/*
 * linux/security/fivm/fivm_dev.c
 *
 * Copyright (C) 2014 Allwinner Ltd.
 *
 * Author: ryan.chen <ryanchen@allwinnertech.com>
 *
 * allwinner fivm controller device
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */
#include <linux/module.h>
#include <linux/version.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/kdev_t.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/cdev.h>
#include <linux/compat.h>
#include <linux/uaccess.h>

#include "fivm.h"

#define CMD_FIVM_INIT		_IO('M', 0)
#define CMD_FIVM_ENABLE		_IO('M', 1)
#define CMD_FIVM_SET		_IOR('M', 2, struct fivm_param)

#ifdef CONFIG_COMPAT
#define CMD_FIVM_SET32		_IOR('M', 2, struct fivm_param_t32)
#endif

static dev_t dev;
static struct cdev c_dev;
static struct class *cl;

static int fivm_open(struct inode *i, struct file *f)
{
	return 0;
}
static int fivm_close(struct inode *i, struct file *f)
{
	return 0;
}

extern int fivm_init(void);
static long fivm_ioctl (
		struct file *file,
		unsigned int cmd,
		unsigned long arg)
{
	int rc = 0;
	switch (cmd) {
	case CMD_FIVM_ENABLE:
		rc = fivm_enable();
		break;
	case CMD_FIVM_SET:
		rc = fivm_set((void *)arg);
		break;
	default:
		rc = -EINVAL;
		break;
	}
	return rc;
}
#ifdef CONFIG_COMPAT
static long fivm_compat_ioctl(struct file *file,
				unsigned int cmd,
				unsigned long arg
		)
{
	int rc = 0;
	struct fivm_param_t32		param_t32;
	struct fivm_param  __user	*param;

	switch (cmd) {
	case CMD_FIVM_ENABLE:
			rc = fivm_enable();
			break;
	case CMD_FIVM_SET32:
			if (copy_from_user(&param_t32,
						(const void __user *)arg,
						sizeof(param_t32))) {
				pr_err("wrong copy from user param\n");
				return -EFAULT;
			}

			param = compat_alloc_user_space(sizeof(*param));
			if (!access_ok(VERIFY_READ, param, sizeof(*param))) {
				pr_err("access read fail for param\n");
				return -EINVAL;
			}
			put_user(compat_ptr(param_t32.sig_head),
					&param->sig_head);
			put_user(param_t32.sig_head_size,
						&param->sig_head_size);
			put_user(compat_ptr(param_t32.sig_table),
					&param->sig_table);
			put_user(param_t32.sig_table_size,
					&param->sig_table_size);

			rc = fivm_set((void *)param);
			break;
	default:
			rc = -EINVAL;
			break;
	}
	return rc;
}
#endif
static const struct file_operations fivm_fops = {
	.owner = THIS_MODULE,
	.open = fivm_open,
	.release = fivm_close,
	.unlocked_ioctl = fivm_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl = fivm_compat_ioctl,
#endif
};

static int __init fivm_dev_init(void) /* Constructor */
{
	if (alloc_chrdev_region(&dev, 0, 1, "fivm_dev") < 0) {
		pr_err("fivm chrdev create fail\n");
		return -1;
	}
	cl = class_create(THIS_MODULE, "fivm_drv");
	if (!cl) {
		pr_err("fivm class create fail\n");
		unregister_chrdev_region(dev, 1);
		return -1;
	}
	if (device_create(cl, NULL, dev, NULL, "fivm") == NULL) {
		pr_err("fivm device create fail\n");
		class_destroy(cl);
		unregister_chrdev_region(dev, 1);
		return -1;
	}
	cdev_init(&c_dev, &fivm_fops);
	if (cdev_add(&c_dev, dev, 1) == -1) {
		pr_err("fivm cdev add fail\n");
		device_destroy(cl, dev);
		class_destroy(cl);
		unregister_chrdev_region(dev, 1);
		return -1;
	}
	if (fivm_init() < 0) {
		pr_err("fivm init fail\n");
		return -1;
	}

	pr_info("FIVM device register ok \n");
	return 0;
}

static void __exit fivm_dev_exit(void) /* Destructor */
{
	cdev_del(&c_dev);
	device_destroy(cl, dev);
	class_destroy(cl);
	unregister_chrdev_region(dev, 1);
	fivm_cleanup();
}

module_init(fivm_dev_init);
module_exit(fivm_dev_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("ryan chen<ryanchen@allsoftwinnertech.com>");
MODULE_DESCRIPTION("Sunxi file integrity verify module for system");