[platforms] add support for Microchip SAMR21 (#2297)

* Add support for Microchip SAMR21 Signed-off-by: Oleksandr Grytsov <[email protected]>
2026-10-02 13:57:38 +00:00 · 2017-11-09 12:25:32 -08:00
parent c46b75d0cf
commit f0d3512317
29 changed files with 3308 additions and 2 deletions
@@ -0,0 +1,170 @@
+/*
+ *  Copyright (c) 2017, The OpenThread Authors.
+ *  All rights reserved.
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions are met:
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the copyright holder nor the
+ *     names of its contributors may be used to endorse or promote products
+ *     derived from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ *  POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/**
+ * @file
+ *   This file implements the OpenThread platform abstraction for UART communication.
+ *
+ */
+
+#include "asf.h"
+
+#include <openthread/platform/uart.h>
+
+enum
+{
+    kBaudRate          = 115200,
+    kReceiveBufferSize = 128,
+};
+
+typedef struct RecvBuffer
+{
+    // The data buffer
+    uint8_t  mBuffer[kReceiveBufferSize];
+    // The offset of the first item written to the list.
+    uint16_t mHead;
+    // The offset of the next item to be written to the list.
+    uint16_t mTail;
+} RecvBuffer;
+
+static struct usart_module sUsartInstance;
+
+static RecvBuffer sReceive;
+
+static bool sTransmitDone = false;
+
+static void usartReadCallback(struct usart_module *const usartModule)
+{
+    if (sReceive.mHead != (sReceive.mTail + 1) % kReceiveBufferSize)
+    {
+        sReceive.mTail = (sReceive.mTail + 1) % kReceiveBufferSize;
+    }
+
+    usart_read_job(&sUsartInstance,
+                   (uint16_t *)&sReceive.mBuffer[sReceive.mTail]);
+}
+
+static void usartWriteCallback(struct usart_module *const usartModule)
+{
+    sTransmitDone = true;
+}
+
+static void processReceive(void)
+{
+    // Copy tail to prevent multiple reads
+    uint16_t tail = sReceive.mTail;
+
+    // If the data wraps around, process the first part
+    if (sReceive.mHead > tail)
+    {
+        otPlatUartReceived(sReceive.mBuffer + sReceive.mHead, kReceiveBufferSize - sReceive.mHead);
+
+        // Reset the buffer mHead back to zero.
+        sReceive.mHead = 0;
+    }
+
+    // For any data remaining, process it
+    if (sReceive.mHead != tail)
+    {
+        otPlatUartReceived(sReceive.mBuffer + sReceive.mHead, tail - sReceive.mHead);
+
+        // Set mHead to the local tail we have cached
+        sReceive.mHead = tail;
+    }
+}
+
+static void processTransmit(void)
+{
+    if (sTransmitDone)
+    {
+        sTransmitDone = false;
+        otPlatUartSendDone();
+    }
+}
+
+void samr21UartProcess(void)
+{
+    processReceive();
+    processTransmit();
+}
+
+otError otPlatUartEnable(void)
+{
+    struct usart_config configUsart;
+
+    usart_get_config_defaults(&configUsart);
+
+    configUsart.baudrate    = 115200;
+    configUsart.mux_setting = UART_SERCOM_MUX_SETTING;
+    configUsart.pinmux_pad0 = UART_SERCOM_PINMUX_PAD0;
+    configUsart.pinmux_pad1 = UART_SERCOM_PINMUX_PAD1;
+    configUsart.pinmux_pad2 = UART_SERCOM_PINMUX_PAD2;
+    configUsart.pinmux_pad3 = UART_SERCOM_PINMUX_PAD3;
+
+    while (usart_init(&sUsartInstance, UART_SERCOM_MODULE, &configUsart)
+           != STATUS_OK);
+
+    usart_enable(&sUsartInstance);
+
+    sReceive.mHead = 0;
+    sReceive.mTail = 0;
+
+    usart_register_callback(&sUsartInstance, usartWriteCallback,
+                            USART_CALLBACK_BUFFER_TRANSMITTED);
+    usart_register_callback(&sUsartInstance, usartReadCallback,
+                            USART_CALLBACK_BUFFER_RECEIVED);
+
+    usart_enable_callback(&sUsartInstance, USART_CALLBACK_BUFFER_TRANSMITTED);
+    usart_enable_callback(&sUsartInstance, USART_CALLBACK_BUFFER_RECEIVED);
+
+    usart_read_job(&sUsartInstance,
+                   (uint16_t *)&sReceive.mBuffer[sReceive.mTail]);
+
+    return OT_ERROR_NONE;
+}
+
+otError otPlatUartDisable(void)
+{
+    usart_disable(&sUsartInstance);
+
+    return OT_ERROR_NONE;
+}
+
+otError otPlatUartSend(const uint8_t *aBuf, uint16_t aBufLength)
+{
+    otError error = OT_ERROR_NONE;
+
+    if (usart_write_buffer_job(&sUsartInstance, (uint8_t *)aBuf,
+                               aBufLength) != STATUS_OK)
+    {
+        error = OT_ERROR_FAILED;
+    }
+
+    return error;
+}
+