linux.git/rust/kernel/regulator.rs, branch v6.18.21

rust: regulator: do not assume that regulator_get() returns non-null

2026-04-02T11:23:14+00:00

[ Upstream commit 8121353a4bf8e38afee26299419a78ec108e14a6 ]

The Rust `Regulator` abstraction uses `NonNull` to wrap the underlying
`struct regulator` pointer. When `CONFIG_REGULATOR` is disabled, the C
stub for `regulator_get` returns `NULL`. `from_err_ptr` does not treat
`NULL` as an error, so it was passed to `NonNull::new_unchecked`,
causing undefined behavior.

Fix this by using a raw pointer `*mut bindings::regulator` instead of
`NonNull`. This allows `inner` to be `NULL` when `CONFIG_REGULATOR` is
disabled, and leverages the C stubs which are designed to handle `NULL`
or are no-ops.

Fixes: 9b614ceada7c ("rust: regulator: add a bare minimum regulator abstraction")
Reported-by: Miguel Ojeda 
Closes: https://lore.kernel.org/r/20260322193830.89324-1-ojeda@kernel.org
Signed-off-by: Alice Ryhl 
Reviewed-by: Daniel Almeida 
Link: https://patch.msgid.link/20260324-regulator-fix-v1-1-a5244afa3c15@google.com
Signed-off-by: Mark Brown 
Signed-off-by: Sasha Levin

rust: regulator: add devm_enable and devm_enable_optional

2025-09-10T20:02:16+00:00

A lot of drivers only care about enabling the regulator for as long as
the underlying Device is bound. This can be easily observed due to the
extensive use of `devm_regulator_get_enable` and
`devm_regulator_get_enable_optional` throughout the kernel.

Therefore, make this helper available in Rust. Also add an example
noting how it should be the default API unless the driver needs more
fine-grained control over the regulator.

Suggested-by: Danilo Krummrich 
Reviewed-by: Boqun Feng 
Reviewed-by: Danilo Krummrich 
Reviewed-by: Alexandre Courbot 
Signed-off-by: Daniel Almeida 
Link: https://patch.msgid.link/20250910-regulator-remove-dynamic-v3-2-07af4dfa97cc@collabora.com
Signed-off-by: Mark Brown

rust: regulator: remove Regulator

2025-09-10T20:02:15+00:00

After some experimenting and further discussion, it is starting to look
like Regulator might be a footgun. It turns out that one can
get the same behavior by correctly using just Regulator and
Regulator, so there is no need to directly expose the manual
refcounting ability of Regulator to clients.

Remove it while we do not have any other users.

Suggested-by: Danilo Krummrich 
Reviewed-by: Alice Ryhl 
Reviewed-by: Danilo Krummrich 
Reviewed-by: Alexandre Courbot 
Signed-off-by: Daniel Almeida 
Link: https://patch.msgid.link/20250910-regulator-remove-dynamic-v3-1-07af4dfa97cc@collabora.com
Signed-off-by: Mark Brown

rust: regulator: use `to_result` for error handling

2025-08-28T09:08:39+00:00

Simplifies error handling by replacing the manual check
of the return value with the `to_result` helper.

Signed-off-by: Onur Özkan 
Reviewed-by: Daniel Almeida 
Message-ID: <20250821090720.23939-1-work@onurozkan.dev>
Signed-off-by: Mark Brown

rust: regulator: implement Send and Sync for Regulator

2025-08-10T20:09:34+00:00

Sending a &Regulator to another thread is safe, as the regulator core
will properly handle the locking for us. Additionally, there are no
restrictions that prevents sending a Regulator to another thread.

Given these two facts, implement Send and Sync.

Signed-off-by: Daniel Almeida 
Link: https://patch.msgid.link/20250729-regulator-send-sync-v1-2-8bcbd546b940@collabora.com
Reviewed-by: Alexandre Courbot 
Reviewed-by: Alice Ryhl 
Signed-off-by: Mark Brown

rust: regulator: remove needless &mut from member functions

2025-08-10T20:09:33+00:00

Regulator functions like "regulator_enable()" and "regulator_disable()"
already provide their own locking through "regulator_lock_dependent()", so
we can safely call the Rust API with a shared reference.

This was already the case with Regulator::set_voltage() on the Rust side,
but it was forgotten for Regulator::enable() and Regulator::disable().

Signed-off-by: Daniel Almeida 
Link: https://patch.msgid.link/20250729-regulator-send-sync-v1-1-8bcbd546b940@collabora.com
Reviewed-by: Alexandre Courbot 
Reviewed-by: Alice Ryhl 
Signed-off-by: Mark Brown

rust: regulator: add a bare minimum regulator abstraction

2025-07-15T14:07:40+00:00

Add a bare minimum regulator abstraction to be used by Rust drivers.
This abstraction adds a small subset of the regulator API, which is
thought to be sufficient for the drivers we have now.

Regulators provide the power needed by many hardware blocks and thus are
likely to be needed by a lot of drivers.

It was tested on rk3588, where it was used to power up the "mali"
regulator in order to power up the GPU.

Reviewed-by: Alexandre Courbot 
Signed-off-by: Daniel Almeida 
Reviewed-by: Alice Ryhl 
Link: https://patch.msgid.link/20250714-topics-tyr-regulator2-v8-1-c7ab3955d524@collabora.com
Signed-off-by: Mark Brown