chore: rewrite field accessors of the Registers with macros (#111)

* chore: rewrite `src/register/capability.rs` with macros

* chore: rewrite `operational.rs` with macros

* chore: rewrite methods with macros

* chore: return a mutable reference to `Self`

* refactor: rewrite `doorbell.rs` with macros

* chore: rewrite `runtime.rs` with macros

Author: toku-sa-n

src/macros.rs

@@ -105,3 +105,46 @@ macro_rules! rw1s_bit {
         w1s_bit!($bit, $method, $name);
     };
 }
+
+macro_rules! field_getter {
+    ($range:expr,$method:ident,$name:literal,$ty:ty) => {
+        #[doc = "Returns the value of the"]
+        #[doc = $name]
+        #[doc = "field."]
+        #[must_use]
+        pub fn $method(self) -> $ty {
+            use bit_field::BitField;
+            use core::convert::TryInto;
+            self.0.get_bits($range).try_into().unwrap()
+        }
+    };
+}
+
+macro_rules! field_setter {
+    ($range:expr,$method:ident,$name:literal,$ty:ty) => {
+        paste::paste! {
+            #[doc = "Sets the value of the"]
+            #[doc = $name]
+            #[doc = "field."]
+            pub fn [<set_ $method>](&mut self,value:$ty) -> &mut Self {
+                use bit_field::BitField;
+                use core::convert::TryInto;
+                self.0.set_bits($range,value.try_into().unwrap());
+                self
+            }
+        }
+    };
+}
+
+macro_rules! ro_field {
+    ($range:expr,$method:ident,$name:literal,$ty:ty) => {
+        field_getter!($range, $method, $name, $ty);
+    };
+}
+
+macro_rules! rw_field {
+    ($range:expr,$method:ident,$name:literal,$ty:ty) => {
+        field_getter!($range, $method, $name, $ty);
+        field_setter!($range, $method, $name, $ty);
+    };
+}

src/registers/capability.rs

@@ -2,7 +2,6 @@
 
 use accessor::Mapper;
 use bit_field::BitField;
-use core::convert::TryInto;
 
 /// Host Controller Capability Registers
 #[derive(Debug)]
@@ -105,23 +104,9 @@ impl InterfaceVersionNumber {
 #[derive(Copy, Clone)]
 pub struct StructuralParameters1(u32);
 impl StructuralParameters1 {
-    /// Returns the number of available device slots.
-    #[must_use]
-    pub fn number_of_device_slots(self) -> u8 {
-        self.0.get_bits(0..=7).try_into().unwrap()
-    }
-
-    /// Returns the number of interrupts implemented on HC.
-    #[must_use]
-    pub fn number_of_interrupts(self) -> u16 {
-        self.0.get_bits(8..=18).try_into().unwrap()
-    }
-
-    /// Returns the number of ports.
-    #[must_use]
-    pub fn number_of_ports(self) -> u8 {
-        self.0.get_bits(24..=31).try_into().unwrap()
-    }
+    ro_field!(0..=7, number_of_device_slots, "Number of Device Slots", u8);
+    ro_field!(8..=18, number_of_interrupts, "Number of Interrupts", u16);
+    ro_field!(24..=31, number_of_ports, "Number of Ports", u8);
 }
 impl_debug_from_methods! {
     StructuralParameters1{
@@ -136,11 +121,12 @@ impl_debug_from_methods! {
 #[derive(Copy, Clone)]
 pub struct StructuralParameters2(u32);
 impl StructuralParameters2 {
-    /// Returns the value of the Isochronous Scheduling Threshold field.
-    #[must_use]
-    pub fn isochronous_scheduling_threshold(self) -> u8 {
-        self.0.get_bits(0..=3).try_into().unwrap()
-    }
+    ro_field!(
+        0..=3,
+        isochronous_scheduling_threshold,
+        "Isochronous Scheduling Threshold",
+        u8
+    );
 
     /// Returns the maximum number of the elements the Event Ring Segment Table can contain.
     ///
@@ -188,17 +174,13 @@ impl_debug_from_methods! {
 #[derive(Copy, Clone)]
 pub struct StructuralParameters3(u32);
 impl StructuralParameters3 {
-    /// Returns the value of the U1 Device Exit Latency field.
-    #[must_use]
-    pub fn u1_device_exit_latency(self) -> u8 {
-        self.0.get_bits(0..=7).try_into().unwrap()
-    }
-
-    /// Returns the value of the U2 Device Exit Latency field.
-    #[must_use]
-    pub fn u2_device_exit_latency(self) -> u16 {
-        self.0.get_bits(16..=31).try_into().unwrap()
-    }
+    ro_field!(0..=7, u1_device_exit_latency, "U1 Device Exit Latency", u8);
+    ro_field!(
+        16..=31,
+        u2_device_exit_latency,
+        "U2 Device Exit Latency",
+        u16
+    );
 }
 impl_debug_from_methods! {
     StructuralParameters3{
@@ -237,20 +219,18 @@ impl CapabilityParameters1 {
         contiguous_frame_id_capability,
         "Contiguous Frame ID Capability"
     );
-
-    /// Returns the value of the Maximum Primary Stream Array Size field.
-    #[must_use]
-    pub fn maximum_primary_stream_array_size(self) -> u8 {
-        self.0.get_bits(12..=15).try_into().unwrap()
-    }
-
-    /// Returns the offset of the xHCI extended capability list from the MMIO base. If this value is
-    /// zero, the list does not exist.
-    /// The base address can be calculated by `(MMIO base) + (xECP) << 2`
-    #[must_use]
-    pub fn xhci_extended_capabilities_pointer(self) -> u16 {
-        self.0.get_bits(16..=31).try_into().unwrap()
-    }
+    ro_field!(
+        12..=15,
+        maximum_primary_stream_array_size,
+        "Maximum Primary Stream Array Size",
+        u8
+    );
+    ro_field!(
+        16..=31,
+        xhci_extended_capabilities_pointer,
+        "xHCI Extended Capabilities Pointer",
+        u16
+    );
 }
 impl_debug_from_methods! {
     CapabilityParameters1 {

src/registers/doorbell.rs

@@ -2,11 +2,7 @@
 
 use super::capability::Capability;
 use accessor::Mapper;
-use bit_field::BitField;
-use core::{
-    convert::{TryFrom, TryInto},
-    fmt,
-};
+use core::{convert::TryFrom, fmt};
 
 /// The element of the Doorbell Array.
 #[repr(transparent)]
@@ -39,27 +35,9 @@ impl Register {
             mapper,
         )
     }
-    /// Get a doorbell target.
-    #[must_use]
-    pub fn doorbell_target(self) -> u8 {
-        self.0.get_bits(0..=7).try_into().unwrap()
-    }
-
-    /// Set a doorbell target.
-    pub fn set_doorbell_target(&mut self, target: u8) {
-        self.0.set_bits(0..=7, target.into());
-    }
 
-    /// Get a Doorbell Stream ID.
-    #[must_use]
-    pub fn doorbell_stream_id(self) -> u16 {
-        self.0.get_bits(16..=31).try_into().unwrap()
-    }
-
-    /// Set a Doorbell Stream ID.
-    pub fn set_doorbell_stream_id(&mut self, id: u16) {
-        self.0.set_bits(16..=31, id.into());
-    }
+    rw_field!(0..=7, doorbell_target, "Doorbell Target", u8);
+    rw_field!(16..=31, doorbell_stream_id, "Doorbell Stream ID", u16);
 }
 impl fmt::Debug for Register {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {