Add RPMh regulator support for PM7550 & PMR735B

Merge series from Luca Weiss <luca.weiss@fairphone.com>:

Document and add support for the regulators on PM7550 and PMR735B, which
can be paired with the Milos SoC.

2 files changed, 11 insertions, 2 deletions

diff --git a/rust/kernel/drm/device.rs b/rust/kernel/drm/device.rs
index 624d7a4c83ea..14c1aa402951 100644
--- a/rust/kernel/drm/device.rs
+++ b/rust/kernel/drm/device.rs
@@ -66,7 +66,7 @@ impl<T: drm::Driver> Device<T> {
         open: Some(drm::File::<T::File>::open_callback),
         postclose: Some(drm::File::<T::File>::postclose_callback),
         unload: None,
-        release: None,
+        release: Some(Self::release),
         master_set: None,
         master_drop: None,
         debugfs_init: None,
@@ -162,6 +162,16 @@ impl<T: drm::Driver> Device<T> {
         // SAFETY: `ptr` is valid by the safety requirements of this function.
         unsafe { &*ptr.cast() }
     }
+
+    extern "C" fn release(ptr: *mut bindings::drm_device) {
+        // SAFETY: `ptr` is a valid pointer to a `struct drm_device` and embedded in `Self`.
+        let this = unsafe { Self::from_drm_device(ptr) };
+
+        // SAFETY:
+        // - When `release` runs it is guaranteed that there is no further access to `this`.
+        // - `this` is valid for dropping.
+        unsafe { core::ptr::drop_in_place(this) };
+    }
 }
 
 impl<T: drm::Driver> Deref for Device<T> {
diff --git a/rust/kernel/drm/driver.rs b/rust/kernel/drm/driver.rs
index acb638086131..af93d46d03d3 100644
--- a/rust/kernel/drm/driver.rs
+++ b/rust/kernel/drm/driver.rs
@@ -10,7 +10,6 @@ use crate::{
     drm,
     error::{to_result, Result},
     prelude::*,
-    str::CStr,
     types::ARef,
 };
 use macros::vtable;