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/*
ChibiOS/RT - Copyright (C) 2006-2007 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT 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.
ChibiOS/RT 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, see <http://www.gnu.org/licenses/>.
*/
/**
* @file STM32/serial_lld.c
* @brief STM32 low level serial driver code
* @addtogroup STM32_SERIAL
* @{
*/
#include <ch.h>
#include <serial.h>
#include <nvic.h>
#include <board.h>
#if USE_STM32_USART1 || defined(__DOXYGEN__)
/** @brief USART1 serial driver identifier.*/
SerialDriver SD1;
#endif
#if USE_STM32_USART2 || defined(__DOXYGEN__)
/** @brief USART2 serial driver identifier.*/
SerialDriver SD2;
#endif
#if USE_STM32_USART3 || defined(__DOXYGEN__)
/** @brief USART3 serial driver identifier.*/
SerialDriver SD3;
#endif
/** @brief Driver default configuration.*/
static const SerialDriverConfig default_config =
{
38400,
0,
USART_CR2_STOP1_BITS | USART_CR2_LINEN,
0
};
/*===========================================================================*/
/* Low Level Driver local functions. */
/*===========================================================================*/
/**
* @brief USART initialization.
* @details This function must be invoked with interrupts disabled.
*
* @param[in] u pointer to an USART I/O block
* @param[in] config the architecture-dependent serial driver configuration
*/
static void usart_init(USART_TypeDef *u, const SerialDriverConfig *config) {
/*
* Baud rate setting.
*/
if (u == USART1)
u->BRR = APB2CLK / config->speed;
else
u->BRR = APB1CLK / config->speed;
/*
* Note that some bits are enforced.
*/
u->CR1 = config->cr1 | USART_CR1_UE | USART_CR1_PEIE | USART_CR1_RXNEIE |
USART_CR1_TE | USART_CR1_RE;
u->CR2 = config->cr2;
u->CR3 = config->cr3 | USART_CR3_EIE;
}
/**
* @brief USART de-initialization.
* @details This function must be invoked with interrupts disabled.
*
* @param[in] u pointer to an USART I/O block
*/
static void usart_deinit(USART_TypeDef *u) {
u->CR1 = 0;
u->CR2 = 0;
u->CR3 = 0;
}
/**
* @brief Error handling routine.
* @param[in] sr USART SR register value
* @param[in] com communication channel associated to the USART
*/
static void set_error(uint16_t sr, SerialDriver *sdp) {
sdflags_t sts = 0;
if (sr & USART_SR_ORE)
sts |= SD_OVERRUN_ERROR;
if (sr & USART_SR_PE)
sts |= SD_PARITY_ERROR;
if (sr & USART_SR_FE)
sts |= SD_FRAMING_ERROR;
if (sr & USART_SR_LBD)
sts |= SD_BREAK_DETECTED;
chSysLockFromIsr();
sdAddFlagsI(sdp, sts);
chSysUnlockFromIsr();
}
/**
* @brief Common IRQ handler.
* @param[in] u pointer to an USART I/O block
* @param[in] com communication channel associated to the USART
*/
static void serve_interrupt(USART_TypeDef *u, SerialDriver *sdp) {
uint16_t sr = u->SR;
if (sr & (USART_SR_ORE | USART_SR_FE | USART_SR_PE | USART_SR_LBD))
set_error(sr, sdp);
if (sr & USART_SR_RXNE) {
chSysLockFromIsr();
sdIncomingDataI(sdp, u->DR);
chSysUnlockFromIsr();
}
if (sr & USART_SR_TXE) {
chSysLockFromIsr();
msg_t b = sdRequestDataI(sdp);
chSysUnlockFromIsr();
if (b < Q_OK)
u->CR1 &= ~USART_CR1_TXEIE;
else
u->DR = b;
}
}
#if USE_STM32_USART1 || defined(__DOXYGEN__)
static void notify1(void) {
USART1->CR1 |= USART_CR1_TXEIE;
}
#endif
#if USE_STM32_USART2 || defined(__DOXYGEN__)
static void notify2(void) {
USART2->CR1 |= USART_CR1_TXEIE;
}
#endif
#if USE_STM32_USART3 || defined(__DOXYGEN__)
static void notify3(void) {
USART3->CR1 |= USART_CR1_TXEIE;
}
#endif
/*===========================================================================*/
/* Low Level Driver interrupt handlers. */
/*===========================================================================*/
#if USE_STM32_USART1 || defined(__DOXYGEN__)
CH_IRQ_HANDLER(VectorD4) {
CH_IRQ_PROLOGUE();
serve_interrupt(USART1, &SD1);
CH_IRQ_EPILOGUE();
}
#endif
#if USE_STM32_USART2 || defined(__DOXYGEN__)
CH_IRQ_HANDLER(VectorD8) {
CH_IRQ_PROLOGUE();
serve_interrupt(USART2, &SD2);
CH_IRQ_EPILOGUE();
}
#endif
#if USE_STM32_USART3 || defined(__DOXYGEN__)
CH_IRQ_HANDLER(VectorDC) {
CH_IRQ_PROLOGUE();
serve_interrupt(USART3, &SD3);
CH_IRQ_EPILOGUE();
}
#endif
/*===========================================================================*/
/* Low Level Driver exported functions. */
/*===========================================================================*/
/**
* Low level serial driver initialization.
*/
void sd_lld_init(void) {
#if USE_STM32_USART1
sdObjectInit(&SD1, NULL, notify1);
GPIOA->CRH = (GPIOA->CRH & 0xFFFFF00F) | 0x000004B0;
#endif
#if USE_STM32_USART2
sdObjectInit(&SD2, NULL, notify2);
GPIOA->CRL = (GPIOA->CRL & 0xFFFF00FF) | 0x00004B00;
#endif
#if USE_STM32_USART3
sdObjectInit(&SD3, NULL, notify3);
GPIOB->CRH = (GPIOB->CRH & 0xFFFF00FF) | 0x00004B00;
#endif
}
/**
* @brief Low level serial driver configuration and (re)start.
*
* @param[in] sdp pointer to a @p SerialDriver object
* @param[in] config the architecture-dependent serial driver configuration.
* If this parameter is set to @p NULL then a default
* configuration is used.
*/
void sd_lld_start(SerialDriver *sdp, const SerialDriverConfig *config) {
if (config == NULL)
config = &default_config;
#if USE_STM32_USART1
if (&SD1 == sdp) {
RCC->APB2ENR |= RCC_APB2ENR_USART1EN;
usart_init(USART1, config);
NVICEnableVector(USART1_IRQn, STM32_USART1_PRIORITY);
return;
}
#endif
#if USE_STM32_USART2
if (&SD2 == sdp) {
RCC->APB1ENR |= RCC_APB1ENR_USART2EN;
usart_init(USART2, config);
NVICEnableVector(USART2_IRQn, STM32_USART2_PRIORITY);
return;
}
#endif
#if USE_STM32_USART3
if (&SD3 == sdp) {
RCC->APB1ENR |= RCC_APB1ENR_USART3EN;
usart_init(USART3, config);
NVICEnableVector(USART3_IRQn, STM32_USART3_PRIORITY);
return;
}
#endif
}
/**
* @brief Low level serial driver stop.
* @details De-initializes the USART, stops the associated clock, resets the
* interrupt vector.
*
* @param[in] sdp pointer to a @p SerialDriver object
*/
void sd_lld_stop(SerialDriver *sdp) {
#if USE_STM32_USART1
if (&SD1 == sdp) {
usart_deinit(USART1);
RCC->APB2ENR &= ~RCC_APB2ENR_USART1EN;
NVICDisableVector(USART1_IRQn);
return;
}
#endif
#if USE_STM32_USART2
if (&SD2 == sdp) {
usart_deinit(USART2);
RCC->APB1ENR &= ~RCC_APB1ENR_USART2EN;
NVICDisableVector(USART2_IRQn);
return;
}
#endif
#if USE_STM32_USART3
if (&SD3 == sdp) {
usart_deinit(USART3);
RCC->APB1ENR &= ~RCC_APB1ENR_USART3EN;
NVICDisableVector(USART3_IRQn);
return;
}
#endif
}
/** @} */
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