+
+/**
+ * drm_atomic_helper_legacy_gamma_set - set the legacy gamma correction table
+ * @crtc: CRTC object
+ * @red: red correction table
+ * @green: green correction table
+ * @blue: green correction table
+ * @start:
+ * @size: size of the tables
+ *
+ * Implements support for legacy gamma correction table for drivers
+ * that support color management through the DEGAMMA_LUT/GAMMA_LUT
+ * properties.
+ */
+void drm_atomic_helper_legacy_gamma_set(struct drm_crtc *crtc,
+ u16 *red, u16 *green, u16 *blue,
+ uint32_t start, uint32_t size)
+{
+ struct drm_device *dev = crtc->dev;
+ struct drm_mode_config *config = &dev->mode_config;
+ struct drm_atomic_state *state;
+ struct drm_crtc_state *crtc_state;
+ struct drm_property_blob *blob = NULL;
+ struct drm_color_lut *blob_data;
+ int i, ret = 0;
+
+ state = drm_atomic_state_alloc(crtc->dev);
+ if (!state)
+ return;
+
+ blob = drm_property_create_blob(dev,
+ sizeof(struct drm_color_lut) * size,
+ NULL);
+ if (IS_ERR(blob)) {
+ ret = PTR_ERR(blob);
+ blob = NULL;
+ goto fail;
+ }
+
+ /* Prepare GAMMA_LUT with the legacy values. */
+ blob_data = (struct drm_color_lut *) blob->data;
+ for (i = 0; i < size; i++) {
+ blob_data[i].red = red[i];
+ blob_data[i].green = green[i];
+ blob_data[i].blue = blue[i];
+ }
+
+ state->acquire_ctx = crtc->dev->mode_config.acquire_ctx;
+retry:
+ crtc_state = drm_atomic_get_crtc_state(state, crtc);
+ if (IS_ERR(crtc_state)) {
+ ret = PTR_ERR(crtc_state);
+ goto fail;
+ }
+
+ /* Reset DEGAMMA_LUT and CTM properties. */
+ ret = drm_atomic_crtc_set_property(crtc, crtc_state,
+ config->degamma_lut_property, 0);
+ if (ret)
+ goto fail;
+
+ ret = drm_atomic_crtc_set_property(crtc, crtc_state,
+ config->ctm_property, 0);
+ if (ret)
+ goto fail;
+
+ ret = drm_atomic_crtc_set_property(crtc, crtc_state,
+ config->gamma_lut_property, blob->base.id);
+ if (ret)
+ goto fail;
+
+ ret = drm_atomic_commit(state);
+ if (ret)
+ goto fail;
+
+ /* Driver takes ownership of state on successful commit. */
+
+ drm_property_unreference_blob(blob);
+
+ return;
+fail:
+ if (ret == -EDEADLK)
+ goto backoff;
+
+ drm_atomic_state_free(state);
+ drm_property_unreference_blob(blob);
+
+ return;
+backoff:
+ drm_atomic_state_clear(state);
+ drm_atomic_legacy_backoff(state);
+
+ goto retry;
+}
+EXPORT_SYMBOL(drm_atomic_helper_legacy_gamma_set);