openblt/Target/Source/ARMCM4_STM32F4/uart.c

270 lines
11 KiB
C

/************************************************************************************//**
* \file Source\ARMCM4_STM32F4\uart.c
* \brief Bootloader UART communication interface source file.
* \ingroup Target_ARMCM4_STM32F4
* \internal
*----------------------------------------------------------------------------------------
* C O P Y R I G H T
*----------------------------------------------------------------------------------------
* Copyright (c) 2013 by Feaser http://www.feaser.com All rights reserved
*
*----------------------------------------------------------------------------------------
* L I C E N S E
*----------------------------------------------------------------------------------------
* This file is part of OpenBLT. OpenBLT is free software: you can redistribute it and/or
* modify it under the terms of the GNU General Public License as published by the Free
* Software Foundation, either version 3 of the License, or (at your option) any later
* version.
*
* OpenBLT is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU General Public License for more details.
*
* You have received a copy of the GNU General Public License along with OpenBLT. It
* should be located in ".\Doc\license.html". If not, contact Feaser to obtain a copy.
*
* \endinternal
****************************************************************************************/
/****************************************************************************************
* Include files
****************************************************************************************/
#include "boot.h" /* bootloader generic header */
#include "stm32f4xx.h" /* STM32 registers */
#include "stm32f4xx_conf.h" /* STM32 peripheral drivers */
#if (BOOT_COM_UART_ENABLE > 0)
/****************************************************************************************
* Macro definitions
****************************************************************************************/
/** \brief Timeout time for the reception of a CTO packet. The timer is started upon
* reception of the first packet byte.
*/
#define UART_CTO_RX_PACKET_TIMEOUT_MS (100u)
/** \brief Timeout for transmitting a byte in milliseconds. */
#define UART_BYTE_TX_TIMEOUT_MS (10u)
/* map the configured UART channel index to the STM32's USART peripheral */
#if (BOOT_COM_UART_CHANNEL_INDEX == 0)
/** \brief Set UART base address to USART1. */
#define USART_CHANNEL USART1
#elif (BOOT_COM_UART_CHANNEL_INDEX == 1)
/** \brief Set UART base address to USART2. */
#define USART_CHANNEL USART2
#elif (BOOT_COM_UART_CHANNEL_INDEX == 2)
/** \brief Set UART base address to USART3. */
#define USART_CHANNEL USART3
#elif (BOOT_COM_UART_CHANNEL_INDEX == 3)
/** \brief Set UART base address to USART4. */
#define USART_CHANNEL USART4
#elif (BOOT_COM_UART_CHANNEL_INDEX == 4)
/** \brief Set UART base address to USART5. */
#define USART_CHANNEL USART5
#elif (BOOT_COM_UART_CHANNEL_INDEX == 5)
/** \brief Set UART base address to USART6. */
#define USART_CHANNEL USART6
#endif
/****************************************************************************************
* Function prototypes
****************************************************************************************/
static blt_bool UartReceiveByte(blt_int8u *data);
static blt_bool UartTransmitByte(blt_int8u data);
/************************************************************************************//**
** \brief Initializes the UART communication interface.
** \return none.
**
****************************************************************************************/
void UartInit(void)
{
USART_InitTypeDef USART_InitStructure;
/* the current implementation supports USART1 - USART6. throw an assertion error in
* case a different UART channel is configured.
*/
ASSERT_CT((BOOT_COM_UART_CHANNEL_INDEX == 0) ||
(BOOT_COM_UART_CHANNEL_INDEX == 1) ||
(BOOT_COM_UART_CHANNEL_INDEX == 2) ||
(BOOT_COM_UART_CHANNEL_INDEX == 3) ||
(BOOT_COM_UART_CHANNEL_INDEX == 4) ||
(BOOT_COM_UART_CHANNEL_INDEX == 5));
/* initialize the uart for the specified communication speed */
USART_InitStructure.USART_BaudRate = BOOT_COM_UART_BAUDRATE;
USART_InitStructure.USART_WordLength = USART_WordLength_8b;
USART_InitStructure.USART_StopBits = USART_StopBits_1;
USART_InitStructure.USART_Parity = USART_Parity_No;
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
USART_Init(USART_CHANNEL, &USART_InitStructure);
/* enable UART */
USART_Cmd(USART_CHANNEL, ENABLE);
} /*** end of UartInit ***/
/************************************************************************************//**
** \brief Transmits a packet formatted for the communication interface.
** \param data Pointer to byte array with data that it to be transmitted.
** \param len Number of bytes that are to be transmitted.
** \return none.
**
****************************************************************************************/
void UartTransmitPacket(blt_int8u *data, blt_int8u len)
{
blt_int16u data_index;
blt_bool result;
/* verify validity of the len-paramenter */
ASSERT_RT(len <= BOOT_COM_UART_TX_MAX_DATA);
/* first transmit the length of the packet */
result = UartTransmitByte(len);
ASSERT_RT(result == BLT_TRUE);
/* transmit all the packet bytes one-by-one */
for (data_index = 0; data_index < len; data_index++)
{
/* keep the watchdog happy */
CopService();
/* write byte */
result = UartTransmitByte(data[data_index]);
ASSERT_RT(result == BLT_TRUE);
}
} /*** end of UartTransmitPacket ***/
/************************************************************************************//**
** \brief Receives a communication interface packet if one is present.
** \param data Pointer to byte array where the data is to be stored.
** \param len Pointer where the length of the packet is to be stored.
** \return BLT_TRUE if a packet was received, BLT_FALSE otherwise.
**
****************************************************************************************/
blt_bool UartReceivePacket(blt_int8u *data, blt_int8u *len)
{
static blt_int8u xcpCtoReqPacket[BOOT_COM_UART_RX_MAX_DATA+1]; /* one extra for length */
static blt_int8u xcpCtoRxLength;
static blt_bool xcpCtoRxInProgress = BLT_FALSE;
static blt_int32u xcpCtoRxStartTime = 0;
/* start of cto packet received? */
if (xcpCtoRxInProgress == BLT_FALSE)
{
/* store the message length when received */
if (UartReceiveByte(&xcpCtoReqPacket[0]) == BLT_TRUE)
{
if ( (xcpCtoReqPacket[0] > 0) &&
(xcpCtoReqPacket[0] <= BOOT_COM_UART_RX_MAX_DATA) )
{
/* store the start time */
xcpCtoRxStartTime = TimerGet();
/* reset packet data count */
xcpCtoRxLength = 0;
/* indicate that a cto packet is being received */
xcpCtoRxInProgress = BLT_TRUE;
}
}
}
else
{
/* store the next packet byte */
if (UartReceiveByte(&xcpCtoReqPacket[xcpCtoRxLength+1]) == BLT_TRUE)
{
/* increment the packet data count */
xcpCtoRxLength++;
/* check to see if the entire packet was received */
if (xcpCtoRxLength == xcpCtoReqPacket[0])
{
/* copy the packet data */
CpuMemCopy((blt_int32u)data, (blt_int32u)&xcpCtoReqPacket[1], xcpCtoRxLength);
/* done with cto packet reception */
xcpCtoRxInProgress = BLT_FALSE;
/* set the packet length */
*len = xcpCtoRxLength;
/* packet reception complete */
return BLT_TRUE;
}
}
else
{
/* check packet reception timeout */
if (TimerGet() > (xcpCtoRxStartTime + UART_CTO_RX_PACKET_TIMEOUT_MS))
{
/* cancel cto packet reception due to timeout. note that that automaticaly
* discards the already received packet bytes, allowing the host to retry.
*/
xcpCtoRxInProgress = BLT_FALSE;
}
}
}
/* packet reception not yet complete */
return BLT_FALSE;
} /*** end of UartReceivePacket ***/
/************************************************************************************//**
** \brief Receives a communication interface byte if one is present.
** \param data Pointer to byte where the data is to be stored.
** \return BLT_TRUE if a byte was received, BLT_FALSE otherwise.
**
****************************************************************************************/
static blt_bool UartReceiveByte(blt_int8u *data)
{
/* check flag to see if a byte was received */
if (USART_GetFlagStatus(USART_CHANNEL, USART_FLAG_RXNE) == SET)
{
/* retrieve and store the newly received byte */
*data = (blt_int8u)USART_ReceiveData(USART_CHANNEL);
/* all done */
return BLT_TRUE;
}
/* still here to no new byte received */
return BLT_FALSE;
} /*** end of UartReceiveByte ***/
/************************************************************************************//**
** \brief Transmits a communication interface byte.
** \param data Value of byte that is to be transmitted.
** \return BLT_TRUE if the byte was transmitted, BLT_FALSE otherwise.
**
****************************************************************************************/
static blt_bool UartTransmitByte(blt_int8u data)
{
blt_int32u timeout;
blt_bool result = BLT_TRUE;
/* check if tx holding register can accept new data */
if (USART_GetFlagStatus(USART_CHANNEL, USART_FLAG_TXE) == RESET)
{
/* UART not ready. should not happen */
return BLT_FALSE;
}
/* write byte to transmit holding register */
USART_SendData(USART_CHANNEL, data);
/* set timeout time to wait for transmit completion. */
timeout = TimerGet() + UART_BYTE_TX_TIMEOUT_MS;
/* wait for tx holding register to be empty */
while (USART_GetFlagStatus(USART_CHANNEL, USART_FLAG_TXE) == RESET)
{
/* keep the watchdog happy */
CopService();
/* break loop upon timeout. this would indicate a hardware failure. */
if (TimerGet() > timeout)
{
result = BLT_FALSE;
break;
}
}
/* give the result back to the caller */
return result;
} /*** end of UartTransmitByte ***/
#endif /* BOOT_COM_UART_ENABLE > 0 */
/*********************************** end of uart.c *************************************/