fpga: bridge: change api, don't use drvdata

Change fpga_bridge_register to not set drvdata.  This is to support
the case where a PCIe device can have more than one bridge.

Add API functions to create/free the fpga bridge struct. Change
fpga_bridge_register/unregister to take FPGA bridge struct as
the only parameter.

  struct fpga_bridge
  *fpga_bridge_create(struct device *dev, const char *name,
                      const struct fpga_bridge_ops *br_ops,
                      void *priv);
  void fpga_bridge_free(struct fpga_bridge *br);
  int fpga_bridge_register(struct fpga_bridge *br);
  void fpga_bridge_unregister(struct fpga_bridge *br);

Update the drivers that call fpga_bridge_register with the new API.

Signed-off-by: Alan Tull <atull@kernel.org>
Reported-by: Jiuyue Ma <majiuyue@huawei.com>
Signed-off-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/fpga/xilinx-pr-decoupler.c b/drivers/fpga/xilinx-pr-decoupler.c
index 0d77430..07ba153 100644
--- a/drivers/fpga/xilinx-pr-decoupler.c
+++ b/drivers/fpga/xilinx-pr-decoupler.c
@@ -94,6 +94,7 @@ MODULE_DEVICE_TABLE(of, xlnx_pr_decoupler_of_match);
 static int xlnx_pr_decoupler_probe(struct platform_device *pdev)
 {
 	struct xlnx_pr_decoupler_data *priv;
+	struct fpga_bridge *br;
 	int err;
 	struct resource *res;
 
@@ -120,16 +121,27 @@ static int xlnx_pr_decoupler_probe(struct platform_device *pdev)
 
 	clk_disable(priv->clk);
 
-	err = fpga_bridge_register(&pdev->dev, "Xilinx PR Decoupler",
-				   &xlnx_pr_decoupler_br_ops, priv);
+	br = fpga_bridge_create(&pdev->dev, "Xilinx PR Decoupler",
+				&xlnx_pr_decoupler_br_ops, priv);
+	if (!br) {
+		err = -ENOMEM;
+		goto err_clk;
+	}
 
+	platform_set_drvdata(pdev, br);
+
+	err = fpga_bridge_register(br);
 	if (err) {
 		dev_err(&pdev->dev, "unable to register Xilinx PR Decoupler");
-		clk_unprepare(priv->clk);
-		return err;
+		goto err_clk;
 	}
 
 	return 0;
+
+err_clk:
+	clk_unprepare(priv->clk);
+
+	return err;
 }
 
 static int xlnx_pr_decoupler_remove(struct platform_device *pdev)
@@ -137,7 +149,7 @@ static int xlnx_pr_decoupler_remove(struct platform_device *pdev)
 	struct fpga_bridge *bridge = platform_get_drvdata(pdev);
 	struct xlnx_pr_decoupler_data *p = bridge->priv;
 
-	fpga_bridge_unregister(&pdev->dev);
+	fpga_bridge_unregister(bridge);
 
 	clk_unprepare(p->clk);