swolisten: Add support for walking USB descriptors

scripts/swolisten.c

@@ -40,8 +40,7 @@
 
 #define VID (0x1d50)
 #define PID (0x6018)
-#define INTERFACE (5)
-#define ENDPOINT (0x85)
+#define IFACE_STR "Black Magic Trace Capture"
 
 #define TRANSFER_SIZE (64)
 #define NUM_FIFOS 32
@@ -417,6 +416,7 @@ int usbFeeder(void)
  unsigned char cbw[TRANSFER_SIZE];
  libusb_device_handle *handle;
  libusb_device *dev;
+ struct libusb_config_descriptor *config;
  int size;
 
  while (1)
@@ -435,10 +435,36 @@ int usbFeeder(void)
  if (!(dev = libusb_get_device(handle)))
  continue;
 
- if (libusb_claim_interface (handle, INTERFACE)<0)
+ uint8_t bmp_interface = 0;
+ uint8_t bmp_endpoint = 0;
+
+ if (libusb_get_active_config_descriptor(dev, &config) < 0)
+ continue;
+
+ int interface_found = 0;
+ for (uint8_t if_num = 0; if_num < config->bNumInterfaces && !interface_found; if_num++) {
+ for (int alt_num = 0; alt_num < config->interface[if_num].num_altsetting && !interface_found; alt_num++) {
+ const struct libusb_interface_descriptor *i = &config->interface[if_num].altsetting[alt_num];
+ char itfString[256] = {0};
+
+ int ret = libusb_get_string_descriptor_ascii(handle, i->iInterface, (unsigned char*)itfString, 256);
+ if (ret < 0)
+ continue;
+ if (strcmp (itfString, IFACE_STR) != 0)
+ continue;
+
+ bmp_interface = i->bInterfaceNumber;
+ bmp_endpoint = i->endpoint[0].bEndpointAddress;
+ interface_found = 1;
+ }
+ }
+
+ libusb_free_config_descriptor(config);
+
+ if (libusb_claim_interface (handle, bmp_interface)<0)
  continue;
 
- while (0==libusb_bulk_transfer(handle, ENDPOINT, cbw, TRANSFER_SIZE, &size, 10))
+ while (0==libusb_bulk_transfer(handle, bmp_endpoint, cbw, TRANSFER_SIZE, &size, 10))
  {
  unsigned char *c=cbw;
  if (options.dump)