[PATCH V7 14/16] rust: Extend OPP bindings with CPU frequency table

[Viresh Kumar <viresh.kumar@linaro.org>]

This commit adds bindings for CPUFreq core related API.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 rust/kernel/opp.rs | 62 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 62 insertions(+)

diff --git a/rust/kernel/opp.rs b/rust/kernel/opp.rs
index 22c4d543f456..147178410c60 100644
--- a/rust/kernel/opp.rs
+++ b/rust/kernel/opp.rs
@@ -16,6 +16,12 @@
     types::{ARef, AlwaysRefCounted, Opaque},
 };
 
+#[cfg(CONFIG_CPU_FREQ)]
+use crate::cpufreq;
+
+#[cfg(CONFIG_CPU_FREQ)]
+use core::ops::Deref;
+
 use core::{marker::PhantomData, ptr};
 
 use macros::vtable;
@@ -337,6 +343,56 @@ extern "C" fn config_regulators(
     }
 }
 
+/// CPU Frequency table created from OPP entries.
+#[cfg(CONFIG_CPU_FREQ)]
+pub struct FreqTable {
+    dev: ARef<Device>,
+    table: cpufreq::Table,
+}
+
+#[cfg(CONFIG_CPU_FREQ)]
+impl FreqTable {
+    /// Creates new instance of [`FreqTable`] from raw pointer.
+    fn new(table: &Table) -> Result<Self> {
+        let mut ptr: *mut bindings::cpufreq_frequency_table = ptr::null_mut();
+
+        // SAFETY: The requirements are satisfied by the existence of `Device` and its safety
+        // requirements.
+        to_result(unsafe {
+            bindings::dev_pm_opp_init_cpufreq_table(table.dev.as_raw(), &mut ptr)
+        })?;
+        Ok(Self {
+            dev: table.dev.clone(),
+            // SAFETY: The `ptr` is guaranteed by the C code to be valid.
+            table: unsafe { cpufreq::Table::from_raw(ptr) },
+        })
+    }
+
+    /// Returns reference to the underlying [`cpufreq::Table`].
+    pub fn table(&self) -> &cpufreq::Table {
+        &self.table
+    }
+}
+
+#[cfg(CONFIG_CPU_FREQ)]
+impl Deref for FreqTable {
+    type Target = cpufreq::Table;
+
+    #[inline]
+    fn deref(&self) -> &Self::Target {
+        &self.table
+    }
+}
+
+#[cfg(CONFIG_CPU_FREQ)]
+impl Drop for FreqTable {
+    fn drop(&mut self) {
+        // SAFETY: The requirements are satisfied by the existence of `Device` and its safety
+        // requirements.
+        unsafe { bindings::dev_pm_opp_free_cpufreq_table(self.dev.as_raw(), &mut self.as_raw()) };
+    }
+}
+
 /// Operating performance point (OPP) table.
 ///
 /// Wraps the kernel's `struct opp_table`.
@@ -541,6 +597,12 @@ pub fn adjust_voltage(
         })
     }
 
+    /// Create cpufreq table from OPP table.
+    #[cfg(CONFIG_CPU_FREQ)]
+    pub fn to_cpufreq_table(&mut self) -> Result<FreqTable> {
+        FreqTable::new(self)
+    }
+
     /// Sets a matching OPP based on frequency.
     pub fn set_rate(&self, freq: usize) -> Result<()> {
         // SAFETY: The requirements are satisfied by the existence of `Device` and its safety
-- 
2.31.1.272.g89b43f80a514