[HID] Portal: Simplified device searching procedure

src/xenia/hid/portal/hardware_portal.cc

@@ -26,53 +26,31 @@ HardwarePortal::~HardwarePortal() {
   libusb_exit(context_);
 }
 
+bool HardwarePortal::IsConnected() { return handle_ != nullptr; }
+
 void HardwarePortal::OpenDevice() {
-  if (!context_ || connected_) {
+  if (!context_ || handle_) {
     return;
   }
 
-  libusb_device** devs;
-  const ssize_t cnt = libusb_get_device_list(context_, &devs);
-  if (cnt < 0) {
-    // No device available... It might appear later.
-    return;
-  }
-
-  for (ssize_t i = 0; i < cnt; ++i) {
-    libusb_device* dev = devs[i];
-
-    libusb_device_descriptor desc;
-    if (libusb_get_device_descriptor(dev, &desc) == 0) {
-      // Check if this device matches the target Vendor ID and Product ID.
-      // Small limitation. We're only supporting one device being connected at
-      // the time.
-      for (const auto& entry : kPortalVendorProductIdList) {
-        if (desc.idVendor == entry.first && desc.idProduct == entry.second) {
-          if (libusb_open(dev, &handle_) == 0) {
-            libusb_claim_interface(handle_, 0);
-            connected_ = true;
-            // We found device. No need to go thorugh remaining IDs.
-            break;
-          }
-        }
-      }
-    }
-    // We found device. No need to go thorugh remaining devices.
-    if (connected_) {
+  // Allow only one portal device at the time.
+  for (const auto& entry : kPortalVendorProductIdList) {
+    handle_ =
+        libusb_open_device_with_vid_pid(context_, entry.first, entry.second);
+    if (handle_) {
+      libusb_claim_interface(handle_, 0);
       break;
     }
   }
-  libusb_free_device_list(devs, 0);
 }
 
 void HardwarePortal::CloseDevice() {
-  if (!connected_) {
+  if (!handle_) {
     return;
   }
 
   libusb_release_interface(handle_, 0);
   libusb_close(handle_);
-  connected_ = false;
   handle_ = nullptr;
 }
 

src/xenia/hid/portal/hardware_portal.h

@@ -28,6 +28,8 @@ class HardwarePortal final : public Portal {
   HardwarePortal();
   ~HardwarePortal() override;
 
+  virtual bool IsConnected() override;
+
   virtual void OnDeviceArrival() override;
   virtual void OnDeviceRemoval() override;
 

src/xenia/hid/portal/portal.cc

@@ -15,16 +15,11 @@ namespace hid {
 Portal::Portal() {}
 Portal::~Portal() {}
 
-bool Portal::IsConnected() {
-  std::lock_guard<xe_mutex> guard(lock_);
-  return connected_;
-}
-
 X_STATUS Portal::Read(std::span<uint8_t> data, uint32_t& bytes_read,
                       uint16_t& state) {
   std::lock_guard<xe_mutex> guard(lock_);
 
-  if (!connected_) {
+  if (!IsConnected()) {
     return X_ERROR_DEVICE_NOT_CONNECTED;
   }
 
@@ -55,7 +50,7 @@ X_STATUS Portal::Read(std::span<uint8_t> data, uint32_t& bytes_read,
 X_STATUS Portal::Write(std::span<uint8_t> data) {
   std::lock_guard<xe_mutex> guard(lock_);
 
-  if (!connected_) {
+  if (!IsConnected()) {
     return X_ERROR_DEVICE_NOT_CONNECTED;
   }
 

src/xenia/hid/portal/portal.h

@@ -25,7 +25,7 @@ class Portal {
   Portal();
   virtual ~Portal();
 
-  bool IsConnected();
+  virtual bool IsConnected() = 0;
 
   virtual X_STATUS Read(std::span<uint8_t> data, uint32_t& bytes_read,
                         uint16_t& state);
@@ -34,9 +34,6 @@ class Portal {
   virtual void OnDeviceArrival() = 0;
   virtual void OnDeviceRemoval() = 0;
 
- protected:
-  bool connected_ = false;
-
  private:
   virtual void OpenDevice() = 0;
   virtual void CloseDevice() = 0;