/*
 *  Copyright (C) 2012 Google Inc. All Rights Reserved.
 *
 *  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.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */
#ifdef CONFIG_REPARTITION
#include <linux/module.h>
#include <linux/types.h>
#include <linux/platform_device.h>
#include <linux/kernel.h>
#include <linux/sysctl.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <mtd/partitionmap.h>
#include "repartition.h"

static int version;
static int nand_size_mb;

#define BADBLOCK_STR_SIZE 512
static char bbinfo[BADBLOCK_STR_SIZE];     /* bad block info */

static struct ctl_table_header *repartition_sysctl_header;

static int repartition_print_bbinfo(void)
{
	return partitionmap_print_bbinfo(bbinfo, sizeof(bbinfo));
}

static int repartition_sysctl_bbinfo(struct ctl_table *ctl, int write,
				     void __user *buffer, size_t *lenp,
				     loff_t *ppos)
{
	if (!*lenp || (*ppos && !write)) {
		*lenp = 0;
		return 0;
	}

	if (repartition_print_bbinfo() < 0) {
		*lenp = 0;
		pr_err("insufficient bad block info buffer\n");
		return -ENOMEM;
	}
	proc_dostring(ctl, write, buffer, lenp, ppos);
	return 0;
}

static int repartition_sysctl_version(struct ctl_table *ctl, int write,
				      void __user *buffer, size_t *lenp,
				      loff_t *ppos)
{
	int ret = 0;
	if (write) {
		pr_err("repartition is disabled\n");
		return -EINVAL;
	} else {
		version = partitionmap_version;
		ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
	}
	return ret;
}

static int repartition_sysctl_nand_size_mb(struct ctl_table *ctl, int write,
				           void __user *buffer, size_t *lenp,
				           loff_t *ppos)
{
	struct mtd_info *mtd;

	if (nand_size_mb == 0) {
		mtd = get_mtd_device_nm("rootfs0");
		if (IS_ERR(mtd)) {
			printk(KERN_WARNING "repartition: no rootfs0: %ld\n",
			       PTR_ERR(mtd));
			nand_size_mb = 0;
		} else {
			if (mtd->size == 0x40000000UL) {
				nand_size_mb = 4096;
			} else if (mtd->size == 0x12000000UL) {
				nand_size_mb = 1024;
			} else {
				nand_size_mb = 0;
			}
		}
	}

	if (!*lenp || (*ppos && !write)) {
		*lenp = 0;
		return 0;
	}

	return proc_dointvec(ctl, write, buffer, lenp, ppos);
}

static struct ctl_table repartition_data_table[] = {
	{
		.procname       = "bbinfo",
		.data           = bbinfo,
		.maxlen         = BADBLOCK_STR_SIZE,
		.mode           = 0444,
		.proc_handler   = repartition_sysctl_bbinfo,
	},
	{
		.procname       = "version",
		.data           = &version,
		.maxlen         = sizeof(int),
		.mode           = 0644,
		.proc_handler   = repartition_sysctl_version,
	},
	{
		.procname	= "nand_size_mb",
		.data		= &nand_size_mb,
		.maxlen		= sizeof(int),
		.mode		= 0444,
		.proc_handler	= repartition_sysctl_nand_size_mb,
	},
	{ }
};

static struct ctl_table repartition_dir_table[] = {
	{
		.procname     = "repartition",
		.mode         = 0555,
		.child        = repartition_data_table
	},
	{ }
};

/* Make sure that /proc/sys/dev is there */
static struct ctl_table repartition_root_table[] = {
	{
		.procname       = "dev",
		.maxlen         = 0,
		.mode           = 0555,
		.child          = repartition_dir_table,
	},
	{ }
};

static int __init repartition_init(void)
{
	static int initialized;

	if (initialized == 1)
		return 0;

	repartition_sysctl_header =
			register_sysctl_table(repartition_root_table);
	initialized = 1;
	return 0;
}

#ifdef MODULE
static int __exit repartition_exit(void)
{
	if (repartition_sysctl_header)
		unregister_sysctl_table(repartition_sysctl_header);
	return 0;
}
module_exit(repartition_exit);
#endif  /* MODULE */

module_init(repartition_init);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Ke Dong <kedong@google.com>");
MODULE_DESCRIPTION("Partition map");

#endif  /* CONFIG_REPARTITION */