Add support for controlling the power LED

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "keylightd"
-version = "1.0.2"
+version = "1.1.0"
 edition = "2021"
 license = "0BSD"
 readme = "README.md"

README.md

@@ -37,13 +37,14 @@ Note that `keylightd` needs to be run as root, since it accesses the Embedded Co
 `keylightd` takes the following command-line arguments:
 
 ```
-Usage: keylightd [--brightness <brightness>] [--timeout <timeout>]
+Usage: keylightd [--brightness <brightness>] [--timeout <timeout>] [--power]
 
 keylightd - automatic keyboard backlight daemon for Framework laptops
 
 Options:
   --brightness      brightness level when active (0-100) [default=30]
   --timeout         activity timeout in seconds [default=10]
+  --power           also control the power LED in the fingerprint module
   --help            display usage information
 ```
 

src/command.rs

@@ -1,3 +1,11 @@
+//! Commands for the Embedded Controller.
+//!
+//! Reference: https://github.com/FrameworkComputer/EmbeddedController/blob/hx20-hx30/include/ec_commands.h
+//!
+//! (command IDs begin with `EC_CMD_`)
+
+#![allow(dead_code)]
+
 use bytemuck::{NoUninit, Pod, Zeroable};
 
 /// Trait implemented by Embedded Controller commands.
@@ -7,7 +15,7 @@ pub trait Command: NoUninit {
 
     /// Command version.
     ///
-    /// Some commands come in multiple versions (although none of the ones supported here).
+    /// Some commands come in multiple versions.
     const VERSION: u32 = 0;
 
     /// The associated response type.
@@ -23,6 +31,7 @@ pub enum Cmd {
     // ...
     GetKeyboardBacklight = 0x0022,
     SetKeyboardBacklight = 0x0023,
+    LedControl = 0x0029,
 }
 
 //////////////////////////////////
@@ -106,3 +115,82 @@ impl Command for SetKeyboardBacklight {
     const CMD: Cmd = Cmd::SetKeyboardBacklight;
     type Response = SetKeyboardBacklightResponse;
 }
+
+//////////////////////////////////
+// LedControl
+//////////////////////////////////
+
+#[derive(Debug, Clone, Copy, Pod, Zeroable)]
+#[repr(C)]
+pub struct LedControl {
+    pub led_id: LedId,
+    pub flags: LedFlags,
+    pub brightness: LedBrightnesses,
+}
+
+impl Command for LedControl {
+    const CMD: Cmd = Cmd::LedControl;
+    // ectool always uses version 1 for this command, version 0 does not work and returns unexpected
+    // data.
+    const VERSION: u32 = 1;
+    type Response = LedControlResponse;
+}
+
+#[derive(Debug, Clone, Copy, Pod, Zeroable)]
+#[repr(transparent)]
+pub struct LedId(u8);
+
+impl LedId {
+    pub const BATTERY: Self = Self(0);
+    pub const POWER: Self = Self(1);
+    pub const ADAPTER: Self = Self(2);
+    pub const LEFT: Self = Self(3);
+    pub const RIGHT: Self = Self(4);
+    pub const RECOVERY_HW_REINIT: Self = Self(5);
+    pub const SYSRQ_DEBUG: Self = Self(6);
+}
+
+#[derive(Debug, Default, Clone, Copy, Pod, Zeroable)]
+#[repr(transparent)]
+pub struct LedFlags(u8);
+
+impl LedFlags {
+    pub const NONE: Self = Self(0);
+    pub const QUERY: Self = Self(1 << 0);
+    pub const AUTO: Self = Self(1 << 1);
+}
+
+pub struct LedColor(u8);
+
+impl LedColor {
+    pub const RED: Self = Self(0);
+    pub const GREEN: Self = Self(1);
+    pub const BLUE: Self = Self(2);
+    pub const YELLOW: Self = Self(3);
+    pub const WHITE: Self = Self(4);
+    pub const AMBER: Self = Self(5);
+    pub const COUNT: usize = 6;
+}
+
+#[derive(Debug, Default, Clone, Copy, Pod, Zeroable)]
+#[repr(transparent)]
+pub struct LedBrightnesses {
+    raw: [u8; LedColor::COUNT],
+}
+
+impl LedBrightnesses {
+    pub fn single(color: LedColor, brightness: u8) -> Self {
+        Self::default().set(color, brightness)
+    }
+
+    pub fn set(mut self, color: LedColor, brightness: u8) -> Self {
+        self.raw[usize::from(color.0)] = brightness;
+        self
+    }
+}
+
+#[derive(Debug, Default, Clone, Copy, Pod, Zeroable)]
+#[repr(transparent)]
+pub struct LedControlResponse {
+    brightness: LedBrightnesses,
+}

src/main.rs

@@ -9,11 +9,13 @@ use argh::FromArgs;
 use command::{GetKeyboardBacklight, SetKeyboardBacklight};
 use ec::EmbeddedController;
 
+use crate::command::{LedBrightnesses, LedControl, LedFlags, LedId};
+
 mod command;
 mod ec;
 
 /// keylightd - automatic keyboard backlight daemon for Framework laptops
-#[derive(FromArgs)]
+#[derive(Debug, FromArgs)]
 struct Args {
     /// brightness level when active (0-100) [default=30]
     #[argh(option, default = "30", from_str_fn(parse_brightness))]
@@ -22,6 +24,10 @@ struct Args {
     /// activity timeout in seconds [default=10]
     #[argh(option, default = "10")]
     timeout: u32,
+
+    /// also control the power LED in the fingerprint module
+    #[argh(switch)]
+    power: bool,
 }
 
 fn parse_brightness(s: &str) -> Result<u8, String> {
@@ -34,10 +40,18 @@ fn parse_brightness(s: &str) -> Result<u8, String> {
 
 fn main() -> anyhow::Result<()> {
     env_logger::builder()
-        .filter_module(env!("CARGO_PKG_NAME"), log::LevelFilter::Info)
+        .filter_module(
+            env!("CARGO_PKG_NAME"),
+            if cfg!(debug_assertions) {
+                log::LevelFilter::Debug
+            } else {
+                log::LevelFilter::Info
+            },
+        )
         .init();
 
     let args: Args = argh::from_env();
+    log::debug!("args={:?}", args);
 
     let ec = EmbeddedController::open()?;
     let fade_to = |target: u8| -> io::Result<()> {
@@ -50,7 +64,27 @@ fn main() -> anyhow::Result<()> {
                 cur += 1;
             }
 
+            if args.power {
+                // The power LED cannot be faded from software (although the beta BIOS apparently
+                // has a switch for dimming it, so maybe it'll work with the next BIOS update).
+                // So instead, we treat 0 as off and set it back to auto for any non-zero value.
+                if cur == 0 {
+                    ec.command(LedControl {
+                        led_id: LedId::POWER,
+                        flags: LedFlags::NONE,
+                        brightness: LedBrightnesses::default(),
+                    })?;
+                } else if cur == 1 {
+                    ec.command(LedControl {
+                        led_id: LedId::POWER,
+                        flags: LedFlags::AUTO,
+                        brightness: LedBrightnesses::default(),
+                    })?;
+                }
+            }
+
             ec.command(SetKeyboardBacklight { percent: cur })?;
+
             thread::sleep(Duration::from_millis(3));
         }
         Ok(())