/**
 ******************************************************************************
 *
 * @file       pios_opahrs.c  
 * @author     The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
 * @brief      IRQ Enable/Disable routines
 * @see        The GNU Public License (GPL) Version 3
 * @defgroup   PIOS_OPAHRS OPAHRS Functions
 * @{
 * 
 *****************************************************************************/
/* 
 * 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
 */

/* Project Includes */
#include "pios.h"

#if defined(PIOS_INCLUDE_OPAHRS)

#include "pios_opahrs_proto.h"
#include "pios_opahrs.h"

/**
* Initialise the OpenPilot AHRS
*/
void PIOS_OPAHRS_Init(void)
{
  PIOS_SPI_SetClockSpeed(PIOS_OPAHRS_SPI, PIOS_SPI_PRESCALER_4);
}

static int32_t opahrs_msg_txrx (const uint8_t * tx, uint8_t * rx, uint32_t len)
{
  int32_t rc;

  PIOS_SPI_RC_PinSet(PIOS_OPAHRS_SPI, 0);
  vTaskDelay(20 / portTICK_RATE_MS);
  rc = PIOS_SPI_TransferBlock(PIOS_OPAHRS_SPI, tx, rx, len, NULL);
  PIOS_SPI_RC_PinSet(PIOS_OPAHRS_SPI, 1);
  return (rc);
}

static enum opahrs_result opahrs_msg_v1_send_req (const struct opahrs_msg_v1 * req)
{
  struct opahrs_msg_v1   link_rx;

  for (uint8_t retries = 0; retries < 20; retries++) {
    struct opahrs_msg_v1 * rsp = &link_rx;

    if (opahrs_msg_txrx((const uint8_t *)req, (uint8_t *)rsp, sizeof(*rsp)) < 0) {
      return OPAHRS_RESULT_FAILED;
    }

    /* Make sure we got a sane response by checking the magic */
    if ((rsp->head.magic != OPAHRS_MSG_MAGIC_HEAD) ||
	(rsp->tail.magic != OPAHRS_MSG_MAGIC_TAIL)) {
      return OPAHRS_RESULT_FAILED;
    }

    switch (rsp->head.type) {
    case OPAHRS_MSG_TYPE_LINK:
      switch (rsp->payload.link.state) {
      case OPAHRS_MSG_LINK_STATE_BUSY:
      case OPAHRS_MSG_LINK_STATE_INACTIVE:
	/* Wait for a small delay and retry */
	vTaskDelay(20 / portTICK_RATE_MS);
	continue;
      case OPAHRS_MSG_LINK_STATE_READY:
	/* Peer was ready when we Tx'd so they have now Rx'd our message */
	return OPAHRS_RESULT_OK;
      }
      break;
    case OPAHRS_MSG_TYPE_USER_V0:
    case OPAHRS_MSG_TYPE_USER_V1:
      /* Wait for a small delay and retry */
      vTaskDelay(20 / portTICK_RATE_MS);
      continue;
    }
  }

  return OPAHRS_RESULT_TIMEOUT;
}

static enum opahrs_result opahrs_msg_v1_recv_rsp (enum opahrs_msg_v1_tag tag, struct opahrs_msg_v1 * rsp)
{
  struct opahrs_msg_v1 link_tx;

  opahrs_msg_v1_init_link_tx(&link_tx, OPAHRS_MSG_LINK_TAG_NOP);

  for (uint8_t retries = 0; retries < 20; retries++) {
    if (opahrs_msg_txrx((const uint8_t *)&link_tx, (uint8_t *)rsp, sizeof(*rsp)) < 0) {
      return OPAHRS_RESULT_FAILED;
    }

    /* Make sure we got a sane response by checking the magic */
    if ((rsp->head.magic != OPAHRS_MSG_MAGIC_HEAD) ||
	(rsp->tail.magic != OPAHRS_MSG_MAGIC_TAIL)) {
      return OPAHRS_RESULT_FAILED;
    }
      
    switch (rsp->head.type) {
    case OPAHRS_MSG_TYPE_LINK:
      switch (rsp->payload.link.state) {
      case OPAHRS_MSG_LINK_STATE_BUSY:
	/* Wait for a small delay and retry */
	vTaskDelay(20 / portTICK_RATE_MS);
	continue;
      case OPAHRS_MSG_LINK_STATE_INACTIVE:
      case OPAHRS_MSG_LINK_STATE_READY:
	/* somehow, we've missed our response */
	return OPAHRS_RESULT_FAILED;
      }
      break;
    case OPAHRS_MSG_TYPE_USER_V0:
      /* This isn't the type we expected */
      return OPAHRS_RESULT_FAILED;
      break;
    case OPAHRS_MSG_TYPE_USER_V1:
      if (rsp->payload.user.t == tag) {
	return OPAHRS_RESULT_OK;
      } else {
	return OPAHRS_RESULT_FAILED;
      }
      break;
    }
  }

  return OPAHRS_RESULT_TIMEOUT;
}

enum opahrs_result PIOS_OPAHRS_GetSerial(struct opahrs_msg_v1 *rsp)
{
  struct opahrs_msg_v1 req;
  enum opahrs_result   rc;

  if (!rsp) {
    return -1;
  }

  /* Make up a serial number request */
  opahrs_msg_v1_init_user_tx (&req, OPAHRS_MSG_V1_REQ_SERIAL);

  /* Send the message until it is received */
  rc = opahrs_msg_v1_send_req (&req);
  if (rc != OPAHRS_RESULT_OK) {
    /* Failed to send the request, bail out */
    return rc;
  }

  return opahrs_msg_v1_recv_rsp (OPAHRS_MSG_V1_RSP_SERIAL, rsp);
}

enum opahrs_result PIOS_OPAHRS_resync(void)
{
  struct opahrs_msg_v1 req;
  struct opahrs_msg_v1 rsp;

  enum opahrs_result rc = OPAHRS_RESULT_FAILED;

  opahrs_msg_v1_init_link_tx(&req, OPAHRS_MSG_LINK_TAG_NOP);

  PIOS_SPI_RC_PinSet(PIOS_OPAHRS_SPI, 0);
  vTaskDelay(20 / portTICK_RATE_MS);

  for (uint32_t i = 0; i < sizeof(req); i++) {
    /* Tx a shortened (by one byte) message to walk through all byte positions */
    opahrs_msg_v1_init_rx(&rsp);
    PIOS_SPI_TransferBlock(PIOS_OPAHRS_SPI, (uint8_t *)&req, (uint8_t *)&rsp, sizeof(req)-1, NULL);

    /* Good magic means we're sync'd */
    if ((rsp.head.magic == OPAHRS_MSG_MAGIC_HEAD) &&
	(rsp.tail.magic == OPAHRS_MSG_MAGIC_TAIL)) {
      /* We need to shift out one more byte to compensate for the short tx */
      PIOS_SPI_TransferByte(PIOS_OPAHRS_SPI, 0x00);
      rc = OPAHRS_RESULT_OK;
      break;
    }
    vTaskDelay(10 / portTICK_RATE_MS);
  }

  PIOS_SPI_RC_PinSet(PIOS_OPAHRS_SPI, 1);
  //vTaskDelay(5 / portTICK_RATE_MS);

  return rc;
}

extern enum opahrs_result PIOS_OPAHRS_Sync(struct opahrs_msg_v1 *rsp)
{
  struct opahrs_msg_v1 req;
  enum opahrs_result   rc;

  if (!rsp) {
    return -1;
  }

  /* Make up a sync request */
  opahrs_msg_v1_init_user_tx (&req, OPAHRS_MSG_V1_REQ_SYNC);
  req.payload.user.v.req.sync.cookie = 0xDEADBEEF;

  /* Send the message until it is received */
  rc = opahrs_msg_v1_send_req (&req);
  if (rc != OPAHRS_RESULT_OK) {
    /* Failed to send the request, bail out */
    return rc;
  }

  return opahrs_msg_v1_recv_rsp (OPAHRS_MSG_V1_RSP_SYNC, rsp);
}


enum opahrs_result PIOS_OPAHRS_GetHeading(struct opahrs_msg_v1 *rsp)
{
  struct opahrs_msg_v1 req;
  enum opahrs_result   rc;

  if (!rsp) {
    return -1;
  }

  /* Make up a serial number request */
  opahrs_msg_v1_init_user_tx (&req, OPAHRS_MSG_V1_REQ_HEADING);

  /* Send the message until it is received */
  rc = opahrs_msg_v1_send_req (&req);
  if (rc != OPAHRS_RESULT_OK) {
    /* Failed to send the request, bail out */
    return rc;
  }

  return opahrs_msg_v1_recv_rsp (OPAHRS_MSG_V1_RSP_HEADING, rsp);
}

enum opahrs_result PIOS_OPAHRS_GetAttitude(struct opahrs_msg_v1 *rsp)
{
  struct opahrs_msg_v1 req;
  enum opahrs_result   rc;

  if (!rsp) {
    return -1;
  }

  /* Make up a serial number request */
  opahrs_msg_v1_init_user_tx (&req, OPAHRS_MSG_V1_REQ_ATTITUDE);

  /* Send the message until it is received */
  rc = opahrs_msg_v1_send_req (&req);
  if (rc != OPAHRS_RESULT_OK) {
    /* Failed to send the request, bail out */
    return rc;
  }

  return opahrs_msg_v1_recv_rsp (OPAHRS_MSG_V1_RSP_ATTITUDE, rsp);
}

#endif /* PIOS_INCLUDE_OPAHRS */