We can now change baud rates on the GR601-W.

This required some unfortunate klugery because the GR601-W is a USB device
that nevertheless has port ID 1 in the u-blox CFG-PRT message (associated
with the primary USART) rather than port ID 3 which is what u-blox USB
would give it.

3 files changed, 37 insertions, 14 deletions

diff --git a/driver_ubx.c b/driver_ubx.c
index b213a675..9205b8f7 100644
--- a/driver_ubx.c
+++ b/driver_ubx.c
@@ -471,6 +471,12 @@ gps_mask_t ubx_parse(struct gps_device_t * session, unsigned char *buf,
 	ubx_msg_inf(buf, data_len, session->context->debug);
 	break;
 
+    case UBX_CFG_PRT:
+	session->driver.ubx.port_id = (int)buf[UBX_MESSAGE_DATA_OFFSET + 0];
+	gpsd_report(session->context->debug, LOG_INF, "UBX_CFG_PRT: port %d\n",
+		    session->driver.ubx.port_id);
+	break;
+
     case UBX_TIM_TP:
 	gpsd_report(session->context->debug, LOG_IO, "UBX_TIM_TP\n");
 	break;
@@ -659,19 +665,35 @@ static void ubx_cfg_prt(struct gps_device_t *session,
     memset(buf, '\0', UBX_CFG_LEN);
 
     /*@ +ignoresigns +charint @*/
-    switch(session->sourcetype) {
-    case source_rs232:
-	buf[0] = USART1_ID;
-	break;
-    case source_usb:
+    /*
+     * When this is called from gpsd, the initial probe for UBX should
+     * have picked up the device's port number from the CFG_PRT response.
+     */
+    if (session->driver.ubx.port_id != 0)
+	buf[0] = session->driver.ubx.port_id;
+    /*
+     * This default can be hit if we haven't sent a CFG_PRT query yet,
+     * which can happen in gpsmon because it doesn't autoprobe.
+     *
+     * What we'd like to do here is dispatch to USART1_ID or
+     * USB_ID intelligently based on whether this is a USB or RS232
+     * source.  Unfortunately the GR601-W screws that up by being
+     * a USB device with port_id 1.  So we bite the bullet and 
+     * default to port 1.
+     *
+     * Without further logic, this means gpsmon wouldn't be able to
+     * change the speed on the EVK 6H's USB port.  But! To pick off
+     * the EVK 6H on Linux as a special case, we notice that its
+     * USB device name is /dev/ACMx - it presents as a USB modem.
+     *
+     * This logic will fail on any USB u-blox device that presents
+     * as an ordinary USB serial device (/dev/USB*) and actually
+     * has port ID 3 the way it ought to.
+     */
+    else if (strstr(session->gpsdata.dev.path, "/ACM") != NULL)
 	buf[0] = USB_ID;
-	break;
-    default:
-	gpsd_report(session->context->debug, LOG_WARN,
-		    "UBX driver sees unexpected source type %d.",
-		    session->sourcetype);
-	return;
-    }
+    else
+	buf[0] = USART1_ID;
 
     putle32(buf, 8, speed);
 
diff --git a/drivers.c b/drivers.c
index db2f288e..f38d2569 100644
--- a/drivers.c
+++ b/drivers.c
@@ -224,10 +224,10 @@ static void nmea_event_hook(struct gps_device_t *session, event_t event)
 #endif /* ASHTECH_ENABLE */
 #ifdef UBLOX_ENABLE
 	case 7:
-	    /* probe for UBX -- query software version */
+	    /* probe for UBX -- query port configuration */
 	    gpsd_report(session->context->debug, LOG_PROG,
 			"=> Probing for UBX\n");
-	    (void)ubx_write(session, 0x0au, 0x04, NULL, 0);
+	    (void)ubx_write(session, 0x06, 0x00, NULL, 0);
 	    break;
 #endif /* UBLOX_ENABLE */
 #ifdef MTK3301_ENABLE
diff --git a/gpsd.h-tail b/gpsd.h-tail
index 28b0f0e5..8a2e37cb 100644
--- a/gpsd.h-tail
+++ b/gpsd.h-tail
@@ -610,6 +610,7 @@ struct gps_device_t {
 #endif /* ZODIAC_ENABLE */
 #ifdef UBLOX_ENABLE
 	struct {
+	    unsigned char port_id;
 	    unsigned char sbas_in_use;
 	    bool user_switched;
     	} ubx;