_create_prop(struct drm_device *dev, + struct drm_plane *plane) +{ + struct drm_property *prop; + + prop = drm_property_create(dev, DRM_MODE_PROP_BLOB, + "PLANE_DEGAMMA_LUT", 0); + if (!prop) + return -ENOMEM; + plane->degamma_lut_property = prop; + + prop = drm_property_create_range(dev, DRM_MODE_PROP_IMMUTABLE, + "PLANE_DEGAMMA_LUT_SIZE", 0, + UINT_MAX); + if (!prop) + return -ENOMEM; + plane->degamma_lut_size_property = prop; + + return 0; +} +EXPORT_SYMBOL(drm_plane_color_create_prop); + +/** * drm_color_lut_check - check validity of lookup table * @lut: property blob containing LUT to check * @tests: bitmask of tests to run diff --git a/include/drm/drm_plane.h b/include/drm/drm_plane.h index 6078c70..757f1e8 100644 --- a/include/drm/drm_plane.h +++ b/include/drm/drm_plane.h @@ -195,6 +195,14 @@ struct drm_plane_state { */ bool visible;
+ /* @degamma_lut: + * + * Lookup table for converting framebuffer pixel data before apply the + * color conversion matrix @ctm. See drm_plane_enable_color_mgmt(). The + * blob (if not NULL) is an array of &struct drm_color_lut_ext. + */ + struct drm_property_blob *degamma_lut; + /** * @commit: Tracks the pending commit to prevent use-after-free conditions, * and for async plane updates. @@ -205,6 +213,8 @@ struct drm_plane_state {
/** @state: backpointer to global drm_atomic_state */ struct drm_atomic_state *state; + + u8 color_mgmt_changed : 1; };
static inline struct drm_rect @@ -705,6 +715,18 @@ struct drm_plane { * See drm_plane_create_color_properties(). */ struct drm_property *color_range_property; + + /** + * @degamma_lut_property: Optional Plane property to set the LUT + * used to convert the framebuffer's colors to linear gamma. + */ + struct drm_property *degamma_lut_property; + + /** + * @degamma_lut_size_property: Optional Plane property for the + * size of the degamma LUT as supported by the driver (read-only). + */ + struct drm_property *degamma_lut_size_property; };
#define obj_to_plane(x) container_of(x, struct drm_plane, base) @@ -754,6 +776,8 @@ static inline u32 drm_plane_mask(const struct drm_plane *plane) int drm_mode_plane_set_obj_prop(struct drm_plane *plane, struct drm_property *property, uint64_t value); +int drm_plane_color_create_prop(struct drm_device *dev, + struct drm_plane *plane);
/** * drm_plane_find - find a &drm_plane