[WIP RFC v2 17/35] rust: drm/kms: Add RawCrtc and RawCrtcState

[Lyude Paul]

Same thing as RawConnector and RawConnectorState, just for CRTCs now.

Signed-off-by: Lyude Paul <lyude at redhat.com>
---
 rust/kernel/drm/kms/crtc.rs | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/rust/kernel/drm/kms/crtc.rs b/rust/kernel/drm/kms/crtc.rs
index 1a3c9c448afcc..246d15a15c14d 100644
--- a/rust/kernel/drm/kms/crtc.rs
+++ b/rust/kernel/drm/kms/crtc.rs
@@ -302,6 +302,25 @@ unsafe fn from_raw<'a>(ptr: *mut bindings::drm_crtc) -> &'a Self {
     }
 }
 
+/// Common methods available on any type which implements [`AsRawCrtc`].
+///
+/// This is implemented internally by DRM, and provides many of the basic methods for working with
+/// CRTCs.
+pub trait RawCrtc: AsRawCrtc {
+    /// Return the index of this CRTC.
+    fn index(&self) -> u32 {
+        // SAFETY: The index is initialized by the time we expose Crtc objects to users, and is
+        // invariant throughout the lifetime of the Crtc
+        unsafe { (*self.as_raw()).index }
+    }
+
+    /// Return the index of this DRM CRTC in the form of a bitmask.
+    fn mask(&self) -> u32 {
+        1 << self.index()
+    }
+}
+impl<T: AsRawCrtc> RawCrtc for T {}
+
 /// A [`struct drm_crtc`] without a known [`DriverCrtc`] implementation.
 ///
 /// This is mainly for situations where our bindings can't infer the [`DriverCrtc`] implementation
@@ -447,8 +466,10 @@ pub trait AsRawCrtcState {
 
 pub(super) use private::AsRawCrtcState as AsRawCrtcStatePrivate;
 
-/// A trait for providing common methods which can be used on any type that can be used as an atomic
-/// CRTC state.
+/// Common methods available on any type which implements [`AsRawCrtcState`].
+///
+/// This is implemented internally by DRM, and provides many of the basic methods for working with
+/// the atomic state of [`Crtc`]s.
 pub trait RawCrtcState: AsRawCrtcState {
     /// Return the CRTC that owns this state.
     fn crtc(&self) -> &Self::Crtc {
-- 
2.46.1