[PATCH POC 7/7] drm: nova: demonstrate interaction with nova-core

[Alexandre Courbot <acourbot@nvidia.com>]

Export a few items from nova-core and use them from nova-drm in order to
print the chipset of the GPU being probed.

Some documentation items are added to make Clippy happy.

This is only meant for demonstration purposes, and won't be merged.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
 drivers/gpu/drm/nova/driver.rs     |  6 ++++++
 drivers/gpu/nova-core/driver.rs    | 20 ++++++++++++++++++--
 drivers/gpu/nova-core/gpu.rs       |  9 ++++++---
 drivers/gpu/nova-core/nova_core.rs |  4 ++--
 4 files changed, 32 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/nova/driver.rs b/drivers/gpu/drm/nova/driver.rs
index b1af0a099551..e18e9fccc067 100644
--- a/drivers/gpu/drm/nova/driver.rs
+++ b/drivers/gpu/drm/nova/driver.rs
@@ -15,6 +15,8 @@
 use crate::file::File;
 use crate::gem::NovaObject;
 
+use nova_core::driver::NovaCore;
+
 pub(crate) struct NovaDriver {
     #[expect(unused)]
     drm: ARef<drm::Device<Self>>,
@@ -54,6 +56,10 @@ impl auxiliary::Driver for NovaDriver {
     const ID_TABLE: auxiliary::IdTable<Self::IdInfo> = &AUX_TABLE;
 
     fn probe(adev: &auxiliary::Device<Core>, _info: &Self::IdInfo) -> impl PinInit<Self, Error> {
+        let chipset = NovaCore::chipset(adev)?;
+
+        pr_info!("Chipset from nova-core: {}\n", chipset);
+
         let data = try_pin_init!(NovaData { adev: adev.into() });
 
         let drm = drm::Device::<Self>::new(adev.as_ref(), data)?;
diff --git a/drivers/gpu/nova-core/driver.rs b/drivers/gpu/nova-core/driver.rs
index 84b0e1703150..985f65e13bd5 100644
--- a/drivers/gpu/nova-core/driver.rs
+++ b/drivers/gpu/nova-core/driver.rs
@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 
+//! Main driver module.
+
 use kernel::{
     auxiliary,
     device::Core,
@@ -23,13 +25,17 @@
     },
 };
 
-use crate::gpu::Gpu;
+use crate::gpu::{
+    self,
+    Gpu, //
+};
 
 /// Counter for generating unique auxiliary device IDs.
 static AUXILIARY_ID_COUNTER: Atomic<u32> = Atomic::new(0);
 
+/// Driver-associated data.
 #[pin_data]
-pub(crate) struct NovaCore {
+pub struct NovaCore {
     #[pin]
     pub(crate) gpu: Gpu,
     #[pin]
@@ -112,3 +118,13 @@ fn unbind(pdev: &pci::Device<Core>, this: Pin<&Self>) {
         this.gpu.unbind(pdev.as_ref());
     }
 }
+
+impl NovaCore {
+    /// Returns the chipset of this GPU.
+    pub fn chipset(adev: &auxiliary::Device<Core>) -> Result<gpu::Chipset> {
+        let dev = adev.parent();
+        let drvdata = dev.drvdata::<Self>()?;
+
+        Ok(drvdata.gpu.spec.chipset)
+    }
+}
diff --git a/drivers/gpu/nova-core/gpu.rs b/drivers/gpu/nova-core/gpu.rs
index 659f6a24ee13..75190ca0693b 100644
--- a/drivers/gpu/nova-core/gpu.rs
+++ b/drivers/gpu/nova-core/gpu.rs
@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 
+//! Declares some core driver types.
+
 use kernel::{
     device,
     devres::Devres,
@@ -31,7 +33,8 @@ macro_rules! define_chipset {
     {
         /// Enum representation of the GPU chipset.
         #[derive(fmt::Debug, Copy, Clone, PartialOrd, Ord, PartialEq, Eq)]
-        pub(crate) enum Chipset {
+        #[allow(missing_docs)]
+        pub enum Chipset {
             $($variant = $value),*,
         }
 
@@ -185,7 +188,7 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 /// Structure holding a basic description of the GPU: `Chipset` and `Revision`.
 #[derive(Clone, Copy)]
 pub(crate) struct Spec {
-    chipset: Chipset,
+    pub(crate) chipset: Chipset,
     revision: Revision,
 }
 
@@ -247,7 +250,7 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 /// Structure holding the resources required to operate the GPU.
 #[pin_data]
 pub(crate) struct Gpu {
-    spec: Spec,
+    pub(crate) spec: Spec,
     /// MMIO mapping of PCI BAR 0
     bar: Arc<Devres<Bar0>>,
     /// System memory page required for flushing all pending GPU-side memory writes done through
diff --git a/drivers/gpu/nova-core/nova_core.rs b/drivers/gpu/nova-core/nova_core.rs
index 3a609f6937e4..ccb98c73457b 100644
--- a/drivers/gpu/nova-core/nova_core.rs
+++ b/drivers/gpu/nova-core/nova_core.rs
@@ -13,11 +13,11 @@
 #[macro_use]
 mod bitfield;
 
-mod driver;
+pub mod driver;
 mod falcon;
 mod fb;
 mod firmware;
-mod gpu;
+pub mod gpu;
 mod gsp;
 #[macro_use]
 mod num;

-- 
2.54.0