Add CompositeEMAC support for Nuvoton M480 (#459)

* Nuvoton M480: use CompositeEMAC

* Fix some bugs, EMAC test passing!

* Fix LwIP tests

* Final cleanup

* Clarify comments

Author: multiplemonomials

connectivity/drivers/emac/TARGET_NUVOTON_EMAC/CMakeLists.txt

@@ -9,12 +9,14 @@ elseif("M460" IN_LIST MBED_TARGET_LABELS)
     add_subdirectory(TARGET_M460)
 endif()
 
-target_include_directories(mbed-emac
-    PUBLIC
-        .
-)
+if(NOT "M480" IN_LIST MBED_TARGET_LABELS)
+    target_include_directories(mbed-emac
+        PUBLIC
+            .
+    )
 
-target_sources(mbed-emac
-    PRIVATE
-        numaker_emac.cpp
-)
+    target_sources(mbed-emac
+        PRIVATE
+            numaker_emac.cpp
+    )
+endif()

connectivity/drivers/emac/TARGET_NUVOTON_EMAC/TARGET_M480/CMakeLists.txt

@@ -8,5 +8,6 @@ target_include_directories(mbed-emac
 
 target_sources(mbed-emac
     PRIVATE
-        m480_eth.c
+        NuvotonM480EthMAC.cpp
+        m480_eth_pins.c
 )

connectivity/drivers/emac/TARGET_NUVOTON_EMAC/TARGET_M480/NuvotonM480EthMAC.cpp

@@ -0,0 +1,339 @@
+/* Copyright (c) 2025 Jamie Smith
+* SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "NuvotonM480EthMAC.h"
+
+#include <mbed_power_mgmt.h>
+#include <mbed_error.h>
+
+#include "m480_eth_pins.h"
+
+namespace mbed {
+
+void NuvotonM480EthMAC::MACDriver::writeMACAddress(size_t index, MACAddress macAddress) {
+    // Find the registers to write the MAC into. Sadly they didn't use an array...
+    volatile uint32_t * highReg = (&base->CAM0M) + 2 * index;
+    volatile uint32_t * lowReg = (&base->CAM0L) + 2 * index;
+
+    // Write the MAC into the registers.
+    *highReg = (static_cast<uint32_t>(macAddress[0]) << 24) | (static_cast<uint32_t>(macAddress[1]) << 16) | (static_cast<uint32_t>(macAddress[2]) << 8) | macAddress[3];
+    *lowReg = (static_cast<uint32_t>(macAddress[4]) << 24) | (static_cast<uint32_t>(macAddress[5]) << 16);
+
+    // Mark the address as valid
+    base->CAMEN |= (1 << index);
+}
+
+CompositeEMAC::ErrCode NuvotonM480EthMAC::MACDriver::init() {
+    sleep_manager_lock_deep_sleep();
+    nu_eth_clk_and_pin_init();
+
+    // Reset MAC
+    base->CTL = EMAC_CTL_RST_Msk;
+    while (base->CTL & EMAC_CTL_RST_Msk) {}
+
+    // Reset class vars
+    numMulticastSubscriptions = 0;
+    passAllMcastEnabled = false;
+    promiscuousEnabled = false;
+
+    /* Configure the MAC interrupt enable register. Note that we need to enable interrupts for all types
+     * of Rx errors, so that we know when any Rx descriptor has been freed up by the DMA. */
+    base->INTEN = EMAC_INTEN_RXIEN_Msk |
+                  EMAC_INTEN_TXIEN_Msk |
+                  EMAC_INTEN_RXGDIEN_Msk |
+                  EMAC_INTEN_TXCPIEN_Msk |
+                  EMAC_INTEN_RXBEIEN_Msk |
+                  EMAC_INTEN_TXBEIEN_Msk |
+                  EMAC_INTEN_CRCEIEN_Msk |
+                  EMAC_INTEN_RXOVIEN_Msk |
+                  EMAC_INTEN_ALIEIEN_Msk |
+                  EMAC_INTEN_RPIEN_Msk |
+                  EMAC_INTEN_MFLEIEN_Msk;
+
+    /* Enable interrupts. */
+    NVIC_SetVector(EMAC_RX_IRQn, reinterpret_cast<uint32_t>(&NuvotonM480EthMAC::rxIrqHandler));
+    NVIC_EnableIRQ(EMAC_RX_IRQn);
+    NVIC_SetVector(EMAC_TX_IRQn, reinterpret_cast<uint32_t>(&NuvotonM480EthMAC::txIrqHandler));
+    NVIC_EnableIRQ(EMAC_TX_IRQn);
+
+    /* Configure the MAC control register. */
+    base->CTL = EMAC_CTL_STRIPCRC_Msk | EMAC_CTL_RMIIEN_Msk;
+
+    /* Accept broadcast packets without using the address filter */
+    base->CAMCTL = EMAC_CAMCTL_CMPEN_Msk |
+                    EMAC_CAMCTL_ABP_Msk;
+
+    // Maximum frame length.
+    // This apparently includes the CRC, so we need to set this 4 bytes higher than the MTU of 1514 bytes
+    // or 1514 byte packets get rejected
+    base->MRFL = 1518;
+
+    /* Set RX FIFO threshold as 8 words */
+    base->FIFOCTL = 0x00200100;
+
+    return ErrCode::SUCCESS;
+}
+
+CompositeEMAC::ErrCode NuvotonM480EthMAC::MACDriver::deinit() {
+    NVIC_DisableIRQ(EMAC_RX_IRQn);
+    NVIC_DisableIRQ(EMAC_TX_IRQn);
+
+    nu_eth_clk_and_pin_deinit();
+
+    sleep_manager_unlock_deep_sleep();
+
+    return ErrCode::SUCCESS;
+}
+
+CompositeEMAC::ErrCode NuvotonM480EthMAC::MACDriver::enable(LinkSpeed speed, Duplex duplex) {
+    if(speed == LinkSpeed::LINK_100MBIT) {
+        base->CTL |= EMAC_CTL_OPMODE_Msk;
+    }
+    else {
+        base->CTL &= ~EMAC_CTL_OPMODE_Msk;
+    }
+
+    if(duplex == Duplex::FULL) {
+        base->CTL |= EMAC_CTL_FUDUP_Msk;
+    }
+    else {
+        base->CTL &= ~EMAC_CTL_FUDUP_Msk;
+    }
+
+    base->CTL |= EMAC_CTL_RXON_Msk | EMAC_CTL_TXON_Msk;
+
+    return ErrCode::SUCCESS;
+}
+
+CompositeEMAC::ErrCode NuvotonM480EthMAC::MACDriver::disable() {
+    base->CTL &= ~(EMAC_CTL_RXON_Msk | EMAC_CTL_TXON_Msk);
+
+    return ErrCode::SUCCESS;
+}
+
+void NuvotonM480EthMAC::MACDriver::setOwnMACAddr(const MACAddress &ownAddress) {
+    writeMACAddress(0, ownAddress);
+}
+
+CompositeEMAC::ErrCode NuvotonM480EthMAC::MACDriver::mdioRead(uint8_t devAddr, uint8_t regAddr, uint16_t &result) {
+    base->MIIMCTL = (devAddr << EMAC_MIIMCTL_PHYADDR_Pos) | regAddr | EMAC_MIIMCTL_BUSY_Msk | EMAC_MIIMCTL_MDCON_Msk;
+    while (base->MIIMCTL & EMAC_MIIMCTL_BUSY_Msk);
+    result = base->MIIMDAT;
+
+    return ErrCode::SUCCESS;
+}
+
+CompositeEMAC::ErrCode NuvotonM480EthMAC::MACDriver::mdioWrite(uint8_t devAddr, uint8_t regAddr, uint16_t data) {
+    base->MIIMDAT = data;
+    base->MIIMCTL = (devAddr << EMAC_MIIMCTL_PHYADDR_Pos) | regAddr | EMAC_MIIMCTL_BUSY_Msk | EMAC_MIIMCTL_WRITE_Msk | EMAC_MIIMCTL_MDCON_Msk;
+
+    while (base->MIIMCTL & EMAC_MIIMCTL_BUSY_Msk);
+    return ErrCode::SUCCESS;
+}
+
+PinName NuvotonM480EthMAC::MACDriver::getPhyResetPin() {
+    return nu_eth_get_phy_reset_pin();
+}
+
+CompositeEMAC::ErrCode NuvotonM480EthMAC::MACDriver::addMcastMAC(MACAddress mac) {
+    if(numMulticastSubscriptions >= 14) {
+        // 14 is the max we can handle in hardware
+        return ErrCode::OUT_OF_MEMORY;
+    }
+    // We use MAC slots 1 through 14 for the multicast subscriptions
+    ++numMulticastSubscriptions;
+    writeMACAddress(numMulticastSubscriptions, mac);
+
+    return ErrCode::SUCCESS;
+}
+
+CompositeEMAC::ErrCode NuvotonM480EthMAC::MACDriver::clearMcastFilter() {
+    // Disable all MAC addresses except CAM0, which is our own unicast MAC
+    base->CAMEN = 1;
+
+    return ErrCode::SUCCESS;
+}
+
+void NuvotonM480EthMAC::MACDriver::setPassAllMcast(bool pass) {
+    passAllMcastEnabled = pass;
+    if(pass) {
+        base->CAMCTL |= EMAC_CAMCTL_AMP_Msk;
+    }
+    else if(!promiscuousEnabled){
+        base->CAMCTL &= ~EMAC_CAMCTL_AMP_Msk;
+    }
+}
+
+void NuvotonM480EthMAC::MACDriver::setPromiscuous(bool enable) {
+    promiscuousEnabled = enable;
+
+    // To enable promiscuous mode on this MAC, we need to enable pass all multicast and pass all unicast.
+    if(enable) {
+        base->CAMCTL |= EMAC_CAMCTL_AMP_Msk | EMAC_CAMCTL_AUP_Msk;
+    }
+    else {
+        base->CAMCTL &= ~EMAC_CAMCTL_AUP_Msk;
+
+        // Only disable the AMP bit if we aren't in pass-all-mcast mode
+        if(!passAllMcastEnabled) {
+            base->CAMCTL &= ~EMAC_CAMCTL_AMP_Msk;
+        }
+    }
+}
+
+void NuvotonM480EthMAC::TxDMA::startDMA() {
+    // Set linked list base address
+    base->TXDSA = reinterpret_cast<uint32_t>(&txDescs[0]);
+}
+
+void NuvotonM480EthMAC::TxDMA::stopDMA() {
+    // No specific disable for DMA. DMA will get disabled when the MAC is disabled.
+}
+
+bool NuvotonM480EthMAC::TxDMA::descOwnedByDMA(size_t descIdx) {
+    return txDescs[descIdx].EMAC_OWN;
+}
+
+bool NuvotonM480EthMAC::TxDMA::isDMAReadableBuffer(uint8_t const *start, size_t size) const {
+    // No restrictions on what DMA can read
+    return true;
+}
+
+void NuvotonM480EthMAC::TxDMA::giveToDMA(size_t descIdx, uint8_t const *buffer, size_t len, bool firstDesc,
+    bool lastDesc) {
+
+    // Populate Tx descriptor fields
+    txDescs[descIdx].PADEN = true;
+    txDescs[descIdx].CRCAPP = true;
+    txDescs[descIdx].INTEN = true;
+    txDescs[descIdx].TXBSA = buffer;
+    txDescs[descIdx].TBC = len;
+    txDescs[descIdx].NTXDSA = &txDescs[(descIdx + 1) % TX_NUM_DESCS];
+
+    // Give to DMA
+    txDescs[descIdx].EMAC_OWN = true;
+
+    // Tell DMA to start writing if stopped
+    base->TXST = 1;
+}
+
+void NuvotonM480EthMAC::RxDMA::startDMA() {
+    // Set linked list base address
+    base->RXDSA = reinterpret_cast<uint32_t>(&rxDescs[0]);
+}
+
+void NuvotonM480EthMAC::RxDMA::stopDMA() {
+    // No specific disable for DMA. DMA will get disabled when the MAC is disabled.
+}
+
+bool NuvotonM480EthMAC::RxDMA::descOwnedByDMA(size_t descIdx) {
+    return rxDescs[descIdx].EMAC_OWN;
+}
+
+// The M480 EMAC enforces a 1:1 descriptor to packet relationship, so every desc is always a first and last desc.
+bool NuvotonM480EthMAC::RxDMA::isFirstDesc(size_t descIdx) {
+    return true;
+}
+bool NuvotonM480EthMAC::RxDMA::isLastDesc(size_t descIdx) {
+    return true;
+}
+
+bool NuvotonM480EthMAC::RxDMA::isErrorDesc(size_t descIdx) {
+    // If it's not a good frame, then it's an error.
+    return !(rxDescs[descIdx].RXGDIF);
+}
+
+void NuvotonM480EthMAC::RxDMA::returnDescriptor(size_t descIdx, uint8_t *buffer) {
+    // Populate descriptor
+    rxDescs[descIdx].RXBSA = buffer;
+    rxDescs[descIdx].NRXDSA = &rxDescs[(descIdx + 1) % RX_NUM_DESCS];
+
+    // Give to DMA
+    rxDescs[descIdx].EMAC_OWN = true;
+
+    // Tell DMA to start receiving if stopped
+    base->RXST = 1;
+}
+
+size_t NuvotonM480EthMAC::RxDMA::getTotalLen(size_t firstDescIdx, size_t lastDescIdx) {
+    return rxDescs[firstDescIdx].RBC;
+}
+
+NuvotonM480EthMAC * NuvotonM480EthMAC::instance = nullptr;
+
+NuvotonM480EthMAC::NuvotonM480EthMAC():
+CompositeEMAC(txDMA, rxDMA, macDriver),
+// Note: we can't use the "EMAC" symbol directly because it conflicts with the EMAC class. So we have to
+// use the integer address and cast it instead.
+base(reinterpret_cast<EMAC_T *>(EMAC_BASE)),
+txDMA(base),
+rxDMA(base),
+macDriver(base)
+{
+    instance = this;
+}
+
+void NuvotonM480EthMAC::txIrqHandler() {
+    const auto base = instance->base;
+    if(base->INTSTS & EMAC_INTSTS_TXBEIF_Msk) {
+        MBED_ERROR(MBED_MAKE_ERROR(MBED_MODULE_DRIVER_ETHERNET, EIO), \
+               "M480 EMAC: Hardware reports fatal DMA Tx bus error\n");
+    }
+
+    if(base->INTSTS & EMAC_INTSTS_TXCPIF_Msk) {
+        // Transmission complete
+        instance->txISR();
+
+        // Clear flag
+        base->INTSTS = EMAC_INTSTS_TXCPIF_Msk;
+    }
+
+    // Clear general Tx interrupt flag
+    base->INTSTS = EMAC_INTSTS_TXIF_Msk;
+}
+
+void NuvotonM480EthMAC::rxIrqHandler() {
+    const auto base = instance->base;
+    if(base->INTSTS & EMAC_INTSTS_RXBEIF_Msk) {
+        MBED_ERROR(MBED_MAKE_ERROR(MBED_MODULE_DRIVER_ETHERNET, EIO), \
+               "M480 EMAC: Hardware reports fatal DMA Rx bus error\n");
+    }
+
+    if(base->INTSTS & EMAC_INTSTS_RXIF_Msk) {
+        // Frames(s) received (good or otherwise)
+        instance->rxISR();
+
+        // Clear flags
+        base->INTSTS = EMAC_INTSTS_RXIF_Msk |
+            EMAC_INTSTS_CRCEIF_Msk |
+            EMAC_INTSTS_RXOVIF_Msk |
+            EMAC_INTSTS_LPIF_Msk |
+            EMAC_INTSTS_RXGDIF_Msk |
+            EMAC_INTSTS_RPIF_Msk |
+            EMAC_INTSTS_MFLEIF_Msk;
+    }
+
+    // Clear general Tx interrupt flag
+    base->INTSTS = EMAC_INTSTS_TXIF_Msk;
+}
+}
+
+// Provide default EMAC driver
+MBED_WEAK EMAC &EMAC::get_default_instance()
+{
+    static mbed::NuvotonM480EthMAC emac;
+    return emac;
+}