usb: Add usb path moniker

Add a new moniker for usb and pyusb driver allowing
to select the usb device using its bus id and port
path like `usb:3-3.4.1`.

3 files changed, 25 insertions, 0 deletions

diff --git a/bumble/transport/pyusb.py b/bumble/transport/pyusb.py
index 5e686d1..2426b75 100644
--- a/bumble/transport/pyusb.py
+++ b/bumble/transport/pyusb.py
@@ -216,6 +216,15 @@ async def open_pyusb_transport(spec: str) -> Transport:
     if ':' in spec:
         vendor_id, product_id = spec.split(':')
         device = usb_find(idVendor=int(vendor_id, 16), idProduct=int(product_id, 16))
+    elif '-' in spec:
+
+        def device_path(device):
+            if device.port_numbers:
+                return f'{device.bus}-{".".join(map(str, device.port_numbers))}'
+            else:
+                return str(device.bus)
+
+        device = usb_find(custom_match=lambda device: device_path(device) == spec)
     else:
         device_index = int(spec)
         devices = list(
diff --git a/bumble/transport/usb.py b/bumble/transport/usb.py
index 1257260..6479016 100644
--- a/bumble/transport/usb.py
+++ b/bumble/transport/usb.py
@@ -396,6 +396,16 @@ async def open_usb_transport(spec: str) -> Transport:
                         break
                     device_index -= 1
                 device.close()
+        elif '-' in spec:
+
+            def device_path(device):
+                return f'{device.getBusNumber()}-{".".join(map(str, device.getPortNumberList()))}'
+
+            for device in context.getDeviceIterator(skip_on_error=True):
+                if device_path(device) == spec:
+                    found = device
+                    break
+                device.close()
         else:
             # Look for a compatible device by index
             def device_is_bluetooth_hci(device):
diff --git a/docs/mkdocs/src/transports/usb.md b/docs/mkdocs/src/transports/usb.md
index e400630..08949f0 100644
--- a/docs/mkdocs/src/transports/usb.md
+++ b/docs/mkdocs/src/transports/usb.md
@@ -10,6 +10,7 @@ The moniker for a USB transport is either:
   * `usb:<vendor>:<product>`
   * `usb:<vendor>:<product>/<serial-number>`
   * `usb:<vendor>:<product>#<index>`
+  * `usb:<bus>-<port_numbers>`
 
 with `<index>` as a 0-based index (0 being the first one) to select amongst all the matching devices when there are more than one.
 In the `usb:<index>` form, matching devices are the ones supporting Bluetooth HCI, as declared by their Class, Subclass and Protocol.
@@ -17,6 +18,8 @@ In the `usb:<vendor>:<product>#<index>` form, matching devices are the ones with
 
 `<vendor>` and `<product>` are a vendor ID and product ID in hexadecimal.
 
+with `<port_numbers>` as a list of all port numbers from root separated with dots `.`
+
 In addition, if the moniker ends with the symbol "!", the device will be used in "forced" mode:
 the first USB interface of the device will be used, regardless of the interface class/subclass.
 This may be useful for some devices that use a custom class/subclass but may nonetheless work as-is.
@@ -37,6 +40,9 @@ This may be useful for some devices that use a custom class/subclass but may non
     `usb:0B05:17CB!`
     The BT USB dongle vendor=0B05 and product=17CB, in "forced" mode.
 
+    `usb:3-3.4.1`
+    The BT USB dongle on bus 3 on port path 3, 4, 1.
+
 
 ## Alternative
 The library includes two different implementations of the USB transport, implemented using different python bindings for `libusb`.