rust: driver: decouple driver private data from driver type

Add a type Data<'bound> associated type to all bus driver traits,
decoupling the driver's bus device private data type from the driver
struct itself.

In the context of adding a 'bound lifetime, making this an associated
type has the advantage that it allows us to avoid a driver trait global
lifetime and it avoids the need for ForLt for bus device private data;
both of which make the subsequent implementation by buses much simpler.

All existing drivers and doc examples set type Data = Self to preserve
the current behavior.

Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/20260525202921.124698-5-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

samples/rust/rust_debugfs.rs

@@ -117,6 +117,7 @@ fn from_str(s: &str) -> Result<Self> {
 
 impl platform::Driver for RustDebugFs {
     type IdInfo = ();
+    type Data = Self;
     const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = None;
     const ACPI_ID_TABLE: Option<acpi::IdTable<Self::IdInfo>> = Some(&ACPI_TABLE);
 

samples/rust/rust_dma.rs

@@ -58,6 +58,7 @@ unsafe impl kernel::transmute::FromBytes for MyStruct {}
 
 impl pci::Driver for DmaSampleDriver {
     type IdInfo = ();
+    type Data = Self;
     const ID_TABLE: pci::IdTable<Self::IdInfo> = &PCI_TABLE;
 
     fn probe(pdev: &pci::Device<Core>, _info: &Self::IdInfo) -> impl PinInit<Self, Error> {

samples/rust/rust_driver_auxiliary.rs

@@ -31,6 +31,7 @@
 
 impl auxiliary::Driver for AuxiliaryDriver {
     type IdInfo = ();
+    type Data = Self;
 
     const ID_TABLE: auxiliary::IdTable<Self::IdInfo> = &AUX_TABLE;
 
@@ -65,6 +66,7 @@ struct ParentDriver {
 
 impl pci::Driver for ParentDriver {
     type IdInfo = ();
+    type Data = Self;
 
     const ID_TABLE: pci::IdTable<Self::IdInfo> = &PCI_TABLE;
 

samples/rust/rust_driver_i2c.rs

@@ -35,6 +35,7 @@
 
 impl i2c::Driver for SampleDriver {
     type IdInfo = u32;
+    type Data = Self;
 
     const ACPI_ID_TABLE: Option<acpi::IdTable<Self::IdInfo>> = Some(&ACPI_TABLE);
     const I2C_ID_TABLE: Option<i2c::IdTable<Self::IdInfo>> = Some(&I2C_TABLE);

samples/rust/rust_driver_pci.rs

@@ -140,6 +140,7 @@ fn config_space(pdev: &pci::Device<Bound>) {
 
 impl pci::Driver for SampleDriver {
     type IdInfo = TestIndex;
+    type Data = Self;
 
     const ID_TABLE: pci::IdTable<Self::IdInfo> = &PCI_TABLE;
 

samples/rust/rust_driver_platform.rs

@@ -101,6 +101,7 @@ struct SampleDriver {
 
 impl platform::Driver for SampleDriver {
     type IdInfo = Info;
+    type Data = Self;
     const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = Some(&OF_TABLE);
     const ACPI_ID_TABLE: Option<acpi::IdTable<Self::IdInfo>> = Some(&ACPI_TABLE);
 

samples/rust/rust_driver_usb.rs

@@ -26,6 +26,7 @@ struct SampleDriver {
 
 impl usb::Driver for SampleDriver {
     type IdInfo = ();
+    type Data = Self;
     const ID_TABLE: usb::IdTable<Self::IdInfo> = &USB_TABLE;
 
     fn probe(

samples/rust/rust_i2c_client.rs

@@ -106,6 +106,7 @@ struct SampleDriver {
 
 impl platform::Driver for SampleDriver {
     type IdInfo = ();
+    type Data = Self;
     const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = Some(&OF_TABLE);
     const ACPI_ID_TABLE: Option<acpi::IdTable<Self::IdInfo>> = Some(&ACPI_TABLE);
 

samples/rust/rust_soc.rs

@@ -37,6 +37,7 @@ struct SampleSocDriver {
 
 impl platform::Driver for SampleSocDriver {
     type IdInfo = ();
+    type Data = Self;
     const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = Some(&OF_TABLE);
     const ACPI_ID_TABLE: Option<acpi::IdTable<Self::IdInfo>> = Some(&ACPI_TABLE);