Implement GetAlsIntegrationTimeFileDescriptor.

And this attempt works now. I guess this is adequate to release
as a throw away implementation to replace later with something better.
Also add strip="symbols" for release builds to get it down to a lean
3.2M size.

Cargo.lock

@@ -296,12 +296,6 @@ dependencies = [
  "crypto-common",
 ]
 
-[[package]]
-name = "dyn"
-version = "0.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dd5d33be9d461be19ff7168302689ed4ca466300600546c93795e845d5fa3faf"
-
 [[package]]
 name = "enumflags2"
 version = "0.7.8"
@@ -778,18 +772,18 @@ dependencies = [
 
 [[package]]
 name = "serde"
-version = "1.0.188"
+version = "1.0.192"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cf9e0fcba69a370eed61bcf2b728575f726b50b55cba78064753d708ddc7549e"
+checksum = "bca2a08484b285dcb282d0f67b26cadc0df8b19f8c12502c13d966bf9482f001"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.188"
+version = "1.0.192"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4eca7ac642d82aa35b60049a6eccb4be6be75e599bd2e9adb5f875a737654af2"
+checksum = "d6c7207fbec9faa48073f3e3074cbe553af6ea512d7c21ba46e434e70ea9fbc1"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -798,9 +792,9 @@ dependencies = [
 
 [[package]]
 name = "serde_repr"
-version = "0.1.16"
+version = "0.1.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8725e1dfadb3a50f7e5ce0b1a540466f6ed3fe7a0fca2ac2b8b831d31316bd00"
+checksum = "3081f5ffbb02284dda55132aa26daecedd7372a42417bbbab6f14ab7d6bb9145"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -876,8 +870,6 @@ checksum = "a2eb9349b6444b326872e140eb1cf5e7c522154d69e7a0ffb0fb81c06b37543f"
 name = "steamos-manager"
 version = "0.9.0"
 dependencies = [
- "dyn",
- "serde",
  "tokio",
  "zbus",
  "zbus_macros",

Cargo.toml

@@ -5,9 +5,10 @@ edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
+[profile.release]
+strip="symbols"
+
 [dependencies]
-dyn = "0.0.0"
-serde = { version = "1.0.188", features = ["derive"] }
 tokio = { version = "1.33.0", features = ["fs", "process", "io-std", "rt-multi-thread", "macros"] }
 zbus = { version = "3.14.1", features = ["tokio"] }
 zbus_macros = "3.14.1"

com.steampowered.SteamOSManager1.xml

@@ -172,15 +172,14 @@
     </method>
 
     <!--
-      SetALSIntegrationTime:
-      @seconds: The number of seconds to use for ALS integration.
-      @success: True on success. False otherwise.
+      GetAlsIntegrationTimeFileDescriptor:
+      @descriptor: A unix file descriptor that can be written to to set ALS integration time.
+      Will be null if unable to open file or other error occurred.
 
-      Set the ALS integration time to the given value.
+      Get the ALS integration time file descriptor.
     -->
-    <method name="SetALSIntegrationTime">
-      <arg type="i" name="seconds" direction="in"/>
-      <arg type="b" name="success" direction="out"/>
+    <method name="GetAlsIntegrationTimeFileDescriptor">
+      <arg type="h" name="descriptor" direction="out"/>
     </method>
 
   </interface>

src/manager.rs

@@ -23,8 +23,9 @@
  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
-use std::{ffi::OsStr};
+use std::{ffi::OsStr, os::fd::{FromRawFd, IntoRawFd}};
 use tokio::{process::Command, fs::File, io::AsyncWriteExt};
+use zbus::zvariant::OwnedFd;
 use zbus_macros::dbus_interface;
 pub struct SMManager {
 }
@@ -237,6 +238,23 @@ impl SMManager {
         }
     }
 
+    async fn get_als_integration_time_file_descriptor(&self) -> Result<zbus::zvariant::OwnedFd, zbus::fdo::Error> {
+        // Get the file descriptor for the als integration time sysfs path
+        // /sys/devices/platform/AMDI0010:00/i2c-0/i2c-PRP0001:01/iio:device0/in_illuminance_integration_time
+        // Return -1 on error
+        let result = File::create("/sys/devices/platform/AMDI0010:00/i2c-0/i2c-PRP0001:01/iio:device0/in_illuminance_integration_time").await;
+        match result {
+            Ok(f) => {
+                let raw = f.into_std().await.into_raw_fd();
+                unsafe {
+                    let fd: OwnedFd = OwnedFd::from_raw_fd(raw);
+                    Ok(fd)
+                }
+            },
+            Err(message) => { println!("Error opening sysfs file for giving file descriptor {message}"); Err(zbus::fdo::Error::IOError(message.to_string())) }
+        }
+    }
+
     /// A version property.
     #[dbus_interface(property)]
     async fn version(&self) -> u32 {