radio/src/targets/horus/gps_driver.cpp

   1 /*
   2  * Copyright (C) OpenTX
   3  *
   4  * Based on code named
   5  *   th9x - http://code.google.com/p/th9x
   6  *   er9x - http://code.google.com/p/er9x
   7  *   gruvin9x - http://code.google.com/p/gruvin9x
   8  *
   9  * License GPLv2: http://www.gnu.org/licenses/gpl-2.0.html
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License version 2 as
  13  * published by the Free Software Foundation.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  */
  20
  21 #include "opentx.h"
  22
  23 #if GPS_USART_BAUDRATE > 9600
  24   Fifo<uint8_t, 256> gpsRxFifo;
  25 #else
  26   Fifo<uint8_t, 64> gpsRxFifo;
  27 #endif
  28
  29 void gpsInit(uint32_t baudrate)
  30 {
  31   GPIO_InitTypeDef GPIO_InitStructure;
  32   USART_InitTypeDef USART_InitStructure;
  33   NVIC_InitTypeDef NVIC_InitStructure;
  34
  35   // RX and TX pins
  36   GPIO_PinAFConfig(GPIOA, GPS_TX_GPIO_PinSource, GPS_GPIO_AF);
  37   GPIO_PinAFConfig(GPIOA, GPS_RX_GPIO_PinSource, GPS_GPIO_AF);
  38   GPIO_InitStructure.GPIO_Pin = (GPS_TX_GPIO_PIN | GPS_RX_GPIO_PIN);
  39   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
  40   GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  41   GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
  42   GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
  43   GPIO_Init(GPS_UART_GPIO, &GPIO_InitStructure);
  44
  45   // UART config
  46   USART_InitStructure.USART_BaudRate = baudrate;
  47   USART_InitStructure.USART_Parity = USART_Parity_No;
  48   USART_InitStructure.USART_StopBits = USART_StopBits_1;
  49   USART_InitStructure.USART_WordLength = USART_WordLength_8b;
  50   USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
  51   USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
  52   USART_Init(GPS_USART, &USART_InitStructure);
  53   USART_Cmd(GPS_USART, ENABLE);
  54   USART_ITConfig(GPS_USART, USART_IT_RXNE, ENABLE);
  55
  56   NVIC_InitStructure.NVIC_IRQChannel = GPS_USART_IRQn;
  57   NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x9;
  58   NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x0;
  59   NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  60   NVIC_Init(&NVIC_InitStructure);
  61 }
  62
  63 #if defined(DEBUG)
  64 uint8_t gpsTraceEnabled = false;
  65 #endif
  66
  67 Fifo<uint8_t, 64> gpsTxFifo;
  68
  69 void gpsSendByte(uint8_t byte)
  70 {
  71   while (gpsTxFifo.isFull());
  72   gpsTxFifo.push(byte);
  73   USART_ITConfig(GPS_USART, USART_IT_TXE, ENABLE);
  74 }
  75
  76 extern "C" void GPS_USART_IRQHandler(void)
  77 {
  78   // Send
  79   if (USART_GetITStatus(GPS_USART, USART_IT_TXE) != RESET) {
  80     uint8_t txchar;
  81     if (gpsTxFifo.pop(txchar)) {
  82       /* Write one byte to the transmit data register */
  83       USART_SendData(GPS_USART, txchar);
  84     }
  85     else {
  86       USART_ITConfig(GPS_USART, USART_IT_TXE, DISABLE);
  87     }
  88   }
  89
  90   // Receive
  91   uint32_t status = GPS_USART->SR;
  92   while (status & (USART_FLAG_RXNE | USART_FLAG_ERRORS)) {
  93     uint8_t data = GPS_USART->DR;
  94     if (!(status & USART_FLAG_ERRORS)) {
  95       gpsRxFifo.push(data);
  96     }
  97     status = GPS_USART->SR;
  98   }
  99 }
 100
 101 uint8_t gpsGetByte(uint8_t * byte)
 102 {
 103   uint8_t result = gpsRxFifo.pop(*byte);
 104 #if defined(DEBUG)
 105   if (gpsTraceEnabled) {
 106     serialPutc(*byte);
 107   }
 108 #endif
 109   return result;
 110 }