// SPDX-License-Identifier: GPL-2.0
/*
 * Firmware security data kernel module
 *
 * Copyright (C) 2020 Daniel Gutson <[email protected]>
 * Copyright (C) 2020 Eclypsium Inc.
 */
#include <linux/kobject.h>
#include <linux/sysfs.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/pci.h>


static ssize_t howareyou_show(struct class *class, struct class_attribute *attr,
                char *buf)
{
    return sprintf(buf, "%s\n", "How are you?");
}
static CLASS_ATTR_RO(howareyou);

static struct class my_class = {
        .name =         "my-class",
        .owner =        THIS_MODULE,
};

struct device* child_device;


static int mypci_probe(struct pci_dev *pdev,
                   const struct pci_device_id *id)
{
    int ret;

    ret = pcim_enable_device(pdev);
    if (ret)
        return ret;

    ret = class_register(&my_class);
    if (ret < 0)
        return ret;


    pr_info("DFG: Recognized. DID: %lx\n", (unsigned long int)id->driver_data);
    pr_info("DFG: device DID: %lx\n", (unsigned long int)pdev->device);

    ret = class_create_file(&my_class, &class_attr_howareyou);
    if (ret != 0)
    {
        pr_err("DFG class create file error: %d\n", ret);
        class_unregister(&my_class);
        return ret;
    }

    child_device = device_create(&my_class, &pdev->dev, MKDEV(0, 0), NULL, "child");
    if (child_device == NULL)
    {
        pr_err("DFG error child device NULL");
    }

    return ret;
}


static void mypci_remove(struct pci_dev *pdev)
{
    /* I tried enabling and disabling this
    if (child_device != NULL)
    {
        put_device(child_device);
        device_unregister(child_device);
    }
    */

    class_remove_file(&my_class, &class_attr_howareyou);
    class_unregister(&my_class);
}

static const struct pci_device_id my_dids[] = {
    { PCI_VDEVICE(INTEL, 0xa30e), (unsigned long)0xa30e },
    { PCI_VDEVICE(INTEL, 0xa324), (unsigned long)0xa324 },
    { },
};
MODULE_DEVICE_TABLE(pci, my_dids);

static struct pci_driver my_pci_driver = {
    .name = "dfg-pci",
    .id_table = my_dids,
    .probe = mypci_probe,
    .remove = mypci_remove,
};

module_pci_driver(my_pci_driver);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Daniel Gutson <[email protected]>");