gpu: nova-core: register auxiliary device for nova-drm

Register an auxiliary device for nova-drm.

For now always use zero for the auxiliary device's ID; we don't use it
yet anyways. However, once it lands, we should switch to XArray.

Acked-by: Dave Airlie <airlied@redhat.com>
Link: https://lore.kernel.org/r/20250424160452.8070-2-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

Author: Danilo Krummrich

drivers/gpu/nova-core/Kconfig

@@ -1,5 +1,6 @@
 config NOVA_CORE
 	tristate "Nova Core GPU driver"
+	depends on AUXILIARY_BUS
 	depends on PCI
 	depends on RUST
 	depends on RUST_FW_LOADER_ABSTRACTIONS

drivers/gpu/nova-core/driver.rs

@@ -1,13 +1,14 @@
 // SPDX-License-Identifier: GPL-2.0
 
-use kernel::{bindings, c_str, device::Core, pci, prelude::*};
+use kernel::{auxiliary, bindings, c_str, device::Core, pci, prelude::*};
 
 use crate::gpu::Gpu;
 
 #[pin_data]
 pub(crate) struct NovaCore {
     #[pin]
     pub(crate) gpu: Gpu,
+    _reg: auxiliary::Registration,
 }
 
 const BAR0_SIZE: usize = 8;
@@ -38,6 +39,12 @@ impl pci::Driver for NovaCore {
         let this = KBox::pin_init(
             try_pin_init!(Self {
                 gpu <- Gpu::new(pdev, bar)?,
+                _reg: auxiliary::Registration::new(
+                    pdev.as_ref(),
+                    c_str!("nova-drm"),
+                    0, // TODO: Once it lands, use XArray; for now we don't use the ID.
+                    crate::MODULE_NAME
+                )?,
             }),
             GFP_KERNEL,
         )?;

drivers/gpu/nova-core/nova_core.rs

@@ -8,6 +8,8 @@ mod gpu;
 mod regs;
 mod util;
 
+pub(crate) const MODULE_NAME: &kernel::str::CStr = <LocalModule as kernel::ModuleMetadata>::NAME;
+
 kernel::module_pci_driver! {
     type: driver::NovaCore,
     name: "NovaCore",