/*
    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 chserial.c
 * @brief Serial Drivers code.
 * @addtogroup Serial
 * @{
 */

#include <ch.h>

#if CH_USE_SERIAL_FULLDUPLEX

/*
 * Interface implementation, the following functions just invoke the equivalent
 * queue-level function or macro.
 */
static bool_t putwouldblock(void *instance) {

  return chOQIsFull(&((FullDuplexDriver *)instance)->d2.oqueue);
}

static bool_t getwouldblock(void *instance) {

  return chIQIsEmpty(&((FullDuplexDriver *)instance)->d2.iqueue);
}

static msg_t put(void *instance, uint8_t b, systime_t timeout) {

  return chOQPutTimeout(&((FullDuplexDriver *)instance)->d2.oqueue, b, timeout);
}

static msg_t get(void *instance, systime_t timeout) {

  return chIQGetTimeout(&((FullDuplexDriver *)instance)->d2.iqueue, timeout);
}

static size_t write(void *instance, uint8_t *buffer, size_t n) {

  return chOQWrite(&((FullDuplexDriver *)instance)->d2.oqueue, buffer, n);
}

static size_t read(void *instance, uint8_t *buffer, size_t n) {

  return chIQRead(&((FullDuplexDriver *)instance)->d2.iqueue, buffer, n);
}

static const struct FullDuplexDriverVMT vmt = {
  {putwouldblock, getwouldblock, put, get},
  {write, read},
  {}
};

/**
 * @brief Initializes a generic full duplex driver.
 * @details The HW dependent part of the initialization has to be performed
 *          outside, usually in the hardware initialization code.
 *
 * @param[out] sd pointer to a @p FullDuplexDriver structure
 * @param[in] ib pointer to a memory area allocated for the Input Queue buffer
 * @param[in] isize size of the Input Queue buffer
 * @param[in] inotify pointer to a callback function that is invoked when
 *                    some data is read from the Queue. The value can be
 *                    @p NULL.
 * @param[in] ob pointer to a memory area allocated for the Output Queue buffer
 * @param[in] osize size of the Output Queue buffer
 * @param[in] onotify pointer to a callback function that is invoked when
 *                    some data is written in the Queue. The value can be
 *                    @p NULL.
 */
void chFDDInit(FullDuplexDriver *sd,
               uint8_t *ib, size_t isize, qnotify_t inotify,
               uint8_t *ob, size_t osize, qnotify_t onotify) {

  chDbgCheck((sd != NULL) && (ib != NULL) && (ob != NULL) &&
             (isize > 0) && (osize > 0), "chFDDInit");

  sd->vmt = &vmt;
  chEvtInit(&sd->d1.ievent);
  chEvtInit(&sd->d1.oevent);
  chEvtInit(&sd->d2.sevent);
  sd->d2.flags = SD_NO_ERROR;
  chIQInit(&sd->d2.iqueue, ib, isize, inotify);
  chOQInit(&sd->d2.oqueue, ob, osize, onotify);
}

/**
 * @brief Handles incoming data.
 * @details This function must be called from the input interrupt service
 *          routine in order to enqueue incoming data and generate the
 *          related events.
 * @param[in] sd pointer to a @p FullDuplexDriver structure
 * @param[in] b the byte to be written in the driver's Input Queue
 */
void chFDDIncomingDataI(FullDuplexDriver *sd, uint8_t b) {

  if (chIQPutI(&sd->d2.iqueue, b) < Q_OK)
    chFDDAddFlagsI(sd, SD_OVERRUN_ERROR);
  else
    chEvtBroadcastI(&sd->d1.ievent);
}

/**
 * @brief Handles outgoing data.
 * @details Must be called from the output interrupt service routine in order
 *          to get the next byte to be transmitted.
 *
 * @param[in] sd pointer to a @p FullDuplexDriver structure
 * @return The byte value read from the driver's output queue.
 * @retval Q_EMPTY if the queue is empty (the lower driver usually disables
 *                 the interrupt source when this happens).
 */
msg_t chFDDRequestDataI(FullDuplexDriver *sd) {

  msg_t b = chOQGetI(&sd->d2.oqueue);
  if (b < Q_OK)
    chEvtBroadcastI(&sd->d1.oevent);
  return b;
}

/**
 * @brief Handles communication events/errors.
 * @details Must be called from the I/O interrupt service routine in order to
 *          notify I/O conditions as errors, signals change etc.
 *
 * @param[in] sd pointer to a @p FullDuplexDriver structure
 * @param[in] mask condition flags to be added to the mask
 */
void chFDDAddFlagsI(FullDuplexDriver *sd, dflags_t mask) {

  sd->d2.flags |= mask;
  chEvtBroadcastI(&sd->d2.sevent);
}

/**
 * @brief Returns and clears the errors mask associated to the driver.
 *
 * @param[in] sd pointer to a @p FullDuplexDriver structure
 * @return The condition flags modified since last time this function was
 *         invoked.
 */
dflags_t chFDDGetAndClearFlags(FullDuplexDriver *sd) {
  dflags_t mask;

  mask = sd->d2.flags;
  sd->d2.flags = SD_NO_ERROR;
  return mask;
}
#endif /* CH_USE_SERIAL_FULLDUPLEX */

/** @} */