samples: rust: add i2c client driver sample

Add a basic sample for using the I2C client driver.

Signed-off-by: Fabien Parent <[email protected]>

Author: Fabo

samples/rust/Kconfig

@@ -30,6 +30,16 @@ config SAMPLE_RUST_PRINT
 
 	  If unsure, say N.
 
+config SAMPLE_RUST_I2C_CLIENT
+	tristate "I2C client device driver"
+	help
+	  This option builds the Rust I2C client driver sample.
+
+	  To compile this as a module, choose M here:
+	  the module will be called rust_i2c_client.
+
+	  If unsure, say N.
+
 config SAMPLE_RUST_HOSTPROGS
 	bool "Host programs"
 	help

samples/rust/Makefile

@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 
+obj-$(CONFIG_SAMPLE_RUST_I2C_CLIENT)		+= rust_i2c_client.o
 obj-$(CONFIG_SAMPLE_RUST_MINIMAL)		+= rust_minimal.o
 obj-$(CONFIG_SAMPLE_RUST_PRINT)			+= rust_print.o
 

samples/rust/rust_i2c_client.rs

@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Rust I2C client sample.
+
+use kernel::{i2c, of, prelude::*};
+
+kernel::module_i2c_driver! {
+    type: Driver,
+    name: "rust_i2c_client",
+    license: "GPL",
+}
+
+kernel::module_i2c_id_table!(I2C_MOD_TABLE, I2C_CLIENT_I2C_ID_TABLE);
+kernel::define_i2c_id_table! {I2C_CLIENT_I2C_ID_TABLE, (), [
+    (i2c::DeviceId(b"rust-sample-i2c"), None),
+]}
+
+kernel::module_of_id_table!(OF_MOD_TABLE, I2C_CLIENT_OF_ID_TABLE);
+kernel::define_of_id_table! {I2C_CLIENT_OF_ID_TABLE, (), [
+    (of::DeviceId::Compatible(b"rust,rust-sample-i2c"), None),
+]}
+
+struct Driver;
+impl i2c::Driver for Driver {
+    kernel::driver_i2c_id_table!(I2C_CLIENT_I2C_ID_TABLE);
+    kernel::driver_of_id_table!(I2C_CLIENT_OF_ID_TABLE);
+
+    fn probe(_client: &mut i2c::Client) -> Result {
+        Ok(())
+    }
+}