[PATCH v5 28/38] gpu: nova-core: Hopper/Blackwell: add FspCotVersion type

[John Hubbard]

Add FspCotVersion to represent the FSP Chain of Trust protocol version,
and Chipset::fsp_cot_version() which returns the version for each
architecture. Hopper uses version 1, Blackwell uses version 2.
Non-FSP architectures return None.

Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx>
---
 drivers/gpu/nova-core/fsp.rs | 19 +++++++++++++++++++
 drivers/gpu/nova-core/gpu.rs | 14 ++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/drivers/gpu/nova-core/fsp.rs b/drivers/gpu/nova-core/fsp.rs
index 20c439fc7f7b..8926dd814a83 100644
--- a/drivers/gpu/nova-core/fsp.rs
+++ b/drivers/gpu/nova-core/fsp.rs
@@ -25,6 +25,25 @@
     NvdmType, //
 };
 
+/// FSP Chain of Trust protocol version.
+///
+/// Hopper (GH100) uses version 1, Blackwell uses version 2.
+#[derive(Debug, Clone, Copy)]
+pub(crate) struct FspCotVersion(u16);
+
+impl FspCotVersion {
+    /// Create a new FSP COT version.
+    pub(crate) const fn new(version: u16) -> Self {
+        Self(version)
+    }
+
+    /// Return the raw protocol version number for the wire format.
+    #[expect(dead_code)]
+    pub(crate) const fn raw(self) -> u16 {
+        self.0
+    }
+}
+
 /// FSP message timeout in milliseconds.
 const FSP_MSG_TIMEOUT_MS: i64 = 2000;
 
diff --git a/drivers/gpu/nova-core/gpu.rs b/drivers/gpu/nova-core/gpu.rs
index 50bf351b64cc..fc34c97a61fc 100644
--- a/drivers/gpu/nova-core/gpu.rs
+++ b/drivers/gpu/nova-core/gpu.rs
@@ -21,6 +21,7 @@
         Falcon, //
     },
     fb::SysmemFlush,
+    fsp::FspCotVersion,
     gfw,
     gsp::Gsp,
     regs,
@@ -127,6 +128,19 @@ pub(crate) const fn arch(&self) -> Architecture {
             | Self::GB207 => Architecture::Blackwell,
         }
     }
+
+    /// Returns the FSP Chain of Trust (COT) protocol version for this chipset.
+    ///
+    /// Hopper (GH100) uses version 1, Blackwell uses version 2.
+    /// Returns `None` for architectures that do not use FSP.
+    #[expect(dead_code)]
+    pub(crate) const fn fsp_cot_version(&self) -> Option<FspCotVersion> {
+        match self.arch() {
+            Architecture::Hopper => Some(FspCotVersion::new(1)),
+            Architecture::Blackwell => Some(FspCotVersion::new(2)),
+            _ => None,
+        }
+    }
 }
 
 // TODO
-- 
2.53.0