Add support for runtime configuration of speed and duplex

Author: Johannes Draaijer

README.md

@@ -103,12 +103,12 @@ To run or build them, the following steps should be taken:
 
 Besides the feature selecting the correct MCU to be used when building and/or running an example, the following additional features are required:
 
-| Example       | Additional required features                         |
-| ------------- | ---------------------------------------------------- |
-| `arp`         | `defmt`                                              |
-| `ip`          | `defmt,smoltcp-phy,smoltcp/defmt,smoltcp/socket-tcp` |
-| `pktgen`      | `defmt`                                              |
-| `rtic-echo`   | `rtic-echo-example`                                  |
+| Example     | Additional required features                         |
+| ----------- | ---------------------------------------------------- |
+| `arp`       | `defmt`                                              |
+| `ip`        | `defmt,smoltcp-phy,smoltcp/defmt,smoltcp/socket-tcp` |
+| `pktgen`    | `defmt`                                              |
+| `rtic-echo` | `rtic-echo-example`                                  |
 
 #### 144-pin nucleo boards
 

src/lib.rs

@@ -4,6 +4,7 @@
 #![no_std]
 #![deny(missing_docs)]
 
+use mac::Speed;
 /// Re-export
 #[cfg(feature = "stm32f7xx-hal")]
 pub use stm32f7xx_hal as hal;
@@ -87,6 +88,9 @@ const MTU: usize = 1522;
 /// and configures the ETH MAC and DMA peripherals.
 /// Automatically sets slew rate to VeryHigh.
 ///
+/// The speed of the MAC is set to [`Speed::FullDuplexBase100Tx`].
+/// This can be changed using [`EthernetMAC::set_speed`].
+///
 /// This method does not initialise the external PHY. Interacting with a PHY
 /// can be done by using the struct returned from [`EthernetMAC::mii`].
 ///
@@ -127,7 +131,7 @@ where
     let dma = EthernetDMA::new(eth_dma, &eth_mac, rx_buffer, tx_buffer);
 
     // Configure the ethernet MAC
-    let mac = EthernetMAC::new(eth_mac, eth_mmc, &dma, clocks)?;
+    let mac = EthernetMAC::new(eth_mac, eth_mmc, &dma, clocks, Speed::FullDuplexBase100Tx)?;
 
     Ok((dma, mac))
 }
@@ -141,6 +145,9 @@ where
 ///
 /// This method does not initialise the external PHY.
 ///
+/// The speed of the MAC is set to [`Speed::FullDuplexBase100Tx`].
+/// This can be changed using [`EthernetMAC::set_speed`].
+///
 /// The MII for the external PHY can be accessed through the
 /// returned [`EthernetMACWithMii`], .
 ///
@@ -185,7 +192,8 @@ where
     let dma = EthernetDMA::new(eth_dma, &eth_mac, rx_buffer, tx_buffer);
 
     // Configure the ethernet MAC
-    let mac = EthernetMAC::new(eth_mac, eth_mmc, &dma, clocks)?.with_mii(mdio, mdc);
+    let mac = EthernetMAC::new(eth_mac, eth_mmc, &dma, clocks, Speed::FullDuplexBase100Tx)?
+        .with_mii(mdio, mdc);
 
     Ok((dma, mac))
 }

src/mac/mod.rs

@@ -11,6 +11,20 @@ use crate::{
 mod miim;
 pub use miim::*;
 
+/// Speeds at which this MAC can be configured
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum Speed {
+    /// 10Base-T half duplex
+    HalfDuplexBase10T,
+    /// 10Base-T full duplex
+    FullDuplexBase10T,
+    /// 100Base-Tx half duplex
+    HalfDuplexBase100Tx,
+    /// 100Base-Tx full duplex
+    FullDuplexBase100Tx,
+}
+
 mod consts {
     /* For HCLK 60-100 MHz */
     pub const ETH_MACMIIAR_CR_HCLK_DIV_42: u8 = 0;
@@ -54,6 +68,7 @@ impl EthernetMAC {
         // this function.
         #[allow(unused)] eth_dma: &EthernetDMA,
         clocks: Clocks,
+        initial_speed: Speed,
     ) -> Result<Self, WrongClock> {
         let clock_frequency = clocks.hclk().to_Hz();
 
@@ -132,7 +147,11 @@ impl EthernetMAC {
             .mmctimr
             .modify(|r, w| unsafe { w.bits(r.bits() | (1 << 21)) });
 
-        Ok(Self { eth_mac })
+        let mut me = Self { eth_mac };
+
+        me.set_speed(initial_speed);
+
+        Ok(me)
     }
 
     /// Borrow access to the MAC's SMI.
@@ -166,6 +185,31 @@ impl EthernetMAC {
             mdc,
         }
     }
+
+    /// Set the Ethernet Speed at which the MAC communicates
+    ///
+    /// Note that this does _not_ affect the PHY in any way. To
+    /// configure the PHY, use [`EthernetMACWithMii`] (see: [`Self::with_mii`])
+    /// or [`Stm32Mii`] (see: [`Self::mii`])
+    pub fn set_speed(&mut self, speed: Speed) {
+        self.eth_mac.maccr.modify(|_, w| match speed {
+            Speed::HalfDuplexBase10T => w.fes().clear_bit().dm().clear_bit(),
+            Speed::FullDuplexBase10T => w.fes().clear_bit().dm().set_bit(),
+            Speed::HalfDuplexBase100Tx => w.fes().set_bit().dm().clear_bit(),
+            Speed::FullDuplexBase100Tx => w.fes().set_bit().dm().set_bit(),
+        });
+    }
+
+    /// Get the Ethernet Speed at which the MAC communicates
+    pub fn get_speed(&self) -> Speed {
+        let cr = self.eth_mac.maccr.read();
+        match (cr.fes().bit_is_set(), cr.dm().bit_is_set()) {
+            (false, false) => Speed::HalfDuplexBase10T,
+            (false, true) => Speed::FullDuplexBase10T,
+            (true, false) => Speed::HalfDuplexBase100Tx,
+            (true, true) => Speed::FullDuplexBase100Tx,
+        }
+    }
 }
 
 /// Ethernet media access control (MAC) with owned MII