1 files changed, 57 insertions, 40 deletions

diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c
index 04796d7d0fdb..925c726ac694 100644
--- a/drivers/gpu/drm/vc4/vc4_dsi.c
+++ b/drivers/gpu/drm/vc4/vc4_dsi.c
@@ -33,6 +33,7 @@
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_mipi_dsi.h>
+#include <drm/drm_of.h>
 #include <drm/drm_panel.h>
 #include <linux/clk.h>
 #include <linux/clk-provider.h>
@@ -504,7 +505,6 @@ struct vc4_dsi {
 	struct mipi_dsi_host dsi_host;
 	struct drm_encoder *encoder;
 	struct drm_bridge *bridge;
-	bool is_panel_bridge;
 
 	void __iomem *regs;
 
@@ -1289,7 +1289,6 @@ static int vc4_dsi_host_attach(struct mipi_dsi_host *host,
 			       struct mipi_dsi_device *device)
 {
 	struct vc4_dsi *dsi = host_to_dsi(host);
-	int ret = 0;
 
 	dsi->lanes = device->lanes;
 	dsi->channel = device->channel;
@@ -1324,34 +1323,12 @@ static int vc4_dsi_host_attach(struct mipi_dsi_host *host,
 		return 0;
 	}
 
-	dsi->bridge = of_drm_find_bridge(device->dev.of_node);
-	if (!dsi->bridge) {
-		struct drm_panel *panel =
-			of_drm_find_panel(device->dev.of_node);
-
-		dsi->bridge = drm_panel_bridge_add(panel,
-						   DRM_MODE_CONNECTOR_DSI);
-		if (IS_ERR(dsi->bridge)) {
-			ret = PTR_ERR(dsi->bridge);
-			dsi->bridge = NULL;
-			return ret;
-		}
-		dsi->is_panel_bridge = true;
-	}
-
-	return drm_bridge_attach(dsi->encoder, dsi->bridge, NULL);
+	return 0;
 }
 
 static int vc4_dsi_host_detach(struct mipi_dsi_host *host,
 			       struct mipi_dsi_device *device)
 {
-	struct vc4_dsi *dsi = host_to_dsi(host);
-
-	if (dsi->is_panel_bridge) {
-		drm_panel_bridge_remove(dsi->bridge);
-		dsi->bridge = NULL;
-	}
-
 	return 0;
 }
 
@@ -1493,16 +1470,13 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
 	struct platform_device *pdev = to_platform_device(dev);
 	struct drm_device *drm = dev_get_drvdata(master);
 	struct vc4_dev *vc4 = to_vc4_dev(drm);
-	struct vc4_dsi *dsi;
+	struct vc4_dsi *dsi = dev_get_drvdata(dev);
 	struct vc4_dsi_encoder *vc4_dsi_encoder;
+	struct drm_panel *panel;
 	const struct of_device_id *match;
 	dma_cap_mask_t dma_mask;
 	int ret;
 
-	dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
-	if (!dsi)
-		return -ENOMEM;
-
 	match = of_match_device(vc4_dsi_dt_match, dev);
 	if (!match)
 		return -ENODEV;
@@ -1517,7 +1491,6 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
 	vc4_dsi_encoder->dsi = dsi;
 	dsi->encoder = &vc4_dsi_encoder->base.base;
 
-	dsi->pdev = pdev;
 	dsi->regs = vc4_ioremap_regs(pdev, 0);
 	if (IS_ERR(dsi->regs))
 		return PTR_ERR(dsi->regs);
@@ -1598,6 +1571,18 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
 		return ret;
 	}
 
+	ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
+					  &panel, &dsi->bridge);
+	if (ret)
+		return ret;
+
+	if (panel) {
+		dsi->bridge = devm_drm_panel_bridge_add(dev, panel,
+							DRM_MODE_CONNECTOR_DSI);
+		if (IS_ERR(dsi->bridge))
+			return PTR_ERR(dsi->bridge);
+	}
+
 	/* The esc clock rate is supposed to always be 100Mhz. */
 	ret = clk_set_rate(dsi->escape_clock, 100 * 1000000);
 	if (ret) {
@@ -1616,12 +1601,11 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
 			 DRM_MODE_ENCODER_DSI, NULL);
 	drm_encoder_helper_add(dsi->encoder, &vc4_dsi_encoder_helper_funcs);
 
-	dsi->dsi_host.ops = &vc4_dsi_host_ops;
-	dsi->dsi_host.dev = dev;
-
-	mipi_dsi_host_register(&dsi->dsi_host);
-
-	dev_set_drvdata(dev, dsi);
+	ret = drm_bridge_attach(dsi->encoder, dsi->bridge, NULL);
+	if (ret) {
+		dev_err(dev, "bridge attach failed: %d\n", ret);
+		return ret;
+	}
 
 	pm_runtime_enable(dev);
 
@@ -1639,8 +1623,6 @@ static void vc4_dsi_unbind(struct device *dev, struct device *master,
 
 	vc4_dsi_encoder_destroy(dsi->encoder);
 
-	mipi_dsi_host_unregister(&dsi->dsi_host);
-
 	if (dsi->port == 1)
 		vc4->dsi1 = NULL;
 }
@@ -1652,12 +1634,47 @@ static const struct component_ops vc4_dsi_ops = {
 
 static int vc4_dsi_dev_probe(struct platform_device *pdev)
 {
-	return component_add(&pdev->dev, &vc4_dsi_ops);
+	struct device *dev = &pdev->dev;
+	struct vc4_dsi *dsi;
+	int ret;
+
+	dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
+	if (!dsi)
+		return -ENOMEM;
+	dev_set_drvdata(dev, dsi);
+
+	dsi->pdev = pdev;
+
+	/* Note, the initialization sequence for DSI and panels is
+	 * tricky.  The component bind above won't get past its
+	 * -EPROBE_DEFER until the panel/bridge probes.  The
+	 * panel/bridge will return -EPROBE_DEFER until it has a
+	 * mipi_dsi_host to register its device to.  So, we register
+	 * the host during pdev probe time, so vc4 as a whole can then
+	 * -EPROBE_DEFER its component bind process until the panel
+	 * successfully attaches.
+	 */
+	dsi->dsi_host.ops = &vc4_dsi_host_ops;
+	dsi->dsi_host.dev = dev;
+	mipi_dsi_host_register(&dsi->dsi_host);
+
+	ret = component_add(&pdev->dev, &vc4_dsi_ops);
+	if (ret) {
+		mipi_dsi_host_unregister(&dsi->dsi_host);
+		return ret;
+	}
+
+	return 0;
 }
 
 static int vc4_dsi_dev_remove(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
+	struct vc4_dsi *dsi = dev_get_drvdata(dev);
+
 	component_del(&pdev->dev, &vc4_dsi_ops);
+	mipi_dsi_host_unregister(&dsi->dsi_host);
+
 	return 0;
 }