Add derived UsbTransport class with USB reset method

For testing there needs to be a way to simulate unplugging and
replugging a device. This change adds support for a USB reset
method that does this.

Also add timeouts, so USB reads/writes don't block forever
on an unresponsive device.

Test: glinux, fastboot tool still works
Test: Reset confirmed working via wireshark Linux URB captures

Change-Id: I7213a2395d4ef1c0238810e4929ab966e78c8b55

1 files changed, 8 insertions, 1 deletions

diff --git a/fastboot/usb.h b/fastboot/usb.h
index 5b44468bb..96eb934d3 100644
--- a/fastboot/usb.h
+++ b/fastboot/usb.h
@@ -52,6 +52,13 @@ struct usb_ifc_info {
     char device_path[256];
 };
 
+class UsbTransport : public Transport {
+    // Resets the underlying transport.  Returns 0 on success.
+    // This effectively simulates unplugging and replugging
+    virtual int Reset() = 0;
+};
+
 typedef int (*ifc_match_func)(usb_ifc_info *ifc);
 
-Transport* usb_open(ifc_match_func callback);
+// 0 is non blocking
+UsbTransport* usb_open(ifc_match_func callback, uint32_t timeout_ms = 0);