support for e1-tracer hardware

Recent work on the e1-tracer firmware is introducing a set of USB
descriptors (as configuration 2) that are mostly compatible to how
osmo-e1d talks to icE1usb.

The main difference is that there's only one ISO IN endpoint per USB
interface, and no ISO OUT or ISU FB endpoints.  So we introduce some
minor adjustments here to accommodate that.

Related: OS#5733
Closes: OS#5734
Change-Id: I855e18c0f229bd473123f96303e60ab2de90677f

1 files changed, 45 insertions, 13 deletions

diff --git a/src/usb.c b/src/usb.c
index c8ad97f..dc89bb0 100644
--- a/src/usb.c
+++ b/src/usb.c
@@ -2,6 +2,7 @@
  * usb.c
  *
  * (C) 2019 by Sylvain Munaut <tnt@246tNt.com>
+ * (C) 2022 by Harald Welte <laforge@gnumonks.org>
  *
  * All Rights Reserved
  *
@@ -42,6 +43,7 @@
 
 #define USB_VID		0x1d50
 #define USB_PID		0x6145
+#define USB_PID_TRACER	0x6151
 
 libusb_context *g_usb = NULL;
 
@@ -809,7 +811,7 @@ _e1_usb_gpsdo_init(struct e1_intf *intf)
 // ---------------------------------------------------------------------------
 
 static int
-_e1_usb_open_device(struct e1_daemon *e1d, struct libusb_device *dev)
+_e1_usb_open_device(struct e1_daemon *e1d, struct libusb_device *dev, bool is_tracer)
 {
 	struct e1_intf *intf;
 	struct e1_line *line;
@@ -873,6 +875,10 @@ _e1_usb_open_device(struct e1_daemon *e1d, struct libusb_device *dev)
 		osmo_talloc_replace_string(intf, &intf->usb.serial_str, serial_str);
 	}
 
+	/* we have prior knowledge that the e1-tracer firmware configuration 2 is the e1d compatible mode. */
+	if (is_tracer)
+		libusb_set_configuration(devh, 2);
+
 	INIT_LLIST_HEAD(&intf_data->ctrl_inprogress);
 
 	ret = libusb_get_active_config_descriptor(dev, &cd);
@@ -892,8 +898,13 @@ _e1_usb_open_device(struct e1_daemon *e1d, struct libusb_device *dev)
 			continue;
 
 		id = &cd->interface[i].altsetting[1];
-		if ((id->bInterfaceClass != 0xff) || (id->bInterfaceSubClass != 0xe1) || (id->bNumEndpoints < 3))
-			continue;
+		if (is_tracer) {
+			if ((id->bInterfaceClass != 0xff) || (id->bInterfaceSubClass != 0xe1) || (id->bNumEndpoints < 1))
+				continue;
+		} else {
+			if ((id->bInterfaceClass != 0xff) || (id->bInterfaceSubClass != 0xe1) || (id->bNumEndpoints < 3))
+				continue;
+		}
 
 		line = e1_intf_find_line(intf, line_nr);
 		if (line) {
@@ -933,9 +944,16 @@ _e1_usb_open_device(struct e1_daemon *e1d, struct libusb_device *dev)
 			}
 		}
 
-		if (!line_data->ep_in || !line_data->ep_out || !line_data->ep_fb || !line_data->pkt_size) {
-			LOGP(DE1D, LOGL_ERROR, "Failed to use interface %d\n", id->bInterfaceNumber);
-			goto next_interface;
+		if (is_tracer) {
+			if (!line_data->ep_in || !line_data->pkt_size) {
+				LOGP(DE1D, LOGL_ERROR, "Failed to use interface %d\n", id->bInterfaceNumber);
+				goto next_interface;
+			}
+		} else {
+			if (!line_data->ep_in || !line_data->ep_out || !line_data->ep_fb || !line_data->pkt_size) {
+				LOGP(DE1D, LOGL_ERROR, "Failed to use interface %d\n", id->bInterfaceNumber);
+				goto next_interface;
+			}
 		}
 
 		if (!line) {
@@ -966,13 +984,18 @@ _e1_usb_open_device(struct e1_daemon *e1d, struct libusb_device *dev)
 		}
 
 		/* Create data flows and start the line */
-		line_data->flow_in  = e1uf_create(line, e1_usb_xfer_in,  line_data->ep_in,  4, line_data->pkt_size, 4);
-		line_data->flow_out = e1uf_create(line, e1_usb_xfer_out, line_data->ep_out, 4, line_data->pkt_size, 4);
-		line_data->flow_fb  = e1uf_create(line, e1_usb_xfer_fb,  line_data->ep_fb,  2, 3, 1);
 
+		/* all supported devices have an IN endpoint */
+		line_data->flow_in  = e1uf_create(line, e1_usb_xfer_in,  line_data->ep_in,  4, line_data->pkt_size, 4);
 		e1uf_start(line_data->flow_in);
-		e1uf_start(line_data->flow_out);
-		e1uf_start(line_data->flow_fb);
+
+		/* e1-tracer has no OUT or FEEDBACK endpoint */
+		if (!is_tracer) {
+			line_data->flow_out = e1uf_create(line, e1_usb_xfer_out, line_data->ep_out, 4, line_data->pkt_size, 4);
+			e1uf_start(line_data->flow_out);
+			line_data->flow_fb  = e1uf_create(line, e1_usb_xfer_fb,  line_data->ep_fb,  2, 3, 1);
+			e1uf_start(line_data->flow_fb);
+		}
 
 		if (line_data->ep_int)
 			resubmit_irq(line);
@@ -1028,10 +1051,19 @@ e1_usb_probe(struct e1_daemon *e1d)
 		if (ret)
 			continue;
 
-		if ((desc.idVendor != USB_VID) || (desc.idProduct != USB_PID))
+		if (desc.idVendor != USB_VID)
 			continue;
 
-		_e1_usb_open_device(e1d, dev_list[i]);
+		switch (desc.idProduct) {
+		case USB_PID:
+			_e1_usb_open_device(e1d, dev_list[i], false);
+			break;
+		case USB_PID_TRACER:
+			_e1_usb_open_device(e1d, dev_list[i], true);
+			break;
+		default:
+			continue;
+		}
 	}
 
 	libusb_free_device_list(dev_list, 1);