[PATCH v9 22/31] gpu: nova-core: Hopper/Blackwell: add FspCotVersion type

[John Hubbard <jhubbard@nvidia.com>]

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@nvidia.com>
---
 drivers/gpu/nova-core/fsp.rs | 19 +++++++++++++++++++
 drivers/gpu/nova-core/gpu.rs | 16 ++++++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/drivers/gpu/nova-core/fsp.rs b/drivers/gpu/nova-core/fsp.rs
index 931d806c3db8..db07fc227aa1 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 8332ad67c0af..ab378c0297c7 100644
--- a/drivers/gpu/nova-core/gpu.rs
+++ b/drivers/gpu/nova-core/gpu.rs
@@ -21,6 +21,7 @@
         Falcon, //
     },
     fb::SysmemFlush,
+    fsp::FspCotVersion,
     gsp::Gsp,
     regs,
 };
@@ -132,6 +133,21 @@ pub(crate) const fn arch(self) -> Architecture {
     pub(crate) const fn needs_fwsec_bootloader(self) -> bool {
         matches!(self.arch(), Architecture::Turing) || matches!(self, Self::GA100)
     }
+
+    /// 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::BlackwellGB10x | Architecture::BlackwellGB20x => {
+                Some(FspCotVersion::new(2))
+            }
+            _ => None,
+        }
+    }
 }
 
 // TODO
-- 
2.53.0