master/fsm_master.c
author Patrick Bruenn <p.bruenn@beckhoff.com>
Tue, 12 Apr 2016 11:17:36 +0200
branchstable-1.5
changeset 2654 b3f6b3e5ef29
parent 2529 c7e1f2616a9d
permissions -rw-r--r--
devices/ccat: revert "limit rx processing to one frame per poll"

revert "limit rx processing to one frame per poll", which caused etherlab
frame timeouts in setups with more than one frame per cycle.
/******************************************************************************
 *
 *  $Id$
 *
 *  Copyright (C) 2006-2012  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 master state machine.
 */

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

#include "globals.h"
#include "master.h"
#include "mailbox.h"
#include "slave_config.h"
#ifdef EC_EOE
#include "ethernet.h"
#endif

#include "fsm_master.h"
#include "fsm_foe.h"

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

/** Time difference [ns] to tolerate without setting a new system time offset.
 */
#define EC_SYSTEM_TIME_TOLERANCE_NS 1000000

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

void ec_fsm_master_state_start(ec_fsm_master_t *);
void ec_fsm_master_state_broadcast(ec_fsm_master_t *);
void ec_fsm_master_state_read_state(ec_fsm_master_t *);
void ec_fsm_master_state_acknowledge(ec_fsm_master_t *);
void ec_fsm_master_state_configure_slave(ec_fsm_master_t *);
void ec_fsm_master_state_clear_addresses(ec_fsm_master_t *);
void ec_fsm_master_state_dc_measure_delays(ec_fsm_master_t *);
void ec_fsm_master_state_scan_slave(ec_fsm_master_t *);
void ec_fsm_master_state_dc_read_offset(ec_fsm_master_t *);
void ec_fsm_master_state_dc_write_offset(ec_fsm_master_t *);
void ec_fsm_master_state_write_sii(ec_fsm_master_t *);
void ec_fsm_master_state_sdo_dictionary(ec_fsm_master_t *);
void ec_fsm_master_state_sdo_request(ec_fsm_master_t *);

void ec_fsm_master_enter_clear_addresses(ec_fsm_master_t *);
void ec_fsm_master_enter_write_system_times(ec_fsm_master_t *);

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

/** Constructor.
 */
void ec_fsm_master_init(
        ec_fsm_master_t *fsm, /**< Master state machine. */
        ec_master_t *master, /**< EtherCAT master. */
        ec_datagram_t *datagram /**< Datagram object to use. */
        )
{
    fsm->master = master;
    fsm->datagram = datagram;

    ec_fsm_master_reset(fsm);

    // init sub-state-machines
    ec_fsm_coe_init(&fsm->fsm_coe);
    ec_fsm_soe_init(&fsm->fsm_soe);
    ec_fsm_pdo_init(&fsm->fsm_pdo, &fsm->fsm_coe);
    ec_fsm_change_init(&fsm->fsm_change, fsm->datagram);
    ec_fsm_slave_config_init(&fsm->fsm_slave_config, fsm->datagram,
            &fsm->fsm_change, &fsm->fsm_coe, &fsm->fsm_soe, &fsm->fsm_pdo);
    ec_fsm_slave_scan_init(&fsm->fsm_slave_scan, fsm->datagram,
            &fsm->fsm_slave_config, &fsm->fsm_pdo);
    ec_fsm_sii_init(&fsm->fsm_sii, fsm->datagram);
}

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

/** Destructor.
 */
void ec_fsm_master_clear(
        ec_fsm_master_t *fsm /**< Master state machine. */
        )
{
    // clear sub-state machines
    ec_fsm_coe_clear(&fsm->fsm_coe);
    ec_fsm_soe_clear(&fsm->fsm_soe);
    ec_fsm_pdo_clear(&fsm->fsm_pdo);
    ec_fsm_change_clear(&fsm->fsm_change);
    ec_fsm_slave_config_clear(&fsm->fsm_slave_config);
    ec_fsm_slave_scan_clear(&fsm->fsm_slave_scan);
    ec_fsm_sii_clear(&fsm->fsm_sii);
}

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

/** Reset state machine.
 */
void ec_fsm_master_reset(
        ec_fsm_master_t *fsm /**< Master state machine. */
        )
{
    ec_device_index_t dev_idx;

    fsm->state = ec_fsm_master_state_start;
    fsm->idle = 0;
    fsm->dev_idx = EC_DEVICE_MAIN;

    for (dev_idx = EC_DEVICE_MAIN;
            dev_idx < ec_master_num_devices(fsm->master); dev_idx++) {
        fsm->link_state[dev_idx] = 0;
        fsm->slaves_responding[dev_idx] = 0;
        fsm->slave_states[dev_idx] = EC_SLAVE_STATE_UNKNOWN;
    }

    fsm->rescan_required = 0;
}

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

/** 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.
 *
 * \return true, if the state machine was executed
 */
int ec_fsm_master_exec(
        ec_fsm_master_t *fsm /**< Master state machine. */
        )
{
    if (fsm->datagram->state == EC_DATAGRAM_SENT
        || fsm->datagram->state == EC_DATAGRAM_QUEUED) {
        // datagram was not sent or received yet.
        return 0;
    }

    fsm->state(fsm);
    return 1;
}

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

/**
 * \return true, if the state machine is in an idle phase
 */
int ec_fsm_master_idle(
        const ec_fsm_master_t *fsm /**< Master state machine. */
        )
{
    return fsm->idle;
}

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

/** Restarts the master state machine.
 */
void ec_fsm_master_restart(
        ec_fsm_master_t *fsm /**< Master state machine. */
        )
{
    fsm->dev_idx = EC_DEVICE_MAIN;
    fsm->state = ec_fsm_master_state_start;
    fsm->state(fsm); // execute immediately
}

/******************************************************************************
 * Master state machine
 *****************************************************************************/

/** Master state: START.
 *
 * Starts with getting slave count and slave states.
 */
void ec_fsm_master_state_start(
        ec_fsm_master_t *fsm /**< Master state machine. */
        )
{
    ec_master_t *master = fsm->master;

    fsm->idle = 1;

    // check for emergency requests
    if (!list_empty(&master->emerg_reg_requests)) {
        ec_reg_request_t *request;

        // get first request
        request = list_entry(master->emerg_reg_requests.next,
                ec_reg_request_t, list);
        list_del_init(&request->list); // dequeue
        request->state = EC_INT_REQUEST_BUSY;

        if (request->transfer_size > fsm->datagram->mem_size) {
            EC_MASTER_ERR(master, "Emergency request data too large!\n");
            request->state = EC_INT_REQUEST_FAILURE;
            wake_up_all(&master->request_queue);
            fsm->state(fsm); // continue
            return;
        }

        if (request->dir != EC_DIR_OUTPUT) {
            EC_MASTER_ERR(master, "Emergency requests must be"
                    " write requests!\n");
            request->state = EC_INT_REQUEST_FAILURE;
            wake_up_all(&master->request_queue);
            fsm->state(fsm); // continue
            return;
        }

        EC_MASTER_DBG(master, 1, "Writing emergency register request...\n");
        ec_datagram_apwr(fsm->datagram, request->ring_position,
                request->address, request->transfer_size);
        memcpy(fsm->datagram->data, request->data, request->transfer_size);
        fsm->datagram->device_index = EC_DEVICE_MAIN;
        request->state = EC_INT_REQUEST_SUCCESS;
        wake_up_all(&master->request_queue);
        return;
    }

    ec_datagram_brd(fsm->datagram, 0x0130, 2);
    ec_datagram_zero(fsm->datagram);
    fsm->datagram->device_index = fsm->dev_idx;
    fsm->state = ec_fsm_master_state_broadcast;
}

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

/** Master state: BROADCAST.
 *
 * Processes the broadcast read slave count and slaves states.
 */
void ec_fsm_master_state_broadcast(
        ec_fsm_master_t *fsm /**< Master state machine. */
        )
{
    ec_datagram_t *datagram = fsm->datagram;
    unsigned int i, size;
    ec_slave_t *slave;
    ec_master_t *master = fsm->master;

    // bus topology change?
    if (datagram->working_counter != fsm->slaves_responding[fsm->dev_idx]) {
        fsm->rescan_required = 1;
        fsm->slaves_responding[fsm->dev_idx] = datagram->working_counter;
        EC_MASTER_INFO(master, "%u slave(s) responding on %s device.\n",
                fsm->slaves_responding[fsm->dev_idx],
                ec_device_names[fsm->dev_idx != 0]);
    }

    if (fsm->link_state[fsm->dev_idx] &&
            !master->devices[fsm->dev_idx].link_state) {
        ec_device_index_t dev_idx;

        EC_MASTER_DBG(master, 1, "Master state machine detected "
                "link down on %s device. Clearing slave list.\n",
                ec_device_names[fsm->dev_idx != 0]);

#ifdef EC_EOE
        ec_master_eoe_stop(master);
        ec_master_clear_eoe_handlers(master);
#endif
        ec_master_clear_slaves(master);

        for (dev_idx = EC_DEVICE_MAIN;
                dev_idx < ec_master_num_devices(master); dev_idx++) {
            fsm->slave_states[dev_idx] = 0x00;
            fsm->slaves_responding[dev_idx] = 0; /* Reset to trigger rescan on
                                                    next link up. */
        }
    }
    fsm->link_state[fsm->dev_idx] = master->devices[fsm->dev_idx].link_state;

    if (datagram->state == EC_DATAGRAM_RECEIVED &&
            fsm->slaves_responding[fsm->dev_idx]) {
        uint8_t states = EC_READ_U8(datagram->data);
        if (states != fsm->slave_states[fsm->dev_idx]) {
            // slave states changed
            char state_str[EC_STATE_STRING_SIZE];
            fsm->slave_states[fsm->dev_idx] = states;
            ec_state_string(states, state_str, 1);
            EC_MASTER_INFO(master, "Slave states on %s device: %s.\n",
                    ec_device_names[fsm->dev_idx != 0], state_str);
        }
    } else {
        fsm->slave_states[fsm->dev_idx] = 0x00;
    }

    fsm->dev_idx++;
    if (fsm->dev_idx < ec_master_num_devices(master)) {
        // check number of responding slaves on next device
        fsm->state = ec_fsm_master_state_start;
        fsm->state(fsm); // execute immediately
        return;
    }

    if (fsm->rescan_required) {
        down(&master->scan_sem);
        if (!master->allow_scan) {
            up(&master->scan_sem);
        } else {
            unsigned int count = 0, next_dev_slave, ring_position;
            ec_device_index_t dev_idx;

            master->scan_busy = 1;
            up(&master->scan_sem);

            // clear all slaves and scan the bus
            fsm->rescan_required = 0;
            fsm->idle = 0;
            fsm->scan_jiffies = jiffies;

#ifdef EC_EOE
            ec_master_eoe_stop(master);
            ec_master_clear_eoe_handlers(master);
#endif
            ec_master_clear_slaves(master);

            for (dev_idx = EC_DEVICE_MAIN;
                    dev_idx < ec_master_num_devices(master); dev_idx++) {
                count += fsm->slaves_responding[dev_idx];
            }

            if (!count) {
                // no slaves present -> finish state machine.
                master->scan_busy = 0;
                wake_up_interruptible(&master->scan_queue);
                ec_fsm_master_restart(fsm);
                return;
            }

            size = sizeof(ec_slave_t) * count;
            if (!(master->slaves =
                        (ec_slave_t *) kmalloc(size, GFP_KERNEL))) {
                EC_MASTER_ERR(master, "Failed to allocate %u bytes"
                        " of slave memory!\n", size);
                master->scan_busy = 0;
                wake_up_interruptible(&master->scan_queue);
                ec_fsm_master_restart(fsm);
                return;
            }

            // init slaves
            dev_idx = EC_DEVICE_MAIN;
            next_dev_slave = fsm->slaves_responding[dev_idx];
            ring_position = 0;
            for (i = 0; i < count; i++, ring_position++) {
                slave = master->slaves + i;
                while (i >= next_dev_slave) {
                    dev_idx++;
                    next_dev_slave += fsm->slaves_responding[dev_idx];
                    ring_position = 0;
                }

                ec_slave_init(slave, master, dev_idx, ring_position, i + 1);

                // do not force reconfiguration in operation phase to avoid
                // unnecesssary process data interruptions
                if (master->phase != EC_OPERATION) {
                    slave->force_config = 1;
                }
            }
            master->slave_count = count;
            master->fsm_slave = master->slaves;

            /* start with first device with slaves responding; at least one
             * has responding slaves, otherwise count would be zero. */
            fsm->dev_idx = EC_DEVICE_MAIN;
            while (!fsm->slaves_responding[fsm->dev_idx]) {
                fsm->dev_idx++;
            }

            ec_fsm_master_enter_clear_addresses(fsm);
            return;
        }
    }

    if (master->slave_count) {

        // application applied configurations
        if (master->config_changed) {
            master->config_changed = 0;

            EC_MASTER_DBG(master, 1, "Configuration changed.\n");

            fsm->slave = master->slaves; // begin with first slave
            ec_fsm_master_enter_write_system_times(fsm);

        } else {
            // fetch state from first slave
            fsm->slave = master->slaves;
            ec_datagram_fprd(fsm->datagram, fsm->slave->station_address,
                    0x0130, 2);
            ec_datagram_zero(datagram);
            fsm->datagram->device_index = fsm->slave->device_index;
            fsm->retries = EC_FSM_RETRIES;
            fsm->state = ec_fsm_master_state_read_state;
        }
    } else {
        ec_fsm_master_restart(fsm);
    }
}

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

/** Check for pending SII write requests and process one.
 *
 * \return non-zero, if an SII write request is processed.
 */
int ec_fsm_master_action_process_sii(
        ec_fsm_master_t *fsm /**< Master state machine. */
        )
{
    ec_master_t *master = fsm->master;
    ec_sii_write_request_t *request;

    // search the first request to be processed
    while (1) {
        if (list_empty(&master->sii_requests))
            break;

        // get first request
        request = list_entry(master->sii_requests.next,
                ec_sii_write_request_t, list);
        list_del_init(&request->list); // dequeue
        request->state = EC_INT_REQUEST_BUSY;

        // found pending SII write operation. execute it!
        EC_SLAVE_DBG(request->slave, 1, "Writing SII data...\n");
        fsm->sii_request = request;
        fsm->sii_index = 0;
        ec_fsm_sii_write(&fsm->fsm_sii, request->slave, request->offset,
                request->words, EC_FSM_SII_USE_CONFIGURED_ADDRESS);
        fsm->state = ec_fsm_master_state_write_sii;
        fsm->state(fsm); // execute immediately
        return 1;
    }

    return 0;
}

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

/** Check for pending SDO requests and process one.
 *
 * \return non-zero, if an SDO request is processed.
 */
int ec_fsm_master_action_process_sdo(
        ec_fsm_master_t *fsm /**< Master state machine. */
        )
{
    ec_master_t *master = fsm->master;
    ec_slave_t *slave;
    ec_sdo_request_t *req;

    // search for internal requests to be processed
    for (slave = master->slaves;
            slave < master->slaves + master->slave_count;
            slave++) {

        if (!slave->config) {
            continue;
        }

        list_for_each_entry(req, &slave->config->sdo_requests, list) {
            if (req->state == EC_INT_REQUEST_QUEUED) {

                if (ec_sdo_request_timed_out(req)) {
                    req->state = EC_INT_REQUEST_FAILURE;
                    EC_SLAVE_DBG(slave, 1, "Internal SDO request"
                            " timed out.\n");
                    continue;
                }

                if (slave->current_state == EC_SLAVE_STATE_INIT) {
                    req->state = EC_INT_REQUEST_FAILURE;
                    continue;
                }

                req->state = EC_INT_REQUEST_BUSY;
                EC_SLAVE_DBG(slave, 1, "Processing internal"
                        " SDO request...\n");
                fsm->idle = 0;
                fsm->sdo_request = req;
                fsm->slave = slave;
                fsm->state = ec_fsm_master_state_sdo_request;
                ec_fsm_coe_transfer(&fsm->fsm_coe, slave, req);
                ec_fsm_coe_exec(&fsm->fsm_coe, fsm->datagram);
                return 1;
            }
        }
    }
    return 0;
}

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

/** Master action: IDLE.
 *
 * Does secondary work.
 */
void ec_fsm_master_action_idle(
        ec_fsm_master_t *fsm /**< Master state machine. */
        )
{
    ec_master_t *master = fsm->master;
    ec_slave_t *slave;

    // Check for pending internal SDO requests
    if (ec_fsm_master_action_process_sdo(fsm)) {
        return;
    }

    // enable processing of requests
    for (slave = master->slaves;
            slave < master->slaves + master->slave_count;
            slave++) {
        ec_fsm_slave_set_ready(&slave->fsm);
    }

    // check, if slaves have an SDO dictionary to read out.
    for (slave = master->slaves;
            slave < master->slaves + master->slave_count;
            slave++) {
        if (!(slave->sii.mailbox_protocols & EC_MBOX_COE)
                || (slave->sii.has_general
                    && !slave->sii.coe_details.enable_sdo_info)
                || slave->sdo_dictionary_fetched
                || slave->current_state == EC_SLAVE_STATE_INIT
                || slave->current_state == EC_SLAVE_STATE_UNKNOWN
                || jiffies - slave->jiffies_preop < EC_WAIT_SDO_DICT * HZ
                ) continue;

        EC_SLAVE_DBG(slave, 1, "Fetching SDO dictionary.\n");

        slave->sdo_dictionary_fetched = 1;

        // start fetching SDO dictionary
        fsm->idle = 0;
        fsm->slave = slave;
        fsm->state = ec_fsm_master_state_sdo_dictionary;
        ec_fsm_coe_dictionary(&fsm->fsm_coe, slave);
        ec_fsm_coe_exec(&fsm->fsm_coe, fsm->datagram); // execute immediately
        fsm->datagram->device_index = fsm->slave->device_index;
        return;
    }

    // check for pending SII write operations.
    if (ec_fsm_master_action_process_sii(fsm)) {
        return; // SII write request found
	}

    ec_fsm_master_restart(fsm);
}

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

/** Master action: Get state of next slave.
 */
void ec_fsm_master_action_next_slave_state(
        ec_fsm_master_t *fsm /**< Master state machine. */
        )
{
    ec_master_t *master = fsm->master;

    // is there another slave to query?
    fsm->slave++;
    if (fsm->slave < master->slaves + master->slave_count) {
        // fetch state from next slave
        fsm->idle = 1;
        ec_datagram_fprd(fsm->datagram,
                fsm->slave->station_address, 0x0130, 2);
        ec_datagram_zero(fsm->datagram);
        fsm->datagram->device_index = fsm->slave->device_index;
        fsm->retries = EC_FSM_RETRIES;
        fsm->state = ec_fsm_master_state_read_state;
        return;
    }

    // all slaves processed
    ec_fsm_master_action_idle(fsm);
}

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

/** Master action: Configure.
 */
void ec_fsm_master_action_configure(
        ec_fsm_master_t *fsm /**< Master state machine. */
        )
{
    ec_master_t *master = fsm->master;
    ec_slave_t *slave = fsm->slave;

    if (master->config_changed) {
        master->config_changed = 0;

        // abort iterating through slaves,
        // first compensate DC system time offsets,
        // then begin configuring at slave 0
        EC_MASTER_DBG(master, 1, "Configuration changed"
                " (aborting state check).\n");

        fsm->slave = master->slaves; // begin with first slave
        ec_fsm_master_enter_write_system_times(fsm);
        return;
    }

    // Does the slave have to be configured?
    if ((slave->current_state != slave->requested_state
                || slave->force_config) && !slave->error_flag) {

        // Start slave configuration
        down(&master->config_sem);
        master->config_busy = 1;
        up(&master->config_sem);

        if (master->debug_level) {
            char old_state[EC_STATE_STRING_SIZE],
                 new_state[EC_STATE_STRING_SIZE];
            ec_state_string(slave->current_state, old_state, 0);
            ec_state_string(slave->requested_state, new_state, 0);
            EC_SLAVE_DBG(slave, 1, "Changing state from %s to %s%s.\n",
                    old_state, new_state,
                    slave->force_config ? " (forced)" : "");
        }

        fsm->idle = 0;
        fsm->state = ec_fsm_master_state_configure_slave;
        ec_fsm_slave_config_start(&fsm->fsm_slave_config, slave);
        fsm->state(fsm); // execute immediately
        fsm->datagram->device_index = fsm->slave->device_index;
        return;
    }

    // process next slave
    ec_fsm_master_action_next_slave_state(fsm);
}

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

/** Master state: READ STATE.
 *
 * Fetches the AL state of a slave.
 */
void ec_fsm_master_state_read_state(
        ec_fsm_master_t *fsm /**< Master state machine. */
        )
{
    ec_slave_t *slave = fsm->slave;
    ec_datagram_t *datagram = fsm->datagram;

    if (datagram->state == EC_DATAGRAM_TIMED_OUT && fsm->retries--) {
        return;
    }

    if (datagram->state != EC_DATAGRAM_RECEIVED) {
        EC_SLAVE_ERR(slave, "Failed to receive AL state datagram: ");
        ec_datagram_print_state(datagram);
        ec_fsm_master_restart(fsm);
        return;
    }

    // did the slave not respond to its station address?
    if (datagram->working_counter != 1) {
        if (!slave->error_flag) {
            slave->error_flag = 1;
            EC_SLAVE_DBG(slave, 1, "Slave did not respond to state query.\n");
        }
        fsm->rescan_required = 1;
        ec_fsm_master_restart(fsm);
        return;
    }

    // A single slave responded
    ec_slave_set_state(slave, EC_READ_U8(datagram->data));

    if (!slave->error_flag) {
        // Check, if new slave state has to be acknowledged
        if (slave->current_state & EC_SLAVE_STATE_ACK_ERR) {
            fsm->idle = 0;
            fsm->state = ec_fsm_master_state_acknowledge;
            ec_fsm_change_ack(&fsm->fsm_change, slave);
            fsm->state(fsm); // execute immediately
            return;
        }

        // No acknowlegde necessary; check for configuration
        ec_fsm_master_action_configure(fsm);
        return;
    }

    // slave has error flag set; process next one
    ec_fsm_master_action_next_slave_state(fsm);
}

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

/** Master state: ACKNOWLEDGE.
 */
void ec_fsm_master_state_acknowledge(
        ec_fsm_master_t *fsm /**< Master state machine. */
        )
{
    ec_slave_t *slave = fsm->slave;

    if (ec_fsm_change_exec(&fsm->fsm_change)) {
        return;
    }

    if (!ec_fsm_change_success(&fsm->fsm_change)) {
        fsm->slave->error_flag = 1;
        EC_SLAVE_ERR(slave, "Failed to acknowledge state change.\n");
    }

    ec_fsm_master_action_configure(fsm);
}

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

/** Start clearing slave addresses.
 */
void ec_fsm_master_enter_clear_addresses(
        ec_fsm_master_t *fsm /**< Master state machine. */
        )
{
    // broadcast clear all station addresses
    ec_datagram_bwr(fsm->datagram, 0x0010, 2);
    EC_WRITE_U16(fsm->datagram->data, 0x0000);
    fsm->datagram->device_index = fsm->dev_idx;
    fsm->retries = EC_FSM_RETRIES;
    fsm->state = ec_fsm_master_state_clear_addresses;
}

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

/** Master state: CLEAR ADDRESSES.
 */
void ec_fsm_master_state_clear_addresses(
        ec_fsm_master_t *fsm /**< Master state machine. */
        )
{
    ec_master_t *master = fsm->master;
    ec_datagram_t *datagram = fsm->datagram;

    if (datagram->state == EC_DATAGRAM_TIMED_OUT && fsm->retries--) {
        return;
    }

    if (datagram->state != EC_DATAGRAM_RECEIVED) {
        EC_MASTER_ERR(master, "Failed to receive address"
                " clearing datagram on %s link: ",
                ec_device_names[fsm->dev_idx != 0]);
        ec_datagram_print_state(datagram);
        master->scan_busy = 0;
        wake_up_interruptible(&master->scan_queue);
        ec_fsm_master_restart(fsm);
        return;
    }

    if (datagram->working_counter != fsm->slaves_responding[fsm->dev_idx]) {
        EC_MASTER_WARN(master, "Failed to clear station addresses on %s link:"
                " Cleared %u of %u",
                ec_device_names[fsm->dev_idx != 0], datagram->working_counter,
                fsm->slaves_responding[fsm->dev_idx]);
    }

    EC_MASTER_DBG(master, 1, "Sending broadcast-write"
            " to measure transmission delays on %s link.\n",
            ec_device_names[fsm->dev_idx != 0]);

    ec_datagram_bwr(datagram, 0x0900, 1);
    ec_datagram_zero(datagram);
    fsm->datagram->device_index = fsm->dev_idx;
    fsm->retries = EC_FSM_RETRIES;
    fsm->state = ec_fsm_master_state_dc_measure_delays;
}

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

/** Master state: DC MEASURE DELAYS.
 */
void ec_fsm_master_state_dc_measure_delays(
        ec_fsm_master_t *fsm /**< Master state machine. */
        )
{
    ec_master_t *master = fsm->master;
    ec_datagram_t *datagram = fsm->datagram;

    if (datagram->state == EC_DATAGRAM_TIMED_OUT && fsm->retries--) {
        return;
    }

    if (datagram->state != EC_DATAGRAM_RECEIVED) {
        EC_MASTER_ERR(master, "Failed to receive delay measuring datagram"
                " on %s link: ", ec_device_names[fsm->dev_idx != 0]);
        ec_datagram_print_state(datagram);
        master->scan_busy = 0;
        wake_up_interruptible(&master->scan_queue);
        ec_fsm_master_restart(fsm);
        return;
    }

    EC_MASTER_DBG(master, 1, "%u slaves responded to delay measuring"
            " on %s link.\n",
            datagram->working_counter, ec_device_names[fsm->dev_idx != 0]);

    do {
        fsm->dev_idx++;
    } while (fsm->dev_idx < ec_master_num_devices(master) &&
            !fsm->slaves_responding[fsm->dev_idx]);
    if (fsm->dev_idx < ec_master_num_devices(master)) {
        ec_fsm_master_enter_clear_addresses(fsm);
        return;
    }

    EC_MASTER_INFO(master, "Scanning bus.\n");

    // begin scanning of slaves
    fsm->slave = master->slaves;
    EC_MASTER_DBG(master, 1, "Scanning slave %u on %s link.\n",
            fsm->slave->ring_position,
            ec_device_names[fsm->slave->device_index != 0]);
    fsm->state = ec_fsm_master_state_scan_slave;
    ec_fsm_slave_scan_start(&fsm->fsm_slave_scan, fsm->slave);
    ec_fsm_slave_scan_exec(&fsm->fsm_slave_scan); // execute immediately
    fsm->datagram->device_index = fsm->slave->device_index;
}

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

/** Master state: SCAN SLAVE.
 *
 * Executes the sub-statemachine for the scanning of a slave.
 */
void ec_fsm_master_state_scan_slave(
        ec_fsm_master_t *fsm /**< Master state machine. */
        )
{
    ec_master_t *master = fsm->master;
#ifdef EC_EOE
    ec_slave_t *slave = fsm->slave;
#endif

    if (ec_fsm_slave_scan_exec(&fsm->fsm_slave_scan)) {
        return;
    }

#ifdef EC_EOE
    if (slave->sii.mailbox_protocols & EC_MBOX_EOE) {
        // create EoE handler for this slave
        ec_eoe_t *eoe;
        if (!(eoe = kmalloc(sizeof(ec_eoe_t), GFP_KERNEL))) {
            EC_SLAVE_ERR(slave, "Failed to allocate EoE handler memory!\n");
        } else if (ec_eoe_init(eoe, slave)) {
            EC_SLAVE_ERR(slave, "Failed to init EoE handler!\n");
            kfree(eoe);
        } else {
            list_add_tail(&eoe->list, &master->eoe_handlers);
        }
    }
#endif

    // another slave to fetch?
    fsm->slave++;
    if (fsm->slave < master->slaves + master->slave_count) {
        EC_MASTER_DBG(master, 1, "Scanning slave %u on %s link.\n",
                fsm->slave->ring_position,
                ec_device_names[fsm->slave->device_index != 0]);
        ec_fsm_slave_scan_start(&fsm->fsm_slave_scan, fsm->slave);
        ec_fsm_slave_scan_exec(&fsm->fsm_slave_scan); // execute immediately
        fsm->datagram->device_index = fsm->slave->device_index;
        return;
    }

    EC_MASTER_INFO(master, "Bus scanning completed in %lu ms.\n",
            (jiffies - fsm->scan_jiffies) * 1000 / HZ);

    master->scan_busy = 0;
    wake_up_interruptible(&master->scan_queue);

    ec_master_calc_dc(master);

    // Attach slave configurations
    ec_master_attach_slave_configs(master);

#ifdef EC_EOE
    // check if EoE processing has to be started
    ec_master_eoe_start(master);
#endif

    if (master->slave_count) {
        master->config_changed = 0;

        fsm->slave = master->slaves; // begin with first slave
        ec_fsm_master_enter_write_system_times(fsm);
    } else {
        ec_fsm_master_restart(fsm);
    }
}

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

/** Master state: CONFIGURE SLAVE.
 *
 * Starts configuring a slave.
 */
void ec_fsm_master_state_configure_slave(
        ec_fsm_master_t *fsm /**< Master state machine. */
        )
{
    ec_master_t *master = fsm->master;

    if (ec_fsm_slave_config_exec(&fsm->fsm_slave_config)) {
        return;
    }

    fsm->slave->force_config = 0;

    // configuration finished
    master->config_busy = 0;
    wake_up_interruptible(&master->config_queue);

    if (!ec_fsm_slave_config_success(&fsm->fsm_slave_config)) {
        // TODO: mark slave_config as failed.
    }

    fsm->idle = 1;
    ec_fsm_master_action_next_slave_state(fsm);
}

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

/** Start writing DC system times.
 */
void ec_fsm_master_enter_write_system_times(
        ec_fsm_master_t *fsm /**< Master state machine. */
        )
{
    ec_master_t *master = fsm->master;

    if (master->has_app_time) {

        while (fsm->slave < master->slaves + master->slave_count) {
            if (!fsm->slave->base_dc_supported
                    || !fsm->slave->has_dc_system_time) {
                fsm->slave++;
                continue;
            }

            EC_SLAVE_DBG(fsm->slave, 1, "Checking system time offset.\n");

            // read DC system time (0x0910, 64 bit)
            //                         gap (64 bit)
            //     and time offset (0x0920, 64 bit)
            ec_datagram_fprd(fsm->datagram, fsm->slave->station_address,
                    0x0910, 24);
            fsm->datagram->device_index = fsm->slave->device_index;
            fsm->retries = EC_FSM_RETRIES;
            fsm->state = ec_fsm_master_state_dc_read_offset;
            return;
        }

    } else {
        if (master->active) {
            EC_MASTER_WARN(master, "No app_time received up to now,"
                    " but master already active.\n");
        } else {
            EC_MASTER_DBG(master, 1, "No app_time received up to now.\n");
        }
    }

    // scanning and setting system times complete
    ec_master_request_op(master);
    ec_fsm_master_restart(fsm);
}

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

/** Configure 32 bit time offset.
 *
 * \return New offset.
 */
u64 ec_fsm_master_dc_offset32(
        ec_fsm_master_t *fsm, /**< Master state machine. */
        u64 system_time, /**< System time register. */
        u64 old_offset, /**< Time offset register. */
        unsigned long jiffies_since_read /**< Jiffies for correction. */
        )
{
    ec_slave_t *slave = fsm->slave;
    u32 correction, system_time32, old_offset32, new_offset;
    s32 time_diff;

    system_time32 = (u32) system_time;
    old_offset32 = (u32) old_offset;

    // correct read system time by elapsed time since read operation
    correction = jiffies_since_read * 1000 / HZ * 1000000;
    system_time32 += correction;
    time_diff = (u32) slave->master->app_time - system_time32;

    EC_SLAVE_DBG(slave, 1, "DC 32 bit system time offset calculation:"
            " system_time=%u (corrected with %u),"
            " app_time=%llu, diff=%i\n",
            system_time32, correction,
            slave->master->app_time, time_diff);

    if (EC_ABS(time_diff) > EC_SYSTEM_TIME_TOLERANCE_NS) {
        new_offset = time_diff + old_offset32;
        EC_SLAVE_DBG(slave, 1, "Setting time offset to %u (was %u)\n",
                new_offset, old_offset32);
        return (u64) new_offset;
    } else {
        EC_SLAVE_DBG(slave, 1, "Not touching time offset.\n");
        return old_offset;
    }
}

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

/** Configure 64 bit time offset.
 *
 * \return New offset.
 */
u64 ec_fsm_master_dc_offset64(
        ec_fsm_master_t *fsm, /**< Master state machine. */
        u64 system_time, /**< System time register. */
        u64 old_offset, /**< Time offset register. */
        unsigned long jiffies_since_read /**< Jiffies for correction. */
        )
{
    ec_slave_t *slave = fsm->slave;
    u64 new_offset, correction;
    s64 time_diff;

    // correct read system time by elapsed time since read operation
    correction = (u64) (jiffies_since_read * 1000 / HZ) * 1000000;
    system_time += correction;
    time_diff = fsm->slave->master->app_time - system_time;

    EC_SLAVE_DBG(slave, 1, "DC 64 bit system time offset calculation:"
            " system_time=%llu (corrected with %llu),"
            " app_time=%llu, diff=%lli\n",
            system_time, correction,
            slave->master->app_time, time_diff);

    if (EC_ABS(time_diff) > EC_SYSTEM_TIME_TOLERANCE_NS) {
        new_offset = time_diff + old_offset;
        EC_SLAVE_DBG(slave, 1, "Setting time offset to %llu (was %llu)\n",
                new_offset, old_offset);
    } else {
        new_offset = old_offset;
        EC_SLAVE_DBG(slave, 1, "Not touching time offset.\n");
    }

    return new_offset;
}

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

/** Master state: DC READ OFFSET.
 */
void ec_fsm_master_state_dc_read_offset(
        ec_fsm_master_t *fsm /**< Master state machine. */
        )
{
    ec_datagram_t *datagram = fsm->datagram;
    ec_slave_t *slave = fsm->slave;
    u64 system_time, old_offset, new_offset;
    unsigned long jiffies_since_read;

    if (datagram->state == EC_DATAGRAM_TIMED_OUT && fsm->retries--)
        return;

    if (datagram->state != EC_DATAGRAM_RECEIVED) {
        EC_SLAVE_ERR(slave, "Failed to receive DC times datagram: ");
        ec_datagram_print_state(datagram);
        fsm->slave++;
        ec_fsm_master_enter_write_system_times(fsm);
        return;
    }

    if (datagram->working_counter != 1) {
        EC_SLAVE_WARN(slave, "Failed to get DC times: ");
        ec_datagram_print_wc_error(datagram);
        fsm->slave++;
        ec_fsm_master_enter_write_system_times(fsm);
        return;
    }

    system_time = EC_READ_U64(datagram->data);     // 0x0910
    old_offset = EC_READ_U64(datagram->data + 16); // 0x0920
    jiffies_since_read = jiffies - datagram->jiffies_sent;

    if (slave->base_dc_range == EC_DC_32) {
        new_offset = ec_fsm_master_dc_offset32(fsm,
                system_time, old_offset, jiffies_since_read);
    } else {
        new_offset = ec_fsm_master_dc_offset64(fsm,
                system_time, old_offset, jiffies_since_read);
    }

    // set DC system time offset and transmission delay
    ec_datagram_fpwr(datagram, slave->station_address, 0x0920, 12);
    EC_WRITE_U64(datagram->data, new_offset);
    EC_WRITE_U32(datagram->data + 8, slave->transmission_delay);
    fsm->datagram->device_index = slave->device_index;
    fsm->retries = EC_FSM_RETRIES;
    fsm->state = ec_fsm_master_state_dc_write_offset;
}

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

/** Master state: DC WRITE OFFSET.
 */
void ec_fsm_master_state_dc_write_offset(
        ec_fsm_master_t *fsm /**< Master state machine. */
        )
{
    ec_datagram_t *datagram = fsm->datagram;
    ec_slave_t *slave = fsm->slave;

    if (datagram->state == EC_DATAGRAM_TIMED_OUT && fsm->retries--)
        return;

    if (datagram->state != EC_DATAGRAM_RECEIVED) {
        EC_SLAVE_ERR(slave,
                "Failed to receive DC system time offset datagram: ");
        ec_datagram_print_state(datagram);
        fsm->slave++;
        ec_fsm_master_enter_write_system_times(fsm);
        return;
    }

    if (datagram->working_counter != 1) {
        EC_SLAVE_ERR(slave, "Failed to set DC system time offset: ");
        ec_datagram_print_wc_error(datagram);
        fsm->slave++;
        ec_fsm_master_enter_write_system_times(fsm);
        return;
    }

    fsm->slave++;
    ec_fsm_master_enter_write_system_times(fsm);
}

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

/** Master state: WRITE SII.
 */
void ec_fsm_master_state_write_sii(
        ec_fsm_master_t *fsm /**< Master state machine. */
        )
{
    ec_master_t *master = fsm->master;
    ec_sii_write_request_t *request = fsm->sii_request;
    ec_slave_t *slave = request->slave;

    if (ec_fsm_sii_exec(&fsm->fsm_sii)) return;

    if (!ec_fsm_sii_success(&fsm->fsm_sii)) {
        EC_SLAVE_ERR(slave, "Failed to write SII data.\n");
        request->state = EC_INT_REQUEST_FAILURE;
        wake_up_all(&master->request_queue);
        ec_fsm_master_restart(fsm);
        return;
    }

    fsm->sii_index++;
    if (fsm->sii_index < request->nwords) {
        ec_fsm_sii_write(&fsm->fsm_sii, slave,
                request->offset + fsm->sii_index,
                request->words + fsm->sii_index,
                EC_FSM_SII_USE_CONFIGURED_ADDRESS);
        ec_fsm_sii_exec(&fsm->fsm_sii); // execute immediately
        return;
    }

    // finished writing SII
    EC_SLAVE_DBG(slave, 1, "Finished writing %zu words of SII data.\n",
            request->nwords);

    if (request->offset <= 4 && request->offset + request->nwords > 4) {
        // alias was written
        slave->sii.alias = EC_READ_U16(request->words + 4);
        // TODO: read alias from register 0x0012
        slave->effective_alias = slave->sii.alias;
    }
    // TODO: Evaluate other SII contents!

    request->state = EC_INT_REQUEST_SUCCESS;
    wake_up_all(&master->request_queue);

    // check for another SII write request
    if (ec_fsm_master_action_process_sii(fsm))
        return; // processing another request

    ec_fsm_master_restart(fsm);
}

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

/** Master state: SDO DICTIONARY.
 */
void ec_fsm_master_state_sdo_dictionary(
        ec_fsm_master_t *fsm /**< Master state machine. */
        )
{
    ec_slave_t *slave = fsm->slave;
    ec_master_t *master = fsm->master;

    if (ec_fsm_coe_exec(&fsm->fsm_coe, fsm->datagram)) {
        return;
    }

    if (!ec_fsm_coe_success(&fsm->fsm_coe)) {
        ec_fsm_master_restart(fsm);
        return;
    }

    // SDO dictionary fetching finished

    if (master->debug_level) {
        unsigned int sdo_count, entry_count;
        ec_slave_sdo_dict_info(slave, &sdo_count, &entry_count);
        EC_SLAVE_DBG(slave, 1, "Fetched %u SDOs and %u entries.\n",
               sdo_count, entry_count);
    }

    // attach pdo names from dictionary
    ec_slave_attach_pdo_names(slave);

    ec_fsm_master_restart(fsm);
}

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

/** Master state: SDO REQUEST.
 */
void ec_fsm_master_state_sdo_request(
        ec_fsm_master_t *fsm /**< Master state machine. */
        )
{
    ec_sdo_request_t *request = fsm->sdo_request;

    if (!request) {
        // configuration was cleared in the meantime
        ec_fsm_master_restart(fsm);
        return;
    }

    if (ec_fsm_coe_exec(&fsm->fsm_coe, fsm->datagram)) {
        return;
    }

    if (!ec_fsm_coe_success(&fsm->fsm_coe)) {
        EC_SLAVE_DBG(fsm->slave, 1,
                "Failed to process internal SDO request.\n");
        request->state = EC_INT_REQUEST_FAILURE;
        wake_up_all(&fsm->master->request_queue);
        ec_fsm_master_restart(fsm);
        return;
    }

    // SDO request finished
    request->state = EC_INT_REQUEST_SUCCESS;
    wake_up_all(&fsm->master->request_queue);

    EC_SLAVE_DBG(fsm->slave, 1, "Finished internal SDO request.\n");

    // check for another SDO request
    if (ec_fsm_master_action_process_sdo(fsm)) {
        return; // processing another request
    }

    ec_fsm_master_restart(fsm);
}

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