/*********************************************************************
   *
   * 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) {
  		IRDA_WARNING("IrDA: Can't allocate dongles hashbin!
  ");
  		return -ENOMEM;
  	}
  	spin_lock_init(&dongles->hb_spinlock);
  
  	tasks = hashbin_new(HB_LOCK);
  	if (tasks == NULL) {
  		IRDA_WARNING("IrDA: Can't allocate tasks hashbin!
  ");
  		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
  ",
  		     reg->type);
  }
  
  void irda_device_cleanup(void)
  {
  	IRDA_DEBUG(4, "%s()
  ", __func__);
  
  	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)
  ", __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);
  		IRDA_DEBUG( 4, "Media busy!
  ");
  	} 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()
  ", __func__);
  
  	if (!dev->netdev_ops->ndo_do_ioctl) {
  		IRDA_ERROR("%s: do_ioctl not impl. by device driver
  ",
  			   __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_DEBUG(2, "%s()
  ", __func__);
  
  	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!
  ",
  				   __func__);
  			irda_task_delete(task);
  			return TRUE;
  		}
  	} while ((timeout == 0) && (task->state != IRDA_TASK_DONE));
  
  	if (timeout < 0) {
  		IRDA_ERROR("%s: Error executing task!
  ", __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 {
  		IRDA_DEBUG(0, "%s(), not finished, and no timeout!
  ",
  			   __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;
  
  	IRDA_DEBUG(2, "%s()
  ", __func__);
  
  	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);
  
  #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