Add Steam Deck capacitive touch sticks, trackpad clicks, and mapping (#15612)

(cherry picked from commit 2ebf23014f8e170ae7df48c51bb72a3644eec16b)

src/joystick/SDL_gamepad.c

@@ -1251,6 +1251,9 @@ static GamepadMapping_t *SDL_CreateMappingForHIDAPIGamepad(SDL_GUID guid)
         if (SDL_IsJoystickSteamController(vendor, product)) {
             // Steam controllers have 2 back paddle buttons
             SDL_strlcat(mapping_string, "paddle1:b11,paddle2:b12,", sizeof(mapping_string));
+        } else if (SDL_IsJoystickSteamDeck(vendor, product)) {
+            // The Steam Deck's built-in controller has QAM, 4 back buttons, L/R trackpads, and L/R capacitive touch sticks
+            SDL_strlcat(mapping_string, "misc1:b11,paddle1:b12,paddle2:b13,paddle3:b14,paddle4:b15,touchpad:b17,misc2:b16,misc3:b19,misc4:b18", sizeof(mapping_string));
         } else if (SDL_IsJoystickSteamTriton(vendor, product)) {
             // Second generation Steam controllers have 4 back paddle buttons
             SDL_strlcat(mapping_string, "misc1:b11,paddle1:b12,paddle2:b13,paddle3:b14,paddle4:b15,touchpad:b17,misc2:b16,misc3:b19,misc4:b18,misc5:b21,misc6:b20", sizeof(mapping_string));

src/joystick/SDL_gamepad_db.h

@@ -721,7 +721,7 @@ static const char *s_GamepadMappings[] = {
     "05000000de2800000212000001000000,Steam Controller,a:b0,b:b1,back:b6,dpdown:b14,dpleft:b15,dpright:b13,dpup:b12,guide:b8,leftshoulder:b4,leftstick:b9,lefttrigger:a2,leftx:a0,lefty:a1,paddle1:b11,paddle2:b10,rightshoulder:b5,righttrigger:a3,start:b7,x:b2,y:b3,",
     "05000000de2800000511000001000000,Steam Controller,a:b0,b:b1,back:b6,dpdown:b14,dpleft:b15,dpright:b13,dpup:b12,guide:b8,leftshoulder:b4,leftstick:b9,lefttrigger:a2,leftx:a0,lefty:a1,paddle1:b11,paddle2:b10,rightshoulder:b5,righttrigger:a3,start:b7,x:b2,y:b3,",
     "05000000de2800000611000001000000,Steam Controller,a:b0,b:b1,back:b6,dpdown:b14,dpleft:b15,dpright:b13,dpup:b12,guide:b8,leftshoulder:b4,leftstick:b9,lefttrigger:a2,leftx:a0,lefty:a1,paddle1:b11,paddle2:b10,rightshoulder:b5,righttrigger:a3,start:b7,x:b2,y:b3,",
-    "03000000de2800000512000000016800,Steam Deck Controller,a:b0,b:b1,back:b4,dpdown:h0.4,dpleft:h0.8,dpright:h0.2,dpup:h0.1,guide:b5,leftshoulder:b9,leftstick:b7,lefttrigger:a4,leftx:a0,lefty:a1,misc1:b11,paddle1:b12,paddle2:b13,paddle3:b14,paddle4:b15,rightshoulder:b10,rightstick:b8,righttrigger:a5,rightx:a2,righty:a3,start:b6,x:b2,y:b3,",
+    "03000000de2800000512000000016800,Steam Deck Controller,a:b0,b:b1,back:b4,dpdown:h0.4,dpleft:h0.8,dpright:h0.2,dpup:h0.1,guide:b5,leftshoulder:b9,leftstick:b7,lefttrigger:a4,leftx:a0,lefty:a1,misc1:b11,paddle1:b12,paddle2:b13,paddle3:b14,paddle4:b15,touchpad:b17,misc2:b16,misc3:b19,misc4:b18,rightshoulder:b10,rightstick:b8,righttrigger:a5,rightx:a2,righty:a3,start:b6,x:b2,y:b3,",
     "03000000de2800000512000011010000,Steam Deck,a:b3,b:b4,back:b11,dpdown:b17,dpleft:b18,dpright:b19,dpup:b16,guide:b13,leftshoulder:b7,leftstick:b14,lefttrigger:a9,leftx:a0,lefty:a1,misc1:b2,paddle1:b21,paddle2:b20,paddle3:b23,paddle4:b22,rightshoulder:b8,rightstick:b15,righttrigger:a8,rightx:a2,righty:a3,start:b12,x:b5,y:b6,",
     "03000000de280000ff11000001000000,Steam Virtual Gamepad,a:b0,b:b1,back:b6,dpdown:h0.4,dpleft:h0.8,dpright:h0.2,dpup:h0.1,guide:b8,leftshoulder:b4,leftstick:b9,lefttrigger:a2,leftx:a0,lefty:a1,rightshoulder:b5,rightstick:b10,righttrigger:a5,rightx:a3,righty:a4,start:b7,x:b2,y:b3,",
     "0500000011010000311400001b010000,SteelSeries Stratus Duo,a:b0,b:b1,back:b10,dpdown:h0.4,dpleft:h0.8,dpright:h0.2,dpup:h0.1,guide:b32,leftshoulder:b6,leftstick:b13,lefttrigger:a5,leftx:a0,lefty:a1,rightshoulder:b7,rightstick:b14,righttrigger:a4,rightx:a2,righty:a3,start:b11,x:b3,y:b4,",

src/joystick/hidapi/SDL_hidapi_steamdeck.c

@@ -39,6 +39,10 @@ enum
     SDL_GAMEPAD_BUTTON_STEAM_DECK_LEFT_PADDLE1,
     SDL_GAMEPAD_BUTTON_STEAM_DECK_RIGHT_PADDLE2,
     SDL_GAMEPAD_BUTTON_STEAM_DECK_LEFT_PADDLE2,
+    SDL_GAMEPAD_BUTTON_STEAM_DECK_RIGHT_TOUCHPAD,
+    SDL_GAMEPAD_BUTTON_STEAM_DECK_LEFT_TOUCHPAD,
+    SDL_GAMEPAD_BUTTON_STEAM_DECK_RIGHT_JOYSTICK_TOUCH,
+    SDL_GAMEPAD_BUTTON_STEAM_DECK_LEFT_JOYSTICK_TOUCH,
     SDL_GAMEPAD_NUM_STEAM_DECK_BUTTONS,
 };
 
@@ -68,6 +72,8 @@ typedef enum
 
     STEAMDECK_HBUTTON_L4            = 0x00000200,
     STEAMDECK_HBUTTON_R4            = 0x00000400,
+    STEAMDECK_HBUTTON_LSTICK_TOUCH  = 0x00004000,
+    STEAMDECK_HBUTTON_RSTICK_TOUCH  = 0x00008000,
     STEAMDECK_HBUTTON_QAM           = 0x00040000,
 } SteamDeckButtons;
 
@@ -191,6 +197,16 @@ static void HIDAPI_DriverSteamDeck_HandleState(SDL_HIDAPI_Device *device,
         SDL_SendJoystickButton(timestamp, joystick, SDL_GAMEPAD_BUTTON_STEAM_DECK_LEFT_PADDLE2,
                                ((pInReport->payload.deckState.ulButtonsL & STEAMDECK_LBUTTON_L5) != 0));
 
+        SDL_SendJoystickButton(timestamp, joystick, SDL_GAMEPAD_BUTTON_STEAM_DECK_RIGHT_TOUCHPAD,
+                               ((pInReport->payload.deckState.ulButtonsL & STEAMDECK_LBUTTON_RIGHT_PAD) != 0));
+        SDL_SendJoystickButton(timestamp, joystick, SDL_GAMEPAD_BUTTON_STEAM_DECK_LEFT_TOUCHPAD,
+                               ((pInReport->payload.deckState.ulButtonsL & STEAMDECK_LBUTTON_LEFT_PAD) != 0));
+
+        SDL_SendJoystickButton(timestamp, joystick, SDL_GAMEPAD_BUTTON_STEAM_DECK_RIGHT_JOYSTICK_TOUCH,
+                               ((pInReport->payload.deckState.ulButtonsH & STEAMDECK_HBUTTON_RSTICK_TOUCH) != 0));
+        SDL_SendJoystickButton(timestamp, joystick, SDL_GAMEPAD_BUTTON_STEAM_DECK_LEFT_JOYSTICK_TOUCH,
+                               ((pInReport->payload.deckState.ulButtonsH & STEAMDECK_HBUTTON_LSTICK_TOUCH) != 0));
+
         if (pInReport->payload.deckState.ulButtonsL & STEAMDECK_LBUTTON_DPAD_UP) {
             hat |= SDL_HAT_UP;
         }