1 files changed, 88 insertions, 2 deletions
diff --git a/src/core/hle/service/hid.h b/src/core/hle/service/hid.h
index b17fcfa86..a077e25cd 100644
--- a/src/core/hle/service/hid.h
+++ b/src/core/hle/service/hid.h
@@ -5,15 +5,101 @@
 #pragma once
 
 #include "core/hle/service/service.h"
+#include "common/bit_field.h"
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 // Namespace HID_User
 
-// This service is used for interfacing to physical user controls... perhaps "Human Interface 
-// Devices"? Uses include game pad controls, accelerometers, gyroscopes, etc.
+// This service is used for interfacing to physical user controls.
+// Uses include game pad controls, touchscreen, accelerometers, gyroscopes, and debug pad.
 
 namespace HID_User {
 
+/** 
+ * Structure of a Pad controller state.
+ */
+struct PadState {
+    union {
+        u32 hex;
+
+        BitField<0, 1, u32> a;
+        BitField<1, 1, u32> b;
+        BitField<2, 1, u32> select;
+        BitField<3, 1, u32> start;
+        BitField<4, 1, u32> right;
+        BitField<5, 1, u32> left;
+        BitField<6, 1, u32> up;
+        BitField<7, 1, u32> down;
+        BitField<8, 1, u32> r;
+        BitField<9, 1, u32> l;
+        BitField<10, 1, u32> x;
+        BitField<11, 1, u32> y;
+
+        BitField<28, 1, u32> circle_right;
+        BitField<29, 1, u32> circle_left;
+        BitField<30, 1, u32> circle_up;
+        BitField<31, 1, u32> circle_down;
+    };
+};
+
+/**
+ * Structure of a single entry in the PadData's Pad state history array.
+ */
+struct PadDataEntry {
+    PadState current_state;
+    PadState delta_additions;
+    PadState delta_removals;
+
+    s16 circle_pad_x;
+    s16 circle_pad_y;
+};
+
+/**
+ * Structure of all data related to the 3DS Pad.
+ */
+struct PadData {
+    s64 index_reset_ticks;
+    s64 index_reset_ticks_previous;
+    u32 index; // the index of the last updated Pad state history element
+
+    u32 pad1;
+    u32 pad2;
+
+    PadState current_state; // same as entries[index].current_state
+    u32 raw_circle_pad_data;
+
+    u32 pad3;
+
+    std::array<PadDataEntry, 8> entries; // Pad state history
+};
+
+// Pre-defined PadStates for single button presses
+const PadState PAD_NONE         = {{0}};
+const PadState PAD_A            = {{1u << 0}};
+const PadState PAD_B            = {{1u << 1}};
+const PadState PAD_SELECT       = {{1u << 2}};
+const PadState PAD_START        = {{1u << 3}};
+const PadState PAD_RIGHT        = {{1u << 4}};
+const PadState PAD_LEFT         = {{1u << 5}};
+const PadState PAD_UP           = {{1u << 6}};
+const PadState PAD_DOWN         = {{1u << 7}};
+const PadState PAD_R            = {{1u << 8}};
+const PadState PAD_L            = {{1u << 9}};
+const PadState PAD_X            = {{1u << 10}};
+const PadState PAD_Y            = {{1u << 11}};
+const PadState PAD_CIRCLE_RIGHT = {{1u << 28}};
+const PadState PAD_CIRCLE_LEFT  = {{1u << 29}};
+const PadState PAD_CIRCLE_UP    = {{1u << 30}};
+const PadState PAD_CIRCLE_DOWN  = {{1u << 31}};
+
+// Methods for updating the HID module's state
+void PadButtonPress(PadState pad_state);
+void PadButtonRelease(PadState pad_state);
+void PadUpdateComplete();
+
+/**
+ * HID service interface.
+ */
 class Interface : public Service::Interface {
 public: