OMAP3630: DSS2: Enable Pre-Multiplied Alpha Support

Enable dss to process color formats with pre-mulitplied alpha.
With this we can have alpha values defined for each pixel
and hence can have different blending values for each pixel.
sysfs entry has been created for this and pre-multiplied alpha
support is turned off by default.
Signed-off-by: NSudeep Basavaraj <sudeep.basavaraj@ti.com>
Signed-off-by: NRajkumar N <rajkumar.nagarajan@ti.com>
Signed-off-by: NSamreen <samreen@ti.com>
Signed-off-by: NArchit Taneja <archit@ti.com>
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@nokia.com>

arch/arm/plat-omap/include/plat/display.h

@@ -268,6 +268,7 @@ struct omap_overlay_info {
 	u16 out_width;	/* if 0, out_width == width */
 	u16 out_height;	/* if 0, out_height == height */
 	u8 global_alpha;
+	u8 pre_mult_alpha;
 };
 
 struct omap_overlay {

drivers/video/omap2/dss/dispc.c

@@ -773,13 +773,26 @@ static void _dispc_set_vid_size(enum omap_plane plane, int width, int height)
 	dispc_write_reg(vsi_reg[plane-1], val);
 }
 
+static void _dispc_set_pre_mult_alpha(enum omap_plane plane, bool enable)
+{
+	if (!dss_has_feature(FEAT_PRE_MULT_ALPHA))
+		return;
+
+	if (!dss_has_feature(FEAT_GLOBAL_ALPHA_VID1) &&
+		plane == OMAP_DSS_VIDEO1)
+		return;
+
+	REG_FLD_MOD(dispc_reg_att[plane], enable ? 1 : 0, 28, 28);
+}
+
 static void _dispc_setup_global_alpha(enum omap_plane plane, u8 global_alpha)
 {
 	if (!dss_has_feature(FEAT_GLOBAL_ALPHA))
 		return;
 
-	BUG_ON(!dss_has_feature(FEAT_GLOBAL_ALPHA_VID1) &&
-			plane == OMAP_DSS_VIDEO1);
+	if (!dss_has_feature(FEAT_GLOBAL_ALPHA_VID1) &&
+		plane == OMAP_DSS_VIDEO1)
+		return;
 
 	if (plane == OMAP_DSS_GFX)
 		REG_FLD_MOD(DISPC_GLOBAL_ALPHA, global_alpha, 7, 0);
@@ -1507,7 +1520,8 @@ static int _dispc_setup_plane(enum omap_plane plane,
 		bool ilace,
 		enum omap_dss_rotation_type rotation_type,
 		u8 rotation, int mirror,
-		u8 global_alpha)
+		u8 global_alpha,
+		u8 pre_mult_alpha)
 {
 	const int maxdownscale = cpu_is_omap34xx() ? 4 : 2;
 	bool five_taps = 0;
@@ -1693,7 +1707,7 @@ static int _dispc_setup_plane(enum omap_plane plane,
 
 	_dispc_set_rotation_attrs(plane, rotation, mirror, color_mode);
 
-	if (plane != OMAP_DSS_VIDEO1)
+	_dispc_set_pre_mult_alpha(plane, pre_mult_alpha);
 	_dispc_setup_global_alpha(plane, global_alpha);
 
 	return 0;
@@ -3138,7 +3152,8 @@ int dispc_setup_plane(enum omap_plane plane,
 		       enum omap_color_mode color_mode,
 		       bool ilace,
 		       enum omap_dss_rotation_type rotation_type,
-		       u8 rotation, bool mirror, u8 global_alpha)
+		       u8 rotation, bool mirror, u8 global_alpha,
+		       u8 pre_mult_alpha)
 {
 	int r = 0;
 
@@ -3160,7 +3175,8 @@ int dispc_setup_plane(enum omap_plane plane,
 			   color_mode, ilace,
 			   rotation_type,
 			   rotation, mirror,
-			   global_alpha);
+			   global_alpha,
+			   pre_mult_alpha);
 
 	enable_clocks(0);
 

drivers/video/omap2/dss/dss.h

@@ -359,7 +359,8 @@ int dispc_setup_plane(enum omap_plane plane,
 		      bool ilace,
 		      enum omap_dss_rotation_type rotation_type,
 		      u8 rotation, bool mirror,
-		      u8 global_alpha);
+		      u8 global_alpha,
+		      u8 pre_mult_alpha);
 
 bool dispc_go_busy(enum omap_channel channel);
 void dispc_go(enum omap_channel channel);

drivers/video/omap2/dss/manager.c

@@ -406,6 +406,7 @@ struct overlay_cache_data {
 	u16 out_width;	/* if 0, out_width == width */
 	u16 out_height;	/* if 0, out_height == height */
 	u8 global_alpha;
+	u8 pre_mult_alpha;
 
 	enum omap_channel channel;
 	bool replication;
@@ -842,7 +843,8 @@ static int configure_overlay(enum omap_plane plane)
 			c->rotation_type,
 			c->rotation,
 			c->mirror,
-			c->global_alpha);
+			c->global_alpha,
+			c->pre_mult_alpha);
 
 	if (r) {
 		/* this shouldn't happen */
@@ -1265,6 +1267,7 @@ static int omap_dss_mgr_apply(struct omap_overlay_manager *mgr)
 		oc->out_width = ovl->info.out_width;
 		oc->out_height = ovl->info.out_height;
 		oc->global_alpha = ovl->info.global_alpha;
+		oc->pre_mult_alpha = ovl->info.pre_mult_alpha;
 
 		oc->replication =
 			dss_use_replication(dssdev, ovl->info.color_mode);

drivers/video/omap2/dss/overlay.c

@@ -257,6 +257,43 @@ static ssize_t overlay_global_alpha_store(struct omap_overlay *ovl,
 	return size;
 }
 
+static ssize_t overlay_pre_mult_alpha_show(struct omap_overlay *ovl,
+		char *buf)
+{
+	return snprintf(buf, PAGE_SIZE, "%d\n",
+			ovl->info.pre_mult_alpha);
+}
+
+static ssize_t overlay_pre_mult_alpha_store(struct omap_overlay *ovl,
+		const char *buf, size_t size)
+{
+	int r;
+	struct omap_overlay_info info;
+
+	ovl->get_overlay_info(ovl, &info);
+
+	/* only GFX and Video2 plane support pre alpha multiplied
+	 * set zero for Video1 plane
+	 */
+	if (!dss_has_feature(FEAT_GLOBAL_ALPHA_VID1) &&
+		ovl->id == OMAP_DSS_VIDEO1)
+		info.pre_mult_alpha = 0;
+	else
+		info.pre_mult_alpha = simple_strtoul(buf, NULL, 10);
+
+	r = ovl->set_overlay_info(ovl, &info);
+	if (r)
+		return r;
+
+	if (ovl->manager) {
+		r = ovl->manager->apply(ovl->manager);
+		if (r)
+			return r;
+	}
+
+	return size;
+}
+
 struct overlay_attribute {
 	struct attribute attr;
 	ssize_t (*show)(struct omap_overlay *, char *);
@@ -280,6 +317,9 @@ static OVERLAY_ATTR(enabled, S_IRUGO|S_IWUSR,
 		overlay_enabled_show, overlay_enabled_store);
 static OVERLAY_ATTR(global_alpha, S_IRUGO|S_IWUSR,
 		overlay_global_alpha_show, overlay_global_alpha_store);
+static OVERLAY_ATTR(pre_mult_alpha, S_IRUGO|S_IWUSR,
+		overlay_pre_mult_alpha_show,
+		overlay_pre_mult_alpha_store);
 
 static struct attribute *overlay_sysfs_attrs[] = {
 	&overlay_attr_name.attr,
@@ -290,6 +330,7 @@ static struct attribute *overlay_sysfs_attrs[] = {
 	&overlay_attr_output_size.attr,
 	&overlay_attr_enabled.attr,
 	&overlay_attr_global_alpha.attr,
+	&overlay_attr_pre_mult_alpha.attr,
 	NULL
 };