On Wed, Mar 26, 2025 at 06:13:49PM +0100, Remo Senekowitsch wrote:
> --- a/samples/rust/rust_driver_platform.rs
> +++ b/samples/rust/rust_driver_platform.rs
> @@ -2,7 +2,7 @@
>
> //! Rust Platform driver sample.
>
> -use kernel::{c_str, of, platform, prelude::*};
> +use kernel::{c_str, of, platform, prelude::*, str::CString};
>
> struct SampleDriver {
> pdev: platform::Device,
> @@ -28,6 +28,60 @@ fn probe(pdev: &mut platform::Device, info: Option<&Self::IdInfo>) -> Result<Pin
> dev_info!(pdev.as_ref(), "Probed with info: '{}'.\n", info.0);
> }
>
> + let dev = pdev.as_ref();
> + if let Ok(idx) = dev.property_match_string(c_str!("compatible"), c_str!("test,rust-device"))
> + {
> + dev_info!(pdev.as_ref(), "matched compatible string idx = {}\n", idx);
> + }
> +
> + if let Ok(str) = dev
> + .property_read::<CString>(c_str!("compatible"))
> + .required()
> + {
> + dev_info!(pdev.as_ref(), "compatible string = {:?}\n", str);
> + }
> +
> + let prop = dev
> + .property_read::<bool>(c_str!("test,bool-prop"))
> + .required()?;
> + dev_info!(dev, "bool prop is {}\n", prop);
> +
> + if dev.property_present(c_str!("test,u32-prop")) {
> + dev_info!(dev, "'test,u32-prop' is present\n");
> + }
> +
> + let prop = dev
> + .property_read::<u32>(c_str!("test,u32-optional-prop"))
> + .or(0x12);
> + dev_info!(
> + dev,
> + "'test,u32-optional-prop' is {:#x} (default = {:#x})\n",
> + prop,
> + 0x12
> + );
Printing the default value looks more like a test, rather than a sample.
> +
> + // Missing property without a default will print an error
> + let _ = dev
> + .property_read::<u32>(c_str!("test,u32-required-prop"))
> + .required()?;
> +
> + let prop: u32 = dev.property_read(c_str!("test,u32-prop")).required()?;
> + dev_info!(dev, "'test,u32-prop' is {:#x}\n", prop);
> +
> + let prop: [i16; 4] = dev.property_read(c_str!("test,i16-array")).required()?;
> + dev_info!(dev, "'test,i16-array' is {:?}\n", prop);
> + dev_info!(
> + dev,
> + "'test,i16-array' length is {}\n",
> + dev.property_count_elem::<u16>(c_str!("test,i16-array"))
> + .unwrap()
Please no unwrap() in the kernel, it may panic.
> + );
> +
> + let prop: KVec<i16> = dev
> + .property_read_array_vec(c_str!("test,i16-array"), 4)?
> + .required()?;
> + dev_info!(dev, "'test,i16-array' is KVec {:?}\n", prop);
> +
Please move this code to a new function, e.g.
impl SampleDriver {
fn properties_parse(dev: &device::Device)) -> Result;
}
in order to keep probe() as clean as possible. If we put too much stuff in
there, it might become too confusing to serve as a simple example showing how to
implement a platform driver in Rust.
Besides that, are we sure we really want to print everything?
