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LibrePilot/flight/pios/stm32f4xx/pios_usart.c
2013-04-25 13:13:41 +03:00

358 lines
10 KiB
C

/**
******************************************************************************
* @addtogroup PIOS PIOS Core hardware abstraction layer
* @{
* @addtogroup PIOS_USART USART Functions
* @brief PIOS interface for USART port
* @{
*
* @file pios_usart.c
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2012.
* @brief USART commands. Inits USARTs, controls USARTs & Interupt handlers. (STM32 dependent)
* @see The GNU Public License (GPL) Version 3
*
*****************************************************************************/
/*
* 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
*/
/*
* @todo This is virtually identical to the F1xx driver and should be merged.
*/
#include "pios.h"
#ifdef PIOS_INCLUDE_USART
#include <pios_usart_priv.h>
/* Provide a COM driver */
static void PIOS_USART_ChangeBaud(uint32_t usart_id, uint32_t baud);
static void PIOS_USART_RegisterRxCallback(uint32_t usart_id, pios_com_callback rx_in_cb, uint32_t context);
static void PIOS_USART_RegisterTxCallback(uint32_t usart_id, pios_com_callback tx_out_cb, uint32_t context);
static void PIOS_USART_TxStart(uint32_t usart_id, uint16_t tx_bytes_avail);
static void PIOS_USART_RxStart(uint32_t usart_id, uint16_t rx_bytes_avail);
const struct pios_com_driver pios_usart_com_driver = {
.set_baud = PIOS_USART_ChangeBaud,
.tx_start = PIOS_USART_TxStart,
.rx_start = PIOS_USART_RxStart,
.bind_tx_cb = PIOS_USART_RegisterTxCallback,
.bind_rx_cb = PIOS_USART_RegisterRxCallback,
};
enum pios_usart_dev_magic {
PIOS_USART_DEV_MAGIC = 0x4152834A,
};
struct pios_usart_dev {
enum pios_usart_dev_magic magic;
const struct pios_usart_cfg * cfg;
pios_com_callback rx_in_cb;
uint32_t rx_in_context;
pios_com_callback tx_out_cb;
uint32_t tx_out_context;
};
static bool PIOS_USART_validate(struct pios_usart_dev * usart_dev)
{
return (usart_dev->magic == PIOS_USART_DEV_MAGIC);
}
#if defined(PIOS_INCLUDE_FREERTOS)
static struct pios_usart_dev * PIOS_USART_alloc(void)
{
struct pios_usart_dev * usart_dev;
usart_dev = (struct pios_usart_dev *)pvPortMalloc(sizeof(*usart_dev));
if (!usart_dev) return(NULL);
usart_dev->rx_in_cb = 0;
usart_dev->rx_in_context = 0;
usart_dev->tx_out_cb = 0;
usart_dev->tx_out_context = 0;
usart_dev->magic = PIOS_USART_DEV_MAGIC;
return(usart_dev);
}
#else
static struct pios_usart_dev pios_usart_devs[PIOS_USART_MAX_DEVS];
static uint8_t pios_usart_num_devs;
static struct pios_usart_dev * PIOS_USART_alloc(void)
{
struct pios_usart_dev * usart_dev;
if (pios_usart_num_devs >= PIOS_USART_MAX_DEVS) {
return (NULL);
}
usart_dev = &pios_usart_devs[pios_usart_num_devs++];
usart_dev->magic = PIOS_USART_DEV_MAGIC;
return (usart_dev);
}
#endif
/* Bind Interrupt Handlers
*
* Map all valid USART IRQs to the common interrupt handler
* and provide storage for a 32-bit device id IRQ to map
* each physical IRQ to a specific registered device instance.
*/
static void PIOS_USART_generic_irq_handler(uint32_t usart_id);
static uint32_t PIOS_USART_1_id;
void USART1_IRQHandler(void) __attribute__ ((alias ("PIOS_USART_1_irq_handler")));
static void PIOS_USART_1_irq_handler (void)
{
PIOS_USART_generic_irq_handler (PIOS_USART_1_id);
}
static uint32_t PIOS_USART_2_id;
void USART2_IRQHandler(void) __attribute__ ((alias ("PIOS_USART_2_irq_handler")));
static void PIOS_USART_2_irq_handler (void)
{
PIOS_USART_generic_irq_handler (PIOS_USART_2_id);
}
static uint32_t PIOS_USART_3_id;
void USART3_IRQHandler(void) __attribute__ ((alias ("PIOS_USART_3_irq_handler")));
static void PIOS_USART_3_irq_handler (void)
{
PIOS_USART_generic_irq_handler (PIOS_USART_3_id);
}
static uint32_t PIOS_USART_4_id;
void USART4_IRQHandler(void) __attribute__ ((alias ("PIOS_USART_4_irq_handler")));
static void PIOS_USART_4_irq_handler (void)
{
PIOS_USART_generic_irq_handler (PIOS_USART_4_id);
}
static uint32_t PIOS_USART_5_id;
void USART5_IRQHandler(void) __attribute__ ((alias ("PIOS_USART_5_irq_handler")));
static void PIOS_USART_5_irq_handler (void)
{
PIOS_USART_generic_irq_handler (PIOS_USART_5_id);
}
static uint32_t PIOS_USART_6_id;
void USART6_IRQHandler(void) __attribute__ ((alias ("PIOS_USART_6_irq_handler")));
static void PIOS_USART_6_irq_handler (void)
{
PIOS_USART_generic_irq_handler (PIOS_USART_6_id);
}
/**
* Initialise a single USART device
*/
int32_t PIOS_USART_Init(uint32_t * usart_id, const struct pios_usart_cfg * cfg)
{
PIOS_DEBUG_Assert(usart_id);
PIOS_DEBUG_Assert(cfg);
struct pios_usart_dev * usart_dev;
usart_dev = (struct pios_usart_dev *) PIOS_USART_alloc();
if (!usart_dev) goto out_fail;
/* Bind the configuration to the device instance */
usart_dev->cfg = cfg;
/* Map pins to USART function */
/* note __builtin_ctz() due to the difference between GPIO_PinX and GPIO_PinSourceX */
if (usart_dev->cfg->remap) {
GPIO_PinAFConfig(usart_dev->cfg->rx.gpio,
__builtin_ctz(usart_dev->cfg->rx.init.GPIO_Pin),
usart_dev->cfg->remap);
GPIO_PinAFConfig(usart_dev->cfg->tx.gpio,
__builtin_ctz(usart_dev->cfg->tx.init.GPIO_Pin),
usart_dev->cfg->remap);
}
/* Initialize the USART Rx and Tx pins */
GPIO_Init(usart_dev->cfg->rx.gpio, (GPIO_InitTypeDef *)&usart_dev->cfg->rx.init);
GPIO_Init(usart_dev->cfg->tx.gpio, (GPIO_InitTypeDef *)&usart_dev->cfg->tx.init);
/* Configure the USART */
USART_Init(usart_dev->cfg->regs, (USART_InitTypeDef *)&usart_dev->cfg->init);
*usart_id = (uint32_t)usart_dev;
/* Configure USART Interrupts */
switch ((uint32_t)usart_dev->cfg->regs) {
case (uint32_t)USART1:
PIOS_USART_1_id = (uint32_t)usart_dev;
break;
case (uint32_t)USART2:
PIOS_USART_2_id = (uint32_t)usart_dev;
break;
case (uint32_t)USART3:
PIOS_USART_3_id = (uint32_t)usart_dev;
break;
case (uint32_t)UART4:
PIOS_USART_4_id = (uint32_t)usart_dev;
break;
case (uint32_t)UART5:
PIOS_USART_5_id = (uint32_t)usart_dev;
break;
case (uint32_t)USART6:
PIOS_USART_6_id = (uint32_t)usart_dev;
break;
}
NVIC_Init((NVIC_InitTypeDef *)&(usart_dev->cfg->irq.init));
USART_ITConfig(usart_dev->cfg->regs, USART_IT_RXNE, ENABLE);
USART_ITConfig(usart_dev->cfg->regs, USART_IT_TXE, ENABLE);
// FIXME XXX Clear / reset uart here - sends NUL char else
/* Enable USART */
USART_Cmd(usart_dev->cfg->regs, ENABLE);
return(0);
out_fail:
return(-1);
}
static void PIOS_USART_RxStart(uint32_t usart_id, uint16_t rx_bytes_avail)
{
struct pios_usart_dev * usart_dev = (struct pios_usart_dev *)usart_id;
bool valid = PIOS_USART_validate(usart_dev);
PIOS_Assert(valid);
USART_ITConfig(usart_dev->cfg->regs, USART_IT_RXNE, ENABLE);
}
static void PIOS_USART_TxStart(uint32_t usart_id, uint16_t tx_bytes_avail)
{
struct pios_usart_dev * usart_dev = (struct pios_usart_dev *)usart_id;
bool valid = PIOS_USART_validate(usart_dev);
PIOS_Assert(valid);
USART_ITConfig(usart_dev->cfg->regs, USART_IT_TXE, ENABLE);
}
/**
* Changes the baud rate of the USART peripheral without re-initialising.
* \param[in] usart_id USART name (GPS, TELEM, AUX)
* \param[in] baud Requested baud rate
*/
static void PIOS_USART_ChangeBaud(uint32_t usart_id, uint32_t baud)
{
struct pios_usart_dev * usart_dev = (struct pios_usart_dev *)usart_id;
bool valid = PIOS_USART_validate(usart_dev);
PIOS_Assert(valid);
USART_InitTypeDef USART_InitStructure;
/* Start with a copy of the default configuration for the peripheral */
USART_InitStructure = usart_dev->cfg->init;
/* Adjust the baud rate */
USART_InitStructure.USART_BaudRate = baud;
/* Write back the new configuration */
USART_Init(usart_dev->cfg->regs, &USART_InitStructure);
}
static void PIOS_USART_RegisterRxCallback(uint32_t usart_id, pios_com_callback rx_in_cb, uint32_t context)
{
struct pios_usart_dev * usart_dev = (struct pios_usart_dev *)usart_id;
bool valid = PIOS_USART_validate(usart_dev);
PIOS_Assert(valid);
/*
* Order is important in these assignments since ISR uses _cb
* field to determine if it's ok to dereference _cb and _context
*/
usart_dev->rx_in_context = context;
usart_dev->rx_in_cb = rx_in_cb;
}
static void PIOS_USART_RegisterTxCallback(uint32_t usart_id, pios_com_callback tx_out_cb, uint32_t context)
{
struct pios_usart_dev * usart_dev = (struct pios_usart_dev *)usart_id;
bool valid = PIOS_USART_validate(usart_dev);
PIOS_Assert(valid);
/*
* Order is important in these assignments since ISR uses _cb
* field to determine if it's ok to dereference _cb and _context
*/
usart_dev->tx_out_context = context;
usart_dev->tx_out_cb = tx_out_cb;
}
static void PIOS_USART_generic_irq_handler(uint32_t usart_id)
{
struct pios_usart_dev * usart_dev = (struct pios_usart_dev *)usart_id;
bool valid = PIOS_USART_validate(usart_dev);
PIOS_Assert(valid);
/* Force read of dr after sr to make sure to clear error flags */
volatile uint16_t sr = usart_dev->cfg->regs->SR;
volatile uint8_t dr = usart_dev->cfg->regs->DR;
/* Check if RXNE flag is set */
bool rx_need_yield = false;
if (sr & USART_SR_RXNE) {
uint8_t byte = dr;
if (usart_dev->rx_in_cb) {
(void) (usart_dev->rx_in_cb)(usart_dev->rx_in_context, &byte, 1, NULL, &rx_need_yield);
}
}
/* Check if TXE flag is set */
bool tx_need_yield = false;
if (sr & USART_SR_TXE) {
if (usart_dev->tx_out_cb) {
uint8_t b;
uint16_t bytes_to_send;
bytes_to_send = (usart_dev->tx_out_cb)(usart_dev->tx_out_context, &b, 1, NULL, &tx_need_yield);
if (bytes_to_send > 0) {
/* Send the byte we've been given */
usart_dev->cfg->regs->DR = b;
} else {
/* No bytes to send, disable TXE interrupt */
USART_ITConfig(usart_dev->cfg->regs, USART_IT_TXE, DISABLE);
}
} else {
/* No bytes to send, disable TXE interrupt */
USART_ITConfig(usart_dev->cfg->regs, USART_IT_TXE, DISABLE);
}
}
#if defined(PIOS_INCLUDE_FREERTOS)
if (rx_need_yield || tx_need_yield) {
vPortYieldFromISR();
}
#endif /* PIOS_INCLUDE_FREERTOS */
}
#endif /* PIOS_INCLUDE_USART */
/**
* @}
* @}
*/