4 files changed, 54 insertions, 31 deletions

diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.c b/drivers/gpu/drm/sun4i/sun4i_backend.c
index ec5943627aa5..4fefd8add714 100644
--- a/drivers/gpu/drm/sun4i/sun4i_backend.c
+++ b/drivers/gpu/drm/sun4i/sun4i_backend.c
@@ -209,22 +209,11 @@ int sun4i_backend_update_layer_buffer(struct sun4i_backend *backend,
 {
 	struct drm_plane_state *state = plane->state;
 	struct drm_framebuffer *fb = state->fb;
-	struct drm_gem_cma_object *gem;
 	u32 lo_paddr, hi_paddr;
 	dma_addr_t paddr;
-	int bpp;
-
-	/* Get the physical address of the buffer in memory */
-	gem = drm_fb_cma_get_gem_obj(fb, 0);
-
-	DRM_DEBUG_DRIVER("Using GEM @ %pad\n", &gem->paddr);
-
-	/* Compute the start of the displayed memory */
-	bpp = fb->format->cpp[0];
-	paddr = gem->paddr + fb->offsets[0];
-	paddr += (state->src_x >> 16) * bpp;
-	paddr += (state->src_y >> 16) * fb->pitches[0];
 
+	/* 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);
 
 	/* Write the 32 lower bits of the address (in bits) */
@@ -369,13 +358,6 @@ static int sun4i_backend_bind(struct device *dev, struct device *master,
 	if (IS_ERR(regs))
 		return PTR_ERR(regs);
 
-	backend->engine.regs = devm_regmap_init_mmio(dev, regs,
-						     &sun4i_backend_regmap_config);
-	if (IS_ERR(backend->engine.regs)) {
-		dev_err(dev, "Couldn't create the backend regmap\n");
-		return PTR_ERR(backend->engine.regs);
-	}
-
 	backend->reset = devm_reset_control_get(dev, NULL);
 	if (IS_ERR(backend->reset)) {
 		dev_err(dev, "Couldn't get our reset line\n");
@@ -421,9 +403,23 @@ static int sun4i_backend_bind(struct device *dev, struct device *master,
 		}
 	}
 
+	backend->engine.regs = devm_regmap_init_mmio(dev, regs,
+						     &sun4i_backend_regmap_config);
+	if (IS_ERR(backend->engine.regs)) {
+		dev_err(dev, "Couldn't create the backend regmap\n");
+		return PTR_ERR(backend->engine.regs);
+	}
+
 	list_add_tail(&backend->engine.list, &drv->engine_list);
 
-	/* Reset the registers */
+	/*
+	 * Many of the backend's layer configuration registers have
+	 * undefined default values. This poses a risk as we use
+	 * regmap_update_bits in some places, and don't overwrite
+	 * the whole register.
+	 *
+	 * Clear the registers here to have something predictable.
+	 */
 	for (i = 0x800; i < 0x1000; i += 4)
 		regmap_write(backend->engine.regs, i, 0);
 
diff --git a/drivers/gpu/drm/sun4i/sun4i_drv.c b/drivers/gpu/drm/sun4i/sun4i_drv.c
index a2012638d5f7..b5879d4620d8 100644
--- a/drivers/gpu/drm/sun4i/sun4i_drv.c
+++ b/drivers/gpu/drm/sun4i/sun4i_drv.c
@@ -226,6 +226,18 @@ struct endpoint_list {
 	struct list_head list;
 };
 
+static bool node_is_in_list(struct list_head *endpoints,
+			    struct device_node *node)
+{
+	struct endpoint_list *endpoint;
+
+	list_for_each_entry(endpoint, endpoints, list)
+		if (endpoint->node == node)
+			return true;
+
+	return false;
+}
+
 static int sun4i_drv_add_endpoints(struct device *dev,
 				   struct list_head *endpoints,
 				   struct component_match **match,
@@ -292,6 +304,10 @@ static int sun4i_drv_add_endpoints(struct device *dev,
 			}
 		}
 
+		/* skip downstream node if it is already in the queue */
+		if (node_is_in_list(endpoints, remote))
+			continue;
+
 		/* Add downstream nodes to the queue */
 		endpoint = kzalloc(sizeof(*endpoint), GFP_KERNEL);
 		if (!endpoint) {
diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi.h b/drivers/gpu/drm/sun4i/sun4i_hdmi.h
index 9b97da39927e..b685ee11623d 100644
--- a/drivers/gpu/drm/sun4i/sun4i_hdmi.h
+++ b/drivers/gpu/drm/sun4i/sun4i_hdmi.h
@@ -72,6 +72,11 @@
 #define SUN4I_HDMI_PAD_CTRL1_HALVE_CLK		BIT(6)
 #define SUN4I_HDMI_PAD_CTRL1_REG_AMP(n)		(((n) & 7) << 3)
 
+/* These bits seem to invert the TMDS data channels */
+#define SUN4I_HDMI_PAD_CTRL1_INVERT_R		BIT(2)
+#define SUN4I_HDMI_PAD_CTRL1_INVERT_G		BIT(1)
+#define SUN4I_HDMI_PAD_CTRL1_INVERT_B		BIT(0)
+
 #define SUN4I_HDMI_PLL_CTRL_REG		0x208
 #define SUN4I_HDMI_PLL_CTRL_PLL_EN		BIT(31)
 #define SUN4I_HDMI_PLL_CTRL_BWS			BIT(30)
diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
index 027b5608dbe6..6ca6e6a74c4a 100644
--- a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
+++ b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
@@ -144,6 +144,22 @@ static void sun4i_hdmi_mode_set(struct drm_encoder *encoder,
 	writel(SUN4I_HDMI_UNKNOWN_INPUT_SYNC,
 	       hdmi->base + SUN4I_HDMI_UNKNOWN_REG);
 
+	/*
+	 * Setup output pad (?) controls
+	 *
+	 * This is done here instead of at probe/bind time because
+	 * the controller seems to toggle some of the bits on its own.
+	 *
+	 * We can't just initialize the register there, we need to
+	 * protect the clock bits that have already been read out and
+	 * cached by the clock framework.
+	 */
+	val = readl(hdmi->base + SUN4I_HDMI_PAD_CTRL1_REG);
+	val &= SUN4I_HDMI_PAD_CTRL1_HALVE_CLK;
+	val |= hdmi->variant->pad_ctrl1_init_val;
+	writel(val, hdmi->base + SUN4I_HDMI_PAD_CTRL1_REG);
+	val = readl(hdmi->base + SUN4I_HDMI_PAD_CTRL1_REG);
+
 	/* Setup timing registers */
 	writel(SUN4I_HDMI_VID_TIMING_X(mode->hdisplay) |
 	       SUN4I_HDMI_VID_TIMING_Y(mode->vdisplay),
@@ -489,16 +505,6 @@ static int sun4i_hdmi_bind(struct device *dev, struct device *master,
 	writel(hdmi->variant->pad_ctrl0_init_val,
 	       hdmi->base + SUN4I_HDMI_PAD_CTRL0_REG);
 
-	/*
-	 * We can't just initialize the register there, we need to
-	 * protect the clock bits that have already been read out and
-	 * cached by the clock framework.
-	 */
-	reg = readl(hdmi->base + SUN4I_HDMI_PAD_CTRL1_REG);
-	reg &= SUN4I_HDMI_PAD_CTRL1_HALVE_CLK;
-	reg |= hdmi->variant->pad_ctrl1_init_val;
-	writel(reg, hdmi->base + SUN4I_HDMI_PAD_CTRL1_REG);
-
 	reg = readl(hdmi->base + SUN4I_HDMI_PLL_CTRL_REG);
 	reg &= SUN4I_HDMI_PLL_CTRL_DIV_MASK;
 	reg |= hdmi->variant->pll_ctrl_init_val;