Fix support for Lizard Mode

Author: ayufan

SteamController/Devices/SteamControllerLizard.cs

@@ -6,6 +6,22 @@ namespace SteamController.Devices
 {
     public partial class SteamController
     {
+        // Based on: https://github.com/torvalds/linux/blob/master/drivers/hid/hid-steam.c
+        public const byte ID_SET_DIGITAL_MAPPINGS = 0x80;
+        public const byte ID_CLEAR_DIGITAL_MAPPINGS = 0x81;
+        public const byte ID_SET_DEFAULT_DIGITAL_MAPPINGS = 0x85;
+        public const byte ID_FACTORY_RESET = 0x86;
+        public const byte ID_SET_SETTINGS_VALUES = 0x87;
+        public const byte ID_DEFAULT_MAPPINGS = 0x8e;
+
+        public const byte SETTING_LEFT_TRACKPAD_MODE = 7;
+        public const byte SETTING_RIGHT_TRACKPAD_MODE = 8;
+        public const byte SETTING_LEFT_TRACKPAD_CLICK_PRESSURE = 52;
+        public const byte SETTING_RIGHT_TRACKPAD_CLICK_PRESSURE = 53;
+        public const byte SETTING_STEAM_WATCHDOG_ENABLE = 71;
+
+        public const ushort TRACKPAD_NONE = 7;
+
         private const int LizardModeUpdateInterval = 250;
 
         public bool LizardMouse { get; set; } = true;
@@ -29,17 +45,20 @@ private void UpdateLizardMouse()
             savedLizardMouse = LizardMouse;
             lizardMouseUpdated = DateTime.Now;
 
+            // Enable or disable mouse emulation
             if (LizardMouse)
             {
-                //Enable mouse emulation
-                byte[] data = new byte[] { 0x8e, 0x00 };
-                neptuneDevice.RequestFeatureReport(data);
+                SendFeatureByte(ID_DEFAULT_MAPPINGS);
             }
             else
             {
-                //Disable mouse emulation
-                byte[] data = new byte[] { 0x87, 0x03, 0x08, 0x07 };
-                neptuneDevice.RequestFeatureReport(data);
+                SendSettings(
+                    (SETTING_LEFT_TRACKPAD_MODE, TRACKPAD_NONE), // disable mouse
+                    (SETTING_RIGHT_TRACKPAD_MODE, TRACKPAD_NONE), // disable mouse
+                    (SETTING_LEFT_TRACKPAD_CLICK_PRESSURE, 0xFFFF), // disable haptic click
+                    (SETTING_RIGHT_TRACKPAD_CLICK_PRESSURE, 0xFFFF), // disable haptic click
+                    (SETTING_STEAM_WATCHDOG_ENABLE, 0) // disable watchdog that tests if Steam is active
+                );
             }
         }
 
@@ -56,18 +75,34 @@ private void UpdateLizardButtons()
             savedLizardButtons = LizardButtons;
             lizardButtonUpdated = DateTime.Now;
 
+            // Enable / Disable esc, enter, cursors
             if (LizardButtons)
-            {
-                //Enable keyboard/mouse button emulation
-                byte[] data = new byte[] { 0x85, 0x00 };
-                neptuneDevice.RequestFeatureReport(data);
-            }
+                SendFeatureByte(ID_SET_DEFAULT_DIGITAL_MAPPINGS);
             else
+                SendFeatureByte(ID_CLEAR_DIGITAL_MAPPINGS);
+        }
+
+        private void SendFeatureByte(byte b)
+        {
+            neptuneDevice.RequestFeatureReport(new byte[] { b, 0 });
+        }
+
+        private void SendSettings(params (byte setting, ushort val)[] settings)
+        {
+            // Format: 0x87 len (reg valLo valHi)*
+            byte[] cmd = new byte[2 + settings.Length * 3];
+            cmd[0] = ID_SET_SETTINGS_VALUES;
+            cmd[1] = (byte)(settings.Length * 3); // length
+
+            int length = 2;
+            foreach (var (setting, val) in settings)
             {
-                //Disable keyboard/mouse button emulation
-                byte[] data = new byte[] { 0x81, 0x00 };
-                neptuneDevice.RequestFeatureReport(data);
+                cmd[length++] = (byte)setting;
+                cmd[length++] = (byte)(val & 0xFF);
+                cmd[length++] = (byte)(val >> 8);
             }
+
+            neptuneDevice.RequestFeatureReport(cmd);
         }
     }
 }