/******************************************************************************
 *
 *  $Id$
 *
 *  Copyright (C) 2006-2008  Florian Pose, Ingenieurgemeinschaft IgH
 *
 *  This file is part of the IgH EtherCAT Master.
 *
 *  The IgH EtherCAT Master is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License version 2, as
 *  published by the Free Software Foundation.
 *
 *  The IgH EtherCAT Master 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 the IgH EtherCAT Master; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 *  ---
 *
 *  The license mentioned above concerns the source code only. Using the
 *  EtherCAT technology and brand is only permitted in compliance with the
 *  industrial property and similar rights of Beckhoff Automation GmbH.
 *
 *****************************************************************************/

/** \file
 * EtherCAT slave (SDO) state machine.
 */

/*****************************************************************************/

#include "globals.h"
#include "master.h"
#include "mailbox.h"

#include "fsm_slave.h"

/*****************************************************************************/

void ec_fsm_slave_state_idle(ec_fsm_slave_t *);
void ec_fsm_slave_state_ready(ec_fsm_slave_t *);
int ec_fsm_slave_action_process_sdo(ec_fsm_slave_t *);
void ec_fsm_slave_state_sdo_request(ec_fsm_slave_t *);
int ec_fsm_slave_action_process_foe(ec_fsm_slave_t *);
void ec_fsm_slave_state_foe_request(ec_fsm_slave_t *);
int ec_fsm_slave_action_process_soe(ec_fsm_slave_t *);
void ec_fsm_slave_state_soe_request(ec_fsm_slave_t *);

/*****************************************************************************/

/** Constructor.
 */
void ec_fsm_slave_init(
        ec_fsm_slave_t *fsm, /**< Slave state machine. */
        ec_slave_t *slave, /**< EtherCAT slave. */
        ec_datagram_t *datagram /**< Datagram object to use. */
        )
{
    fsm->slave = slave;
    fsm->datagram = datagram;
    fsm->datagram->data_size = 0;

    EC_SLAVE_DBG(slave, 1, "Init FSM.\n");

    fsm->state = ec_fsm_slave_state_idle;

    // init sub-state-machines
    ec_fsm_coe_init(&fsm->fsm_coe, fsm->datagram);
    ec_fsm_foe_init(&fsm->fsm_foe, fsm->datagram);
    ec_fsm_soe_init(&fsm->fsm_soe, fsm->datagram);
}

/*****************************************************************************/

/** Destructor.
 */
void ec_fsm_slave_clear(
        ec_fsm_slave_t *fsm /**< Master state machine. */
        )
{
    // clear sub-state machines
    ec_fsm_coe_clear(&fsm->fsm_coe);
    ec_fsm_foe_clear(&fsm->fsm_foe);
    ec_fsm_soe_clear(&fsm->fsm_soe);
}

/*****************************************************************************/

/** Executes the current state of the state machine.
 *
 * If the state machine's datagram is not sent or received yet, the execution
 * of the state machine is delayed to the next cycle.
 */
void ec_fsm_slave_exec(
        ec_fsm_slave_t *fsm /**< Slave state machine. */
        )
{
    if (fsm->datagram->state == EC_DATAGRAM_SENT
        || fsm->datagram->state == EC_DATAGRAM_QUEUED) {
        // datagram was not sent or received yet.
        return;
    }

    fsm->state(fsm);
}

/*****************************************************************************/

/** Sets the current state of the state machine to READY
 */
void ec_fsm_slave_ready(
        ec_fsm_slave_t *fsm /**< Slave state machine. */
        )
{
    if (fsm->state == ec_fsm_slave_state_idle) {
        EC_SLAVE_DBG(fsm->slave, 1, "Ready for requests.\n");
        fsm->state = ec_fsm_slave_state_ready;
    }
}

/******************************************************************************
 * Slave state machine
 *****************************************************************************/

/** Slave state: IDLE.
 */
void ec_fsm_slave_state_idle(
        ec_fsm_slave_t *fsm /**< Slave state machine. */
        )
{
    // do nothing
}


/*****************************************************************************/

/** Slave state: READY.
 */
void ec_fsm_slave_state_ready(
        ec_fsm_slave_t *fsm /**< Slave state machine. */
        )
{
    // Check for pending external SDO requests
    if (ec_fsm_slave_action_process_sdo(fsm)) {
        return;
    }

    // Check for pending FoE requests
    if (ec_fsm_slave_action_process_foe(fsm)) {
        return;
    }

    // Check for pending SoE requests
    if (ec_fsm_slave_action_process_soe(fsm)) {
        return;
    }
}

/*****************************************************************************/

/** Check for pending SDO requests and process one.
 *
 * \return non-zero, if an SDO request is processed.
 */
int ec_fsm_slave_action_process_sdo(
        ec_fsm_slave_t *fsm /**< Slave state machine. */
        )
{
    ec_slave_t *slave = fsm->slave;
    ec_master_sdo_request_t *request, *next;

    // search the first external request to be processed
    list_for_each_entry_safe(request, next, &slave->slave_sdo_requests, list) {

        list_del_init(&request->list); // dequeue
        if (slave->current_state & EC_SLAVE_STATE_ACK_ERR) {
            EC_SLAVE_WARN(slave, "Aborting SDO request,"
                    " slave has error flag set.\n");
            request->req.state = EC_INT_REQUEST_FAILURE;
            wake_up(&slave->sdo_queue);
            fsm->sdo_request = NULL;
            fsm->state = ec_fsm_slave_state_idle;
            return 0;
        }

        if (slave->current_state == EC_SLAVE_STATE_INIT) {
            EC_SLAVE_WARN(slave, "Aborting SDO request, slave is in INIT.\n");
            request->req.state = EC_INT_REQUEST_FAILURE;
            wake_up(&slave->sdo_queue);
            fsm->sdo_request = NULL;
            fsm->state = ec_fsm_slave_state_idle;
            return 0;
        }

        request->req.state = EC_INT_REQUEST_BUSY;

        // Found pending SDO request. Execute it!
        EC_SLAVE_DBG(slave, 1, "Processing SDO request...\n");

        // Start SDO transfer
        fsm->sdo_request = &request->req;
        fsm->state = ec_fsm_slave_state_sdo_request;
        ec_fsm_coe_transfer(&fsm->fsm_coe, slave, &request->req);
        ec_fsm_coe_exec(&fsm->fsm_coe); // execute immediately
        ec_master_queue_external_datagram(fsm->slave->master, fsm->datagram);
        return 1;
    }
    return 0;
}

/*****************************************************************************/

/** Slave state: SDO_REQUEST.
 */
void ec_fsm_slave_state_sdo_request(
        ec_fsm_slave_t *fsm /**< Slave state machine. */
        )
{
    ec_slave_t *slave = fsm->slave;
    ec_sdo_request_t *request = fsm->sdo_request;

    if (ec_fsm_coe_exec(&fsm->fsm_coe)) {
        ec_master_queue_external_datagram(fsm->slave->master, fsm->datagram);
        return;
    }
    if (!ec_fsm_coe_success(&fsm->fsm_coe)) {
        EC_SLAVE_ERR(slave, "Failed to process SDO request.\n");
        request->state = EC_INT_REQUEST_FAILURE;
        wake_up(&slave->sdo_queue);
        fsm->sdo_request = NULL;
        fsm->state = ec_fsm_slave_state_idle;
        return;
    }

    EC_SLAVE_DBG(slave, 1, "Finished SDO request.\n");

    // SDO request finished
    request->state = EC_INT_REQUEST_SUCCESS;
    wake_up(&slave->sdo_queue);

    fsm->sdo_request = NULL;
    fsm->state = ec_fsm_slave_state_ready;
}

/*****************************************************************************/

/** Check for pending FOE requests and process one.
 *
 * \return non-zero, if an FOE request is processed.
 */
int ec_fsm_slave_action_process_foe(
        ec_fsm_slave_t *fsm /**< Slave state machine. */
        )
{
    ec_slave_t *slave = fsm->slave;
    ec_master_foe_request_t *request, *next;

    // search the first request to be processed
    list_for_each_entry_safe(request, next, &slave->foe_requests, list) {
        if (slave->current_state & EC_SLAVE_STATE_ACK_ERR) {
            EC_SLAVE_WARN(slave, "Aborting FOE request,"
                    " slave has error flag set.\n");
            request->req.state = EC_INT_REQUEST_FAILURE;
            wake_up(&slave->sdo_queue);
            fsm->sdo_request = NULL;
            fsm->state = ec_fsm_slave_state_idle;
            return 0;
        }
        list_del_init(&request->list); // dequeue
        request->req.state = EC_INT_REQUEST_BUSY;

        EC_SLAVE_DBG(slave, 1, "Processing FoE request.\n");

        fsm->foe_request = &request->req;
        fsm->state = ec_fsm_slave_state_foe_request;
        ec_fsm_foe_transfer(&fsm->fsm_foe, slave, &request->req);
        ec_fsm_foe_exec(&fsm->fsm_foe);
        ec_master_queue_external_datagram(fsm->slave->master, fsm->datagram);
        return 1;
    }
    return 0;
}

/*****************************************************************************/

/** Slave state: FOE REQUEST.
 */
void ec_fsm_slave_state_foe_request(
        ec_fsm_slave_t *fsm /**< Slave state machine. */
        )
{
    ec_slave_t *slave = fsm->slave;
    ec_foe_request_t *request = fsm->foe_request;

    if (ec_fsm_foe_exec(&fsm->fsm_foe)) {
        ec_master_queue_external_datagram(fsm->slave->master, fsm->datagram);
        return;
    }

    if (!ec_fsm_foe_success(&fsm->fsm_foe)) {
        EC_SLAVE_ERR(slave, "Failed to handle FoE request.\n");
        request->state = EC_INT_REQUEST_FAILURE;
        wake_up(&slave->foe_queue);
        fsm->foe_request = NULL;
        fsm->state = ec_fsm_slave_state_idle;
        return;
    }

    // finished transferring FoE
    EC_SLAVE_DBG(slave, 1, "Successfully transferred %zu bytes of FoE"
            " data.\n", request->data_size);

    request->state = EC_INT_REQUEST_SUCCESS;
    wake_up(&slave->foe_queue);

    fsm->foe_request = NULL;
    fsm->state = ec_fsm_slave_state_ready;
}

/*****************************************************************************/

/** Check for pending SoE requests and process one.
 *
 * \return non-zero, if a request is processed.
 */
int ec_fsm_slave_action_process_soe(
        ec_fsm_slave_t *fsm /**< Slave state machine. */
        )
{
    ec_slave_t *slave = fsm->slave;
    ec_master_soe_request_t *req, *next;

    // search the first request to be processed
    list_for_each_entry_safe(req, next, &slave->soe_requests, list) {

        list_del_init(&req->list); // dequeue
        if (slave->current_state & EC_SLAVE_STATE_ACK_ERR) {
            EC_SLAVE_WARN(slave, "Aborting SoE request,"
                    " slave has error flag set.\n");
            req->req.state = EC_INT_REQUEST_FAILURE;
            wake_up(&slave->soe_queue);
            fsm->state = ec_fsm_slave_state_idle;
            return 0;
        }

        if (slave->current_state == EC_SLAVE_STATE_INIT) {
            EC_SLAVE_WARN(slave, "Aborting SoE request, slave is in INIT.\n");
            req->req.state = EC_INT_REQUEST_FAILURE;
            wake_up(&slave->soe_queue);
            fsm->state = ec_fsm_slave_state_idle;
            return 0;
        }

        req->req.state = EC_INT_REQUEST_BUSY;

        // Found pending request. Execute it!
        EC_SLAVE_DBG(slave, 1, "Processing SoE request...\n");

        // Start SoE transfer
        fsm->soe_request = &req->req;
        fsm->state = ec_fsm_slave_state_soe_request;
        ec_fsm_soe_transfer(&fsm->fsm_soe, slave, &req->req);
        ec_fsm_soe_exec(&fsm->fsm_soe); // execute immediately
        ec_master_queue_external_datagram(fsm->slave->master, fsm->datagram);
        return 1;
    }
    return 0;
}

/*****************************************************************************/

/** Slave state: SOE_REQUEST.
 */
void ec_fsm_slave_state_soe_request(
        ec_fsm_slave_t *fsm /**< Slave state machine. */
        )
{
    ec_slave_t *slave = fsm->slave;
    ec_soe_request_t *request = fsm->soe_request;

    if (ec_fsm_soe_exec(&fsm->fsm_soe)) {
        ec_master_queue_external_datagram(fsm->slave->master, fsm->datagram);
        return;
    }

    if (!ec_fsm_soe_success(&fsm->fsm_soe)) {
        EC_SLAVE_ERR(slave, "Failed to process SoE request.\n");
        request->state = EC_INT_REQUEST_FAILURE;
        wake_up(&slave->soe_queue);
        fsm->soe_request = NULL;
        fsm->state = ec_fsm_slave_state_idle;
        return;
    }

    EC_SLAVE_DBG(slave, 1, "Finished SoE request.\n");

    // SoE request finished
    request->state = EC_INT_REQUEST_SUCCESS;
    wake_up(&slave->soe_queue);

    fsm->soe_request = NULL;
    fsm->state = ec_fsm_slave_state_ready;
}

/*****************************************************************************/