Improve ring detection when polarity reversals are present.

(closes issue #9264)
Reported by: mjagdis
Patches:
      zaptel-ring.diff uploaded by mjagdis (modified by me to add support in wctdm24xxp as well)
Tested by: benbrown


git-svn-id: http://svn.digium.com/svn/zaptel/branches/1.4@3674 5390a7c7-147a-4af0-8ec9-7488f05a26cb

3 files changed, 38 insertions, 30 deletions

diff --git a/wctdm.c b/wctdm.c
index 9d6e503..9040c75 100644
--- a/wctdm.c
+++ b/wctdm.c
@@ -1,5 +1,5 @@
 /*
- * Wilcard TDM400P TDM FXS/FXO Interface Driver for Zapata Telephony interface
+ * Wildcard TDM400P TDM FXS/FXO Interface Driver for Zapata Telephony interface
  *
  * Written by Mark Spencer <markster@digium.com>
  *            Matthew Fredrickson <creslin@digium.com>
@@ -312,6 +312,7 @@ struct wctdm {
 #else			
 			int wasringing;
 #endif			
+			int lastrdtx;
 			int ringdebounce;
 			int offhook;
 			int battdebounce;
@@ -857,30 +858,28 @@ static inline void wctdm_voicedaa_check_hook(struct wctdm *wc, int card)
 		return;
 #ifndef AUDIO_RINGCHECK
 	if (!wc->mod[card].fxo.offhook) {
-		res = wc->reg0shadow[card];
-		if ((res & 0x60) && wc->mod[card].fxo.battery) {
-			wc->mod[card].fxo.ringdebounce += (ZT_CHUNKSIZE * 16);
-			if (wc->mod[card].fxo.ringdebounce >= ZT_CHUNKSIZE * ringdebounce) {
+		res = wc->reg0shadow[card] & 0x60;
+		if (wc->mod[card].fxo.ringdebounce--) {
+			if (res && (res != wc->mod[card].fxo.lastrdtx) && wc->mod[card].fxo.battery) {
 				if (!wc->mod[card].fxo.wasringing) {
 					wc->mod[card].fxo.wasringing = 1;
-					zt_hooksig(&wc->chans[card], ZT_RXSIG_RING);
 					if (debug)
 						printk("RING on %d/%d!\n", wc->span.spanno, card + 1);
+					zt_hooksig(&wc->chans[card], ZT_RXSIG_RING);
 				}
-				wc->mod[card].fxo.ringdebounce = ZT_CHUNKSIZE * ringdebounce;
-			}
-		} else {
-			wc->mod[card].fxo.ringdebounce -= ZT_CHUNKSIZE * 4;
-			if (wc->mod[card].fxo.ringdebounce <= 0) {
-				if (wc->mod[card].fxo.wasringing) {
+				wc->mod[card].fxo.lastrdtx = res;
+				wc->mod[card].fxo.ringdebounce = 10;
+			} else if (!res) {
+				if ((wc->mod[card].fxo.ringdebounce == 0) && wc->mod[card].fxo.wasringing) {
 					wc->mod[card].fxo.wasringing = 0;
-					zt_hooksig(&wc->chans[card], ZT_RXSIG_OFFHOOK);
 					if (debug)
 						printk("NO RING on %d/%d!\n", wc->span.spanno, card + 1);
+					zt_hooksig(&wc->chans[card], ZT_RXSIG_OFFHOOK);
 				}
-				wc->mod[card].fxo.ringdebounce = 0;
 			}
-				
+		} else if (res && wc->mod[card].fxo.battery) {
+			wc->mod[card].fxo.lastrdtx = res;
+			wc->mod[card].fxo.ringdebounce = 10;
 		}
 	}
 #endif
@@ -1505,6 +1504,10 @@ static int wctdm_init_voicedaa(struct wctdm *wc, int card, int fast, int manual,
 	reg16 |= (fxo_modes[_opermode].rz << 1);
 	reg16 |= (fxo_modes[_opermode].rt);
 	wctdm_setreg(wc, card, 16, reg16);
+
+	/* Enable ring detector full-wave rectifier mode */
+	wctdm_setreg(wc, card, 18, 2);
+	wctdm_setreg(wc, card, 24, 0);
 	
 	/* Set DC Termination:
 	   Tip/Ring voltage adjust, minimum operational current, current limitation */
diff --git a/wctdm24xxp/base.c b/wctdm24xxp/base.c
index 32b4230..b67cae5 100644
--- a/wctdm24xxp/base.c
+++ b/wctdm24xxp/base.c
@@ -1327,33 +1327,33 @@ static inline void wctdm_voicedaa_check_hook(struct wctdm *wc, int card)
 		if (b != 0x8)
 			wctdm_setreg_intr(wc, card, 5, 0x8);
 	}
+
 	if (!wc->mods[card].fxo.offhook) {
 		res = wc->cmdq[card].isrshadow[0];	/* Hook/Ring state */
-		if ((res & 0x60) && wc->mods[card].fxo.battery) {
-			wc->mods[card].fxo.ringdebounce += (ZT_CHUNKSIZE * 4);
-			if (wc->mods[card].fxo.ringdebounce >= ZT_CHUNKSIZE * ringdebounce) {
+		if (wc->mods[card].fxo.ringdebounce--) {
+			if (res && (res != wc->mods[card].fxo.lastrdtx) && wc->mods[card].fxo.battery) {
 				if (!wc->mods[card].fxo.wasringing) {
 					wc->mods[card].fxo.wasringing = 1;
-					zt_hooksig(&wc->chans[card], ZT_RXSIG_RING);
-					if (debug & DEBUG_CARD)
+					if (debug)
 						printk("RING on %d/%d!\n", wc->span.spanno, card + 1);
+					zt_hooksig(&wc->chans[card], ZT_RXSIG_RING);
 				}
-				wc->mods[card].fxo.ringdebounce = ZT_CHUNKSIZE * ringdebounce;
-			}
-		} else {
-			wc->mods[card].fxo.ringdebounce -= ZT_CHUNKSIZE;
-			if (wc->mods[card].fxo.ringdebounce <= 0) {
-				if (wc->mods[card].fxo.wasringing) {
+				wc->mods[card].fxo.lastrdtx = res;
+				wc->mods[card].fxo.ringdebounce = 10;
+			} else if (!res) {
+				if ((wc->mods[card].fxo.ringdebounce == 0) && wc->mods[card].fxo.wasringing) {
 					wc->mods[card].fxo.wasringing = 0;
-					zt_hooksig(&wc->chans[card], ZT_RXSIG_OFFHOOK);
-					if (debug & DEBUG_CARD)
+					if (debug)
 						printk("NO RING on %d/%d!\n", wc->span.spanno, card + 1);
+					zt_hooksig(&wc->chans[card], ZT_RXSIG_OFFHOOK);
 				}
-				wc->mods[card].fxo.ringdebounce = 0;
 			}
-				
+		} else if (res && wc->mods[card].fxo.battery) {
+			wc->mods[card].fxo.lastrdtx = res;
+			wc->mods[card].fxo.ringdebounce = 10;
 		}
 	}
+
 	b = wc->cmdq[card].isrshadow[1]; /* Voltage */
 
 	if (fxovoltage) {
@@ -2097,6 +2097,10 @@ static int wctdm_init_voicedaa(struct wctdm *wc, int card, int fast, int manual,
 	reg16 |= (fxo_modes[_opermode].rt);
 	wctdm_setreg(wc, card, 16, reg16);
 	
+	/* Enable ring detector full-wave rectifier mode */
+	wctdm_setreg(wc, card, 18, 2);
+	wctdm_setreg(wc, card, 24, 0);
+	
 	/* Set DC Termination:
 	   Tip/Ring voltage adjust, minimum operational current, current limitation */
 	reg26 |= (fxo_modes[_opermode].dcv << 6);
diff --git a/wctdm24xxp/wctdm24xxp.h b/wctdm24xxp/wctdm24xxp.h
index c801c24..7f76a0a 100644
--- a/wctdm24xxp/wctdm24xxp.h
+++ b/wctdm24xxp/wctdm24xxp.h
@@ -225,6 +225,7 @@ struct wctdm {
 			int lastpol;
 			int polarity;
 			int polaritydebounce;
+			int lastrdtx;
 		} fxo;
 		struct {
 			int oldrxhook;