[PATCH v3 weston 1/5] compositor-drm: Implement support for GAMMA_LUT drm property

[harsha.manjulamallikarjun at in.bosch.com]

From: Harsha M M <harsha.manjulamallikarjun at in.bosch.com>

drmModeCrtcSetGamma is a legacy now. Use the generic drm property
to set Gamma. If GAMMA_LUT is not supported then legacy api will
be used.

Signed-off-by: Harsha M M <harsha.manjulamallikarjun at in.bosch.com>
---
 libweston/compositor-drm.c | 83 ++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 77 insertions(+), 6 deletions(-)

diff --git a/libweston/compositor-drm.c b/libweston/compositor-drm.c
index 8b1ea66..27c95da 100644
--- a/libweston/compositor-drm.c
+++ b/libweston/compositor-drm.c
@@ -196,12 +196,16 @@ static const struct drm_property_info connector_props[] = {
 enum wdrm_crtc_property {
 	WDRM_CRTC_MODE_ID = 0,
 	WDRM_CRTC_ACTIVE,
+	WDRM_CRTC_GAMMA_LUT,
+	WDRM_CRTC_GAMMA_LUT_SIZE,
 	WDRM_CRTC__COUNT
 };
 
 static const struct drm_property_info crtc_props[] = {
 	[WDRM_CRTC_MODE_ID] = { .name = "MODE_ID", },
 	[WDRM_CRTC_ACTIVE] = { .name = "ACTIVE", },
+	[WDRM_CRTC_GAMMA_LUT] = { .name = "GAMMA_LUT", },
+	[WDRM_CRTC_GAMMA_LUT_SIZE] = { .name = "GAMMA_LUT_SIZE", },
 };
 
 /**
@@ -1752,16 +1756,63 @@ drm_output_set_gamma(struct weston_output *output_base,
 	struct drm_output *output = to_drm_output(output_base);
 	struct drm_backend *backend =
 		to_drm_backend(output->base.compositor);
+	uint32_t gamma_prop_id;
+	uint32_t gamma_size_prop_id;
+	struct drm_color_lut *lut = NULL;
+	uint32_t gamma_blobid = 0;
+	uint32_t loop;
+
 
 	/* check */
 	if (output_base->gamma_size != size)
 		return;
 
-	rc = drmModeCrtcSetGamma(backend->drm.fd,
-				 output->crtc_id,
-				 size, r, g, b);
-	if (rc)
-		weston_log("set gamma failed: %m\n");
+	gamma_prop_id = output->props_crtc[WDRM_CRTC_GAMMA_LUT].prop_id;
+	gamma_size_prop_id = output->props_crtc[WDRM_CRTC_GAMMA_LUT_SIZE].
+								prop_id;
+
+	if (gamma_prop_id && gamma_size_prop_id) {
+		lut = malloc(sizeof(struct drm_color_lut) * size);
+		if (!lut) {
+			weston_log("failed to allocate memory for gamma lut\n");
+			goto out;
+		}
+
+		for (loop = 0; loop < size; loop++) {
+			lut[loop].red = r[loop];
+			lut[loop].green = g[loop];
+			lut[loop].blue = b[loop];
+		}
+
+		rc = drmModeCreatePropertyBlob(backend->drm.fd, lut,
+		      sizeof(struct drm_color_lut) * size, &gamma_blobid);
+		if (rc) {
+			weston_log("failed to create drm gamma blob: %m\n");
+			goto out;
+		}
+
+		rc = drmModeObjectSetProperty(backend->drm.fd, output->crtc_id,
+			DRM_MODE_OBJECT_CRTC, gamma_prop_id, gamma_blobid);
+
+		if (rc)
+			weston_log("set of gamma lut property failed for crtc %d: %m\n",
+			     output->crtc_id);
+	} else {
+		rc = drmModeCrtcSetGamma(backend->drm.fd,
+					 output->crtc_id,
+					 size, r, g, b);
+		if (rc)
+			weston_log("set gamma failed for crtc %d: %m\n",
+				   output->crtc_id);
+
+		return;
+	}
+out:
+	if (lut)
+		free(lut);
+	if (gamma_blobid)
+		drmModeDestroyPropertyBlob(backend->drm.fd, gamma_blobid);
+
 }
 
 /* Determine the type of vblank synchronization to use for the output.
@@ -4758,15 +4809,35 @@ drm_output_init_gamma_size(struct drm_output *output)
 {
 	struct drm_backend *backend = to_drm_backend(output->base.compositor);
 	drmModeCrtc *crtc;
+	uint32_t gamma_prop_id;
+	uint32_t gamma_size_prop_id;
+	struct drm_property_info *props_crtc;
+	drmModeObjectProperties *props;
 
 	assert(output->base.compositor);
 	assert(output->crtc_id != 0);
+
 	crtc = drmModeGetCrtc(backend->drm.fd, output->crtc_id);
 	if (!crtc)
 		return -1;
 
 	output->base.gamma_size = crtc->gamma_size;
-
+	props_crtc = &output->props_crtc[0];
+	gamma_prop_id = props_crtc[WDRM_CRTC_GAMMA_LUT].prop_id;
+	gamma_size_prop_id = props_crtc[WDRM_CRTC_GAMMA_LUT_SIZE].prop_id;
+
+	if (gamma_prop_id && gamma_size_prop_id) {
+		props  = drmModeObjectGetProperties(backend->drm.fd,
+						   output->crtc_id,
+						   DRM_MODE_OBJECT_CRTC);
+		if (props) {
+			output->base.gamma_size = drm_property_get_value(
+				       &props_crtc[WDRM_CRTC_GAMMA_LUT_SIZE],
+				       props,
+				       WDRM_CRTC__COUNT);
+		}
+	}
+
 	drmModeFreeCrtc(crtc);
 
 	return 0;
-- 
2.7.4