[WIP RFC v2 12/35] rust: drm/kms: Add ConnectorGuard::set_preferred_mode

[Lyude Paul]

Add a wrapper for `drm_set_preferred_mode()` for our new
`ConnectorGuard` type so we can set the preferred mode for RVKMS
connectors.

Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx>
---
 rust/kernel/drm/kms/connector.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/rust/kernel/drm/kms/connector.rs b/rust/kernel/drm/kms/connector.rs
index 7d0f67c3bdaf8..ec842ebc111ae 100644
--- a/rust/kernel/drm/kms/connector.rs
+++ b/rust/kernel/drm/kms/connector.rs
@@ -387,6 +387,12 @@ pub fn add_modes_noedid(&self, (max_h, max_v): (i32, i32)) -> i32 {
         // SAFETY: We hold the locks required to call this via our type invariants.
         unsafe { bindings::drm_add_modes_noedid(self.as_raw(), max_h, max_v) }
     }
+
+    /// Set the preferred display mode for the underlying [`Connector`].
+    pub fn set_preferred_mode(&self, (h_pref, w_pref): (i32, i32)) {
+        // SAFETY: We hold the locks required to call this via our type invariants.
+        unsafe { bindings::drm_set_preferred_mode(self.as_raw(), h_pref, w_pref) }
+    }
 }
 
 // SAFETY: DRM expects this struct to be zero-initialized
-- 
2.46.1