1 files changed, 767 insertions, 0 deletions

diff --git a/drivers/net/hamradio/hdlcdrv.c b/drivers/net/hamradio/hdlcdrv.c
new file mode 100644
index 000000000..2263029d1
--- /dev/null
+++ b/drivers/net/hamradio/hdlcdrv.c
@@ -0,0 +1,767 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*****************************************************************************/
+
+/*
+ *	hdlcdrv.c  -- HDLC packet radio network driver.
+ *
+ *	Copyright (C) 1996-2000  Thomas Sailer (sailer@ife.ee.ethz.ch)
+ *
+ *  Please note that the GPL allows you to use the driver, NOT the radio.
+ *  In order to use the radio, you need a license from the communications
+ *  authority of your country.
+ *
+ *  The driver was derived from Donald Beckers skeleton.c
+ *	Written 1993-94 by Donald Becker.
+ *
+ *  History:
+ *   0.1  21.09.1996  Started
+ *        18.10.1996  Changed to new user space access routines 
+ *                    (copy_{to,from}_user)
+ *   0.2  21.11.1996  various small changes
+ *   0.3  03.03.1997  fixed (hopefully) IP not working with ax.25 as a module
+ *   0.4  16.04.1997  init code/data tagged
+ *   0.5  30.07.1997  made HDLC buffers bigger (solves a problem with the
+ *                    soundmodem driver)
+ *   0.6  05.04.1998  add spinlocks
+ *   0.7  03.08.1999  removed some old compatibility cruft
+ *   0.8  12.02.2000  adapted to softnet driver interface
+ */
+
+/*****************************************************************************/
+
+#include <linux/capability.h>
+#include <linux/compat.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/net.h>
+#include <linux/in.h>
+#include <linux/if.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/bitops.h>
+
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/skbuff.h>
+#include <linux/hdlcdrv.h>
+#include <linux/random.h>
+#include <net/ax25.h> 
+#include <linux/uaccess.h>
+
+#include <linux/crc-ccitt.h>
+
+/* --------------------------------------------------------------------- */
+
+#define KISS_VERBOSE
+
+/* --------------------------------------------------------------------- */
+
+#define PARAM_TXDELAY   1
+#define PARAM_PERSIST   2
+#define PARAM_SLOTTIME  3
+#define PARAM_TXTAIL    4
+#define PARAM_FULLDUP   5
+#define PARAM_HARDWARE  6
+#define PARAM_RETURN    255
+
+/* --------------------------------------------------------------------- */
+/*
+ * the CRC routines are stolen from WAMPES
+ * by Dieter Deyke
+ */
+
+
+/*---------------------------------------------------------------------------*/
+
+static inline void append_crc_ccitt(unsigned char *buffer, int len)
+{
+	unsigned int crc = crc_ccitt(0xffff, buffer, len) ^ 0xffff;
+	buffer += len;
+	*buffer++ = crc;
+	*buffer++ = crc >> 8;
+}
+
+/*---------------------------------------------------------------------------*/
+
+static inline int check_crc_ccitt(const unsigned char *buf, int cnt)
+{
+	return (crc_ccitt(0xffff, buf, cnt) & 0xffff) == 0xf0b8;
+}
+
+/*---------------------------------------------------------------------------*/
+
+#if 0
+static int calc_crc_ccitt(const unsigned char *buf, int cnt)
+{
+	unsigned int crc = 0xffff;
+
+	for (; cnt > 0; cnt--)
+		crc = (crc >> 8) ^ crc_ccitt_table[(crc ^ *buf++) & 0xff];
+	crc ^= 0xffff;
+	return crc & 0xffff;
+}
+#endif
+
+/* ---------------------------------------------------------------------- */
+
+#define tenms_to_2flags(s,tenms) ((tenms * s->par.bitrate) / 100 / 16)
+
+/* ---------------------------------------------------------------------- */
+/*
+ * The HDLC routines
+ */
+
+static int hdlc_rx_add_bytes(struct hdlcdrv_state *s, unsigned int bits, 
+			     int num)
+{
+	int added = 0;
+	
+	while (s->hdlcrx.rx_state && num >= 8) {
+		if (s->hdlcrx.len >= sizeof(s->hdlcrx.buffer)) {
+			s->hdlcrx.rx_state = 0;
+			return 0;
+		}
+		*s->hdlcrx.bp++ = bits >> (32-num);
+		s->hdlcrx.len++;
+		num -= 8;
+		added += 8;
+	}
+	return added;
+}
+
+static void hdlc_rx_flag(struct net_device *dev, struct hdlcdrv_state *s)
+{
+	struct sk_buff *skb;
+	int pkt_len;
+	unsigned char *cp;
+
+	if (s->hdlcrx.len < 4) 
+		return;
+	if (!check_crc_ccitt(s->hdlcrx.buffer, s->hdlcrx.len)) 
+		return;
+	pkt_len = s->hdlcrx.len - 2 + 1; /* KISS kludge */
+	if (!(skb = dev_alloc_skb(pkt_len))) {
+		printk("%s: memory squeeze, dropping packet\n", dev->name);
+		dev->stats.rx_dropped++;
+		return;
+	}
+	cp = skb_put(skb, pkt_len);
+	*cp++ = 0; /* KISS kludge */
+	memcpy(cp, s->hdlcrx.buffer, pkt_len - 1);
+	skb->protocol = ax25_type_trans(skb, dev);
+	netif_rx(skb);
+	dev->stats.rx_packets++;
+}
+
+void hdlcdrv_receiver(struct net_device *dev, struct hdlcdrv_state *s)
+{
+	int i;
+	unsigned int mask1, mask2, mask3, mask4, mask5, mask6, word;
+	
+	if (!s || s->magic != HDLCDRV_MAGIC) 
+		return;
+	if (test_and_set_bit(0, &s->hdlcrx.in_hdlc_rx))
+		return;
+
+	while (!hdlcdrv_hbuf_empty(&s->hdlcrx.hbuf)) {
+		word = hdlcdrv_hbuf_get(&s->hdlcrx.hbuf);	
+
+#ifdef HDLCDRV_DEBUG
+		hdlcdrv_add_bitbuffer_word(&s->bitbuf_hdlc, word);
+#endif /* HDLCDRV_DEBUG */
+	       	s->hdlcrx.bitstream >>= 16;
+		s->hdlcrx.bitstream |= word << 16;
+		s->hdlcrx.bitbuf >>= 16;
+		s->hdlcrx.bitbuf |= word << 16;
+		s->hdlcrx.numbits += 16;
+		for(i = 15, mask1 = 0x1fc00, mask2 = 0x1fe00, mask3 = 0x0fc00,
+		    mask4 = 0x1f800, mask5 = 0xf800, mask6 = 0xffff; 
+		    i >= 0; 
+		    i--, mask1 <<= 1, mask2 <<= 1, mask3 <<= 1, mask4 <<= 1, 
+		    mask5 <<= 1, mask6 = (mask6 << 1) | 1) {
+			if ((s->hdlcrx.bitstream & mask1) == mask1)
+				s->hdlcrx.rx_state = 0; /* abort received */
+			else if ((s->hdlcrx.bitstream & mask2) == mask3) {
+				/* flag received */
+				if (s->hdlcrx.rx_state) {
+					hdlc_rx_add_bytes(s, s->hdlcrx.bitbuf 
+							  << (8+i),
+							  s->hdlcrx.numbits
+							  -8-i);
+					hdlc_rx_flag(dev, s);
+				}
+				s->hdlcrx.len = 0;
+				s->hdlcrx.bp = s->hdlcrx.buffer;
+				s->hdlcrx.rx_state = 1;
+				s->hdlcrx.numbits = i;
+			} else if ((s->hdlcrx.bitstream & mask4) == mask5) {
+				/* stuffed bit */
+				s->hdlcrx.numbits--;
+				s->hdlcrx.bitbuf = (s->hdlcrx.bitbuf & (~mask6)) |
+					((s->hdlcrx.bitbuf & mask6) << 1);
+			}
+		}
+		s->hdlcrx.numbits -= hdlc_rx_add_bytes(s, s->hdlcrx.bitbuf,
+						       s->hdlcrx.numbits);
+	}
+	clear_bit(0, &s->hdlcrx.in_hdlc_rx);
+}
+
+/* ---------------------------------------------------------------------- */
+
+static inline void do_kiss_params(struct hdlcdrv_state *s,
+				  unsigned char *data, unsigned long len)
+{
+
+#ifdef KISS_VERBOSE
+#define PKP(a,b) printk(KERN_INFO "hdlcdrv.c: channel params: " a "\n", b)
+#else /* KISS_VERBOSE */	      
+#define PKP(a,b) 
+#endif /* KISS_VERBOSE */	      
+
+	if (len < 2)
+		return;
+	switch(data[0]) {
+	case PARAM_TXDELAY:
+		s->ch_params.tx_delay = data[1];
+		PKP("TX delay = %ums", 10 * s->ch_params.tx_delay);
+		break;
+	case PARAM_PERSIST:   
+		s->ch_params.ppersist = data[1];
+		PKP("p persistence = %u", s->ch_params.ppersist);
+		break;
+	case PARAM_SLOTTIME:  
+		s->ch_params.slottime = data[1];
+		PKP("slot time = %ums", s->ch_params.slottime);
+		break;
+	case PARAM_TXTAIL:    
+		s->ch_params.tx_tail = data[1];
+		PKP("TX tail = %ums", s->ch_params.tx_tail);
+		break;
+	case PARAM_FULLDUP:   
+		s->ch_params.fulldup = !!data[1];
+		PKP("%s duplex", s->ch_params.fulldup ? "full" : "half");
+		break;
+	default:
+		break;
+	}
+#undef PKP
+}
+
+/* ---------------------------------------------------------------------- */
+
+void hdlcdrv_transmitter(struct net_device *dev, struct hdlcdrv_state *s)
+{
+	unsigned int mask1, mask2, mask3;
+	int i;
+	struct sk_buff *skb;
+	int pkt_len;
+
+	if (!s || s->magic != HDLCDRV_MAGIC) 
+		return;
+	if (test_and_set_bit(0, &s->hdlctx.in_hdlc_tx))
+		return;
+	for (;;) {
+		if (s->hdlctx.numbits >= 16) {
+			if (hdlcdrv_hbuf_full(&s->hdlctx.hbuf)) {
+				clear_bit(0, &s->hdlctx.in_hdlc_tx);
+				return;
+			}
+			hdlcdrv_hbuf_put(&s->hdlctx.hbuf, s->hdlctx.bitbuf);
+			s->hdlctx.bitbuf >>= 16;
+			s->hdlctx.numbits -= 16;
+		}
+		switch (s->hdlctx.tx_state) {
+		default:
+			clear_bit(0, &s->hdlctx.in_hdlc_tx);
+			return;
+		case 0:
+		case 1:
+			if (s->hdlctx.numflags) {
+				s->hdlctx.numflags--;
+				s->hdlctx.bitbuf |= 
+					0x7e7e << s->hdlctx.numbits;
+				s->hdlctx.numbits += 16;
+				break;
+			}
+			if (s->hdlctx.tx_state == 1) {
+				clear_bit(0, &s->hdlctx.in_hdlc_tx);
+				return;
+			}
+			if (!(skb = s->skb)) {
+				int flgs = tenms_to_2flags(s, s->ch_params.tx_tail);
+				if (flgs < 2)
+					flgs = 2;
+				s->hdlctx.tx_state = 1;
+				s->hdlctx.numflags = flgs;
+				break;
+			}
+			s->skb = NULL;
+			netif_wake_queue(dev);
+			pkt_len = skb->len-1; /* strip KISS byte */
+			if (pkt_len >= HDLCDRV_MAXFLEN || pkt_len < 2) {
+				s->hdlctx.tx_state = 0;
+				s->hdlctx.numflags = 1;
+				dev_kfree_skb_irq(skb);
+				break;
+			}
+			skb_copy_from_linear_data_offset(skb, 1,
+							 s->hdlctx.buffer,
+							 pkt_len);
+			dev_kfree_skb_irq(skb);
+			s->hdlctx.bp = s->hdlctx.buffer;
+			append_crc_ccitt(s->hdlctx.buffer, pkt_len);
+			s->hdlctx.len = pkt_len+2; /* the appended CRC */
+			s->hdlctx.tx_state = 2;
+			s->hdlctx.bitstream = 0;
+			dev->stats.tx_packets++;
+			break;
+		case 2:
+			if (!s->hdlctx.len) {
+				s->hdlctx.tx_state = 0;
+				s->hdlctx.numflags = 1;
+				break;
+			}
+			s->hdlctx.len--;
+			s->hdlctx.bitbuf |= *s->hdlctx.bp <<
+				s->hdlctx.numbits;
+			s->hdlctx.bitstream >>= 8;
+			s->hdlctx.bitstream |= (*s->hdlctx.bp++) << 16;
+			mask1 = 0x1f000;
+			mask2 = 0x10000;
+			mask3 = 0xffffffff >> (31-s->hdlctx.numbits);
+			s->hdlctx.numbits += 8;
+			for(i = 0; i < 8; i++, mask1 <<= 1, mask2 <<= 1, 
+			    mask3 = (mask3 << 1) | 1) {
+				if ((s->hdlctx.bitstream & mask1) != mask1) 
+					continue;
+				s->hdlctx.bitstream &= ~mask2;
+				s->hdlctx.bitbuf = 
+					(s->hdlctx.bitbuf & mask3) |
+						((s->hdlctx.bitbuf & 
+						 (~mask3)) << 1);
+				s->hdlctx.numbits++;
+				mask3 = (mask3 << 1) | 1;
+			}
+			break;
+		}
+	}
+}
+
+/* ---------------------------------------------------------------------- */
+
+static void start_tx(struct net_device *dev, struct hdlcdrv_state *s)
+{
+	s->hdlctx.tx_state = 0;
+	s->hdlctx.numflags = tenms_to_2flags(s, s->ch_params.tx_delay);
+	s->hdlctx.bitbuf = s->hdlctx.bitstream = s->hdlctx.numbits = 0;
+	hdlcdrv_transmitter(dev, s);
+	s->hdlctx.ptt = 1;
+	s->ptt_keyed++;
+}
+
+/* ---------------------------------------------------------------------- */
+
+void hdlcdrv_arbitrate(struct net_device *dev, struct hdlcdrv_state *s)
+{
+	if (!s || s->magic != HDLCDRV_MAGIC || s->hdlctx.ptt || !s->skb) 
+		return;
+	if (s->ch_params.fulldup) {
+		start_tx(dev, s);
+		return;
+	}
+	if (s->hdlcrx.dcd) {
+		s->hdlctx.slotcnt = s->ch_params.slottime;
+		return;
+	}
+	if ((--s->hdlctx.slotcnt) > 0)
+		return;
+	s->hdlctx.slotcnt = s->ch_params.slottime;
+	if (get_random_u8() > s->ch_params.ppersist)
+		return;
+	start_tx(dev, s);
+}
+
+/* --------------------------------------------------------------------- */
+/*
+ * ===================== network driver interface =========================
+ */
+
+static netdev_tx_t hdlcdrv_send_packet(struct sk_buff *skb,
+				       struct net_device *dev)
+{
+	struct hdlcdrv_state *sm = netdev_priv(dev);
+
+	if (skb->protocol == htons(ETH_P_IP))
+		return ax25_ip_xmit(skb);
+
+	if (skb->data[0] != 0) {
+		do_kiss_params(sm, skb->data, skb->len);
+		dev_kfree_skb(skb);
+		return NETDEV_TX_OK;
+	}
+	if (sm->skb) {
+		dev_kfree_skb(skb);
+		return NETDEV_TX_OK;
+	}
+	netif_stop_queue(dev);
+	sm->skb = skb;
+	return NETDEV_TX_OK;
+}
+
+/* --------------------------------------------------------------------- */
+
+static int hdlcdrv_set_mac_address(struct net_device *dev, void *addr)
+{
+	struct sockaddr *sa = (struct sockaddr *)addr;
+
+	/* addr is an AX.25 shifted ASCII mac address */
+	dev_addr_set(dev, sa->sa_data);
+	return 0;                                         
+}
+
+/* --------------------------------------------------------------------- */
+/*
+ * Open/initialize the board. This is called (in the current kernel)
+ * sometime after booting when the 'ifconfig' program is run.
+ *
+ * This routine should set everything up anew at each open, even
+ * registers that "should" only need to be set once at boot, so that
+ * there is non-reboot way to recover if something goes wrong.
+ */
+
+static int hdlcdrv_open(struct net_device *dev)
+{
+	struct hdlcdrv_state *s = netdev_priv(dev);
+	int i;
+
+	if (!s->ops || !s->ops->open)
+		return -ENODEV;
+
+	/*
+	 * initialise some variables
+	 */
+	s->opened = 1;
+	s->hdlcrx.hbuf.rd = s->hdlcrx.hbuf.wr = 0;
+	s->hdlcrx.in_hdlc_rx = 0;
+	s->hdlcrx.rx_state = 0;
+	
+	s->hdlctx.hbuf.rd = s->hdlctx.hbuf.wr = 0;
+	s->hdlctx.in_hdlc_tx = 0;
+	s->hdlctx.tx_state = 1;
+	s->hdlctx.numflags = 0;
+	s->hdlctx.bitstream = s->hdlctx.bitbuf = s->hdlctx.numbits = 0;
+	s->hdlctx.ptt = 0;
+	s->hdlctx.slotcnt = s->ch_params.slottime;
+	s->hdlctx.calibrate = 0;
+
+	i = s->ops->open(dev);
+	if (i)
+		return i;
+	netif_start_queue(dev);
+	return 0;
+}
+
+/* --------------------------------------------------------------------- */
+/* 
+ * The inverse routine to hdlcdrv_open(). 
+ */
+
+static int hdlcdrv_close(struct net_device *dev)
+{
+	struct hdlcdrv_state *s = netdev_priv(dev);
+	int i = 0;
+
+	netif_stop_queue(dev);
+
+	if (s->ops && s->ops->close)
+		i = s->ops->close(dev);
+	dev_kfree_skb(s->skb);
+	s->skb = NULL;
+	s->opened = 0;
+	return i;
+}
+
+/* --------------------------------------------------------------------- */
+
+static int hdlcdrv_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
+				  void __user *data, int cmd)
+{
+	struct hdlcdrv_state *s = netdev_priv(dev);
+	struct hdlcdrv_ioctl bi;
+
+	if (cmd != SIOCDEVPRIVATE)
+		return -ENOIOCTLCMD;
+
+	if (in_compat_syscall()) /* to be implemented */
+		return -ENOIOCTLCMD;
+
+	if (copy_from_user(&bi, data, sizeof(bi)))
+		return -EFAULT;
+
+	switch (bi.cmd) {
+	default:
+		if (s->ops && s->ops->ioctl)
+			return s->ops->ioctl(dev, data, &bi, cmd);
+		return -ENOIOCTLCMD;
+
+	case HDLCDRVCTL_GETCHANNELPAR:
+		bi.data.cp.tx_delay = s->ch_params.tx_delay;
+		bi.data.cp.tx_tail = s->ch_params.tx_tail;
+		bi.data.cp.slottime = s->ch_params.slottime;
+		bi.data.cp.ppersist = s->ch_params.ppersist;
+		bi.data.cp.fulldup = s->ch_params.fulldup;
+		break;
+
+	case HDLCDRVCTL_SETCHANNELPAR:
+		if (!capable(CAP_NET_ADMIN))
+			return -EACCES;
+		s->ch_params.tx_delay = bi.data.cp.tx_delay;
+		s->ch_params.tx_tail = bi.data.cp.tx_tail;
+		s->ch_params.slottime = bi.data.cp.slottime;
+		s->ch_params.ppersist = bi.data.cp.ppersist;
+		s->ch_params.fulldup = bi.data.cp.fulldup;
+		s->hdlctx.slotcnt = 1;
+		return 0;
+		
+	case HDLCDRVCTL_GETMODEMPAR:
+		bi.data.mp.iobase = dev->base_addr;
+		bi.data.mp.irq = dev->irq;
+		bi.data.mp.dma = dev->dma;
+		bi.data.mp.dma2 = s->ptt_out.dma2;
+		bi.data.mp.seriobase = s->ptt_out.seriobase;
+		bi.data.mp.pariobase = s->ptt_out.pariobase;
+		bi.data.mp.midiiobase = s->ptt_out.midiiobase;
+		break;
+
+	case HDLCDRVCTL_SETMODEMPAR:
+		if ((!capable(CAP_SYS_RAWIO)) || netif_running(dev))
+			return -EACCES;
+		dev->base_addr = bi.data.mp.iobase;
+		dev->irq = bi.data.mp.irq;
+		dev->dma = bi.data.mp.dma;
+		s->ptt_out.dma2 = bi.data.mp.dma2;
+		s->ptt_out.seriobase = bi.data.mp.seriobase;
+		s->ptt_out.pariobase = bi.data.mp.pariobase;
+		s->ptt_out.midiiobase = bi.data.mp.midiiobase;
+		return 0;	
+	
+	case HDLCDRVCTL_GETSTAT:
+		bi.data.cs.ptt = hdlcdrv_ptt(s);
+		bi.data.cs.dcd = s->hdlcrx.dcd;
+		bi.data.cs.ptt_keyed = s->ptt_keyed;
+		bi.data.cs.tx_packets = dev->stats.tx_packets;
+		bi.data.cs.tx_errors = dev->stats.tx_errors;
+		bi.data.cs.rx_packets = dev->stats.rx_packets;
+		bi.data.cs.rx_errors = dev->stats.rx_errors;
+		break;		
+
+	case HDLCDRVCTL_OLDGETSTAT:
+		bi.data.ocs.ptt = hdlcdrv_ptt(s);
+		bi.data.ocs.dcd = s->hdlcrx.dcd;
+		bi.data.ocs.ptt_keyed = s->ptt_keyed;
+		break;		
+
+	case HDLCDRVCTL_CALIBRATE:
+		if(!capable(CAP_SYS_RAWIO))
+			return -EPERM;
+		if (s->par.bitrate <= 0)
+			return -EINVAL;
+		if (bi.data.calibrate > INT_MAX / s->par.bitrate)
+			return -EINVAL;
+		s->hdlctx.calibrate = bi.data.calibrate * s->par.bitrate / 16;
+		return 0;
+
+	case HDLCDRVCTL_GETSAMPLES:
+#ifndef HDLCDRV_DEBUG
+		return -EPERM;
+#else /* HDLCDRV_DEBUG */
+		if (s->bitbuf_channel.rd == s->bitbuf_channel.wr) 
+			return -EAGAIN;
+		bi.data.bits = 
+			s->bitbuf_channel.buffer[s->bitbuf_channel.rd];
+		s->bitbuf_channel.rd = (s->bitbuf_channel.rd+1) %
+			sizeof(s->bitbuf_channel.buffer);
+		break;
+#endif /* HDLCDRV_DEBUG */
+				
+	case HDLCDRVCTL_GETBITS:
+#ifndef HDLCDRV_DEBUG
+		return -EPERM;
+#else /* HDLCDRV_DEBUG */
+		if (s->bitbuf_hdlc.rd == s->bitbuf_hdlc.wr) 
+			return -EAGAIN;
+		bi.data.bits = 
+			s->bitbuf_hdlc.buffer[s->bitbuf_hdlc.rd];
+		s->bitbuf_hdlc.rd = (s->bitbuf_hdlc.rd+1) %
+			sizeof(s->bitbuf_hdlc.buffer);
+		break;		
+#endif /* HDLCDRV_DEBUG */
+
+	case HDLCDRVCTL_DRIVERNAME:
+		if (s->ops && s->ops->drvname) {
+			strscpy(bi.data.drivername, s->ops->drvname,
+				sizeof(bi.data.drivername));
+			break;
+		}
+		bi.data.drivername[0] = '\0';
+		break;
+		
+	}
+	if (copy_to_user(data, &bi, sizeof(bi)))
+		return -EFAULT;
+	return 0;
+
+}
+
+/* --------------------------------------------------------------------- */
+
+static const struct net_device_ops hdlcdrv_netdev = {
+	.ndo_open	= hdlcdrv_open,
+	.ndo_stop	= hdlcdrv_close,
+	.ndo_start_xmit = hdlcdrv_send_packet,
+	.ndo_siocdevprivate  = hdlcdrv_siocdevprivate,
+	.ndo_set_mac_address = hdlcdrv_set_mac_address,
+};
+
+/*
+ * Initialize fields in hdlcdrv
+ */
+static void hdlcdrv_setup(struct net_device *dev)
+{
+	static const struct hdlcdrv_channel_params dflt_ch_params = { 
+		20, 2, 10, 40, 0 
+	};
+	struct hdlcdrv_state *s = netdev_priv(dev);
+
+	/*
+	 * initialize the hdlcdrv_state struct
+	 */
+	s->ch_params = dflt_ch_params;
+	s->ptt_keyed = 0;
+
+	spin_lock_init(&s->hdlcrx.hbuf.lock);
+	s->hdlcrx.hbuf.rd = s->hdlcrx.hbuf.wr = 0;
+	s->hdlcrx.in_hdlc_rx = 0;
+	s->hdlcrx.rx_state = 0;
+	
+	spin_lock_init(&s->hdlctx.hbuf.lock);
+	s->hdlctx.hbuf.rd = s->hdlctx.hbuf.wr = 0;
+	s->hdlctx.in_hdlc_tx = 0;
+	s->hdlctx.tx_state = 1;
+	s->hdlctx.numflags = 0;
+	s->hdlctx.bitstream = s->hdlctx.bitbuf = s->hdlctx.numbits = 0;
+	s->hdlctx.ptt = 0;
+	s->hdlctx.slotcnt = s->ch_params.slottime;
+	s->hdlctx.calibrate = 0;
+
+#ifdef HDLCDRV_DEBUG
+	s->bitbuf_channel.rd = s->bitbuf_channel.wr = 0;
+	s->bitbuf_channel.shreg = 0x80;
+
+	s->bitbuf_hdlc.rd = s->bitbuf_hdlc.wr = 0;
+	s->bitbuf_hdlc.shreg = 0x80;
+#endif /* HDLCDRV_DEBUG */
+
+
+	/* Fill in the fields of the device structure */
+
+	s->skb = NULL;
+	
+	dev->netdev_ops = &hdlcdrv_netdev;
+	dev->header_ops = &ax25_header_ops;
+	
+	dev->type = ARPHRD_AX25;           /* AF_AX25 device */
+	dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
+	dev->mtu = AX25_DEF_PACLEN;        /* eth_mtu is the default */
+	dev->addr_len = AX25_ADDR_LEN;     /* sizeof an ax.25 address */
+	memcpy(dev->broadcast, &ax25_bcast, AX25_ADDR_LEN);
+	dev_addr_set(dev, (u8 *)&ax25_defaddr);
+	dev->tx_queue_len = 16;
+}
+
+/* --------------------------------------------------------------------- */
+struct net_device *hdlcdrv_register(const struct hdlcdrv_ops *ops,
+				    unsigned int privsize, const char *ifname,
+				    unsigned int baseaddr, unsigned int irq, 
+				    unsigned int dma) 
+{
+	struct net_device *dev;
+	struct hdlcdrv_state *s;
+	int err;
+
+	if (privsize < sizeof(struct hdlcdrv_state))
+		privsize = sizeof(struct hdlcdrv_state);
+
+	dev = alloc_netdev(privsize, ifname, NET_NAME_UNKNOWN, hdlcdrv_setup);
+	if (!dev)
+		return ERR_PTR(-ENOMEM);
+
+	/*
+	 * initialize part of the hdlcdrv_state struct
+	 */
+	s = netdev_priv(dev);
+	s->magic = HDLCDRV_MAGIC;
+	s->ops = ops;
+	dev->base_addr = baseaddr;
+	dev->irq = irq;
+	dev->dma = dma;
+
+	err = register_netdev(dev);
+	if (err < 0) {
+		printk(KERN_WARNING "hdlcdrv: cannot register net "
+		       "device %s\n", dev->name);
+		free_netdev(dev);
+		dev = ERR_PTR(err);
+	}
+	return dev;
+}
+
+/* --------------------------------------------------------------------- */
+
+void hdlcdrv_unregister(struct net_device *dev) 
+{
+	struct hdlcdrv_state *s = netdev_priv(dev);
+
+	BUG_ON(s->magic != HDLCDRV_MAGIC);
+
+	if (s->opened && s->ops->close)
+		s->ops->close(dev);
+	unregister_netdev(dev);
+	
+	free_netdev(dev);
+}
+
+/* --------------------------------------------------------------------- */
+
+EXPORT_SYMBOL(hdlcdrv_receiver);
+EXPORT_SYMBOL(hdlcdrv_transmitter);
+EXPORT_SYMBOL(hdlcdrv_arbitrate);
+EXPORT_SYMBOL(hdlcdrv_register);
+EXPORT_SYMBOL(hdlcdrv_unregister);
+
+/* --------------------------------------------------------------------- */
+
+static int __init hdlcdrv_init_driver(void)
+{
+	printk(KERN_INFO "hdlcdrv: (C) 1996-2000 Thomas Sailer HB9JNX/AE4WA\n");
+	printk(KERN_INFO "hdlcdrv: version 0.8\n");
+	return 0;
+}
+
+/* --------------------------------------------------------------------- */
+
+static void __exit hdlcdrv_cleanup_driver(void)
+{
+	printk(KERN_INFO "hdlcdrv: cleanup\n");
+}
+
+/* --------------------------------------------------------------------- */
+
+MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
+MODULE_DESCRIPTION("Packet Radio network interface HDLC encoder/decoder");
+MODULE_LICENSE("GPL");
+module_init(hdlcdrv_init_driver);
+module_exit(hdlcdrv_cleanup_driver);
+
+/* --------------------------------------------------------------------- */