nsyshid: Add backends for cross platform USB passthrough support (#950)

src/Cafe/OS/libs/nsyshid/Backend.h

@@ -0,0 +1,141 @@
+#ifndef CEMU_NSYSHID_BACKEND_H
+#define CEMU_NSYSHID_BACKEND_H
+
+#include <list>
+#include <memory>
+#include <mutex>
+
+#include "Common/precompiled.h"
+
+namespace nsyshid
+{
+	typedef struct
+	{
+		/* +0x00 */ uint32be handle;
+		/* +0x04 */ uint32 ukn04;
+		/* +0x08 */ uint16 vendorId;  // little-endian ?
+		/* +0x0A */ uint16 productId; // little-endian ?
+		/* +0x0C */ uint8 ifIndex;
+		/* +0x0D */ uint8 subClass;
+		/* +0x0E */ uint8 protocol;
+		/* +0x0F */ uint8 paddingGuessed0F;
+		/* +0x10 */ uint16be maxPacketSizeRX;
+		/* +0x12 */ uint16be maxPacketSizeTX;
+	} HID_t;
+
+	static_assert(offsetof(HID_t, vendorId) == 0x8, "");
+	static_assert(offsetof(HID_t, productId) == 0xA, "");
+	static_assert(offsetof(HID_t, ifIndex) == 0xC, "");
+	static_assert(offsetof(HID_t, protocol) == 0xE, "");
+
+	class Device {
+	  public:
+		Device() = delete;
+
+		Device(uint16 vendorId,
+			   uint16 productId,
+			   uint8 interfaceIndex,
+			   uint8 interfaceSubClass,
+			   uint8 protocol);
+
+		Device(const Device& device) = delete;
+
+		Device& operator=(const Device& device) = delete;
+
+		virtual ~Device() = default;
+
+		HID_t* m_hid; // this info is passed to applications and must remain intact
+
+		uint16 m_vendorId;
+		uint16 m_productId;
+		uint8 m_interfaceIndex;
+		uint8 m_interfaceSubClass;
+		uint8 m_protocol;
+		uint16 m_maxPacketSizeRX;
+		uint16 m_maxPacketSizeTX;
+
+		virtual void AssignHID(HID_t* hid);
+
+		virtual bool Open() = 0;
+
+		virtual void Close() = 0;
+
+		virtual bool IsOpened() = 0;
+
+		enum class ReadResult
+		{
+			Success,
+			Error,
+			ErrorTimeout,
+		};
+
+		virtual ReadResult Read(uint8* data, sint32 length, sint32& bytesRead) = 0;
+
+		enum class WriteResult
+		{
+			Success,
+			Error,
+			ErrorTimeout,
+		};
+
+		virtual WriteResult Write(uint8* data, sint32 length, sint32& bytesWritten) = 0;
+
+		virtual bool GetDescriptor(uint8 descType,
+								   uint8 descIndex,
+								   uint8 lang,
+								   uint8* output,
+								   uint32 outputMaxLength) = 0;
+
+		virtual bool SetProtocol(uint32 ifIndef, uint32 protocol) = 0;
+
+		virtual bool SetReport(uint8* reportData, sint32 length, uint8* originalData, sint32 originalLength) = 0;
+	};
+
+	class Backend {
+	  public:
+		Backend();
+
+		Backend(const Backend& backend) = delete;
+
+		Backend& operator=(const Backend& backend) = delete;
+
+		virtual ~Backend() = default;
+
+		void DetachAllDevices();
+
+		// called from nsyshid when this backend is attached - do not call this yourself!
+		void OnAttach();
+
+		// called from nsyshid when this backend is detached - do not call this yourself!
+		void OnDetach();
+
+		bool IsBackendAttached();
+
+		virtual bool IsInitialisedOk() = 0;
+
+	  protected:
+		// try to attach a device - only works if this backend is attached
+		bool AttachDevice(const std::shared_ptr<Device>& device);
+
+		void DetachDevice(const std::shared_ptr<Device>& device);
+
+		std::shared_ptr<Device> FindDevice(std::function<bool(const std::shared_ptr<Device>&)> isWantedDevice);
+
+		bool IsDeviceWhitelisted(uint16 vendorId, uint16 productId);
+
+		// called from OnAttach() - attach devices that your backend can see here
+		virtual void AttachVisibleDevices() = 0;
+
+	  private:
+		std::list<std::shared_ptr<Device>> m_devices;
+		std::recursive_mutex m_devicesMutex;
+		bool m_isAttached;
+	};
+
+	namespace backend
+	{
+		void AttachDefaultBackends();
+	}
+} // namespace nsyshid
+
+#endif // CEMU_NSYSHID_BACKEND_H