/*
 * Ultra Wide Band
 * Debug support
 *
 * Copyright (C) 2005-2006 Intel Corporation
 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
 * Copyright (C) 2008 Cambridge Silicon Radio Ltd.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License 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.
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 *
 * FIXME: doc
 */

#include <linux/spinlock.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/notifier.h>
#include <linux/device.h>
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/seq_file.h>

#include <linux/uwb/debug-cmd.h>

#include "uwb-internal.h"

/*
 * Debug interface
 *
 * Per radio controller debugfs files (in uwb/uwbN/):
 *
 * command: Flexible command interface (see <linux/uwb/debug-cmd.h>).
 *
 * reservations: information on reservations.
 *
 * accept: Set to true (Y or 1) to accept reservation requests from
 * peers.
 *
 * drp_avail: DRP availability information.
 */

struct uwb_dbg {
        struct uwb_pal pal;

        u32 accept;
        struct list_head rsvs;

        struct dentry *root_d;
        struct dentry *command_f;
        struct dentry *reservations_f;
        struct dentry *accept_f;
        struct dentry *drp_avail_f;
        spinlock_t list_lock;
};

static struct dentry *root_dir;

static void uwb_dbg_rsv_cb(struct uwb_rsv *rsv)
{
        struct uwb_dbg *dbg = rsv->pal_priv;

        uwb_rsv_dump("debug", rsv);

        if (rsv->state == UWB_RSV_STATE_NONE) {
                spin_lock(&dbg->list_lock);
                list_del(&rsv->pal_node);
                spin_unlock(&dbg->list_lock);
                uwb_rsv_destroy(rsv);
        }
}

static int cmd_rsv_establish(struct uwb_rc *rc,
                             struct uwb_dbg_cmd_rsv_establish *cmd)
{
        struct uwb_mac_addr macaddr;
        struct uwb_rsv *rsv;
        struct uwb_dev *target;
        int ret;

        memcpy(&macaddr, cmd->target, sizeof(macaddr));
        target = uwb_dev_get_by_macaddr(rc, &macaddr);
        if (target == NULL)
                return -ENODEV;

        rsv = uwb_rsv_create(rc, uwb_dbg_rsv_cb, rc->dbg);
        if (rsv == NULL) {
                uwb_dev_put(target);
                return -ENOMEM;
        }

        rsv->target.type  = UWB_RSV_TARGET_DEV;
        rsv->target.dev   = target;
        rsv->type         = cmd->type;
        rsv->max_mas      = cmd->max_mas;
        rsv->min_mas      = cmd->min_mas;
        rsv->max_interval = cmd->max_interval;

        ret = uwb_rsv_establish(rsv);
        if (ret)
                uwb_rsv_destroy(rsv);
        else {
                spin_lock(&(rc->dbg)->list_lock);
                list_add_tail(&rsv->pal_node, &rc->dbg->rsvs);
                spin_unlock(&(rc->dbg)->list_lock);
        }
        return ret;
}

static int cmd_rsv_terminate(struct uwb_rc *rc,
                             struct uwb_dbg_cmd_rsv_terminate *cmd)
{
        struct uwb_rsv *rsv, *found = NULL;
        int i = 0;

        spin_lock(&(rc->dbg)->list_lock);

        list_for_each_entry(rsv, &rc->dbg->rsvs, pal_node) {
                if (i == cmd->index) {
                        found = rsv;
                        uwb_rsv_get(found);
                        break;
                }
                i++;
        }

        spin_unlock(&(rc->dbg)->list_lock);

        if (!found)
                return -EINVAL;

        uwb_rsv_terminate(found);
        uwb_rsv_put(found);

        return 0;
}

static int cmd_ie_add(struct uwb_rc *rc, struct uwb_dbg_cmd_ie *ie_to_add)
{
        return uwb_rc_ie_add(rc,
                             (const struct uwb_ie_hdr *) ie_to_add->data,
                             ie_to_add->len);
}

static int cmd_ie_rm(struct uwb_rc *rc, struct uwb_dbg_cmd_ie *ie_to_rm)
{
        return uwb_rc_ie_rm(rc, ie_to_rm->data[0]);
}

static int command_open(struct inode *inode, struct file *file)
{
        file->private_data = inode->i_private;

        return 0;
}

static ssize_t command_write(struct file *file, const char __user *buf,
                         size_t len, loff_t *off)
{
        struct uwb_rc *rc = file->private_data;
        struct uwb_dbg_cmd cmd;
        int ret = 0;
        
        if (len != sizeof(struct uwb_dbg_cmd))
                return -EINVAL;

        if (copy_from_user(&cmd, buf, len) != 0)
                return -EFAULT;

        switch (cmd.type) {
        case UWB_DBG_CMD_RSV_ESTABLISH:
                ret = cmd_rsv_establish(rc, &cmd.rsv_establish);
                break;
        case UWB_DBG_CMD_RSV_TERMINATE:
                ret = cmd_rsv_terminate(rc, &cmd.rsv_terminate);
                break;
        case UWB_DBG_CMD_IE_ADD:
                ret = cmd_ie_add(rc, &cmd.ie_add);
                break;
        case UWB_DBG_CMD_IE_RM:
                ret = cmd_ie_rm(rc, &cmd.ie_rm);
                break;
        case UWB_DBG_CMD_RADIO_START:
                ret = uwb_radio_start(&rc->dbg->pal);
                break;
        case UWB_DBG_CMD_RADIO_STOP:
                uwb_radio_stop(&rc->dbg->pal);
                break;
        default:
                return -EINVAL;
        }

        return ret < 0 ? ret : len;
}

static const struct file_operations command_fops = {
        .open   = command_open,
        .write  = command_write,
        .read   = NULL,
        .llseek = no_llseek,
        .owner  = THIS_MODULE,
};

static int reservations_print(struct seq_file *s, void *p)
{
        struct uwb_rc *rc = s->private;
        struct uwb_rsv *rsv;

        mutex_lock(&rc->rsvs_mutex);

        list_for_each_entry(rsv, &rc->reservations, rc_node) {
                struct uwb_dev_addr devaddr;
                char owner[UWB_ADDR_STRSIZE], target[UWB_ADDR_STRSIZE];
                bool is_owner;
                char buf[72];

                uwb_dev_addr_print(owner, sizeof(owner), &rsv->owner->dev_addr);
                if (rsv->target.type == UWB_RSV_TARGET_DEV) {
                        devaddr = rsv->target.dev->dev_addr;
                        is_owner = &rc->uwb_dev == rsv->owner;
                } else {
                        devaddr = rsv->target.devaddr;
                        is_owner = true;
                }
                uwb_dev_addr_print(target, sizeof(target), &devaddr);

                seq_printf(s, "%c %s -> %s: %s\n",
                           is_owner ? 'O' : 'T',
                           owner, target, uwb_rsv_state_str(rsv->state));
                seq_printf(s, "  stream: %d  type: %s\n",
                           rsv->stream, uwb_rsv_type_str(rsv->type));
                bitmap_scnprintf(buf, sizeof(buf), rsv->mas.bm, UWB_NUM_MAS);
                seq_printf(s, "  %s\n", buf);
        }

        mutex_unlock(&rc->rsvs_mutex);

        return 0;
}

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

static const struct file_operations reservations_fops = {
        .open    = reservations_open,
        .read    = seq_read,
        .llseek  = seq_lseek,
        .release = single_release,
        .owner   = THIS_MODULE,
};

static int drp_avail_print(struct seq_file *s, void *p)
{
        struct uwb_rc *rc = s->private;
        char buf[72];

        bitmap_scnprintf(buf, sizeof(buf), rc->drp_avail.global, UWB_NUM_MAS);
        seq_printf(s, "global:  %s\n", buf);
        bitmap_scnprintf(buf, sizeof(buf), rc->drp_avail.local, UWB_NUM_MAS);
        seq_printf(s, "local:   %s\n", buf);
        bitmap_scnprintf(buf, sizeof(buf), rc->drp_avail.pending, UWB_NUM_MAS);
        seq_printf(s, "pending: %s\n", buf);

        return 0;
}

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

static const struct file_operations drp_avail_fops = {
        .open    = drp_avail_open,
        .read    = seq_read,
        .llseek  = seq_lseek,
        .release = single_release,
        .owner   = THIS_MODULE,
};

static void uwb_dbg_channel_changed(struct uwb_pal *pal, int channel)
{
        struct device *dev = &pal->rc->uwb_dev.dev;

        if (channel > 0)
                dev_info(dev, "debug: channel %d started\n", channel);
        else
                dev_info(dev, "debug: channel stopped\n");
}

static void uwb_dbg_new_rsv(struct uwb_pal *pal, struct uwb_rsv *rsv)
{
        struct uwb_dbg *dbg = container_of(pal, struct uwb_dbg, pal);

        if (dbg->accept) {
                spin_lock(&dbg->list_lock);
                list_add_tail(&rsv->pal_node, &dbg->rsvs);
                spin_unlock(&dbg->list_lock);
                uwb_rsv_accept(rsv, uwb_dbg_rsv_cb, dbg);
        }
}

/**
 * uwb_dbg_add_rc - add a debug interface for a radio controller
 * @rc: the radio controller
 */
void uwb_dbg_add_rc(struct uwb_rc *rc)
{
        rc->dbg = kzalloc(sizeof(struct uwb_dbg), GFP_KERNEL);
        if (rc->dbg == NULL)
                return;

        INIT_LIST_HEAD(&rc->dbg->rsvs);
        spin_lock_init(&(rc->dbg)->list_lock);

        uwb_pal_init(&rc->dbg->pal);
        rc->dbg->pal.rc = rc;
        rc->dbg->pal.channel_changed = uwb_dbg_channel_changed;
        rc->dbg->pal.new_rsv = uwb_dbg_new_rsv;
        uwb_pal_register(&rc->dbg->pal);

        if (root_dir) {
                rc->dbg->root_d = debugfs_create_dir(dev_name(&rc->uwb_dev.dev),
                                                     root_dir);
                rc->dbg->command_f = debugfs_create_file("command", 0200,
                                                         rc->dbg->root_d, rc,
                                                         &command_fops);
                rc->dbg->reservations_f = debugfs_create_file("reservations", 0444,
                                                              rc->dbg->root_d, rc,
                                                              &reservations_fops);
                rc->dbg->accept_f = debugfs_create_bool("accept", 0644,
                                                        rc->dbg->root_d,
                                                        &rc->dbg->accept);
                rc->dbg->drp_avail_f = debugfs_create_file("drp_avail", 0444,
                                                           rc->dbg->root_d, rc,
                                                           &drp_avail_fops);
        }
}

/**
 * uwb_dbg_del_rc - remove a radio controller's debug interface
 * @rc: the radio controller
 */
void uwb_dbg_del_rc(struct uwb_rc *rc)
{
        struct uwb_rsv *rsv, *t;

        if (rc->dbg == NULL)
                return;

        list_for_each_entry_safe(rsv, t, &rc->dbg->rsvs, pal_node) {
                uwb_rsv_terminate(rsv);
        }

        uwb_pal_unregister(&rc->dbg->pal);

        if (root_dir) {
                debugfs_remove(rc->dbg->drp_avail_f);
                debugfs_remove(rc->dbg->accept_f);
                debugfs_remove(rc->dbg->reservations_f);
                debugfs_remove(rc->dbg->command_f);
                debugfs_remove(rc->dbg->root_d);
        }
}

/**
 * uwb_dbg_exit - initialize the debug interface sub-module
 */
void uwb_dbg_init(void)
{
        root_dir = debugfs_create_dir("uwb", NULL);
}

/**
 * uwb_dbg_exit - clean-up the debug interface sub-module
 */
void uwb_dbg_exit(void)
{
        debugfs_remove(root_dir);
}

/**
 * uwb_dbg_create_pal_dir - create a debugfs directory for a PAL
 * @pal: The PAL.
 */
struct dentry *uwb_dbg_create_pal_dir(struct uwb_pal *pal)
{
        struct uwb_rc *rc = pal->rc;

        if (root_dir && rc->dbg && rc->dbg->root_d && pal->name)
                return debugfs_create_dir(pal->name, rc->dbg->root_d);
        return NULL;
}