[PATCH 4/9] rust: regulator: add abstraction for Regulator's modes

[Fabien Parent <parent.f@gmail.com>]

From: Fabien Parent <fabien.parent@linaro.org>

The type regulator::Mode is used by both the regulator consumer
abstraction and the regulator driver abstraction. This commits
adds a shared abstraction for it.

Signed-off-by: Fabien Parent <fabien.parent@linaro.org>
---
 MAINTAINERS                     |  1 +
 rust/bindings/bindings_helper.h |  1 +
 rust/kernel/lib.rs              |  2 ++
 rust/kernel/regulator.rs        | 42 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 46 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index acb3942eb1b66ec2bc09ac50f51c2054b7b45355..90c231f0aa7381aa8d206fb94c5d1f013dfcae41 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -25159,6 +25159,7 @@ F:	Documentation/power/regulator/
 F:	drivers/regulator/
 F:	include/dt-bindings/regulator/
 F:	include/linux/regulator/
+F:	rust/kernel/regulator.rs
 K:	regulator_get_optional
 
 VOLTAGE AND CURRENT REGULATOR IRQ HELPERS
diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index 48d2b91b34067e7e9ee9c64c2e42681e988e9aad..b18d772bc3a0e78d749cc9e5ae81a4237a57f8c5 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -29,6 +29,7 @@
 #include <linux/poll.h>
 #include <linux/refcount.h>
 #include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
 #include <linux/sched.h>
 #include <linux/security.h>
 #include <linux/slab.h>
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 456e979724d1079045cb157086ff2b2ed0fcca3b..3aa36648e9571e305a89f5d1353c0dd44e136384 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -68,6 +68,8 @@
 pub mod rbtree;
 #[cfg(CONFIG_REGMAP)]
 pub mod regmap;
+#[cfg(CONFIG_REGULATOR)]
+pub mod regulator;
 pub mod revocable;
 pub mod security;
 pub mod seq_file;
diff --git a/rust/kernel/regulator.rs b/rust/kernel/regulator.rs
new file mode 100644
index 0000000000000000000000000000000000000000..d695ac955193efcfda62770784a92d70d606b93d
--- /dev/null
+++ b/rust/kernel/regulator.rs
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! SoC Regulators
+
+use crate::{
+    bindings,
+    error::{code::*, Error, Result},
+};
+
+/// Regulators operating modes
+#[derive(Copy, Clone)]
+#[repr(u32)]
+pub enum Mode {
+    /// Invalid mode
+    Invalid = bindings::REGULATOR_MODE_INVALID,
+    /// Regulator can handle fast changes in it's load
+    Fast = bindings::REGULATOR_MODE_FAST,
+    /// Normal regulator power supply mode
+    Normal = bindings::REGULATOR_MODE_NORMAL,
+    /// Regulator runs in a more efficient mode for light loads
+    Idle = bindings::REGULATOR_MODE_IDLE,
+    /// Regulator runs in the most efficient mode for very light loads
+    Standby = bindings::REGULATOR_MODE_STANDBY,
+}
+
+impl TryFrom<core::ffi::c_uint> for Mode {
+    type Error = Error;
+
+    /// Convert a mode represented as an unsigned integer into its Rust enum equivalent
+    ///
+    /// If the integer does not match any of the [`Mode`], then [`EINVAL`] is returned
+    fn try_from(mode: core::ffi::c_uint) -> Result<Self> {
+        match mode {
+            bindings::REGULATOR_MODE_FAST => Ok(Self::Fast),
+            bindings::REGULATOR_MODE_NORMAL => Ok(Self::Normal),
+            bindings::REGULATOR_MODE_IDLE => Ok(Self::Idle),
+            bindings::REGULATOR_MODE_STANDBY => Ok(Self::Standby),
+            bindings::REGULATOR_MODE_INVALID => Ok(Self::Invalid),
+            _ => Err(EINVAL),
+        }
+    }
+}

-- 
2.45.2