Start on MAC v1 driver

Author: multiplemonomials

connectivity/drivers/emac/TARGET_STM/CMakeLists.txt

@@ -25,4 +25,12 @@ if("STM32H7" IN_LIST MBED_TARGET_LABELS OR "STM32H5" IN_LIST MBED_TARGET_LABELS)
     )
 endif()
 
+if("STM32F2" IN_LIST MBED_TARGET_LABELS OR "STM32F4" IN_LIST MBED_TARGET_LABELS OR "STM32F7" IN_LIST MBED_TARGET_LABELS)
+    target_sources(mbed-emac
+        PRIVATE
+            STM32EthMACv1.cpp
+    )
+endif()
+
+
 target_compile_options(mbed-emac PRIVATE -Wno-packed-bitfield-compat)

connectivity/drivers/emac/TARGET_STM/STM32EthMACCommon.h

@@ -0,0 +1,84 @@
+/* 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.
+ */
+
+#pragma once
+
+#include "device.h"
+#include "CompositeEMAC.h"
+#include "MbedCRC.h"
+
+// Figure out the Ethernet IP version in use
+#ifdef TARGET_STM32H5 || TARGET_STM32H7
+#define ETH_IP_VERSION_V2
+#else
+#define ETH_IP_VERSION_V1
+#endif
+
+namespace mbed
+{
+constexpr auto MDIO_TRANSACTION_TIMEOUT = std::chrono::milliseconds(1); // used by STMicro HAL
+
+inline constexpr size_t NUM_PERFECT_FILTER_REGS = 3;
+static const std::pair<volatile uint32_t *, volatile uint32_t *> MAC_ADDR_PERF_FILTER_REGS[NUM_PERFECT_FILTER_REGS] = {
+    {&ETH->MACA1HR, &ETH->MACA1LR},
+    {&ETH->MACA2HR, &ETH->MACA2LR},
+    {&ETH->MACA3HR, &ETH->MACA3LR}
+};
+
+/// Write a MAC address into the given registers with the needed encoding
+static inline void writeMACAddress(const CompositeEMAC::MACAddress & mac, volatile uint32_t *addrHighReg, volatile uint32_t *addrLowReg)
+{
+    /* Set MAC addr bits 32 to 47 */
+    *addrHighReg = (static_cast<uint32_t>(mac[5]) << 8) | static_cast<uint32_t>(mac[4]) | ETH_MACA1HR_AE_Msk;
+    /* Set MAC addr bits 0 to 31 */
+    *addrLowReg = (static_cast<uint32_t>(mac[3]) << 24) | (static_cast<uint32_t>(mac[2]) << 16) |
+                  (static_cast<uint32_t>(mac[1]) << 8) | static_cast<uint32_t>(mac[0]);
+}
+
+/// Add a MAC address to the multicast hash filter.
+void addHashFilterMAC(ETH_TypeDef * base, const CompositeEMAC::MACAddress & mac) {
+#if defined(ETH_IP_VERSION_V2)
+    uint32_t volatile * hashRegs[] = {
+        &base->MACHT0R,
+        &base->MACHT1R
+    };
+#else
+    uint32_t volatile * hashRegs[] = {
+        &base->MACHTLR,
+        &base->MACHTHR
+    };
+#endif
+
+    // Note: as always, the datasheet description of how to do this CRC was vague and slightly wrong.
+    // This forum thread figured it out: https://community.st.com/t5/stm32-mcus-security/calculating-ethernet-multicast-filter-hash-value/td-p/416984
+    // What the datasheet SHOULD say is:
+    // Compute the Ethernet CRC-32 of the MAC address, with initial value of 1s, final XOR of ones, and input reflection on but output reflection off
+    // Then, take the upper 6 bits and use that to index the hash table.
+
+    mbed::MbedCRC<POLY_32BIT_ANSI> crcCalc(0xFFFFFFFF, 0xFFFFFFFF, true, false);
+
+    // Compute Ethernet CRC-32 of the MAC address
+    uint32_t crc;
+    crcCalc.compute(mac.data(), mac.size(), &crc);
+
+    // Take upper 6 bits
+    uint32_t hashVal = crc >> 26;
+
+    // Set correct bit in hash filter
+    *hashRegs[hashVal >> 5] |= (1 << (hashVal & 0x1F));
+}
+
+}