From: Bhawanpreet Lakha Bhawanpreet.Lakha@amd.com
Due to the way displays and human vision work it is most effective to encode luminance information in a non-linear space.
For SDR this non-linear mapping is assumed to roughly use a gamma 2.2 curve. This was due to the way CRTs worked and was fine for SDR content with a low luminance range.
The large luminance range (0-10,000 nits) for HDR exposes some short-comings of a simple gamma curve that have been addressed through various Electro-Optical Transfer Functions (EOTFs).
Rather than assuming how framebuffer content is encoded we want to make sure userspace presenting HDR content is explicit about the EOTF of the content, so a driver can decide whether the content can be supported or not.
This Patch adds common color transfer functions for SDR/HDR. These can be used to communicate with the driver regarding the transformation to use for a given plane.
enums added: DRM_COLOR_TF_SRGB roughly 2.4 gamma with initial linear section DRM_COLOR_TF_BT709 Similar to Gamma 2.2-2.8 DRM_COLOR_TF_PQ2084 most common tf used for HDR video (HDR10/Dolby). Can support up to 10,000 nits
The usage is similar to color_encoding and color_range where the driver can specify the default and supported tfs and pass it into drm_plane_create_color_properties().
Signed-off-by: Bhawanpreet Lakha Bhawanpreet.Lakha@amd.com Signed-off-by: Harry Wentland harry.wentland@amd.com --- .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 4 +- .../gpu/drm/arm/display/komeda/komeda_plane.c | 4 +- drivers/gpu/drm/arm/malidp_planes.c | 4 +- drivers/gpu/drm/armada/armada_overlay.c | 4 +- drivers/gpu/drm/drm_atomic_uapi.c | 4 ++ drivers/gpu/drm/drm_color_mgmt.c | 63 +++++++++++++++++-- drivers/gpu/drm/i915/display/intel_sprite.c | 4 +- .../drm/i915/display/skl_universal_plane.c | 4 +- drivers/gpu/drm/nouveau/dispnv04/overlay.c | 4 +- drivers/gpu/drm/omapdrm/omap_plane.c | 4 +- drivers/gpu/drm/sun4i/sun8i_vi_layer.c | 4 +- drivers/gpu/drm/tidss/tidss_plane.c | 6 +- include/drm/drm_color_mgmt.h | 15 ++++- include/drm/drm_plane.h | 16 +++++ 14 files changed, 124 insertions(+), 16 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index 6985362c367d..28481540327f 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -7127,7 +7127,9 @@ static int amdgpu_dm_plane_init(struct amdgpu_display_manager *dm, BIT(DRM_COLOR_YCBCR_BT2020), BIT(DRM_COLOR_YCBCR_LIMITED_RANGE) | BIT(DRM_COLOR_YCBCR_FULL_RANGE), - DRM_COLOR_YCBCR_BT709, DRM_COLOR_YCBCR_LIMITED_RANGE); + BIT(DRM_COLOR_TF_SRGB), + DRM_COLOR_YCBCR_BT709, DRM_COLOR_YCBCR_LIMITED_RANGE, + DRM_COLOR_TF_SRGB); }
supported_rotations = diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_plane.c b/drivers/gpu/drm/arm/display/komeda/komeda_plane.c index 2d5066ea270c..eb8ccf805408 100644 --- a/drivers/gpu/drm/arm/display/komeda/komeda_plane.c +++ b/drivers/gpu/drm/arm/display/komeda/komeda_plane.c @@ -299,8 +299,10 @@ static int komeda_plane_add(struct komeda_kms_dev *kms, BIT(DRM_COLOR_YCBCR_BT2020), BIT(DRM_COLOR_YCBCR_LIMITED_RANGE) | BIT(DRM_COLOR_YCBCR_FULL_RANGE), + BIT(DRM_COLOR_TF_SRGB), DRM_COLOR_YCBCR_BT601, - DRM_COLOR_YCBCR_LIMITED_RANGE); + DRM_COLOR_YCBCR_LIMITED_RANGE, + DRM_COLOR_TF_SRGB); if (err) goto cleanup;
diff --git a/drivers/gpu/drm/arm/malidp_planes.c b/drivers/gpu/drm/arm/malidp_planes.c index 351a85088d0e..0d77a2c0c829 100644 --- a/drivers/gpu/drm/arm/malidp_planes.c +++ b/drivers/gpu/drm/arm/malidp_planes.c @@ -1020,7 +1020,9 @@ int malidp_de_planes_init(struct drm_device *drm) BIT(DRM_COLOR_YCBCR_BT2020), BIT(DRM_COLOR_YCBCR_LIMITED_RANGE) | \ BIT(DRM_COLOR_YCBCR_FULL_RANGE), - enc, range); + BIT(DRM_COLOR_SRGB), + enc, range, + DRM_COLOR_SRGB); if (!ret) /* program the HW registers */ malidp_de_set_color_encoding(plane, enc, range); diff --git a/drivers/gpu/drm/armada/armada_overlay.c b/drivers/gpu/drm/armada/armada_overlay.c index 6346b890279a..ad3a743242f0 100644 --- a/drivers/gpu/drm/armada/armada_overlay.c +++ b/drivers/gpu/drm/armada/armada_overlay.c @@ -589,8 +589,10 @@ int armada_overlay_plane_create(struct drm_device *dev, unsigned long crtcs) BIT(DRM_COLOR_YCBCR_BT601) | BIT(DRM_COLOR_YCBCR_BT709), BIT(DRM_COLOR_YCBCR_LIMITED_RANGE), + BIT(DRM_COLOR_TF_SRGB), DEFAULT_ENCODING, - DRM_COLOR_YCBCR_LIMITED_RANGE); + DRM_COLOR_YCBCR_LIMITED_RANGE, + DRM_COLOR_TF_SRGB);
return ret; } diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c index 268bb69c2e2f..ea95c1224253 100644 --- a/drivers/gpu/drm/drm_atomic_uapi.c +++ b/drivers/gpu/drm/drm_atomic_uapi.c @@ -595,6 +595,8 @@ 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->color_tf_property) { + state->color_tf = val; } else if (property == config->prop_fb_damage_clips) { ret = drm_atomic_replace_property_blob_from_id(dev, &state->fb_damage_clips, @@ -661,6 +663,8 @@ drm_atomic_plane_get_property(struct drm_plane *plane, *val = state->color_encoding; } else if (property == plane->color_range_property) { *val = state->color_range; + } else if (property == plane->color_tf_property) { + *val = state->color_tf; } 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 a183ebae2941..2404b07046c5 100644 --- a/drivers/gpu/drm/drm_color_mgmt.c +++ b/drivers/gpu/drm/drm_color_mgmt.c @@ -106,6 +106,11 @@ * Optional plane enum property to support different non RGB * color parameter ranges. The driver can provide a subset of * standard enum values supported by the DRM plane. + * + * "COLOR_TRANFER_FUNCTION": + * Optional plane enum property to support different + * color luminance mappings. The driver can provide a subset of + * standard enum values supported by the DRM plane. */
/** @@ -480,6 +485,10 @@ static const char * const color_range_name[] = { [DRM_COLOR_YCBCR_LIMITED_RANGE] = "YCbCr limited range", };
+static const char * const color_tf_name[] = { + [DRM_COLOR_TF_SRGB] = "sRGB", + [DRM_COLOR_TF_PQ2084] = "PQ2084", +}; /** * drm_get_color_encoding_name - return a string for color encoding * @encoding: color encoding to compute name of @@ -510,30 +519,49 @@ const char *drm_get_color_range_name(enum drm_color_range range) return color_range_name[range]; }
+/** + * drm_get_color_transfer_function - return a string for color transfer function + * @tf: transfer function to compute name of + * + * In contrast to the other drm_get_*_name functions this one here returns a + * const pointer and hence is threadsafe. + */ +const char *drm_get_color_transfer_function_name(enum drm_color_transfer_function tf) +{ + if (WARN_ON(tf >= ARRAY_SIZE(color_tf_name))) + return "unknown"; + + return color_tf_name[tf]; +} /** * drm_plane_create_color_properties - color encoding related plane properties * @plane: plane object * @supported_encodings: bitfield indicating supported color encodings * @supported_ranges: bitfileld indicating supported color ranges + * @supported_tfs: bitfileld indicating supported color transfer functions * @default_encoding: default color encoding * @default_range: default color range + * @default_tf: default color transfer function * - * Create and attach plane specific COLOR_ENCODING and COLOR_RANGE - * properties to @plane. The supported encodings and ranges should - * be provided in supported_encodings and supported_ranges bitmasks. + * Create and attach plane specific COLOR_ENCODING, COLOR_RANGE and COLOR_TRANSFER_FUNCTION + * properties to @plane. The supported encodings, ranges and tfs should + * be provided in supported_encodings, supported_ranges and supported_tfs bitmasks. * Each bit set in the bitmask indicates that its number as enum * value is supported. */ int drm_plane_create_color_properties(struct drm_plane *plane, u32 supported_encodings, u32 supported_ranges, + u32 supported_tfs, enum drm_color_encoding default_encoding, - enum drm_color_range default_range) + enum drm_color_range default_range, + enum drm_color_transfer_function default_tf) { struct drm_device *dev = plane->dev; struct drm_property *prop; struct drm_prop_enum_list enum_list[max_t(int, DRM_COLOR_ENCODING_MAX, - DRM_COLOR_RANGE_MAX)]; + max_t(int, DRM_COLOR_RANGE_MAX, + DRM_COLOR_TF_MAX))]; int i, len;
if (WARN_ON(supported_encodings == 0 || @@ -546,6 +574,11 @@ int drm_plane_create_color_properties(struct drm_plane *plane, (supported_ranges & BIT(default_range)) == 0)) return -EINVAL;
+ if (WARN_ON(supported_tfs == 0 || + (supported_tfs & -BIT(DRM_COLOR_TF_MAX)) != 0 || + (supported_tfs & BIT(default_tf)) == 0)) + return -EINVAL; + len = 0; for (i = 0; i < DRM_COLOR_ENCODING_MAX; i++) { if ((supported_encodings & BIT(i)) == 0) @@ -584,6 +617,26 @@ int drm_plane_create_color_properties(struct drm_plane *plane, if (plane->state) plane->state->color_range = default_range;
+ + len = 0; + for (i = 0; i < DRM_COLOR_TF_MAX; i++) { + if ((supported_tfs & BIT(i)) == 0) + continue; + + enum_list[len].type = i; + enum_list[len].name = color_tf_name[i]; + len++; + } + + prop = drm_property_create_enum(dev, 0, "COLOR_TRANSFER_FUNCTION", + enum_list, len); + if (!prop) + return -ENOMEM; + plane->color_tf_property = prop; + drm_object_attach_property(&plane->base, prop, default_tf); + if (plane->state) + plane->state->color_tf = default_tf; + return 0; } EXPORT_SYMBOL(drm_plane_create_color_properties); diff --git a/drivers/gpu/drm/i915/display/intel_sprite.c b/drivers/gpu/drm/i915/display/intel_sprite.c index 4cbdb8fd4bb1..2208c3d82246 100644 --- a/drivers/gpu/drm/i915/display/intel_sprite.c +++ b/drivers/gpu/drm/i915/display/intel_sprite.c @@ -1881,8 +1881,10 @@ intel_sprite_plane_create(struct drm_i915_private *dev_priv, BIT(DRM_COLOR_YCBCR_BT709), BIT(DRM_COLOR_YCBCR_LIMITED_RANGE) | BIT(DRM_COLOR_YCBCR_FULL_RANGE), + BIT(DRM_COLOR_TF_SRGB), DRM_COLOR_YCBCR_BT709, - DRM_COLOR_YCBCR_LIMITED_RANGE); + DRM_COLOR_YCBCR_LIMITED_RANGE, + DRM_COLOR_TF_SRGB);
zpos = sprite + 1; drm_plane_create_zpos_immutable_property(&plane->base, zpos); diff --git a/drivers/gpu/drm/i915/display/skl_universal_plane.c b/drivers/gpu/drm/i915/display/skl_universal_plane.c index 1f335cb09149..c2d64ef9ae3b 100644 --- a/drivers/gpu/drm/i915/display/skl_universal_plane.c +++ b/drivers/gpu/drm/i915/display/skl_universal_plane.c @@ -2091,8 +2091,10 @@ skl_universal_plane_create(struct drm_i915_private *dev_priv, supported_csc, BIT(DRM_COLOR_YCBCR_LIMITED_RANGE) | BIT(DRM_COLOR_YCBCR_FULL_RANGE), + BIT(DRM_COLOR_TF_SRGB), DRM_COLOR_YCBCR_BT709, - DRM_COLOR_YCBCR_LIMITED_RANGE); + DRM_COLOR_YCBCR_LIMITED_RANGE, + DRM_COLOR_TF_SRGB);
drm_plane_create_alpha_property(&plane->base); drm_plane_create_blend_mode_property(&plane->base, diff --git a/drivers/gpu/drm/nouveau/dispnv04/overlay.c b/drivers/gpu/drm/nouveau/dispnv04/overlay.c index 37e63e98cd08..fe40e24469d1 100644 --- a/drivers/gpu/drm/nouveau/dispnv04/overlay.c +++ b/drivers/gpu/drm/nouveau/dispnv04/overlay.c @@ -345,8 +345,10 @@ nv10_overlay_init(struct drm_device *device) BIT(DRM_COLOR_YCBCR_BT601) | BIT(DRM_COLOR_YCBCR_BT709), BIT(DRM_COLOR_YCBCR_LIMITED_RANGE), + BIT(DRM_COLOR_TF_SRGB), DRM_COLOR_YCBCR_BT601, - DRM_COLOR_YCBCR_LIMITED_RANGE); + DRM_COLOR_YCBCR_LIMITED_RANGE, + DRM_COLOR_TF_SRGB);
plane->set_params = nv10_set_params; nv10_set_params(plane); diff --git a/drivers/gpu/drm/omapdrm/omap_plane.c b/drivers/gpu/drm/omapdrm/omap_plane.c index 51dc24acea73..0929e1c39653 100644 --- a/drivers/gpu/drm/omapdrm/omap_plane.c +++ b/drivers/gpu/drm/omapdrm/omap_plane.c @@ -319,8 +319,10 @@ struct drm_plane *omap_plane_init(struct drm_device *dev, BIT(DRM_COLOR_YCBCR_BT709), BIT(DRM_COLOR_YCBCR_FULL_RANGE) | BIT(DRM_COLOR_YCBCR_LIMITED_RANGE), + BIT(DRM_COLOR_TF_SRGB), DRM_COLOR_YCBCR_BT601, - DRM_COLOR_YCBCR_FULL_RANGE); + DRM_COLOR_YCBCR_FULL_RANGE, + DRM_COLOR_TF_SRGB);
return plane;
diff --git a/drivers/gpu/drm/sun4i/sun8i_vi_layer.c b/drivers/gpu/drm/sun4i/sun8i_vi_layer.c index 8abb59e2f0c0..d15267db2274 100644 --- a/drivers/gpu/drm/sun4i/sun8i_vi_layer.c +++ b/drivers/gpu/drm/sun4i/sun8i_vi_layer.c @@ -584,8 +584,10 @@ struct sun8i_vi_layer *sun8i_vi_layer_init_one(struct drm_device *drm, ret = drm_plane_create_color_properties(&layer->plane, supported_encodings, supported_ranges, + BIT(DRM_COLOR_TF_SRGB), DRM_COLOR_YCBCR_BT709, - DRM_COLOR_YCBCR_LIMITED_RANGE); + DRM_COLOR_YCBCR_LIMITED_RANGE, + DRM_COLOR_TF_SRGB); if (ret) { dev_err(drm->dev, "Couldn't add encoding and range properties!\n"); return ERR_PTR(ret); diff --git a/drivers/gpu/drm/tidss/tidss_plane.c b/drivers/gpu/drm/tidss/tidss_plane.c index 35067ae674ea..e50857cfd212 100644 --- a/drivers/gpu/drm/tidss/tidss_plane.c +++ b/drivers/gpu/drm/tidss/tidss_plane.c @@ -179,8 +179,10 @@ struct tidss_plane *tidss_plane_create(struct tidss_device *tidss, BIT(DRM_COLOR_YCBCR_BT709)); u32 color_ranges = (BIT(DRM_COLOR_YCBCR_FULL_RANGE) | BIT(DRM_COLOR_YCBCR_LIMITED_RANGE)); + u32 color_tfs = BIT(DRM_COLOR_TF_SRGB; u32 default_encoding = DRM_COLOR_YCBCR_BT601; u32 default_range = DRM_COLOR_YCBCR_FULL_RANGE; + u32 default_tf = DRM_COLOR_TF_SRGB;; u32 blend_modes = (BIT(DRM_MODE_BLEND_PREMULTI) | BIT(DRM_MODE_BLEND_COVERAGE)); int ret; @@ -210,8 +212,10 @@ struct tidss_plane *tidss_plane_create(struct tidss_device *tidss, ret = drm_plane_create_color_properties(&tplane->plane, color_encodings, color_ranges, + color_tfs, default_encoding, - default_range); + default_range, + default_tf); if (ret) goto err;
diff --git a/include/drm/drm_color_mgmt.h b/include/drm/drm_color_mgmt.h index 3043dd73480c..f59806366855 100644 --- a/include/drm/drm_color_mgmt.h +++ b/include/drm/drm_color_mgmt.h @@ -91,11 +91,24 @@ enum drm_color_range { DRM_COLOR_RANGE_MAX, };
+/** + * enum drm_color_transfer_function - common transfer function used for sdr/hdr formats + * + * DRM_COLOR_TF_SRGB - Based on gamma curve and is used for printer/monitors/web + * DRM_COLOR_TF_PQ2084 - Used for HDR and allows for up to 10,000 nit support. +*/ +enum drm_color_transfer_function { + DRM_COLOR_TF_SRGB, + DRM_COLOR_TF_PQ2084, + DRM_COLOR_TF_MAX, +}; int drm_plane_create_color_properties(struct drm_plane *plane, u32 supported_encodings, u32 supported_ranges, + u32 supported_tf, enum drm_color_encoding default_encoding, - enum drm_color_range default_range); + enum drm_color_range default_range, + enum drm_color_transfer_function default_tf);
/** * enum drm_color_lut_tests - hw-specific LUT tests to perform diff --git a/include/drm/drm_plane.h b/include/drm/drm_plane.h index 95ab14a4336a..c85c59501a7a 100644 --- a/include/drm/drm_plane.h +++ b/include/drm/drm_plane.h @@ -179,6 +179,14 @@ struct drm_plane_state { */ enum drm_color_range color_range;
+ /** + * @color_transfer_function: + * + * Transfer function for HDR color/luminance mapping. This will allow the + * driver to know what transfer function should be used to for the current + * format for a proper HDR color/luminance output. + */ + enum drm_color_transfer_function color_tf; /** * @fb_damage_clips: * @@ -741,6 +749,14 @@ struct drm_plane { * See drm_plane_create_color_properties(). */ struct drm_property *color_range_property; + /** + * @color_tf_property: + * + * Optional "COLOR_TRANSFER_FUNCTION" enum property for specifying + * color transfer function for non RGB formats, mostly used for HDR. + * See drm_plane_create_color_properties(). + */ + struct drm_property *color_tf_property;
/** * @scaling_filter_property: property to apply a particular filter while