fix(ROG Ally): invert gyro yaw for deck-uhid target

src/input/target/steam_deck.rs

@@ -56,6 +56,10 @@ pub struct SteamDeckConfig {
     pub vendor: String,
     pub name: String,
     pub product_id: ProductId,
+    /// Invert gyro yaw written to the Deck HID report. Enabled only on ASUS ROG
+    /// Ally hardware (see `GYRO_YAW_INVERT_BOARD_NAMES` in steam_deck_uhid.rs)
+    /// when using the deck-uhid target.
+    pub invert_gyro_yaw: bool,
 }
 
 impl Default for SteamDeckConfig {
@@ -64,6 +68,7 @@ impl Default for SteamDeckConfig {
             vendor: "InputPlumber".to_string(),
             name: "Generic Steam Controller".to_string(),
             product_id: ProductId::Generic,
+            invert_gyro_yaw: false,
         }
     }
 }

src/input/target/steam_deck_uhid.rs

@@ -16,6 +16,7 @@ use uhid_virt::{Bus, CreateParams, StreamError, UHIDDevice};
 
 use crate::{
     config::CompositeDeviceConfig,
+    dmi::get_dmi_data,
     drivers::steam_deck::{
         hid_report::{
             PackedHapticReport, PackedInputDataReport, PackedRumbleReport, ReportType,
@@ -49,6 +50,11 @@ use super::{
 // a button down event.
 const MIN_FRAME_TIME: Duration = Duration::from_millis(80);
 
+/// DMI `board_name` values for ASUS ROG Ally hardware that need gyro yaw sign
+/// correction when emulating via deck-uhid. See `matches.dmi_data.board_name`
+/// in `/usr/share/inputplumber/devices/50-rog_*.yaml`.
+const GYRO_YAW_INVERT_BOARD_NAMES: &[&str] = &["RC71L", "RC72LA", "RC73XA", "RC73YA"];
+
 pub struct SteamDeckUhidDevice {
     chip_id: [u8; 15],
     config: SteamDeckConfig,
@@ -308,7 +314,10 @@ impl SteamDeckUhidDevice {
                             self.state.pitch = Integer::from_primitive(x as i16);
                         }
                         if let Some(y) = y {
-                            self.state.yaw = Integer::from_primitive(y as i16);
+                            self.state.yaw = Integer::from_primitive(gyro_yaw_to_hid(
+                                y,
+                                self.config.invert_gyro_yaw,
+                            ));
                         }
                         if let Some(z) = z {
                             self.state.roll = Integer::from_primitive(z as i16);
@@ -386,7 +395,10 @@ impl SteamDeckUhidDevice {
                         self.state.pitch = Integer::from_primitive(x as i16);
                     }
                     if let Some(y) = y {
-                        self.state.yaw = Integer::from_primitive(y as i16);
+                        self.state.yaw = Integer::from_primitive(gyro_yaw_to_hid(
+                            y,
+                            self.config.invert_gyro_yaw,
+                        ));
                     }
                     if let Some(z) = z {
                         self.state.roll = Integer::from_primitive(z as i16);
@@ -621,6 +633,7 @@ impl TargetInputDevice for SteamDeckUhidDevice {
     ) -> Result<(), InputError> {
         let (tx, rx) = channel();
         let mut device_config = self.config.clone();
+        let board_name = get_dmi_data().board_name;
 
         // Spawn a task to wait for the composite device config. This is done
         // to prevent potential deadlocks if the composite device and target
@@ -706,11 +719,16 @@ impl TargetInputDevice for SteamDeckUhidDevice {
                 _ => {}
             };
 
+            device_config.invert_gyro_yaw =
+                GYRO_YAW_INVERT_BOARD_NAMES.contains(&board_name.as_str());
+
             log::debug!(
-                "Found Steam Deck target config: {} {} PID: {:?}",
+                "Found Steam Deck target config: {} {} PID: {:?} board_name: {} invert_gyro_yaw: {}",
                 device_config.vendor,
                 device_config.name,
                 device_config.product_id.to_u16(),
+                board_name,
+                device_config.invert_gyro_yaw,
             );
 
             if let Err(e) = tx.send(device_config) {
@@ -989,3 +1007,8 @@ impl Debug for SteamDeckUhidDevice {
             .finish()
     }
 }
+
+fn gyro_yaw_to_hid(value: f64, invert: bool) -> i16 {
+    let value = if invert { -value } else { value };
+    value as i16
+}