alistair23-linux/drivers/fpga/dfl-fme-main.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Driver for FPGA Management Engine (FME)
 *
 * Copyright (C) 2017-2018 Intel Corporation, Inc.
 *
 * Authors:
 *   Kang Luwei <luwei.kang@intel.com>
 *   Xiao Guangrong <guangrong.xiao@linux.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/kernel.h>
#include <linux/module.h>

#include "dfl.h"

static int fme_hdr_init(struct platform_device *pdev,
			struct dfl_feature *feature)
{
	dev_dbg(&pdev->dev, "FME HDR Init.\n");

	return 0;
}

static void fme_hdr_uinit(struct platform_device *pdev,
			  struct dfl_feature *feature)
{
	dev_dbg(&pdev->dev, "FME HDR UInit.\n");
}

static const struct dfl_feature_ops fme_hdr_ops = {
	.init = fme_hdr_init,
	.uinit = fme_hdr_uinit,
};

static struct dfl_feature_driver fme_feature_drvs[] = {
	{
		.id = FME_FEATURE_ID_HEADER,
		.ops = &fme_hdr_ops,
	},
	{
		.ops = NULL,
	},
};

static int fme_open(struct inode *inode, struct file *filp)
{
	struct platform_device *fdev = dfl_fpga_inode_to_feature_dev(inode);
	struct dfl_feature_platform_data *pdata = dev_get_platdata(&fdev->dev);
	int ret;

	if (WARN_ON(!pdata))
		return -ENODEV;

	ret = dfl_feature_dev_use_begin(pdata);
	if (ret)
		return ret;

	dev_dbg(&fdev->dev, "Device File Open\n");
	filp->private_data = pdata;

	return 0;
}

static int fme_release(struct inode *inode, struct file *filp)
{
	struct dfl_feature_platform_data *pdata = filp->private_data;
	struct platform_device *pdev = pdata->dev;

	dev_dbg(&pdev->dev, "Device File Release\n");
	dfl_feature_dev_use_end(pdata);

	return 0;
}

static long fme_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
	struct dfl_feature_platform_data *pdata = filp->private_data;
	struct platform_device *pdev = pdata->dev;
	struct dfl_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 or other
		 * error code if cmd is handled.
		 */
		dfl_fpga_dev_for_each_feature(pdata, f) {
			if (f->ops && f->ops->ioctl) {
				ret = f->ops->ioctl(pdev, f, cmd, arg);
				if (ret != -ENODEV)
					return ret;
			}
		}
	}

	return -EINVAL;
}

static const struct file_operations fme_fops = {
	.owner		= THIS_MODULE,
	.open		= fme_open,
	.release	= fme_release,
	.unlocked_ioctl = fme_ioctl,
};

static int fme_probe(struct platform_device *pdev)
{
	int ret;

	ret = dfl_fpga_dev_feature_init(pdev, fme_feature_drvs);
	if (ret)
		goto exit;

	ret = dfl_fpga_dev_ops_register(pdev, &fme_fops, THIS_MODULE);
	if (ret)
		goto feature_uinit;

	return 0;

feature_uinit:
	dfl_fpga_dev_feature_uinit(pdev);
exit:
	return ret;
}

static int fme_remove(struct platform_device *pdev)
{
	dfl_fpga_dev_ops_unregister(pdev);
	dfl_fpga_dev_feature_uinit(pdev);

	return 0;
}

static struct platform_driver fme_driver = {
	.driver	= {
		.name    = DFL_FPGA_FEATURE_DEV_FME,
	},
	.probe   = fme_probe,
	.remove  = fme_remove,
};

module_platform_driver(fme_driver);

MODULE_DESCRIPTION("FPGA Management Engine driver");
MODULE_AUTHOR("Intel Corporation");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:dfl-fme");