1 files changed, 94 insertions, 0 deletions

diff --git a/embassy-stm32/src/eth/sma/v2.rs b/embassy-stm32/src/eth/sma/v2.rs
new file mode 100644
index 000000000..6bc5230b5
--- /dev/null
+++ b/embassy-stm32/src/eth/sma/v2.rs
@@ -0,0 +1,94 @@
+use embassy_hal_internal::Peri;
+pub(crate) use regs::{Macmdioar as AddressRegister, Macmdiodr as DataRegister};
+use stm32_metapac::eth::regs;
+
+use super::{Instance, StationManagement};
+use crate::eth::{MDCPin, MDIOPin};
+use crate::gpio::{AfType, AnyPin, OutputType, SealedPin, Speed};
+
+/// Station Management Agent.
+///
+/// This peripheral is used for SMI reads and writes to the connected
+/// ethernet PHY/device(s).
+pub struct Sma<'d, T: Instance> {
+    _peri: Peri<'d, T>,
+    pins: [Peri<'d, AnyPin>; 2],
+    clock_range: u8,
+}
+
+impl<'d, T: Instance> Sma<'d, T> {
+    /// Create a new instance of this peripheral.
+    pub fn new(peri: Peri<'d, T>, mdio: Peri<'d, impl MDIOPin<T>>, mdc: Peri<'d, impl MDCPin<T>>) -> Self {
+        set_as_af!(mdio, AfType::output(OutputType::PushPull, Speed::VeryHigh));
+        set_as_af!(mdc, AfType::output(OutputType::PushPull, Speed::VeryHigh));
+
+        // Enable necessary clocks.
+        critical_section::with(|_| {
+            crate::pac::RCC.ahb1enr().modify(|w| {
+                w.set_ethen(true);
+            })
+        });
+
+        let hclk = unsafe { crate::rcc::get_freqs().hclk1.to_hertz() };
+        let hclk = unwrap!(hclk, "SMA requires HCLK to be enabled, but it was not.");
+        let hclk_mhz = hclk.0 / 1_000_000;
+
+        // Set the MDC clock frequency in the range 1MHz - 2.5MHz
+        let clock_range = match hclk_mhz {
+            0..=34 => 2,    // Divide by 16
+            35..=59 => 3,   // Divide by 26
+            60..=99 => 0,   // Divide by 42
+            100..=149 => 1, // Divide by 62
+            150..=249 => 4, // Divide by 102
+            250..=310 => 5, // Divide by 124
+            _ => {
+                panic!("HCLK results in MDC clock > 2.5MHz even for the highest CSR clock divider")
+            }
+        };
+
+        Self {
+            _peri: peri,
+            clock_range,
+            pins: [mdio.into(), mdc.into()],
+        }
+    }
+}
+
+impl<T: Instance> StationManagement for Sma<'_, T> {
+    fn smi_read(&mut self, phy_addr: u8, reg: u8) -> u16 {
+        let (macmdioar, macmdiodr) = T::regs();
+
+        macmdioar.modify(|w| {
+            w.set_pa(phy_addr);
+            w.set_rda(reg);
+            w.set_goc(0b11); // read
+            w.set_cr(self.clock_range);
+            w.set_mb(true);
+        });
+
+        while macmdioar.read().mb() {}
+
+        macmdiodr.read().md()
+    }
+
+    fn smi_write(&mut self, phy_addr: u8, reg: u8, val: u16) {
+        let (macmdioar, macmdiodr) = T::regs();
+
+        macmdiodr.write(|w| w.set_md(val));
+        macmdioar.modify(|w| {
+            w.set_pa(phy_addr);
+            w.set_rda(reg);
+            w.set_goc(0b01); // write
+            w.set_cr(self.clock_range);
+            w.set_mb(true);
+        });
+
+        while macmdioar.read().mb() {}
+    }
+}
+
+impl<T: Instance> Drop for Sma<'_, T> {
+    fn drop(&mut self) {
+        self.pins.iter_mut().for_each(|p| p.set_as_disconnected());
+    }
+}