drm: samsung: fix dsim component model/probing order

Revert a912aa0d802a ("drm: samsung: fix encoder sequence for DSIM") and
address issues with component model and dsim/panel probing order.

Bug: 275278929
Test: force probe deferral of dsim driver, observe boot logs
Change-Id: Ic9585eb8224992d8869ce0449c95e23a5ac1646c
Signed-off-by: Adrian Salido <salidoa@google.com>
(cherry picked from commit 428b0c700d36ccd4080dc8f11d53a0aeba869927)

1 files changed, 74 insertions, 40 deletions

diff --git a/samsung/exynos_drm_dsim.c b/samsung/exynos_drm_dsim.c
index ca6114d..1232973 100644
--- a/samsung/exynos_drm_dsim.c
+++ b/samsung/exynos_drm_dsim.c
@@ -25,6 +25,7 @@
 
 #include <linux/clk.h>
 #include <linux/console.h>
+#include <linux/errno.h>
 #include <linux/gpio/consumer.h>
 #include <linux/irq.h>
 #include <linux/of_address.h>
@@ -1375,6 +1376,45 @@ static int dsim_parse_panel_name(struct dsim_device *dsim)
 	return -ENODEV;
 }
 
+static int dsim_attach_bridge(struct dsim_device *dsim)
+{
+	struct drm_bridge *bridge;
+	struct device_node *np;
+	int ret;
+
+	if (!dsim->dsi_device)
+		return -ENODEV;
+
+	np = dsim->dsi_device->dev.of_node;
+	if (!np)
+		return -ENOENT;
+
+	bridge = of_drm_find_bridge(np);
+	if (!bridge) {
+		struct drm_panel *panel;
+
+		panel = of_drm_find_panel(np);
+		if (IS_ERR(panel)) {
+			dsim_err(dsim, "failed to find panel\n");
+			return PTR_ERR(panel);
+		}
+
+		bridge = devm_drm_panel_bridge_add_typed(dsim->dev, panel, DRM_MODE_CONNECTOR_DSI);
+		if (IS_ERR(bridge)) {
+			dsim_err(dsim, "failed to create panel bridge\n");
+			return PTR_ERR(bridge);
+		}
+	}
+
+	ret = drm_bridge_attach(&dsim->encoder, bridge, NULL, 0);
+	if (ret)
+		dsim_err(dsim, "Unable to attach panel bridge\n");
+	else
+		dsim->panel_bridge = bridge;
+
+	return ret;
+}
+
 static int dsim_bind(struct device *dev, struct device *master, void *data)
 {
 	struct drm_encoder *encoder = dev_get_drvdata(dev);
@@ -1384,9 +1424,13 @@ static int dsim_bind(struct device *dev, struct device *master, void *data)
 
 	dsim_debug(dsim, "%s +\n", __func__);
 
-	if (dsim->dual_dsi == DSIM_DUAL_DSI_SEC)
+	/* ignore cases where there's no dsi device to be attached */
+	if (PTR_ERR(dsim->dsi_device) == -ENODEV)
 		return 0;
 
+	if (!dsim->dsi_device)
+		return -EPROBE_DEFER;
+
 	drm_encoder_init(drm_dev, encoder, &dsim_encoder_funcs,
 			 DRM_MODE_ENCODER_DSI, NULL);
 	drm_encoder_helper_add(encoder, &dsim_encoder_helper_funcs);
@@ -1399,7 +1443,7 @@ static int dsim_bind(struct device *dev, struct device *master, void *data)
 		return -ENOTSUPP;
 	}
 
-	ret = mipi_dsi_host_register(&dsim->dsi_host);
+	ret = dsim_attach_bridge(dsim);
 
 	dsim_debug(dsim, "%s -\n", __func__);
 
@@ -1416,8 +1460,6 @@ static void dsim_unbind(struct device *dev, struct device *master,
 
 	if (dsim->dual_dsi == DSIM_DUAL_DSI_SEC)
 		return;
-
-	mipi_dsi_host_unregister(&dsim->dsi_host);
 }
 
 static const struct component_ops dsim_component_ops = {
@@ -1764,41 +1806,11 @@ static int dsim_host_attach(struct mipi_dsi_host *host,
 				  struct mipi_dsi_device *device)
 {
 	struct dsim_device *dsim = host_to_dsi(host);
-	struct drm_bridge *bridge;
 	int ret;
 
 	dsim_debug(dsim, "%s +\n", __func__);
 
-	bridge = of_drm_find_bridge(device->dev.of_node);
-	if (!bridge) {
-		struct drm_panel *panel;
-
-		panel = of_drm_find_panel(device->dev.of_node);
-		if (IS_ERR(panel)) {
-			dsim_err(dsim, "failed to find panel\n");
-			return PTR_ERR(panel);
-		}
-
-		bridge = devm_drm_panel_bridge_add_typed(host->dev, panel,
-						   DRM_MODE_CONNECTOR_DSI);
-		if (IS_ERR(bridge)) {
-			dsim_err(dsim, "failed to create panel bridge\n");
-			return PTR_ERR(bridge);
-		}
-	}
-
-	if (IS_ERR_OR_NULL(dsim->encoder.dev)) {
-		dsim_err(dsim, "encoder is not initialized\n");
-		return PTR_ERR(dsim->encoder.dev);
-	}
-
-	ret = drm_bridge_attach(&dsim->encoder, bridge, NULL, 0);
-	if (ret) {
-		dsim_err(dsim, "Unable to attach panel bridge\n");
-	} else {
-		dsim->panel_bridge = bridge;
-		dsim->dsi_device = device;
-	}
+	dsim->dsi_device = device;
 
 	ret = sysfs_create_link(&device->dev.kobj, &host->dev->kobj, "dsim");
 	if (ret)
@@ -1806,7 +1818,7 @@ static int dsim_host_attach(struct mipi_dsi_host *host,
 
 	dsim_debug(dsim, "%s -\n", __func__);
 
-	return ret;
+	return component_add(dsim->dev, &dsim_component_ops);
 }
 
 static int dsim_host_detach(struct mipi_dsi_host *host,
@@ -1816,7 +1828,9 @@ static int dsim_host_detach(struct mipi_dsi_host *host,
 
 	dsim_info(dsim, "%s +\n", __func__);
 
-	_dsim_disable(dsim);
+	if (dsim->state != DSIM_STATE_HANDOVER)
+		_dsim_disable(dsim);
+
 	if (dsim->panel_bridge) {
 		struct drm_bridge *bridge = dsim->panel_bridge;
 
@@ -2720,7 +2734,7 @@ static int dsim_probe(struct platform_device *pdev)
 	dsim->state = DSIM_STATE_HANDOVER;
 
 	/* parse the panel name to select the dsi device for the detected panel */
-	dsim_parse_panel_name(dsim);
+	ret = dsim_parse_panel_name(dsim);
 
 	// TODO: get which panel is active from bootloader?
 
@@ -2734,8 +2748,25 @@ static int dsim_probe(struct platform_device *pdev)
 			phy_init(dsim->res.phy_ex);
 	}
 
+	if ((ret < 0) || dsim->dual_dsi == DSIM_DUAL_DSI_SEC) {
+		/* ignore cases where unable to find panel */
+		dsim->dsi_device = ERR_PTR(-ENODEV);
+
+		ret = component_add(dsim->dev, &dsim_component_ops);
+		if (ret < 0) {
+			dsim_err(dsim, "unable to add dsim component\n");
+			goto err;
+		}
+	} else {
+		ret = mipi_dsi_host_register(&dsim->dsi_host);
+		if (ret) {
+			dsim_err(dsim, "unable to register dsi host\n");
+			goto err;
+		}
+	}
+
 	dsim_info(dsim, "driver has been probed.\n");
-	return component_add(dsim->dev, &dsim_component_ops);
+	return 0;
 
 err:
 	dsim_err(dsim, "failed to probe exynos dsim driver\n");
@@ -2750,7 +2781,10 @@ static int dsim_remove(struct platform_device *pdev)
 	device_remove_file(dsim->dev, &dev_attr_hs_clock);
 	pm_runtime_disable(&pdev->dev);
 
-	component_del(&pdev->dev, &dsim_component_ops);
+	if (PTR_ERR(dsim->dsi_device) == -ENODEV)
+		component_del(&pdev->dev, &dsim_component_ops);
+
+	mipi_dsi_host_unregister(&dsim->dsi_host);
 
 	iounmap(dsim->res.ss_reg_base);
 	iounmap(dsim->res.phy_regs_ex);