/****************************************************************************
* sdla_fr.c	WANPIPE(tm) Multiprotocol WAN Link Driver. Frame relay module.
*
* Author(s):	Gene Kozin	
*		Jaspreet Singh		<jaspreet@sangoma.com>
*
* Copyright:	(c) 1995-1997 Sangoma Technologies Inc.
*
*		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.
* ============================================================================
* Nov 26, 1997	Jaspreet Singh	o Improved load sharing with multiple boards
*				o Added Cli() to protect enabling of interrupts
*				  while polling is called.
* Nov 24, 1997	Jaspreet Singh	o Added counters to avoid enabling of interrupts
*				  when they have been disabled by another
*				  interface or routine (eg. wpf_poll).
* Nov 06, 1997	Jaspreet Singh	o Added INTR_TEST_MODE to avoid polling	
*				  routine disable interrupts during interrupt
*				  testing.
* Oct 20, 1997  Jaspreet Singh  o Added hooks in for Router UP time.
* Oct 16, 1997  Jaspreet Singh  o The critical flag is used to maintain flow
*                                 control by avoiding RACE conditions.  The
*                                 cli() and restore_flags() are taken out.
*                                 The fr_channel structure is appended for 
*                                 Driver Statistics.
* Oct 15, 1997  Farhan Thawar    o updated if_send() and receive for IPX
* Aug 29, 1997  Farhan Thawar    o Removed most of the cli() and sti()
*                                o Abstracted the UDP management stuff
*                                o Now use tbusy and critical more intelligently
* Jul 21, 1997  Jaspreet Singh	 o Can configure T391, T392, N391, N392 & N393
*				   through router.conf.
*				 o Protected calls to sdla_peek() by adDing 
*				   save_flags(), cli() and restore_flags().
*				 o Added error message for Inactive DLCIs in
*				   fr_event() and update_chan_state().
*				 o Fixed freeing up of buffers using kfree() 
*			           when packets are received.
* Jul 07, 1997	Jaspreet Singh	 o Added configurable TTL for UDP packets 
*				 o Added ability to discard multicast and 
*				   broadcast source addressed packets
* Jun 27, 1997	Jaspreet Singh	 o Added FT1 monitor capabilities 
*				   New case (0x44) statement in if_send routine *				   Added a global variable rCount to keep track
*			 	   of FT1 status enabled on the board.
* May 29, 1997	Jaspreet Singh	 o Fixed major Flow Control Problem
*				   With multiple boards a problem was seen where
*				   the second board always stopped transmitting
*				   packet after running for a while. The code
*				   got into a stage where the interrupts were
*				   disabled and dev->tbusy was set to 1.
*                  		   This caused the If_send() routine to get into*                                  the if clause for it(0,dev->tbusy) 
*				   forever.
*				   The code got into this stage due to an 
*				   interrupt occuring within the if clause for 
*				   set_bit(0,dev->tbusy).  Since an interrupt 
*				   disables furhter transmit interrupt and 
* 				   makes dev->tbusy = 0, this effect was undone *                                  by making dev->tbusy = 1 in the if clause.
*				   The Fix checks to see if Transmit interrupts
*				   are disabled then do not make dev->tbusy = 1
* 	   			   Introduced a global variable: int_occur and
*				   added tx_int_enabled in the wan_device 
*				   structure.	
* May 21, 1997  Jaspreet Singh   o Fixed UDP Management for multiple
*                                  boards.
*
* Apr 25, 1997  Farhan Thawar    o added UDP Management stuff
*                                o fixed bug in if_send() and tx_intr() to
*                                  sleep and wakeup all devices
* Mar 11, 1997  Farhan Thawar   Version 3.1.1
*                                o fixed (+1) bug in fr508_rx_intr()
*                                o changed if_send() to return 0 if
*                                  wandev.critical() is true
*                                o free socket buffer in if_send() if
*                                  returning 0 
*                                o added tx_intr() routine
* Jan 30, 1997	Gene Kozin	Version 3.1.0
*				 o implemented exec() entry point
*				 o fixed a bug causing driver configured as
*				   a FR switch to be stuck in WAN_
*				   mode
* Jan 02, 1997	Gene Kozin	Initial version.
*****************************************************************************/

#if	!defined(__KERNEL__) || !defined(MODULE)
#error	This code MUST be compiled as a kernel module!
#endif

#include <linux/config.h>	/* OS configuration options */
#include <linux/kernel.h>	/* printk(), and other useful stuff */
#include <linux/stddef.h>	/* offsetof(), etc. */
#include <linux/errno.h>	/* return codes */
#include <linux/string.h>	/* inline memset(), etc. */
#include <linux/malloc.h>	/* kmalloc(), kfree() */
#include <linux/init.h>		/* __initfunc */
#include <linux/wanrouter.h>	/* WAN router definitions */
#include <linux/wanpipe.h>	/* WANPIPE common user API definitions */
#include <linux/if_arp.h>	/* ARPHRD_* defines */
#include <asm/byteorder.h>	/* htons(), etc. */
#include <asm/io.h>		/* for inb(), outb(), etc. */
#include <asm/uaccess.h>
#include <linux/time.h>	 	/* for do_gettimeofday */	

#define	_GNUC_
#include <linux/sdla_fr.h>	/* frame relay firmware API definitions */
/****** Defines & Macros ****************************************************/

#define	MAX_CMD_RETRY	10		/* max number of firmware retries */

#define	FR_HEADER_LEN	8		/* max encapsulation header size */
#define	FR_CHANNEL_MTU	1500		/* unfragmented logical channel MTU */

/* Q.922 frame types */
#define	Q922_UI		0x03		/* Unnumbered Info frame */
#define	Q922_XID	0xAF		/* ??? */

/* DLCI configured or not */
#define DLCI_NOT_CONFIGURED	0x00
#define DLCI_CONFIG_PENDING	0x01
#define DLCI_CONFIGURED		0x02

/* CIR enabled or not */
#define CIR_ENABLED	0x00
#define CIR_DISABLED	0x01

/* Interrupt mode for DLCI = 0 */
#define BUFFER_INTR_MODE	0x00
#define DLCI_LIST_INTR_MODE	0x01

/* Transmit Interrupt Status */
#define DISABLED 		0x00
#define WAITING_TO_BE_ENABLED	0x01

/* For handle_IPXWAN() */
#define CVHexToAscii(b) (((unsigned char)(b) > (unsigned char)9) ? ((unsigned char)'A' + ((unsigned char)(b) - (unsigned char)10)) : ((unsigned char)'0' + (unsigned char)(b)))
 
/****** Data Structures *****************************************************/

/* This is an extention of the 'struct device' we create for each network
 * interface to keep the rest of channel-specific data.
 */
typedef struct fr_channel
{
	char name[WAN_IFNAME_SZ+1];	/* interface name, ASCIIZ */
	unsigned dlci_configured  ;	/* check whether configured or not */
	unsigned cir_status;		/* check whether CIR enabled or not */
	unsigned dlci;			/* logical channel number */
	unsigned cir;			/* committed information rate */
	unsigned bc;			/* committed burst size */
	unsigned be;			/* excess burst size */
	unsigned mc;			/* multicast support on or off */
	unsigned tx_int_status;		/* Transmit Interrupt Status */	
	unsigned short pkt_length;	/* Packet Length */
	unsigned long router_start_time;/* Router start time in seconds */
	unsigned long tick_counter;	/* counter for transmit time out */
	char dev_pending_devtint;	/* interface pending dev_tint() */
	char state;			/* channel state */
	void* dlci_int_interface;	/* pointer to the DLCI Interface */ 
	unsigned long IB_addr;		/* physical address of Interface Byte */
	unsigned long state_tick;	/* time of the last state change */
	sdla_t* card;			/* -> owner */
	struct enet_statistics ifstats;	/* interface statistics */
	
	unsigned long if_send_entry;
	unsigned long if_send_skb_null;
	unsigned long if_send_broadcast;
	unsigned long if_send_multicast;
	unsigned long if_send_critical_ISR;
	unsigned long if_send_critical_non_ISR;
	unsigned long if_send_busy;
	unsigned long if_send_busy_timeout;
	unsigned long if_send_FPIPE_request;
	unsigned long if_send_DRVSTATS_request;
	unsigned long if_send_wan_disconnected;
	unsigned long if_send_dlci_disconnected;
	unsigned long if_send_no_bfrs;
	unsigned long if_send_adptr_bfrs_full;
	unsigned long if_send_bfrs_passed_to_adptr;

	unsigned long rx_intr_no_socket;
	unsigned long rx_intr_dev_not_started;
	unsigned long rx_intr_FPIPE_request;
	unsigned long rx_intr_DRVSTATS_request;
	unsigned long rx_intr_bfr_not_passed_to_stack;
	unsigned long rx_intr_bfr_passed_to_stack;

	unsigned long UDP_FPIPE_mgmt_kmalloc_err;
	unsigned long UDP_FPIPE_mgmt_direction_err;
	unsigned long UDP_FPIPE_mgmt_adptr_type_err;
	unsigned long UDP_FPIPE_mgmt_adptr_cmnd_OK;
	unsigned long UDP_FPIPE_mgmt_adptr_cmnd_timeout;
	unsigned long UDP_FPIPE_mgmt_adptr_send_passed;
	unsigned long UDP_FPIPE_mgmt_adptr_send_failed;
	unsigned long UDP_FPIPE_mgmt_not_passed_to_stack;
	unsigned long UDP_FPIPE_mgmt_passed_to_stack;
	unsigned long UDP_FPIPE_mgmt_no_socket;
	unsigned long UDP_DRVSTATS_mgmt_kmalloc_err;
	unsigned long UDP_DRVSTATS_mgmt_adptr_cmnd_OK;
	unsigned long UDP_DRVSTATS_mgmt_adptr_cmnd_timeout;
	unsigned long UDP_DRVSTATS_mgmt_adptr_send_passed;
	unsigned long UDP_DRVSTATS_mgmt_adptr_send_failed;
	unsigned long UDP_DRVSTATS_mgmt_not_passed_to_stack;
	unsigned long UDP_DRVSTATS_mgmt_passed_to_stack;
	unsigned long UDP_DRVSTATS_mgmt_no_socket;
	unsigned long router_up_time;
} fr_channel_t;

typedef struct dlci_status
{
	unsigned short dlci	PACKED;
	unsigned char state	PACKED;
} dlci_status_t;

typedef struct dlci_IB_mapping
{
	unsigned short dlci		PACKED;
	unsigned long  addr_value	PACKED;
} dlci_IB_mapping_t;

/* This structure is used for DLCI list Tx interrupt mode.  It is used to
   enable interrupt bit and set the packet length for transmission
 */
typedef struct fr_dlci_interface 
{
	unsigned char gen_interrupt	PACKED;
	unsigned short packet_length	PACKED;
	unsigned char reserved		PACKED;
} fr_dlci_interface_t; 

static unsigned short num_frames;
static unsigned long curr_trace_addr;
static unsigned long start_trace_addr;
static unsigned short available_buffer_space;
static char TracingEnabled;

/* variable for keeping track of enabling/disabling FT1 monitor status */
static int rCount = 0;

extern void disable_irq(unsigned int);
extern void enable_irq(unsigned int);

/* variable for keeping track of number of interrupts generated during 
 * interrupt test routine 
 */
static int Intr_test_counter;

/****** Function Prototypes *************************************************/

/* WAN link driver entry points. These are called by the WAN router module. */
static int update (wan_device_t* wandev);
static int new_if (wan_device_t* wandev, struct device* dev,
	wanif_conf_t* conf);
static int del_if (wan_device_t* wandev, struct device* dev);

/* WANPIPE-specific entry points */
static int wpf_exec (struct sdla* card, void* u_cmd, void* u_data);

/* Network device interface */
static int if_init   (struct device* dev);
static int if_open   (struct device* dev);
static int if_close  (struct device* dev);
static int if_header (struct sk_buff* skb, struct device* dev,
	unsigned short type, void* daddr, void* saddr, unsigned len);
static int if_rebuild_hdr (struct sk_buff* skb);
static int if_send (struct sk_buff* skb, struct device* dev);
static struct enet_statistics* if_stats (struct device* dev);

/* Interrupt handlers */
static void fr502_isr (sdla_t* card);
static void fr508_isr (sdla_t* card);
static void fr502_rx_intr (sdla_t* card);
static void fr508_rx_intr (sdla_t* card);
static void tx_intr (sdla_t* card);
static void spur_intr (sdla_t* card);

/* Background polling routines */
static void wpf_poll (sdla_t* card);

/* Frame relay firmware interface functions */
static int fr_read_version (sdla_t* card, char* str);
static int fr_configure (sdla_t* card, fr_conf_t *conf);
static int fr_dlci_configure (sdla_t* card, fr_dlc_conf_t *conf, unsigned dlci);
static int fr_set_intr_mode (sdla_t* card, unsigned mode, unsigned mtu);
static int fr_comm_enable (sdla_t* card);
static int fr_comm_disable (sdla_t* card);
static int fr_get_err_stats (sdla_t* card);
static int fr_get_stats (sdla_t* card);
static int fr_add_dlci (sdla_t* card, int dlci, int num);
static int fr_activate_dlci (sdla_t* card, int dlci, int num);
static int fr_issue_isf (sdla_t* card, int isf);
static int fr502_send (sdla_t* card, int dlci, int attr, int len, void *buf);
static int fr508_send (sdla_t* card, int dlci, int attr, int len, void *buf);

/* Firmware asynchronous event handlers */
static int fr_event (sdla_t* card, int event, fr_mbox_t* mbox);
static int fr_modem_failure (sdla_t *card, fr_mbox_t* mbox);
static int fr_dlci_change (sdla_t *card, fr_mbox_t* mbox);

/* Miscellaneous functions */
static int update_chan_state (struct device* dev);
static void set_chan_state (struct device* dev, int state);
static struct device* find_channel (sdla_t* card, unsigned dlci);
static int is_tx_ready (sdla_t* card, fr_channel_t* chan);
static unsigned int dec_to_uint (unsigned char* str, int len);
static int reply_udp( unsigned char *data, unsigned int mbox_len );

static int intr_test( sdla_t* card );
static void init_chan_statistics( fr_channel_t* chan );
static void init_global_statistics( sdla_t* card );
static void read_DLCI_IB_mapping( sdla_t* card, fr_channel_t* chan );

/* Udp management functions */
static int process_udp_mgmt_pkt(char udp_pkt_src, sdla_t* card, struct sk_buff *skb, struct device* dev, int dlci, fr_channel_t* chan);
static int process_udp_driver_call(char udp_pkt_src, sdla_t* card, struct sk_buff *skb, struct device* dev, int dlci, fr_channel_t* chan);
static int udp_pkt_type( struct sk_buff *skb, sdla_t* card );

/* IPX functions */
static void switch_net_numbers(unsigned char *sendpacket, unsigned long network_number, unsigned char incoming);
static int handle_IPXWAN(unsigned char *sendpacket, char *devname, unsigned char enable_IPX, unsigned long network_number);

/****** Public Functions ****************************************************/

/*============================================================================
 * Frame relay protocol initialization routine.
 *
 * This routine is called by the main WANPIPE module during setup.  At this
 * point adapter is completely initialized and firmware is running.
 *  o read firmware version (to make sure it's alive)
 *  o configure adapter
 *  o initialize protocol-specific fields of the adapter data space.
 *
 * Return:	0	o.k.
 *		< 0	failure.
 */
__initfunc(int wpf_init(sdla_t * card, wandev_conf_t * conf))
{
	union {
		char str[80];
		fr_conf_t cfg;
	} u;

	/* Verify configuration ID */
	if (conf->config_id != WANCONFIG_FR) {
		printk(KERN_INFO "%s: invalid configuration ID %u!\n",
		       card->devname, conf->config_id);
		return -EINVAL;
	}
	/* Initialize protocol-specific fields of adapter data space */
	switch (card->hw.fwid) 
	{
		case SFID_FR502:
			card->mbox = (void *) (card->hw.dpmbase + FR502_MBOX_OFFS);
			card->rxmb = (void *) (card->hw.dpmbase + FR502_RXMB_OFFS);
			card->flags = (void *) (card->hw.dpmbase + FR502_FLAG_OFFS);
			card->isr = &fr502_isr;
			break;

		case SFID_FR508:
			card->mbox = (void *) (card->hw.dpmbase + FR508_MBOX_OFFS);
			card->flags = (void *) (card->hw.dpmbase + FR508_FLAG_OFFS);
			card->isr = &fr508_isr;
			break;

		default:
			return -EINVAL;
	}

	/* Read firmware version.  Note that when adapter initializes, it
	 * clears the mailbox, so it may appear that the first command was
	 * executed successfully when in fact it was merely erased. To work
	 * around this, we execute the first command twice.
	 */
	if (fr_read_version(card, NULL) || fr_read_version(card, u.str))
		return -EIO
		    ;
	printk(KERN_INFO "%s: running frame relay firmware v%s\n",
	       card->devname, u.str);

	/* Adjust configuration */
	conf->mtu = max(min(conf->mtu, 4080), FR_CHANNEL_MTU + FR_HEADER_LEN);
	conf->bps = min(conf->bps, 2048000);

	/* Configure adapter firmware */
	memset(&u.cfg, 0, sizeof(u.cfg));
	u.cfg.mtu = conf->mtu;
	u.cfg.t391 = 10;
	u.cfg.t392 = 15;
	u.cfg.n391 = 6;
	u.cfg.n392 = 3;
	u.cfg.n393 = 4;
	u.cfg.kbps = conf->bps / 1000;
	u.cfg.cir_fwd = 16;
	u.cfg.cir_bwd = u.cfg.bc_fwd = u.cfg.bc_bwd = u.cfg.cir_fwd;
	u.cfg.options = 0x0081;	/* direct Rx, no CIR check */
	
	switch (conf->u.fr.signalling) 
	{
		case WANOPT_FR_Q933:
			u.cfg.options |= 0x0200;
			break;
		case WANOPT_FR_LMI:
			u.cfg.options |= 0x0400;
			break;
	}

	if (conf->station == WANOPT_CPE) 
	{
		u.cfg.options |= 0x8000;	/* auto config DLCI */
	}
	else
	{
		u.cfg.station = 1;	/* switch emulation mode */
		card->u.f.node_dlci = conf->u.fr.dlci ? conf->u.fr.dlci : 16;
		card->u.f.dlci_num = min(max(conf->u.fr.dlci_num, 1), 100);
	}

	if (conf->clocking == WANOPT_INTERNAL)
		u.cfg.port |= 0x0001
		    ;
	if (conf->interface == WANOPT_RS232)
		u.cfg.port |= 0x0002
		    ;
	if (conf->u.fr.t391)
		u.cfg.t391 = min(conf->u.fr.t391, 30);
	if (conf->u.fr.t392)
		u.cfg.t392 = min(conf->u.fr.t392, 30);
	if (conf->u.fr.n391)
		u.cfg.n391 = min(conf->u.fr.n391, 255);
	if (conf->u.fr.n392)
		u.cfg.n392 = min(conf->u.fr.n392, 10);
	if (conf->u.fr.n393)
		u.cfg.n393 = min(conf->u.fr.n393, 10);

	if (fr_configure(card, &u.cfg))
		return -EIO
		    ;

	if (card->hw.fwid == SFID_FR508) 
	{
		fr_buf_info_t *buf_info =
		(void *) (card->hw.dpmbase + FR508_RXBC_OFFS);

		card->rxmb =
		    (void *) (buf_info->rse_next -
			      FR_MB_VECTOR + card->hw.dpmbase);
		card->u.f.rxmb_base =
		    (void *) (buf_info->rse_base -
			      FR_MB_VECTOR + card->hw.dpmbase);
		card->u.f.rxmb_last =
		    (void *) (buf_info->rse_base +
			 (buf_info->rse_num - 1) * sizeof(fr_buf_ctl_t) -
			      FR_MB_VECTOR + card->hw.dpmbase);
		card->u.f.rx_base = buf_info->buf_base;
		card->u.f.rx_top = buf_info->buf_top;
	}
	card->wandev.mtu = conf->mtu;
	card->wandev.bps = conf->bps;
	card->wandev.interface = conf->interface;
	card->wandev.clocking = conf->clocking;
	card->wandev.station = conf->station;
	card->poll = &wpf_poll;
	card->exec = &wpf_exec;
	card->wandev.update = &update;
	card->wandev.new_if = &new_if;
	card->wandev.del_if = &del_if;
	card->wandev.state = WAN_DISCONNECTED;
	card->wandev.udp_port = conf->udp_port;
	TracingEnabled = '0';
	return 0;
}

/******* WAN Device Driver Entry Points *************************************/

/*============================================================================
 * Update device status & statistics.
 */
static int update(wan_device_t * wandev)
{
	sdla_t *card;

	/* sanity checks */
	if ((wandev == NULL) || (wandev->private == NULL))
		return -EFAULT
		    ;
	if (wandev->state == WAN_UNCONFIGURED)
		return -ENODEV
		    ;
	if (test_and_set_bit(0, (void *) &wandev->critical))
		return -EAGAIN
		    ;
	card = wandev->private;
	fr_get_err_stats(card);
	fr_get_stats(card);
	wandev->critical = 0;
	return 0;
}

/*============================================================================
 * Create new logical channel.
 * This routine is called by the router when ROUTER_IFNEW IOCTL is being
 * handled.
 * o parse media- and hardware-specific configuration
 * o make sure that a new channel can be created
 * o allocate resources, if necessary
 * o prepare network device structure for registaration.
 *
 * Return:	0	o.k.
 *		< 0	failure (channel will not be created)
 */
static int new_if(wan_device_t * wandev, struct device *dev, wanif_conf_t * conf)
{
	sdla_t *card = wandev->private;
	fr_channel_t *chan;
	int err = 0;

	if ((conf->name[0] == '\0') || (strlen(conf->name) > WAN_IFNAME_SZ)) {
		printk(KERN_INFO "%s: invalid interface name!\n",
		       card->devname);
		return -EINVAL;
	}
	/* allocate and initialize private data */
	chan = kmalloc(sizeof(fr_channel_t), GFP_KERNEL);
	if (chan == NULL)
		return -ENOMEM
		    ;
	memset(chan, 0, sizeof(fr_channel_t));
	strcpy(chan->name, conf->name);
	chan->card = card;

	/* verify media address */
	if (is_digit(conf->addr[0])) {
		int dlci = dec_to_uint(conf->addr, 0);

		if (dlci && (dlci <= 4095)) {
			chan->dlci = dlci;
		} else {
			printk(KERN_ERR
			       "%s: invalid DLCI %u on interface %s!\n",
			       wandev->name, dlci, chan->name);
			err = -EINVAL;
		}
	} else {
		printk(KERN_ERR
		       "%s: invalid media address on interface %s!\n",
		       wandev->name, chan->name);
		err = -EINVAL;
	}
	if (err) {
		kfree(chan);
		return err;
	}

	/* place cir,be,bc and other channel specific information into the
	 * chan structure 
         */
	if (conf->cir) 
	{
		chan->cir = max( 1, min( conf->cir, 512 ) );
		chan->cir_status = CIR_ENABLED; 

		if (conf->bc)
			chan->bc = max( 1, min( conf->bc, 512 ) );
		if (conf->be)
			chan->be = max( 0, min( conf->be, 511) ); 

	}
	else
		chan->cir_status = CIR_DISABLED;

	chan->mc = conf->mc;

	chan->dlci_configured = DLCI_NOT_CONFIGURED;	

	chan->tx_int_status = DISABLED;	

	init_chan_statistics( chan );

	/* prepare network device data space for registration */
	dev->name = chan->name;
	dev->init = &if_init;
	dev->priv = chan;
	return 0;
}

/*============================================================================
 * Delete logical channel.
 */
static int del_if(wan_device_t * wandev, struct device *dev)
{
	if (dev->priv) {
		kfree(dev->priv);
		dev->priv = NULL;
	}
	return 0;
}

/****** WANPIPE-specific entry points ***************************************/

/*============================================================================
 * Execute adapter interface command.
 */
static int wpf_exec(struct sdla *card, void *u_cmd, void *u_data)
{
	fr_mbox_t *mbox = card->mbox;
	int retry = MAX_CMD_RETRY;
	int err, len;
	fr_cmd_t cmd;

	if (copy_from_user((void *) &cmd, u_cmd, sizeof(cmd)))
		return -EFAULT;
	/* execute command */
	do {
		memcpy(&mbox->cmd, &cmd, sizeof(cmd));
		if (cmd.length)
			if (copy_from_user((void *) &mbox->data, u_data, cmd.length))
				return -EFAULT;
		if (sdla_exec(mbox))
			err = mbox->cmd.result;
		else
			return -EIO;
	}
	while (err && retry-- && fr_event(card, err, mbox));

	/* return result */
	if (copy_to_user(u_cmd, (void *) &mbox->cmd, sizeof(fr_cmd_t)))
		return -EFAULT;
	len = mbox->cmd.length;
	if (len && u_data && copy_to_user(u_data, (void *) &mbox->data, len))
		return -EFAULT;
	return 0;
}

/****** Network Device Interface ********************************************/

/*============================================================================
 * Initialize Linux network interface.
 *
 * This routine is called only once for each interface, during Linux network
 * interface registration.  Returning anything but zero will fail interface
 * registration.
 */
static int if_init(struct device *dev)
{
	fr_channel_t *chan = dev->priv;
	sdla_t *card = chan->card;
	wan_device_t *wandev = &card->wandev;
	int i;

	/* Initialize device driver entry points */
	dev->open = &if_open;
	dev->stop = &if_close;
	dev->hard_header = &if_header;
	dev->rebuild_header = &if_rebuild_hdr;
	dev->hard_start_xmit = &if_send;
	dev->get_stats = &if_stats;

	/* Initialize media-specific parameters */
	dev->family = AF_INET;	/* address family */
	dev->type = ARPHRD_DLCI;	/* ARP h/w type */
	dev->mtu = FR_CHANNEL_MTU;
	dev->hard_header_len = FR_HEADER_LEN;	/* media header length */
	dev->addr_len = 2;	/* hardware address length */
	*(unsigned short *) dev->dev_addr = htons(chan->dlci);

	/* Initialize hardware parameters (just for reference) */
	dev->irq = wandev->irq;
	dev->dma = wandev->dma;
	dev->base_addr = wandev->ioport;
	dev->mem_start = wandev->maddr;
	dev->mem_end = wandev->maddr + wandev->msize - 1;

	/* Set transmit buffer queue length */
	dev->tx_queue_len = 30;

	dev_init_buffers(dev);
	
	set_chan_state(dev, WAN_DISCONNECTED);
	return 0;
}

/*============================================================================
 * Open network interface.
 * o if this is the first open, then enable communications and interrupts.
 * o prevent module from unloading by incrementing use count
 *
 * Return 0 if O.k. or errno.
 */

static int if_open(struct device *dev)
{
	fr_channel_t *chan = dev->priv;
	sdla_t *card = chan->card;
	struct device *dev2;
	int err = 0;
	fr508_flags_t *flags = card->flags;
	struct timeval tv;
	
	if (dev->start)
		return -EBUSY;	/* only one open is allowed */

	if (test_and_set_bit(0, (void *) &card->wandev.critical))
		return -EAGAIN;

	if (!card->open_cnt) 
	{
		Intr_test_counter = 0;
		card->intr_mode = INTR_TEST_MODE;
		err = intr_test( card );
		
		if ((err) || (Intr_test_counter !=(MAX_INTR_TEST_COUNTER +1))) {
			printk(KERN_INFO 
				"%s: Interrupt Test Failed, Counter: %i\n", 
				card->devname, Intr_test_counter);
			err = -EIO;
			card->wandev.critical = 0;
			return err;
		}

		printk(KERN_INFO "%s: Interrupt Test Passed, Counter: %i\n"
			,card->devname, Intr_test_counter);
		
		/* The following allocates and intializes a circular
		 * link list of interfaces per card.
		 */
		
		card->devs_struct = kmalloc(sizeof(load_sharing_t), GFP_KERNEL);
		if (card->devs_struct == NULL)
			return -ENOMEM;	
		card->dev_to_devtint_next = card->devs_struct;
		
		for (dev2 = card->wandev.dev; dev2; dev2 = dev2->slave) {
			(card->devs_struct)->dev_ptr = dev2;
			if(dev2->slave == NULL)
				(card->devs_struct)->next = card->dev_to_devtint_next;
			else {
				(card->devs_struct)->next = kmalloc(
					sizeof(load_sharing_t), GFP_KERNEL);
				if ((card->devs_struct)->next == NULL)
					return -ENOMEM;	
				card->devs_struct = (card->devs_struct)->next;
			}	
		}

		card->devs_struct = card->dev_to_devtint_next;
	
		card->intr_mode = BUFFER_INTR_MODE;	

		/* 
		check all the interfaces for the device to see if CIR has
	 	been enabled for any DLCI(s). If so then use the DLCI list
		Interrupt mode for fr_set_intr_mode(), otherwise use the			default global interrupt mode
		*/ 
	
		for (dev2 = card->wandev.dev; dev2; dev2 = dev2->slave) {
			
			if( ((fr_channel_t *)dev2->priv)->cir_status 
							== CIR_ENABLED)  {
				card->intr_mode = DLCI_LIST_INTR_MODE;
				break;
			}
		}

		/* 
		 *	If you enable comms and then set ints, you get a Tx int as you
		 *	perform the SET_INT_TRIGGERS command. So, we only set int
		 *	triggers and then adjust the interrupt mask (to disable Tx ints)		before enabling comms. 
		 */
		if (card->intr_mode == BUFFER_INTR_MODE) 
		{
			if (fr_set_intr_mode(card, 0x03, card->wandev.mtu)) 
			{
				err = -EIO;
				card->wandev.critical = 0;
				return err;
			}

			printk( KERN_INFO 
				"%s: Global Buffering Tx Interrupt Mode\n"
				, card->devname);

		} 
		else if (card->intr_mode == DLCI_LIST_INTR_MODE) 
		{	
			if (fr_set_intr_mode(card, 0x83, card->wandev.mtu)) 
			{
				err = -EIO;
				card->wandev.critical = 0;
				return err;
			}

			printk( KERN_INFO "%s: DLCI list Tx Interrupt Mode\n", 
				card->devname);

		}

		flags->imask &= ~0x02;
	
		if (fr_comm_enable(card)) 
		{
			err = -EIO;
			card->wandev.critical = 0;
			return err;
		}	

		wanpipe_set_state(card, WAN_CONNECTED);

		if (card->wandev.station == WANOPT_CPE) 
		{
			/* CPE: issue full status enquiry */
			fr_issue_isf(card, FR_ISF_FSE);
		}
		else
		{	/* FR switch: activate DLCI(s) */
		
			/* For Switch emulation we have to ADD and ACTIVATE
			 * the DLCI(s) that were configured with the SET_DLCI_
			 * CONFIGURATION command. Add and Activate will fail if
			 * DLCI specified is not included in the list.
			 *
			 * Also If_open is called once for each interface. But
			 * it does not get in here for all the interface. So
		 	 * we have to pass the entire list of DLCI(s) to add 
			 * activate routines.  
			 */ 
	
			fr_add_dlci(card, card->u.f.node_dlci[0], card->u.f.dlci_num);
			fr_activate_dlci(card, card->u.f.node_dlci, card->u.f.dlci_num);
		}
	}
	dev->mtu = min(dev->mtu, card->wandev.mtu - FR_HEADER_LEN);
	dev->interrupt = 0;
	dev->tbusy = 0;
	dev->start = 1;
	wanpipe_open(card);
	update_chan_state(dev);

	do_gettimeofday( &tv );
	chan->router_start_time = tv.tv_sec;
	card->wandev.critical = 0;
	return err;
}

/*============================================================================
 * Close network interface.
 * o if this is the last open, then disable communications and interrupts.
 * o reset flags.
 */
static int if_close(struct device *dev)
{
	fr_channel_t *chan = dev->priv;
	sdla_t *card = chan->card;

	if (test_and_set_bit(0, (void *) &card->wandev.critical))
		return -EAGAIN;
	;
	dev->start = 0;
	wanpipe_close(card);
	if (!card->open_cnt) {
		wanpipe_set_state(card, WAN_DISCONNECTED);
		fr_set_intr_mode(card, 0, 0);
		fr_comm_disable(card);
	}
	card->wandev.critical = 0;
	return 0;
}

/*============================================================================
 * Build media header.
 * o encapsulate packet according to encapsulation type.
 *
 * The trick here is to put packet type (Ethertype) into 'protocol' field of
 * the socket buffer, so that we don't forget it.  If encapsulation fails,
 * set skb->protocol to 0 and discard packet later.
 *
 * Return:	media header length.
 */
static int if_header(struct sk_buff *skb, struct device *dev,
	     unsigned short type, void *daddr, void *saddr, unsigned len)
{
	int hdr_len = 0;

	skb->protocol = type;
	hdr_len = wan_encapsulate(skb, dev);
	if (hdr_len < 0) {
		hdr_len = 0;
		skb->protocol = 0;
	}
	skb_push(skb, 1);
	skb->data[0] = Q922_UI;
	++hdr_len;
	return hdr_len;
}

/*============================================================================
 * Re-build media header.
 *
 * Return:	1	physical address resolved.
 *		0	physical address not resolved
 */
static int if_rebuild_hdr(struct sk_buff *skb)
{
	fr_channel_t *chan = skb->dev->priv;
	sdla_t *card = chan->card;

	printk(KERN_INFO "%s: rebuild_header() called for interface %s!\n",
	       card->devname, skb->dev->name);
	return 1;
}

/*============================================================================
 * Send a packet on a network interface.
 * o set tbusy flag (marks start of the transmission) to block a timer-based
 *   transmit from overlapping.
 * o check link state. If link is not up, then drop the packet.
 * o check channel status. If it's down then initiate a call.
 * o pass a packet to corresponding WAN device.
 * o free socket buffer
 *
 * Return:	0	complete (socket buffer must be freed)
 *		non-0	packet may be re-transmitted (tbusy must be set)
 *
 * Notes:
 * 1. This routine is called either by the protocol stack or by the "net
 *    bottom half" (with interrupts enabled).
 * 2. Setting tbusy flag will inhibit further transmit requests from the
 *    protocol stack and can be used for flow control with protocol layer.
 */
static int if_send(struct sk_buff *skb, struct device *dev)
{
	fr_channel_t *chan = dev->priv;
	sdla_t *card = chan->card;
	int retry = 0, err;
	struct device *dev2;
    	fr508_flags_t* adptr_flags = card->flags;
	fr_dlci_interface_t* dlci_interface = chan->dlci_int_interface;
	unsigned long host_cpu_flags;
	int send_data = 0;
   	++chan->if_send_entry;

    	if (dev->tbusy) 
    	{
		/* If our device stays busy for at least 5 seconds then we will
                 * kick start the device by making dev->tbusy = 0.  We expect
                 * that our device never stays busy more than 5 seconds. So this                 * is only used as a last resort.
                 */
		
		++chan->if_send_busy;
		++chan->ifstats.collisions;

		if ((jiffies - chan->tick_counter) < (5*HZ))
			return 1;

		printk(KERN_INFO "%s: Transmit timed out\n", chan->name);
		
		++chan->if_send_busy_timeout;

		/* unbusy all the interfaces on the card */
       		for (dev2 = card->wandev.dev; dev2; dev2 = dev2->slave)
			dev2->tbusy = 0;
    	}

	if (test_and_set_bit(0, (void *) &card->wandev.critical)) {
#ifdef _DEBUG_
		printk(KERN_INFO "%s: if_send() hit critical section!\n",
		       card->devname);
#endif
		dev_kfree_skb(skb, FREE_WRITE);
		return 0;
	}
    	disable_irq(card->hw.irq);
	++card->irq_dis_if_send_count;

	if (test_and_set_bit(0, (void*)&card->wandev.critical)) 
	{
		if (card->wandev.critical == CRITICAL_IN_ISR) 
		{	
			++chan->if_send_critical_ISR;

			if (card->intr_mode == DLCI_LIST_INTR_MODE)
			{
				/* The enable_tx_int flag is set here so that if
			 	 * the critical flag is set due to an interrupt 
				 * then we want to enable transmit interrupts 
				 * again.
			 	 */ 
		
				card->wandev.enable_tx_int = 1;

				/* Setting this flag to WAITING_TO_BE_ENABLED 
				 * specifies that interrupt bit has to be 
				 * enabled for that particular interface. 
				 * (delayed interrupt)
			 	 */
				
				chan->tx_int_status = WAITING_TO_BE_ENABLED;

				/* This is used for enabling dynamic calculation
				 * of CIRs relative to the packet length.
			 	 */
	
	       			chan->pkt_length = skb->len;			
				dev->tbusy = 1;
				chan->tick_counter = jiffies;
			}
			else
			{
				card->wandev.enable_tx_int = 1;
				dev->tbusy = 1;
				chan->tick_counter = jiffies;
			}
			save_flags(host_cpu_flags);
			cli();
			if ((!(--card->irq_dis_if_send_count)) && 
					(!card->irq_dis_poll_count))
				enable_irq(card->hw.irq);
			restore_flags(host_cpu_flags);
			return 1;
		}

		++chan->if_send_critical_non_ISR;
		++chan->ifstats.tx_dropped;
		dev_kfree_skb(skb, FREE_WRITE);
		save_flags(host_cpu_flags);
		cli();
                if ((!(--card->irq_dis_if_send_count)) &&
					 (!card->irq_dis_poll_count))
                	enable_irq(card->hw.irq);
		restore_flags(host_cpu_flags);
		return 0;
	}
 	
	card->wandev.critical = 0x21;
    
	if (card->wandev.state != WAN_CONNECTED) 
	{
		++chan->if_send_wan_disconnected;
		++chan->ifstats.tx_dropped;
		++card->wandev.stats.tx_dropped;
	}
	else if (chan->state != WAN_CONNECTED)
	{
		++chan->if_send_dlci_disconnected;
		update_chan_state(dev);
		++chan->ifstats.tx_dropped;
		++card->wandev.stats.tx_dropped;
	}
	else if (!is_tx_ready(card, chan)) 
	{
		if (card->intr_mode == DLCI_LIST_INTR_MODE )
		{
			dlci_interface->gen_interrupt |= 0x40;
			dlci_interface->packet_length = skb->len;	
		}  
       		dev->tbusy = 1;
		chan->tick_counter = jiffies;

		adptr_flags->imask |= 0x02;

		++ chan->if_send_no_bfrs;
		retry = 1;
	}
	else 
	{
		send_data = 1;
		/* If it's an IPX packet */
		if( sendpacket[1] == 0x00 &&
		    sendpacket[2] == 0x80 &&
		    sendpacket[6] == 0x81 &&
		    sendpacket[7] == 0x37) 
		{
			if( card->wandev.enable_IPX ) 
			{
				switch_net_numbers(sendpacket, 
					card->wandev.network_number, 0);
			}
			else
			{
				/* increment some statistic here! */
				send_data = 0;
			}
		}

		if (send_data)
		{
        		err = (card->hw.fwid == SFID_FR508) ?
        		fr508_send(card, chan->dlci, 0, skb->len, skb->data) :
        		fr502_send(card, chan->dlci, 0, skb->len, skb->data);

			if (err) 
			{
				if (card->intr_mode == DLCI_LIST_INTR_MODE) 
				{
					dlci_interface->gen_interrupt |= 0x40;
					dlci_interface->packet_length = skb->len;	
				} 
                		dev->tbusy = 1;
				chan->tick_counter = jiffies;
            			adptr_flags->imask |= 0x02;
				retry = 1;
           			++ chan->if_send_adptr_bfrs_full;
				++ chan->ifstats.tx_errors;
            			++ card->wandev.stats.tx_errors;
			} 
			else
			{
				++ chan->if_send_bfrs_passed_to_adptr;
				++chan->ifstats.tx_packets;
				++card->wandev.stats.tx_packets;
			}
		}
	}

	if (!retry)
		dev_kfree_skb(skb, FREE_WRITE);

	card->wandev.critical = 0;
	save_flags(host_cpu_flags);
	cli();
        if ((!(--card->irq_dis_if_send_count)) && (!card->irq_dis_poll_count))
        	enable_irq(card->hw.irq);
	restore_flags(host_cpu_flags);
	return retry;
}

/*
 *	If incoming is 0 (outgoing)- if the net numbers is ours make it 0
 *	if incoming is 1 - if the net number is 0 make it ours 
 *
 */
 
static void switch_net_numbers(unsigned char *sendpacket, unsigned long network_number, unsigned char incoming)
{
	unsigned long pnetwork_number;

	pnetwork_number = (unsigned long)((sendpacket[14] << 24) + 
			  (sendpacket[15] << 16) + (sendpacket[16] << 8) + 
			  sendpacket[17]);

	if (!incoming) {
		if( pnetwork_number == network_number) {
			sendpacket[14] = sendpacket[15] = sendpacket[16] = 
					 sendpacket[17] = 0x00;
		}
	} else {
		if( pnetwork_number == 0) {
			sendpacket[14] = (unsigned char)(network_number >> 24);
			sendpacket[15] = (unsigned char)((network_number & 
					 0x00FF0000) >> 16);
			sendpacket[16] = (unsigned char)((network_number & 
					 0x0000FF00) >> 8);
			sendpacket[17] = (unsigned char)(network_number & 
					 0x000000FF);
		}
	}


	pnetwork_number = (unsigned long)((sendpacket[26] << 24) + 
			  (sendpacket[27] << 16) + (sendpacket[28] << 8) + 
			  sendpacket[29]);

	if( !incoming ) {
		if( pnetwork_number == network_number) {
			sendpacket[26] = sendpacket[27] = sendpacket[28] = 
					 sendpacket[29] = 0x00;
		}
	} else {
		if( pnetwork_number == 0 ) {
			sendpacket[26] = (unsigned char)(network_number >> 24);
			sendpacket[27] = (unsigned char)((network_number & 
					 0x00FF0000) >> 16);
			sendpacket[28] = (unsigned char)((network_number & 
					 0x0000FF00) >> 8);
			sendpacket[29] = (unsigned char)(network_number & 
					 0x000000FF);
		}
	}
} /* switch_net_numbers */


/*============================================================================
 * Get ethernet-style interface statistics.
 * Return a pointer to struct enet_statistics.
 */
static struct net_device_stats *if_stats(struct device *dev)
{
	fr_channel_t *chan = dev->priv;

	return &chan->ifstats;
}

/****** Interrupt Handlers **************************************************/

/*============================================================================
 * S502 frame relay interrupt service routine.
 */
static void fr502_isr(sdla_t * card)
{
	fr502_flags_t *flags = card->flags;

	switch (flags->iflag) 
	{
		case 0x01:		/* receive interrupt */
			fr502_rx_intr(card);
			break;

		case 0x02:		/* transmit interrupt */
			flags->imask &= ~0x02;
			tx_intr(card);
			break;

		default:
			spur_intr(card);
	}
	flags->iflag = 0;
}

/*============================================================================
 * S508 frame relay interrupt service routine.
 */
static void fr508_isr(sdla_t * card)
{
	fr508_flags_t *flags = card->flags;
	fr_buf_ctl_t *bctl;
	char *ptr = &flags->iflag;
	struct device* dev = card->wandev.dev;
	struct device* dev2;
	int i;
	unsigned long host_cpu_flags;
	unsigned disable_tx_intr =1;
	fr_channel_t* chan;
	fr_dlci_interface_t* dlci_interface;	

	/* This flag prevents nesting of interrupts.  See sdla_isr() routine
         * in sdlamain.c. 
	 */
	card->in_isr = 1;
	
	++card->statistics.isr_entry;

	if (test_and_set_bit(0, (void*)&card->wandev.critical)) 
	{
 		printk(KERN_INFO "fr508_isr: %s, wandev.critical set to 0x%02X, int type = 0x%02X\n", card->devname, card->wandev.critical, flags->iflag);
		++card->statistics.isr_already_critical;
		card->in_isr = 0;
		return;
	}
	int_occur = 1;

	/* For all interrupts set the critical flag to CRITICAL_RX_INTR.
         * If the if_send routine is called with this flag set it will set
         * the enable transmit flag to 1. (for a delayed interrupt)
         */
	card->wandev.critical = CRITICAL_IN_ISR;

	card->dlci_int_mode_unbusy = 0;
	card->buff_int_mode_unbusy = 0;	

	switch (flags->iflag) {
		case 0x01:  /* receive interrupt */
	    		++card->statistics.isr_rx;
            		fr508_rx_intr(card);
            		break;

		case 0x02:  /* transmit interrupt */
	    		++card->statistics.isr_tx;  
	    		bctl = (void*)(flags->tse_offs - FR_MB_VECTOR + 
				card->hw.dpmbase);
			bctl->flag = 0xA0;
		
			if (card->intr_mode == DLCI_LIST_INTR_MODE )
			{
				/* Find the structure and make it unbusy */
				dev = find_channel( card, flags->dlci);
				dev->tbusy = 0;

				/* This is used to perform devtint at the
				 * end of the isr 
				 */
				card->dlci_int_mode_unbusy = 1;
	
				/* check to see if any other interfaces are
				 * busy. If so then do not disable the tx
				 * interrupts 
				 */		 
				for (dev2 = card->wandev.dev; dev2; 
						dev2 = dev2->slave)
				{
					if ( dev2->tbusy == 1)
					{
						disable_tx_intr = 0;
						break;
            				}
				}
				if (disable_tx_intr)
					flags->imask &= ~0x02;
				  
			}
			else if (card->intr_mode == BUFFER_INTR_MODE) 
			{
				for (dev2 = card->wandev.dev; dev2; 
							dev2 = dev2->slave) 
				{
					if ( !dev2 || !dev2->start ) 
					{
						++card->statistics.
						tx_intr_dev_not_started;
						continue;
					}
					if(dev2->tbusy)
					{
						card->buff_int_mode_unbusy = 1;
						((fr_channel_t*)dev2->priv)->dev_pending_devtint = 1;
						dev2->tbusy = 0;
					} else 
						((fr_channel_t*)dev2->priv)->dev_pending_devtint = 0;
				}
				flags->imask &= ~0x02;	
			}
            		break;

		case 0x08:
	    		Intr_test_counter++;
			++card->statistics.isr_intr_test;
	    		break;	

		default:
	    		++card->statistics.isr_spurious;
            		spur_intr(card);
	    		printk(KERN_INFO "%s: Interrupt Type 0x%02X!\n", 
				card->devname, flags->iflag);
	    
			printk(KERN_INFO "%s: ID Bytes = ",card->devname);
 	    		for(i = 0; i < 8; i ++)
				printk(KERN_INFO "0x%02X ", *(ptr + 0x28 + i));
	   	 	printk(KERN_INFO "\n");	
            
			break;
    	}

	card->wandev.critical = CRITICAL_INTR_HANDLED;
	if (card->wandev.enable_tx_int) 
	{
		if( card->intr_mode == DLCI_LIST_INTR_MODE )
		{	
			for (dev2 = card->wandev.dev; dev2; dev2 = dev2->slave)
			{
	 			chan = dev2->priv;
				if ( chan->tx_int_status == 
						WAITING_TO_BE_ENABLED ) 
				{
					dlci_interface = 
						chan->dlci_int_interface;
					dlci_interface->gen_interrupt |= 0x40;
					dlci_interface->packet_length = 
							chan->pkt_length;	
					chan->tx_int_status = DISABLED;
				}
			}
		}
		card->wandev.enable_tx_int = 0;
		flags->imask |= 0x02;
		++card->statistics.isr_enable_tx_int;
   	}
	save_flags(host_cpu_flags);
	cli();
	card->in_isr = 0;
	card->wandev.critical = 0xD1;
	flags->iflag = 0;
	card->wandev.critical = 0;
	restore_flags(host_cpu_flags);

	/*
	 *	Device is now ready to send. The instant this is executed the If_Send
	 *	routine is called. That is why this is put at the bottom of the ISR
	 *	to prevent a endless loop condition caused by repeated Interrupts and
	 *	enable_tx_int flag.
	 */

	if(card->dlci_int_mode_unbusy)
		dev_tint(dev);
	
	if(card->buff_int_mode_unbusy)
	{
		for (;;) 
		{
			if (((fr_channel_t*)((card->devs_struct)->dev_ptr)->priv)->dev_pending_devtint == 1){
		
				((fr_channel_t*)((card->devs_struct)->dev_ptr)->priv)->dev_pending_devtint=0;
				dev_tint((card->devs_struct)->dev_ptr);
			}
			if ((card->devs_struct)->next == card->dev_to_devtint_next)
				break;
			card->devs_struct = (card->devs_struct)->next;
		}
		card->devs_struct = (card->dev_to_devtint_next)->next;
		card->dev_to_devtint_next = card->devs_struct; 
	}
}

/*============================================================================
 * Receive interrupt handler.
 */

static void fr502_rx_intr(sdla_t * card)
{
	fr_mbox_t *mbox = card->rxmb;
	struct sk_buff *skb;
	struct device *dev;
	fr_channel_t *chan;
	unsigned dlci, len;
	void *buf;

	sdla_mapmem(&card->hw, FR502_RX_VECTOR);

	dlci = mbox->cmd.dlci;
	len = mbox->cmd.length;

	/* Find network interface for this packet */
	dev = find_channel(card, dlci);
	if (dev == NULL) {
		/* Invalid channel, discard packet */
		printk(KERN_INFO "%s: receiving on orphaned DLCI %d!\n",
		       card->devname, dlci);
		sdla_mapmem(&card->hw, FR_MB_VECTOR);
	}
	chan = dev->priv;
	if (!dev->start) {
		++chan->ifstats.rx_dropped;
		sdla_mapmem(&card->hw, FR_MB_VECTOR);
	}
	/* Allocate socket buffer */
	skb = dev_alloc_skb(len);
	if (skb == NULL) {
		printk(KERN_INFO "%s: no socket buffers available!\n",
		       card->devname);
		++chan->ifstats.rx_dropped;
		sdla_mapmem(&card->hw, FR_MB_VECTOR);
	}
	/* Copy data to the socket buffer */
	buf = skb_put(skb, len);
	memcpy(buf, mbox->data, len);
	sdla_mapmem(&card->hw, FR_MB_VECTOR);

	/* Decapsulate packet and pass it up the protocol stack */
	skb->dev = dev;
	buf = skb_pull(skb, 1);	/* remove hardware header */
	if (!wan_type_trans(skb, dev)) {
		/* can't decapsulate packet */
		dev_kfree_skb(skb, FREE_READ);
		++chan->ifstats.rx_errors;
		++card->wandev.stats.rx_errors;
	} else {
		netif_rx(skb);
		++chan->ifstats.rx_packets;
		++card->wandev.stats.rx_packets;
	}
	sdla_mapmem(&card->hw, FR_MB_VECTOR);
}

/*============================================================================
 * Receive interrupt handler.
 */
static void fr508_rx_intr(sdla_t * card)
{
	fr_buf_ctl_t *frbuf = card->rxmb;
	struct sk_buff *skb;
	struct device *dev;
	fr_channel_t *chan;
	unsigned dlci, len, offs;
	void *buf;
	unsigned rx_count = 0;
	fr508_flags_t* flags = card->flags;
	char *ptr = &flags->iflag;
	int i, err;

	if (frbuf->flag != 0x01) {
		printk(KERN_INFO "%s: corrupted Rx buffer @ 0x%X!\n",
		       card->devname, (unsigned) frbuf);
		printk(KERN_INFO "%s: ID Bytes = ",card->devname);
 		for(i = 0; i < 8; i ++)
			printk(KERN_INFO "0x%02X ", *(ptr + 0x28 + i));
		printk(KERN_INFO "\n");
	
		++card->statistics.rx_intr_corrupt_rx_bfr;
		return;
	}

	do
	{
		len  = frbuf->length;
		dlci = frbuf->dlci;
		offs = frbuf->offset;

		/* Find network interface for this packet */
		dev = find_channel(card, dlci);
		chan = dev->priv;
        
		if (dev == NULL) 
		{
			/* Invalid channel, discard packet */
			printk(KERN_INFO "%s: receiving on orphaned DLCI %d!\n"
				, card->devname, dlci);
			++card->statistics.rx_intr_on_orphaned_DLCI; 
        	}
		else
		{
	   		skb = dev_alloc_skb(len); 
 			if (!dev->start || (skb == NULL)) 
 			{ 
				++chan->ifstats.rx_dropped;
				if(dev->start) 
				{
					printk(KERN_INFO 
					"%s: no socket buffers available!\n", 
					card->devname);
		    			++chan->rx_intr_no_socket;
                		
				} 
				else
					++ chan->rx_intr_dev_not_started;
			} 
			else
			{
				/* Copy data to the socket buffer */
				if ((offs + len) > card->u.f.rx_top + 1) 
				{
					unsigned tmp = card->u.f.rx_top - 
							offs + 1;

					buf = skb_put(skb, tmp);
					sdla_peek(&card->hw, offs, buf, tmp);
					offs = card->u.f.rx_base;
                    			len -= tmp;
                		}

				buf = skb_put(skb, len);
				sdla_peek(&card->hw, offs, buf, len);
#ifdef CONFIG_SANGOMA_MANAGER
				if (management_check(skb,card))
				{
					++chan->rx_intr_DRVSTATS_request;
				}				
				else
#endif				
				if (handle_IPXWAN(skb->data,card->devname, card->wandev.enable_IPX, card->wandev.network_number)) 
				{
					if (card->wandev.enable_IPX) 
					{
						fr508_send(card, dlci, 0, skb->len, skb->data);
					} else {
						/* increment some statistic! */
					}
				}
				else 
				{
                    			/* Decapsulate packet and pass it up the
				   	   protocol stack */
					skb->dev = dev;

					/* remove hardware header */
					buf = skb_pull(skb, 1); 
				
					if (!wan_type_trans(skb, dev)) 
					{
						/* can't decapsulate packet */
						dev_kfree_skb(skb, FREE_READ);
						++chan->rx_intr_bfr_not_passed_to_stack;
 						++chan->ifstats.rx_errors;
		                        	++card->wandev.stats.rx_errors;
					}
					else
					{
						netif_rx(skb);
						++ chan->rx_intr_bfr_passed_to_stack;
						++ chan->ifstats.rx_packets;
						++ card->wandev.stats.rx_packets;
					}
                		}
            		}
       		}

        	/* Release buffer element and calculate a pointer to the next 
		   one */
        	frbuf->flag = 0;
		card->rxmb = ++frbuf;
        
		if ((void*)frbuf > card->u.f.rxmb_last)
			card->rxmb = card->u.f.rxmb_base;

		/* The loop put in is temporary, that is why the break is
 		 * placed here. (?????)
		 */
		break;

	        frbuf = card->rxmb;

    	} while (frbuf->flag && ((++ rx_count) < 4));
}

/*============================================================================
 * Transmit interrupt handler.
 * o print a warning
 * o 
 * If number of spurious interrupts exceeded some limit, then ???
 */
static void tx_intr(sdla_t * card)
{
	struct device *dev = card->wandev.dev;

	if (card->intr_mode == BUFFER_INTR_MODE) 
	{ 
		for (; dev; dev = dev->slave) 
		{
			if ( !dev || !dev->start ) 
			{ 
				++ card->statistics.tx_intr_dev_not_started;
				continue;
			}
	
			dev->tbusy = 0;
			dev_tint(dev);
		}
	}
	else
	{
		dev->tbusy = 0;
		dev_tint(dev);
	}
}

/*============================================================================
 * Spurious interrupt handler.
 * o print a warning
 * o 
 * If number of spurious interrupts exceeded some limit, then ???
 */
static void spur_intr(sdla_t * card)
{
	printk(KERN_INFO "%s: spurious interrupt!\n", card->devname);
}

/*
  Return 0 for non-IPXWAN packet
         1 for IPXWAN packet or IPX is not enabled!

*/

static int handle_IPXWAN(unsigned char *sendpacket, char *devname, unsigned char enable_IPX, unsigned long network_number)
{
	int i;

	if( sendpacket[1] == 0x00 &&
	    sendpacket[2] == 0x80 &&
	    sendpacket[6] == 0x81 &&
	    sendpacket[7] == 0x37) { 

		if(!enable_IPX) {
			return 1;
		}
	} else {
		return 0;
	}

	if( sendpacket[24] == 0x90 &&
	    sendpacket[25] == 0x04)
	{
		if( sendpacket[10] == 0x02 &&
		    sendpacket[42] == 0x00)
		{
			printk(KERN_INFO "%s: Received IPXWAN Timer Request packet\n",devname);

			for(i = 49; sendpacket[i] == 0x00; i += 5)
			{
				if( sendpacket[i + 4] != 0x02)
				{
					sendpacket[i + 1] = 0;
				}
			}

			if( sendpacket[i] == 0x04 )
			{
				i += 8;
			}

			for(; sendpacket[i] == 0x80 ;)
			{
				sendpacket[i + 1] = 0;
				i += (sendpacket[i + 2] << 8) + (sendpacket[i + 3]) + 4;
			}

			sendpacket[42] = 0x01;

			printk(KERN_INFO "%s: Sending IPXWAN Timer Response\n",devname);
		}
		else if( sendpacket[42] == 0x02 )
		{
			printk(KERN_INFO "%s: Received IPXWAN Information Request packet\n",devname);

			sendpacket[42] = 0x03;

			sendpacket[59] = 'F';
			sendpacket[60] = 'P';
			sendpacket[61] = 'I';
			sendpacket[62] = 'P';
			sendpacket[63] = 'E';
			sendpacket[64] = '-';
			sendpacket[65] = CVHexToAscii(network_number >> 28);
			sendpacket[66] = CVHexToAscii((network_number & 0x0F000000)>> 24);
			sendpacket[67] = CVHexToAscii((network_number & 0x00F00000)>> 20);
			sendpacket[68] = CVHexToAscii((network_number & 0x000F0000)>> 16);
			sendpacket[69] = CVHexToAscii((network_number & 0x0000F000)>> 12);
			sendpacket[70] = CVHexToAscii((network_number & 0x00000F00)>> 8);
			sendpacket[71] = CVHexToAscii((network_number & 0x000000F0)>> 4);
			sendpacket[72] = CVHexToAscii(network_number & 0x0000000F);
			for(i = 73; i < 107; i+= 1)
			{
				sendpacket[i] = 0;
			}

			printk(KERN_INFO "%s: Sending IPXWAN Information Response packet\n",devname);
		}
		else
		{
			printk(KERN_INFO "%s: Unknown IPXWAN packet!\n",devname);
			return 0;
		}

		sendpacket[43] = (unsigned char)(network_number >> 24);
		sendpacket[44] = (unsigned char)((network_number & 0x00FF0000) >> 16);
		sendpacket[45] = (unsigned char)((network_number & 0x0000FF00) >> 8);
		sendpacket[46] = (unsigned char)(network_number & 0x000000FF);

		return 1;
	}

	switch_net_numbers(sendpacket, network_number ,1);
	return 0;
}


/****** Background Polling Routines  ****************************************/

/*============================================================================
 * Main polling routine.
 * This routine is repeatedly called by the WANPIPE 'thead' to allow for
 * time-dependent housekeeping work.
 *
 * o fetch asynchronous network events.
 *
 * Notes:
 * 1. This routine may be called on interrupt context with all interrupts
 *    enabled. Beware!
 */

static void wpf_poll(sdla_t * card)
{
	fr508_flags_t *flags;
	unsigned long host_cpu_flags;

	++card->statistics.poll_entry;

 	if (((jiffies - card->state_tick) < HZ) || 
				(card->intr_mode == INTR_TEST_MODE))
		return;

	disable_irq(card->hw.irq);
	++card->irq_dis_poll_count;

	if (test_and_set_bit(0, (void *)&card->wandev.critical)) 
	{
		++ card->statistics.poll_already_critical;
		save_flags(host_cpu_flags);
		cli();
		if ((!card->irq_dis_if_send_count) &&
                		(!(--card->irq_dis_poll_count)))
                	enable_irq(card->hw.irq);
		restore_flags(host_cpu_flags);

		return;
	}

	card->wandev.critical = 0x11;

	++ card->statistics.poll_processed;

	if (flags->event) {
		fr_mbox_t* mbox = card->mbox;
		int err;

		memset(&mbox->cmd, 0, sizeof(fr_cmd_t));
		mbox->cmd.command = FR_READ_STATUS;
		err = sdla_exec(mbox) ? mbox->cmd.result : CMD_TIMEOUT;
		if (err)
			fr_event(card, err, mbox);
	}

	card->wandev.critical = 0;

	save_flags(host_cpu_flags);
	cli();
        if ((!card->irq_dis_if_send_count) && (!(--card->irq_dis_poll_count)))
		enable_irq(card->hw.irq);
	restore_flags(host_cpu_flags);

	card->state_tick = jiffies;
}


/****** Frame Relay Firmware-Specific Functions *****************************/

/*============================================================================
 * Read firmware code version.
 * o fill string str with firmware version info. 
 */
static int fr_read_version(sdla_t * card, char *str)
{
	fr_mbox_t *mbox = card->mbox;
	int retry = MAX_CMD_RETRY;
	int err;

	do {
		memset(&mbox->cmd, 0, sizeof(fr_cmd_t));
		mbox->cmd.command = FR_READ_CODE_VERSION;
		err = sdla_exec(mbox) ? mbox->cmd.result : CMD_TIMEOUT;
	}
	while (err && retry-- && fr_event(card, err, mbox));
	if (!err && str) {
		int len = mbox->cmd.length;

		memcpy(str, mbox->data, len);
		str[len] = '\0';
	}
	return err;
}

/*============================================================================
 * Set global configuration.
 */
static int fr_configure(sdla_t * card, fr_conf_t * conf)
{
	fr_mbox_t *mbox = card->mbox;
	int retry = MAX_CMD_RETRY;
	int dlci_num = card->u.f.dlci_num;
	int err, i;

	do {
		memset(&mbox->cmd, 0, sizeof(fr_cmd_t));
		memcpy(mbox->data, conf, sizeof(fr_conf_t));

		if (dlci_num) for (i = 0; i < dlci_num; ++i)
			((fr_conf_t*)mbox->data)->dlci[i] = 
					card->u.f.node_dlci[i]; 
		
		mbox->cmd.command = FR_SET_CONFIG;
		mbox->cmd.length =
		    sizeof(fr_conf_t) + dlci_num * sizeof(short);
		err = sdla_exec(mbox) ? mbox->cmd.result : CMD_TIMEOUT;
	}
	while (err && retry-- && fr_event(card, err, mbox));
	return err;
}

/*============================================================================
 * Set DLCI configuration.
 */
static int fr_dlci_configure (sdla_t* card, fr_dlc_conf_t *conf, unsigned dlci)
{
	fr_mbox_t* mbox = card->mbox;
	int retry = MAX_CMD_RETRY;
	int err;

	do
	{
		memset(&mbox->cmd, 0, sizeof(fr_cmd_t));
		memcpy(mbox->data, conf, sizeof(fr_dlc_conf_t));
		mbox->cmd.dlci = (unsigned short) dlci; 
		mbox->cmd.command = FR_SET_CONFIG;
		mbox->cmd.length = 0x0E;

		err = sdla_exec(mbox) ? mbox->cmd.result : CMD_TIMEOUT;
	
	} while (err && retry--);
	
	return err;
}

/*============================================================================
 * Set interrupt mode.
 */
static int fr_set_intr_mode(sdla_t * card, unsigned mode, unsigned mtu)
{
	fr_mbox_t *mbox = card->mbox;
	int retry = MAX_CMD_RETRY;
	int err;

	do {
		memset(&mbox->cmd, 0, sizeof(fr_cmd_t));
		if (card->hw.fwid == SFID_FR502) {
			fr502_intr_ctl_t *ictl = (void *) mbox->data;

			memset(ictl, 0, sizeof(fr502_intr_ctl_t));
			ictl->mode = mode;
			ictl->tx_len = mtu;
			mbox->cmd.length = sizeof(fr502_intr_ctl_t);
		} else {
			fr508_intr_ctl_t *ictl = (void *) mbox->data;

			memset(ictl, 0, sizeof(fr508_intr_ctl_t));
			ictl->mode = mode;
			ictl->tx_len = mtu;
			ictl->irq = card->hw.irq;
			mbox->cmd.length = sizeof(fr508_intr_ctl_t);
		}
		mbox->cmd.command = FR_SET_INTR_MODE;
		err = sdla_exec(mbox) ? mbox->cmd.result : CMD_TIMEOUT;
	}
	while (err && retry-- && fr_event(card, err, mbox));
	return err;
}

/*============================================================================
 * Enable communications.
 */
static int fr_comm_enable(sdla_t * card)
{
	fr_mbox_t *mbox = card->mbox;
	int retry = MAX_CMD_RETRY;
	int err;

	do {
		memset(&mbox->cmd, 0, sizeof(fr_cmd_t));
		mbox->cmd.command = FR_COMM_ENABLE;
		err = sdla_exec(mbox) ? mbox->cmd.result : CMD_TIMEOUT;
	}
	while (err && retry-- && fr_event(card, err, mbox));
	return err;
}

/*============================================================================
 * Disable communications. 
 */
static int fr_comm_disable(sdla_t * card)
{
	fr_mbox_t *mbox = card->mbox;
	int retry = MAX_CMD_RETRY;
	int err;

	do {
		memset(&mbox->cmd, 0, sizeof(fr_cmd_t));
		mbox->cmd.command = FR_COMM_DISABLE;
		err = sdla_exec(mbox) ? mbox->cmd.result : CMD_TIMEOUT;
	}
	while (err && retry-- && fr_event(card, err, mbox));
	return err;
}

/*============================================================================
 * Get communications error statistics. 
 */
static int fr_get_err_stats(sdla_t * card)
{
	fr_mbox_t *mbox = card->mbox;
	int retry = MAX_CMD_RETRY;
	int err;

	do {
		memset(&mbox->cmd, 0, sizeof(fr_cmd_t));
		mbox->cmd.command = FR_READ_ERROR_STATS;
		err = sdla_exec(mbox) ? mbox->cmd.result : CMD_TIMEOUT;
	}
	while (err && retry-- && fr_event(card, err, mbox));

	if (!err) {
		fr_comm_stat_t* stats = (void*)mbox->data;

		card->wandev.stats.rx_over_errors    = stats->rx_overruns;
		card->wandev.stats.rx_crc_errors     = stats->rx_bad_crc;
		card->wandev.stats.rx_missed_errors  = stats->rx_aborts;
		card->wandev.stats.rx_length_errors  = stats->rx_too_long;
		card->wandev.stats.tx_aborted_errors = stats->tx_aborts;
	}
	return err;
}

/*============================================================================
 * Get statistics. 
 */
static int fr_get_stats(sdla_t * card)
{
	fr_mbox_t *mbox = card->mbox;
	int retry = MAX_CMD_RETRY;
	int err;

	do {
		memset(&mbox->cmd, 0, sizeof(fr_cmd_t));
		mbox->cmd.command = FR_READ_STATISTICS;
		err = sdla_exec(mbox) ? mbox->cmd.result : CMD_TIMEOUT;
	}
	while (err && retry-- && fr_event(card, err, mbox));

	if (!err) {
		fr_link_stat_t *stats = (void *) mbox->data;

		card->wandev.stats.rx_frame_errors = stats->rx_bad_format;
		card->wandev.stats.rx_dropped =
		    stats->rx_dropped + stats->rx_dropped2
		    ;
	}
	return err;
}

/*============================================================================
 * Add DLCI(s) (Access Node only!). 
 */
 
static int fr_add_dlci(sdla_t * card, int dlci, int num)
{
	fr_mbox_t *mbox = card->mbox;
	int retry = MAX_CMD_RETRY;
	int err, i;

	do {
		unsigned short *dlci_list = (void *) mbox->data;

		memset(&mbox->cmd, 0, sizeof(fr_cmd_t));
		for (i = 0; i < num; ++i)
			dlci_list[i] = card->u.f.node_dlci[i];

		mbox->cmd.length = num * sizeof(short);
		mbox->cmd.command = FR_ADD_DLCI;
		err = sdla_exec(mbox) ? mbox->cmd.result : CMD_TIMEOUT;
	}
	while (err && retry-- && fr_event(card, err, mbox));
	return err;
}

/*============================================================================
 * Activate DLCI(s) (Access Node only!). 
 */
static int fr_activate_dlci(sdla_t * card, int dlci, int num)
{
	fr_mbox_t *mbox = card->mbox;
	int retry = MAX_CMD_RETRY;
	int err, i;

	do {
		unsigned short *dlci_list = (void *) mbox->data;

		memset(&mbox->cmd, 0, sizeof(fr_cmd_t));
		for (i = 0; i < num; ++i)
			dlci_list[i] = card->u.f.node_dlci[i];

		mbox->cmd.length = num * sizeof(short);
		mbox->cmd.command = FR_ACTIVATE_DLCI;
		err = sdla_exec(mbox) ? mbox->cmd.result : CMD_TIMEOUT;
	}
	while (err && retry-- && fr_event(card, err, mbox));
	return err;
}

/*============================================================================
 * Issue in-channel signalling frame. 
 */
static int fr_issue_isf(sdla_t * card, int isf)
{
	fr_mbox_t *mbox = card->mbox;
	int retry = MAX_CMD_RETRY;
	int err;

	do {
		memset(&mbox->cmd, 0, sizeof(fr_cmd_t));
		mbox->data[0] = isf;
		mbox->cmd.length = 1;
		mbox->cmd.command = FR_ISSUE_IS_FRAME;
		err = sdla_exec(mbox) ? mbox->cmd.result : CMD_TIMEOUT;
	}
	while (err && retry-- && fr_event(card, err, mbox));
	return err;
}

/*============================================================================
 * Send a frame (S502 version). 
 */
static int fr502_send(sdla_t * card, int dlci, int attr, int len, void *buf)
{
	fr_mbox_t *mbox = card->mbox;
	int retry = MAX_CMD_RETRY;
	int err;

	do {
		memset(&mbox->cmd, 0, sizeof(fr_cmd_t));
		memcpy(mbox->data, buf, len);
		mbox->cmd.dlci = dlci;
		mbox->cmd.attr = attr;
		mbox->cmd.length = len;
		mbox->cmd.command = FR_WRITE;
		err = sdla_exec(mbox) ? mbox->cmd.result : CMD_TIMEOUT;
	}
	while (err && retry-- && fr_event(card, err, mbox));
	return err;
}

/*============================================================================
 * Send a frame (S508 version). 
 */
static int fr508_send(sdla_t * card, int dlci, int attr, int len, void *buf)
{
	fr_mbox_t *mbox = card->mbox;
	int retry = MAX_CMD_RETRY;
	int err;

	do {
		memset(&mbox->cmd, 0, sizeof(fr_cmd_t));
		mbox->cmd.dlci = dlci;
		mbox->cmd.attr = attr;
		mbox->cmd.length = len;
		mbox->cmd.command = FR_WRITE;
		err = sdla_exec(mbox) ? mbox->cmd.result : CMD_TIMEOUT;
	}
	while (err && retry-- && fr_event(card, err, mbox));

	if (!err) {
		fr_buf_ctl_t *frbuf = (void *) (*(unsigned long *) mbox->data -
					FR_MB_VECTOR + card->hw.dpmbase);
		sdla_poke(&card->hw, frbuf->offset, buf, len);
		frbuf->flag = 0x01;
	}
	return err;
}

/****** Firmware Asynchronous Event Handlers ********************************/

/*============================================================================
 * Main asyncronous event/error handler.
 *	This routine is called whenever firmware command returns non-zero
 *	return code.
 *
 * Return zero if previous command has to be cancelled.
 */
static int fr_event(sdla_t * card, int event, fr_mbox_t * mbox)
{
	fr508_flags_t* flags = card->flags;
	char *ptr = &flags->iflag;
	int i;

	switch (event) 
	{
		case FRRES_MODEM_FAILURE:
			return fr_modem_failure(card, mbox);

		case FRRES_CHANNEL_DOWN:
			wanpipe_set_state(card, WAN_DISCONNECTED);
			return 1;

		case FRRES_CHANNEL_UP:
			wanpipe_set_state(card, WAN_CONNECTED);
			return 1;

		case FRRES_DLCI_CHANGE:
			return fr_dlci_change(card, mbox);

		case FRRES_DLCI_MISMATCH:
			printk(KERN_INFO "%s: DLCI list mismatch!\n", card->devname);
			return 1;

		case CMD_TIMEOUT:
			printk(KERN_ERR "%s: command 0x%02X timed out!\n",
			       card->devname, mbox->cmd.command);
			printk(KERN_INFO "%s: ID Bytes = ",card->devname);
 	    		for(i = 0; i < 8; i ++)
				printk(KERN_INFO "0x%02X ", *(ptr + 0x28 + i));
	   	 	printk(KERN_INFO "\n");	
            		break;

		case FRRES_DLCI_INACTIVE:
			printk(KERN_ERR "%s: DLCI %u is inactive!\n", 
				card->devname, mbox->cmd.dlci);
			break;
 
		case FRRES_CIR_OVERFLOW:
			break;
		case FRRES_BUFFER_OVERFLOW:
			break; 
		default:
			printk(KERN_INFO "%s: command 0x%02X returned 0x%02X!\n",
				card->devname, mbox->cmd.command, event);
	}
	return 0;
}

/*============================================================================
 * Handle modem error.
 *
 * Return zero if previous command has to be cancelled.
 */
static int fr_modem_failure(sdla_t * card, fr_mbox_t * mbox)
{
	printk(KERN_INFO "%s: physical link down! (modem error 0x%02X)\n",
	       card->devname, mbox->data[0]);
	switch (mbox->cmd.command) 
	{
		case FR_WRITE:
		case FR_READ:
			return 0;
	}
	return 1;
}

/*============================================================================
 * Handle DLCI status change.
 *
 * Return zero if previous command has to be cancelled.
 */
static int fr_dlci_change(sdla_t * card, fr_mbox_t * mbox)
{
	dlci_status_t *status = (void *) mbox->data;
	int cnt = mbox->cmd.length / sizeof(dlci_status_t);
	fr_dlc_conf_t cfg;
	fr_channel_t *chan;
	struct device* dev2;
	
	for (; cnt; --cnt, ++status) {
		unsigned short dlci = status->dlci;
		struct device *dev = find_channel(card, dlci);

		if (dev == NULL)
		{
			printk(KERN_INFO "%s: CPE contains unconfigured DLCI= %d\n", 
				card->devname, dlci); 	
		}
		else
		{
			if (status->state & 0x01) 
			{
				printk(KERN_INFO
				       "%s: DLCI %u has been deleted!\n",
				       card->devname, dlci);
				if (dev && dev->start)
					set_chan_state(dev, WAN_DISCONNECTED);
			}
			else if (status->state & 0x02) 
			{
				printk(KERN_INFO
					"%s: DLCI %u becomes active!\n",
					card->devname, dlci);
				chan = dev->priv;
				/* This flag is used for configuring specific 
				   DLCI(s) when they become active.
			 	*/ 
				chan->dlci_configured = DLCI_CONFIG_PENDING;
			
				if (dev && dev->start)
					set_chan_state(dev, WAN_CONNECTED);
			}
		}
	}
	
	for (dev2 =card->wandev.dev; dev2; dev2 = dev2->slave)
	{	
		chan = dev2->priv;
		
		if (chan->dlci_configured == DLCI_CONFIG_PENDING)
		{
			memset(&cfg, 0, sizeof(cfg));
	
			if ( chan->cir_status == CIR_DISABLED) 
			{
				cfg.cir_fwd = cfg.cir_bwd  = 16;
				cfg.bc_fwd = cfg.bc_bwd = 16;
				cfg.conf_flags = 0x0001;	
				printk(KERN_INFO "%s: CIR Disabled for %s\n", 
					card->devname, chan->name);	
			}
			else if (chan->cir_status == CIR_ENABLED) 
			{	
				cfg.cir_fwd = cfg.cir_bwd = chan->cir;
				cfg.bc_fwd  = cfg.bc_bwd  = chan->bc;
				cfg.be_fwd  = cfg.be_bwd  = chan->be;
				cfg.conf_flags = 0x0000;
				printk(KERN_INFO "%s: CIR Enabled for %s\n",
					card->devname, chan->name);
			
			}
			
			if (fr_dlci_configure( card, &cfg , chan->dlci))
			{
				printk(KERN_INFO 
					"%s: DLCI Configure failed for %d\n",
					card->devname, chan->dlci);
				return 1;	
			}
			
			chan->dlci_configured = DLCI_CONFIGURED;
			
			/*
			 *	Read the interface byte mapping into the channel 
			 *	structure.
			 */
			if (card->intr_mode == DLCI_LIST_INTR_MODE)
				read_DLCI_IB_mapping( card, chan );
		}		
	}
	return 1;
}

/******* Miscellaneous ******************************************************/

/*============================================================================
 * Update channel state. 
 */
static int update_chan_state(struct device *dev)
{
	fr_channel_t *chan = dev->priv;
	sdla_t *card = chan->card;
	fr_mbox_t *mbox = card->mbox;
	int retry = MAX_CMD_RETRY;
	int err;
	int dlci_found = 0;

	do {
		memset(&mbox->cmd, 0, sizeof(fr_cmd_t));
		mbox->cmd.command = FR_LIST_ACTIVE_DLCI;
		err = sdla_exec(mbox) ? mbox->cmd.result : CMD_TIMEOUT;
	}
	while (err && retry-- && fr_event(card, err, mbox));

	if (!err) {
		unsigned short *list = (void *) mbox->data;
		int cnt = mbox->cmd.length / sizeof(short);

		for (; cnt; --cnt, ++list) 
		{
			if (*list == chan->dlci) 
			{
				dlci_found = 1;
				set_chan_state(dev, WAN_CONNECTED);
				break;
			}
		}

		if(!dlci_found) 
			printk(KERN_INFO "%s: DLCI %u is inactive\n", 
				card->devname, chan->dlci);
	}
	return err;
}

/*============================================================================
 * Set channel state.
 */
static void set_chan_state(struct device *dev, int state)
{
	fr_channel_t *chan = dev->priv;
	sdla_t *card = chan->card;
	unsigned long flags;

	save_flags(flags);
	cli();

	if (chan->state != state) 
	{
		switch (state) 
		{
			case WAN_CONNECTED:
				printk(KERN_INFO "%s: interface %s connected!\n"
					, card->devname, dev->name);
				break;
			case WAN_CONNECTING:
				printk(KERN_INFO 
					"%s: interface %s connecting...\n",
					card->devname, dev->name);
				break;
			case WAN_DISCONNECTED:
				printk (KERN_INFO 
					"%s: interface %s disconnected!\n",
					card->devname, dev->name);
				break;
		}
		chan->state = state;
	}
	chan->state_tick = jiffies;
	restore_flags(flags);
}

/*============================================================================
 * Find network device by its channel number.
 */
static struct device *find_channel(sdla_t * card, unsigned dlci)
{
	struct device *dev;

	for (dev = card->wandev.dev; dev; dev = dev->slave)
		if (((fr_channel_t *) dev->priv)->dlci == dlci)
			break
			    ;
	return dev;
}

/*============================================================================
 * Check to see if a frame can be sent. If no transmit buffers available,
 * enable transmit interrupts.
 *
 * Return:	1 - Tx buffer(s) available
 *		0 - no buffers available
 */

static int is_tx_ready(sdla_t * card)
{
	if (card->hw.fwid == SFID_FR508) 
	{
		unsigned char sb = inb(card->hw.port);

		if (sb & 0x02)
			return 1;
	} else {
		fr502_flags_t* flags = card->flags;

		if (flags->tx_ready) 
			return 1;
		flags->imask |= 0x02;
	}
	return 0;
}

/*============================================================================
 * Convert decimal string to unsigned integer.
 * If len != 0 then only 'len' characters of the string are converted.
 */
static unsigned int dec_to_uint(unsigned char *str, int len)
{
	unsigned val;

	if (!len)
		len = strlen(str);
	for (val = 0; len && is_digit(*str); ++str, --len)
		val = (val * 10) + (*str - (unsigned) '0');
	return val;
}

/*==============================================================================
 * Perform the Interrupt Test by running the READ_CODE_VERSION command MAX_INTR_
 * TEST_COUNTER times.
 */
static int intr_test( sdla_t* card )
{
	fr_mbox_t* mb = card->mbox;
	int err,i;

	/*
	 *	 The critical flag is unset here because we want to get into the
	 *	ISR without the flag already set. The If_open sets the flag.
	 */
	 
	card->wandev.critical = 0;

	err = fr_set_intr_mode( card, 0x08, card->wandev.mtu );
	
	if (err == CMD_OK) 
	{
		for ( i = 0; i < MAX_INTR_TEST_COUNTER; i++ ) 
		{
 			/* Run command READ_CODE_VERSION */
			memset(&mb->cmd, 0, sizeof(fr_cmd_t));
			mb->cmd.length  = 0;
			mb->cmd.command = 0x40;
			err = sdla_exec(mb) ? mb->cmd.result : CMD_TIMEOUT;
			
			if (err != CMD_OK) 
				fr_event(card, err, mb);
		}
	}
	else
		return err;	

	err = fr_set_intr_mode( card, 0, card->wandev.mtu );

	if( err != CMD_OK ) 
		return err;

	card->wandev.critical = 1;
	return 0;
}

/*==============================================================================
 * Initializes the Statistics values in the Sdla_t structure.
 */

void init_global_statistics( sdla_t* card )
{
	/* Intialize global statistics for a card */
	card->statistics.isr_entry 		  = 0;
	card->statistics.isr_already_critical 	  = 0;
	card->statistics.isr_rx			  = 0;
	card->statistics.isr_tx			  = 0;
	card->statistics.isr_intr_test		  = 0;
	card->statistics.isr_spurious		  = 0;
	card->statistics.isr_enable_tx_int	  = 0;
	card->statistics.rx_intr_corrupt_rx_bfr	  = 0;
	card->statistics.rx_intr_on_orphaned_DLCI = 0;
	card->statistics.tx_intr_dev_not_started  = 0;
	card->statistics.poll_entry		  = 0;
	card->statistics.poll_already_critical	  = 0;
	card->statistics.poll_processed		  = 0;
}

static void read_DLCI_IB_mapping( sdla_t* card, fr_channel_t* chan )
{
	fr_mbox_t* mbox = card->mbox;
	int retry = MAX_CMD_RETRY;	
	dlci_IB_mapping_t* result; 
	int err, counter, found;	

	do {
		memset(&mbox->cmd, 0, sizeof(fr_cmd_t));
		mbox->cmd.command = FR_READ_DLCI_IB_MAPPING;
		
		err = sdla_exec(mbox) ? mbox->cmd.result : CMD_TIMEOUT;
	
	} while (err && retry-- && fr_event(card, err, mbox));

	if( mbox->cmd.result != 0)
		printk(KERN_INFO "%s: Read DLCI IB Mapping failed\n", 
			chan->name);

	counter = mbox->cmd.length / sizeof(dlci_IB_mapping_t);
	result = (void *)mbox->data;
	
	found = 0;
	for (; counter; --counter, ++result) {
		if ( result->dlci == chan->dlci ) {
			printk( KERN_INFO "%s: DLCI= %d, IB addr = %lx for %s\n"
				,card->devname,result->dlci, result->addr_value
				,chan->name);
			chan->IB_addr = result->addr_value;
			chan->dlci_int_interface = (void*)(card->hw.dpmbase + 
					( chan->IB_addr & 0x00001FFF));
			found = 1;
			break;	
		} 
	}
	if (!found)
		printk( KERN_INFO "%s: DLCI %d not found by IB MAPPING cmd\n", 
		card->devname, chan->dlci);
}

/****** End *****************************************************************/
