feature: add support for screenpad brightness

rog-platform/src/backlight.rs

@@ -0,0 +1,75 @@
+use std::path::PathBuf;
+
+use log::{info, warn};
+
+use crate::error::{PlatformError, Result};
+use crate::{attr_num, to_device};
+
+/// The "backlight" device provides access to screen brightness control
+#[derive(Debug, PartialEq, Eq, PartialOrd, Clone)]
+pub struct Backlight {
+    path: PathBuf,
+    device_type: BacklightType,
+}
+
+#[derive(Debug, PartialEq, Eq, PartialOrd, Clone)]
+pub enum BacklightType {
+    Primary,
+    Screenpad,
+}
+
+impl Backlight {
+    attr_num!("brightness", path, i32);
+
+    attr_num!("max_brightness", path, i32);
+
+    attr_num!("bl_power", path, i32);
+
+    pub fn new(device_type: BacklightType) -> Result<Self> {
+        let mut enumerator = udev::Enumerator::new().map_err(|err| {
+            warn!("{}", err);
+            PlatformError::Udev("enumerator failed".into(), err)
+        })?;
+        enumerator.match_subsystem("backlight").map_err(|err| {
+            warn!("{}", err);
+            PlatformError::Udev("match_subsystem failed".into(), err)
+        })?;
+
+        for device in enumerator.scan_devices().map_err(|err| {
+            warn!("{}", err);
+            PlatformError::Udev("scan_devices failed".into(), err)
+        })? {
+            info!("Backlight: Checking {:?}", device.syspath());
+            match device_type {
+                BacklightType::Primary => {
+                    if device.sysname().to_string_lossy() == "intel_backlight" {
+                        info!("Found primary backlight at {:?}", device.sysname());
+                        return Ok(Self {
+                            path: device.syspath().to_path_buf(),
+                            device_type,
+                        });
+                    }
+                }
+                BacklightType::Screenpad => {
+                    let name = device.sysname().to_string_lossy();
+                    if name == "asus_screenpad" || name == "asus_screenpad_backlight" {
+                        info!("Found screenpad backlight at {:?}", device.sysname());
+                        return Ok(Self {
+                            path: device.syspath().to_path_buf(),
+                            device_type,
+                        });
+                    }
+                }
+            }
+        }
+
+        Err(PlatformError::MissingFunction(format!(
+            "Backlight {:?} not found",
+            device_type
+        )))
+    }
+
+    pub fn device_type(&self) -> &BacklightType {
+        &self.device_type
+    }
+}

rog-platform/src/keyboard_led.rs

@@ -3,7 +3,7 @@ use std::path::PathBuf;
 use log::{info, warn};
 
 use crate::error::{PlatformError, Result};
-use crate::{attr_u8, has_attr, set_attr_u8_array, to_device};
+use crate::{attr_num, has_attr, set_attr_u8_array, to_device};
 
 /// The sysfs control for backlight levels. This is only for the 3-step
 /// backlight setting, and for TUF laptops. It is not a hard requirement
@@ -14,7 +14,7 @@ pub struct KeyboardBacklight {
 }
 
 impl KeyboardBacklight {
-    attr_u8!("brightness", path);
+    attr_num!("brightness", path, u8);
 
     has_attr!("kbd_rgb_mode" path);
 

rog-platform/src/lib.rs

@@ -2,6 +2,7 @@
 //! on ROG, Strix, and TUF laptops.
 
 pub mod asus_armoury;
+pub mod backlight;
 pub mod cpu;
 pub mod error;
 pub mod hid_raw;
@@ -55,18 +56,29 @@ pub fn write_attr_bool(device: &mut Device, attr: &str, value: bool) -> Result<(
         })
 }
 
-pub fn read_attr_u8(device: &Device, attr_name: &str) -> Result<u8> {
+pub fn read_attr_num<T>(device: &Device, attr_name: &str) -> Result<T>
+where
+    T: std::str::FromStr,
+    <T as std::str::FromStr>::Err: std::fmt::Debug,
+{
     if let Some(value) = device.attribute_value(attr_name) {
         let tmp = value.to_string_lossy();
-        return tmp.parse::<u8>().map_err(|_e| PlatformError::ParseNum);
+        return tmp.parse::<T>().map_err(|_e| PlatformError::ParseNum);
     }
     Err(PlatformError::AttrNotFound(attr_name.to_owned()))
 }
 
-pub fn write_attr_u8(device: &mut Device, attr: &str, value: u8) -> Result<()> {
-    device
-        .set_attribute_value(attr, value.to_string())
-        .map_err(|e| PlatformError::IoPath(attr.into(), e))
+pub fn write_attr_num<T>(device: &mut Device, attr_name: &str, value: T) -> Result<()>
+where
+    T: std::fmt::Display,
+{
+    if device
+        .set_attribute_value(attr_name, format!("{value}"))
+        .is_err()
+    {
+        return Err(PlatformError::AttrNotFound(attr_name.to_owned()));
+    }
+    Ok(())
 }
 
 pub fn read_attr_u8_array(device: &Device, attr_name: &str) -> Result<Vec<u8>> {

rog-platform/src/macros.rs

@@ -74,36 +74,41 @@ macro_rules! attr_bool {
 }
 
 #[macro_export]
-macro_rules! get_attr_u8 {
-    ($(#[$attr:meta])* $attr_name:literal $item:ident) => {
+macro_rules! get_attr_num {
+    ($(#[$attr:meta])* $attr_name:literal $item:ident $type:ty) => {
         concat_idents::concat_idents!(fn_name = get_, $attr_name {
             $(#[$attr])*
-            pub fn fn_name(&self) -> Result<u8> {
-                $crate::read_attr_u8(&to_device(&self.$item)?, $attr_name)
+            pub fn fn_name(&self) -> Result<$type> {
+                $crate::read_attr_num::<$type>(&to_device(&self.$item)?, $attr_name)
             }
         });
     };
+    ($(#[$attr:meta])* $attr_name:literal $item:ident) => {
+        $crate::get_attr_num!($(#[$attr])* $attr_name $item $type);
+    };
 }
 
-/// Most attributes expect `u8` as a char, so `1` should be written as `b'1'`.
 #[macro_export]
-macro_rules! set_attr_u8 {
-    ($(#[$attr:meta])* $attr_name:literal $item:ident) => {
+macro_rules! set_attr_num {
+    ($(#[$attr:meta])* $attr_name:literal $item:ident $type:ty) => {
         concat_idents::concat_idents!(fn_name = set_, $attr_name {
             $(#[$attr])*
-            pub fn fn_name(&self, value: u8) -> Result<()> {
-                $crate::write_attr_u8(&mut to_device(&self.$item)?, $attr_name, value)
+            pub fn fn_name(&self, value: $type) -> Result<()> {
+                $crate::write_attr_num(&mut to_device(&self.$item)?, $attr_name, value as $type)
             }
         });
     };
+    ($(#[$attr:meta])* $attr_name:literal $item:ident) => {
+        $crate::set_attr_num!($(#[$attr])* $attr_name $item $type);
+    };
 }
 
 #[macro_export]
-macro_rules! attr_u8 {
-    ($(#[$attr:meta])* $attr_name:literal, $item:ident) => {
+macro_rules! attr_num {
+    ($(#[$attr:meta])* $attr_name:literal, $item:ident, $type:ty) => {
         $crate::has_attr!($(#[$attr])* $attr_name $item);
-        $crate::get_attr_u8!($(#[$attr])* $attr_name $item);
-        $crate::set_attr_u8!($(#[$attr])* $attr_name $item);
+        $crate::get_attr_num!($(#[$attr])* $attr_name $item $type);
+        $crate::set_attr_num!($(#[$attr])* $attr_name $item $type);
         $crate::watch_attr!($(#[$attr])* $attr_name $item);
     };
 }

rog-platform/src/power.rs

@@ -3,7 +3,7 @@ use std::path::PathBuf;
 use log::{info, warn};
 
 use crate::error::{PlatformError, Result};
-use crate::{attr_u8, to_device};
+use crate::{attr_num, to_device};
 
 /// The "platform" device provides access to things like:
 /// - `dgpu_disable`
@@ -20,9 +20,9 @@ pub struct AsusPower {
 }
 
 impl AsusPower {
-    attr_u8!("charge_control_end_threshold", battery);
+    attr_num!("charge_control_end_threshold", battery, u8);
 
-    attr_u8!("online", mains);
+    attr_num!("online", mains, u8);
 
     /// When checking for battery this will look in order:
     /// - if attr `manufacturer` contains `asus`