psvr: match on interface_number

Instead of trying to parse the device path to match the interface
number, use the interface_number field in hid_device_info. This
currently does not work on recent Mac OS X [1]. Since there is nothing
we can do about it here, warn loudly.

Also ignore all but the IMU interfaces when building the device list.
Besides removing bogus devices from the list, this should also fix
multiple PSVR headsets connected at the same time.

[1] https://github.com/signal11/hidapi/pull/380

src/drv_psvr/psvr.c

@@ -146,31 +146,28 @@ static void close_device(ohmd_device* device)
 	free(device);
 }
 
-static hid_device* open_device_idx(int manufacturer, int product, int iface, int iface_tot, int device_index)
+static hid_device* open_device_idx(int manufacturer, int product, int iface, int device_index)
 {
 	struct hid_device_info* devs = hid_enumerate(manufacturer, product);
 	struct hid_device_info* cur_dev = devs;
 
 	int idx = 0;
-	int iface_cur = 0;
 	hid_device* ret = NULL;
 
 	while (cur_dev) {
 		LOGI("%04x:%04x %s\n", manufacturer, product, cur_dev->path);
 
-		if(findEndPoint(cur_dev->path, device_index) > 0 && iface == iface_cur){
-			ret = hid_open_path(cur_dev->path);
-			LOGI("opening\n");
-		}
-
-		cur_dev = cur_dev->next;
-
-		iface_cur++;
+		if (cur_dev->interface_number == iface) {
+			if(idx == device_index){
+				ret = hid_open_path(cur_dev->path);
+				LOGI("opening\n");
+				break;
+			}
 
-		if(iface_cur >= iface_tot){
 			idx++;
-			iface_cur = 0;
 		}
+
+		cur_dev = cur_dev->next;
 	}
 
 	hid_free_enumeration(devs);
@@ -187,8 +184,10 @@ static ohmd_device* open_device(ohmd_driver* driver, ohmd_device_desc* desc)
 
 	priv->base.ctx = driver->ctx;
 
+	int idx = atoi(desc->path);
+
 	// Open the HMD device
-	priv->hmd_handle = open_device_idx(SONY_ID, PSVR_HMD, 0, 0, 4);
+	priv->hmd_handle = open_device_idx(SONY_ID, PSVR_HMD, 4, idx);
 
 	if(!priv->hmd_handle)
 		goto cleanup;
@@ -199,7 +198,7 @@ static ohmd_device* open_device(ohmd_driver* driver, ohmd_device_desc* desc)
 	}
 
 	// Open the HMD Control device
-	priv->hmd_control = open_device_idx(SONY_ID, PSVR_HMD, 0, 0, 5);
+	priv->hmd_control = open_device_idx(SONY_ID, PSVR_HMD, 5, idx);
 
 	if(!priv->hmd_control)
 		goto cleanup;
@@ -258,23 +257,38 @@ static void get_device_list(ohmd_driver* driver, ohmd_device_list* list)
 
 	int idx = 0;
 	while (cur_dev) {
-		ohmd_device_desc* desc = &list->devices[list->num_devices++];
+		ohmd_device_desc* desc;
+
+		// Warn if hidapi does not provide interface numbers
+		if (cur_dev->interface_number == -1) {
+			LOGE("hidapi does not provide PSVR interface numbers\n");
+#ifdef __APPLE__
+			LOGE("see https://github.com/signal11/hidapi/pull/380\n");
+#endif
+			break;
+		}
+
+		// Register one device for each IMU sensor interface
+		if (cur_dev->interface_number == 4) {
+			desc = &list->devices[list->num_devices++];
+
+			strcpy(desc->driver, "OpenHMD Sony PSVR Driver");
+			strcpy(desc->vendor, "Sony");
+			strcpy(desc->product, "PSVR");
 
-		strcpy(desc->driver, "OpenHMD Sony PSVR Driver");
-		strcpy(desc->vendor, "Sony");
-		strcpy(desc->product, "PSVR");
+			desc->revision = 0;
 
-		desc->revision = 0;
+			snprintf(desc->path, OHMD_STR_SIZE, "%d", idx);
 
-		snprintf(desc->path, OHMD_STR_SIZE, "%d", idx);
+			desc->driver_ptr = driver;
 
-		desc->driver_ptr = driver;
-		
-		desc->device_class = OHMD_DEVICE_CLASS_HMD;
-		desc->device_flags = OHMD_DEVICE_FLAGS_ROTATIONAL_TRACKING;
+			desc->device_class = OHMD_DEVICE_CLASS_HMD;
+			desc->device_flags = OHMD_DEVICE_FLAGS_ROTATIONAL_TRACKING;
+
+			idx++;
+		}
 
 		cur_dev = cur_dev->next;
-		idx++;
 	}
 
 	hid_free_enumeration(devs);