disp: msm: dsi: validate display probe dependencies early

DSI display configuration can be either DT or firmware file driven.
When probed with firmware path, asynchronous firmware file read
callback function will be too late to check for dependencies and
defer the probe when the dependencies are not met.

Move all the dependency checks before the firmware file read request.
Since the panel data will not be available before the DT/firmware read,
this change limits the check to the dsi display layer.

Change-Id: Ib26ed7839389027c2fe2dc15f70a572df3990ed9
Signed-off-by: Jeykumar Sankaran <[email protected]>

msm/dsi/dsi_display.c

@@ -3966,6 +3966,37 @@ end:
 	return rc;
 }
 
+static int dsi_display_validate_res(struct dsi_display *display)
+{
+	struct device_node *of_node = display->pdev->dev.of_node;
+	struct of_phandle_iterator it;
+	struct dsi_ctrl *dsi_ctrl;
+	bool ctrl_avail = false;
+
+	of_phandle_iterator_init(&it, of_node, "qcom,dsi-ctrl", NULL, 0);
+	while (of_phandle_iterator_next(&it) == 0) {
+		dsi_ctrl = dsi_ctrl_get(it.node);
+		if (IS_ERR(dsi_ctrl)) {
+			int rc = PTR_ERR(dsi_ctrl);
+
+			if (rc == -EPROBE_DEFER)
+				return rc;
+			/*
+			 * With dual display mode, the seconday display needs at least
+			 * one ctrl to proceed through the probe. Exact ctrl match
+			 * will be done after parsing the DT or firmware data.
+			 */
+			if (rc == -EBUSY)
+				ctrl_avail |= false;
+		} else {
+			dsi_ctrl_put(dsi_ctrl);
+			ctrl_avail = true;
+		}
+	}
+
+	return ctrl_avail ? 0 : -EBUSY;
+}
+
 static int dsi_display_get_phandle_count(struct dsi_display *display,
 			const char *propname)
 {
@@ -5813,10 +5844,28 @@ int dsi_display_dev_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, display);
 
+	rc = dsi_display_validate_res(display);
+	if (rc) {
+		/*
+		 * Display's bailing out without probe deferral must register its
+		 * components to complete MDSS binding. Scheduled to be fixed in the future
+		 * with dynamic component binding.
+		 */
+		if (rc == -EBUSY) {
+			int ret = component_add(&pdev->dev,
+					&dsi_display_comp_ops);
+			if (ret)
+				DSI_ERR(
+					"component add failed for display type: %s, rc=%d\n"
+					, display->type, ret);
+		}
+
+		goto end;
+	}
+
 	/* initialize display in firmware callback */
 	if (!boot_disp->boot_disp_en &&
-			IS_ENABLED(CONFIG_DSI_PARSER) &&
-			!display->trusted_vm_env) {
+			IS_ENABLED(CONFIG_DSI_PARSER)) {
 		if (!strcmp(display->display_type, "primary"))
 			firm_req = !request_firmware_nowait(
 				THIS_MODULE, 1, "dsi_prop",