From: Bhawanpreet Lakha Bhawanpreet.Lakha@amd.com
SDR is typically mastered at 200 nits and HDR is mastered at up to 10,000 nits. Due to this luminance range difference if we blend a SDR and HDR plane together, we can run into problems where the HDR plane is too bright or the SDR plane is too dim
A common solution to this problem is to boost the SDR plane so that its not too dim.
This patch introduces a "sdr_white_level" property, this property can be used by the userspace to boost the SDR content luminance. The boost value is a explicit luiminance value in nits. This allows the userspace to set the maximum white level for the SDR plane.
Signed-off-by: Bhawanpreet Lakha Bhawanpreet.Lakha@amd.com Signed-off-by: Harry Wentland harry.wentland@amd.com --- drivers/gpu/drm/drm_atomic_uapi.c | 4 ++++ drivers/gpu/drm/drm_color_mgmt.c | 17 +++++++++++++++++ include/drm/drm_color_mgmt.h | 6 ++++++ include/drm/drm_plane.h | 14 ++++++++++++++ 4 files changed, 41 insertions(+)
diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c index ea95c1224253..b3b6de7b74aa 100644 --- a/drivers/gpu/drm/drm_atomic_uapi.c +++ b/drivers/gpu/drm/drm_atomic_uapi.c @@ -597,6 +597,8 @@ static int drm_atomic_plane_set_property(struct drm_plane *plane, state->color_range = val; } else if (property == plane->color_tf_property) { state->color_tf = val; + } else if (property == plane->sdr_white_level_property) { + state->sdr_white_level = val; } else if (property == config->prop_fb_damage_clips) { ret = drm_atomic_replace_property_blob_from_id(dev, &state->fb_damage_clips, @@ -665,6 +667,8 @@ drm_atomic_plane_get_property(struct drm_plane *plane, *val = state->color_range; } else if (property == plane->color_tf_property) { *val = state->color_tf; + } else if (property == plane->sdr_white_level_property) { + *val = state->sdr_white_level; } 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 2404b07046c5..a0b77d7d0565 100644 --- a/drivers/gpu/drm/drm_color_mgmt.c +++ b/drivers/gpu/drm/drm_color_mgmt.c @@ -519,6 +519,23 @@ const char *drm_get_color_range_name(enum drm_color_range range) return color_range_name[range]; }
+int drm_plane_create_sdr_white_level_property(struct drm_plane *plane){ + + struct drm_property *prop; + + prop = drm_property_create_range(plane->dev, 0, "SDR_WHITE_LEVEL", 0, UINT_MAX); + + if (!prop) + return -ENOMEM; + + plane->sdr_white_level_property = prop; + drm_object_attach_property(&plane->base, prop, DRM_DEFAULT_SDR_WHITE_LEVEL); + + if (plane->state) + plane->state->sdr_white_level = DRM_DEFAULT_SDR_WHITE_LEVEL; + + return 0; +} /** * drm_get_color_transfer_function - return a string for color transfer function * @tf: transfer function to compute name of diff --git a/include/drm/drm_color_mgmt.h b/include/drm/drm_color_mgmt.h index f59806366855..a020346b1747 100644 --- a/include/drm/drm_color_mgmt.h +++ b/include/drm/drm_color_mgmt.h @@ -26,6 +26,12 @@ #include <linux/ctype.h> #include <drm/drm_property.h>
+/** + * Default SDR white level in nits. Although there is no standard SDR nit level, 200 + * is chosen as the default since that is the generally accepted value. + */ +#define DRM_DEFAULT_SDR_WHITE_LEVEL 200 + struct drm_crtc; struct drm_plane;
diff --git a/include/drm/drm_plane.h b/include/drm/drm_plane.h index c85c59501a7a..fad8b7dd430c 100644 --- a/include/drm/drm_plane.h +++ b/include/drm/drm_plane.h @@ -187,6 +187,11 @@ struct drm_plane_state { * format for a proper HDR color/luminance output. */ enum drm_color_transfer_function color_tf; + /** + * @sdr_white_level: + * SDR white level boost for HDR+SDR multi plane usecases. max white level in nits + */ + unsigned int sdr_white_level; /** * @fb_damage_clips: * @@ -757,6 +762,15 @@ struct drm_plane { * See drm_plane_create_color_properties(). */ struct drm_property *color_tf_property; + /** + * @sdr_white_level: + * + * Optional sdr_white_level. When HDR and SDR are combined in multi plane + * overlay cases, the sdr plane will be very dim. This property allows + * the driver to boost the sdr plane's white level. The value should be + * max white level in nits. + */ + struct drm_property *sdr_white_level_property;
/** * @scaling_filter_property: property to apply a particular filter while