Re: [PATCH v5 20/28] fpga: dfl: add fpga bridge platform driver for FME

This patch adds fpga bridge platform driver for FPGA Management Engine.
It implements the enable_set callback for fpga bridge.

Signed-off-by: Tim Whisonant <redacted>
Signed-off-by: Enno Luebbers <redacted>
Signed-off-by: Shiva Rao <redacted>
Signed-off-by: Christopher Rauer <redacted>
Signed-off-by: Wu Hao <redacted>
Acked-by: Alan Tull <atull@kernel.org>
Acked-by: Moritz Fischer <mdf@kernel.org>
---
v3: rename driver to fpga-dfl-fme-br
    remove useless dev_dbg in probe function.
    rebased due to fpga api change.
v4: rename to dfl-fme-br and fix SPDX license issue
    include dfl-fme-pr.h instead of dfl-fme.h
    add Acked-by from Alan and Moritz
v5: rebase due to API changes.
    defer port and its ops finding when really need.
---
 drivers/fpga/Kconfig      |   6 +++
 drivers/fpga/Makefile     |   1 +
 drivers/fpga/dfl-fme-br.c | 114 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 121 insertions(+)
 create mode 100644 drivers/fpga/dfl-fme-br.c

diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
index 89f76e8..a8f939a 100644
--- a/drivers/fpga/Kconfig
+++ b/drivers/fpga/Kconfig

@@ -156,6 +156,12 @@ config FPGA_DFL_FME_MGR
        help
          Say Y to enable FPGA Manager driver for FPGA Management Engine.

+config FPGA_DFL_FME_BRIDGE
+       tristate "FPGA DFL FME Bridge Driver"
+       depends on FPGA_DFL_FME
+       help
+         Say Y to enable FPGA Bridge driver for FPGA Management Engine.
+
 config FPGA_DFL_PCI
        tristate "FPGA Device Feature List (DFL) PCIe Device Driver"
        depends on PCI && FPGA_DFL

diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
index f82814a..75096e9 100644
--- a/drivers/fpga/Makefile
+++ b/drivers/fpga/Makefile

@@ -32,6 +32,7 @@ obj-$(CONFIG_OF_FPGA_REGION)          += of-fpga-region.o
 obj-$(CONFIG_FPGA_DFL)                 += dfl.o
 obj-$(CONFIG_FPGA_DFL_FME)             += dfl-fme.o
 obj-$(CONFIG_FPGA_DFL_FME_MGR)         += dfl-fme-mgr.o
+obj-$(CONFIG_FPGA_DFL_FME_BRIDGE)      += dfl-fme-br.o

 dfl-fme-objs := dfl-fme-main.o dfl-fme-pr.o

diff --git a/drivers/fpga/dfl-fme-br.c b/drivers/fpga/dfl-fme-br.c
new file mode 100644
index 0000000..5c51b08
--- /dev/null
+++ b/drivers/fpga/dfl-fme-br.c

@@ -0,0 +1,114 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * FPGA Bridge Driver for FPGA Management Engine (FME)
+ *
+ * Copyright (C) 2017 Intel Corporation, Inc.
+ *
+ * Authors:
+ *   Wu Hao <hao.wu@intel.com>
+ *   Joseph Grecco <joe.grecco@intel.com>
+ *   Enno Luebbers <enno.luebbers@intel.com>
+ *   Tim Whisonant <tim.whisonant@intel.com>
+ *   Ananda Ravuri <ananda.ravuri@intel.com>
+ *   Henry Mitchel <henry.mitchel@intel.com>
+ */
+
+#include <linux/module.h>
+#include <linux/fpga/fpga-bridge.h>
+
+#include "dfl.h"
+#include "dfl-fme-pr.h"
+
+struct fme_br_priv {
+       struct dfl_fme_br_pdata *pdata;
+       struct dfl_fpga_port_ops *port_ops;
+       struct platform_device *port_pdev;
+};
+
+static int fme_bridge_enable_set(struct fpga_bridge *bridge, bool enable)
+{
+       struct fme_br_priv *priv = bridge->priv;
+       struct platform_device *port_pdev;
+       struct dfl_fpga_port_ops *ops;
+
+       if (!priv->port_pdev) {
+               port_pdev = dfl_fpga_cdev_find_port(priv->pdata->cdev,
+                                                   &priv->pdata->port_id,
+                                                   dfl_fpga_check_port_id);
+               if (!port_pdev)
+                       return -ENODEV;
+
+               priv->port_pdev = port_pdev;
+       }
+
+       if (priv->port_pdev && !priv->port_ops) {
+               ops = dfl_fpga_get_port_ops(priv->port_pdev);
+               if (!ops || !ops->enable_set)
+                       return -ENOENT;
+
+               priv->port_ops = ops;
+       }