drm: introduce pipe color correction properties

Patch based on a previous series by Shashank Sharma.

This introduces optional properties to enable color correction at the
pipe level. It relies on 3 transformations applied to every pixels
displayed. First a lookup into a degamma table, then a multiplication
of the rgb components by a 3x3 matrix and finally another lookup into
a gamma table.

The following properties can be added to a pipe :
  - DEGAMMA_LUT : blob containing degamma LUT
  - DEGAMMA_LUT_SIZE : number of elements in DEGAMMA_LUT
  - CTM : transformation matrix applied after the degamma LUT
  - GAMMA_LUT : blob containing gamma LUT
  - GAMMA_LUT_SIZE : number of elements in GAMMA_LUT

DEGAMMA_LUT_SIZE and GAMMA_LUT_SIZE are read only properties, set by
the driver to tell userspace applications what sizes should be the
lookup tables in DEGAMMA_LUT and GAMMA_LUT.

A helper is also provided so legacy gamma correction is redirected
through these new properties.

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

v5: Rename CTM_MATRIX property to CTM (Doh!)
    Add legacy gamma_set atomic helper
    Describe CTM/LUT acronyms in the kernel doc

v6: Fix missing blob unref in drm_atomic_helper_crtc_reset

Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
Signed-off-by: Kumar, Kiran S <kiran.s.kumar@intel.com>
Signed-off-by: Kausal Malladi <kausalmalladi@gmail.com>
Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Acked-by: Rob Bradford <robert.bradford@intel.com>
[danvet: CrOS maintainers are also happy with the userspacde side:
https://codereview.chromium.org/1182063002/ ]
Reviewed-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1456506302-640-4-git-send-email-lionel.g.landwerlin@intel.com

1 files changed, 86 insertions, 2 deletions

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 8fb469c..c7e7a95 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 +389,59 @@ 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 void
+drm_atomic_replace_property_blob(struct drm_property_blob **blob,
+				 struct drm_property_blob *new_blob,
+				 bool *replaced)
+{
+	struct drm_property_blob *old_blob = *blob;
+
+	if (old_blob == new_blob)
+		return;
+
+	if (old_blob)
+		drm_property_unreference_blob(old_blob);
+	if (new_blob)
+		drm_property_reference_blob(new_blob);
+	*blob = new_blob;
+	*replaced = true;
+
+	return;
+}
+
+static int
+drm_atomic_replace_property_blob_from_id(struct drm_crtc *crtc,
+					 struct drm_property_blob **blob,
+					 uint64_t blob_id,
+					 ssize_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;
+		if (expected_size > 0 && expected_size != new_blob->length)
+			return -EINVAL;
+	}
+
+	drm_atomic_replace_property_blob(blob, new_blob, replaced);
+
+	return 0;
+}
+
+/**
  * 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
@@ -409,6 +463,7 @@ int drm_atomic_crtc_set_property(struct drm_crtc *crtc,
 {
 	struct drm_device *dev = crtc->dev;
 	struct drm_mode_config *config = &dev->mode_config;
+	bool replaced = false;
 	int ret;
 
 	if (property == config->prop_active)
@@ -419,8 +474,31 @@ 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) {
+		ret = drm_atomic_replace_property_blob_from_id(crtc,
+					&state->degamma_lut,
+					val,
+					-1,
+					&replaced);
+		state->color_mgmt_changed = replaced;
+		return ret;
+	} else if (property == config->ctm_property) {
+		ret = drm_atomic_replace_property_blob_from_id(crtc,
+					&state->ctm,
+					val,
+					sizeof(struct drm_color_ctm),
+					&replaced);
+		state->color_mgmt_changed = replaced;
+		return ret;
+	} else if (property == config->gamma_lut_property) {
+		ret = drm_atomic_replace_property_blob_from_id(crtc,
+					&state->gamma_lut,
+					val,
+					-1,
+					&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 +534,12 @@ 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_property)
+		*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 (crtc->funcs->atomic_get_property)
 		return crtc->funcs->atomic_get_property(crtc, state, property, val);
 	else