drm/sun4i: Implement zpos for DE2

Initial implementation of DE2 planes only supported fixed zpos.

Expand implementation with configurable zpos property.

Implementation background:
Channel in DE2 driver represents one DRM plane, whereas pipe is just
mapped channel to known Z position. Pipe 0 will always be at the bottom,
pipe 1 just above pipe 0 and so on. If, for example, channel 1 is mapped
at pipe 0 and channel 0 at pipe 1, whatever is on channel 0 will appear
on top.

Before this commit, channel id was used for addressing channel related
registers (prefixed with SUN8I_MIXER_CHAN_UI_ or SUN8I_MIXER_CHAN_VI_)
and pipe registers (prefixed with SUN8I_MIXER_BLEND_). Additionally,
register SUN8I_MIXER_BLEND_ROUTE, which takes care for mapping channels
to pipes had fixed value. It mapped channel 0 to pipe 0, 1 to 1 and so
on. Consequence of all that was fixed Z order of planes.

With this commit, pipe registers are using zpos property as index and
channel related registers still use channel id as index. Pipe mapping
register is now set dynamically too and pipe enable register is rebuild
every time to make sure only active pipes are enabled.

Testing was done to confirm that there is no issues if bottom plane
contains pixels with alpha value < 0xff and if it doesn't whole screen.
Tested-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180706164732.24166-1-jernej.skrabec@siol.net

drivers/gpu/drm/sun4i/sun8i_mixer.c

@@ -261,6 +261,17 @@ const struct de2_fmt_info *sun8i_mixer_format_info(u32 format)
 	return NULL;
 }
 
+static void sun8i_mixer_atomic_begin(struct sunxi_engine *engine,
+				     struct drm_crtc_state *old_state)
+{
+	/*
+	 * Disable all pipes at the beginning. They will be enabled
+	 * again if needed in plane update callback.
+	 */
+	regmap_update_bits(engine->regs, SUN8I_MIXER_BLEND_PIPE_CTL,
+			   SUN8I_MIXER_BLEND_PIPE_CTL_EN_MSK, 0);
+}
+
 static void sun8i_mixer_commit(struct sunxi_engine *engine)
 {
 	DRM_DEBUG_DRIVER("Committing changes\n");
@@ -312,6 +323,7 @@ static struct drm_plane **sun8i_layers_init(struct drm_device *drm,
 }
 
 static const struct sunxi_engine_ops sun8i_engine_ops = {
+	.atomic_begin	= sun8i_mixer_atomic_begin,
 	.commit		= sun8i_mixer_commit,
 	.layers_init	= sun8i_layers_init,
 };
@@ -477,9 +489,6 @@ static int sun8i_mixer_bind(struct device *dev, struct device *master,
 	regmap_write(mixer->engine.regs, SUN8I_MIXER_BLEND_ATTR_FCOLOR(0),
 		     SUN8I_MIXER_BLEND_COLOR_BLACK);
 
-	/* Fixed zpos for now */
-	regmap_write(mixer->engine.regs, SUN8I_MIXER_BLEND_ROUTE, 0x43210);
-
 	plane_cnt = mixer->cfg->vi_num + mixer->cfg->ui_num;
 	for (i = 0; i < plane_cnt; i++)
 		regmap_write(mixer->engine.regs, SUN8I_MIXER_BLEND_MODE(i),

drivers/gpu/drm/sun4i/sun8i_mixer.h

@@ -44,6 +44,7 @@
 #define SUN8I_MIXER_BLEND_CK_MIN(x)		(0x10e0 + 0x04 * (x))
 #define SUN8I_MIXER_BLEND_OUTCTL		0x10fc
 
+#define SUN8I_MIXER_BLEND_PIPE_CTL_EN_MSK	GENMASK(12, 8)
 #define SUN8I_MIXER_BLEND_PIPE_CTL_EN(pipe)	BIT(8 + pipe)
 #define SUN8I_MIXER_BLEND_PIPE_CTL_FC_EN(pipe)	BIT(pipe)
 /* colors are always in AARRGGBB format */
@@ -51,6 +52,9 @@
 /* The following numbers are some still unknown magic numbers */
 #define SUN8I_MIXER_BLEND_MODE_DEF		0x03010301
 
+#define SUN8I_MIXER_BLEND_ROUTE_PIPE_MSK(n)	(0xf << ((n) << 2))
+#define SUN8I_MIXER_BLEND_ROUTE_PIPE_SHIFT(n)	((n) << 2)
+
 #define SUN8I_MIXER_BLEND_OUTCTL_INTERLACED	BIT(1)
 
 #define SUN8I_MIXER_FBFMT_ARGB8888	0

drivers/gpu/drm/sun4i/sun8i_ui_layer.c

@@ -27,7 +27,7 @@
 #include "sun8i_ui_scaler.h"
 
 static void sun8i_ui_layer_enable(struct sun8i_mixer *mixer, int channel,
-				  int overlay, bool enable)
+				  int overlay, bool enable, unsigned int zpos)
 {
 	u32 val;
 
@@ -43,18 +43,24 @@ static void sun8i_ui_layer_enable(struct sun8i_mixer *mixer, int channel,
 			   SUN8I_MIXER_CHAN_UI_LAYER_ATTR(channel, overlay),
 			   SUN8I_MIXER_CHAN_UI_LAYER_ATTR_EN, val);
 
-	if (enable)
-		val = SUN8I_MIXER_BLEND_PIPE_CTL_EN(channel);
-	else
-		val = 0;
+	if (enable) {
+		val = SUN8I_MIXER_BLEND_PIPE_CTL_EN(zpos);
+
+		regmap_update_bits(mixer->engine.regs,
+				   SUN8I_MIXER_BLEND_PIPE_CTL, val, val);
+
+		val = channel << SUN8I_MIXER_BLEND_ROUTE_PIPE_SHIFT(zpos);
 
 		regmap_update_bits(mixer->engine.regs,
-			   SUN8I_MIXER_BLEND_PIPE_CTL,
-			   SUN8I_MIXER_BLEND_PIPE_CTL_EN(channel), val);
+				   SUN8I_MIXER_BLEND_ROUTE,
+				   SUN8I_MIXER_BLEND_ROUTE_PIPE_MSK(zpos),
+				   val);
+	}
 }
 
 static int sun8i_ui_layer_update_coord(struct sun8i_mixer *mixer, int channel,
-				       int overlay, struct drm_plane *plane)
+				       int overlay, struct drm_plane *plane,
+				       unsigned int zpos)
 {
 	struct drm_plane_state *state = plane->state;
 	u32 src_w, src_h, dst_w, dst_h;
@@ -137,10 +143,10 @@ static int sun8i_ui_layer_update_coord(struct sun8i_mixer *mixer, int channel,
 			 state->dst.x1, state->dst.y1);
 	DRM_DEBUG_DRIVER("Layer destination size W: %d H: %d\n", dst_w, dst_h);
 	regmap_write(mixer->engine.regs,
-		     SUN8I_MIXER_BLEND_ATTR_COORD(channel),
+		     SUN8I_MIXER_BLEND_ATTR_COORD(zpos),
 		     SUN8I_MIXER_COORD(state->dst.x1, state->dst.y1));
 	regmap_write(mixer->engine.regs,
-		     SUN8I_MIXER_BLEND_ATTR_INSIZE(channel),
+		     SUN8I_MIXER_BLEND_ATTR_INSIZE(zpos),
 		     outsize);
 
 	return 0;
@@ -238,28 +244,30 @@ static void sun8i_ui_layer_atomic_disable(struct drm_plane *plane,
 	struct sun8i_ui_layer *layer = plane_to_sun8i_ui_layer(plane);
 	struct sun8i_mixer *mixer = layer->mixer;
 
-	sun8i_ui_layer_enable(mixer, layer->channel, layer->overlay, false);
+	sun8i_ui_layer_enable(mixer, layer->channel, layer->overlay, false, 0);
 }
 
 static void sun8i_ui_layer_atomic_update(struct drm_plane *plane,
 					 struct drm_plane_state *old_state)
 {
 	struct sun8i_ui_layer *layer = plane_to_sun8i_ui_layer(plane);
+	unsigned int zpos = plane->state->normalized_zpos;
 	struct sun8i_mixer *mixer = layer->mixer;
 
 	if (!plane->state->visible) {
 		sun8i_ui_layer_enable(mixer, layer->channel,
-				      layer->overlay, false);
+				      layer->overlay, false, 0);
 		return;
 	}
 
 	sun8i_ui_layer_update_coord(mixer, layer->channel,
-				    layer->overlay, plane);
+				    layer->overlay, plane, zpos);
 	sun8i_ui_layer_update_formats(mixer, layer->channel,
 				      layer->overlay, plane);
 	sun8i_ui_layer_update_buffer(mixer, layer->channel,
 				     layer->overlay, plane);
-	sun8i_ui_layer_enable(mixer, layer->channel, layer->overlay, true);
+	sun8i_ui_layer_enable(mixer, layer->channel, layer->overlay,
+			      true, zpos);
 }
 
 static struct drm_plane_helper_funcs sun8i_ui_layer_helper_funcs = {
@@ -307,6 +315,7 @@ struct sun8i_ui_layer *sun8i_ui_layer_init_one(struct drm_device *drm,
 	enum drm_plane_type type = DRM_PLANE_TYPE_OVERLAY;
 	int channel = mixer->cfg->vi_num + index;
 	struct sun8i_ui_layer *layer;
+	unsigned int plane_cnt;
 	int ret;
 
 	layer = devm_kzalloc(drm->dev, sizeof(*layer), GFP_KERNEL);
@@ -327,8 +336,10 @@ struct sun8i_ui_layer *sun8i_ui_layer_init_one(struct drm_device *drm,
 		return ERR_PTR(ret);
 	}
 
-	/* fixed zpos for now */
-	ret = drm_plane_create_zpos_immutable_property(&layer->plane, channel);
+	plane_cnt = mixer->cfg->ui_num + mixer->cfg->vi_num;
+
+	ret = drm_plane_create_zpos_property(&layer->plane, channel,
+					     0, plane_cnt - 1);
 	if (ret) {
 		dev_err(drm->dev, "Couldn't add zpos property\n");
 		return ERR_PTR(ret);

drivers/gpu/drm/sun4i/sun8i_vi_layer.c

@@ -21,7 +21,7 @@
 #include "sun8i_vi_scaler.h"
 
 static void sun8i_vi_layer_enable(struct sun8i_mixer *mixer, int channel,
-				  int overlay, bool enable)
+				  int overlay, bool enable, unsigned int zpos)
 {
 	u32 val;
 
@@ -37,18 +37,24 @@ static void sun8i_vi_layer_enable(struct sun8i_mixer *mixer, int channel,
 			   SUN8I_MIXER_CHAN_VI_LAYER_ATTR(channel, overlay),
 			   SUN8I_MIXER_CHAN_VI_LAYER_ATTR_EN, val);
 
-	if (enable)
-		val = SUN8I_MIXER_BLEND_PIPE_CTL_EN(channel);
-	else
-		val = 0;
+	if (enable) {
+		val = SUN8I_MIXER_BLEND_PIPE_CTL_EN(zpos);
+
+		regmap_update_bits(mixer->engine.regs,
+				   SUN8I_MIXER_BLEND_PIPE_CTL, val, val);
+
+		val = channel << SUN8I_MIXER_BLEND_ROUTE_PIPE_SHIFT(zpos);
 
 		regmap_update_bits(mixer->engine.regs,
-			   SUN8I_MIXER_BLEND_PIPE_CTL,
-			   SUN8I_MIXER_BLEND_PIPE_CTL_EN(channel), val);
+				   SUN8I_MIXER_BLEND_ROUTE,
+				   SUN8I_MIXER_BLEND_ROUTE_PIPE_MSK(zpos),
+				   val);
+	}
 }
 
 static int sun8i_vi_layer_update_coord(struct sun8i_mixer *mixer, int channel,
-				       int overlay, struct drm_plane *plane)
+				       int overlay, struct drm_plane *plane,
+				       unsigned int zpos)
 {
 	struct drm_plane_state *state = plane->state;
 	const struct drm_format_info *format = state->fb->format;
@@ -130,10 +136,10 @@ static int sun8i_vi_layer_update_coord(struct sun8i_mixer *mixer, int channel,
 			 state->dst.x1, state->dst.y1);
 	DRM_DEBUG_DRIVER("Layer destination size W: %d H: %d\n", dst_w, dst_h);
 	regmap_write(mixer->engine.regs,
-		     SUN8I_MIXER_BLEND_ATTR_COORD(channel),
+		     SUN8I_MIXER_BLEND_ATTR_COORD(zpos),
 		     SUN8I_MIXER_COORD(state->dst.x1, state->dst.y1));
 	regmap_write(mixer->engine.regs,
-		     SUN8I_MIXER_BLEND_ATTR_INSIZE(channel),
+		     SUN8I_MIXER_BLEND_ATTR_INSIZE(zpos),
 		     outsize);
 
 	return 0;
@@ -266,28 +272,30 @@ static void sun8i_vi_layer_atomic_disable(struct drm_plane *plane,
 	struct sun8i_vi_layer *layer = plane_to_sun8i_vi_layer(plane);
 	struct sun8i_mixer *mixer = layer->mixer;
 
-	sun8i_vi_layer_enable(mixer, layer->channel, layer->overlay, false);
+	sun8i_vi_layer_enable(mixer, layer->channel, layer->overlay, false, 0);
 }
 
 static void sun8i_vi_layer_atomic_update(struct drm_plane *plane,
 					 struct drm_plane_state *old_state)
 {
 	struct sun8i_vi_layer *layer = plane_to_sun8i_vi_layer(plane);
+	unsigned int zpos = plane->state->normalized_zpos;
 	struct sun8i_mixer *mixer = layer->mixer;
 
 	if (!plane->state->visible) {
 		sun8i_vi_layer_enable(mixer, layer->channel,
-				      layer->overlay, false);
+				      layer->overlay, false, 0);
 		return;
 	}
 
 	sun8i_vi_layer_update_coord(mixer, layer->channel,
-				    layer->overlay, plane);
+				    layer->overlay, plane, zpos);
 	sun8i_vi_layer_update_formats(mixer, layer->channel,
 				      layer->overlay, plane);
 	sun8i_vi_layer_update_buffer(mixer, layer->channel,
 				     layer->overlay, plane);
-	sun8i_vi_layer_enable(mixer, layer->channel, layer->overlay, true);
+	sun8i_vi_layer_enable(mixer, layer->channel, layer->overlay,
+			      true, zpos);
 }
 
 static struct drm_plane_helper_funcs sun8i_vi_layer_helper_funcs = {
@@ -351,6 +359,7 @@ struct sun8i_vi_layer *sun8i_vi_layer_init_one(struct drm_device *drm,
 					       int index)
 {
 	struct sun8i_vi_layer *layer;
+	unsigned int plane_cnt;
 	int ret;
 
 	layer = devm_kzalloc(drm->dev, sizeof(*layer), GFP_KERNEL);
@@ -368,8 +377,10 @@ struct sun8i_vi_layer *sun8i_vi_layer_init_one(struct drm_device *drm,
 		return ERR_PTR(ret);
 	}
 
-	/* fixed zpos for now */
-	ret = drm_plane_create_zpos_immutable_property(&layer->plane, index);
+	plane_cnt = mixer->cfg->ui_num + mixer->cfg->vi_num;
+
+	ret = drm_plane_create_zpos_property(&layer->plane, index,
+					     0, plane_cnt - 1);
 	if (ret) {
 		dev_err(drm->dev, "Couldn't add zpos property\n");
 		return ERR_PTR(ret);