/* Copyright (c) 2017 The Linux Foundation. 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 version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#define pr_fmt(fmt) "cnss_utils: " fmt

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/etherdevice.h>
#include <linux/debugfs.h>
#include <net/cnss_utils.h>

#define CNSS_MAX_CH_NUM 45
struct cnss_unsafe_channel_list {
	u16 unsafe_ch_count;
	u16 unsafe_ch_list[CNSS_MAX_CH_NUM];
};

struct cnss_dfs_nol_info {
	void *dfs_nol_info;
	u16 dfs_nol_info_len;
};

#define MAX_NO_OF_MAC_ADDR 4
#define MAC_PREFIX_LEN 2
struct cnss_wlan_mac_addr {
	u8 mac_addr[MAX_NO_OF_MAC_ADDR][ETH_ALEN];
	u32 no_of_mac_addr_set;
};

enum mac_type {
	CNSS_MAC_PROVISIONED,
	CNSS_MAC_DERIVED,
};

static struct cnss_utils_priv {
	struct cnss_unsafe_channel_list unsafe_channel_list;
	struct cnss_dfs_nol_info dfs_nol_info;
	/* generic mutex for unsafe channel */
	struct mutex unsafe_channel_list_lock;
	/* generic spin-lock for dfs_nol info */
	spinlock_t dfs_nol_info_lock;
	int driver_load_cnt;
	struct cnss_wlan_mac_addr wlan_mac_addr;
	struct cnss_wlan_mac_addr wlan_der_mac_addr;
	enum cnss_utils_cc_src cc_source;
	struct dentry *root_dentry;
} *cnss_utils_priv;

int cnss_utils_set_wlan_unsafe_channel(struct device *dev,
				       u16 *unsafe_ch_list, u16 ch_count)
{
	struct cnss_utils_priv *priv = cnss_utils_priv;

	if (!priv)
		return -EINVAL;

	mutex_lock(&priv->unsafe_channel_list_lock);
	if ((!unsafe_ch_list) || (ch_count > CNSS_MAX_CH_NUM)) {
		mutex_unlock(&priv->unsafe_channel_list_lock);
		return -EINVAL;
	}

	priv->unsafe_channel_list.unsafe_ch_count = ch_count;

	if (ch_count == 0)
		goto end;

	memcpy(priv->unsafe_channel_list.unsafe_ch_list,
	       unsafe_ch_list, ch_count * sizeof(u16));

end:
	mutex_unlock(&priv->unsafe_channel_list_lock);

	return 0;
}
EXPORT_SYMBOL(cnss_utils_set_wlan_unsafe_channel);

int cnss_utils_get_wlan_unsafe_channel(struct device *dev,
				       u16 *unsafe_ch_list,
				       u16 *ch_count, u16 buf_len)
{
	struct cnss_utils_priv *priv = cnss_utils_priv;

	if (!priv)
		return -EINVAL;

	mutex_lock(&priv->unsafe_channel_list_lock);
	if (!unsafe_ch_list || !ch_count) {
		mutex_unlock(&priv->unsafe_channel_list_lock);
		return -EINVAL;
	}

	if (buf_len <
	    (priv->unsafe_channel_list.unsafe_ch_count * sizeof(u16))) {
		mutex_unlock(&priv->unsafe_channel_list_lock);
		return -ENOMEM;
	}

	*ch_count = priv->unsafe_channel_list.unsafe_ch_count;
	memcpy(unsafe_ch_list, priv->unsafe_channel_list.unsafe_ch_list,
	       priv->unsafe_channel_list.unsafe_ch_count * sizeof(u16));
	mutex_unlock(&priv->unsafe_channel_list_lock);

	return 0;
}
EXPORT_SYMBOL(cnss_utils_get_wlan_unsafe_channel);

int cnss_utils_wlan_set_dfs_nol(struct device *dev,
				const void *info, u16 info_len)
{
	void *temp;
	void *old_nol_info;
	struct cnss_dfs_nol_info *dfs_info;
	struct cnss_utils_priv *priv = cnss_utils_priv;

	if (!priv)
		return -EINVAL;

	if (!info || !info_len)
		return -EINVAL;

	temp = kmalloc(info_len, GFP_ATOMIC);
	if (!temp)
		return -ENOMEM;

	memcpy(temp, info, info_len);
	spin_lock_bh(&priv->dfs_nol_info_lock);
	dfs_info = &priv->dfs_nol_info;
	old_nol_info = dfs_info->dfs_nol_info;
	dfs_info->dfs_nol_info = temp;
	dfs_info->dfs_nol_info_len = info_len;
	spin_unlock_bh(&priv->dfs_nol_info_lock);
	kfree(old_nol_info);

	return 0;
}
EXPORT_SYMBOL(cnss_utils_wlan_set_dfs_nol);

int cnss_utils_wlan_get_dfs_nol(struct device *dev,
				void *info, u16 info_len)
{
	int len;
	struct cnss_dfs_nol_info *dfs_info;
	struct cnss_utils_priv *priv = cnss_utils_priv;

	if (!priv)
		return -EINVAL;

	if (!info || !info_len)
		return -EINVAL;

	spin_lock_bh(&priv->dfs_nol_info_lock);

	dfs_info = &priv->dfs_nol_info;
	if (!dfs_info->dfs_nol_info ||
	    dfs_info->dfs_nol_info_len == 0) {
		spin_unlock_bh(&priv->dfs_nol_info_lock);
		return -ENOENT;
	}

	len = min(info_len, dfs_info->dfs_nol_info_len);
	memcpy(info, dfs_info->dfs_nol_info, len);
	spin_unlock_bh(&priv->dfs_nol_info_lock);

	return len;
}
EXPORT_SYMBOL(cnss_utils_wlan_get_dfs_nol);

void cnss_utils_increment_driver_load_cnt(struct device *dev)
{
	struct cnss_utils_priv *priv = cnss_utils_priv;

	if (!priv)
		return;

	++(priv->driver_load_cnt);
}
EXPORT_SYMBOL(cnss_utils_increment_driver_load_cnt);

int cnss_utils_get_driver_load_cnt(struct device *dev)
{
	struct cnss_utils_priv *priv = cnss_utils_priv;

	if (!priv)
		return -EINVAL;

	return priv->driver_load_cnt;
}
EXPORT_SYMBOL(cnss_utils_get_driver_load_cnt);

static int set_wlan_mac_address(const u8 *mac_list, const uint32_t len,
				enum mac_type type)
{
	struct cnss_utils_priv *priv = cnss_utils_priv;
	u32 no_of_mac_addr;
	struct cnss_wlan_mac_addr *addr = NULL;
	int iter;
	u8 *temp = NULL;

	if (!priv)
		return -EINVAL;

	if (len == 0 || (len % ETH_ALEN) != 0) {
		pr_err("Invalid length %d\n", len);
		return -EINVAL;
	}

	no_of_mac_addr = len / ETH_ALEN;
	if (no_of_mac_addr > MAX_NO_OF_MAC_ADDR) {
		pr_err("Exceed maximum supported MAC address %u %u\n",
		       MAX_NO_OF_MAC_ADDR, no_of_mac_addr);
		return -EINVAL;
	}

	if (type == CNSS_MAC_PROVISIONED)
		addr = &priv->wlan_mac_addr;
	else
		addr = &priv->wlan_der_mac_addr;

	if (addr->no_of_mac_addr_set) {
		pr_err("WLAN MAC address is already set, num %d type %d\n",
		       addr->no_of_mac_addr_set, type);
		return 0;
	}

	addr->no_of_mac_addr_set = no_of_mac_addr;
	temp = &addr->mac_addr[0][0];

	for (iter = 0; iter < no_of_mac_addr;
	     ++iter, temp += ETH_ALEN, mac_list += ETH_ALEN) {
		ether_addr_copy(temp, mac_list);
		pr_debug("MAC_ADDR:%02x:%02x:%02x:%02x:%02x:%02x\n",
			 temp[0], temp[1], temp[2],
			 temp[3], temp[4], temp[5]);
	}
	return 0;
}

int cnss_utils_set_wlan_mac_address(const u8 *mac_list, const uint32_t len)
{
	return set_wlan_mac_address(mac_list, len, CNSS_MAC_PROVISIONED);
}
EXPORT_SYMBOL(cnss_utils_set_wlan_mac_address);

int cnss_utils_set_wlan_derived_mac_address(
				const u8 *mac_list, const uint32_t len)
{
	return set_wlan_mac_address(mac_list, len, CNSS_MAC_DERIVED);
}
EXPORT_SYMBOL(cnss_utils_set_wlan_derived_mac_address);

static u8 *get_wlan_mac_address(struct device *dev,
				u32 *num, enum mac_type type)
{
	struct cnss_utils_priv *priv = cnss_utils_priv;
	struct cnss_wlan_mac_addr *addr = NULL;

	if (!priv)
		goto out;

	if (type == CNSS_MAC_PROVISIONED)
		addr = &priv->wlan_mac_addr;
	else
		addr = &priv->wlan_der_mac_addr;

	if (!addr->no_of_mac_addr_set) {
		pr_err("WLAN MAC address is not set, type %d\n", type);
		goto out;
	}
	*num = addr->no_of_mac_addr_set;
	return &addr->mac_addr[0][0];

out:
	*num = 0;
	return NULL;
}

u8 *cnss_utils_get_wlan_mac_address(struct device *dev, uint32_t *num)
{
	return get_wlan_mac_address(dev, num, CNSS_MAC_PROVISIONED);
}
EXPORT_SYMBOL(cnss_utils_get_wlan_mac_address);

u8 *cnss_utils_get_wlan_derived_mac_address(
			struct device *dev, uint32_t *num)
{
	return get_wlan_mac_address(dev, num, CNSS_MAC_DERIVED);
}
EXPORT_SYMBOL(cnss_utils_get_wlan_derived_mac_address);

void cnss_utils_set_cc_source(struct device *dev,
			      enum cnss_utils_cc_src cc_source)
{
	struct cnss_utils_priv *priv = cnss_utils_priv;

	if (!priv)
		return;

	priv->cc_source = cc_source;
}
EXPORT_SYMBOL(cnss_utils_set_cc_source);

enum cnss_utils_cc_src cnss_utils_get_cc_source(struct device *dev)
{
	struct cnss_utils_priv *priv = cnss_utils_priv;

	if (!priv)
		return -EINVAL;

	return priv->cc_source;
}
EXPORT_SYMBOL(cnss_utils_get_cc_source);

static ssize_t cnss_utils_mac_write(struct file *fp,
				    const char __user *user_buf,
				    size_t count, loff_t *off)
{
	struct cnss_utils_priv *priv =
		((struct seq_file *)fp->private_data)->private;
	char buf[128];
	char *input, *mac_type, *mac_address;
	u8 *dest_mac;
	u8 val;
	const char *delim = " \n";
	size_t len = 0;
	char temp[3] = "";

	len = min_t(size_t, count, sizeof(buf) - 1);
	if (copy_from_user(buf, user_buf, len))
		return -EINVAL;
	buf[len] = '\0';

	input = buf;

	mac_type = strsep(&input, delim);
	if (!mac_type)
		return -EINVAL;
	if (!input)
		return -EINVAL;

	mac_address = strsep(&input, delim);
	if (!mac_address)
		return -EINVAL;
	if (strncmp("0x", mac_address, MAC_PREFIX_LEN)) {
		pr_err("Invalid MAC prefix\n");
		return -EINVAL;
	}

	len = strlen(mac_address);
	mac_address += MAC_PREFIX_LEN;
	len -= MAC_PREFIX_LEN;
	if (len < ETH_ALEN * 2 || len > ETH_ALEN * 2 * MAX_NO_OF_MAC_ADDR ||
	    len % (ETH_ALEN * 2) != 0) {
		pr_err("Invalid MAC address length %zu\n", len);
		return -EINVAL;
	}

	if (!strcmp("provisioned", mac_type)) {
		dest_mac = &priv->wlan_mac_addr.mac_addr[0][0];
		priv->wlan_mac_addr.no_of_mac_addr_set = len / (ETH_ALEN * 2);
	} else if (!strcmp("derived", mac_type)) {
		dest_mac = &priv->wlan_der_mac_addr.mac_addr[0][0];
		priv->wlan_der_mac_addr.no_of_mac_addr_set =
			len / (ETH_ALEN * 2);
	} else {
		pr_err("Invalid MAC address type %s\n", mac_type);
		return -EINVAL;
	}

	while (len--) {
		temp[0] = *mac_address++;
		temp[1] = *mac_address++;
		if (kstrtou8(temp, 16, &val))
			return -EINVAL;
		*dest_mac++ = val;
	}
	return count;
}

static int cnss_utils_mac_show(struct seq_file *s, void *data)
{
	u8 mac[6];
	int i;
	struct cnss_utils_priv *priv = s->private;
	struct cnss_wlan_mac_addr *addr = NULL;

	addr = &priv->wlan_mac_addr;
	if (addr->no_of_mac_addr_set) {
		seq_puts(s, "\nProvisioned MAC addresseses\n");
		for (i = 0; i < addr->no_of_mac_addr_set; i++) {
			ether_addr_copy(mac, addr->mac_addr[i]);
			seq_printf(s, "MAC_ADDR:%02x:%02x:%02x:%02x:%02x:%02x\n",
				   mac[0], mac[1], mac[2],
				   mac[3], mac[4], mac[5]);
		}
	}

	addr = &priv->wlan_der_mac_addr;
	if (addr->no_of_mac_addr_set) {
		seq_puts(s, "\nDerived MAC addresseses\n");
		for (i = 0; i < addr->no_of_mac_addr_set; i++) {
			ether_addr_copy(mac, addr->mac_addr[i]);
			seq_printf(s, "MAC_ADDR:%02x:%02x:%02x:%02x:%02x:%02x\n",
				   mac[0], mac[1], mac[2],
				   mac[3], mac[4], mac[5]);
		}
	}

	return 0;
}

static int cnss_utils_mac_open(struct inode *inode, struct file *file)
{
	return single_open(file, cnss_utils_mac_show, inode->i_private);
}

static const struct file_operations cnss_utils_mac_fops = {
	.read		= seq_read,
	.write		= cnss_utils_mac_write,
	.release	= single_release,
	.open		= cnss_utils_mac_open,
	.owner		= THIS_MODULE,
	.llseek		= seq_lseek,
};

static int cnss_utils_debugfs_create(struct cnss_utils_priv *priv)
{
	int ret = 0;
	struct dentry *root_dentry;

	root_dentry = debugfs_create_dir("cnss_utils", NULL);

	if (IS_ERR(root_dentry)) {
		ret = PTR_ERR(root_dentry);
		pr_err("Unable to create debugfs %d\n", ret);
		goto out;
	}
	priv->root_dentry = root_dentry;
	debugfs_create_file("mac_address", 0600, root_dentry, priv,
			    &cnss_utils_mac_fops);
out:
	return ret;
}

static int __init cnss_utils_init(void)
{
	struct cnss_utils_priv *priv = NULL;

	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	priv->cc_source = CNSS_UTILS_SOURCE_CORE;

	mutex_init(&priv->unsafe_channel_list_lock);
	spin_lock_init(&priv->dfs_nol_info_lock);
	cnss_utils_debugfs_create(priv);
	cnss_utils_priv = priv;

	return 0;
}

static void __exit cnss_utils_exit(void)
{
	kfree(cnss_utils_priv);
	cnss_utils_priv = NULL;
}

module_init(cnss_utils_init);
module_exit(cnss_utils_exit);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION(DEVICE "CNSS Utilities Driver");