[PATCH v6 8/9] sample: rust: pci: use `register!` macro

[Alexandre Courbot]

Convert the direct IO accesses to properly defined registers.

Signed-off-by: Alexandre Courbot <acourbot@xxxxxxxxxx>
---
 samples/rust/rust_driver_pci.rs | 84 +++++++++++++++++++++++++++++++----------
 1 file changed, 64 insertions(+), 20 deletions(-)

diff --git a/samples/rust/rust_driver_pci.rs b/samples/rust/rust_driver_pci.rs
index d3d4a7931deb..f2e1904507f1 100644
--- a/samples/rust/rust_driver_pci.rs
+++ b/samples/rust/rust_driver_pci.rs
@@ -8,27 +8,58 @@
     device::Bound,
     device::Core,
     devres::Devres,
-    io::Io,
+    io::{
+        Io,
+        IoRef, //
+    },
+    num::Bounded,
     pci,
     prelude::*,
+    register,
     sync::aref::ARef, //
 };
 
-struct Regs;
+mod regs {
+    use super::*;
 
-impl Regs {
-    const TEST: usize = 0x0;
-    const OFFSET: usize = 0x4;
-    const DATA: usize = 0x8;
-    const COUNT: usize = 0xC;
-    const END: usize = 0x10;
+    register! {
+        pub(super) TEST(u8) @ 0x0 {
+            7:0 index => TestIndex;
+        }
+
+        pub(super) OFFSET(u32) @ 0x4 {
+            31:0 offset;
+        }
+
+        pub(super) DATA(u8) @ 0x8 {
+            7:0 data;
+        }
+
+        pub(super) COUNT(u32) @ 0xC {
+            31:0 count;
+        }
+    }
+
+    pub(super) const END: usize = 0x10;
 }
 
-type Bar0 = pci::Bar<{ Regs::END }>;
+type Bar0 = pci::Bar<{ regs::END }>;
 
 #[derive(Copy, Clone, Debug)]
 struct TestIndex(u8);
 
+impl From<Bounded<u8, 8>> for TestIndex {
+    fn from(value: Bounded<u8, 8>) -> Self {
+        Self(value.into())
+    }
+}
+
+impl From<TestIndex> for Bounded<u8, 8> {
+    fn from(value: TestIndex) -> Self {
+        value.0.into()
+    }
+}
+
 impl TestIndex {
     const NO_EVENTFD: Self = Self(0);
 }
@@ -54,40 +85,53 @@ struct SampleDriver {
 impl SampleDriver {
     fn testdev(index: &TestIndex, bar: &Bar0) -> Result<u32> {
         // Select the test.
-        bar.write8(index.0, Regs::TEST);
+        bar.write(regs::TEST.init(|r| r.with_index(*index)));
 
-        let offset = bar.read32(Regs::OFFSET) as usize;
-        let data = bar.read8(Regs::DATA);
+        let offset = bar.read(regs::OFFSET).into_raw() as usize;
+        let data = bar.read(regs::DATA).into();
 
         // Write `data` to `offset` to increase `count` by one.
         //
         // Note that we need `try_write8`, since `offset` can't be checked at compile-time.
         bar.try_write8(data, offset)?;
 
-        Ok(bar.read32(Regs::COUNT))
+        Ok(bar.read(regs::COUNT).into())
     }
 
     fn config_space(pdev: &pci::Device<Bound>) {
         let config = pdev.config_space();
 
-        // TODO: use the register!() macro for defining PCI configuration space registers once it
-        // has been move out of nova-core.
+        // Some PCI configuration space registers.
+        register! {
+            VENDOR_ID(u16) @ 0x0 {
+                15:0 vendor_id;
+            }
+
+            REVISION_ID(u8) @ 0x8 {
+                7:0 revision_id;
+            }
+
+            BAR(u32)[6] @ 0x10 {
+                31:0 value;
+            }
+        }
+
         dev_info!(
             pdev,
             "pci-testdev config space read8 rev ID: {:x}\n",
-            config.read8(0x8)
+            config.read(REVISION_ID).revision_id()
         );
 
         dev_info!(
             pdev,
             "pci-testdev config space read16 vendor ID: {:x}\n",
-            config.read16(0)
+            config.read(VENDOR_ID).vendor_id()
         );
 
         dev_info!(
             pdev,
             "pci-testdev config space read32 BAR 0: {:x}\n",
-            config.read32(0x10)
+            config.read(BAR::at(0)).value()
         );
     }
 }
@@ -111,7 +155,7 @@ fn probe(pdev: &pci::Device<Core>, info: &Self::IdInfo) -> impl PinInit<Self, Er
             pdev.set_master();
 
             Ok(try_pin_init!(Self {
-                bar <- pdev.iomap_region_sized::<{ Regs::END }>(0, c"rust_driver_pci"),
+                bar <- pdev.iomap_region_sized::<{ regs::END }>(0, c"rust_driver_pci"),
                 index: *info,
                 _: {
                     let bar = bar.access(pdev.as_ref())?;
@@ -131,7 +175,7 @@ fn probe(pdev: &pci::Device<Core>, info: &Self::IdInfo) -> impl PinInit<Self, Er
     fn unbind(pdev: &pci::Device<Core>, this: Pin<&Self>) {
         if let Ok(bar) = this.bar.access(pdev.as_ref()) {
             // Reset pci-testdev by writing a new test index.
-            bar.write8(this.index.0, Regs::TEST);
+            bar.write(regs::TEST.init(|r| r.with_index(this.index)));
         }
     }
 }

-- 
2.53.0