rust: sample: misc: implement device driver sample
In order to demonstrate and test a MiscDeviceRegistration with a parent
device, introduce CONFIG_SAMPLE_RUST_MISC_DEVICE_WITH_PARENT.
If CONFIG_SAMPLE_RUST_MISC_DEVICE_WITH_PARENT=y the misc device sample
is initialized with a parent device (faux), otherwise it is initialized
without a parent device, i.e. the exact same way as without this patch.
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
diff --git a/samples/rust/Kconfig b/samples/rust/Kconfig
index b1006ab..9948ec0 100644
--- a/samples/rust/Kconfig
+++ b/samples/rust/Kconfig
@@ -30,6 +30,14 @@
If unsure, say N.
+config SAMPLE_RUST_MISC_DEVICE_WITH_PARENT
+ bool "Create a misc device with a parent device"
+ depends on SAMPLE_RUST_MISC_DEVICE
+ default n
+ help
+ Say Y here if you want the misc device sample to create a misc
+ device with a parent device.
+
config SAMPLE_RUST_PRINT
tristate "Printing macros"
help
diff --git a/samples/rust/rust_misc_device.rs b/samples/rust/rust_misc_device.rs
index 9bf1a0f..175638d 100644
--- a/samples/rust/rust_misc_device.rs
+++ b/samples/rust/rust_misc_device.rs
@@ -167,6 +167,9 @@
uaccess::{UserSlice, UserSliceReader, UserSliceWriter},
};
+#[cfg(CONFIG_SAMPLE_RUST_MISC_DEVICE_WITH_PARENT)]
+use kernel::faux;
+
const RUST_MISC_DEV_HELLO: u32 = _IO('|' as u32, 0x80);
const RUST_MISC_DEV_GET_VALUE: u32 = _IOR::<i32>('|' as u32, 0x81);
const RUST_MISC_DEV_SET_VALUE: u32 = _IOW::<i32>('|' as u32, 0x82);
@@ -181,19 +184,33 @@
license: "GPL",
}
+#[cfg(not(CONFIG_SAMPLE_RUST_MISC_DEVICE_WITH_PARENT))]
#[pin_data]
struct RustMiscDeviceModule {
#[pin]
_miscdev: MiscDeviceRegistration<RustMiscDevice>,
}
-impl kernel::InPlaceModule for RustMiscDeviceModule {
- fn init(_module: &'static ThisModule) -> impl PinInit<Self, Error> {
+#[cfg(CONFIG_SAMPLE_RUST_MISC_DEVICE_WITH_PARENT)]
+struct RustMiscDeviceModule {
+ _faux: faux::Registration,
+ _miscdev: Pin<KBox<MiscDeviceRegistration<RustMiscDevice>>>,
+}
+
+impl RustMiscDeviceModule {
+ fn init() -> MiscDeviceOptions {
pr_info!("Initializing Rust Misc Device Sample\n");
- let options = MiscDeviceOptions {
+ MiscDeviceOptions {
name: c_str!("rust-misc-device"),
- };
+ }
+ }
+}
+
+#[cfg(not(CONFIG_SAMPLE_RUST_MISC_DEVICE_WITH_PARENT))]
+impl kernel::InPlaceModule for RustMiscDeviceModule {
+ fn init(_module: &'static ThisModule) -> impl PinInit<Self, Error> {
+ let options = Self::init();
try_pin_init!(Self {
_miscdev <- MiscDeviceRegistration::register(
@@ -205,6 +222,31 @@ fn init(_module: &'static ThisModule) -> impl PinInit<Self, Error> {
}
}
+#[cfg(CONFIG_SAMPLE_RUST_MISC_DEVICE_WITH_PARENT)]
+impl kernel::Module for RustMiscDeviceModule {
+ fn init(_module: &'static ThisModule) -> Result<Self> {
+ let options = Self::init();
+ let faux = faux::Registration::new(c_str!("rust-misc-device-sample"), None)?;
+
+ // For every other bus, this would be called from Driver::probe(), which would return a
+ // `Result<Pin<KBox<T>>>`, but faux always binds to a "dummy" driver, hence probe() is
+ // not required.
+ let misc = KBox::pin_init(
+ MiscDeviceRegistration::register(
+ options,
+ Arc::pin_init(new_mutex!(Inner { value: 0_i32 }), GFP_KERNEL),
+ Some(faux.as_ref()),
+ ),
+ GFP_KERNEL,
+ )?;
+
+ Ok(Self {
+ _faux: faux,
+ _miscdev: misc,
+ })
+ }
+}
+
struct Inner {
value: i32,
}
