riscv: define mvendorid CSR with macro helpers

Uses CSR macro helpers to define the `mvendorid` CSR register.

Author: rmsyn

riscv/CHANGELOG.md

@@ -28,6 +28,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Use CSR helper macros to define `mstatus` register
 - Use CSR helper macros to define `mstatush` register
 - Use CSR helper macros to define `mtvec` register
+- Use CSR helper macros to define `mtvendorid` register
 
 ## [v0.12.1] - 2024-10-20
 

riscv/src/register/mvendorid.rs

@@ -1,34 +1,30 @@
 //! mvendorid register
 
-use core::num::NonZeroUsize;
-
-/// mvendorid register
-#[derive(Clone, Copy, Debug)]
-pub struct Mvendorid {
-    bits: NonZeroUsize,
+read_only_csr! {
+    /// `mvendorid` register
+    Mvendorid: 0xF11,
+    mask: 0xffff_ffff,
+    sentinel: 0,
 }
 
-impl Mvendorid {
-    /// Returns the contents of the register as raw bits
-    #[inline]
-    pub fn bits(&self) -> usize {
-        self.bits.get()
-    }
-
-    /// Returns the JEDEC manufacturer ID
-    #[inline]
-    pub fn jedec_manufacturer(&self) -> usize {
-        self.bits() >> 7
-    }
+read_only_csr_field! {
+    Mvendorid,
+    /// Represents the number of continuation bytes (`0x7f`) in the JEDEC manufacturer ID.
+    bank: [7:31],
 }
 
-read_csr!(0xF11);
+read_only_csr_field! {
+    Mvendorid,
+    /// Represents the final offset field in the JEDEC manufacturer ID.
+    offset: [0:6],
+}
 
-/// Reads the CSR
-#[inline]
-pub fn read() -> Option<Mvendorid> {
-    let r = unsafe { _read() };
-    // When mvendorid is hardwired to zero it means that the mvendorid
-    // csr isn't implemented.
-    NonZeroUsize::new(r).map(|bits| Mvendorid { bits })
+impl Mvendorid {
+    /// Gets the JEDEC manufacturer ID decoded into parts:
+    ///
+    /// - `bank`: the number of continuation bytes (`0x7f`)
+    /// - `offset`: specific offset in the JEDEC bank number
+    pub fn jedec_manufacturer(&self) -> (usize, usize) {
+        (self.bank() as usize, (0x80 | self.offset()) as usize)
+    }
 }