[PATCH v2 18/22] fpga: intel: add FPGA Accelerated Function Unit driver basic framework

[Wu Hao]

On Intel FPGA devices, the Accelerated Function Unit (AFU), can be
reprogrammed for different functions. It connects to the FPGA
infrastructure("blue bistream") via a Port. Port CSRs are implemented
separately from the AFU CSRs to provide control and status of the Port.
Once valid green bitstream is programmed into the AFU, it allows access
to the AFU CSRs in the AFU MMIO space.

This patch only implements basic driver framework for AFU, including
device file operation framework.

Signed-off-by: Tim Whisonant <tim.whisonant@xxxxxxxxx>
Signed-off-by: Enno Luebbers <enno.luebbers@xxxxxxxxx>
Signed-off-by: Shiva Rao <shiva.rao@xxxxxxxxx>
Signed-off-by: Christopher Rauer <christopher.rauer@xxxxxxxxx>
Signed-off-by: Xiao Guangrong <guangrong.xiao@xxxxxxxxxxxxxxx>
Signed-off-by: Wu Hao <hao.wu@xxxxxxxxx>
---
v2: moved the code to drivers/fpga folder as suggested by Alan Tull.
    switched to GPLv2 license.
---
 drivers/fpga/Kconfig          |   9 +++
 drivers/fpga/Makefile         |   2 +
 drivers/fpga/intel-afu-main.c | 159 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 170 insertions(+)
 create mode 100644 drivers/fpga/intel-afu-main.c

diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
index db1a6ea..4658a13 100644
--- a/drivers/fpga/Kconfig
+++ b/drivers/fpga/Kconfig
@@ -172,6 +172,15 @@ config INTEL_FPGA_FME_REGION
 	  Say Y to enable FPGA Region driver for Intel FPGA Management
 	  Engine.
 
+config INTEL_FPGA_AFU
+	tristate "Intel FPGA AFU Driver"
+	depends on INTEL_FPGA_PCI
+	help
+	  This is the driver for FPGA Accelerated Function Unit (AFU) which
+	  implements AFU and Port management features. A User AFU connects
+	  to the FPGA infrastructure via a Port. There may be more than 1
+	  Port/AFU per Intel FPGA.
+
 endif
 
 endif # FPGA
diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
index fd0a71f..ce08833 100644
--- a/drivers/fpga/Makefile
+++ b/drivers/fpga/Makefile
@@ -34,6 +34,8 @@ obj-$(CONFIG_INTEL_FPGA_FME)		+= intel-fpga-fme.o
 obj-$(CONFIG_INTEL_FPGA_FME_MGR)	+= intel-fpga-fme-mgr.o
 obj-$(CONFIG_INTEL_FPGA_FME_BRIDGE)	+= intel-fpga-fme-br.o
 obj-$(CONFIG_INTEL_FPGA_FME_REGION)	+= intel-fpga-fme-region.o
+obj-$(CONFIG_INTEL_FPGA_AFU)		+= intel-fpga-afu.o
 
 intel-fpga-pci-objs := intel-pcie.o intel-feature-dev.o
 intel-fpga-fme-objs := intel-fme-main.o intel-fme-pr.o
+intel-fpga-afu-objs := intel-afu-main.o
diff --git a/drivers/fpga/intel-afu-main.c b/drivers/fpga/intel-afu-main.c
new file mode 100644
index 0000000..96d0367
--- /dev/null
+++ b/drivers/fpga/intel-afu-main.c
@@ -0,0 +1,159 @@
+/*
+ * Driver for Intel FPGA Accelerated Function Unit (AFU)
+ *
+ * Copyright (C) 2017 Intel Corporation, Inc.
+ *
+ * Authors:
+ *   Wu Hao <hao.wu@xxxxxxxxx>
+ *   Xiao Guangrong <guangrong.xiao@xxxxxxxxxxxxxxx>
+ *   Joseph Grecco <joe.grecco@xxxxxxxxx>
+ *   Enno Luebbers <enno.luebbers@xxxxxxxxx>
+ *   Tim Whisonant <tim.whisonant@xxxxxxxxx>
+ *   Ananda Ravuri <ananda.ravuri@xxxxxxxxx>
+ *   Henry Mitchel <henry.mitchel@xxxxxxxxx>
+ *
+ * This work is licensed under the terms of the GNU GPL version 2. See
+ * the COPYING file in the top-level directory.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include "intel-feature-dev.h"
+
+static int port_hdr_init(struct platform_device *pdev, struct feature *feature)
+{
+	dev_dbg(&pdev->dev, "PORT HDR Init.\n");
+
+	return 0;
+}
+
+static void port_hdr_uinit(struct platform_device *pdev,
+					struct feature *feature)
+{
+	dev_dbg(&pdev->dev, "PORT HDR UInit.\n");
+}
+
+struct feature_ops port_hdr_ops = {
+	.init = port_hdr_init,
+	.uinit = port_hdr_uinit,
+};
+
+static struct feature_driver port_feature_drvs[] = {
+	{
+		.name = PORT_FEATURE_HEADER,
+		.ops = &port_hdr_ops,
+	},
+	{
+		.ops = NULL,
+	}
+};
+
+static int afu_open(struct inode *inode, struct file *filp)
+{
+	struct platform_device *fdev = fpga_inode_to_feature_dev(inode);
+	struct feature_platform_data *pdata;
+	int ret;
+
+	pdata = dev_get_platdata(&fdev->dev);
+	if (WARN_ON(!pdata))
+		return -ENODEV;
+
+	ret = feature_dev_use_begin(pdata);
+	if (ret)
+		return ret;
+
+	dev_dbg(&fdev->dev, "Device File Open\n");
+	filp->private_data = fdev;
+
+	return 0;
+}
+
+static int afu_release(struct inode *inode, struct file *filp)
+{
+	struct platform_device *pdev = filp->private_data;
+	struct feature_platform_data *pdata = dev_get_platdata(&pdev->dev);
+
+	dev_dbg(&pdev->dev, "Device File Release\n");
+
+	feature_dev_use_end(pdata);
+	return 0;
+}
+
+static long afu_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+	struct platform_device *pdev = filp->private_data;
+	struct feature_platform_data *pdata = dev_get_platdata(&pdev->dev);
+	struct feature *f;
+	long ret;
+
+	dev_dbg(&pdev->dev, "%s cmd 0x%x\n", __func__, cmd);
+
+	switch (cmd) {
+	default:
+		/*
+		 * Let sub-feature's ioctl function to handle the cmd
+		 * Sub-feature's ioctl returns -ENODEV when cmd is not
+		 * handled in this sub feature, and returns 0 and other
+		 * error code if cmd is handled.
+		 */
+		fpga_dev_for_each_feature(pdata, f)
+			if (f->ops && f->ops->ioctl) {
+				ret = f->ops->ioctl(pdev, f, cmd, arg);
+				if (ret == -ENODEV)
+					continue;
+				else
+					return ret;
+			}
+	}
+
+	return -EINVAL;
+}
+
+static const struct file_operations afu_fops = {
+	.owner = THIS_MODULE,
+	.open = afu_open,
+	.release = afu_release,
+	.unlocked_ioctl = afu_ioctl,
+};
+
+static int afu_probe(struct platform_device *pdev)
+{
+	int ret;
+
+	dev_dbg(&pdev->dev, "%s\n", __func__);
+
+	ret = fpga_dev_feature_init(pdev, port_feature_drvs);
+	if (ret)
+		return ret;
+
+	ret = fpga_register_dev_ops(pdev, &afu_fops, THIS_MODULE);
+	if (ret)
+		fpga_dev_feature_uinit(pdev);
+
+	return ret;
+}
+
+static int afu_remove(struct platform_device *pdev)
+{
+	dev_dbg(&pdev->dev, "%s\n", __func__);
+
+	fpga_dev_feature_uinit(pdev);
+	fpga_unregister_dev_ops(pdev);
+	return 0;
+}
+
+static struct platform_driver afu_driver = {
+	.driver	= {
+		.name    = "intel-fpga-port",
+	},
+	.probe   = afu_probe,
+	.remove  = afu_remove,
+};
+
+module_platform_driver(afu_driver);
+
+MODULE_DESCRIPTION("Intel FPGA Accelerated Function Unit driver");
+MODULE_AUTHOR("Intel Corporation");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:intel-fpga-port");
-- 
1.8.3.1