1 files changed, 240 insertions, 8 deletions

diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.c b/drivers/gpu/drm/sun4i/sun4i_backend.c
index 847eecbe4d14..245b189fc4d8 100644
--- a/drivers/gpu/drm/sun4i/sun4i_backend.c
+++ b/drivers/gpu/drm/sun4i/sun4i_backend.c
@@ -11,6 +11,7 @@
  */
 
 #include <drm/drmP.h>
+#include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_crtc.h>
 #include <drm/drm_crtc_helper.h>
@@ -26,6 +27,7 @@
 
 #include "sun4i_backend.h"
 #include "sun4i_drv.h"
+#include "sun4i_frontend.h"
 #include "sun4i_layer.h"
 #include "sunxi_engine.h"
 
@@ -93,7 +95,7 @@ void sun4i_backend_layer_enable(struct sun4i_backend *backend,
 static int sun4i_backend_drm_format_to_layer(struct drm_plane *plane,
 					     u32 format, u32 *mode)
 {
-	if ((plane->type == DRM_PLANE_TYPE_PRIMARY) &&
+	if (plane && (plane->type == DRM_PLANE_TYPE_PRIMARY) &&
 	    (format == DRM_FORMAT_ARGB8888))
 		format = DRM_FORMAT_XRGB8888;
 
@@ -141,7 +143,6 @@ int sun4i_backend_update_layer_coord(struct sun4i_backend *backend,
 				     int layer, struct drm_plane *plane)
 {
 	struct drm_plane_state *state = plane->state;
-	struct drm_framebuffer *fb = state->fb;
 
 	DRM_DEBUG_DRIVER("Updating layer %d\n", layer);
 
@@ -153,12 +154,6 @@ int sun4i_backend_update_layer_coord(struct sun4i_backend *backend,
 						   state->crtc_h));
 	}
 
-	/* Set the line width */
-	DRM_DEBUG_DRIVER("Layer line width: %d bits\n", fb->pitches[0] * 8);
-	regmap_write(backend->engine.regs,
-		     SUN4I_BACKEND_LAYLINEWIDTH_REG(layer),
-		     fb->pitches[0] * 8);
-
 	/* Set height and width */
 	DRM_DEBUG_DRIVER("Layer size W: %u H: %u\n",
 			 state->crtc_w, state->crtc_h);
@@ -210,6 +205,30 @@ int sun4i_backend_update_layer_formats(struct sun4i_backend *backend,
 	return 0;
 }
 
+int sun4i_backend_update_layer_frontend(struct sun4i_backend *backend,
+					int layer, uint32_t fmt)
+{
+	u32 val;
+	int ret;
+
+	ret = sun4i_backend_drm_format_to_layer(NULL, fmt, &val);
+	if (ret) {
+		DRM_DEBUG_DRIVER("Invalid format\n");
+		return ret;
+	}
+
+	regmap_update_bits(backend->engine.regs,
+			   SUN4I_BACKEND_ATTCTL_REG0(layer),
+			   SUN4I_BACKEND_ATTCTL_REG0_LAY_VDOEN,
+			   SUN4I_BACKEND_ATTCTL_REG0_LAY_VDOEN);
+
+	regmap_update_bits(backend->engine.regs,
+			   SUN4I_BACKEND_ATTCTL_REG1(layer),
+			   SUN4I_BACKEND_ATTCTL_REG1_LAY_FBFMT, val);
+
+	return 0;
+}
+
 int sun4i_backend_update_layer_buffer(struct sun4i_backend *backend,
 				      int layer, struct drm_plane *plane)
 {
@@ -218,6 +237,12 @@ int sun4i_backend_update_layer_buffer(struct sun4i_backend *backend,
 	u32 lo_paddr, hi_paddr;
 	dma_addr_t paddr;
 
+	/* Set the line width */
+	DRM_DEBUG_DRIVER("Layer line width: %d bits\n", fb->pitches[0] * 8);
+	regmap_write(backend->engine.regs,
+		     SUN4I_BACKEND_LAYLINEWIDTH_REG(layer),
+		     fb->pitches[0] * 8);
+
 	/* Get the start of the displayed memory */
 	paddr = drm_fb_cma_get_gem_addr(fb, state, 0);
 	DRM_DEBUG_DRIVER("Setting buffer address to %pad\n", &paddr);
@@ -246,6 +271,176 @@ int sun4i_backend_update_layer_buffer(struct sun4i_backend *backend,
 	return 0;
 }
 
+int sun4i_backend_update_layer_zpos(struct sun4i_backend *backend, int layer,
+				    struct drm_plane *plane)
+{
+	struct drm_plane_state *state = plane->state;
+	unsigned int priority = state->normalized_zpos;
+
+	DRM_DEBUG_DRIVER("Setting layer %d's priority to %d\n", layer, priority);
+
+	regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_ATTCTL_REG0(layer),
+			   SUN4I_BACKEND_ATTCTL_REG0_LAY_PRISEL_MASK,
+			   SUN4I_BACKEND_ATTCTL_REG0_LAY_PRISEL(priority));
+
+	return 0;
+}
+
+static bool sun4i_backend_plane_uses_scaler(struct drm_plane_state *state)
+{
+	u16 src_h = state->src_h >> 16;
+	u16 src_w = state->src_w >> 16;
+
+	DRM_DEBUG_DRIVER("Input size %dx%d, output size %dx%d\n",
+			 src_w, src_h, state->crtc_w, state->crtc_h);
+
+	if ((state->crtc_h != src_h) || (state->crtc_w != src_w))
+		return true;
+
+	return false;
+}
+
+static bool sun4i_backend_plane_uses_frontend(struct drm_plane_state *state)
+{
+	struct sun4i_layer *layer = plane_to_sun4i_layer(state->plane);
+	struct sun4i_backend *backend = layer->backend;
+
+	if (IS_ERR(backend->frontend))
+		return false;
+
+	return sun4i_backend_plane_uses_scaler(state);
+}
+
+static void sun4i_backend_atomic_begin(struct sunxi_engine *engine,
+				       struct drm_crtc_state *old_state)
+{
+	u32 val;
+
+	WARN_ON(regmap_read_poll_timeout(engine->regs,
+					 SUN4I_BACKEND_REGBUFFCTL_REG,
+					 val, !(val & SUN4I_BACKEND_REGBUFFCTL_LOADCTL),
+					 100, 50000));
+}
+
+static int sun4i_backend_atomic_check(struct sunxi_engine *engine,
+				      struct drm_crtc_state *crtc_state)
+{
+	struct drm_atomic_state *state = crtc_state->state;
+	struct drm_device *drm = state->dev;
+	struct drm_plane *plane;
+	unsigned int num_planes = 0;
+	unsigned int num_alpha_planes = 0;
+	unsigned int num_frontend_planes = 0;
+
+	DRM_DEBUG_DRIVER("Starting checking our planes\n");
+
+	if (!crtc_state->planes_changed)
+		return 0;
+
+	drm_for_each_plane_mask(plane, drm, crtc_state->plane_mask) {
+		struct drm_plane_state *plane_state =
+			drm_atomic_get_plane_state(state, plane);
+		struct sun4i_layer_state *layer_state =
+			state_to_sun4i_layer_state(plane_state);
+		struct drm_framebuffer *fb = plane_state->fb;
+		struct drm_format_name_buf format_name;
+
+		if (sun4i_backend_plane_uses_frontend(plane_state)) {
+			DRM_DEBUG_DRIVER("Using the frontend for plane %d\n",
+					 plane->index);
+
+			layer_state->uses_frontend = true;
+			num_frontend_planes++;
+		} else {
+			layer_state->uses_frontend = false;
+		}
+
+		DRM_DEBUG_DRIVER("Plane FB format is %s\n",
+				 drm_get_format_name(fb->format->format,
+						     &format_name));
+		if (fb->format->has_alpha)
+			num_alpha_planes++;
+
+		num_planes++;
+	}
+
+	/*
+	 * The hardware is a bit unusual here.
+	 *
+	 * Even though it supports 4 layers, it does the composition
+	 * in two separate steps.
+	 *
+	 * The first one is assigning a layer to one of its two
+	 * pipes. If more that 1 layer is assigned to the same pipe,
+	 * and if pixels overlaps, the pipe will take the pixel from
+	 * the layer with the highest priority.
+	 *
+	 * The second step is the actual alpha blending, that takes
+	 * the two pipes as input, and uses the eventual alpha
+	 * component to do the transparency between the two.
+	 *
+	 * This two steps scenario makes us unable to guarantee a
+	 * robust alpha blending between the 4 layers in all
+	 * situations, since this means that we need to have one layer
+	 * with alpha at the lowest position of our two pipes.
+	 *
+	 * However, we cannot even do that, since the hardware has a
+	 * bug where the lowest plane of the lowest pipe (pipe 0,
+	 * priority 0), if it has any alpha, will discard the pixel
+	 * entirely and just display the pixels in the background
+	 * color (black by default).
+	 *
+	 * This means that we effectively have only three valid
+	 * configurations with alpha, all of them with the alpha being
+	 * on pipe1 with the lowest position, which can be 1, 2 or 3
+	 * depending on the number of planes and their zpos.
+	 */
+	if (num_alpha_planes > SUN4I_BACKEND_NUM_ALPHA_LAYERS) {
+		DRM_DEBUG_DRIVER("Too many planes with alpha, rejecting...\n");
+		return -EINVAL;
+	}
+
+	if (num_frontend_planes > SUN4I_BACKEND_NUM_FRONTEND_LAYERS) {
+		DRM_DEBUG_DRIVER("Too many planes going through the frontend, rejecting\n");
+		return -EINVAL;
+	}
+
+	DRM_DEBUG_DRIVER("State valid with %u planes, %u alpha, %u video\n",
+			 num_planes, num_alpha_planes, num_frontend_planes);
+
+	return 0;
+}
+
+static void sun4i_backend_vblank_quirk(struct sunxi_engine *engine)
+{
+	struct sun4i_backend *backend = engine_to_sun4i_backend(engine);
+	struct sun4i_frontend *frontend = backend->frontend;
+
+	if (!frontend)
+		return;
+
+	/*
+	 * In a teardown scenario with the frontend involved, we have
+	 * to keep the frontend enabled until the next vblank, and
+	 * only then disable it.
+	 *
+	 * This is due to the fact that the backend will not take into
+	 * account the new configuration (with the plane that used to
+	 * be fed by the frontend now disabled) until we write to the
+	 * commit bit and the hardware fetches the new configuration
+	 * during the next vblank.
+	 *
+	 * So we keep the frontend around in order to prevent any
+	 * visual artifacts.
+	 */
+	spin_lock(&backend->frontend_lock);
+	if (backend->frontend_teardown) {
+		sun4i_frontend_exit(frontend);
+		backend->frontend_teardown = false;
+	}
+	spin_unlock(&backend->frontend_lock);
+};
+
 static int sun4i_backend_init_sat(struct device *dev) {
 	struct sun4i_backend *backend = dev_get_drvdata(dev);
 	int ret;
@@ -330,11 +525,43 @@ static int sun4i_backend_of_get_id(struct device_node *node)
 	return ret;
 }
 
+/* TODO: This needs to take multiple pipelines into account */
+static struct sun4i_frontend *sun4i_backend_find_frontend(struct sun4i_drv *drv,
+							  struct device_node *node)
+{
+	struct device_node *port, *ep, *remote;
+	struct sun4i_frontend *frontend;
+
+	port = of_graph_get_port_by_id(node, 0);
+	if (!port)
+		return ERR_PTR(-EINVAL);
+
+	for_each_available_child_of_node(port, ep) {
+		remote = of_graph_get_remote_port_parent(ep);
+		if (!remote)
+			continue;
+
+		/* does this node match any registered engines? */
+		list_for_each_entry(frontend, &drv->frontend_list, list) {
+			if (remote == frontend->node) {
+				of_node_put(remote);
+				of_node_put(port);
+				return frontend;
+			}
+		}
+	}
+
+	return ERR_PTR(-EINVAL);
+}
+
 static const struct sunxi_engine_ops sun4i_backend_engine_ops = {
+	.atomic_begin			= sun4i_backend_atomic_begin,
+	.atomic_check			= sun4i_backend_atomic_check,
 	.commit				= sun4i_backend_commit,
 	.layers_init			= sun4i_layers_init,
 	.apply_color_correction		= sun4i_backend_apply_color_correction,
 	.disable_color_correction	= sun4i_backend_disable_color_correction,
+	.vblank_quirk			= sun4i_backend_vblank_quirk,
 };
 
 static struct regmap_config sun4i_backend_regmap_config = {
@@ -360,6 +587,7 @@ static int sun4i_backend_bind(struct device *dev, struct device *master,
 	if (!backend)
 		return -ENOMEM;
 	dev_set_drvdata(dev, backend);
+	spin_lock_init(&backend->frontend_lock);
 
 	backend->engine.node = dev->of_node;
 	backend->engine.ops = &sun4i_backend_engine_ops;
@@ -367,6 +595,10 @@ static int sun4i_backend_bind(struct device *dev, struct device *master,
 	if (backend->engine.id < 0)
 		return backend->engine.id;
 
+	backend->frontend = sun4i_backend_find_frontend(drv, dev->of_node);
+	if (IS_ERR(backend->frontend))
+		dev_warn(dev, "Couldn't find matching frontend, frontend features disabled\n");
+
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	regs = devm_ioremap_resource(dev, res);
 	if (IS_ERR(regs))