+static int open_device(am7xxx_context *ctx,
+ unsigned int device_index,
+ libusb_device* usb_dev,
+ am7xxx_device **dev)
+{
+ int ret;
+
+ *dev = find_device(ctx, device_index);
+ if (*dev == NULL) {
+ ret = -ENODEV;
+ goto out;
+ }
+
+ /* the usb device has already been opened */
+ if ((*dev)->usb_device) {
+ debug(ctx, "(*dev)->usb_device already set\n");
+ ret = 1;
+ goto out;
+ }
+
+ ret = libusb_open(usb_dev, &((*dev)->usb_device));
+ if (ret < 0) {
+ debug(ctx, "libusb_open failed\n");
+ goto out;
+ }
+
+ /* XXX, the device is now open, if any of the calls below fail we need
+ * to close it again before bailing out.
+ */
+
+ ret = libusb_set_configuration((*dev)->usb_device,
+ (*dev)->desc->configuration);
+ if (ret < 0) {
+ debug(ctx, "libusb_set_configuration failed\n");
+ debug(ctx, "Cannot set configuration %hhu\n",
+ (*dev)->desc->configuration);
+ goto out_libusb_close;
+ }
+
+ ret = libusb_claim_interface((*dev)->usb_device,
+ (*dev)->desc->interface_number);
+ if (ret < 0) {
+ debug(ctx, "libusb_claim_interface failed\n");
+ debug(ctx, "Cannot claim interface %hhu\n",
+ (*dev)->desc->interface_number);
+out_libusb_close:
+ libusb_close((*dev)->usb_device);
+ (*dev)->usb_device = NULL;
+ }
+out:
+ return ret;
+}
+