diff --git a/rust/kernel/regulator.rs b/rust/kernel/regulator.rs index 4f7837c7e53a..41e730cedc81 100644 --- a/rust/kernel/regulator.rs +++ b/rust/kernel/regulator.rs @@ -23,7 +23,10 @@ prelude::*, }; -use core::{marker::PhantomData, mem::ManuallyDrop, ptr::NonNull}; +use core::{ + marker::PhantomData, + mem::ManuallyDrop, // +}; mod private { pub trait Sealed {} @@ -229,15 +232,17 @@ pub fn devm_enable_optional(dev: &Device, name: &CStr) -> Result { /// /// # Invariants /// -/// - `inner` is a non-null wrapper over a pointer to a `struct -/// regulator` obtained from [`regulator_get()`]. +/// - `inner` is a pointer obtained from a successful call to +/// [`regulator_get()`]. It is treated as an opaque token that may only be +/// accessed using C API methods (e.g., it may be `NULL` if the C API returns +/// `NULL`). /// /// [`regulator_get()`]: https://docs.kernel.org/driver-api/regulator.html#c.regulator_get pub struct Regulator where State: RegulatorState, { - inner: NonNull, + inner: *mut bindings::regulator, _phantom: PhantomData, } @@ -249,7 +254,7 @@ pub fn set_voltage(&self, min_voltage: Voltage, max_voltage: Voltage) -> Result // SAFETY: Safe as per the type invariants of `Regulator`. to_result(unsafe { bindings::regulator_set_voltage( - self.inner.as_ptr(), + self.inner, min_voltage.as_microvolts(), max_voltage.as_microvolts(), ) @@ -259,7 +264,7 @@ pub fn set_voltage(&self, min_voltage: Voltage, max_voltage: Voltage) -> Result /// Gets the current voltage of the regulator. pub fn get_voltage(&self) -> Result { // SAFETY: Safe as per the type invariants of `Regulator`. - let voltage = unsafe { bindings::regulator_get_voltage(self.inner.as_ptr()) }; + let voltage = unsafe { bindings::regulator_get_voltage(self.inner) }; to_result(voltage).map(|()| Voltage::from_microvolts(voltage)) } @@ -270,10 +275,8 @@ fn get_internal(dev: &Device, name: &CStr) -> Result> { // received from the C code. from_err_ptr(unsafe { bindings::regulator_get(dev.as_raw(), name.as_char_ptr()) })?; - // SAFETY: We can safely trust `inner` to be a pointer to a valid - // regulator if `ERR_PTR` was not returned. - let inner = unsafe { NonNull::new_unchecked(inner) }; - + // INVARIANT: `inner` is a pointer obtained from `regulator_get()`, and + // the call was successful. Ok(Self { inner, _phantom: PhantomData, @@ -282,12 +285,12 @@ fn get_internal(dev: &Device, name: &CStr) -> Result> { fn enable_internal(&self) -> Result { // SAFETY: Safe as per the type invariants of `Regulator`. - to_result(unsafe { bindings::regulator_enable(self.inner.as_ptr()) }) + to_result(unsafe { bindings::regulator_enable(self.inner) }) } fn disable_internal(&self) -> Result { // SAFETY: Safe as per the type invariants of `Regulator`. - to_result(unsafe { bindings::regulator_disable(self.inner.as_ptr()) }) + to_result(unsafe { bindings::regulator_disable(self.inner) }) } } @@ -349,7 +352,7 @@ impl Regulator { /// Checks if the regulator is enabled. pub fn is_enabled(&self) -> bool { // SAFETY: Safe as per the type invariants of `Regulator`. - unsafe { bindings::regulator_is_enabled(self.inner.as_ptr()) != 0 } + unsafe { bindings::regulator_is_enabled(self.inner) != 0 } } } @@ -359,11 +362,11 @@ fn drop(&mut self) { // SAFETY: By the type invariants, we know that `self` owns a // reference on the enabled refcount, so it is safe to relinquish it // now. - unsafe { bindings::regulator_disable(self.inner.as_ptr()) }; + unsafe { bindings::regulator_disable(self.inner) }; } // SAFETY: By the type invariants, we know that `self` owns a reference, // so it is safe to relinquish it now. - unsafe { bindings::regulator_put(self.inner.as_ptr()) }; + unsafe { bindings::regulator_put(self.inner) }; } }