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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 AT91SAM7/serial_lld.c
* @brief AT91SAM7 low level serial driver code.
* @addtogroup AT91SAM7_SERIAL
* @{
*/
#include "ch.h"
#include "hal.h"
#if CH_HAL_USE_SERIAL || defined(__DOXYGEN__)
#if SAM7_PLATFORM == SAM7S256
#define SAM7_USART0_RX AT91C_PA5_RXD0
#define SAM7_USART0_TX AT91C_PA6_TXD0
#define SAM7_USART1_RX AT91C_PA21_RXD1
#define SAM7_USART1_TX AT91C_PA22_TXD1
#elif SAM7_PLATFORM == SAM7X256
#define SAM7_USART0_RX AT91C_PA0_RXD0
#define SAM7_USART0_TX AT91C_PA1_TXD0
#define SAM7_USART1_RX AT91C_PA5_RXD1
#define SAM7_USART1_TX AT91C_PA6_TXD1
#else
#error "serial lines not defined for this SAM7 version"
#endif
/*===========================================================================*/
/* Driver exported variables. */
/*===========================================================================*/
#if USE_SAM7_USART0 || defined(__DOXYGEN__)
/** @brief USART0 serial driver identifier.*/
SerialDriver SD1;
#endif
#if USE_SAM7_USART1 || defined(__DOXYGEN__)
/** @brief USART1 serial driver identifier.*/
SerialDriver SD2;
#endif
/*===========================================================================*/
/* Driver local variables. */
/*===========================================================================*/
/** @brief Driver default configuration.*/
static const SerialDriverConfig default_config = {
38400,
AT91C_US_USMODE_NORMAL | AT91C_US_CLKS_CLOCK |
AT91C_US_CHRL_8_BITS | AT91C_US_PAR_NONE | AT91C_US_NBSTOP_1_BIT
};
/*===========================================================================*/
/* Driver local functions. */
/*===========================================================================*/
/**
* @brief USART initialization.
* @param[in] u pointer to an USART I/O block
* @param[in] config the architecture-dependent serial driver configuration
*/
static void usart_init(AT91PS_USART u, const SerialDriverConfig *config) {
/* Disables IRQ sources and stop operations.*/
u->US_IDR = 0xFFFFFFFF;
u->US_CR = AT91C_US_RSTRX | AT91C_US_RSTTX | AT91C_US_RSTSTA;
/* New parameters setup.*/
if (config->mr & AT91C_US_OVER)
u->US_BRGR = MCK / (config->speed * 8);
else
u->US_BRGR = MCK / (config->speed * 16);
u->US_MR = config->mr;
u->US_RTOR = 0;
u->US_TTGR = 0;
/* Enables operations and IRQ sources.*/
u->US_CR = AT91C_US_RXEN | AT91C_US_TXEN | AT91C_US_DTREN | AT91C_US_RTSEN;
u->US_IER = AT91C_US_RXRDY | AT91C_US_OVRE | AT91C_US_FRAME | AT91C_US_PARE |
AT91C_US_RXBRK;
}
/**
* @brief USART de-initialization.
* @param[in] u pointer to an USART I/O block
*/
static void usart_deinit(AT91PS_USART u) {
/* Disables IRQ sources and stop operations.*/
u->US_IDR = 0xFFFFFFFF;
u->US_CR = AT91C_US_RSTRX | AT91C_US_RSTTX | AT91C_US_RSTSTA;
u->US_MR = 0;
u->US_RTOR = 0;
u->US_TTGR = 0;
}
/**
* @brief Error handling routine.
* @param[in] err USART CSR register value
* @param[in] sdp communication channel associated to the USART
*/
static void set_error(AT91_REG csr, SerialDriver *sdp) {
sdflags_t sts = 0;
if (csr & AT91C_US_OVRE)
sts |= SD_OVERRUN_ERROR;
if (csr & AT91C_US_PARE)
sts |= SD_PARITY_ERROR;
if (csr & AT91C_US_FRAME)
sts |= SD_FRAMING_ERROR;
if (csr & AT91C_US_RXBRK)
sts |= SD_BREAK_DETECTED;
chSysLockFromIsr();
sdAddFlagsI(sdp, sts);
chSysUnlockFromIsr();
}
#if defined(__GNU__)
__attribute__((noinline))
#endif
/**
* @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(AT91PS_USART u, SerialDriver *sdp) {
if (u->US_CSR & AT91C_US_RXRDY) {
chSysLockFromIsr();
sdIncomingDataI(sdp, u->US_RHR);
chSysUnlockFromIsr();
}
if (u->US_CSR & AT91C_US_TXRDY) {
chSysLockFromIsr();
msg_t b = sdRequestDataI(sdp);
chSysUnlockFromIsr();
if (b < Q_OK)
u->US_IDR = AT91C_US_TXRDY;
else
u->US_THR = b;
}
if (u->US_CSR & (AT91C_US_OVRE | AT91C_US_FRAME | AT91C_US_PARE | AT91C_US_RXBRK)) {
set_error(u->US_CSR, sdp);
u->US_CR = AT91C_US_RSTSTA;
}
AT91C_BASE_AIC->AIC_EOICR = 0;
}
#if USE_SAM7_USART0 || defined(__DOXYGEN__)
static void notify1(void) {
AT91C_BASE_US0->US_IER = AT91C_US_TXRDY;
}
#endif
#if USE_SAM7_USART1 || defined(__DOXYGEN__)
static void notify2(void) {
AT91C_BASE_US1->US_IER = AT91C_US_TXRDY;
}
#endif
/*===========================================================================*/
/* Driver interrupt handlers. */
/*===========================================================================*/
#if USE_SAM7_USART0 || defined(__DOXYGEN__)
CH_IRQ_HANDLER(USART0IrqHandler) {
CH_IRQ_PROLOGUE();
serve_interrupt(AT91C_BASE_US0, &SD1);
CH_IRQ_EPILOGUE();
}
#endif
#if USE_SAM7_USART1 || defined(__DOXYGEN__)
CH_IRQ_HANDLER(USART1IrqHandler) {
CH_IRQ_PROLOGUE();
serve_interrupt(AT91C_BASE_US1, &SD2);
CH_IRQ_EPILOGUE();
}
#endif
/*===========================================================================*/
/* Driver exported functions. */
/*===========================================================================*/
/**
* Low level serial driver initialization.
*/
void sd_lld_init(void) {
#if USE_SAM7_USART0
sdObjectInit(&SD1, NULL, notify1);
AT91C_BASE_PIOA->PIO_PDR = SAM7_USART0_RX | SAM7_USART0_TX;
AT91C_BASE_PIOA->PIO_ASR = SAM7_USART0_RX | SAM7_USART0_TX;
AT91C_BASE_PIOA->PIO_PPUDR = SAM7_USART0_RX | SAM7_USART0_TX;
AIC_ConfigureIT(AT91C_ID_US0,
AT91C_AIC_SRCTYPE_HIGH_LEVEL | SAM7_USART0_PRIORITY,
USART0IrqHandler);
#endif
#if USE_SAM7_USART1
sdObjectInit(&SD2, NULL, notify2);
AT91C_BASE_PIOA->PIO_PDR = SAM7_USART1_RX | SAM7_USART1_TX;
AT91C_BASE_PIOA->PIO_ASR = SAM7_USART1_RX | SAM7_USART1_TX;
AT91C_BASE_PIOA->PIO_PPUDR = SAM7_USART1_RX | SAM7_USART1_TX;
AIC_ConfigureIT(AT91C_ID_US1,
AT91C_AIC_SRCTYPE_HIGH_LEVEL | SAM7_USART1_PRIORITY,
USART1IrqHandler);
#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_SAM7_USART0
if (&SD1 == sdp) {
/* Starts the clock and clears possible sources of immediate interrupts.*/
AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_US0);
/* USART initialization.*/
usart_init(AT91C_BASE_US0, config);
/* Enables associated interrupt vector.*/
AIC_EnableIT(AT91C_ID_US0);
return;
}
#endif
#if USE_SAM7_USART1
if (&SD2 == sdp) {
/* Starts the clock and clears possible sources of immediate interrupts.*/
AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_US1);
/* USART initialization.*/
usart_init(AT91C_BASE_US1, config);
/* Enables associated interrupt vector.*/
AIC_EnableIT(AT91C_ID_US1);
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_SAM7_USART0
if (&SD1 == sdp) {
usart_deinit(AT91C_BASE_US0);
AT91C_BASE_PMC->PMC_PCDR = (1 << AT91C_ID_US0);
AIC_DisableIT(AT91C_ID_US0);
return;
}
#endif
#if USE_SAM7_USART1
if (&SD2 == sdp) {
usart_deinit(AT91C_BASE_US1);
AT91C_BASE_PMC->PMC_PCDR = (1 << AT91C_ID_US1);
AIC_DisableIT(AT91C_ID_US1);
return;
}
#endif
}
#endif /* CH_HAL_USE_SERIAL */
/** @} */
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