# Translate the D channels to a standard channel data.
# The HFC chipset provides us the D channel as data, but
# Zaptel expects it as a standard channel with 1000 samples
# per second.

--- a/include/dahdi/kernel.h
+++ b/include/dahdi/kernel.h
@@ -132,6 +132,13 @@ struct dahdi_chan {
 	int do_ppp_error;
 	struct sk_buff_head ppp_rq;
 #endif
+#ifdef CONFIG_DAHDI_BRI_DCHANS
+	int bytes2receive;
+	int maxbytes2transmit; /* size of the tx buffer in the card driver */
+	int bytes2transmit;
+	int eofrx;
+	int eoftx;
+#endif
 	spinlock_t lock;
 	char name[40];
 	/* Specified by DAHDI */
@@ -462,6 +469,9 @@ enum {
 	DAHDI_FLAGBIT_LOOPED	= 18,	/*!< Loopback the receive data from the channel to the transmit */
 	DAHDI_FLAGBIT_MTP2	= 19,	/*!< Repeats last message in buffer and also discards repeating messages sent to us */
 	DAHDI_FLAGBIT_HDLC56	= 20,	/*!< Sets the given channel (if in HDLC mode) to use 56K HDLC instead of 64K  */
+#if defined(CONFIG_DAHDI_BRI_DCHANS)
+	DAHDI_FLAGBIT_BRIDCHAN   = 21,	/*!< hardhdlc-like handling of the D channel */
+#endif
 };
 
 /* map flagbits to flag masks */
@@ -500,6 +510,7 @@ enum {
 #define DAHDI_FLAG_LOOPED	DAHDI_FLAG(LOOPED)
 #define DAHDI_FLAG_MTP2		DAHDI_FLAG(MTP2)
 #define DAHDI_FLAG_HDLC56	DAHDI_FLAG(HDLC56)
+#define DAHDI_FLAG_BRIDCHAN	DAHDI_FLAG(BRIDCHAN)
 
 struct dahdi_span {
 	spinlock_t lock;
--- a/include/dahdi/dahdi_config.h
+++ b/include/dahdi/dahdi_config.h
@@ -174,4 +174,10 @@
  */
 /* #define	OPTIMIZE_CHANMUTE */
 
+/*
+ * Uncomment the following for BRI D channels
+ *
+ */
+#define CONFIG_DAHDI_BRI_DCHANS
+
 #endif
--- a/drivers/dahdi/dahdi-base.c
+++ b/drivers/dahdi/dahdi-base.c
@@ -5907,11 +5907,40 @@ static inline void __dahdi_getbuf_chunk(
 					*(txb++) = fasthdlc_tx_run_nocheck(&ms->txhdlc);
 				}
 				bytes -= left;
+#ifdef CONFIG_DAHDI_BRI_DCHANS
+			} else if (test_bit(DAHDI_FLAGBIT_BRIDCHAN, &ms->flags)) {
+			    /*
+			     * Let's get this right, we want to transmit complete frames only.
+			     * The card driver will do the dirty HDLC work for us.
+			     * txb (transmit buffer) is supposed to be big enough to store one frame
+			     * we will make this as big as the D fifo (1KB or 2KB)
+			     */
+
+			    /* there are 'left' bytes in the user buffer left to transmit */
+			    left = ms->writen[ms->outwritebuf] - ms->writeidx[ms->outwritebuf] - 2;
+			    if (left > ms->maxbytes2transmit) {
+				memcpy(txb, buf + ms->writeidx[ms->outwritebuf], ms->maxbytes2transmit);
+				ms->writeidx[ms->outwritebuf] += ms->maxbytes2transmit;
+				txb += ms->maxbytes2transmit;
+				ms->bytes2transmit = ms->maxbytes2transmit;
+				ms->eoftx = 0;
+			    } else {
+				memcpy(txb, buf + ms->writeidx[ms->outwritebuf], left);
+				ms->writeidx[ms->outwritebuf] += left + 2;
+				txb += left + 2;
+				ms->bytes2transmit = left;
+				ms->eoftx = 1;
+			    }
+			    bytes = 0;
+#endif
 			} else {
 				memcpy(txb, buf + ms->writeidx[ms->outwritebuf], left);
 				ms->writeidx[ms->outwritebuf]+=left;
 				txb += left;
 				bytes -= left;
+#if defined(CONFIG_DAHDI_BRI_DCHANS)	
+				ms->bytes2transmit=DAHDI_CHUNKSIZE;
+#endif
 			}
 			/* Check buffer status */
 			if (ms->writeidx[ms->outwritebuf] >= ms->writen[ms->outwritebuf]) {
@@ -5968,6 +5997,17 @@ out in the later versions, and is put ba
 				/* Transmit a flag if this is an HDLC channel */
 				if (ms->flags & DAHDI_FLAG_HDLC)
 					fasthdlc_tx_frame_nocheck(&ms->txhdlc);
+#if defined(CONFIG_DAHDI_BRI_DCHANS)	
+				if (test_bit(DAHDI_FLAGBIT_BRIDCHAN, &ms->flags)) {
+			//	    if (ms->bytes2transmit > 0) {
+					// txb += 2;
+					// ms->bytes2transmit -= 2;
+					bytes=0;
+					ms->eoftx = 1;
+//					printk(KERN_CRIT "zaptel EOF(%d) bytes2transmit %d\n",ms->eoftx,ms->bytes2transmit);
+			//	    }
+				}
+#endif
 #ifdef CONFIG_DAHDI_NET
 				if (ms->flags & DAHDI_FLAG_NETDEV)
 					netif_wake_queue(ztchan_to_dev(ms));
@@ -6028,6 +6068,12 @@ out in the later versions, and is put ba
 				memset(txb, 0xFF, bytes);
 			}
 			bytes = 0;
+#if defined(CONFIG_DAHDI_BRI_DCHANS)	
+		} else if (test_bit(DAHDI_FLAGBIT_BRIDCHAN, &ms->flags)) {
+		    ms->bytes2transmit = 0;
+		    ms->eoftx = 0;
+		    bytes = 0;
+#endif
 		} else {
 			memset(txb, DAHDI_LIN2X(0, ms), bytes);	/* Lastly we use silence on telephony channels */
 			bytes = 0;
@@ -6840,6 +6886,14 @@ static inline void __putbuf_chunk(struct
 	int res;
 	int left, x;
 
+#if defined(CONFIG_DAHDI_BRI_DCHANS)	
+	if (test_bit(DAHDI_FLAGBIT_BRIDCHAN, &ms->flags)) {
+	    bytes = ms->bytes2receive;
+	    if (bytes < 1) return;
+//	    printk(KERN_CRIT "bytes2receive %d\n",ms->bytes2receive);
+	}
+#endif
+
 	while(bytes) {
 #if defined(CONFIG_DAHDI_NET)  || defined(CONFIG_DAHDI_PPP)
 		skb = NULL;
@@ -6897,6 +6951,19 @@ static inline void __putbuf_chunk(struct
 						}
 					}
 				}
+#ifdef CONFIG_DAHDI_BRI_DCHANS
+			} else if (test_bit(DAHDI_FLAGBIT_BRIDCHAN, &ms->flags)) {
+			    memcpy(buf + ms->readidx[ms->inreadbuf], rxb, left);
+			    rxb += left;
+			    ms->readidx[ms->inreadbuf] += left;
+			    bytes -= left;
+			    if (ms->eofrx == 1) {
+				eof=1;
+			    }
+//			    printk(KERN_CRIT "receiving %d bytes\n",ms->bytes2receive);
+			    ms->bytes2receive = 0;
+			    ms->eofrx = 0;
+#endif
 			} else {
 				/* Not HDLC */
 				memcpy(buf + ms->readidx[ms->inreadbuf], rxb, left);