/**
******************************************************************************
*
* @file pios_usart.c
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
* Parts by Thorsten Klose (tk@midibox.org) (tk@midibox.org)
* @brief USART commands. Inits USARTs, controls USARTs & Interupt handlers.
* @see The GNU Public License (GPL) Version 3
* @defgroup PIOS_USART USART Functions
* @{
*
*****************************************************************************/
/*
* This program 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.
*
* This program 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 should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/* Project Includes */
#include "pios.h"
#if defined(PIOS_INCLUDE_USART)
/* Global Variables */
extern SettingsTypeDef Settings;
xSemaphoreHandle PIOS_USART1_Buffer;
xSemaphoreHandle PIOS_USART2_Buffer;
xSemaphoreHandle PIOS_USART3_Buffer;
static portBASE_TYPE xHigherPriorityTaskWoken;
/* Local Variables */
static uint8_t rx_buffer[PIOS_USART_NUM][PIOS_USART_RX_BUFFER_SIZE];
static volatile uint8_t rx_buffer_tail[PIOS_USART_NUM];
static volatile uint8_t rx_buffer_head[PIOS_USART_NUM];
static volatile uint8_t rx_buffer_size[PIOS_USART_NUM];
static uint8_t tx_buffer[PIOS_USART_NUM][PIOS_USART_TX_BUFFER_SIZE];
static volatile uint8_t tx_buffer_tail[PIOS_USART_NUM];
static volatile uint8_t tx_buffer_head[PIOS_USART_NUM];
static volatile uint8_t tx_buffer_size[PIOS_USART_NUM];
/**
* Initialise the GPS and TELEM onboard USARTs
*/
void PIOS_USART_Init(void)
{
/* Clear buffer counters */
uint8_t i;
for(i = 0; i < PIOS_USART_NUM; ++i) {
rx_buffer_tail[i] = rx_buffer_head[i] = rx_buffer_size[i] = 0;
tx_buffer_tail[i] = tx_buffer_head[i] = tx_buffer_size[i] = 0;
}
/* Configure USART Pins */
GPIO_InitTypeDef GPIO_InitStructure;
GPIO_StructInit(&GPIO_InitStructure);
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD;
/* Configure and Init USARTs */
USART_InitTypeDef USART_InitStructure;
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;
/* Configure the USART Interrupts */
NVIC_InitTypeDef NVIC_InitStructure;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
#if (PIOS_USART1_ENABLED)
/* Enable the USART Pins Software Remapping */
PIOS_USART1_REMAP_FUNC;
/* Configure and Init USART Tx as alternate function open-drain */
GPIO_InitStructure.GPIO_Pin = PIOS_USART1_TX_PIN;
GPIO_Init(PIOS_USART1_GPIO_PORT, &GPIO_InitStructure);
/* Configure and Init USART Rx input with internal pull-ups */
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
GPIO_InitStructure.GPIO_Pin = PIOS_USART1_RX_PIN;
GPIO_Init(PIOS_USART1_GPIO_PORT, &GPIO_InitStructure);
/* Enable USART clock */
PIOS_USART1_CLK_FUNC;
/* Enable USART Receive and Transmit interrupts */
USART_InitStructure.USART_BaudRate = PIOS_USART1_BAUDRATE;
USART_Init(PIOS_USART1_USART, &USART_InitStructure);
USART_ITConfig(PIOS_USART1_USART, USART_IT_RXNE, ENABLE);
USART_ITConfig(PIOS_USART1_USART, USART_IT_TXE, ENABLE);
/* Configure the USART Interrupts */
NVIC_InitStructure.NVIC_IRQChannel = PIOS_USART1_IRQ_CHANNEL;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = PIOS_USART1_NVIC_PRIO;
NVIC_Init(&NVIC_InitStructure);
USART_ITConfig(PIOS_USART1_USART, USART_IT_RXNE, ENABLE);
/* Enable USART */
USART_Cmd(PIOS_USART1_USART, ENABLE);
#endif
#if (PIOS_USART2_ENABLED)
/* Enable the USART Pins Software Remapping */
PIOS_USART2_REMAP_FUNC;
/* Configure and Init USART Tx as alternate function open-drain */
GPIO_InitStructure.GPIO_Pin = PIOS_USART2_TX_PIN;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD;
GPIO_Init(PIOS_USART2_GPIO_PORT, &GPIO_InitStructure);
/* Configure and Init USART Rx input with internal pull-ups */
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
GPIO_InitStructure.GPIO_Pin = PIOS_USART2_RX_PIN;
GPIO_Init(PIOS_USART2_GPIO_PORT, &GPIO_InitStructure);
/* Enable USART clock */
PIOS_USART2_CLK_FUNC;
/* Enable USART Receive and Transmit interrupts */
USART_InitStructure.USART_BaudRate = PIOS_USART2_BAUDRATE;
USART_Init(PIOS_USART2_USART, &USART_InitStructure);
USART_ITConfig(PIOS_USART2_USART, USART_IT_RXNE, ENABLE);
USART_ITConfig(PIOS_USART2_USART, USART_IT_TXE, ENABLE);
/* Configure the USART Interrupts */
NVIC_InitStructure.NVIC_IRQChannel = PIOS_USART2_IRQ_CHANNEL;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = PIOS_USART2_NVIC_PRIO;
NVIC_Init(&NVIC_InitStructure);
USART_ITConfig(PIOS_USART2_USART, USART_IT_RXNE, ENABLE);
/* Enable USART */
USART_Cmd(PIOS_USART2_USART, ENABLE);
#endif
#if (PIOS_USART3_ENABLED)
/* Enable the USART Pins Software Remapping */
PIOS_USART3_REMAP_FUNC;
/* Configure and Init USART Tx as alternate function open-drain */
GPIO_InitStructure.GPIO_Pin = PIOS_USART3_TX_PIN;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD;
GPIO_Init(PIOS_USART3_GPIO_PORT, &GPIO_InitStructure);
/* Configure and Init USART Rx input with internal pull-ups */
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
GPIO_InitStructure.GPIO_Pin = PIOS_USART3_RX_PIN;
GPIO_Init(PIOS_USART3_GPIO_PORT, &GPIO_InitStructure);
/* Enable USART clock */
PIOS_USART3_CLK_FUNC;
/* Enable USART Receive and Transmit interrupts */
USART_InitStructure.USART_BaudRate = PIOS_USART3_BAUDRATE;
USART_Init(PIOS_USART3_USART, &USART_InitStructure);
USART_ITConfig(PIOS_USART3_USART, USART_IT_RXNE, ENABLE);
USART_ITConfig(PIOS_USART3_USART, USART_IT_TXE, ENABLE);
/* Configure the USART Interrupts */
NVIC_InitStructure.NVIC_IRQChannel = PIOS_USART3_IRQ_CHANNEL;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = PIOS_USART3_NVIC_PRIO;
NVIC_Init(&NVIC_InitStructure);
USART_ITConfig(PIOS_USART3_USART, USART_IT_RXNE, ENABLE);
/* Enable USART */
USART_Cmd(PIOS_USART3_USART, ENABLE);
#endif
vSemaphoreCreateBinary(PIOS_USART1_Buffer);
vSemaphoreCreateBinary(PIOS_USART2_Buffer);
vSemaphoreCreateBinary(PIOS_USART3_Buffer);
}
/**
* Changes the baud rate of the USART peripheral without re-initialising.
* \param[in] USARTx USART name (GPS, TELEM, AUX)
* \param[in] Baud Requested baud rate
*/
void PIOS_USART_ChangeBaud(USART_TypeDef* USARTx, uint32_t Baud)
{
/* USART BRR Configuration */
/* Configure the USART Baud Rate */
/* Adapted from stm32f01x_usart.c */
uint32_t TmpReg = 0x00, ApbClock = 0x00;
uint32_t IntegerDivider = 0x00;
uint32_t FractionalDivider = 0x00;
uint32_t USARTxBase = (uint32_t)USARTx;
RCC_ClocksTypeDef RCC_ClocksStatus;
RCC_GetClocksFreq(&RCC_ClocksStatus);
if (USARTxBase == USART1_BASE) {
ApbClock = RCC_ClocksStatus.PCLK2_Frequency;
} else {
ApbClock = RCC_ClocksStatus.PCLK1_Frequency;
}
/* Determine the integer part */
IntegerDivider = ((0x19 * ApbClock) / (0x04 * (Baud)));
TmpReg = (IntegerDivider / 0x64) << 0x04;
/* Determine the fractional part */
FractionalDivider = IntegerDivider - (0x64 * (TmpReg >> 0x04));
TmpReg |= ((((FractionalDivider * 0x10) + 0x32) / 0x64)) & ((uint8_t)0x0F);
/* Write to USART BRR */
USARTx->BRR = (uint16_t)TmpReg;
}
/**
* Returns number of free bytes in receive buffer
* \param[in] USART USART name
* \return USART number of free bytes
* \return 1: USART available
* \return 0: USART not available
*/
int32_t PIOS_USART_RxBufferFree(USARTNumTypeDef usart)
{
if(usart >= PIOS_USART_NUM) {
return 0;
} else {
return PIOS_USART_RX_BUFFER_SIZE - rx_buffer_size[usart];
}
}
/**
* Returns number of used bytes in receive buffer
* \param[in] USART USART name
* \return > 0: number of used bytes
* \return 0 if USART not available
* \note Applications shouldn't call these functions directly, instead please use \ref PIOS_COM layer functions
*/
int32_t PIOS_USART_RxBufferUsed(USARTNumTypeDef usart)
{
if(usart >= PIOS_USART_NUM) {
return 0;
} else {
return rx_buffer_size[usart];
}
}
/**
* Gets a byte from the receive buffer
* \param[in] USART USART name
* \return -1 if USART not available
* \return -2 if no new byte available
* \return >= 0: number of received bytes
* \note Applications shouldn't call these functions directly, instead please use \ref PIOS_COM layer functions
*/
int32_t PIOS_USART_RxBufferGet(USARTNumTypeDef usart)
{
if(usart >= PIOS_USART_NUM) {
/* USART not available */
return -1;
}
if(!rx_buffer_size[usart]) {
/* nothing new in buffer */
return -2;
}
/* get byte - this operation should be atomic! */
PIOS_IRQ_Disable();
uint8_t b = rx_buffer[usart][rx_buffer_tail[usart]];
if(++rx_buffer_tail[usart] >= PIOS_USART_RX_BUFFER_SIZE) {
rx_buffer_tail[usart] = 0;
}
--rx_buffer_size[usart];
PIOS_IRQ_Enable();
/* Return received byte */
return b;
}
/**
* Returns the next byte of the receive buffer without taking it
* \param[in] USART USART name
* \return -1 if USART not available
* \return -2 if no new byte available
* \return >= 0: number of received bytes
* \note Applications shouldn't call these functions directly, instead please use \ref PIOS_COM layer functions
*/
int32_t PIOS_USART_RxBufferPeek(USARTNumTypeDef usart)
{
if(usart >= PIOS_USART_NUM) {
/* USART not available */
return -1;
}
if(!rx_buffer_size[usart]) {
/* Nothing new in buffer */
return -2;
}
/* Get byte - this operation should be atomic! */
PIOS_IRQ_Disable();
uint8_t b = rx_buffer[usart][rx_buffer_tail[usart]];
PIOS_IRQ_Enable();
/* Return received byte */
return b;
}
/**
* puts a byte onto the receive buffer
* \param[in] USART USART name
* \param[in] b byte which should be put into Rx buffer
* \return 0 if no error
* \return -1 if USART not available
* \return -2 if buffer full (retry)
* \note Applications shouldn't call these functions directly, instead please use \ref PIOS_COM layer functions
*/
int32_t PIOS_USART_RxBufferPut(USARTNumTypeDef usart, uint8_t b)
{
if(usart >= PIOS_USART_NUM) {
/* USART not available */
return -1;
}
if(rx_buffer_size[usart] >= PIOS_USART_RX_BUFFER_SIZE) {
/* Buffer full (retry) */
return -2;
}
/* Copy received byte into receive buffer */
/* This operation should be atomic! */
PIOS_IRQ_Disable();
rx_buffer[usart][rx_buffer_head[usart]] = b;
if(++rx_buffer_head[usart] >= PIOS_USART_RX_BUFFER_SIZE) {
rx_buffer_head[usart] = 0;
}
++rx_buffer_size[usart];
PIOS_IRQ_Enable();
switch(usart) {
case USART_1:
xSemaphoreGiveFromISR(PIOS_USART1_Buffer, &xHigherPriorityTaskWoken);
break;
case USART_2:
xSemaphoreGiveFromISR(PIOS_USART2_Buffer, &xHigherPriorityTaskWoken);
break;
case USART_3:
xSemaphoreGiveFromISR(PIOS_USART3_Buffer, &xHigherPriorityTaskWoken);
break;
}
/* No error */
return 0;
}
/**
* returns number of free bytes in transmit buffer
* \param[in] USART USART name
* \return number of free bytes
* \return 0 if USART not available
* \note Applications shouldn't call these functions directly, instead please use \ref PIOS_COM layer functions
*/
int32_t PIOS_USART_TxBufferFree(USARTNumTypeDef usart)
{
if(usart >= PIOS_USART_NUM) {
return 0;
} else {
return PIOS_USART_TX_BUFFER_SIZE - tx_buffer_size[usart];
}
}
/**
* returns number of used bytes in transmit buffer
* \param[in] USART USART name
* \return number of used bytes
* \return 0 if USART not available
* \note Applications shouldn't call these functions directly, instead please use \ref PIOS_COM layer functions
*/
int32_t PIOS_USART_TxBufferUsed(USARTNumTypeDef usart)
{
if(usart >= PIOS_USART_NUM) {
return 0;
} else {
return tx_buffer_size[usart];
}
}
/**
* gets a byte from the transmit buffer
* \param[in] USART USART name
* \return -1 if USART not available
* \return -2 if no new byte available
* \return >= 0: transmitted byte
* \note Applications shouldn't call these functions directly, instead please use \ref PIOS_COM layer functions
*/
int32_t PIOS_USART_TxBufferGet(USARTNumTypeDef usart)
{
if(usart >= PIOS_USART_NUM) {
/* USART not available */
return -1;
}
if(!tx_buffer_size[usart]) {
/* Nothing new in buffer */
return -2;
}
/* Get byte - this operation should be atomic! */
PIOS_IRQ_Disable();
uint8_t b = tx_buffer[usart][tx_buffer_tail[usart]];
if(++tx_buffer_tail[usart] >= PIOS_USART_TX_BUFFER_SIZE) {
tx_buffer_tail[usart] = 0;
}
--tx_buffer_size[usart];
PIOS_IRQ_Enable();
/* Return transmitted byte */
return b;
}
/**
* puts more than one byte onto the transmit buffer (used for atomic sends)
* \param[in] USART USART name
* \param[in] *buffer pointer to buffer to be sent
* \param[in] len number of bytes to be sent
* \return 0 if no error
* \return -1 if USART not available
* \return -2 if buffer full or cannot get all requested bytes (retry)
* \return -3 if USART not supported by USARTTxBufferPut Routine
* \note Applications shouldn't call these functions directly, instead please use \ref PIOS_COM layer functions
*/
int32_t PIOS_USART_TxBufferPutMoreNonBlocking(USARTNumTypeDef usart, uint8_t *buffer, uint16_t len)
{
if(usart >= PIOS_USART_NUM) {
/* USART not available */
return -1;
}
if((tx_buffer_size[usart]+len) >= PIOS_USART_TX_BUFFER_SIZE) {
/* Buffer full or cannot get all requested bytes (retry) */
return -2;
}
/* Copy bytes to be transmitted into transmit buffer */
/* This operation should be atomic! */
PIOS_IRQ_Disable();
uint16_t i;
for(i = 0; i < len; ++i) {
tx_buffer[usart][tx_buffer_head[usart]] = *buffer++;
if(++tx_buffer_head[usart] >= PIOS_USART_TX_BUFFER_SIZE) {
tx_buffer_head[usart] = 0;
}
/* Enable Tx interrupt if buffer was empty */
if(++tx_buffer_size[usart] == 1) {
switch(usart) {
/* Enable TXE interrupt (TXEIE=1) */
case 0: PIOS_USART1_USART->CR1 |= (1 << 7); break;
/* Enable TXE interrupt (TXEIE=1) */
case 1: PIOS_USART2_USART->CR1 |= (1 << 7); break;
/* Enable TXE interrupt (TXEIE=1) */
case 2: PIOS_USART3_USART->CR1 |= (1 << 7); break;
/* USART not supported by routine (yet) */
default: PIOS_IRQ_Enable(); return -3;
}
}
}
PIOS_IRQ_Enable();
/* No error */
return 0;
}
/**
* puts more than one byte onto the transmit buffer (used for atomic sends)
* (blocking function)
* \param[in] USART USART name
* \param[in] *buffer pointer to buffer to be sent
* \param[in] len number of bytes to be sent
* \return 0 if no error
* \return -1 if USART not available
* \return -3 if USART not supported by USARTTxBufferPut Routine
* \note Applications shouldn't call these functions directly, instead please use \ref PIOS_COM layer functions
*/
int32_t PIOS_USART_TxBufferPutMore(USARTNumTypeDef usart, uint8_t *buffer, uint16_t len)
{
int error;
while((error = PIOS_USART_TxBufferPutMoreNonBlocking(usart, buffer, len)) == -2);
return error;
}
/**
* puts a byte onto the transmit buffer
* \param[in] USART USART name
* \param[in] b byte which should be put into Tx buffer
* \return 0 if no error
* \return -1 if USART not available
* \return -2 if buffer full (retry)
* \return -3 if USART not supported by USARTTxBufferPut Routine
* \note Applications shouldn't call these functions directly, instead please use \ref PIOS_COM layer functions
*/
int32_t PIOS_USART_TxBufferPut_NonBlocking(USARTNumTypeDef usart, uint8_t b)
{
/* For more comfortable usage... */
/* -> Just forward to USARTTxBufferPutMore */
return PIOS_USART_TxBufferPutMore(usart, &b, 1);
}
/**
* puts a byte onto the transmit buffer
* (blocking function)
* \param[in] USART USART name
* \param[in] b byte which should be put into Tx buffer
* \return 0 if no error
* \return -1 if USART not available
* \return -3 if USART not supported by USARTTxBufferPut Routine
* \note Applications shouldn't call these functions directly, instead please use \ref PIOS_COM layer functions
*/
int32_t PIOS_USART_TxBufferPut(USARTNumTypeDef usart, uint8_t b)
{
int error;
while((error = PIOS_USART_TxBufferPutMore(usart, &b, 1)) == -2);
return error;
}
#if (PIOS_USART1_ENABLED)
/* Interrupt handler for USART1 */
PIOS_USART1_IRQHANDLER_FUNC
{
/* Check if RXNE flag is set */
if(PIOS_USART1_USART->SR & (1 << 5)) {
uint8_t b = PIOS_USART1_USART->DR;
if(PIOS_USART_RxBufferPut(USART_1, b) < 0) {
/* Here we could add some error handling */
}
}
/* Check if TXE flag is set */
if(PIOS_USART1_USART->SR & (1 << 7)) {
if(PIOS_USART_TxBufferUsed(USART_1) > 0) {
int b = PIOS_USART_TxBufferGet(USART_1);
if( b < 0 ) {
/* Here we could add some error handling */
PIOS_USART1_USART->DR = 0xff;
} else {
PIOS_USART1_USART->DR = b;
}
} else {
/* Disable TXE interrupt (TXEIE=0) */
PIOS_USART1_USART->CR1 &= ~(1 << 7);
}
}
}
#endif
#if (PIOS_USART1_ENABLED)
/* Interrupt handler for USART2 */
PIOS_USART2_IRQHANDLER_FUNC
{
/* check if RXNE flag is set */
if(PIOS_USART2_USART->SR & (1 << 5)) {
uint8_t b = PIOS_USART2_USART->DR;
if(PIOS_USART_RxBufferPut(USART_2, b) < 0) {
/* Here we could add some error handling */
}
}
/* Check if TXE flag is set */
if(PIOS_USART2_USART->SR & (1 << 7)) {
if(PIOS_USART_TxBufferUsed(USART_2) > 0) {
int b = PIOS_USART_TxBufferGet(USART_2);
if(b < 0) {
/* Here we could add some error handling */
PIOS_USART2_USART->DR = 0xff;
} else {
PIOS_USART2_USART->DR = b;
}
} else {
/* Disable TXE interrupt (TXEIE=0) */
PIOS_USART2_USART->CR1 &= ~(1 << 7);
}
}
}
#endif
#if (PIOS_USART1_ENABLED)
/* Interrupt handler for USART3 */
PIOS_USART3_IRQHANDLER_FUNC
{
/* check if RXNE flag is set */
if(PIOS_USART3_USART->SR & (1 << 5)) {
uint8_t b = PIOS_USART3_USART->DR;
if(PIOS_USART_RxBufferPut(USART_3, b) < 0) {
/* Here we could add some error handling */
}
}
if(PIOS_USART3_USART->SR & (1 << 7)) { // check if TXE flag is set
if(PIOS_USART_TxBufferUsed(USART_3) > 0) {
int b = PIOS_USART_TxBufferGet(USART_3);
if(b < 0) {
/* Here we could add some error handling */
PIOS_USART3_USART->DR = 0xff;
} else {
PIOS_USART3_USART->DR = b;
}
} else {
/* Disable TXE interrupt (TXEIE=0) */
PIOS_USART3_USART->CR1 &= ~(1 << 7);
}
}
}
#endif
#endif