msm: mdss: Document mdss driver parameters
mdss driver parameters, visible to userland, are documented,
giving out short descriptions of their role.
Change-Id: I34bfe0152c7f7629c18a968a474ab0a3369560fa
Signed-off-by: Adrian Salido-Moreno <adrianm@codeaurora.org>
Signed-off-by: Mayank Chopra <makchopra@codeaurora.org>
diff --git a/include/linux/msm_mdp.h b/include/linux/msm_mdp.h
index 3425386..58fbb1f 100644
--- a/include/linux/msm_mdp.h
+++ b/include/linux/msm_mdp.h
@@ -479,6 +479,48 @@
uint32_t roi_w[MAX_PLANES];
};
+/**
+ * struct mdp_overlay - overlay surface structure
+ * @src: Source image information (width, height, format).
+ * @src_rect: Source crop rectangle, portion of image that will be fetched.
+ * This should always be within boundaries of source image.
+ * @dst_rect: Destination rectangle, the position and size of image on screen.
+ * This should always be within panel boundaries.
+ * @z_order: Blending stage to occupy in display, if multiple layers are
+ * present, highest z_order usually means the top most visible
+ * layer. The range acceptable is from 0-3 to support blending
+ * up to 4 layers.
+ * @is_fg: This flag is used to disable blending of any layers with z_order
+ * less than this overlay. It means that any layers with z_order
+ * less than this layer will not be blended and will be replaced
+ * by the background border color.
+ * @alpha: Used to set plane opacity. The range can be from 0-255, where
+ * 0 means completely transparent and 255 means fully opaque.
+ * @transp_mask: Color used as color key for transparency. Any pixel in fetched
+ * image matching this color will be transparent when blending.
+ * The color should be in same format as the source image format.
+ * @flags: This is used to customize operation of overlay. See MDP flags
+ * for more information.
+ * @user_data: DEPRECATED* Used to store user application specific information.
+ * @horz_deci: Horizontal decimation value, this indicates the amount of pixels
+ * dropped for each pixel that is fetched from a line. The value
+ * given should be power of two of decimation amount.
+ * 0: no decimation
+ * 1: decimate by 2 (drop 1 pixel for each pixel fetched)
+ * 2: decimate by 4 (drop 3 pixels for each pixel fetched)
+ * 3: decimate by 8 (drop 7 pixels for each pixel fetched)
+ * 4: decimate by 16 (drop 15 pixels for each pixel fetched)
+ * @vert_deci: Vertical decimation value, this indicates the amount of lines
+ * dropped for each line that is fetched from overlay. The value
+ * given should be power of two of decimation amount.
+ * 0: no decimation
+ * 1: decimation by 2 (drop 1 line for each line fetched)
+ * 2: decimation by 4 (drop 3 lines for each line fetched)
+ * 3: decimation by 8 (drop 7 lines for each line fetched)
+ * 4: decimation by 16 (drop 15 lines for each line fetched)
+ * @overlay_pp_cfg: Overlay post processing configuration, for more information
+ * see struct mdp_overlay_pp_params.
+ */
struct mdp_overlay {
struct msmfb_img src;
struct mdp_rect src_rect;