disp: msm: modify handling of debugfs initialization

Add support to allow creation of debugfs node only if
CONFIG_DEBUG_FS is enabled.

Change-Id: Iaeaf51b3654c9458cf8131a9756e6b905007c4ae
Signed-off-by: Krishna Manikandan <mkrishn@codeaurora.org>
Signed-off-by: Samantha Tran <samtran@codeaurora.org>

msm/sde_dbg.c

@@ -6003,14 +6003,37 @@ static const struct file_operations sde_reg_fops = {
 #endif
 };
 
-int sde_dbg_debugfs_register(struct dentry *debugfs_root)
+int sde_dbg_debugfs_register(struct device *dev)
 {
 	static struct sde_dbg_base *dbg = &sde_dbg_base;
 	struct sde_dbg_reg_base *blk_base;
 	char debug_name[80] = "";
+	struct dentry *debugfs_root = NULL;
+	struct platform_device *pdev = to_platform_device(dev);
+	struct drm_device *ddev = platform_get_drvdata(pdev);
+	struct msm_drm_private *priv = NULL;
 
-	if (!debugfs_root)
+	if (!ddev) {
+		pr_err("Invalid drm device node\n");
 		return -EINVAL;
+	}
+
+	priv = ddev->dev_private;
+	if (!priv) {
+		pr_err("Invalid msm drm private node\n");
+		return -EINVAL;
+	}
+
+	debugfs_root = debugfs_create_dir("debug",
+			ddev->primary->debugfs_root);
+	if (IS_ERR_OR_NULL(debugfs_root)) {
+		pr_err("debugfs_root create_dir fail, error %ld\n",
+				PTR_ERR(debugfs_root));
+		priv->debug_root = NULL;
+		return -EINVAL;
+	}
+
+	priv->debug_root = debugfs_root;
 
 	debugfs_create_file("dbg_ctrl", 0600, debugfs_root, NULL,
 			&sde_dbg_ctrl_fops);