tinySA/ports/MSP430/msp430_serial.c

/*
    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 ports/MSP430/msp430_serial.c
 * @brief MSP430 Serial driver code.
 * @addtogroup MSP430_SERIAL
 * @{
 */

#include <ch.h>
#include <signal.h>

#include "board.h"
#include "msp430_serial.h"

static void SetError(uint8_t urctl, FullDuplexDriver *com) {
  dflags_t sts = 0;

  if (urctl & OE)
    sts |= SD_OVERRUN_ERROR;
  if (urctl & PE)
    sts |= SD_PARITY_ERROR;
  if (urctl & FE)
    sts |= SD_FRAMING_ERROR;
  if (urctl & BRK)
    sts |= SD_BREAK_DETECTED;
  chSysLockFromIsr();
  chFDDAddFlagsI(com, sts);
  chSysUnlockFromIsr();
}

#if USE_MSP430_USART0 || defined(__DOXYGEN__)

/** @brief USART0 serial driver identifier.*/
FullDuplexDriver COM1;

static uint8_t ib1[SERIAL_BUFFERS_SIZE];
static uint8_t ob1[SERIAL_BUFFERS_SIZE];

CH_IRQ_HANDLER(USART0TX_VECTOR) {
  msg_t b;

  CH_IRQ_PROLOGUE();

  chSysLockFromIsr();
  b = chFDDRequestDataI(&COM1);
  chSysUnlockFromIsr();
  if (b < Q_OK)
    U0IE &= ~UTXIE0;
  else
    U0TXBUF = b;

  CH_IRQ_EPILOGUE();
}

CH_IRQ_HANDLER(USART0RX_VECTOR) {
  uint8_t urctl;

  CH_IRQ_PROLOGUE();

  if ((urctl = U0RCTL) & RXERR)
    SetError(urctl, &COM1);
  chSysLockFromIsr();
  chFDDIncomingDataI(&COM1, U0RXBUF);
  chSysUnlockFromIsr();

  CH_IRQ_EPILOGUE();
}

static void OutNotify1(void) {

  if (!(U0IE & UTXIE0)) {
    chSysLockFromIsr();
    U0TXBUF = (uint8_t)chFDDRequestDataI(&COM1);
    chSysUnlockFromIsr();
    U0IE |= UTXIE0;
  }
}

/**
 * @brief USART0 setup.
 * @details This function must be invoked with interrupts disabled.
 * @param div The divider value as calculated by the @p UBR() macro.
 * @param mod The value for the @p U0MCTL register.
 * @param ctl The value for the @p U0CTL register.
 * @note Does not reset the I/O queues.
 */
void usart0_setup(uint16_t div, uint8_t mod, uint8_t ctl) {

  U0CTL = SWRST;                /* Resets the USART, it should already be */
  /* USART init */
  U0TCTL = SSEL0 | SSEL1;       /* SMCLK as clock source */
  U0MCTL = mod;                 /* Modulator */
  U0BR1 = (uint8_t)(div >> 8);  /* Divider high */
  U0BR0 = (uint8_t)(div >> 0);  /* Divider low */
  /* Clear USART status */
  (void)U0RXBUF;
  U0RCTL = 0;
  /* USART enable */
  P3SEL |= BV(4) + BV(5);       /* I/O pins for USART 0 */
  U0ME |= UTXE0 + URXE0;        /* Enables the USART */
  U0CTL = ctl & ~SWRST;         /* Various settings, clears reset state */
  U0IE |= URXIE0;               /* Enables RX interrupt */
}
#endif /* USE_MSP430_USART0 */

#if USE_MSP430_USART1 || defined(__DOXYGEN__)

/** @brief USART1 serial driver identifier.*/
FullDuplexDriver COM2;

static uint8_t ib2[SERIAL_BUFFERS_SIZE];
static uint8_t ob2[SERIAL_BUFFERS_SIZE];

CH_IRQ_HANDLER(USART1TX_VECTOR) {
  msg_t b;

  CH_IRQ_PROLOGUE();

  chSysLockFromIsr();
  b = chFDDRequestDataI(&COM2);
  chSysUnlockFromIsr();
  if (b < Q_OK)
    U1IE &= ~UTXIE1;
  else
    U1TXBUF = b;

  CH_IRQ_EPILOGUE();
}

CH_IRQ_HANDLER(USART1RX_VECTOR) {
  uint8_t urctl;

  CH_IRQ_PROLOGUE();

  if ((urctl = U1RCTL) & RXERR)
    SetError(urctl, &COM2);
  chSysLockFromIsr();
  chFDDIncomingDataI(&COM2, U1RXBUF);
  chSysUnlockFromIsr();

  CH_IRQ_EPILOGUE();
}

static void OutNotify2(void) {

  if (!(U1IE & UTXIE1)) {
    U1TXBUF = (uint8_t)chFDDRequestDataI(&COM2);
    U1IE |= UTXIE1;
  }
}

/**
 * @brief USART1 setup.
 * @details This function must be invoked with interrupts disabled.
 * @param[in] div the divider value as calculated by the @p UBR() macro
 * @param[in] mod the value for the @p U1MCTL register
 * @param[in] ctl the value for the @p U1CTL register.
 * @note Must be invoked with interrupts disabled.
 * @note Does not reset the I/O queues.
 */
void usart1_setup(uint16_t div, uint8_t mod, uint8_t ctl) {

  U1CTL = SWRST;                /* Resets the USART, it should already be */
  /* USART init */
  U1TCTL = SSEL0 | SSEL1;       /* SMCLK as clock source */
  U1MCTL = mod;                 /* Modulator */
  U1BR1 = (uint8_t)(div >> 8);  /* Divider high */
  U1BR0 = (uint8_t)(div >> 0);  /* Divider low */
  /* Clear USART status */
  (void)U0RXBUF;
  U1RCTL = 0;
  /* USART enable */
  P3SEL |= BV(6) + BV(7);       /* I/O pins for USART 1 */
  U1ME |= UTXE0 + URXE0;        /* Enables the USART */
  U1CTL = ctl & ~SWRST;         /* Various settings, clears reset state */
  U1IE |= URXIE0;               /* Enables RX interrupt */
}
#endif

/**
 * @brief Serial driver initialization.
 * @note The serial ports are initialized at @p 38400-8-N-1 by default.
 */
void serial_init(void) {

  /* I/O queues setup.*/
#if USE_MSP430_USART0
  chFDDInit(&COM1, ib1, sizeof ib1, NULL, ob1, sizeof ob1, OutNotify1);
  usart0_setup(UBR(DEFAULT_USART_BITRATE), 0, CHAR);
#endif

#if USE_MSP430_USART1
  chFDDInit(&COM2, ib2, sizeof ib2, NULL, ob2, sizeof ob2, OutNotify2);
  usart1_setup(UBR(DEFAULT_USART_BITRATE), 0, CHAR);
#endif
}

/** @} */