third_party/openthread/repo/examples/platforms/efr32mg1/uart.c

   1 /*
   2  *  Copyright (c) 2020, The OpenThread Authors.
   3  *  All rights reserved.
   4  *
   5  *  Redistribution and use in source and binary forms, with or without
   6  *  modification, are permitted provided that the following conditions are met:
   7  *  1. Redistributions of source code must retain the above copyright
   8  *     notice, this list of conditions and the following disclaimer.
   9  *  2. Redistributions in binary form must reproduce the above copyright
  10  *     notice, this list of conditions and the following disclaimer in the
  11  *     documentation and/or other materials provided with the distribution.
  12  *  3. Neither the name of the copyright holder nor the
  13  *     names of its contributors may be used to endorse or promote products
  14  *     derived from this software without specific prior written permission.
  15  *
  16  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  17  *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
  20  *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  21  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  22  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  23  *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  24  *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  25  *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  26  *  POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 /**
  30  * @file
  31  *   This file implements the OpenThread platform abstraction for UART communication.
  32  *
  33  */
  34
  35 #include <stddef.h>
  36
  37 #include "openthread-system.h"
  38 #include <openthread/platform/uart.h>
  39
  40 #include "utils/code_utils.h"
  41
  42 #include "em_core.h"
  43 #include "uartdrv.h"
  44
  45 #include "hal-config.h"
  46
  47 enum
  48 {
  49     kReceiveFifoSize = 128,
  50 };
  51
  52 #define USART_INIT                                                                               \
  53     {                                                                                            \
  54         USART0,                                               /* USART port */                   \
  55             115200,                                           /* Baud rate */                    \
  56             BSP_SERIAL_APP_TX_LOC,                            /* USART Tx pin location number */ \
  57             BSP_SERIAL_APP_RX_LOC,                            /* USART Rx pin location number */ \
  58             (USART_Stopbits_TypeDef)USART_FRAME_STOPBITS_ONE, /* Stop bits */                    \
  59             (USART_Parity_TypeDef)USART_FRAME_PARITY_NONE,    /* Parity */                       \
  60             (USART_OVS_TypeDef)USART_CTRL_OVS_X16,            /* Oversampling mode*/             \
  61             false,                                            /* Majority vote disable */        \
  62             HAL_SERIAL_APP_FLOW_CONTROL,                      /* Flow control */                 \
  63             BSP_SERIAL_APP_CTS_PORT,                          /* CTS port number */              \
  64             BSP_SERIAL_APP_CTS_PIN,                           /* CTS pin number */               \
  65             BSP_SERIAL_APP_RTS_PORT,                          /* RTS port number */              \
  66             BSP_SERIAL_APP_RTS_PIN,                           /* RTS pin number */               \
  67             (UARTDRV_Buffer_FifoQueue_t *)&sUartRxQueue,      /* RX operation queue */           \
  68             (UARTDRV_Buffer_FifoQueue_t *)&sUartTxQueue,      /* TX operation queue */           \
  69             BSP_SERIAL_APP_CTS_LOC,                           /* CTS location */                 \
  70             BSP_SERIAL_APP_RTS_LOC                            /* RTS location */                 \
  71     }
  72
  73 DEFINE_BUF_QUEUE(EMDRV_UARTDRV_MAX_CONCURRENT_RX_BUFS, sUartRxQueue);
  74 DEFINE_BUF_QUEUE(EMDRV_UARTDRV_MAX_CONCURRENT_TX_BUFS, sUartTxQueue);
  75
  76 static UARTDRV_HandleData_t sUartHandleData;
  77 static UARTDRV_Handle_t     sUartHandle = &sUartHandleData;
  78 static uint8_t              sReceiveBuffer[2];
  79 static const uint8_t *      sTransmitBuffer = NULL;
  80 static volatile uint16_t    sTransmitLength = 0;
  81
  82 typedef struct ReceiveFifo_t
  83 {
  84     // The data buffer
  85     uint8_t mBuffer[kReceiveFifoSize];
  86     // The offset of the first item written to the list.
  87     volatile uint16_t mHead;
  88     // The offset of the next item to be written to the list.
  89     volatile uint16_t mTail;
  90 } ReceiveFifo_t;
  91
  92 static ReceiveFifo_t sReceiveFifo;
  93
  94 static void processReceive(void);
  95
  96 static void receiveDone(UARTDRV_Handle_t aHandle, Ecode_t aStatus, uint8_t *aData, UARTDRV_Count_t aCount)
  97 {
  98     // We can only write if incrementing mTail doesn't equal mHead
  99     if (sReceiveFifo.mHead != (sReceiveFifo.mTail + 1) % kReceiveFifoSize)
 100     {
 101         sReceiveFifo.mBuffer[sReceiveFifo.mTail] = aData[0];
 102         sReceiveFifo.mTail                       = (sReceiveFifo.mTail + 1) % kReceiveFifoSize;
 103     }
 104
 105     UARTDRV_Receive(aHandle, aData, 1, receiveDone);
 106     otSysEventSignalPending();
 107 }
 108
 109 static void transmitDone(UARTDRV_Handle_t aHandle, Ecode_t aStatus, uint8_t *aData, UARTDRV_Count_t aCount)
 110 {
 111     sTransmitLength = 0;
 112     otSysEventSignalPending();
 113 }
 114
 115 static void processReceive(void)
 116 {
 117     // Copy tail to prevent multiple reads
 118     uint16_t tail = sReceiveFifo.mTail;
 119
 120     // If the data wraps around, process the first part
 121     if (sReceiveFifo.mHead > tail)
 122     {
 123         otPlatUartReceived(sReceiveFifo.mBuffer + sReceiveFifo.mHead, kReceiveFifoSize - sReceiveFifo.mHead);
 124
 125         // Reset the buffer mHead back to zero.
 126         sReceiveFifo.mHead = 0;
 127     }
 128
 129     // For any data remaining, process it
 130     if (sReceiveFifo.mHead != tail)
 131     {
 132         otPlatUartReceived(sReceiveFifo.mBuffer + sReceiveFifo.mHead, tail - sReceiveFifo.mHead);
 133
 134         // Set mHead to the local tail we have cached
 135         sReceiveFifo.mHead = tail;
 136     }
 137 }
 138
 139 otError otPlatUartFlush(void)
 140 {
 141     return OT_ERROR_NOT_IMPLEMENTED;
 142 }
 143
 144 static void processTransmit(void)
 145 {
 146     if (sTransmitBuffer != NULL && sTransmitLength == 0)
 147     {
 148         sTransmitBuffer = NULL;
 149         otPlatUartSendDone();
 150     }
 151 }
 152
 153 otError otPlatUartEnable(void)
 154 {
 155     UARTDRV_Init_t uartInit = USART_INIT;
 156
 157     sReceiveFifo.mHead = 0;
 158     sReceiveFifo.mTail = 0;
 159
 160     UARTDRV_Init(sUartHandle, &uartInit);
 161
 162     for (uint8_t i = 0; i < sizeof(sReceiveBuffer); i++)
 163     {
 164         UARTDRV_Receive(sUartHandle, &sReceiveBuffer[i], sizeof(sReceiveBuffer[i]), receiveDone);
 165     }
 166
 167     return OT_ERROR_NONE;
 168 }
 169
 170 otError otPlatUartDisable(void)
 171 {
 172     return OT_ERROR_NOT_IMPLEMENTED;
 173 }
 174
 175 otError otPlatUartSend(const uint8_t *aBuf, uint16_t aBufLength)
 176 {
 177     otError error = OT_ERROR_NONE;
 178
 179     otEXPECT_ACTION(sTransmitBuffer == NULL, error = OT_ERROR_BUSY);
 180
 181     sTransmitBuffer = aBuf;
 182     sTransmitLength = aBufLength;
 183
 184     UARTDRV_Transmit(sUartHandle, (uint8_t *)sTransmitBuffer, sTransmitLength, transmitDone);
 185
 186 exit:
 187     return error;
 188 }
 189
 190 void efr32UartProcess(void)
 191 {
 192     processReceive();
 193     processTransmit();
 194 }