From: Kieran Bingham <kieran.bingham+rene...@ideasonboard.com>
Extend the existing color management properties to support provision
of a 3D cubic look up table, allowing for color specific adjustments.
Signed-off-by: Kieran Bingham <kieran.bingham+rene...@ideasonboard.com>
Co-developed-by: Laurent Pinchart <laurent.pinchart+rene...@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+rene...@ideasonboard.com>
---
drivers/gpu/drm/drm_atomic_helper.c | 1 +
drivers/gpu/drm/drm_atomic_state_helper.c | 3 ++
drivers/gpu/drm/drm_atomic_uapi.c | 10 ++++++
drivers/gpu/drm/drm_color_mgmt.c | 41 +++++++++++++++++++----
drivers/gpu/drm/drm_mode_config.c | 14 ++++++++
include/drm/drm_crtc.h | 9 +++++
include/drm/drm_mode_config.h | 11 ++++++
7 files changed, 82 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/drm_atomic_helper.c
b/drivers/gpu/drm/drm_atomic_helper.c
index ba1507036f26..0f54897d3c8d 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -3558,6 +3558,7 @@ int drm_atomic_helper_legacy_gamma_set(struct drm_crtc
*crtc,
replaced = drm_property_replace_blob(&crtc_state->degamma_lut, NULL);
replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL);
replaced |= drm_property_replace_blob(&crtc_state->gamma_lut, blob);
+ replaced |= drm_property_replace_blob(&crtc_state->cubic_lut, NULL);
crtc_state->color_mgmt_changed |= replaced;
ret = drm_atomic_commit(state);
diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c
b/drivers/gpu/drm/drm_atomic_state_helper.c
index ddcf5c2c8e6a..61c685b50677 100644
--- a/drivers/gpu/drm/drm_atomic_state_helper.c
+++ b/drivers/gpu/drm/drm_atomic_state_helper.c
@@ -141,6 +141,8 @@ void __drm_atomic_helper_crtc_duplicate_state(struct
drm_crtc *crtc,
drm_property_blob_get(state->ctm);
if (state->gamma_lut)
drm_property_blob_get(state->gamma_lut);
+ if (state->cubic_lut)
+ drm_property_blob_get(state->cubic_lut);
state->mode_changed = false;
state->active_changed = false;
state->planes_changed = false;
@@ -213,6 +215,7 @@ void __drm_atomic_helper_crtc_destroy_state(struct
drm_crtc_state *state)
drm_property_blob_put(state->degamma_lut);
drm_property_blob_put(state->ctm);
drm_property_blob_put(state->gamma_lut);
+ drm_property_blob_put(state->cubic_lut);
}
EXPORT_SYMBOL(__drm_atomic_helper_crtc_destroy_state);
diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
index 268bb69c2e2f..07229acab71c 100644
--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -471,6 +471,14 @@ static int drm_atomic_crtc_set_property(struct drm_crtc
*crtc,
&replaced);
state->color_mgmt_changed |= replaced;
return ret;
+ } else if (property == config->cubic_lut_property) {
+ ret = drm_atomic_replace_property_blob_from_id(dev,
+ &state->cubic_lut,
+ val,
+ -1, sizeof(struct drm_color_lut),
+ &replaced);
+ state->color_mgmt_changed |= replaced;
+ return ret;
} else if (property == config->prop_out_fence_ptr) {
s32 __user *fence_ptr = u64_to_user_ptr(val);
@@ -516,6 +524,8 @@ drm_atomic_crtc_get_property(struct drm_crtc *crtc,
*val = (state->ctm) ? state->ctm->base.id : 0;
else if (property == config->gamma_lut_property)
*val = (state->gamma_lut) ? state->gamma_lut->base.id : 0;
+ else if (property == config->cubic_lut_property)
+ *val = (state->cubic_lut) ? state->cubic_lut->base.id : 0;
else if (property == config->prop_out_fence_ptr)
*val = 0;
else if (property == crtc->scaling_filter_property)
diff --git a/drivers/gpu/drm/drm_color_mgmt.c b/drivers/gpu/drm/drm_color_mgmt.c
index 3bcabc2f6e0e..85bbbc8ce8e5 100644
--- a/drivers/gpu/drm/drm_color_mgmt.c
+++ b/drivers/gpu/drm/drm_color_mgmt.c
@@ -33,7 +33,7 @@
/**
* DOC: overview
*
- * Color management or color space adjustments is supported through a set of 5
+ * Color management or color space adjustments is supported through a set of 7
* properties on the &drm_crtc object. They are set up by calling
* drm_crtc_enable_color_mgmt().
*
@@ -60,7 +60,7 @@
* “CTM”:
* Blob property to set the current transformation matrix (CTM) apply to
* pixel data after the lookup through the degamma LUT and before the
- * lookup through the gamma LUT. The data is interpreted as a struct
+ * lookup through the cubic LUT. The data is interpreted as a struct
* &drm_color_ctm.
*
* Setting this to NULL (blob property value set to 0) means a
@@ -68,13 +68,40 @@
* boot-up state too. Drivers can access the blob for the color conversion
* matrix through &drm_crtc_state.ctm.
*
+ * ”CUBIC_LUT”:
+ * Blob property to set the cubic (3D) lookup table performing color
+ * mapping after the transformation matrix and before the lookup through
+ * the gamma LUT. Unlike the degamma and gamma LUTs that map color
+ * components independently, the 3D LUT converts an input color to an
+ * output color by indexing into the 3D table using the color components
+ * as a 3D coordinate. The LUT is subsampled as 8-bit (or more) precision
+ * would require too much storage space in the hardware, so the precision
+ * of the color components is reduced before the look up, and the low
+ * order bits may be used to interpolate between the nearest points in 3D
+ * space.
+ *
+ * The data is interpreted as an array of &struct drm_color_lut elements.
+ * Hardware might choose not to use the full precision of the LUT
+ * elements.
+ *
+ * Setting this to NULL (blob property value set to 0) means the output
+ * color is identical to the input color. This is generally the driver
+ * boot-up state too. Drivers can access this blob through
+ * &drm_crtc_state.cubic_lut.
+ *
+ * ”CUBIC_LUT_SIZE”:
+ * Unsigned range property to give the size of the lookup table to be set
+ * on the CUBIC_LUT property (the size depends on the underlying hardware).
+ * If drivers support multiple LUT sizes then they should publish the
+ * largest size, and sub-sample smaller sized LUTs appropriately.
+ *
* “GAMMA_LUT”:
* Blob property to set the gamma lookup table (LUT) mapping pixel data
- * after the transformation matrix to data sent to the connector. The
- * data is interpreted as an array of &struct drm_color_lut elements.
- * Hardware might choose not to use the full precision of the LUT elements
- * nor use all the elements of the LUT (for example the hardware might
- * choose to interpolate between LUT[0] and LUT[4]).
+ * after the cubic LUT to data sent to the connector. The data is
+ * interpreted as an array of &struct drm_color_lut elements. Hardware
+ * might choose not to use the full precision of the LUT elements nor use
+ * all the elements of the LUT (for example the hardware might choose to
+ * interpolate between LUT[0] and LUT[4]).
*
* Setting this to NULL (blob property value set to 0) means a
* linear/pass-thru gamma table should be used. This is generally the
diff --git a/drivers/gpu/drm/drm_mode_config.c
b/drivers/gpu/drm/drm_mode_config.c
index f1affc1bb679..6c3324f60e7d 100644
--- a/drivers/gpu/drm/drm_mode_config.c
+++ b/drivers/gpu/drm/drm_mode_config.c
@@ -364,6 +364,20 @@ static int drm_mode_create_standard_properties(struct
drm_device *dev)
return -ENOMEM;
dev->mode_config.gamma_lut_size_property = prop;
+ prop = drm_property_create(dev,
+ DRM_MODE_PROP_BLOB,
+ "CUBIC_LUT", 0);
+ if (!prop)
+ return -ENOMEM;
+ dev->mode_config.cubic_lut_property = prop;
+
+ prop = drm_property_create_range(dev,
+ DRM_MODE_PROP_IMMUTABLE,
+ "CUBIC_LUT_SIZE", 0, UINT_MAX);
+ if (!prop)
+ return -ENOMEM;
+ dev->mode_config.cubic_lut_size_property = prop;
+
prop = drm_property_create(dev,
DRM_MODE_PROP_IMMUTABLE | DRM_MODE_PROP_BLOB,
"IN_FORMATS", 0);
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 5f43d64d2a07..df5cc2239adb 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -288,6 +288,15 @@ struct drm_crtc_state {
*/
struct drm_property_blob *gamma_lut;
+ /**
+ * @cubic_lut:
+ *
+ * Cubic Lookup table for converting pixel data. See
+ * drm_crtc_enable_color_mgmt(). The blob (if not NULL) is a 3D array
+ * of &struct drm_color_lut.
+ */
+ struct drm_property_blob *cubic_lut;
+
/**
* @target_vblank:
*
diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
index ab424ddd7665..8edb0094e5a7 100644
--- a/include/drm/drm_mode_config.h
+++ b/include/drm/drm_mode_config.h
@@ -800,6 +800,17 @@ struct drm_mode_config {
*/
struct drm_property *gamma_lut_size_property;
+ /**
+ * @cubic_lut_property: Optional CRTC property to set the 3D LUT used to
+ * convert color spaces.
+ */
+ struct drm_property *cubic_lut_property;
+ /**
+ * @cubic_lut_size_property: Optional CRTC property for the size of the
+ * 3D LUT as supported by the driver (read-only).
+ */
+ struct drm_property *cubic_lut_size_property;
+
/**
* @suggested_x_property: Optional connector property with a hint for
* the position of the output on the host's screen.
