/*********************************************************************
 *
 * 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, write to the Free Software
 *     Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 *     MA 02111-1307 USA
 *
 ********************************************************************/

#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 <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;

#ifdef CONFIG_IRDA_DEBUG
static const char *task_state[] = {
        "IRDA_TASK_INIT",
        "IRDA_TASK_DONE",
        "IRDA_TASK_WAIT",
        "IRDA_TASK_WAIT1",
        "IRDA_TASK_WAIT2",
        "IRDA_TASK_WAIT3",
        "IRDA_TASK_CHILD_INIT",
        "IRDA_TASK_CHILD_WAIT",
        "IRDA_TASK_CHILD_DONE",
};
#endif  /* CONFIG_IRDA_DEBUG */

static void irda_task_timer_expired(void *data);

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

        tasks = hashbin_new(HB_LOCK);
        if (tasks == NULL) {
                IRDA_WARNING("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;
        IRDA_WARNING("IrDA: Dongle type %x not unregistered\n",
                     reg->type);
}

void irda_device_cleanup(void)
{
        IRDA_DEBUG(4, "%s()\n", __FUNCTION__);

        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;

        IRDA_DEBUG(4, "%s(%s)\n", __FUNCTION__, 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);
                IRDA_DEBUG( 4, "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;

        IRDA_DEBUG(2, "%s()\n", __FUNCTION__);

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

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

        return req.ifr_receiving;
}

void irda_task_next_state(struct irda_task *task, IRDA_TASK_STATE state)
{
        IRDA_DEBUG(2, "%s(), state = %s\n", __FUNCTION__, task_state[state]);

        task->state = state;
}
EXPORT_SYMBOL(irda_task_next_state);

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

        kfree(task);
}

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

        __irda_task_delete(task);
}
EXPORT_SYMBOL(irda_task_delete);

/*
 * 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_DEBUG(2, "%s()\n", __FUNCTION__);

        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) {
                        IRDA_ERROR("%s: error in task handler!\n",
                                   __FUNCTION__);
                        irda_task_delete(task);
                        return TRUE;
                }
        } while ((timeout == 0) && (task->state != IRDA_TASK_DONE));

        if (timeout < 0) {
                IRDA_ERROR("%s: Error executing task!\n", __FUNCTION__);
                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 {
                IRDA_DEBUG(0, "%s(), not finished, and no timeout!\n",
                           __FUNCTION__);
                finished = FALSE;
        }

        return finished;
}

/*
 * Function irda_task_execute (instance, function, finished)
 *
 *    This function registers and tries to execute tasks that may take some
 *    time to complete. We do it this hairy way since we may have been
 *    called from interrupt context, so it's not possible to use
 *    schedule_timeout()
 * Two important notes :
 *      o Make sure you irda_task_delete(task); in case you delete the
 *        calling instance.
 *      o No real need to lock when calling this function, but you may
 *        want to lock within the task handler.
 * Jean II
 */
struct irda_task *irda_task_execute(void *instance,
                                    IRDA_TASK_CALLBACK function,
                                    IRDA_TASK_CALLBACK finished,
                                    struct irda_task *parent, void *param)
{
        struct irda_task *task;

        IRDA_DEBUG(2, "%s()\n", __FUNCTION__);

        task = kmalloc(sizeof(struct irda_task), GFP_ATOMIC);
        if (!task)
                return NULL;

        task->state    = IRDA_TASK_INIT;
        task->instance = instance;
        task->function = function;
        task->finished = finished;
        task->parent   = parent;
        task->param    = param;
        task->magic    = IRDA_TASK_MAGIC;

        init_timer(&task->timer);

        /* Register task */
        hashbin_insert(tasks, (irda_queue_t *) task, (long) task, NULL);

        /* No time to waste, so lets get going! */
        return irda_task_kick(task) ? NULL : task;
}
EXPORT_SYMBOL(irda_task_execute);

/*
 * 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;

        IRDA_DEBUG(2, "%s()\n", __FUNCTION__);

        task = (struct irda_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", irda_device_setup);
}
EXPORT_SYMBOL(alloc_irdadev);

/*
 * Function irda_device_init_dongle (self, type, qos)
 *
 *    Initialize attached dongle.
 *
 * Important : request_module require us to call this function with
 * a process context and irq enabled. - Jean II
 */
dongle_t *irda_device_dongle_init(struct net_device *dev, int type)
{
        struct dongle_reg *reg;
        dongle_t *dongle = kzalloc(sizeof(dongle_t), GFP_KERNEL);

        might_sleep();

        spin_lock(&dongles->hb_spinlock);
        reg = hashbin_find(dongles, type, NULL);

#ifdef CONFIG_KMOD
        /* Try to load the module needed */
        if (!reg && capable(CAP_SYS_MODULE)) {
                spin_unlock(&dongles->hb_spinlock);

                request_module("irda-dongle-%d", type);

                spin_lock(&dongles->hb_spinlock);
                reg = hashbin_find(dongles, type, NULL);
        }
#endif

        if (!reg || !try_module_get(reg->owner) ) {
                IRDA_ERROR("IrDA: Unable to find requested dongle type %x\n",
                           type);
                kfree(dongle);
                dongle = NULL;
        }
        if (dongle) {
                /* Bind the registration info to this particular instance */
                dongle->issue = reg;
                dongle->dev = dev;
        }
        spin_unlock(&dongles->hb_spinlock);
        return dongle;
}
EXPORT_SYMBOL(irda_device_dongle_init);

/*
 * Function irda_device_dongle_cleanup (dongle)
 */
int irda_device_dongle_cleanup(dongle_t *dongle)
{
        IRDA_ASSERT(dongle != NULL, return -1;);

        dongle->issue->close(dongle);
        module_put(dongle->issue->owner);
        kfree(dongle);

        return 0;
}
EXPORT_SYMBOL(irda_device_dongle_cleanup);

/*
 * Function irda_device_register_dongle (dongle)
 */
int irda_device_register_dongle(struct dongle_reg *new)
{
        spin_lock(&dongles->hb_spinlock);
        /* Check if this dongle has been registered before */
        if (hashbin_find(dongles, new->type, NULL)) {
                IRDA_MESSAGE("%s: Dongle type %x already registered\n",
                             __FUNCTION__, new->type);
        } else {
                /* Insert IrDA dongle into hashbin */
                hashbin_insert(dongles, (irda_queue_t *) new, new->type, NULL);
        }
        spin_unlock(&dongles->hb_spinlock);

        return 0;
}
EXPORT_SYMBOL(irda_device_register_dongle);

/*
 * Function irda_device_unregister_dongle (dongle)
 *
 *    Unregister dongle, and remove dongle from list of registered dongles
 *
 */
void irda_device_unregister_dongle(struct dongle_reg *dongle)
{
        struct dongle *node;

        spin_lock(&dongles->hb_spinlock);
        node = hashbin_remove(dongles, dongle->type, NULL);
        if (!node)
                IRDA_ERROR("%s: dongle not found!\n", __FUNCTION__);
        spin_unlock(&dongles->hb_spinlock);
}
EXPORT_SYMBOL(irda_device_unregister_dongle);

#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