[Intel-gfx] [PATCH 2/6] drm: introduce color correction properties

Lionel Landwerlin lionel.g.landwerlin at intel.com
Tue Feb 9 12:19:14 UTC 2016


Patch based on a previous series by Shashank Sharma.

v2: Register LUT size properties as range

v3: Fix round in drm_color_lut_get_value() helper
    More docs on how degamma/gamma properties are used

v4: Update contributors

Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>
Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
Signed-off-by: Kumar, Kiran S <kiran.s.kumar at intel.com>
Signed-off-by: Kausal Malladi <kausalmalladi at gmail.com>
---
 Documentation/DocBook/gpu.tmpl      |  58 +++++++++++++++++++-
 drivers/gpu/drm/drm_atomic.c        | 102 +++++++++++++++++++++++++++++++++++-
 drivers/gpu/drm/drm_atomic_helper.c |  10 ++++
 drivers/gpu/drm/drm_crtc.c          |  35 +++++++++++++
 drivers/gpu/drm/drm_crtc_helper.c   |  33 ++++++++++++
 include/drm/drm_crtc.h              |  44 +++++++++++++++-
 include/drm/drm_crtc_helper.h       |   3 ++
 include/uapi/drm/drm_mode.h         |  15 ++++++
 8 files changed, 295 insertions(+), 5 deletions(-)

diff --git a/Documentation/DocBook/gpu.tmpl b/Documentation/DocBook/gpu.tmpl
index fe6b36a..7c49a92 100644
--- a/Documentation/DocBook/gpu.tmpl
+++ b/Documentation/DocBook/gpu.tmpl
@@ -1816,7 +1816,7 @@ void intel_crt_init(struct drm_device *dev)
 	<td valign="top" >Description/Restrictions</td>
 	</tr>
 	<tr>
-	<td rowspan="37" valign="top" >DRM</td>
+	<td rowspan="42" valign="top" >DRM</td>
 	<td valign="top" >Generic</td>
 	<td valign="top" >“rotation”</td>
 	<td valign="top" >BITMASK</td>
@@ -2068,7 +2068,7 @@ void intel_crt_init(struct drm_device *dev)
 	<td valign="top" >property to suggest an Y offset for a connector</td>
 	</tr>
 	<tr>
-	<td rowspan="3" valign="top" >Optional</td>
+	<td rowspan="8" valign="top" >Optional</td>
 	<td valign="top" >“scaling mode”</td>
 	<td valign="top" >ENUM</td>
 	<td valign="top" >{ "None", "Full", "Center", "Full aspect" }</td>
@@ -2092,6 +2092,60 @@ void intel_crt_init(struct drm_device *dev)
 	<td valign="top" >TBD</td>
 	</tr>
 	<tr>
+	<td valign="top" >“DEGAMMA_LUT”</td>
+	<td valign="top" >BLOB</td>
+	<td valign="top" >0</td>
+	<td valign="top" >CRTC</td>
+	<td valign="top" >DRM property to set the degamma LUT mapping
+		pixel data from the framebuffer before it is given to the
+		transformation matrix. The data is an 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]). </td>
+	</tr>
+	<tr>
+	<td valign="top" >“DEGAMMA_LUT_SIZE”</td>
+	<td valign="top" >RANGE | IMMUTABLE</td>
+	<td valign="top" >Min=0, Max=UINT_MAX</td>
+	<td valign="top" >CRTC</td>
+	<td valign="top" >DRM property to gives the size of the LUT to
+		be set on the DEGAMMA_LUT property (the size depends on the
+		underlying hardware).</td>
+	</tr>
+	<tr>
+	<td valign="top" >“CTM_MATRIX”</td>
+	<td valign="top" >BLOB</td>
+	<td valign="top" >0</td>
+	<td valign="top" >CRTC</td>
+	<td valign="top" >DRM property to set the transformation
+		matrix apply to pixel data after the lookup through the
+		degamma LUT and before the lookup through the gamma LUT. The
+		data is an interpreted as a struct drm_color_ctm.</td>
+	</tr>
+	<tr>
+	<td valign="top" >“GAMMA_LUT”</td>
+	<td valign="top" >BLOB</td>
+	<td valign="top" >0</td>
+	<td valign="top" >CRTC</td>
+	<td valign="top" >DRM property to set the gamma LUT mapping
+		pixel data after to the transformation matrix to data sent to
+		the connector. The data is an 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]).</td>
+	</tr>
+	<tr>
+	<td valign="top" >“GAMMA_LUT_SIZE”</td>
+	<td valign="top" >RANGE | IMMUTABLE</td>
+	<td valign="top" >Min=0, Max=UINT_MAX</td>
+	<td valign="top" >CRTC</td>
+	<td valign="top" >DRM property to gives the size of the LUT to
+		be set on the GAMMA_LUT property (the size depends on the
+		underlying hardware).</td>
+	</tr>
+	<tr>
 	<td rowspan="20" valign="top" >i915</td>
 	<td rowspan="2" valign="top" >Generic</td>
 	<td valign="top" >"Broadcast RGB"</td>
diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 8fb469c..7507762 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -28,6 +28,7 @@
 
 #include <drm/drmP.h>
 #include <drm/drm_atomic.h>
+#include <drm/drm_mode.h>
 #include <drm/drm_plane_helper.h>
 
 /**
@@ -388,6 +389,58 @@ int drm_atomic_set_mode_prop_for_crtc(struct drm_crtc_state *state,
 EXPORT_SYMBOL(drm_atomic_set_mode_prop_for_crtc);
 
 /**
+ * drm_atomic_replace_property_blob - replace a blob property
+ * @blob: a pointer to the member blob to be replaced
+ * @new_blob: the new blob to replace with
+ * @expected_size: the expected size of the new blob
+ * @replaced: whether the blob has been replaced
+ *
+ * RETURNS:
+ * Zero on success, error code on failure
+ */
+static int
+drm_atomic_replace_property_blob(struct drm_property_blob **blob,
+				 struct drm_property_blob *new_blob,
+				 size_t expected_size,
+				 bool *replaced)
+{
+	struct drm_property_blob *old_blob = *blob;
+
+	if (old_blob == new_blob)
+		return 0;
+
+	if (new_blob != NULL && new_blob->length != expected_size)
+		return -EINVAL;
+
+	if (old_blob != NULL)
+		drm_property_unreference_blob(old_blob);
+	*blob = new_blob;
+	*replaced = true;
+
+	return 0;
+}
+
+static int
+drm_atomic_replace_property_blob_from_id(struct drm_crtc *crtc,
+					 struct drm_property_blob **blob,
+					 uint64_t blob_id,
+					 size_t expected_size,
+					 bool *replaced)
+{
+	struct drm_device *dev = crtc->dev;
+	struct drm_property_blob *new_blob = NULL;
+
+	if (blob_id != 0) {
+		new_blob = drm_property_lookup_blob(dev, blob_id);
+		if (new_blob == NULL)
+			return -EINVAL;
+	}
+
+	return drm_atomic_replace_property_blob(blob, new_blob,
+						expected_size, replaced);
+}
+
+/**
  * drm_atomic_crtc_set_property - set property on CRTC
  * @crtc: the drm CRTC to set a property on
  * @state: the state object to update with the new property value
@@ -419,8 +472,47 @@ int drm_atomic_crtc_set_property(struct drm_crtc *crtc,
 		ret = drm_atomic_set_mode_prop_for_crtc(state, mode);
 		drm_property_unreference_blob(mode);
 		return ret;
-	}
-	else if (crtc->funcs->atomic_set_property)
+	} else if (property == config->degamma_lut_property) {
+		bool replaced = false;
+		uint64_t lut_size = 0;
+
+		ret = drm_object_property_get_value(&crtc->base,
+					config->degamma_lut_size_property,
+					&lut_size);
+		if (ret == 0)
+			ret = drm_atomic_replace_property_blob_from_id(crtc,
+					&state->degamma_lut,
+					val,
+					lut_size * sizeof(struct drm_color_lut),
+					&replaced);
+		state->color_mgmt_changed = replaced;
+		return ret;
+	} else if (property == config->ctm_matrix_property) {
+		bool replaced = false;
+
+		ret = drm_atomic_replace_property_blob_from_id(crtc,
+					&state->ctm_matrix,
+					val,
+					sizeof(struct drm_color_ctm),
+							       &replaced);
+		state->color_mgmt_changed = replaced;
+		return ret;
+	} else if (property == config->gamma_lut_property) {
+		bool replaced = false;
+		uint64_t lut_size = 0;
+
+		ret = drm_object_property_get_value(&crtc->base,
+					config->gamma_lut_size_property,
+					&lut_size);
+		if (ret == 0)
+			ret = drm_atomic_replace_property_blob_from_id(crtc,
+					&state->gamma_lut,
+					val,
+					lut_size * sizeof(struct drm_color_lut),
+					&replaced);
+		state->color_mgmt_changed = replaced;
+		return ret;
+	} else if (crtc->funcs->atomic_set_property)
 		return crtc->funcs->atomic_set_property(crtc, state, property, val);
 	else
 		return -EINVAL;
@@ -456,6 +548,12 @@ drm_atomic_crtc_get_property(struct drm_crtc *crtc,
 		*val = state->active;
 	else if (property == config->prop_mode_id)
 		*val = (state->mode_blob) ? state->mode_blob->base.id : 0;
+	else if (property == config->degamma_lut_property)
+		*val = (state->degamma_lut) ? state->degamma_lut->base.id : 0;
+	else if (property == config->ctm_matrix_property)
+		*val = (state->ctm_matrix) ? state->ctm_matrix->base.id : 0;
+	else if (property == config->gamma_lut_property)
+		*val = (state->gamma_lut) ? state->gamma_lut->base.id : 0;
 	else if (crtc->funcs->atomic_get_property)
 		return crtc->funcs->atomic_get_property(crtc, state, property, val);
 	else
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 2b430b0..d13dfd8 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -2513,10 +2513,17 @@ void __drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc,
 
 	if (state->mode_blob)
 		drm_property_reference_blob(state->mode_blob);
+	if (state->degamma_lut)
+		drm_property_reference_blob(state->degamma_lut);
+	if (state->ctm_matrix)
+		drm_property_reference_blob(state->ctm_matrix);
+	if (state->gamma_lut)
+		drm_property_reference_blob(state->gamma_lut);
 	state->mode_changed = false;
 	state->active_changed = false;
 	state->planes_changed = false;
 	state->connectors_changed = false;
+	state->color_mgmt_changed = false;
 	state->event = NULL;
 }
 EXPORT_SYMBOL(__drm_atomic_helper_crtc_duplicate_state);
@@ -2557,6 +2564,9 @@ void __drm_atomic_helper_crtc_destroy_state(struct drm_crtc *crtc,
 					    struct drm_crtc_state *state)
 {
 	drm_property_unreference_blob(state->mode_blob);
+	drm_property_unreference_blob(state->degamma_lut);
+	drm_property_unreference_blob(state->ctm_matrix);
+	drm_property_unreference_blob(state->gamma_lut);
 }
 EXPORT_SYMBOL(__drm_atomic_helper_crtc_destroy_state);
 
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index b19c8f4..8e8f57a 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -1565,6 +1565,41 @@ static int drm_mode_create_standard_properties(struct drm_device *dev)
 		return -ENOMEM;
 	dev->mode_config.prop_mode_id = prop;
 
+	prop = drm_property_create(dev,
+			DRM_MODE_PROP_BLOB,
+			"DEGAMMA_LUT", 0);
+	if (!prop)
+		return -ENOMEM;
+	dev->mode_config.degamma_lut_property = prop;
+
+	prop = drm_property_create_range(dev,
+			DRM_MODE_PROP_IMMUTABLE,
+			"DEGAMMA_LUT_SIZE", 0, UINT_MAX);
+	if (!prop)
+		return -ENOMEM;
+	dev->mode_config.degamma_lut_size_property = prop;
+
+	prop = drm_property_create(dev,
+			DRM_MODE_PROP_BLOB,
+			"CTM_MATRIX", 0);
+	if (!prop)
+		return -ENOMEM;
+	dev->mode_config.ctm_matrix_property = prop;
+
+	prop = drm_property_create(dev,
+			DRM_MODE_PROP_BLOB,
+			"GAMMA_LUT", 0);
+	if (!prop)
+		return -ENOMEM;
+	dev->mode_config.gamma_lut_property = prop;
+
+	prop = drm_property_create_range(dev,
+			DRM_MODE_PROP_IMMUTABLE,
+			"GAMMA_LUT_SIZE", 0, UINT_MAX);
+	if (!prop)
+		return -ENOMEM;
+	dev->mode_config.gamma_lut_size_property = prop;
+
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c
index 9f8b894..3cd8cbb 100644
--- a/drivers/gpu/drm/drm_crtc_helper.c
+++ b/drivers/gpu/drm/drm_crtc_helper.c
@@ -1073,3 +1073,36 @@ int drm_helper_crtc_mode_set_base(struct drm_crtc *crtc, int x, int y,
 	return drm_plane_helper_commit(plane, plane_state, old_fb);
 }
 EXPORT_SYMBOL(drm_helper_crtc_mode_set_base);
+
+/**
+ * drm_helper_crtc_enable_color_mgmt - enable color management properties
+ * @crtc: DRM CRTC
+ * @degamma_lut_size: the size of the degamma lut (before CSC)
+ * @gamma_lut_size: the size of the gamma lut (after CSC)
+ *
+ * This function lets the driver enable the color correction properties on a
+ * CRTC. This includes 3 degamma, csc and gamma properties that userspace can
+ * set and 2 size properties to inform the userspace of the lut sizes.
+ */
+void drm_helper_crtc_enable_color_mgmt(struct drm_crtc *crtc,
+				       int degamma_lut_size,
+				       int gamma_lut_size)
+{
+	struct drm_device *dev = crtc->dev;
+	struct drm_mode_config *config = &dev->mode_config;
+
+	drm_object_attach_property(&crtc->base,
+				   config->degamma_lut_property, 0);
+	drm_object_attach_property(&crtc->base,
+				   config->ctm_matrix_property, 0);
+	drm_object_attach_property(&crtc->base,
+				   config->gamma_lut_property, 0);
+
+	drm_object_attach_property(&crtc->base,
+				   config->degamma_lut_size_property,
+				   degamma_lut_size);
+	drm_object_attach_property(&crtc->base,
+				   config->gamma_lut_size_property,
+				   gamma_lut_size);
+}
+EXPORT_SYMBOL(drm_helper_crtc_enable_color_mgmt);
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 8c7fb3d..e07b174 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -305,6 +305,8 @@ struct drm_plane_helper_funcs;
  * @mode_changed: crtc_state->mode or crtc_state->enable has been changed
  * @active_changed: crtc_state->active has been toggled.
  * @connectors_changed: connectors to this crtc have been updated
+ * @color_mgmt_changed: color management properties have changed (degamma or
+ *	gamma LUT or CSC matrix)
  * @plane_mask: bitmask of (1 << drm_plane_index(plane)) of attached planes
  * @connector_mask: bitmask of (1 << drm_connector_index(connector)) of attached connectors
  * @encoder_mask: bitmask of (1 << drm_encoder_index(encoder)) of attached encoders
@@ -312,6 +314,11 @@ struct drm_plane_helper_funcs;
  * 	update to ensure framebuffer cleanup isn't done too early
  * @adjusted_mode: for use by helpers and drivers to compute adjusted mode timings
  * @mode: current mode timings
+ * @degamma_lut: Lookup table for converting framebuffer pixel data
+ *	before apply the conversion matrix
+ * @ctm_matrix: Transformation matrix
+ * @gamma_lut: Lookup table for converting pixel data after the
+ *	conversion matrix
  * @event: optional pointer to a DRM event to signal upon completion of the
  * 	state update
  * @state: backpointer to global drm_atomic_state
@@ -333,6 +340,7 @@ struct drm_crtc_state {
 	bool mode_changed : 1;
 	bool active_changed : 1;
 	bool connectors_changed : 1;
+	bool color_mgmt_changed : 1;
 
 	/* attached planes bitmask:
 	 * WARNING: transitional helpers do not maintain plane_mask so
@@ -355,6 +363,11 @@ struct drm_crtc_state {
 	/* blob property to expose current mode to atomic userspace */
 	struct drm_property_blob *mode_blob;
 
+	/* blob property to expose color management to userspace */
+	struct drm_property_blob *degamma_lut;
+	struct drm_property_blob *ctm_matrix;
+	struct drm_property_blob *gamma_lut;
+
 	struct drm_pending_vblank_event *event;
 
 	struct drm_atomic_state *state;
@@ -757,7 +770,7 @@ struct drm_crtc {
 	int x, y;
 	const struct drm_crtc_funcs *funcs;
 
-	/* CRTC gamma size for reporting to userspace */
+	/* Legacy FB CRTC gamma size for reporting to userspace */
 	uint32_t gamma_size;
 	uint16_t *gamma_store;
 
@@ -2025,6 +2038,15 @@ struct drm_mode_config_funcs {
  * @property_blob_list: list of all the blob property objects
  * @blob_lock: mutex for blob property allocation and management
  * @*_property: core property tracking
+ * @degamma_lut_property: LUT used to convert the framebuffer's colors to linear
+ *	gamma
+ * @degamma_lut_size_property: size of the degamma LUT as supported by the
+ *	driver (read-only)
+ * @ctm_matrix_property: Matrix used to convert colors after the lookup in the
+ *	degamma LUT
+ * @gamma_lut_property: LUT used to convert the colors, after the CSC matrix, to
+ *	the gamma space of the connected screen (read-only)
+ * @gamma_lut_size_property: size of the gamma LUT as supported by the driver
  * @preferred_depth: preferred RBG pixel depth, used by fb helpers
  * @prefer_shadow: hint to userspace to prefer shadow-fb rendering
  * @async_page_flip: does this device support async flips on the primary plane?
@@ -2126,6 +2148,13 @@ struct drm_mode_config {
 	struct drm_property *aspect_ratio_property;
 	struct drm_property *dirty_info_property;
 
+	/* Optional color correction properties */
+	struct drm_property *degamma_lut_property;
+	struct drm_property *degamma_lut_size_property;
+	struct drm_property *ctm_matrix_property;
+	struct drm_property *gamma_lut_property;
+	struct drm_property *gamma_lut_size_property;
+
 	/* properties for virtual machine layout */
 	struct drm_property *suggested_x_property;
 	struct drm_property *suggested_y_property;
@@ -2548,6 +2577,19 @@ static inline struct drm_property *drm_property_find(struct drm_device *dev,
 	return mo ? obj_to_property(mo) : NULL;
 }
 
+/*
+ * Extract a degamma/gamma LUT value provided by user and round it to the
+ * precision supported by the hardware.
+ */
+static inline uint32_t drm_color_lut_extract(uint32_t user_input,
+					     uint32_t bit_precision)
+{
+	uint32_t val = ((user_input << 1) + 1) >> (16 - bit_precision + 1);
+	uint32_t max = 0xffff >> (16 - bit_precision);
+
+	return clamp_val(val, 0, max);
+}
+
 /* Plane list iterator for legacy (overlay only) planes. */
 #define drm_for_each_legacy_plane(plane, dev) \
 	list_for_each_entry(plane, &(dev)->mode_config.plane_list, head) \
diff --git a/include/drm/drm_crtc_helper.h b/include/drm/drm_crtc_helper.h
index 4b37afa..97fa894 100644
--- a/include/drm/drm_crtc_helper.h
+++ b/include/drm/drm_crtc_helper.h
@@ -48,6 +48,9 @@ extern bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
 				     struct drm_display_mode *mode,
 				     int x, int y,
 				     struct drm_framebuffer *old_fb);
+extern void drm_helper_crtc_enable_color_mgmt(struct drm_crtc *crtc,
+					      int degamma_lut_size,
+					      int gamma_lut_size);
 extern bool drm_helper_crtc_in_use(struct drm_crtc *crtc);
 extern bool drm_helper_encoder_in_use(struct drm_encoder *encoder);
 
diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h
index 50adb46..c021743 100644
--- a/include/uapi/drm/drm_mode.h
+++ b/include/uapi/drm/drm_mode.h
@@ -487,6 +487,21 @@ struct drm_mode_crtc_lut {
 	__u64 blue;
 };
 
+struct drm_color_ctm {
+	/* Conversion matrix in S31.32 format. */
+	__s64 matrix[9];
+};
+
+struct drm_color_lut {
+	/*
+	 * Data is U0.16 fixed point format.
+	 */
+	__u16 red;
+	__u16 green;
+	__u16 blue;
+	__u16 reserved;
+};
+
 #define DRM_MODE_PAGE_FLIP_EVENT 0x01
 #define DRM_MODE_PAGE_FLIP_ASYNC 0x02
 #define DRM_MODE_PAGE_FLIP_FLAGS (DRM_MODE_PAGE_FLIP_EVENT|DRM_MODE_PAGE_FLIP_ASYNC)
-- 
2.7.0



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