/*********************************************************************
 *
 * Filename:      irda_device.c
 * Version:       0.9
 * Description:   Utility functions used by the device drivers
 * Status:        Experimental.
 * Author:        Dag Brattli <dagb@cs.uit.no>
 * Created at:    Sat Oct  9 09:22:27 1999
 * Modified at:   Sun Jan 23 17:41:24 2000
 * Modified by:   Dag Brattli <dagb@cs.uit.no>
 *
 *     Copyright (c) 1999-2000 Dag Brattli, All Rights Reserved.
 *     Copyright (c) 2000-2001 Jean Tourrilhes <jt@hpl.hp.com>
 *
 *     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.
 *
 *     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, see <http://www.gnu.org/licenses/>.
 *
 ********************************************************************/

#include <linux/string.h>
#include <linux/proc_fs.h>
#include <linux/skbuff.h>
#include <linux/capability.h>
#include <linux/if.h>
#include <linux/if_ether.h>
#include <linux/if_arp.h>
#include <linux/netdevice.h>
#include <linux/init.h>
#include <linux/tty.h>
#include <linux/kmod.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/export.h>

#include <asm/ioctls.h>
#include <asm/uaccess.h>
#include <asm/dma.h>
#include <asm/io.h>

#include <net/irda/irda_device.h>
#include <net/irda/irlap.h>
#include <net/irda/timer.h>
#include <net/irda/wrapper.h>

static void __irda_task_delete(struct irda_task *task);

static hashbin_t *dongles = NULL;
static hashbin_t *tasks = NULL;

static void irda_task_timer_expired(void *data);

int __init irda_device_init( void)
{
        dongles = hashbin_new(HB_NOLOCK);
        if (dongles == NULL) {
                net_warn_ratelimited("IrDA: Can't allocate dongles hashbin!\n");
                return -ENOMEM;
        }
        spin_lock_init(&dongles->hb_spinlock);

        tasks = hashbin_new(HB_LOCK);
        if (tasks == NULL) {
                net_warn_ratelimited("IrDA: Can't allocate tasks hashbin!\n");
                hashbin_delete(dongles, NULL);
                return -ENOMEM;
        }

        /* We no longer initialise the driver ourselves here, we let
         * the system do it for us... - Jean II */

        return 0;
}

static void leftover_dongle(void *arg)
{
        struct dongle_reg *reg = arg;
        net_warn_ratelimited("IrDA: Dongle type %x not unregistered\n",
                             reg->type);
}

void irda_device_cleanup(void)
{
        hashbin_delete(tasks, (FREE_FUNC) __irda_task_delete);

        hashbin_delete(dongles, leftover_dongle);
}

/*
 * Function irda_device_set_media_busy (self, status)
 *
 *    Called when we have detected that another station is transmitting
 *    in contention mode.
 */
void irda_device_set_media_busy(struct net_device *dev, int status)
{
        struct irlap_cb *self;

        pr_debug("%s(%s)\n", __func__, status ? "TRUE" : "FALSE");

        self = (struct irlap_cb *) dev->atalk_ptr;

        /* Some drivers may enable the receive interrupt before calling
         * irlap_open(), or they may disable the receive interrupt
         * after calling irlap_close().
         * The IrDA stack is protected from this in irlap_driver_rcv().
         * However, the driver calls directly the wrapper, that calls
         * us directly. Make sure we protect ourselves.
         * Jean II */
        if (!self || self->magic != LAP_MAGIC)
                return;

        if (status) {
                self->media_busy = TRUE;
                if (status == SMALL)
                        irlap_start_mbusy_timer(self, SMALLBUSY_TIMEOUT);
                else
                        irlap_start_mbusy_timer(self, MEDIABUSY_TIMEOUT);
                pr_debug("Media busy!\n");
        } else {
                self->media_busy = FALSE;
                irlap_stop_mbusy_timer(self);
        }
}
EXPORT_SYMBOL(irda_device_set_media_busy);


/*
 * Function irda_device_is_receiving (dev)
 *
 *    Check if the device driver is currently receiving data
 *
 */
int irda_device_is_receiving(struct net_device *dev)
{
        struct if_irda_req req;
        int ret;

        if (!dev->netdev_ops->ndo_do_ioctl) {
                net_err_ratelimited("%s: do_ioctl not impl. by device driver\n",
                                    __func__);
                return -1;
        }

        ret = (dev->netdev_ops->ndo_do_ioctl)(dev, (struct ifreq *) &req,
                                              SIOCGRECEIVING);
        if (ret < 0)
                return ret;

        return req.ifr_receiving;
}

static void __irda_task_delete(struct irda_task *task)
{
        del_timer(&task->timer);

        kfree(task);
}

static void irda_task_delete(struct irda_task *task)
{
        /* Unregister task */
        hashbin_remove(tasks, (long) task, NULL);

        __irda_task_delete(task);
}

/*
 * Function irda_task_kick (task)
 *
 *    Tries to execute a task possible multiple times until the task is either
 *    finished, or askes for a timeout. When a task is finished, we do post
 *    processing, and notify the parent task, that is waiting for this task
 *    to complete.
 */
static int irda_task_kick(struct irda_task *task)
{
        int finished = TRUE;
        int count = 0;
        int timeout;

        IRDA_ASSERT(task != NULL, return -1;);
        IRDA_ASSERT(task->magic == IRDA_TASK_MAGIC, return -1;);

        /* Execute task until it's finished, or askes for a timeout */
        do {
                timeout = task->function(task);
                if (count++ > 100) {
                        net_err_ratelimited("%s: error in task handler!\n",
                                            __func__);
                        irda_task_delete(task);
                        return TRUE;
                }
        } while ((timeout == 0) && (task->state != IRDA_TASK_DONE));

        if (timeout < 0) {
                net_err_ratelimited("%s: Error executing task!\n", __func__);
                irda_task_delete(task);
                return TRUE;
        }

        /* Check if we are finished */
        if (task->state == IRDA_TASK_DONE) {
                del_timer(&task->timer);

                /* Do post processing */
                if (task->finished)
                        task->finished(task);

                /* Notify parent */
                if (task->parent) {
                        /* Check if parent is waiting for us to complete */
                        if (task->parent->state == IRDA_TASK_CHILD_WAIT) {
                                task->parent->state = IRDA_TASK_CHILD_DONE;

                                /* Stop timer now that we are here */
                                del_timer(&task->parent->timer);

                                /* Kick parent task */
                                irda_task_kick(task->parent);
                        }
                }
                irda_task_delete(task);
        } else if (timeout > 0) {
                irda_start_timer(&task->timer, timeout, (void *) task,
                                 irda_task_timer_expired);
                finished = FALSE;
        } else {
                pr_debug("%s(), not finished, and no timeout!\n",
                         __func__);
                finished = FALSE;
        }

        return finished;
}

/*
 * Function irda_task_timer_expired (data)
 *
 *    Task time has expired. We now try to execute task (again), and restart
 *    the timer if the task has not finished yet
 */
static void irda_task_timer_expired(void *data)
{
        struct irda_task *task;

        task = data;

        irda_task_kick(task);
}

/*
 * Function irda_device_setup (dev)
 *
 *    This function should be used by low level device drivers in a similar way
 *    as ether_setup() is used by normal network device drivers
 */
static void irda_device_setup(struct net_device *dev)
{
        dev->hard_header_len = 0;
        dev->addr_len        = LAP_ALEN;

        dev->type            = ARPHRD_IRDA;
        dev->tx_queue_len    = 8; /* Window size + 1 s-frame */

        memset(dev->broadcast, 0xff, LAP_ALEN);

        dev->mtu = 2048;
        dev->flags = IFF_NOARP;
}

/*
 * Funciton  alloc_irdadev
 *      Allocates and sets up an IRDA device in a manner similar to
 *      alloc_etherdev.
 */
struct net_device *alloc_irdadev(int sizeof_priv)
{
        return alloc_netdev(sizeof_priv, "irda%d", NET_NAME_UNKNOWN,
                            irda_device_setup);
}
EXPORT_SYMBOL(alloc_irdadev);

#ifdef CONFIG_ISA_DMA_API
/*
 * Function setup_dma (idev, buffer, count, mode)
 *
 *    Setup the DMA channel. Commonly used by LPC FIR drivers
 *
 */
void irda_setup_dma(int channel, dma_addr_t buffer, int count, int mode)
{
        unsigned long flags;

        flags = claim_dma_lock();

        disable_dma(channel);
        clear_dma_ff(channel);
        set_dma_mode(channel, mode);
        set_dma_addr(channel, buffer);
        set_dma_count(channel, count);
        enable_dma(channel);

        release_dma_lock(flags);
}
EXPORT_SYMBOL(irda_setup_dma);
#endif