Automatically detect CI-V echo state

Some Icom rigs use USB for the CI-V connection. This can be set to echo or not. This mod permits a check of the echo state on start-up & flags the frame handling accordingly.

A new member of the icom_priv_caps is defined to flag that this check should be done. A new icom_rig_open function performs this check & sets a flag in priv_data which frame.c then uses to process the input accordingly.

icom/frame.c

@@ -127,7 +127,7 @@ int icom_one_transaction (RIG *rig, int cmd, int subcmd, const unsigned char *pa
 			return retval;
 	}
 
-	if (priv_caps->serial_full_duplex == 0) {
+	if (!priv_caps->serial_full_duplex && !priv->serial_USB_echo_off) {
 
 		/*
 		 * read what we just sent, because TX and RX are looped,

icom/icom.c

@@ -450,6 +450,42 @@ int icom_cleanup(RIG *rig)
 }
 
 
+/*
+ * ICOM rig open routine
+ * Detect echo state of USB serial port
+ */
+int icom_rig_open(RIG *rig)
+{
+    unsigned char ackbuf[MAXFRAMELEN];
+    int ack_len=sizeof(ackbuf);
+    int retval = RIG_OK;
+
+    rig_debug(RIG_DEBUG_VERBOSE, "%s called\n", __func__);
+
+    struct rig_state *rs = &rig->state;
+    struct icom_priv_data *priv = (struct icom_priv_data*)rs->priv;
+	struct icom_priv_caps *priv_caps = (struct icom_priv_caps *) rig->caps->priv;
+
+    if (priv_caps->serial_USB_echo_check) {
+
+        priv->serial_USB_echo_off = 0;
+        retval = icom_transaction (rig, C_RD_TRXID, 0x00, NULL, 0, ackbuf, &ack_len);
+        if (retval == RIG_OK) {
+            rig_debug(RIG_DEBUG_VERBOSE, "USB echo on detected\n");
+        return RIG_OK;
+        }
+        priv->serial_USB_echo_off = 1;
+        retval = icom_transaction (rig, C_RD_TRXID, 0x00, NULL, 0, ackbuf, &ack_len);
+        if (retval == RIG_OK) {
+            rig_debug(RIG_DEBUG_VERBOSE, "USB echo off detected\n");
+            return RIG_OK;
+        }
+    }
+    priv->serial_USB_echo_off = 0;
+	return retval;
+}
+
+
 /*
  * icom_set_freq
  * Assumes rig!=NULL, rig->state.priv!=NULL

icom/icom.h

@@ -113,6 +113,7 @@ struct icom_priv_caps {
 	int serial_full_duplex; /*!< Whether RXD&TXD are not tied together */
 	unsigned char civ_version; // default to 0, 1=IC7200,IC7300,etc differences
 	int offs_len; /* Number of bytes in offset frequency field. 0 defaults to 3 */
+	int serial_USB_echo_check; /* Flag to test USB echo state */
 };
 
 
@@ -124,6 +125,7 @@ struct icom_priv_data {
 	int split_on;									/* record split state */
 	pltstate_t *pltstate;	/* only on optoscan */
 	unsigned char civ_version; /* 0=default, 1=new commands for IC7200,IC7300, etc */
+	int serial_USB_echo_off; /* USB is not set to echo */
 };
 
 extern const struct ts_sc_list r8500_ts_sc_list[];
@@ -149,6 +151,7 @@ extern const pbwidth_t rtty_fil[];	/* rtty filter passband width; available on 7
 pbwidth_t icom_get_dsp_flt(RIG *rig, rmode_t mode);
 
 int icom_init(RIG *rig);
+int icom_rig_open(RIG *rig);
 int icom_cleanup(RIG *rig);
 int icom_set_freq(RIG *rig, vfo_t vfo, freq_t freq);
 int icom_get_freq(RIG *rig, vfo_t vfo, freq_t *freq);