X-Git-Url: http://sigrok.org/gitweb/?a=blobdiff_plain;f=hardware%2Fcommon%2Fusb.c;h=efe4eb432a1444c854da118a3a15945707a0c40a;hb=76e107d68c010ee3aaede5a1eec2893f82062184;hp=9a38c089ef8630883d4e7637d64504d94023178f;hpb=e7f378fd1ab895259cda8b0545663b39c7bc16f0;p=libsigrok.git

diff --git a/hardware/common/usb.c b/hardware/common/usb.c
index 9a38c089..efe4eb43 100644
--- a/hardware/common/usb.c
+++ b/hardware/common/usb.c
@@ -25,10 +25,14 @@
 #include "libsigrok.h"
 #include "libsigrok-internal.h"
 
-/* SR_HWCAP_CONN takes one of these: */
+/* SR_CONF_CONN takes one of these: */
 #define CONN_USB_VIDPID  "^([0-9a-z]{1,4})\\.([0-9a-z]{1,4})$"
 #define CONN_USB_BUSADDR "^(\\d+)\\.(\\d+)$"
 
+/* Some USBTMC-specific enums, as defined in the USBTMC standard. */
+#define SUBCLASS_USBTMC 0x03
+#define USBTMC_USB488   0x01
+
 /* Message logging helpers with driver-specific prefix string. */
 #define DRIVER_LOG_DOMAIN "usb: "
 #define sr_log(l, s, args...) sr_log(l, DRIVER_LOG_DOMAIN s, ## args)
@@ -138,13 +142,70 @@ SR_PRIV GSList *sr_usb_find(libusb_context *usb_ctx, const char *conn)
 	return devices;
 }
 
+/**
+ * Find USB devices supporting the USBTMC class
+ *
+ * @param usb_ctx libusb context to use while scanning.
+ *
+ * @return A GSList of struct sr_usb_dev_inst, with bus and address fields
+ * indicating devices with USBTMC support.
+ */
+SR_PRIV GSList *sr_usb_find_usbtmc(libusb_context *usb_ctx)
+{
+	struct sr_usb_dev_inst *usb;
+	struct libusb_device **devlist;
+	struct libusb_device_descriptor des;
+	struct libusb_config_descriptor *confdes;
+	const struct libusb_interface_descriptor *intfdes;
+	GSList *devices;
+	int confidx, intfidx, ret, i;
+
+	devices = NULL;
+	libusb_get_device_list(usb_ctx, &devlist);
+	for (i = 0; devlist[i]; i++) {
+		if ((ret = libusb_get_device_descriptor(devlist[i], &des))) {
+			sr_err("Failed to get device descriptor: %s.",
+			       libusb_error_name(ret));
+			continue;
+		}
+
+		for (confidx = 0; confidx < des.bNumConfigurations; confidx++) {
+			if (libusb_get_config_descriptor(devlist[i], confidx, &confdes) != 0) {
+				sr_err("Failed to get configuration descriptor.");
+				break;
+			}
+			for (intfidx = 0; intfidx < confdes->bNumInterfaces; intfidx++) {
+				intfdes = confdes->interface[intfidx].altsetting;
+				if (intfdes->bInterfaceClass != LIBUSB_CLASS_APPLICATION
+						|| intfdes->bInterfaceSubClass != SUBCLASS_USBTMC
+						|| intfdes->bInterfaceProtocol != USBTMC_USB488)
+					continue;
+				sr_dbg("Found USBTMC device (VID:PID = %04x:%04x, bus.address = "
+					   "%d.%d).", des.idVendor, des.idProduct,
+					   libusb_get_bus_number(devlist[i]),
+					   libusb_get_device_address(devlist[i]));
+
+				usb = sr_usb_dev_inst_new(libusb_get_bus_number(devlist[i]),
+						libusb_get_device_address(devlist[i]), NULL);
+				devices = g_slist_append(devices, usb);
+			}
+			libusb_free_config_descriptor(confdes);
+		}
+	}
+	libusb_free_device_list(devlist, 1);
+
+	sr_dbg("Found %d device(s).", g_slist_length(devices));
+
+	return devices;
+}
+
 SR_PRIV int sr_usb_open(libusb_context *usb_ctx, struct sr_usb_dev_inst *usb)
 {
 	struct libusb_device **devlist;
 	struct libusb_device_descriptor des;
 	int ret, r, cnt, i, a, b;
 
-	sr_dbg("Trying to open USB device.");
+	sr_dbg("Trying to open USB device %d.%d.", usb->bus, usb->address);
 
 	if ((cnt = libusb_get_device_list(usb_ctx, &devlist)) < 0) {
 		sr_err("Failed to retrieve device list: %s.",
@@ -162,11 +223,8 @@ SR_PRIV int sr_usb_open(libusb_context *usb_ctx, struct sr_usb_dev_inst *usb)
 
 		b = libusb_get_bus_number(devlist[i]);
 		a = libusb_get_device_address(devlist[i]);
-
-		if (b != usb->bus || a != usb->address) {
-			sr_spew("bus.address = %d.%d does not match.", b, a);
+		if (b != usb->bus || a != usb->address)
 			continue;
-		}
 
 		if ((r = libusb_open(devlist[i], &usb->devhdl)) < 0) {
 			sr_err("Failed to open device: %s.",