rust: net::phy support probe callback

Support phy_driver probe callback, used to set up device-specific
structures.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rust/kernel/net/phy.rs

@@ -338,6 +338,21 @@ impl<T: Driver> Adapter<T> {
         })
     }
 
+    /// # Safety
+    ///
+    /// `phydev` must be passed by the corresponding callback in `phy_driver`.
+    unsafe extern "C" fn probe_callback(phydev: *mut bindings::phy_device) -> core::ffi::c_int {
+        from_result(|| {
+            // SAFETY: This callback is called only in contexts
+            // where we can exclusively access `phy_device` because
+            // it's not published yet, so the accessors on `Device` are okay
+            // to call.
+            let dev = unsafe { Device::from_raw(phydev) };
+            T::probe(dev)?;
+            Ok(0)
+        })
+    }
+
     /// # Safety
     ///
     /// `phydev` must be passed by the corresponding callback in `phy_driver`.
@@ -511,6 +526,11 @@ pub const fn create_phy_driver<T: Driver>() -> DriverVTable {
         } else {
             None
         },
+        probe: if T::HAS_PROBE {
+            Some(Adapter::<T>::probe_callback)
+        } else {
+            None
+        },
         get_features: if T::HAS_GET_FEATURES {
             Some(Adapter::<T>::get_features_callback)
         } else {
@@ -583,6 +603,11 @@ pub trait Driver {
         kernel::build_error(VTABLE_DEFAULT_ERROR)
     }
 
+    /// Sets up device-specific structures during discovery.
+    fn probe(_dev: &mut Device) -> Result {
+        kernel::build_error(VTABLE_DEFAULT_ERROR)
+    }
+
     /// Probes the hardware to determine what abilities it has.
     fn get_features(_dev: &mut Device) -> Result {
         kernel::build_error(VTABLE_DEFAULT_ERROR)